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Sample records for divergent imprint status

  1. Sexual imprinting on ecologically divergent traits leads to sexual isolation in sticklebacks.

    Science.gov (United States)

    Kozak, Genevieve M; Head, Megan L; Boughman, Janette W

    2011-09-07

    During sexual imprinting, offspring learn parental phenotypes and then select mates who are similar to their parents. Imprinting has been thought to contribute to the process of speciation in only a few rare cases; this is despite imprinting's potential to generate assortative mating and solve the problem of recombination in ecological speciation. If offspring imprint on parental traits under divergent selection, these traits will then be involved in both adaptation and mate preference. Such 'magic traits' easily generate sexual isolation and facilitate speciation. In this study, we show that imprinting occurs in two ecologically divergent stickleback species (benthics and limnetics: Gasterosteus spp.). Cross-fostered females preferred mates of their foster father's species. Furthermore, imprinting is essential for sexual isolation between species; isolation was reduced when females were raised without fathers. Daughters imprinted on father odour and colour during a critical period early in development. These traits have diverged between the species owing to differences in ecology. Therefore, we provide the first evidence that imprinting links ecological adaptation to sexual isolation between species. Our results suggest that imprinting may facilitate the evolution of sexual isolation during ecological speciation, may be especially important in cases of rapid diversification, and thus play an integral role in the generation of biodiversity.

  2. Convergent and divergent evolution of genomic imprinting in the marsupial Monodelphis domestica

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    Das Radhika

    2012-08-01

    Full Text Available Abstract Background Genomic imprinting is an epigenetic phenomenon resulting in parent-of-origin specific monoallelic gene expression. It is postulated to have evolved in placental mammals to modulate intrauterine resource allocation to the offspring. In this study, we determined the imprint status of metatherian orthologues of eutherian imprinted genes. Results L3MBTL and HTR2A were shown to be imprinted in Monodelphis domestica (the gray short-tailed opossum. MEST expressed a monoallelic and a biallelic transcript, as in eutherians. In contrast, IMPACT, COPG2, and PLAGL1 were not imprinted in the opossum. Differentially methylated regions (DMRs involved in regulating imprinting in eutherians were not found at any of the new imprinted loci in the opossum. Interestingly, a novel DMR was identified in intron 11 of the imprinted IGF2R gene, but this was not conserved in eutherians. The promoter regions of the imprinted genes in the opossum were enriched for the activating histone modification H3 Lysine 4 dimethylation. Conclusions The phenomenon of genomic imprinting is conserved in Therians, but the marked difference in the number and location of imprinted genes and DMRs between metatherians and eutherians indicates that imprinting is not fully conserved between the two Therian infra-classes. The identification of a novel DMR at a non-conserved location as well as the first demonstration of histone modifications at imprinted loci in the opossum suggest that genomic imprinting may have evolved in a common ancestor of these two Therian infra-classes with subsequent divergence of regulatory mechanisms in the two lineages.

  3. Genomic imprinting status of IGF-II and H19 in placentas of fetal ...

    Indian Academy of Sciences (India)

    velop metabolic syndrome later in life, manifesting as obe- ... Venous blood samples were collected from both the parents .... and five families of the group B2 were informative for H19. .... that may have impacts on the imprinting status of imprinted genes ... This work was supported by a grant from National Natural Science.

  4. The evolution of the DLK1-DIO3 imprinted domain in mammals.

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    Carol A Edwards

    2008-06-01

    Full Text Available A comprehensive, domain-wide comparative analysis of genomic imprinting between mammals that imprint and those that do not can provide valuable information about how and why imprinting evolved. The imprinting status, DNA methylation, and genomic landscape of the Dlk1-Dio3 cluster were determined in eutherian, metatherian, and prototherian mammals including tammar wallaby and platypus. Imprinting across the whole domain evolved after the divergence of eutherian from marsupial mammals and in eutherians is under strong purifying selection. The marsupial locus at 1.6 megabases, is double that of eutherians due to the accumulation of LINE repeats. Comparative sequence analysis of the domain in seven vertebrates determined evolutionary conserved regions common to particular sub-groups and to all vertebrates. The emergence of Dlk1-Dio3 imprinting in eutherians has occurred on the maternally inherited chromosome and is associated with region-specific resistance to expansion by repetitive elements and the local introduction of noncoding transcripts including microRNAs and C/D small nucleolar RNAs. A recent mammal-specific retrotransposition event led to the formation of a completely new gene only in the eutherian domain, which may have driven imprinting at the cluster.

  5. Study on the Imprinting Status of Insulin-Like Growth Factor II (IGF-II Gene in Villus during 6–10 Gestational Weeks

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    Jianhong Chen

    2010-01-01

    Full Text Available Objective. To compare the difference of imprinting status of insulin-like growth factor II (IGF-II gene in villus between normal embryo development group and abnormal embryo development group and to investigate the relationship between karyotype and the imprinting status of IGF-II gene. Methods. A total of 85 pregnant women with singleton pregnancy were divided into two groups: one with abnormal embryo development (n=38 and the other with normal embryo development (n=47. Apa I polymorphism of IGF-II gene in chorionic villus was assayed with reverse transcriptase polymerase chain reaction (RT-PCR and restriction fragment length polymorphism (RFLP. The relationship between chromosomal abnormal karyotype and IGF-II gene imprinting status was analyzed by primary cell culture and G-banding chromosomal karyotype analysis. Results. IGF-II imprinting loss rate was higher in the abnormal embryo development group than the normal embryo development group (44.7% versus 31.6%, but without significant difference (P>.05. The percentage of abnormal chromosomes of chorionic villus in the abnormal embryo development group was 42.5%, in which IGF-II imprinting loss rate reached 64.7%. No abnormal karyotypes were found in the normal embryo development group. However, there was significant difference in IGF-II imprinting loss rate between two groups (P>.05. Conclusion. During weeks 6–10 of gestation, abnormal embryonic development is correlated with chromosomal abnormalities. The imprinting status of IGF-II gene played important roles in embryonic development, and imprinting loss might be related to chromosomal abnormalities.

  6. Ancestral TCDD exposure promotes epigenetic transgenerational inheritance of imprinted gene Igf2: Methylation status and DNMTs

    International Nuclear Information System (INIS)

    Ma, Jing; Chen, Xi; Liu, Yanan; Xie, Qunhui; Sun, Yawen; Chen, Jingshan; Leng, Ling; Yan, Huan; Zhao, Bin; Tang, Naijun

    2015-01-01

    Ancestral TCDD exposure could induce epigenetic transgenerational phenotypes, which may be mediated in part by imprinted gene inheritance. The aim of our study was to evaluate the transgenerational effects of ancestral TCDD exposure on the imprinted gene insulin-like growth factor-2 (Igf2) in rat somatic tissue. TCDD was administered daily by oral gavage to groups of F0 pregnant SD rats at dose levels of 0 (control), 200 or 800 ng/kg bw during gestation day 8–14. Animal transgenerational model of ancestral exposure to TCDD was carefully built, avoiding sibling inbreeding. Hepatic Igf2 expression of the TCDD male progeny was decreased concomitantly with hepatic damage and increased activities of serum hepatic enzymes both in the F1 and F3 generation. Imprinted Control Region (ICR) of Igf2 manifested a hypermethylated pattern, whereas methylation status in the Differentially Methylated Region 2 (DMR2) showed a hypomethylated manner in the F1 generation. These epigenetic alterations in these two regions maintained similar trends in the F3 generation. Meanwhile, the expressions of DNA methyltransferases (DNMT1, DNMT3A and DNMT3B) changed in a non-monotonic manner both in the F1 and F3 generation. This study provides evidence that ancestral TCDD exposure may promote epigenetic transgenerational alterations of imprinted gene Igf2 in adult somatic tissue. - Highlights: • Ancestral TCDD exposure induces epigenetic transgenerational inheritance. • Ancestral TCDD exposure affects methylation status in ICR and DMR2 region of Igf2. • DNMTs play a role in TCDD induced epigenetic transgenerational changes of Igf2.

  7. Ancestral TCDD exposure promotes epigenetic transgenerational inheritance of imprinted gene Igf2: Methylation status and DNMTs

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Jing; Chen, Xi; Liu, Yanan [Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin 300070 (China); Xie, Qunhui [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Sun, Yawen; Chen, Jingshan; Leng, Ling; Yan, Huan [Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin 300070 (China); Zhao, Bin, E-mail: binzhao@rcees.ac.cn [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Tang, Naijun, E-mail: tangnaijun@tijmu.edu.cn [Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin 300070 (China)

    2015-12-01

    Ancestral TCDD exposure could induce epigenetic transgenerational phenotypes, which may be mediated in part by imprinted gene inheritance. The aim of our study was to evaluate the transgenerational effects of ancestral TCDD exposure on the imprinted gene insulin-like growth factor-2 (Igf2) in rat somatic tissue. TCDD was administered daily by oral gavage to groups of F0 pregnant SD rats at dose levels of 0 (control), 200 or 800 ng/kg bw during gestation day 8–14. Animal transgenerational model of ancestral exposure to TCDD was carefully built, avoiding sibling inbreeding. Hepatic Igf2 expression of the TCDD male progeny was decreased concomitantly with hepatic damage and increased activities of serum hepatic enzymes both in the F1 and F3 generation. Imprinted Control Region (ICR) of Igf2 manifested a hypermethylated pattern, whereas methylation status in the Differentially Methylated Region 2 (DMR2) showed a hypomethylated manner in the F1 generation. These epigenetic alterations in these two regions maintained similar trends in the F3 generation. Meanwhile, the expressions of DNA methyltransferases (DNMT1, DNMT3A and DNMT3B) changed in a non-monotonic manner both in the F1 and F3 generation. This study provides evidence that ancestral TCDD exposure may promote epigenetic transgenerational alterations of imprinted gene Igf2 in adult somatic tissue. - Highlights: • Ancestral TCDD exposure induces epigenetic transgenerational inheritance. • Ancestral TCDD exposure affects methylation status in ICR and DMR2 region of Igf2. • DNMTs play a role in TCDD induced epigenetic transgenerational changes of Igf2.

  8. Early embryonic failure: Expression and imprinted status of candidate genes on human chromosome 21

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    Sherman, L.S.; Bennett, P.R.; Moore, G.E. [Queen Charlotte`s and Chelsea Hospital, London (United Kingdom)

    1994-09-01

    Two cases of maternal uniparental (hetero)disomy for human chromosome 21 (mUPD21) have been identified in a systematic search for UPD in 23 cases of early embryonic failure (EEF). Bi-parental origin of the other chromosome pairs was confirmed using specific VNTR probes or dinucleotide repeat analysis. Both maternally and paternally derived isochromosomes 21q have previously been identified in two individuals with normal phenotypes. Full UPD21 has a different mechanism of origin than uniparental isochromosome 21q and its effect on imprinted genes and phenotypic outcome will therefore not necessarily be the same. EEF associated with mUPD21 suggests that developmentally important genes on HSA 21 may be imprinted such that they are only expressed from either the maternally or paternally derived alleles. We have searched for monoallelic expression of candidate genes on HSA 21 in human pregnancy (CBS, IFNAR, COL6A1) using intragenic DNA polymorphisms. These genes were chosen either because their murine homologues lie in imprinted regions or because they are potentially important in embryogenesis. Once imprinted candidate genes have been identified, their methylation status and expression in normal, early embryonic failure and uniparental disomy 21 pregnancies will be studied. At the same time, a larger number of cases of EEF are being examined to further investigate the incidence of UPD21 in this group.

  9. [Evolution of genomic imprinting in mammals: what a zoo!].

    Science.gov (United States)

    Proudhon, Charlotte; Bourc'his, Déborah

    2010-05-01

    Genomic imprinting imposes an obligate mode of biparental reproduction in mammals. This phenomenon results from the monoparental expression of a subset of genes. This specific gene regulation mechanism affects viviparous mammals, especially eutherians, but also marsupials to a lesser extent. Oviparous mammals, or monotremes, do not seem to demonstrate monoparental allele expression. This phylogenic confinement suggests that the evolution of the placenta imposed a selective pressure for the emergence of genomic imprinting. This physiological argument is now complemented by recent genomic evidence facilitated by the sequencing of the platypus genome, a rare modern day case of a monotreme. Analysis of the platypus genome in comparison to eutherian genomes shows a chronological and functional coincidence between the appearance of genomic imprinting and transposable element accumulation. The systematic comparative analyses of genomic sequences in different species is essential for the further understanding of genomic imprinting emergence and divergent evolution along mammalian speciation.

  10. Imprinting.

    Science.gov (United States)

    McCabe, Brian J

    2013-07-01

    Imprinting is a type of learning by which an animal restricts its social preferences to an object after exposure to that object. Filial imprinting occurs shortly after birth or hatching and sexual imprinting, around the onset of sexual maturity; both have sensitive periods. This review is concerned mainly with filial imprinting. Filial imprinting in the domestic chick is an effective experimental system for investigating mechanisms underlying learning and memory. Extensive evidence implicates a restricted part of the chick forebrain, the intermediate and medial mesopallium (IMM), as a memory store for visual imprinting. After imprinting to a visual stimulus, neuronal responsiveness in IMM is specifically biased toward the imprinting stimulus. Both this bias and the strength of imprinting measured behaviorally depend on uninterrupted sleep shortly after training. When learning-related changes in IMM are lateralized they occur predominantly or completely on the left side. Ablation experiments indicate that the left IMM is responsible for long-term storage of information about the imprinting stimulus; the right side is also a store but additionally is necessary for extra storage outside IMM, in a region necessary for flexible use of information acquired through imprinting. Auditory imprinting gives rise to biochemical, neuroanatomical, and electrophysiological changes in the medio-rostral nidopallium/mesopallium, anterior to IMM. Auditory imprinting has not been shown to produce learning-related changes in IMM. Imprinting may be facilitated by predispositions. Similar predispositions for faces and biological motion occur in domestic chicks and human infants. WIREs Cogn Sci 2013, 4:375-390. doi: 10.1002/wcs.1231 For further resources related to this article, please visit the WIREs website. Copyright © 2013 John Wiley & Sons, Ltd.

  11. GATM, the human ortholog of the mouse imprinted Gatm gene, escapes genomic imprinting in placenta

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    Toshinobu Miyamoto

    2005-03-01

    Full Text Available The GATM gene encodes L-arginine:glycine amidinotransferase, which catalyzes the conversion of L-arginine into guanidinoacetate, the rate-limiting step in the synthesis of creatine. Since, deficiencies in creatine synthesis and transport lead to certain forms of mental retardation in human, the human GATM gene appears to be involved in brain development. Recently it has been demonstrated that the mouse Gatm is expressed during development and is imprinted with maternal expression in the placenta and yolk sac, but not in embryonic tissues. We investigated the imprinting status of the human GATM by analyzing its expression in four human placentas. GATM was biallelically expressed, thus suggesting that this gene escapes genomic imprinting in placentas, differently from what has been reported in mouse extra-embryonic tissues.

  12. Patterns of hybrid loss of imprinting reveal tissue- and cluster-specific regulation.

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    Christopher D Wiley

    Full Text Available Crosses between natural populations of two species of deer mice, Peromyscus maniculatus (BW, and P. polionotus (PO, produce parent-of-origin effects on growth and development. BW females mated to PO males (bwxpo produce growth-retarded but otherwise healthy offspring. In contrast, PO females mated to BW males (POxBW produce overgrown and severely defective offspring. The hybrid phenotypes are pronounced in the placenta and include POxBW conceptuses which lack embryonic structures. Evidence to date links variation in control of genomic imprinting with the hybrid defects, particularly in the POxBW offspring. Establishment of genomic imprinting is typically mediated by gametic DNA methylation at sites known as gDMRs. However, imprinted gene clusters vary in their regulation by gDMR sequences.Here we further assess imprinted gene expression and DNA methylation at different cluster types in order to discern patterns. These data reveal POxBW misexpression at the Kcnq1ot1 and Peg3 clusters, both of which lose ICR methylation in placental tissues. In contrast, some embryonic transcripts (Peg10, Kcnq1ot1 reactivated the silenced allele with little or no loss of DNA methylation. Hybrid brains also display different patterns of imprinting perturbations. Several cluster pairs thought to use analogous regulatory mechanisms are differentially affected in the hybrids.These data reinforce the hypothesis that placental and somatic gene regulation differs significantly, as does that between imprinted gene clusters and between species. That such epigenetic regulatory variation exists in recently diverged species suggests a role in reproductive isolation, and that this variation is likely to be adaptive.

  13. Changes in Parthenogenetic Imprinting Patterns during Reprogramming by Cell Fusion.

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    Hyun Sik Jang

    Full Text Available Differentiated somatic cells can be reprogrammed into the pluripotent state by cell-cell fusion. In the pluripotent state, reprogrammed cells may then self-renew and differentiate into all three germ layers. Fusion-induced reprogramming also epigenetically modifies the somatic cell genome through DNA demethylation, X chromosome reactivation, and histone modification. In this study, we investigated whether fusion with embryonic stem cells (ESCs also reprograms genomic imprinting patterns in somatic cells. In particular, we examined imprinting changes in parthenogenetic neural stem cells fused with biparental ESCs, as well as in biparental neural stem cells fused with parthenogenetic ESCs. The resulting hybrid cells expressed the pluripotency markers Oct4 and Nanog. In addition, methylation of several imprinted genes except Peg3 was comparable between hybrid cells and ESCs. This finding indicates that reprogramming by cell fusion does not necessarily reverse the status of all imprinted genes to the state of pluripotent fusion partner.

  14. Congenital imprinting disorders

    DEFF Research Database (Denmark)

    Eggermann, Thomas; Netchine, Irène; Temple, I Karen

    2015-01-01

    Imprinting disorders (IDs) are a group of eight rare but probably underdiagnosed congenital diseases affecting growth, development and metabolism. They are caused by similar molecular changes affecting regulation, dosage or the genomic sequence of imprinted genes. Each ID is characterised...... by specific clinical features, and, as each appeared to be associated with specific imprinting defects, they have been widely regarded as separate entities. However, they share clinical characteristics and can show overlapping molecular alterations. Nevertheless, IDs are usually studied separately despite...... EUCID.net (European network of congenital imprinting disorders) now aims to promote better clinical care and scientific investigation of imprinting disorders by establishing a concerted multidisciplinary alliance of clinicians, researchers, patients and families. By encompassing all IDs and establishing...

  15. Imprinting disorders

    DEFF Research Database (Denmark)

    Eggermann, Thomas; Perez de Nanclares, Guiomar; Maher, Eamonn R

    2015-01-01

    Congenital imprinting disorders (IDs) are characterised by molecular changes affecting imprinted chromosomal regions and genes, i.e. genes that are expressed in a parent-of-origin specific manner. Recent years have seen a great expansion in the range of alterations in regulation, dosage or DNA...... sequence shown to disturb imprinted gene expression, and the correspondingly broad range of resultant clinical syndromes. At the same time, however, it has become clear that this diversity of IDs has common underlying principles, not only in shared molecular mechanisms, but also in interrelated clinical...

  16. Preparation of Molecularly Imprinted Composite Membranes for Inducing Bergenin Crystallization in Supercritical CO2 and Adsorption Properties

    International Nuclear Information System (INIS)

    Zhang, Wencheng; Wang, Ruixia; Cui, Yanfang; Hong, Lile; Zhang, Qing; Zhang, Xingyuan

    2012-01-01

    The process of molecular imprinting is composed of three steps: covalent conjugate or noncovalent adduct between a functional monomer and a template molecule, which is the preorganization step; polymerization of this monomer-template conjugate (or adduct) and removal of the template from the polymer. In the above procedures, the molecular memory is strongly dependent on the formation and status of the template-monomer preorganization conjugate (or adduct). Therefore, to study these conjugates/adducts in detail is crucially important for understanding the imprinting mechanism and designing efficient molecular imprinting systems. On the other hand, one of the most important and facile ways to realize the molecular imprinting is using the molecularly imprinted membranes (MIMs), which were first introduced by Piletsky et al. In MIMs systems, the combination of the imprinting technique can provide membranes with specific selectivity for the separation of targeted organic compounds and thus make the MIMs possess the advantages of both molecular imprinting and membrane technology

  17. [Neurobiology of imprinting].

    Science.gov (United States)

    Ohki-Hamazaki, Hiroko

    2012-06-01

    Imprinting is an example of learning and memory acquisition in infancy. In the case of precocial birds, such as geese, ducks, and chickens, the baby birds learn the characteristics of the first moving object that they see within a critical period, and they imprint on it and follow it around. We analyzed the neural basis of this behavior in order to understand the neural mechanism of learning and memory in infancy. Information pertaining to a visual imprinting stimulus is recognized and processed in the visual Wulst, a region that corresponds to the mammalian visual cortex. It is then transmitted to the posterior region of the telencephalon, followed by the core region of the hyperpallium densocellulare (HDCo), periventricular region of the hyperpallium densocellulare (HDPe), and finally, the intermediate medial mesopallium (IMM), a region similar to the mammalian association cortex. Memory is stored in the IMM. After imprint training, plastic changes are observed in the visual Wulst as well as in the neurons of this circuit. HDCo cells, located at the center of this circuit, express N-methyl-D-aspartate (NMDA) receptors containing the NMDA receptor (NR) 2B subunit; the expression of this receptor increased after the imprint training. Inhibition of this receptor in the cells of the HDCo region leads to failure of imprinting and inactivation of this circuit. Thus, NMDA receptors bearing the NR2B subunit play a critical role in plastic changes in this circuit and in induction of imprinting.

  18. Preparation of Molecularly Imprinted Composite Membranes for Inducing Bergenin Crystallization in Supercritical CO{sub 2} and Adsorption Properties

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wencheng; Wang, Ruixia; Cui, Yanfang; Hong, Lile [Hefei University of Technology, Hefei (China); Zhang, Qing; Zhang, Xingyuan [University of Science and Technology of China, Hefei (China)

    2012-02-15

    The process of molecular imprinting is composed of three steps: covalent conjugate or noncovalent adduct between a functional monomer and a template molecule, which is the preorganization step; polymerization of this monomer-template conjugate (or adduct) and removal of the template from the polymer. In the above procedures, the molecular memory is strongly dependent on the formation and status of the template-monomer preorganization conjugate (or adduct). Therefore, to study these conjugates/adducts in detail is crucially important for understanding the imprinting mechanism and designing efficient molecular imprinting systems. On the other hand, one of the most important and facile ways to realize the molecular imprinting is using the molecularly imprinted membranes (MIMs), which were first introduced by Piletsky et al. In MIMs systems, the combination of the imprinting technique can provide membranes with specific selectivity for the separation of targeted organic compounds and thus make the MIMs possess the advantages of both molecular imprinting and membrane technology.

  19. The rational development of molecularly imprinted polymer-based sensors for protein detection.

    Science.gov (United States)

    Whitcombe, Michael J; Chianella, Iva; Larcombe, Lee; Piletsky, Sergey A; Noble, James; Porter, Robert; Horgan, Adrian

    2011-03-01

    The detection of specific proteins as biomarkers of disease, health status, environmental monitoring, food quality, control of fermenters and civil defence purposes means that biosensors for these targets will become increasingly more important. Among the technologies used for building specific recognition properties, molecularly imprinted polymers (MIPs) are attracting much attention. In this critical review we describe many methods used for imprinting recognition for protein targets in polymers and their incorporation with a number of transducer platforms with the aim of identifying the most promising approaches for the preparation of MIP-based protein sensors (277 references).

  20. Comprehensive analyses of imprinted differentially methylated regions reveal epigenetic and genetic characteristics in hepatoblastoma

    International Nuclear Information System (INIS)

    Rumbajan, Janette Mareska; Aoki, Shigehisa; Kohashi, Kenichi; Oda, Yoshinao; Hata, Kenichiro; Saji, Tsutomu; Taguchi, Tomoaki; Tajiri, Tatsuro; Soejima, Hidenobu; Joh, Keiichiro; Maeda, Toshiyuki; Souzaki, Ryota; Mitsui, Kazumasa; Higashimoto, Ken; Nakabayashi, Kazuhiko; Yatsuki, Hitomi; Nishioka, Kenichi; Harada, Ryoko

    2013-01-01

    Aberrant methylation at imprinted differentially methylated regions (DMRs) in human 11p15.5 has been reported in many tumors including hepatoblastoma. However, the methylation status of imprinted DMRs in imprinted loci scattered through the human genome has not been analyzed yet in any tumors. The methylation statuses of 33 imprinted DMRs were analyzed in 12 hepatoblastomas and adjacent normal liver tissue by MALDI-TOF MS and pyrosequencing. Uniparental disomy (UPD) and copy number abnormalities were investigated with DNA polymorphisms. Among 33 DMRs analyzed, 18 showed aberrant methylation in at least 1 tumor. There was large deviation in the incidence of aberrant methylation among the DMRs. KvDMR1 and IGF2-DMR0 were the most frequently hypomethylated DMRs. INPP5Fv2-DMR and RB1-DMR were hypermethylated with high frequencies. Hypomethylation was observed at certain DMRs not only in tumors but also in a small number of adjacent histologically normal liver tissue, whereas hypermethylation was observed only in tumor samples. The methylation levels of long interspersed nuclear element-1 (LINE-1) did not show large differences between tumor tissue and normal liver controls. Chromosomal abnormalities were also found in some tumors. 11p15.5 and 20q13.3 loci showed the frequent occurrence of both genetic and epigenetic alterations. Our analyses revealed tumor-specific aberrant hypermethylation at some imprinted DMRs in 12 hepatoblastomas with additional suggestion for the possibility of hypomethylation prior to tumor development. Some loci showed both genetic and epigenetic alterations with high frequencies. These findings will aid in understanding the development of hepatoblastoma

  1. The evolution of imprinting: chromosomal mapping of orthologues of mammalian imprinted domains in monotreme and marsupial mammals

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    Dunham Ian

    2007-09-01

    Full Text Available Abstract Background The evolution of genomic imprinting, the parental-origin specific expression of genes, is the subject of much debate. There are several theories to account for how the mechanism evolved including the hypothesis that it was driven by the evolution of X-inactivation, or that it arose from an ancestrally imprinted chromosome. Results Here we demonstrate that mammalian orthologues of imprinted genes are dispersed amongst autosomes in both monotreme and marsupial karyotypes. Conclusion These data, along with the similar distribution seen in birds, suggest that imprinted genes were not located on an ancestrally imprinted chromosome or associated with a sex chromosome. Our results suggest imprinting evolution was a stepwise, adaptive process, with each gene/cluster independently becoming imprinted as the need arose.

  2. Generation of Five Human Lactoferrin Transgenic Cloned Goats Using Fibroblast Cells and Their Methylation Status of Putative Differential Methylation Regions of IGF2R and H19 Imprinted Genes

    Science.gov (United States)

    Sun, Yanyan; Zhang, Yanli; Wang, Ziyu; Song, Yang; Wang, Feng

    2013-01-01

    Background Somatic cell nuclear transfer (SCNT) is a promising technique to produce transgenic cloned mammalian, including transgenic goats which may produce Human Lactoferrin (hLF). However, success percentage of SCNT is low, because of gestational and neonatal failure of transgenic embryos. According to the studies on cattle and mice, DNA methylation of some imprinted genes, which plays a vital role in the reprogramming of embryo in NT maybe an underlying mechanism. Methodology/Principal Findings Fibroblast cells were derived from the ear of a two-month-old goat. The vector expressing hLF was constructed and transfected into fibroblasts. G418 selection, EGFP expression, PCR, and cell cycle distribution were applied sequentially to select transgenic cells clones. After NT and embryo transfer, five transgenic cloned goats were obtained from 240 cloned transgenic embryos. These transgenic goats were identified by 8 microsatellites genotyping and southern blot. Of the five transgenic goats, 3 were lived after birth, while 2 were dead during gestation. We compared differential methylation regions (DMR) pattern of two paternally imprinted genes (H19 and IGF2R) of the ear tissues from the lived transgenic goats, dead transgenic goats, and control goats from natural reproduction. Hyper-methylation pattern appeared in cloned aborted goats, while methylation status was relatively normal in cloned lived goats compared with normal goats. Conclusions/Significance In this study, we generated five hLF transgenic cloned goats by SCNT. This is the first time the DNA methylation of lived and dead transgenic cloned goats was compared. The results demonstrated that the methylation status of DMRs of H19 and IGF2R were different in lived and dead transgenic goats and therefore this may be potentially used to assess the reprogramming status of transgenic cloned goats. Understanding the pattern of gene imprinting may be useful to improve cloning techniques in future. PMID:24204972

  3. Epigenetic Mechanisms of Genomic Imprinting: Common Themes in the Regulation of Imprinted Regions in Mammals, Plants, and Insects

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    William A. MacDonald

    2012-01-01

    Full Text Available Genomic imprinting is a form of epigenetic inheritance whereby the regulation of a gene or chromosomal region is dependent on the sex of the transmitting parent. During gametogenesis, imprinted regions of DNA are differentially marked in accordance to the sex of the parent, resulting in parent-specific expression. While mice are the primary research model used to study genomic imprinting, imprinted regions have been described in a broad variety of organisms, including other mammals, plants, and insects. Each of these organisms employs multiple, interrelated, epigenetic mechanisms to maintain parent-specific expression. While imprinted genes and imprint control regions are often species and locus-specific, the same suites of epigenetic mechanisms are often used to achieve imprinted expression. This review examines some examples of the epigenetic mechanisms responsible for genomic imprinting in mammals, plants, and insects.

  4. The imprinted gene neuronatin is regulated by metabolic status and associated with obesity

    DEFF Research Database (Denmark)

    Vrang, Niels; Meyre, David; Froguel, Phillippe

    2010-01-01

    Using restriction fragment differential display (RFDD) technology, we have identified the imprinted gene neuronatin (Nnat) as a hypothalamic target under the influence of leptin. Nnat mRNA expression is decreased in several key appetite regulatory hypothalamic nuclei in rodents with impaired leptin...

  5. Expression and imprinting of insulin-like growth factor II (IGF2) and H19 genes in uterine leiomyomas

    DEFF Research Database (Denmark)

    Rainho, C A; Pontes, A; Rogatto, S R

    1999-01-01

    status of IGF2 and H19 genes in 47 uterine leiomyomas. Using allelic transcription assay, we detected the expression of the IGF2 gene in 10 of a total of 15 informative cases. No loss of imprinting, as determined by the finding of biallelic expression, was detected in any case. The expression of H19 gene...... was detected in 10 of 20 informative cases and the imprinting pattern was also maintained in all of them. Our data suggest that alterations in IGF2 and H19 genes expression by loss of imprinting do not occur in uterine leiomyomas....

  6. A Novel Biomimetic Tool for Assessing Vitamin K Status Based on Molecularly Imprinted Polymers

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    Kasper Eersels

    2018-06-01

    Full Text Available Vitamin K was originally discovered as a cofactor required to activate clotting factors and has recently been shown to play a key role in the regulation of soft tissue calcification. This property of vitamin K has led to an increased interest in novel methods for accurate vitamin K detection. Molecularly Imprinted Polymers (MIPs could offer a solution, as they have been used as synthetic receptors in a large variety of biomimetic sensors for the detection of similar molecules over the past few decades, because of their robust nature and remarkable selectivity. In this article, the authors introduce a novel imprinting approach to create a MIP that is able to selectively rebind vitamin K1. As the native structure of the vitamin does not allow for imprinting, an alternative imprinting strategy was developed, using the synthetic compound menadione (vitamin K3 as a template. Target rebinding was analyzed by means of UV-visible (UV-VIS spectroscopy and two custom-made thermal readout techniques. This analysis reveals that the MIP-based sensor reacts to an increasing concentration of both menadione and vitamin K1. The Limit of Detection (LoD for both compounds was established at 700 nM for the Heat Transfer Method (HTM, while the optimized readout approach, Thermal Wave Transport Analysis (TWTA, displayed an increased sensitivity with a LoD of 200 nM. The sensor seems to react to a lesser extent to Vitamin E, the analogue under study. To further demonstrate its potential application in biochemical research, the sensor was used to measure the absorption of vitamin K in blood serum after taking vitamin K supplements. By employing a gradual enrichment strategy, the sensor was able to detect the difference between baseline and peak absorption samples and was able to quantify the vitamin K concentration in good agreement with a validation experiment using High-Performance Liquid Chromatography (HPLC. In this way, the authors provide a first proof of

  7. DNA Methylation of Regulatory Regions of Imprinted Genes at Birth and Its Relation to Infant Temperament

    Directory of Open Access Journals (Sweden)

    Bernard F. Fuemmeler

    2016-01-01

    Full Text Available BACKGROUND DNA methylation of the differentially methylated regions (DMRs of imprinted genes is relevant to neurodevelopment. METHODS DNA methylation status of the DMRs of nine imprinted genes in umbilical cord blood leukocytes was analyzed in relation to infant behaviors and temperament (n = 158. RESULTS MEG3 DMR levels were positively associated with internalizing ( β = 0.15, P = 0.044 and surgency ( β = 0.19, P = 0.018 behaviors, after adjusting for birth weight, gender, gestational age at birth, maternal age at delivery, race/ethnicity, education level, smoking status, parity, and a history of anxiety or depression. Higher methylation levels at the intergenic MEG3-IG methylation regions were associated with surgency ( β = 0.28, P = 0.0003 and PEG3 was positively related to externalizing ( β = 0.20, P = 0.01 and negative affectivity ( β = 0.18, P = 0.02. CONCLUSION While the small sample size limits inference, these pilot data support gene-specific associations between epigenetic differences in regulatory regions of imprinted domains at birth and later infant temperament.

  8. DDC and COBL, flanking the imprinted GRB10 gene on 7p12, are biallelically expressed.

    Science.gov (United States)

    Hitchins, Megan P; Bentley, Louise; Monk, David; Beechey, Colin; Peters, Jo; Kelsey, Gavin; Ishino, Fumitoshi; Preece, Michael A; Stanier, Philip; Moore, Gudrun E

    2002-12-01

    Maternal duplication of human 7p11.2-p13 has been associated with Silver-Russell syndrome (SRS) in two familial cases. GRB10 is the only imprinted gene identified within this region to date. GRB10 demonstrates an intricate tissue- and isoform-specific imprinting profile in humans, with paternal expression in fetal brain and maternal expression of one isoform in skeletal muscle. The mouse homolog is maternally transcribed. The GRB10 protein is a potent growth inhibitor and represents a candidate for SRS, which is characterized by pre- and postnatal growth retardation and a spectrum of additional dysmorphic features. Since imprinted genes tend to be grouped in clusters, we investigated the imprinting status of the dopa-decarboxylase gene (DDC) and the Cordon-bleu gene (COBL) which flank GRB10 within the 7p11.2-p13 SRS duplicated region. Although both genes were found to replicate asynchronously, suggestive of imprinting, SNP expression analyses showed that neither gene was imprinted in multiple human fetal tissues. The mouse homologues, Ddc and Cobl, which map to the homologous imprinted region on proximal Chr 11, were also biallelically expressed in mice with uniparental maternal or paternal inheritance of this region. With the intent of using mouse Grb10 as an imprinted control, biallelic expression was consistently observed in fetal, postnatal, and adult brain of these mice, in contrast to the maternal-specific transcription previously demonstrated in brain in inter-specific F1 progeny. This may be a further example of over-expression of maternally derived transcripts in inter-specific mouse crosses. GRB10 remains the only imprinted gene identified within 7p11.2-p13.

  9. Molecular Imprinting of Macromolecules for Sensor Applications.

    Science.gov (United States)

    Saylan, Yeşeren; Yilmaz, Fatma; Özgür, Erdoğan; Derazshamshir, Ali; Yavuz, Handan; Denizli, Adil

    2017-04-19

    Molecular recognition has an important role in numerous living systems. One of the most important molecular recognition methods is molecular imprinting, which allows host compounds to recognize and detect several molecules rapidly, sensitively and selectively. Compared to natural systems, molecular imprinting methods have some important features such as low cost, robustness, high recognition ability and long term durability which allows molecularly imprinted polymers to be used in various biotechnological applications, such as chromatography, drug delivery, nanotechnology, and sensor technology. Sensors are important tools because of their ability to figure out a potentially large number of analytical difficulties in various areas with different macromolecular targets. Proteins, enzymes, nucleic acids, antibodies, viruses and cells are defined as macromolecules that have wide range of functions are very important. Thus, macromolecules detection has gained great attention in concerning the improvement in most of the studies. The applications of macromolecule imprinted sensors will have a spacious exploration according to the low cost, high specificity and stability. In this review, macromolecules for molecularly imprinted sensor applications are structured according to the definition of molecular imprinting methods, developments in macromolecular imprinting methods, macromolecular imprinted sensors, and conclusions and future perspectives. This chapter follows the latter strategies and focuses on the applications of macromolecular imprinted sensors. This allows discussion on how sensor strategy is brought to solve the macromolecules imprinting.

  10. 21 CFR 206.10 - Code imprint required.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Code imprint required. 206.10 Section 206.10 Food...: GENERAL IMPRINTING OF SOLID ORAL DOSAGE FORM DRUG PRODUCTS FOR HUMAN USE § 206.10 Code imprint required... imprint that, in conjunction with the product's size, shape, and color, permits the unique identification...

  11. The Drosophila homolog of the mammalian imprint regulator, CTCF, maintains the maternal genomic imprint in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Rasheva Vanya

    2010-07-01

    Full Text Available Abstract Background CTCF is a versatile zinc finger DNA-binding protein that functions as a highly conserved epigenetic transcriptional regulator. CTCF is known to act as a chromosomal insulator, bind promoter regions, and facilitate long-range chromatin interactions. In mammals, CTCF is active in the regulatory regions of some genes that exhibit genomic imprinting, acting as insulator on only one parental allele to facilitate parent-specific expression. In Drosophila, CTCF acts as a chromatin insulator and is thought to be actively involved in the global organization of the genome. Results To determine whether CTCF regulates imprinting in Drosophila, we generated CTCF mutant alleles and assayed gene expression from the imprinted Dp(1;fLJ9 mini-X chromosome in the presence of reduced CTCF expression. We observed disruption of the maternal imprint when CTCF levels were reduced, but no effect was observed on the paternal imprint. The effect was restricted to maintenance of the imprint and was specific for the Dp(1;fLJ9 mini-X chromosome. Conclusions CTCF in Drosophila functions in maintaining parent-specific expression from an imprinted domain as it does in mammals. We propose that Drosophila CTCF maintains an insulator boundary on the maternal X chromosome, shielding genes from the imprint-induced silencing that occurs on the paternally inherited X chromosome. See commentary: http://www.biomedcentral.com/1741-7007/8/104

  12. Topological imprint for periodic orbits

    International Nuclear Information System (INIS)

    Martín, Jesús San; Moscoso, Ma José; Gómez, A González

    2012-01-01

    The more self-crossing points an orbit has the more complex it is. We introduce the topological imprint to characterize crossing points and focus on the period-doubling cascade. The period-doubling cascade topological imprint determines the topological imprint for orbits in chaotic bands. In addition, there is a closer link between this concept and the braids studied by Lettelier et al (2000 J. Phys. A: Math. Gen. 33 1809–25). (paper)

  13. Molecularly Imprinted Polymer Synthesis Using RAFT Polymerisation

    International Nuclear Information System (INIS)

    Cormack, P.A.G.; Faizatul Shimal Mehamod; Faizatul Shimal Mehamod

    2013-01-01

    In this paper, the synthesis and characterisation of caffeine-imprinted polymers are described. The polymers were prepared in monolithic form via both reversible addition-fragmentation chain-transfer (RAFT) polymerisation and conventional free radical polymerisation, using methacrylic acid and ethylene glycol dimethacrylate as the functional monomer and crosslinking agent, respectively. The potential benefits in applying RAFT polymerisation techniques towards the synthesis of molecularly imprinted polymers (MIPs) are explored and elucidated. The pore structures of the polymers produced were characterised by nitrogen sorption porosimetry and the molecular recognition properties of representative products were evaluated in high-performance liquid chromatography (HPLC) mode. Molecular imprinting effects were confirmed by analysing the relative retentions of analytes on imprinted and non-imprinted HPLC stationary phases. It was found that a caffeine-imprinted polymer synthesised by RAFT polymerisation was superior to a polymer prepared using a conventional synthetic approach; the imprinting factor and column efficiency were found to be higher for the former material. (author)

  14. High-throughput analysis of candidate imprinted genes and allele-specific gene expression in the human term placenta

    Directory of Open Access Journals (Sweden)

    Clark Taane G

    2010-04-01

    Full Text Available Abstract Background Imprinted genes show expression from one parental allele only and are important for development and behaviour. This extreme mode of allelic imbalance has been described for approximately 56 human genes. Imprinting status is often disrupted in cancer and dysmorphic syndromes. More subtle variation of gene expression, that is not parent-of-origin specific, termed 'allele-specific gene expression' (ASE is more common and may give rise to milder phenotypic differences. Using two allele-specific high-throughput technologies alongside bioinformatics predictions, normal term human placenta was screened to find new imprinted genes and to ascertain the extent of ASE in this tissue. Results Twenty-three family trios of placental cDNA, placental genomic DNA (gDNA and gDNA from both parents were tested for 130 candidate genes with the Sequenom MassArray system. Six genes were found differentially expressed but none imprinted. The Illumina ASE BeadArray platform was then used to test 1536 SNPs in 932 genes. The array was enriched for the human orthologues of 124 mouse candidate genes from bioinformatics predictions and 10 human candidate imprinted genes from EST database mining. After quality control pruning, a total of 261 informative SNPs (214 genes remained for analysis. Imprinting with maternal expression was demonstrated for the lymphocyte imprinted gene ZNF331 in human placenta. Two potential differentially methylated regions (DMRs were found in the vicinity of ZNF331. None of the bioinformatically predicted candidates tested showed imprinting except for a skewed allelic expression in a parent-specific manner observed for PHACTR2, a neighbour of the imprinted PLAGL1 gene. ASE was detected for two or more individuals in 39 candidate genes (18%. Conclusions Both Sequenom and Illumina assays were sensitive enough to study imprinting and strong allelic bias. Previous bioinformatics approaches were not predictive of new imprinted genes

  15. Imprinting alterations in sperm may not significantly influence ART outcomes and imprinting patterns in the cord blood of offspring.

    Science.gov (United States)

    Tang, Li; Liu, Zichao; Zhang, Ruopeng; Su, Cunmei; Yang, Wenjuan; Yao, Youlin; Zhao, Shuhua

    2017-01-01

    An increase in imprinting disorders in children conceived though assisted reproductive technologies (ARTs) has been the subject of several reports. The transmission of imprinting errors from the sperm of infertile fathers is believed to be a possible reason for the increased occurrence of these disorders. However, whether the imprinting alterations in sperm affect ART outcomes and the imprinting of offspring is unclear. In the current study, we analyzed the methylation of H19, SNRPN and KCNQ1OT1 by pyrosequencing sperm samples from 97 infertile patients and 31 proven fertile males as well as cord blood samples from 13 infantswho were conceived by infertile parents through intracytoplasmic sperm injection (ICSI) and 30 healthy newborns who were conceived naturally. After four cases were excluded owing to the lack of a sequencing signal, the infertile patients were subgrouped into normal (69 cases) and abnormal (24 cases) imprinting groups according to the reference range set by the control group. Between the groups, there were no significant differences in ART outcomes. Significantly different levels of methylation were detected in H19, but none of the imprinted genes were determined to be outside of the methylation reference range set by the values derived from the naturally conceived controls. Three CpG loci were found to be significantly hypomethylated in the maternally imprinted gene KCNQ1OT1 in two patients from the abnormal imprinting group, none of which were caused by sperm imprinting errors. In addition, the paternal H19 gene exhibited discrepant methylation patterns between the sperm controls and the cord blood controls. Our data suggest that increased imprinting errors in the sperm of infertile patients do not have an obvious influence on ART outcomes or the imprinting of offspring.

  16. Soluble Molecularly Imprinted Nanorods for Homogeneous Molecular Recognition

    Directory of Open Access Journals (Sweden)

    Rongning Liang

    2018-03-01

    Full Text Available Nowadays, it is still difficult for molecularly imprinted polymers (MIPs to achieve homogeneous recognition since they cannot be easily dissolved in organic or aqueous phase. To address this issue, soluble molecularly imprinted nanorods have been synthesized by using soluble polyaniline doped with a functionalized organic protonic acid as the polymer matrix. By employing 1-naphthoic acid as a model, the proposed imprinted nanorods exhibit an excellent solubility and good homogeneous recognition ability. The imprinting factor for the soluble imprinted nanoroads is 6.8. The equilibrium dissociation constant and the apparent maximum number of the proposed imprinted nanorods are 248.5 μM and 22.1 μmol/g, respectively. We believe that such imprinted nanorods may provide an appealing substitute for natural receptors in homogeneous recognition related fields.

  17. Soluble Molecularly Imprinted Nanorods for Homogeneous Molecular Recognition

    Science.gov (United States)

    Liang, Rongning; Wang, Tiantian; Zhang, Huan; Yao, Ruiqing; Qin, Wei

    2018-03-01

    Nowadays, it is still difficult for molecularly imprinted polymer (MIPs) to achieve homogeneous recognition since they cannot be easily dissolved in organic or aqueous phase. To address this issue, soluble molecularly imprinted nanorods have been synthesized by using soluble polyaniline doped with a functionalized organic protonic acid as the polymer matrix. By employing 1-naphthoic acid as a model, the proposed imprinted nanorods exhibit an excellent solubility and good homogeneous recognition ability. The imprinting factor for the soluble imprinted nanoroads is 6.8. The equilibrium dissociation constant and the apparent maximum number of the proposed imprinted nanorods are 248.5 μM and 22.1 μmol/g, respectively. We believe that such imprinted nanorods may provide an appealing substitute for natural receptors in homogeneous recognition related fields.

  18. [Werkgartner's muzzle imprint mark--a literature study].

    Science.gov (United States)

    Geserick, Gunther; Vendura, Klaus; Wirth, Ingo

    2009-01-01

    Since Werkgartner described and correctly interpreted the muzzle imprint mark around the gunshot entrance wound in 1922, this finding has been generally accepted as a sign of a contact shot. In further studies, it could finally be clarified that the muzzle imprint mark is caused by the expansive power of the powder gases with pressure on and abrasion of the skin at the muzzle (weapon imprint). Its shape depends on the firearm, the ammunition and the anatomical conditions, but does not require a bullet. Examinations under a magnifying glass microscope and histological investigations can complete the macroscopic findings. Occasionally, the muzzle imprint mark requires a certain "drying period" in order to become clearly visible. In rare cases, muzzle imprint marks also form on textiles perforated by the projectile. Characteristically shaped muzzled imprint marks can provide clues to the type of the firearm and its position at the time of discharge.

  19. Recent Advances in Imprinting Disorders

    DEFF Research Database (Denmark)

    Soellner, L; Begemann, M; Mackay, D J G

    2017-01-01

    Imprinting disorders (ImpDis) are a group of currently 12 congenital diseases with common underlying (epi)genetic etiologies and overlapping clinical features affecting growth, development and metabolism. In the last years it has emerged that ImpDis are characterized by the same types of mutations...... and epimutations, i.e. uniparental disomies, copy number variations, epimutations, and point mutations. Each ImpDis is associated with a specific imprinted locus, but the same imprinted region can be involved in different ImpDis. Additionally, even the same aberrant methylation patterns are observed in different...

  20. Evidence for geomagnetic imprinting as a homing mechanism in Pacific salmon.

    Science.gov (United States)

    Putman, Nathan F; Lohmann, Kenneth J; Putman, Emily M; Quinn, Thomas P; Klimley, A Peter; Noakes, David L G

    2013-02-18

    In the final phase of their spawning migration, Pacific salmon use chemical cues to identify their home river, but how they navigate from the open ocean to the correct coastal area has remained enigmatic. To test the hypothesis that salmon imprint on the magnetic field that exists where they first enter the sea and later seek the same field upon return, we analyzed a 56-year fisheries data set on Fraser River sockeye salmon, which must detour around Vancouver Island to approach the river through either a northern or southern passageway. We found that the proportion of salmon using each route was predicted by geomagnetic field drift: the more the field at a passage entrance diverged from the field at the river mouth, the fewer fish used the passage. We also found that more fish used the northern passage in years with warmer sea surface temperature (presumably because fish were constrained to more northern latitudes). Field drift accounted for 16% of the variation in migratory route used, temperature 22%, and the interaction between these variables 28%. These results provide the first empirical evidence of geomagnetic imprinting in any species and imply that forecasting salmon movements is possible using geomagnetic models. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Comparative anatomy of chromosomal domains with imprinted and non-imprinted allele-specific DNA methylation.

    Science.gov (United States)

    Paliwal, Anupam; Temkin, Alexis M; Kerkel, Kristi; Yale, Alexander; Yotova, Iveta; Drost, Natalia; Lax, Simon; Nhan-Chang, Chia-Ling; Powell, Charles; Borczuk, Alain; Aviv, Abraham; Wapner, Ronald; Chen, Xiaowei; Nagy, Peter L; Schork, Nicholas; Do, Catherine; Torkamani, Ali; Tycko, Benjamin

    2013-08-01

    Allele-specific DNA methylation (ASM) is well studied in imprinted domains, but this type of epigenetic asymmetry is actually found more commonly at non-imprinted loci, where the ASM is dictated not by parent-of-origin but instead by the local haplotype. We identified loci with strong ASM in human tissues from methylation-sensitive SNP array data. Two index regions (bisulfite PCR amplicons), one between the C3orf27 and RPN1 genes in chromosome band 3q21 and the other near the VTRNA2-1 vault RNA in band 5q31, proved to be new examples of imprinted DMRs (maternal alleles methylated) while a third, between STEAP3 and C2orf76 in chromosome band 2q14, showed non-imprinted haplotype-dependent ASM. Using long-read bisulfite sequencing (bis-seq) in 8 human tissues we found that in all 3 domains the ASM is restricted to single differentially methylated regions (DMRs), each less than 2kb. The ASM in the C3orf27-RPN1 intergenic region was placenta-specific and associated with allele-specific expression of a long non-coding RNA. Strikingly, the discrete DMRs in all 3 regions overlap with binding sites for the insulator protein CTCF, which we found selectively bound to the unmethylated allele of the STEAP3-C2orf76 DMR. Methylation mapping in two additional genes with non-imprinted haplotype-dependent ASM, ELK3 and CYP2A7, showed that the CYP2A7 DMR also overlaps a CTCF site. Thus, two features of imprinted domains, highly localized DMRs and allele-specific insulator occupancy by CTCF, can also be found in chromosomal domains with non-imprinted ASM. Arguing for biological importance, our analysis of published whole genome bis-seq data from hES cells revealed multiple genome-wide association study (GWAS) peaks near CTCF binding sites with ASM.

  2. Comparative anatomy of chromosomal domains with imprinted and non-imprinted allele-specific DNA methylation.

    Directory of Open Access Journals (Sweden)

    Anupam Paliwal

    2013-08-01

    Full Text Available Allele-specific DNA methylation (ASM is well studied in imprinted domains, but this type of epigenetic asymmetry is actually found more commonly at non-imprinted loci, where the ASM is dictated not by parent-of-origin but instead by the local haplotype. We identified loci with strong ASM in human tissues from methylation-sensitive SNP array data. Two index regions (bisulfite PCR amplicons, one between the C3orf27 and RPN1 genes in chromosome band 3q21 and the other near the VTRNA2-1 vault RNA in band 5q31, proved to be new examples of imprinted DMRs (maternal alleles methylated while a third, between STEAP3 and C2orf76 in chromosome band 2q14, showed non-imprinted haplotype-dependent ASM. Using long-read bisulfite sequencing (bis-seq in 8 human tissues we found that in all 3 domains the ASM is restricted to single differentially methylated regions (DMRs, each less than 2kb. The ASM in the C3orf27-RPN1 intergenic region was placenta-specific and associated with allele-specific expression of a long non-coding RNA. Strikingly, the discrete DMRs in all 3 regions overlap with binding sites for the insulator protein CTCF, which we found selectively bound to the unmethylated allele of the STEAP3-C2orf76 DMR. Methylation mapping in two additional genes with non-imprinted haplotype-dependent ASM, ELK3 and CYP2A7, showed that the CYP2A7 DMR also overlaps a CTCF site. Thus, two features of imprinted domains, highly localized DMRs and allele-specific insulator occupancy by CTCF, can also be found in chromosomal domains with non-imprinted ASM. Arguing for biological importance, our analysis of published whole genome bis-seq data from hES cells revealed multiple genome-wide association study (GWAS peaks near CTCF binding sites with ASM.

  3. Catalytic silica particles via template-directed molecular imprinting

    Energy Technology Data Exchange (ETDEWEB)

    Markowitz, M.A.; Kust, P.R.; Deng, G.; Schoen, P.E.; Dordick, J.S.; Clark, D.S.; Gaber, B.P.

    2000-02-22

    The surfaces of silica particle were molecularly imprinted with an {alpha}-chymotrypsin transition-state analogue (TSA) by utilizing the technique of template-directed synthesis of mineralized materials. The resulting catalytic particles hydrolyzed amides in an enantioselective manner. A mixture of a nonionic surfactant and the acylated chymotrysin TSA, with the TSA acting as the headgroup at the surfactant-water interface, was used to form a microemulsion for silica particle formation. Incorporation of amine-, dihydroimidazole-, and carboxylate-terminated trialkoxysilanes into the particles during imprinting resulted in enhancement of the rates of amide hydrolysis. Acylated imprint molecules formed more effective imprints in the presence of the functionalized silanes than nonacylated imprint molecules. Particles surface-imprinted with the chymotrypsin TSA were selective for the trypsin substrate, and particles surface-imprinted with the L-isomer of the enzyme TSA were enantioselective for the D-isomer of the substrate.

  4. Dopamine-imprinted monolithic column for capillary electrochromatography.

    Science.gov (United States)

    Aşır, Süleyman; Sarı, Duygu; Derazshamshir, Ali; Yılmaz, Fatma; Şarkaya, Koray; Denizli, Adil

    2017-11-01

    A dopamine-imprinted monolithic column was prepared and used in capillary electrochromatography as stationary phase for the first time. Dopamine was selectively separated from aqueous solution containing the competitor molecule norepinephrine, which is similar in size and shape to the template molecule. Morphology of the dopamine-imprinted column was observed by scanning electron microscopy. The influence of the organic solvent content of mobile phase, applied pressure and pH of the mobile phase on the recognition of dopamine by the imprinted monolithic column has been evaluated, and the imprinting effect in the dopamine-imprinted monolithic polymer was verified. Developed dopamine-imprinted monolithic column resulted in excellent separation of dopamine from structurally related competitor molecule, norepinephrine. Separation was achieved in a short period of 10 min, with the electrophoretic mobility of 5.81 × 10 -5  m 2 V -1 s -1 at pH 5.0 and 500 mbar pressure. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Molecularly Imprinted Nanomaterials for Sensor Applications

    Science.gov (United States)

    Irshad, Muhammad; Iqbal, Naseer; Mujahid, Adnan; Afzal, Adeel; Hussain, Tajamal; Sharif, Ahsan; Ahmad, Ejaz; Athar, Muhammad Makshoof

    2013-01-01

    Molecular imprinting is a well-established technology to mimic antibody-antigen interaction in a synthetic platform. Molecularly imprinted polymers and nanomaterials usually possess outstanding recognition capabilities. Imprinted nanostructured materials are characterized by their small sizes, large reactive surface area and, most importantly, with rapid and specific analysis of analytes due to the formation of template driven recognition cavities within the matrix. The excellent recognition and selectivity offered by this class of materials towards a target analyte have found applications in many areas, such as separation science, analysis of organic pollutants in water, environmental analysis of trace gases, chemical or biological sensors, biochemical assays, fabricating artificial receptors, nanotechnology, etc. We present here a concise overview and recent developments in nanostructured imprinted materials with respect to various sensor systems, e.g., electrochemical, optical and mass sensitive, etc. Finally, in light of recent studies, we conclude the article with future perspectives and foreseen applications of imprinted nanomaterials in chemical sensors. PMID:28348356

  6. 77 FR 25082 - Picture Permit Imprint Indicia

    Science.gov (United States)

    2012-04-27

    ... POSTAL SERVICE 39 CFR Part 111 Picture Permit Imprint Indicia AGENCY: Postal Service\\TM\\. ACTION... Service, Domestic Mail Manual (DMM[supreg]) 604.5 to add picture permit imprint indicia standards allowing...: The use of picture permit imprint indicia is designed to improve the effectiveness of a mailpiece by...

  7. Neuronal plasticity and multisensory integration in filial imprinting.

    Science.gov (United States)

    Town, Stephen Michael; McCabe, Brian John

    2011-03-10

    Many organisms sample their environment through multiple sensory systems and the integration of multisensory information enhances learning. However, the mechanisms underlying multisensory memory formation and their similarity to unisensory mechanisms remain unclear. Filial imprinting is one example in which experience is multisensory, and the mechanisms of unisensory neuronal plasticity are well established. We investigated the storage of audiovisual information through experience by comparing the activity of neurons in the intermediate and medial mesopallium of imprinted and naïve domestic chicks (Gallus gallus domesticus) in response to an audiovisual imprinting stimulus and novel object and their auditory and visual components. We find that imprinting enhanced the mean response magnitude of neurons to unisensory but not multisensory stimuli. Furthermore, imprinting enhanced responses to incongruent audiovisual stimuli comprised of mismatched auditory and visual components. Our results suggest that the effects of imprinting on the unisensory and multisensory responsiveness of IMM neurons differ and that IMM neurons may function to detect unexpected deviations from the audiovisual imprinting stimulus.

  8. Neuronal Plasticity and Multisensory Integration in Filial Imprinting

    Science.gov (United States)

    Town, Stephen Michael; McCabe, Brian John

    2011-01-01

    Many organisms sample their environment through multiple sensory systems and the integration of multisensory information enhances learning. However, the mechanisms underlying multisensory memory formation and their similarity to unisensory mechanisms remain unclear. Filial imprinting is one example in which experience is multisensory, and the mechanisms of unisensory neuronal plasticity are well established. We investigated the storage of audiovisual information through experience by comparing the activity of neurons in the intermediate and medial mesopallium of imprinted and naïve domestic chicks (Gallus gallus domesticus) in response to an audiovisual imprinting stimulus and novel object and their auditory and visual components. We find that imprinting enhanced the mean response magnitude of neurons to unisensory but not multisensory stimuli. Furthermore, imprinting enhanced responses to incongruent audiovisual stimuli comprised of mismatched auditory and visual components. Our results suggest that the effects of imprinting on the unisensory and multisensory responsiveness of IMM neurons differ and that IMM neurons may function to detect unexpected deviations from the audiovisual imprinting stimulus. PMID:21423770

  9. Neural basis of imprinting behavior in chicks.

    Science.gov (United States)

    Nakamori, Tomoharu; Maekawa, Fumihiko; Sato, Katsushige; Tanaka, Kohichi; Ohki-Hamazaki, Hiroko

    2013-01-01

    Newly hatched chicks memorize the characteristics of the first moving object they encounter, and subsequently show a preference for it. This "imprinting" behavior is an example of infant learning and is elicited by visual and/or auditory cues. Visual information of imprinting stimuli in chicks is first processed in the visual Wulst (VW), a telencephalic area corresponding to the mammalian visual cortex, congregates in the core region of the hyperpallium densocellulare (HDCo) cells, and transmitted to the intermediate medial mesopallium (IMM), a region similar to the mammalian association cortex. The imprinting memory is stored in the IMM, and activities of IMM neurons are altered by imprinting. Imprinting also induces functional and structural plastic changes of neurons in the circuit that links the VW and the IMM. Of these neurons, the activity of the HDCo cells is strongly influenced by imprinting. Expression and modulation of NR2B subunit-containing N-methyl-D-aspartate (NMDA) receptors in the HDCo cells are crucial for plastic changes in this circuit as well as the process of visual imprinting. Thus, elucidation of cellular and molecular mechanisms underlying the plastic changes that occurred in the HDCo cells may provide useful knowledge about infant learning. © 2012 The Authors Development, Growth & Differentiation © 2012 Japanese Society of Developmental Biologists.

  10. Molecular Imprinting Techniques Used for the Preparation of Biosensors

    Directory of Open Access Journals (Sweden)

    Gizem Ertürk

    2017-02-01

    Full Text Available Molecular imprinting is the technology of creating artificial recognition sites in polymeric matrices which are complementary to the template in their size, shape and spatial arrangement of the functional groups. Molecularly imprinted polymers (MIPs and their incorporation with various transducer platforms are among the most promising approaches for detection of several analytes. There are a variety of molecular imprinting techniques used for the preparation of biomimetic sensors including bulk imprinting, surface imprinting (soft lithography, template immobilization, grafting, emulsion polymerization and epitope imprinting. This chapter presents an overview of all of these techniques with examples from particular publications.

  11. Disturbed Placental Imprinting in Preeclampsia Leads to Altered Expression of DLX5, a Human-Specific Early Trophoblast Marker.

    Science.gov (United States)

    Zadora, Julianna; Singh, Manvendra; Herse, Florian; Przybyl, Lukasz; Haase, Nadine; Golic, Michaela; Yung, Hong Wa; Huppertz, Berthold; Cartwright, Judith E; Whitley, Guy; Johnsen, Guro M; Levi, Giovanni; Isbruch, Annette; Schulz, Herbert; Luft, Friedrich C; Müller, Dominik N; Staff, Anne Cathrine; Hurst, Laurence D; Dechend, Ralf; Izsvák, Zsuzsanna

    2017-11-07

    Preeclampsia is a complex and common human-specific pregnancy syndrome associated with placental pathology. The human specificity provides both intellectual and methodological challenges, lacking a robust model system. Given the role of imprinted genes in human placentation and the vulnerability of imprinted genes to loss of imprinting changes, there has been extensive speculation, but no robust evidence, that imprinted genes are involved in preeclampsia. Our study aims to investigate whether disturbed imprinting contributes to preeclampsia. We first aimed to confirm that preeclampsia is a disease of the placenta by generating and analyzing genome-wide molecular data on well-characterized patient material. We performed high-throughput transcriptome analyses of multiple placenta samples from healthy controls and patients with preeclampsia. Next, we identified differentially expressed genes in preeclamptic placentas and intersected them with the list of human imprinted genes. We used bioinformatics/statistical analyses to confirm association between imprinting and preeclampsia and to predict biological processes affected in preeclampsia. Validation included epigenetic and cellular assays. In terms of human specificity, we established an in vitro invasion-differentiation trophoblast model. Our comparative phylogenetic analysis involved single-cell transcriptome data of human, macaque, and mouse preimplantation embryogenesis. We found disturbed placental imprinting in preeclampsia and revealed potential candidates, including GATA3 and DLX5 , with poorly explored imprinted status and no prior association with preeclampsia. As a result of loss of imprinting, DLX5 was upregulated in 69% of preeclamptic placentas. Levels of DLX5 correlated with classic preeclampsia markers. DLX5 is expressed in human but not in murine trophoblast. The DLX5 high phenotype resulted in reduced proliferation, increased metabolism, and endoplasmic reticulum stress-response activation in

  12. Endosperm imprinting: a child custody battle?

    Science.gov (United States)

    Becraft, Philip W

    2012-02-07

    Endosperm gene imprinting has long been speculated to control nutrient allocation to seeds. For the first time, an imprinted gene directly involved in this process has been identified. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Molecularly Imprinted Polymers: Present and Future Prospective

    Directory of Open Access Journals (Sweden)

    Giuseppe Vasapollo

    2011-09-01

    Full Text Available Molecular Imprinting Technology (MIT is a technique to design artificial receptors with a predetermined selectivity and specificity for a given analyte, which can be used as ideal materials in various application fields. Molecularly Imprinted Polymers (MIPs, the polymeric matrices obtained using the imprinting technology, are robust molecular recognition elements able to mimic natural recognition entities, such as antibodies and biological receptors, useful to separate and analyze complicated samples such as biological fluids and environmental samples. The scope of this review is to provide a general overview on MIPs field discussing first general aspects in MIP preparation and then dealing with various application aspects. This review aims to outline the molecularly imprinted process and present a summary of principal application fields of molecularly imprinted polymers, focusing on chemical sensing, separation science, drug delivery and catalysis. Some significant aspects about preparation and application of the molecular imprinting polymers with examples taken from the recent literature will be discussed. Theoretical and experimental parameters for MIPs design in terms of the interaction between template and polymer functionalities will be considered and synthesis methods for the improvement of MIP recognition properties will also be presented.

  14. Molecularly Imprinted Membranes

    Science.gov (United States)

    Trotta, Francesco; Biasizzo, Miriam; Caldera, Fabrizio

    2012-01-01

    Although the roots of molecularly imprinted polymers lie in the beginning of 1930s in the past century, they have had an exponential growth only 40–50 years later by the works of Wulff and especially by Mosbach. More recently, it was also proved that molecular imprinted membranes (i.e., polymer thin films) that show recognition properties at molecular level of the template molecule are used in their formation. Different procedures and potential application in separation processes and catalysis are reported. The influences of different parameters on the discrimination abilities are also discussed. PMID:24958291

  15. Imprinted Polymers in Wastewater Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Eastman, Christopher; Goodrich, Scott; Gartner, Isabelle; Mueller, Anja

    2004-03-31

    In wastewater treatment, a method that specifically recognizes a variety of impurities in a flexible manner would be useful for treatment facilities with varying needs. Current purification techniques (i.e. bacteria, oxidation, reduction, precipitation and filtration) are nonspecific and difficult to control in complex mixtures. Heavy metal removal is particularly important in improving the efficiency of wastewater treatment, as they inhibit or even destroy the bacteria used for filtration. Imprinting polymerization is a technique that allows for the efficient removal of specific compounds and has been used in purification of enantiomers. It has potential to be applied in wastewater systems with the impurities acting as the template for the imprinting polymerization. The polymer with the bound impurities intact can then be removed via precipitation. After removal of the impurity the polymer can be reused. Data for the imprinting polymerization of polyacrylates and polyacrylamides for several metal complexes will be presented. Imprinting polymerization in combination with emulsion polymerization to improve the removal of hydrophobic contaminants will be described. Removal efficiencies will be presented and compared with conventional wastewater treatment methods.

  16. Causal imprinting in causal structure learning.

    Science.gov (United States)

    Taylor, Eric G; Ahn, Woo-Kyoung

    2012-11-01

    Suppose one observes a correlation between two events, B and C, and infers that B causes C. Later one discovers that event A explains away the correlation between B and C. Normatively, one should now dismiss or weaken the belief that B causes C. Nonetheless, participants in the current study who observed a positive contingency between B and C followed by evidence that B and C were independent given A, persisted in believing that B causes C. The authors term this difficulty in revising initially learned causal structures "causal imprinting." Throughout four experiments, causal imprinting was obtained using multiple dependent measures and control conditions. A Bayesian analysis showed that causal imprinting may be normative under some conditions, but causal imprinting also occurred in the current study when it was clearly non-normative. It is suggested that causal imprinting occurs due to the influence of prior knowledge on how reasoners interpret later evidence. Consistent with this view, when participants first viewed the evidence showing that B and C are independent given A, later evidence with only B and C did not lead to the belief that B causes C. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Potential roles for transposable elements in creating imprinted expression.

    Science.gov (United States)

    Anderson, Sarah N; Springer, Nathan M

    2018-04-01

    Changes in gene expression can have profound effects on phenotype. Nature has provided many complex patterns of gene regulation such as imprinting. Imprinted genes exhibit differences in the expression of the maternal and paternal alleles, even though they reside in the same nucleus with access to the same trans-acting factors. Significant attention has been focused on the potential reasons that imprinted expression could be beneficial and stabilized by selection. However, less attention has focused on understanding how imprinted expression might arise or decay. We discuss the evidence for frequent turnover of imprinted expression based on evolutionary analyses in plants and the potential role for transposable elements (TEs) in creating imprinted expression patterns. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Imprinting disorders after assisted reproductive technologies

    DEFF Research Database (Denmark)

    Lidegaard, Øjvind; Pinborg, Anja; Andersen, Anders Nyboe

    2006-01-01

    To assess the evidence of an increased risk of imprinting diseases in children born after use of assisted reproductive technologies.......To assess the evidence of an increased risk of imprinting diseases in children born after use of assisted reproductive technologies....

  19. Fluorescense Anisotropy Studies of Molecularly Imprinted Polymer Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yin-Chu; Wang, Zheming; Yan, Mingdi; Prahl, Scott A.

    2005-08-03

    Molecularly imprinted polymers (MIPs) are used as recognition elements in biochemical sensors. In a fluorescence-based MIP sensor system, it is difficult to distinguish the analyte fluorescence from the background fluorescence of the polymer itself. We studied steady-state fluorescence anisotropy of anthracene imprinted in a polymer (polyurethane) matrix. Vertically polarized excitation light was incident on MIP films coated on silicon wafers; vertically and horizontally polarized emission was measured. We compared the fluorescence anisotropy of MIPs with imprinted molecules, MIPs with the imprinted molecules extracted, MIPs with rebound molecules, and nonimprinted control polymers (without binding cavities). It is shown that differences in fluorescence anisotropy between the polymers and imprinted fluorescent molecules may provide a means to discriminate the fluorescence of analyte from that of the background polymer.

  20. Methylation status of imprinted genes DLK1-GTL2, MEST (PEG1), ZAC (PLAGL1), and LINE-1 elements in spermatozoa of normozoospermic men, unlike H19 imprinting control regions, is not associated with idiopathic recurrent spontaneous miscarriages.

    Science.gov (United States)

    Ankolkar, Mandar; Salvi, Vinita; Warke, Himangi; Vundinti, Babu Rao; Balasinor, N H

    2013-05-01

    To study methylation aberrations in spermatozoa at developmentally important imprinted regions to ascertain their role in early embryo loss in idiopathic recurrent spontaneous miscarriages (RSM). Case-control study. Academic research setting at National Institute for Research in Reproductive Health, Parel, Mumbai. Male partners of couples with a history of RSM and male partners of couples with proven fertility (control group). None. DNA methylation levels at imprinting control regions of DLK1-GTL2, MEST (PEG1), and ZAC (PLAGL1) by Epityper Massarray and global methylation levels as measured by LINE-1 methylation and anti-5-methyl cytosine antibody in spermatozoa of 23 men in control group and 23 men in RSM group. We did not observe any aberration in the total methylation levels in any of the imprinted genes or global methylation analyzed. Our results indicate that paternal methylation aberrations at imprinting control regions of DLK1-GTL2, MEST (PEG1), and ZAC (PLAGL1) and global methylation levels are not associated with idiopathic RSM and may not be good epigenetic markers (unlike the H-19 imprinting control region) for diagnosis of idiopathic RSM. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  1. Imprinting can cause a maladaptive preference for infectious conspecifics.

    Science.gov (United States)

    Stephenson, Jessica F; Reynolds, Michael

    2016-04-01

    Recognizing and associating with specific individuals, such as conspecifics or kin, brings many benefits. One mechanism underlying such recognition is imprinting: the long-term memory of cues encountered during development. Typically, juveniles imprint on cues of nearby individuals and may later associate with phenotypes matching their 'recognition template'. However, phenotype matching could lead to maladaptive social decisions if, for instance, individuals imprint on the cues of conspecifics infected with directly transmitted diseases. To investigate the role of imprinting in the sensory ecology of disease transmission, we exposed juvenile guppies,Poecilia reticulata, to the cues of healthy conspecifics, or to those experiencing disease caused by the directly transmitted parasite Gyrodactylus turnbulli In a dichotomous choice test, adult 'disease-imprinted' guppies preferred to associate with the chemical cues of G. turnbulli-infected conspecifics, whereas 'healthy-imprinted' guppies preferred to associate with cues of uninfected conspecifics. These responses were only observed when stimulus fish were in late infection, suggesting imprinted fish responded to cues of disease, but not of infection alone. We discuss how maladaptive imprinting may promote disease transmission in natural populations of a social host. © 2016 The Author(s).

  2. Pattern imprinting in CMOS static RAMs from Co-60 irradiation

    International Nuclear Information System (INIS)

    Schott, J.T.; Zugich, M.H.

    1987-01-01

    Total dose irradiation of various CMOS SRAMs is shown to imprint the pattern stored in the memory during irradiation. This imprinted pattern is the preferred state of the memory at subsequent power-up. Imprinting can occur at dose levels significantly below the failure level of the devices and is consistent with the bias dependent radiation induced threshold shifts of the individual transistors of the memory cells. However, before total imprinting occurs, other unusual imprinting phenomena can occur, such as a reverse imprinting effect seen in SOS memories, which is probably related to the bias dependence of back-channel leakage

  3. Sexual imprinting: what strategies should we expect to see in nature?

    Science.gov (United States)

    Chaffee, Dalton W; Griffin, Hayes; Gilman, R Tucker

    2013-12-01

    Sexual imprinting occurs when juveniles learn mate preferences by observing the phenotypes of other members of their populations, and it is ubiquitous in nature. Imprinting strategies, that is which individuals and phenotypes are observed and how strong preferences become, vary among species. Imprinting can affect trait evolution and the probability of speciation, and different imprinting strategies are expected to have different effects. However, little is known about how and why different imprinting strategies evolve, or which strategies we should expect to see in nature. We used a mathematical model to study how the evolution of sexual imprinting depends on (1) imprinting costs and (2) the sex-specific fitness effects of the phenotype on which individuals imprint. We found that even small fixed costs prevent the evolution of sexual imprinting, but small relative costs do not. When imprinting does evolve, we identified the conditions under which females should evolve to imprint on their fathers, their mothers, or on other members of their populations. Our results provide testable hypotheses for empirical work and help to explain the conditions under which sexual imprinting might evolve to promote speciation. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  4. Metal films with imprinted nanostructures by template stripping

    DEFF Research Database (Denmark)

    Eriksen, René Lynge; Pors, Anders; Dreier, Jes

    We present a novel template stripping procedure for fabricating metal films with imprinted nanostructures. The basic idea is to deposit a gold film onto a nano-structured substrate and subsequently strip the film from the substrate surface thereby revealing imprinted nanostructures in the film...... result is a thin gold film with imprinted nano-cavities....

  5. Pending templates imprinted polymers-hypothesis, synthesis, adsorption, and chromatographic properties.

    Science.gov (United States)

    Yang, Chun; Luan, Xinjie; Zhao, Meifeng; Liu, Guofeng; Wang, Jian; Qu, Qishu; Hu, Xiaoya

    2013-05-01

    This is the first time when protein-imprinted polymers are prepared with "pending templates." The polymers were synthesized in the presence of a real sample (chicken egg white), rather than any known commercial proteins. Compared with a simultaneously synthesized nonimprinted control polymer, the polymers show higher adsorption capacity for abundant components (as "pending templates") in the original sample. Chromatography experiments indicated that the columns made of the imprinted polymers could retain abundant species (imprinted) and separate them from those not imprinted. Thus, the sample could be split into dimidiate subfractions with reduced complexities. "Pending template imprinting" suggests a new way to investigate molecular imprinting, especially to dissect, simplify, and analyze complicated samples through a series of polymers just imprinted by the samples per se. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Functional mapping imprinted quantitative trait loci underlying developmental characteristics

    Directory of Open Access Journals (Sweden)

    Li Gengxin

    2008-03-01

    Full Text Available Abstract Background Genomic imprinting, a phenomenon referring to nonequivalent expression of alleles depending on their parental origins, has been widely observed in nature. It has been shown recently that the epigenetic modification of an imprinted gene can be detected through a genetic mapping approach. Such an approach is developed based on traditional quantitative trait loci (QTL mapping focusing on single trait analysis. Recent studies have shown that most imprinted genes in mammals play an important role in controlling embryonic growth and post-natal development. For a developmental character such as growth, current approach is less efficient in dissecting the dynamic genetic effect of imprinted genes during individual ontology. Results Functional mapping has been emerging as a powerful framework for mapping quantitative trait loci underlying complex traits showing developmental characteristics. To understand the genetic architecture of dynamic imprinted traits, we propose a mapping strategy by integrating the functional mapping approach with genomic imprinting. We demonstrate the approach through mapping imprinted QTL controlling growth trajectories in an inbred F2 population. The statistical behavior of the approach is shown through simulation studies, in which the parameters can be estimated with reasonable precision under different simulation scenarios. The utility of the approach is illustrated through real data analysis in an F2 family derived from LG/J and SM/J mouse stains. Three maternally imprinted QTLs are identified as regulating the growth trajectory of mouse body weight. Conclusion The functional iQTL mapping approach developed here provides a quantitative and testable framework for assessing the interplay between imprinted genes and a developmental process, and will have important implications for elucidating the genetic architecture of imprinted traits.

