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Sample records for activatable cell penetrating

  1. Single-cell resolution imaging of retinal ganglion cell apoptosis in vivo using a cell-penetrating caspase-activatable peptide probe.

    Xudong Qiu

    Full Text Available Peptide probes for imaging retinal ganglion cell (RGC apoptosis consist of a cell-penetrating peptide targeting moiety and a fluorophore-quencher pair flanking an effector caspase consensus sequence. Using ex vivo fluorescence imaging, we previously validated the capacity of these probes to identify apoptotic RGCs in cell culture and in an in vivo rat model of N-methyl- D-aspartate (NMDA-induced neurotoxicity. Herein, using TcapQ488, a new probe designed and synthesized for compatibility with clinically-relevant imaging instruments, and real time imaging of a live rat RGC degeneration model, we fully characterized time- and dose-dependent probe activation, signal-to-noise ratios, and probe safety profiles in vivo. Adult rats received intravitreal injections of four NMDA concentrations followed by varying TcapQ488 doses. Fluorescence fundus imaging was performed sequentially in vivo using a confocal scanning laser ophthalmoscope and individual RGCs displaying activated probe were counted and analyzed. Rats also underwent electroretinography following intravitreal injection of probe. In vivo fluorescence fundus imaging revealed distinct single-cell probe activation as an indicator of RGC apoptosis induced by intravitreal NMDA injection that corresponded to the identical cells observed in retinal flat mounts of the same eye. Peak activation of probe in vivo was detected 12 hours post probe injection. Detectable fluorescent RGCs increased with increasing NMDA concentration; sensitivity of detection generally increased with increasing TcapQ488 dose until saturating at 0.387 nmol. Electroretinography following intravitreal injections of TcapQ488 showed no significant difference compared with control injections. We optimized the signal-to-noise ratio of a caspase-activatable cell penetrating peptide probe for quantitative non-invasive detection of RGC apoptosis in vivo. Full characterization of probe performance in this setting creates an important in

  2. Polypeptide micelles with dual pH activatable dyes for sensing cells and cancer imaging

    Gong, Ping; Yang, Yueting; Yi, Huqiang; Fang, Shengtao; Zhang, Pengfei; Sheng, Zonghai; Gao, Guanhui; Gao, Duyang; Cai, Lintao

    2014-04-01

    pH is an important control parameter for maintenance of cell viability and tissue functions. pH monitoring provides valuable information on cell metabolic processes and the living environment. In this study, we prepared dual pH-sensitive, fluorescent dye-loaded polypeptide nanoparticles (DPNs) for ratiometric sensing of pH changes in living cells. DPNs contain two types of dyes: N-(rhodamine B) lactam cystamine (RBLC), an acid activatable fluorescent dye with increased fluorescence in an acidic environment, and fluorescein isothiocyanate (FITC), a base activatable fluorescent dye with enhanced fluorescence in an alkaline environment. Hence, DPNs exhibited a dual response signal with strong red fluorescence and weak green fluorescence under acidic conditions; in contrast, they showed strong green fluorescence and almost no red fluorescence under alkaline and neutral conditions. The favorable inverse pH responses of the two fluorescent dyes resulted in ratiometric pH determination for DPNs with an optimized pH-sensitive range of pH 4.5-7.5. Quantitative analysis of the intracellular pH of intact MCF-7 cells has been successfully demonstrated with our nanosensor. Moreover, single acid activatable fluorescent dye doped polypeptide nanoparticles that only contained RBLC can distinguish tumor tissue from normal tissue by monitoring the acidic extracellular environment.pH is an important control parameter for maintenance of cell viability and tissue functions. pH monitoring provides valuable information on cell metabolic processes and the living environment. In this study, we prepared dual pH-sensitive, fluorescent dye-loaded polypeptide nanoparticles (DPNs) for ratiometric sensing of pH changes in living cells. DPNs contain two types of dyes: N-(rhodamine B) lactam cystamine (RBLC), an acid activatable fluorescent dye with increased fluorescence in an acidic environment, and fluorescein isothiocyanate (FITC), a base activatable fluorescent dye with enhanced fluorescence

  3. Fluorescence in vivo imaging of live tumor cells with pH-activatable targeted probes via receptor-mediated endocytosis

    Asanuma, Daisuke; Urano, Yasuteru; Nagano, Tetsuo; Hama, Yukihiro; Koyama, Yoshinori; Kobayashi, Hisataka

    2009-02-01

    One goal of molecular imaging is to establish a widely applicable technique for specific detection of tumors with minimal background. Here, we achieve specific in vivo tumor visualization with a newly-designed "activatable" targeted fluorescence probe. This agent is activated after cellular internalization by sensing the pH change in the lysosome. Novel acidic pH-activatable probes based on the BODIPY fluorophore were synthesized, and then conjugated to a cancer-targeting monoclonal antibody, Trastuzumab, or galactosyl serum albumin (GSA). As proof of concept, ex and in vivo imaging of two different tumor mouse models was performed: HER2-overexpressed lung metastasis tumor with Trastuzumab-pH probe conjugates and lectin-overexpressed i.p. disseminated tumor with GSA-pH probe conjugates. These pH-activatable targeted probes were highly specific for tumors with minimal background signal. Because the acidic pH in lysosomes is maintained by the energy-consuming proton pump, only viable cancer cells were successfully visualized. Furthermore, this strategy was also applied to fluorescence endoscopy in tumor mouse models, resulting in specific visualization of tumors as small as submillimeter in size that could hardly detected by naked eyes because of their poor contrast against normal tissues. The design concept can be widely adapted to cancer-specific cell-surface-targeting molecules that result in cellular internalization.

  4. Activated thrombin-activatable fibrinolysis inhibitor (TAFIa) attenuates breast cancer cell metastatic behaviors through inhibition of plasminogen activation and extracellular proteolysis

    Bazzi, Zainab A.; Lanoue, Danielle; El-Youssef, Mouhanned; Romagnuolo, Rocco; Tubman, Janice; Cavallo-Medved, Dora; Porter, Lisa A.; Boffa, Michael B.

    2016-01-01

    Background Thrombin activatable fibrinolysis inhibitor (TAFI) is a plasma zymogen, which can be converted to activated TAFI (TAFIa) through proteolytic cleavage by thrombin, plasmin, and most effectively thrombin in complex with the endothelial cofactor thrombomodulin (TM). TAFIa is a carboxypeptidase that cleaves carboxyl terminal lysine and arginine residues from protein and peptide substrates, including plasminogen-binding sites on cell surface receptors. Carboxyl terminal lysine residues ...

  5. A Cell-Based Internalization and Degradation Assay with an Activatable Fluorescence-Quencher Probe as a Tool for Functional Antibody Screening.

    Li, Yan; Liu, Peter Corbett; Shen, Yang; Snavely, Marshall D; Hiraga, Kaori

    2015-08-01

    For the development of therapeutically potent anti-cancer antibody drugs, it is often important to identify antibodies that internalize into cells efficiently, rather than just binding to antigens on the cell surface. Such antibodies can mediate receptor endocytosis, resulting in receptor downregulation on the cell surface and potentially inhibiting receptor function and tumor growth. Also, efficient antibody internalization is a prerequisite for the delivery of cytotoxic drugs into target cells and is critical for the development of antibody-drug conjugates. Here we describe a novel activatable fluorescence-quencher pair to quantify the extent of antibody internalization and degradation in the target cells. In this assay, candidate antibodies were labeled with a fluorescent dye and a quencher. Fluorescence is inhibited outside and on the surface of cells, but activated upon endocytosis and degradation of the antibody. This assay enabled the development of a process for rapid characterization of candidate antibodies potentially in a high-throughput format. By employing an activatable secondary antibody, primary antibodies in purified form or in culture supernatants can be screened for internalization and degradation. Because purification of candidate antibodies is not required, this method represents a direct functional screen to identify antibodies that internalize efficiently early in the discovery process. PMID:26024945

  6. Molecular Imaging with Activatable Reporter Systems

    Gang Niu, Xiaoyuan Chen

    2012-01-01

    Full Text Available Molecular imaging is a newly emerged multiple disciplinary field that aims to visualize, characterize and quantitatively measure biological processes at cellular and molecular levels in humans and other living systems. A reporter gene is a piece of DNA encoding reporter protein, which presents as a readily measurable phenotype that can be distinguished easily from the background of endogenous protein. After being transferred into cells of organ systems (transgenes, the reporter gene can be utilized to visualize transcriptional and posttranscriptional regulation of gene expression, protein-protein interactions, or trafficking of proteins or cells in living subjects. Herein, we review previous classification of reporter genes and regroup the reporter gene based imaging as basic, inducible and activatable, based on the regulation of reporter gene transcription and post-translational modification of reporter proteins. We then focus on activatable reporters, in which the signal can be activated at the posttranslational level for visualizing protein-protein interactions, protein phosphorylation or tertiary structure changes. The applications of several types of activatable reporters will also be summarized. We conclude that activatable reporter imaging can benefit both basic biomedical research and drug development.

  7. Extending the cross-linking/mass spectrometry strategy: Facile incorporation of photo-activatable amino acids into the model protein calmodulin in Escherichia coli cells.

    Piotrowski, Christine; Ihling, Christian H; Sinz, Andrea

    2015-11-01

    Photo-induced cross-linking is a highly promising technique to investigate protein conformations and protein-protein interactions in their natural cellular environment. One strategy relies on the non-directed incorporation of diazirine-containing photo-activatable amino acids into proteins and a subsequent cross-link formation induced by UV-A irradiation. The advantage of this photo-cross-linking strategy is that it is not restricted to lysine residues and that hydrophobic regions in proteins can also be targeted, which is advantageous for investigating membrane proteins. Here, we present a simplified protocol that relies on the use of mineral salts medium without any special requirements for the incorporation of photo-methionines into proteins in Escherichia coli cells. The possibility to perform these experiments in E. coli is especially valuable as it is the major system for recombinant protein production. The method is exemplified for the Ca(2+) regulating protein calmodulin containing nine methionines, which were found to be replaced by their photo-activatable analogues. Our protocol allows the facile and stochastic incorporation of photo-methionines as the basis for conducting photo-cross-linking experiments in E. coli in an efficient manner. PMID:25726908

  8. Cell penetration to nanofibrous scaffolds

    Rampichová, Michala; Buzgo, Matej; Chvojka, J.; Prosecká, Eva; Kofroňová, Olga; Amler, Evžen

    2014-01-01

    Roč. 8, č. 1 (2014), s. 36-41. ISSN 1933-6918 Grant ostatní: GA UK(CZ) 384311; GA UK(CZ) 626012; GA UK(CZ) 270513; GA UK(CZ) 330611; GA UK(CZ) 648112; GA MZd(CZ) NT12156; GA MŠk(CZ) project IPv6 Institutional support: RVO:68378041 ; RVO:61388971 Keywords : fibrous scaffold * mesenchymal stem cell s * Forcespinning (R) Subject RIV: FP - Other Medical Disciplines Impact factor: 4.505, year: 2014

  9. Cell-penetrating peptides transport therapeutics into cells.

    Ramsey, Joshua D; Flynn, Nicholas H

    2015-10-01

    Nearly 30years ago, certain small, relatively nontoxic peptides were discovered to be capable of traversing the cell membrane. These cell-penetrating peptides, as they are now called, have been shown to not only be capable of crossing the cell membrane themselves but can also carry many different therapeutic agents into cells, including small molecules, plasmid DNA, siRNA, therapeutic proteins, viruses, imaging agents, and other various nanoparticles. Many cell-penetrating peptides have been derived from natural proteins, but several other cell-penetrating peptides have been developed that are either chimeric or completely synthetic. How cell-penetrating peptides are internalized into cells has been a topic of debate, with some peptides seemingly entering cells through an endocytic mechanism and others by directly penetrating the cell membrane. Although the entry mechanism is still not entirely understood, it seems to be dependent on the peptide type, the peptide concentration, the cargo the peptide transports, and the cell type tested. With new intracellular disease targets being discovered, cell-penetrating peptides offer an exciting approach for delivering drugs to these intracellular targets. There are hundreds of cell-penetrating peptides being studied for drug delivery, and ongoing studies are demonstrating their success both in vitro and in vivo. PMID:26210404

  10. Market penetration scenarios for fuel cell vehicles

    Thomas, C.E.; James, B.D.; Lomax, F.D. Jr. [Directed Technologies, Inc., Arlington, VA (United States)

    1997-12-31

    Fuel cell vehicles may create the first mass market for hydrogen as an energy carrier. Directed Technologies, Inc., working with the US Department of Energy hydrogen systems analysis team, has developed a time-dependent computer market penetration model. This model estimates the number of fuel cell vehicles that would be purchased over time as a function of their cost and the cost of hydrogen relative to the costs of competing vehicles and fuels. The model then calculates the return on investment for fuel cell vehicle manufacturers and hydrogen fuel suppliers. The model also projects the benefit/cost ratio for government--the ratio of societal benefits such as reduced oil consumption, reduced urban air pollution and reduced greenhouse gas emissions to the government cost for assisting the development of hydrogen energy and fuel cell vehicle technologies. The purpose of this model is to assist industry and government in choosing the best investment strategies to achieve significant return on investment and to maximize benefit/cost ratios. The model can illustrate trends and highlight the sensitivity of market penetration to various parameters such as fuel cell efficiency, cost, weight, and hydrogen cost. It can also illustrate the potential benefits of successful R and D and early demonstration projects. Results will be shown comparing the market penetration and return on investment estimates for direct hydrogen fuel cell vehicles compared to fuel cell vehicles with onboard fuel processors including methanol steam reformers and gasoline partial oxidation systems. Other alternative fueled vehicles including natural gas hybrids, direct injection diesels and hydrogen-powered internal combustion hybrid vehicles will also be analyzed.

  11. XTEN as Biological Alternative to PEGylation Allows Complete Expression of a Protease-Activatable Killin-Based Cytostatic.

    Haeckel, Akvile; Appler, Franziska; Ariza de Schellenberger, Angela; Schellenberger, Eyk

    2016-01-01

    Increased effectiveness and reduced side effects are general goals in drug research, especially important in cancer therapy. The aim of this study was to design a long-circulating, activatable cytostatic drug that is completely producible in E. coli. Crucial for this goal was the novel unstructured polypeptide XTEN, which acts like polyethylene glycol (PEG) but has many important advantages. Most importantly, it can be produced in E. coli, is less immunogenic, and is biodegradable. We tested constructs containing a fragment of Killin as cytostatic/cytotoxic element, a cell-penetrating peptide, an MMP-2 cleavage site for specific activation, and XTEN for long blood circulation and deactivation of Killin. One of three sequence variants was efficiently expressed in E. coli. As typical for XTEN, it allowed efficient purification of the E. coli lysate by a heat step (10 min 75°C) and subsequent anion exchange chromatography using XTEN as purification tag. After 24 h XTEN-Killin reduced the number of viable cells of HT-1080 tumor cell line to 3.8 ±2.0% (p<0.001) compared to untreated controls. In contrast, liver derived non-tumor cells (BRL3A) did not show significant changes in viability. Our results demonstrate the feasibility of completely producing a complex protease-activatable, potentially long-circulating cytostatic/cytotoxic prodrug in E. coli-a concept that could lead to efficient production of highly multifunctional drugs in the future. PMID:27295081

  12. Cell Penetration Properties of a Highly Efficient Mini Maurocalcine Peptide

    Michel De Waard

    2013-03-01

    Full Text Available Maurocalcine is a highly potent cell-penetrating peptide isolated from the Tunisian scorpion Maurus palmatus. Many cell-penetrating peptide analogues have been derived from the full-length maurocalcine by internal cysteine substitutions and sequence truncation. Herein we have further characterized the cell-penetrating properties of one such peptide, MCaUF1-9, whose sequence matches that of the hydrophobic face of maurocalcine. This peptide shows very favorable cell-penetration efficacy compared to Tat, penetratin or polyarginine. The peptide appears so specialized in cell penetration that it seems hard to improve by site directed mutagenesis. A comparative analysis of the efficacies of similar peptides isolated from other toxin members of the same family leads to the identification of hadrucalcin’s hydrophobic face as an even better CPP. Protonation of the histidine residue at position 6 renders the cell penetration of MCaUF1-9 pH-sensitive. Greater cell penetration at acidic pH suggests that MCaUF1-9 can be used to specifically target cancer cells in vivo where tumor masses grow in more acidic environments.

  13. Cell-penetrating peptides for drug delivery across membrane barriers

    Foged, Camilla; Nielsen, Hanne Moerck

    2008-01-01

    -penetrating peptides as transmembrane drug delivery agents, according to the recent literature, and discusses critical issues and future challenges in relation to fully understanding the fundamental principles of the cell-penetrating peptide-mediated membrane translocation of cargoes and the exploitation of their...

  14. Cell Penetrating Peptides: How Do They Do It?

    Herce, Henry D.; Garcia, Angel E.

    2007-01-01

    Cell penetrating peptides consist of short sequences of amino acids containing a large net positive charge that are able to penetrate almost any cell, carrying with them relatively large cargoes such as proteins, oligonucleotides, and drugs. During the 10 years since their discovery, the question of how they manage to translocate across the membrane has remained unanswered. The main discussion has been centered on whether they follow an energy-independent or an energy-dependent pathway. Recen...

  15. Prediction of cell penetrating peptides by support vector machines.

    William S Sanders

    2011-07-01

    Full Text Available Cell penetrating peptides (CPPs are those peptides that can transverse cell membranes to enter cells. Once inside the cell, different CPPs can localize to different cellular components and perform different roles. Some generate pore-forming complexes resulting in the destruction of cells while others localize to various organelles. Use of machine learning methods to predict potential new CPPs will enable more rapid screening for applications such as drug delivery. We have investigated the influence of the composition of training datasets on the ability to classify peptides as cell penetrating using support vector machines (SVMs. We identified 111 known CPPs and 34 known non-penetrating peptides from the literature and commercial vendors and used several approaches to build training data sets for the classifiers. Features were calculated from the datasets using a set of basic biochemical properties combined with features from the literature determined to be relevant in the prediction of CPPs. Our results using different training datasets confirm the importance of a balanced training set with approximately equal number of positive and negative examples. The SVM based classifiers have greater classification accuracy than previously reported methods for the prediction of CPPs, and because they use primary biochemical properties of the peptides as features, these classifiers provide insight into the properties needed for cell-penetration. To confirm our SVM classifications, a subset of peptides classified as either penetrating or non-penetrating was selected for synthesis and experimental validation. Of the synthesized peptides predicted to be CPPs, 100% of these peptides were shown to be penetrating.

