561 research outputs found

    Implementing graphene and other materials into Cash in transit (CIT) boxes to enhance security

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    Graphene was said to adhere to substrates due to strong pi-pi forces; therefore the ability to stick to polypropylene was tested. (Koenig et al., 2011) The ability of Graphene to adhere to most materials is true. However, these forces are only ultra-strong for mechanically exfoliated pristine Graphene. When Graphene is contaminated by molecules, the adhesion with the substrate is diminished. As the process of liquid exfoliated of Graphene consists of many areas of contamination, the Graphene electrodes are another part of this study. Many methods of producing Graphene electrodes are being investigated: film growth and etch, large scale conductive Graphene inks and reduction of graphene oxide. The study moved towards Silver inks as it provide far better materials specifications, for the application as a security tamper sensor for Spinnaker International. This study also goes into great depth of the electronics, which were designed to provide better sensing abilities using less power. A power consumption naturally goes up with any material other than solid copper.Innovate U

    A Pharmacognostic review of Liquorice: Pharmacological actions, Current uses and Future prospects

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    Herbs used as medicines are one of the widely adopted treatment alternatives which is in effect since ancient times. Herbal drugs are of great importance to the population because of its ease of availability and the relief of having no side effects. Majority of the herbal drugs are possessed to have more than one pharmacological effect. One such classic example of well-known herbal drug is Liquorice which is commonly known as Sweet Wood or Mulethi. Liquorice is available in dried root or rhizome form and it is widely used as natural sweetener, expectorant and as a hepato-protectant. The herb is widely grown in Baluchistan, Spain and in certain parts of Himalayan region of India. There are various active chemical compounds of Liquorice which include saponins and flavonoids. The pharmacological actions of this drug are attributed to its major active chemical compound named Glycyrrhizin. Liquorice is also found to have specific anti-viral activity against certain viral cells. The current article focusses on the pharmacognostic review of Liquorice and its uses. The multiple pharmacological effects of this drug and the future prospects of using Liquorice in developing formulations have been discussed in detail

    Regulation of Meiotic Cohesion and Chromosome Core Morphogenesis during Pachytene in Drosophila Oocytes

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    During meiosis, cohesion between sister chromatids is required for normal levels of homologous recombination, maintenance of chiasmata and accurate chromosome segregation during both divisions. In Drosophila, null mutations in the ord gene abolish meiotic cohesion, although how ORD protein promotes cohesion has remained elusive. We show that SMC subunits of the cohesin complex colocalize with ORD at centromeres of ovarian germ-line cells. In addition, cohesin SMCs and ORD are visible along the length of meiotic chromosomes during pachytene and remain associated with chromosome cores following DNase I digestion. In flies lacking ORD activity, cohesin SMCs fail to accumulate at oocyte centromeres. Although SMC1 and SMC3 localization along chromosome cores appears normal during early pachytene in ord mutant oocytes, the cores disassemble as meiosis progresses. These data suggest that cohesin loading and/or accumulation at centromeres versus arms is under differential control during Drosophila meiosis. Our experiments also reveal that the alpha-kleisin C(2)M is required for the assembly of chromosome cores during pachytene but is not involved in recruitment of cohesin SMCs to the centromeres. We present a model for how chromosome cores are assembled during Drosophila meiosis and the role of ORD in meiotic cohesion, chromosome core maintenance and homologous recombination

    Pluripotent stem cell-derived hepatocyte-like cells

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    Liver disease is an important clinical problem, impacting over 30 million Americans and over 600 million people worldwide. It is the 12th leading cause of death in the United States and the 16th worldwide. Due to a paucity of donor organs, several thousand Americans die yearly while waiting for liver transplantation. Unfortunately, alternative tissue sources such as fetal hepatocytes and hepatic cell lines are unreliable, difficult to reproduce, and do not fully recapitulate hepatocyte phenotype and functions. As a consequence, alternative cell sources that do not have these limitations have been sought. Human embryonic stem (hES) cell- and induced pluripotent stem (iPS) cell-derived hepatocyte-like cells may enable cell based therapeutics, the study of the mechanisms of human disease and human development, and provide a platform for screening the efficacy and toxicity of pharmaceuticals. iPS cells can be differentiated in a step-wise fashion with high efficiency and reproducibility into hepatocyte-like cells that exhibit morphologic and phenotypic characteristics of hepatocytes. In addition, iPS-derived hepatocyte-like cells (iHLCs) possess some functional hepatic activity as they secrete urea, alpha-1-antitrypsin, and albumin. However, the combined phenotypic and functional traits exhibited by iHLCs resemble a relatively immature hepatic phenotype that more closely resembles that of fetal hepatocytes rather than adult hepatocytes. Specifically, iHLCs express fetal markers such as alpha-fetoprotein and lack key mature hepatocyte functions, as reflected by drastically reduced activity (~ 0.1%) of important detoxification enzymes (i.e. CYP2A6, CYP3A4). These key differences between iHLCs and primary adult human hepatocytes have limited the use of stem cells as a renewable source of functional adult hepatocytes for in vitro and in vivo applications. Unfortunately, the developmental pathways that control hepatocyte maturation from a fetal into an adult hepatocyte are poorly understood, which has hampered the field in its efforts to induce further maturation of iPS-derived hepatic lineage cells. This review analyzes recent developments in the derivation of hepatocyte-like cells, and proposes important points to consider and assays to perform during their characterization. In the future, we envision that iHLCs will be used as in vitro models of human disease, and in the longer term, provide an alternative cell source for drug testing and clinical therapy.National Institutes of Health (U.S.) (Roadmap for Medical Research Grant 1 R01 DK085713-01))American Gastroenterological Association (Research Scholar Award