  7. Synthesis of a Molecularly Imprinted Polymer for Dioxin

    Directory of Open Access Journals (Sweden)

    Magda Brattoli

    2006-08-01

    Full Text Available A molecularly imprinted polymer for recognising selectively 2,3,7,8-tetrachlorodibenzodioxin (TCDD was made by a new non-covalent method employing a“dummy” template. The proposed way represents a simplification of a synthetic schemeproposed by Lübke et al.[1] for covalent imprinting. Comparison of extraction yields of thenovel polymer, a non imprinted polymer and an imprinting polymer, prepared by theoriginal procedure demonstrates the binding capacity of the proposed polymer, which is inprinciple applicable to solid phase extraction (SPE of dioxin.

  8. Rational preparation of dibenzothiophene-imprinted polymers by surface imprinting technique combined with atom transfer radical polymerization

    International Nuclear Information System (INIS)

    Yang, Wenming; Liu, Lukuan; Zhou, Zhiping; Liu, Hong; Xie, Binze; Xu, Wanzhen

    2013-01-01

    A computational simulation method is introduced to simulate the dibenzothiophene-monomer pre-assembly system of molecular imprinted polymers. The interaction type and intensity between dibenzothiophene and monomer are discussed from the binding energy and spatial position distribution. The simulation and analysis results indicate that the amount of the function monomer is not the more the better in preparing molecular imprinted polymers. Based on the above results, a novel dibenzothiophene-imprinted polymers with the favorable specific adsorption effect was prepared by surface imprinting technique combined with atom transfer radical polymerization. This combined technologies are used for preparing a desulfurization adsorbent for the first time. Various measures were selected to characterize the structure and morphology of the prepared adsorbent. The characterization results show that the adsorbent has suitable features for further adsorption process. A series of static adsorption experiments were conducted to analyze its adsorption performance. The adsorption process follows Elovich model by the kinetic analysis and Sips equation by the isothermal analysis. The approach we described will provide another opportunity in the deep desulfurization field.

  9. Role of imprint/exfoliative cytology in ulcerated skin neoplasms.

    Science.gov (United States)

    Ramakrishnaiah, Vishnu Prasad Nelamangala; Babu, Ravindra; Pai, Dinker; Verma, Surendra Kumar

    2013-12-01

    Imprint cytology is a method of studying cells by taking an imprint from the cut surface of a wedge biopsy specimen or from the resected margins of a surgical specimen. It is rapid, simple and fairly accurate. Exfoliative cytology is an offshoot from the imprint cytology where in cells obtained from the surface of ulcers, either by scrape or brush, are analyzed for the presence of malignant cells. We undertook this study to see the role of imprint/exfoliative cytology in the diagnosis of ulcerated skin neoplasm and to check the adequacy of resected margins intra-operatively. This was a prospective investigative study conducted from September 2003 to July 2005. All patients presenting to surgical clinic with ulcerated skin and soft tissue tumours were included in the study. A wedge biopsy obtained from the ulcer and imprint smears were taken from the cut surface. Exfoliative cytology was analyzed from the surface smears. Wedge biopsy specimen was sent for histopathological (HPE) examination. The cytology and HPE were analyzed by a separate pathologist. Imprint cytology was also used to check the adequacy of resected margins in case of wide excision. This was compared with final HPE. Total of 107 patients was included in the present study and 474 imprint smears were done, with an average of 4.43 slides per lesion. Out of 59 wide excision samples, 132 imprint smears were prepared for assessing resected margins accounting for an average of 2.24 slides per each excised lesion. On combining imprint cytology with exfoliative cytology the overall sensitivity, specificity and positive predictive value were 90.38 %, 100 % and 90.38 % respectively. Only one out of 59 cases had a positive resected margin which was not picked by imprint cytology. Imprint cytology can be used for rapid and accurate diagnosis of various skin malignancies. It can also be used to check the adequacy of the resected margin intraoperatively.

  10. Molecularly Imprinted Polymer/Metal Organic Framework Based Chemical Sensors

    Directory of Open Access Journals (Sweden)

    Zhenzhong Guo

    2016-10-01

    Full Text Available The present review describes recent advances in the concept of molecular imprinting using metal organic frameworks (MOF for development of chemical sensors. Two main strategies regarding the fabrication, performance and applications of recent sensors based on molecularly imprinted polymers associated with MOF are presented: molecularly imprinted MOF films and molecularly imprinted core-shell nanoparticles using MOF as core. The associated transduction modes are also discussed. A brief conclusion and future expectations are described herein.

  11. Effects of Assisted Reproduction Technology on Placental Imprinted Gene Expression

    Science.gov (United States)

    Katagiri, Yukiko; Aoki, Chizu; Tamaki-Ishihara, Yuko; Fukuda, Yusuke; Kitamura, Mamoru; Matsue, Yoichi; So, Akiko; Morita, Mineto

    2010-01-01

    We used placental tissue to compare the imprinted gene expression of IGF2, H19, KCNQ1OT1, and CDKN1C of singletons conceived via assisted reproduction technology (ART) with that of spontaneously conceived (SC) singletons. Of 989 singletons examined (ART n = 65; SC n = 924), neonatal weight was significantly lower (P < .001) in the ART group than in the SC group, but placental weight showed no significant difference. Gene expression analyzed by real-time PCR was similar for both groups with appropriate-for-date (AFD) birth weight. H19 expression was suppressed in fetal growth retardation (FGR) cases in the ART and SC groups compared with AFD cases (P < .02 and P < .05, resp.). In contrast, CDKN1C expression was suppressed in FGR cases in the ART group (P < .01), while KCNQ1OT1 expression was hyperexpressed in FGR cases in the SC group (P < .05). As imprinted gene expression patterns differed between the ART and SC groups, we speculate that ART modifies epigenetic status even though the possibilities always exist. PMID:20706653

  12. Foster parenting, human imprinting and conventional handling ...

    African Journals Online (AJOL)

    p2492989

    Foster parenting, human imprinting and conventional handling affects survival and early .... bird may subsequently direct its sexual attention to those humans on whom it was imprinted (Bubier et al., ..... The mind through chicks' eyes: memory,.

  13. Distinguishing epigenetic marks of developmental and imprinting regulation

    Directory of Open Access Journals (Sweden)

    McEwen Kirsten R

    2010-01-01

    Full Text Available Abstract Background The field of epigenetics is developing rapidly, however we are only beginning to comprehend the complexity of its influence on gene regulation. Using genomic imprinting as a model we examine epigenetic profiles associated with different forms of gene regulation. Imprinting refers to the expression of a gene from only one of the chromosome homologues in a parental-origin-specific manner. This is dependent on heritable germline epigenetic control at a cis-acting imprinting control region that influences local epigenetic states. Epigenetic modifications associated with imprinting regulation can be compared to those associated with the more canonical developmental regulation, important for processes such as differentiation and tissue specificity. Here we test the hypothesis that these two mechanisms are associated with different histone modification enrichment patterns. Results Using high-throughput data extraction with subsequent analysis, we have found that particular histone modifications are more likely to be associated with either imprinting repression or developmental repression of imprinted genes. H3K9me3 and H4K20me3 are together enriched at imprinted genes with differentially methylated promoters and do not show a correlation with developmental regulation. H3K27me3 and H3K4me3, however, are more often associated with developmental regulation. We find that imprinted genes are subject to developmental regulation through bivalency with H3K4me3 and H3K27me3 enrichment on the same allele. Furthermore, a specific tri-mark signature comprising H3K4me3, H3K9me3 and H4K20me3 has been identified at all imprinting control regions. Conclusion A large amount of data is produced from whole-genome expression and epigenetic profiling studies of cellular material. We have shown that such publicly available data can be mined and analysed in order to generate novel findings for categories of genes or regulatory elements. Comparing two

  14. Review: Biological imprinting: Some genetic considerations | Saad ...

    African Journals Online (AJOL)

    ... as for interpretation of possible mechanisms implicated in its occurrence. Keywords: Genetic imprinting; Mutations; Re-sense mutation; Epigenetic alterations; DNA methylation/demethylation; Parthenogenesis; Position-effect variegation; Post-fertilization genomic imprinting; microRNA; Chromatin modifications; Pyknons ...

  15. Current Progress of Nanomaterials in Molecularly Imprinted Electrochemical Sensing.

    Science.gov (United States)

    Zhong, Chunju; Yang, Bin; Jiang, Xinxin; Li, Jianping

    2018-01-02

    Nanomaterials have received much attention during the past decade because of their excellent optical, electronic, and catalytic properties. Nanomaterials possess high chemical reactivity, also high surface energy. Thus, provide a stable immobilization platform for biomolecules, while preserving their reactivity. Due to the conductive and catalytic properties, nanomaterials can also enhance the sensitivity of molecularly imprinted electrochemical sensors by amplifying the electrode surface, increasing the electron transfer, and catalyzing the electrochemical reactions. Molecularly imprinted polymers that contain specific molecular recognition sites can be designed for a particular target analyte. Incorporating nanomaterials into molecularly imprinted polymers is important because nanomaterials can improve the response signal, increase the sensitivity, and decrease the detection limit of the sensors. This study describes the classification of nanomaterials in molecularly imprinted polymers, their analytical properties, and their applications in the electrochemical sensors. The progress of the research on nanomaterials in molecularly imprinted polymers and the application of nanomaterials in molecularly imprinted polymers is also reviewed.

  16. Preparation of polyhedral oligomeric silsesquioxane based imprinted monolith.

    Science.gov (United States)

    Li, Fang; Chen, Xiu-Xiu; Huang, Yan-Ping; Liu, Zhao-Sheng

    2015-12-18

    Polyhedral oligomeric silsesquioxane (POSS) was successfully applied, for the first time, to prepare imprinted monolithic column with high porosity and good permeability. The imprinted monolithic column was synthesized with a mixture of PSS-(1-Propylmethacrylate)-heptaisobutyl substituted (MA 0702), naproxon (template), 4-vinylpyridine, and ethylene glycol dimethacrylate, in ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4). The influence of synthesis parameters on the retention factor and imprinting effect, including the amount of MA 0702, the ratio of template to monomer, and the ratio of monomer to crosslinker, was investigated. The greatest imprinting factor on the imprinted monolithic column prepared with MA 0702 was 22, about 10 times higher than that prepared in absence of POSS. The comparisons between MIP monoliths synthesized with POSS and without POSS were made in terms of permeability, column efficiency, surface morphology and pore size distribution. In addition, thermodynamic and Van Deemter analysis were used to evaluate the POSS-based MIP monolith. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Molecularly imprinted polymers for the detection of illegal drugs and additives: a review.

    Science.gov (United States)

    Xiao, Deli; Jiang, Yue; Bi, Yanping

    2018-04-04

    This review (with 154 refs.) describes the current status of using molecularly imprinted polymers in the extraction and quantitation of illicit drugs and additives. The review starts with an introduction into some synthesis methods (lump MIPs, spherical MIPs, surface imprinting) of MIPs using illicit drugs and additives as templates. The next section covers applications, with subsections on the detection of illegal additives in food, of doping in sports, and of illicit addictive drugs. A particular focus is directed towards current limitations and challenges, on the optimization of methods for preparation of MIPs, their applicability to aqueous samples, the leakage of template molecules, and the identification of the best balance between adsorption capacity and selectivity factor. At last, the need for convincing characterization methods, the lack of uniform parameters for defining selectivity, and the merits and demerits of MIPs prepared using nanomaterials are addressed. Strategies are suggested to solve existing problems, and future developments are discussed with respect to a more widespread use in relevant fields. Graphical abstract This review gives a comprehensive overview of the advances made in molecularly imprinting of polymers for use in the extraction and quantitation of illicit drugs and additives. Methods for syntheses, highlighted applications, limitations and current challenges are specifically addressed.

  18. Genome Imprinting

    Indian Academy of Sciences (India)

    the cell nucleus (mitochondrial and chloroplast genomes), and. (3) traits governed ... tively good embryonic development but very poor development of membranes and ... Human homologies for the type of situation described above are naturally ..... imprint; (b) New modifications of the paternal genome in germ cells of each ...

  19. Sb(III)-Imprinted Organic-Inorganic Hybrid Sorbent Prepared by Hydrothermal-Assisted Surface Imprinting Technique for Selective Adsorption of Sb(III)

    Science.gov (United States)

    Zhang, Dan; Zhao, Yue; Xu, Hong-Bo

    2018-03-01

    Sb(III)-imprinted organic-inorganic hybrid sorbent was prepared by hydrothermal-assisted surface imprinting technique and was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy coupled to an energy dispersive spectrometer and N2 adsorption/desorption isotherms. Hydrothermal-assisted process can improve the selectivity of the Sb(III)-imprinted hybrid sorbent for Sb(III) due to stable control of temperature and pressure. The Sb(III)-imprinted hybrid sorbent IIS indicated higher selectivity for Sb(III), had high static adsorption capacity of 37.3 mg g-1 for Sb(III), displayed stable adsorption capacity in pH range from 4 to 8, reached an rapid adsorption equilibrium within 30 min. According to the correlation coefficient ( r 2 > 0.99), the experimental data fitted better the pseudo-second-order kinetic model and Langmuir equilibrium isotherm.

  20. Molecularly Imprinted Microrods via Mesophase Polymerization.

    Science.gov (United States)

    Parisi, Ortensia Ilaria; Scrivano, Luca; Candamano, Sebastiano; Ruffo, Mariarosa; Vattimo, Anna Francesca; Spanedda, Maria Vittoria; Puoci, Francesco

    2017-12-28

    The aim of the present research work was the synthesis of molecularly imprinted polymers (MIPs) with a rod-like geometry via "mesophase polymerization". The ternary lyotropic system consisting of sodium dodecyl sulfate (SDS), water, and decanol was chosen to prepare a hexagonal mesophase to direct the morphology of the synthesized imprinted polymers using theophylline, methacrylic acid, and ethylene glycol dimethacrylate as a drug model template, a functional monomer, and a crosslinker, respectively. The obtained molecularly imprinted microrods (MIMs) were assessed by performing binding experiments and in vitro release studies, and the obtained results highlighted good selective recognition abilities and sustained release properties. In conclusion, the adopted synthetic strategy involving a lyotropic mesophase system allows for the preparation of effective MIPs characterized by a rod-like morphology.

  1. Imprint cytology: A boon in tissue diagnosis

    Directory of Open Access Journals (Sweden)

    Charusheela Rajesh Gore

    2017-01-01

    Full Text Available Background: The technique of imprint cytology has provided great impetus to cytodiagnosis due to its simplicity, cost effectiveness, rapid results. It plays a significant role in the rapid diagnosis of the lesions. Objectives: To analyze the sensitivity and specificity of imprint cytology and thereby to evaluate its diagnostic utility. Materials and Methods: The prospective study was carried out in a tertiary care hospital. It included 105 cases. Both benign and malignant lesions from different organ systems were included in the study. Various techniques like touch imprints scrape cytology and squash preparations were used according to the nature of tissue sample. The cytodiagnosis was correlated with histopathological (HP diagnosis to evaluate the sensitivity and specificity of imprint cytology. Results: Maximum lesions were of central nervous system (25.7% followed by breast, head, and neck. Imprint cytology diagnosis had sensitivity of 95.5% with 100% specificity for detection of benign and malignant lesions. Overall accuracy of detecting type of lesion was 98.1%. Total discordance with HP diagnosis was found in 1.9% of cases. Conclusion: The use of smear technique in intraoperative diagnosis provides a rapid and efficient means of pathological assessment which in experienced hand, is capable of obtaining a high degree of accuracy. Its use is highly recommended routinely.

  2. Wealth gradient-based divergence in the prevalence of underweight among women by marital status in Quoc Oai district, Vietnam.

    Science.gov (United States)

    Heo, Jongho; Yu, Soo-Young; Yi, Jinseon; Nam, You-Seon; Son, Dinh Thai; Oh, Juhwan; Lee, Jong-Koo

    2018-01-01

    The prevalence of underweight is high among women in Asian countries, despite nutritional changes in the region. Previous studies have demonstrated independent associations between female body weight, marital status and economic status. However, few studies have investigated possible interaction between marital and economic status in relation to Asian women's body weight. This study aimed to test associations between household wealth, marital status and underweight among women living in the Quoc Oai district of Vietnam and to identify wealth-marital status interaction in relation to body weight in these women. Data from 1087 women aged 19-60 years were collected via a baseline community survey conducted in the Quoc Oai district of Hanoi, Vietnam, in 2016. Underweight was defined using an Asian-specific body mass index cut-off (wealth index quintiles. Multivariable logistic regressions tested association between wealth and underweight after adjusting for marital status and other confounders. An interaction term (wealth index*marital status) was fitted to determine whether the association between wealth and body weight is modified by marital status. Our results show that underweight was independently associated with a wealth status (odds ratio [OR]: 0.88, 95% confidence interval [CI]: 0.79-0.98, p = 0.026) and ever-married status (OR: 0.50, 95% CI: 0.34-0.75, p = 0.002). A significant interaction effect (OR: 0.67, 95% CI: 0.50-0.90, p = 0.010) indicated that wealthy married women were less likely to be underweight, whereas wealthy never-married women were more likely to be underweight. Our results suggest that the interaction between wealth and marital status has divergent effects on underweight among Asian women. Interventions to reduce underweight among Asian women should simultaneously consider economic and marital status.

  3. Quantum-dots-encoded-microbeads based molecularly imprinted polymer.

    Science.gov (United States)

    Liu, Yixi; Liu, Le; He, Yonghong; He, Qinghua; Ma, Hui

    2016-03-15

    Quantum dots encoded microbeads have various advantages such as large surface area, superb optical properties and the ability of multiplexing. Molecularly imprinted polymer that can mimic the natural recognition entities has high affinity and selectivity for the specific analyte. Here, the concept of utilizing the quantum dots encoded microbeads as the supporting material and the polydopamine as the functional monomer to form the core-shell molecular imprinted polymer was proposed for the first time. The resulted imprinted polymer can provide various merits: polymerization can complete in aqueous environment; fabrication procedure is facile and universal; the obvious economic advantage; the thickness of the imprinting layer is highly controllable; polydopamine coating can improve the biocompatibility of the quantum dot encoded microbeads. The rabbit IgG binding and flow cytometer experiment result showed the distinct advantages of this strategy: cost-saving, facile and fast preparation procedure. Most importantly, the ability for the multichannel detection, which makes the imprinted polydopamine modified encoded-beads very attractive in protein pre-concentration, recognition, separation and biosensing. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Molecular Imprinting Applications in Forensic Science.

    Science.gov (United States)

    Yılmaz, Erkut; Garipcan, Bora; Patra, Hirak K; Uzun, Lokman

    2017-03-28

    Producing molecular imprinting-based materials has received increasing attention due to recognition selectivity, stability, cast effectiveness, and ease of production in various forms for a wide range of applications. The molecular imprinting technique has a variety of applications in the areas of the food industry, environmental monitoring, and medicine for diverse purposes like sample pretreatment, sensing, and separation/purification. A versatile usage, stability and recognition capabilities also make them perfect candidates for use in forensic sciences. Forensic science is a demanding area and there is a growing interest in molecularly imprinted polymers (MIPs) in this field. In this review, recent molecular imprinting applications in the related areas of forensic sciences are discussed while considering the literature of last two decades. Not only direct forensic applications but also studies of possible forensic value were taken into account like illicit drugs, banned sport drugs, effective toxins and chemical warfare agents in a review of over 100 articles. The literature was classified according to targets, material shapes, production strategies, detection method, and instrumentation. We aimed to summarize the current applications of MIPs in forensic science and put forth a projection of their potential uses as promising alternatives for benchmark competitors.

  5. Role of imprint cytology in intra operative diagnosis of thyroid lesions.

    Science.gov (United States)

    Anila, K R; Krishna, G

    2014-07-01

    Intra-operative imprint cytology is an important diagnostic modality in the diagnosis of thyroid lesions. A correct intra-operative diagnosis helps eliminate the need for second surgery. To study diagnostic accuracy of imprint cytology and to compare the imprint cytology results with that of the corresponding paraffin section diagnosis in thyroidectomy cases. This is a prospective study of 84 patients who have undergone thyroidectomies over a period of one year at the Department of Surgery, Thiruvananthapuram, Kerala, India. The intraoperative imprint cytology smears were stained by Papanicolaou method. The imprint cytology interpretation was later compared with the paraffin section diagnosis. Of the 84 patients using haematoxylin and eosin stained histopathology sections as the gold standard, the diagnostic sensitivity of imprint cytology was 75% and specificity was 100%. Positive predictive value was 100%. Negative predictive value was 98.74%. Imprint cytology has high sensitivity and specificity in diagnosing lesions of the thyroid. The problems faced were in diagnosing follicular carcinomas and differentiating low grade lymphoma from lymphocytic thyroiditis. Imprint cytology is a simple, reliable diagnostic technique. It has high sensitivity and specificity in intra-operative diagnosis of lesions of thyroid. In spite of the advent of newer diagnostic modalities like frozen sections, imprint cytology still holds its unique position in the current perspective.

  6. Highly selective determination of methylmercury with methylmercury-imprinted polymers

    Energy Technology Data Exchange (ETDEWEB)

    Liu Yongwen [Department of Chemistry, Shanxi Datong University, Datong 037009 (China)]. E-mail: dtlyw@263.net; Zai Yunhui [School of Chemistry and Chemical Engineering of Lanzhou University, Lanzhou 730000 (China); Chang Xijun [School of Chemistry and Chemical Engineering of Lanzhou University, Lanzhou 730000 (China); Guo Yong [Department of Chemistry, Shanxi Datong University, Datong 037009 (China); Meng Shuangming [Department of Chemistry, Shanxi Datong University, Datong 037009 (China); Feng Feng [Department of Chemistry, Shanxi Datong University, Datong 037009 (China)

    2006-08-11

    Methylmercury-imprinted and non-imprinted polymers were prepared by formation monomer complex of methylmercury with (4-ethenylphenyl)-4-formate-6-phenyl-2,2'-bipyridine and thermally polymerizing with divinylbenzene (crosslinker) in the presence of 2,2'-azobisisobutyronitrile as initiator and subsequently leached with the acidic thiourea solution (1.0 mol L{sup -1} of thiourea and 4.0 mol L{sup -1} of HCl). In the same way, non-imprinted copolymers were prepared without methylmercury chloride added. The separation and preconcentration characteristics of the polymers for methylmercury were investigated by batch and column procedures. The results demonstrated that the methylmercury-imprinted polymers had higher adsorption capacity (170 {mu}mol g{sup -1} of dry microbeads) and good selectivity for methylmercury compared to non-imprinted polymers. The distribution ratio (D) values of the methylmercury-imprinted polymers increased for methylmercury with respect to both D values of Hg(II), Cu(II), Zn(II), Cd(II) and non-imprinted polymers. The relatively selective factor ({alpha} {sub r}) values of CH{sub 3}Hg{sup +}/Hg(II), CH{sub 3}Hg{sup +}/Cu(II), CH{sub 3}Hg{sup +}/Zn(II), and CH{sub 3}Hg{sup +}/Cd(II) are 24.0, 46.7, 50.7, and 40.2, which are greater than 1. The methylmercury-imprinted polymers can be used at least twenty times with recoveries no less than 95%. Based on the packed columns with methylmercury-imprinted polymers, a highly selective solid-phase extraction (SPE) and preconcentration method for methylmercury was developed. The metal ion imprinted polymer solid-phase extraction (MIIP-SPE) preconcentration procedure showed a linear calibration curve within concentration range from 0.093 to 22 {mu}g L{sup -1}. The detection limit and quantification limit were 0.041 and 0.093 {mu}g L{sup -1} (3{sigma}) for cold vapor atomic absorption spectrometry (CVAAS). The relative standard deviation of the 10 replicate determinations was 3.5% for the

  7. Parental genome dosage imbalance deregulates imprinting in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Pauline E Jullien

    2010-03-01

    Full Text Available In mammals and in plants, parental genome dosage imbalance deregulates embryo growth and might be involved in reproductive isolation between emerging new species. Increased dosage of maternal genomes represses growth while an increased dosage of paternal genomes has the opposite effect. These observations led to the discovery of imprinted genes, which are expressed by a single parental allele. It was further proposed in the frame of the parental conflict theory that parental genome imbalances are directly mirrored by antagonistic regulations of imprinted genes encoding maternal growth inhibitors and paternal growth enhancers. However these hypotheses were never tested directly. Here, we investigated the effect of parental genome imbalance on the expression of Arabidopsis imprinted genes FERTILIZATION INDEPENDENT SEED2 (FIS2 and FLOWERING WAGENINGEN (FWA controlled by DNA methylation, and MEDEA (MEA and PHERES1 (PHE1 controlled by histone methylation. Genome dosage imbalance deregulated the expression of FIS2 and PHE1 in an antagonistic manner. In addition increased dosage of inactive alleles caused a loss of imprinting of FIS2 and MEA. Although FIS2 controls histone methylation, which represses MEA and PHE1 expression, the changes of PHE1 and MEA expression could not be fully accounted for by the corresponding fluctuations of FIS2 expression. Our results show that parental genome dosage imbalance deregulates imprinting using mechanisms, which are independent from known regulators of imprinting. The complexity of the network of regulations between expressed and silenced alleles of imprinted genes activated in response to parental dosage imbalance does not support simple models derived from the parental conflict hypothesis.

  8. Retrotransposon silencing by DNA methylation can drive mammalian genomic imprinting.

    Directory of Open Access Journals (Sweden)

    Shunsuke Suzuki

    2007-04-01

    Full Text Available Among mammals, only eutherians and marsupials are viviparous and have genomic imprinting that leads to parent-of-origin-specific differential gene expression. We used comparative analysis to investigate the origin of genomic imprinting in mammals. PEG10 (paternally expressed 10 is a retrotransposon-derived imprinted gene that has an essential role for the formation of the placenta of the mouse. Here, we show that an orthologue of PEG10 exists in another therian mammal, the marsupial tammar wallaby (Macropus eugenii, but not in a prototherian mammal, the egg-laying platypus (Ornithorhynchus anatinus, suggesting its close relationship to the origin of placentation in therian mammals. We have discovered a hitherto missing link of the imprinting mechanism between eutherians and marsupials because tammar PEG10 is the first example of a differentially methylated region (DMR associated with genomic imprinting in marsupials. Surprisingly, the marsupial DMR was strictly limited to the 5' region of PEG10, unlike the eutherian DMR, which covers the promoter regions of both PEG10 and the adjacent imprinted gene SGCE. These results not only demonstrate a common origin of the DMR-associated imprinting mechanism in therian mammals but provide the first demonstration that DMR-associated genomic imprinting in eutherians can originate from the repression of exogenous DNA sequences and/or retrotransposons by DNA methylation.

  9. Imprinted Expression of SNRPN in Human Preimplantation Embryos

    OpenAIRE

    Huntriss, John; Daniels, Robert; Bolton, Virginia; Monk, Marilyn

    1998-01-01

    Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are two clinically distinct neurogenetic disorders arising from a loss of expression of imprinted genes within the human chromosome region 15q11-q13. Recent evidence suggests that the SNRPN gene, which is defective in PWS, plays a central role in the imprinting-center regulation of the PWS/AS region. To increase our understanding of the regulation of expression of this imprinted gene, we have developed single-cell-sensitive procedures for...

  10. Differential regulation of genomic imprinting by TET proteins in embryonic stem cells.

    Science.gov (United States)

    Liu, Lizhi; Mao, Shi-Qing; Ray, Chelsea; Zhang, Yu; Bell, Fong T; Ng, Sheau-Fang; Xu, Guo-Liang; Li, Xiajun

    2015-09-01

    TET proteins have been found to play an important role in active demethylation at CpG sites in mammals. There are some reports implicating their functions in removal of DNA methylation imprint at the imprinted regions in the germline. However, it is not well established whether TET proteins can also be involved in demethylation of DNA methylation imprint in embryonic stem (ES) cells. Here we report that loss of TET proteins caused a significant increase in DNA methylation at the Igf2-H19 imprinted region in ES cells. We also observed a variable increase in DNA methylation at the Peg1 imprinted region in the ES clones devoid of TET proteins, in particular in the differentiated ES cells. By contrast, we did not observe a significant increase of DNA methylation imprint at the Peg3, Snrpn and Dlk1-Dio3 imprinted regions in ES cells lacking TET proteins. Interestingly, loss of TET proteins did not result in a significant increase of DNA methylation imprint at the Igf2-H19 and Peg1 imprinted regions in the embryoid bodies (EB). Therefore, TET proteins seem to be differentially involved in maintaining DNA methylation imprint at a subset of imprinted regions in ES cells and EBs. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  11. Designing Fingers in Simulation based on Imprints

    DEFF Research Database (Denmark)

    Wolniakowski, Adam; Krüger, Norbert; Werner, Andrzej

    process of doing so. This method takes root in the idea of using the imprint to produce the finger geometry. We furthermore provide a verification of our newly introduced imprinting method and a comparison to the previously introduced parametrized geometry method. This verification is done through a set...

  12. Designing Fingers in Simulation based on Imprints

    DEFF Research Database (Denmark)

    Wiuf Schwartz, Lukas Christoffer Malte; Wolniakowski, Adam; Werner, Andrzej

    2017-01-01

    process of doing so. This method takes root in the idea of using the imprint to produce the finger geometry. We furthermore provide a verification of our newly introduced imprinting method and a comparison to the previously introduced parametrized geometry method. This verification is done through a set...

  13. Design of molecular imprinted polymers compatible with aqueous environment.

    Science.gov (United States)

    Piletska, Elena V; Guerreiro, Antonio R; Romero-Guerra, Maria; Chianella, Iva; Turner, Anthony P F; Piletsky, Sergey A

    2008-01-21

    The main problem of poor water compatibility of molecularly imprinted polymers (MIPs) was addressed in examples describing design of synthetic receptors with high affinity for drugs of abuse. An extensive potentiometric titration of 10 popular functional monomers and corresponding imprinted and blank polymers was conducted in order to evaluate the subtleties of functional groups ionisation under aqueous conditions. It was found that polymers prepared using 2-trifluoromethacrylic acid (TFMAA) in combination with toluene as porogen possess superior properties which make them suitable for effective template recognition in water. The potential impact of phase separation during polymerisation on formation of high quality imprints has been discussed. Three drugs of abuse such as cocaine, deoxyephedrine and methadone were used as template models in polymer preparation for the practical validation of obtained results. The polymer testing showed that synthesized molecularly imprinted polymers have high affinity and selectivity for corresponding templates in aqueous environment, with imprinting factors of 2.6 for cocaine and 1.4 for methadone and deoxyephedrine. Corresponding blank polymers were unable to differentiate between analytes, suggesting that imprinting phenomenon was responsible for the recognition properties.

  14. Molecularly Imprinted Microrods via Mesophase Polymerization

    Directory of Open Access Journals (Sweden)

    Ortensia Ilaria Parisi

    2017-12-01

    Full Text Available The aim of the present research work was the synthesis of molecularly imprinted polymers (MIPs with a rod-like geometry via “mesophase polymerization”. The ternary lyotropic system consisting of sodium dodecyl sulfate (SDS, water, and decanol was chosen to prepare a hexagonal mesophase to direct the morphology of the synthesized imprinted polymers using theophylline, methacrylic acid, and ethylene glycol dimethacrylate as a drug model template, a functional monomer, and a crosslinker, respectively. The obtained molecularly imprinted microrods (MIMs were assessed by performing binding experiments and in vitro release studies, and the obtained results highlighted good selective recognition abilities and sustained release properties. In conclusion, the adopted synthetic strategy involving a lyotropic mesophase system allows for the preparation of effective MIPs characterized by a rod-like morphology.

  15. Imprint switch mutations at Rasgrf1 support conflict hypothesis of imprinting and define a growth control mechanism upstream of IGF1

    Science.gov (United States)

    Drake, Nadia M.; Park, Yoon Jung; Shirali, Aditya S.; Cleland, Thomas A.

    2010-01-01

    Rasgrf1 is imprinted and expressed preferentially from the paternal allele in neonatal mouse brain. At weaning, expression becomes biallelic. Using a mouse model, we assayed the effects of perturbing imprinted Rasgrf1 expression in mice with the following imprinted expression patterns: monoallelic paternal (wild type), monoallelic maternal (maternal only), biallelic (both alleles transcribed), and null (neither allele transcribed). All genotypes exhibit biallelic expression around weaning. Consequences of this transient imprinting perturbation are manifested as overall size differences that correspond to the amount of neonatal Rasgrf1 expressed and are persistent, extending into adulthood. Biallelic mice are the largest and overexpress Rasgrf1 relative to wild-type mice, null mice are the smallest and underexpress Rasgrf1 as neonates, and the two monoallelically expressing genotypes are intermediate and indistinguishable from one another, in both size and Rasgrf1 expression level. Importantly, these data support one of the key underlying assumptions of the “conflict hypothesis” that describes the evolution of genomic imprinting in mammals and supposes that equivalent amounts of imprinted gene expression produce equivalent phenotypes, regardless of which parental allele is transcribed. Concordant with the difference in overall body size, we identify differences in IGF-1 levels, both in serum protein and as liver transcript, and identify additional differential expression of components upstream of IGF-1 release in the GH/IGF-1 axis. These data suggest that imprinted Rasgrf1 expression affects GH/IGF-1 axis function, and that the consequences of Rasgrf1 inputs to this axis persist beyond the time period when expression is restricted via epigenetic mechanisms, suggesting that proper neonatal Rasgrf1 expression levels are critical for development. PMID:19513790

  16. Sexual dimorphism in parental imprint ontogeny and contribution to embryonic development.

    Science.gov (United States)

    Bourc'his, Déborah; Proudhon, Charlotte

    2008-01-30

    Genomic imprinting refers to the functional non-equivalence of parental genomes in mammals that results from the parent-of-origin allelic expression of a subset of genes. Parent-specific expression is dependent on the germ line acquisition of DNA methylation marks at imprinting control regions (ICRs), coordinated by the DNA-methyltransferase homolog DNMT3L. We discuss here how the gender-specific stages of DNMT3L expression may have influenced the various sexually dimorphic aspects of genomic imprinting: (1) the differential developmental timing of methylation establishment at paternally and maternally imprinted genes in each parental germ line, (2) the differential dependence on DNMT3L of parental methylation imprint establishment, (3) the unequal duration of paternal versus maternal methylation imprints during germ cell development, (4) the biased distribution of methylation-dependent ICRs towards the maternal genome, (5) the different genomic organization of paternal versus maternal ICRs, and finally (6) the overwhelming contribution of maternal germ line imprints to development compared to their paternal counterparts.

  17. Smart coumarin-tagged imprinted polymers for the rapid detection of tamoxifen.

    Science.gov (United States)

    Ray, Judith V; Mirata, Fosca; Pérollier, Celine; Arotcarena, Michel; Bayoudh, Sami; Resmini, Marina

    2016-03-01

    A signalling molecularly imprinted polymer was synthesised for easy detection of tamoxifen and its metabolites. 6-Vinylcoumarin-4-carboxylic acid (VCC) was synthesised from 4-bromophenol to give a fluorescent monomer, designed to switch off upon binding of tamoxifen. Clomiphene, a chlorinated analogue, was used as the template for the imprinting, and its ability to quench the coumarin fluorescence when used in a 1:1 ratio was demonstrated. Tamoxifen and 4-hydroxytamoxifen were also shown to quench coumarin fluorescence. Imprinted and non-imprinted polymers were synthesised using VCC, methacrylic acid as a backbone monomer and ethylene glycol dimethacrylate as cross-linker, and were ground and sieved to particle sizes ranging between 45 and 25 μm. Rebinding experiments demonstrate that the imprinted polymer shows very strong affinity for both clomiphene and tamoxifen, while the non-imprinted polymer shows negligible rebinding. The fluorescence of the imprinted polymer is quenched by clomiphene, tamoxifen and 4-hydroxytamoxifen. The switch off in fluorescence of the imprinted polymer under these conditions could also be detected under a UV lamp with the naked eye, making this matrix suitable for applications when coupled with a sample preparation system.

  18. Finite Divergence

    DEFF Research Database (Denmark)

    Hansen, Michael Edberg; Pandya, P. K.; Chaochen, Zhou

    1995-01-01

    the framework of duration calculus. Axioms and proof rules are given. Patterns of occurrence of divergence are classified into dense divergence, accumulative divergence and discrete divergence by appropriate axioms. Induction rules are given for reasoning about discrete divergence...

  19. Enhanced Absorption in Organic Thin-Films from Imprinted Concave Nanostructures

    DEFF Research Database (Denmark)

    Goszczak, Arkadiusz Jaroslaw; Rubahn, Horst-Günter; Madsen, Morten

    2017-01-01

    In this work, a rapid, replicable method for imprinting concave nanostructures to be used as functional light-trapping nanostructures in organic thin-films is presented. Porous anodic alumina templates were fabricated both by anodization of thick Al foils and by anodization of submicrometer thin Al...... patterns and used for imprinting of spin coated photoresist on glass substrates. We have investigated semi-periodic and aperiodic imprinted large concave patterns fabricated from rigid masters after anodization of Al in H3PO4. We show that metal covered imprinted concaves show enhancement in absorption...

  20. Genomic imprinting of IGF2 in marsupials is methylation dependent

    Directory of Open Access Journals (Sweden)

    Imumorin Ikhide

    2008-05-01

    Full Text Available Abstract Background- Parent-specific methylation of specific CpG residues is critical to imprinting in eutherian mammals, but its importance to imprinting in marsupials and, thus, the evolutionary origins of the imprinting mechanism have been the subject of controversy. This has been particularly true for the imprinted Insulin-like Growth Factor II (IGF2, a key regulator of embryonic growth in vertebrates and a focal point of the selective forces leading to genomic imprinting. The presence of the essential imprinting effector, DNMT3L, in marsupial genomes and the demonstration of a differentially methylated region (DMR in the retrotransposon-derived imprinted gene, PEG10, in tammar wallaby argue for a role for methylation in imprinting, but several studies have found no evidence of parent-specific methylation at other imprinted loci in marsupials. Results- We performed the most extensive search to date for allele-specific patterns of CpG methylation within CpG isochores or CpG enriched segments across a 22 kilobase region surrounding the IGF2 gene in the South American opossum Monodelphis domestica. We identified a previously unknown 5'-untranslated exon for opossum IGF2, which is flanked by sequences defining a putative neonatal promoter, a DMR and an active Matrix Attachment Region (MAR. Demethylation of this DMR in opossum neonatal fibroblasts results in abherrant biallelic expression of IGF2. Conclusion- The demonstration of a DMR and an active MAR in the 5' flank of opossum IGF2 mirrors the regulatory features of the 5' flank of Igf2 in mice. However, demethylation induced activation of the maternal allele of IGF2 in opossum differs from the demethylation induced repression of the paternal Igf2 allele in mice. While it can now be concluded that parent-specific DNA methylation is an epigentic mark common to Marsupialia and Eutheria, the molecular mechanisms of transcriptional silencing at imprinted loci have clearly evolved along independent

  1. Gene dosage effects of the imprinted delta-like homologue 1 (dlk1/pref1 in development: implications for the evolution of imprinting.

    Directory of Open Access Journals (Sweden)

    Simao Teixeira da Rocha

    2009-02-01

    Full Text Available Genomic imprinting is a normal process that causes genes to be expressed according to parental origin. The selective advantage conferred by imprinting is not understood but is hypothesised to act on dosage-critical genes. Here, we report a unique model in which the consequences of a single, double, and triple dosage of the imprinted Dlk1/Pref1, normally repressed on the maternally inherited chromosome, can be assessed in the growing embryo. BAC-transgenic mice were generated that over-express Dlk1 from endogenous regulators at all sites of embryonic activity. Triple dosage causes lethality associated with major organ abnormalities. Embryos expressing a double dose of Dlk1, recapitulating loss of imprinting, are growth enhanced but fail to thrive in early life, despite the early growth advantage. Thus, any benefit conferred by increased embryonic size is offset by postnatal lethality. We propose a negative correlation between gene dosage and survival that fixes an upper limit on growth promotion by Dlk1, and we hypothesize that trade-off between growth and lethality might have driven imprinting at this locus.

  2. Using IMPRINT to Guide Experimental Design with Simulated Task Environments

    Science.gov (United States)

    2015-06-18

    USING IMPRINT TO GUIDE EXPERIMENTAL DESIGN OF SIMULATED TASK ENVIRONMENTS THESIS Gregory...ENG-MS-15-J-052 USING IMPRINT TO GUIDE EXPERIMENTAL DESIGN WITH SIMULATED TASK ENVIRONMENTS THESIS Presented to the Faculty Department...Civilian, USAF June 2015 DISTRIBUTION STATEMENT A. APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED. AFIT-ENG-MS-15-J-052 USING IMPRINT

  3. Mycotoxin analysis using imprinted materials technology: Recent developments

    Science.gov (United States)

    Molecular imprinting technology is an attractive, cost effective, and robust alternative to address the limitations of highly selective natural receptors, such as antibodies and aptamers. The field of molecular imprinting has seen a recent surge in growth with several commercially available products...

  4. Selective enrichment and separation of phosphotyrosine peptides by thermosensitive molecularly imprinted polymers.

    Science.gov (United States)

    Yang, Xiaoqing; Xia, Yan

    2016-01-01

    Novel thermosensitive molecularly imprinted polymers were successfully prepared using the epitope imprinting approach in the presence of the mimic template phenylphosphonic acid, the functional monomer vinylphosphonic acid-Ti(4+) , the temperature-sensitive monomer N-isopropylacrylamide and the crosslinker N,N'-methylenebisacrylamide. The ratio of the template/thermosensitive monomers/crosslinker was optimized, and when the ratio was 2:2:1, the prepared thermosensitive molecularly imprinted polymers had the highest imprinting factor. The synthetic thermosensitive molecularly imprinted polymers were characterized by Fourier transform infrared spectroscopy to reveal the combination and elution processes of the template. Then, the adsorption capacity and thermosensitivity was measured. When the temperature was 28°C, the imprinting factor was the highest. The selectivity and adsorption capacity of the thermosensitive molecularly imprinted polymers for phosphotyrosine peptides from a mixture of three tailor-made peptides were measured by high-performance liquid chromatography. The results showed that the thermosensitive molecularly imprinted polymers have good selectivity for phosphotyrosine peptides. Finally, the imprinted hydrogels were applied to specifically adsorb phosphotyrosine peptides from a sample mixture containing phosphotyrosine and a tryptic digest of β-casein, which demonstrated high selectivity. After four rebinding cycles, 78.9% adsorption efficiency was still retained. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Loss of insulin-like growth factor-II imprinting and the presence of screen-detected colorectal adenomas in women.

    Science.gov (United States)

    Woodson, Karen; Flood, Andrew; Green, Lisa; Tangrea, Joseph A; Hanson, Jeffrey; Cash, Brooks; Schatzkin, Arthur; Schoenfeld, Phillip

    2004-03-03

    Loss of imprinting (LOI) of insulin-like growth factor-II (IGF-II) may be an inherited epigenetic trait that is polymorphic in the population, and its presence may predispose an individual to the development of colorectal cancer. We evaluated the association between LOI of IGF-II in normal colonic mucosal samples and adenomas in women participating in a colonoscopy screening study. Among 40 participants, 11 (27.5%) had LOI of IGF-II in their normal colonic mucosal tissue. After adjusting for body mass index and family history of colorectal cancer, LOI status was associated with a fivefold increased risk of adenoma formation (odds ratio = 5.2, 95% confidence interval = 1.0 to 26.7). On average, IGF-II expression was more than threefold higher among women with LOI of IGF-II than among women with normal imprinting status. Our findings support the hypothesis that LOI of IGF-II is an epigenetic trait polymorphic in the population and suggest that LOI of IGF-II may play a role in colorectal cancer. These findings are intriguing and need to be confirmed in larger studies.

  6. Molecularly Imprinted Polymers: Novel Discovery for Drug Delivery.

    Science.gov (United States)

    Dhanashree, Surve; Priyanka, Mohite; Manisha, Karpe; Vilasrao, Kadam

    2016-01-01

    Molecularly imprinted polymers (MIP) are novel carriers synthesized by imprinting of a template over a polymer. This paper presents the recent application of MIP for diagnostic and therapeutic drug delivery. MIP owing to their 3D polymeric structures and due to bond formation with the template serves as a reservoir of active causing stimuli sensitive, enantioselective, targetted and/or controlled release. The review elaborates about key factors for optimization of MIP, controlled release by MIP for various administration routes various forms like patches, contact lenses, nanowires along with illustrations. To overcome the limitation of organic solvent usage causing increased cost, water compatible MIP and use of supercritical fluid technology for molecular imprinting were developed. Novel methods for developing water compatible MIP like pickering emulsion polymerization, co-precipitation method, cyclodextrin imprinting, surface grafting, controlled/living radical chain polymerization methods are described with illustration in this review. Various protein imprinting methods like bulk, epitope and surface imprinting are described along with illustrations. Further, application of MIP in microdevices as biomimetic sensing element for personalized therapy is elaborated. Although development and application of MIP in drug delivery is still at its infancy, constant efforts of researchers will lead to a novel intelligent drug delivery with commercial value. Efforts should be directed in developing solid oral dosage forms consisting of MIP for therapeutic protein and peptide delivery and targeted release of potent drugs addressing life threatening disease like cancer. Amalgamation of bio-engineering and pharmaceutical techniques can make these future prospects into reality.

  7. Evidence for a Peripheral Olfactory Memory in Imprinted Salmon

    Science.gov (United States)

    Nevitt, Gabrielle A.; Dittman, Andrew H.; Quinn, Thomas P.; Moody, William J., Jr.

    1994-05-01

    The remarkable homing ability of salmon relies on olfactory cues, but its cellular basis is unknown. To test the role of peripheral olfactory receptors in odorant memory retention, we imprinted coho salmon (Oncorhynchus kisutch) to micromolar concentrations of phenyl ethyl alcohol during parr-smolt transformation. The following year, we measured phenyl ethyl alcohol responses in the peripheral receptor cells using patch clamp. Cells from imprinted fish showed increased sensitivity to phenyl ethyl alcohol compared either to cells from naive fish or to sensitivity to another behaviorally important odorant (L-serine). Field experiments verified an increased behavioral preference for phenyl ethyl alcohol by imprinted salmon as adults. Thus, some component of the imprinted olfactory homestream memory appears to be retained peripherally.

  8. Cosmological imprints of pre-inflationary particles

    Energy Technology Data Exchange (ETDEWEB)

    Fialkov, Anastasia; Itzhaki, Nissan; Kovetz, Ely D., E-mail: anastasia.fialkov@gmail.com, E-mail: nitzhaki@post.tau.ac.il, E-mail: elykovetz@gmail.com [Tel-Aviv University, Ramat-Aviv, 69978 (Israel)

    2010-02-01

    We study some of the cosmological imprints of pre-inflationary particles. We show that each such particle provides a seed for a spherically symmetric cosmic defect. The profile of this cosmic defect is fixed and its magnitude is linear in a single parameter that is determined by the mass of the pre-inflationary particle. We study the CMB and peculiar velocity imprints of this cosmic defect and suggest that it could explain some of the large scale cosmological anomalies.

  9. Cosmological imprints of pre-inflationary particles

    International Nuclear Information System (INIS)

    Fialkov, Anastasia; Itzhaki, Nissan; Kovetz, Ely D.

    2010-01-01

    We study some of the cosmological imprints of pre-inflationary particles. We show that each such particle provides a seed for a spherically symmetric cosmic defect. The profile of this cosmic defect is fixed and its magnitude is linear in a single parameter that is determined by the mass of the pre-inflationary particle. We study the CMB and peculiar velocity imprints of this cosmic defect and suggest that it could explain some of the large scale cosmological anomalies

  10. Bio-Mimetic Sensors Based on Molecularly Imprinted Membranes

    Directory of Open Access Journals (Sweden)

    Catia Algieri

    2014-07-01

    Full Text Available An important challenge for scientific research is the production of artificial systems able to mimic the recognition mechanisms occurring at the molecular level in living systems. A valid contribution in this direction resulted from the development of molecular imprinting. By means of this technology, selective molecular recognition sites are introduced in a polymer, thus conferring it bio-mimetic properties. The potential applications of these systems include affinity separations, medical diagnostics, drug delivery, catalysis, etc. Recently, bio-sensing systems using molecularly imprinted membranes, a special form of imprinted polymers, have received the attention of scientists in various fields. In these systems imprinted membranes are used as bio-mimetic recognition elements which are integrated with a transducer component. The direct and rapid determination of an interaction between the recognition element and the target analyte (template was an encouraging factor for the development of such systems as alternatives to traditional bio-assay methods. Due to their high stability, sensitivity and specificity, bio-mimetic sensors-based membranes are used for environmental, food, and clinical uses. This review deals with the development of molecularly imprinted polymers and their different preparation methods. Referring to the last decades, the application of these membranes as bio-mimetic sensor devices will be also reported.

  11. Bio-Mimetic Sensors Based on Molecularly Imprinted Membranes

    Science.gov (United States)

    Algieri, Catia; Drioli, Enrico; Guzzo, Laura; Donato, Laura

    2014-01-01

    An important challenge for scientific research is the production of artificial systems able to mimic the recognition mechanisms occurring at the molecular level in living systems. A valid contribution in this direction resulted from the development of molecular imprinting. By means of this technology, selective molecular recognition sites are introduced in a polymer, thus conferring it bio-mimetic properties. The potential applications of these systems include affinity separations, medical diagnostics, drug delivery, catalysis, etc. Recently, bio-sensing systems using molecularly imprinted membranes, a special form of imprinted polymers, have received the attention of scientists in various fields. In these systems imprinted membranes are used as bio-mimetic recognition elements which are integrated with a transducer component. The direct and rapid determination of an interaction between the recognition element and the target analyte (template) was an encouraging factor for the development of such systems as alternatives to traditional bio-assay methods. Due to their high stability, sensitivity and specificity, bio-mimetic sensors-based membranes are used for environmental, food, and clinical uses. This review deals with the development of molecularly imprinted polymers and their different preparation methods. Referring to the last decades, the application of these membranes as bio-mimetic sensor devices will be also reported. PMID:25196110

  12. Highly Selective Fluorescent Sensing of Proteins Based on a Fluorescent Molecularly Imprinted Nanosensor

    Directory of Open Access Journals (Sweden)

    Shuo Wang

    2013-09-01

    Full Text Available A fluorescent molecularly imprinted nanosensor was obtained by grafting imprinted polymer onto the surface of multi-wall carbon nanotubes and post-imprinting treatment with fluorescein isothiocyanate (FITC. The fluorescence of lysozyme-imprinted polymer (Lys-MIP was quenched more strongly by Lys than that of nonimprinted polymer (NIP, which indicated that the Lys-MIP could recognize Lys. The resulted imprinted material has the ability to selectively sense a target protein, and an imprinting factor of 3.34 was achieved. The Lys-MIP also showed selective detection for Lys among other proteins such as cytochrome C (Cyt C, hemoglobin (HB and bovine serum albumin (BSA due to the imprinted sites in the Lys-MIP. This approach combines the high selectivity of surface molecular imprinting technology and fluorescence, and converts binding events into detectable signals by monitoring fluorescence spectra. Therefore, it will have further applications for Lys sensing.

  13. Synthesis of molecular imprinting polymers for extraction of gallic acid from urine.

    Science.gov (United States)

    Bhawani, Showkat Ahmad; Sen, Tham Soon; Ibrahim, Mohammad Nasir Mohammad

    2018-02-21

    The molecularly imprinted polymers for gallic acid were synthesized by precipitation polymerization. During the process of synthesis a non-covalent approach was used for the interaction of template and monomer. In the polymerization process, gallic acid was used as a template, acrylic acid as a functional monomer, ethylene glycol dimethacrylate as a cross-linker and 2,2'-azobisisobutyronitrile as an initiator and acetonitrile as a solvent. The synthesized imprinted and non-imprinted polymer particles were characterized by using Fourier-transform infrared spectroscopy and scanning electron microscopy. The rebinding efficiency of synthesized polymer particles was evaluated by batch binding assay. The highly selective imprinted polymer for gallic acid was MIPI1 with a composition (molar ratio) of 1:4:20, template: monomer: cross-linker, respectively. The MIPI1 showed highest binding efficiency (79.50%) as compared to other imprinted and non-imprinted polymers. The highly selective imprinted polymers have successfully extracted about 80% of gallic acid from spiked urine sample.

  14. Deregulation of an imprinted gene network in prostate cancer.

    Science.gov (United States)

    Ribarska, Teodora; Goering, Wolfgang; Droop, Johanna; Bastian, Klaus-Marius; Ingenwerth, Marc; Schulz, Wolfgang A

    2014-05-01

    Multiple epigenetic alterations contribute to prostate cancer progression by deregulating gene expression. Epigenetic mechanisms, especially differential DNA methylation at imprinting control regions (termed DMRs), normally ensure the exclusive expression of imprinted genes from one specific parental allele. We therefore wondered to which extent imprinted genes become deregulated in prostate cancer and, if so, whether deregulation is due to altered DNA methylation at DMRs. Therefore, we selected presumptive deregulated imprinted genes from a previously conducted in silico analysis and from the literature and analyzed their expression in prostate cancer tissues by qRT-PCR. We found significantly diminished expression of PLAGL1/ZAC1, MEG3, NDN, CDKN1C, IGF2, and H19, while LIT1 was significantly overexpressed. The PPP1R9A gene, which is imprinted in selected tissues only, was strongly overexpressed, but was expressed biallelically in benign and cancerous prostatic tissues. Expression of many of these genes was strongly correlated, suggesting co-regulation, as in an imprinted gene network (IGN) reported in mice. Deregulation of the network genes also correlated with EZH2 and HOXC6 overexpression. Pyrosequencing analysis of all relevant DMRs revealed generally stable DNA methylation between benign and cancerous prostatic tissues, but frequent hypo- and hyper-methylation was observed at the H19 DMR in both benign and cancerous tissues. Re-expression of the ZAC1 transcription factor induced H19, CDKN1C and IGF2, supporting its function as a nodal regulator of the IGN. Our results indicate that a group of imprinted genes are coordinately deregulated in prostate cancers, independently of DNA methylation changes.

  15. S-Layer Based Bio-Imprinting - Synthetic S-Layer Polymers

    Science.gov (United States)

    2015-07-09

    AFRL-OSR-VA-TR-2015-0161 S-Layer Based Bio- Imprinting - Synthetic S-Layer Polymers Dietmar Pum ZENTRUM FUER NANOBIOTECHNOLOGIE Final Report 07/09...COVERED (From - To)      01-06-2012 to 31-05-2015 4.  TITLE AND SUBTITLE S-Layer Based Bio- Imprinting - Synthetic S-Layer Polymers 5a.  CONTRACT...technology for the fabrication of nano patterned thin film imprints by using functional S-layer protein arrays as templates. The unique feature of

  16. Electropolymerized molecularly imprinted polypyrrole film for sensing of clofibric acid.

    Science.gov (United States)

    Schweiger, Bianca; Kim, Jungtae; Kim, Young Jun; Ulbricht, Mathias

    2015-02-26

    Piezoelectric quartz crystals and analogous gold substrates were electrochemically coated with molecularly imprinted polypyrrole films for pulsed amperometric detection (PAD) of clofibric acid, a metabolite of clofibrate. Cyclic voltammetry data obtained during polymerization and deposited weight estimations revealed a decrease of the polymerization rate with increasing clofibric acid concentration. XPS measurements indicated that clofibric acid could be removed after imprinting with an aqueous ethanol solution, which was further optimized by using PAD. Zeta potential and contact angle measurements revealed differences between molecularly imprinted (MIP) and non-imprinted polymer (NIP) layers. Binding experiments with clofibric acid and other substances showed a pronounced selectivity of the MIP for clofibric acid vs. carbamazepine, but the response of MIP and NIP to 2,4-dichlorophenoxyacetic acid was higher than that for clofibric acid. A smooth surface, revealed by AFM measurements, with roughness of 6-8 nm for imprinted and non-imprinted layers, might be a reason for an excessively low density of specific binding sites for clofibric acid. Furthermore, the decreased polymerization rate in the presence of clofibric acid might not result in well-defined polymer structures, which could be the reason for the lower sensitivity.

  17. Electropolymerized Molecularly Imprinted Polypyrrole Film for Sensing of Clofibric Acid

    Directory of Open Access Journals (Sweden)

    Bianca Schweiger

    2015-02-01

    Full Text Available Piezoelectric quartz crystals and analogous gold substrates were electrochemically coated with molecularly imprinted polypyrrole films for pulsed amperometric detection (PAD of clofibric acid, a metabolite of clofibrate. Cyclic voltammetry data obtained during polymerization and deposited weight estimations revealed a decrease of the polymerization rate with increasing clofibric acid concentration. XPS measurements indicated that clofibric acid could be removed after imprinting with an aqueous ethanol solution, which was further optimized by using PAD. Zeta potential and contact angle measurements revealed differences between molecularly imprinted (MIP and non-imprinted polymer (NIP layers. Binding experiments with clofibric acid and other substances showed a pronounced selectivity of the MIP for clofibric acid vs. carbamazepine, but the response of MIP and NIP to 2,4-dichlorophenoxyacetic acid was higher than that for clofibric acid. A smooth surface, revealed by AFM measurements, with roughness of 6–8 nm for imprinted and non-imprinted layers, might be a reason for an excessively low density of specific binding sites for clofibric acid. Furthermore, the decreased polymerization rate in the presence of clofibric acid might not result in well-defined polymer structures, which could be the reason for the lower sensitivity.

  18. Molecular imprinted polypyrrole modified glassy carbon electrode for the determination of tobramycin

    International Nuclear Information System (INIS)

    Gupta, Vinod Kumar; Yola, Mehmet Lütfi; Özaltın, Nuran; Atar, Necip; Üstündağ, Zafer; Uzun, Lokman

    2013-01-01

    Graphical abstract: Atomic force microscopic images of (A) bare GCE and (B) TOB imprinted PPy/GCE surface. - Highlights: • Glassy carbon electrode based on molecularly imprinted polypyrrole was prepared. • The developed surfaces were characterized by AFM, FTIR, EIS and CV. • The developed nanosensor was applied to egg and milk samples. - Abstract: Over the past two decades, molecular imprinted polymers have attracted a broad interest from scientists in sensor development. In the preparation of molecular imprinted polymers the desired molecule (template) induces the creation of specific recognition sites in the polymer. In this study, the glassy carbon electrode (GCE) based on molecularly imprinted polypyrrole (PPy) was fabricated for the determination of tobramycin (TOB). The developed electrode was prepared by incorporation of a template molecule (TOB) during the electropolymerization of pyrrole on GCE in aqueous solution using cyclic voltammetry (CV) method. The performance of the imprinted and non-imprinted electrodes was evaluated by square wave voltammetry (SWV). The effect of pH, monomer and template concentrations, electropolymerization cycles on the performance of the imprinted and non-imprinted electrodes was investigated and optimized. The non-modified and TOB-imprinted surfaces were characterized by using atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS) and CV. The linearity range of TOB was 5.0 × 10 −10 –1.0 × 10 −8 M with the detection limit of 1.4 × 10 −10 M. The developed nanosensor was applied successfully for the determination of TOB in egg and milk

  19. Dimensional characterization of biperiodic imprinted structures using optical scatterometry

    KAUST Repository

    Gereige, Issam

    2013-12-01

    In this paper, we report on the characterization of biperiodic imprinted structures using a non-destructive optical technique commonly called scatterometry. The nanostructures consist of periodic arrays of square and circular dots which were imprinted in a thermoplastic polymer by thermal nanoimprint lithography. Optical measurements were performed using spectroscopic ellipsometry in the spectral region of 1.5-4 eV. The geometrical profiles of the imprinted structures were reconstructed using the Rigorous Coupled-Wave Analysis (RCWA) to model the diffraction phenomena by periodic gratings. The technique was also adapted for large scale evaluation of the imprint process. Uniqueness of the solution was examined by analyzing the diffraction of the structure at different experimental conditions, for instance at various angles of incidence. © 2013 Elsevier B.V. All rights reserved.

  20. Imprinting of Phenylalanine ethyl ester in cyclodextrin polymers in aqueous solution

    DEFF Research Database (Denmark)

    Detcheva, Anna Hr.; Yu, Donghong; Larsen, Kim Lambertsen

    During the last decades there has been a wide interest of developing molecularly imprinted polymers, which selectively can recognize small molecules. Cyclodextrins offer relatively strong binding site of a wide range of small molecules in water and molecular imprinted polymers of these have...... previously been produced with some success. Nevertheless most molecules of interest for molecular imprinting are too samll to accommodate more than one cyclodextrin per molecule and thus limited selectivity may be expected. In order to improve the selectivity of cyclodextrin based molecular imprinted polymer...

  1. Does imprint cytology improve the accuracy of transrectal prostate needle biopsy?

    Science.gov (United States)

    Sayar, Hamide; Bulut, Burak Besir; Bahar, Abdulkadir Yasir; Bahar, Mustafa Remzi; Seringec, Nurten; Resim, Sefa; Çıralık, Harun

    2015-02-01

    To evaluate the accuracy of imprint cytology of core needle biopsy specimens in the diagnosis of prostate cancer. Between December 24, 2011 and May 9, 2013, patients with an abnormal DRE and/or serum PSA level of >2.5 ng/mL underwent transrectal prostate needle biopsy. Samples with positive imprint cytology but negative initial histologic exam underwent repeat sectioning and histological examination. 1,262 transrectal prostate needle biopsy specimens were evaluated from 100 patients. Malignant imprint cytology was found in 236 specimens (18.7%), 197 (15.6%) of which were confirmed by histologic examination, giving an initial 3.1% (n = 39) rate of discrepant results by imprint cytology. Upon repeat sectioning and histologic examination of these 39 biopsy samples, 14 (1.1% of the original specimens) were then diagnosed as malignant, 3 (0.2%) as atypical small acinar proliferation (ASAP), and 5 (0.4%) as high-grade prostatic intraepithelial neoplasia (HGPIN). Overall, 964 (76.4%) specimens were negative for malignancy by imprint cytology. Seven (0.6%) specimens were benign by cytology but malignant cells were found on histological evaluation. On imprint cytology examination, nonmalignant but abnormal findings were seen in 62 specimens (4.9%). These were all due to benign processes. After reexamination, the accuracy, sensitivity, specificity, positive predictive value, negative predictive value, false-positive rate, false-negative rate of imprint preparations were 98.1, 96.9, 98.4, 92.8, 99.3, 1.6, 3.1%, respectively. Imprint cytology is valuable tool for evaluating TRUS-guided core needle biopsy specimens from the prostate. Use of imprint cytology in combination with histopathology increases diagnostic accuracy when compared with histopathologic assessment alone. © 2014 Wiley Periodicals, Inc.

  2. Local divergence and curvature divergence in first order optics

    Science.gov (United States)

    Mafusire, Cosmas; Krüger, Tjaart P. J.

    2018-06-01

    The far-field divergence of a light beam propagating through a first order optical system is presented as a square root of the sum of the squares of the local divergence and the curvature divergence. The local divergence is defined as the ratio of the beam parameter product to the beam width whilst the curvature divergence is a ratio of the space-angular moment also to the beam width. It is established that the beam’s focusing parameter can be defined as a ratio of the local divergence to the curvature divergence. The relationships between the two divergences and other second moment-based beam parameters are presented. Their various mathematical properties are presented such as their evolution through first order systems. The efficacy of the model in the analysis of high power continuous wave laser-based welding systems is briefly discussed.

  3. Adsorptive molecularly imprinted composite membranes for chiral separation of phenylalanine

    Directory of Open Access Journals (Sweden)

    Shah Nasrullah

    2016-09-01

    Full Text Available Two types of composite imprinted membranes, i.e., composite membrane comprised of D-Phe imprinted beads and D-Phe imprinted membrane or DCM and composite membrane comprised of L-Phe imprinted beads and L-Phe imprinted membranes or LCM, were synthesized by phase inversion technique after a uniform dispersion of beads within the polymeric solutions using simple physico-mechanical process. The assemblies of the prepared DCM, LCM and control membranes were employed in ultrafiltration for chiral separation of D, L-Phenylalanine racemate solution. DCM and LCM showed an improved adsorption capacity (0.334 mg g-1 and 0.365 mg g-1 respectively, and adsorption selectivity (2.72 and 2.98 respectively. However, the percent rejection of the template and counter enantiomer were lower than that of control membranes. Compared to control membrane, the DCM and LCM showed inverse permselectivity. These composite membranes having better adsorption and separation ability for Phenylalanine racemate solution will be suitable in the future for various other applications.

  4. Molecularly Imprinted Polymers for 5-Fluorouracil Release in Biological Fluids

    Directory of Open Access Journals (Sweden)

    Franco Alhaique

    2007-04-01

    Full Text Available The aim of this work was to investigate the possibility of employing Molecularly Imprinted Polymers (MIPs as a controlled release device for 5-fluorouracil (5-FU in biological fluids, especially gastrointestinal ones, compared to Non Imprinted Polymers (NIPs. MIPs were synthesized using methacrylic acid (MAA as functional monomer and ethylene glycol dimethacrylate (EGDMA as crosslinking agent. The capacity of the polymer to recognize and to bind the template selectively in both organic and aqueous media was evaluated. An in vitro release study was performed both in gastrointestinal and in plasma simulating fluids. The imprinted polymers bound much more 5-Fu than the corresponding non-imprinted ones and showed a controlled/sustained drug release, with MIPs release rate being indeed much more sustained than that obtained from NIPs. These polymers represent a potential valid system for drug delivery and this study indicates that the selective binding characteristic of molecularly imprinted polymers is promising for the preparation of novel controlled release drug dosage form.

  5. Genomic Imprinting Was Evolutionarily Conserved during Wheat Polyploidization.

    Science.gov (United States)

    Yang, Guanghui; Liu, Zhenshan; Gao, Lulu; Yu, Kuohai; Feng, Man; Yao, Yingyin; Peng, Huiru; Hu, Zhaorong; Sun, Qixin; Ni, Zhongfu; Xin, Mingming

    2018-01-01

    Genomic imprinting is an epigenetic phenomenon that causes genes to be differentially expressed depending on their parent of origin. To evaluate the evolutionary conservation of genomic imprinting and the effects of ploidy on this process, we investigated parent-of-origin-specific gene expression patterns in the endosperm of diploid ( Aegilops spp), tetraploid, and hexaploid wheat ( Triticum spp) at various stages of development via high-throughput transcriptome sequencing. We identified 91, 135, and 146 maternally or paternally expressed genes (MEGs or PEGs, respectively) in diploid, tetraploid, and hexaploid wheat, respectively, 52.7% of which exhibited dynamic expression patterns at different developmental stages. Gene Ontology enrichment analysis suggested that MEGs and PEGs were involved in metabolic processes and DNA-dependent transcription, respectively. Nearly half of the imprinted genes exhibited conserved expression patterns during wheat hexaploidization. In addition, 40% of the homoeolog pairs originating from whole-genome duplication were consistently maternally or paternally biased in the different subgenomes of hexaploid wheat. Furthermore, imprinted expression was found for 41.2% and 50.0% of homolog pairs that evolved by tandem duplication after genome duplication in tetraploid and hexaploid wheat, respectively. These results suggest that genomic imprinting was evolutionarily conserved between closely related Triticum and Aegilops species and in the face of polyploid hybridization between species in these genera. © 2018 American Society of Plant Biologists. All rights reserved.

  6. Elevated expression of brain-derived neurotrophic factor facilitates visual imprinting in chicks.

    Science.gov (United States)

    Suzuki, Keiko; Maekawa, Fumihiko; Suzuki, Shingo; Nakamori, Tomoharu; Sugiyama, Hayato; Kanamatsu, Tomoyuki; Tanaka, Kohichi; Ohki-Hamazaki, Hiroko

    2012-12-01

    With the aim of elucidating the neural mechanisms of early learning, we studied the role of brain-derived neurotrophic factor (BDNF) in visual imprinting in birds. The telencephalic neural circuit connecting the visual Wulst and intermediate medial mesopallium is critical for imprinting, and the core region of the hyperpallium densocellulare (HDCo), situated at the center of this circuit, has a key role in regulating the activity of the circuit. We found that the number of BDNF mRNA-positive cells in the HDCo was elevated during the critical period, particularly at its onset, on the day of hatching (P0). After imprinting training on P1, BDNF mRNA-positive cells in the HDCo increased in number, and tyrosine phosphorylation of TrkB was observed. BDNF infusion into the HDCo at P1 induced imprinting, even with a weak training protocol that does not normally induce imprinting. In contrast, K252a, an antagonist of Trk, inhibited imprinting. Injection of BDNF at P7, after the critical period, did not elicit imprinting. These results suggest that BDNF promotes the induction of imprinting through TrkB exclusively during the critical period. © 2012 The Authors Journal of Neurochemistry © 2012 International Society for Neurochemistry.

  7. Molecularly Imprinted Polypyrrole Based Impedimentric Sensor for Theophylline Determination

    International Nuclear Information System (INIS)

    Ratautaite, Vilma; Janssens, Stoffel D.; Haenen, Ken; Nesládek, Milos; Ramanaviciene, Almira; Baleviciute, Ieva; Ramanavicius, Arunas

    2014-01-01

    Highlights: • Sensor based on polypyrrole imprinted by theophylline (MIP) deposited on oxygen terminated boron-doped nanocrystalline diamond was developed. • This structure was applied as impedimetric sensor sensitive for theophylline. • Optimal polymer formation conditions suitable for MIP formation were elaborated. • Some analytical parameters were determined and evaluated. - Abstract: In this study development of impedimetric sensor based on oxygen terminated boron-doped nanocrystalline diamond (B:NCD:O) modified with theophylline imprinted polypyrrole is described. Hydrogen peroxide induced chemical formation of polypyrrole molecularly imprinted by theophylline was applied for the modification of conducting silicon substrate covered by B:NCD:O film. Non-imprinted polypyrrole layer was formed on similar substrate in order to prove efficiency of imprinted polypyrrole. Electrochemical impedance spectroscopy was applied for the evaluation of analyte-induced changes in electrochemical capacitance/resistance. The impact of polymerization duration on the capacitance of impedimetric sensor was estimated. A different impedance behavior was observed at different ratio of polymerized monomer and template molecule in the polymerization media. The influence of ethanol as additive to polymerization media on registered changes in capacitance/resistance was evaluated. Degradation of sensor stored in buffer solution was evaluated

  8. Molecularly imprinted titania nanoparticles for selective recognition and assay of uric acid

    Science.gov (United States)

    Mujahid, Adnan; Khan, Aimen Idrees; Afzal, Adeel; Hussain, Tajamal; Raza, Muhammad Hamid; Shah, Asma Tufail; uz Zaman, Waheed

    2015-06-01

    Molecularly imprinted titania nanoparticles are su ccessfully synthesized by sol-gel method for the selective recognition of uric acid. Atomic force microscopy is used to study the morphology of uric acid imprinted titania nanoparticles with diameter in the range of 100-150 nm. Scanning electron microscopy images of thick titania layer indicate the formation of fine network of titania nanoparticles with uniform distribution. Molecular imprinting of uric acid as well as its subsequent washing is confirmed by Fourier transformation infrared spectroscopy measurements. Uric acid rebinding studies reveal the recognition capability of imprinted particles in the range of 0.01-0.095 mmol, which is applicable in monitoring normal to elevated levels of uric acid in human blood. The optical shift (signal) of imprinted particles is six times higher in comparison with non-imprinted particles for the same concentration of uric acid. Imprinted titania particles have shown substantially reduced binding affinity toward interfering and structurally related substances, e.g. ascorbic acid and guanine. These results suggest the possible application of titania nanoparticles in uric acid recognition and quantification in blood serum.

  9. Gas Sensors Based on Molecular Imprinting Technology

    OpenAIRE

    Zhang, Yumin; Zhang, Jin; Liu, Qingju

    2017-01-01

    Molecular imprinting technology (MIT); often described as a method of designing a material to remember a target molecular structure (template); is a technique for the creation of molecularly imprinted polymers (MIPs) with custom-made binding sites complementary to the target molecules in shape; size and functional groups. MIT has been successfully applied to analyze; separate and detect macromolecular organic compounds. Furthermore; it has been increasingly applied in assays of biological mac...

  10. Molecular imprinting-chemiluminescence determination of trimethoprim using trimethoprim-imprinted polymer as recognition material.

    Science.gov (United States)

    He, Yunhua; Lu, Jiuru; Liu, Mei; Du, Jianxiu

    2005-07-01

    A new molecular imprinting-chemiluminescence method for the determination of trimethoprim was developed, in which trimethoprim-imprinted polymer was used as the molecular recognition material and the CL reaction of trimethoprim with potassium permanganate in acidic medium was used as the detection system. The CL intensity responds linearly to the concentration of trimethoprim within the 5.0 x 10(-8)-5.0 x 10(-6) g mL(-1) range (r= 0.9983) with a detection limit of 2 x 10(-8) g mL(-1). The relative standard deviation for the determination of 1.0 x 10(-7) g mL(-1) trimethoprim solutions is 4.8% (n= 9). The method has been applied to the determination of trimethoprim in pharmaceutical preparations and body fluids, and satisfactory results were obtained.

  11. "On-off" switchable tool for food sample preparation: merging molecularly imprinting technology with stimuli-responsive blocks. Current status, challenges and highlighted applications.

    Science.gov (United States)

    Garcia, Raquel; Gomes da Silva, Marco D R; Cabrita, Maria João

    2018-01-01

    Sample preparation still remains a great challenge in the analytical workflow representing the most time-consuming and laborious step in analytical procedures. Ideally, sample pre-treatment procedures must be more selective, cheap, quick and environmental friendly. Molecular imprinting technology is a powerful tool in the development of highly selective sample preparation methodologies enabling to preconcentrate the analytes from a complex food matrix. Actually, the design and development of molecularly imprinted polymers-based functional materials that merge an enhancement of selectivity with a controllable and switchable mode of action by means of specific stimulus constitutes a hot research topic in the field of food analysis. Thus, combining the stimuli responsive mechanism and imprinting technology a new generation of materials are emerging. The application of these smart materials in sample preparation is in early stage of development, nevertheless new improvements will promote a new driven in the demanding field of food sample preparation. The new trends in the advancement of food sample preparation using these smart materials will be presented in this review and highlighted the most relevant applications in this particular area of knowledge. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Gas Sensors Based on Molecular Imprinting Technology.

    Science.gov (United States)

    Zhang, Yumin; Zhang, Jin; Liu, Qingju

    2017-07-04

    Molecular imprinting technology (MIT); often described as a method of designing a material to remember a target molecular structure (template); is a technique for the creation of molecularly imprinted polymers (MIPs) with custom-made binding sites complementary to the target molecules in shape; size and functional groups. MIT has been successfully applied to analyze; separate and detect macromolecular organic compounds. Furthermore; it has been increasingly applied in assays of biological macromolecules. Owing to its unique features of structure specificity; predictability; recognition and universal application; there has been exploration of the possible application of MIPs in the field of highly selective gas sensors. In this present study; we outline the recent advances in gas sensors based on MIT; classify and introduce the existing molecularly imprinted gas sensors; summarize their advantages and disadvantages; and analyze further research directions.