  16. Prediction of cell-penetrating peptides with feature selection techniques.

    Tang, Hua; Su, Zhen-Dong; Wei, Huan-Huan; Chen, Wei; Lin, Hao

    2016-08-12

    Cell-penetrating peptides are a group of peptides which can transport different types of cargo molecules such as drugs across plasma membrane and have been applied in the treatment of various diseases. Thus, the accurate prediction of cell-penetrating peptides with bioinformatics methods will accelerate the development of drug delivery systems. The study aims to develop a powerful model to accurately identify cell-penetrating peptides. At first, the peptides were translated into a set of vectors with the same dimension by using dipeptide compositions. Secondly, the Analysis of Variance-based technique was used to reduce the dimension of the vector and explore the optimized features. Finally, the support vector machine was utilized to discriminate cell-penetrating peptides from non-cell-penetrating peptides. The five-fold cross-validated results showed that our proposed method could achieve an overall prediction accuracy of 83.6%. Based on the proposed model, we constructed a free webserver called C2Pred (http://lin.uestc.edu.cn/server/C2Pred). PMID:27291150

  17. Antimicrobial and cell-penetrating properties of penetratin analogs

    Bahnsen, Jesper Søborg; Franzyk, Henrik; Sandberg-Schaal, Anne;

    2013-01-01

    Cell-penetrating peptides (CPPs) and antimicrobial peptides (AMPs) show great potential as drug delivery vectors and new antibiotic drug entities, respectively. The current study deals with the properties of a variety of peptide analogs derived from the well-known CPP penetratin as well as...

  18. Bioportide: an emergent concept of bioactive cell-penetrating peptides

    Howl, J.; Matou-Nasri, S.; West, D. C.; Farquhar, M.; Slaninová, Jiřina; Ostenson, C. G.; Zorko, M.; Ostlund, P.; Kumar, S.; Langel, U.; McKeating, J.; Jones, S.

    2012-01-01

    Roč. 69, č. 17 (2012), s. 2951-2966. ISSN 1420-682X Institutional research plan: CEZ:AV0Z40550506 Keywords : angiogenesis * bioportide * cell-penetrating peptide * second messenger * insulin secretion Subject RIV: CE - Biochemistry Impact factor: 5.615, year: 2012

  19. Cationic Cell-Penetrating Peptides Are Potent Furin Inhibitors.

    Bruno Ramos-Molina

    Full Text Available Cationic cell-penetrating peptides have been widely used to enhance the intracellular delivery of various types of cargoes, such as drugs and proteins. These reagents are chemically similar to the multi-basic peptides that are known to be potent proprotein convertase inhibitors. Here, we report that both HIV-1 TAT47-57 peptide and the Chariot reagent are micromolar inhibitors of furin activity in vitro. In agreement, HIV-1 TAT47-57 reduced HT1080 cell migration, thought to be mediated by proprotein convertases, by 25%. In addition, cyclic polyarginine peptides containing hydrophobic moieties which have been previously used as transfection reagents also exhibited potent furin inhibition in vitro and also inhibited intracellular convertases. Our finding that cationic cell-penetrating peptides exert potent effects on cellular convertase activity should be taken into account when biological effects are assessed.

  20. Strategies to stabilize cell penetrating peptides for in vivo applications.

    Fominaya, Jesús; Bravo, Jerónimo; Rebollo, Angelita

    2015-10-01

    In the era of biomedicines and engineered carrier systems, cell penetrating peptides (CPPs) have been established as a promising tool for therapeutic application. Likewise, other therapeutic peptides, successful in vivo application of CPPs will strongly depend on peptide stability, the bottleneck for this type of biodegradable molecules. In this review, the authors describe the current knowledge of the in vivo degradation for known CPPs and the different strategies available to provide a higher resistance to metabolic degradation while preserving cell penetration efficiency. Peptide stability can be improved by different means, either modifying the structure to make it unrecognizable to proteases, or preventing access of proteolytic enzymes by applying conformation restriction or shielding strategies. PMID:26448473

  1. Cell penetrating peptides: how do they do it?

    Herce, Henry D; Garcia, Angel E

    2007-12-01

    Cell penetrating peptides consist of short sequences of amino acids containing a large net positive charge that are able to penetrate almost any cell, carrying with them relatively large cargoes such as proteins, oligonucleotides, and drugs. During the 10 years since their discovery, the question of how they manage to translocate across the membrane has remained unanswered. The main discussion has been centered on whether they follow an energy-independent or an energy-dependent pathway. Recently, we have discovered the possibility of an energy-independent pathway that challenges fundamental concepts associated with protein-membrane interactions (Herce and Garcia, PNAS, 104: 20805 (2007) [1]). It involves the translocation of charged residues across the hydrophobic core of the membrane and the passive diffusion of these highly charged peptides across the membrane through the formation of aqueous toroidal pores. The aim of this review is to discuss the details of the mechanism and interpret some experimental results consistent with this view. PMID:19669523

  2. Investigation of penetration force of living cell using an atomic force microscope

    Kwon, Eun Young; Kim, Young Tae; Kim, Dae Eun [Yonsei University, Seoul (Korea, Republic of)

    2009-07-15

    Recently, the manipulation of a single cell has been receiving much attention in transgenesis, in-vitro fertilization, individual cell based diagnosis, and pharmaceutical applications. As these techniques require precise injection and manipulation of cells, issues related to penetration force arise. In this work the penetration force of living cell was studied using an atomic force microscope (AFM). L929, HeLa, 4T1, and TA3 HA II cells were used for the experiments. The results showed that the penetration force was in the range of 2{approx}22 nN. It was also found that location of cell penetration and stiffness of the AFM cantilever affected the penetration force significantly. Furthermore, double penetration events could be detected, due to the multi-membrane layers of the cell. The findings of this work are expected to aid in the development of precision micro-medical instruments for cell manipulation and treatment

  3. Cell penetrating recombinant Foxp3 protein enhances Treg function and ameliorates arthritis

    Yomogida, Kentaro; Wu, Shili; Baravati, Bobby; Avendano, Camilo; Caldwell, Tom; Maniaci, Brian; Zhu, Yong; CHU, CONG-QIU

    2013-01-01

    Foxp3 is the master transcription factor for T regulatory (Treg) cell differentiation and function. This study aimed to test the therapeutic potential of cell penetrating recombinant Foxp3 protein in arthritis. Recombinant Foxp3 protein was fused to a cell penetrating polyarginine (Foxp3-11R) tag to facilitate intracellular transduction. In vitro Foxp3-11R treated CD4+ T cells showed a 50% increase in suppressive function compared with control protein treated cells. Severity of arthritis in F...

  4. Electrochemistry of a ferrocene-grafted cell-penetrating peptide

    A cationic cell-penetrating peptide (CPP) labeled with both a ferrocenyl (Fc) moiety and a biotin (B) was successfully synthesized and investigated by electrochemistry. This original CPP derivative noted as Fc-CPP-B could be electrochemically detected, at a micromolar concentration, at a naked gold bead electrode. The presence of a biotin tag in the Fc-CPP-B complex allowed its complexation with avidin, which was itself tethered to a thiolated self-assembled monolayer. Such an avidin-modified gold surface, characterized by atomic force microscopy (AFM), allowed the immobilization of Fc-CPP-B onto the electrode surface, which greatly enhanced its electrochemical detection. Nevertheless, under these conditions the electrogenerated ferrocenium cation could not be reduced during the backward scan, indicating its unexpected reactivity when tethered within the avidin environment. In terms of detection and redox probe regeneration the best results were obtained at a glassy carbon electrode modified with a cation-exchange polymer. Ion-exchange voltammetry, performed under these conditions, allowed the pre-concentration of the peptide at the electrode surface thanks to the net positive charge of the CPP derivative. Interestingly, the anionic character of the polymer contributed to retain the electrogenerated cation Fc+ in the film so that it could be reduced back to its original neutral form during the reverse voltammetric scans.

  5. Activatable thermo-sensitive ICG encapsulated pluronic nanocapsules for temperature sensitive fluorescence tomography

    Kwong, Tiffany C.; Nouizi, Farouk; Sampathkumaran, Uma; Zhu, Yue; Alam, Maksudul M.; Gulsen, Gultekin

    2015-03-01

    Fluorescent tomography has been hindered by poor tissue penetration and weak signal which results in poor spatial resolution and quantification accuracy. Recently, it has been reported that activatable temperature responsive fluorescent probes which respond to focused ultrasound heating can improve the resolution and quantification of fluorescent tomography in deep tissue. This has lead to a new imaging modality, "Temperature-modulated fluorescent tomography." This technique relies on activatable thermo-sensitive fluorescent nanocapsules for whose fluorescence quantum efficiency is temperature dependent. Within a 4-5° C temperature range, the fluorescent signal increase more than 10-fold. In this molecular probe, Indocyanine Green (ICG) is encapsulated inside the core of a thermo-reversible pluronic micelle. Here we show the fluorescence response and temperature range of the nanocapsules which have been optimized for a higher temperature range to be used for in vivo animal imaging. We report on the feasibility of these temperature-sensitive reversible nanocapsules for in vivo applications by studying the pharmacokinetics in a subcutaneous mouse tumor model in vivo.

  6. Enthalpy-driven interactions with sulfated glycosaminoglycans promote cell membrane penetration of arginine peptides.

    Takechi-Haraya, Yuki; Nadai, Ryo; Kimura, Hitoshi; Nishitsuji, Kazuchika; Uchimura, Kenji; Sakai-Kato, Kumiko; Kawakami, Kohsaku; Shigenaga, Akira; Kawakami, Toru; Otaka, Akira; Hojo, Hironobu; Sakashita, Naomi; Saito, Hiroyuki

    2016-06-01

    The first step of cell membrane penetration of arginine peptides is thought to occur via electrostatic interactions between positive charges of arginine residues and negative charges of sulfated glycosaminoglycans (GAGs) on the cell surface. However, the molecular interaction of arginine peptides with GAG still remains unclear. Here, we compared the interactions of several arginine peptides of Tat, R8, and Rev and their analogues with heparin in relation to the cell membrane penetration efficiency. The high-affinity binding of arginine peptides to heparin was shown to be driven by large favorable enthalpy contributions, possibly reflecting multidentate hydrogen bondings of arginine residues with sulfate groups of heparin. Interestingly, the lysine peptides in which all arginine residues are substituted with lysine residues exhibited negligible binding enthalpy despite of their considerable binding to heparin. In CHO-K1 cells, arginine peptides exhibited a great cell-penetrating ability whereas their corresponding lysine peptides did not penetrate into cells. The degree of cell penetration of arginine peptides markedly decreased by the chlorate treatment of cells which prevents the sulfation of GAG chains. Significantly, the cell penetration efficiency of arginine peptides was found to be correlated with the favorable enthalpy of binding to heparin. These results suggest that the enthalpy-driven strong interaction with sulfated GAGs such as heparan sulfate plays a critical role in the efficient cell membrane penetration of arginine peptides. PMID:27003128

  7. [Penetration of polyene antibiotics into human embryonic kidney tissue cell cultures].

    Kravchenko, L S; Sokolov, V N; Vaĭnshteĭn, V A; Diment, A V; Tereshin, I M

    1977-12-01

    Penetration of 14C-amphotericin AM-2 into the cells of the tissue culture of the human embryon kidneys was studied by means of light autoradiography after incubation with the antibiotic. Microscopic examination of the autographs of the cell slices revealed the presence of the radioactive label in the cytoplasm and nucleoplasm of the cells. The revealed intracellular localization of the label was evident of the antibiotic penetration into the cells. PMID:596858

  8. Infectious rotavirus enters cells by direct cell membrane penetration, not by endocytosis

    Kaljot, K.T.; Shaw, R.D.; Greenberg, H.B. (Stanford Univ. School of Medicine, CA (USA) Palo Alto Veterans Administration Medical Center, CA (USA)); Rubin, D.H. (Univ. of Pennsylvania, Philadelphia (USA))

    1988-04-01

    Rotaviruses are icosahedral viruses with a segmented, double-stranded RNA genome. They are the major cause of severe infantile infectious diarrhea. Rotavirus growth in tissue culture is markedly enhanced by pretreatment of virus with trypsin. Trypsin activation is associated with cleavage of the viral hemagglutinin (viral protein 3 (VP3); 88 kilodaltons) into two fragments (60 and 28 kilodaltons). The mechanism by which proteolytic cleavage leads to enhanced growth is unknown. To determine whether trypsin treatment affected rotavirus internalization, the authors studied the kinetics of entry of infectious rhesus rotavirus (RRV) into MA104 cells. Trypsin-activated RRV was internalized with a half-time of 3 to 5 min, while nonactivated virus disappeared from the cell surface with a half-time of 30 to 50 min. In contrast to trypsin-activated RRV, loss of nonactivated RRV from the cell surface did not result in the appearance of infection, as measured by plaque formation. Purified trypsin-activated RRV added to cell monolayers at pH 7.4 mediated {sup 51}Cr, ({sup 14}C)choline, and ({sup 3}H)inositol released from prelabeled MA104 cells. This release could be specifically blocked by neutralizing antibodies to VP3. These results suggest that MA104 cell infection follows the rapid entry of trypsin-activated RRV by direct cell membrane penetration. Cell membrane penetration of infectious RRV is initiated by trypsin cleavage of VP3. Neutralizing antibodies can inhibit this direct membrane penetration.

  9. Antibody penetration into living cells. V. Interference between two fc gamma receptor-mediated functions: antibody penetration and antibody-dependent cellular cytotoxicity.

    Llerena, J M; Ruíz-Argüelles, A; Alarcón-Segovia, D; Llorente, L; Díaz-Jouanen, E

    1981-01-01

    The same Fc gamma receptor appears to be shared for two important phenomena: antibody-dependent cellular cytotoxicity (ADCC) and antibody penetration into living cells. ADCC is inhibited through interaction with the Fc gamma receptor during the antibody penetration process, indicating that both mechanisms may modulate each other in vitro. PMID:6972908

  10. Membrane Oxidation Enables the Cytosolic Entry of Polyarginine Cell-penetrating Peptides.

    Wang, Ting-Yi; Sun, Yusha; Muthukrishnan, Nandhini; Erazo-Oliveras, Alfredo; Najjar, Kristina; Pellois, Jean-Philippe

    2016-04-01

    Arginine-rich peptides can penetrate cells and consequently be used as delivery agents in various cellular applications. The activity of these reagents is often context-dependent, and the parameters that impact cell entry are not fully understood, giving rise to variability and limiting progress toward their usage. Herein, we report that the cytosolic penetration of linear polyarginine peptides is dependent on the oxidation state of the cell. In particular, we find that hypoxia and cellular antioxidants inhibit cell penetration. In contrast, oxidants promote cytosolic cell entry with an efficiency proportional to the level of reactive oxygen species generated within membranes. Moreover, an antibody that binds to oxidized lipids inhibits cell penetration, whereas extracellularly administered pure oxidized lipids enhance peptide transport into cells. Overall, these data indicate that oxidized lipids are capable of mediating the transport of polyarginine peptides across membranes. These data may also explain variability in cell-penetrating peptide performance in different experimental conditions. These new findings therefore provide new opportunities for the rational design of future cell-permeable compounds and for the optimization of delivery protocols. PMID:26888085

  11. Visualization of the Nucleolus in Living Cells with Cell-Penetrating Fluorescent Peptides.

    Martin, Robert M; Herce, Henry D; Ludwig, Anne K; Cardoso, M Cristina

    2016-01-01

    The nucleolus is the hallmark of nuclear compartmentalization and has been shown to exert multiple roles in cellular metabolism besides its main function as the place of ribosomal RNA synthesis and assembly of ribosomes. The nucleolus plays also a major role in nuclear organization as the largest compartment within the nucleus. The prominent structure of the nucleolus can be detected using contrast light microscopy providing an approximate localization of the nucleolus, but this approach does not allow to determine accurately the three-dimensional structure of the nucleolus in cells and tissues. Immunofluorescence staining with antibodies specific to nucleolar proteins albeit very useful is time consuming, normally antibodies recognize their epitopes only within a small range of species and is applicable only in fixed cells. Here, we present a simple method to selectively and accurately label this ubiquitous subnuclear compartment in living cells of a large range of species using a fluorescently labeled cell-penetrating peptide. PMID:27576711

  12. Oligonucleotide delivery with cell surface binding and cell penetrating Peptide amphiphile nanospheres.

    Mumcuoglu, Didem; Sardan, Melis; Tekinay, Turgay; Guler, Mustafa O; Tekinay, Ayse B

    2015-05-01

    A drug delivery system designed specifically for oligonucleotide therapeutics can ameliorate the problems associated with the in vivo delivery of these molecules. The internalization of free oligonucleotides is challenging, and cytotoxicity is the main obstacle for current transfection vehicles. To develop nontoxic delivery vehicles for efficient transfection of oligonucleotides, we designed a self-assembling peptide amphiphile (PA) nanosphere delivery system decorated with cell penetrating peptides (CPPs) containing multiple arginine residues (R4 and R8), and a cell surface binding peptide (KRSR), and report the efficiency of this system in delivering G-3129, a Bcl-2 antisense oligonucleotide (AON). PA/AON (peptide amphiphile/antisense oligonucleotide) complexes were characterized with regards to their size and secondary structure, and their cellular internalization efficiencies were evaluated. The effect of the number of arginine residues on the cellular internalization was investigated by both flow cytometry and confocal imaging, and the results revealed that uptake efficiency improved as the number of arginines in the sequence increased. The combined effect of cell penetration and surface binding property on the cellular internalization and its uptake mechanism was also evaluated by mixing R8-PA and KRSR-PA. R8 and R8/KRSR decorated PAs were found to drastically increase the internalization of AONs compared to nonbioactive PA control. Overall, the KRSR-decorated self-assembled PA nanospheres were demonstrated to be noncytotoxic delivery vectors with high transfection rates and may serve as a promising delivery system for AONs. PMID:25828697

  13. Transduction of peptides and proteins into live cells by cell penetrating peptides.

    Mussbach, Franziska; Franke, Martin; Zoch, Ansgar; Schaefer, Buerk; Reissmann, Siegmund

    2011-12-01

    Internalization of peptides and proteins into live cells is an essential prerequisite for studies on intracellular signal pathways, for treatment of certain microbial diseases and for signal transduction therapy, especially for cancer treatment. Cell penetrating peptides (CPPs) facilitate the transport of cargo-proteins through the cell membrane into live cells. CPPs which allow formation of non-covalent complexes with the cargo are used primarily in this study due to the relatively easy handling procedure. Efficiency of the protein uptake is estimated qualitatively by fluorescence microscopy and quantitatively by SDS-PAGE. Using the CPP cocktail JBS-Proteoducin, the intracellular concentrations of a secondary antibody and bovine serum albumin can reach the micromolar range. Internalization of antibodies allows mediation of intracellular pathways including knock down of signal transduction. The high specificity and affinity of antibodies makes them potentially more powerful than siRNA. Thus, CPPs represent a significant new possibility to study signal transduction processes in competition or in comparison to the commonly used other techniques. To estimate the highest attainable intracellular concentrations of cargo proteins, the CPPs are tested for cytotoxicity. Cell viability and membrane integrity relative to concentration of CPPs are investigated. Viability as estimated by the reductive activity of mitochondria (MTT-test) is more sensitive to higher concentrations of CPPs versus membrane integrity, as measured by the release of dead cell protease. Distinct differences in uptake efficiency and cytotoxic effects are found using six different CPPs and six different adhesion and suspension cell lines. PMID:21826709

  14. Nanoformulated cell-penetrating survivin mutant and its dual actions

    Sriramoju B

    2014-07-01

    Full Text Available Bhasker Sriramoju, Rupinder K Kanwar, Jagat R Kanwar Nanomedicine Laboratory of Immunology and Molecular Biomedical Research (NLIMBR, School of Medicine, Faculty of Health, Deakin University, Geelong, Australia Abstract: In this study, we investigated the differential actions of a dominant-negative survivin mutant (SurR9-C84A against cancerous SK-N-SH neuroblastoma cell lines and differentiated SK-N-SH neurons. In both the cases, the mutant protein displayed dual actions, where its effects were cytotoxic toward cancerous cells and proliferative toward the differentiated neurons. This can be explained by the fact that tumorous (undifferentiated SK-N-SH cells have a high endogenous survivin pool and upon treatment with mutant SuR9-C84A causes forceful survivin expression. These events significantly lowered the microtubule dynamics and stability, eventually leading to apoptosis. In the case of differentiated SK-N-SH neurons that express negligible levels of wild-type survivin, the mutant indistinguishably behaved in a wild-type fashion. It also favored cell-cycle progression, forming the chromosome-passenger complex, and stabilized the microtubule-organizing center. Therefore, mutant SurR9-C84A represents a novel therapeutic with its dual actions (cytotoxic toward tumor cells and protective and proliferative toward neuronal cells, and hence finds potential applications against a variety of neurological disorders. In this study, we also developed a novel poly(lactic-co-glycolic acid nanoparticulate formulation to surmount the hurdles associated with the delivery of SurR9-C84A, thus enhancing its effective therapeutic outcome. Keywords: survivin mutant, neurological disorders, protein therapeutics, inhibitor of apoptosis protein family, poly(lactic-co-glycolic acid

  15. Binding and Clustering of Glycosaminoglycans: A Common Property of Mono- and Multivalent Cell-Penetrating Compounds

    Ziegler, André; Seelig, Joachim

    2007-01-01

    Recent observations in cell culture provide evidence that negatively charged glycosaminoglycans (GAGs) at the surface of biological cells bind cationic cell-penetrating compounds (CPCs) and cluster during CPC binding, thereby contributing to their endocytotic uptake. The GAG binding and clustering occur in the low-micromolar concentration range and suggest a tight interaction between GAGs and CPCs, although the relation between binding affinity and specificity of this interaction remains to b...