    Bounded Search for de Novo Identification of Degenerate Cis-Regulatory Elements

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    The identification of statistically overrepresented sequences in the upstream regions of coregulated genes should theoretically permit the identification of potential cis-regulatory elements. However, in practice many cis-regulatory elements are highly degenerate, precluding the use of an exhaustive word-counting strategy for their identification. While numerous methods exist for inferring base distributions using a position weight matrix, recent studies suggest that the independence assumptions inherent in the model, as well as the inability to reach a global optimum, limit this approach

    A Novel Ensemble Learning Method for de Novo Computational Identification of DNA Binding Sites

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    Despite the diversity of motif representations and search algorithms, the de novo computational identification of transcription factor binding sites remains constrained by the limited accuracy of existing algorithms and the need for user-specified input parameters that describe the motif being sought.ResultsWe present a novel ensemble learning method, SCOPE, that is based on the assumption that transcription factor binding sites belong to one of three broad classes of motifs: non-degenerate, degenerate and gapped motifs. SCOPE employs a unified scoring metric to combine the results from three motif finding algorithms each aimed at the discovery of one of these classes of motifs. We found that SCOPE\u27s performance on 78 experimentally characterized regulons from four species was a substantial and statistically significant improvement over that of its component algorithms. SCOPE outperformed a broad range of existing motif discovery algorithms on the same dataset by a statistically significant margin

    Microenvironmental regulation of the sinusoidal endothelial cell phenotype in vitro

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    Author Manuscript: 2010 June 23.Liver sinusoidal endothelial cells (LSECs) differ, both structurally and functionally, from endothelial cells (ECs) lining blood vessels of other tissues. For example, in contrast to other ECs, LSECs possess fenestrations, have low detectable levels of platelet endothelial cell adhesion molecule 1 expression, and in rat tissue, they distinctively express a cell surface marker recognized by the SE-1 antibody. These unique phenotypic characteristics seen in hepatic tissue are lost over time upon culture in vitro; therefore, this study sought to systematically examine the effects of microenvironmental stimuli—namely, extracellular matrix and neighboring cells, on the LSEC phenotype in vitro. In probing the role of the underlying extracellular matrix, we identified collagen I and collagen III as well as mixtures of collagen I/collagen IV/fibronectin as having a positive effect on LSEC survival. Furthermore, using a stable hepatocellular model (hepatocyte–fibroblast) we were able to prolong the expression of both SE-1 and phenotypic functions of LSEC such as factor VIII activity and AcLOL uptake in cocultured LSECs through the production of short-range paracrine signals. In the course of these experiments, we identified the antigen recognized by SE-1 as CD32b. Conclusion: Collectively, this study has identified several microenvironmental regulators of liver sinusoidal endothelial cells that prolong their phenotypic functions for up to 2 weeks in culture, enabling the development of better in vitro models of liver physiology and disease

    Quantum dots to monitor RNAi delivery and improve gene silencing

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    A critical issue in using RNA interference for identifying genotype/phenotype correlations is the uniformity of gene silencing within a cell population. Variations in transfection efficiency, delivery-induced cytotoxicity and ‘off target’ effects at high siRNA concentrations can confound the interpretation of functional studies. To address this problem, we have developed a novel method of monitoring siRNA delivery that combines unmodified siRNA with seminconductor quantum dots (QDs) as multi color biological probes. We co-transfected siRNA with QDs using standard transfection techniques, thereby leveraging the photostable fluorescent nanoparticles to track delivery of nucleic acid, sort cells by degree of transfection and purify homogenously-silenced subpopulations. Compared to alternative RNAi tracking methods (co-delivery of reporter plasmids and end-labeling the siRNA), QDs exhibit superior photostability and tunable optical properties for an extensive selection of non-overlapping colors. Thus this simple, modular system can be extended toward multiplexed gene knockdown studies, as demonstrated in a two color proof-of-principle study with two biological targets. When the method was applied to investigate the functional role of T-cadherin (T-cad) in cell–cell communication, a subpopulation of highly silenced cells obtained by QD labeling was required to observe significant downstream effects of gene knockdown

    Psychometric Properties of the Young Children's Participation and Environment Measure

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    AbstractObjectiveTo evaluate the psychometric properties of the newly developed Young Children's Participation and Environment Measure (YC-PEM).DesignCross-sectional study.SettingData were collected online and by telephone.ParticipantsConvenience and snowball sampling methods were used to survey caregivers of children (N=395, comprising children with [n=93] and without [n=302] developmental disabilities and delays) between the ages of 0 and 5 years (mean age ± SD, 35.33±20.29mo) and residing in North America.InterventionsNot applicable.Main Outcome MeasuresThe YC-PEM includes 3 participation scales and 1 environment scale. Each scale is assessed across 3 settings: home, daycare/preschool, and community. Data were analyzed to derive estimates of internal consistency, test-retest reliability, and construct validity.ResultsInternal consistency ranged from .68 to .96 and .92 to .96 for the participation and environment scales, respectively. Test-retest reliability (2–4wk) ranged from .31 to .93 for participation scales and from .91 to .94 for the environment scale. One of 3 participation scales and the environment scale demonstrated significant group differences by disability status across all 3 settings, and all 4 scales discriminated between disability groups for the daycare/preschool setting. The participation scales exhibited small to moderate positive associations with functional performance scores.ConclusionsResults lend initial support for the use of the YC-PEM in research to assess the participation of young children with disabilities and delays in terms of (1) home, daycare/preschool, and community participation patterns; (2) perceived environmental supports and barriers to participation; and (3) activity-specific parent strategies to promote participation
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