  13. Producing superfluid circulation states using phase imprinting

    Science.gov (United States)

    Kumar, Avinash; Dubessy, Romain; Badr, Thomas; De Rossi, Camilla; de Goër de Herve, Mathieu; Longchambon, Laurent; Perrin, Hélène

    2018-04-01

    We propose a method to prepare states of given quantized circulation in annular Bose-Einstein condensates (BEC) confined in a ring trap using the method of phase imprinting without relying on a two-photon angular momentum transfer. The desired phase profile is imprinted on the atomic wave function using a short light pulse with a tailored intensity pattern generated with a spatial light modulator. We demonstrate the realization of "helicoidal" intensity profiles suitable for this purpose. Due to the diffraction limit, the theoretical steplike intensity profile is not achievable in practice. We investigate the effect of imprinting an intensity profile smoothed by a finite optical resolution onto the annular BEC with a numerical simulation of the time-dependent Gross-Pitaevskii equation. This allows us to optimize the intensity pattern for a given target circulation to compensate for the limited resolution.

  14. Synthesis of molecular imprinted beta cyclodextrins oligomers in water

    DEFF Research Database (Denmark)

    Yu, Donghong; Nielsen, Anne Louise; Bach, Lone

    2003-01-01

    compounds in aqueous solution and, therefore, molecular imprinting of cyclodextrins polymers in aqueous solution is of great interest. In this paper, molecular imprinting of beta cyclodextrins has been performed in water by use of diiodobenzene as template and epichlorohydrin as a crosslinker. Inclusion...

  15. Preparation and recognition of surface molecularly imprinted core-shell microbeads for protein in aqueous solutions

    International Nuclear Information System (INIS)

    Lu Yan; Yan Changling; Gao Shuyan

    2009-01-01

    In this paper, a surface molecular imprinting technique was reported for preparing core-shell microbeads of protein imprinting, and bovine hemoglobin or bovine serum albumin were used as model proteins for studying the imprinted core-shell microbeads. 3-Aminophenylboronic acid (APBA) was polymerized onto the surface of polystyrene microbead in the presence of the protein templates to create protein-imprinted core-shell microbeads. The various samples were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) methods. The effect of pH on rebinding of the template hemoglobin, the specific binding and selective recognition were studied for the imprinted microbeads. The results show that the bovine hemoglobin-imprinted core-shell microbeads were successfully created. The shell was a sort of imprinted thin films with porous structure and larger surface areas. The imprinted microbeads have good selectivity for templates and high stability. Due to the recognition sites locating at or closing to the surface, these imprinted microbeads have good property of mass-transport. Unfortunately, the imprint technology was not successfully applied to imprinting bovine serum albumin (BSA).

  16. Preparation and recognition of surface molecularly imprinted core-shell microbeads for protein in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Lu Yan, E-mail: yanlu2001@sohu.com [College of Chemistry and Environmental Science, Henan Normal University, 46 Jlanshe Road, Xinxiang 453007 (China); Yan Changling; Gao Shuyan [College of Chemistry and Environmental Science, Henan Normal University, 46 Jlanshe Road, Xinxiang 453007 (China)

    2009-04-01

    In this paper, a surface molecular imprinting technique was reported for preparing core-shell microbeads of protein imprinting, and bovine hemoglobin or bovine serum albumin were used as model proteins for studying the imprinted core-shell microbeads. 3-Aminophenylboronic acid (APBA) was polymerized onto the surface of polystyrene microbead in the presence of the protein templates to create protein-imprinted core-shell microbeads. The various samples were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) methods. The effect of pH on rebinding of the template hemoglobin, the specific binding and selective recognition were studied for the imprinted microbeads. The results show that the bovine hemoglobin-imprinted core-shell microbeads were successfully created. The shell was a sort of imprinted thin films with porous structure and larger surface areas. The imprinted microbeads have good selectivity for templates and high stability. Due to the recognition sites locating at or closing to the surface, these imprinted microbeads have good property of mass-transport. Unfortunately, the imprint technology was not successfully applied to imprinting bovine serum albumin (BSA).

  17. Influence of surface-imprinted nanoparticles on trypsin activity.

    Science.gov (United States)

    Guerreiro, António; Poma, Alessandro; Karim, Kal; Moczko, Ewa; Takarada, Jessica; de Vargas-Sansalvador, Isabel Perez; Turner, Nicholas; Piletska, Elena; de Magalhães, Cristiana Schmidt; Glazova, Natalia; Serkova, Anastasia; Omelianova, Aleksandra; Piletsky, Sergey

    2014-09-01

    Here, the modulation of enzyme activity is presented by protein-imprinted nanoparticles produced using a solid-phase approach. Using trypsin as target, binding of the nanoparticles to the enzyme results in its inhibition or in stabilization, depending on the orientation of the immobilized enzyme used during imprinting. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Determination of fusaric acid in maize using molecularly imprinted SPE clean-up

    Science.gov (United States)

    A new liquid chromatography method to detect fusaric acid in maize is reported based on molecularly imprinted polymer solid phase extraction clean-up (MISPE) using mimic-templated molecularly-imprinted polymers. Picolinic acid was used as a toxin analog for imprinting polymers during a thermolytic s...

  19. New generation ion-imprinted nanocarrier for removal of Cr(VI) from wastewater

    International Nuclear Information System (INIS)

    Uygun, Murat; Feyzioğlu, Esra; Özçalışkan, Emir; Caka, Müşerref; Ergen, Aygen; Akgöl, Sinan; Denizli, Adil

    2013-01-01

    The purpose of this study was to prepare a novel ion-imprinted nanoparticle to remove Cr(VI) ions from waste water. For this, Cr(VI) ions were complexed with 2-methacryloylamido histidine (MAH) and then Cr(VI)-imprinted poly(HEMAH) nanoparticles were synthesized by surfactant-free emulsion polymerization technique. The templates, Cr(VI) ions, were removed from the nanoparticles using 0.1 M of HNO 3 solution. The specific surface area of the Cr(VI)-imprinted poly(HEMAH) nanoparticles was found to be 1,397.85 m 2 /g, and the particle size was calculated as 155.3 nm. These Cr(VI)-imprinted nanoparticles were used for the adsorption/desorption of Cr(VI) ions from its aqueous solutions. The effects of initial Cr(VI) concentration and medium pH on the Cr(VI) adsorption capacity were also studied. The maximum adsorbed amount of Cr(VI) on the imprinted nanoparticles was found to be 3,830.58 mg/g nanoparticle in pH 4.0. In order to investigate the selectivity of the imprinted nanoparticle, adsorption studies were repeated using Cr(III) ions. The selectivity results demonstrated that Cr(VI)-imprinted poly(HEMAH) nanoparticles showed high affinity for the Cr(VI) ions than Cr(III). The Cr(VI)-imprinted nanoparticles were used several times without decreasing their Cr(VI) adsorption capacities

  20. New generation ion-imprinted nanocarrier for removal of Cr(VI) from wastewater

    Science.gov (United States)

    Uygun, Murat; Feyzioğlu, Esra; Özçalışkan, Emir; Caka, Müşerref; Ergen, Aygen; Akgöl, Sinan; Denizli, Adil

    2013-08-01

    The purpose of this study was to prepare a novel ion-imprinted nanoparticle to remove Cr(VI) ions from waste water. For this, Cr(VI) ions were complexed with 2-methacryloylamido histidine (MAH) and then Cr(VI)-imprinted poly(HEMAH) nanoparticles were synthesized by surfactant-free emulsion polymerization technique. The templates, Cr(VI) ions, were removed from the nanoparticles using 0.1 M of HNO3 solution. The specific surface area of the Cr(VI)-imprinted poly(HEMAH) nanoparticles was found to be 1,397.85 m2/g, and the particle size was calculated as 155.3 nm. These Cr(VI)-imprinted nanoparticles were used for the adsorption/desorption of Cr(VI) ions from its aqueous solutions. The effects of initial Cr(VI) concentration and medium pH on the Cr(VI) adsorption capacity were also studied. The maximum adsorbed amount of Cr(VI) on the imprinted nanoparticles was found to be 3,830.58 mg/g nanoparticle in pH 4.0. In order to investigate the selectivity of the imprinted nanoparticle, adsorption studies were repeated using Cr(III) ions. The selectivity results demonstrated that Cr(VI)-imprinted poly(HEMAH) nanoparticles showed high affinity for the Cr(VI) ions than Cr(III). The Cr(VI)-imprinted nanoparticles were used several times without decreasing their Cr(VI) adsorption capacities.

  1. New generation ion-imprinted nanocarrier for removal of Cr(VI) from wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Uygun, Murat, E-mail: muygun@adu.edu.tr [Adnan Menderes University, Kocarl Latin-Small-Letter-Dotless-I Vocational and Training School (Turkey); Feyzioglu, Esra; Oezcal Latin-Small-Letter-Dotless-I skan, Emir; Caka, Mueserref; Ergen, Aygen; Akgoel, Sinan [Ege University, Department of Biochemistry, Faculty of Science (Turkey); Denizli, Adil [Hacettepe University, Department of Chemistry, Faculty of Science (Turkey)

    2013-08-15

    The purpose of this study was to prepare a novel ion-imprinted nanoparticle to remove Cr(VI) ions from waste water. For this, Cr(VI) ions were complexed with 2-methacryloylamido histidine (MAH) and then Cr(VI)-imprinted poly(HEMAH) nanoparticles were synthesized by surfactant-free emulsion polymerization technique. The templates, Cr(VI) ions, were removed from the nanoparticles using 0.1 M of HNO{sub 3} solution. The specific surface area of the Cr(VI)-imprinted poly(HEMAH) nanoparticles was found to be 1,397.85 m{sup 2}/g, and the particle size was calculated as 155.3 nm. These Cr(VI)-imprinted nanoparticles were used for the adsorption/desorption of Cr(VI) ions from its aqueous solutions. The effects of initial Cr(VI) concentration and medium pH on the Cr(VI) adsorption capacity were also studied. The maximum adsorbed amount of Cr(VI) on the imprinted nanoparticles was found to be 3,830.58 mg/g nanoparticle in pH 4.0. In order to investigate the selectivity of the imprinted nanoparticle, adsorption studies were repeated using Cr(III) ions. The selectivity results demonstrated that Cr(VI)-imprinted poly(HEMAH) nanoparticles showed high affinity for the Cr(VI) ions than Cr(III). The Cr(VI)-imprinted nanoparticles were used several times without decreasing their Cr(VI) adsorption capacities.

  2. Imprinting and recalling cortical ensembles.

    Science.gov (United States)

    Carrillo-Reid, Luis; Yang, Weijian; Bando, Yuki; Peterka, Darcy S; Yuste, Rafael

    2016-08-12

    Neuronal ensembles are coactive groups of neurons that may represent building blocks of cortical circuits. These ensembles could be formed by Hebbian plasticity, whereby synapses between coactive neurons are strengthened. Here we report that repetitive activation with two-photon optogenetics of neuronal populations from ensembles in the visual cortex of awake mice builds neuronal ensembles that recur spontaneously after being imprinted and do not disrupt preexisting ones. Moreover, imprinted ensembles can be recalled by single- cell stimulation and remain coactive on consecutive days. Our results demonstrate the persistent reconfiguration of cortical circuits by two-photon optogenetics into neuronal ensembles that can perform pattern completion. Copyright © 2016, American Association for the Advancement of Science.

  3. Protein imprinting and recognition via forming nanofilms on microbeads surfaces in aqueous media

    International Nuclear Information System (INIS)

    Lu Yan; Yan Changling; Wang Xuejing; Wang Gongke

    2009-01-01

    In this paler, we present a technique of forming nanofilms of poly-3-aminophenylboronic acid (pAPBA) on the surfaces of polystyrene (PS) microbeads for proteins (papain and trypsin) in aqueous. Papain was chosen as a model to study the feasibility of the technique and trypsin as an extension. Obtained core-shell microbeads were characterized using scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and BET methods. The results show that pAPBA formed nanofilms (60-100 nm in thickness) on the surfaces of PS microbeads. The specific surface area of the papain-imprinted beads was about 180 m 2 g -1 and its pore size was 31 nm. These imprinted microbeads exhibit high recognition specificity and fast mass transfer kinetics. The specificity of these imprinted beads mainly originates from the spatial effect of imprinted sites. Because the protein-imprinted sites were located at, or close to, the surface, the imprinted beads have good site accessibility toward the template molecules. The facility of the imprinting protocol and the high recognition properties of imprinted microbeads make the approach an attractive solution to problems in the field of biotechnology.

  4. Short interspersed transposable elements (SINEs) are excluded from imprinted regions in the human genome.

    Science.gov (United States)

    Greally, John M

    2002-01-08

    To test whether regions undergoing genomic imprinting have unique genomic characteristics, imprinted and nonimprinted human loci were compared for nucleotide and retroelement composition. Maternally and paternally expressed subgroups of imprinted genes were found to differ in terms of guanine and cytosine, CpG, and retroelement content, indicating a segregation into distinct genomic compartments. Imprinted regions have been normally permissive to L1 long interspersed transposable element retroposition during mammalian evolution but universally and significantly lack short interspersed transposable elements (SINEs). The primate-specific Alu SINEs, as well as the more ancient mammalian-wide interspersed repeat SINEs, are found at significantly low densities in imprinted regions. The latter paleogenomic signature indicates that the sequence characteristics of currently imprinted regions existed before the mammalian radiation. Transitions from imprinted to nonimprinted genomic regions in cis are characterized by a sharp inflection in SINE content, demonstrating that this genomic characteristic can help predict the presence and extent of regions undergoing imprinting. During primate evolution, SINE accumulation in imprinted regions occurred at a decreased rate compared with control loci. The constraint on SINE accumulation in imprinted regions may be mediated by an active selection process. This selection could be because of SINEs attracting and spreading methylation, as has been found at other loci. Methylation-induced silencing could lead to deleterious consequences at imprinted loci, where inactivation of one allele is already established, and expression is often essential for embryonic growth and survival.

  5. Polymer Catalysts Imprinted with Metal Ions as Biomimics of Metalloenzymes

    Directory of Open Access Journals (Sweden)

    Joanna Czulak

    2013-01-01

    Full Text Available This work presents the preparation and properties of molecularly imprinted polymers (MIPs with catalytic centers that mimic the active sites of metalloenzymes. The MIP synthesis was based on suspension polymerization of functional monomers (4-vinylpyridine and acrylonitrile with trimethylolpropane trimethacrylate as a crosslinker in the presence of transition metal ions and 4-methoxybenzyl alcohol as a template. Four metal ions have been chosen for imprinting from among the microelements that are the most essential in the native enzymes: Cu2+, Co2+, Mn2+, and Zn2+. To prepare catalysts, the required loading of metal ions was obtained during sorption process. The catalysts imprinted with Cu2+, Co2+, and Zn2+ were successfully used for hydroquinone oxidation in the presence of hydrogen peroxide. The Mn2+-imprinted catalyst showed no activity due to the insufficient metal loading. Cu2+ MIP showed the highest efficiency. In case of Cu- and Co-MIP catalysts, their activity was additionally increased by the use of surface imprinting technique.

  6. Evaluation of accuracy of intra operative imprint cytology for detection of breast lesions

    International Nuclear Information System (INIS)

    Mahmood, Z.; Shahbaz, A.; Qureshi, A.; Aziz, N.; Niazi, S.; Qureshi, S.; Bukhari, M.H.

    2010-01-01

    Objective: To determine the accuracy of imprint cytology as an intraoperative diagnostic procedure for breast lesions with histopathological correlation. Materials and Methods: This was a descriptive study on 40 cases of breast lesions comprising of inflammatory, benign and malignant lesions including their margins etc. It was conducted at King Edward Medical University, Lahore in collaboration with all Surgical Departments of Mayo Hospital. Relevant clinical data was recorded in a proforma. Both touch and scrape imprints were prepared from all the lesions and stained with May-Grunwaled Giemsa and Haematoxylin and Eosin stains. The imprints were subsequently compared with histopathology sections. Results: When we used atypical cases as negative both touch and scrape imprints gave sensitivity, specificity, positive predictive value, negative predictive value and accuracy at 100%. However when we used cases with atypia as positive, sensitivity and negative predictive value were 100% with both touch and scrape imprints. Specificity, positive predictive value and accuracy were 71%, 86%, 85.5% respectively with touch imprints and 78%, 89%, 89% respectively with scrape imprints. No diagnostic difference was noted between the results of both stains. All the imprints were well correlated with histopathological diagnosis. Conclusion: Imprint cytology is an accurate and simple intraoperative method for diagnosing breast lesions. It can provide the surgeons with information regarding immediate clinical and surgical interventions. (author)

  7. Schedules of electric shock presentation in the behavioral control of imprinted ducklings.

    Science.gov (United States)

    Barrett, J E

    1972-09-01

    The behavioral effects of various schedules of electric shock presentation were investigated during and after the imprinting of Peking ducklings to moving stimuli. The behavior of following a moving imprinted stimulus was differentially controlled by a multiple schedule of punishment and avoidance that respectively suppressed and maintained following behavior. Pole-pecking, reinforced by presentations of the imprinted stimulus, was suppressed by response-produced shock (punishment); various schedules of response-independent shock and delayed punishment had an overall minimal effect. The delivery of response-independent shock in the presence of one of two stimuli, both during and after imprinting, resulted in a marked reduction in choice of the stimulus paired with shock. The experiments provide no support for a differentiation of imprinting from learning on the basis of the behavioral effects of aversive stimuli. Instead, as is the case with other organisms, the schedule under which shock is delivered to imprinted ducklings appears to be an important determinant of the temporal patterning of subsequent behavior.

  8. New molecular imprinted voltammetric sensor for determination of ochratoxin A

    Energy Technology Data Exchange (ETDEWEB)

    Yola, Mehmet Lütfi, E-mail: mehmetyola@gmail.com [Department of Metallurgical and Materials Engineering, Faculty of Engineering, Sinop University, Sinop (Turkey); Gupta, Vinod Kumar, E-mail: vinodfcy@iitr.ac.in [Indian Institute of Technology, Department of Chemistry, Roorkee, Roorkee 247667 (India); Department of Applied Chemistry, University of Johannesburg, Johannesburg (South Africa); Atar, Necip [Department of Chemical Engineering, Faculty of Engineering, Pamukkale University, Denizli (Turkey)

    2016-04-01

    In this report, a novel molecular imprinted voltammetric sensor based on silver nanoparticles (AgNPs) involved in a polyoxometalate (H{sub 3}PW{sub 12}O{sub 40}, POM) functionalized reduced graphene oxide (rGO) modified glassy carbon electrode (GCE) was presented for determination of ochrattoxin A (OCH). The developed surfaces were characterized using scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) method. OCH imprinted GCE was prepared via electropolymerization process of 100 mM phenol as monomer in the presence of phosphate buffer solution (pH 6.0) containing 25 mM OCH. The linearity range and the detection limit of the method were calculated as 5.0 × 10{sup −11} − 1.5 × 10{sup −9} M and 1.6 × 10{sup −11} M, respectively. The voltammetric sensor was applied to grape juice and wine samples with good selectivity and recovery. The stability of the voltammetric sensor was also reported. - Highlights: • Ochratoxin A-imprinted electrochemical sensor is developed for the sensitive detection of ochratoxin A • The nanomaterial and ochratoxin A-imprinted surfaces were characterized by several methods • Ochratoxin A-imprinted electrochemical sensor is sensitive and selective in analysis of food • Ochratoxin A-imprinted electrochemical sensor is preferred to the other methods.

  9. Sensitive determination of citrinin based on molecular imprinted electrochemical sensor

    Energy Technology Data Exchange (ETDEWEB)

    Atar, Necip [Department of Chemical Engineering, Faculty of Engineering, Pamukkale University, Denizli (Turkey); Yola, Mehmet Lütfi, E-mail: mehmetyola@gmail.com [Department of Metallurgical and Materials Engineering, Faculty of Engineering, Sinop University, Sinop (Turkey); Eren, Tanju [Department of Chemical Engineering, Faculty of Engineering, Pamukkale University, Denizli (Turkey)

    2016-01-30

    Graphical abstract: - Highlights: • Citrinin-imprinted electrochemical sensor is developed for the sensitive detection of citrinin. • The nanomaterial and citrinin-imprinted surfaces were characterized by several methods. • Citrinin-imprinted electrochemical sensor is sensitive and selective in analysis of food. • Citrinin-imprinted electrochemical sensor is preferred to the other methods. - Abstract: In this report, a novel molecular imprinted voltammetric sensor based on glassy carbon electrode (GCE) modified with platinum nanoparticles (PtNPs) involved in a polyoxometalate (H{sub 3}PW{sub 12}O{sub 40}, POM) functionalized reduced graphene oxide (rGO) was prepared for the determination of citrinin (CIT). The developed surfaces were characterized by using scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) method. CIT imprinted GCE was prepared via electropolymerization process of 80.0 mM pyrrole as monomer in the presence of phosphate buffer solution (pH 6.0) containing 20.0 mM CIT. The linearity range and the detection limit of the developed method were calculated as 1.0 × 10{sup −12}–1.0 × 10{sup −10} M and 2.0 × 10{sup −13} M, respectively. In addition, the voltammetric sensor was applied to rye samples. The stability and selectivity of the voltammetric sensor were also reported.

  10. Sensitive determination of citrinin based on molecular imprinted electrochemical sensor

    International Nuclear Information System (INIS)

    Atar, Necip; Yola, Mehmet Lütfi; Eren, Tanju

    2016-01-01

    Graphical abstract: - Highlights: • Citrinin-imprinted electrochemical sensor is developed for the sensitive detection of citrinin. • The nanomaterial and citrinin-imprinted surfaces were characterized by several methods. • Citrinin-imprinted electrochemical sensor is sensitive and selective in analysis of food. • Citrinin-imprinted electrochemical sensor is preferred to the other methods. - Abstract: In this report, a novel molecular imprinted voltammetric sensor based on glassy carbon electrode (GCE) modified with platinum nanoparticles (PtNPs) involved in a polyoxometalate (H_3PW_1_2O_4_0, POM) functionalized reduced graphene oxide (rGO) was prepared for the determination of citrinin (CIT). The developed surfaces were characterized by using scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) method. CIT imprinted GCE was prepared via electropolymerization process of 80.0 mM pyrrole as monomer in the presence of phosphate buffer solution (pH 6.0) containing 20.0 mM CIT. The linearity range and the detection limit of the developed method were calculated as 1.0 × 10"−"1"2–1.0 × 10"−"1"0 M and 2.0 × 10"−"1"3 M, respectively. In addition, the voltammetric sensor was applied to rye samples. The stability and selectivity of the voltammetric sensor were also reported.

  11. New molecular imprinted voltammetric sensor for determination of ochratoxin A

    International Nuclear Information System (INIS)

    Yola, Mehmet Lütfi; Gupta, Vinod Kumar; Atar, Necip

    2016-01-01

    In this report, a novel molecular imprinted voltammetric sensor based on silver nanoparticles (AgNPs) involved in a polyoxometalate (H_3PW_1_2O_4_0, POM) functionalized reduced graphene oxide (rGO) modified glassy carbon electrode (GCE) was presented for determination of ochrattoxin A (OCH). The developed surfaces were characterized using scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) method. OCH imprinted GCE was prepared via electropolymerization process of 100 mM phenol as monomer in the presence of phosphate buffer solution (pH 6.0) containing 25 mM OCH. The linearity range and the detection limit of the method were calculated as 5.0 × 10"−"1"1 − 1.5 × 10"−"9 M and 1.6 × 10"−"1"1 M, respectively. The voltammetric sensor was applied to grape juice and wine samples with good selectivity and recovery. The stability of the voltammetric sensor was also reported. - Highlights: • Ochratoxin A-imprinted electrochemical sensor is developed for the sensitive detection of ochratoxin A • The nanomaterial and ochratoxin A-imprinted surfaces were characterized by several methods • Ochratoxin A-imprinted electrochemical sensor is sensitive and selective in analysis of food • Ochratoxin A-imprinted electrochemical sensor is preferred to the other methods

  12. Adsorption characteristics, recognition properties, and preliminary application of nordihydroguaiaretic acid molecularly imprinted polymers prepared by sol–gel surface imprinting technology

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Sen; Zhang, Wen; Long, Wei; Hou, Dan; Yang, Xuechun; Tan, Ni, E-mail: tannii@21cn.com

    2016-02-28

    Graphical abstract: - Highlights: • Nordihydroguaiaretic acid imprinted polymer with imprinting factor 2.12 was prepared for the first time through hydrogen bonding and hydrophobic interaction between the template molecules and the bifunctional monomers. • The obtained surface molecularly imprinting polymers exhibited high affinity and selectivity to the template molecules. • The prepared surface molecularly imprinted polymers were used in separation the natural active component nordihydroguaiaretic acid from medicinal plants. - Abstract: In this paper, a new core-shell composite of nordihydroguaiaretic acid (NDGA) molecularly imprinted polymers layer-coated silica gel (MIP@SiO{sub 2}) was prepared through sol–gel technique and applied as a material for extraction of NDGA from Ephedra. It was synthesized using NDGA as the template molecule, γ-aminopropyltriethoxysilane (APTS) and methyltriethoxysilane (MTEOS) as the functional monomers, tetraethyl orthosilicate (TEOS) as the cross-linker and ethanol as the porogenic solvent in the surface of silica. The non-imprinted polymers layer-coated silica gel (NIP@SiO{sub 2}) were prepared with the same procedure, but with the absence of template molecule. In addition, the optimum adsorption affinity occurred when the molar ratio of NDGA:APTS:MTEOS:TEOS was 1:6:2:80. The prepared MIP@SiO{sub 2} and NIP@SiO{sub 2} were analyzed by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Fourier transform-infrared spectroscopy (FT-IR). Their affinity properties to NDGA were evaluated through dynamic adsorption, static adsorption, and selective recognition experiments, and the results showed the saturated adsorption capacity of MIP@SiO{sub 2} could reach to 5.90 mg g{sup −1}, which was two times more than that of NIP@SiO{sub 2}. High performance liquid chromatography (HPLC) was used to evaluate the extraction of NDGA from the medicinal plant ephedra by the above prepared materials, and the results

  13. Adsorption characteristics, recognition properties, and preliminary application of nordihydroguaiaretic acid molecularly imprinted polymers prepared by sol–gel surface imprinting technology

    International Nuclear Information System (INIS)

    Liao, Sen; Zhang, Wen; Long, Wei; Hou, Dan; Yang, Xuechun; Tan, Ni

    2016-01-01

    Graphical abstract: - Highlights: • Nordihydroguaiaretic acid imprinted polymer with imprinting factor 2.12 was prepared for the first time through hydrogen bonding and hydrophobic interaction between the template molecules and the bifunctional monomers. • The obtained surface molecularly imprinting polymers exhibited high affinity and selectivity to the template molecules. • The prepared surface molecularly imprinted polymers were used in separation the natural active component nordihydroguaiaretic acid from medicinal plants. - Abstract: In this paper, a new core-shell composite of nordihydroguaiaretic acid (NDGA) molecularly imprinted polymers layer-coated silica gel (MIP@SiO_2) was prepared through sol–gel technique and applied as a material for extraction of NDGA from Ephedra. It was synthesized using NDGA as the template molecule, γ-aminopropyltriethoxysilane (APTS) and methyltriethoxysilane (MTEOS) as the functional monomers, tetraethyl orthosilicate (TEOS) as the cross-linker and ethanol as the porogenic solvent in the surface of silica. The non-imprinted polymers layer-coated silica gel (NIP@SiO_2) were prepared with the same procedure, but with the absence of template molecule. In addition, the optimum adsorption affinity occurred when the molar ratio of NDGA:APTS:MTEOS:TEOS was 1:6:2:80. The prepared MIP@SiO_2 and NIP@SiO_2 were analyzed by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Fourier transform-infrared spectroscopy (FT-IR). Their affinity properties to NDGA were evaluated through dynamic adsorption, static adsorption, and selective recognition experiments, and the results showed the saturated adsorption capacity of MIP@SiO_2 could reach to 5.90 mg g"−"1, which was two times more than that of NIP@SiO_2. High performance liquid chromatography (HPLC) was used to evaluate the extraction of NDGA from the medicinal plant ephedra by the above prepared materials, and the results indicated that the MIP@SiO_2 had

  14. Synthesis of molecularly imprinted dye-silica nanocomposites with high selectivity and sensitivity: Fluorescent imprinted sensor for rapid and efficient detection of τ-fluvalinate in vodka.

    Science.gov (United States)

    Wang, Yunyun; Wang, Jixiang; Cheng, Rujia; Sun, Lin; Dai, Xiaohui; Yan, Yongsheng

    2018-04-01

    An imprinted fluorescent sensor was fabricated based on SiO 2 nanoparticles encapsulated with a molecularly imprinted polymer containing allyl fluorescein. High fluorine cypermethirin as template molecules, methyl methacrylate as functional monomer, and allyl fluorescein as optical materials synthesized a core-shell fluorescent molecular imprinted sensor, which showed a high and rapid sensitivity and selectivity for the detection of τ-fluvalinate. The sensor presented appreciable sensitivity with a limit of 13.251 nM, rapid detection that reached to equilibrium within 3 min, great linear relationship in the relevant concentration range from 0 to 150 nM, and excellent selectivity over structural analogues. In addition, the fluorescent sensor demonstrated desirable regeneration ability (eight cycling operations). The molecularly imprinted polymers ensured specificity, while the fluorescent dyes provided the stabile sensitivity. Finally, an effective application of the sensor was implemented by the detection of τ-fluvalinate in real samples from vodka. The molecularly imprinted fluorescent sensor showed a promising potential in environmental monitoring and food safety. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Characterization of Conserved and Nonconserved Imprinted Genes in Swine

    Science.gov (United States)

    Genomic imprinting results in the silencing of a subset of mammalian alleles due to parent-of-origin inheritance. Due to the nature of their expression patterns they play a critical role in placental and early embryonic development. In order to increase our understanding of imprinted genes specifi...

  16. Pyrogallol-imprinted polymers with methyl methacrylate via precipitation polymerization

    Science.gov (United States)

    Mehamod, Faizatul Shimal; Othman, Nor Amira; Bulat, Ku Halim Ku; Suah, Faiz Bukhari Mohd

    2018-06-01

    Molecular simulation techniques are important to study the understanding of chemical and physical properties of any material. Computational modeling is considered as time reducer in finding the best recipes for Molecularly-Imprinted Polymers (MIPs). In this study, Pyrogallol-imprinted polymers (PIP) and non-imprinted polymers (NIPs) were synthesized via precipitation polymerization using Pyrogallol (Py), methyl methacrylate (MMA), divinylbenzene (DVB) as template, functional monomer and cross-linker, respectively. The recipe was according to the results from computational techniques. The synthesized PIP and NIPs were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) and UV-visible spectroscopy (UV-vis). Studies on adsorption isotherm showed that PIP and NIPs follow Scatchard isotherm models. Sorption kinetic study found that PIP and NIPs follow pseudo-second order which indicates the rate-limiting step is the surface adsorption. The imprinting factor of PIP was determined by selectivity study and showed the value of k >1, which proved that PIP was selective toward Pyrogallol compared to NIP.

  17. Halloysite-based dopamine-imprinted polymer for selective protein capture.

    Science.gov (United States)

    Zhu, Xiaohong; Li, Hui; Liu, Hui; Peng, Wei; Zhong, Shian; Wang, Yan

    2016-06-01

    We describe a facile, general, and highly efficient approach to obtain polydopamine-coated molecularly imprinted polymer based on halloysite nanotubes for bovine serum albumin. The method combined surface molecular imprinting and one-step immobilized template technique. Hierarchically structured polymer was prepared in physiological conditions adopting dopamine as functional monomer. A thin layer of polydopamine can be coated on the surface of amino-modified halloysite nanotubes by self-polymerization, and the thickness of the imprinted shells can be controlled by the mass ratio of matrix and dopamine. The polymer was characterized by Fourier transform infrared spectrometry, transmission electron microscopy, and thermogravimetric analysis. The prepared material showed high binding capacity (45.4 mg/g) and specific recognition behavior toward the template protein. In addition, stability and regeneration analyses indicated that the imprinted polymer exhibited excellent reusability (relative standard deviation < 9% for batch-to-batch evaluation). Therefore, the developed polymer is effective for protein recognition and separation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Nano- and Micro-sized Molecularly Imprinted Polymer Particles on Solid Surfaces

    OpenAIRE

    Kamra, Tripta

    2015-01-01

    Molecularly imprinted polymers (MIPs) are artificial receptors made by imprinting template molecules in a polymer matrix followed by their removal through washing to obtain a specific and selective template cavities. This property of the MIPs have made them a very efficient material for diverse applications such as chromatography, purification, drug sensing, etc. Recently, zero-dimensional polymer materials, in the present case molecularly imprinted polymer nanoparticles (MIP nanoparticles), ...

  19. Histopathology-like categories based on endometrial imprint cytology in dysfunctional uterine bleeding.

    Science.gov (United States)

    Baxi, Seema N; Panchal, Nirav S

    2015-01-01

    Cytology of the endometrium is an underused technique in diagnostic pathology. It has been used in the past for endometrial hyperplasia and carcinoma. Only few studies have used cytology in the diagnosis of dysfunctional uterine bleeding (DUB). Endometrial imprint cytology has been rarely used except for application of immunocytochemistry in diagnosis of endometrial carcinoma. The present study was conducted to evaluate whether it is possible to assign histopathology-like diagnosis by imprint cytology and also to evaluate its usefulness in the assessment of patients of dysfunctional uterine bleeding of low clinical suspicion. Imprint smears were made from 93 curettage materials during a study of DUB. Blinded analysis of imprint smears was performed by using McKenzie's criteria and some criteria devised for the requirements of this study. Results of cytology were correlated with histopathology. Statistical analysis was carried out by GraphpadInStat Demo. Majority of the patterns classifiable in histopathology could also be classified in this study on imprint cytology. The overall sensitivity and specificity of cytology in the detection of endometrial patterns in DUB patients were 91.23% and 83.87%, respectively, although the sensitivities and specificities differ according to the phase of endometrium. Histopathology-like categories can be assigned on imprint smears in the diagnosis of DUB. Endometrial imprint cytology can be helpful in centers where histopathology laboratories are not available and even in well-established institutes. It is possible to improve the sensitivity and specificity with better imprinting techniques.

  20. Epigenetic status of H19/IGF2 and SNRPN imprinted genes in aborted and successfully derived embryonic stem cell lines in non-human primates

    Directory of Open Access Journals (Sweden)

    Florence Wianny

    2016-05-01

    Full Text Available The imprinted genes of primate embryonic stem cells (ESCs often show altered DNA methylation. It is unknown whether these alterations emerge while deriving the ESCs. Here we studied the methylation patterns of two differentially methylated regions (DMRs, SNRPN and H19/IGF2 DMRs, during the derivation of monkey ESCs. We show that the SNRPN DMR is characteristically methylated at maternal alleles, whereas the H19/IGF2 DMR is globally highly methylated, with unusual methylation on the maternal alleles. These methylation patterns remain stable from the early stages of ESC derivation to late passages of monkey ESCs and following differentiation. Importantly, the methylation status of H19/IGF2 DMR and the expression levels of IGF2, H19, and DNMT3B mRNAs in early embryo-derived cells were correlated with their capacity to generate genuine ESC lines. Thus, we propose that these markers could be useful to predict the outcomes of establishing an ESC line in primates.

  1. Interfacial pattern changes of imprinted multilayered material in milli- and microscales

    Science.gov (United States)

    Yonekura, Kazuhiro; Tokumaru, Kazuki; Tsumori, Fujio

    2018-06-01

    Nanoimprint lithography (NIL) is a technique that transfers a mold pattern of nanometer order to the surface of a resist material by heating and pressing. NIL is an excellent technology in terms of high productivity, accuracy, and resolution. Recently, NIL has been applied to the processing of different multilayered materials, in which it is possible to process multiple materials simultaneously. In this processing of multilayered materials, it is possible to form an interfacial pattern between the upper layer and the lower layer simultaneously with patterning on the mold surface. This interface pattern can be controlled by the deformation characteristics, initial thickness, and so forth. In this research, we compared the interfacial pattern changes of imprinted multilayered materials in milli- and microscales. For multilayered imprint using multiple materials, it is important to know the flow of the resist and its dependence on the scale. If there is similarity in the relationship produced by the scale on the imprinted samples, a process design with a number of feedbacks could be realized. It also becomes easier to treat structures in the millimeter scale for the experiment. In this study, we employed micropowder imprint (µPI) for multilayered material imprint. A compound sheet of alumina powder and polymer binder was used for imprint. Two similar experiments in different scales, micro- and millimeter scales, were carried out. Results indicate that the interfacial patterns of micro- and millimeter-scale-imprinted samples are similar.

  2. Polarization imprint effects on the photovoltaic effect in Pb(Zr,Ti)O3 thin films

    Science.gov (United States)

    Tan, Zhengwei; Tian, Junjiang; Fan, Zhen; Lu, Zengxing; Zhang, Luyong; Zheng, Dongfeng; Wang, Yadong; Chen, Deyang; Qin, Minghui; Zeng, Min; Lu, Xubing; Gao, Xingsen; Liu, Jun-Ming

    2018-04-01

    The polarization imprint along with the photovoltaic (PV) effect has been studied in Pt/Pb(Zr0.3Ti0.7)O3/SrRuO3 ferroelectric capacitors. It is shown that the positive DC poling induces the imprint with a downward direction whereas the negative DC poling suppresses the imprint (i.e., rejuvenation). In the polarization up state, the imprinted capacitor exhibits degraded PV properties compared with the rejuvenated one. This may be because the imprint reduces the number of upward domains, thus lowering the driving force for the PV effect. In the polarization down state, however, the rejuvenated capacitor enters the imprinted state spontaneously. This rejuvenation-to-imprint transition can be further aggravated by applying positive voltages and ultraviolet illumination. It is proposed that the domain pinning/depinning, which are associated with the oxygen vacancies and trapped electrons modulated by polarization, voltage, and illumination, may be responsible for the polarization imprint and rejuvenation. Our study therefore sheds light on the correlation between the polarization imprint and the PV effect in the ferroelectrics and also provides some viable suggestions to address the imprint-induced degradation of PV performance.

  3. Synthesis and Theoretical Study of Molecularly Imprinted Nanospheres for Recognition of Tocopherols

    Directory of Open Access Journals (Sweden)

    Chartchalerm Isarankura-Na-Ayudhya

    2009-08-01

    Full Text Available Molecular imprinting is a technology that facilitates the production of artificial receptors toward compounds of interest. The molecularly imprinted polymers act as artificial antibodies, artificial receptors, or artificial enzymes with the added benefit over their biological counterparts of being highly durable. In this study, we prepared molecularly imprinted polymers for the purpose of binding specifically to tocopherol (vitamin E and its derivative, tocopherol acetate. Binding of the imprinted polymers to the template was found to be two times greater than that of the control, non-imprinted polymers, when using only 10 mg of polymers. Optimization of the rebinding solvent indicated that ethanol-water at a molar ratio of 6:4 (v/v was the best solvent system as it enhanced the rebinding performance of the imprinted polymers toward both tocopherol and tocopherol acetate with a binding capacity of approximately 2 mg/g of polymer. Furthermore, imprinted nanospheres against tocopherol was successfully prepared by precipitation polymerization with ethanol-water at a molar ratio of 8:2 (v/v as the optimal rebinding solvent. Computer simulation was also performed to provide mechanistic insights on the binding mode of template-monomer complexes. Such polymers show high potential for industrial and medical applications, particularly for selective separation of tocopherol and derivatives.

  4. Imprinting modulates processing of visual information in the visual wulst of chicks

    Directory of Open Access Journals (Sweden)

    Uchimura Motoaki

    2006-11-01

    Full Text Available Abstract Background Imprinting behavior is one form of learning and memory in precocial birds. With the aim of elucidating of the neural basis for visual imprinting, we focused on visual information processing. Results A lesion in the visual wulst, which is similar functionally to the mammalian visual cortex, caused anterograde amnesia in visual imprinting behavior. Since the color of an object was one of the important cues for imprinting, we investigated color information processing in the visual wulst. Intrinsic optical signals from the visual wulst were detected in the early posthatch period and the peak regions of responses to red, green, and blue were spatially organized from the caudal to the nasal regions in dark-reared chicks. This spatial representation of color recognition showed plastic changes, and the response pattern along the antero-posterior axis of the visual wulst altered according to the color the chick was imprinted to. Conclusion These results indicate that the thalamofugal pathway is critical for learning the imprinting stimulus and that the visual wulst shows learning-related plasticity and may relay processed visual information to indicate the color of the imprint stimulus to the memory storage region, e.g., the intermediate medial mesopallium.

  5. 21 CFR 330.3 - Imprinting of solid oral dosage form drug products.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Imprinting of solid oral dosage form drug products... AS SAFE AND EFFECTIVE AND NOT MISBRANDED General Provisions § 330.3 Imprinting of solid oral dosage form drug products. A requirement to imprint an identification code on solid oral dosage form drug...

  6. Imprinting diseases and IVF: Danish National IVF cohort study

    DEFF Research Database (Denmark)

    Lidegaard, Ojvind; Pinborg, Anja; Andersen, Anders Nyboe

    2005-01-01

    The aim of this study was to compare the frequency of imprinting diseases in children born after IVF with the incidence in naturally conceived children.......The aim of this study was to compare the frequency of imprinting diseases in children born after IVF with the incidence in naturally conceived children....

  7. DNA replication: stalling a fork for imprinting and switching

    DEFF Research Database (Denmark)

    Egel, Richard

    2004-01-01

    Mating-type switching in fission yeast has long been known to be directed by a DNA 'imprint'. This imprint has now been firmly characterized as a protected site-specific and strand-specific nick. New work also links the widely conserved Swi1-Swi3 complex to the protection of stalled replication...

  8. ZFP57 maintains the parent-of-origin-specific expression of the imprinted genes and differentially affects non-imprinted targets in mouse embryonic stem cells

    DEFF Research Database (Denmark)

    Riso, Vincenzo; Cammisa, Marco; Kukreja, Harpreet

    2016-01-01

    ZFP57 is necessary for maintaining repressive epigenetic modifications at Imprinting control regions (ICRs). In mouse embryonic stem cells (ESCs), ZFP57 binds ICRs (ICRBS) and many other loci (non-ICRBS). To address the role of ZFP57 on all its target sites, we performed high-throughput and multi......-locus analyses of inbred and hybrid mouse ESC lines carrying different gene knockouts. By using an allele-specific RNA-seq approach, we demonstrate that ZFP57 loss results in derepression of the imprinted allele of multiple genes in the imprinted clusters. We also find marked epigenetic differences between ICRBS...... the imprinted expression over long distances. At non-ICRBS, ZFP57 inactivation results in acquisition of epigenetic features that are characteristic of poised enhancers, suggesting that another function of ZFP57 in early embryogenesis is to repress cis-acting regulatory elements whose activity is not yet...

  9. Identification and resolution of artifacts in the interpretation of imprinted gene expression.

    Science.gov (United States)

    Proudhon, Charlotte; Bourc'his, Déborah

    2010-12-01

    Genomic imprinting refers to genes that are epigenetically programmed in the germline to express exclusively or preferentially one allele in a parent-of-origin manner. Expression-based genome-wide screening for the identification of imprinted genes has failed to uncover a significant number of new imprinted genes, probably because of the high tissue- and developmental-stage specificity of imprinted gene expression. A very large number of technical and biological artifacts can also lead to the erroneous evidence of imprinted gene expression. In this article, we focus on three common sources of potential confounding effects: (i) random monoallelic expression in monoclonal cell populations, (ii) genetically determined monoallelic expression and (iii) contamination or infiltration of embryonic tissues with maternal material. This last situation specifically applies to genes that occur as maternally expressed in the placenta. Beside the use of reciprocal crosses that are instrumental to confirm the parental specificity of expression, we provide additional methods for the detection and elimination of these situations that can be misinterpreted as cases of imprinted expression.

  10. [The lymph nodes imprint for the diagnosis of lymphoid neoplasms].

    Science.gov (United States)

    Peniche-Alvarado, Carolina; Ramos-Peñafiel, Christian Omar; Martínez-Murillo, Carlos; Romero-Guadarrama, Mónica; Olarte-Carrillo, Irma; Rozen-Fuller, Etta; Martínez-Tovar, Adolfo; Collazo-Jaloma, Juan; Mendoza-García, Carlos Alberto

    2013-01-01

    lymphoma is the most frequent lymphoid neoplasm in our country. Its diagnosis is based on histopathological findings. The lymph node imprint has been used for more than 40 years. The aim was to establish the sensitivity, specificity, positive predictive value and negative predictive value of lymph node imprint and estimate the inter-observer rate. we did an observational, retrospective, prolective study, based on the lymph node imprint obtained by excisional biopsies over a period of 6 years. the inclusion criteria was met on 199 samples, 27.1 % were considered as reactive (n = 54), 16.1 % Hodgkin lymphoma (n = 32), 40.2 % (n = 80) non-Hodgkin lymphoma and 16.6 % (n = 33) as metastatic carcinoma. Comparing with the final histopathology report, the sensitivity and specificity of lymph node imprint were 88 % (0.81-0.95) and 64 % (0.55-0.73) respectively, the positive predictive value was 67 % (0.59-0.76) and the negative predictive value was 86 % (0.79-0.94). The interobserver kappa index was 0.467. the lymph node imprint remains as a useful tool for the diagnosis of lymphoid neoplasm. The agreement between observers was acceptable.

  11. Molecularly imprinted solid-phase extraction in the analysis of agrochemicals.

    Science.gov (United States)

    Yi, Ling-Xiao; Fang, Rou; Chen, Guan-Hua

    2013-08-01

    The molecular imprinting technique is a highly predeterminative recognition technology. Molecularly imprinted polymers (MIPs) can be applied to the cleanup and preconcentration of analytes as the selective adsorbent of solid-phase extraction (SPE). In recent years, a new type of SPE has formed, molecularly imprinted polymer solid-phase extraction (MISPE), and has been widely applied to the extraction of agrochemicals. In this review, the mechanism of the molecular imprinting technique and the methodology of MIP preparations are explained. The extraction modes of MISPE, including offline and online, are discussed, and the applications of MISPE in the analysis of agrochemicals such as herbicides, fungicides and insecticides are summarized. It is concluded that MISPE is a powerful tool to selectively isolate agrochemicals from real samples with higher extraction and cleanup efficiency than commercial SPE and that it has great potential for broad applications.

  12. Does genomic imprinting play a role in autoimmunity?

    Science.gov (United States)

    Camprubí, Cristina; Monk, David

    2011-01-01

    In the 19th century Gregor Mendel defined the laws of genetic inheritance by crossing different types of peas. From these results arose his principle of equivalence: the gene will have the same behaviour whether it is inherited from the mother or the father. Today, several key exceptions to this principle are known, for example sex-linked traits and genes in the mitochondrial genome, whose inheritance patterns are referred to as 'non mendelian'. A third, important exception in mammals is that of genomic imprinting, where transcripts are expressed in a monoallelic fashion from only the maternal or the paternal chromosome. In this chapter, we discuss how parent-of-origin effects and genomic imprinting may play a role in autoimmunity and speculate how imprinted miRNAs may influence the expression of many target autoimmune associated genes.

  13. Characterization of molecularly imprinted polymers using a new polar solvent titration method.

    Science.gov (United States)

    Song, Di; Zhang, Yagang; Geer, Michael F; Shimizu, Ken D

    2014-07-01

    A new method of characterizing molecularly imprinted polymers (MIPs) was developed and tested, which provides a more accurate means of identifying and measuring the molecular imprinting effect. In the new polar solvent titration method, a series of imprinted and non-imprinted polymers were prepared in solutions containing increasing concentrations of a polar solvent. The polar solvent additives systematically disrupted the templation and monomer aggregation processes in the prepolymerization solutions, and the extent of disruption was captured by the polymerization process. The changes in binding capacity within each series of polymers were measured, providing a quantitative assessment of the templation and monomer aggregation processes in the imprinted and non-imprinted polymers. The new method was tested using three different diphenyl phosphate imprinted polymers made using three different urea functional monomers. Each monomer had varying efficiencies of templation and monomer aggregation. The new MIP characterization method was found to have several advantages. To independently verify the new characterization method, the MIPs were also characterized using traditional binding isotherm analyses. The two methods appeared to give consistent conclusions. First, the polar solvent titration method is less susceptible to false positives in identifying the imprinting effect. Second, the method is able to differentiate and quantify changes in binding capacity, as measured at a fixed guest and polymer concentration, arising from templation or monomer aggregation processes in the prepolymerization solution. Third, the method was also easy to carry out, taking advantage of the ease of preparing MIPs. Copyright © 2014 John Wiley & Sons, Ltd.

  14. Molecularly imprinted electrochemical sensor based on nickel nanoparticle-modified electrodes for phenobarbital determination

    International Nuclear Information System (INIS)

    Yu, Hui Cheng; Huang, Xue Yi; Lei, Fu Hou; Tan, Xue Cai; Wei, Yi Chun; Li, Hao

    2014-01-01

    Highlights: • Uniform Ni nanoparticles were synthesized. • A Ni nanoparticle-modified imprinted sensor was developed to detect phenobarbital. • The modified sensor exhibited high sensitivity for phenobarbital. • The electrochemical properties of the modified sensor were investigated. • The prepared sensor was applied to detect phenobarbital in fish samples. - Abstract: Uniform nickel nanoparticles were applied to improve the sensitivity of sensors for phenobarbital (PB) determination. A Ni nanoparticle-modified imprinted electrochemical sensor was developed by thermal polymerization with the use of methacrylic acid as the functional monomer and ethylene glycol maleic rosinate acrylate as the crosslinking agent. The chemical structures and morphologies of the imprinted films were characterized using Fourier transform infrared spectroscopy and scanning electron microscopy. The success of the fabrication of Ni nanoparticles, as well as the Ni nanoparticle-modified imprinted electrochemical sensor, was confirmed by the analytical results. The electrochemical properties of the modified molecularly imprinted and non-imprinted polymer sensors were investigated by cyclic voltammetry, differential pulse voltammetry, electrochemical impedance spectroscopy, and chronoamperometry. Results showed that the electrochemical properties of the molecularly imprinted sensor were remarkably different from those of the non-imprinted sensor. Linear responses of the imprinted sensor to PB were observed for concentrations ranging from 1.4 × 10 −7 mol L −1 to 1.3 × 10 −4 mol L −1 (r 2 = 0.9976), with a detection limit of 8.2 × 10 −9 mol L −1 (S/N = 3). The imprinted electrochemical sensor was used to determine PB in actual fish samples, in which average recoveries between 95.60% and 104.67% were achieved. The developed Ni nanoparticle-modified electrochemical sensor exhibited high sensitivity, high selectivity, and good recovery

  15. MOLECULARLY IMPRINTED SOLID PHASE EXTRACTION FOR TRACE ANALYSIS OF DIAZINON IN DRINKING WATER

    Directory of Open Access Journals (Sweden)

    M. Rahiminejad ، S. J. Shahtaheri ، M. R. Ganjali ، A. Rahimi Forushani ، F. Golbabaei

    2009-04-01

    Full Text Available Amongst organophosphate pesticides, the one most widely used and common environmental contaminant is diazinon; thus methods for its trace analysis in environmental samples must be developed. Use of diazinon imprinted polymers such as sorbents in solid phase extraction, is a prominent and novel application area of molecular imprinted polymers. For diazinon extraction, high performance liquid chromatography analysis was demonstrated in this study. During optimization of the molecular imprinted solid phase extraction procedure for efficient solid phase extraction of diazinon, Plackett-Burman design was conducted. Eight experimental factors with critical influence on molecular imprinted solid phase extraction performance were selected, and 12 different experimental runs based on Plackett-Burman design were carried out. The applicability of diazinon imprinted polymers as the sorbent in solid phase extraction, presented obtained good recoveries of diazinon from LC-grade water. An increase in pH caused an increase in the recovery on molecular imprinted solid phase extraction. From these results, the optimal molecular imprinted solid phase extraction procedure was as follows: solid phase extraction packing with 100 mg diazinon imprinted polymers; conditioning with 5 mL of methanol and 6 mL of LC-grade water; sample loading containing diazinon (pH=10; washing with 1 mL of LC-grade water, 1 mL LC- grade water containing 30% acetonitrile and 0.5 mL of acetonitrile, respectively; eluting with 1 mL of methanol containing 2% acetic acid. The percentage recoveries obtained by the optimized molecular imprinted solid phase extraction were more than 90% with drinking water spiked at different trace levels of diazinon. Generally speaking, the molecular imprinted solid phase extraction procedure and subsequent high performance liquid chromatography analysis can be a relatively fast and proper approach for qualitative and quantitative analysis of diazinon in

  16. Self-oriented nanoparticles for site-selective immunoglobulin G recognition via epitope imprinting approach.

    Science.gov (United States)

    Çorman, Mehmet Emin; Armutcu, Canan; Uzun, Lokman; Say, Rıdvan; Denizli, Adil

    2014-11-01

    Molecular imprinting is a polymerization technique that provides synthetic analogs for template molecules. Molecularly imprinted polymers (MIPs) have gained much attention due to their unique properties such as selectivity and specificity for target molecules. In this study, we focused on the development of polymeric materials with molecular recognition ability, so molecular imprinting was combined with miniemulsion polymerization to synthesize self-orienting nanoparticles through the use of an epitope imprinting approach. Thus, L-lysine imprinted nanoparticles (LMIP) were synthesized via miniemulsion polymerization technique. Immunoglobulin G (IgG) was then bound to the cavities that specifically formed for L-lysine molecules that are typically found at the C-terminus of the Fc region of antibody molecules. The resulting nanoparticles makes it possible to minimize the nonspecific interaction between monomer and template molecules. In addition, the orientation of the entire IgG molecule was controlled, and random imprinting of the IgG was prevented. The optimum conditions were determined for IgG recognition using the imprinted nanoparticles. The selectivity of the nanoparticles against IgG molecules was also evaluated using albumin and hemoglobin as competitor molecules. In order to show the self-orientation capability of imprinted nanoparticles, human serum albumin (HSA) adsorption onto both the plain nanoparticles and immobilized nanoparticles by anti-human serum albumin antibody (anti-HSA antibody) was also carried out. Due to anti-HSA antibody immobilization on the imprinted nanoparticles, the adsorption capability of nanoparticles against HSA molecules vigorously enhanced. It is proved that the oriented immobilization of antibodies was appropriately succeeded. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Fabrication of Surface Protein-Imprinted Nanoparticles Using a Metal Chelating Monomer via Aqueous Precipitation Polymerization.

    Science.gov (United States)

    Li, Wei; Sun, Yan; Yang, Chongchong; Yan, Xianming; Guo, Hao; Fu, Guoqi

    2015-12-16

    Molecular imprinting is a promising way for constructing artificial protein recognition materials, but it has been challenged by difficulties such as restricted biomacromolecule transfer in the cross-linked polymer networks, and reduced template-monomer interactions that are due to the required aqueous media. Herein, we propose a strategy for imprinting of histidine (His)-exposed proteins by combining previous approaches such as surface imprinting over nanostructures, utilization of metal coordination interactions, and adoption of aqueous precipitation polymerization capable of forming reversible physical crosslinks. With lysozyme as a model template bearing His residues, imprinted polymer nanoshells were grafted over vinyl-modified nanoparticles by aqueous precipitation copolymerization of a Cu(2+) chelating monomer with a temperature-responsive monomer carried out at 37 °C, above the volume phase-transition temperature (VPTT) of the final copolymer. The imprinted nanoshells showed significant temperature sensitivity and the template removal could be facilitated by swelling of the imprinted layers at 4 °C, below the VPTT. The resultant core-shell imprinted nanoparticles exhibited strikingly high rebinding selectivity against a variety of nontemplate proteins. An imprinting factor up to 22.7 was achieved, which is among the best values reported for protein imprinting, and a rather high specific binding capacity of 67.3 mg/g was obtained. Moreover, this approach was successfully extended to preliminary imprinting of hemoglobin, another protein with accessible His. Therefore, it may be a versatile method for fabrication of high-performance surface-imprinted nanoparticles toward His-exposed proteins.

  18. Preparation and Property Recognition of Nimodipine Molecularly Imprinted Polymer

    Directory of Open Access Journals (Sweden)

    Fei-fei CHEN

    2015-09-01

    Full Text Available Objective: To explore the application of molecular imprinting technique in the separation and detection of nimodipine. Methods: Methacrylic acid as functional monomer, pentaerythritol triacrylate as cross-linking agent were used to prepare molecularly imprinted polymer (MIP with the feature of specific recognition performance on imprinting molecule nimodipine under condition of template molecule nimodipine. The preparation conditions, recognition performance of MIP on nimodipine, different proportions of template molecule and functional monomer, the selectivity to other substrate, and the relationship between adsorption quantity (Q and time were observed. Results: MIP was prepared successfully bynimodipine as template and pentaerythritol triacrylate as cross-linking agent, with the feature of specific recognition performance on nimodipine. The static adsorption distribution coefficient (KD was 0.2264. The equation of Q and the concentration of substrate of template MIP was y = -0.21x+0.2204. Combining capacity of template molecule at the same concentration enhanced with the increasing proportion of functional monomer.Conclusion: Nimodipine MIP based on molecular imprinting technique may become a new approach to chiral separation for nimodipine.

  19. Kainic Acid-Induced Post-Status Epilepticus Models of Temporal Lobe Epilepsy with Diverging Seizure Phenotype and Neuropathology

    Directory of Open Access Journals (Sweden)

    Daniele Bertoglio

    2017-11-01

    Full Text Available The aim of epilepsy models is to investigate disease ontogenesis and therapeutic interventions in a consistent and prospective manner. The kainic acid-induced status epilepticus (KASE rat model is a widely used, well-validated model for temporal lobe epilepsy (TLE. As we noted significant variability within the model between labs potentially related to the rat strain used, we aimed to describe two variants of this model with diverging seizure phenotype and neuropathology. In addition, we evaluated two different protocols to induce status epilepticus (SE. Wistar Han (Charles River, France and Sprague-Dawley (Harlan, The Netherlands rats were subjected to KASE using the Hellier kainic acid (KA and a modified injection scheme. Duration of SE and latent phase were characterized by video-electroencephalography (vEEG in a subgroup of animals, while animals were sacrificed 1 week (subacute phase and 12 weeks (chronic phase post-SE. In the 12 weeks post-SE groups, seizures were monitored with vEEG. Neuronal loss (neuronal nuclei, microglial activation (OX-42 and translocator protein, and neurodegeneration (Fluorojade C were assessed. First, the Hellier protocol caused very high mortality in WH/CR rats compared to SD/H animals. The modified protocol resulted in a similar SE severity for WH/CR and SD/H rats, but effectively improved survival rates. The latent phase was significantly shorter (p < 0.0001 in SD/H (median 8.3 days animals compared to WH/CR (median 15.4 days. During the chronic phase, SD/H rats had more seizures/day compared to WH/CR animals (p < 0.01. However, neuronal degeneration and cell loss were overall more extensive in WH/CR than in SD/H rats; microglia activation was similar between the two strains 1 week post-SE, but higher in WH/CR rats 12 weeks post-SE. These neuropathological differences may be more related to the distinct neurotoxic effects of KA in the two rat strains than being the outcome of seizure

  20. Kainic Acid-Induced Post-Status Epilepticus Models of Temporal Lobe Epilepsy with Diverging Seizure Phenotype and Neuropathology

    Science.gov (United States)

    Bertoglio, Daniele; Amhaoul, Halima; Van Eetveldt, Annemie; Houbrechts, Ruben; Van De Vijver, Sebastiaan; Ali, Idrish; Dedeurwaerdere, Stefanie

    2017-01-01

    The aim of epilepsy models is to investigate disease ontogenesis and therapeutic interventions in a consistent and prospective manner. The kainic acid-induced status epilepticus (KASE) rat model is a widely used, well-validated model for temporal lobe epilepsy (TLE). As we noted significant variability within the model between labs potentially related to the rat strain used, we aimed to describe two variants of this model with diverging seizure phenotype and neuropathology. In addition, we evaluated two different protocols to induce status epilepticus (SE). Wistar Han (Charles River, France) and Sprague-Dawley (Harlan, The Netherlands) rats were subjected to KASE using the Hellier kainic acid (KA) and a modified injection scheme. Duration of SE and latent phase were characterized by video-electroencephalography (vEEG) in a subgroup of animals, while animals were sacrificed 1 week (subacute phase) and 12 weeks (chronic phase) post-SE. In the 12 weeks post-SE groups, seizures were monitored with vEEG. Neuronal loss (neuronal nuclei), microglial activation (OX-42 and translocator protein), and neurodegeneration (Fluorojade C) were assessed. First, the Hellier protocol caused very high mortality in WH/CR rats compared to SD/H animals. The modified protocol resulted in a similar SE severity for WH/CR and SD/H rats, but effectively improved survival rates. The latent phase was significantly shorter (p < 0.0001) in SD/H (median 8.3 days) animals compared to WH/CR (median 15.4 days). During the chronic phase, SD/H rats had more seizures/day compared to WH/CR animals (p < 0.01). However, neuronal degeneration and cell loss were overall more extensive in WH/CR than in SD/H rats; microglia activation was similar between the two strains 1 week post-SE, but higher in WH/CR rats 12 weeks post-SE. These neuropathological differences may be more related to the distinct neurotoxic effects of KA in the two rat strains than being the outcome of seizure burden

  1. Recognition of lysozyme using surface imprinted bacterial cellulose nanofibers.

    Science.gov (United States)

    Saylan, Yeşeren; Tamahkar, Emel; Denizli, Adil

    2017-11-01

    Here, we developed the lysozyme imprinted bacterial cellulose (Lyz-MIP/BC) nanofibers via the surface imprinting strategy that was designed to recognize lysozyme. This study includes the molecular imprinting method onto the surface of bacterial cellulose nanofibers in the presence of lysozyme by metal ion coordination, as well as further characterizations methods FTIR, SEM and contact angle measurements. The maximum lysozyme adsorption capacity of Lyz-MIP/BC nanofibers was found to be 71 mg/g. The Lyz-MIP/BC nanofibers showed high selectivity for lysozyme towards bovine serum albumin and cytochrome c. Overall, the Lyz-MIP/BC nanofibers hold great potential for lysozyme recognition due to the high binding capacity, significant selectivity and excellent reusability.

  2. Planar self-aligned imprint lithography for coplanar plasmonic nanostructures fabrication

    KAUST Repository

    Wan, Weiwei

    2014-03-01

    Nanoimprint lithography (NIL) is a cost-efficient nanopatterning technology because of its promising advantages of high throughput and high resolution. However, accurate multilevel overlay capability of NIL required for integrated circuit manufacturing remains a challenge due to the high cost of achieving mechanical alignment precision. Although self-aligned imprint lithography was developed to avoid the need of alignment for the vertical layered structures, it has limited usage in the manufacture of the coplanar structures, such as integrated plasmonic devices. In this paper, we develop a new process of planar self-alignment imprint lithography (P-SAIL) to fabricate the metallic and dielectric structures on the same plane. P-SAIL transfers the multilevel imprint processes to a single-imprint process which offers higher efficiency and less cost than existing manufacturing methods. Such concept is demonstrated in an example of fabricating planar plasmonic structures consisting of different materials. © 2014 Springer-Verlag Berlin Heidelberg.

  3. Predicting the performance of molecularly imprinted polymers: Selective extraction of caffeine by molecularly imprinted solid phase extraction

    Energy Technology Data Exchange (ETDEWEB)

    Farrington, Keith [School of Chemical Sciences, Dublin City University, Glasnevin, Dublin 9 (Ireland); Magner, Edmond [Materials and Surface Science Institute, Chemical and Environmental Sciences Department, University of Limerick, Limerick (Ireland); Regan, Fiona [School of Chemical Sciences, Dublin City University, Glasnevin, Dublin 9 (Ireland)]. E-mail: fiona.regan@dcu.ie

    2006-04-27

    A rational design approach was taken to the planning and synthesis of a molecularly imprinted polymer capable of extracting caffeine (the template molecule) from a standard solution of caffeine and further from a food sample containing caffeine. Data from NMR titration experiments in conjunction with a molecular modelling approach was used in predicting the relative ratios of template to functional monomer and furthermore determined both the choice of solvent (porogen) and the amount used for the study. In addition the molecular modelling program yielded information regarding the thermodynamic stability of the pre-polymerisation complex. Post-polymerisation analysis of the polymer itself by analysis of the pore size distribution by BET yielded significant information regarding the nature of the size and distribution of the pores within the polymer matrix. Here is proposed a stepwise procedure for the development and testing of a molecularly imprinted polymer using a well-studied compound-caffeine as a model system. It is shown that both the physical characteristics of a molecularly imprinted polymer (MIP) and the analysis of the pre-polymerisation complex can yield vital information, which can predict how well a given MIP will perform.

  4. Predicting the performance of molecularly imprinted polymers: Selective extraction of caffeine by molecularly imprinted solid phase extraction

    International Nuclear Information System (INIS)

    Farrington, Keith; Magner, Edmond; Regan, Fiona

    2006-01-01

    A rational design approach was taken to the planning and synthesis of a molecularly imprinted polymer capable of extracting caffeine (the template molecule) from a standard solution of caffeine and further from a food sample containing caffeine. Data from NMR titration experiments in conjunction with a molecular modelling approach was used in predicting the relative ratios of template to functional monomer and furthermore determined both the choice of solvent (porogen) and the amount used for the study. In addition the molecular modelling program yielded information regarding the thermodynamic stability of the pre-polymerisation complex. Post-polymerisation analysis of the polymer itself by analysis of the pore size distribution by BET yielded significant information regarding the nature of the size and distribution of the pores within the polymer matrix. Here is proposed a stepwise procedure for the development and testing of a molecularly imprinted polymer using a well-studied compound-caffeine as a model system. It is shown that both the physical characteristics of a molecularly imprinted polymer (MIP) and the analysis of the pre-polymerisation complex can yield vital information, which can predict how well a given MIP will perform

  5. Inspection of imprint lithography patterns for semiconductor and patterned media

    Science.gov (United States)

    Resnick, Douglas J.; Haase, Gaddi; Singh, Lovejeet; Curran, David; Schmid, Gerard M.; Luo, Kang; Brooks, Cindy; Selinidis, Kosta; Fretwell, John; Sreenivasan, S. V.

    2010-03-01

    Imprint lithography has been shown to be an effective technique for replication of nano-scale features. Acceptance of imprint lithography for manufacturing will require demonstration that it can attain defect levels commensurate with the requirements of cost-effective device production. This work summarizes the results of defect inspections of semiconductor masks, wafers and hard disks patterned using Jet and Flash Imprint Lithography (J-FILTM). Inspections were performed with optical and e-beam based automated inspection tools. For the semiconductor market, a test mask was designed which included dense features (with half pitches ranging between 32 nm and 48 nm) containing an extensive array of programmed defects. For this work, both e-beam inspection and optical inspection were used to detect both random defects and the programmed defects. Analytical SEMs were then used to review the defects detected by the inspection. Defect trends over the course of many wafers were observed with another test mask using a KLA-T 2132 optical inspection tool. The primary source of defects over 2000 imprints were particle related. For the hard drive market, it is important to understand the defectivity of both the template and the imprinted disk. This work presents a methodology for automated pattern inspection and defect classification for imprint-patterned media. Candela CS20 and 6120 tools from KLA-Tencor map the optical properties of the disk surface, producing highresolution grayscale images of surface reflectivity, scattered light, phase shift, etc. Defects that have been identified in this manner are further characterized according to the morphology

  6. Surface imprinting on nano-TiO{sub 2} as sacrificial material for the preparation of hollow chlorogenic acid imprinted polymer and its recognition behavior

    Energy Technology Data Exchange (ETDEWEB)

    Li Hui, E-mail: lihuijsdx@163.com [College of Chemistry and Chemical Engineering, Jishou University, Hunan 416000, Jishou (China); Key Laboratory of Plant Resource Conservation and Utilization, Jishou University, Hunan 416000, Jishou (China); Li Gui [Key Laboratory of Plant Resource Conservation and Utilization, Jishou University, Hunan 416000, Jishou (China); Li Zhiping; Lu Cuimei; Li Yanan [College of Chemistry and Chemical Engineering, Jishou University, Hunan 416000, Jishou (China); Tan Xianzhou [Key Laboratory of Plant Resource Conservation and Utilization, Jishou University, Hunan 416000, Jishou (China)

    2013-01-01

    Highlights: Black-Right-Pointing-Pointer Used surface imprinting technique with nano-TiO{sub 2} as sacrificial support material. Black-Right-Pointing-Pointer Improved adsorption capability of the H-MIP1 compared with the previous work. Black-Right-Pointing-Pointer Excellent mass transfer dynamics for the H-MIP1. Black-Right-Pointing-Pointer Investigated adsorption thermodynamic of the H-MIP1. - Abstract: Surface imprinting chlorogenic acid (CGA) on nano-TiO{sub 2} particles as sacrificial support material was successfully performed by using 4-vinylpyridine (4-VP) as functional monomer to obtain a hollow CGA-imprinted polymer (H-MIP1). Fourier transmission infrared spectrometry (FTIR) and scanning electron microscopy (SEM) were utilized for structurally characterizing the polymers obtained and adsorption dynamics and thermodynamic behavior investigated according to different models. Binding selectivity, adsorption capacity and the reusability for this H-MIP1 were also evaluated. This hollow CGA imprinted polymer shows rapid binding dynamics and higher binding capability toward the template molecules. The pseudo first-order kinetic model was shown best to describe the binding process of CGA on the H-MIP1 and Langmuir isotherm model best to fit the experimental adsorption isotherm data. Through adsorption isotherms at different temperatures, thermodynamic parameter values were obtained. Selectivity coefficients for the H-MIP1 toward the template were 2.209, 3.213, 1.746 and 2.353 relative to CA, VA, PCA and GA, respectively. This H-MIP1 was also indicated with a good imprint effect and a high capability to capture CGA from methanol extract of Eucommia ulmoides (E. ulmoides) leaves. Additionally, a good reusability for this imprinted polymer was exhibited during repeated adsorption-desorption use.

  7. Synthesis and characterization of oxytetracycline imprinted magnetic polymer for application in food

    Science.gov (United States)

    Aggarwal, Sneha; Rajput, Yudhishthir Singh; Singh, Gulab; Sharma, Rajan

    2016-02-01

    Magnetic imprinted polymer was prepared by polymerization of methacrylate and ethyleneglycoldimethacrylate in the presence of oxytetracycline on the surface of iron magnetite. Selectivity of prepared polymer was calculated from ratio of partition coefficient of oxytetracycline for imprinted and non- imprinted polymer in water, acetonitrile, methanol and at different pH in aqueous buffer. pH of solvent exhibited pronounced effect on selectivity. Selectivity at pH 7.0, 6.0 and 5.0 was 36.0, 2.25 and 1.61 fold higher than at pH 4.0. Imprinted polymer was not selective for oxytetracycline in methanol. However, selectivity in water and acetonitrile was 19.42 and 2.86, respectively. Oxytetracycline did bind to imprinted polymer in water or aqueous buffer (pH 7.0) and could be eluted with methanol. Prepared polymer extracted 75-80 % oxytetracycline from water, honey and egg white.

  8. Characterization of Conserved and Non-conserved Imprinted Genes in Swine

    Science.gov (United States)

    In order to increase our understanding of the role of imprinted genes in swine reproduction we used two complementary approaches, analysis of imprinting by pyrosequencing, and expression profiling of parthenogenetic fetuses, to carry out a comprehensive analysis of this gene family in swine. Using A...

  9. Determination of stamp deformation during imprinting on semi-spherical surfaces

    DEFF Research Database (Denmark)

    Kafka, Jan; Matschuk, Maria; Pranov, Henrik

    of sol-gel was applied onto spherical injection mold inserts and subsequently imprinted using a flexible stamp. A hard curing step transformed the sol-gel into a quartz-like and durable material. As an example, we present theory and results regarding the imprint of pillar nanostructures on semi......-spherical mold surfaces. Imprints were realized on three different radii of circumferenceof the spherical mold: R = 0.5 mm, R = 1.0 mm, and R = 2 mm. After hard-curing of theimprinted sol-gel, the inserts were used for cold-mold as well as vario-therm injection molding.The polymer replicas and the inserts were...

  10. Cultural relativism: maintenance of genomic imprints in pluripotent stem cell culture systems.

    Science.gov (United States)

    Greenberg, Maxim Vc; Bourc'his, Déborah

    2015-04-01

    Pluripotent stem cells (PSCs) in culture have become a widely used model for studying events occurring during mammalian development; they also present an exciting avenue for therapeutics. However, compared to their in vivo counterparts, cultured PSC derivatives have unique properties, and it is well established that their epigenome is sensitive to medium composition. Here we review the specific effects on genomic imprints in various PSC types and culture systems. Imprinted gene regulation is developmentally important, and imprinting defects have been associated with several human diseases. Therefore, imprint abnormalities in PSCs may have considerable consequences for downstream applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Innovative Design and Performance Evaluation of Bionic Imprinting Toothed Wheel.

    Science.gov (United States)

    Zhang, Zhihong; Wang, Xiaoyang; Tong, Jin; Stephen, Carr

    2018-01-01

    A highly efficient soil-burrowing dung beetle possesses an intricate outer contour curve on its foreleg end-tooth. This study was carried out based on evidence that this special outer contour curve has the potential of reducing soil penetration resistance and could enhance soil-burrowing efficiency. A toothed wheel is a typical agricultural implement for soil imprinting, to increase its working efficiency; the approach of the bionic geometrical structure was utilized to optimize the innovative shape of imprinting toothed wheel. Characteristics in the dung beetle's foreleg end-tooth were extracted and studied by the edge detection technique. Then, this special outer contour curve was modeled by a nine-order polynomial function and used for the innovative design of imprinting the tooth's cutting edge. Both the conventional and bionic teeth were manufactured, and traction tests in a soil bin were conducted. Taking required draft force and volume of imprinted microbasin as the evaluating indexes, operating efficiency and quality of different toothed wheels were compared and investigated. Results indicate that compared with the conventional toothed wheel, a bionic toothed wheel possesses a better forward resistance reduction property against soil and, meanwhile, can enhance the quality of soil imprinting by increasing the volume of the created micro-basin.

  12. Molecular imprinting at walls of silica nanotubes for TNT recognition.

    Science.gov (United States)

    Xie, Chenggen; Liu, Bianhua; Wang, Zhenyang; Gao, Daming; Guan, Guijian; Zhang, Zhongping

    2008-01-15

    This paper reports the molecular imprinting at the walls of highly uniform silica nanotubes for the recognition of 2,4,6-trinitrotoluene (TNT). It has been demonstrated that TNT templates were efficiently imprinted into the matrix of silica through the strong acid-base pairing interaction between TNT and 3-aminopropyltriethoxysilane (APTS). TNT-imprinted silica nanotubes were synthesized by the gelation reaction between APTS and tetraethylorthosilicate (TEOS), selectively occurring at the porous walls of APTS-modified alumina membranes. The removal of the original TNT templates leaves the imprinted cavities with covalently anchored amine groups at the cavity walls. A high density of recognition sites with molecular selectivity to the TNT analyte was created at the wall of silica nanotubes. Furthermore, most of these recognition sites are situated at the inside and outside surfaces of tubular walls and in the proximity of the two surfaces due to the ultrathin wall thickness of only 15 nm, providing a better site accessibility and lower mass-transfer resistance. Therefore, greater capacity and faster kinetics of uptaking target species were achieved. The silica nanotube reported herein is an ideal form of material for imprinting various organic or biological molecules toward applications in chemical/biological sensors and bioassay.