  16. Application of Cell Penetrating Peptide in Magnetic Resonance Imaging of Bone Marrow Mesenchymal Stem Cells

    Min LIU; You-Min GUO; Jun-Le YANG; Peng WANG; Lin-Yu ZHAO; Nian SHEN; Si-Cen WANG; Xiao-Juan GUO; Qi-Fei WU

    2006-01-01

    Tracking the distribution and differentiation of stem cells by high-resolution imaging techniques would have significant clinical and research implications. In this study, a model cell-penetrating peptide was used to carry gadolinium particles for magnetic resonance imaging (MRI) of mesenchymal stem cells (MSCs).MSCs were isolated from rat bone marrow and identified by osteogenic differentiation in vitro. The cellpenetrating peptide labeled with fluorescein-5-isothiocyanate (FITC) and gadolinium was synthesized by a solid-phase peptide synthesis method. Fluorescein imaging analysis confirmed that this new peptide could internalize into the cytoplasm and nucleus at room temperature, 4℃ and 37℃. Gadolinium were efficiently internalized into mesenchymal stem cells by the peptide in a time or concentration-dependent manner,resulting in intercellular shortening of longitudinal relaxation enhancements, which were obviously detected by 1.5 Tesla Magnetic Resonance Imaging. Cytotoxicity assay and flow cytometric analysis showed that the intercellular contrast medium incorporation did not affect cell viability at the tested concentrations. The in vitro experiment results suggested that the new constructed peptides could be a vector for tracking MSCs.

  17. Cationic cell-penetrating peptides induce ceramide formation via acid sphingomyelinase: implications for uptake.

    Verdurmen, W.P.R.; Thanos, M.; Ruttekolk, I.R.R.; Gulbins, E.; Brock, R.E.

    2010-01-01

    Cationic cell-penetrating peptides (CPP) are receiving increasing attention as molecular transporters of membrane-impermeable molecules. Import of cationic CPP occurs both via endocytosis and - at higher peptide concentrations - in an endocytosis-independent manner via localized regions of the plasm

  18. A cell-penetrating peptide derived from human lactoferrin with conformation-dependent uptake efficiency.

    Duchardt, F.; Ruttekolk, I.R.R.; Verdurmen, W.P.R.; Lortat-Jacob, H.; Burck, J.; Hufnagel, H.; Fischer, R.; Heuvel, M. van den; Lowik, D.W.; Vuister, G.W.; Ulrich, A.; Waard, M. de; Brock, R.E.

    2009-01-01

    The molecular events that contribute to the cellular uptake of cell-penetrating peptides (CPP) are still a matter of intense research. Here, we report on the identification and characterization of a 22-amino acid CPP derived from the human milk protein, lactoferrin. The peptide exhibits a conformati

  19. Delivering aminopyridine ligands into cancer cells through conjugation to the cell-penetrating peptide BP16

    Soler Vives, Marta; González-Bártulos, Marta; Figueras, Eduard; Massaguer i Vall-llovera, Anna; Feliu Soley, Lídia; Planas i Grabuleda, Marta; Ribas Salamaña, Xavi; Costas Salgueiro, Miquel

    2016-01-01

    Peptide conjugates incorporating the red-ox active ligands Me2PyTACN or (S,S')-BPBP at the N- or the C-terminus of the cell-penetrating peptide BP16 were synthesized (PyTACN-BP16 (BP341), BP16-PyTACN (BP342), BPBP-BP16 (BP343), and BP16-BPBP (BP344)). Metal binding peptides bearing at the N-terminus the ligand, an additional Lys and a β-Ala were also prepared (PyTACN-βAK-BP16 (BP345) and BPBP-βAK-BP16 (BP346)). Moreover, taking into account the clathrin-dependent endocytic mechanism of BP16, ...

  20. Efficient Cargo Delivery into Adult Brain Tissue Using Short Cell-Penetrating Peptides.

    Caghan Kizil

    Full Text Available Zebrafish brains can regenerate lost neurons upon neurogenic activity of the radial glial progenitor cells (RGCs that reside at the ventricular region. Understanding the molecular events underlying this ability is of great interest for translational studies of regenerative medicine. Therefore, functional analyses of gene function in RGCs and neurons are essential. Using cerebroventricular microinjection (CVMI, RGCs can be targeted efficiently but the penetration capacity of the injected molecules reduces dramatically in deeper parts of the brain tissue, such as the parenchymal regions that contain the neurons. In this report, we tested the penetration efficiency of five known cell-penetrating peptides (CPPs and identified two- polyR and Trans - that efficiently penetrate the brain tissue without overt toxicity in a dose-dependent manner as determined by TUNEL staining and L-Plastin immunohistochemistry. We also found that polyR peptide can help carry plasmid DNA several cell diameters into the brain tissue after a series of coupling reactions using DBCO-PEG4-maleimide-based Michael's addition and azide-mediated copper-free click reaction. Combined with the advantages of CVMI, such as rapidness, reproducibility, and ability to be used in adult animals, CPPs improve the applicability of the CVMI technique to deeper parts of the central nervous system tissues.

  1. A cell penetrating peptide-integrated and enediyne-energized fusion protein shows potent antitumor activity.

    Ru, Qin; Shang, Bo-Yang; Miao, Qing-Fang; Li, Liang; Wu, Shu-Ying; Gao, Rui-Juan; Zhen, Yong-Su

    2012-11-20

    Arginine-rich peptides belong to a subclass of cell penetrating peptides that are taken up by living cells and can be detected freely diffusing inside the cytoplasm and nucleoplasm. This phenomenon has been attributed to either an endocytotic mode of uptake and a subsequent release from vesicles or a direct membrane penetration. Lidamycin is an antitumor antibiotic, which consists of an active enediyne chromophore (AE) and a noncovalently bound apoprotein (LDP). In the present study, a fusion protein (Arg)(9)-LDP composed of cell penetrating peptide (Arg)(9) and LDP was prepared by DNA recombination, and the enediyne-energized fusion protein (Arg)(9)-LDP-AE was prepared by molecular reconstitution. The data in fixed cells demonstrated that (Arg)(9)-LDP could rapidly enter cells, and the results based on fluorescence activated cell sorting indicated that the major route for (Arg)(9)-mediated cellular uptake of protein molecules was endocytosis. (Arg)(9)-LDP-AE demonstrated more potent cytotoxicity against different carcinoma cell lines than lidamycin in vitro. In the mouse hepatoma 22 model, (Arg)(9)-LDP-AE (0.3mg/kg) suppressed the tumor growth by 89.2%, whereas lidamycin (0.05 mg/kg) by 74.6%. Furthermore, in the glioma U87 xenograft model in nude mice, (Arg)(9)-LDP-AE at 0.2mg/kg suppressed tumor growth by 88.8%, compared with that of lidamycin by 62.9% at 0.05 mg/kg. No obvious toxic effects were observed in all groups during treatments. The results showed that energized fusion protein (Arg)(9)-LDP-AE was more effective than lidamycin and would be a promising candidate for glioma therapy. In addition, this approach to manufacturing fusion proteins might serve as a technology platform for the development of new cell penetrating peptides-based drugs. PMID:22982402

  2. Alternative Mechanisms for the Interaction of the Cell-Penetrating Peptides Penetratin and the TAT Peptide with Lipid Bilayers

    Yesylevskyy, Semen; Marrink, Siewert-Jan; Mark, Alan E.

    2009-01-01

    Cell-penetrating peptides (CPPs) have recently attracted much interest due to their apparent ability to penetrate cell membranes in an energy-independent manner. Here molecular-dynamics simulation techniques were used to study the interaction of two CPPs: penetratin and the TAT peptide with 1,2-Dipa

  3. Conformational analysis of Infectious bursal disease virus (IBDV derived cell penetrating peptide (CPP analogs

    Vinay G. Joshi

    2013-12-01

    Full Text Available Aim: This study was designed to develop peptide analogs of Infectious Bursal Disease (IBD virus VP5 protein segment having cell penetrating ability to improve their interaction with cargo molecule (Nucleic acid without affecting the backbone conformation. Materials and Methods: IBDV VP5 protein segment designated as RATH peptide were synthesized using solid phase peptide synthesis and their solution conformation was elucidated using CD spectroscopy in polar (water and apolar (TFE solvents. Cell penetrating ability of RATH-CONH2 was observed using FITC labeled peptide internalization in to HeLa cells under fluorescent microscopy. The efficacy of RATH analog interactions with nucleic acids was evaluated using FITC labeled oligonucleotides by fluorescence spectroscopy and plasmid constructs in gel retardation assay. Results: CD spectra of RATH analogs in water and apolar trifluroethanol (TFE helped to compare their secondary structures which were almost similar with dominant beta conformations suggesting successful induction of positive charge in the analogs without affecting back bone conformation of CPP designed. Cell penetrating ability of RATH CONH2 in HeLa cell was more than 90%. The fluorescence spectroscopy and plasmid constructs in gel retardation assay demonstrated successful interaction of amide analogs with nucleic acid. Conclusion: Intentional changes made in IBDV derived peptide RATH COOH to RATH CONH2 did not showed major changes in backbone conformation and such modifications may help to improve the cationic charge in most CPPs to interact with nucleic acid. [Vet World 2013; 6(6.000: 307-312

  4. Expression,purification and cell penetrativity of fusion protein PDT/GR-ΔLBD

    Fang ZHANG

    2011-01-01

    Full Text Available Objective To construct the fusion gene expression vector of penetrating peptide(PDT and the glucocorticoid receptor lack of ligand binding domain(GR-ΔLBD,and evaluate the prokaryotic expression,purification and cell penetrativity of fusion protein PDT/GR-ΔLBD.Methods The target gene fragment GR-ΔLBD was obtained from plasmid pEGFP-GR-ΔLBD by double digestion,and sub-cloned into the prokaryotic expression vector pGEX-PDT to construct the fusion gene expression vector pGEX-PDT/GR-ΔLBD.PDT/GR-ΔLBD fusion protein was obtained after the expression vector was transformed into E.coli,followed by sequential induction with IPTG,treatment with glutathione-agarose resin and elution with glutathione.SDS-PAGE was performed to determine the expression of PDT/GR-ΔLBD fusion protein,and it which was diluted into a final concentration of 0,500 and 1000nmol/L,labeled with fluorescein FITC and co-cultivated with TC-1 cells for 2 hours,and the penetrativity was observed by fluorescence microscopy.Results The successfully constructed prokaryotic expression vector pPDT/GR-ΔLBD had the capacity of expressing protein,and it was 78.6kD in molecular weight,which was consistent with the theoretical value(80kD of the fusion protein PDT/GR-ΔLBD.PDT-GR-ΔLBD,penetrating the nuclear membrane in a concentration-dependent manner,was concentrated within nuclei.Conclusion PDT/GR-ΔLBD fusion protein,with good solubility and cell penetrativity,paves the way for further research on its anti-inflammatory effects.

  5. The bacteriophage ϕ29 tail possesses a pore-forming loop for cell membrane penetration.

    Xu, Jingwei; Gui, Miao; Wang, Dianhong; Xiang, Ye

    2016-06-23

    Most bacteriophages are tailed bacteriophages with an isometric or a prolate head attached to a long contractile, long non-contractile, or short non-contractile tail. The tail is a complex machine that plays a central role in host cell recognition and attachment, cell wall and membrane penetration, and viral genome ejection. The mechanisms involved in the penetration of the inner host cell membrane by bacteriophage tails are not well understood. Here we describe structural and functional studies of the bacteriophage ϕ29 tail knob protein gene product 9 (gp9). The 2.0 Å crystal structure of gp9 shows that six gp9 molecules form a hexameric tube structure with six flexible hydrophobic loops blocking one end of the tube before DNA ejection. Sequence and structural analyses suggest that the loops in the tube could be membrane active. Further biochemical assays and electron microscopy structural analyses show that the six hydrophobic loops in the tube exit upon DNA ejection and form a channel that spans the lipid bilayer of the membrane and allows the release of the bacteriophage genomic DNA, suggesting that cell membrane penetration involves a pore-forming mechanism similar to that of certain non-enveloped eukaryotic viruses. A search of other phage tail proteins identified similar hydrophobic loops, which indicates that a common mechanism might be used for membrane penetration by prokaryotic viruses. These findings suggest that although prokaryotic and eukaryotic viruses use apparently very different mechanisms for infection, they have evolved similar mechanisms for breaching the cell membrane. PMID:27309813

  6. Paramagnetic particles carried by cell-penetrating peptide tracking of bone marrow mesenchymal stem cells, a research in vitro

    The ability to track the distribution and differentiation of stem cells by high-resolution imaging techniques would have significant clinical and research implications. In this study, a model cell-penetrating peptide was used to carry gadolinium particles for magnetic resonance imaging of the mesenchymal stem cells. The mesenchymal stem cells were isolated from rat bone marrow by Percoll and identified by osteogenic differentiation in vitro. The cell-penetrating peptides labeled with fluorescein-5-isothiocyanate and gadolinium were synthesized by a solid-phase peptide synthesis method and the relaxivity of cell-penetrating peptide-gadolinium paramagnetic conjugate on 400 MHz nuclear magnetic resonance was 5.7311 ± 0.0122 mmol-1 s-1, higher than that of diethylenetriamine pentaacetic acid gadolinium (p < 0.05). Fluorescein imaging confirmed that this new peptide could internalize into the cytoplasm and nucleus. Gadolinium was efficiently internalized into mesenchymal stem cells by the peptide in a time- or concentration-dependent fashion, resulting in intercellular T1 relaxation enhancement, which was obviously detected by 1.5 T magnetic resonance imaging. Cytotoxicity assay and flow cytometric analysis showed the intercellular contrast medium incorporation did not affect cell viability and membrane potential gradient. The research in vitro suggests that the newly constructed peptides could be a vector for tracking mesenchymal stem cells

  7. Peptide Internalization Enabled by Folding: Triple Helical Cell-Penetrating Peptides

    Shinde, Aparna; Feher, Katie M.; Hu, Chloe; Slowinska, Katarzyna

    2014-01-01

    Cell-Penetrating Peptides (CPPs) are known as efficient transporters of molecular cargo across cellular membranes. Their properties make them ideal candidates for in vivo applications. However, challenges in development of effective CPPs still exist: CPPs are often fast degraded by proteases and large concentration of CPPs required for cargo transporting can cause cytotoxicity. It was previously shown that restricting peptide flexibility can improve peptide stability against enzymatic degrada...

  8. Cell-penetrating peptides; chemical modification, mechanism of uptake and formulation development

    Ezzat, Kariem

    2012-01-01

    Gene therapy holds the promise of revolutionizing the way we treat diseases. By using recombinant DNA and oligonucleotides (ONs), gene functions can be restored, altered or silenced according to the therapeutic need. However, gene therapy approaches require the delivery of large and charged nucleic acid-based molecules to their intracellular targets across the plasma membrane, which is inherently impermeable to such molecules. In this thesis, two chemically modified cell-penetrating peptides ...

  9. The Role of Cell-Penetrating Peptide and Transferrin on Enhanced Delivery of Drug to Brain

    Gitanjali Sharma; Sushant Lakkadwala; Amit Modgil; Jagdish Singh

    2016-01-01

    The challenge of effectively delivering therapeutic agents to brain has led to an entire field of active research devoted to overcome the blood brain barrier (BBB) and efficiently deliver drugs to brain. This review focusses on exploring the facets of a novel platform designed for the delivery of drugs to brain. The platform was constructed based on the hypothesis that a combination of receptor-targeting agent, like transferrin protein, and a cell-penetrating peptide (CPP) will enhance the de...

  10. Cell-Penetrating Ability of Peptide Hormones: Key Role of Glycosaminoglycans Clustering

    Armelle Tchoumi Neree

    2015-11-01

    Full Text Available Over the last two decades, the potential usage of cell-penetrating peptides (CPPs for the intracellular delivery of various molecules has prompted the identification of novel peptidic identities. However, cytotoxic effects and unpredicted immunological responses have often limited the use of various CPP sequences in the clinic. To overcome these issues, the usage of endogenous peptides appears as an appropriate alternative approach. The hormone pituitary adenylate-cyclase-activating polypeptide (PACAP38 has been recently identified as a novel and very efficient CPP. This 38-residue polycationic peptide is a member of the secretin/glucagon/growth hormone-releasing hormone (GHRH superfamily, with which PACAP38 shares high structural and conformational homologies. In this study, we evaluated the cell-penetrating ability of cationic peptide hormones in the context of the expression of cell surface glycosaminoglycans (GAGs. Our results indicated that among all peptides evaluated, PACAP38 was unique for its potent efficiency of cellular uptake. Interestingly, the abilities of the peptides to reach the intracellular space did not correlate with their binding affinities to sulfated GAGs, but rather to their capacity to clustered heparin in vitro. This study demonstrates that the uptake efficiency of a given cationic CPP does not necessarily correlate with its affinity to sulfated GAGs and that its ability to cluster GAGs should be considered for the identification of novel peptidic sequences with potent cellular penetrating properties.