  13. A Molecularly Imprinted Polymer (MIP)-Coated Microbeam MEMS Sensor for Chemical Detection

    Science.gov (United States)

    2015-09-01

    ARL-RP-0536 ● SEP 2015 US Army Research Laboratory A Molecularly Imprinted Polymer (MIP)- Coated Microbeam MEMS Sensor for...ARL-RP-0536 ● SEP 2015 US Army Research Laboratory A Molecularly Imprinted Polymer (MIP)- Coated Microbeam MEMS Sensor for Chemical...TITLE AND SUBTITLE A Molecularly Imprinted Polymer (MIP)-Coated Microbeam MEMS Sensor for Chemical Detection 5a. CONTRACT NUMBER 5b. GRANT NUMBER

  14. Magnetic-graphene based molecularly imprinted polymer nanocomposite for the recognition of bovine hemoglobin.

    Science.gov (United States)

    Guo, Junxia; Wang, Yuzhi; Liu, Yanjin; Zhang, Cenjin; Zhou, Yigang

    2015-11-01

    The protein imprinted technique combining surface imprinting and nanomaterials has been an attractive strategy for recognition and rapid separation of proteins. In this work, magnetic-graphene (MG) was chosen as the supporting substrate for the magnetic nanomaterials, which served to absorb the targeting imprinting molecules, bovine hemoglobin (BHb). Acryl amide (AAm) with a high affinity to BHb and N,N'- methylenebisacrylamide (MBA) were selected as the functional monomer and cross-linking agent, respectively. After in-situ polymerization, the proposed magnetic-graphene based molecularly imprinted polymer (MG-MIP) was obtained with a further extraction step of imprinted BHb. Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), raman spectroscopy(RS), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) were employed to characterize the resulted MG-MIP. The maximum adsorption capability (Qmax) was determined by Langmuir Isotherm Plots and was 186.73 mg/g for imprinted nanomaterials (MIP) with an imprinting factor of 1.96. The selectivity of MG-MIP was investigated by using several proteins that are different in molecular mass and isoelectric points as the reference. The results showed that the shape memory effect of imprinted cavities, the size of proteins and the charge effect of proteins were the major factors for the selective recognition. The proposed method was also employed to specifically capture BHb from a binary protein mixture. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Biological imprinting: Some genetic considerations

    African Journals Online (AJOL)

    Mohammad Saad Zaghloul Salem

    2014-06-21

    Jun 21, 2014 ... Role of chromatin in imprinting . .... flict theory in placental mammals assumes that paternal alleles in pregnancy ... The theory also postulates that maternal alleles, on ..... postulating contributory roles of mitDNA in mediation of.

  16. Angular dependence of imprinting levels in laser-target interactions on planar CH foils

    International Nuclear Information System (INIS)

    Smalyuk, V.A.; Goncharov, V.N.; Boehly, T.R.; Delettrez, J.A.; Li, D.Y.; Marozas, J.A.; Meyerhofer, D.D.; Regan, S.P.; Sangster, T.C.

    2005-01-01

    Imprinting of laser-beam modulations at various angles of incidence is measured for the first time in planar CH foils. The imprinted target modulations were seeded by special probe beams at a spatial wavelength of 60 μm and subsequently amplified by five drive beams. The measured imprint efficiency decreases by a factor of 3 as the angle of incidence of the probe beam is increased from 20 deg. to 60 deg., as predicted by theoretical modeling. The imprinting is very sensitive to the relative arrival time of the probe and drive beams

  17. Optimal synthesis of a Ni(II)-dimethylglyoxime ion-imprinted polymer ...

    African Journals Online (AJOL)

    A Ni(II)-dimethylglyoxime ion-imprinted polymer {Ni(II)-DMG IIP} was optimised by the uniform design experimental ... The bonds formed between the template and the functional monomers in ion- imprinted polymerisation reactions are weaker, non-covalent. (Arshady and Mosbach, 1981; ..... where the polymer did not form.

  18. Thermometric sensing of nitrofurantoin by noncovalently imprinted polymers containing two complementary functional monomers.

    Science.gov (United States)

    Athikomrattanakul, Umporn; Gajovic-Eichelmann, Nenad; Scheller, Frieder W

    2011-10-15

    Molecularly imprinted polymers (MIPs) for nitrofurantoin (NFT) recognition addressing in parallel of two complementary functional groups were created using a noncovalent imprinting approach. Specific tailor-made functional monomers were synthesized: a diaminopyridine derivative as the receptor for the imide residue and three (thio)urea derivatives for the interaction with the nitro group of NFT. A significantly improved binding of NFT to the new MIPs was revealed from the imprinting factor, efficiency of binding, affinity constants and maximum binding number as compared to previously reported MIPs, which addressed either the imide or the nitro residue. Substances possessing only one functionality (either the imide group or nitro group) showed significantly weaker binding to the new imprinted polymers than NFT. However, the compounds lacking both functionalities binds extremely weak to all imprinted polymers. The new imprinted polymers were applied in a flow-through thermistor in organic solvent for the first time. The MIP-thermistor allows the detection of NFT down to a concentration of 5 μM in acetonitrile + 0.2% dimethyl sulfoxide (DMSO). The imprinting factor of 3.91 at 0.1 mM of NFT as obtained by thermistor measurements is well comparable to the value obtained by batch binding experiments. © 2011 American Chemical Society

  19. The parental non-equivalence of imprinting control regions during mammalian development and evolution.

    Directory of Open Access Journals (Sweden)

    Reiner Schulz

    2010-11-01

    Full Text Available In mammals, imprinted gene expression results from the sex-specific methylation of imprinted control regions (ICRs in the parental germlines. Imprinting is linked to therian reproduction, that is, the placenta and imprinting emerged at roughly the same time and potentially co-evolved. We assessed the transcriptome-wide and ontology effect of maternally versus paternally methylated ICRs at the developmental stage of setting of the chorioallantoic placenta in the mouse (8.5dpc, using two models of imprinting deficiency including completely imprint-free embryos. Paternal and maternal imprints have a similar quantitative impact on the embryonic transcriptome. However, transcriptional effects of maternal ICRs are qualitatively focused on the fetal-maternal interface, while paternal ICRs weakly affect non-convergent biological processes, with little consequence for viability at 8.5dpc. Moreover, genes regulated by maternal ICRs indirectly influence genes regulated by paternal ICRs, while the reverse is not observed. The functional dominance of maternal imprints over early embryonic development is potentially linked to selection pressures favoring methylation-dependent control of maternal over paternal ICRs. We previously hypothesized that the different methylation histories of ICRs in the maternal versus the paternal germlines may have put paternal ICRs under higher mutational pressure to lose CpGs by deamination. Using comparative genomics of 17 extant mammalian species, we show here that, while ICRs in general have been constrained to maintain more CpGs than non-imprinted sequences, the rate of CpG loss at paternal ICRs has indeed been higher than at maternal ICRs during evolution. In fact, maternal ICRs, which have the characteristics of CpG-rich promoters, have gained CpGs compared to non-imprinted CpG-rich promoters. Thus, the numerical and, during early embryonic development, functional dominance of maternal ICRs can be explained as the

  20. The parental non-equivalence of imprinting control regions during mammalian development and evolution.

    Science.gov (United States)

    Schulz, Reiner; Proudhon, Charlotte; Bestor, Timothy H; Woodfine, Kathryn; Lin, Chyuan-Sheng; Lin, Shau-Ping; Prissette, Marine; Oakey, Rebecca J; Bourc'his, Déborah

    2010-11-18

    In mammals, imprinted gene expression results from the sex-specific methylation of imprinted control regions (ICRs) in the parental germlines. Imprinting is linked to therian reproduction, that is, the placenta and imprinting emerged at roughly the same time and potentially co-evolved. We assessed the transcriptome-wide and ontology effect of maternally versus paternally methylated ICRs at the developmental stage of setting of the chorioallantoic placenta in the mouse (8.5dpc), using two models of imprinting deficiency including completely imprint-free embryos. Paternal and maternal imprints have a similar quantitative impact on the embryonic transcriptome. However, transcriptional effects of maternal ICRs are qualitatively focused on the fetal-maternal interface, while paternal ICRs weakly affect non-convergent biological processes, with little consequence for viability at 8.5dpc. Moreover, genes regulated by maternal ICRs indirectly influence genes regulated by paternal ICRs, while the reverse is not observed. The functional dominance of maternal imprints over early embryonic development is potentially linked to selection pressures favoring methylation-dependent control of maternal over paternal ICRs. We previously hypothesized that the different methylation histories of ICRs in the maternal versus the paternal germlines may have put paternal ICRs under higher mutational pressure to lose CpGs by deamination. Using comparative genomics of 17 extant mammalian species, we show here that, while ICRs in general have been constrained to maintain more CpGs than non-imprinted sequences, the rate of CpG loss at paternal ICRs has indeed been higher than at maternal ICRs during evolution. In fact, maternal ICRs, which have the characteristics of CpG-rich promoters, have gained CpGs compared to non-imprinted CpG-rich promoters. Thus, the numerical and, during early embryonic development, functional dominance of maternal ICRs can be explained as the consequence of two

  1. Capacitive Biosensors and Molecularly Imprinted Electrodes.

    Science.gov (United States)

    Ertürk, Gizem; Mattiasson, Bo

    2017-02-17

    Capacitive biosensors belong to the group of affinity biosensors that operate by registering direct binding between the sensor surface and the target molecule. This type of biosensors measures the changes in dielectric properties and/or thickness of the dielectric layer at the electrolyte/electrode interface. Capacitive biosensors have so far been successfully used for detection of proteins, nucleotides, heavy metals, saccharides, small organic molecules and microbial cells. In recent years, the microcontact imprinting method has been used to create very sensitive and selective biorecognition cavities on surfaces of capacitive electrodes. This chapter summarizes the principle and different applications of capacitive biosensors with an emphasis on microcontact imprinting method with its recent capacitive biosensor applications.

  2. Stop grating for perfect replication of micro Fresnel lens by thermal imprinting

    International Nuclear Information System (INIS)

    Gao, Yulong; Lin, Jie; Jin, Peng; Tan, Jiubin; Davies, Graham; Prewett, Philip D

    2012-01-01

    A stop grating concept is proposed to improve polymer filling in the thermal imprinting of a micro Fresnel lens structure. The stop grating consists of line and space structures outside the Fresnel lens pattern zone area. The experimental results have proved that the stop grating can help to achieve the complete filling of a mold, at the same time acting as a stop to prevent possible damage to the mold surface relief structures during imprinting press. A computer simulation was carried out to identify the phenomena of micro-holes at the edge of imprinted pattern. By removing the cavity between the pattern area and stop grating, perfect imprinting results have been achieved. (paper)

  3. 3D Laser Imprint Using a Smoother Ray-Traced Power Deposition Method

    Science.gov (United States)

    Schmitt, Andrew J.

    2017-10-01

    Imprinting of laser nonuniformities in directly-driven icf targets is a challenging problem to accurately simulate with large radiation-hydro codes. One of the most challenging aspects is the proper construction of the complex and rapidly changing laser interference structure driving the imprint using the reduced laser propagation models (usually ray-tracing) found in these codes. We have upgraded the modelling capability in our massively-parallel fastrad3d code by adding a more realistic EM-wave interference structure. This interference model adds an axial laser speckle to the previous transverse-only laser structure, and can be impressed on our improved smoothed 3D raytrace package. This latter package, which connects rays to form bundles and performs power deposition calculations on the bundles, is intended to decrease ray-trace noise (which can mask or add to imprint) while using fewer rays. We apply this improved model to 3D simulations of recent imprint experiments performed on the Omega-EP laser and the Nike laser that examined the reduction of imprinting due to very thin high-Z target coatings. We report on the conditions in which this new model makes a significant impact on the development of laser imprint. Supported by US DoE/NNSA.

  4. Effect of template on chiral separation of phenylalanine using molecularly imprinted membrane in aqueous medium

    International Nuclear Information System (INIS)

    Haq, N.U.

    2014-01-01

    Wet phase inversion method was used to prepare L-Phenylalanine (L-Phe) and D-Phenylalanine (D-Phe) imprinted poly ((acrylonitrile)-co-(acrylic acid)) membranes for chiral separation. Ultrafiltration experiments were conducted to evaluate the chiral separation ability of the prepared membrane towards racemate aqueous solution of Phenylalanine. The continuous permselectivity was observed by novel membrane. The chiral resolution ability of L-Phe imprinted membrane was much better than that of D-Phe. It was observed that both membranes simultaneously, selectively reject, selectively adsorbed and selectively permeate solute. The achieved adsorption selectivities of L-Phe imprinted membrane (AlphaAds)L and D-Phe imprinted membrane (AlphaAds)D were 2.6 and 2.40 respectively. Permselectivity of L-Phe imprinted membrane (AlphaPerm)L was 2.56 while D-Phe imprinted membrane permselectivity (AlphaPerm)D was 2.03. The rejection selectivities of L-Phe and D-Phe imprinted membranes were (AlphaRej)L=0.32 and (AlphaRej)D =0.28 respectively. (author)

  5. Naproxen-imprinted xerogels in the micro- and nanospherical formsby emulsion technique.

    Science.gov (United States)

    Ornelas, Mariana; Azenha, Manuel; Pereira, Carlos; Silva, A Fernando

    2015-11-27

    Naproxen-imprinted xerogels in the microspherical and nanospherical forms were prepared by W/O emulsion and microemulsion, respectively. The work evolved from a sol–gel mixture previously reported for bulk synthesis. It was relatively simple to convert the original sol–gel mixture to one amenable to emulsion technique. The microspheres thus produced presented mean diameter of 3.7 μm, surface area ranging 220–340 m2/g, selectivity factor 4.3 (against ibuprofen) and imprinting factor 61. A superior capacity (9.4 μmol/g) was found, when comparing with imprints obtained from similar pre-gelification mixtures. However, slow mass transfer kinetics was deduced from column efficiency results. Concerning the nanospherical format, which constituted the first example of the production of molecularly imprinted xerogels in that format by microemulsion technique, adapting the sol–gel mixture was troublesome. In the end, nanoparticles with diameter in the order of 10 nm were finally obtained, exhibiting good indications of an efficient molecular imprinting process. Future refinements are necessary to solve serious aggregation issues, before moving to more accurate characterization of the binding characteristics or to real applications of the nanospheres.

  6. Polycarbonate as an Elasto-Plastic Material Model for Simulation of the Microstructure Hot Imprint Process

    Directory of Open Access Journals (Sweden)

    Rokas Šakalys

    2013-08-01

    Full Text Available The thermal imprint process of polymer micro-patterning is widely applied in areas such as manufacturing of optical parts, solar energy, bio-mechanical devices and chemical chips. Polycarbonate (PC, as an amorphous polymer, is often used in thermoforming processes because of its good replication characteristics. In order to obtain replicas of the best quality, the imprint parameters (e.g., pressure, temperature, time, etc. must be determined. Therefore finite element model of the hot imprint process of lamellar periodical microstructure into PC has been created using COMSOL Multiphysics. The mathematical model of the hot imprint process includes three steps: heating, imprinting and demolding. The material properties of amorphous PC strongly depend on the imprint temperature and loading pressure. Polycarbonate was modelled as an elasto-plastic material, since it was analyzed below the glass transition temperature. The hot imprint model was solved using the heat transfer and the solid stress-strain application modes with thermal contact problem between the mold and polycarbonate. It was used for the evaluation of temperature and stress distributions in the polycarbonate during the hot imprint process. The quality of the replica, by means of lands filling ratio, was determined as well.

  7. Ultrafast direct imprinting of nanostructures in metals by pulsed laser melting

    International Nuclear Information System (INIS)

    Cui Bo; Keimel, Chris; Chou, Stephen Y

    2010-01-01

    We report a method of one-step direct patterning of metallic nanostructures. In the method, termed laser assisted direct imprinting (LADI), the surface of a metal film on a substrate is melted by a single excimer laser pulse and subsequently imprinted within ∼100 ns using a transparent quartz mold, while the substrate is kept at a low temperature and in a solid phase. Using LADI, we imprinted gratings with ∼100 nm linewidth, 100 nm depth, and 200 nm pitch, as well as isolated mesas of ∼20 μm size, in Al, Au, Cu and Ni thin films. We found that the quartz mold was able to imprint metals even at temperatures higher than its melting point. The technique could be extended to other metals regardless of their ductility and hardness, and would find applications in photonic and plasmonic device production.

  8. Highly selective BSA imprinted polyacrylamide hydrogels facilitated by a metal-coding MIP approach.

    Science.gov (United States)

    El-Sharif, H F; Yapati, H; Kalluru, S; Reddy, S M

    2015-12-01

    We report the fabrication of metal-coded molecularly imprinted polymers (MIPs) using hydrogel-based protein imprinting techniques. A Co(II) complex was prepared using (E)-2-((2 hydrazide-(4-vinylbenzyl)hydrazono)methyl)phenol; along with iron(III) chloroprotoporphyrin (Hemin), vinylferrocene (VFc), zinc(II) protoporphyrin (ZnPP) and protoporphyrin (PP), these complexes were introduced into the MIPs as co-monomers for metal-coding of non-metalloprotein imprints. Results indicate a 66% enhancement for bovine serum albumin (BSA) protein binding capacities (Q, mg/g) via metal-ion/ligand exchange properties within the metal-coded MIPs. Specifically, Co(II)-complex-based MIPs exhibited 92 ± 1% specific binding with Q values of 5.7 ± 0.45 mg BSA/g polymer and imprinting factors (IF) of 14.8 ± 1.9 (MIP/non-imprinted (NIP) control). The selectivity of our Co(II)-coded BSA MIPs were also tested using bovine haemoglobin (BHb), lysozyme (Lyz), and trypsin (Tryp). By evaluating imprinting factors (K), each of the latter proteins was found to have lower affinities in comparison to cognate BSA template. The hydrogels were further characterised by thermal analysis and differential scanning calorimetry (DSC) to assess optimum polymer composition. The development of hydrogel-based molecularly imprinted polymer (HydroMIPs) technology for the memory imprinting of proteins and for protein biosensor development presents many possibilities, including uses in bio-sample clean-up or selective extraction, replacement of biological antibodies in immunoassays and biosensors for medicine and the environment. Biosensors for proteins and viruses are currently expensive to develop because they require the use of expensive antibodies. Because of their biomimicry capabilities (and their potential to act as synthetic antibodies), HydroMIPs potentially offer a route to the development of new low-cost biosensors. Herein, a metal ion-mediated imprinting approach was employed to metal-code our

  9. Short interspersed element (SINE) depletion and long interspersed element (LINE) abundance are not features universally required for imprinting.

    Science.gov (United States)

    Cowley, Michael; de Burca, Anna; McCole, Ruth B; Chahal, Mandeep; Saadat, Ghazal; Oakey, Rebecca J; Schulz, Reiner

    2011-04-20

    Genomic imprinting is a form of gene dosage regulation in which a gene is expressed from only one of the alleles, in a manner dependent on the parent of origin. The mechanisms governing imprinted gene expression have been investigated in detail and have greatly contributed to our understanding of genome regulation in general. Both DNA sequence features, such as CpG islands, and epigenetic features, such as DNA methylation and non-coding RNAs, play important roles in achieving imprinted expression. However, the relative importance of these factors varies depending on the locus in question. Defining the minimal features that are absolutely required for imprinting would help us to understand how imprinting has evolved mechanistically. Imprinted retrogenes are a subset of imprinted loci that are relatively simple in their genomic organisation, being distinct from large imprinting clusters, and have the potential to be used as tools to address this question. Here, we compare the repeat element content of imprinted retrogene loci with non-imprinted controls that have a similar locus organisation. We observe no significant differences that are conserved between mouse and human, suggesting that the paucity of SINEs and relative abundance of LINEs at imprinted loci reported by others is not a sequence feature universally required for imprinting.

  10. Short interspersed element (SINE depletion and long interspersed element (LINE abundance are not features universally required for imprinting.

    Directory of Open Access Journals (Sweden)

    Michael Cowley

    2011-04-01

    Full Text Available Genomic imprinting is a form of gene dosage regulation in which a gene is expressed from only one of the alleles, in a manner dependent on the parent of origin. The mechanisms governing imprinted gene expression have been investigated in detail and have greatly contributed to our understanding of genome regulation in general. Both DNA sequence features, such as CpG islands, and epigenetic features, such as DNA methylation and non-coding RNAs, play important roles in achieving imprinted expression. However, the relative importance of these factors varies depending on the locus in question. Defining the minimal features that are absolutely required for imprinting would help us to understand how imprinting has evolved mechanistically. Imprinted retrogenes are a subset of imprinted loci that are relatively simple in their genomic organisation, being distinct from large imprinting clusters, and have the potential to be used as tools to address this question. Here, we compare the repeat element content of imprinted retrogene loci with non-imprinted controls that have a similar locus organisation. We observe no significant differences that are conserved between mouse and human, suggesting that the paucity of SINEs and relative abundance of LINEs at imprinted loci reported by others is not a sequence feature universally required for imprinting.

  11. Preliminary evidence of a neurophysiological basis for individual discrimination in filial imprinting.

    Science.gov (United States)

    Town, Stephen Michael

    2011-12-01

    Filial imprinting involves a predisposition for biologically important stimuli and a learning process directing preferences towards a particular stimulus. Learning underlies discrimination between imprinted and unfamiliar individuals and depends upon the IMM (intermediate and medial mesopallium). Here, IMM neurons responded differentially to familiar and unfamiliar conspecifics following socialization and the neurophysiological effects of social experience differed between hemispheres. Such findings may provide a neurophysiological basis for individual discrimination in imprinting. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Synthesis of L-lysine imprinted cryogels for immunoglobulin G adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Çulha, Senem; Armutcu, Canan; Uzun, Lokman; Şenel, Serap, E-mail: senel@hacettepe.edu.tr; Denizli, Adil

    2015-07-01

    L-Lysine imprinted poly(2-hydroxyethyl methacrylate-co-N-methacryloyl-L-aspartic acid) [P(HEMA-co-MAAsp)] cryogels were synthesized and characterized with Fourier transform infrared spectroscopy, scanning electron microscopy, surface area measurements, swelling, and squeezing tests. Specific surface area for imprinted cryogel was 34.2 m{sup 2}/g while the value was 21.3 m{sup 2}/g for non-imprinted cryogel. IgG adsorption from aqueous solution was examined in continuous mode examining the factors effecting adsorption capacity such as pH, concentration, flow rate, temperature, ionic strength, and incubation time. 0.5 M NaCl was used as desorption agent. The IgG adsorption capacity was determined as 55.1 mg/g for 1.0 mg/mL IgG original concentration at 25.0 °C while pH and flow rate were 7.0 and 0.5 mL/min, respectively. When human serum was used as IgG source, the removal of 90.4% of crude IgG was attained for 1/20 diluted plasma sample. The imprinted cryogel was used in ten successive cycles without significant loss in adsorption capacity. The cryogel was determined to be 1.79 times more selective to IgG than albumin and 1.45 times more selective than hemoglobin. The adsorption behavior well suited to Langmuir isotherm and the kinetics followed pseudo-second-order model. Thermodynamic parameters ΔH°, ΔS° and ΔG° for this adsorption process were also calculated. - Highlights: • L-Lysine imprinted cryogels through epitope imprinting approach • Optimization of recognition conditions for template (L-lysine) and target (IgG) biomolecules • Efficient reusability (upto 10 cycles) without any significant change in capacity • A great potential for specific and selective IgG purification • Promising, cost-friendly, specific and selective adsorbent • IgG separation/purification from complex feeding solutions like human serum.

  13. Molecular imprinting polymer with polyoxometalate/carbon nitride nanotubes for electrochemical recognition of bilirubin

    International Nuclear Information System (INIS)

    Yola, Mehmet Lütfi; Göde, Ceren; Atar, Necip

    2017-01-01

    Highlights: •Bilirubin-imprinted sensor is developed for the sensitive detection of bilirubin •The prepared based on nanocomposite were characterized by several methods. •Bilirubin-imprinted sensor offers the important advantages •Bilirubin-imprinted sensor is preferred to the other methods for analysis -- Abstract: In this work, a new molecular imprinted sensor based on polyoxometalate (H 3 PW 12 O 40 , POM) functionalized carbon nitride nanotubes (C 3 N 4 NTs) nanocomposite was prepared for bilirubin (BR) analysis. The structures of prepared surfaces based on the nanocomposite were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS) and energy dispersive x-ray analysis (EDX). After that, BR imprinted electrode on H 3 PW 12 O 40 /C 3 N 4 NTs nanocomposite was developed by cyclic voltammetry (CV) in 100 mM pyrrole containing 25 mM BR. The linearity range and the detection limit of the developed method were calculated as 1.0 × 10 −12 –1.0 × 10 −10 M and 3.0 × 10 −13 M, respectively. In addition, the imprinted sensor was applied to human plasma samples with high recovery and selectivity.

  14. Selective solid-phase extraction of Hg(II) using silica gel surface - imprinting technique

    International Nuclear Information System (INIS)

    Zheng, H.; Geng, T.; Hu, L.

    2008-01-01

    A new ion-imprinted amino-functionalized silica gel sorbent was synthesized by surface-imprinting technique for preconcentration and separation of Hg(II) prior to its determination by inductively coupled plasma optical emission spectrometry (ICP-OES). Compared to the traditional solid sorbents and non-imprinted polymer particles, the ion-imprinted polymers (IIPs) have higher adsorption capacity and selectivity for Hg(II). The maximum static adsorption capacity of the imprinted and non-imprinted sorbent for Hg(II) was 29.89 mg g -1 and 11.21 mg g -1 , respectively. The highest selectivity coefficient for Hg(II) in the presence of Zn(II) exceeded 230. The detection limit (3σ) of the method was 0.25 μg L -1 . The relative standard deviation of the method was 2.5% for eight replicate determinations of 10 μg of Hg 2+ in 200 mL-in-volume water sample. The procedure was validated by performing the analysis of the certified river sediment sample (GBW 08603, China) using the standard addition method. The developed method was also successfully applied to the determination of trace mercury in Chinese traditional medicine and water samples with satisfactory results. (authors)

  15. Chemical point detection using differential fluorescence from molecularly imprinted polymers

    Science.gov (United States)

    Pestov, Dmitry; Anderson, John E.; Nelson, Jean; Tepper, Gary C.

    2004-12-01

    Fluorescence represents one of the most attractive approaches for chemical sensing due to the abundant light produced by most fluorophores, resulting in excellent detection sensitivity. However, the broad and overlapping emission spectra of target and background species have made it difficult to perform species identification in a field instrument because of the need to perform spectral decomposition and analysis. This paper describes a new chemical sensing strategy based on differential fluorescence measurements from molecularly imprinted polymers, which eliminates the need to perform any spectral analysis. Species identification is accomplished by measuring the differential light output from a pair of polymers-one imprinted to a target species and the other identical, but not imprinted. The imprinted polymer selectively concentrates the target molecule and controls the energy (wavelength) of the emitted fluorescence signal and the differential output eliminates common mode signals associated with non-specific background interference. Because no spectral analysis is required, the sensors can be made extremely small and require very little power. Preliminary performance parameters from a prototype sensor are presented and discussed.

  16. Enhanced Absorption in Organic Thin-Films from Imprinted Concave Nanostructures

    Directory of Open Access Journals (Sweden)

    Arkadiusz Jarosław GOSZCZAK

    2017-02-01

    Full Text Available In this work, a rapid, replicable method for imprinting concave nanostructures to be used as functional light-trapping nanostructures in organic thin-films is presented. Porous anodic alumina templates were fabricated both by anodization of thick Al foils and by anodization of submicrometer thin Al films evaporated via e-beam evaporation on Si substrates. The template formation leads to natural patterning of the underlying Al layers that are used as rigid masters for stamp fabrication, after selective etching of the porous anodic alumina. PDMS stamps were made after replicating the Al concave patterns and used for imprinting of spin coated photoresist on glass substrates. We have investigated semi-periodic and aperiodic imprinted large concave patterns fabricated from rigid masters after anodization of Al in H3PO4. We show that metal covered imprinted concaves show enhancement in absorption that is attributed to field enhancement and diffuse scattering, leading to efficient light trapping for a selected active layer material (P3HT:PCBM.DOI: http://dx.doi.org/10.5755/j01.ms.23.1.14188

  17. Surface imprinted beads for the recognition of human serum albumin.

    Science.gov (United States)

    Bonini, Francesca; Piletsky, Sergey; Turner, Anthony P F; Speghini, Adolfo; Bossi, Alessandra

    2007-04-15

    The synthesis of poly-aminophenylboronic acid (ABPA) imprinted beads for the recognition of the protein human serum albumin (HSA) is reported. In order to create homogeneous recognition sites, covalent immobilisation of the template HSA was exploited. The resulting imprinted beads were selective for HSA. The indirect imprinting factor (IF) calculated from supernatant was 1.6 and the direct IF, evaluated from the protein recovered from the beads, was 1.9. The binding capacity was 1.4 mg/g, which is comparable to commercially available affinity materials. The specificity of the HSA recognition was evaluated with competitive experiments, indicating a molar ratio 4.5/1 of competitor was necessary to displace half of the bound HSA. The recognition and binding of the imprinted beads was also tested with a complex sample, human serum and targeted removal of HSA without a loss of the other protein components was demonstrated. The easy preparation protocol of derivatised beads and a good protein recognition properties make the approach an attractive solution to analytical and bio-analytical problems in the field of biotechnology.

  18. Using SNP markers to estimate additive, dominance and imprinting genetic variance

    DEFF Research Database (Denmark)

    Lopes, M S; Bastiaansen, J W M; Janss, Luc

    The contributions of additive, dominance and imprinting effects to the variance of number of teats (NT) were evaluated in two purebred pig populations using SNP markers. Three different random regression models were evaluated, accounting for the mean and: 1) additive effects (MA), 2) additive...... and dominance effects (MAD) and 3) additive, dominance and imprinting effects (MADI). Additive heritability estimates were 0.30, 0.28 and 0.27-0.28 in both lines using MA, MAD and MADI, respectively. Dominance heritability ranged from 0.06 to 0.08 using MAD and MADI. Imprinting heritability ranged from 0.......01 to 0.02. Dominance effects make an important contribution to the genetic variation of NT in the two lines evaluated. Imprinting effects appeared less important for NT than additive and dominance effects. The SNP random regression model presented and evaluated in this study is a feasible approach...

  19. Vitamin-caused faulty perinatal hormonal imprinting and its consequences in adult age.

    Science.gov (United States)

    Csaba, G

    2017-09-01

    Lipid-soluble vitamins (vitamins A, D, E, and K) are actually hormones (exohormones), as they can be directly bound by hormone receptors or are in connection with molecules, which influence hormone receptors. Vitamin D is a transition between endo- and exohormones and the possibility of similar situation in case of other lipid-soluble hormones is discussed. The perinatal exposition with these "vitamins" can cause faulty perinatal hormonal imprinting with similar consequences as the faulty imprinting by the synthetic endohormones, members of the same hormone family or industrial, communal, or medical endocrine disruptors. The faulty imprinting leads to late (lifelong) consequences with altered hormone binding by receptors, altered sexuality, brain function, immunity, bone development, and fractures, etc. In addition, as hormonal imprinting is an epigenetic process, the effect of a single exposure by fat-soluble vitamins is inherited to the progeny generations. As vitamins are handled differently from hormones; however, perinatal treatments take place frequently and sometimes it is forced, the negative late effect of faulty perinatal vitamin-caused hormonal imprinting must be considered.

  20. Elucidation of Type of Molecular Interactions for the Imprinting of Shikimic Acid

    International Nuclear Information System (INIS)

    Beng, Y.C.; Nor Azah Yusof

    2016-01-01

    During the preparation of shikimic acid imprinted polymer, the effect of rebinding solution water content on the rebinding performance of shikimic acid (SA) imprinted polymer was studied. Result showed that the highest affinity toward SA was in a 100 % aqueous rebinding solution, suggesting that the interactions occurred between SA and the polymer were ionic and/ or hydrophobic in nature. Further study on the effect of rebinding solution pH to the SA imprinted polymer rebinding performance showed that the performance of the SA imprinted polymer depended on the rebinding solution pH and the highest affinity occurred at pH 4.0; this confirmed that ionic interaction played an important role in the rebinding of SA. Taking into account the deductions made from the combined results of the rebinding solution water content and effect of pH, together with observation of the red shift in the SA spectral during ultraviolet-visible spectroscopic titration experiments, suggest that the specificity shown by SA imprinted polymer in the aqueous solution was due to both ionic and π-π hydrophobic interactions. (author)

  1. Biopolymeric receptor for peptide recognition by molecular imprinting approach—Synthesis, characterization and application

    International Nuclear Information System (INIS)

    Singh, Lav Kumar; Singh, Monika; Singh, Meenakshi

    2014-01-01

    The present work is focused on the development of a biocompatible zwitterionic hydrogel for various applications in analytical chemistry. Biopolymer chitosan was derivatized to obtain a series of zwitterionic hydrogel samples. Free amino groups hanging on the biopolymeric chain were reacted with γ-butyrolactone to quaternize the N-centers of polymeric chain. N,N-methylene-bis-acrylamide acts as a crosslinker via Michael-type addition in the subsequent step and facilitated gelation of betainized chitosan. These biopolymeric hydrogel samples were fully characterized by FTIR, 1 H NMR, 13 C NMR spectra, SEM and XRD. Hydrogels were further characterized for their swelling behavior at varying parameters. The extent of swelling was perceived to be dictated by solvent composition such as pH, ionic strength and temperature. This valuable polymeric format is herein chosen to design an artificial receptor for dipeptide ‘carnosine’, which has adequate societal significance to be analytically determined, by molecular imprinting. Electrostatic interactions along with complementary H-bonding and other hydrophobic interactions inducing additional synergetic effect between the template (carnosine) and the imprinted polymer led to the formation of imprinted sites. The MIP was able to selectively and specifically take up carnosine from aqueous solution quantitatively. Thus prepared MIPs were characterized by FTIR spectroscopy, SEM providing evidence for the quality and quantity of imprinted gels. The binding studies showed that the MIP illustrated good recognition for carnosine as compared to non-imprinted polymers (NIPs). Detection limit was estimated as 3.3 μg mL −1 . Meanwhile, selectivity experiments demonstrated that imprinted gel had a high affinity to carnosine in the presence of close structural analogues (interferrants). - Highlights: • Development of a biocompatible zwitterionic hydrogel • A series of chitosan-derived zwitterionic hydrogel samples • Polymeric

  2. Optimal synthesis of a Ni(II)-dimethylglyoxime ion-imprinted polymer ...

    African Journals Online (AJOL)

    A Ni(II)-dimethylglyoxime ion-imprinted polymer {Ni(II)-DMG IIP} was optimised by the uniform design experimental method and used to adsorb Ni(II) ions from water, soil and mine tailing samples. This aimed to improve the performance of this ion-imprinted polymer in trapping Ni(II) ions from soil and mine tailing samples ...

  3. Charged hydrogels for post-loading, release, and molecular imprinting of proteins

    NARCIS (Netherlands)

    Schillemans, J.P.|info:eu-repo/dai/nl/304835137

    2010-01-01

    Molecular imprinting is a technique to create template-shaped cavities in polymer matrices with memory of the template molecules, to be used in molecular recognition. Molecular imprinting of low molecular weight compounds is a well established technique used to create high affinity materials. On the

  4. Cholesterol-imprinted macroporous monoliths: Preparation and characterization.

    Science.gov (United States)

    Stepanova, Mariia А; Kinziabulatova, Lilia R; Nikitina, Anna A; Korzhikova-Vlakh, Evgenia G; Tennikova, Tatiana B

    2017-11-01

    The development of sorbents for selective binding of cholesterol, which is a risk factor for cardiovascular disease, has a great importance for analytical science and medicine. In this work, two series of macroporous cholesterol-imprinted monolithic sorbents differing in the composition of functional monomers (methacrylic acid, butyl methacrylate, 2-hydroxyethyl methacrylate and ethylene dimethacrylate), amount of a template (4, 6 and 8 mol%) used for molecular imprinting, as well as mean pore size were synthesized by in situ free-radical process in stainless steel housing of 50 mm × 4.6 mm i.d. All prepared materials were characterized regarding to their hydrodynamic permeability and porous properties, as well as examined by BET and SEM methods. Imprinting factors, apparent dynamic dissociation constants, the maximum binding capacity, the number of theoretical plates and the height equivalent to a theoretical palate of MIP monoliths at different mobile phase flow rates were determined. The separation of a mixture of structural analogues, namely, cholesterol and prednisolone, was demonstrated. Additionally, the possibility of using the developed monoliths for cholesterol solid-phase extraction from simulated biological solution was shown. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Molecular imprinting of enzymes with water-insoluble ligands for nonaqueous biocatalysis.

    Science.gov (United States)

    Rich, Joseph O; Mozhaev, Vadim V; Dordick, Jonathan S; Clark, Douglas S; Khmelnitsky, Yuri L

    2002-05-15

    Attaining higher levels of catalytic activity of enzymes in organic solvents is one of the major challenges in nonaqueous enzymology. One of the most successful strategies for enhancing enzyme activity in organic solvents involves tuning the enzyme active site by molecular imprinting with substrates or their analogues. Unfortunately, numerous imprinters of potential importance are poorly soluble in water, which significantly limits the utility of this method. In the present study, we have developed strategies that overcome this limitation of the molecular-imprinting technique and that thus expand its applicability beyond water-soluble ligands. The solubility problem can be addressed either by converting the ligands into a water-soluble form or by adding relatively high concentrations of organic cosolvents, such as tert-butyl alcohol and 1,4-dioxane, to increase their solubility in the lyophilization medium. We have succeeded in applying both of these strategies to produce imprinted thermolysin, subtilisin, and lipase TL possessing up to 26-fold higher catalytic activity in the acylation of paclitaxel and 17beta-estradiol compared to nonimprinted enzymes. Furthermore, we have demonstrated for the first time that molecular imprinting and salt activation, applied in combination, produce a strong additive activation effect (up to 110-fold), suggesting different mechanisms of action involved in these enzyme activation techniques.

  6. Phytosterol Recognition via Rationally Designed Molecularly Imprinted Polymers

    Directory of Open Access Journals (Sweden)

    Lachlan J. Schwarz

    2018-02-01

    Full Text Available Molecularly imprinted polymers (MIPs prepared via a semi-covalent imprinting strategy using stigmasteryl methacrylate as a polymerisable template have been evaluated by static binding methods for their ability to selectively capture other valuable phytosterol targets, including campesterol and brassicasterol. Design criteria based on molecular modelling procedures and interaction energy calculations were employed to aid the selection of the co-monomer type, as well as the choice of co-monomer:template ratios for the formation of the pre-polymerisation complex. These novel hybrid semi-covalently imprinted polymers employed N,N′-dimethylacryl-amide (N,N′-DMAAM as the functional co-monomer and displayed specific binding capacities in the range 5.2–5.9 mg sterol/g MIP resin. Their binding attributes and selectivities towards phytosterol compounds were significantly different to the corresponding MIPs prepared via non-covalent procedures or when compared to non-imprinted polymers. Cross-reactivity studies using stigmasterol, ergosterol, cholesterol, campesterol, and brassicasterol as single analytes revealed the importance of the A-ring C-3-β-hydroxyl group and the orientational preferences of the D-ring alkyl chain structures in their interaction in the templated cavity with the N,N′-dimethylamide functional groups of the MIP. Finally, to obtain useful quantities of both campersterol and brassicasterol for these investigations, improved synthetic routes have been developed to permit the conversion of the more abundant, lower cost stigmasterol via a reactive aldehyde intermediate to these other sterols.

  7. Selectivity enhancement of phosphate based functional polymeric gels towards Uranium(VI) using ion imprinting

    International Nuclear Information System (INIS)

    Chappa, Sankararao; Agarwal, Chhavi; Pandey, A.K.

    2015-01-01

    The imprinting of gel containing polymer chains of ethylene glycol methacrylate phosphate (EGMP) for U(VI) ions were carried out. The U(VI) imprinting has been carried out in pure EGMP and in EGMP: poly(ethylene glycol) methacrylate (PEGMA) = 1:9 composition. Complexation of the monomer with template (U(VI)) followed by polymerization have been used to imprint the U(VI) onto the polymer chains. The comparison of uptake studies of U(VI) and Pu(IV) at 3 M HNO 3 shows increased selectivity of U(VI) relative to Pu(IV) for both the gel compositions. The less uptake of U(VI) for imprinted EGMP:PEGMA gel relative to pure imprinted EGMP gel at tracer level can be possibly due to the requirement of two EGMP units in the vicinity for U(VI) complexation. (author)

  8. Highly sensitive and selective hyphenated technique (molecularly imprinted polymer solid-phase microextraction-molecularly imprinted polymer sensor) for ultra trace analysis of aspartic acid enantiomers.

    Science.gov (United States)

    Prasad, Bhim Bali; Srivastava, Amrita; Tiwari, Mahavir Prasad

    2013-03-29

    The present work is related to combination of molecularly imprinted solid-phase microextraction and complementary molecularly imprinted polymer-sensor. The molecularly imprinted polymer grafted on titanium dioxide modified silica fiber was used for microextraction, while the same polymer immobilized on multiwalled carbon nanotubes/titanium dioxide modified pencil graphite electrode served as a detection tool. In both cases, the surface initiated polymerization was found to be advantageous to obtain a nanometer thin imprinted film. The modified silica fiber exhibited high adsorption capacity and enantioselective diffusion of aspartic acid isomers into respective molecular cavities. This combination enabled double preconcentrations of d- and l-aspartic acid that helped sensing both isomers in real samples, without any cross-selectivity and matrix complications. Taking into account 6×10(4)-fold dilution of serum and 2×10(3)-fold dilution of cerebrospinal fluid required by the proposed method, the limit of detection for l-aspartic acid is 0.031ngmL(-1). Also, taking into account 50-fold dilution required by the proposed method, the limit of detection for d-aspartic acid is 0.031ngmL(-1) in cerebrospinal fluid. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Imprint cytology on microcalcifications excised by Vacuum-Assisted Breast Biopsy: A rapid preliminary diagnosis

    Directory of Open Access Journals (Sweden)

    Drouveli Theodora

    2007-04-01

    Full Text Available Abstract Background To evaluate imprint cytology in the context of specimens with microcalcifications derived from Vacuum-Assisted Breast Biopsy (VABB. Patients and methods A total of 93 women with microcalcifications BI-RADS 3 and 4 underwent VABB and imprint samples were examined. VABB was performed on Fischer's table using 11-gauge Mammotome vacuum probes. A mammogram of the cores after the procedure confirmed the excision of microcalcifications. For the application of imprint cytology, the cores with microcalcifications confirmed by mammogram were gently rolled against glass microscope slides and thus imprint smears were made. For rapid preliminary diagnosis Diff-Quick stain, modified Papanicolaou stain and May Grunwald Giemsa were used. Afterwards, the core was dipped into a CytoRich Red Collection fluid for a few seconds in order to obtain samples with the use of the specimen wash. After the completion of cytological procedures, the core was prepared for routine histological study. The pathologist was blind to the preliminary cytological results. The cytological and pathological diagnoses were comparatively evaluated. Results According to the pathological examination, 73 lesions were benign, 15 lesions were carcinomas (12 ductal carcinomas in situ, 3 invasive ductal carcinomas, and 5 lesions were precursor: 3 cases of atypical ductal hyperplasia (ADH and 2 cases of lobular neoplasia (LN. The observed sensitivity and specificity of the cytological imprints for cancer were 100% (one-sided, 97.5% CI: 78.2%–100%. Only one case of ADH could be detected by imprint cytology. Neither of the two LN cases was detected by the imprints. The imprints were uninformative in 11 out of 93 cases (11.8%. There was no uninformative case among women with malignancy. Conclusion Imprint cytology provides a rapid, accurate preliminary diagnosis in a few minutes. This method might contribute to the diagnosis of early breast cancer and possibly attenuates

  10. Fabrication and nano-imprintabilities of Zr-, Pd- and Cu-based glassy alloy thin films

    International Nuclear Information System (INIS)

    Takenaka, Kana; Saidoh, Noriko; Nishiyama, Nobuyuki; Inoue, Akihisa

    2011-01-01

    With the aim of investigating nano-imprintability of glassy alloys in a film form, Zr 49 Al 11 Ni 8 Cu 32 , Pd 39 Cu 29 Ni 13 P 19 and Cu 38 Zr 47 Al 9 Ag 6 glassy alloy thin films were fabricated on Si substrate by a magnetron sputtering method. These films exhibit a very smooth surface, a distinct glass transition phenomenon and a large supercooled liquid region of about 80 K, which are suitable for imprinting materials. Moreover, thermal nano-imprintability of these obtained films is demonstrated by using a dot array mold with a dot diameter of 90 nm. Surface observations revealed that periodic nano-hole arrays with a hole diameter of 90 nm were successfully imprinted on the surface of these films. Among them, Pd-based glassy alloy thin film indicated more precise pattern imprintability, namely, flatter residual surface plane and sharper hole edge. It is said that these glassy alloy thin films, especially Pd-based glassy alloy thin film, are one of the promising materials for fabricating micro-machines and nano-devices by thermal imprinting.

  11. Synthesis and application of magnetic molecularly imprinted polymers in sample preparation.

    Science.gov (United States)

    Huang, Shuyao; Xu, Jianqiao; Zheng, Jiating; Zhu, Fang; Xie, Lijun; Ouyang, Gangfeng

    2018-04-12

    Magnetic molecularly imprinted polymers (MMIPs) have superior advantages in sample pretreatment because of their high selectivity for target analytes and the fast and easy isolation from samples. To meet the demand of both good magnetic property and good extraction performance, MMIPs with various structures, from traditional core-shell structures to novel composite structures with a larger specific surface area and more accessible binding sites, are fabricated by different preparation technologies. Moreover, as the molecularly imprinted polymer (MIP) layers determine the affinity, selectivity, and saturated adsorption amount of MMIPs, the development and innovation of the MIP layer are attracting attention and are reviewed here. Many studies that used MMIPs as sorbents in dispersive solid-phase extraction of complex samples, including environmental, food, and biofluid samples, are summarized. Graphical abstract The application of magnetic molecularly imprinted polymers (MIPs) in the sample preparation procedure improves the analytical performances for complex samples. MITs molecular imprinting technologies.

  12. Characterization of the imprinting and expression patterns of ZAG2 in maize endosperm and embryo

    Directory of Open Access Journals (Sweden)

    Chaoxian Liu

    2015-02-01

    Full Text Available ZAG2 has been identified as a maternally expressed imprinted gene in maize endosperm. Our study revealed that paternally inherited ZAG2 alleles were imprinted in maize endosperm and embryo at 14 days after pollination (DAP, and consistently imprinted in endosperm at 10, 12, 16, 18, 20, 22, 24, 26, and 28 DAP in reciprocal crosses between B73 and Mo17. ZAG2 alleles were also imprinted in reciprocal crosses between Zheng 58 and Chang 7-2 and between Huang C and 178. ZAG2 alleles exhibited differential imprinting in hybrids of 178 × Huang C and B73 × Mo17, while in other hybrids ZAG2 alleles exhibited binary imprinting. The tissue-specific expression pattern of ZAG2 showed that ZAG2 was expressed at a high level in immature ears, suggesting that ZAG2 plays important roles in not only kernel but ear development.

  13. Effects of imprint training procedure at birth on the reactions of foals at age six months.

    Science.gov (United States)

    Williams, J L; Friend, T H; Collins, M N; Toscano, M J; Sisto-Burt, A; Nevill, C H

    2003-03-01

    While imprint training procedures have been promoted in popular magazines, they have received limited scientific investigation. To determine the effects of a neonatal imprint training procedure on 6-month-old foals and to determine if any one session had a greater effect than others. Foals (n = 131) were divided into the following treatments: no imprint training, imprint training at birth, 12, 24 and 48 h after birth or imprint training only at birth, 12, 24, 48, or 72 h after birth. Foals then received minimal human handling until they were tested at 6 months. During training, time to complete exposure to the stimulus was significant for only 2 of 6 stimuli. Percentage change in baseline heart rate was significant for only 2 of 10 stimuli. These 4 effects were randomly spread across treatments. Neither the number of imprint training sessions (0, 1, or 4) nor the timing of imprint training sessions (none, birth, 12, 24, 48, or 72 h after birth) influenced the foal's behaviour at 6 months of age. In this study, imprint training did not result in better behaved, less reactive foals.

  14. The effect of increased irradiation uniformity on imprinting by 351-nm laser light

    International Nuclear Information System (INIS)

    Boehly, T.R.; Smalyuk, V.A.; Meyerhofer, D.D.; Knauer, J.P.; Bradley, D.K.; Verdon, C.P.; Kalantar, D.

    1997-01-01

    The acceleration-driven growth of perturbations initially seeded (or imprinted) by irradiation nonuniformities is a major concern for direct-drive ICF. We report on experiments where unperturbed, CH 2 targets were irradiated with 3-ns square pulses at 2x10 14 W/cm 2 using five overlapped UV beams. The uniformity of these beams was varied and subsequent unstable growth of irradiation imprinting was observed using time-gated x-radiography. We demonstrate that increased irradiation uniformity reduces imprinting, and we show the beneficial effects of distributed polarization rotators a new beam-smoothing device. In addition, we discuss experiments using a ' perturbing beam' to study the time dependence of imprinting. copyright 1997 American Institute of Physics

  15. Verification of epigenetic inheritance in a unicellular model system: multigenerational effects of hormonal imprinting.

    Science.gov (United States)

    Kőhidai, László; Lajkó, Eszter; Pállinger, Eva; Csaba, György

    2012-10-01

    The unicellular Tetrahymena has receptors for hormones of higher vertebrates, produces these hormones, and their signal pathways are similar. The first encounter with a hormone in higher dose provokes the phenomenon of hormonal imprinting, by which the reaction of the cell is quantitatively modified. This modification is transmitted to the progeny generations. The duration of the single imprinter effect of two representative signal molecules, insulin and 5-HT (5-hydroxytryptamine), in two concentrations (10(-6) and 10(-15) M) were studied. The effects of imprinting were followed in 5 physiological indices: (i) insulin binding, (ii) 5-HT synthesis, (iii) swimming behaviour, (iv) cell growth and (v) chemotaxis in progeny generations 500 and 1000. The result of each index was different from the non-imprinted control functions, growth rate, swimming behaviour and chemotactic activity to insulin being enhanced, while others, e.g. synthesis and chemotactic responsiveness of 5-HT and the binding of insulin were reduced. This means that a function-specific heritable epigenetic change during imprinting occurs, and generally a single encounter with a femtomolar hormone concentration is enough for provoking durable and heritable imprinting in Tetrahymena. The experiments demonstrate the possibility of epigenetic effects at a unicellular level and call attention to the possibility that the character of unicellular organisms has changed through to the present day due to an enormous amount of non-physiological imprinter substances in their environment. The results - together with results obtained earlier in mammals - point to the validity of epigenetic imprinting effects throughout the animal world.

  16. Electropolymerized Molecularly Imprinted Polypyrrole Film for Sensing of Clofibric Acid

    OpenAIRE

    Schweiger, Bianca; Kim, Jungtae; Kim, Young; Ulbricht, Mathias

    2015-01-01

    Piezoelectric quartz crystals and analogous gold substrates were electrochemically coated with molecularly imprinted polypyrrole films for pulsed amperometric detection (PAD) of clofibric acid, a metabolite of clofibrate. Cyclic voltammetry data obtained during polymerization and deposited weight estimations revealed a decrease of the polymerization rate with increasing clofibric acid concentration. XPS measurements indicated that clofibric acid could be removed after imprinting with an aqueo...

  17. From 3D to 2D: a review of the molecular imprinting of proteins.

    Science.gov (United States)

    Turner, Nicholas W; Jeans, Christopher W; Brain, Keith R; Allender, Christopher J; Hlady, Vladimir; Britt, David W

    2006-01-01

    Molecular imprinting is a generic technology that allows for the introduction of sites of specific molecular affinity into otherwise homogeneous polymeric matrices. Commonly this technique has been shown to be effective when targeting small molecules of molecular weight proteins has proven difficult. A number of key inherent problems in protein imprinting have been identified, including permanent entrapment, poor mass transfer, denaturation, and heterogeneity in binding pocket affinity, which have been addressed using a variety of approaches. This review focuses on protein imprinting in its various forms, ranging from conventional bulk techniques to novel thin film and monolayer surface imprinting approaches.

  18. Molecularly Imprinted Polymers: Thermodynamic and Kinetic Considerations on the Specific Sorption and Molecular Recognition

    Directory of Open Access Journals (Sweden)

    Kejun Tong

    2008-04-01

    Full Text Available This article presents a work aiming at thermodynamically and kinetically interpreting the specific sorption and recognition by a molecularly imprinted polymer. Using Boc-L-Phe-OH as a template, the imprinted material was prepared. The result indicates that the prepared polymer can well discriminate the imprint species from its analogue (Boc-D-Phe-OH, so as to adsorb more for the former but less for the latter. Kinetic analysis indicates that this specific sorption, in nature, can be a result of a preferential promotion. The imprint within the polymer causes a larger adsorption rate for the template than for the analogue. Thermodynamic study also implies that the molecular induction from the specific imprint to the template is larger than to the analogue, which thus makes the polymer capable of preferentially alluring the template to bind.

  19. Transgenerational effects of the endocrine disruptor vinclozolin on the methylation pattern of imprinted genes in the mouse sperm.

    Science.gov (United States)

    Stouder, Christelle; Paoloni-Giacobino, Ariane

    2010-02-01

    Endocrine-disrupting chemicals (EDCs), among which is the antiandrogen vinclozolin (VCZ), have been reported to affect the male reproductive system. In this study, VCZ was administered to pregnant mice at the time of embryo sex determination, and its possible effects on the differentially methylated domains (DMDs) of two paternally (H19 and Gtl2) and three maternally (Peg1, Snrpn, and Peg3) imprinted genes were tested in the male offspring. The CpGs methylation status within the five gene DMDs was analyzed in the sperm, tail, liver, and skeletal muscle DNAs by pyrosequencing. In the sperm of controls, the percentages of methylated CpGs were close to the theoretical values of 100 and 0% in paternally or maternally imprinted genes respectively. VCZ decreased the percentages of methylated CpGs of H19 and Gtl2 (respective values 83.1 and 91.5%) and increased those of Peg1, Snrpn, and Peg3 (respective values 11.3, 18.3, and 11.2%). The effects of VCZ were transgenerational, but they disappeared gradually from F1 to F3. The mean sperm concentration of the VCZ-administered female offspring was only 56% of that of the controls in the F1 offspring, and it was back to normal values in the F2 and F3 offspring. In the somatic cells of controls, the percentages of methylated CpGs were close to the theoretical value of 50% and, surprisingly, VCZ altered the methylation of Peg3. We propose that the deleterious effects of VCZ on the male reproductive system are mediated by imprinting defects in the sperm. The reported effects of EDCs on human male spermatogenesis might be mediated by analogous imprinting alterations.

  20. Familiarity interferes with filial imprinting

    NARCIS (Netherlands)

    vanKampen, HS; deVos, GJ

    1996-01-01

    The present study was performed to investigate whether and how pre-exposure to an object affects subsequent filial imprinting to that object. In Experiment 1 junglefowl chicks (Gallus gallus spadiceus) were first exposed to either a red object alone (control group), or a red and a yellow object

  1. Synthesis of thermo-responsive bovine hemoglobin imprinted nanoparticles by combining ionic liquid immobilization with aqueous precipitation polymerization.

    Science.gov (United States)

    Wang, Yongmei; Yang, Chongchong; Sun, Yan; Qiu, Fengtao; Xiang, Yang; Fu, Guoqi

    2018-02-01

    Surface molecular imprinting over functionalized nanoparticles has proved to be an effective approach for construction of artificial nanomaterials for protein recognition. Herein, we report a strategy for synthesis of core-shell protein-imprinted nanoparticles by the functionalization of nano-cores with ionic liquids followed by aqueous precipitation polymerization to build thermo-responsive imprinted polymer nano-shells. The immobilized ionic liquids can form multiple interactions with the protein template. The polymerization process can produce thermo-reversible physical crosslinks, which are advantageous to enhancing imprinting and facilitating template removal. With bovine hemoglobin as a model template, the imprinted nanoparticles showed temperature-sensitivity in both dispersion behaviors and rebinding capacities. Compared with the ionic-liquid-modified core nanoparticles, the imprinted particles exhibited greatly increased selectivity and two orders of magnitude higher binding affinity for the template protein. The imprinted nanoparticles achieved relatively high imprinting factor up to 5.0 and specific rebinding capacity of 67.7 mg/g, respectively. These nanoparticles also demonstrated rapid rebinding kinetics and good reproducibility after five cycles of adsorption-regeneration. Therefore, the presented approach may be viable for the fabrication of high-performance protein-imprinted nanoparticles with temperature sensitivity. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Genomic imprinting, growth control and the allocation of nutritional resources: consequences for postnatal life.

    Science.gov (United States)

    Charalambous, Marika; da Rocha, Simão Teixeira; Ferguson-Smith, Anne C

    2007-02-01

    Genes subject to genomic imprinting are predominantly expressed from one of the two parental chromosomes, are often clustered in the genome, and their activity and repression are epigenetically regulated. The role of imprinted genes in growth control has been apparent since the discovery of imprinting in the early 1980s. Drawing from studies in the mouse, we propose three distinct classes of imprinted genes - those expressed, imprinted and acting predominantly within the placenta, those with no associated foetal growth effects that act postnatally to regulate metabolic processes, and those expressed in the embryo and placenta that programme the development of organs participating in metabolic processes. Members of this latter class may interact in functional networks regulating the interaction between the mother and the foetus, affecting generalized foetal well-being, growth and organ development; they may also coordinately regulate the development of particular organ systems. The mono-allelic behaviour and sensitivity to changes in regional epigenetic states renders imprinted genes adaptable and vulnerable; in all cases, their perturbed dosage can compromise prenatal and/or postnatal control of nutritional resources. This finding has implications for understanding the relationships between prenatal events and diseases later in life.

  3. Chronic exposure to a low concentration of bisphenol A during follicle culture affects the epigenetic status of germinal vesicles and metaphase II oocytes.

    Science.gov (United States)

    Trapphoff, Tom; Heiligentag, Martyna; El Hajj, Nady; Haaf, Thomas; Eichenlaub-Ritter, Ursula

    2013-12-01

    To determine whether exposure to low concentrations of the endocrine disrupting chemical bisphenol A (BPA) during follicle culture and oocyte growth alters the methylation status of differentially methylated regions (DMRs) of imprinted genes and histone posttranslational modification patterns in mammalian oocytes. Comparative and control study. Experimental laboratory. C57/Bl6JxCBA/Ca mice. Exposure of oocytes to 3 nM or 300 nM BPA during follicle culture from preantral to antral stage. Methylation status of DMRs of maternally imprinted (Snrpn, Igf2r, and Mest) and paternally imprinted gene(s) (H19) in mouse germinal vesicle oocytes; trimethylation of histone H3K9, acetylation of histone H4K12, and distance between centromeres of sister chromatids in metaphase II oocytes. Exposure to 3 nM BPA was associated with slightly accelerated follicle development, statistically significant increases in allele methylation errors in DMRs of maternally imprinted genes, and statistically significant decreases in histone H3K9 trimethylation and interkinetochore distance. The disturbances in oocyte genomic imprinting and modification of posttranslational histone and centromere architecture provide the first link between low BPA exposures and induction of epigenetic changes that may contribute to chromosome congression failures and meiotic errors, and to altered gene expression that might affect health of the offspring. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  4. Molecularly imprinted poly (methacrylamide-co-methacrylic acid) composite membranes for recognition of curcumin

    International Nuclear Information System (INIS)

    Wang Ping; Hu Wenming; Su Weike

    2008-01-01

    In this study, molecularly imprinted poly (methacrylamide-co-methacrylic acid) composite membranes with different ratio of methacrylamide (MAM) versus methacrylic acid (MAA) were prepared via UV initiated photo-copolymerization on the commercial filter paper. Curcumin was chosen as the template molecule. Infra-red (IR) spectroscopy was used to study the binding mechanism between the imprinted sites and the templates. The morphology of the resultant membranes was visualized by scanning electron microscopy (SEM). Static equilibrium binding and recognition properties of the imprinted composite membranes to curcumin (cur-I) and its analogues demethoxycurcumin (cur-II) or bisdemethoxycurcumin (cur-III) were tested. The results showed that curcumin-imprinted membranes had the best recognition ability to curcumin compared to its analogues. From the results, the biggest selectivity factor of α cur-I/cur-II and α cur-I/cur-III were 1.50 and 5.94, and they were obtained from the composite membranes in which MAM/MAA were 1:4 and 0:1, respectively. The results of this study implied that the molecularly imprinted composite membranes could be used as separation membranes for curcumin enrichment

  5. Dispersive solid-phase imprinting of proteins for the production of plastic antibodies

    DEFF Research Database (Denmark)

    Ashley, Jon; Feng, Xiaotong; Halder, Arnab

    2018-01-01

    We describe a novel dispersive solid-phase imprinting technique for the production of nano-sized molecularly imprinted polymers (nanoMIPs) as plastic antibodies. The template was immobilized on in-house synthesized magnetic microspheres instead of conventional glass beads. As a result, high...

  6. Imprinted Genes and the Environment: Links to the Toxic Metals Arsenic, Cadmium and Lead

    Science.gov (United States)

    Smeester, Lisa; Yosim, Andrew E.; Nye, Monica D.; Hoyo, Cathrine; Murphy, Susan K.; Fry, Rebecca C.

    2014-01-01

    Imprinted genes defy rules of Mendelian genetics with their expression tied to the parent from whom each allele was inherited. They are known to play a role in various diseases/disorders including fetal growth disruption, lower birth weight, obesity, and cancer. There is increasing interest in understanding their influence on environmentally-induced disease. The environment can be thought of broadly as including chemicals present in air, water and soil, as well as food. According to the Agency for Toxic Substances and Disease Registry (ATSDR), some of the highest ranking environmental chemicals of concern include metals/metalloids such as arsenic, cadmium, and lead. The complex relationships between toxic metal exposure, imprinted gene regulation/expression and health outcomes are understudied. Herein we examine trends in imprinted gene biology, including an assessment of the imprinted genes and their known functional roles in the cell, particularly as they relate to toxic metals exposure and disease. The data highlight that many of the imprinted genes have known associations to developmental diseases and are enriched for their role in the TP53 and AhR pathways. Assessment of the promoter regions of the imprinted genes resulted in the identification of an enrichment of binding sites for two transcription factor families, namely the zinc finger family II and PLAG transcription factors. Taken together these data contribute insight into the complex relationships between toxic metals in the environment and imprinted gene biology. PMID:24921406

  7. Imprinted Genes and the Environment: Links to the Toxic Metals Arsenic, Cadmium and Lead

    Directory of Open Access Journals (Sweden)

    Lisa Smeester

    2014-06-01

    Full Text Available Imprinted genes defy rules of Mendelian genetics with their expression tied to the parent from whom each allele was inherited. They are known to play a role in various diseases/disorders including fetal growth disruption, lower birth weight, obesity, and cancer. There is increasing interest in understanding their influence on environmentally-induced disease. The environment can be thought of broadly as including chemicals present in air, water and soil, as well as food. According to the Agency for Toxic Substances and Disease Registry (ATSDR, some of the highest ranking environmental chemicals of concern include metals/metalloids such as arsenic, cadmium, lead and mercury. The complex relationships between toxic metal exposure, imprinted gene regulation/expression and health outcomes are understudied. Herein we examine trends in imprinted gene biology, including an assessment of the imprinted genes and their known functional roles in the cell, particularly as they relate to toxic metals exposure and disease. The data highlight that many of the imprinted genes have known associations to developmental diseases and are enriched for their role in the TP53 and AhR pathways. Assessment of the promoter regions of the imprinted genes resulted in the identification of an enrichment of binding sites for two transcription factor families, namely the zinc finger family II and PLAG transcription factors. Taken together these data contribute insight into the complex relationships between toxic metals in the environment and imprinted gene biology.

  8. A role for chromatin topology in imprinted domain regulation.

    Science.gov (United States)

    MacDonald, William A; Sachani, Saqib S; White, Carlee R; Mann, Mellissa R W

    2016-02-01

    Recently, many advancements in genome-wide chromatin topology and nuclear architecture have unveiled the complex and hidden world of the nucleus, where chromatin is organized into discrete neighbourhoods with coordinated gene expression. This includes the active and inactive X chromosomes. Using X chromosome inactivation as a working model, we utilized publicly available datasets together with a literature review to gain insight into topologically associated domains, lamin-associated domains, nucleolar-associating domains, scaffold/matrix attachment regions, and nucleoporin-associated chromatin and their role in regulating monoallelic expression. Furthermore, we comprehensively review for the first time the role of chromatin topology and nuclear architecture in the regulation of genomic imprinting. We propose that chromatin topology and nuclear architecture are important regulatory mechanisms for directing gene expression within imprinted domains. Furthermore, we predict that dynamic changes in chromatin topology and nuclear architecture play roles in tissue-specific imprint domain regulation during early development and differentiation.

  9. Aberrant epigenetic reprogramming of imprinted microRNA-127 and Rtl1 in cloned mouse embryos

    International Nuclear Information System (INIS)

    Cui Xiangshun; Zhang Dingxiao; Ko, Yoeung-Gyu; Kim, Nam-Hyung

    2009-01-01

    The microRNA (miRNA) genes mir-127 and mir-136 are located near two CpG islands in the imprinted mouse retrotransposon-like gene Rtl1, a key gene involved in placenta formation. These miRNAs appear to be involved in regulating the imprinting of Rtl1. To obtain insights into the epigenetic reprogramming of cloned embryos, we compared the expression levels of mir-127 and mir-136 in fertilized mouse embryos, parthenotes, androgenotes and cloned embryos developing in vitro. We also examined the DNA methylation status of the promoter regions of Rtl1 and mir-127 in these embryos. Our data showed that mir-127 and mir-136 were highly expressed in parthenotes, but rarely expressed in androgenotes. Interestingly, the expression levels of mir-127 and mir-136 in parthenotes were almost twice that seen in the fertilized embryos, but were much lower in the cloned embryos. The Rtl1 promoter region was hyper-methylated in blastocyst stage parthenotes (75.0%), moderately methylated (32.4%) in the fertilized embryos and methylated to a much lower extent (∼10%) in the cloned embryos. Conversely, the promoter region of mir-127 was hypo-methylated in parthenogenetically activated embryos (0.4%), moderately methylated (30.0%) in fertilized embryos and heavily methylated in cloned blastocysts (63-70%). These data support a role for mir-127 and mir-136 in the epigenetic reprogramming of the Rtl1 imprinting process. Analysis of the aberrant epigenetic reprogramming of mir-127 and Rtl1 in cloned embryos may help to explain the nuclear reprogramming procedures that occur in donor cells following somatic cell nuclear transfer (SCNT).

  10. Preparation of mixed molecularly imprinted polymer magnetic nanoparticles and its application in separation of Chinese traditional medicine

    Science.gov (United States)

    Xie, Yihui; Ma, Yajuan; Bai, Wenting; Zhu, Xiaofang; Liu, Min; Huang, Liping

    2017-08-01

    A mixed imprinted polymer which can rapidly adsorb all flavonoids from raspberry extract was prepared and recycled. The hybrid molecular surface imprinted polymers were prepared by using quercetin as the template molecule and Fe3O4 magnetic nanospheres as the carrier. The molecular imprinting polymer was prepared by using the "initial template molecule, molecularly imprinted polymer, mixed template molecule, molecularly imprint ted polymers (MIPS)". The adsorption performance and durability of the hybrid molecularly imprinted polymers were investigated by using the fingerprints of the ethyl acetate fraction of raspberry as an index. The adsorption of flavonoids from raspberry extract, lindenoside, cis-lindenin, quercetin, kaempferol and other flavonoids was completely adsorbed by mixed molecular-imprinted polymer, and the other components were basically adsorbed. When Mix-IMPs were repeatedly used 10 times, the fingerprints showed that the content and content of flavonoids were basically the same. The experimental results show that Mix-IMPs has good adsorption performance, can be recycled and used for rapid enrichment of flavonoids in raspberry.

  11. Ni(II) ion-imprinted solid-phase extraction and preconcentration in aqueous solutions by packed-bed columns

    International Nuclear Information System (INIS)

    Ersoez, Arzu; Say, Ridvan; Denizli, Adil

    2004-01-01

    Solid-phase extraction (SPE) columns packed with materials based on molecularly imprinted polymers (MIPs) were used to develop selective separation and preconcentration for Ni(II) ion from aqueous solutions. SPE is more rapid, simple and economical method than the traditional liquid-liquid extraction. MIPs were used as column sorbent to increase the grade of selectivity in SPE columns. In this study, we have developed a polymer obtained by imprinting with Ni(II) ion as a ion-imprinted SPE sorbent. For this purpose, NI(II)-methacryloylhistidinedihydrate (MAH/Ni(II)) complex monomer was synthesized and polymerized with cross-linking ethyleneglycoldimethacrylate to obtain [poly(EGDMA-MAH/Ni(II))]. Then, Ni(II) ions were removed from the polymer getting Ni(II) ion-imprinted sorbent. The MIP-SPE preconcentration procedure showed a linear calibration curve within concentration range from 0.3 to 25 ng/ml and the detection limit was 0.3 ng/ml (3 s) for flame atomic absorption spectrometry (FAAS). Ni(II) ion-imprinted microbeads can be used several times without considerable loss of adsorption capacity. When the adsorption capacity of nickel imprinted microbeads were compared with non-imprinted microbeads, nickel imprinted microbeads have higher adsorption capacity. The K d (distribution coefficient) values for the Ni(II)-imprinted microbeads show increase in K d for Ni(II) with respect to both K d values of Zn(II), Cu(II) and Co(II) ions and non-imprinted polymer. During that time K d decreases for Zn(II), Cu(II) and Co(II) ions and the k' (relative selectivity coefficient) values which are greater than 1 for imprinted microbeads of Ni(II)/Cu(II), Ni(II)/Zn(II) and Ni(II)/Co(II) are 57.3, 53.9, and 17.3, respectively. Determination of Ni(II) ion in sea water showed that the interfering matrix had been almost removed during preconcentration. The column was good enough for Ni determination in matrixes containing similar ionic radii ions such as Cu(II), Zn(II) and Co(II)

  12. Diverging Cohesion?

    DEFF Research Database (Denmark)

    Charron, Nicholas

    2016-01-01

    – which we define here as a combination of impartial bureaucratic practices, corruption and the rule of law – limits, and in some cases reverses the tendency towards greater divergence linked to trade. Countries with high levels of state capacity – that is, those that have greater government effectiveness......, stronger rule of law and lower corruption – experience lower levels of divergence, as they have the mechanisms to counterbalance the strong centripetal forces linked to openness. This claim is tested on countries that have experienced relatively high levels of increases in levels of economic and political......Why do increases in globalisation in the face of European expansion lead to sharp levels of regional divergences in wealth in some countries but not in others? The central crux of this paper is that convergence/divergence trends in European states are conditioned by ‘state capacity’. State capacity...

  13. Molecularly Imprinted Polymers as Extracting Media for the Chromatographic Determination of Antibiotics in Milk

    Directory of Open Access Journals (Sweden)

    Dimitrios Bitas

    2018-02-01

    Full Text Available Milk-producing animals are typically kept stationary in overcrowded large-scale farms and in most cases under unsanitary conditions, which promotes the development of infections. In order to maintain sufficient health status among the herd or promote growth and increase production, farmers administer preventative antibiotic doses to the animals through their feed. However, many antibiotics used in cattle farms are intended for the treatment of bacterial infections in humans. This results in the development of antibiotic-resistant bacteria which pose a great risk for public health. Additionally, antibiotic residues are found in milk and dairy products, with potential toxic effects for the consumers. Hence the need of antibiotic residues monitoring in milk arises. Analytical methods were developed for the determination of antibiotics in milk, with key priority given to the analyte extraction and preconcentration step. Extraction can benefit from the production of molecularly imprinted polymers (MIPs that can be applied as sorbents for the extraction of specific antibiotics. This review focuses on the principals of molecular imprinting technology and synthesis methods of MIPs, as well as the application of MIPs and MIPs composites for the chromatographic determination of various antibiotic categories in milk found in the recent literature.

  14. ADSORPTION PROCESS OF MOLECULARLY IMPRINTED SILICA FOR EXTRACTION OF LACTOSE FROM MILK

    Directory of Open Access Journals (Sweden)

    A. L. Balieiro

    Full Text Available Abstract In Brazil, about 25-30% of the population has some degree of intolerance to lactose, a disorder associated with the inability of the body to digest lactose due to a disability or absence of the enzyme lactase. The goal of this study was to evaluate the performance of adsorption of lactose from fresh milk using a fixed bed column of molecularly imprinted polymer (MIP. The polymeric material was characterized using Scanning electron microscopy (SEM analysis, thermal analysis (e.g., differential scanning calorimetric (DSC and thermogravimetric analysis (TGA, Fourier Transform Infrared Spectroscopy (FTIR, and the method of Braunauer, Emmet and Teller (BET. The adsorption column dynamics and performance were studied by the breakthrough curves using a 24-1 fractional factorial design. The chemical and structural characterization of the pure matrix and imprinted polymers confirmed the molecularly imprinted polymer (MIP imprinted with lactose. The highest capacity was 62.21 mgg-1, obtained at 307.1 K and a flow rate of 12.5 mL.min-1, with central point conditions, 320.1 K and 9 mL.min-1, with an average value of 50.9 mg.g-1. The results indicate that the molecularly imprinted polymer is efficient.

  15. Towards bilirubin imprinted poly(methacrylic acid-co-ethylene glycol dimethylacrylate) for the specific binding of α-bilirubin

    International Nuclear Information System (INIS)

    Syu, M.-J.; Deng, J.-H.; Nian, Y.-M.

    2004-01-01

    With α-bilirubin as a molecular template, polymerization of methacrylic acid (MAA) was carried out with the aid of the initiator 2,2-azobisisobutyronitrile (AIBN) and the cross-linking agent ethylene glycol dimethylacrylate (EGDMA). Bulk polymerization was successfully carried out so that poly(methacrylic acid-co-ethylene glycol dimethylacrylate) (poly(MAA-EGDMA)) imprinted with α-bilirubin was first developed. UV irradiation polymerization and heated polymerization methods were compared. Effect of different ratios of monomer to EGDMA during the polymerization was also discussed. Proper solvent for better desorption of α-bilirubin from the imprinted poly(MAA-EGDMA) was investigated. In addition, SEM photos were provided for observing the differences between the surfaces of the imprinted poly(MAA-EGDMA) before and after extraction. The corresponding binding results of α-bilirubin imprinted poly(MAA-EGDMA) and non-imprinted poly(MAA-EGDMA) both after extraction were compared. How the pH values during extraction stage affected the binding capacities of the imprinted polymer as well as non-imprinted polymer were also discussed. Similar study and comparison were made for different binding pH values. Different compounds of similar molecular weight were used to show the specific binding of the imprinted polymer for bilirubin. The results further confirmed the successful binding as well as specificity of the imprinted poly(MAA-EGDMA) for α-bilirubin

  16. Muzzle imprint mark: a patterned injury which may be constituted of intradermal blood extravasations.

    Science.gov (United States)

    Pircher, R; Bielefeld, L; Geisenberger, D; Große Perdekamp, M; Pollak, S; Thierauf-Emberger, A

    2014-11-01

    The muzzle imprint mark in contact shots is usually regarded as a patterned pressure abrasion depicting the barrel end as well as adjacent constructional components of the weapon. Due to parching after exposure to air, the affected skin assumes a brown color, especially along the contours of the impacting structures. Apart from this well-known type of epidermal damage, the imprint mark may also be formed by intradermal hemorrhages. In some cases, these intracutaneous bleedings manifest themselves as circular, curved or straight reddish lines mirroring the surface relief of the weapon's muzzle end. To estimate the frequency of skin hematomas in muzzle imprints, 35 consecutive contact shots to the head (temple, forehead, submental and occipital region) were evaluated. In 3 cases, the muzzle imprint mark exclusively consisted of intracutaneous bruises surrounding the bullet entrance hole. In 14 cases, the muzzle imprint was composed of both excoriations and intradermal hematomas. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  17. Distinct Circuits for the Formation and Retrieval of an Imprinted Olfactory Memory.