  11. Parametric analysis of neutron streaming through major penetrations in the 0.914 m TFTR test cell floor

    Neutron streaming through penetrations in the 0.914 m TFTR test cell floor has two distinct features: (1) the oblique angle of incidence; and (2) the high order of anisotropy in the angular distribution for incident neutrons with energies > 10 keV. The effects of these features on the neutron streaming into the TFTR basement were studied parametrically for isolated penetrations. Variations with respect to the source energies, angular distributions, and sizes of the penetrations were made. The results form a data base from which the spatial distribution of the neutron flux in the basement due to multiple penetrations may be evaluated

  12. Parametric analysis of neutron streaming through major penetrations in the 0. 914 m TFTR test cell floor

    Ku, L.P.; Liew, S.L.; Kolibal, J.G.

    1985-09-01

    Neutron streaming through penetrations in the 0.914 m TFTR test cell floor has two distinct features: (1) the oblique angle of incidence; and (2) the high order of anisotropy in the angular distribution for incident neutrons with energies > 10 keV. The effects of these features on the neutron streaming into the TFTR basement were studied parametrically for isolated penetrations. Variations with respect to the source energies, angular distributions, and sizes of the penetrations were made. The results form a data base from which the spatial distribution of the neutron flux in the basement due to multiple penetrations may be evaluated.

  13. Backbone rigidity and static presentation of guanidinium groups increases cellular uptake of arginine-rich cell-penetrating peptides

    Lättig-Tünnemann, Gisela; Prinz, Manuel; Hoffmann, Daniel; Behlke, Joachim; Palm-Apergi, Caroline; Morano, Ingo; Herce, Henry D.; Cardoso, M. Cristina

    2011-01-01

    In addition to endocytosis-mediated cellular uptake, hydrophilic cell-penetrating peptides are able to traverse biological membranes in a non-endocytic mode termed transduction, resulting in immediate bioavailability. Here we analysed structural requirements for the non-endocytic uptake mode of arginine-rich cell-penetrating peptides, by a combination of live-cell microscopy, molecular dynamics simulations and analytical ultracentrifugation. We demonstrate that the transduction efficiency of ...

  14. 18F-Labeled phosphopeptide-cell-penetrating peptide dimers with enhanced cell uptake properties in human cancer cells

    Introduction: Phosphopeptides represent interesting compounds to study and elucidate cellular protein phosphorylation/dephosphorylation processes underlying various signal transduction pathways. However, studies of phosphopeptide action in cells are severely constrained by the negatively charged phosphate moiety of the phosphopeptide resulting in poor transport through the cell membrane. The following study describes the synthesis and radiopharmacological evaluation of two 18F-labeled phosphopeptide-cell-penetrating peptide dimers. The polo-like kinase-1-binding hexaphosphopeptide H-Met-Gln-Ser-pThr-Pro-Leu-OH was coupled to cell-penetrating peptides (CPPs), either sC18, a cathelicidin-derived peptide, or the human calcitonin derivative hCT(18-32)-k7. Methods: Radiolabeling was accomplished with the prosthetic group N-succinimidyl 4-[18F]fluorobenzoate ([18F]SFB) using both, conventional and microfluidic-based bioconjugation of [18F]SFB to N-terminal end of phosphopeptide part of the peptide dimers. Cellular uptake studies in human cancer cell lines HT-29 and FaDu cells at 4 °C and 37 °C and small animal PET in BALB/c mice were utilized for radiopharmacological characterization. Results: Isolated radiochemical yields ranged from 2% to 4% for conventional bioconjugation with [18F]SFB. Significantly improved isolated radiochemical yields of up to 26% were achieved using microfluidic technology. Cellular uptake studies of radiolabeled phosphopeptide and phosphopeptide-CPP dimers indicate enhanced internalization of 50% ID/mg protein after 2 h for both phosphopeptide dimers compared to the phosphopeptide alone (18F-labeled peptide dimers was determined with small animal PET revealing a superior biodistribution pattern of sC18-containing peptide dimer MQSpTPL-sC18 [18F]4. Conclusion: [18F]SFB labeling of the phosphopeptide-CPP dimers using a microfluidic system leads to an improved chemoselectivity towards the N-terminal NH2 group compared to the conventional labeling

  15. Penetration of fosfomycin into IPEC-J2 cells in the presence or absence of deoxynivalenol.

    Guadalupe Martínez

    Full Text Available Fosfomycin (FOS is an antibiotic used in pig farms for treatment and prevention of infections caused by resistant bacteria during the post-weaning period. Antibiotics and non-toxic concentrations of mycotoxins, such as deoxynivalenol (DON are frequently found in the diet of animals. These compounds can establish interactions in the intestinal tract, which could affect and/or modify the penetration of FOS to enterocytes. The aim of this study was to determine the penetration of FOS into IPECJ-2 cells, a cell line derived from the small intestine of piglets, in the presence and absence of DON. The results from this study showed that there was statistically significant difference in the intracellular concentration of FOS between cells incubated with 580 µg/ml FOS and cells incubated with 580 µg/ml FOS and 1 µg/ml DON. The Cmax of the intracellular antibiotic in the culture plates incubated with FOS in absence of DON was 45.81 µg/ml with a tmax of 4 h. When IPEC-2 cells were incubated with FOS and DON the Cmax was 20.06 µg/ml and the tmax was 30 min. It is concluded that the non-toxic concentration of DON on IPEC-J2 cells after short-term exposure, interferes with the pharmacokinetics of the antibiotic.

  16. Backbone rigidity and static presentation of guanidinium groups increases cellular uptake of arginine-rich cell-penetrating peptides.

    Lättig-Tünnemann, Gisela; Prinz, Manuel; Hoffmann, Daniel; Behlke, Joachim; Palm-Apergi, Caroline; Morano, Ingo; Herce, Henry D; Cardoso, M Cristina

    2011-01-01

    In addition to endocytosis-mediated cellular uptake, hydrophilic cell-penetrating peptides are able to traverse biological membranes in a non-endocytic mode termed transduction, resulting in immediate bioavailability. Here we analysed structural requirements for the non-endocytic uptake mode of arginine-rich cell-penetrating peptides, by a combination of live-cell microscopy, molecular dynamics simulations and analytical ultracentrifugation. We demonstrate that the transduction efficiency of arginine-rich peptides increases with higher peptide structural rigidity. Consequently, cyclic arginine-rich cell-penetrating peptides showed enhanced cellular uptake kinetics relative to their linear and more flexible counterpart. We propose that guanidinium groups are forced into maximally distant positions by cyclization. This orientation increases membrane contacts leading to enhanced cell penetration. PMID:21878907

  17. Reduced activity of TAFI (thrombin-activatable fibrinolysis inhibitor) in acute promyelocytic leukaemia

    Meijers, JCM; Oudijk, EJD; Mosnier, LO; Nieuwenhuis, HK; Fijnheer, R; Bouma, Bonno N.; Bos, R

    2000-01-01

    Acute promyelocytic leukaemia (APL) is a disease that is distinguished from other leukaemias by the high potential for early haemorrhagic death. Several processes are involved, such as disseminated intravascular coagulation and hyperfibrinolysis. Recently, TAFI (thrombin-activatable fibrinolysis inh

  18. Antibacterial Effects of a Cell-Penetrating Peptide Isolated from Kefir.

    Miao, Jianyin; Guo, Haoxian; Chen, Feilong; Zhao, Lichao; He, Liping; Ou, Yangwen; Huang, Manman; Zhang, Yi; Guo, Baoyan; Cao, Yong; Huang, Qingrong

    2016-04-27

    Kefir is a traditional fermented milk beverage used throughout the world for centuries. A cell-penetrating peptide, F3, was isolated from kefir by Sephadex G-50 gel filtration, DEAE-52 ion exchange, and reverse-phase high-performance liquid chromatography. F3 was determined to be a low molecular weight peptide containing one leucine and one tyrosine with two phosphate radicals. This peptide displayed antimicrobial activity across a broad spectrum of organisms including several Gram-positive and Gram-negative bacteria as well as fungi, with minimal inhibitory concentration (MIC) values ranging from 125 to 500 μg/mL. Cellular penetration and accumulation of F3 were determined by confocal laser scanning microscopy. The peptide was able to penetrate the cellular membrane of Escherichia coli and Staphylococcus aureus. Changes in cell morphology were observed by scanning electron microscopy (SEM). The results indicate that peptide F3 may be a good candidate for use as an effective biological preservative in agriculture and the food industry. PMID:27003578

  19. Relationships between Cargo, Cell Penetrating Peptides and Cell Type for Uptake of Non-Covalent Complexes into Live Cells

    Andrea-Anneliese Keller

    2013-02-01

    Full Text Available Modulating signaling pathways for research and therapy requires either suppression or expression of selected genes or internalization of proteins such as enzymes, antibodies, nucleotide binding proteins or substrates including nucleoside phosphates and enzyme inhibitors. Peptides, proteins and nucleotides are transported by fusing or conjugating them to cell penetrating peptides or by formation of non-covalent complexes. The latter is often preferred because of easy handling, uptake efficiency and auto-release of cargo into the live cell. In our studies complexes are formed with labeled or readily detectable cargoes for qualitative and quantitative estimation of their internalization. Properties and behavior of adhesion and suspension vertebrate cells as well as the protozoa Leishmania tarentolae are investigated with respect to proteolytic activity, uptake efficiency, intracellular localization and cytotoxicity. Our results show that peptide stability to membrane-bound, secreted or intracellular proteases varies between different CPPs and that the suitability of individual CPPs for a particular cargo in complex formation by non-covalent interactions requires detailed studies. Cells vary in their sensitivity to increasing concentrations of CPPs. Thus, most cells can be efficiently transduced with peptides, proteins and nucleotides with intracellular concentrations in the low micromole range. For each cargo, cell type and CPP the optimal conditions must be determined separately.

  20. Single wall carbon nanotubes enter cells by endocytosis and not membrane penetration

    Lösche Mathias

    2011-09-01

    Full Text Available Abstract Background Carbon nanotubes are increasingly being tested for use in cellular applications. Determining the mode of entry is essential to control and regulate specific interactions with cells, to understand toxicological effects of nanotubes, and to develop nanotube-based cellular technologies. We investigated cellular uptake of Pluronic copolymer-stabilized, purified ~145 nm long single wall carbon nanotubes (SWCNTs through a series of complementary cellular, cell-mimetic, and in vitro model membrane experiments. Results SWCNTs localized within fluorescently labeled endosomes, and confocal Raman spectroscopy showed a dramatic reduction in SWCNT uptake into cells at 4°C compared with 37°C. These data suggest energy-dependent endocytosis, as shown previously. We also examined the possibility for non-specific physical penetration of SWCNTs through the plasma membrane. Electrochemical impedance spectroscopy and Langmuir monolayer film balance measurements showed that Pluronic-stabilized SWCNTs associated with membranes but did not possess sufficient insertion energy to penetrate through the membrane. SWCNTs associated with vesicles made from plasma membranes but did not rupture the vesicles. Conclusions These measurements, combined, demonstrate that Pluronic-stabilized SWCNTs only enter cells via energy-dependent endocytosis, and association of SWCNTs to membrane likely increases uptake.

  1. Poly(NIPAm-AMPS) nanoparticles for targeted delivery of anti-inflammatory cell penetrating peptides

    Bartlett, Rush Lloyd, II

    Inflammatory diseases such as osteoarthritis and rheumatoid arthritis cause $127.8 billion in US healthcare expenditures each year and are the cause of disability for 27% of disabled persons in the United States. Current treatment options rarely halt disease progression and often result in significant unwanted and debilitating side effects. Our laboratory has previously developed a family of cell penetrating peptides (CPPs) which inhibit the activity of mitogen activated protein kinase activate protein kinase 2 (MK2). MK2 mediates the inflammatory response by activating Tristetraprline (TTP). Once activated, TTP rapidly stabilizes AU rich regions of pro-inflammatory cytokine mRNA which allows translation of pro-inflammatory cytokines to occur. Blocking MK2 with our labs CPPs yields a decrease in inflammatory activity but CPPs by are highly non specific and prone to rapid enzymatic degradation in vivo.. In order to increase the potency of MK2 inhibiting CPPs we have developed a novel nanoparticle drug carrier composed of poly(N-isopropylacrylamide-co-2-acrylamido-2-methyl-1-propanesulfonic acid). This drug carrier has been shown to have preliminary efficacy in vitro and ex vivo for suppressing pro-inflammatory cytokine production when releasing CPPs. This thesis will present progress made on three aims: Specific Aim 1) Create and validate a NIPAm based drug delivery system that mimics the binding and release previously observed between cell penetrating peptides and glycosaminoglycans. Specific Aim 2) Engineer degradability into poly(NIPAm-AMPS) nanoparticles to enable more drug to be released and qualify that system in vitro. Specific Aim 3) Validate poly(NIPAm-AMPS) nanoparticles for targeted drug delivery in an ex vivo inflammatory model. Overall we have developed a novel anionic nanoparticle system that is biocompatible and efficient at loading and releasing cell penetrating peptides to inflamed tissue. Once loaded with a CPP the nanoparticle drug complex is

  2. Cell-Penetrating Peptides: A Comparative Study on Lipid Affinity and Cargo Delivery Properties

    Paolo Ruzza

    2010-03-01

    Full Text Available A growing number of natural and/or synthetic peptides with cell membrane penetrating capability have been identified and described in the past years. These molecules have been considered promising tools for delivering bioactive compounds into various cell types. Although the mechanism of uptake is still unclear, it is reasonable to assume that the relative contribute of each proposed mechanism could differ for the same peptide, depending on experimental protocol and cargo molecule composition. In this work we try to connect the capability to interact with model lipid membrane and structural and chemical characteristics of CPPs in order to obtain a biophysical classification that predicts the behavior of CPP-cargo molecules in cell systems. Indeed, the binding with cell membrane is one of the primary step in the interaction of CPPs with cells, and consequently the studies on model membrane could become important for understanding peptide-membrane interaction on a molecular level, explaining how CPPs may translocate a membrane without destroying it and how this interactions come into play in shuttling CPPs via different routes with different efficiency. We analyzed by CD and fluorescence spectroscopies the binding properties of six different CPPs (kFGF, Nle54-Antp and Tat derived peptides, and oligoarginine peptides containing 6, 8 or 10 residues in absence or presence of the same cargo peptide (the 392-401pTyr396 fragment of HS1 protein. The phospholipid binding properties were correlated to the conformational and chemical characteristics of peptides, as well as to the cell penetrating properties of the CPP-cargo conjugates. Results show that even if certain physico-chemical properties (conformation, positive charge govern CPP capability to interact with the model membrane, these cannot fully explain cell-permeability properties.

  3. Polymeric pH nanosensor with extended measurement range bearing octaarginine as cell penetrating peptide

    Ke, Peng; Sun, Honghao; Liu, Mingxing;

    2016-01-01

    A synthetic peptide octaarginine which mimics human immunodeficiency virus-1, Tat protein is used as cell penetrating moiety for new pH nanosensors which demonstrate enhanced cellular uptake and expanded measurement range from pH 3.9 to pH 7.3 by simultaneously incorporating two complemental p......H-sensitive fluorophores in a same nanoparticle. The authors believe that this triple fluorescent pH sensor provides a new tool to pH measurements that can have application in cellular uptake mechanism study and new nanomedicine design....

  4. A Cell-Penetrating Peptide with a Guanidinylethyl Amine Structure Directed to Gene Delivery

    Oba, Makoto; Kato, Takuma; Furukawa, Kaori; Tanaka, Masakazu

    2016-01-01

    A peptide composed of lysine with a guanidinylethyl (GEt) amine structure in the side chain [Lys(GEt)] was developed as a cell-penetrating peptide directed to plasmid DNA (pDNA) delivery. The GEt amine adopted a diprotonated form at neutral pH, which may have led to the more efficient cellular uptake of a Lys(GEt)-peptide than an arginine-peptide at a low concentration. Lys(GEt)-peptide/pDNA complexes showed the highest transfection efficiency due to efficient endosomal escape without any cytotoxicity. Lys(GEt)-peptide may be a promising candidate as a gene delivery carrier.

  5. SAP(E) - A cell-penetrating polyproline helix at lipid interfaces.

    Franz, Johannes; Lelle, Marco; Peneva, Kalina; Bonn, Mischa; Weidner, Tobias

    2016-09-01

    Cell-penetrating peptides (CPPs) are short membrane-permeating amino acid sequences that can be used to deliver cargoes, e.g. drugs, into cells. The mechanism for CPP internalization is still subject of ongoing research. An interesting family of CPPs is the sweet arrow peptides - SAP(E) - which are known to adopt a polyproline II helical secondary structure. SAP(E) peptides stand out among CPPs because they carry a net negative charge while most CPPs are positively charged, the latter being conducive to electrostatic interaction with generally negatively charged membranes. For SAP(E)s, an internalization mechanism has been proposed, based on polypeptide aggregation on the cell surface, followed by an endocytic uptake. However, this process has not yet been observed directly - since peptide-membrane interactions are inherently difficult to monitor on a molecular scale. Here, we use sum frequency generation (SFG) vibrational spectroscopy to investigate molecular interactions of SAP(E) with differently charged model membranes, in both mono- and bi-layer configurations. The data suggest that the initial binding mechanism is accompanied by structural changes of the peptide. Also, the peptide-model membrane interaction depends on the charge of the lipid headgroup with phosphocholine being a favorable binding site. Moreover, while direct penetration has also been observed for some CPPs, the spectroscopy reveals that for SAP(E), its interaction with model membranes remains limited to the headgroup region, and insertion into the hydrophobic core of the lipid layer does not occur. PMID:27237727

  6. Cell penetrating peptide delivery of splice directing oligonucleotides as a treatment for Duchenne muscular dystrophy.

    Betts, Corinne A; Wood, Matthew J A

    2013-01-01

    Duchenne muscular dystrophy is a severe, X-linked muscle wasting disorder caused by the absence of an integral structural protein called dystrophin. This is caused by mutations or deletions in the dystrophin gene which disrupt the reading frame, thereby halting the production of a functional protein. A number of potential therapies have been investigated for the treatment of this disease including utrophin upregulation, 'stop-codon read through' aminoglycosides and adeno-associated virus gene replacement as well as stem cell therapy. However, the most promising treatment to date is the use of antisense oligonucleotides which cause exon skipping by binding to a specific mRNA sequence, skipping the desired exon, thereby restoring the reading frame and producing a truncated yet functional protein. The results from recent 2'OMePS and morpholino clinical trials have renewed hope for Duchenne patients; however in vivo studies in a mouse model, mdx, have revealed low systemic distribution and poor delivery of oligonucleotides to affected tissues such as the brain and heart. However a variety of cell penetrating peptides directly conjugated to antisense oligonucleotides have been shown to enhance delivery in Duchenne model systems with improved systemic distribution and greater efficacy compared to 'naked' antisense oligonucleotides. These cell penetrating peptides, combined with an optimised dose and dosing regimen, as well as thorough toxicity profile have the potential to be developed into a promising treatment which may be progressed to clinical trial. PMID:23140454

  7. Potent inhibition of late stages of hepadnavirus replication by a modified cell penetrating peptide

    Abdul, Fabien; Ndeboko, Bénédicte; Buronfosse, Thierry;

    2012-01-01

    Cationic cell-penetrating peptides (CPPs) and their lipid domain-conjugates (CatLip) are agents for the delivery of (uncharged) biologically active molecules into the cell. Using infection and transfection assays we surprisingly discovered that CatLip peptides were able to inhibit replication of...... particle secretion. This is the first report showing that a CPP is able to drastically block hepadnaviral release from infected cells by altering late stages of viral morphogenesis via interference with enveloped particle formation, without affecting naked nucleocapsid egress, thus giving a view inside the...... mode of inhibition. Deca-(Arg)8 may be a useful tool for elucidating the hepadnaviral secretory pathway, which is not yet fully understood. Moreover we provide the first evidence that a modified CPP displays a novel antiviral mechanism targeting another step of viral life cycle compared to what has...