    Science.gov (United States)

    Jin, Xin; Pokala, Navin; Bargmann, Cornelia I

    2016-02-11

    Memories formed early in life are particularly stable and influential, representing privileged experiences that shape enduring behaviors. We show that exposing newly hatched C. elegans to pathogenic bacteria results in persistent aversion to those bacterial odors, whereas adult exposure generates only transient aversive memory. Long-lasting imprinted aversion has a critical period in the first larval stage and is specific to the experienced pathogen. Distinct groups of neurons are required during formation (AIB, RIM) and retrieval (AIY, RIA) of the imprinted memory. RIM synthesizes the neuromodulator tyramine, which is required in the L1 stage for learning. AIY memory retrieval neurons sense tyramine via the SER-2 receptor, which is essential for imprinted, but not for adult-learned, aversion. Odor responses in several neurons, most notably RIA, are altered in imprinted animals. These findings provide insight into neuronal substrates of different forms of memory, and lay a foundation for further understanding of early learning. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Recognition of conformational changes in beta-lactoglobulin by molecularly imprinted thin films.

    Science.gov (United States)

    Turner, Nicholas W; Liu, Xiao; Piletsky, Sergey A; Hlady, Vladimir; Britt, David W

    2007-09-01

    Pathogenesis in protein conformational diseases is initiated by changes in protein secondary structure. This molecular restructuring presents an opportunity for novel shape-based detection approaches, as protein molecular weight and chemistry are otherwise unaltered. Here we apply molecular imprinting to discriminate between distinct conformations of the model protein beta-lactoglobulin (BLG). Thermal- and fluoro-alcohol-induced BLG isoforms were imprinted in thin films of 3-aminophenylboronic acid on quartz crystal microbalance chips. Enhanced rebinding of the template isoform was observed in all cases when compared to the binding of nontemplate isoforms over the concentration range of 1-100 microg mL(-1). Furthermore, it was observed that the greater the changes in the secondary structure of the template protein the lower the binding of native BLG challenges to the imprint, suggesting a strong steric influence in the recognition system. This feasibility study is a first demonstration of molecular imprints for recognition of distinct conformations of the same protein.

  19. Recognition of Conformational Changes in β-Lactoglobulin by Molecularly Imprinted Thin Films

    Science.gov (United States)

    Turner, Nicholas W.; Liu, Xiao; Piletsky, Sergey A.; Hlady, Vladimir; Britt, David W.

    2008-01-01

    Pathogenesis in protein conformational diseases is initiated by changes in protein secondary structure. This molecular restructuring presents an opportunity for novel shape-based detection approaches, as protein molecular weight and chemistry are otherwise unaltered. Here we apply molecular imprinting to discriminate between distinct conformations of the model protein β-lactoglobulin (BLG). Thermal- and fluoro-alcohol-induced BLG isoforms were imprinted in thin films of 3-aminophenylboronic acid on quartz crystal microbalance chips. Enhanced rebinding of the template isoform was observed in all cases when compared to the binding of nontemplate isoforms over the concentration range of 1–100 µg mL−1. Furthermore, it was observed that the greater the changes in the secondary structure of the template protein the lower the binding of native BLG challenges to the imprint, suggesting a strong steric influence in the recognition system. This feasibility study is a first demonstration of molecular imprints for recognition of distinct conformations of the same protein. PMID:17665947

  20. Biomimetic Silica Nanoparticles Prepared by a Combination of Solid-Phase Imprinting and Ostwald Ripening.

    Science.gov (United States)

    Piletska, Elena; Yawer, Heersh; Canfarotta, Francesco; Moczko, Ewa; Smolinska-Kempisty, Katarzyna; Piletsky, Stanislav S; Guerreiro, Antonio; Whitcombe, Michael J; Piletsky, Sergey A

    2017-09-14

    Herein we describe the preparation of molecularly imprinted silica nanoparticles by Ostwald ripening in the presence of molecular templates immobilised on glass beads (the solid-phase). To achieve this, a seed material (12 nm diameter silica nanoparticles) was incubated in phosphate buffer in the presence of the solid-phase. Phosphate ions act as a catalyst in the ripening process which is driven by differences in surface energy between particles of different size, leading to the preferential growth of larger particles. Material deposited in the vicinity of template molecules results in the formation of sol-gel molecular imprints after around 2 hours. Selective washing and elution allows the higher affinity nanoparticles to be isolated. Unlike other strategies commonly used to prepare imprinted silica nanoparticles this approach is extremely simple in nature and can be performed under physiological conditions, making it suitable for imprinting whole proteins and other biomacromolecules in their native conformations. We have demonstrated the generic nature of this method by preparing imprinted silica nanoparticles against targets of varying molecular mass (melamine, vancomycin and trypsin). Binding to the imprinted particles was demonstrated in an immunoassay (ELISA) format in buffer and complex media (milk or blood plasma) with sub-nM detection ability.

  1. Molecularly Imprinted Polymer Technology: A Powerful, Generic ...

    African Journals Online (AJOL)

    Molecularly Imprinted Polymer Technology: A Powerful, Generic, Facile and Cost Effective Alternative for Enantio-recognition and Separation: A Glance at Advances and Applications. ... Tanzania Journal of Science. Journal Home · ABOUT ...

  2. Imprint lithography: lab curiosity or the real NGL

    Science.gov (United States)

    Resnick, Douglas J.; Dauksher, William J.; Mancini, David P.; Nordquist, Kevin J.; Bailey, Todd C.; Johnson, Stephen C.; Stacey, Nicholas A.; Ekerdt, John G.; Willson, C. Grant; Sreenivasan, S. V.; Schumaker, Norman E.

    2003-06-01

    The escalating cost for Next Generation Lithography (NGL) tools is driven in part by the need for complex sources and optics. The cost for a single NGL tool could exceed $50M in the next few years, a prohibitive number for many companies. As a result, several researchers are looking at low cost alternative methods for printing sub-100 nm features. In the mid-1990s, several resarech groups started investigating different methods for imprinting small features. Many of these methods, although very effective at printing small features across an entire wafer, are limited in their ability to do precise overlay. In 1999, Willson and Sreenivasan discovered that imprinting could be done at low pressures and at room temperatures by using low viscosity UV curable monomers. The technology is typically referred to as Step and Flash Imprint Lithography. The use of a quartz template enabled the photocuring process to occur and also opened up the potential for optical alignment of teh wafer and template. This paper traces the development of nanoimprint lithography and addresses the issues that must be solved if this type of technology is to be applied to high-density silicon integrated circuitry.

  3. Detection of nicotine based on molecularly imprinted TiO{sub 2}-modified electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Wu, C.-T.; Chen, P.-Y.; Chen, J.-G.; Suryanarayanan, Vembu [Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Ho, K.-C. [Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Institute of Polymer Science and Engineering, National Taiwan University, Taipei 10617, Taiwan (China)], E-mail: kcho@ntu.edu.tw

    2009-02-02

    Amperometric detection of nicotine (NIC) was carried out on a titanium dioxide (TiO{sub 2})/poly(3,4-ethylenedioxythiophene) (PEDOT)-modified electrode by a molecular imprinting technique. In order to improve the conductivity of the substrate, PEDOT was coated onto the sintered electrode by in situ electrochemical polymerization of the monomer. The sensing potential of the NIC-imprinted TiO{sub 2} electrode (ITO/TiO{sub 2}[NIC]/PEDOT) in a phosphate-buffered saline (PBS) solution (pH 7.4) containing 0.1 M KCl was determined to be 0.88 V (vs. Ag/AgCl/saturated KCl). The linear detection range for NIC oxidation on the so-called ITO/TiO{sub 2}[NIC]/PEDOT electrode was 0-5 mM, with a sensitivity and limit of detection of 31.35 {mu}A mM{sup -1} cm{sup -2} and 4.9 {mu}M, respectively. When comparing with the performance of the non-imprinted one, the sensitivity ratio was about 1.24. The sensitivity enhancement was attributed to the increase in the electroactive area of the imprinted electrode. The at-rest stability of the ITO/TiO{sub 2}[NIC]/PEDOT electrode was tested over a period of 3 days. The current response remained about 85% of its initial value at the end of 2 days. The ITO/TiO{sub 2}[NIC]/PEDOT electrode showed reasonably good selectivity in distinguishing NIC from its major interferent, (-)-cotinine (COT). Moreover, scanning electrochemical microscopy (SECM) was employed to elucidate the surface morphology of the imprinted and non-imprinted electrodes using Fe(CN){sub 6}{sup 3-}/Fe(CN){sub 6}{sup 4-} as a redox probe on a platinum tip. The imprinted electrode was further characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR)

  4. Obesity-related DNA methylation at imprinted genes in human sperm: Results from the TIEGER study.

    Science.gov (United States)

    Soubry, Adelheid; Guo, Lisa; Huang, Zhiqing; Hoyo, Cathrine; Romanus, Stephanie; Price, Thomas; Murphy, Susan K

    2016-01-01

    Epigenetic reprogramming in mammalian gametes resets methylation marks that regulate monoallelic expression of imprinted genes. In males, this involves erasure of the maternal methylation marks and establishment of paternal-specific methylation to appropriately guide normal development. The degree to which exogenous factors influence the fidelity of methylation reprogramming is unknown. We previously found an association between paternal obesity and altered DNA methylation in umbilical cord blood, suggesting that the father's endocrine, nutritional, or lifestyle status could potentiate intergenerational heritable epigenetic abnormalities. In these analyses, we examine the relationship between male overweight/obesity and DNA methylation status of imprinted gene regulatory regions in the gametes. Linear regression models were used to compare sperm DNA methylation percentages, quantified by bisulfite pyrosequencing, at 12 differentially methylated regions (DMRs) from 23 overweight/obese and 44 normal weight men. Our study population included 69 volunteers from The Influence of the Environment on Gametic Epigenetic Reprogramming (TIEGER) study, based in NC, USA. After adjusting for age and fertility patient status, semen from overweight or obese men had significantly lower methylation percentages at the MEG3 (β = -1.99; SE = 0.84; p = 0.02), NDN (β = -1.10; SE = 0.47; p = 0.02), SNRPN (β = -0.65; SE = 0.27; p = 0.02), and SGCE/PEG10 (β = -2.5; SE = 1.01; p = 0.01) DMRs. Our data further suggest a slight increase in DNA methylation at the MEG3-IG DMR (β = +1.22; SE = 0.59; p = 0.04) and H19 DMR (β = +1.37; SE = 0.62; p = 0.03) in sperm of overweight/obese men. Our data support that male overweight/obesity status is traceable in the sperm epigenome. Further research is needed to understand the effect of such changes and the point of origin of DNA methylation differences between lean and

  5. Translational control of auditory imprinting and structural plasticity by eIF2α

    Science.gov (United States)

    Batista, Gervasio; Johnson, Jennifer Leigh; Dominguez, Elena; Costa-Mattioli, Mauro; Pena, Jose L

    2016-01-01

    The formation of imprinted memories during a critical period is crucial for vital behaviors, including filial attachment. Yet, little is known about the underlying molecular mechanisms. Using a combination of behavior, pharmacology, in vivo surface sensing of translation (SUnSET) and DiOlistic labeling we found that, translational control by the eukaryotic translation initiation factor 2 alpha (eIF2α) bidirectionally regulates auditory but not visual imprinting and related changes in structural plasticity in chickens. Increasing phosphorylation of eIF2α (p-eIF2α) reduces translation rates and spine plasticity, and selectively impairs auditory imprinting. By contrast, inhibition of an eIF2α kinase or blocking the translational program controlled by p-eIF2α enhances auditory imprinting. Importantly, these manipulations are able to reopen the critical period. Thus, we have identified a translational control mechanism that selectively underlies auditory imprinting. Restoring translational control of eIF2α holds the promise to rejuvenate adult brain plasticity and restore learning and memory in a variety of cognitive disorders. DOI: http://dx.doi.org/10.7554/eLife.17197.001 PMID:28009255

  6. Loss of Gnas imprinting differentially affects REM/NREM sleep and cognition in mice.

    Directory of Open Access Journals (Sweden)

    Glenda Lassi

    Full Text Available It has been suggested that imprinted genes are important in the regulation of sleep. However, the fundamental question of whether genomic imprinting has a role in sleep has remained elusive up to now. In this work we show that REM and NREM sleep states are differentially modulated by the maternally expressed imprinted gene Gnas. In particular, in mice with loss of imprinting of Gnas, NREM and complex cognitive processes are enhanced while REM and REM-linked behaviors are inhibited. This is the first demonstration that a specific overexpression of an imprinted gene affects sleep states and related complex behavioral traits. Furthermore, in parallel to the Gnas overexpression, we have observed an overexpression of Ucp1 in interscapular brown adipose tissue (BAT and a significant increase in thermoregulation that may account for the REM/NREM sleep phenotypes. We conclude that there must be significant evolutionary advantages in the monoallelic expression of Gnas for REM sleep and for the consolidation of REM-dependent memories. Conversely, biallelic expression of Gnas reinforces slow wave activity in NREM sleep, and this results in a reduction of uncertainty in temporal decision-making processes.

  7. The imprinted brain: how genes set the balance between autism and psychosis.

    Science.gov (United States)

    Badcock, Christopher

    2011-06-01

    The imprinted brain theory proposes that autism spectrum disorder (ASD) represents a paternal bias in the expression of imprinted genes. This is reflected in a preference for mechanistic cognition and in the corresponding mentalistic deficits symptomatic of ASD. Psychotic spectrum disorder (PSD) would correspondingly result from an imbalance in favor of maternal and/or X-chromosome gene expression. If differences in gene expression were reflected locally in the human brain as mouse models and other evidence suggests they are, ASD would represent not so much an 'extreme male brain' as an extreme paternal one, with PSD correspondingly representing an extreme maternal brain. To the extent that copy number variation resembles imprinting and aneuploidy in nullifying or multiplying the expression of particular genes, it has been found to conform to the diametric model of mental illness peculiar to the imprinted brain theory. The fact that nongenetic factors such as nutrition in pregnancy can mimic and/or interact with imprinted gene expression suggests that the theory might even be able to explain the notable effect of maternal starvation on the risk of PSD - not to mention the 'autism epidemic' of modern affluent societies. Finally, the theory suggests that normality represents balanced cognition, and that genius is an extraordinary extension of cognitive configuration in both mentalistic and mechanistic directions. Were it to be proven correct, the imprinted brain theory would represent one of the biggest single advances in our understanding of the mind and of mental illness that has ever taken place, and would revolutionize psychiatric diagnosis, prevention and treatment - not to mention our understanding of epigenomics.

  8. [The peculiar morphological features of the imprints of straight and wavy head hair dirtied with blood].

    Science.gov (United States)

    Leonova, E N; Nagornov, M N; Prokhorenko, A S

    2018-01-01

    The objective of the present study was to elucidate the specific morphological features of the imprints of blood-soaked straight and wavy head hair. The contact imprints of straight and wavy head hair dirtied with blood were obtained experimentally. The imprints of straight hair were shown to exhibit the elements in the form of the rectilinear and bow-shaped slightly bent stripes. The imprints of wavy hair were shaped as the arches, waves, circles, and a large number of various small elements, such as dashes and commas.

  9. Laser imprint and implications for direct drive ignition with the National Ignition Facility

    International Nuclear Information System (INIS)

    Weber, S.V.; Glendinning, S.G.; Kalantar, D.H.; Remington, B.A.; Rothenberg, J.E.

    1996-01-01

    For direct drive ICF, nonuniformities in laser illumination can seed ripples at the ablation front in a process called imprint. Such nonuniformities will grow during the capsule implosion and can penetrate the capsule shell impede ignition, or degrade burn. We have simulated imprint for a number of experiments on tile Nova laser. Results are in generally good agreement with experimental data. We leave also simulated imprint upon National Ignition Facility (NIF) direct drive ignition capsules. Imprint modulation amplitude comparable to the intrinsic surface finish of ∼40 nm is predicted for a laser bandwidth of 0.5 THz. Ablation front modulations experience growth factors up to several thousand, carrying modulation well into the nonlinear regime. Saturation modeling predicts that the shell should remain intact at the time of peak velocity, but penetration at earlier times appears more marginal

  10. Controlled Vectorial Electron Transfer and Photoelectrochemical Applications of Layered Relay/Photosensitizer-Imprinted Au Nanoparticle Architectures on Electrodes.

    Science.gov (United States)

    Metzger, Tzuriel S; Tel-Vered, Ran; Willner, Itamar

    2016-03-23

    Two configurations of molecularly imprinted bis-aniline-bridged Au nanoparticles (NPs) for the specific binding of the electron acceptor N,N'-dimethyl-4,4'-bipyridinium (MV(2+) ) and for the photosensitizer Zn(II)-protoporphyrin IX (Zn(II)-PP-IX) are assembled on electrodes, and the photoelectrochemical features of the two configurations are discussed. Configuration I includes the MV(2+) -imprinted Au NPs matrix as a base layer, on which the Zn(II)-PP-IX-imprinted Au NPs layer is deposited, while configuration II consists of a bilayer corresponding to the reversed imprinting order. Irradiation of the two electrodes in the presence of a benzoquinone/benzohydroquinone redox probe yields photocurrents of unique features: (i) Whereas configuration I yields an anodic photocurrent, the photocurrent generated by configuration II is cathodic. (ii) The photocurrents obtained upon irradiation of the imprinted electrodes are substantially higher as compared to the nonimprinted surfaces. The high photocurrents generated by the imprinted Au NPs-modified electrodes are attributed to the effective loading of the imprinted matrices with the MV(2+) and Zn(II)-PP-IX units and to the effective charge separation proceeding in the systems. The directional anodic/cathodic photocurrents are rationalized in terms of vectorial electron transfer processes dictated by the imprinting order and by the redox potentials of the photosensitizer/electron acceptor units associated with the imprinted sites in the two configurations. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Magnetic deep eutectic solvents molecularly imprinted polymers for the selective recognition and separation of protein

    International Nuclear Information System (INIS)

    Liu, Yanjin; Wang, Yuzhi; Dai, Qingzhou; Zhou, Yigang

    2016-01-01

    A novel and facile magnetic deep eutectic solvents (DES) molecularly imprinted polymers (MIPs) for the selective recognition and separation of Bovine hemoglobin (BHb) was prepared. The new-type DES was adopted as the functional monomer which would bring molecular imprinted technology to a new direction. The amounts of DES were optimized. The obtained magnetic DES-MIPs were characterized with fourier transform infrared spectrometry (FT-IR), thermogravimetric analysis (TGA), field emission scanning electron microscope (FESEM), dynamic light scattering (DLS), elemental analysis and vibrating sample magnetometer (VSM). The results suggested that the imprinted polymers were successfully formed and possessed a charming magnetism. The maximum adsorption capability (Q_m_a_x) and dissociation constant (K_L) were analyzed by Langmuir isotherms (R"2 = 0.9983) and the value were estimated to be 175.44 mg/g and 0.035 mg/mL for the imprinted particles. And the imprinted particles showed a high imprinting factor of 4.77. In addition, the magnetic DES-MIPs presented outstanding recognition specificity and selectivity so that it can be utilized to separate template protein from the mixture of proteins and real samples. Last but not least, the combination of deep eutectic solvents and molecular imprinted technology in this paper provides a new perspective for the recognition and separation of proteins. - Highlights: • Combined green deep eutectic solvents (DES) and molecular imprinted technology in recognition and separation of proteins. • DES was adopted as a new-type functional monomer. • The obtained magnetic DES-MIPs can separate proteins rapidly by an external magnetic field. • Adsorption and selectivity properties were discussed.

  12. Magnetic deep eutectic solvents molecularly imprinted polymers for the selective recognition and separation of protein

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yanjin [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Wang, Yuzhi, E-mail: wyzss@hnu.edu.cn [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Dai, Qingzhou [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Zhou, Yigang [Department of Microbiology, College of Basic Medicine, Central South University, Changsha, 410083 (China)

    2016-09-14

    A novel and facile magnetic deep eutectic solvents (DES) molecularly imprinted polymers (MIPs) for the selective recognition and separation of Bovine hemoglobin (BHb) was prepared. The new-type DES was adopted as the functional monomer which would bring molecular imprinted technology to a new direction. The amounts of DES were optimized. The obtained magnetic DES-MIPs were characterized with fourier transform infrared spectrometry (FT-IR), thermogravimetric analysis (TGA), field emission scanning electron microscope (FESEM), dynamic light scattering (DLS), elemental analysis and vibrating sample magnetometer (VSM). The results suggested that the imprinted polymers were successfully formed and possessed a charming magnetism. The maximum adsorption capability (Q{sub max}) and dissociation constant (K{sub L}) were analyzed by Langmuir isotherms (R{sup 2} = 0.9983) and the value were estimated to be 175.44 mg/g and 0.035 mg/mL for the imprinted particles. And the imprinted particles showed a high imprinting factor of 4.77. In addition, the magnetic DES-MIPs presented outstanding recognition specificity and selectivity so that it can be utilized to separate template protein from the mixture of proteins and real samples. Last but not least, the combination of deep eutectic solvents and molecular imprinted technology in this paper provides a new perspective for the recognition and separation of proteins. - Highlights: • Combined green deep eutectic solvents (DES) and molecular imprinted technology in recognition and separation of proteins. • DES was adopted as a new-type functional monomer. • The obtained magnetic DES-MIPs can separate proteins rapidly by an external magnetic field. • Adsorption and selectivity properties were discussed.

  13. Synthesis of uranyl ion imprinted polymer and its application in analysis

    International Nuclear Information System (INIS)

    Xiao Jingshui; Liu Huijun; Xiao Xilin; Huang Shengli

    2011-01-01

    Uranyl ion imprinted polymer beads were prepared by the copolymerization of styrene monomer and divinyl benzene as crosslinking agent in methanol solution,with the UO 2 2+ -o-dihydroxybenzene-4-vinyl pyridine ternary complex as template, the 2, 2'-azo-bis-isobutyronitrile as initiator and UO 2 2+ as the imprinting ion. The uranyl ions were removed from the polymer beads by treating with 6 mol/L HCl, leaving behind cavities that match uranyl ion in size. The treated polymer beads can preconcentrate uranyl ions from dilute aqueous solutions. The adsorption efficiency can reach 99% or above with good selectivity when pH is in the range of 5-7 and the adsorption time is more than 20 min. The elution rate can reach above 99% under the conditions of concentration of HCl being above 1.0 mol/L, elution time more than 20 min and the elution Janume more than 5 times the Janume of ion imprinted polymer. The uranyl ion imprinted polymer beads have been successfully applied to determine micro-uranium in brine samples. The results are satisfactory compared with NBS method.(authors)

  14. Improvement of imprinting effect of ionic liquid molecularly imprinted polymers by use of a molecular crowding agent.

    Science.gov (United States)

    Jia, Man; Yang, Jian; Sun, Ya Kun; Bai, Xi; Wu, Tao; Liu, Zhao Sheng; Aisa, Haji Akber

    2018-01-01

    We aimed to improve the imprinting effect of ionic liquid molecularly imprinted polymers (MIPs) by use of a molecular crowding agent. The ionic liquid 1-vinyl-3-ethylimidazolium tetrafluoroborate ([VEIm][BF 4 ]) was used as the functional monomer and aesculetin was used as the template molecule in a crowding environment, which was made up of a tetrahydrofuran solution of polystyrene. The ionic liquid MIPs that were prepared in the crowding environment displayed an enhanced imprinting effect. NMR peak shifts of active hydrogen of aesculetin suggested that interaction between the functional monomer and the template could be increased by the use of a crowding agent in the self-assembly process. The retention and selectivity of aesculetin were affected greatly by high molecular crowding, the amount of high molecular weight crowding agent, and the ratio of [VEIm][BF 4 ] to aesculetin. The optimal MIPs were used as solid-phase extraction sorbents to extract aesculetin from Cichorium glandulosum. A calibration curve was obtained with aesculetin concentrations from 0.0005 to 0.05 mg mL -1 (correlation coefficient R 2 of 0.9999, y = 1519x + 0.0923). The limit of quantification was 0.12 μg mL -1 , and the limit of detection was 0.05 μg mL -1 . The absolute recovery of aesculetin was (80 ± 2)% (n = 3), and the purity of aesculetin was (92 ± 0.5)% (n = 5). As a conclusion, molecular crowding is an effective approach to obtain ionic liquid MIPs with high selectivity even in a polar solvent environment.

  15. The role of imprinted genes in humans

    OpenAIRE

    Ishida, Miho; Moore, Gudrun E.

    2013-01-01

    Detailed comprehensive molecular analysis using families and multiple matched tissues is essential to determine whether imprinted genes have a functional role in humans. See research article: http://genomebiology.com/2011/12/3/R25

  16. Histamine-imprinted microspheres: Comparison between conventional and raft-mediated polymerization techniques

    International Nuclear Information System (INIS)

    Romano, Edwin F. Jr.; So, Regina C.; Holdsworth, Clovia I.

    2015-01-01

    Molecularly imprinted microspheres (MIM) were synthesized via conventional free radical polymerization (CTP) and RAFT-mediated controlled radical polymerization (CRP) method using histamine as the template molecule. Optimal polymerization conditions were achieved using 4%(w/w) monomer feed concentration with 80=90% EGDMA as crosslinker, and histamine: MAA ratio of 1:4 in acetonitrile at 60°C for 24 hours. The size of CTP-M90 and CTP-M80 imprinted microspheres are comparable with that of RAFT polymer CRP-M80 at 264.5 ±12 nm in the swollen (DLS-DMSO) and collapsed state (SEM). For the CTP method, the presence of the template allows for a bigger particle size compared to the non-imprinted counterpart (NIM). Further, controlled growth was observed for the CRP technique, where the size of the imprinted microsphere, CRP-M80, is comparable to CRP-N80. The binding studies of CTP and CRP microspheres toward histamine were studied at concentrations well below biding with buffer concentration of 25mM at pH7. Results showed that the binding isotherms were found to conform to the Freundlich model. Moreover, results revealed that the difference in binding capacity (N) between MIM and NIM imparted by the imprinting process is significantly higher in CTP-80 (26 μmol/g) than both CTP-90 and CRP-80 (9 μmol/g). Non-competitive and competitive binding assays with L-histidine, imidazole, and tryptamine using CTP-80 and CRP-80 were also carried out. MIMs were shown to exhibit binding preference towards the template. (author)

  17. Imprinted genes and the environment: links to the toxic metals arsenic, cadmium, lead and mercury.

    Science.gov (United States)

    Smeester, Lisa; Yosim, Andrew E; Nye, Monica D; Hoyo, Cathrine; Murphy, Susan K; Fry, Rebecca C

    2014-06-11

    Imprinted genes defy rules of Mendelian genetics with their expression tied to the parent from whom each allele was inherited. They are known to play a role in various diseases/disorders including fetal growth disruption, lower birth weight, obesity, and cancer. There is increasing interest in understanding their influence on environmentally-induced disease. The environment can be thought of broadly as including chemicals present in air, water and soil, as well as food. According to the Agency for Toxic Substances and Disease Registry (ATSDR), some of the highest ranking environmental chemicals of concern include metals/metalloids such as arsenic, cadmium, lead and mercury. The complex relationships between toxic metal exposure, imprinted gene regulation/expression and health outcomes are understudied. Herein we examine trends in imprinted gene biology, including an assessment of the imprinted genes and their known functional roles in the cell, particularly as they relate to toxic metals exposure and disease. The data highlight that many of the imprinted genes have known associations to developmental diseases and are enriched for their role in the TP53 and AhR pathways. Assessment of the promoter regions of the imprinted genes resulted in the identification of an enrichment of binding sites for two transcription factor families, namely the zinc finger family II and PLAG transcription factors. Taken together these data contribute insight into the complex relationships between toxic metals in the environment and imprinted gene biology.

  18. Preparation of diclofenac-imprinted polymer beads for selective molecular separation in water.

    Science.gov (United States)

    Zhou, Tongchang; Kamra, Tripta; Ye, Lei

    2018-03-01

    Molecular imprinting technique is an attractive strategy to prepare materials for target recognition and rapid separation. In this work, a new type of diclofenac (DFC)-imprinted polymer beads was synthesized by Pickering emulsion polymerization using 2-(dimethylamino)ethyl methacrylate as the functional monomer. The selectivity and capacity of the molecularly imprinted polymers (MIPs) were investigated in aqueous solution. Equilibrium binding results show that the MIPs have a high selectivity to bind DFC in a wide range of pH values. Moreover, in liquid chromatography experiment, the imprinted polymer beads were packed into column to investigate the binding selectivity under nonequilibrium conditions. The retention time of DFC on the MIP column is significantly longer than its structural analogues. Also, retention of DFC on the MIP column was significantly longer than on the nonimprinted polymer column under aqueous condition. As the new MIP beads can be used to achieve direct separation of DFC from water, the synthetic method and the affinity beads developed in this work opened new possibilities for removing toxic chemicals from environmental and drinking water. Copyright © 2017 John Wiley & Sons, Ltd.

  19. Microcontact imprinted surface plasmon resonance sensor for myoglobin detection

    International Nuclear Information System (INIS)

    Osman, Bilgen; Uzun, Lokman; Beşirli, Necati; Denizli, Adil

    2013-01-01

    In this study, we prepared surface plasmon resonance (SPR) sensor using the molecular imprinting technique for myoglobin detection in human serum. For this purpose, we synthesized myoglobin imprinted poly(hydroxyethyl methacrylate-N-methacryloyl-L-tryptophan methyl ester) [poly(HEMA-MATrp)] nanofilm on the surface of SPR sensor. We also synthesized non-imprinted poly(HEMA-MATrp) nanofilm without myoglobin for the control experiments. The SPR sensor was characterized with contact angle measurements, atomic force microscopy, X-ray photoelectron spectroscopy, and ellipsometry. We investigated the effectiveness of the sensor using the SPR system. We evaluated the ability of SPR sensor to sense myoglobin with myoglobin solutions (pH 7.4, phosphate buffer) in different concentration range and in the serum taken from a patient with acute myocardial infarction. We found that the Langmuir adsorption model was the most suitable for the sensor system. The detection limit was 87.6 ng/mL. In order to show the selectivity of the SPR sensor, we investigated the competitive detection of myoglobin, lysozyme, cytochrome c and bovine serum albumin. The results showed that the SPR sensor has high selectivity and sensitivity for myoglobin. - Highlights: • Micro-contact imprinted surface plasmon resonance sensor. • Real-time myoglobin detection in the serum taken from a patient with acute myocardial infarction • Reproducible results for consecutive myoglobin solution supplement • LOD and LOQ values of the SPR sensor were determined to be 26.3 and 87.6 ng/mL. • The SPR sensor has potential for myoglobin sensing during acute MI cases

  20. Glucose metabolism, islet architecture, and genetic homogeneity in imprinting of [Ca2+](i and insulin rhythms in mouse islets.

    Directory of Open Access Journals (Sweden)

    Craig S Nunemaker

    2009-12-01

    Full Text Available We reported previously that islets isolated from individual, outbred Swiss-Webster mice displayed oscillations in intracellular calcium ([Ca2+](i that varied little between islets of a single mouse but considerably between mice, a phenomenon we termed "islet imprinting." We have now confirmed and extended these findings in several respects. First, imprinting occurs in both inbred (C57BL/6J as well as outbred mouse strains (Swiss-Webster; CD1. Second, imprinting was observed in NAD(PH oscillations, indicating a metabolic component. Further, short-term exposure to a glucose-free solution, which transiently silenced [Ca2+](i oscillations, reset the oscillatory patterns to a higher frequency. This suggests a key role for glucose metabolism in maintaining imprinting, as transiently suppressing the oscillations with diazoxide, a K(ATP-channel opener that blocks [Ca2+](i influx downstream of glucose metabolism, did not change the imprinted patterns. Third, imprinting was not as readily observed at the level of single beta cells, as the [Ca2+](i oscillations of single cells isolated from imprinted islets exhibited highly variable, and typically slower [Ca2+](i oscillations. Lastly, to test whether the imprinted [Ca2+](i patterns were of functional significance, a novel microchip platform was used to monitor insulin release from multiple islets in real time. Insulin release patterns correlated closely with [Ca2+](i oscillations and showed significant mouse-to-mouse differences, indicating imprinting. These results indicate that islet imprinting is a general feature of islets and is likely to be of physiological significance. While islet imprinting did not depend on the genetic background of the mice, glucose metabolism and intact islet architecture may be important for the imprinting phenomenon.

  1. Nanosecond Characterization of Regional Domain Imprint from Fast Domain Switching Currents in Pb(Zr,Ti)O_3 Thin Films

    International Nuclear Information System (INIS)

    Jun Jiang; An-Quan Jiang

    2016-01-01

    The traditional imprint characterization of ferroelectric thin films estimates imprint time dependence of the mean coercive voltage of all domains from a polarization-voltage hysteresis loop, which shows a semilogarithmic time dependence above an initial imprint time of τ_0 > 1 μs at room temperature. Below τ_0, the imprint effect is believed to be weak. In consideration of region-by-region domain reversal under a rising pulsed voltage with ordered coercive voltages increasing from zero up to the maximum applied voltage during capacitor charging time, we can estimate the imprinted coercive voltage of each domain from domain switching current transient separately with imprint time as short as 20 ns. In disagreement with the previous observations, all imprinted coercive voltages for the domains in Pt/Pb(Zr_0_._4Ti_0_._6)O_3/Pt thin-film capacitors show step-like increases at two characteristic times of 300 ns and 0.27s. The imprint effect is surprisingly strong enough even at shortened time down to 20 ns without any evidence of weakening. (paper)

  2. Simulations of laser imprint for Nova experiments and for ignition capsules. Revision 1

    International Nuclear Information System (INIS)

    Weber, S.V.; Glendinning, S.G.; Kalantar, D.H.; Key, M.H.; Remington, B.A.; Rothenberg, J.L.; Wolfrum, E.; Verdon, C.P.; Knauer, J.P.

    1996-12-01

    In direct drive ICF, nonuniformities in laser illumination seed ripples at the ablation front in a process called ''imprint''. These nonuniformities grow during the capsule implosion and, if initially large enough, can penetrate the capsule shell, impede ignition, or degrade burn. Imprint has been simulated for recent experiments performed on the Nova laser at LLNL examining a variety of beam smoothing conditions. Most used laser intensities similar to the early part of an ignition capsule pulse shape, 1 ≅ 10 13 W/cm 2 . The simulations matched most of the measurements of imprint modulation. The effect of imprint upon National Ignition Facility (NIF) direct drive ignition capsules has also been simulated. Imprint is predicted to give modulation comparable to an intrinsic surface finish of ∼10 nm RMS. Modulation growth was examined using the Haan [Phys. Rev. A 39, 5812 (1989)] model, with linear growth factors as a function of spherical harmonic mode number obtained from an analytic dispersion relation. Ablation front amplitudes are predicted to become substantially nonlinear, so that saturation corrections are large. Direct numerical simulations of two-dimensional multimode growth were also performed. The capsule shell is predicted to remain intact, which gives a basis for believing that ignition can be achieved. 27 refs., 10 figs

  3. Molecularly imprinted polymers for sample preparation and biosensing in food analysis: Progress and perspectives

    DEFF Research Database (Denmark)

    Ashley, Jon; Shahbazi, Mohammad-Ali; Kant, Krishna

    2017-01-01

    Molecularly imprinted polymers (MIPs) are biomimetics which can selectively bind to analytes of interest. One of the most interesting areas where MIPs have shown the biggest potential is food analysis. MIPs have found use as sorbents in sample preparation attributed to the high selectivity and high...... the imprinting methods which are applicable for imprinting food templates, summarize the recent progress in using MIPs for preparing and analysing food samples, and discuss the current limitations in the commercialisation of MIPs technology. Finally, future perspectives will be given....

  4. Molecularly imprinted polymer beads for nicotine recognition prepared by RAFT precipitation polymerization: a step forward towards multifunctionalities

    DEFF Research Database (Denmark)

    Zhou, Tongchang; Jørgensen, Lars; Mattebjerg, Maria Ahlm

    2014-01-01

    A nicotine imprinted polymer was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization using methacrylic acid (MAA) as a functional monomer. The resulting molecularly imprinted polymers were monodispersed beads with an average diameter of 1.55 mm. The molecular...... selectivity of the imprinted polymer beads was evaluated by studying the uptake of nicotine and its structural analogs by the polymer beads. Equilibrium binding results indicate that the amount of nicotine bound to the imprinted polymer beads is significantly higher than that bound to the nonimprinted polymer...

  5. Microcontact Imprinted Plasmonic Nanosensors: Powerful Tools in the Detection of Salmonella paratyphi

    Directory of Open Access Journals (Sweden)

    Işık Perçin

    2017-06-01

    Full Text Available Identification of pathogenic microorganisms by traditional methods is slow and cumbersome. Therefore, the focus today is on developing new and quicker analytical methods. In this study, a Surface Plasmon Resonance (SPR sensor with a microcontact imprinted sensor chip was developed for detecting Salmonella paratyphi. For this purpose, the stamps of the target microorganism were prepared and then, microcontact S. paratyphi-imprinted SPR chips were prepared with the functional monomer N-methacryloyl-L-histidine methyl ester (MAH. Characterization studies of the SPR chips were carried out with ellipsometry and scanning electron microscopy (SEM. The real-time Salmonella paratyphi detection was performed within the range of 2.5 × 106–15 × 106 CFU/mL. Selectivity of the prepared sensors was examined by using competing bacterial strains such as Escherichia coli, Staphylococcus aureus and Bacillus subtilis. The imprinting efficiency of the prepared sensor system was determined by evaluating the responses of the SPR chips prepared with both molecularly imprinted polymers (MIPs and non-imprinted polymers (NIPs. Real sample experiments were performed with apple juice. The recognition of Salmonella paratyphi was achieved using these SPR sensor with a detection limit of 1.4 × 106 CFU/mL. In conclusion, SPR sensor has the potential to serve as an excellent candidate for monitoring Salmonella paratyphi in food supplies or contaminated water and clearly makes it possible to develop rapid and appropriate control strategies.

  6. Quantum skew divergence

    Energy Technology Data Exchange (ETDEWEB)

    Audenaert, Koenraad M. R., E-mail: koenraad.audenaert@rhul.ac.uk [Department of Mathematics, Royal Holloway University of London, Egham TW20 0EX, United Kingdom and Department of Physics and Astronomy, University of Ghent, S9, Krijgslaan 281, B-9000 Ghent (Belgium)

    2014-11-15

    In this paper, we study the quantum generalisation of the skew divergence, which is a dissimilarity measure between distributions introduced by Lee in the context of natural language processing. We provide an in-depth study of the quantum skew divergence, including its relation to other state distinguishability measures. Finally, we present a number of important applications: new continuity inequalities for the quantum Jensen-Shannon divergence and the Holevo information, and a new and short proof of Bravyi's Small Incremental Mixing conjecture.

  7. On Hölder Projective Divergences

    KAUST Repository

    Nielsen, Frank

    2017-03-16

    We describe a framework to build distances by measuring the tightness of inequalities and introduce the notion of proper statistical divergences and improper pseudo-divergences. We then consider the Holder ordinary and reverse inequalities and present two novel classes of Holder divergences and pseudo-divergences that both encapsulate the special case of the Cauchy-Schwarz divergence. We report closed-form formulas for those statistical dissimilarities when considering distributions belonging to the same exponential family provided that the natural parameter space is a cone (e.g., multivariate Gaussians) or affine (e.g., categorical distributions). Those new classes of Holder distances are invariant to rescaling and thus do not require distributions to be normalized. Finally, we show how to compute statistical Holder centroids with respect to those divergences and carry out center-based clustering toy experiments on a set of Gaussian distributions which demonstrate empirically that symmetrized Holder divergences outperform the symmetric Cauchy-Schwarz divergence.

  8. On Hölder Projective Divergences

    KAUST Repository

    Nielsen, Frank; Sun, Ke; Marchand-Maillet, Stephane

    2017-01-01

    We describe a framework to build distances by measuring the tightness of inequalities and introduce the notion of proper statistical divergences and improper pseudo-divergences. We then consider the Holder ordinary and reverse inequalities and present two novel classes of Holder divergences and pseudo-divergences that both encapsulate the special case of the Cauchy-Schwarz divergence. We report closed-form formulas for those statistical dissimilarities when considering distributions belonging to the same exponential family provided that the natural parameter space is a cone (e.g., multivariate Gaussians) or affine (e.g., categorical distributions). Those new classes of Holder distances are invariant to rescaling and thus do not require distributions to be normalized. Finally, we show how to compute statistical Holder centroids with respect to those divergences and carry out center-based clustering toy experiments on a set of Gaussian distributions which demonstrate empirically that symmetrized Holder divergences outperform the symmetric Cauchy-Schwarz divergence.

  9. Separation and purification of hyaluronic acid by glucuronic acid imprinted microbeads

    Energy Technology Data Exchange (ETDEWEB)

    Akdamar, H.Acelya; Sarioezlue, Nalan Yilmaz [Department of Biology, Anadolu University, Eskisehir (Turkey); Ozcan, Ayca Atilir; Ersoez, Arzu [Department of Chemistry, Anadolu University, Eskisehir (Turkey); Denizli, Adil [Department of Chemistry, Hacettepe University, Ankara (Turkey); Say, Ridvan, E-mail: rsay@anadolu.edu.tr [Department of Chemistry, Anadolu University, Eskisehir (Turkey); BIBAM (Plant, Drug and Scientific Researches Center), Anadolu University, Eskisehir (Turkey)

    2009-05-05

    The purification of hyaluronic acid (HA) is relatively significant to use in biomedical applications. The structure of HA is formed by the repetitive units of glucuronic acid and N-acetyl glucosamine. In this study, glucuronic acid-imprinted microbeads have been supplied for the purification of HA from cell culture (Streptococcus equi). Histidine-functional monomer, methacryloylamidohistidine (MAH) was chosen as the metal-complexing monomer. The glucuronic acid-imprinted poly(ethyleneglycoldimethacrylate-MAH-Copper(II)) [p(EDMA-MAH-Cu{sup 2+})] microbeads have been synthesized by typical suspension polymerization procedure. The template glucuronic acid has been removed by employing 5 M methanolic KOH solution. p(EDMA-MAH-Cu{sup 2+}) microbeads have been characterized by elemental analysis, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) images and swelling studies. Moreover, HA adsorption experiments have been performed in a batch experimental set-up. Purification of HA from cell culture supernatant has been also investigated by determining the hyaluronidase activity using purified HA as substrate. The glucuronic acid imprinted p(EDMA-MAH-Cu{sup 2+}) particles can be used many times with no significant loss in adsorption capacities. Also, the selectivity of prepared molecular imprinted polymers (MIP) has been examined. Results have showed that MIP particles are 19 times more selective for glucuronic acid than N-acetylglucose amine.

  10. Urine mercury levels correlate with DNA methylation of imprinting gene H19 in the sperm of reproductive-aged men.

    Directory of Open Access Journals (Sweden)

    Zhaoxu Lu

    Full Text Available Mercury (Hg is a well-recognized environmental pollutant known by its toxicity of development and neurotoxicity, which results in adverse health outcomes. However, the mechanisms underlying the teratogenic effects of Hg are not well understood. Imprinting genes are emerging regulators for fetal development subjecting to environmental pollutants impacts. In this study, we examined the association between preconceptional Hg exposure and the alteration of DNA methylation of imprinting genes H19, Meg3, and Peg3 in human sperm DNA.A total of 616 men, aged from 22 to 59, were recruited from Reproductive Medicine Clinic of Maternal and Child Care Service Center and the Urologic Surgery Clinic of Shanxi Academy of Medical Sciences during April 2015 and March 2016. Demographic information was collected through questionnaires. Urine was collected and urinary Hg concentrations were measured using a fully-automatic double-channel hydride generation atomic fluorescence spectrometer. Methylation of imprinting genes H19, Meg3 and Peg3 of sperm DNA from 242 participants were examined by bisulfite pyrosequencing. Spearman's rank and multivariate regression analysis were used for correlation analysis between sperm DNA methylation status of imprinting genes and urinary Hg levels.The median concentration of Hg for 616 participants was 9.14μg/l (IQR: 5.56-12.52 μg/l; ranging 0.16-71.35μg/l. A total of 42.7% of the participants are beyond normal level for non-occupational exposure according to the criterion of Hg poisoning (≥10 μg/L. Spearman's rank analysis indicated a negative correlation between urinary Hg concentrations and average DNA methylation levels of imprinted genes H19 (rs = -0.346, p <0.05, but there was no such a correlation for Peg3 and Meg3. Further, we analyzed the correlation between methylation level at individual CpG site of H19 and urinary Hg level. The results showed a negative correlation between urinary Hg concentrations and three out of

  11. Matrix molecularly imprinted mesoporous sol–gel sorbent for efficient solid-phase extraction of chloramphenicol from milk

    International Nuclear Information System (INIS)

    Samanidou, Victoria; Kehagia, Maria; Kabir, Abuzar; Furton, Kenneth G.

    2016-01-01

    Highly selective and efficient chloramphenicol imprinted sol–gel silica based inorganic polymeric sorbent (sol–gel MIP) was synthesized via matrix imprinting approach for the extraction of chloramphenicol in milk. Chloramphenicol was used as the template molecule, 3-aminopropyltriethoxysilane (3-APTES) and triethoxyphenylsilane (TEPS) as the functional precursors, tetramethyl orthosilicate (TMOS) as the cross-linker, isopropanol as the solvent/porogen, and HCl as the sol–gel catalyst. Non-imprinted sol–gel polymer (sol–gel NIP) was synthesized under identical conditions in absence of template molecules for comparison purpose. Both synthesized materials were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and nitrogen adsorption porosimetry, which unambiguously confirmed their significant structural and morphological differences. The synthesized MIP and NIP materials were evaluated as sorbents for molecularly imprinted solid phase extraction (MISPE) of chloramphenicol in milk. The effect of critical extraction parameters (flow rate, elution solvent, sample and eluent volume, selectivity coefficient, retention capacity) was studied in terms of retention and desorption of chloramphenicol. Competition and cross reactivity tests have proved that sol–gel MIP sorbent possesses significantly higher specific retention and enrichment capacity for chloramphenicol compared to its non-imprinted analogue. The maximum imprinting factor (IF) was found as 9.7, whereas the highest adsorption capacity of chloramphenicol by sol–gel MIP was 23 mg/g. The sol–gel MIP was found to be adequately selective towards chloramphenicol to provide the necessary minimum required performance limit (MRPL) of 0.3 μg/kg set forth by European Commission after analysis by LC-MS even without requiring time consuming solvent evaporation and sample reconstitution step, often considered as an integral part in solid phase extraction work

  12. Matrix molecularly imprinted mesoporous sol–gel sorbent for efficient solid-phase extraction of chloramphenicol from milk

    Energy Technology Data Exchange (ETDEWEB)

    Samanidou, Victoria, E-mail: samanidu@chem.auth.gr [Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki (Greece); Kehagia, Maria [Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki (Greece); Kabir, Abuzar, E-mail: akabir@fiu.edu [International Forensic Research Institute, Department of Chemistry and Biochemistry, Florida International University, Miami, FL (United States); Furton, Kenneth G. [International Forensic Research Institute, Department of Chemistry and Biochemistry, Florida International University, Miami, FL (United States)

    2016-03-31

    Highly selective and efficient chloramphenicol imprinted sol–gel silica based inorganic polymeric sorbent (sol–gel MIP) was synthesized via matrix imprinting approach for the extraction of chloramphenicol in milk. Chloramphenicol was used as the template molecule, 3-aminopropyltriethoxysilane (3-APTES) and triethoxyphenylsilane (TEPS) as the functional precursors, tetramethyl orthosilicate (TMOS) as the cross-linker, isopropanol as the solvent/porogen, and HCl as the sol–gel catalyst. Non-imprinted sol–gel polymer (sol–gel NIP) was synthesized under identical conditions in absence of template molecules for comparison purpose. Both synthesized materials were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and nitrogen adsorption porosimetry, which unambiguously confirmed their significant structural and morphological differences. The synthesized MIP and NIP materials were evaluated as sorbents for molecularly imprinted solid phase extraction (MISPE) of chloramphenicol in milk. The effect of critical extraction parameters (flow rate, elution solvent, sample and eluent volume, selectivity coefficient, retention capacity) was studied in terms of retention and desorption of chloramphenicol. Competition and cross reactivity tests have proved that sol–gel MIP sorbent possesses significantly higher specific retention and enrichment capacity for chloramphenicol compared to its non-imprinted analogue. The maximum imprinting factor (IF) was found as 9.7, whereas the highest adsorption capacity of chloramphenicol by sol–gel MIP was 23 mg/g. The sol–gel MIP was found to be adequately selective towards chloramphenicol to provide the necessary minimum required performance limit (MRPL) of 0.3 μg/kg set forth by European Commission after analysis by LC-MS even without requiring time consuming solvent evaporation and sample reconstitution step, often considered as an integral part in solid phase extraction work

  13. A 3,3′-dichlorobenzidine-imprinted polymer gel surface plasmon resonance sensor based on template-responsive shrinkage

    International Nuclear Information System (INIS)

    Zhou, Chunyan; Gao, Jigang; Zhang, Lili; Zhou, Jie

    2014-01-01

    Graphical abstract: -- Highlights: •Based on template-responsive shrinkage of imprinted gel film, a novel surface plasmon resonance (SPR) sensor is prepared. •The relevant electrochemical parameters are optimized. •The imprinted gel-SPR system has great capability for providing highly sensitive and selective analysis of 3,3′-dichlorobenzidine. •The present SPR sensor was successfully employed to detect 3,3′-dichlorobenzidine in tap water and soil samples. -- Abstract: Molecularly imprinted polymer gel film on the gold substrate of a chip was prepared with minute amount of cross-linker for the fabrication of a surface plasmon resonance (SPR) sensor sensitive to 3,3′-dichlorobenzidine. The molecularly imprinted gel film was anchored on a gold chip by a surface-bound photo-radical initiator. The sensing of 3,3′-dichlorobenzidine is based on responsive shrinkage of the imprinted polymer gel film that is triggered by target binding. This change can improve the responsiveness of the imprinted SPR sensor to 3,3′-dichlorobenzidine. The molecularly imprinted polymer gel film was characterized with contact angle measurements, electrochemical impedance spectroscopy, cyclic voltammogram, swelling measurements and atomic force microscopy. The changes of SPR spectroscopy wavenumber shifts revealed that the imprinted gel sensing film can ‘memorize’ the binding of 3,3′-dichlorobenzidine compared to non-imprinted one. The imprinted gel-SPR sensor showed a linear response in the range of 9.0 × 10 −12 to 5.0 × 10 −10 mol L −1 (R 2 = 0.9998) for the detection of 3,3′-dichlorobenzidine, and it also exhibited high selectivity to 3,3′-dichlorobenzidine compared to its structurally related analogues. We calculated the detection limits to be 0.471 ng L −1 for tap water and 0.772 ng kg −1 for soil based on a signal to noise ratio of 3. The method showed good recoveries and precision for the samples spiked with 3,3′-dichlorobenzidine. This suggest

  14. Synthesis of Homoveratric Acid-Imprinted Polymers and Their Evaluation as Selective Separation Materials

    Directory of Open Access Journals (Sweden)

    Mariusz Dana

    2011-05-01

    Full Text Available A bulk polymerization method was used to easily and efficiently prepare homo-veratric acid (3,4-dimethoxyphenylacetic acid-imprinted polymers from eight basic monomers: 2-vinylpyridine, 4-vinylpyridine, 1-vinylimidazole, N-allylaniline, N-allylpiperazine, allylurea, allylthiourea, and allylamine, in the presence of homoveratric acid as a template in N,N-dimethylformamide as a porogen. The imprinted polymer prepared from allylamine had the highest affinity to the template, showing an imprinting factor of 3.43, and allylamine polymers MIP8/NIP8 were selected for further studies. Their binding properties were analyzed using the Scatchard method. The results showed that the imprinted polymers have two classes of heterogeneous binding sites characterized by two pairs of Kd, Bmax values: Kd(1 = 0.060 μmol/mL, Bmax(1 = 0.093 μmol/mg for the higher affinity binding sites, and Kd(2 = 0.455 μmol/mL, Bmax(2 = 0.248 μmol/mg for the lower affinity binding sites. Non-imprinted polymer has only one class of binding site, with Kd = 0.417 μmol/mL and Bmax = 0.184 μmol/mg. A computational analysis of the energies of the prepolymerization complexes was in agreement with the experimental results. It showed that the selective binding interactions arose from cooperative three point interactions between the carboxylic acid and the two methoxy groups in the template and amino groups in the polymer cavities. Those results were confirmed by the recognition studies performed with the set of structurally related compounds. Allylamine polymer MIP8 had no affinity towards biogenic amines. The obtained imprinted polymer could be used for selective separation of homoveratric acid.

  15. Imprinting, latchment and displacement: a mini review of early instinctual behaviour in newborn infants influencing breastfeeding success.

    Science.gov (United States)

    Mobbs, Elsie J; Mobbs, George A; Mobbs, Anthony E D

    2016-01-01

    Instinctive behaviours have evolved favouring the mother-infant dyad based on fundamental processes of neurological development, including oral tactile imprinting and latchment. Latchment is the first stage of emotional development based on the successful achievement of biological imprinting. The mechanisms underpinning imprinting are identified and the evolutionary benefits discussed. It is proposed that the oral tactile imprint to the breast is a keystone for optimal latchment and breastfeeding, promoting evolutionary success. ©2015 The Authors. Acta Paediatrica published by John Wiley & Sons Ltd on behalf of Foundation Acta Paediatrica.

  16. Computational modeling and molecular imprinting for the development of acrylic polymers with high affinity for bile salts.

    Science.gov (United States)

    Yañez, Fernando; Chianella, Iva; Piletsky, Sergey A; Concheiro, Angel; Alvarez-Lorenzo, Carmen

    2010-02-05

    This work has focused on the rational development of polymers capable of acting as traps of bile salts. Computational modeling was combined with molecular imprinting technology to obtain networks with high affinity for cholate salts in aqueous medium. The screening of a virtual library of 18 monomers, which are commonly used for imprinted networks, identified N-(3-aminopropyl)-methacrylate hydrochloride (APMA.HCl), N,N-diethylamino ethyl methacrylate (DEAEM) and ethyleneglycol methacrylate phosphate (EGMP) as suitable functional monomers with medium-to-high affinity for cholic acid. The polymers were prepared with a fix cholic acid:functional monomer mole ratio of 1:4, but with various cross-linking densities. Compared to polymers prepared without functional monomer, both imprinted and non-imprinted microparticles showed a high capability to remove sodium cholate from aqueous medium. High affinity APMA-based particles even resembled the performance of commercially available cholesterol-lowering granules. The imprinting effect was evident in most of the networks prepared, showing that computational modeling and molecular imprinting can act synergistically to improve the performance of certain polymers. Nevertheless, both the imprinted and non-imprinted networks prepared with the best monomer (APMA.HCl) identified by the modeling demonstrated such high affinity for the template that the imprinting effect was less important. The fitting of adsorption isotherms to the Freundlich model indicated that, in general, imprinting increases the population of high affinity binding sites, except when the affinity of the functional monomer for the target molecule is already very high. The cross-linking density was confirmed as a key parameter that determines the accessibility of the binding points to sodium cholate. Materials prepared with 9% mol APMA and 91% mol cross-linker showed enough affinity to achieve binding levels of up to 0.4 mmol g(-1) (i.e., 170 mg g(-1)) under flow

  17. Multi-level single mode 2D polymer waveguide optical interconnects using nano-imprint lithography

    NARCIS (Netherlands)

    Khan, M.U.; Justice, J.; Petäjä, J.; Korhonen, T.; Boersma, A.; Wiegersma, S.; Karppinen, M.; Corbett, B.

    2015-01-01

    Single and multi-layer passive optical interconnects using single mode polymer waveguides are demonstrated using UV nano-imprint lithography. The fabrication tolerances associated with imprint lithography are investigated and we show a way to experimentally quantify a small variation in index

  18. Experimental evaluation of imprinting and the role innate preference plays in habitat selection in a coral reef fish.

    Science.gov (United States)

    Dixson, Danielle L; Jones, Geoffrey P; Munday, Philip L; Planes, Serge; Pratchett, Morgan S; Thorrold, Simon R

    2014-01-01

    When facing decisions about where to live, juveniles have a strong tendency to choose habitats similar to where their parents successfully bred. Developing larval fishes can imprint on the chemical cues from their natal habitat. However, to demonstrate that imprinting is ecologically important, it must be shown that settlers respond and distinguish among different imprinted cues, and use imprinting for decisions in natural environments. In addition, the potential role innate preferences play compared to imprinted choices also needs to be examined. As environmental variability increases due to anthropogenic causes these two recognition mechanisms, innate and imprinting, could provide conflicting information. Here we used laboratory rearing and chemical choice experiments to test imprinting in larval anemonefish (Amphiprion percula). Individuals exposed to a variety of benthic habitat or novel olfactory cues as larvae either developed a preference for (spent >50% of their time in the cue) or increased their attraction to (increased preference but did not spend >50% of their time in the cue) the cue when re-exposed as settlers. Results indicate not only the capacity for imprinting but also the ability to adjust innate preferences after early exposure to a chemical cue. To test ecological relevance in the natural system, recruits were collected from anemones and related to their parents, using genetic parentage analysis, providing information on the natal anemone species and the species chosen at settlement. Results demonstrated that recruits did not preferentially return to their natal species, conflicting with laboratory results indicating the importance imprinting might have in habitat recognition.

  19. Electrochemical sensor based on magnetic molecularly imprinted nanoparticles modified magnetic electrode for determination of Hb.

    Science.gov (United States)

    Sun, Binghua; Ni, Xinjiong; Cao, Yuhua; Cao, Guangqun

    2017-05-15

    A fast and selective electrochemical sensor for determination of hemoglobin (Hb) was developed based on magnetic molecularly imprinted nanoparticles modified on the magnetic glassy carbon electrode. The nanoparticles Fe 3 O 4 @SiO 2 with a magnetic core and a molecularly imprinted shell had regular structures and good monodispersity. Hb could be determined directly by electrochemical oxidization with the modified electrode. A magnetic field increased electrochemical response to Hb by two times. Imprinting Hb on the surface of Fe 3 O 4 @SiO 2 shortened the response time within 7min. Under optimum conditions, the imprinting factor toward the non-imprinted sensor was 2.8, and the separation factor of Hb to horseradish peroxidase was 2.6. The oxidation peak current had a linear relationship with Hb concentration ranged from 0.005mg/ml to 0.1mg/ml with a detection limit (S/N =3) of 0.0010mg/ml. The sensors were successfully applied to analysis of Hb in whole blood samples with recoveries between 95.7% and 105%. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. High resolution beam profiling of X-ray free electron laser radiation by polymer imprint development.

    Science.gov (United States)

    Rösner, Benedikt; Döring, Florian; Ribič, Primož R; Gauthier, David; Principi, Emiliano; Masciovecchio, Claudio; Zangrando, Marco; Vila-Comamala, Joan; De Ninno, Giovanni; David, Christian

    2017-11-27

    High resolution metrology of beam profiles is presently a major challenge at X-ray free electron lasers. We demonstrate a characterization method based on beam imprints in poly (methyl methacrylate). By immersing the imprints formed at 47.8 eV into organic solvents, the regions exposed to the beam are removed similar to resist development in grayscale lithography. This allows for extending the sensitivity of the method by more than an order of magnitude compared to the established analysis of imprints created solely by ablation. Applying the Beer-Lambert law for absorption, the intensity distribution in a micron-sized focus can be reconstructed from one single shot with a high dynamic range, exceeding 10 3 . The procedure described here allows for beam characterization at free electron lasers revealing even faint beam tails, which are not accessible when using ablation imprint methods. We demonstrate the greatly extended dynamic range on developed imprints taken in focus of conventional Fresnel zone plates and spiral zone plates producing beams with a topological charge.

  1. String perturbation theory diverges

    International Nuclear Information System (INIS)

    Gross, D.J.; Periwal, V.

    1988-01-01

    We prove that perturbation theory for the bosonic string diverges for arbitrary values of the coupling constant and is not Borel summable. This divergence is independent of the existence of the infinities that occur in the theory due to the presence of tachyons and dilaton tadpoles. We discuss the physical implications of such a divergence

  2. An imprinted non-coding genomic cluster at 14q32 defines clinically relevant molecular subtypes in osteosarcoma across multiple independent datasets

    OpenAIRE

    Hill, Katherine E.; Kelly, Andrew D.; Kuijjer, Marieke L.; Barry, William; Rattani, Ahmed; Garbutt, Cassandra C.; Kissick, Haydn; Janeway, Katherine; Perez-Atayde, Antonio; Goldsmith, Jeffrey; Gebhardt, Mark C.; Arredouani, Mohamed S.; Cote, Greg; Hornicek, Francis; Choy, Edwin

    2017-01-01

    Background: A microRNA (miRNA) collection on the imprinted 14q32 MEG3 region has been associated with outcome in osteosarcoma. We assessed the clinical utility of this miRNA set and their association with methylation status. Methods: We integrated coding and non-coding RNA data from three independent annotated clinical osteosarcoma cohorts (n = 65, n = 27, and n = 25) and miRNA and methylation data from one in vitro (19 cell lines) and one clinical (NCI Therapeutically Applicable Research to ...

  3. Clinical spectrum and molecular diagnosis of Angelman and Prader-Willi syndrome patients with an imprinting mutation

    Energy Technology Data Exchange (ETDEWEB)

    Saitoh, S.; Cassidy, S.B.; Conroy, J.M. [Univ. of Hospitals of Cleveland, OH (United States)] [and others

    1997-01-20

    Recent studies have identified a new class of Prader-Willi syndrome (PWS) and Angelman syndrome (AS) patients who have biparental inheritance, but neither the typical deletion nor uniparental disomy (UPD) or translocation. However, these patients have uniparental DNA methylation throughout 15q11-q13, and thus appear to have a mutation in the imprinting process for this region. Here we describe detailed clinical findings of five AS imprinting mutation patients (three families) and two PWS imprinting mutation patients (one new family). All these patients have essentially the classical clinical phenotype for the respective syndrome, except that the incidence of microcephaly is lower in imprinting mutation AS patients than in deletion AS patients. Furthermore, imprinting mutation AS and PWS patients do not typically have hypopigmentation, which is commonly found in patients with the usual large deletion. Molecular diagnosis of these cases is initially achieved by DNA methylation analyses of the DN34/ZNF127, PW71 (D15S63), and SNRPN loci. The latter two probes have clear advantages in the simple molecular diagnostic analysis of PWS and AS patients with an imprinting mutation, as has been found for typical deletion or UPD PWS and AS cases. With the recent finding of inherited microdeletions in PWS and AS imprinting mutation families, our studies define a new class of these two syndromes. The clinical and molecular identification of these PWS and AS patients has important genetic counseling consequences. 49 refs., 4 figs., 3 tabs.

  4. Recent acquisition of imprinting at the rodent Sfmbt2 locus correlates with insertion of a large block of miRNAs

    Directory of Open Access Journals (Sweden)

    Chung Eu Ddeum

    2011-04-01

    Full Text Available Abstract Background The proximal region of murine Chr 2 has long been known to harbour one or more imprinted genes from classic genetic studies involving reciprocal translocations. No imprinted gene had been identified from this region until our study demonstrated that the PcG gene Sfmbt2 is expressed from the paternally inherited allele in early embryos and extraembryonic tissues. Imprinted genes generally reside in clusters near elements termed Imprinting Control Regions (ICRs, suggesting that Sfmbt2 might represent an anchor for a new imprinted domain. Results We analyzed allelic expression of approximately 20 genes within a 3.9 Mb domain and found that Sfmbt2 and an overlapping non-coding antisense transcript are the only imprinted genes in this region. These transcripts represent a very narrow imprinted gene locus. We also demonstrate that rat Sfmbt2 is imprinted in extraembryonic tissues. An interesting feature of both mouse and rat Sfmbt2 genes is the presence of a large block of miRNAs in intron 10. Other mammals, including the bovine, lack this block of miRNAs. Consistent with this association, we show that human and bovine Sfmbt2 are biallelic. Other evidence indicates that pig Sfmbt2 is also not imprinted. Further strengthening the argument for recent evolution of Sfmbt2 is our demonstration that a more distant muroid rodent, Peromyscus also lacks imprinting and the block of miRNAs. Conclusions These observations are consistent with the hypothesis that the block of miRNAs are driving imprinting at this locus. Our results are discussed in the context of ncRNAs at other imprinted loci. Accession numbers for Peromyscus cDNA and intron 10 genomic DNA are [Genbank:HQ416417 and Genbank:HQ416418], respectively.

  5. Fabrication of subwavelength metallic structures by using a metal direct imprinting process

    International Nuclear Information System (INIS)

    Hsieh, C W; Hsiung, H Y; Lu, Y T; Sung, C K; Wang, W H

    2007-01-01

    This work employs a metal direct imprinting process, which possesses the characteristics of simplicity, low-cost and high resolution, for the fabrication of subwavelength structures on a metallic thin film. Herein, the mould featuring periodic line structures is manufactured by using E-beam lithography and followed by a dry etching process; meanwhile, the thin film is fabricated by sputtering Al on a silicon substrate. AFM section analyses are employed to measure imprinting depths of the subwavelength metallic structures and it is found that the uniformity of the imprinting depths is affected by the designed patterns, the material property of thin film and mould deformation. The process temperature and the mould filling that influence the transferred quality are investigated. In addition, TEM is also utilized to examine defects in the subwavelength metallic structures. Finally, good quality subwavelength metallic structures are fabricated under a pressure of 300 MPa for 60 s at room temperature. In this study, we have demonstrated that subwavelength metallic structures with a minimum linewidth of less than 100 nm on the Al thin film are successfully constructed by the metal direct imprinting process

  6. Synthesis and Characterization of Molecular Imprinting Polymer Microspheres of Piperine: Extraction of Piperine from Spiked Urine

    Directory of Open Access Journals (Sweden)

    Rachel Marcella Roland

    2016-01-01

    Full Text Available Molecularly imprinted polymer (MIP microspheres for Piperine were synthesized by precipitation polymerization with a noncovalent approach. In this research Piperine was used as a template, acrylic acid as a functional monomer, ethylene glycol dimethacrylate as a cross-linker, and 2,2′-azobisisobutyronitrile (AIBN as an initiator and acetonitrile as a solvent. The imprinted and nonimprinted polymer particles were characterized by using Fourier transform infrared spectroscopy (FT-IR and Scanning Electron Microscopy (SEM. The synthesized polymer particles were further evaluated for their rebinding efficiency by batch binding assay. The highly selected imprinted polymer for Piperine was MIP 3 with a composition (molar ratio of 0.5 : 3 : 8, template : monomer : cross-linker, respectively. The MIP 3 exhibits highest binding capacity (84.94% as compared to other imprinted and nonimprinted polymers. The extraction efficiency of highly selected imprinted polymer of Piperine from spiked urine was above 80%.

  7. Grafting of molecularly imprinted polymer to porous polyethylene filtration membranes by plasma polymerization.

    Science.gov (United States)

    Cowieson, D; Piletska, E; Moczko, E; Piletsky, S

    2013-08-01

    An application of plasma-induced grafting of polyethylene membranes with a thin layer of molecularly imprinted polymer (MIP) was presented. High-density polyethylene (HDPE) membranes, "Vyon," were used as a substrate for plasma grafting modification. The herbicide atrazine, one of the most popular targets of the molecular imprinting, was chosen as a template. The parameters of the plasma treatment were optimized in order to achieve a good balance between polymerization and ablation processes. Modified HDPE membranes were characterized, and the presence of the grafted polymeric layer was confirmed based on the observed weight gain, pore size measurements, and infrared spectrometry. Since there was no significant change in the porosity of the modified membranes, it was assumed that only a thin layer of the polymer was introduced on the surface. The experiments on the re-binding of the template atrazine to the membranes modified with MIP and blank polymers were performed. HDPE membranes which were grafted with polymer using continuous plasma polymerization demonstrated the best result which was expressed in an imprinted factor equal to 3, suggesting that molecular imprinting was successfully achieved.

  8. The Drosophila melanogaster homolog of UBE3A is not imprinted in neurons.

    Science.gov (United States)

    Hope, Kevin A; LeDoux, Mark S; Reiter, Lawrence T

    2016-09-01

    In mammals, expression of UBE3A is epigenetically regulated in neurons and expression is restricted to the maternal copy of UBE3A. A recent report claimed that Drosophila melanogaster UBE3A homolog (Dube3a) is preferentially expressed from the maternal allele in fly brain, inferring an imprinting mechanism. However, complex epigenetic regulatory features of the mammalian imprinting center are not present in Drosophila, and allele specific expression of Dube3a has not been documented. We used behavioral and electrophysiological analysis of the Dube3a loss-of-function allele (Dube3a 15b ) to investigate Dube3a imprinting in fly neurons. We found that motor impairment (climbing ability) and a newly-characterized defect in synaptic transmission are independent of parental inheritance of the Dube3a 15b allele. Furthermore, expression analysis of coding single nucleotide polymorphisms (SNPs) in Dube3a did not reveal allele specific expression differences among reciprocal crosses. These data indicate that Dube3a is neither imprinted nor preferentially expressed from the maternal allele in fly neurons.

  9. Transcription is required to establish maternal imprinting at the Prader-Willi syndrome and Angelman syndrome locus.

    Directory of Open Access Journals (Sweden)

    Emily Y Smith

    2011-12-01

    Full Text Available The Prader-Willi syndrome (PWS [MIM 17620] and Angelman syndrome (AS [MIM 105830] locus is controlled by a bipartite imprinting center (IC consisting of the PWS-IC and the AS-IC. The most widely accepted model of IC function proposes that the PWS-IC activates gene expression from the paternal allele, while the AS-IC acts to epigenetically inactivate the PWS-IC on the maternal allele, thus silencing the paternally expressed genes. Gene order and imprinting patterns at the PWS/AS locus are well conserved from human to mouse; however, a murine AS-IC has yet to be identified. We investigated a potential regulatory role for transcription from the Snrpn alternative upstream exons in silencing the maternal allele using a murine transgene containing Snrpn and three upstream exons. This transgene displayed appropriate imprinted expression and epigenetic marks, demonstrating the presence of a functional AS-IC. Transcription of the upstream exons from the endogenous locus correlates with imprint establishment in oocytes, and this upstream exon expression pattern was conserved on the transgene. A transgene bearing targeted deletions of each of the three upstream exons exhibited loss of imprinting upon maternal transmission. These results support a model in which transcription from the Snrpn upstream exons directs the maternal imprint at the PWS-IC.

  10. Foster parenting, human imprinting and conventional handling ...

    African Journals Online (AJOL)

    ... the present study indicates that improvements can be made by adopting alternative approaches. Further studies are needed to ascertain how foster parenting and imprinting may be utilized to optimize chick performance, including the long-term consequences of these practices. Keywords: Parental care, Struthio camelus, ...

  11. Macroscopic Ensembles of Aligned Carbon Nanotubes in Bubble Imprints Studied by Polarized Raman Microscopy

    Directory of Open Access Journals (Sweden)

    Shota Ushiba

    2014-01-01

    Full Text Available We study the alignment of single-wall carbon nanotubes (SWCNTs in bubble imprints through polarized Raman microscopy. A hemispherical bubble containing SWCNTs is pressed against a glass substrate, resulting in an imprint of the bubble membrane with a coffee ring on the substrate. We find that macroscopic ensembles of aligned SWCNTs are obtained in the imprints, in which there are three patterns of orientations: (i azimuthal alignment on the coffee ring, (ii radial alignment at the edge of the membrane, and (iii random orientation at the center of the membrane. We also find that the alignment of SWCNTs in the imprints can be manipulated by spinning bubbles. The orientation of SWCNTs on the coffee ring is directed radially, which is orthogonal to the case of unspun bubbles. This approach enables one to align SWCNTs in large quantities and in a short time, potentially opening up a wide range of CNT-based electronic and optical applications.

  12. Piezoelectric sensors based on molecular imprinted polymers for detection of low molecular mass analytes.

    Science.gov (United States)

    Uludağ, Yildiz; Piletsky, Sergey A; Turner, Anthony P F; Cooper, Matthew A

    2007-11-01

    Biomimetic recognition elements employed for the detection of analytes are commonly based on proteinaceous affibodies, immunoglobulins, single-chain and single-domain antibody fragments or aptamers. The alternative supra-molecular approach using a molecularly imprinted polymer now has proven utility in numerous applications ranging from liquid chromatography to bioassays. Despite inherent advantages compared with biochemical/biological recognition (which include robustness, storage endurance and lower costs) there are few contributions that describe quantitative analytical applications of molecularly imprinted polymers for relevant small molecular mass compounds in real-world samples. There is, however, significant literature describing the use of low-power, portable piezoelectric transducers to detect analytes in environmental monitoring and other application areas. Here we review the combination of molecularly imprinted polymers as recognition elements with piezoelectric biosensors for quantitative detection of small molecules. Analytes are classified by type and sample matrix presentation and various molecularly imprinted polymer synthetic fabrication strategies are also reviewed.

  13. Estrone specific molecularly imprinted polymeric nanospheres: synthesis, characterization and applications for electrochemical sensor development.

    Science.gov (United States)

    Congur, Gulsah; Senay, Hilal; Turkcan, Ceren; Canavar, Ece; Erdem, Arzum; Akgol, Sinan

    2013-06-28

    The aim of this study is (i) to prepare estrone-imprinted nanospheres (nano-EST-MIPs) and (ii) to integrate them into the electrochemical sensor as a recognition layer. N-methacryloyl-(l)-phenylalanine (MAPA) was chosen as the complexing monomer. Firstly, estrone (EST) was complexed with MAPA and the EST-imprinted poly(2-hyroxyethylmethacrylate-co-N-methacryloyl-(l)-phenylalanine) [EST-imprinted poly(HEMA-MAPA)] nanospheres were synthesized by surfactant- free emulsion polymerization method. The specific surface area of the EST-imprinted poly(HEMA-MAPA) nanospheres was found to be 1275 m2/g with a size of 163.2 nm in diameter. According to the elemental analysis results, the nanospheres contained 95.3 mmole MAPA/g nanosphere. The application of EST specific MIP nanospheres for the development of an electrochemical biosensor was introduced for the first time in our study by using electrochemical impedance spectroscopy (EIS) technique. This nano-MIP based sensor presented a great specificity and selectivity for EST.

  14. Divergent Cumulative Cultural Evolution

    OpenAIRE

    Marriott, Chris; Chebib, Jobran

    2016-01-01

    Divergent cumulative cultural evolution occurs when the cultural evolutionary trajectory diverges from the biological evolutionary trajectory. We consider the conditions under which divergent cumulative cultural evolution can occur. We hypothesize that two conditions are necessary. First that genetic and cultural information are stored separately in the agent. Second cultural information must be transferred horizontally between agents of different generations. We implement a model with these ...

  15. Biotin-specific synthetic receptors prepared using molecular imprinting

    Energy Technology Data Exchange (ETDEWEB)

    Piletska, Elena; Piletsky, Sergey; Karim, Kal; Terpetschnig, Ewald; Turner, Anthony

    2004-02-16

    The composition of new molecularly imprinted polymers (MIPs) specific for biotin was optimised using molecular modelling software. Three functional monomers: methacrylic acid (MAA), 2-(trifluoromethyl)acrylic acid (TFAA) and 2-acrylamido-2-methylpropanesulfonic acid (AMPSA), which demonstrated the highest binding scores with biotin, were tested on their ability to generate specific binding sites. The imprinted polymers were photografted to the surface of polystyrene microspheres in water. The affinity of the synthetic 'receptor' sites was evaluated in binding experiments using horseradish peroxidase-labelled biotin. Good correlation was found between the modelling results and the performance of the materials in the template re-binding study. The dissociation constants for all MIPs were 1.4-16.8 nM, which is sufficient for most analytical applications where biotin is used as a label.

  16. Biotin-specific synthetic receptors prepared using molecular imprinting

    International Nuclear Information System (INIS)

    Piletska, Elena; Piletsky, Sergey; Karim, Kal; Terpetschnig, Ewald; Turner, Anthony

    2004-01-01

    The composition of new molecularly imprinted polymers (MIPs) specific for biotin was optimised using molecular modelling software. Three functional monomers: methacrylic acid (MAA), 2-(trifluoromethyl)acrylic acid (TFAA) and 2-acrylamido-2-methylpropanesulfonic acid (AMPSA), which demonstrated the highest binding scores with biotin, were tested on their ability to generate specific binding sites. The imprinted polymers were photografted to the surface of polystyrene microspheres in water. The affinity of the synthetic 'receptor' sites was evaluated in binding experiments using horseradish peroxidase-labelled biotin. Good correlation was found between the modelling results and the performance of the materials in the template re-binding study. The dissociation constants for all MIPs were 1.4-16.8 nM, which is sufficient for most analytical applications where biotin is used as a label

  17. Preparation and Characterization of Nonylphenol Magnetic Molecularly Imprinted Polymer

    International Nuclear Information System (INIS)

    Chen, F. Y.; Ba, S. P.; Tang, Y. B.; Wang, X. G.

    2015-01-01

    Nonylphenol (NP) is a toxic xenobiotic compound classified as an endocrine disrupter, which can interface with the hormonal system of numerous organisms, and then cause a series of pathological changes. It is of great significance to remove nonyl phenol from the environment. In this paper, an effective method for the preparation of molecularly imprinted nanoparticles was reported. Firstly, Fe/sub 3/O/sub 4/ at the rate SiO/sub 2/ magnetic carrier material modified by trimethoxysilane was achieved through three-step reaction. After that, the selective magnetic molecularly imprinted polymer sorbent for NP (Fe/sub 3/O/sub 4/ at the rate SiO/sub 2/-MIP) was synthesized by surface molecular imprinting technique, using NP as template, 4-vinyl pyridine(4-Vpy) as functional monomers, ethylene glycol dimethacrylate (EGDMA) as cross linker and azobisisobutyronitrile (AIBN) as initiator. The morphous, composition, structure and performance of polymer adsorbent was characterized by SEM, TEM, FT-IR, XRD, EDS, VSM and nitrogen adsorption-desorption techniques. The results indicated that the polymer adsorbent was successfully prepared. The size of the polymer particle was about 50 nm, the aperture on the surface was 3.71 nm, the BET specific surface area was 61.80 m/sup 2/g and the Langmuir specific surface area was 101.24 m/sup 2/g. The selective adsorption rate for NP of 0.5 mmol/L attained value of 86.5%, and for NP with low concentration (less than 2.0 mg/L), the selective adsorption rate reached more than 90%. The synthesized magnetic molecularly imprinted polymer had higher selective recognition ability towards the template molecule nonylphenol. It has good magnetism and can be rapidly separated after being employed by using adscititious magnetic field. It has potential application value in treatment and enrichment of nonylphenol. (author)

  18. Improvement of the homogeneity of protein-imprinted polymer films by orientated immobilization of the template

    Energy Technology Data Exchange (ETDEWEB)

    Liu Lijian; Zheng Jingjing; Fang Guijie [Key Laboratory of Fermentation Engineering (Ministry of Education), College of Bioengineering, Hubei University of Technology, Nanhu Li Jia Dun 1, Wuhan 430068 (China); Xie Weihong, E-mail: weihong.xie@yahoo.com.cn [Key Laboratory of Fermentation Engineering (Ministry of Education), College of Bioengineering, Hubei University of Technology, Nanhu Li Jia Dun 1, Wuhan 430068 (China)

    2012-05-13

    Highlights: Black-Right-Pointing-Pointer MPH was genetically modified at its C-terminal with (Gly-Ser){sub 5}-Cys. Black-Right-Pointing-Pointer MPH-L was immobilized with fixed orientation via disulfide chemistry. Black-Right-Pointing-Pointer The immobilized MPH-L retained the activity of MPH. Black-Right-Pointing-Pointer MPH-L formed a homogeneous template. Black-Right-Pointing-Pointer Homogeneous MIP film was obtained with orientated immobilization of the template. - Abstract: A method for preparing homogeneous protein-imprinted polymer films with orientated immobilization of template is described. The template methyl parathion hydrolase (MPH) was modified with a peptide linker (Gly-Ser){sub 5}-Cys and was immobilized on a cover glass with a fixed orientation via the linker. The activity of the fusion enzyme (MPH-L) was evaluated by determining the product's absorbance at 405 nm (A{sub 405}). Both the free and the immobilized MPH-L showed higher retention of the bioactivity than the wide type enzyme (MPH-W) as revealed by the A{sub 405} values for MPH-L{sub free}/MPH-W{sub free} (1.159/1.111) and for MPH-L{sub immobilized}/MPH-W{sub immobilized} (0.348/0.118). The immobilized MPH-L also formed a more homogeneous template stamp compared to the immobilized MPH-W. The molecularly imprinted polymer films prepared with the immobilized MPH-L exhibited high homogeneity with low Std. Deviations of 80 and 200 from the CL intensity mean volumes which were observed for batch-prepared films and an individual film, respectively. MPH-L-imprinted polymer film also had a larger template binding capacity indicated by higher CL intensity mean volume of 3900 INT over 2500 INT for MPH-W-imprinted films. The imprinted film prepared with the orientated immobilization of template showed an imprinting factor of 1.7, while the controls did not show an imprinting effect.

  19. Improvement of the homogeneity of protein-imprinted polymer films by orientated immobilization of the template

    International Nuclear Information System (INIS)

    Liu Lijian; Zheng Jingjing; Fang Guijie; Xie Weihong

    2012-01-01

    Highlights: ► MPH was genetically modified at its C-terminal with (Gly-Ser) 5 –Cys. ► MPH-L was immobilized with fixed orientation via disulfide chemistry. ► The immobilized MPH-L retained the activity of MPH. ► MPH-L formed a homogeneous template. ► Homogeneous MIP film was obtained with orientated immobilization of the template. - Abstract: A method for preparing homogeneous protein-imprinted polymer films with orientated immobilization of template is described. The template methyl parathion hydrolase (MPH) was modified with a peptide linker (Gly-Ser) 5 –Cys and was immobilized on a cover glass with a fixed orientation via the linker. The activity of the fusion enzyme (MPH-L) was evaluated by determining the product's absorbance at 405 nm (A 405 ). Both the free and the immobilized MPH-L showed higher retention of the bioactivity than the wide type enzyme (MPH-W) as revealed by the A 405 values for MPH-L free /MPH-W free (1.159/1.111) and for MPH-L immobilized /MPH-W immobilized (0.348/0.118). The immobilized MPH-L also formed a more homogeneous template stamp compared to the immobilized MPH-W. The molecularly imprinted polymer films prepared with the immobilized MPH-L exhibited high homogeneity with low Std. Deviations of 80 and 200 from the CL intensity mean volumes which were observed for batch-prepared films and an individual film, respectively. MPH-L-imprinted polymer film also had a larger template binding capacity indicated by higher CL intensity mean volume of 3900 INT over 2500 INT for MPH-W-imprinted films. The imprinted film prepared with the orientated immobilization of template showed an imprinting factor of 1.7, while the controls did not show an imprinting effect.

  20. Creatinine sensor based on a molecularly imprinted polymer-modified hanging mercury drop electrode.

    Science.gov (United States)

    Lakshmi, Dhana; Prasad, Bhim Bali; Sharma, Piyush Sindhu

    2006-09-15

    Molecularly imprinted polymers (MIP) have been elucidated to work as artificial receptors. In our present study, a MIP was applied as a molecular recognition element to a chemical sensor. We have constructed a creatinine sensor based on a MIP layer selective for creatinine and its differential pulse, cathodic stripping voltammetric detection (DPCSV) on a hanging mercury drop electrode (HMDE). The creatinine sensor was fabricated by the drop coating of dimethylformamide (DMF) solution of a creatinine-imprinted polymer onto the surface of HMDE. The modified-HMDE, preanodised in neutral medium at +0.4V versus Ag/AgCl for 120s, exhibited a marked enhancement in DPCSV current in comparison to the less anodised (imprinted polymer-modified electrode did not show linear response to creatinine. The imprinting factor as high as 9.4 implies that the imprinted polymer exclusively acts as a recognition element of creatinine sensor. The proposed procedure can be used to determine creatinine in human blood serum without any preliminary treatment of the sample in an accurate, rapid and simple way.

  1. Deep phylogeographic divergence and cytonuclear discordance in the grasshopper Oedaleus decorus.

    Science.gov (United States)

    Kindler, Eveline; Arlettaz, Raphaël; Heckel, Gerald

    2012-11-01

    The grasshopper Oedaleus decorus is a thermophilic insect with a large, mostly south-Palaearctic distribution range, stretching from the Mediterranean regions in Europe to Central-Asia and China. In this study, we analyzed the extent of phylogenetic divergence and the recent evolutionary history of the species based on 274 specimens from 26 localities across the distribution range in Europe. Phylogenetic relationships were determined using sequences of two mitochondrial loci (ctr, ND2) with neighbour-joining and Bayesian methods. Additionally, genetic differentiation was analyzed based on mitochondrial DNA and 11 microsatellite markers using F-statistics, model-free multivariate and model-based Bayesian clustering approaches. Phylogenetic analyses detected consistently two highly divergent, allopatrically distributed lineages within O. decorus. The divergence among these Western and Eastern lineages meeting in the region of the Alps was similar to the divergence of each lineage to the sister species O. asiaticus. Genetic differentiation for ctr was extremely high between Western and Eastern grasshopper populations (F(ct)=0.95). Microsatellite markers detected much lower but nevertheless very significant genetic structure among population samples. The nuclear data also demonstrated a case of cytonuclear discordance because the affiliation with mitochondrial lineages was incongruent in Northern Italy. Taken together these results provide evidence of an ancient separation within Oedaleus and either historical introgression of mtDNA among lineages and/or ongoing sex-specific gene flow in this grasshopper. Our study stresses the importance of multilocus approaches for unravelling the history and status of taxa of uncertain evolutionary divergence. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. In vitro culture and somatic cell nuclear transfer affect imprinting of SNRPN gene in pre- and post-implantation stages of development in cattle

    Directory of Open Access Journals (Sweden)

    Goff Alan K

    2009-02-01

    Full Text Available Abstract Background Embryo in vitro manipulations during early development are thought to increase mortality by altering the epigenetic regulation of some imprinted genes. Using a bovine interspecies model with a single nucleotide polymorphism, we assessed the imprinting status of the small nuclear ribonucleoprotein polypeptide N (SNRPN gene in bovine embryos produced by artificial insemination (AI, in vitro culture (IVF and somatic cell nuclear transfer (SCNT and correlated allelic expression with the DNA methylation patterns of a differentially methylated region (DMR located on the SNRPN promoter. Results In the AI group, SNRPN maternal expression is silenced at day 17 and 40 of development and a third of the alleles analyzed are methylated in the DMR. In the IVF group, maternal transcripts were identified at day 17 but methylation levels were similar to the AI group. However, day-40 fetuses in the IVF group showed significantly less methylation when compared to the AI group and SNRPN expression was mostly paternal in all fetal tissues studied, except in placenta. Finally, the SCNT group presented severe loss of DMR methylation in both day-17 embryos and 40 fetuses and biallelic expression was observed in all stages and tissues analyzed. Conclusion Together these results suggest that artificial reproductive techniques, such as prolonged in vitro culture and SCNT, lead to abnormal reprogramming of imprinting of SNRPN gene by altering methylation levels at this locus.

  3. Pattern imprinting in deep sub-micron static random access memories induced by total dose irradiation

    Science.gov (United States)

    Zheng, Qi-Wen; Yu, Xue-Feng; Cui, Jiang-Wei; Guo, Qi; Ren, Di-Yuan; Cong, Zhong-Chao; Zhou, Hang

    2014-10-01

    Pattern imprinting in deep sub-micron static random access memories (SRAMs) during total dose irradiation is investigated in detail. As the dose accumulates, the data pattern of memory cells loading during irradiation is gradually imprinted on their background data pattern. We build a relationship between the memory cell's static noise margin (SNM) and the background data, and study the influence of irradiation on the probability density function of ΔSNM, which is the difference between two data sides' SNMs, to discuss the reason for pattern imprinting. Finally, we demonstrate that, for micron and deep sub-micron devices, the mechanism of pattern imprinting is the bias-dependent threshold shift of the transistor, but for a deep sub-micron device the shift results from charge trapping in the shallow trench isolation (STI) oxide rather than from the gate oxide of the micron-device.

  4. Imprinted Oxide and MIP/Oxide Hybrid Nanomaterials for Chemical Sensors †.

    Science.gov (United States)

    Afzal, Adeel; Dickert, Franz L

    2018-04-20

    The oxides of transition, post-transition and rare-earth metals have a long history of robust and fast responsive recognition elements for electronic, optical, and gravimetric devices. A wide range of applications successfully utilized pristine or doped metal oxides and polymer-oxide hybrids as nanostructured recognition elements for the detection of biologically relevant molecules, harmful organic substances, and drugs as well as for the investigative process control applications. An overview of the selected recognition applications of molecularly imprinted sol-gel phases, metal oxides and hybrid nanomaterials composed of molecularly imprinted polymers (MIP) and metal oxides is presented herein. The formation and fabrication processes for imprinted sol-gel layers, metal oxides, MIP-coated oxide nanoparticles and other MIP/oxide nanohybrids are discussed along with their applications in monitoring bioorganic analytes and processes. The sensor characteristics such as dynamic detection range and limit of detection are compared as the performance criterion and the miniaturization and commercialization possibilities are critically discussed.

  5. Composite vascular repair grafts via micro-imprinting and electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yuanyuan, E-mail: yuanyuan-liu@shu.edu.cn; Hu, Qingxi, E-mail: huqingxi@shu.edu.cn [Rapid Manufacturing Engineering Center, Shanghai University, Shanghai 200444 (China); Shanghai Key Laboratory of Intelligent Manufacturing and Robotics, Shanghai 200072 (China); Xiang, Ke, E-mail: xiangke@shu.edu.cn; Chen, Haiping, E-mail: 519673062@qq.com; Li, Yu, E-mail: liyu@hpu.edu.cn [Rapid Manufacturing Engineering Center, Shanghai University, Shanghai 200444 (China)

    2015-04-15

    Composite vascular grafts formed by micro-imprinting and electrospinning exhibited improved mechanical properties relative to those formed by electrospinning alone. The three-layered composite grafts mimic the three-layered structure of natural blood vessels. The middle layer is made by micro-imprinting poly-p-dioxanone (PPDO), while the inner and outer layers are electrospun mixtures of chitosan and polyvinyl alcohol. The graft morphology is characterized with scanning electron microscopy. For constant graft thicknesses, the PPDO increases the mechanical strength. Cells cultivated on the vascular grafts adhere and proliferate better because of the natural, biological chitosan in the inner and outer layers. Overall, the composite scaffolds could be good candidates for blood vessel repair.

  6. Virtual Screening of Receptor Sites for Molecularly Imprinted Polymers.

    Science.gov (United States)

    Bates, Ferdia; Cela-Pérez, María Concepción; Karim, Kal; Piletsky, Sergey; López-Vilariño, José Manuel

    2016-08-01

    Molecularly Imprinted Polymers (MIPs) are highly advantageous in the field of analytical chemistry. However, interference from secondary molecules can also impede capture of a target by a MIP receptor. This greatly complicates the design process and often requires extensive laboratory screening which is time consuming, costly, and creates substantial waste products. Herein, is presented a new technique for screening of "virtually imprinted receptors" for rebinding of the molecular template as well as secondary structures, correlating the virtual predictions with experimentally acquired data in three case studies. This novel technique is particularly applicable to the evaluation and prediction of MIP receptor specificity and efficiency in complex aqueous systems. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Synthesis, characterization and evaluation of uniformly sized core-shell imprinted microspheres for the separation trans-resveratrol from giant knotweed

    International Nuclear Information System (INIS)

    Zhang Zhaohui; Liu Li; Li Hui; Yao Shouzhuo

    2009-01-01

    A novel core-shell molecularly imprinting microspheres (MIMs) with trans-resveratrol as the template molecule; acrylamide (AA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as cross-linker, was prepared based on SiO 2 microspheres with surface imprinting technique. These core-shell trans-resveratrol imprinted microspheres were characterized by infrared spectra (IR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and high performance liquid chromatography (HPLC). The results showed that these core-shell imprinted microspheres, which take on perfect spherical shape with average shell thickness of 150 nm, exhibit especially selective recognition for trans-resveratrol. These imprinted microspheres were applied as solid-phase extraction materials for selective extraction of trans-resveratrol from giant knotweed extracting solution successfully.

  8. Synthesis, characterization and evaluation of uniformly sized core-shell imprinted microspheres for the separation trans-resveratrol from giant knotweed

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Zhaohui, E-mail: zhaohuizhang77@hotmail.com [College of Chemistry and Chemical Engineering, Jishou University, Jishou, 416000 (China); State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, 410082 (China); Liu Li; Li Hui [College of Chemistry and Chemical Engineering, Jishou University, Jishou, 416000 (China); Yao Shouzhuo [State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, 410082 (China)

    2009-09-15

    A novel core-shell molecularly imprinting microspheres (MIMs) with trans-resveratrol as the template molecule; acrylamide (AA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as cross-linker, was prepared based on SiO{sub 2} microspheres with surface imprinting technique. These core-shell trans-resveratrol imprinted microspheres were characterized by infrared spectra (IR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and high performance liquid chromatography (HPLC). The results showed that these core-shell imprinted microspheres, which take on perfect spherical shape with average shell thickness of 150 nm, exhibit especially selective recognition for trans-resveratrol. These imprinted microspheres were applied as solid-phase extraction materials for selective extraction of trans-resveratrol from giant knotweed extracting solution successfully.

  9. Comparison of molecular imprinted particles prepared using precipitation polymerization in water and chloroform for fluorescent detection of nitroaromatics

    Energy Technology Data Exchange (ETDEWEB)

    Stringer, R. Cody, E-mail: rcsm84@mail.mizzou.edu [Department of Biological Engineering, University of Missouri, Columbia, MO (United States); Gangopadhyay, Shubhra, E-mail: gangopadhyays@missouri.edu [Department of Electrical and Computer Engineering, University of Missouri, Columbia, MO (United States); Grant, Sheila A., E-mail: grantsa@missouri.edu [Department of Biological Engineering, University of Missouri, Columbia, MO (United States)

    2011-10-10

    Highlights: {yields} Imprinted polymers prepared using precipitation polymerization. {yields} Comparison of chloroform and water as polymerization solvent. {yields} Imprinted polymer doped with quantum dots for fluorescent sensor. {yields} Fluorescent imprinted polymer used to detect nitroaromatic explosives. {yields} Chloroform is ideal solvent for molecular imprinting of nitroaromatics. - Abstract: A comparative study was conducted to study the effects that two different polymerization solvents would have on the properties of imprinted polymer microparticles prepared using precipitation polymerization. Microparticles prepared in chloroform, which previous results indicated was the optimal solvent for molecular imprinting of nitroaromatic explosive compounds, were compared to water, which was hypothesized to decrease water swelling of the polymer and allow enhanced rebinding of aqueous template. The microparticles were characterized and were integrated into a fluorescence sensing mechanism for detection of nitroaromatic explosive compounds. The performance of the sensing mechanisms was compared to illustrate which polymerization solvent produced optimal imprinted polymer microparticles for detection of nitroaromatic molecules. Results indicated that the structures of microparticles synthesized in chloroform versus water varied greatly. Sensor performance studies showed that the microparticles prepared in chloroform had greater imprinting efficiency and higher template rebinding than those prepared in water. For detection of 2,4,6-trinitrotoluene, the chloroform-based fluorescent microparticles achieved a lower limit of detection of 0.1 {mu}M, as compared to 100 {mu}M for the water-based fluorescent microparticles. Detection limits for 2,4-dinitrotoluene, as well as time response studies, also demonstrated that the chloroform-based particles are more effective for detection of nitroaromatic compounds than water-based particles. These results illustrate that the

  10. Comparison of molecular imprinted particles prepared using precipitation polymerization in water and chloroform for fluorescent detection of nitroaromatics

    International Nuclear Information System (INIS)

    Stringer, R. Cody; Gangopadhyay, Shubhra; Grant, Sheila A.

    2011-01-01

    Highlights: → Imprinted polymers prepared using precipitation polymerization. → Comparison of chloroform and water as polymerization solvent. → Imprinted polymer doped with quantum dots for fluorescent sensor. → Fluorescent imprinted polymer used to detect nitroaromatic explosives. → Chloroform is ideal solvent for molecular imprinting of nitroaromatics. - Abstract: A comparative study was conducted to study the effects that two different polymerization solvents would have on the properties of imprinted polymer microparticles prepared using precipitation polymerization. Microparticles prepared in chloroform, which previous results indicated was the optimal solvent for molecular imprinting of nitroaromatic explosive compounds, were compared to water, which was hypothesized to decrease water swelling of the polymer and allow enhanced rebinding of aqueous template. The microparticles were characterized and were integrated into a fluorescence sensing mechanism for detection of nitroaromatic explosive compounds. The performance of the sensing mechanisms was compared to illustrate which polymerization solvent produced optimal imprinted polymer microparticles for detection of nitroaromatic molecules. Results indicated that the structures of microparticles synthesized in chloroform versus water varied greatly. Sensor performance studies showed that the microparticles prepared in chloroform had greater imprinting efficiency and higher template rebinding than those prepared in water. For detection of 2,4,6-trinitrotoluene, the chloroform-based fluorescent microparticles achieved a lower limit of detection of 0.1 μM, as compared to 100 μM for the water-based fluorescent microparticles. Detection limits for 2,4-dinitrotoluene, as well as time response studies, also demonstrated that the chloroform-based particles are more effective for detection of nitroaromatic compounds than water-based particles. These results illustrate that the enhanced chemical properties of

  11. Relaxation of IGF2/H19 imprinting in Wilms tumour is associated with a switch in DNA methylation

    Energy Technology Data Exchange (ETDEWEB)

    Reeve, A.E.; Taniguchi, T.; Sullivan, M.J.; Ogawa, O. [Univ. of Otago, Dunedin (New Zealand)

    1994-09-01

    We and others have recently shown that the normal imprinting of the insulin-like growth factor 2 (IGF2) gene is disrupted in Wilms tumor. The process of relaxation of IGF2 imprinting leads to the activation of transcription of the normally silent maternally inherited IGF2 allele such that both alleles of the IGF2 gene are transcribed. Relaxation of IGF2 imprinting has also been detected as a constitutional event in patients with the Beckwith-Wiedemann syndrom and a patient with gigantism and Wilms tumor. We have now shown that in Wilms tumors in which imprinting is relaxed, IGF2 is transcribed from the maternal allele and there is a concomitant transcriptional inactivation of the H19 maternal allele. Furthermore, the patterns of methylation of the IGF2 and H19 gene are reversed on the maternal chromosome. Relaxation of imprinting in Wilms tumors appear, therefore, to be associated with a switch in gene expression and methylation at the IGF2/H19 locus. The data supports the notion of a disrupted IGF2/H19 imprinting switch in Wilms tumor.

  12. Identification of imprinted genes subject to parent-of-origin specific expression in Arabidopsis thaliana seeds.

    NARCIS (Netherlands)

    Mckeown, P.C.; Laouielle-Duprat, S.; Prins, J.C.P.; Wolff, de P.; Schmid, M.W.; Donoghue, M.T.; Fort, A.; Duszynska, D.; Comte, A.; Lao, N.T.; Wennblom, T.J.; Smant, G.; Köhler, C.; Grossniklaus, U.; Spillane, C.

    2011-01-01

    Background: Epigenetic regulation of gene dosage by genomic imprinting of some autosomal genes facilitates normal reproductive development in both mammals and flowering plants. While many imprinted genes have been identified and intensively studied in mammals, smaller numbers have been characterized

  13. Measurements of laser-imprinting sensitivity to relative beam mistiming in planar plastic foils driven by multiple overlapping laser beams

    International Nuclear Information System (INIS)

    Smalyuk, V.A.; Goncharov, V.N.; Boehly, T.R.; Delettrez, J.A.; Li, D.Y.; Marozas, J.A.; Maximov, A.V.; Meyerhofer, D.D.; Regan, S.P.; Sangster, T.C.

    2005-01-01

    In a direct-drive, inertial confinement fusion implosion, a spherical target is irradiated by a large number of overlapped laser beams. Imprinting of laser modulations depends on the relative arrival time of laser beams and their angles of incidence. This dependence was measured in planar plastic targets using six overlapping beams on the OMEGA laser system [T. R. Boehly, D. L. Brown, R. S. Craxton, R. L. Keck, J. P. Knauer, J. H. Kelly, T. J. Kessler, S. A. Kumpan, S. J. Loucks, S. A. Letzring, F. J. Marshall, R. L. McCrory, S. F. B. Morse, W. Seka, J. M. Soures, and C. P. Verdon, Opt. Commun. 133, 495 (1997)]. One of the beams (the imprint beam) had a special phase plate that produced two-dimensional modulations on the target, easily distinguishable from the features imprinted by the other five drive beams. The timing of the imprint beam was varied with respect to the drive beams to study imprinting sensitivity to beam mistiming. Shifting the imprint beam to arrive before the other beams significantly increased the imprint efficiency. The results are in very good agreement with the model predictions

  14. Imprinting Hatchery Reared Salmon and Steelhead Trout for Homing, Volume III of III; Disease and Physiology Supplements, 1978-1983 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Slatick, Emil; Gilbreath, Lyle G.; Harmon, Jerrel R. (Northwest and Alaska Fisheries Science Centr, Coastal Zone and Estuarine Studies Division, Seattle, WA)

    1988-02-03

    The main functions of the National Marine Fisheries Service (NMFS) Aquaculture Task biologists and contractual scientists involved in the 1978 homing studies were primarily a surveillance of fish physiology, disease, and relative survival during culture in marine net-pens, to determine if there were any unusual factors that might affect imprinting and homing behavior. The studies were conducted with little background knowledge of the implications of disease and physiology on imprinting and homing in salmonids. The health status of the stocks was quite variable as could be expected. The Dworshak and Wells Hatcheries steelhead suffered from some early stresses in seawater, probably osmoregulatory. The incidences of latent BKD in the Wells and Chelan Hatcheries steelhead and Kooskia Hatchery spring chinook salmon were extremely high, and how these will affect survival in the ocean is not known. Gill enzyme activity in the Dworshak and Chelan Hatcheries steelhead at release was low. Of the steelhead, survival in the Tucannon Hatchery stock will probably be the highest, with Dworshak Hatchery stock the lowest. This report contains five previously published papers.

  15. Genomic Imprinting and the Expression of Affect in Angelman Syndrome: What's in the Smile?

    Science.gov (United States)

    Oliver, Chris; Horsler, Kate; Berg, Katy; Bellamy, Gail; Dick, Katie; Griffiths, Emily

    2007-01-01

    Background: Kinship theory (or the genomic conflict hypothesis) proposes that the phenotypic effects of genomic imprinting arise from conflict between paternally and maternally inherited alleles. A prediction arising for social behaviour from this theory is that imbalance in this conflict resulting from a deletion of a maternally imprinted gene,…

  16. k-Means Clustering with Hölder Divergences

    KAUST Repository

    Nielsen, Frank

    2017-10-24

    We introduced two novel classes of Hölder divergences and Hölder pseudo-divergences that are both invariant to rescaling, and that both encapsulate the Cauchy-Schwarz divergence and the skew Bhattacharyya divergences. We review the elementary concepts of those parametric divergences, and perform a clustering analysis on two synthetic datasets. It is shown experimentally that the symmetrized Hölder divergences consistently outperform significantly the Cauchy-Schwarz divergence in clustering tasks.

  17. k-Means Clustering with Hölder Divergences

    KAUST Repository

    Nielsen, Frank; Sun, Ke; Marchand-Maillet, Sté phane

    2017-01-01

    We introduced two novel classes of Hölder divergences and Hölder pseudo-divergences that are both invariant to rescaling, and that both encapsulate the Cauchy-Schwarz divergence and the skew Bhattacharyya divergences. We review the elementary concepts of those parametric divergences, and perform a clustering analysis on two synthetic datasets. It is shown experimentally that the symmetrized Hölder divergences consistently outperform significantly the Cauchy-Schwarz divergence in clustering tasks.

  18. Imprint cytology from ultrasound-guided core biopsies: accurate and immediate diagnosis in a one-stop breast clinic

    International Nuclear Information System (INIS)

    Jones, L.; Lott, M.F.; Calder, C.J.; Kutt, E.

    2004-01-01

    AIM: To investigate whether imprint cytology from ultrasound-guided core biopsy specimens was adequate for the National Health Service Breast Screening Programme (NHSBSP) guidelines. METHODS: We prospectively audited imprint cytology from ultrasound-guided core biopsy specimens. The performance indicators for imprint cytology specimens from 111 consecutive ultrasound-guided core biopsy were compared with standards set by the NHSBSP for fine-needle aspiration cytology (FNAC). RESULTS: Imprint cytology fulfilled the 'preferred' targets for absolute and complete sensitivity, specificity, positive predictive value, false-positive and false-negative rates, inadequate rate and inadequate rate from cancers. It also satisfied the minimum target for suspicious rate. The complete sensitivity was 97%, full specificity 78%, with 100% positive predictive value for C5 cytology and an inadequate rate from cancers of 1.5%. CONCLUSION: Imprint cytology from ultrasound-guided core biopsy allows same-day diagnosis and the collection of data regarding the grade of the carcinoma for treatment decisions from a single needle test

  19. Radiation-induced molecular imprinting of D-glucose onto poly(2-hydroxyethyl methacrylate) matrices using various crosslinking agents

    International Nuclear Information System (INIS)

    Ates, Zeliha; Gueven, Olgun

    2010-01-01

    Radiation-induced molecular imprinting of D-glucose onto poly(2-hydroxyethyl methacrylate) matrix was achieved to create three-dimensional cavities to recognize and bind D-glucose. The optimization of imprinting capability of matrices was achieved by investigating the effects of various parameters such as the type and amount of crosslinking agent, type of solvent, template to monomer ratio and total absorbed dose. Crosslinking agents with increasing chain lengths and different flexibilities were used in an attempt to elucidate the impact of relevant imprint parameters on the effectiveness of imprinting technique. The absorbed dose varied from 1 to 15 kGy. Cavity sizes of MIPs were measured by positron annihilation lifetime (PAL) experiments. Control matrices were synthesized with exactly the same composition in the absence of D-glucose. Separation of D-glucose has been shown to be successfully achieved in HPLC columns filled with MIPs whereas no separation was observed for non-imprint matrices.

  20. 3D Simulation of Nano-Imprint Lithography

    DEFF Research Database (Denmark)

    Román Marín, José Manuel; Rasmussen, Henrik K.; Hassager, Ole

    2010-01-01

    A proof of concept study of the feasibility of fully three-dimensional (3D) time-dependent simulation of nano-imprint lithography of polymer melt, where the polymer is treated as a structured liquid, has been presented. Considering the flow physics of the polymer as a structured liquid, we have...

  1. Imprint of Galactic dynamics on Earth's climate

    DEFF Research Database (Denmark)

    Svensmark, Henrik

    2006-01-01

    A connection between climate and the Solar system's motion perpendicular to the Galactic plane during the last 200 Myr years is studied. An imprint of galactic dynamics is found in a long-term record of the Earth's climate that is consistent with variations in the Solar system oscillation around...

  2. Synthesis of a specific monolithic column with artificial recognition sites for L-glutamic acid via cryo-crosslinking of imprinted nanoparticles.

    Science.gov (United States)

    Göktürk, Ilgım; Üzek, Recep; Uzun, Lokman; Denizli, Adil

    2016-06-01

    In this study, a new molecular imprinting (MIP)-based monolithic cryogel column was prepared using chemically crosslinked molecularly imprinted nanoparticles, to achieve a simplified chromatographic separation (SPE) for a model compound, L-glutamic acid (L-Glu). Cryogelation through crosslinking of imprinted nanoparticles forms stable monolithic cryogel columns. This technique reduces the leakage of nanoparticles and increases the surface area, while protecting the structural features of the cryogel for stable and efficient recognition of the template molecule. A non-imprinted monolithic cryogel column (NIP) was also prepared, using non-imprinted nanoparticles produced without the addition of L-Glu during polymerization. The molecularly imprinted monolithic cryogel column (MIP) indicates apparent recognition selectivity and a good adsorption capacity compared to the NIP. Also, we have achieved a significant increase in the adsorption capacity, using the advantage of high surface area of the nanoparticles.

  3. Pattern imprinting in deep sub-micron static random access memories induced by total dose irradiation

    International Nuclear Information System (INIS)

    Zheng Qi-Wen; Yu Xue-Feng; Cui Jiang-Wei; Guo Qi; Ren Di-Yuan; Cong Zhong-Chao; Zhou Hang

    2014-01-01

    Pattern imprinting in deep sub-micron static random access memories (SRAMs) during total dose irradiation is investigated in detail. As the dose accumulates, the data pattern of memory cells loading during irradiation is gradually imprinted on their background data pattern. We build a relationship between the memory cell's static noise margin (SNM) and the background data, and study the influence of irradiation on the probability density function of ΔSNM, which is the difference between two data sides' SNMs, to discuss the reason for pattern imprinting. Finally, we demonstrate that, for micron and deep sub-micron devices, the mechanism of pattern imprinting is the bias-dependent threshold shift of the transistor, but for a deep sub-micron device the shift results from charge trapping in the shallow trench isolation (STI) oxide rather than from the gate oxide of the micron-device. (condensed matter: structural, mechanical, and thermal properties)

  4. Kin recognition in zebrafish: a 24-hour window for olfactory imprinting.

    Science.gov (United States)

    Gerlach, Gabriele; Hodgins-Davis, Andrea; Avolio, Carla; Schunter, Celia

    2008-09-22

    Distinguishing kin from non-kin profoundly impacts the evolution of social behaviour. Individuals able to assess the genetic relatedness of conspecifics can preferentially allocate resources towards related individuals and avoid inbreeding. We have addressed the question of how animals acquire the ability to recognize kin by studying the development of olfactory kin preference in zebrafish (Danio rerio). Previously, we showed that zebrafish use an olfactory template to recognize even unfamiliar kin through phenotype matching. Here, we show for the first time that this phenotype matching is based on a learned olfactory imprinting process in which exposure to kin individuals on day 6 post fertilization (pf) is necessary and sufficient for imprinting. Larvae that were exposed to kin before or after but not on day 6 pf did not recognize kin. Larvae isolated from all contact with conspecifics did not imprint on their own chemical cues; therefore, we see no evidence for kin recognition through self-matching in this species. Surprisingly, exposure to non-kin odour during the sensitive phase of development did not result in imprinting on the odour cues of unrelated individuals, suggesting a genetic predisposition to kin odour. Urine-born peptides expressed by genes of the immune system (MHC) are important messengers carrying information about 'self' and 'other'. We suggest that phenotype matching is acquired through a time-sensitive learning process that, in zebrafish, includes a genetic predisposition potentially involving MHC genes expressed in the olfactory receptor neurons.

  5. Investigating the Incorporation of Personality Constructs into IMPRINT

    National Research Council Canada - National Science Library

    Dickason, David; Sargent, Bob; Bagnall, Tim

    2009-01-01

    ... in the Army, for use in Navy ship acquisitions. The objective of this study was to determine if it was feasible to incorporate non-cognitive attributes such as stress tolerance into IMPRINT for use as human performance moderators...

  6. Measurements of direct drive laser imprint in thin foils by radiography using an x-ray laser backlighter

    International Nuclear Information System (INIS)

    Kalantar, D.H.; Key, M.H.; Da Silva, L.B.; Glendinning, S.G.; Remington, B.A.; Rothenberg, J.E.; Weber, F.; Weber, S.V.; Wolfrum, E.; Kim, N.S.; Neely, D.; Zhang, J.; Wark, J.S.; Demir, A.; Lin, J.; Smith, R.; Tallents, G.J.; Lewis, C.L.; MacPhee, A.; Warwick, J.; Knauer, J.P.

    1997-01-01

    In direct drive inertial confinement fusion, the residual speckle pattern remaining after beam smoothing plays an important role in the seeding of instabilities at the ablation front. An x-ray laser is used as an extreme ultraviolet backlighter to characterize the imprinted modulation in thin foils for smoothing by random phase plate and by spectral dispersion for both 0.35 and 0.53 μm irradiation, and by induced spatial incoherence for 0.53 μm irradiation. Measurements of the imprinted modulation due to a single optical mode generated by two beam interference, and modification of the imprint with a superposed smooth irradiation to study time dependence of the imprinting process are demonstrated. copyright 1997 American Institute of Physics

  7. Hyperreal Numbers for Infinite Divergent Series

    OpenAIRE

    Bartlett, Jonathan

    2018-01-01

    Treating divergent series properly has been an ongoing issue in mathematics. However, many of the problems in divergent series stem from the fact that divergent series were discovered prior to having a number system which could handle them. The infinities that resulted from divergent series led to contradictions within the real number system, but these contradictions are largely alleviated with the hyperreal number system. Hyperreal numbers provide a framework for dealing with divergent serie...

  8. Magnetization dynamics of imprinted non-collinear spin textures

    Energy Technology Data Exchange (ETDEWEB)

    Streubel, Robert, E-mail: r.streubel@ifw-dresden.de; Kopte, Martin; Makarov, Denys, E-mail: d.makarov@ifw-dresden.de [Institute for Integrative Nanosciences, IFW Dresden, 01069 Dresden (Germany); Fischer, Peter [Center for X-Ray Optics, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Physics Department, UC Santa Cruz, Santa Cruz, California 95064 (United States); Schmidt, Oliver G. [Institute for Integrative Nanosciences, IFW Dresden, 01069 Dresden (Germany); Material Systems for Nanoelectronics, Chemnitz University of Technology, 09107 Chemnitz (Germany)

    2015-09-14

    We study the magnetization dynamics of non-collinear spin textures realized via imprint of the magnetic vortex state in soft permalloy into magnetically hard out-of-plane magnetized Co/Pd nanopatterned heterostructures. Tuning the interlayer exchange coupling between soft- and hard-magnetic subsystems provides means to tailor the magnetic state in the Co/Pd stack from being vortex- to donut-like with different core sizes. While the imprinted vortex spin texture leads to the dynamics similar to the one observed for vortices in permalloy disks, the donut-like state causes the appearance of two gyrofrequencies characteristic of the early and later stages of the magnetization dynamics. The dynamics are described using the Thiele equation supported by the full scale micromagnetic simulations by taking into account an enlarged core size of the donut states compared to magnetic vortices.

  9. The divergence theorem for divergence measure vectorfields on sets with fractal boundaries

    Czech Academy of Sciences Publication Activity Database

    Šilhavý, Miroslav

    2009-01-01

    Roč. 14, č. 5 (2009), s. 445-455 ISSN 1081-2865 Institutional research plan: CEZ:AV0Z10190503 Keywords : divergence measure vectorfields * fractal s * divergence theorem Subject RIV: BA - General Mathematics Impact factor: 1.065, year: 2009

  10. The Patchwork Divergence Theorem

    OpenAIRE

    Dray, Tevian; Hellaby, Charles

    1994-01-01

    The divergence theorem in its usual form applies only to suitably smooth vector fields. For vector fields which are merely piecewise smooth, as is natural at a boundary between regions with different physical properties, one must patch together the divergence theorem applied separately in each region. We give an elegant derivation of the resulting "patchwork divergence theorem" which is independent of the metric signature in either region, and which is thus valid if the signature changes. (PA...

  11. Quantitative analysis of DNA methylation at all human imprinted regions reveals preservation of epigenetic stability in adult somatic tissue

    Directory of Open Access Journals (Sweden)

    Woodfine Kathryn

    2011-01-01

    Full Text Available Abstract Background Genes subject to genomic imprinting are mono-allelically expressed in a parent-of-origin dependent manner. Each imprinted locus has at least one differentially methylated region (DMR which has allele specific DNA methylation and contributes to imprinted gene expression. Once DMRs are established, they are potentially able to withstand normal genome reprogramming events that occur during cell differentiation and germ-line DMRs are stably maintained throughout development. These DMRs, in addition to being either maternally or paternally methylated, have differences in whether methylation was acquired in the germ-line or post fertilization and are present in a variety of genomic locations with different Cytosine-phosphate guanine (CpG densities and CTCF binding capacities. We therefore examined the stability of maintenance of DNA methylation imprints and determined the normal baseline DNA methylation levels in several adult tissues for all imprinted genes. In order to do this, we first developed and validated 50 highly specific, quantitative DNA methylation pyrosequencing assays for the known DMRs associated with human imprinted genes. Results Remarkable stability of the DNA methylation imprint was observed in all germ-line DMRs and paternally methylated somatic DMRs (which maintained average methylation levels of between 35% - 65% in all somatic tissues, independent of gene expression. Maternally methylated somatic DMRs were found to have more variation with tissue specific methylation patterns. Most DMRs, however, showed some intra-individual variability for DNA methylation levels in peripheral blood, suggesting that more than one DMR needs to be examined in order to get an overall impression of the epigenetic stability in a tissue. The plasticity of DNA methylation at imprinted genes was examined in a panel of normal and cancer cell lines. All cell lines showed changes in DNA methylation, especially at the paternal germ

  12. Molecularly imprinted solid-phase extraction of glutathione from urine samples

    International Nuclear Information System (INIS)

    Song, Renyuan; Hu, Xiaoling; Guan, Ping; Li, Ji; Zhao, Na; Wang, Qiaoli

    2014-01-01

    Molecularly imprinted polymer (MIP) particles for glutathione were synthesized through iniferter-controlled living radical precipitation polymerization (IRPP) under ultraviolet radiation at ambient temperature. Static adsorption, solid-phase extraction, and high-performance liquid chromatography were carried out to evaluate the adsorption properties and selective recognition characteristics of the polymers for glutathione and its structural analogs. The obtained IRPP-MIP particles exhibited a regularly spherical shape, rapid binding kinetics, high imprinting factor, and high selectivity compared with the MIP particles prepared using traditional free-radical precipitation polymerization. The selective separation and enrichment of glutathione from the mixture of glycyl-glycine and glutathione disulfide could be achieved on the IRPP-MIP cartridge. The recoveries of glutathione, glycyl-glycine, and glutathione disulfide were 95.6% ± 3.65%, 29.5% ± 1.26%, and 49.9% ± 1.71%, respectively. The detection limit (S/N = 3) of glutathione was 0.5 mg·L −1 . The relative standard deviations (RSDs) for 10 replicate detections of 50 mg·L −1 of glutathione were 5.76%, and the linear range of the calibration curve was 0.5 mg·L −1 to 200 mg·L −1 under optimized conditions. The proposed approach was successfully applied to determine glutathione in spiked human urine samples with recoveries of 90.24% to 96.20% and RSDs of 0.48% to 5.67%. - Highlights: • Imprinted polymer particles were prepared by IRPP at ambient temperature. • High imprinting factor, high selectivity, and rapid binding kinetics were achieved. • Selective solid-phase extraction of glutathione from human urine samples

  13. An Assay Study of Molecular Recognition of Amino Acids in Water: Covalent Imprinting of Cysteine

    DEFF Research Database (Denmark)

    Burri, Harsha Vardhan Reddy; Yu, Donghong

    2015-01-01

    A novel synthetic N-(9-fluorenyl methoxy carbonyl)-L-Cysteine (Fmoc-Cys(SH)-OH) receptor was pre- pared by co-polymerizing (9-fluorenyl methoxy carbonyl)-S-(1-propene-2-thiol)-L-Cysteine (Fmoc-Cys(SCH2CHCH2)-OH) and a non-imprinted polymer prepared from 1-propene-1-thiol photo-chemically 15 h...... at room temperature and additional 3 h thermally at 80℃. Subsequently, disulfides were reduced with lithium aluminum hydride (LiAlH4) from imprinted polymers. The imprinted polymers selectively recognized Fmoc-Cys(SH)-OH with high binding constants in aqueous and protic solvents by thiol...

  14. Development of andrographolide molecularly imprinted polymer for solid-phase extraction

    Science.gov (United States)

    Yin, Xiaoying; Liu, Qingshan; Jiang, Yifan; Luo, Yongming

    2011-06-01

    A method employing molecularly imprinted polymer (MIP) as selective sorbent for solid-phase extraction (SPE) to pretreat samples was developed. The polymers were prepared by precipitation polymerization with andrographolide as template molecule. The structure of MIP was characterized and its static adsorption capacity was measured by the Scatchard equation. In comparison with C 18-SPE and non-imprinted polymer (NIP) SPE column, MIP-SPE column displays high selectivity and good affinity for andrographolide and dehydroandrographolide for extract of herb Andrographis paniculata ( Burm.f.) Nees (APN). MIP-SPE column capacity was 11.9 ± 0.6 μmol/g and 12.1 ± 0.5 μmol/g for andrographolide and dehydroandrographolide, respectively and was 2-3 times higher than that of other two columns. The precision and accuracy of the method developed were satisfactory with recoveries between 96.4% and 103.8% (RSD 3.1-4.3%, n = 5) and 96.0% and 104.2% (RSD 2.9-3.7%, n = 5) for andrographolide and dehydroandrographolide, respectively. Various real samples were employed to confirm the feasibility of method. This developed method demonstrates the potential of molecularly imprinted solid phase extraction for rapid, selective, and effective sample pretreatment.

  15. Detour behaviour, imprinting and visual lateralization in the domestic chick.

    Science.gov (United States)

    Vallortigara, G; Regolin, L; Pagni, P

    1999-01-01

    Detour behaviour was studied in chicks faced with a vertical-bar barrier behind where an imprinting object (a red ball) was located. Right-eyed chicks took less time to detour the barrier than left-eyed chicks, and binocular chicks showed a bias to detour the barrier on the left side, thus maintaining visual contact with the imprinting object using the lateral field of the right eye, while circling around the barrier. In males, the asymmetries were consistent all along the first two weeks of life, whereas in females they disappeared on days 8 and 11. When tested with a slightly novel version of the original imprinting object (i.e., a ball of a different color), binocular chicks showed a bias to detour the barrier on the right side, thus showing preferential use of the left eye. The same bias occurred when unfamiliar conspecifics were used as goal-objects. Results suggest that cerebral lateralization in birds can directly affect visually-guided motor responses through selective use of the lateral field of vision of the eye contralateral to the hemisphere which has to be put in charge of control of overt behaviour. Copyright 1999 Elsevier Science B.V.

  16. Recommendations for a nomenclature system for reporting methylation aberrations in imprinted domains

    DEFF Research Database (Denmark)

    Monk, David; Morales, Joannella; den Dunnen, Johan T

    2018-01-01

    Disorders we have discussed these issues and designed a nomenclature for naming imprinted DMRs as well as for reporting methylation values. We apply these recommendations for imprinted DMRs that are commonly assayed in clinical laboratories and show how they support standardized database submission....... The recommendations are in line with existing recommendations, most importantly the Human Genome Variation Society nomenclature, and should facilitate accurate reporting and data exchange among laboratories and thereby help to avoid future confusion....

  17. Identification of imprinted genes subject to parent-of-origin specific expression in Arabidopsis thaliana seeds

    LENUS (Irish Health Repository)

    McKeown, Peter C

    2011-08-12

    Abstract Background Epigenetic regulation of gene dosage by genomic imprinting of some autosomal genes facilitates normal reproductive development in both mammals and flowering plants. While many imprinted genes have been identified and intensively studied in mammals, smaller numbers have been characterized in flowering plants, mostly in Arabidopsis thaliana. Identification of additional imprinted loci in flowering plants by genome-wide screening for parent-of-origin specific uniparental expression in seed tissues will facilitate our understanding of the origins and functions of imprinted genes in flowering plants. Results cDNA-AFLP can detect allele-specific expression that is parent-of-origin dependent for expressed genes in which restriction site polymorphisms exist in the transcripts derived from each allele. Using a genome-wide cDNA-AFLP screen surveying allele-specific expression of 4500 transcript-derived fragments, we report the identification of 52 maternally expressed genes (MEGs) displaying parent-of-origin dependent expression patterns in Arabidopsis siliques containing F1 hybrid seeds (3, 4 and 5 days after pollination). We identified these MEGs by developing a bioinformatics tool (GenFrag) which can directly determine the identities of transcript-derived fragments from (i) their size and (ii) which selective nucleotides were added to the primers used to generate them. Hence, GenFrag facilitates increased throughput for genome-wide cDNA-AFLP fragment analyses. The 52 MEGs we identified were further filtered for high expression levels in the endosperm relative to the seed coat to identify the candidate genes most likely representing novel imprinted genes expressed in the endosperm of Arabidopsis thaliana. Expression in seed tissues of the three top-ranked candidate genes, ATCDC48, PDE120 and MS5-like, was confirmed by Laser-Capture Microdissection and qRT-PCR analysis. Maternal-specific expression of these genes in Arabidopsis thaliana F1 seeds was

  18. Identification of imprinted genes subject to parent-of-origin specific expression in Arabidopsis thaliana seeds

    Directory of Open Access Journals (Sweden)

    Wennblom Trevor J

    2011-08-01

    Full Text Available Abstract Background Epigenetic regulation of gene dosage by genomic imprinting of some autosomal genes facilitates normal reproductive development in both mammals and flowering plants. While many imprinted genes have been identified and intensively studied in mammals, smaller numbers have been characterized in flowering plants, mostly in Arabidopsis thaliana. Identification of additional imprinted loci in flowering plants by genome-wide screening for parent-of-origin specific uniparental expression in seed tissues will facilitate our understanding of the origins and functions of imprinted genes in flowering plants. Results cDNA-AFLP can detect allele-specific expression that is parent-of-origin dependent for expressed genes in which restriction site polymorphisms exist in the transcripts derived from each allele. Using a genome-wide cDNA-AFLP screen surveying allele-specific expression of 4500 transcript-derived fragments, we report the identification of 52 maternally expressed genes (MEGs displaying parent-of-origin dependent expression patterns in Arabidopsis siliques containing F1 hybrid seeds (3, 4 and 5 days after pollination. We identified these MEGs by developing a bioinformatics tool (GenFrag which can directly determine the identities of transcript-derived fragments from (i their size and (ii which selective nucleotides were added to the primers used to generate them. Hence, GenFrag facilitates increased throughput for genome-wide cDNA-AFLP fragment analyses. The 52 MEGs we identified were further filtered for high expression levels in the endosperm relative to the seed coat to identify the candidate genes most likely representing novel imprinted genes expressed in the endosperm of Arabidopsis thaliana. Expression in seed tissues of the three top-ranked candidate genes, ATCDC48, PDE120 and MS5-like, was confirmed by Laser-Capture Microdissection and qRT-PCR analysis. Maternal-specific expression of these genes in Arabidopsis thaliana F1

  19. Molecular mechanisms of memory in imprinting.

    Science.gov (United States)

    Solomonia, Revaz O; McCabe, Brian J

    2015-03-01

    Converging evidence implicates the intermediate and medial mesopallium (IMM) of the domestic chick forebrain in memory for a visual imprinting stimulus. During and after imprinting training, neuronal responsiveness in the IMM to the familiar stimulus exhibits a distinct temporal profile, suggesting several memory phases. We discuss the temporal progression of learning-related biochemical changes in the IMM, relative to the start of this electrophysiological profile. c-fos gene expression increases <15 min after training onset, followed by a learning-related increase in Fos expression, in neurons immunopositive for GABA, taurine and parvalbumin (not calbindin). Approximately simultaneously or shortly after, there are increases in phosphorylation level of glutamate (AMPA) receptor subunits and in releasable neurotransmitter pools of GABA and taurine. Later, the mean area of spine synapse post-synaptic densities, N-methyl-D-aspartate receptor number and phosphorylation level of further synaptic proteins are elevated. After ∼ 15 h, learning-related changes in amounts of several synaptic proteins are observed. The results indicate progression from transient/labile to trophic synaptic modification, culminating in stable recognition memory. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  20. Synthesis of a nanoporous molecularly imprinted polymers for dibutyl Phthalate extracted from Trichoderma Harzianum

    Directory of Open Access Journals (Sweden)

    Maede Shahiri Tabarestani

    2016-07-01

    Full Text Available In this study, molecularly imprinted polymers were synthesized for dibutyl phthalate as a bioactive chemical compound with antifungal activity which produced by Trichoderma Harzianum (JX1738521. The molecularly imprinted polymers were synthesized via precipitation polymerization method from methacrylic acid, dibutyl phthalate and trimetylolpropantrimethacrylate as a functional monomer, template and cross-linker, respectively. After removal of the template by the eluent from the MIPs, the leached nanoparticles of the MIPs had a good binding capacity as equal 830 mg/g. The polymer particles have been evaluated by field emission scan electron microscopy and Brunauer–Emmett–Teller  techniques. The excellent specific surface area in the molecularly imprinted polymers as equal to 690.301 m2/g comparatively to non-imprinted polymers (ca. 89.894 m2/g, confirms that the nanoporous MIPs were synthesized, successfully. The results indicated that the nanoporous MIPs can be used in solid phase extraction. This is a novel method for separation of the bioactive compounds from fungi secondary metabolites in biological control.

  1. A highly selective molecularly imprinted electrochemiluminescence sensor for ultra-trace beryllium detection

    International Nuclear Information System (INIS)

    Li, Jianping; Ma, Fei; Wei, Xiaoping; Fu, Cong; Pan, Hongcheng

    2015-01-01

    Graphical abstract: A novel molecular imprinted electrochemiluminescence sensor was fabricated for ultra-trace Be 2+ detection with an extremely lower detection limit based on the luminol–H 2 O 2 ECL system. - Highlights: • A novel molecular imprinted electrochemiluminescence sensor was fabricated for ultra-trace Be 2+ detection. • Imprint cavities in the MIPs from elution the Be–PAR complex could provide more recognition sites for analytes. • ECL emission produced by the luminol–H 2 O 2 ECL system, which was applied to detect Be 2+ . • It gave an extremely lower detection limit (2.35 × 10 −11 mol L −1 ) than the reported methods. - Abstract: A new molecularly imprinted electrochemiluminescence (ECL) sensor was proposed for highly sensitive and selective determination of ultratrace Be 2+ determination. The complex of Be 2+ with 4-(2-pyridylazo)-resorcinol (PAR) was chosen as the template molecule for the molecularly imprinted polymer (MIP). In this assay, the complex molecule could be eluted from the MIP, and the cavities formed could then selectively recognize the complex molecules. The cavities formed could also work as the tunnel for the transfer of probe molecules to produce sound responsive signal. The determination was based on the intensity of the signal, which was proportional to the concentrations of the complex molecule in the sample solution, and the Be 2+ concentration could then be determined indirectly. The results showed that in the range of 7 × 10 −11 mol L −1 to 8.0 × 10 −9 mol L −1 , the ECL intensity had a linear relationship with the Be 2+ concentrations, with the limit of detection of 2.35 × 10 −11 mol L −1 . This method was successfully used to detect Be 2+ in real water samples

  2. Imprinted and injection-molded nano-structured optical surfaces

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun; Højlund-Nielsen, Emil; Clausen, Jeppe Sandvik

    2013-01-01

    . In this paper, nanostructured polymer surfaces suitable for up-scalable polymer replication methods, such as imprinting/embossing and injection-molding, are discussed. The limiting case of injection-moulding compatible designs is investigated. Anti-reflective polymer surfaces are realized by replication...

  3. Molecularly imprinted polymers for the recognition of proteins: the state of the art.

    Science.gov (United States)

    Bossi, A; Bonini, F; Turner, A P F; Piletsky, S A

    2007-01-15

    Molecular imprinting has proved to be an effective technique for the creation of recognition sites on a polymer scaffold. Protein imprinting has been a focus for many chemists working in the area of molecular recognition, since the creation of synthetic polymers that can specifically recognise proteins is a very challenging but potentially extremely rewarding objective. It is expected that molecularly imprinted polymers (MIPs) with specificity for proteins will find application in medicine, diagnostics, proteomics, environmental analysis, sensors and drug delivery. In this review, the authors provide an overview of the progress achieved in the decade between 1994 and 2005, with respect to the challenging area of MIPs for protein recognition. The discussion furnishes a comparative analysis of different approaches developed, underlining their relative advantages and disadvantages and highlighting trends and possible future directions.

  4. One-by-one imprinting in two eccentric layers of hollow core-shells: Sequential electroanalysis of anti-HIV drugs.

    Science.gov (United States)

    Singh, Kislay; Jaiswal, Swadha; Singh, Richa; Fatma, Sana; Prasad, Bhim Bali

    2018-07-15

    Double layered one-by-one imprinted hollow core-shells@ pencil graphite electrode was fabricated for sequential sensing of anti-HIV drugs. For this, two eccentric layers were developed on the surface of vinylated silica nanospheres to obtain double layered one-by-one imprinted solid core-shells. This yielded hollow core-shells on treatment with hydrofluoric acid. The modified hollow core-shells (single layered dual imprinted) evolved competitive diffusion of probe/analyte molecules. However, the corresponding double layered one-by-one imprinted hollow core-shells (outer layer imprinted with Zidovudine, and inner layer with Lamivudine) were found relatively better owing to their bilateral diffusions into molecular cavities, without any competition. The entire work is based on differential pulse anodic stripping voltammetry at double layered one-by-one imprinted hollow core-shells. This resulted in indirect detection of electro inactive targets with limits of detection as low as 0.91 and 0.12 (aqueous sample), 0.94 and 0.13 (blood serum), and 0.99 and 0.20 ng mL -1 (pharmaceutics) for lamivudine and zidovudine, respectively in anti-HIV drug combination. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Preparation of molecularly imprinted adsorptive resin for trapping of ligustrazine from the traditional Chinese herb Ligusticum chuanxiong Hort

    International Nuclear Information System (INIS)

    Guo Zhifeng; Guo Tingting; Guo Mufan

    2008-01-01

    A highly selective molecularly imprinted adsorptive resin for ligustrazine was prepared by melamine-urea-formaldehyde (MUF) gel. In the experiments, two pieces of MUF gel were synthesized firstly; one was added ligustrazine hydrochloride as the template molecule in it to prepare the imprinted adsorptive resin, and the other was not. Scanning electron microscopy (SEM) revealed that both resins were the porous with a network structure whether or not it was added template molecule. The imprinted adsorptive resin had an absorbability of 85.22% measured by a 200 mg L -1 solution of ligustrazine hydrochloride at room temperature. The resin of MUF without template, on the other hand, displayed an adsorption capacity of almost zero. It illuminated the imprinted adsorptive resin formed ligustrazine recognition sites when the template molecule had been eluted. In the present paper, ligustrazine was effectively separated and enriched from herbs by using a solid-phase adsorptive column filled with the imprinted adsorptive resin. Its eluate, obtained from three kinds of solvents, was analyzed by GC-MS, and the results indicated that the imprinted adsorptive resin showed a high selectivity for ligustrazine. This is believed to be beneficial for extracting natural and highly purified ligustrazine

  6. Double-layer imprint lithography on wafers and foils from the submicrometer to the millimeter scale

    NARCIS (Netherlands)

    Moonen, P.F.; Yakimets, I.; Peter, M.; Meinders, E.R.; Huskens, J.

    2011-01-01

    In this paper, a thermal imprint technique, double-layer nanoimprint lithography (dlNIL), is introduced, allowing complete filling of features in the dimensional range of submicrometer to millimeter. The imprinting and filling quality of dlNIL was studied on Si substrates as a model system and

  7. Use of computational modeling in preparation and evaluation of surface imprinted xerogels for binding tetracycline

    International Nuclear Information System (INIS)

    Pace, Samantha J.; Nguyen, Eric; Baria, Maximillian P.; Mojica, Elmer-Rico E.

    2015-01-01

    Linear alkyl alkoxysilanes (methoxy and ethoxy-based) of varying length were used in preparing tetracycline surface imprinted silica xerogels by the sol–gel process. The resulting xerogels were characterized in terms of binding tetracycline (TC) by using tritium-labeled TC. Results showed preferential binding in the ethoxysilane based xerogels in comparison to methoxysilane based xerogels. A computational approach using the interaction energy (IE) between TC and each alkyl alkoxysilane was deduced as a rational way of predicting the formulation that would provide the best analytical performance for a given molecularly imprinted xerogel (MIX). Hartree-Fock calculations revealed an increase in IE as the length of the carbon chain increases until an optimum value at C6 in both alkoxysilanes. This is consistent with the experimental results wherein the C6 xerogel formulation has the highest imprinting factor. These results show the potential of using computational modeling as a rational way of preparing surface imprinted materials. (author)

  8. Visual detection of 2,4,6-trinitrotolune by molecularly imprinted colloidal array photonic crystal

    International Nuclear Information System (INIS)

    Lu, Wei; Asher, Sanford A.; Meng, Zihui; Yan, Zequn; Xue, Min; Qiu, Lili; Yi, Da

    2016-01-01

    Graphical abstract: Molecularly imprinted colloidal array (MICA) was explored for the selective visual detection of TNT with color changing from green to red. And molecularly imprinted colloidal particles (MICs) were evaluated for the adsorption capacity and the imprinting efficiency. The MICA had excellent flexibility, reversibility and stability. It promised high potential for the visual semi-quantitative detection of other explosives. - Highlights: • Molecularly imprinted colloidal array (MICA) was used to visually detect TNT. • The relationship of particle size, diffracted wavelength and color was discussed. • The adsorption capacity and imprinting efficiency of MICs were calculated. • MICA had short response time, high selectivity, good reversibility and stability. • MICA had high potential to be used in other customed visual explosive detection. - Abstract: We developed a photonic crystal (PhC) sensor for the quantification of 2,4,6-trinitrotoluene (TNT) in solution. Monodisperse (210 nm in diameter) molecularly imprinted colloidal particles (MICs) for TNT were prepared by the emulsion polymerization of methyl methacrylate and acrylamide in the presence of TNT as a template. The MICs were then self-assembled into close-packed opal PhC films. The adsorption capacity of the MICs for TNT was 64 mg TNT/g. The diffraction from the PhC depended on the TNT concentration in a methanol/water (3/2, v/v) potassium dihydrogen phosphate buffer solution (pH = 7.0, 30 mM). The limit of detection (LOD) of the sensor was 1.03 μg. The color of the molecularly imprinted colloidal array (MICA) changed from green to red with an 84 nm diffraction red shift when the TNT concentration increased to 20 mM. The sensor response time was 3 min. The PhC sensor was selective for TNT compared to similar compounds such as 2,4,6-trinitrophenol, 2,4-dinitrotoluene, 2,6-dinitrotoluene, 2-nitromesitylene, 4-nitrotoluene, 2-nitrotoluene, 1,3-dinitrobenzene, methylbenzene, 4-nitrophenol

  9. Visual detection of 2,4,6-trinitrotolune by molecularly imprinted colloidal array photonic crystal

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Wei [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China); Asher, Sanford A., E-mail: asher@pitt.edu [Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Meng, Zihui, E-mail: m_zihui@yahoo.com [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China); Yan, Zequn [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China); Xue, Min, E-mail: minxue@bit.edu.cn [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China); Qiu, Lili, E-mail: qiulili@bit.edu.cn [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China); Yi, Da [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China)

    2016-10-05

    Graphical abstract: Molecularly imprinted colloidal array (MICA) was explored for the selective visual detection of TNT with color changing from green to red. And molecularly imprinted colloidal particles (MICs) were evaluated for the adsorption capacity and the imprinting efficiency. The MICA had excellent flexibility, reversibility and stability. It promised high potential for the visual semi-quantitative detection of other explosives. - Highlights: • Molecularly imprinted colloidal array (MICA) was used to visually detect TNT. • The relationship of particle size, diffracted wavelength and color was discussed. • The adsorption capacity and imprinting efficiency of MICs were calculated. • MICA had short response time, high selectivity, good reversibility and stability. • MICA had high potential to be used in other customed visual explosive detection. - Abstract: We developed a photonic crystal (PhC) sensor for the quantification of 2,4,6-trinitrotoluene (TNT) in solution. Monodisperse (210 nm in diameter) molecularly imprinted colloidal particles (MICs) for TNT were prepared by the emulsion polymerization of methyl methacrylate and acrylamide in the presence of TNT as a template. The MICs were then self-assembled into close-packed opal PhC films. The adsorption capacity of the MICs for TNT was 64 mg TNT/g. The diffraction from the PhC depended on the TNT concentration in a methanol/water (3/2, v/v) potassium dihydrogen phosphate buffer solution (pH = 7.0, 30 mM). The limit of detection (LOD) of the sensor was 1.03 μg. The color of the molecularly imprinted colloidal array (MICA) changed from green to red with an 84 nm diffraction red shift when the TNT concentration increased to 20 mM. The sensor response time was 3 min. The PhC sensor was selective for TNT compared to similar compounds such as 2,4,6-trinitrophenol, 2,4-dinitrotoluene, 2,6-dinitrotoluene, 2-nitromesitylene, 4-nitrotoluene, 2-nitrotoluene, 1,3-dinitrobenzene, methylbenzene, 4-nitrophenol

  10. Fabrication of an organic field effect transistor using nano imprinting of Ag inks and semiconducting polymers

    International Nuclear Information System (INIS)

    Hu, PingAn; Li, Kun; O'Neill, William; Chen, Weilin; Peng, Li; Chu, Daping

    2010-01-01

    A simple and cheap procedure for flexible electronics fabrication was demonstrated by imprinting metallic nanoparticles (NPs) on flexible substrates. Silver NPs with an average diameter of 10 nm were prepared via an improved chemical approach and Ag Np ink was produced in α-terpineol with a concentration up to 15%. Silver micro/nanostructures with a dimension varying from nanometres to microns were produced on a flexible substrate (polyimide) by imprinting the as-prepared silver ink. The fine fluidic properties of an Ag NP/α-terpineol solution and low melting temperatures of silver nanoparticles render a low pressure and low temperature procedure, which is well suited for flexible electronics fabrication. The effects of sintering and mechanical bending on the conductivity of imprinted silver contacts were also investigated. Large area organic field effect transistors (OFET) on flexible substrates were fabricated using an imprinted silver electrode and semiconducting polymer. The OFET with silver electrodes imprinted from our prepared oleic acid stabilized Ag nanoparticle ink show an ideal ohmic contact; therefore, the OFET exhibit high performance (I on /I off ratio: 1 × 10 3 ; mobility: 0.071 cm 2 V −1 s −1 ).

  11. Carprofen-imprinted monolith prepared by reversible addition-fragmentation chain transfer polymerization in room temperature ionic liquids.

    Science.gov (United States)

    Ban, Lu; Han, Xu; Wang, Xian-Hua; Huang, Yan-Ping; Liu, Zhao-Sheng

    2013-10-01

    To obtain fast separation, ionic liquids were used as porogens first in combination with reversible addition-fragmentation chain transfer (RAFT) polymerization to prepare a new type of molecularly imprinted polymer (MIP) monolith. The imprinted monolithic column was synthesized using a mixture of carprofen (template), 4-vinylpyridine, ethylene glycol dimethacrylate, [BMIM]BF4, and chain transfer agent (CTA). Some polymerization factors, such as template-monomer molar ratio, the degree of crosslinking, the composition of the porogen, and the content of CTA, on the column efficiency and imprinting effect of the resulting MIP monolith were systematically investigated. Affinity screening of structurally similar compounds with the template can be achieved in 200 s on the MIP monolith due to high column efficiency (up to 12,070 plates/m) and good column permeability. Recognition mechanism of the imprinted monolith was also investigated.

  12. Sexual imprinting on facial traits of opposite-sex parents in humans.

    Science.gov (United States)

    Marcinkowska, Urszula M; Rantala, Markus J

    2012-09-05

    Positive sexual imprinting is a process by which individuals use the phenotype of their opposite-sex parent as a template for acquiring mates. Recent studies in humans have concluded that an imprinting-like mechanism influences human mate choice in facial traits. However, some of the previous studies have had methodological problems or flaws which might have invalidated or led to an overgeneralization of the original interpretation of their results. In this study, 70 heterosexual adults were used to test if their partners resembled facially their opposite-sex parent as the sexual imprinting hypothesis predicts. Judges assessed the subjective facial similarity between each participant's partner and their parent. We found that there was no perceived facial similarity between women's partners and their fathers. However, men tended to pair more often with women that were perceived as resembling the men's own mothers. In contrast to previous studies, the quality of the relationship between participants and their parents did not predict the level of facial resemblance between the participant's spouse and their parent.

  13. New potentiometric sensor based on molecularly imprinted nanoparticles for cocaine detection.

    Science.gov (United States)

    Smolinska-Kempisty, K; Ahmad, O Sheej; Guerreiro, A; Karim, K; Piletska, E; Piletsky, S

    2017-10-15

    Here we present a potentiometric sensor for cocaine detection based on molecularly imprinted polymer nanoparticles (nanoMIPs) produced by the solid-phase imprinting method. The composition of polymers with high affinity for cocaine was optimised using molecular modelling. Four compositions were selected and polymers prepared using two protocols: chemical polymerisation in water and UV-initiated polymerisation in organic solvent. All synthesised nanoparticles had very good affinity to cocaine with dissociation constants between 0.6nM and 5.3nM. Imprinted polymers produced in organic solvent using acrylamide as a functional monomer demonstrated the highest yield and affinity, and so were selected for further sensor development. For this, nanoparticles were incorporated within a PVC matrix which was then used to prepare an ion-selective membrane integrated with a potentiometric transducer. It was demonstrated that the sensor was able to quantify cocaine in blood serum samples in the range of concentrations between 1nM and 1mM. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Sexual Imprinting on Facial Traits of Opposite-Sex Parents in Humans

    Directory of Open Access Journals (Sweden)

    Urszula M Marcinkowska

    2012-07-01

    Full Text Available Positive sexual imprinting is a process by which individuals use the phenotype of their opposite-sex parent as a template for acquiring mates. Recent studies in humans have concluded that an imprinting-like mechanism influences human mate choice in facial traits. However, some of the previous studies have had methodological problems or flaws which might have invalidated or led to an overgeneralization of the original interpretation of their results. In this study, 70 heterosexual adults were used to test if their partners resembled facially their opposite-sex parent as the sexual imprinting hypothesis predicts. Judges assessed the subjective facial similarity between each participant's partner and their parent. We found that there was no perceived facial similarity between women's partners and their fathers. However, men tended to pair more often with women that were perceived as resembling the men's own mothers. In contrast to previous studies, the quality of the relationship between participants and their parents did not predict the level of facial resemblance between the participant's spouse and their parent.

  15. Mapping of imprinted quantitative trait loci using immortalized F2 populations.

    Directory of Open Access Journals (Sweden)

    Yongxian Wen

    Full Text Available Mapping of imprinted quantitative trait loci (iQTLs is helpful for understanding the effects of genomic imprinting on complex traits in animals and plants. At present, the experimental designs and corresponding statistical methods having been proposed for iQTL mapping are all based on temporary populations including F2 and BC1, which can be used only once and suffer some other shortcomings respectively. In this paper, we propose a framework for iQTL mapping, including methods of interval mapping (IM and composite interval mapping (CIM based on conventional low-density genetic maps and point mapping (PM and composite point mapping (CPM based on ultrahigh-density genetic maps, using an immortalized F2 (imF2 population generated by random crosses between recombinant inbred lines or doubled haploid lines. We demonstrate by simulations that imF2 populations are very desirable and the proposed statistical methods (especially CIM and CPM are very powerful for iQTL mapping, with which the imprinting effects as well as the additive and dominance effects of iQTLs can be unbiasedly estimated.

  16. Convergence accommodation to convergence CA/C ratio: convergence versus divergence.

    Science.gov (United States)

    Simmons, Joshua M; Firth, Alison Y

    2014-09-01

    To determine whether the convergence accommodation to convergence (CA/C) ratio during divergence with base-in (BI) prisms is of a similar or different magnitude to that measured during convergence with base-out (BO) prisms. Eighteen participants with normal binocular single vision were recruited. The participants viewed a pseudo-Gaussian target, which consisted of a light emitting diode (LED) behind a diffusing screen at 40 cm. After 5 minutes of dark adaptation, the refractive status of the eye was measured without any prism using a Shin-Nippon SRW-5000 autorefractor. The participant held the selected prism (5Δ or 10Δ BO or BI, counterbalanced) in front of their right eye and obtained a single, fused image of the target while refractive measures were taken with each. A 30-second rest period was given between measurements. The mean age of the participants was 20.6±3.22 years. The mean CA/C ratios for the 5Δ BO, 10Δ BO, 5Δ BI, and 10Δ BI were 0.108 (±0.074) D/Δ, 0.110 (±0.056) D/Δ, 0.100 (±0.090) D/Δ, and 0.089 (±0.055) D/Δ, respectively. A 2-factor repeated measures ANOVA found that the CA/C ratio did not significantly change with differing levels of prism-induced convergence and divergence (p=0.649). Change in accommodation induced by manipulating vergence is similar whether convergence or divergence are induced. The CA/C ratio did not show any change with differing levels of prism-induced convergence and divergence.

  17. On infrared divergences

    International Nuclear Information System (INIS)

    Parisi, G.

    1979-01-01

    The structure of infrared divergences is studied in superrenormalizable interactions. It is conjectured that there is an extension of the Bogoliubov-Parasiuk-Hepp theorem which copes also with infrared divergences. The consequences of this conjecture on the singularities of the Borel transform in a massless asymptotic free field theory are discussed. The application of these ideas to gauge theories is briefly discussed. (Auth.)

  18. Solvent influence upon structure & throughput of poly vinyledene fluoride thin film nano-patterns by imprint lithography

    Science.gov (United States)

    Sankar, M. S. Ravi; Gangineni, R. B.

    2018-04-01

    This work aims at understanding the solvent influence upon the throughput and structure of poly vinyledene fluoride (PVDF)nano-patterned films. The PVDF thin films are deposited by spin coating method using Dimethylsulfoxide (DMSO), Tetrahydrofuran (THF) and 2-butanone solvents. The nano-patterns are realized by imprinting SONY 700 MB CD aluminum constructions on PVDF thin filmsusing imprint lithography technique under ambient annealing temperature and pressure. Surface morphology &imprint pattern transfer quality is evaluated with Atomic force microscopy (AFM). Raman spectroscopy is used for evaluating the structural evolutions with respect to solvent & patterning.

  19. String loop divergences and effective lagrangians

    International Nuclear Information System (INIS)

    Fischler, W.; Klebanov, I.; Susskind, L.

    1988-01-01

    We isolate logarithmic divergences from bosonic string amplitudes on a disc. These divergences are compared with 'tadpole' divergences in the effective field theory, with a covariant cosmological term implied by the counting of string coupling constants. We find an inconsistency between the two. This might be a problem in eliminating divergences from the bosonic string. (orig.)