  8. p53 Aggregates penetrate cells and induce the co-aggregation of intracellular p53.

    Karolyn J Forget

    Full Text Available Prion diseases are unique pathologies in which the infectious particles are prions, a protein aggregate. The prion protein has many particular features, such as spontaneous aggregation, conformation transmission to other native PrP proteins and transmission from an individual to another. Protein aggregation is now frequently associated to many human diseases, for example Alzheimer's disease, Parkinson's disease or type 2 diabetes. A few proteins associated to these conformational diseases are part of a new category of proteins, called prionoids: proteins that share some, but not all, of the characteristics associated with prions. The p53 protein, a transcription factor that plays a major role in cancer, has recently been suggested to be a possible prionoid. The protein has been shown to accumulate in multiple cancer cell types, and its aggregation has also been reproduced in vitro by many independent groups. These observations suggest a role for p53 aggregates in cancer development. This study aims to test the «prion-like» features of p53. Our results show in vitro aggregation of the full length and N-terminally truncated protein (p53C, and penetration of these aggregates into cells. According to our findings, the aggregates enter cells using macropinocytosis, a non-specific pathway of entry. Lastly, we also show that once internalized by the cell, p53C aggregates can co-aggregate with endogenous p53 protein. Together, these findings suggest prion-like characteristics for p53 protein, based on the fact that p53 can spontaneously aggregate, these aggregates can penetrate cells and co-aggregate with cellular p53.

  9. Selective mono-radioiodination and characterization of a cell-penetrating peptide. L-Tyr-maurocalcine

    Mono-and poly-iodinated peptides form frequently during radioiodination procedures. However, the formation of a single species in its mono-iodinated form is essential for quantitative studies such as determination of tissue concentration or image quantification. Therefore, the aim of the present study was to define the optimal experimental conditions in order to exclusively obtain the mono-iodinated form of L-maurocalcine (L-MCa). L-MCa is an animal venom toxin which was shown to act as a cell-penetrating peptide. In order to apply the current direct radioiodination technique using oxidative agents including chloramine T, Iodo-Gen registered or lactoperoxidase, an analogue of this peptide containing a tyrosine residue (Tyr-L-MCa) was synthesized and was shown to fold/oxidize properly. The enzymatic approach using lactoperoxidase/H2O2 was found to be the best method for radioiodination of Tyr-L-MCa. MALDI-TOF mass spectrometry analyses were then used for identification of the chromatographic eluting components of the reaction mixtures. We observed that the production of different radioiodinated species depended upon the reaction conditions. Our results successfully described the experimental conditions of peptide radioiodination allowing the exclusive production of the mono-iodinated form with high radiochemical purity and without the need for a purification step. Mono-radioiodination of L-Tyr-MCa will be crucial for future quantitative studies, investigating the mechanism of cell penetration and in vivo biodistribution.

  10. Selective mono-radioiodination and characterization of a cell-penetrating peptide. L-Tyr-maurocalcine

    Ahmadi, Mitra; Bacot, Sandrine; Perret, Pascale; Riou, Laurent; Ghezzi, Catherine [Universite Joseph Fourier, Grenoble (France); INSERM U1039, Grenoble (France). Radiopharmaceutiques Biocliniques; Poillot, Cathy; Cestele, Sandrine [INSERM U836, Grenoble (France). Grenoble Inst. of Neuroscience; Universite Joseph Fourier, Grenoble (France); Desruet, Marie-Dominique [INSERM U1039, Grenoble (France). Radiopharmaceutiques Biocliniques; Couvet, Morgane; Bourgoin, Sandrine; Seve, Michel [CRI-INSERM U823, Grenoble (France). Inst. of Albert Bonniot; Universite Joseph Fourier, Grenoble (France); Waard, Michel de [INSERM U836, Grenoble (France). Grenoble Inst. of Neuroscience; Universite Joseph Fourier, Grenoble (France); Smartox Biotechnologies, Grenoble (France)

    2014-07-01

    Mono-and poly-iodinated peptides form frequently during radioiodination procedures. However, the formation of a single species in its mono-iodinated form is essential for quantitative studies such as determination of tissue concentration or image quantification. Therefore, the aim of the present study was to define the optimal experimental conditions in order to exclusively obtain the mono-iodinated form of L-maurocalcine (L-MCa). L-MCa is an animal venom toxin which was shown to act as a cell-penetrating peptide. In order to apply the current direct radioiodination technique using oxidative agents including chloramine T, Iodo-Gen {sup registered} or lactoperoxidase, an analogue of this peptide containing a tyrosine residue (Tyr-L-MCa) was synthesized and was shown to fold/oxidize properly. The enzymatic approach using lactoperoxidase/H{sub 2}O{sub 2} was found to be the best method for radioiodination of Tyr-L-MCa. MALDI-TOF mass spectrometry analyses were then used for identification of the chromatographic eluting components of the reaction mixtures. We observed that the production of different radioiodinated species depended upon the reaction conditions. Our results successfully described the experimental conditions of peptide radioiodination allowing the exclusive production of the mono-iodinated form with high radiochemical purity and without the need for a purification step. Mono-radioiodination of L-Tyr-MCa will be crucial for future quantitative studies, investigating the mechanism of cell penetration and in vivo biodistribution.

  11. CpG expedites regression of local and systemic tumors when combined with activatable nanodelivery.

    Kheirolomoom, Azadeh; Ingham, Elizabeth S; Mahakian, Lisa M; Tam, Sarah M; Silvestrini, Matthew T; Tumbale, Spencer K; Foiret, Josquin; Hubbard, Neil E; Borowsky, Alexander D; Murphy, William J; Ferrara, Katherine W

    2015-12-28

    Ultrasonic activation of nanoparticles provides the opportunity to deliver a large fraction of the injected dose to insonified tumors and produce a complete local response. Here, we evaluate whether the local and systemic response to chemotherapy can be enhanced by combining such a therapy with locally-administered CpG as an immune adjuvant. In order to create stable, activatable particles, a complex between copper and doxorubicin (CuDox) was created within temperature-sensitive liposomes. Whereas insonation of the CuDox liposomes alone has been shown to produce a complete response in murine breast cancer after 8 treatments of 6 mg/kg delivered over 4 weeks, combining this treatment with CpG resolved local cancers within 3 treatments delivered over 7 days. Further, contralateral tumors regressed as a result of the combined treatment, and survival was extended in systemic disease. In both the treated and contralateral tumor site, the combined treatment increased leukocytes and CD4+ and CD8+ T-effector cells and reduced myeloid-derived suppressor cells (MDSCs). Taken together, the results suggest that this combinatorial treatment significantly enhances the systemic efficacy of locally-activated nanotherapy. PMID:26471394

  12. Metabolic cleavage of cell-penetrating peptides in contact with epithelial models

    Tréhin, Rachel; Nielsen, Hanne Mørck; Jahnke, Heinz-Georg;

    2004-01-01

    We assessed the metabolic degradation kinetics and cleavage patterns of some selected CPP (cell-penetrating peptides) after incubation with confluent epithelial models. Synthesis of N-terminal CF [5(6)-carboxyfluorescein]-labelled CPP, namely hCT (human calcitonin)-derived sequences, Tat(47-57) and...... penetratin(43-58), was through Fmoc (fluoren-9-ylmethoxycarbonyl) chemistry. Metabolic degradation kinetics of the tested CPP in contact with three cell-cultured epithelial models, MDCK (Madin-Darby canine kidney), Calu-3 and TR146, was evaluated by reversed-phase HPLC. Identification of the resulting...... models and the CPP. The Calu-3 model exhibited the highest proteolytic activity. The patterns of metabolic cleavage of hCT(9-32) were similar in all three models. Initial cleavage of this peptide occurred at the N-terminal domain, possibly by endopeptidase activity yielding both the N- and the C...

  13. Plasmid DNA delivery by arginine-rich cell-penetrating peptides containing unnatural amino acids.

    Kato, Takuma; Yamashita, Hiroko; Misawa, Takashi; Nishida, Koyo; Kurihara, Masaaki; Tanaka, Masakazu; Demizu, Yosuke; Oba, Makoto

    2016-06-15

    Cell-penetrating peptides (CPPs) have been developed as drug, protein, and gene delivery tools. In the present study, arginine (Arg)-rich CPPs containing unnatural amino acids were designed to deliver plasmid DNA (pDNA). The transfection ability of one of the Arg-rich CPPs examined here was more effective than that of the Arg nonapeptide, which is the most frequently used CPP. The transfection efficiencies of Arg-rich CPPs increased with longer post-incubation times and were significantly higher at 48-h and 72-h post-incubation than that of the commercially available transfection reagent TurboFect. These Arg-rich CPPs were complexed with pDNA for a long time in cells and effectively escaped from the late endosomes/lysosomes into the cytoplasm. These results will be helpful for designing novel CPPs for pDNA delivery. PMID:27132868

  14. Cell membrane penetration and mitochondrial targeting by platinum-decorated ceria nanoparticles.

    Torrano, Adriano A; Herrmann, Rudolf; Strobel, Claudia; Rennhak, Markus; Engelke, Hanna; Reller, Armin; Hilger, Ingrid; Wixforth, Achim; Bräuchle, Christoph

    2016-07-01

    In this work we investigate the interaction between endothelial cells and nanoparticles emitted by catalytic converters. Although catalyst-derived particles are recognized as growing burden added to environmental pollution, very little is known about their health impact. We use platinum-decorated ceria nanoparticles as model compounds for the actual emitted particles and focus on their fast uptake and association with mitochondria, the cell's powerhouse. Using live-cell imaging and electron microscopy we clearly show that 46 nm platinum-decorated ceria nanoparticles can rapidly penetrate cell membranes and reach the cytosol. Moreover, if suitably targeted, these particles are able to selectively attach to mitochondria. These results are complemented by cytotoxicity assays, thus providing insights into the biological effects of these particles on cells. Interestingly, no permanent membrane disruption or any other significant adverse effects on cells were observed. The unusual uptake behavior observed for 46 nm nanoparticles was not observed for equivalent but larger 143 nm and 285 nm platinum-decorated particles. Our results demonstrate a remarkable particle size effect in which particles smaller than ∼50-100 nm escape the usual endocytic pathway and translocate directly into the cytosol, while particles larger than ∼150 nm are internalized by conventional endocytosis. Since the small particles are able to bypass endocytosis they could be explored as drug and gene delivery vehicles. Platinum-decorated nanoparticles are therefore highly interesting in the fields of nanotoxicology and nanomedicine. PMID:27341699

  15. HIV fusion peptide penetrates, disorders, and softens T-cell membrane mimics.

    Tristram-Nagle, Stephanie; Chan, Rob; Kooijman, Edgar; Uppamoochikkal, Pradeep; Qiang, Wei; Weliky, David P; Nagle, John F

    2010-09-10

    This work investigates the interaction of N-terminal gp41 fusion peptide (FP) of human immunodeficiency virus type 1 (HIV-1) with model membranes in order to elucidate how FP leads to fusion of HIV and T-cell membranes. FP constructs were (i) wild-type FP23 (23 N-terminal amino acids of gp41), (ii) water-soluble monomeric FP that adds six lysines on the C-terminus of FP23 (FPwsm), and (iii) the C-terminus covalently linked trimeric version (FPtri) of FPwsm. Model membranes were (i) LM3 (a T-cell mimic), (ii) 1,2-dioleoyl-sn-glycero-3-phosphocholine, (iii) 1,2-dioleoyl-sn-glycero-3-phosphocholine/30 mol% cholesterol, (iv) 1,2-dierucoyl-sn-glycero-3-phosphocholine, and (v) 1,2-dierucoyl-sn-glycero-3-phosphocholine/30 mol% cholesterol. Diffuse synchrotron low-angle x-ray scattering from fully hydrated samples, supplemented by volumetric data, showed that FP23 and FPtri penetrate into the hydrocarbon region and cause membranes to thin. Depth of penetration appears to depend upon a complex combination of factors including bilayer thickness, presence of cholesterol, and electrostatics. X-ray data showed an increase in curvature in hexagonal phase 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine, which further indicates that FP23 penetrates into the hydrocarbon region rather than residing in the interfacial headgroup region. Low-angle x-ray scattering data also yielded the bending modulus K(C), a measure of membrane stiffness, and wide-angle x-ray scattering yielded the S(xray) orientational order parameter. Both FP23 and FPtri decreased K(C) and S(xray) considerably, while the weak effect of FPwsm suggests that it did not partition strongly into LM3 model membranes. Our results are consistent with the HIV FP disordering and softening the T-cell membrane, thereby lowering the activation energy for viral membrane fusion. PMID:20655315

  16. Therapeutic Potential of Cell Penetrating Peptides (CPPs) and Cationic Polymers for Chronic Hepatitis B

    Ndeboko, Bénédicte; Lemamy, Guy Joseph; Nielsen, Peter E;

    2015-01-01

    Chronic hepatitis B virus (HBV) infection remains a major health problem worldwide. Because current anti-HBV treatments are only virostatic, there is an urgent need for development of alternative antiviral approaches. In this context, cell-penetrating peptides (CPPs) and cationic polymers, such as...... chitosan (CS), appear of particular interest as nonviral vectors due to their capacity to facilitate cellular delivery of bioactive cargoes including peptide nucleic acids (PNAs) or DNA vaccines. We have investigated the ability of a PNA conjugated to different CPPs to inhibit the replication of duck...... hepatitis B virus (DHBV), a reference model for human HBV infection. The in vivo administration of PNA-CPP conjugates to neonatal ducklings showed that they reached the liver and inhibited DHBV replication. Interestingly, our results indicated also that a modified CPP (CatLip) alone, in the absence of its...

  17. Enhanced cellular delivery of cell-penetrating peptide-peptide nucleic acid conjugates by photochemical internalization

    Shiraishi, Takehiko; Nielsen, Peter E

    2011-01-01

    Cell-penetrating peptides (CPPs) have been widely used for a cellular delivery of biologically relevant cargoes including antisense peptide nucleic acids (PNAs). Although chemical conjugation of PNA to a variety of CPPs significantly improves the cellular uptake of the PNAs, bioavailability...... (antisense activity) is still limited by endocytotic entrapment. We have shown that this low bioavailability can be greatly improved by combining CPP-PNA conjugate administration with a photochemical internalization technique using photosensitizers such as aluminum phthalocyanine (AlPcS(2a)) or...... cellular efficacy of CPP conjugates were evaluated by measuring luciferase activity as a result of splicing correction and was also confirmed by RT-PCR analysis of luciferase pre-mRNA....

  18. Cell membrane penetration and mitochondrial targeting by platinum-decorated ceria nanoparticles

    Torrano, Adriano A.; Herrmann, Rudolf; Strobel, Claudia; Rennhak, Markus; Engelke, Hanna; Reller, Armin; Hilger, Ingrid; Wixforth, Achim; Bräuchle, Christoph

    2016-07-01

    In this work we investigate the interaction between endothelial cells and nanoparticles emitted by catalytic converters. Although catalyst-derived particles are recognized as growing burden added to environmental pollution, very little is known about their health impact. We use platinum-decorated ceria nanoparticles as model compounds for the actual emitted particles and focus on their fast uptake and association with mitochondria, the cell's powerhouse. Using live-cell imaging and electron microscopy we clearly show that 46 nm platinum-decorated ceria nanoparticles can rapidly penetrate cell membranes and reach the cytosol. Moreover, if suitably targeted, these particles are able to selectively attach to mitochondria. These results are complemented by cytotoxicity assays, thus providing insights into the biological effects of these particles on cells. Interestingly, no permanent membrane disruption or any other significant adverse effects on cells were observed. The unusual uptake behavior observed for 46 nm nanoparticles was not observed for equivalent but larger 143 nm and 285 nm platinum-decorated particles. Our results demonstrate a remarkable particle size effect in which particles smaller than ~50-100 nm escape the usual endocytic pathway and translocate directly into the cytosol, while particles larger than ~150 nm are internalized by conventional endocytosis. Since the small particles are able to bypass endocytosis they could be explored as drug and gene delivery vehicles. Platinum-decorated nanoparticles are therefore highly interesting in the fields of nanotoxicology and nanomedicine.In this work we investigate the interaction between endothelial cells and nanoparticles emitted by catalytic converters. Although catalyst-derived particles are recognized as growing burden added to environmental pollution, very little is known about their health impact. We use platinum-decorated ceria nanoparticles as model compounds for the actual emitted particles and

  19. Endothelial cell counts after Descemet’s stripping automated endothelial keratoplasty versus penetrating keratoplasty in Asian eyes

    Ang M

    2012-04-01

    Full Text Available Marcus Ang1,2, Jodhbir S Mehta1–4, Arundhati Anshu1,2, Hon Kiat Wong5, Hla M Htoon2, Donald Tan1–31Singapore National Eye Centre, 2Singapore Eye Research Institute, 3Department of Ophthalmology, National University Health Systems, 4Department of Clinical Sciences, Duke-NUS Graduate Medical School, 5Department of Ophthalmology, Tan Tock Seng Hospital, SingaporeBackground: The purpose of this study was to compare endothelial cell counts after Descemet’s stripping automated endothelial keratoplasty (DSAEK and penetrating keratoplasty in Asian eyes.Methods: This was a retrospective study of patients from our prospective Singapore Corneal Transplant Study cohort who received corneal transplantation in 2006–2008. We compared eyes that underwent DSAEK or penetrating keratoplasty for Fuchs’ endothelial dystrophy or pseudophakic and aphakic bullous keratopathy. Clinical data, and donor and recipient characteristics were recorded. Of 241 patients who met our inclusion criteria, 68 underwent DSAEK and 173 underwent penetrating keratoplasty. The main outcome measure was endothelial cell loss at 1 year. Secondary outcome measures were graft survival and visual outcomes at 1-year follow-up.Results: There were no significant differences in baseline characteristics of patients between the treatment groups. Percent endothelial cell loss at 1-year follow-up was greater in penetrating keratoplasty eyes (40.9% ± 2.9% compared with DSAEK eyes (22.4% ± 2.3%; P < 0.001. DSAEK-treated eyes had significantly superior uncorrected visual acuity (mean difference = 0.42 ± 0.0059; P < 0.001 and best spectacle-corrected visual acuity (mean difference = 0.14 ± 0.032; P < 0.001 as compared with penetrating keratoplasty-treated eyes. Penetrating keratoplasty-treated eyes had worse astigmatism as compared with DSAEK-treated eyes (-3.0 ± 2.1 versus -1.7 ± 0.8; P < 0.001. Graft survival at 1 year was comparable in both groups, ie, 66/68 (97.0% DSAEK-treated eyes