  20. Synthesis and application of surface-imprinted activated carbon sorbent for solid-phase extraction and determination of copper (II)

    Science.gov (United States)

    Li, Zhenhua; Li, Jingwen; Wang, Yanbin; Wei, Yajun

    2014-01-01

    A new Cu(II)-imprinted amino-functionalized activated carbon sorbent was prepared by a surface imprinting technique for selective solid-phase extraction (SPE) of Cu(II) prior to its determination by inductively coupled plasma atomic emission spectrometry (ICP-AES). Experimental conditions for effective adsorption of Cu(II) were optimized with respect to different experimental parameters using static and dynamic procedures in detail. Compared with non-imprinted sorbent, the ion-imprinted sorbent had higher selectivity and adsorption capacity for Cu(II). The maximum static adsorption capacity of the ion-imprinted and non-imprinted sorbent for Cu(II) was 26.71 and 6.86 mg g-1, respectively. The relatively selectivity factor values (αr) of Cu(II)/Zn(II), Cu(II)/Ni(II), Cu(II)/Co(II) and Cu(II)/Pb(II) were 166.16, 50.77, 72.26 and 175.77, respectively, which were greater than 1. Complete elution of the adsorbed Cu(II) from Cu(II)-imprinted sorbent was carried out using 2 mL of 0.1 mol L-1 EDTA solution. The relative standard deviation of the method was 2.4% for eleven replicate determinations. The method was validated for the analysis by two certified reference materials (GBW 08301, GBW 08303), the results obtained is in good agreement with standard values. The developed method was also successfully applied to the determination of trace copper in natural water samples with satisfactory results.

  1. Stability of XIST repression in relation to genomic imprinting following global genome demethylation in a human cell line

    International Nuclear Information System (INIS)

    Araújo, E.S.S. de; Vasques, L.R.; Stabellini, R.; Krepischi, A.C.V.; Pereira, L.V.

    2014-01-01

    DNA methylation is essential in X chromosome inactivation and genomic imprinting, maintaining repression of XIST in the active X chromosome and monoallelic repression of imprinted genes. Disruption of the DNA methyltransferase genes DNMT1 and DNMT3B in the HCT116 cell line (DKO cells) leads to global DNA hypomethylation and biallelic expression of the imprinted gene IGF2 but does not lead to reactivation of XIST expression, suggesting that XIST repression is due to a more stable epigenetic mark than imprinting. To test this hypothesis, we induced acute hypomethylation in HCT116 cells by 5-aza-2′-deoxycytidine (5-aza-CdR) treatment (HCT116-5-aza-CdR) and compared that to DKO cells, evaluating DNA methylation by microarray and monitoring the expression of XIST and imprinted genes IGF2, H19, and PEG10. Whereas imprinted genes showed biallelic expression in HCT116-5-aza-CdR and DKO cells, the XIST locus was hypomethylated and weakly expressed only under acute hypomethylation conditions, indicating the importance of XIST repression in the active X to cell survival. Given that DNMT3A is the only active DNMT in DKO cells, it may be responsible for ensuring the repression of XIST in those cells. Taken together, our data suggest that XIST repression is more tightly controlled than genomic imprinting and, at least in part, is due to DNMT3A

  2. Stability of XIST repression in relation to genomic imprinting following global genome demethylation in a human cell line

    Energy Technology Data Exchange (ETDEWEB)

    Araújo, E.S.S. de [Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP (Brazil); Centro Internacional de Pesquisa, A.C. Camargo Cancer Center, São Paulo, SP (Brazil); Vasques, L.R. [Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP (Brazil); Stabellini, R.; Krepischi, A.C.V. [Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP (Brazil); Centro Internacional de Pesquisa, A.C. Camargo Cancer Center, São Paulo, SP (Brazil); Pereira, L.V. [Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP (Brazil)

    2014-10-17

    DNA methylation is essential in X chromosome inactivation and genomic imprinting, maintaining repression of XIST in the active X chromosome and monoallelic repression of imprinted genes. Disruption of the DNA methyltransferase genes DNMT1 and DNMT3B in the HCT116 cell line (DKO cells) leads to global DNA hypomethylation and biallelic expression of the imprinted gene IGF2 but does not lead to reactivation of XIST expression, suggesting that XIST repression is due to a more stable epigenetic mark than imprinting. To test this hypothesis, we induced acute hypomethylation in HCT116 cells by 5-aza-2′-deoxycytidine (5-aza-CdR) treatment (HCT116-5-aza-CdR) and compared that to DKO cells, evaluating DNA methylation by microarray and monitoring the expression of XIST and imprinted genes IGF2, H19, and PEG10. Whereas imprinted genes showed biallelic expression in HCT116-5-aza-CdR and DKO cells, the XIST locus was hypomethylated and weakly expressed only under acute hypomethylation conditions, indicating the importance of XIST repression in the active X to cell survival. Given that DNMT3A is the only active DNMT in DKO cells, it may be responsible for ensuring the repression of XIST in those cells. Taken together, our data suggest that XIST repression is more tightly controlled than genomic imprinting and, at least in part, is due to DNMT3A.

  3. Statistical inference based on divergence measures

    CERN Document Server

    Pardo, Leandro

    2005-01-01

    The idea of using functionals of Information Theory, such as entropies or divergences, in statistical inference is not new. However, in spite of the fact that divergence statistics have become a very good alternative to the classical likelihood ratio test and the Pearson-type statistic in discrete models, many statisticians remain unaware of this powerful approach.Statistical Inference Based on Divergence Measures explores classical problems of statistical inference, such as estimation and hypothesis testing, on the basis of measures of entropy and divergence. The first two chapters form an overview, from a statistical perspective, of the most important measures of entropy and divergence and study their properties. The author then examines the statistical analysis of discrete multivariate data with emphasis is on problems in contingency tables and loglinear models using phi-divergence test statistics as well as minimum phi-divergence estimators. The final chapter looks at testing in general populations, prese...

  4. Molecularly imprinted layer-coated silica nanoparticles for selective solid-phase extraction of bisphenol A from chemical cleansing and cosmetics samples

    International Nuclear Information System (INIS)

    Zhu Rong; Zhao Wenhui; Zhai Meijuan; Wei Fangdi; Cai Zheng; Sheng Na; Hu Qin

    2010-01-01

    Highly selective molecularly imprinted layer-coated silica nanoparticles for bisphenol A (BPA) were synthesized by molecular imprinting technique with a sol-gel process on the supporter of silica nanoparticles. The BPA-imprinted silica nanoparticles were characterized by fourier transform infrared spectrometer, transmission electron microscope, dynamic adsorption and static adsorption tests. The equilibrium association constant, K a , and the apparent maximum number of binding sites, Q max , were estimated to be 1.25 x 10 5 mL μmol -1 and 16.4 μmol g -1 , respectively. The BPA-imprinted silica nanoparticles solid-phase extraction (SPE) column had higher selectivity for BPA than the commercial C18-SPE column. The results of the study indicated that the prepared BPA-imprinted silica nanoparticles exhibited high adsorption capacity and selectivity, and offered a fast kinetics for the rebinding of BPA. The BPA-imprinted silica nanoparticles were successfully used in SPE to selectively enrich and determine BPA from shampoo, bath lotion and cosmetic cream samples.

  5. Acylated-naproxen as the surface-active template in the preparation of micro- and nanospherical imprinted xerogels by emulsion techniques.

    Science.gov (United States)

    Ornelas, Mariana; Azenha, Manuel; Araújo, Maria João; Marques, Eduardo F; Dias-Cabral, A C; Pereira, Carlos; Silva, A Fernando

    2016-03-11

    A strategy based on water-in-oil emulsion for the dispersion of a sol-gel mixture into small droplets was employed with the view of the production of naproxen-imprinted micro- and nanospheres. The procedure, aiming at a surface imprinting process, comprised the synthesis of a naproxen-derived surfactant. The imprinting process occurred at the interface of the emulsions or microemulsions, by the migration of the NAP-surfactant head into the sol-gel drops to leave surficial imprints due mainly to ion-pair interaction with a cationic group contained within the growing sol-gel network. The surface-imprinted microspheric particles exhibited a log-normal size distribution with geometric mean diameter of 3.1μm. A mesoporous texture was found from measurements of the specific surface area (206m(2)/g) and pore diameter (Dp 2nm). Evaluation of the microspheres as packed HPLC stationary phases resulted in the determination of the selectivity factor against ibuprofen (α=2.1), demonstrating the successful imprinting. Chromatographic efficiency, evaluated by the number of theoretical plates (222platescm(-3)), emerged as an outstanding feature among the set of all relatable formats produced before, an advantage intrinsic to the location of the imprinted sites on the surface. The material presented a capacity of 3.2μmolg(-1). Additionally, exploratory work conducted on their nanoscale counterparts resulted in the production of nanospheres in the size order of 10nm providing good indications of a successful imprinting process. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Loss of insulin-like growth factor II imprinting is a hallmark associated with enhanced chemo/radiotherapy resistance in cancer stem cells.

    Science.gov (United States)

    Zhao, Xin; Liu, Xiaoliang; Wang, Guanjun; Wen, Xue; Zhang, Xiaoying; Hoffman, Andrew R; Li, Wei; Hu, Ji-Fan; Cui, Jiuwei

    2016-08-09

    Insulin-like growth factor II (IGF2) is maternally imprinted in most tissues, but the epigenetic regulation of the gene in cancer stem cells (CSCs) has not been defined. To study the epigenetic mechanisms underlying self-renewal, we isolated CSCs and non-CSCs from colon cancer (HT29, HRT18, HCT116), hepatoma (Hep3B), breast cancer (MCF7) and prostate cancer (ASPC) cell lines. In HT29 and HRT18 cells that show loss of IGF2 imprinting (LOI), IGF2 was biallelically expressed in the isolated CSCs. Surprisingly, we also found loss of IGF2 imprinting in CSCs derived from cell lines HCT116 and ASPC that overall demonstrate maintenance of IGF2 imprinting. Using chromatin conformation capture (3C), we found that intrachromosomal looping between the IGF2 promoters and the imprinting control region (ICR) was abrogated in CSCs, in parallel with loss of IGF2 imprinting in these CSCs. Loss of imprinting led to increased IGF2 expression in CSCs, which have a higher rate of colony formation and greater resistance to chemotherapy and radiotherapy in vitro. These studies demonstrate that IGF2 LOI is a common feature in CSCs, even when the stem cells are derived from a cell line in which the general population of cells maintain IGF2 imprinting. This finding suggests that aberrant IGF2 imprinting may be an intrinsic epigenetic control mechanism that enhances stemness, self-renewal and chemo/radiotherapy resistance in cancer stem cells.

  7. DNA sequence polymorphisms within the bovine guanine nucleotide-binding protein Gs subunit alpha (Gsα-encoding (GNAS genomic imprinting domain are associated with performance traits

    Directory of Open Access Journals (Sweden)

    Mullen Michael P

    2011-01-01

    43101491 SNP. Following adjustment for multiple-testing, significant association (q ≤ 0.05 remained between the rs41694646 SNP and four traits (animal stature, body depth, direct calving difficulty and milk yield only. Notably, the single SNP in the bovine NESP55 gene (rs41694656 was associated (P ≤ 0.01 with somatic cell count--an often-cited indicator of resistance to mastitis and overall health status of the mammary system--and previous studies have demonstrated that the chromosomal region to where the GNAS domain maps underlies an important quantitative trait locus for this trait. This association, however, was not significant after adjustment for multiple testing. The three remaining SNPs assayed were not associated with any of the performance traits analysed in this study. Analysis of all pairwise linkage disequilibrium (r2 values suggests that most allele substitution effects for the assayed SNPs observed are independent. Finally, the polymorphic coding SNP in the putative bovine NESP55 gene was used to test the imprinting status of this gene across a range of foetal bovine tissues. Conclusions Previous studies in other mammalian species have shown that DNA sequence variation within the imprinted GNAS gene cluster contributes to several physiological and metabolic disorders, including obesity in humans and mice. Similarly, the results presented here indicate an important role for the imprinted GNAS cluster in underlying complex performance traits in cattle such as animal growth, calving, fertility and health. These findings suggest that GNAS domain-associated polymorphisms may serve as important genetic markers for future livestock breeding programs and support previous studies that candidate imprinted loci may act as molecular targets for the genetic improvement of agricultural populations. In addition, we present new evidence that the bovine NESP55 gene is epigenetically regulated as a maternally expressed imprinted gene in placental and intestinal tissues

  8. The part and the whole: voids, supervoids, and their ISW imprint

    Science.gov (United States)

    Kovács, András

    2018-04-01

    The integrated Sachs-Wolfe (ISW) imprint of extreme structures in the cosmic web probes the dynamical nature of dark energy. Looking through typical cosmic voids, no anomalous signal has been reported. On the contrary, supervoids, associated with large-scale fluctuations in the gravitational potential, have shown potentially disturbing excess signals. In this study, we used the Jubilee ISW simulation to demonstrate how the stacked signal depends on the void definition. We found that large underdensities, with at least ≈5 merged sub-voids, show a peculiar ISW imprint shape with central cold spots and surrounding hot rings, offering a natural way to define supervoids in the cosmic web. We then inspected the real-world Baryon Oscillations Spectroscopic Survey data release 12 (BOSS DR12) data using the simulated imprints as templates. The imprinted profile of BOSS supervoids appears to be more compact than in simulations, requiring an extra α ≈ 0.7 re-scaling of filter sizes. The data reveal an excess ISW-like signal with AISW ≈ 9 amplitude at the ≈2.5σ significance level, unlike previous studies that used isolated voids and reported good consistency with AISW = 1. The tension with the Jubilee-based Λ cold dark matter predictions is ≳2σ, in consistency with independent analyses of supervoids in Dark Energy Survey data. We show that such a very large enhancement of the AISW parameter hints at a possible causal relation between the cosmic microwave background Cold Spot and the Eridanus supervoid. The origin of these findings remains unclear.

  9. Rational design of molecularly imprinted polymer: the choice of cross-linker.

    Science.gov (United States)

    Muhammad, Turghun; Nur, Zohre; Piletska, Elena V; Yimit, Osmanjan; Piletsky, Sergey A

    2012-06-07

    The paper describes a rational approach for the selection of cross-linkers during the development of molecularly imprinted polymers (MIPs). As a model system for this research MIPs specific for the drug zidovudine (AZT) were designed and tested. Three cross-linkers trimethylolpropane trimethacrylate (TRIM), ethylene glycol dimethacrylate (EGDMA) and divinylbenzene (DVB) were studied. The analogue of zidovudine (AZT) ester (AZT-ES) was used as a dummy template. The imprinting factors for all of the polymers in the static adsorption experiments were calculated. The data on the AZT adsorption by control polymers (CP), which were prepared with different cross-linkers without a functional monomer, was also analyzed. DVB was found to be more inert towards zidovudine than EGDMA and TRIM, which was confirmed by both molecular modelling and adsorption experiments. It was demonstrated that DVB-based polymers had a higher imprinting factor (I = 1.85) compared with other tested cross-linked polymers. It was suggested that the selection of the cross-linker should be based on the strength of the interaction with the template: the cross-linker which displays lower binding of the template should be preferential because it generates MIPs with lower non-specific binding and a higher imprinting factor, and therefore specificity. Which cross-linker to use for the preparation of any particular MIP can be determined by analysis of the interactions between the cross-linker and template. This could be done either virtually using computational modelling or by template adsorption using a small library of polymers prepared using different cross-linkers.

  10. Molecularly imprinted photo-sensitive polyglutamic acid nanoparticles for electrochemical sensing of hemoglobin

    International Nuclear Information System (INIS)

    Zhang, Rongli; Xu, Sheng; Luo, Jing; Liu, Xiaoya

    2015-01-01

    A voltammetric sensor for hemoglobin (Hb) was prepared from molecularly imprinted polymer nanoparticles (MINPs) via electrophoretic deposition. A photo-sensitive copolymer composed of poly-γ-glutamic grafted with the fluorophore 7-amino-4-methylcoumarin was converted into nanoparticles that were imprinted with Hb. The resultant MINPs were then placed on a glassy carbon electrode (GCE) via electrophoretic deposition. Subsequent photo-crosslinking locks the recognition sites. The template was removed by extraction with a mixture of acetic acid and methanol at a ratio of 1:9 (v:v) to obtain a voltammetric sensor for Hb. The current response of the sensor at a working voltage of −260 mV is linearly related to the concentration of Hb in the range from 5 to 100 μg mL −1 , and recoveries range from 98.7 to 102.3 %. Compared to the respective non-imprinted nanoparticles, the sensor displays high recognition capability and affinity for Hb. (author)

  11. A hierarchical structure through imprinting of a polyimide precursor without residual layers

    International Nuclear Information System (INIS)

    Pai, I-Ting; Hon, Min-Hsiung; Leu, Ing-Chi

    2008-01-01

    A patterned polyimide without a residual layer is obtained by imprinting with the assistance of a residual solvent. The effects of the wetting behaviors of the poly-amic acid (PAA) solution coated on various surfaces are examined and the formation of hierarchical patterns without residual layers is demonstrated. polydimethylsiloxane (PDMS) and PEI/PDMS are used as imprinting molds with Si and 300 nm SiO 2 /Si as substrates. The results indicate that the various ambits of patterns without a residual layer are formed due to the dewetting phenomena caused by surface tension (Suh 2006 Small 2 832). During imprinting, PDMS with a low surface energy makes the PAA solution flow away from its surface exposing the contact area due to dewetting. Self-organized hierarchical structures are also obtained from this process due to effective dewetting. The present study provides a new approach for fabricating patterns without residual layers and the consequent preparation of hierarchical structures, which is considered to be impossible using the lithographic technique

  12. Efficient methods of nanoimprint stamp cleaning based on imprint self-cleaning effect

    Energy Technology Data Exchange (ETDEWEB)

    Meng Fantao; Chu Jinkui [Key Laboratory for Micro/Nano Technology and System of Liaoning Province, Dalian University of Technology, 116024 Dalian (China); Luo Gang; Zhou Ye; Carlberg, Patrick; Heidari, Babak [Obducat AB, SE-20125 Malmoe (Sweden); Maximov, Ivan; Montelius, Lars; Xu, H Q [Division of Solid State Physics, Lund University, Box 118, S-22100 Lund (Sweden); Nilsson, Lars, E-mail: ivan.maximov@ftf.lth.se [Department of Food Technology, Engineering and Nutrition, Lund University, Box 117, S-22100 Lund (Sweden)

    2011-05-06

    Nanoimprint lithography (NIL) is a nonconventional lithographic technique that promises low-cost, high-throughput patterning of structures with sub-10 nm resolution. Contamination of nanoimprint stamps is one of the key obstacles to industrialize the NIL technology. Here, we report two efficient approaches for removal of typical contamination of particles and residual resist from stamps: thermal and ultraviolet (UV) imprinting cleaning-both based on the self-cleaning effect of imprinting process. The contaminated stamps were imprinted onto polymer substrates and after demolding, they were treated with an organic solvent. The images of the stamp before and after the cleaning processes show that the two cleaning approaches can effectively remove contamination from stamps without destroying the stamp structures. The contact angles of the stamp before and after the cleaning processes indicate that the cleaning methods do not significantly degrade the anti-sticking layer. The cleaning processes reported in this work could also be used for substrate cleaning.

  13. Ion-imprinted polymethacrylic microbeads as new sorbent for preconcentration and speciation of mercury.

    Science.gov (United States)

    Dakova, Ivanka; Karadjova, Irina; Georgieva, Ventsislava; Georgiev, George

    2009-04-30

    Metal ion-imprinted polymer particles have been prepared by copolymerization of methacrylic acid as monomer, trimethylolpropane trimethacrylate as cross-linking agent and 2,2'-azobisisobutyronitrile as initiator, in the presence of Hg(II)-1-(2-thiazolylazo)-2-naphthol complex. The separation and preconcentration characteristics of the Hg-ion-imprinted microbeads for inorganic mercury have been investigated by batch procedure. The optimal pH value for the quantitative sorption is 7. The adsorbed inorganic mercury is easily eluted by 2 mL 4M HNO(3). The adsorption capacity of the newly synthesized Hg ion-imprinted microbeads is 32.0 micromol g(-1) for dry copolymer. The selectivity of the copolymer toward inorganic mercury (Hg(II)) ion is confirmed through the comparison of the competitive adsorptions of Cd(II), Co(II), Cu(II), Ni(II), Pb(II), Zn(II)) and high values of the selectivity and distribution coefficients have been calculated. Experiments performed for selective determination of inorganic mercury in mineral and sea waters showed that the interfering matrix does not influence the extraction efficiency of Hg ion-imprinted microbeads. The detection limit for inorganic mercury is 0.006 microg L(-1) (3 sigma), determined by cold vapor atomic adsorption spectrometry. The relative standard deviation varied in the range 5-9 % at 0.02-1 microg L(-1) Hg levels. The new Hg-ion-imprinted microbeads have been tested and applied for the speciation of Hg in river and mineral waters: inorganic mercury has been determined selectively in nondigested sample, while total mercury e.g. sum of inorganic and methylmercury, has been determined in digested sample.

  14. Divergent thinking and constructing episodic simulations.

    Science.gov (United States)

    Addis, Donna Rose; Pan, Ling; Musicaro, Regina; Schacter, Daniel L

    2016-01-01

    Divergent thinking likely plays an important role in simulating autobiographical events. We investigated whether divergent thinking is differentially associated with the ability to construct detailed imagined future and imagined past events as opposed to recalling past events. We also examined whether age differences in divergent thinking might underlie the reduced episodic detail generated by older adults. The richness of episodic detail comprising autobiographical events in young and older adults was assessed using the Autobiographical Interview. Divergent thinking abilities were measured using the Alternative Uses Task. Divergent thinking was significantly associated with the amount of episodic detail for imagined future events. Moreover, while age was significantly associated with imagined episodic detail, this effect was strongly related to age-related changes in episodic retrieval rather than divergent thinking.

  15. Fabrication of ridge waveguide structure from photosensitive TiO2/ormosil hybrid films by using an ultraviolet soft imprint technique

    International Nuclear Information System (INIS)

    Zhang, Xuehua; Que, Wenxiu; Chen, Jing; Gao, Tianxi; Hu, Jiaxing; Liu, Weiguo

    2013-01-01

    Photosensitive TiO 2 /organically modified silane hybrid films were prepared by combining a low-temperature sol–gel process with a spin-coating technique. Optical properties and photochemical activities of the as-prepared hybrid sol–gel films under different UV irradiation time were characterized and monitored by prism coupling technique, UV–visible spectroscopy, and Fourier transform infrared spectroscopy. Surface morphology of the hybrid films was also observed by an atomic force microscopy. Advantages for fabrication of ridge waveguide structure based on the photosensitive hybrid films were demonstrated by an ultraviolet soft imprint technique. Effects of imprint force, imprint time, and UV irradiation time on high replication fidelity of the ridge waveguide structure were also investigated. An altitude replication fidelity of 99.7% can be obtained when the imprint force of 2 MPa, imprint time of 30 min and UV irradiation time of 45 min were chosen. Scanning electron microscopy and surface profiler were used to characterize the morphological and surface profile properties of the as fabricated ridge waveguide structure. Results indicate that the as-prepared photosensitive hybrid materials have great applicability for the fabrication of micro-optical elements and advantage as the imprint layer under the ultraviolet soft imprint technique. - Highlights: ► Photosensitive TiO 2 /ormosil hybrid film is prepared by a sol–gel process. ► Optical properties of the films change a little with UV exposure time. ► Photo-chemical property of the film changes a lot with UV exposure time. ► The imprint force and time, and the UV exposure time affect the imprint fidelity. ► A fidelity value of 99.7% is obtained under an optimized condition

  16. Dimensional characterization of biperiodic imprinted structures using optical scatterometry

    KAUST Repository

    Gereige, Issam; Pietroy, David; Eid, Jessica; Gourgon, Cé cile

    2013-01-01

    In this paper, we report on the characterization of biperiodic imprinted structures using a non-destructive optical technique commonly called scatterometry. The nanostructures consist of periodic arrays of square and circular dots which were

  17. Analysis of the expression of putatively imprinted genes in bovine peri-implantation embryos

    DEFF Research Database (Denmark)

    Tveden-Nyborg, Pernille Yde; Alexopoulos, N.I.; Cooney, M.A.

    2008-01-01

    The application of assisted reproductive technologies (ART) has been shown to induce changes in the methylation of the embryonic genome, leading to aberrant gene expression, including that of imprinted genes. Aberrant methylation and gene expression has been linked to the large offspring syndrome...... (LOS) in bovine embryos resulting in increased embryonic morbidity and mortality. In the bovine, limited numbers of imprinted genes have been studied and studies have primarily been restricted to pre-implantation stages. This study reports original data on the expression pattern of 8 putatively...... imprinted genes (Ata3, Dlk1, Gnas, Grb10, Magel2, Mest-1, Ndn and Sgce) in bovine peri-implantation embryos. Two embryonic developmental stages were examined, Day 14 and Day 21. The gene expression pattern of single embryos was recorded for in vivo, in vitro produced (IVP) and parthenogenetic embryos...

  18. A molecular imprinted SPR biosensor for sensitive determination of citrinin in red yeast rice.

    Science.gov (United States)

    Atar, Necip; Eren, Tanju; Yola, Mehmet Lütfi

    2015-10-01

    A novel and sensitive molecular imprinted surface plasmon resonance (SPR) biosensor was developed for selective determination of citrinin (CIT) in red yeast rice. Firstly, the gold surface of SPR chip was modified with allyl mercaptane. Then, CIT-imprinted poly(2-hydroxyethyl methacrylate-methacryloylamidoglutamic acid) (p(HEMA-MAGA)) film was generated on the gold surface modified with allyl mercaptane. The unmodified and imprinted surfaces were characterized by Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM) and contact angle measurements. The linearity range and the detection limit were obtained as 0.005-1.0 ng/mL and 0.0017 ng/mL, respectively. The SPR biosensor was applied to determination of CIT in red yeast rice sample. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Measurements of direct drive laser imprint in thin foils by XUV radiography using an X-ray laser backlighter

    International Nuclear Information System (INIS)

    Kalantar, D.H.; Key, M.H.; DaSilva, L.B.

    1996-11-01

    In direct drive inertial confinement fusion, the residual speckle pattern remaining after beam smoothing plays an important role in the seeding of instabilities at the ablation front. We have used an x-ray laser as an XUV backlighter to characterize the imprinted modulation in thin foils for smoothing by random phase plate and spectral dispersion at both 0.35 pm and 0.53 pm irradiation, and induced spatial incoherence at 0.53 pm irradiation. We also demonstrate measurements of the modulation due to a single mode optical imprint generated by a narrow slit interference pattern, and modification of the imprint with a superposed smooth irradiation to study time dependence of the imprinting process. 8 refs., 10 figs

  20. Consequences of Morphology on Molecularly Imprinted Polymer-Ligand Recognition

    Directory of Open Access Journals (Sweden)

    Annika M. Rosengren

    2013-01-01

    Full Text Available The relationship between molecularly imprinted polymer (MIP morphology and template-rebinding over a series of warfarin-imprinted methacrylic acid co(ethylene dimethacrylate polymers has been explored. Detailed investigations of the nature of template recognition revealed that an optimal template binding was obtained with polymers possessing a narrow population of pores (~3–4 nm in the mesopore size range. Importantly, the warfarin-polymer rebinding analyses suggest strategies for regulating ligand binding capacity and specificity through variation of the degree of cross-linking, where polymers prepared with a lower degree of cross-linking afford higher capacity though non-specific in character. In contrast, the co-existence of specific and non-specific binding was found in conjunction with higher degrees of cross-linking and resultant meso- and macropore size distributions.

  1. Molecular dynamics approaches to the design and synthesis of PCB targeting molecularly imprinted polymers: interference to monomer-template interactions in imprinting of 1,2,3-trichlorobenzene.

    Science.gov (United States)

    Cleland, Dougal; Olsson, Gustaf D; Karlsson, Björn C G; Nicholls, Ian A; McCluskey, Adam

    2014-02-07

    The interactions between each component of the pre-polymerisation mixtures used in the synthesis of molecularly imprinted polymers (MIP) specific for 1,2,3,4,5-pentachlorobenzene (1) and 1,2,3-trichlorobenzene (2) were examined in four molecular dynamics simulations. These simulations revealed that the relative frequency of functional monomer-template (FM-T) interactions was consistent with results obtained by the synthesis and evaluation of the actual MIPs. The higher frequency of 1 interaction with trimethylstyrene (TMS; 54.7%) than 1 interaction with pentafluorostyrene (PFS; 44.7%) correlated with a higher imprinting factor (IF) of 2.1 vs. 1.7 for each functional monomer respectively. The higher frequency of PFS interactions with 2 (29.6%) than TMS interactions with 2 (1.9%) also correlated well with the observed differences in IF (3.7) of 2 MIPs imprinted using PFS as the FM than the IF (2.8) of 2 MIPs imprinted using TMS as the FM. The TMS-1 interaction dominated the molecular simulation due to high interaction energies, but the weaker TMS-2 resulted in low interaction maintenance, and thus lower IF values. Examination of the other pre-polymerisation mixture components revealed that the low levels of TMS-2 interaction was, in part, due to interference caused by the cross linker (CL) ethyleneglycol dimethylacrylate (EGDMA) interactions with TMS. The main reason was, however, attributed to MeOH interactions with TMS in both a hydrogen bond and perpendicular configuration. This positioned a MeOH directly above the π-orbital of all TMS for an average of 63.8% of MD2 creating significant interference to π-π stacking interactions between 2 and TMS. These findings are consistent with the deviation from the 'normal' molecularly imprinted polymer synthesis ratio of 1 : 4 : 20 (T : FM : CL) of 20 : 1 : 29 and 15 : 6 : 29 observed with 2 and TMS and PFS respectively. Our molecular dynamics simulations correctly predicted the high level

  2. Translational control of auditory imprinting and structural plasticity by eIF2?

    OpenAIRE

    Batista, Gervasio; Johnson, Jennifer Leigh; Dominguez, Elena; Costa-Mattioli, Mauro; Pena, Jose L

    2016-01-01

    eLife digest Shortly after hatching, a chick recognizes the sight and sound of its mother and follows her around. This requires a type of learning called imprinting, which only occurs during a short period of time in young life known as the ?critical period?. This process has been reported in a variety of birds and other animals where long-term memory formed during a critical period guides vital behaviors. In order to form imprinted memories, neurons must produce new proteins. However, it is ...

  3. Molecularly imprinted fluorescent probe based on FRET for selective and sensitive detection of doxorubicin

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhifeng, E-mail: 897061147@qq.com [College of Chemistry and Materials Science, Hengyang Normal University, Key Laboratory of Functional Organometallic Materials of Hunan Province University, Hengyang 421008 (China); Deng, Peihong; Li, Junhua [College of Chemistry and Materials Science, Hengyang Normal University, Key Laboratory of Functional Organometallic Materials of Hunan Province University, Hengyang 421008 (China); Xu, Li [Department of Applied Chemistry, College of Materials and Energy, South China Agricultural University, Guangzhou 510642 (China); Tang, Siping [College of Chemistry and Materials Science, Hengyang Normal University, Key Laboratory of Functional Organometallic Materials of Hunan Province University, Hengyang 421008 (China)

    2017-04-15

    Highlights: • FRET-based molecularly imprinted probe for detection of doxorubicin was prepared. • The detection limit of the probe was 13.8 nM for doxorubicin. • The FRET-based probe had a higher selectivity for the template than ordinary MIMs. - Abstract: In this work, a new type of fluorescent probe for detection of doxorubicin has been constructed by the combined use of fluorescence resonance energy transfer (FRET) technology and molecular imprinting technique (MIT). Using doxorubicin as the template, the molecularly imprinted polymer thin layer was fabricated on the surfaces of carbon dot (CD) modified silica by sol-gel polymerization. The excitation energy of the fluorescent donor (CDs) could be transferred to the fluorescent acceptor (doxorubicin). The FRET based fluorescent probe demonstrated high sensitivity and selectivity for doxorubicin. The detection limit was 13.8 nM. The fluorescent probe was successfully applied for detecting doxorubicin in doxorubicin-spiked plasmas with a recovery of 96.8–103.8%, a relative standard deviation (RSD) of 1.3–2.8%. The strategy for construction of FRET-based molecularly imprinted materials developed in this work is very promising for analytical applications.

  4. Photoresponsive surface molecularly imprinted polymer on ZnO nanorods for uric acid detection in physiological fluids

    International Nuclear Information System (INIS)

    Tang, Qian; Li, Zai-yong; Wei, Yu-bo; Yang, Xia; Liu, Lan-tao; Gong, Cheng-bin; Ma, Xue-bing; Lam, Michael Hon-wah; Chow, Cheuk-fai

    2016-01-01

    A photoresponsive surface molecularly imprinted polymer for uric acid in physiological fluids was fabricated through a facile and effective method using bio-safe and biocompatible ZnO nanorods as a support. The strategy was carried out by introducing double bonds on the surface of the ZnO nanorods with 3-methacryloxypropyltrimethoxysilane. The surface molecularly imprinted polymer on ZnO nanorods was then prepared by surface polymerization using uric acid as template, water-soluble 5-[(4-(methacryloyloxy)phenyl)diazenyl]isophthalic acid as functional monomer, and triethanolamine trimethacryl ester as cross-linker. The surface molecularly imprinted polymer on ZnO nanorods showed good photoresponsive properties, high recognition ability, and fast binding kinetics toward uric acid, with a dissociation constant of 3.22 × 10"−"5 M in aqueous NaH_2PO_4 buffer at pH = 7.0 and a maximal adsorption capacity of 1.45 μmol g"−"1. Upon alternate irradiation at 365 and 440 nm, the surface molecularly imprinted polymer on ZnO nanorods can quantitatively uptake and release uric acid. - Highlights: • Novel surface molecularly imprinted polymer on ZnO nanorods was synthesized. • ZnO-SMIP showed good selectivity toward uric acid in physiological fluids. • ZnO-SMIP displayed good photoresponsive properties.

  5. Electrochemical Preparation of a Molecularly Imprinted Polypyrrole-modified Pencil Graphite Electrode for Determination of Ascorbic Acid

    Directory of Open Access Journals (Sweden)

    Yücel Sahin

    2008-09-01

    Full Text Available A molecularly imprinted polymer (MIP polypyrrole (PPy-based film was fabricated for the determination of ascorbic acid. The film was prepared by incorporation of a template molecule (ascorbic acid during the electropolymerization of pyrrole onto a pencil graphite electrode (PGE in aqueous solution using a cyclic voltammetry method. The performance of the imprinted and non-imprinted (NIP films was evaluated by differential pulse voltammetry (DPV. The effect of pH, monomer and template concentrations, electropolymerization cycles and interferents on the performance of the MIP electrode was investigated and optimized. The molecularly imprinted film exhibited a high selectivity and sensitivity toward ascorbic acid. The DPV peak current showed a linear dependence on the ascorbic acid concentration and a linear calibration curve was obtained in the range of 0.25 to 7.0 mM of ascorbic acid with a correlation coefficient of 0.9946. The detection limit (3σ was determined as 7.4x10-5 M (S/N=3. The molecularly-imprinted polypyrrole-modified pencil graphite electrode showed a stable and reproducible response, without any influence of interferents commonly existing in pharmaceutical samples. The proposed method is simple and quick. The PPy electrodes have a low response time, good mechanical stability and are disposable simple to construct.

  6. Photoresponsive surface molecularly imprinted polymer on ZnO nanorods for uric acid detection in physiological fluids

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Qian [The Key Laboratory of Applied Chemistry of Chongqing Municipality, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Department of Science and Environmental Studies, The Hong Kong Institute of Education (Hong Kong); Li, Zai-yong; Wei, Yu-bo; Yang, Xia; Liu, Lan-tao [The Key Laboratory of Applied Chemistry of Chongqing Municipality, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Gong, Cheng-bin, E-mail: gongcbtq@swu.edu.cn [The Key Laboratory of Applied Chemistry of Chongqing Municipality, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Ma, Xue-bing [The Key Laboratory of Applied Chemistry of Chongqing Municipality, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Lam, Michael Hon-wah [Department of Biology and Chemistry, City University of Hong Kong (Hong Kong); Chow, Cheuk-fai, E-mail: cfchow@ied.edu.hk [Department of Science and Environmental Studies, The Hong Kong Institute of Education (Hong Kong)

    2016-09-01

    A photoresponsive surface molecularly imprinted polymer for uric acid in physiological fluids was fabricated through a facile and effective method using bio-safe and biocompatible ZnO nanorods as a support. The strategy was carried out by introducing double bonds on the surface of the ZnO nanorods with 3-methacryloxypropyltrimethoxysilane. The surface molecularly imprinted polymer on ZnO nanorods was then prepared by surface polymerization using uric acid as template, water-soluble 5-[(4-(methacryloyloxy)phenyl)diazenyl]isophthalic acid as functional monomer, and triethanolamine trimethacryl ester as cross-linker. The surface molecularly imprinted polymer on ZnO nanorods showed good photoresponsive properties, high recognition ability, and fast binding kinetics toward uric acid, with a dissociation constant of 3.22 × 10{sup −5} M in aqueous NaH{sub 2}PO{sub 4} buffer at pH = 7.0 and a maximal adsorption capacity of 1.45 μmol g{sup −1}. Upon alternate irradiation at 365 and 440 nm, the surface molecularly imprinted polymer on ZnO nanorods can quantitatively uptake and release uric acid. - Highlights: • Novel surface molecularly imprinted polymer on ZnO nanorods was synthesized. • ZnO-SMIP showed good selectivity toward uric acid in physiological fluids. • ZnO-SMIP displayed good photoresponsive properties.

  7. Molecularly Imprinted Sol-Gel-Based QCM Sensor Arrays for the Detection and Recognition of Volatile Aldehydes

    Directory of Open Access Journals (Sweden)

    Chuanjun Liu

    2017-02-01

    Full Text Available The detection and recognition of metabolically derived aldehydes, which have been identified as important products of oxidative stress and biomarkers of cancers; are considered as an effective approach for early cancer detection as well as health status monitoring. Quartz crystal microbalance (QCM sensor arrays based on molecularly imprinted sol-gel (MISG materials were developed in this work for highly sensitive detection and highly selective recognition of typical aldehyde vapors including hexanal (HAL; nonanal (NAL and bezaldehyde (BAL. The MISGs were prepared by a sol-gel procedure using two matrix precursors: tetraethyl orthosilicate (TEOS and tetrabutoxytitanium (TBOT. Aminopropyltriethoxysilane (APT; diethylaminopropyltrimethoxysilane (EAP and trimethoxy-phenylsilane (TMP were added as functional monomers to adjust the imprinting effect of the matrix. Hexanoic acid (HA; nonanoic acid (NA and benzoic acid (BA were used as psuedotemplates in view of their analogous structure to the target molecules as well as the strong hydrogen-bonding interaction with the matrix. Totally 13 types of MISGs with different components were prepared and coated on QCM electrodes by spin coating. Their sensing characters towards the three aldehyde vapors with different concentrations were investigated qualitatively. The results demonstrated that the response of individual sensors to each target strongly depended on the matrix precursors; functional monomers and template molecules. An optimization of the 13 MISG materials was carried out based on statistical analysis such as principle component analysis (PCA; multivariate analysis of covariance (MANCOVA and hierarchical cluster analysis (HCA. The optimized sensor array consisting of five channels showed a high discrimination ability on the aldehyde vapors; which was confirmed by quantitative comparison with a randomly selected array. It was suggested that both the molecularly imprinting (MIP effect and the matrix

  8. Acetic and Acrylic Acid Molecular Imprinted Model Silicone Hydrogel Materials for Ciprofloxacin-HCl Delivery

    Directory of Open Access Journals (Sweden)

    Lyndon Jones

    2012-01-01

    Full Text Available Contact lenses, as an alternative drug delivery vehicle for the eye compared to eye drops, are desirable due to potential advantages in dosing regimen, bioavailability and patient tolerance/compliance. The challenge has been to engineer and develop these materials to sustain drug delivery to the eye for a long period of time. In this study, model silicone hydrogel materials were created using a molecular imprinting strategy to deliver the antibiotic ciprofloxacin. Acetic and acrylic acid were used as the functional monomers, to interact with the ciprofloxacin template to efficiently create recognition cavities within the final polymerized material. Synthesized materials were loaded with 9.06 mM, 0.10 mM and 0.025 mM solutions of ciprofloxacin, and the release of ciprofloxacin into an artificial tear solution was monitored over time. The materials were shown to release for periods varying from 3 to 14 days, dependent on the loading solution, functional monomer concentration and functional monomer:template ratio, with materials with greater monomer:template ratio (8:1 and 16:1 imprinted tending to release for longer periods of time. Materials with a lower monomer:template ratio (4:1 imprinted tended to release comparatively greater amounts of ciprofloxacin into solution, but the release was somewhat shorter. The total amount of drug released from the imprinted materials was sufficient to reach levels relevant to inhibit the growth of common ocular isolates of bacteria. This work is one of the first to demonstrate the feasibility of molecular imprinting in model silicone hydrogel-type materials.

  9. IMPRINT Analysis of an Unmanned Air System Geospatial Information Process

    National Research Council Canada - National Science Library

    Hunn, Bruce P; Schweitzer, Kristin M; Cahir, John A; Finch, Mary M

    2008-01-01

    ... intelligence, geospatial analysis cell. The Improved Performance Research Integration Tool (IMPRINT) modeling program was used to understand this process and to assess crew workload during several test scenarios...

  10. Cellulose acetate-based molecularly imprinted polymeric membrane for separation of vanillin and o-vanillin

    OpenAIRE

    Zhang,Chunjing; Zhong,Shian; Yang,Zhengpeng

    2008-01-01

    Cellulose acetate-based molecularly imprinted polymeric membranes were prepared using vanillin as template molecule. The microscopic structure of the resultant polymeric membranes was characterized by SEM and FTIR spectroscopy, and the selective binding properties and separation capacity of the membranes for vanillin and o-vanillin were tested with binding experiments and separate experiments, respectively. The results showed that the vanillin-imprinted polymeric membranes displayed higher bi...

  11. Molecularly imprinted layer-coated silica nanoparticles for selective solid-phase extraction of bisphenol A from chemical cleansing and cosmetics samples

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Rong; Zhao Wenhui; Zhai Meijuan; Wei Fangdi; Cai Zheng; Sheng Na [School of Pharmacy, Nanjing Medical University, Hanzhong Road 140, Nanjing, Jiangsu 210029 (China); Hu Qin, E-mail: huqin@njmu.edu.cn [School of Pharmacy, Nanjing Medical University, Hanzhong Road 140, Nanjing, Jiangsu 210029 (China)

    2010-01-25

    Highly selective molecularly imprinted layer-coated silica nanoparticles for bisphenol A (BPA) were synthesized by molecular imprinting technique with a sol-gel process on the supporter of silica nanoparticles. The BPA-imprinted silica nanoparticles were characterized by fourier transform infrared spectrometer, transmission electron microscope, dynamic adsorption and static adsorption tests. The equilibrium association constant, K{sub a}, and the apparent maximum number of binding sites, Q{sub max}, were estimated to be 1.25 x 10{sup 5} mL {mu}mol{sup -1} and 16.4 {mu}mol g{sup -1}, respectively. The BPA-imprinted silica nanoparticles solid-phase extraction (SPE) column had higher selectivity for BPA than the commercial C18-SPE column. The results of the study indicated that the prepared BPA-imprinted silica nanoparticles exhibited high adsorption capacity and selectivity, and offered a fast kinetics for the rebinding of BPA. The BPA-imprinted silica nanoparticles were successfully used in SPE to selectively enrich and determine BPA from shampoo, bath lotion and cosmetic cream samples.

  12. Synthesis of core-shell molecularly imprinted polymer microspheres by precipitation polymerization for the inline molecularly imprinted solid-phase extraction of thiabendazole from citrus fruits and orange juice samples.

    Science.gov (United States)

    Barahona, Francisco; Turiel, Esther; Cormack, Peter A G; Martín-Esteban, Antonio

    2011-01-01

    In this work, the synthesis of molecularly imprinted polymer microspheres with narrow particle size distributions and core-shell morphology by a two-step precipitation polymerization procedure is described. Polydivinylbenzene (poly DVB-80) core particles were used as seed particles in the production of molecularly imprinted polymer shells by copolymerization of divinylbenzene-80 with methacrylic acid in the presence of thiabendazole (TBZ) and an appropriate porogen. Thereafter, polymer particles were packed into refillable stainless steel HPLC columns used in the development of an inline molecularly imprinted SPE method for the determination of TBZ in citrus fruits and orange juice samples. Under optimized chromatographic conditions, recoveries of TBZ within the range 81.1-106.4%, depending upon the sample, were obtained, with RSDs lower than 10%. This novel method permits the unequivocal determination of TBZ in the samples under study, according to the maximum residue levels allowed within Europe, in less than 20 min and without any need for a clean-up step in the analytical protocol. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. One-dimensional surface-imprinted polymeric nanotubes for specific biorecognition by initiated chemical vapor deposition (iCVD).

    Science.gov (United States)

    Ince, Gozde Ozaydin; Armagan, Efe; Erdogan, Hakan; Buyukserin, Fatih; Uzun, Lokman; Demirel, Gokhan

    2013-07-24

    Molecular imprinting is a powerful, generic, and cost-effective technique; however, challenges still remain related to the fabrication and development of these systems involving nonhomogeneous binding sites, insufficient template removing, incompatibility with aqueous media, low rebinding capacity, and slow mass transfer. The vapor-phase deposition of polymers is a unique technique because of the conformal nature of coating and offers new possibilities in a number of applications including sensors, microfluidics, coating, and bioaffinity platforms. Herein, we demonstrated a simple but versatile concept to generate one-dimensional surface-imprinted polymeric nanotubes within anodic aluminum oxide (AAO) membranes based on initiated chemical vapor deposition (iCVD) technique for biorecognition of immunoglobulin G (IgG). It is reported that the fabricated surface-imprinted nanotubes showed high binding capacity and significant specific recognition ability toward target molecules compared with the nonimprinted forms. Given its simplicity and universality, the iCVD method can offer new possibilities in the field of molecular imprinting.

  14. Ion imprinted activated carbon solid-phase extraction coupled to flame atomic absorption spectrometry for selective determination of lead ions in environmental samples

    International Nuclear Information System (INIS)

    Naraghi, Kiyana; Panahi, Homayon Ahmad; Hassani, Amir Hesam; Moniri, Elham

    2014-01-01

    A simple lead ion imprinted sorbent was synthesized by coupling activated carbon with a known metal chelating compound, iminodiacetic acid. The ion imprinted sorbent has been characterized using Fourier transform infrared spectroscopy, elemental analysis and thermogravimetric analysis and subjected for the extraction and determination of trace Pb(II) in environmental water samples. The optimum pH value for sorption of the lead ion was 6.5. The sorption capacity of lead imprinted sorbent was 42.2 mg g"−"1. The chelating imprinted sorbent can be reused for five cycles of sorption-desorption without any significant change in sorption capacity. Compared with non-imprinted polymer particles, the lead ion imprinted sorbent showed high adsorption capacity, significant selectivity, good site accessibility for Pb(II). The equilibrium adsorption data of Pb(II) by modified resin were analyzed by Langmuir, Freundlich, Temkin and Redlich-Peterson models

  15. All-silica nanofluidic devices for DNA-analysis fabricated by imprint of sol-gel silica with silicon stamp

    DEFF Research Database (Denmark)

    Mikkelsen, Morten Bo Lindholm; Letailleur, Alban A; Søndergård, Elin

    2011-01-01

    We present a simple and cheap method for fabrication of silica nanofluidic devices for single-molecule studies. By imprinting sol-gel materials with a multi-level stamp comprising micro- and nanofeatures, channels of different depth are produced in a single process step. Calcination of the imprin......We present a simple and cheap method for fabrication of silica nanofluidic devices for single-molecule studies. By imprinting sol-gel materials with a multi-level stamp comprising micro- and nanofeatures, channels of different depth are produced in a single process step. Calcination...... of the imprinted hybrid sol-gel material produces purely inorganic silica, which has very low autofluorescence and can be fusion bonded to a glass lid. Compared to top-down processing of fused silica or silicon substrates, imprint of sol-gel silica enables fabrication of high-quality nanofluidic devices without...

  16. Detection of creatinine enriched on a surface imprinted polystyrene film using FT-ATR-IR.

    Science.gov (United States)

    Sreenivasan, K

    2006-01-01

    The surface of polystyrene (PS) was chemically modified by coating a thin layer of polyaniline (PANI) by oxidizing aniline using ammonium persulfate. Affinity sites for creatinine, a clinically relevant molecule, were created in the coated layer by adding creatinine as print molecules during the oxidation. The imprinted layer adsorbed creatinine was compared to non-imprinted surface reflecting the creation of creatinine-specific sites on the surface. The equilibrium was attained rapidly, indicating that a material of this kind is suitable for sensing applications. The adsorbed creatinine on the surface was detected using the technique of Fourier transform attenuated total internal reflection infra red spectroscopy (FT-ATR-IR). The results show that molecularly imprinted surface can enrich molecules of interest and the enriched molecules can be detected using FT-IR.

  17. PREPARATION AND CHARACTERIZATION OF MOLECULARLY IMPRINTED ELECTROPOLYMERIZED CARBON ELECTRODES

    Science.gov (United States)

    Molecularly imprinted polymers (MIP) selective for fluorescein, rhodamine or 2,4-dichlorophenoxyacetic acid (2,4-D) were electropolymerized onto graphite electrodes using an aqueous solution equimolar in resorsinol/ortho-phenylenediamine and in the presence of the template mole...

  18. Determination of organophosphorus pesticides using molecularly imprinted polymer solid phase extraction

    International Nuclear Information System (INIS)

    Mohd Marsin Sanagi; Syairah Salleh; Wan Aini Wan Ibrahim

    2011-01-01

    Molecularly imprinted polymer solid phase extraction (MIP-SPE) method has been developed for the determination of organophosphorus pesticides (OPPs) in water samples. The MIP was prepared by thermo-polymerization method using methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as crosslinker, acetonitrile as porogenic solvent and quinalphos as the template molecule. The three OPPs (diazinon, quinalphos and chloropyrifos) were selected as target analytes as they are widely used in agriculture sector. Various parameters affecting the extraction efficiency of the imprinted polymers have been evaluated to optimize the selective preconcentration of OPPs from aqueous samples. The characteristics of the MIP-SPE method were validated by high performance liquid chromatography (HPLC). The accuracy and selectivity of the MIP-SPE process developed were verified using non-imprinted polymer solid phase extraction (NIP-SPE) and a commercial C 18 -SPE was used for comparison. The recoveries of the target analytes obtained using the MIPs as the solid phase sorbent ranged from 83% to 98% (RSDs 1.05 - 1.98 %; n=3) for water sample. The developed MIP-SPE method demonstrates that it could be applied for the determination of OPPs in water samples. (author)

  19. Imprint reduction in rotating heavy ions beam energy deposition

    Energy Technology Data Exchange (ETDEWEB)

    Bret, A., E-mail: antoineclaude.bret@uclm.es [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-51, Cambridge, MA 02138 (United States); ETSI Industriales, Universidad Castilla-La Mancha, 13071 Ciudad Real (Spain); Instituto de Investigaciones Energéticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real (Spain); Piriz, A.R., E-mail: Roberto.Piriz@uclm.es [ETSI Industriales, Universidad Castilla-La Mancha, 13071 Ciudad Real (Spain); Instituto de Investigaciones Energéticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real (Spain); Tahir, N.A., E-mail: n.tahir@gsi.de [GSI Darmstadt, Plankstrasse 1, 64291 Darmstadt (Germany)

    2014-01-01

    The compression of a cylindrical target by a rotating heavy ions beam is contemplated in certain inertial fusion schemes or in heavy density matter experiments. Because the beam has its proper temporal profile, the energy deposition is asymmetric and leaves an imprint which can have important consequences for the rest of the process. In this paper, the Fourier components of the deposited ion density are computed exactly in terms of the beam temporal profile and its rotation frequency Ω. We show that for any beam profile of duration T, there exist an infinite number of values of ΩT canceling exactly any given harmonic. For the particular case of a parabolic profile, we find possible to cancel exactly the first harmonic and nearly cancel every other odd harmonics. In such case, the imprint amplitude is divided by 4 without any increase of Ω.

  20. Imprint reduction in rotating heavy ions beam energy deposition

    International Nuclear Information System (INIS)

    Bret, A.; Piriz, A.R.; Tahir, N.A.

    2014-01-01

    The compression of a cylindrical target by a rotating heavy ions beam is contemplated in certain inertial fusion schemes or in heavy density matter experiments. Because the beam has its proper temporal profile, the energy deposition is asymmetric and leaves an imprint which can have important consequences for the rest of the process. In this paper, the Fourier components of the deposited ion density are computed exactly in terms of the beam temporal profile and its rotation frequency Ω. We show that for any beam profile of duration T, there exist an infinite number of values of ΩT canceling exactly any given harmonic. For the particular case of a parabolic profile, we find possible to cancel exactly the first harmonic and nearly cancel every other odd harmonics. In such case, the imprint amplitude is divided by 4 without any increase of Ω

  1. Fabrication of ridge waveguide structure from photosensitive TiO{sub 2}/ormosil hybrid films by using an ultraviolet soft imprint technique

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xuehua [Electronic Materials Research Laboratory, International Center for Dielectric Research, Xi' an Jiaotong University, Xi' an 710049, Shaanxi (China); Que, Wenxiu, E-mail: wxque@mail.xjtu.edu.cn [Electronic Materials Research Laboratory, International Center for Dielectric Research, Xi' an Jiaotong University, Xi' an 710049, Shaanxi (China); Chen, Jing; Gao, Tianxi; Hu, Jiaxing [Electronic Materials Research Laboratory, International Center for Dielectric Research, Xi' an Jiaotong University, Xi' an 710049, Shaanxi (China); Liu, Weiguo [Micro-optoelectronic Systems Laboratories, Xi' an Technological University, Xi' an 710032, Shaanxi (China)

    2013-03-01

    Photosensitive TiO{sub 2}/organically modified silane hybrid films were prepared by combining a low-temperature sol–gel process with a spin-coating technique. Optical properties and photochemical activities of the as-prepared hybrid sol–gel films under different UV irradiation time were characterized and monitored by prism coupling technique, UV–visible spectroscopy, and Fourier transform infrared spectroscopy. Surface morphology of the hybrid films was also observed by an atomic force microscopy. Advantages for fabrication of ridge waveguide structure based on the photosensitive hybrid films were demonstrated by an ultraviolet soft imprint technique. Effects of imprint force, imprint time, and UV irradiation time on high replication fidelity of the ridge waveguide structure were also investigated. An altitude replication fidelity of 99.7% can be obtained when the imprint force of 2 MPa, imprint time of 30 min and UV irradiation time of 45 min were chosen. Scanning electron microscopy and surface profiler were used to characterize the morphological and surface profile properties of the as fabricated ridge waveguide structure. Results indicate that the as-prepared photosensitive hybrid materials have great applicability for the fabrication of micro-optical elements and advantage as the imprint layer under the ultraviolet soft imprint technique. - Highlights: ► Photosensitive TiO{sub 2}/ormosil hybrid film is prepared by a sol–gel process. ► Optical properties of the films change a little with UV exposure time. ► Photo-chemical property of the film changes a lot with UV exposure time. ► The imprint force and time, and the UV exposure time affect the imprint fidelity. ► A fidelity value of 99.7% is obtained under an optimized condition.

  2. Olefin Metathesis in Peptidomimetics, Dynamic Combinatorial Chemistry, and Molecular Imprinting

    National Research Council Canada - National Science Library

    Low, Tammy K

    2006-01-01

    .... Our research goals consisted of employing olefin metathesis in the synthesis of peptidomimetics, and studying the feasibility of this method in dynamic combinatorial chemistry and molecular imprinting of nerve agents...

  3. Maintenance of Xist Imprinting Depends on Chromatin Condensation State and Rnf12 Dosage in Mice.

    Directory of Open Access Journals (Sweden)

    Atsushi Fukuda

    2016-10-01

    Full Text Available In female mammals, activation of Xist (X-inactive specific transcript is essential for establishment of X chromosome inactivation. During early embryonic development in mice, paternal Xist is preferentially expressed whereas maternal Xist (Xm-Xist is silenced. Unlike autosomal imprinted genes, Xist imprinting for Xm-Xist silencing was erased in cloned or parthenogenetic but not fertilized embryos. However, the molecular mechanism underlying the variable nature of Xm-Xist imprinting is poorly understood. Here, we revealed that Xm-Xist silencing depends on chromatin condensation states at the Xist/Tsix genomic region and on Rnf12 expression levels. In early preimplantation, chromatin decondensation via H3K9me3 loss and histone acetylation gain caused Xm-Xist derepression irrespective of embryo type. Although the presence of the paternal genome during pronuclear formation impeded Xm-Xist derepression, Xm-Xist was robustly derepressed when the maternal genome was decondensed before fertilization. Once Xm-Xist was derepressed by chromatin alterations, the derepression was stably maintained and rescued XmXpΔ lethality, indicating that loss of Xm-Xist imprinting was irreversible. In late preimplantation, Oct4 served as a chromatin opener to create transcriptional permissive states at Xm-Xist/Tsix genomic loci. In parthenogenetic embryos, Rnf12 overdose caused Xm-Xist derepression via Xm-Tsix repression; physiological Rnf12 levels were essential for Xm-Xist silencing maintenance in fertilized embryos. Thus, chromatin condensation and fine-tuning of Rnf12 dosage were crucial for Xist imprint maintenance by silencing Xm-Xist.

  4. A Facile Approach to Preparing Molecularly Imprinted Chitosan for Detecting 2,4,6-Tribromophenol with a Widely Linear Range

    Directory of Open Access Journals (Sweden)

    Limei Huang

    2017-04-01

    Full Text Available The environmental pollution of 2,4,6-tribromophenol (TBP has attracted attention. Based on an urgent need for the better provision of clean water, in situ determination of TBP is of great importance. Here, a facile and effective approach for detecting TBP is developed, based on coupling molecular imprinting technique with electrodeposition of chitosan (CS on the gold electrode. The TBP imprinting CS film was fabricated by using CS as functional material and TBP as template molecule. The experiments show that the morphologies and electrochemical properties of the imprinted film sensor was different from non-imprinted film electrode. The current of the imprinted film was linearly proportional to the TBP concentration, with a wide linear range of 1.0 × 10−7 mol•L−1 to 1.0 × 10−3 mol•L−1. By selecting drop-coating method as a reference for controlled trials with the same functional material, the results illustrated that the electrodeposition enjoyed a widely linear range advantage.

  5. Molecularly imprinted polymeric stir bar: Preparation and application for the determination of naftopidil in plasma and urine samples.

    Science.gov (United States)

    Peng, Jun; Xiao, Deli; He, Hua; Zhao, Hongyan; Wang, Cuixia; Shi, Tian; Shi, Kexin

    2016-01-01

    In this study, molecularly imprinting technology and stir bar absorption technology were combined to develop a microextraction approach based on a molecularly imprinted polymeric stir bar. The molecularly imprinted polymer stir bar has a high performance, is specific, economical, and simple to prepare. The obtained naftopidil-imprinted polymer-coated bars could simultaneously agitate and adsorb naftopidil in the sample solution. The ratio of template/monomer/cross-linker and conditions of template removal were optimized to prepare a stir bar with highly efficient adsorption. Fourier transform infrared spectroscopy, scanning electron microscopy, selectivity, and extraction capacity experiments showed that the molecularly imprinted polymer stir bar was prepared successfully. To utilize the molecularly imprinted polymer stir bar for the determination of naftopidil in complex body fluid matrices, the extraction time, stirring speed, eluent, and elution time were optimized. The limits of detection of naftopidil in plasma and urine sample were 7.5 and 4.0 ng/mL, respectively, and the recoveries were in the range of 90-112%. The within-run precision and between-run precision were acceptable (relative standard deviation bar based microextraction with high-performance liquid chromatography was a convenient, rapid, efficient, and specific method for the precise determination of trace naftopidil in clinical analysis. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Chained Kullback-Leibler Divergences

    Science.gov (United States)

    Pavlichin, Dmitri S.; Weissman, Tsachy

    2017-01-01

    We define and characterize the “chained” Kullback-Leibler divergence minw D(p‖w) + D(w‖q) minimized over all intermediate distributions w and the analogous k-fold chained K-L divergence min D(p‖wk−1) + … + D(w2‖w1) + D(w1‖q) minimized over the entire path (w1,…,wk−1). This quantity arises in a large deviations analysis of a Markov chain on the set of types – the Wright-Fisher model of neutral genetic drift: a population with allele distribution q produces offspring with allele distribution w, which then produce offspring with allele distribution p, and so on. The chained divergences enjoy some of the same properties as the K-L divergence (like joint convexity in the arguments) and appear in k-step versions of some of the same settings as the K-L divergence (like information projections and a conditional limit theorem). We further characterize the optimal k-step “path” of distributions appearing in the definition and apply our findings in a large deviations analysis of the Wright-Fisher process. We make a connection to information geometry via the previously studied continuum limit, where the number of steps tends to infinity, and the limiting path is a geodesic in the Fisher information metric. Finally, we offer a thermodynamic interpretation of the chained divergence (as the rate of operation of an appropriately defined Maxwell’s demon) and we state some natural extensions and applications (a k-step mutual information and k-step maximum likelihood inference). We release code for computing the objects we study. PMID:29130024

  7. Exercise-associated DNA methylation change in skeletal muscle and the importance of imprinted genes: a bioinformatics meta-analysis.

    Science.gov (United States)

    Brown, William M

    2015-12-01

    Epigenetics is the study of processes--beyond DNA sequence alteration--producing heritable characteristics. For example, DNA methylation modifies gene expression without altering the nucleotide sequence. A well-studied DNA methylation-based phenomenon is genomic imprinting (ie, genotype-independent parent-of-origin effects). We aimed to elucidate: (1) the effect of exercise on DNA methylation and (2) the role of imprinted genes in skeletal muscle gene networks (ie, gene group functional profiling analyses). Gene ontology (ie, gene product elucidation)/meta-analysis. 26 skeletal muscle and 86 imprinted genes were subjected to g:Profiler ontology analysis. Meta-analysis assessed exercise-associated DNA methylation change. g:Profiler found four muscle gene networks with imprinted loci. Meta-analysis identified 16 articles (387 genes/1580 individuals) associated with exercise. Age, method, sample size, sex and tissue variation could elevate effect size bias. Only skeletal muscle gene networks including imprinted genes were reported. Exercise-associated effect sizes were calculated by gene. Age, method, sample size, sex and tissue variation were moderators. Six imprinted loci (RB1, MEG3, UBE3A, PLAGL1, SGCE, INS) were important for muscle gene networks, while meta-analysis uncovered five exercise-associated imprinted loci (KCNQ1, MEG3, GRB10, L3MBTL1, PLAGL1). DNA methylation decreased with exercise (60% of loci). Exercise-associated DNA methylation change was stronger among older people (ie, age accounted for 30% of the variation). Among older people, genes exhibiting DNA methylation decreases were part of a microRNA-regulated gene network functioning to suppress cancer. Imprinted genes were identified in skeletal muscle gene networks and exercise-associated DNA methylation change. Exercise-associated DNA methylation modification could rewind the 'epigenetic clock' as we age. CRD42014009800. Published by the BMJ Publishing Group Limited. For permission to use (where

  8. Ion imprinted activated carbon solid-phase extraction coupled to flame atomic absorption spectrometry for selective determination of lead ions in environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Naraghi, Kiyana; Panahi, Homayon Ahmad; Hassani, Amir Hesam [Islamic Azad University, Tehran (Korea, Republic of); Moniri, Elham [Islamic Azad University, Varamin (Iran, Islamic Republic of)

    2014-10-15

    A simple lead ion imprinted sorbent was synthesized by coupling activated carbon with a known metal chelating compound, iminodiacetic acid. The ion imprinted sorbent has been characterized using Fourier transform infrared spectroscopy, elemental analysis and thermogravimetric analysis and subjected for the extraction and determination of trace Pb(II) in environmental water samples. The optimum pH value for sorption of the lead ion was 6.5. The sorption capacity of lead imprinted sorbent was 42.2 mg g{sup −1}. The chelating imprinted sorbent can be reused for five cycles of sorption-desorption without any significant change in sorption capacity. Compared with non-imprinted polymer particles, the lead ion imprinted sorbent showed high adsorption capacity, significant selectivity, good site accessibility for Pb(II). The equilibrium adsorption data of Pb(II) by modified resin were analyzed by Langmuir, Freundlich, Temkin and Redlich-Peterson models.

  9. Design of foam-buffered high gain target with Fokker-Planck implosion simulation for thermal insulation and imprint mitigation

    International Nuclear Information System (INIS)

    Takeda, T.; Mima, K.; Norimatsu, T.; Nagatomo, H.; Nishiguchi, A.

    2003-01-01

    It is proposed that a thick foam layer on a plastic capsule of fusion pellet is effective not only for reducing the initial imprint, but also for solving the melting problem of cryogenic deuterium-tritium layer, in a reactor chamber. Investigated are the dependences of gain, thermal insulation for preventing the melting, and imprint mitigation of a foam-buffered target on the foam layer thickness. The imprint mitigation, the Rayleigh-Taylor growth factor and the fusion gain of a foam-buffered target are evaluated by the hydrodynamic implosion code HIMICO [A. Nishiguchi et al., Phys. Fluids B 4, 417 (1992)], which includes a Fokker-Planck transport code. As the result, it is found that high gain can be achieved by the foam-buffered target together with thermal insulation and imprint mitigation

  10. Application of molecularly imprinted and non-imprinted polymers for removal of emerging contaminants in water and wastewater treatment: a review.

    Science.gov (United States)

    Murray, Audrey; Ormeci, Banu

    2012-11-01

    Over the past decade, several studies have reported trace levels of endocrine disrupting compounds, pharmaceuticals, and personal care products in surface waters, drinking water, and wastewater effluents. There has also been an increased concern about the ecological and human health impact of these contaminants, and their removal from water and wastewater has become a priority. Traditional treatment processes are limited in their ability to remove emerging contaminants from water, and there is a need for new technologies that are effective and feasible. This paper presents a review on recent research results on molecularly imprinted (MIP) and non-imprinted (NIP) polymers and evaluates their potential as a treatment method for the removal of emerging contaminants from water and wastewater. It also discusses the relative benefits and limitations of using MIP or NIP for water and wastewater treatment. MIP, and in particular NIP, offer promising applications for wastewater treatment, but their toxicity and possible health effects should be carefully studied before they are considered for drinking water treatment. More research is also required to determine how best to incorporate MIP and NIP in treatment plants.

  11. Effectiveness of combined use of imprint cytological and histological examination in CT-guided tissue-core biopsy

    International Nuclear Information System (INIS)

    Yamagami, Takuji; Yoshimatsu, Rika; Kajiwara, Kenji; Ishikawa, Masaki; Awai, Kazuo; Matsumoto, Tomohiro; Hasebe, Terumitsu; Kakizawa, Hideaki; Toyoda, Naoyuki

    2014-01-01

    This study evaluated the efficacy of the combination of imprint cytology and histology in tissue-core percutaneous biopsy under real-time computed tomography (CT) fluoroscopic guidance. Between October 2009 and June 2013, 156 percutaneous needle biopsies were performed in our institution. Those obtained by tissue-core biopsy underwent both imprint cytological and histological examinations routinely after touch imprint cytology was performed on site to evaluate the samples' sufficiency for cytological and pathological examination. Final diagnosis was confirmed by independent surgical pathology, independent culture results or clinical follow-up. Rates of adequate specimens and precise diagnosis, by combined cytological and histological examination were 100 % (156/156) and 96.2 % (150/156), by cytology 94.4 % (152/156) and 83.3 % (130/156) and by histology 99.3 % (155/156) and 92.3 % (144/156). Precise diagnosis was achieved by combined examinations in 94.7 % (89/94) of thoracic lesions, 97.6 % (40/41) of musculoskeletal lesions, and 100 % (21/21) of abdominal, pelvic and retroperitoneal lesions. In all 104 lesions diagnosed as malignant by CT-guided biopsy and in 30 of 52 diagnosed as benign, specific cell types could be proved by combined examinations. Combined imprint cytology and histology performed after on-site touch imprint cytological evaluation improved the diagnostic ability of CT fluoroscopically guided biopsy. (orig.)

  12. Effectiveness of combined use of imprint cytological and histological examination in CT-guided tissue-core biopsy

    Energy Technology Data Exchange (ETDEWEB)

    Yamagami, Takuji; Yoshimatsu, Rika; Kajiwara, Kenji; Ishikawa, Masaki; Awai, Kazuo [Hiroshima University, Department of Diagnostic Radiology, Institute and Graduate School of Biomedical Sciences, Minami-Ku, Hiroshima (Japan); Matsumoto, Tomohiro; Hasebe, Terumitsu [Tokai University Hachioji Hospital, Tokai University School of Medicine, Department of Radiology, Hachioji, Tokyo (Japan); Kakizawa, Hideaki [Hiroshima University, Department of Diagnostic Radiology, Institute and Graduate School of Biomedical Sciences, Minami-Ku, Hiroshima (Japan); Hiroshima Red Cross Hospital and Atomic-bomb Survivors Hospital, Department of Diagnostic Radiology, Naka-Ku, Hiroshima (Japan); Toyoda, Naoyuki [Hiroshima University, Department of Diagnostic Radiology, Institute and Graduate School of Biomedical Sciences, Minami-Ku, Hiroshima (Japan); National Hospital Organisation Kure Medical Centre, Department of Diagnostic Radiology, Kure, Hiroshima (Japan)

    2014-05-15

    This study evaluated the efficacy of the combination of imprint cytology and histology in tissue-core percutaneous biopsy under real-time computed tomography (CT) fluoroscopic guidance. Between October 2009 and June 2013, 156 percutaneous needle biopsies were performed in our institution. Those obtained by tissue-core biopsy underwent both imprint cytological and histological examinations routinely after touch imprint cytology was performed on site to evaluate the samples' sufficiency for cytological and pathological examination. Final diagnosis was confirmed by independent surgical pathology, independent culture results or clinical follow-up. Rates of adequate specimens and precise diagnosis, by combined cytological and histological examination were 100 % (156/156) and 96.2 % (150/156), by cytology 94.4 % (152/156) and 83.3 % (130/156) and by histology 99.3 % (155/156) and 92.3 % (144/156). Precise diagnosis was achieved by combined examinations in 94.7 % (89/94) of thoracic lesions, 97.6 % (40/41) of musculoskeletal lesions, and 100 % (21/21) of abdominal, pelvic and retroperitoneal lesions. In all 104 lesions diagnosed as malignant by CT-guided biopsy and in 30 of 52 diagnosed as benign, specific cell types could be proved by combined examinations. Combined imprint cytology and histology performed after on-site touch imprint cytological evaluation improved the diagnostic ability of CT fluoroscopically guided biopsy. (orig.)

  13. Molecularly imprinted polymer based quartz crystal microbalance sensor system for sensitive and label-free detection of synthetic cannabinoids in urine.

    Science.gov (United States)

    Battal, Dilek; Akgönüllü, Semra; Yalcin, M Serkan; Yavuz, Handan; Denizli, Adil

    2018-07-15

    Herein, we prepared a novel quartz crystal microbalance (QCM) sensor for synthetic cannabinoids (JWH-073, JWH-073 butanoic acid, JWH-018 and JWH-018 pentanoic acid,) detection. Firstly, the synthetic cannabinoid (SCs) imprinted (MIP) and non-imprinted (NIP) nanoparticles were synthesized by mini-emulsion polymerization system. The SCs-imprinted nanoparticles were first characterized by SEM, TEM, zeta-size and FTIR-ATR analysis and then were dropped onto the gold QCM surface. The SCs-imprinted QCM sensor was characterized by an ellipsometer, contact angle, and AFM. The limit of detection was found as 0.3, 0.45, 0.4, 0.2 pg/mL JWH-018, JWH-073, JWH-018 pentanoic acid and JWH-073 butanoic acid, respectively. The selectivity of the SCs-imprinted QCM sensor was shown by using JWH-018, JWH-018 pentanoic acid, JWH-073 and JWH-073 butanoic acid. According to the results, the SCs-imprinted QCM sensors show highly selective and sensitive in a broad range of synthetic cannabinoid concentrations (0.0005-1.0 ng/mL) in both aqueous and synthetic urine solutions. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Electrochromic Molecular Imprinting Sensor for Visual and Smartphone-Based Detections.

    Science.gov (United States)

    Capoferri, Denise; Álvarez-Diduk, Ruslan; Del Carlo, Michele; Compagnone, Dario; Merkoçi, Arben

    2018-05-01

    Electrochromic effect and molecularly imprinted technology have been used to develop a sensitive and selective electrochromic sensor. The polymeric matrices obtained using the imprinting technology are robust molecular recognition elements and have the potential to mimic natural recognition entities with very high selectivity. The electrochromic behavior of iridium oxide nanoparticles (IrOx NPs) as physicochemical transducer together with a molecularly imprinted polymer (MIP) as recognition layer resulted in a fast and efficient translation of the detection event. The sensor was fabricated using screen-printing technology with indium tin oxide as a transparent working electrode; IrOx NPs where electrodeposited onto the electrode followed by thermal polymerization of polypyrrole in the presence of the analyte (chlorpyrifos). Two different approaches were used to detect and quantify the pesticide: direct visual detection and smartphone imaging. Application of different oxidation potentials for 10 s resulted in color changes directly related to the concentration of the analyte. For smartphone imaging, at fixed potential, the concentration of the analyte was dependent on the color intensity of the electrode. The electrochromic sensor detects a highly toxic compound (chlorpyrifos) with a 100 fM and 1 mM dynamic range. So far, to the best of our knowledge, this is the first work where an electrochromic MIP sensor uses the electrochromic properties of IrOx to detect a certain analyte with high selectivity and sensitivity.

  15. Semi-synthetic biotin imprinting onto avidin crosslinked gold-silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    At Latin-Small-Letter-Dotless-I l Latin-Small-Letter-Dotless-I r Oezcan, Ayca, E-mail: aatilir@anadolu.edu.tr; Ersoez, Arzu; Huer, Deniz; Y Latin-Small-Letter-Dotless-I lmaz, Filiz [Anadolu University, Department of Chemistry (Turkey); Gueltekin, Aytac [Karamanoglu Mehmetbey University, Department of Engineering of Energy Systems (Turkey); Denizli, Adil [Hacettepe University, Department of Chemistry (Turkey); Say, R Latin-Small-Letter-Dotless-I dvan [Anadolu University, Department of Chemistry (Turkey)

    2012-06-15

    This study is a different and new application of molecular imprinted polymers (MIPs) based on sensor technologies. In this study, semi-synthetic biotin imprinted polymeric shell has been decorated onto the surface of avidin crosslinked Au/Ag nanoclusters using bis (2-2 Prime -bipyridyl) MATyr-MATrp-ruthenium(II) (MATyr-Ru-MATrp) as photosensitive monomer. The synthesized nanoclusters have been used the recognition of biotin by flourometric method. Synthesis of the photosensitive monomers has been realized by AmiNoAcid (monomer) Decorated and Light Underpinning Conjugation Approach (ANADOLUCA) method. This method provides a strategy for the preparation of photosensitive ruthenium based aminoacid monomers and oligomers, aminoacid monomer-protein crosslinking using photosensitation and conjugation approach on micro and nano-structures by ruthenium-chelate based monomers. The affinity constant (K{sub a}) of biotin imprinted Au/Ag nanoclusters has been determined using the Scatchard method and found to be 3.89 Multiplication-Sign 10{sup 5} M{sup -1}. The obtained calibration graph is linear for the range of 0.051 and 2.50 {mu}M of biotin. The detection limit of biotin has been found to be 15 nM. Also, the reusability of these nanoclusters has been investigated and it has been observed that the same clusters could be used 10 times during a long period without any binding capacity decreasing.

  16. Semi-synthetic biotin imprinting onto avidin crosslinked gold–silver nanoparticles

    International Nuclear Information System (INIS)

    Atılır Özcan, Ayça; Ersöz, Arzu; Hür, Deniz; Yılmaz, Filiz; Gültekin, Aytaç; Denizli, Adil; Say, Rıdvan

    2012-01-01

    This study is a different and new application of molecular imprinted polymers (MIPs) based on sensor technologies. In this study, semi-synthetic biotin imprinted polymeric shell has been decorated onto the surface of avidin crosslinked Au/Ag nanoclusters using bis (2-2′-bipyridyl) MATyr-MATrp-ruthenium(II) (MATyr-Ru-MATrp) as photosensitive monomer. The synthesized nanoclusters have been used the recognition of biotin by flourometric method. Synthesis of the photosensitive monomers has been realized by AmiNoAcid (monomer) Decorated and Light Underpinning Conjugation Approach (ANADOLUCA) method. This method provides a strategy for the preparation of photosensitive ruthenium based aminoacid monomers and oligomers, aminoacid monomer-protein crosslinking using photosensitation and conjugation approach on micro and nano-structures by ruthenium-chelate based monomers. The affinity constant (K a ) of biotin imprinted Au/Ag nanoclusters has been determined using the Scatchard method and found to be 3.89 × 10 5 M −1 . The obtained calibration graph is linear for the range of 0.051 and 2.50 μM of biotin. The detection limit of biotin has been found to be 15 nM. Also, the reusability of these nanoclusters has been investigated and it has been observed that the same clusters could be used 10 times during a long period without any binding capacity decreasing.

  17. Electrochemical sensor based on a carbon nanotube-modified imprinted sol–gel for selective and sensitive determination of β2-agonists

    International Nuclear Information System (INIS)

    Xu, Wei; Liu, Ping; Guo, Chunhui; Dong, Chao; Zhang, Xiuhua; Wang, Shengfu

    2013-01-01

    We describe a molecularly imprinted electrochemical sensor for selective and sensitive determination of β2-agonists. It is making use of a combination of single-wall carbon nanotubes (SWNTs) with a molecularly imprinted sol–gel. The SWNTs were introduced in order to enhance electron transport and sensitivity. The imprinted sol–gel film with its specific binding sites acts as a selective recognition element and as a preconcentrator for β 2 -agonists. The morphology of the imprinted film was characterized by scanning electron microscopy. The optimized sensor displays high sensitivity and excellent selectivity for the β 2 -agonists as shown for their determination in human serum samples. (author)

  18. Influence of Exogenous Factors on Genomic Imprinting. 2. Effect of Bad Habits of Parents on Genomic Imprinting of the Descendants

    Directory of Open Access Journals (Sweden)

    A.E. Abaturov

    2016-09-01

    Full Text Available The article presents research data, which suggest that alcohol abuse and smoking of parents have an adverse effect on fetal development and the health of the child. These factors disrupt the processes of DNA methylation of imprinted genes, causing an increased risk of intrauterine growth retardation, and of pathological abnormalities in fetal neurogenesis.

  19. Conductometric Sensor for PAH Detection with Molecularly Imprinted Polymer as Recognition Layer

    Directory of Open Access Journals (Sweden)

    Usman Latif

    2018-03-01

    Full Text Available A conductometric sensor based on screen-printed interdigital gold electrodes on glass substrate coated with molecularly imprinted polyurethane layers was fabricated to detect polycyclic aromatic hydrocarbons (PAHs in water. The results prove that screen-printed interdigital electrodes are very suitable transducers to fabricate low-cost sensor systems for measuring change in resistance of PAH-imprinted layers while exposing to different PAHs. The sensor showed good selectivity to its templated molecules and high sensitivity with a detection limit of 1.3 nmol/L e.g., for anthracene in water which is lower than WHO’s permissible limit.

  20. Gametophyte differentiation and imprinting control in plants: Crosstalk between RBR and chromatin.

    Science.gov (United States)

    Johnston, Amal J; Gruissem, Wilhelm

    2009-01-01

    The Retinoblastoma (pRb) pathway has been implicated as a convergent regulatory unit in the control of cell cycle and disease. We have shown that a crosstalk between RETINOBLASTOMA RELATED (RBR), the Arabidopsis homologue of pRb, and the genes encoding proteins of the chromatin complexes involved in DNA or histone methylation, controls gametophytic and post-fertilization differentiation events and a subset of imprinting effects. We describe here a plausible model that incorporates several components of the plant Retinoblastoma pathway, thus offering a novel paradigm that merges the traditional cell cycle and the chromatin components in the control of cell differentiation and imprinting.

  1. Replacement of Antibodies in Pseudo-ELISAs: Molecularly Imprinted Nanoparticles for Vancomycin Detection.

    Science.gov (United States)

    Canfarotta, Francesco; Smolinska-Kempisty, Katarzyna; Piletsky, Sergey

    2017-01-01

    The enzyme-linked immunosorbent assay (ELISA) is a widely employed analytical test used to quantify a given molecule. It relies on the use of specific antibodies, linked to an enzyme, to target the desired molecule. The reaction between the enzyme and its substrate gives rise to the analytical signal that can be quantified. Thanks to their robustness and low cost, molecularly imprinted polymer nanoparticles (nanoMIPs) are a viable alternative to antibodies. Herein, we describe the synthesis of nanoMIPs imprinted for vancomycin and their subsequent application in an ELISA-like format for direct replacement of antibodies.

  2. Coatings of molecularly imprinted polymers based on polyhedral oligomeric silsesquioxane for open tubular capillary electrochromatography.

    Science.gov (United States)

    Zhao, Qing-Li; Zhou, Jin; Zhang, Li-Shun; Huang, Yan-Ping; Liu, Zhao-Sheng

    2016-05-15

    Polyhedral oligomeric silsesquioxane (POSS) was successfully applied, for the first time, to prepare imprinted monolithic coating for capillary electrochromatography. The imprinted monolithic coating was synthesized with a mixture of PSS-(1-Propylmethacrylate)-heptaisobutyl substituted (MA 0702), S-amlodipine (template), methacrylic acid (functional monomer), and 2-methacrylamidopropyl methacrylate (crosslinker), in a porogenic mixture of toluene-isooctane. The influence of synthesis parameters on the imprinting effect and separation performance, including the amount of MA 0702, the ratio of template to monomer, and the ratio of monomer to crosslinker, was investigated. The greatest resolution for enantiomers separation on the imprinted monolithic column prepared with MA 0702 was up to 22.3, about 2 times higher than that prepared in absence of the POSS. Column efficiency on the POSS-based MIP coatings was beyond 30,000 plate m(-1). The comparisons between MIP coating synthesized with the POSS and without the POSS were made in terms of selectivity, column efficiency, and resolution. POSS-based MIP capillaries with naproxen or zopiclone was also prepared and separation of enantiomers can be achieved. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Natural breaking of the maternal silence at the mouse and human imprinted Prader-Willi locus: A whisper with functional consequences.

    Science.gov (United States)

    Matarazzo, Valery; Muscatelli, Françoise

    2013-01-01

    Genomic imprinting is a normal process of epigenetic regulation leading some autosomal genes to be expressed from one parental allele only, the other parental allele being silenced. The reasons why this mechanism has been selected throughout evolution are not clear; however, expression dosage is critical for imprinted genes. There is a paradox between the fact that genomic imprinting is a robust mechanism controlling the expression of specific genes and the fact that this mechanism is based on epigenetic regulation that, per se, should present some flexibility. The robustness has been well studied, revealing the epigenetic modifications at the imprinted locus, but the flexibility has been poorly investigated.   Prader-Willi syndrome is the best-studied disease involving imprinted genes caused by the absence of expression of paternally inherited alleles of genes located in the human 15q11-q13 region. Until now, the silencing of the maternally inherited alleles was like a dogma. Rieusset et al. showed that in absence of the paternal Ndn allele, in Ndn +m/-p mice, the maternal Ndn allele is expressed at an extremely low level with a high degree of non-genetic heterogeneity. In about 50% of these mutant mice, this stochastic expression reduces birth lethality and severity of the breathing deficiency, correlated with a reduction in the loss of serotonergic neurons. Furthermore, using several mouse models, they reveal a competition between non-imprinted Ndn promoters, which results in monoallelic (paternal or maternal) Ndn expression, suggesting that Ndn monoallelic expression occurs in the absence of imprinting regulation. Importantly, specific expression of the maternal NDN allele is also detected in post-mortem brain samples of PWS individuals. Here, similar expression of the Magel2 maternal allele is reported in Magel2 +m/-p mice, suggesting that this loss of imprinting can be extended to other PWS genes. These data reveal an unexpected epigenetic flexibility of PWS

  4. Molecularly Imprinted Porous Monolithic Materials from Melamine-Formaldehyde for Selective Trapping of Phosphopeptides

    DEFF Research Database (Denmark)

    Liu, Mingquan; Tran, Tri Minh; Abbas Elhaj, Ahmed Awad

    2017-01-01

    monoliths, chosen based on the combination of meso- and macropores providing optimal percolative flow and accessible surface area, was synthesized in the presence of N-Fmoc and O-Et protected phosphoserine and phosphotyrosine to prepare molecularly imprinted monoliths with surface layers selective...... for phosphopeptides. These imprinted monoliths were characterized alongside nonimprinted monoliths by a variety of techniques and finally evaluated by liquid chromatography-mass spectrometry in the capillary format to assess their abilities to trap and release phosphorylated amino acids and peptides from partly...

  5. Process and device for forming imprints on ceramic tubes

    International Nuclear Information System (INIS)

    1985-01-01

    The purpose of the present invention is a process and a device for making imprints on ceramic tubes and these ceramic tubes with imprints. It is known that in uranium enrichment processes by gaseous diffusion, microporous tubes are used to made the diffuser units used for the application of this isotope enrichment process. It is known that these microporous tubes are generally made in two stages. In a first stage, a macroporous ceramic tube called a ''support'' is made. In a second stage, an internal microporous deposit is made which makes it possible to obtain a tube called a ''barrier'' finally having the required porosity to apply the gaseous diffusion enrichment process. The present invention involves the first stage of the manufacturing process of the barriers and, more precisely, a step in the manufacturing process of the supports that makes it possible to improve the efficiency of these barriers

  6. Experimental demonstration of laser imprint reduction using underdense foams

    International Nuclear Information System (INIS)

    Delorme, B.; Casner, A.; Olazabal-Loumé, M.; Nicolaï, Ph.; Breil, J.; Tikhonchuk, V. T.; Michel, D. T.; Seka, W.; Froula, D. H.; Goncharov, V.; Riazuelo, G.; Borisenko, N.; Orekhov, A.; Fujioka, S.; Sunahara, A.; Grech, M.

    2016-01-01

    Reducing the detrimental effect of the Rayleigh-Taylor (RT) instability on the target performance is a critical challenge. In this purpose, the use of targets coated with low density foams is a promising approach to reduce the laser imprint. This article presents results of ablative RT instability growth measurements, performed on the OMEGA laser facility in direct-drive for plastic foils coated with underdense foams. The laser beam smoothing is explained by the parametric instabilities developing in the foam and reducing the laser imprint on the plastic (CH) foil. The initial perturbation pre-imposed by the means of a specific phase plate was shown to be smoothed using different foam characteristics. Numerical simulations of the laser beam smoothing in the foam and of the RT growth are performed with a suite of paraxial electromagnetic and radiation hydrodynamic codes. They confirmed the foam smoothing effect in the experimental conditions.

  7. Experimental demonstration of laser imprint reduction using underdense foams

    Energy Technology Data Exchange (ETDEWEB)

    Delorme, B.; Casner, A. [CEA, DAM, DIF, F-91297 Arpajon (France); CELIA, University of Bordeaux-CNRS-CEA, F-33400 Talence (France); Olazabal-Loumé, M. [CEA, DAM, CESTA, 15 Avenue des Sablières, F-33114 Le Barp (France); CELIA, University of Bordeaux-CNRS-CEA, F-33400 Talence (France); Nicolaï, Ph.; Breil, J.; Tikhonchuk, V. T. [CELIA, University of Bordeaux-CNRS-CEA, F-33400 Talence (France); Michel, D. T.; Seka, W.; Froula, D. H.; Goncharov, V. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Riazuelo, G. [CEA, DAM, DIF, F-91297 Arpajon (France); Borisenko, N.; Orekhov, A. [P. N. Lebedev Physical Institute, RAS, 53 Leninskii Prospect, Moscow 119991 (Russian Federation); Fujioka, S.; Sunahara, A. [Institute of Laser Engineering, Osaka University, Suita, Osaka 565 (Japan); Grech, M. [LULI, Ecole Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France)

    2016-04-15

    Reducing the detrimental effect of the Rayleigh-Taylor (RT) instability on the target performance is a critical challenge. In this purpose, the use of targets coated with low density foams is a promising approach to reduce the laser imprint. This article presents results of ablative RT instability growth measurements, performed on the OMEGA laser facility in direct-drive for plastic foils coated with underdense foams. The laser beam smoothing is explained by the parametric instabilities developing in the foam and reducing the laser imprint on the plastic (CH) foil. The initial perturbation pre-imposed by the means of a specific phase plate was shown to be smoothed using different foam characteristics. Numerical simulations of the laser beam smoothing in the foam and of the RT growth are performed with a suite of paraxial electromagnetic and radiation hydrodynamic codes. They confirmed the foam smoothing effect in the experimental conditions.

  8. Matrix molecularly imprinted mesoporous sol-gel sorbent for efficient solid-phase extraction of chloramphenicol from milk.

    Science.gov (United States)

    Samanidou, Victoria; Kehagia, Maria; Kabir, Abuzar; Furton, Kenneth G

    2016-03-31

    Highly selective and efficient chloramphenicol imprinted sol-gel silica based inorganic polymeric sorbent (sol-gel MIP) was synthesized via matrix imprinting approach for the extraction of chloramphenicol in milk. Chloramphenicol was used as the template molecule, 3-aminopropyltriethoxysilane (3-APTES) and triethoxyphenylsilane (TEPS) as the functional precursors, tetramethyl orthosilicate (TMOS) as the cross-linker, isopropanol as the solvent/porogen, and HCl as the sol-gel catalyst. Non-imprinted sol-gel polymer (sol-gel NIP) was synthesized under identical conditions in absence of template molecules for comparison purpose. Both synthesized materials were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and nitrogen adsorption porosimetry, which unambiguously confirmed their significant structural and morphological differences. The synthesized MIP and NIP materials were evaluated as sorbents for molecularly imprinted solid phase extraction (MISPE) of chloramphenicol in milk. The effect of critical extraction parameters (flow rate, elution solvent, sample and eluent volume, selectivity coefficient, retention capacity) was studied in terms of retention and desorption of chloramphenicol. Competition and cross reactivity tests have proved that sol-gel MIP sorbent possesses significantly higher specific retention and enrichment capacity for chloramphenicol compared to its non-imprinted analogue. The maximum imprinting factor (IF) was found as 9.7, whereas the highest adsorption capacity of chloramphenicol by sol-gel MIP was 23 mg/g. The sol-gel MIP was found to be adequately selective towards chloramphenicol to provide the necessary minimum required performance limit (MRPL) of 0.3 μg/kg set forth by European Commission after analysis by LC-MS even without requiring time consuming solvent evaporation and sample reconstitution step, often considered as an integral part in solid phase extraction work-flow. Intra and

  9. Rapid degradation of Congo red by molecularly imprinted polypyrrole-coated magnetic TiO2 nanoparticles in dark at ambient conditions

    International Nuclear Information System (INIS)

    Wei, Shoutai; Hu, Xiaolei; Liu, Hualong; Wang, Qiang; He, Chiyang

    2015-01-01

    Highlights: • Molecularly imprinted polypyrrole-coated magnetic TiO 2 catalyst was prepared. • The catalyst degraded Congo red rapidly in dark at ambient conditions. • Degradation mechanism was proposed according to LC–MS analysis. • The catalyst can be easily recycled by a magnet. - Abstract: A novel molecularly imprinted polymer (MIP)-coated magnetic TiO 2 nanocomposite was prepared, using methyl orange (MO) as the dummy template and pyrrole as functional monomer, for degradation of Congo red (CR). The nanocomposite was characterized by Fourier transform infrared spectroscopy, thermo-gravimetric analysis, X-ray diffraction, transmission electron microscopy, and vibrating sample magnetometer. The imprinting efficiency of the imprinted nanoparticles was investigated by static binding test, and their degradation ability toward CR was also studied. Moreover, the effects of pH, temperature, dissolved oxygen and oscillation rate on degradation rate of CR were investigated. Results showed that the imprinted nanocomposite had higher adsorption ability for MO compared with the non-imprinted one. Moreover, it could degrade CR rapidly in dark at room temperature and atmospheric pressure and could be recycled easily by a magnet with a good reusability. A degradation mechanism was proposed according to LC–MS analysis of degradation products of CR. The new imprinted nanoparticles showed high catalytic activity at ambient conditions without light illumination and additional chemicals, and therefore, it can be potentially applied to the rapid, “green” and low-cost degradation of CR in industrial printing and dyeing wastewater

  10. Colloidal crystal templated molecular imprinted polymer for the detection of 2-butoxyethanol in water contaminated by hydraulic fracturing.

    Science.gov (United States)

    Dai, Jingjing; Vu, Danh; Nagel, Susan; Lin, Chung-Ho; Fidalgo de Cortalezzi, Maria

    2017-12-06

    The authors describe a molecularly imprinted polymer (MIP) that enables detection of 2-butoxyethanol (2BE), a pollutant associated with hydraulic fracturing contamination. Detection is based on a combination of a colloidal crystal templating and a molecular imprinting. The MIPs are shown to display higher binding capacity for 2BE compared to non-imprinted films (NIPs), with imprinting efficiencies of ∼ 2. The tests rely on the optical effects that are displayed by the uniformly ordered porous structure of the material. The reflectance spectra of the polymer films have characteristic Bragg peaks whose location varies with the concentration of 2BE. Peaks undergo longwave red shifts up to 50 nm on exposure of the MIP to 2BE in concentrations in the range from 1 ppb to 100 ppm. This allows for quantitative estimates of the 2BE concentrations present in aqueous solutions. The material is intended for use in the early detection of contamination at hydraulic fracturing sites. Graphical abstract Molecularly imprinted polymers (MIPs) sensor with the sensing ability on reflectance spectra responding to the presence of 2-butoxyethanol (2BE) for early detection of hydraulic fracking contamination.

  11. Synthesis and assessment of imprinted polymers for the separation of f elements. Application to liquid chromatography

    International Nuclear Information System (INIS)

    Vigneau, Olivier

    2002-01-01

    Within the frame of the CEA's SPIN programme which aims at separate lanthanides (Ln) and actinides (An) in order to decrease the volume and activity of nuclear wastes to be stored, and after a presentation of lanthanides and actinides, of the main methods of inter-group and intra-group separation, this research thesis presents the principles and applications of the molecular print and ionic print which are then used to perform the Ln/Ln and Ln/an separation. The author discusses the choice and synthesis of selective complexing monomers which are used for the synthesis of imprinted polymers. The next chapter reports the synthesis of imprinted polymers, the assessment of their properties (selectivity and extraction power) in Ln/Ln competitive extraction in a batch reactor, and the optimization of synthesis conditions. Then, the author reports the assessment of properties of imprinted material in terms of ability to perform an inter-group Am 241 / Eu 152 separation in a batch reactor. The last part addresses Ln/Ln separation by High Performance Liquid Chromatography by using synthesised imprinted polymers as steady phase [fr

  12. Collinearity, convergence and cancelling infrared divergences

    International Nuclear Information System (INIS)

    Lavelle, Martin; McMullan, David

    2006-01-01

    The Lee-Nauenberg theorem is a fundamental quantum mechanical result which provides the standard theoretical response to the problem of collinear and infrared divergences. Its argument, that the divergences due to massless charged particles can be removed by summing over degenerate states, has been successfully applied to systems with final state degeneracies such as LEP processes. If there are massless particles in both the initial and final states, as will be the case at the LHC, the theorem requires the incorporation of disconnected diagrams which produce connected interference effects at the level of the cross-section. However, this aspect of the theory has never been fully tested in the calculation of a cross-section. We show through explicit examples that in such cases the theorem introduces a divergent series of diagrams and hence fails to cancel the infrared divergences. It is also demonstrated that the widespread practice of treating soft infrared divergences by the Bloch-Nordsieck method and handling collinear divergences by the Lee-Nauenberg method is not consistent in such cases

  13. Prenatal imprinting by environmental toxicants: really an important issue?

    Directory of Open Access Journals (Sweden)

    Karl Ernst v. Mühlendahl

    2015-06-01

    Full Text Available Prenatal imprinting of sexual behaviour and of other traits by environmental toxicants has been one important topic in the ongoing discussions in environmental medicine. This review of the literature shows that, so far, concrete data are sparse and, in part, contradictory.

  14. Shape recognition of microbial cells by colloidal cell imprints

    NARCIS (Netherlands)

    Borovicka, J.; Stoyanov, S.D.; Paunov, V.N.

    2013-01-01

    We have engineered a class of colloids which can recognize the shape and size of targeted microbial cells and selectively bind to their surfaces. These imprinted colloid particles, which we called "colloid antibodies", were fabricated by partial fragmentation of silica shells obtained by templating

  15. A proteomic study of memory after imprinting in the domestic chick

    Directory of Open Access Journals (Sweden)

    Maia eMeparishvili

    2015-11-01

    Full Text Available The intermediate and medial mesopallium (IMM of the domestic chick forebrain has previously been shown to be a memory system for visual imprinting. Learning-related changes occur in certain plasma membrane and mitochondrial proteins in the IMM. Two-dimensional gel electrophoresis/mass spectrometry has been employed to identify more comprehensively learning-related expression of proteins in the membrane-mitochondrial fraction of the IMM 24 h after training. We inquired whether amounts of these proteins in the IMM and a control region (posterior pole of the nidopallium, PPN are correlated with a behavioural estimate of memory for the imprinting stimulus. Learning-related increases in amounts of the following proteins were found in the left IMM, but not the right IMM or the left or right PPN: (i membrane cognin; (ii a protein resembling the P32 subunit of splicing factor SF2; (iii voltage-dependent anionic channel-1; (iv dynamin-1; (v heterogeneous nuclear ribonucleoprotein A2/B1. Learning-related increases in some transcription factors involved in mitochondrial biogenesis were also found, without significant change in mitochondrial DNA copy number. The results indicate that the molecular processes involved in learning and memory underlying imprinting include protein stabilization, increased mRNA trafficking, synaptic vesicle recycling and specific changes in the mitochondrial proteome.

  16. The putative imprinted locus D15S9 within the common deletion region for the Prader-Willi and Angelman syndromes encodes two overlapping mRNAs transcribed from opposite strands

    Energy Technology Data Exchange (ETDEWEB)

    Glenn, C.C.; Driscoll, D.J. [Univ. of Florida, Gainesville, FL (United States); Saitoh, S. [Case Western Reserve Univ., Cleveland, OH (United States)] [and others

    1994-09-01

    Prader-Willi syndrome is typically caused by a deletion of paternal 15q11-q13, or maternal uniparental disomy (UPD) of chromosome 15, while Angelman syndrome is caused by a maternal deletion or paternal UPD of the same region. Therefore, these two clinically distinct neurobehavioral syndromes result from differential expression of imprinted genes within 15q11-q13. A 3.1 kb cDNA, DN34, from the D15S9 locus within 15q11-q13 was isolated from a human fetal brain library. We showed previously that DN34 probe detects a DNA methylation imprint and therefore may represent a candidate imprinted gene. Isolation of genomic clones and DNA sequencing demonstrated that the gene segment encoding the partial cDNA DN34 was split by a 2 kb intron, but did not encode a substantial open reading frame (ORF). Preliminary analysis of expression by RT-PCR suggests that this gene is expressed in fetal but not in tested tissue types from the adult, and thus its imprinting status has not been possible to assess at present. Surprisingly, we found an ORF on the antisense strand of the DN34 cDNA. This ORF encodes a putative polypeptide of 505 amino acid residues containing a RING C{sub 3}HC{sub 4} zinc-finger motif and other features of nuclear proteins. Subsequent characterization of this gene, ZNF127, and a mouse homolog, demonstrated expression of 3.2 kb transcript from all tested fetal and adult tissues. Transcripts initiate from within a CpG-island, shown to be differentially methylated on parental alleles in the human. Interestingly, functional imprinting of the mouse homolog was subsequently demonstrated in an F{sub 1} cross by analyzing a VNTR polymorphism in the mRNA. The ZNF127 gene is intronless, has significant overlap with the DN34 gene on the antisense strand, and a 1 kb 3{prime} end within the 2 kb DN34 intron.

  17. Extraction of tributyltin by magnetic molecularly imprinted polymers

    International Nuclear Information System (INIS)

    Zhu, Shanshan; Pan, Daodong; Hu, Futao; Gan, Ning; Li, Yi; Cao, Yuting; Wu, Dazhen; Yang, Ting

    2013-01-01

    We have prepared core-shell magnetic molecularly imprinted polymer nanoparticles for recognition and extraction of tributyl tin (TBT). The use of particles strongly improves the imprinting effect and leads to fast adsorption kinetics and high adsorption capacities. The functional monomer acrylamide was grafted to the surface of Fe 3 O 4 nanospheres in two steps, and MIP layers were then formed on the surface by creating a MIP layer on the surface consisting of poly(ethyleneglycol dimethacrylate) with a TBT template. The particles were characterized in terms of morphological, magnetic, adsorption, and recognition properties. We then have developed a method for the extraction of TBT from spiked mussel (Mytilidae), and its determination by liquid chromatography-tandem mass spectrometry. The method has a limit of detection of 1.0 ng g −1 (n = 5) of TBT, with a linear response between 5.0 and 1,000 ng g −1 . The proposed method was successfully applied to the determination of trace TBT in marine food samples with recoveries in the range of 78.3–95.6 %. (author)

  18. Molecularly imprinted hydrogels as functional active packaging materials.

    Science.gov (United States)

    Benito-Peña, Elena; González-Vallejo, Victoria; Rico-Yuste, Alberto; Barbosa-Pereira, Letricia; Cruz, José Manuel; Bilbao, Ainhoa; Alvarez-Lorenzo, Carmen; Moreno-Bondi, María Cruz

    2016-01-01

    This paper describes the synthesis of novel molecularly imprinted hydrogels (MIHs) for the natural antioxidant ferulic acid (FA), and their application as packaging materials to prevent lipid oxidation of butter. A library of MIHs was synthesized using a synthetic surrogate of FA, 3-(4-hydroxy-3-methoxyphenyl)propionic acid (HFA), as template molecule, ethyleneglycol dimethacrylate (EDMA) as cross-linker, and 1-allylpiperazine (1-ALPP) or 2-(dimethylamino)ethyl methacrylate (DMAEMA), in combination with 2-hydroxyethyl methacrylate (HEMA) as functional monomers, at different molar concentrations. The DMAEMA/HEMA-based MIHs showed the greatest FA loading capacity, while the 1-ALLP/HEMA-based polymers exhibited the highest imprinting effect. During cold storage, FA-loaded MIHs protected butter from oxidation and led to TBARs values that were approximately half those of butter stored without protection and 25% less than those recorded for butter covered with hydrogels without FA, potentially extending the shelf life of butter. Active packaging is a new field of application for MIHs with great potential in the food industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Contractile response of bovine lateral saphenous vein to ergotamine tartrate exposed to different concentrations of molecularly imprinted polymers

    Science.gov (United States)

    Ergot alkaloids, in their active isomeric form, affect animal health and performance and adsorbents are used to mitigate toxicities by reducing bioavailability. Adsorbents with high specificity (molecularly imprinted: MIP and non-imprinted: NIP polymers) adsorb ergot alkaloids in vitro, but require ...

  20. Development and characterization of an electrochemical sensor for furosemide detection based on electropolymerized molecularly imprinted polymer.

    Science.gov (United States)

    Kor, Kamalodin; Zarei, Kobra

    2016-01-01

    A novel electrochemical sensor based on a molecularly imprinted polymer, poly(o-phenylenediamine) (PoPD), has been developed for selective and sensitive detection of furosemide. The sensor was prepared by incorporating of furosemide as template molecules during the electropolymerization of o-phenylenediamine on a gold electrode. To develop the molecularly imprinted polymer (MIP), the template molecules were removed from the modified electrode's surface by washing it with 0.25 mol L(-1) NaOH solution. The imprinted layer was characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and atomic force microscopy (AFM). The sensor's preparation conditions including furosemide concentration, the number of CV cycles in the electropolymerization process, extraction solution of the template from the imprinted film, the incubation time and the pH level were optimized. The incubation of the MIP-modified electrode, with respect to furosemide concentration, resulted in a suppression of the K4[Fe(CN)6] oxidation process. Under the optimal experimental conditions, the response of the imprinted sensor was linear in the range of 1.0×10(-7)-7.0×10(-6) mol L(-1) of furosemide. The detection limit was obtained as 7.0×10(-8) mol L(-1) for furosemide by using this sensor. The sensor was successfully used to determine the furosemide amount in the tablet and in human urine samples with satisfactory results. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Planar self-aligned imprint lithography for coplanar plasmonic nanostructures fabrication

    KAUST Repository

    Wan, Weiwei; Lin, Liang; Xu, Yelong; Guo, Xu; Liu, Xiaoping; Ge, Haixiong; Lu, Minghui; Cui, Bo; Chen, Yanfeng

    2014-01-01

    manufacturing remains a challenge due to the high cost of achieving mechanical alignment precision. Although self-aligned imprint lithography was developed to avoid the need of alignment for the vertical layered structures, it has limited usage

  2. Nonparametric Information Geometry: From Divergence Function to Referential-Representational Biduality on Statistical Manifolds

    Directory of Open Access Journals (Sweden)

    Jun Zhang

    2013-12-01

    Full Text Available Divergence functions are the non-symmetric “distance” on the manifold, Μθ, of parametric probability density functions over a measure space, (Χ,μ. Classical information geometry prescribes, on Μθ: (i a Riemannian metric given by the Fisher information; (ii a pair of dual connections (giving rise to the family of α-connections that preserve the metric under parallel transport by their joint actions; and (iii a family of divergence functions ( α-divergence defined on Μθ x Μθ, which induce the metric and the dual connections. Here, we construct an extension of this differential geometric structure from Μθ (that of parametric probability density functions to the manifold, Μ, of non-parametric functions on X, removing the positivity and normalization constraints. The generalized Fisher information and α-connections on M are induced by an α-parameterized family of divergence functions, reflecting the fundamental convex inequality associated with any smooth and strictly convex function. The infinite-dimensional manifold, M, has zero curvature for all these α-connections; hence, the generally non-zero curvature of M can be interpreted as arising from an embedding of Μθ into Μ. Furthermore, when a parametric model (after a monotonic scaling forms an affine submanifold, its natural and expectation parameters form biorthogonal coordinates, and such a submanifold is dually flat for α = ± 1, generalizing the results of Amari’s α-embedding. The present analysis illuminates two different types of duality in information geometry, one concerning the referential status of a point (measurable function expressed in the divergence function (“referential duality” and the other concerning its representation under an arbitrary monotone scaling (“representational duality”.

  3. Semantic search during divergent thinking.

    Science.gov (United States)

    Hass, Richard W

    2017-09-01

    Divergent thinking, as a method of examining creative cognition, has not been adequately analyzed in the context of modern cognitive theories. This article casts divergent thinking responding in the context of theories of memory search. First, it was argued that divergent thinking tasks are similar to semantic fluency tasks, but are more constrained, and less well structured. Next, response time distributions from 54 participants were analyzed for temporal and semantic clustering. Participants responded to two prompts from the alternative uses test: uses for a brick and uses for a bottle, for two minutes each. Participants' cumulative response curves were negatively accelerating, in line with theories of search of associative memory. However, results of analyses of semantic and temporal clustering suggested that clustering is less evident in alternative uses responding compared to semantic fluency tasks. This suggests either that divergent thinking responding does not involve an exhaustive search through a clustered memory trace, but rather that the process is more exploratory, yielding fewer overall responses that tend to drift away from close associates of the divergent thinking prompt. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Highly selective coextraction of rhodamine B and dibenzyl phthalate based on high-density dual-template imprinted shells on silica microparticles.

    Science.gov (United States)

    Long, Zerong; Xu, Weiwei; Peng, Yumei; Lu, Yi; Luo, Qian; Qiu, Hongdeng

    2017-01-01

    A simple one-pot approach based on molecularly imprinted polymer shells dispersed on the surface of silica for simultaneous determination of rhodamine B and dibenzyl phthalate (DBzP) has been developed. Highly dense molecularly imprinted polymer shells were formed in the mixture of acetonitrile and toluene by the copolymerization of methacrylic acid and ethylene glycol dimethacrylate, as well as two templates, rhodamine B and dibenzyl phthalate, directed by the vinyl end groups functional monolayer at surface silica microspheres after 3-methacryloxypropyl trimethoxysilane modification. The obtained imprinted polymer shells showed large average pore diameter (102.5 nm) and about 100 nm shell thickness. The imprinted particles also showed high imprinting factor (α RhB = 3.52 and α DBzP = 3.94), rapid binding kinetics, and excellent selective affinity capacity for rhodamine B and dibenzyl phthalate containing another three competitors in mixed solution. Moreover, the imprinted particles coupled with ultra high performance liquid chromatography was successfully applied to simultaneous analysis of rhodamine B and dibenzyl phthalate in two spiked beverage samples with average recoveries in the range of 88.0-93.0% for rhodamine B and 84.0-92.0% for dibenzyl phthalate with the relative standard deviation lower than 5.1%. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Electrochemical detection of cardiac biomarker myoglobin using polyphenol as imprinted polymer receptor.

    Science.gov (United States)

    Ribeiro, J A; Pereira, C M; Silva, A F; Sales, M Goreti F

    2017-08-15

    An electrochemical biosensor was developed by merging the features of Molecular Imprinting technique and Screen-Printed Electrode (SPE) for the simple and fast screening of cardiac biomarker myoglobin (Myo) in point-of-care (POC). The MIP artificial receptor for Myo was prepared by electrooxidative polymerization of phenol (Ph) on a AuSPE in the presence of Myo as template molecule. The choice of the most effective protein extraction procedure from the various extraction methods tested (mildly acidic/basic solutions, pure/mixed organic solvents, solutions containing surfactants and enzymatic digestion methods), and the optimization of the thickness of the polymer film was carefully undertaken in order to improve binding characteristics of Myo to the imprinted polymer receptor and increase the sensitivity of the MIP biosensor. The film thickness was optimized by adjusting scan rate and the number of cycles during cyclic voltammetric electropolymerization of Ph. The thickness of the polyphenol nanocoating of only few nanometres (∼4.4 nm), and similar to the protein diameter, brought in significant improvements in terms of sensor sensitivity. The binding affinity of MIP receptor film was estimated by fitting the experimental data to Freundlich isotherm and a ∼8 fold increase in the binding affinity of Myo to the imprinted polymer (K F = 0.119 ± 0.002 ng -1  mL) when compared to the non-imprinted polymer (K F  = 0.015 ± 0.002 ng -1  mL) which demonstrated excellent (re)binding affinity for the imprinted protein. The incubation of the Myo MIP receptor modified electrode with increasing concentration of protein (from 0.001 ng mL -1 to 100 μg mL -1 ) resulted in a decrease of the ferro/ferricyanide redox current. LODs of 2.1 and 14 pg mL -1 were obtained from calibration curves built in neutral buffer and diluted artificial serum, respectively, using SWV technique, enabling the detection of the protein biomarker at clinically relevant levels. The

  6. Selection of imprinted nanoparticles by affinity chromatography.

    Science.gov (United States)

    Guerreiro, António R; Chianella, Iva; Piletska, Elena; Whitcombe, Michael J; Piletsky, Sergey A

    2009-04-15

    Soluble molecularly imprinted nanoparticles were synthesised via iniferter initiated polymerisation and separated by size via gel permeation chromatography. Subsequent fractionation of these particles by affinity chromatography allowed the separation of high affinity fractions from the mixture of nanoparticles. Fractions selected this way possess affinity similar to that of natural antibodies (K(d) 6.6x10(-8)) M and were also able to discriminate between related functional analogues of the template.

  7. Imprinting: When Early Life Memories Make Food Smell Bad.

    Science.gov (United States)

    Rayes, Diego; Alkema, Mark J

    2016-05-09

    A recent study has found that pathogen exposure early in the life of the nematode Caenorhabditis elegans leads to a long-lasting aversion that requires distinct sets of neurons for the formation and retrieval of the imprinted memory. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Chiral recognition of proteins having L-histidine residues on the surface with lanthanide ion complex incorporated-molecularly imprinted fluorescent nanoparticles

    International Nuclear Information System (INIS)

    Uzun, Lokman; Uzek, Recep; Şenel, Serap; Say, Ridvan; Denizli, Adil

    2013-01-01

    In this study, lanthanide ion complex incorporated molecularly imprinted fluorescent nanoparticles were synthesized. A combination of three novel approaches was applied for the purpose. First, lanthanide ions [Terbium(III)] were complexed with N-methacryloyl-L-histidine (MAH), polymerizable derivative of L-histidine amino acid, in order to incorporate the complex directly into the polymeric backbone. At the second stage, L-histidine molecules imprinted nanoparticles were utilized instead of whole protein imprinting in order to avoid whole drawbacks such as fragility, complexity, denaturation tendency, and conformation dependency. At the third stage following the first two steps mentioned above, imprinted L-histidine was coordinated with cupric ions [Cu(II)] to conduct the study under mild conditions. Then, molecularly imprinted fluorescent nanoparticles synthesized were used for L-histidine adsorption from aqueous solution to optimize conditions for adsorption and fluorimetric detection. Finally, usability of nanoparticles was investigated for chiral biorecognition using stereoisomer, D-histidine, racemic mixture, D,L-histidine, proteins with surface L-histidine residue, lysozyme, cytochrome C, or without ribonuclease A. The results revealed that the proposed polymerization strategy could make significant contribution to the solution of chronic problems of fluorescent component introduction into polymers. Additionally, the fluorescent nanoparticles reported here could be used for selective separation and fluorescent monitoring purposes. Highlights: • Lanthanide ion complex incorporated molecularly imprinted fluorescent nanoparticles • Direct incorporation of the fluorescent complex into polymeric backbone. • Imprinting by assistance of cupric ion coordination into nanoparticles • Evaluation of the chiral biorecognition ability of nanoparticles • Simultaneous selective separation and fluorescent monitoring

  9. Selective Dispersive Solid Phase Extraction of Ser-traline Using Surface Molecularly Imprinted Polymer Grafted on SiO2/Graphene Oxide

    Directory of Open Access Journals (Sweden)

    Faezeh Khalilian

    2017-01-01

    Full Text Available A surface molecularly imprinted dispersive solid phase extraction coupled with liquid chromatography–ultraviolet detection is proposed as a selective and fast clean-up technique for the determination of sertraline in biological sample. Surface sertraline-molecular imprinted polymer was grafted and synthesized on the SiO2/graphene oxide surface. Firstly SiO2 was coated on synthesized graphene oxide sheet using sol-gel technique. Prior to polymerization, the vinyl group was incorporated on to the surface of SiO2/graphene oxide to direct selective polymerization on the surface. Methacrylic acid, ethylene glycol dimethacrylate and ethanol were used as monomer, cross-linker and progen, respectively. Non-imprinted polymer was also prepared for comparing purposes. The properties of the molecular imprinted polymer were characterized using field emission-scanning electron microscopy and Fourier transform infrared spectroscopy methods. The surface molecular imprinted polymer was utilized as an adsorbent of dispersive solid phase extraction for separation and preconcentration of sertraline. The effects of the different parameters influencing the extraction efficiency, such as sample pH were investigated and optimized. The specificity of the molecular imprinted polymer over the non-imprinted polymer was examined in absence and presence of competitive drugs. Sertraline calibration curve showed linearity in the ranges 1–500 µg L-1. The limits of detection and quantification under optimized conditions were obtained 0.2 and 0.5 µg L-1. The within-day and between-day relative standard deviations (n=3 were 4.3 and 7.1%, respectively. Furthermore, the relative recoveries for spiked biological samples were above 92%.

  10. Chiral recognition of proteins having L-histidine residues on the surface with lanthanide ion complex incorporated-molecularly imprinted fluorescent nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Uzun, Lokman, E-mail: lokman@hacettepe.edu.tr [Hacettepe University, Department of Chemistry, 06381, Ankara (Turkey); Uzek, Recep; Şenel, Serap [Hacettepe University, Department of Chemistry, 06381, Ankara (Turkey); Say, Ridvan [Anadolu University, Department of Chemistry, 26470, Eskisehir (Turkey); Denizli, Adil [Hacettepe University, Department of Chemistry, 06381, Ankara (Turkey)

    2013-08-01

    In this study, lanthanide ion complex incorporated molecularly imprinted fluorescent nanoparticles were synthesized. A combination of three novel approaches was applied for the purpose. First, lanthanide ions [Terbium(III)] were complexed with N-methacryloyl-L-histidine (MAH), polymerizable derivative of L-histidine amino acid, in order to incorporate the complex directly into the polymeric backbone. At the second stage, L-histidine molecules imprinted nanoparticles were utilized instead of whole protein imprinting in order to avoid whole drawbacks such as fragility, complexity, denaturation tendency, and conformation dependency. At the third stage following the first two steps mentioned above, imprinted L-histidine was coordinated with cupric ions [Cu(II)] to conduct the study under mild conditions. Then, molecularly imprinted fluorescent nanoparticles synthesized were used for L-histidine adsorption from aqueous solution to optimize conditions for adsorption and fluorimetric detection. Finally, usability of nanoparticles was investigated for chiral biorecognition using stereoisomer, D-histidine, racemic mixture, D,L-histidine, proteins with surface L-histidine residue, lysozyme, cytochrome C, or without ribonuclease A. The results revealed that the proposed polymerization strategy could make significant contribution to the solution of chronic problems of fluorescent component introduction into polymers. Additionally, the fluorescent nanoparticles reported here could be used for selective separation and fluorescent monitoring purposes. Highlights: • Lanthanide ion complex incorporated molecularly imprinted fluorescent nanoparticles • Direct incorporation of the fluorescent complex into polymeric backbone. • Imprinting by assistance of cupric ion coordination into nanoparticles • Evaluation of the chiral biorecognition ability of nanoparticles • Simultaneous selective separation and fluorescent monitoring.

  11. Linear energy divergences in Coulomb gauge QCD

    OpenAIRE

    Andrasi, A.

    2011-01-01

    The structure of linear energy divergences is analysed on the example of one graph to 3-loop order. Such dangerous divergences do cancel when all graphs are added, but next to leading divergences do not cancel out.

  12. Selective extraction of dimethoate from cucumber samples by use of molecularly imprinted microspheres

    Directory of Open Access Journals (Sweden)

    Jiao-Jiao Du

    2015-06-01

    Full Text Available Molecularly imprinted polymers for dimethoate recognition were synthesized by the precipitation polymerization technique using methyl methacrylate (MMA as the functional monomer and ethylene glycol dimethacrylate (EGDMA as the cross-linker. The morphology, adsorption and recognition properties were investigated by scanning electron microscopy (SEM, static adsorption test, and competitive adsorption test. To obtain the best selectivity and binding performance, the synthesis and adsorption conditions of MIPs were optimized through single factor experiments. Under the optimized conditions, the resultant polymers exhibited uniform size, satisfactory binding capacity and significant selectivity. Furthermore, the imprinted polymers were successfully applied as a specific solid-phase extractants combined with high performance liquid chromatography (HPLC for determination of dimethoate residues in the cucumber samples. The average recoveries of three spiked samples ranged from 78.5% to 87.9% with the relative standard deviations (RSDs less than 4.4% and the limit of detection (LOD obtained for dimethoate as low as 2.3 μg/mL. Keywords: Molecularly imprinted polymer, Precipitation polymerization, Dimethoate, Cucumber, HPLC

  13. Fabrication of high-aspect-ratio microstructures using dielectrophoresis-electrocapillary force-driven UV-imprinting

    International Nuclear Information System (INIS)

    Li, Xiangming; Shao, Jinyou; Tian, Hongmiao; Ding, Yucheng; Li, Xiangmeng

    2011-01-01

    We propose a novel method for fabricating high-aspect-ratio micro-/nano-structures by dielectrophoresis-electrocapillary force (DEP-ECF)-driven UV-imprinting. The force of DEP-ECF, acting on an air–liquid interface and an air–liquid–solid three-phase contact line, is generated by applying voltage between an electrically conductive mold and a substrate, and tends to pull the dielectric liquid (a UV-curable pre-polymer) into the mold micro-cavities. The existence of DEP-ECF is explained theoretically and demonstrated experimentally by the electrically induced reduction of the contact angle. Furthermore, DEP-ECF is proven to play a critical role in forcing the polymer to fill into the mold cavities by the real-time observation of the dynamic filling process. Using the DEP-ECF-driven UV-imprinting process, high-aspect-ratio polymer micro-/nano-structures (more than 10:1) are fabricated with high consistency. This patterning method can overcome the drawbacks of the mechanically induced mold deformation and position shift in conventional imprinting lithography and maximize the pattern uniformity which is usually poor in capillary force lithography

  14. Otx2 expression and implications for olfactory imprinting in the anemonefish, Amphiprion percula

    Directory of Open Access Journals (Sweden)

    Heather D. Veilleux

    2013-07-01

    The otx2 gene encodes a transcription factor (OTX2 essential in the formation of the brain and sensory systems. Specifically, OTX2-positive cells are associated with axons in the olfactory system of mice and otx2 is upregulated in odour-exposed zebrafish, indicating a possible role in olfactory imprinting. In this study, otx2 was used as a candidate gene to investigate the molecular mechanisms of olfactory imprinting to settlement cues in the coral reef anemonefish, Amphiprion percula. The A. percula otx2 (Ap-otx2 gene was elucidated, validated, and its expression tested in settlement-stage A. percula by exposing them to behaviourally relevant olfactory settlement cues in the first 24 hours post-hatching, or daily throughout the larval phase. In-situ hybridisation revealed expression of Ap-otx2 throughout the olfactory epithelium with increased transcript staining in odour-exposed settlement-stage larval fish compared to no-odour controls, in all scenarios. This suggests that Ap-otx2 may be involved in olfactory imprinting to behaviourally relevant settlement odours in A. percula.

  15. Guises and disguises of quadratic divergences

    Energy Technology Data Exchange (ETDEWEB)

    Cherchiglia, A.L., E-mail: adriano@fisica.ufmg.br [Departamento de Física, ICEx, Universidade Federal de Minas Gerais, P.O. BOX 702, 30.161-970, Belo Horizonte, MG (Brazil); Vieira, A.R., E-mail: arvieira@fisica.ufmg.br [Departamento de Física, ICEx, Universidade Federal de Minas Gerais, P.O. BOX 702, 30.161-970, Belo Horizonte, MG (Brazil); Hiller, Brigitte, E-mail: brigitte@teor.fis.uc.pt [Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, 3004-516 Coimbra (Portugal); Baêta Scarpelli, A.P., E-mail: scarpelli.apbs@dpf.gov.br [Setor Técnico-Científico, Departamento de Polícia Federal, Rua Hugo D’Antola, 95 - Lapa, São Paulo (Brazil); Sampaio, Marcos, E-mail: marcos.sampaio@durham.ac.uk [Departamento de Física, ICEx, Universidade Federal de Minas Gerais, P.O. BOX 702, 30.161-970, Belo Horizonte, MG (Brazil); Centre for Particle Theory, Department of Mathematical Sciences, Durham University, South Road Durham DH1 3LE (United Kingdom)

    2014-12-15

    In this contribution, we present a new perspective on the control of quadratic divergences in quantum field theory, in general, and in the Higgs naturalness problem, in particular. Our discussion is essentially based on an approach where UV divergences are parameterized, after being reduced to basic divergent integrals (BDI) in one internal momentum, as functions of a cutoff and a renormalization group scale λ. We illustrate our proposal with well-known examples, such as the gluon vacuum self energy of QCD and the Higgs decay in two photons within this approach. We also discuss frameworks in effective low-energy QCD models, where quadratic divergences are indeed fundamental.

  16. Reactive Imprint Lithography: Combined Topographical Patterning and Chemical Surface Functionalization of Polystyrene-block-poly(tert-butyl acrylate) Films

    NARCIS (Netherlands)

    Duvigneau, Joost; Cornelissen, Stijn; Bardajı´Valls, Nuria; Schönherr, Holger; Vancso, Gyula J.

    2009-01-01

    Here, reactive imprint lithography (RIL) is introduced as a new, one-step lithographic tool for the fabrication of large-area topographically patterned, chemically activated polymer platforms. Films of polystyrene-block-poly(tert-butyl acrylate) (PS-b-PtBA) are imprinted with PDMS master stamps at

  17. Understanding the relationships between molecule structure and imprinting effect of two acetyl-nitrogen heterocyclic compounds.

    Science.gov (United States)

    Wang, Jian; Dong, Xiao; Xue, Min; Dong, Xuemin; Xu, Zhibin; Meng, Zihui; Luo, Jun

    2016-06-01

    The molecularly imprinted polymers (MIPs) for two structural analogs, 1,3,5-triacetyl-1,3,5-triazacyclohexane (TRAT) and 1,3,5,7-tetraacetyl-1,3,5,7-tetraazacyclooctane (TAT), have been synthesized respectively under the same conditions. The TAT-MIP showed excellent imprinting effect, whereas the TRAT-MIP did not. To understand the different imprinting effects of the MIPs prepared from these two templates, the geometric structures and energetic properties of complexes formed around TAT and TRAT were studied computationally. The results indicate that in liquid phase, for the complexes formed with TAT and its nearest neighbor molecules, the magnitude of the binding energy increases with the number of surrounding TAT, methacrylic acid, and acetonitrile (ACT), whereas for the cases of TRAT, the magnitude of the binding energy increases with the number of surrounding TRAT and trimethylolpropane trimethacrylate. The studied systems form stronger and thus more stable networks encapsulating TAT than with TRAT. ACT may also play an important role in the polymerization phase in stabilizing the shapes of the cavities that TATs reside in. We propose these as the major factors that affect the different imprinting effects of the two MIPs. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  18. Ducklings imprint on the relational concept of "same or different".

    Science.gov (United States)

    Martinho, Antone; Kacelnik, Alex

    2016-07-15

    The ability to identify and retain logical relations between stimuli and apply them to novel stimuli is known as relational concept learning. This has been demonstrated in a few animal species after extensive reinforcement training, and it reveals the brain's ability to deal with abstract properties. Here we describe relational concept learning in newborn ducklings without reinforced training. Newly hatched domesticated mallards that were briefly exposed to a pair of objects that were either the same or different in shape or color later preferred to follow pairs of new objects exhibiting the imprinted relation. Thus, even in a seemingly rigid and very rapid form of learning such as filial imprinting, the brain operates with abstract conceptual reasoning, a faculty often assumed to be reserved to highly intelligent organisms. Copyright © 2016, American Association for the Advancement of Science.

  19. Magnetic molecularly imprinted polymer for aspirin recognition and controlled release

    Energy Technology Data Exchange (ETDEWEB)

    Kan Xianwen; Geng Zhirong; Zhao Yao; Wang Zhilin; Zhu Junjie [State Key Laboratory of Coordination Chemistry, MOE Key Lab of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, 22 Hankou Road, Nanjing 210093 (China)], E-mail: wangzl@nju.edu.cn, E-mail: jjzhu@nju.edu.cn

    2009-04-22

    Core-shell structural magnetic molecularly imprinted polymers (magnetic MIPs) with combined properties of molecular recognition and controlled release were prepared and characterized. Magnetic MIPs were synthesized by the co-polymerization of methacrylic acid (MAA) and trimethylolpropane trimethacrylate (TRIM) around aspirin (ASP) at the surface of double-bond-functionalized Fe{sub 3}O{sub 4} nanoparticles in chloroform. The obtained spherical magnetic MIPs with diameters of about 500 nm had obvious superparamagnetism and could be separated quickly by an external magnetic field. Binding experiments were carried out to evaluate the properties of magnetic MIPs and magnetic non-molecularly imprinted polymers (magnetic NIPs). The results demonstrated that the magnetic MIPs had high adsorption capacity and selectivity to ASP. Moreover, release profiles and release rate of ASP from the ASP-loaded magnetic MIPs indicated that the magnetic MIPs also had potential applications in drug controlled release.

  20. Magnetic molecularly imprinted polymer for aspirin recognition and controlled release

    International Nuclear Information System (INIS)

    Kan Xianwen; Geng Zhirong; Zhao Yao; Wang Zhilin; Zhu Junjie

    2009-01-01

    Core-shell structural magnetic molecularly imprinted polymers (magnetic MIPs) with combined properties of molecular recognition and controlled release were prepared and characterized. Magnetic MIPs were synthesized by the co-polymerization of methacrylic acid (MAA) and trimethylolpropane trimethacrylate (TRIM) around aspirin (ASP) at the surface of double-bond-functionalized Fe 3 O 4 nanoparticles in chloroform. The obtained spherical magnetic MIPs with diameters of about 500 nm had obvious superparamagnetism and could be separated quickly by an external magnetic field. Binding experiments were carried out to evaluate the properties of magnetic MIPs and magnetic non-molecularly imprinted polymers (magnetic NIPs). The results demonstrated that the magnetic MIPs had high adsorption capacity and selectivity to ASP. Moreover, release profiles and release rate of ASP from the ASP-loaded magnetic MIPs indicated that the magnetic MIPs also had potential applications in drug controlled release.

  1. Computational Design of Molecularly Imprinted Polymers

    Science.gov (United States)

    Subrahmanyam, Sreenath; Piletsky, Sergey A.

    Artificial receptors have been in use for several decades as sensor elements, in affinity separation, and as models for investigation of molecular recognition. Although there have been numerous publications on the use of molecular modeling in characterization of their affinity and selectivity, very few attempts have been made on the application of molecular modeling in computational design of synthetic receptors. This chapter discusses recent successes in the use of computational design for the development of one particular branch of synthetic receptors - molecularly imprinted polymers.

  2. Molecularly imprinted macroporous monoliths for solid-phase extraction: Effect of pore size and column length on recognition properties.

    Science.gov (United States)

    Vlakh, E G; Stepanova, M A; Korneeva, Yu M; Tennikova, T B

    2016-09-01

    The series of macroporous monolithic molecularly imprinted monoliths differed by pore size, column length (volume) and amount of template used for imprinting was synthesized using methacrylic acid and glycerol dimethacrylate as co-monomers and antibiotic ciprofloxacin as a template. The prepared monoliths were characterized regarding to their permeability, pore size, porosity, and resistance to the flow of a mobile phase. The surface morphology was also analyzed. The slight dependence of imprinting factor on flow rate, as well as its independence on pore size of macroporous molecularly imprinted monolithic media was observed. The column obtained at different conditions exhibited different affinity of ciprofloxacin to the imprinted sites that was characterized with Kdiss values in the range of 10(-5)-10(-4)M. The solid-phase extraction of ciprofloxacin from such biological liquids as human blood serum, human urine and cow milk serum was performed using the developed monolithic columns. In all cases, the extraction was found to be 95.0-98.6%. Additionally, the comparison of extraction of three fluoroqinolone analogues, e.g. ciprofloxacin, levofloxacin and moxifloxacin, from human blood plasma was carried out. Contrary to ciprofloxacin extracted with more than 95%, this parameter did not exceed 40% for its analogues. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Rapid degradation of Congo red by molecularly imprinted polypyrrole-coated magnetic TiO{sub 2} nanoparticles in dark at ambient conditions

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Shoutai; Hu, Xiaolei; Liu, Hualong; Wang, Qiang; He, Chiyang, E-mail: chiyanghe@hotmail.com

    2015-08-30

    Highlights: • Molecularly imprinted polypyrrole-coated magnetic TiO{sub 2} catalyst was prepared. • The catalyst degraded Congo red rapidly in dark at ambient conditions. • Degradation mechanism was proposed according to LC–MS analysis. • The catalyst can be easily recycled by a magnet. - Abstract: A novel molecularly imprinted polymer (MIP)-coated magnetic TiO{sub 2} nanocomposite was prepared, using methyl orange (MO) as the dummy template and pyrrole as functional monomer, for degradation of Congo red (CR). The nanocomposite was characterized by Fourier transform infrared spectroscopy, thermo-gravimetric analysis, X-ray diffraction, transmission electron microscopy, and vibrating sample magnetometer. The imprinting efficiency of the imprinted nanoparticles was investigated by static binding test, and their degradation ability toward CR was also studied. Moreover, the effects of pH, temperature, dissolved oxygen and oscillation rate on degradation rate of CR were investigated. Results showed that the imprinted nanocomposite had higher adsorption ability for MO compared with the non-imprinted one. Moreover, it could degrade CR rapidly in dark at room temperature and atmospheric pressure and could be recycled easily by a magnet with a good reusability. A degradation mechanism was proposed according to LC–MS analysis of degradation products of CR. The new imprinted nanoparticles showed high catalytic activity at ambient conditions without light illumination and additional chemicals, and therefore, it can be potentially applied to the rapid, “green” and low-cost degradation of CR in industrial printing and dyeing wastewater.

  4. Computer recognition of divergences in Feynman graphs

    Energy Technology Data Exchange (ETDEWEB)

    Calmet, J

    1973-05-01

    The program described recognizes whether or not a graph is divergent. It determines the kind of the divergences found: vacuum polarizations, electron self energies and vertices. it does not consider infrared divergences. The programming language used is REDUCE. A LISP version is also available. The nature of the divergences and their counter terms was extensively used to write down this program, therefore it is limited to the case of quantum electrodynamics. (auth)

  5. Diagnostic accuracy of touch imprint cytology for head and neck malignancies: a useful intra-operative tool in resource limited countries.

    Science.gov (United States)

    Naveed, Hania; Abid, Mariam; Hashmi, Atif Ali; Edhi, Muhammad Muzammamil; Sheikh, Ahmareen Khalid; Mudassir, Ghazala; Khan, Amir

    2017-01-01

    Intraoperative consultation is an important tool for the evaluation of the upper aerodigestive tract (UAT) malignancies. Although frozen section analysis is a preferred method of intra-operative consultation, however in resource limited countries like Pakistan, this facility is not available in most institutes; therefore, we aimed to evaluate the diagnostic accuracy of touch imprint cytology for UAT malignancies using histopathology of the same tissue as gold standard. The study involved 70 cases of UAT lesions operated during the study period. Intraoperatively, after obtaining the fresh biopsy specimen and prior to placing them in fixative, each specimen was imprinted on 4-6 glass slides, fixed immediately in 95% alcohol and stained with Hematoxylin and Eosin stain. After completion of the cytological procedure, the surgical biopsy specimen was processed. The slides of both touch Imprint cytology and histopathology were examined by two consultant histopathologists. The result of touch imprint cytology showed that touch imprint cytology was diagnostic in 68 cases (97.1%), 55 (78.6%) being malignant, 2 cases (2.9%) were suspicious for malignancy, 11 cases (15.7%) were negative for malignancy while 2 cases (2.9%) were false negative. Amongst the 70 cases, 55 cases (78.6%) were malignant showing squamous cell carcinoma in 49 cases (70%), adenoid cystic carcinoma in 2 cases (2.9%), non-Hodgkin lymphoma 2 cases (2.9%), Mucoepidermoid carcinoma 1 case (1.4%), spindle cell sarcoma in 1 case (1.4%). Two cases (2.9%) were suspicious of malignancy showing atypical squamoid cells on touch imprint cytology, while 13 cases (18.6%) were negative for malignancy, which also included 2 false negative cases. The overall diagnostic accuracy of touch imprint cytology came out to be 96.7% with a sensitivity and specificity of 96 and 100%, respectively while PPV and NPV of touch imprint cytology was found to be 100 and 84%, respectively. Our experience in this study has demonstrated

  6. Water-compatible 'aspartame'-imprinted polymer grafted on silica surface for selective recognition in aqueous solution.

    Science.gov (United States)

    Singh, Meenakshi; Kumar, Abhishek; Tarannum, Nazia

    2013-05-01

    Molecularly imprinted polymers selective for aspartame have been prepared using N-[2-ammonium-ethyl-piperazinium) maleimidopropane sulfonate copolymer bearing zwitterionic centres along the backbone via a surface-confined grafting procedure. Aspartame, a dipeptide, is commonly used as an artificial sweetener. Polymerisation on the surface was propagated by means of Michael addition reaction on amino-grafted silica surface. Electrostatic interactions along with complementary H-bonding and other hydrophobic interactions inducing additional synergetic effect between the template (aspartame) and the imprinted surface led to the formation of imprinted sites. The MIP was able to selectively and specifically take up aspartame from aqueous solution and certain pharmaceutical samples quantitatively. Hence, a facile, specific and selective technique using surface-grafted specific molecular contours developed for specific and selective uptake of aspartame in the presence of various interferrants, in different kinds of matrices is presented.

  7. Genetic divergence of common bean cultivars.

    Science.gov (United States)

    Veloso, J S; Silva, W; Pinheiro, L R; Dos Santos, J B; Fonseca, N S; Euzebio, M P

    2015-09-22

    The aim of this study was to evaluate genetic divergence in the 'Carioca' (beige with brown stripes) common bean cultivar used by different institutions and in 16 other common bean cultivars used in the Rede Cooperativa de Pesquisa de Feijão (Cooperative Network of Common Bean Research), by using simple sequence repeats associated with agronomic traits that are highly distributed in the common bean genome. We evaluated 22 polymorphic loci using bulks containing DNA from 30 plants. There was genetic divergence among the Carioca cultivar provided by the institutions. Nevertheless, there was lower divergence among them than among the other cultivars. The cultivar used by Instituto Agronômico do Paraná was the most divergent in relation to the Carioca samples. The least divergence was observed among the samples used by Universidade Federal de Lavras and by Embrapa Arroz e Feijão. Of all the cultivars, 'CNFP 10104' and 'BRSMG Realce' showed the greatest dissimilarity. The cultivars were separated in two groups of greatest similarity using the Structure software. Genetic variation among cultivars was greater than the variation within or between the groups formed. This fact, together with the high estimate of heterozygosity observed and the genetic divergence of the samples of the Carioca cultivar in relation to the original provided by Instituto Agronômico de Campinas, indicates a mixture of cultivars. The high divergence among cultivars provides potential for the utilization of this genetic variability in plant breeding.

  8. A DNMT3A2-HDAC2 Complex Is Essential for Genomic Imprinting and Genome Integrity in Mouse Oocytes

    Directory of Open Access Journals (Sweden)

    Pengpeng Ma

    2015-11-01

    Full Text Available Maternal genomic imprints are established during oogenesis. Histone deacetylases (HDACs 1 and 2 are required for oocyte development in mouse, but their role in genomic imprinting is unknown. We find that Hdac1:Hdac2−/− double-mutant growing oocytes exhibit global DNA hypomethylation and fail to establish imprinting marks for Igf2r, Peg3, and Srnpn. Global hypomethylation correlates with increased retrotransposon expression and double-strand DNA breaks. Nuclear-associated DNMT3A2 is reduced in double-mutant oocytes, and injecting these oocytes with Hdac2 partially restores DNMT3A2 nuclear staining. DNMT3A2 co-immunoprecipitates with HDAC2 in mouse embryonic stem cells. Partial loss of nuclear DNMT3A2 and HDAC2 occurs in Sin3a−/− oocytes, which exhibit decreased DNA methylation of imprinting control regions for Igf2r and Srnpn, but not Peg3. These results suggest seminal roles of HDAC1/2 in establishing maternal genomic imprints and maintaining genomic integrity in oocytes mediated in part through a SIN3A complex that interacts with DNMT3A2.

  9. Creation, transport and detection of imprinted magnetic solitons stabilized by spin-polarized current

    Science.gov (United States)

    Loreto, R. P.; Moura-Melo, W. A.; Pereira, A. R.; Zhang, X.; Zhou, Y.; Ezawa, M.; de Araujo, C. I. L.

    2018-06-01

    With the recent proposition of skyrmion utilization in racetrack memories at room temperature, skyrmionics has become a very attractive field. However, for the stability of skyrmions, it is essential to incorporate the Dzyaloshinskii-Moriya interaction (DMI) and the out-of-plane magnetic field into the system. In this work, we explore a system without these interactions. First, we propose a controlled way for the creation of magnetic skyrmions and skyrmioniums imprinted on a ferromagnetic nanotrack via a nanopatterned nanodisk with the magnetic vortex state. Then we investigate the detachment of the imprinted spin textures from the underneath of the nanodisk, as well as its transport by the spin-transfer torque imposed by spin-polarized current pulses applied in the nanotrack. A prominent feature of the moving imprinted spin texture is that its topological number Q is oscillating around the averaged value of Q = 0 as if it is a resonant state between the skyrmions with Q = ± 1 and the bubble with Q = 0 . We may call it a resonant magnetic soliton (RMS). A RMS moves along a straight line since it is free from the skyrmion Hall effect. In our studied device, the same electrodes are employed to realize the imprinted spin texture detachment and its transport. In addition, we have investigated the interaction between the RMS and a magnetic tunnel junction sensor, where the passing of the RMS in the nanotrack can be well detected. Our results would be useful for the development of novel spintronic devices based on moveable spin textures.

  10. Molecularly imprinted polymer for selective extraction of malachite green from seawater and seafood coupled with high-performance liquid chromatographic determination.

    Science.gov (United States)

    Lian, Ziru; Wang, Jiangtao

    2012-12-01

    In this paper, a highly selective sample cleanup procedure combining molecular imprinting technique (MIT) and solid-phase extraction (SPE) was developed for the isolation of malachite green in seawater and seafood samples. The molecularly imprinted polymer (MIP) was prepared using malachite green as the template molecule, methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linking monomer. The imprinted polymer and non-imprinted polymer were characterized by scanning electron microscope and static adsorption experiments. The MIP showed a high adsorption capacity and was used as selective sorbent for the SPE of malachite green. An off-line molecularly imprinted solid-phase extraction (MISPE) method followed by high-performance liquid chromatography with diodearray detection for the analysis of malachite green in seawater and seafood samples was also established. Finally, five samples were determined. The results showed that malachite green concentration in one seawater sample was at 1.30 μg L⁻¹ and the RSD (n=3) was 4.15%. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  11. Properties of classical and quantum Jensen-Shannon divergence

    NARCIS (Netherlands)

    J. Briët (Jop); P. Harremoës (Peter)

    2009-01-01

    htmlabstractJensen-Shannon divergence (JD) is a symmetrized and smoothed version of the most important divergence measure of information theory, Kullback divergence. As opposed to Kullback divergence it determines in a very direct way a metric; indeed, it is the square of a metric. We consider a

  12. Selective isolation of gonyautoxins 1,4 from the dinoflagellate Alexandrium minutum based on molecularly imprinted solid-phase extraction.

    Science.gov (United States)

    Lian, Ziru; Wang, Jiangtao

    2017-09-15

    Gonyautoxins 1,4 (GTX1,4) from Alexandrium minutum samples were isolated selectively and recognized specifically by an innovative and effective extraction procedure based on molecular imprinting technology. Novel molecularly imprinted polymer microspheres (MIPMs) were prepared by double-templated imprinting strategy using caffeine and pentoxifylline as dummy templates. The synthesized polymers displayed good affinity to GTX1,4 and were applied as sorbents. Further, an off-line molecularly imprinted solid-phase extraction (MISPE) protocol was optimized and an effective approach based on the MISPE coupled with HPLC-FLD was developed for selective isolation of GTX1,4 from the cultured A. minutum samples. The separation method showed good extraction efficiency (73.2-81.5%) for GTX1,4 and efficient removal of interferences matrices was also achieved after the MISPE process for the microalgal samples. The outcome demonstrated the superiority and great potential of the MISPE procedure for direct separation of GTX1,4 from marine microalgal extracts. Copyright © 2017. Published by Elsevier Ltd.

  13. On the relationship between field cycling and imprint in ferroelectric Hf0.5Zr0.5O2

    Science.gov (United States)

    Fengler, F. P. G.; Hoffmann, M.; Slesazeck, S.; Mikolajick, T.; Schroeder, U.

    2018-05-01

    Manifold research has been done to understand the detailed mechanisms behind the performance instabilities of ferroelectric capacitors based on hafnia. The wake-up together with the imprint might be the most controversially discussed phenomena so far. Among crystallographic phase change contributions and oxygen vacancy diffusion, electron trapping as the origin has been discussed recently. In this publication, we provide evidence that the imprint is indeed caused by electron trapping into deep states at oxygen vacancies. This impedes the ferroelectric switching and causes a shift of the hysteresis. Moreover, we show that the wake-up mechanism can be caused by a local imprint of the domains in the pristine state by the very same root cause. The various domain orientations together with an electron trapping can cause a constriction of the hysteresis and an internal bias field in the pristine state. Additionally, we show that this local imprint can even cause almost anti-ferroelectric like behavior in ferroelectric films.

  14. PEG-Stabilized Core–Shell Surface-Imprinted Nanoparticles

    OpenAIRE

    Moczko, Ewa; Guerreiro, Antonio; Piletska, Elena; Piletsky, Sergey

    2013-01-01

    Here we present a simple technique to produce target-specific molecularly imprinted polymeric nanoparticles (MIP NPs) and their surface modification in order to prevent the aggregation process that is ever-present in most nanomaterial suspensions/dispersions. Specifically, we studied the influence of surface modification of MIP NPs with polymerizable poly(ethylene glycol) on their degree of stability in water, in phosphate buffer, and in the presence of serum proteins. Grafting a polymer shel...

  15. Neurodevelopmental consequences in offspring of mothers with preeclampsia during pregnancy: underlying biological mechanism via imprinting genes.

    Science.gov (United States)

    Nomura, Yoko; John, Rosalind M; Janssen, Anna Bugge; Davey, Charles; Finik, Jackie; Buthmann, Jessica; Glover, Vivette; Lambertini, Luca

    2017-06-01

    Preeclampsia is known to be a leading cause of mortality and morbidity among mothers and their infants. Approximately 3-8% of all pregnancies in the US are complicated by preeclampsia and another 5-7% by hypertensive symptoms. However, less is known about its long-term influence on infant neurobehavioral development. The current review attempts to demonstrate new evidence for imprinting gene dysregulation caused by hypertension, which may explain the link between maternal preeclampsia and neurocognitive dysregulation in offspring. Pub Med and Web of Science databases were searched using the terms "preeclampsia," "gestational hypertension," "imprinting genes," "imprinting dysregulation," and "epigenetic modification," in order to review the evidence demonstrating associations between preeclampsia and suboptimal child neurodevelopment, and suggest dysregulation of placental genomic imprinting as a potential underlying mechanism. The high mortality and morbidity among mothers and fetuses due to preeclampsia is well known, but there is little research on the long-term biological consequences of preeclampsia and resulting hypoxia on the fetal/child neurodevelopment. In the past decade, accumulating evidence from studies that transcend disciplinary boundaries have begun to show that imprinted genes expressed in the placenta might hold clues for a link between preeclampsia and impaired cognitive neurodevelopment. A sudden onset of maternal hypertension detected by the placenta may result in misguided biological programming of the fetus via changes in the epigenome, resulting in suboptimal infant development. Furthering our understanding of the molecular and cellular mechanisms through which neurodevelopmental trajectories of the fetus/infant are affected by preeclampsia and hypertension will represent an important first step toward preventing adverse neurodevelopment in infants.

  16. Fine-Needle Aspiration, Touch Imprint, and Crush Preparation Cytology for Diagnosing Thyroid Malignancies in Thyroid Nodules.

    Science.gov (United States)

    Ahmadinejad, Mojtaba; Aliepour, Asghar; Anbari, Khatereh; Kaviani, Mojhgan; Ganjizadeh, Hasan; Nadri, Sedigheh; Foroutani, Niloufar; Meysami, Masoumeh; Almasi, Vahid

    2015-12-01

    Several methods are used to evaluate the thyroid nodules. The aim of this study was to determine the sensitivity, specificity, false positive and negative rates, positive predictive value (PPV), and negative predictive value (NPV) of touch imprint, crush preparation, and fine-needle aspiration (FNA) methods. This cross-sectional study was done in Shohada-ye Ashayer University Hospital in Khorramabad. All the patients who underwent thyroid surgery due to thyroid nodules in this hospital between March and September 2011 were evaluated. The thyroid nodules of all the patients were evaluated by touch imprint, crush preparation, FNA, and permanent pathology methods. Finally, the results of the first three methods were compared with the result of permanent pathology method. The mean age of 104 patients who underwent thyroid surgery was 42.6 ± 11.9 years old. Based on permanent pathology, touch imprint, crush preparation, and FNA methods, 15.3, 6.25, 6.25, and 4.4 % of thyroid nodules were malignant, respectively. Sensitivity, specificity, false positive rate, false negative rate, PPV, and NPV of FNA biopsy were 62.5, 100, 0, 37.5, 100, and 95.3 %, respectively. Also, sensitivity, specificity, false positive rate, false negative rate, PPV, and NPV of touch imprint and crush preparation were equal and were 80, 100, 0, 20, 100, and 96.7 %, respectively. Using touch imprint and crush preparation in evaluation of thyroid nodules for rapid evaluation of these nodules in operating rooms seems to be logical, and it can prevent further surgeries.

  17. Lake Roosevelt Fisheries Monitoring Program; Artificial Imprinting and Smoltification in Juvenile Kokanee Salmon Implications for Operating Lake Roosevelt Kokanee Salmon Hatcheries; 1994 Supplement Report.

    Energy Technology Data Exchange (ETDEWEB)

    Tilson, Mary Beth; Scholz, Allan T.; White, Ronald J. (Eastern Washington University, Upper Columbia United Tribes Fisheries Research Center, Cheney, WA)

    1995-02-01

    At the kokanee salmon hatcheries on Lake Roosevelt, constructed as partial mitigation for effects from Grand Coulee Dam, adult returns have been poor. The reason may be in the imprinting or in the smoltification. A study was initiated in 1992 to determine if there was a critical period for thyroxine induced alfactory imprinting in kokanee salmon; experiments were conducted on imprinting to morpholine and phenethyl alcohol. Other results showed that chemical imprinting coincided with elevated thyroxine levels in 1991 kokanee exposed to synthetic chemicals in 1992. In this report, imprinting experiments were repeated; results showed that imprinting occurred concomitant with elevated thyroxine levels in 1991 kokanee exposed to synthetic chemicals in 1992 and tested in 1994 as age 3 spawners. Imprinting also occurred at the same time as thyroxine peaks in 1992 kokanee exposed to synthetic chemicals in 1993 and tested as age 2 spawners. In both groups fish that had the highest whole body thyroxine content (swimup stage) also had the highest percentage of fish that were attracted to their exposure odor in behavioral tests. So, kokanee salmon imprinted to chemical cues during two sensitive periods during development, at the alevin/swimup and smolt stages. A field test was conducted in Lake Roosevelt on coded wire tagged fish. Smoltification experiments were conducted from 1992 to 1994. Recommendations are made for the Lake Roosevelt kokanee hatcheries.

  18. Molecularly imprinted polymer for selective extraction of malachite green from seawater and seafood coupled with high-performance liquid chromatographic determination

    International Nuclear Information System (INIS)

    Lian Ziru; Wang Jiangtao

    2012-01-01

    Highlights: ► The malachite green molecularly imprinted polymer (MG-MIP) was prepared. ► The characteristics and regeneration property of MIP were studied. ► An off-line method for MG was developed using MIP as solid-pha