  20. Generation of GFP Native Protein for Detection of Its Intracellular Uptake by Cell-Penetrating Peptides.

    Kadkhodayan, S; Sadat, S M; Irani, S; Fotouhi, F; Bolhassani, A

    2016-01-01

    Different types of lipid- and polymer-based vectors have been developed to deliver proteins into cells, but these methods showed relatively poor efficiency. Recently, a group of short, highly basic peptides known as cell-penetrating peptides (CPPs) were used to carry polypeptides and proteins into cells. In this study, expression and purification of GFP protein was performed using the prokaryotic pET expression system. We used two amphipathic CPPs (Pep-1 and CADY-2) as a novel delivery system to transfer the GFP protein into cells. The morphological features of the CPP/GFP complexes were studied by scanning electron microscopy (SEM), Zetasizer, and SDS-PAGE. The efficiency of GFP transfection using Pep-1 and CADY-2 peptides and TurboFect reagent was compared with FITC-antibody protein control delivered by these transfection vehicles in the HEK-293T cell line. SEM data confirmed formation of discrete nanoparticles with a diameter of below 300 nm. Moreover, formation of the complexes was detected using SDS-PAGE as two individual bands, indicating non-covalent interaction. The size and homogeneity of Pep-1/GFP and CADY-2/GFP complexes were dependent on the ratio of peptide/cargo formulations, and responsible for their biological efficiency. The cells transfected by Pep-1/GFP and CADY-2/GFP complexes at a molar ratio of 20 : 1 demonstrated spreading green regions using fluorescent microscopy. Flow cytometry results showed that the transfection efficiency of Pep-based nanoparticles was similar to CADY-based nanoparticles and comparable with TurboFect-protein complexes. These data open an efficient way for future therapeutic purposes. PMID:27516189

  1. Cell penetrating peptides improve tumor delivery of cargos through neuropilin-1-dependent extravasation.

    Kadonosono, Tetsuya; Yamano, Akihiro; Goto, Toshiki; Tsubaki, Takuya; Niibori, Mizuho; Kuchimaru, Takahiro; Kizaka-Kondoh, Shinae

    2015-03-10

    Cell-penetrating peptides (CPPs), also referred to as protein transduction domains (PTDs), can mediate the cellular uptake of a wide range of macromolecules including peptides, proteins, oligonucleotides, and nanoparticles, and thus have received considerable attention as a promising method for drug delivery in vivo. Here, we report that CPP/PTDs facilitate the extravasation of fused proteins by binding to neuropilin-1 (NRP1), a vascular endothelial growth factor (VEGF) co-receptor expressed on the surface of endothelial and some tumor cells. In this study, we examined the capacity of the amphipathic and cationic CPP/PTDs, PTD-3 and TAT-PTD, respectively, to bind cells in vitro and accumulate in xenograft tumors in vivo. Notably, these functions were significantly suppressed by pre-treatment with NRP1-neutralizing Ab. Furthermore, co-injection of iRGD, a cyclic peptide known to increase NRP1-dependent vascular permeability, significantly reduced CPP/PTD tumor delivery. This data demonstrates a mechanism by which NRP1 promotes the extravasation of CPP/PTDs that may open new avenues for the development of more efficient CPP/PTD delivery systems. PMID:25592386

  2. Conjugation to the cell-penetrating peptide TAT potentiates the photodynamic effect of carboxytetramethylrhodamine.

    Divyamani Srinivasan

    Full Text Available BACKGROUND: Cell-penetrating peptides (CPPs can transport macromolecular cargos into live cells. However, the cellular delivery efficiency of these reagents is often suboptimal because CPP-cargo conjugates typically remain trapped inside endosomes. Interestingly, irradiation of fluorescently labeled CPPs with light increases the release of the peptide and its cargos into the cytosol. However, the mechanism of this phenomenon is not clear. Here we investigate the molecular basis of the photo-induced endosomolytic activity of the prototypical CPPs TAT labeled to the fluorophore 5(6-carboxytetramethylrhodamine (TMR. METHODOLOGY/PRINCIPAL FINDINGS: We report that TMR-TAT acts as a photosensitizer that can destroy membranes. TMR-TAT escapes from endosomes after exposure to moderate light doses. However, this is also accompanied by loss of plasma membrane integrity, membrane blebbing, and cell-death. In addition, the peptide causes the destruction of cells when applied extracellularly and also triggers the photohemolysis of red blood cells. These photolytic and photocytotoxic effects were inhibited by hydrophobic singlet oxygen quenchers but not by hydrophilic quenchers. CONCLUSIONS/SIGNIFICANCE: Together, these results suggest that TAT can convert an innocuous fluorophore such as TMR into a potent photolytic agent. This effect involves the targeting of the fluorophore to cellular membranes and the production of singlet oxygen within the hydrophobic environment of the membranes. Our findings may be relevant for the design of reagents with photo-induced endosomolytic activity. The photocytotoxicity exhibited by TMR-TAT also suggests that CPP-chromophore conjugates could aid the development of novel Photodynamic Therapy agents.

  3. Design and screening of a glial cell-specific, cell penetrating peptide for therapeutic applications in multiple sclerosis.

    Corey Heffernan

    Full Text Available Multiple Sclerosis (MS is an autoimmune, neurodegenerative disease of the central nervous system (CNS characterized by demyelination through glial cell loss. Current and proposed therapeutic strategies to arrest demyelination and/or promote further remyelination include: (i modulation of the host immune system; and/or (ii transplantation of myelinating/stem or progenitor cells to the circulation or sites of injury. However, significant drawbacks are inherent with both approaches. Cell penetrating peptides (CPP are short amino acid sequences with an intrinsic ability to translocate across plasma membranes, and theoretically represent an attractive vector for delivery of therapeutic peptides or nanoparticles to glia to promote cell survival or remyelination. The CPPs described to date are commonly non-selective in the cell types they transduce, limiting their therapeutic application in vivo. Here, we describe a theoretical framework for design of a novel CPP sequence that selectively transduces human glial cells (excluding non-glial cell types, and conduct preliminary screens of purified, recombinant CPPs with immature and matured human oligodendrocytes and astrocytes, and two non-glial cell types. A candidate peptide, termed TD2.2, consistently transduced glial cells, was significantly more effective at transducing immature oligodendrocytes than matured progeny, and was virtually incapable of transducing two non-glial cell types: (i human neural cells and (ii human dermal fibroblasts. Time-lapse confocal microscopy confirms trafficking of TD2.2 (fused to EGFP to mature oligodendrocytes 3-6 hours after protein application in vitro. We propose selectivity of TD2.2 for glial cells represents a new therapeutic strategy for the treatment of glial-related disease, such as MS.

  4. Nanocarriers Conjugated with Cell Penetrating Peptides: New Trojan Horses by Modern Ulysses.

    Zappavigna, Silvia; Misso, Gabriella; Falanga, Annarita; Perillo, Emiliana; Novellino, Ettore; Galdiero, Massimiliano; Grieco, Paolo; Caraglia, Michele; Galdiero, Stefania

    2016-01-01

    Nanomedicine has opened the way to the design of more efficient diagnostics and therapeutics. Moreover, recent literature has illustrated the use of short cationic and/or amphipathic peptides, known as cell-penetrating peptides (CPPs), for mediating advanced drug delivery. CPPs exploit their ability to enter cells and enhance the uptake of many cargoes ranging from small molecules to proteins. The distinctive properties of nanocarriers (NC) based systems provide unforeseen benefits over pure drugs for biomedical applications and constitute a challenging research field particularly focused on imaging and delivery; nonetheless, several problems have to be overcome to make them a viable option in clinic. The use of CPPs improves significantly their delivery to specific intracellular targets and thus readily contributes to their use both for effective tumor therapy and gene therapy. A key issue is related to their mechanism of uptake, because although classical CPPs enhance NCs' uptake, the entry mechanism involves the endocytic pathway, which means that the delivered material is sequestered within vesicles and only a small amount will escape from this environment and reach the desired target. In this review, we will summarize recent advances in the use of CPP for enhanced delivery of nanocarriers, nucleic acids, and drugs, we will discuss their uptake mechanisms and we will describe novel approaches to improve endosomal escape of internalized nanosystems. PMID:27087493

  5. Intracellular Target-Specific Accretion of Cell Penetrating Peptides and Bioportides: Ultrastructural and Biological Correlates.

    Jones, Sarah; Uusna, Julia; Langel, Ülo; Howl, John

    2016-01-20

    Cell penetrating peptide (CPP) technologies provide a viable strategy to regulate the activities of intracellular proteins that may be intractable to other biological agents. In particular, the cationic helical domains of proteins have proven to be a reliable source of proteomimetic bioportides, CPPs that modulate the activities of intracellular proteins. In this study we have employed live cell imaging confocal microscopy to determine the precise intracellular distribution of a chemically diverse set of CPPs and bioportides. Our findings indicate that, following efficient cellular entry, peptides are usually accreted at intracellular sites rather than being freely maintained in an aqueous cytosolic environment. The binding of CPPs to proteins in a relatively stable manner provides a molecular explanation for our findings. By extension, it is probable that many bioportides influence biological processes through a dominant-negative influence upon discrete protein-protein interactions. As an example, we report that bioportides derived from the leucine-rich repeat kinase 2 discretely influence the biology and stability of this key therapeutic target in Parkinson's disease. The intracellular site-specific accretion of CPPs and bioportides can also be readily modulated by the attachment of larger cargoes or, more conveniently, short homing motifs. We conclude that site-specific intracellular targeting could be further exploited to expand the scope of CPP technologies. PMID:26623479

  6. The targeted transduction of MMP-overexpressing tumor cells by ACPP-HPMA copolymer-coated adenovirus conjugates.

    Shuhua Li

    Full Text Available We have designed and tested a new way to selectively deliver HPMA polymer-coated adenovirus type 5 (Ad5 particles into matrix metalloproteinase (MMP-overexpressing tumor cells. An activatable cell penetrating peptide (ACPP was designed and attached to the reactive 4-nitrophenoxy groups of HPMA polymers by the C-terminal amino acid (asparagine, N. ACPPs are activatable cell penetrating peptides (CPPs with a linker between polycationic and polyanionic domains, and MMP-mediated cleavage releases the CPP portion and its attached cargo to enable cell entry. Our data indicate that the transport of these HPMA polymer conjugates by a single ACPP molecule to the cytoplasm occurs via a nonendocytotic and concentration-independent process. The uptake was observed to finish within 20 minutes by inverted fluorescence microscopy. In contrast, HPMA polymer-coated Ad5 without ACPPs was internalized solely by endocytosis. The optimal formulation was not affected by the presence of Ad5 neutralizing antibodies during transduction, and ACPP/polymer-coated Ad5 also retained high targeting capability to several MMP-overexpressing tumor cell types. For the first time, ACPP-mediated cytoplasmic delivery of polymer-bound Ad5 to MMP-overexpressing tumor cells was demonstrated. These findings are significant, as they demonstrate the use of a polymer-based system for the targeted delivery into MMP-overexpressing solid tumors and highlight how to overcome major cellular obstacles to achieve intracellular macromolecular delivery.

  7. Precise quantification of cellular uptake of cell-penetrating peptides using fluorescence-activated cell sorting and fluorescence correlation spectroscopy.

    Rezgui, Rachid; Blumer, Katy; Yeoh-Tan, Gilbert; Trexler, Adam J; Magzoub, Mazin

    2016-07-01

    Cell-penetrating peptides (CPPs) have emerged as a potentially powerful tool for drug delivery due to their ability to efficiently transport a whole host of biologically active cargoes into cells. Although concerted efforts have shed some light on the cellular internalization pathways of CPPs, quantification of CPP uptake has proved problematic. Here we describe an experimental approach that combines two powerful biophysical techniques, fluorescence-activated cell sorting (FACS) and fluorescence correlation spectroscopy (FCS), to directly, accurately and precisely measure the cellular uptake of fluorescently-labeled molecules. This rapid and technically simple approach is highly versatile and can readily be applied to characterize all major CPP properties that normally require multiple assays, including amount taken up by cells (in moles/cell), uptake efficiency, internalization pathways, intracellular distribution, intracellular degradation and toxicity threshold. The FACS-FCS approach provides a means for quantifying any intracellular biochemical entity, whether expressed in the cell or introduced exogenously and transported across the plasma membrane. PMID:27033412

  8. Novel Bioluminescent Activatable Reporter for Src Tyrosine Kinase Activity in Living Mice.

    Leng, Weibing; Li, Dezhi; Chen, Liang; Xia, Hongwei; Tang, Qiulin; Chen, Baoqin; Gong, Qiyong; Gao, Fabao; Bi, Feng

    2016-01-01

    Aberrant activation of the Src kinase is implicated in the development of a variety of human malignancies. However, it is almost impossible to monitor Src activity in an in vivo setting with current biochemical techniques. To facilitate the noninvasive investigation of the activity of Src kinase both in vitro and in vivo, we developed a genetically engineered, activatable bioluminescent reporter using split-luciferase complementation. The bioluminescence of this reporter can be used as a surrogate for Src activity in real time. This hybrid luciferase reporter was constructed by sandwiching a Src-dependent conformationally responsive unit (SH2 domain-Srcpep) between the split luciferase fragments. The complementation bioluminescence of this reporter was dependent on the Src activity status. In our study, Src kinase activity in cultured cells and tumor xenografts was monitored quantitatively and dynamically in response to clinical small-molecular kinase inhibitors, dasatinib and saracatinib. This system was also applied for high-throughput screening of Src inhibitors against a kinase inhibitor library in living cells. These results provide unique insights into drug development and pharmacokinetics/phoarmocodynamics of therapeutic drugs targeting Src signaling pathway enabling the optimization of drug administration schedules for maximum benefit. Using both Firefly and Renilla luciferase imaging, we have successfully monitored Src tyrosine kinase activity and Akt serine/threonine kinase activity concurrently in one tumor xenograft. This dual luciferase reporter imaging system will be helpful in exploring the complex signaling networks in vivo. The strategies reported here can also be extended to study and image other important kinases and the cross-talks among them. PMID:26941850

  9. Studies on penetration of antibiotic in bacterial cells in space conditions (7-IML-1)

    Tixador, R.

    1992-01-01

    The Cytos 2 experiment was performed aboard Salyut 7 in order to test the antibiotic sensitivity of bacteria cultivated in vitro in space. An increase of the Minimal Inhibitory Concentration (MIC) in the inflight cultures (i.e., an increase of the antibiotic resistance) was observed. Complementary studies of the ultrastructure showed a thickening of the cell envelope. In order to confirm the results of the Cytos 2 experiment, we performed the ANTIBIO experiment during the D1 mission to try to differentiate, by means of the 1 g centrifuge in the Biorack, between the biological effects of cosmic rays and those caused by microgravity conditions. The originality of this experiment was in the fact that it was designed to test the antibiotic sensitivity of bacteria cultivated in vitro during the orbital phase of the flight. The results show an increase in resistance to Colistin in in-flight bacteria. The MIC is practically double in the in-flight cultures. A cell count of living bacteria in the cultures containing the different Colistin concentrations showed a significant difference between the cultures developed during space flight and the ground based cultures. The comparison between the 1 g and 0 g in-flight cultures show similar behavior for the two sets. Nevertheless, a small difference between the two sets of ground based control cultures was noted. The cultures developed on the ground centrifuge (1.4 g) present a slight decrease in comparison with the cultures developed in the static rack (1 g). In order to approach the mechanisms of the increase of antibiotic resistance on bacteria cultivated in vitro in space, we have proposed the study on penetration of antibiotics in bacterial cells in space conditions. This experiment was selected for the International Microgravity Laboratory 1 (IML-1) mission.

  10. Cellular uptake but low permeation of human calcitonin-derived cell penetrating peptides and Tat(47-57) through well-differentiated epithelial models

    Tréhin, Rachel; Krauss, Ulrike; Beck-Sickinger, Annette G;

    2004-01-01

    To investigate whether cell penetrating peptides (CPP) derived from human calcitonin (hCT) possess, in addition to cellular uptake, the capacity to deliver their cargo through epithelial barriers.......To investigate whether cell penetrating peptides (CPP) derived from human calcitonin (hCT) possess, in addition to cellular uptake, the capacity to deliver their cargo through epithelial barriers....

  11. Biofunctionalized nanoparticles with pH-responsive and cell penetrating blocks for gene delivery

    Gaspar, V. M.; Marques, J. G.; Sousa, F.; Louro, R. O.; Queiroz, J. A.; Correia, I. J.

    2013-07-01

    Bridging the gap between nanoparticulate delivery systems and translational gene therapy is a long sought after requirement in nanomedicine-based applications. However, recent developments regarding nanoparticle functionalization have brought forward the ability to synthesize materials with biofunctional moieties that mimic the evolved features of viral particles. Herein we report the versatile conjugation of both cell penetrating arginine and pH-responsive histidine moieties into the chitosan polymeric backbone, to improve the physicochemical characteristics of the native material. Amino acid coupling was confirmed by 2D TOCSY NMR and Fourier transform infrared spectroscopy. The synthesized chitosan-histidine-arginine (CH-H-R) polymer complexed plasmid DNA biopharmaceuticals, and spontaneously assembled into stable 105 nm nanoparticles with spherical morphology and positive surface charge. The functionalized delivery systems were efficiently internalized into the intracellular compartment, and exhibited remarkably higher transfection efficiency than unmodified chitosan without causing any cytotoxic effect. Additional findings regarding intracellular trafficking events reveal their preferential escape from degradative lysosomal pathways and nuclear localization. Overall, this assembly of nanocarriers with bioinspired moieties provides the foundations for the design of efficient and customizable materials for cancer gene therapy.

  12. Biofunctionalized nanoparticles with pH-responsive and cell penetrating blocks for gene delivery

    Bridging the gap between nanoparticulate delivery systems and translational gene therapy is a long sought after requirement in nanomedicine-based applications. However, recent developments regarding nanoparticle functionalization have brought forward the ability to synthesize materials with biofunctional moieties that mimic the evolved features of viral particles. Herein we report the versatile conjugation of both cell penetrating arginine and pH-responsive histidine moieties into the chitosan polymeric backbone, to improve the physicochemical characteristics of the native material. Amino acid coupling was confirmed by 2D TOCSY NMR and Fourier transform infrared spectroscopy. The synthesized chitosan–histidine–arginine (CH–H–R) polymer complexed plasmid DNA biopharmaceuticals, and spontaneously assembled into stable 105 nm nanoparticles with spherical morphology and positive surface charge. The functionalized delivery systems were efficiently internalized into the intracellular compartment, and exhibited remarkably higher transfection efficiency than unmodified chitosan without causing any cytotoxic effect. Additional findings regarding intracellular trafficking events reveal their preferential escape from degradative lysosomal pathways and nuclear localization. Overall, this assembly of nanocarriers with bioinspired moieties provides the foundations for the design of efficient and customizable materials for cancer gene therapy. (paper)

  13. Effects of Tryptophan Content and Backbone Spacing on the Uptake Efficiency of Cell-Penetrating Peptides

    Rydberg, Hanna A.

    2012-07-10

    Cell-penetrating peptides (CPPs) are able to traverse cellular membranes and deliver macromolecular cargo. Uptake occurs through both endocytotic and nonendocytotic pathways, but the molecular requirements for efficient internalization are not fully understood. Here we investigate how the presence of tryptophans and their position within an oligoarginine influence uptake mechanism and efficiency. Flow cytometry and confocal fluorescence imaging are used to estimate uptake efficiency, intracellular distribution and toxicity in Chinese hamster ovarian cells. Further, membrane leakage and lipid membrane affinity are investigated. The peptides contain eight arginine residues and one to four tryptophans, the tryptophans positioned either at the N-terminus, in the middle, or evenly distributed along the amino acid sequence. Our data show that the intracellular distribution varies among peptides with different tryptophan content and backbone spacing. Uptake efficiency is higher for the peptides with four tryptophans in the middle, or evenly distributed along the peptide sequence, than for the peptide with four tryptophans at the N-terminus. All peptides display low cytotoxicity except for the one with four tryptophans at the N-terminus, which was moderately toxic. This finding is consistent with their inability to induce efficient leakage of dye from lipid vesicles. All peptides have comparable affinities for lipid vesicles, showing that lipid binding is not a decisive parameter for uptake. Our results indicate that tryptophan content and backbone spacing can affect both the CPP uptake efficiency and the CPP uptake mechanism. The low cytotoxicity of these peptides and the possibilities of tuning their uptake mechanism are interesting from a therapeutic point of view. © 2012 American Chemical Society.

  14. Design of Oligothiophene-Based Tetrazoles for Laser-Triggered Photoclick Chemistry in Living Cells

    An, Peng; Yu, Zhipeng; Lin, Qing

    2013-01-01

    A 405 nm light-activatable terthiophene-based tetrazole was designed that reacts with a fumarate dipolarophile with the second-order rate constant k2 exceeding 103 M−1 s−1. The utility of this laser-activatable tetrazole in imaging microtubules in a spatiotemporally controlled manner in live cells was demonstrated.

  15. Cell-Penetrating Peptides as Carriers for Oral Delivery of Biopharmaceuticals.

    Kristensen, Mie; Nielsen, Hanne Mørck

    2016-02-01

    Oral delivery of biopharmaceuticals, for example peptides and proteins, constitutes a great challenge in drug delivery due to their low chemical stability and poor permeation across the intestinal mucosa, to a large extent limiting the mode of administration to injections, which is not favouring patient compliance. Nevertheless, cell-penetrating peptides (CPPs) have shown promising potential as carriers to overcome the epithelium, and this minireview highlights recent knowledge gained within the field of CPP-mediated transepithelial delivery of therapeutic peptides and proteins from the intestine. Two approaches may be pursued: co-administration of the carrier and therapeutic peptide in the form of complexes obtained by simple bulk mixing, or administration of covalent conjugates demanding more advanced production methodologies. These formulation approaches have their pros and cons, and which is to be preferred depends on the physicochemical properties of both the specific CPP and the specific cargo. In addition to the physical epithelial barrier, a metabolic barrier must be overcome in order to obtain CPP-mediated delivery of a cargo drug from the intestine, and a number of strategies have been employed to delay enzymatic degradation of the CPP. The mechanisms by which CPPs translocate across membranes are not fully understood, but possibly involve endocytosis as well as direct translocation, and the CPP-mediated transepithelial delivery of cargo drugs thus likely involves similar mechanisms for the initial membrane interaction and translocation. However, the mechanisms responsible for transcytosis of the cargo drug, if taken up by an endocytic mechanism, or direct translocation across the epithelium are so far not known. PMID:26525297

  16. Effect of the infectious laryngotracheitis virus (ILTV) glycoprotein G on virus attachment, penetration, growth curve and direct cell-to-cell spread

    SUN; Zhaogang; ZHANG; Manfu

    2005-01-01

    The secreted alphaherpesvirus glycoprotein G (gG) works differently from other proteins. Analysis of the role of ILTV gG in virus attachment, penetration, direct cell-to-cell spread (CTCS) and the growth curve showed that gG or its antibody had no effect on ILTV attachment and penetration and that the gG antibody reduced the virus plaque size and the one-step growth curve on chicken embryo liver (CEL) cells, but gG did not affect the virus plaque size or the one-step growth curve on CEL cells. Laser scanning confocal microscopy (LSCM) detection showed that ILTV gG is located in the perinuclear region and the membrane of the CEL cells. These results suggested that ILTV gG might contribute to direct cell-to-cell transmission.

  17. Cell-penetrating peptides as noninvasive transmembrane vectors for the development of novel multifunctional drug-delivery systems.

    Zhang, Dongdong; Wang, Jiaxi; Xu, Donggang

    2016-05-10

    Unique characteristics, such as nontoxicity and rapid cellular internalization, allow the cell-penetrating peptides (CPPs) to transport hydrophilic macromolecules into cells, thus, enabling them to execute biological functions. However, some CPPs have limitations due to nonspecificity and easy proteolysis. To overcome such defects, the CPP amino acid sequence can be modified, replaced, and reconstructed for optimization. CPPs can also be used in combination with other drug vectors, fused with their preponderances to create novel multifunctional drug-delivery systems that increase the stability during blood circulation, and also develop novel preparations capable of targeted delivery, along with sustainable and controllable release. Further improvements in CPP structure can facilitate the penetration of macromolecules into diverse biomembrane structures, such as the blood brain barrier, gastroenteric mucosa, and skin dermis. The ability of CPP to act as transmembrane vectors improves the clinical application of some biomolecules to treat central nervous system diseases, increase oral bioavailability, and develop percutaneous-delivery dosage form. PMID:26993425

  18. Effects of Lipid Composition on the Entry of Cell-Penetrating Peptide Oligoarginine into Single Vesicles.

    Sharmin, Sabrina; Islam, Md Zahidul; Karal, Mohammad Abu Sayem; Alam Shibly, Sayed Ul; Dohra, Hideo; Yamazaki, Masahito

    2016-08-01

    The cell-penetrating peptide R9, an oligoarginine comprising nine arginines, has been used to transport biological cargos into cells. However, the mechanisms underlying its translocation across membranes remain unclear. In this report, we investigated the entry of carboxyfluorescein (CF)-labeled R9 (CF-R9) into single giant unilamellar vesicles (GUVs) of various lipid compositions and the CF-R9-induced leakage of a fluorescent probe, Alexa Fluor 647 hydrazide (AF647), using a method developed recently by us. First, we investigated the interaction of CF-R9 with dioleoylphosphatidylglycerol (DOPG)/dioleoylphosphatidylcholine (DOPC) GUVs containing AF647 and small DOPG/DOPC vesicles. The fluorescence intensity of the GUV membrane due to CF-R9 (i.e., the rim intensity) increased with time to a steady-state value, and then the fluorescence intensity of the membranes of the small vesicles in the GUV lumen increased without leakage of AF647. This result indicates that CF-R9 entered the GUV lumen from the outside by translocating across the lipid membrane without forming pores through which AF647 could leak. The fraction of entry of CF-R9 at 6 min in the absence of pore formation, Pentry (6 min), increased with an increase in CF-R9 concentration, but the CF-R9 concentration in the lumen was low. We obtained similar results for dilauroyl-PG (DLPG)/ditridecanoyl-PC (DTPC) (2/8) GUVs. The values of Pentry (6 min) of CF-R9 for DLPG/DTPC (2/8) GUVs were larger than those obtained with DOPG/DOPC (2/8) GUVs at the same CF-R9 concentrations. In contrast, a high concentration of CF-R9 induced pores in DLPG/DTPC (4/6) GUVs through which CF-R9 entered the GUV lumen, so the CF-R9 concentration in the lumen was higher. However, CF-R9 could not enter DOPG/DOPC/cholesterol (2/6/4) GUVs. Analysis of the rim intensity showed that CF-R9 was located only in the outer monolayer of the DOPG/DOPC/cholesterol (2/6/4) GUVs. On the basis of analyses of these results, we discuss the elementary

  19. Imaging Dendrimer-Grafted Graphene Oxide Mediated Anti-miR-21 Delivery With an Activatable Luciferase Reporter.

    Wang, Fu; Zhang, Beilei; Zhou, Lin; Shi, Yaru; Li, Zhiqiang; Xia, Yuqiong; Tian, Jie

    2016-04-13

    MicroRNAs (miRNAs) are a class of post-transcriptional gene regulators involved in various physiological processes including carcinogenesis, and they have emerged as potential targets for tumor theranostics. However, the employment of antisense oligonucleotides, termed anti-miRs, for antagonizing miRNA functions in vivo has largely been impeded by a lack of effective delivery carriers. Here, we describe the development of polyamidoamine (PAMAM) dendrimer and polyethylene glycol (PEG)-functionalized nanographene oxide (NGO) conjugate (NGO-PEG-dendrimer) for the efficient delivery of anti-miR-21 into non-small-cell lung cancer cells. To monitor the delivery of anti-miR-21 into cells and tumors, we also constructed an activatable luciferase reporter (Fluc-3xPS) containing three perfectly complementary sequences against miR-21 in the 3' untranslated region (UTR) of the reporter. Compared with bare dendrimer and Lipofectamine 2000 (Lipo2000), NGO-PEG-dendrimer showed considerably lower cytotoxicity and higher transfection efficiency. As demonstrated by in vitro bioluminescence imaging and Western blotting assays, NGO-PEG-dendrimer effectively delivered anti-miR-21 into the cytoplasm and resulted in the upregulation of luciferase intensity and PTEN target protein expression in a dose-dependent manner. Moreover, transfection with anti-miR-21 by NGO-PEG-dendrimer led to stronger inhibition of cell migration and invasion than did bare dendrimer or Lipo2000 transfection. The intravenous delivery of anti-miR-21 via NGO-PEG-dendrimer induced a significant increase in the bioluminescence signal within the Fluc-3xPS reporter-transplanted tumor areas. These results suggest that NGO-PEG-dendrimer could be an efficient and a potential nanocarrier for delivering RNA oligonucleotides. In addition, the strategy of combining NGO-PEG-dendrimer with an activatable luciferase reporter allows the image-guided monitoring of the delivery process, which can provide insights into the RNA

  20. Quantitative & qualitative analysis of endothelial cells of donor cornea before & after penetrating keratoplasty in different pathological conditions

    Aruna K.R. Gupta

    2016-01-01

    Full Text Available Background & objectives: Endothelial cells of the donor cornea are known to be affected quantitatively and qualitatively in different pathological conditions after penetrating keratoplasty (PK and this has direct effect on the clarity of vision obtained after PK. This study was undertaken to analyze the qualitative and quantitative changes in donor endothelial cells before and after PK in different pathological conditions. Methods: A prospective investigational analysis of 100 consecutive donor corneas used for penetrating keratoplasty between June 2006 and June 2008, was conducted. The patients were evaluated on the first day, at the end of first week, first month, third and six months and one year. Results: A decrease was observed in endothelial cell count in all pathological conditions. After one year of follow up the loss was 33.1 per cent in corneal opacity, 45.9 per cent in acute infective keratitis (AIK, 58.5 per cent in regrafts, 28.5 per cent in pseudophakic bullous keratopathy (PBK, 37 per cent in descemetocele, 27 per cent in keratoconus and 35.5 per cent in aphakic bullous keratopathy (ABK cases. Interpretation & conclusions: The endothelial cell loss was highest in regraft cases which was significant (P<0.05, while the least endothelial cell loss was seen in keratoconus cases. The cell loss was associated with increase in coefficient of variation (CV, i.e. polymegathism and pleomorphism. Inspite of this polymegathism and pleomorphism, the clarity of the graft was maintained.

  1. Enhancing tumor-specific intracellular delivering efficiency of cell-penetrating peptide by fusion with a peptide targeting to EGFR.

    Nguyen, Long The; Yang, Xu-Zhong; Du, Xuan; Wang, Jia-Wei; Zhang, Rui; Zhao, Jian; Wang, Fu-Jun; Dong, Yang; Li, Peng-Fei

    2015-05-01

    Cell-penetrating peptides (CPPs) are well known as intracellular delivery vectors. However, unsatisfactory delivery efficiency and poor specificity are challenging barriers to CPP applications at the clinical trial stage. Here, we showed that S3, an EGFR-binding domain derived from vaccinia virus growth factor, when fused to a CPP such as HBD or TAT can substantially enhance its internalization efficiency and tumor selectivity. The uptake of S3-HBD (S3H) recombinant molecule by tumor cells was nearly 80 folds increased compared to HBD alone. By contrast, the uptake of S3H by non-neoplastic cells still remained at a low level. The specific recognition between S3 and its receptor, EGFR, as well as between HBD and heparan sulfate proteoglycans on the cell surface was essential for these improvements, suggesting a syngeneic effect between the two functional domains in conjugation. This syngeneic effect is likely similar to that of the heparin-binding epidermal growth factor, which is highly abundant particularly in metastatic tumors. The process that S3H entered cells was dependent on time, dosage, and energy, via macropinocytosis pathway. With excellent cell-penetrating efficacy and a novel tumor-targeting ability, S3H appears as a promising candidate vector for targeted anti-cancer drug delivery. PMID:25655386

  2. Quantitative & qualitative analysis of endothelial cells of donor cornea before & after penetrating keratoplasty in different pathological conditions

    Gupta, Aruna K.R.; Gupta, Roopam K.R.

    2016-01-01

    Background & objectives: Endothelial cells of the donor cornea are known to be affected quantitatively and qualitatively in different pathological conditions after penetrating keratoplasty (PK) and this has direct effect on the clarity of vision obtained after PK. This study was undertaken to analyze the qualitative and quantitative changes in donor endothelial cells before and after PK in different pathological conditions. Methods: A prospective investigational analysis of 100 consecutive donor corneas used for penetrating keratoplasty between June 2006 and June 2008, was conducted. The patients were evaluated on the first day, at the end of first week, first month, third and six months and one year. Results: A decrease was observed in endothelial cell count in all pathological conditions. After one year of follow up the loss was 33.1 per cent in corneal opacity, 45.9 per cent in acute infective keratitis (AIK), 58.5 per cent in regrafts, 28.5 per cent in pseudophakic bullous keratopathy (PBK), 37 per cent in descemetocele, 27 per cent in keratoconus and 35.5 per cent in aphakic bullous keratopathy (ABK) cases. Interpretation & conclusions: The endothelial cell loss was highest in regraft cases which was significant (P<0.05), while the least endothelial cell loss was seen in keratoconus cases. The cell loss was associated with increase in coefficient of variation (CV), i.e. polymegathism and pleomorphism. Inspite of this polymegathism and pleomorphism, the clarity of the graft was maintained. PMID:27121519

  3. The construction and in vitro testing of photo-activatable cancer targeting folated anti-CD3 conjugates

    The construction and in vitro testing of a photo-activatable anti-tumour immuno-regulatory antibody is described. In this 'cloaked' folated anti-CD3 antibody conjugate, the folate portion of the conjugate is free to bind to folate receptor expressing cancer cells, whilst the anti-CD3 activity is effectively rendered inert by a coating of photo-labile 2-nitrobenzyl groups. On irradiation with UV-A light the activity of the anti-CD3 antibody is restored, not only when it is required, but more importantly, only where it is required. The conjugate can then attract killer T-cells to the surface of the tumour cells and kill them. Unirradiated normal tissues, to which the conjugate has been targeted by specific and non-specific binding, remain unharmed. We believe that these 'photo-switchable' conjugates could be used to markedly improve the targeting of the immune response to folate receptor (FR) expressing ovarian and breast cancers whilst minimising the side effects in the rest of the body

  4. Recombinant expression and purification of a MAP30-cell penetrating peptide fusion protein with higher anti-tumor bioactivity.

    Lv, Qiang; Yang, Xu-Zhong; Fu, Long-Yun; Lu, Yv-Ting; Lu, Yan-Hua; Zhao, Jian; Wang, Fu-Jun

    2015-07-01

    MAP30 (Momordica Antiviral Protein 30 Kd), a single-stranded type-I ribosome inactivating protein, possesses versatile biological activities including anti-tumor abilities. However, the low efficiency penetrating into tumor cells hampers the tumoricidal effect of MAP30. This paper describes MAP30 fused with a human-derived cell penetrating peptide HBD which overcome the low uptake efficiency by tumor cells and exhibits higher anti-tumor bioactivity. MAP30 gene was cloned from the genomic DNA of Momordica charantia and the recombinant plasmid pET28b-MAP30-HBD was established and transferred into Escherichia coli BL21 (DE3). The recombinant MAP30-HBD protein (rMAP30-HBD) was expressed in a soluble form after being induced by 0.5mM IPTG for 14h at 15°C. The recombinant protein was purified to greater than 95% purity with Ni-NTA affinity chromatography. The rMAP30-HBD protein not only has topological inactivation and protein translation inhibition activity but also showed significant improvements in cytotoxic activity compared to that of the rMAP30 protein without HBD in the tested tumor cell lines, and induced higher apoptosis rates in HeLa cells analyzed by Annexin V-FITC with FACS. This paper demonstrated a new method for improving MAP30 protein anti-tumor activity and might have potential applications in cancer therapy area. PMID:25797209

  5. Cyclization of a cell-penetrating peptide via click-chemistry increases proteolytic resistance and improves drug delivery.

    Reichart, Florian; Horn, Mareike; Neundorf, Ines

    2016-06-01

    In this work we report synthesis and biological evaluation of a cell-penetrating peptide (CPP), that is partly cyclized via a triazole bridge. Recently, beneficious properties have been reported for cyclized peptides concerning their metabolic stability and intracellular uptake. A CPP based on human calcitonin was used in this study, and side chain cyclization was achieved via copper catalyzed alkyne-azide click reaction. Cell viability studies in several cell-lines revealed no cytotoxic effects. Furthermore, efficient uptake in breast cancer MCF-7 cells could be determined. Moreover, preliminary studies using this novel peptide as drug transporter for daunorubicin were performed. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. PMID:27197760

  6. Cell-penetrating peptide-doxorubicin conjugate loaded NGR-modified nanobubbles for ultrasound triggered drug delivery.

    Lin, Wen; Xie, Xiangyang; Deng, Jianping; Liu, Hui; Chen, Ying; Fu, Xudong; Liu, Hong; Yang, Yang

    2016-01-01

    A new drug-targeting system for CD13(+) tumors has been developed, based on ultrasound-sensitive nanobubbles (NBs) and cell-permeable peptides (CPPs). Here, the CPP-doxorubicin conjugate (CPP-DOX) was entrapped in the asparagine-glycine-arginine (NGR) peptide modified NB (CPP-DOX/NGR-NB) and the penetration of CPP-DOX was temporally masked; local ultrasound stimulation could trigger the CPP-DOX release from NB and activate its penetration. The CPP-DOX/NGR-NBs had particle sizes of about 200 nm and drug entrapment efficiency larger than 90%. In vitro release results showed that over 85% of the encapsulated DOX or CPP-DOX would release from NBs in the presence of ultrasound, while less than 1.5% of that (30 min) without ultrasound. Cell experiments showed the higher cellular CPP-DOX uptake of CPP-DOX/NGR-NB among the various NB formulations in Human fibrosarcoma cells (HT-1080, CD13(+)). The CPP-DOX/NGR-NB with ultrasound treatment exhibited an increased cytotoxic activity than the one without ultrasound. In nude mice xenograft of HT-1080 cells, CPP-DOX/NGR-NB with ultrasound showed a higher tumor inhibition effect (3.1% of T/C%, day 24), longer median survival time (50 days) and excellent body safety compared with the normal DOX injection group. These results indicate that the constructed vesicle would be a promising drug delivery system for specific cancer treatment. PMID:26176270

  7. Cell-Penetrating, Guanidinium-Rich Oligophosphoesters: Effective and Versatile Molecular Transporters for Drug and Probe Delivery.

    McKinlay, Colin J; Waymouth, Robert M; Wender, Paul A

    2016-03-16

    The design, synthesis, and biological evaluation of a new family of highly effective cell-penetrating molecular transporters, guanidinium-rich oligophosphoesters, are described. These unique transporters are synthesized in two steps, irrespective of oligomer length, by the organocatalytic ring-opening polymerization (OROP) of 5-membered cyclic phospholane monomers followed by oligomer deprotection. Varying the initiating alcohol results in a wide variety of cargo attachment strategies for releasable or nonreleasable transporter applications. Initiation of oligomerization with a fluorescent probe produces, upon deprotection, a transporter-probe conjugate that is shown to readily enter multiple cell lines in a dose-dependent manner. These new transporters are superior in cell uptake to previously studied guanidinium-rich oligocarbonates and oligoarginines, showing over 2-fold higher uptake than the former and 6-fold higher uptake than the latter. Initiation with a protected thiol gives, upon deprotection, thiol-terminated transporters which can be thiol-click conjugated to a variety of probes, drugs and other cargos as exemplified by the conjugation and delivery of the model probe fluorescein-maleimide and the medicinal agent paclitaxel (PTX) into cells. Of particular significance given that drug resistance is a major cause of chemotherapy failure, the PTX-transporter conjugate, designed to evade Pgp export and release free PTX after cell entry, shows efficacy against PTX-resistant ovarian cancer cells. Collectively this study introduces a new and highly effective class of guanidinium-rich cell-penetrating transporters and methodology for their single-step conjugation to drugs and probes, and demonstrates that the resulting drug/probe-conjugates readily enter cells, outperforming previously reported guanidinium-rich oligocarbonates and peptide transporters. PMID:26900771

  8. Intracellular delivery of cell-penetrating peptide-transcriptional factor fusion protein and its role in selective osteogenesis

    Suh JS

    2014-03-01

    Full Text Available Jin Sook Suh,1,* Jue Yeon Lee,2,* Yoon Jung Choi,1 Hyung Keun You,3 Seong-Doo Hong,4 Chong Pyoung Chung,2 Yoon Jeong Park1,2 1Dental Regenerative Biotechnology, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, 2Central Research Institute, Nano Intelligent Biomedical Engineering Corporation (NIBEC, Seoul, 3Department of Periodontology, College of Dentistry, Wonkwang University, Iksan, 4Department of Oral Pathology, School of Dentistry, Seoul National University, Seoul, Republic of Korea *These authors contributed equally to this work Abstract: Protein-transduction technology has been attempted to deliver macromolecular materials, including protein, nucleic acids, and polymeric drugs, for either diagnosis or therapeutic purposes. Herein, fusion protein composed of an arginine-rich cell-penetrating peptide, termed low-molecular-weight protamine (LMWP, and a transcriptional coactivator with a PDZ-binding motif (TAZ protein was prepared and applied in combination with biomaterials to increase bone-forming capacity. TAZ has been recently identified as a specific osteogenic stimulating transcriptional coactivator in human mesenchymal stem cell (hMSC differentiation, while simultaneously blocking adipogenic differentiation. However, TAZ by itself cannot penetrate the cells, and thus needs a transfection tool for translocalization. The LMWP-TAZ fusion proteins were efficiently translocalized into the cytosol of hMSCs. The hMSCs treated with cell-penetrating LMWP-TAZ exhibited increased expression of osteoblastic genes and protein, producing significantly higher quantities of mineralized matrix compared to free TAZ. In contrast, adipogenic differentiation of the hMSCs was blocked by treatment of LMWP-TAZ fusion protein, as reflected by reduced marker-protein expression, adipocyte fatty acid-binding protein 2, and peroxisome proliferator-activated receptor-γ messenger ribonucleic acid levels. LMWP-TAZ was applied in

  9. Improved cellular uptake of antisense Peptide nucleic acids by conjugation to a cell-penetrating Peptide and a lipid domain

    Shiraishi, Takehiko; Nielsen, Peter E

    2011-01-01

    peptides known as cell-penetrating peptides (CPPs) is attracting wide attention for a variety of biologically active molecules. CPP-mediated delivery is typically based on the covalent conjugation of the (therapeutic) cargo to CPPs, and is particularly relevant for the delivery of noncharged RNA...... interference agents such as peptide nucleic acids (PNAs) and morpholino oligomers. Although chemical conjugation to a variety of CPPs significantly improves the cellular uptake of PNAs, the bioavailability (and hence antisense activity) of CPP-PNA -conjugates is still highly limited by endocytotic entrapment...

  10. Combined effect of a peptide–morpholino oligonucleotide conjugate and a cell-penetrating peptide as an antibiotic

    Wesolowski, Donna; Alonso, Dulce; Altman, Sidney

    2013-01-01

    A cell-penetrating peptide (CPP)–morpholino oligonucleotide (MO) conjugate (PMO) that has an antibiotic effect in culture had some contaminating CPPs in earlier preparations. The mixed conjugate had gene-specific and gene-nonspecific effects. An improved purification procedure separates the PMO from the free CPP and MO. The gene-specific effects are a result of the PMO, and the nonspecific effects are a result of the unlinked, unreacted CPP. The PMO and the CPP can be mixed together, as has b...

  11. Conjugation of a cell-penetrating peptide to parathyroid hormone affects its structure, potency, and transepithelial permeation

    Kristensen, Mie; de Groot, Anne Marit; Berthelsen, Jens;

    2015-01-01

    Delivery of therapeutic peptides and proteins by the use of cell-penetrating peptides (CPPs) as carriers has been suggested as a feasible strategy. The aim of the present study was to investigate the effect of conjugating a series of well-known CPPs to the biologically active part of parathyroid...... hormone, i.e. PTH(1-34), and to evaluate the effect with regards to secondary structure, potency in Saos-2 cells, immunogenicity, safety as well as the transepithelial permeation across monolayers by using the Caco-2 cell culture model. Further, co-administration of CPP and PTH(1-34) as an alternative to...... covalent conjugation was compared with regards to the transepithelial permeation. CPP-conjugated PTH(1-34) fusion peptides were successfully expressed in Escherichia coli and purified from inclusion bodies. No clear correlation between the degree of secondary structure of the CPP-conjugated PTH(1...

  12. Conjugation of doxorubicin to cell penetrating peptides sensitizes human breast MDA-MB 231 cancer cells to endogenous TRAIL-induced apoptosis.

    Aroui, Sonia; Brahim, Souhir; Hamelin, Jocelyne; De Waard, Michel; Bréard, Jacqueline; Kenani, Abderraouf

    2009-01-01

    International audience Previous work from our laboratory has shown that coupling doxorubicin (Dox) to cell penetrating peptides (Dox-CPPs) is a good strategy to overcome Dox resistance in MDA-MB 231 breast cancer cells. We also reported that, in contrast to unconjugated Dox-induced cell death, the increase in apoptotic response does not involve the mitochondrial apoptotic pathway. In this study, we demonstrate that both Dox and Dox-CPPs can increase the density of the TRAIL receptors DR4 a...

  13. Synthesis of an artificial cell surface receptor that enables oligohistidine affinity tags to function as metal-dependent cell-penetrating peptides.

    Boonyarattanakalin, Siwarutt; Athavankar, Sonalee; Sun, Qi; Peterson, Blake R

    2006-01-18

    Cell-penetrating peptides and proteins (CPPs) are important tools for the delivery of impermeable molecules into living mammalian cells. To enable these cells to internalize proteins fused to common oligohistidine affinity tags, we synthesized an artificial cell surface receptor comprising an N-alkyl derivative of 3beta-cholesterylamine linked to the metal chelator nitrilotriacetic acid (NTA). This synthetic receptor inserts into cellular plasma membranes, projects NTA headgroups from the cell surface, and rapidly cycles between the plasma membrane and intracellular endosomes. Jurkat lymphocytes treated with the synthetic receptor (10 microM) for 1 h displayed approximately 8,400,000 [corrected]NTA groups on the cell surface. Subsequent addition of the green fluorescent protein AcGFP fused to hexahistidine or decahistidine peptides (3 microM) and Ni(OAc)(2) (100 microM) enhanced the endocytosis of AcGFP by 150-fold (hexahistidine fusion protein) or 600-fold (decahistidine fusion protein) within 4 h at 37 degrees C. No adverse effects on cellular proliferation or morphology were observed under these conditions. By enabling common oligohistidine affinity tags to function as cell-penetrating peptides, this metal-chelating cell surface receptor provides a useful tool for studies of cellular biology [corrected] PMID:16402806

  14. Cell-penetration by Co(III)cyclen-based peptide-cleaving catalysts selective for pathogenic proteins of amyloidoses.

    Chei, Woo Suk; Lee, Joo-Won; Kim, Jae Bum; Suh, Junghun

    2010-07-15

    Derivatives of the Co(III) complex of 1,4,7,10-tetraazacyclododecane (cyclen) with various organic pendants have been reported as target-selective peptide-cleaving catalysts, which can be exploited as catalytic drugs. In order to provide a firm basis for the catalytic drugs based on Co(III)cyclen, the ability of the Co(III)cyclen-containing peptide-cleaving catalysts to penetrate animal cells such as mouse fibroblast NIH-3T 3 or human embryonic kidney (HEK) 293 cells is demonstrated in the present study. Since the catalysts destroy pathogenic proteins for amyloidoses, results of the present study are expected to initiate extensive efforts to obtain therapeutically safe catalytic drugs for amyloidoses such as Alzheimer's disease, type 2 diabetes mellitus, Parkinson's disease, Huntington's disease, mad cow disease, and so on. PMID:20542701

  15. Peptide nucleic acid (PNA) cell penetrating peptide (CPP) conjugates as carriers for cellular delivery of antisense oligomers

    Shiraishi, Takehiko; Nielsen, Peter E

    2012-01-01

    We have explored the merits of a novel delivery strategy for the antisense oligomers based on cell penetrating peptide (CPP) conjugated to a carrier PNA with sequence complementary to part of the antisense oligomer. The effect of these carrier CPP-PNAs was evaluated by using antisense PNA targeting...... splicing correction of the mutated luciferase gene in the HeLa pLuc705 cell line, reporting cellular (nuclear) uptake of the antisense PNA via luciferase activity measurement. Carrier CPP-PNA constructs were studied in terms of construct modification (with octaarginine and/or decanoic acid) and carrier PNA...... length (to adjust binding affinity). In general, the carrier CPP-PNA constructs including the ones with decanoyl modification provided significant increase of the activity of unmodified antisense PNA as well as of antisense octaarginine-PNA conjugates. Antisense activity, and by inference cellular...

  16. Applications and Challenges for Use of Cell-Penetrating Peptides as Delivery Vectors for Peptide and Protein Cargos

    Kristensen, Mie; Birch, Ditlev; Mørck Nielsen, Hanne

    2016-01-01

    -penetrating peptides (CPPs) constitute a promising tool and have shown applications for peptide and protein delivery into cells as well as across various epithelia and the blood-brain barrier (BBB). CPP-mediated delivery of peptides and proteins may be pursued via covalent conjugation of the CPP to the cargo peptide...... or protein or via physical complexation obtained by simple bulk-mixing of the CPP with its cargo. Both approaches have their pros and cons, and which is the better choice likely relates to the physicochemical properties of the CPP and its cargo as well as the route of administration, the specific...... barrier and the target cell. Besides the physical barrier, a metabolic barrier must be taken into consideration when applying peptide-based delivery vectors, such as the CPPs, and stability-enhancing strategies are commonly employed to prolong the CPP half-life. The mechanisms by which CPPs translocate...

  17. Stearylated antimicrobial peptide [D]-K6L9 with cell penetrating property for efficient gene transfer.

    Zhang, Wei; Song, Jingjing; Liang, Ranran; Zheng, Xin; Chen, Jianbo; Li, Guolin; Zhang, Bangzhi; Wang, Kairong; Yan, Xiang; Wang, Rui

    2013-08-01

    Stearyl-cell penetrating peptides (CPPs) have been proved to be efficient nonviral gene vectors. Due to the similarities between antimicrobial peptides and CPPs, we constructed a novel type of gene vectors by introducing stearyl moiety to the N-terminus of antimicrobial peptide [D]-K6L9. In this study, stearyl-[D]-K6L9 delivered plasmids into cells by clathrin- and caveolin-mediated endocytosis. Gratifyingly, stearyl-[D]-K6L9 exhibited high transfection efficiency and almost reached the level of Lipofectamine 2000. Taken together, the combination of the stearyl moiety with [D]-K6L9 provides a novel framework for the development of excellent nonviral gene vectors. PMID:23727033

  18. Biochemical characterization of bovine plasma thrombin-activatable fibrinolysis inhibitor (TAFI)

    Valnickova, Zuzana; Thaysen-Andersen, Morten; Højrup, Peter;

    2009-01-01

    BACKGROUND: TAFI is a plasma protein assumed to be an important link between coagulation and fibrinolysis. The three-dimensional crystal structures of authentic mature bovine TAFI (TAFIa) in complex with tick carboxypeptidase inhibitor, authentic full lenght bovine plasma thrombin-activatable fib......BACKGROUND: TAFI is a plasma protein assumed to be an important link between coagulation and fibrinolysis. The three-dimensional crystal structures of authentic mature bovine TAFI (TAFIa) in complex with tick carboxypeptidase inhibitor, authentic full lenght bovine plasma thrombin...

  19. Efficient siRNA Delivery Using Novel Cell-Penetrating Peptide-siRNA Conjugate-Loaded Nanobubbles and Ultrasound.

    Xie, Xiangyang; Lin, Wen; Li, Mingyuan; Yang, Yang; Deng, Jianping; Liu, Hui; Chen, Ying; Fu, Xudong; Liu, Hong; Yang, Yanfang

    2016-06-01

    Because of the absence of tolerable and effective carriers for in vivo delivery, the applications of small interfering RNA (siRNA) in the clinic for therapeutic purposes have been limited. In this study, development of a novel siRNA delivery system based on ultrasound-sensitive nanobubbles (NBs, nano-sized echogenic liposomes) and cell-permeable peptides (CPPs) is described. A CPP-siRNA conjugate was entrapped in an NB, (CPP-siRNA)-NB, and the penetration of CPP-siRNA was temporally masked; local ultrasound stimulation triggered the release of CPP-siRNA from the NBs and activated its penetration. Subsequent research revealed that the (CPP-siRNA)-NBs had a mean particle size of 201 ± 2.05 nm and a siRNA entrapment efficiency >85%. In vitro release results indicated that >90% of the encapsulated CPP-siRNA was released from NBs in the presence of ultrasound, whereas 1080). Additionally, after systemic administration in mice, (CPP-siRNA)-NBs accumulated in the tumor, augmented c-myc silencing and delayed tumor progression. In conclusion, the application of (CPP-siRNA)-NBs with ultrasound may constitute an approach to selective targeted delivery of siRNA. PMID:27012462

  20. A specific aptamer-cell penetrating peptides complex delivered siRNA efficiently and suppressed prostate tumor growth in vivo.

    Diao, Yanjun; Liu, Jiayun; Ma, Yueyun; Su, Mingquan; Zhang, Hongyi; Hao, Xiaoke

    2016-05-01

    Specific and efficient delivery of siRNA into intended tumor cells remains as a challenge, even though RNAi has been exploited as a new strategy for prostate cancer therapy. This work aims to address both specificity and efficiency of SURVIVIN-siRNA delivery by constructing a therapeutic complex using combinatorial strategies. A fusion protein STD was first expressed to serve as a backbone, consisting of streptavidin, a cell-penetrating peptide called Trans-Activator of Transcription (TAT) and a double-stranded RNA binding domain. A biotinylated Prostate Specific Membrane Antigen (PSMA) specific aptamer A10 and SURVIVIN-siRNA were then linked to STD protein to form the therapeutic complex. This complex could specifically targeted PSMA(+) tumor cells. Compared to lipofectamine and A10-siRNA chimera, it demonstrated higher efficiency in delivering siRNA into target cells by 19.2% and 59.9%, and increased apoptosis by 16.8% and 26.1% respectively. Upon systemic administration, this complex also showed significant efficacy in suppressing tumor growth in athymic mice (p efficiently deliver SURVIVIN-siRNA to target cells and suppressed tumor growth in vivo, which indicates its potential to be used as a new strategy in prostate cancer therapy. PMID:26954374

  1. Development of an Optimized Activatable MMP-14 targeted SPECT Imaging Probe

    Watkins, Gregory A.; Jones, Ella Fung; Shell, M. Scott; VanBrocklin, Henry F.; Pan, Mei-Hsiu; Hanrahan, Stephen M.; Feng, Jin Jin; He, Jiang; Sounni, Nor Eddine; Dill, Ken A.; Contag, Christopher H.; Coussens, Lisa M; Franc, Benjamin L.

    2008-01-01

    Matrix Metalloproteinase-14 (MT1-MMP or MMP-14) is a membrane-associated protease implicated in a variety of tissue remodeling processes and a molecular hallmark of select metastatic cancers. The ability to detect MMP-14 in vivo would be useful in studying its role in pathologic processes and may potentially serve as a guide for the development of targeted molecular therapies. Four MMP-14 specific probes containing a positively charged cell penetrating peptide (CPP) d-arginine octamer (r8) li...

  2. Pressure Measurement during Penetration Experiments

    Krause, C.; Demming, J.; Flecht, T.; Heller, S.

    2014-04-01

    Penetration experiments are common tools for the investigation of physical surface properties. Additionally penetration experiments will find several applications in exploration missions in the near future. A penetration test stand has been flown for the investigation of penetration force reduction under reduced gravity in the 2nd Joint European Partial-G Parabolic Flight Campaign (JEPPF-2) of ESA, CNES and DLR [1]. The main contribution to the bearing resistance of a soil is combined of shaft and base resistance. During the penetration the grains of the granular material will be squeezed into the surrounding material. The penetration will cause a change in the pressure distribution inside the surrounding soil [2],[3]. An experimental setup has been designed and built for understanding and measurement of this induced pressure distribution. In the last year the parabolic flight test stand has been further developed for the measurement of pressure during the penetration process. The main part of the experiments stayed the same with a steel rod penetration into a sample cell measuring the penetration force and recording it in relation to the depth. The sample cell is equipped with a supporting sieving mechanism for sample preparation. The pressure sensors are mounted at the sample cell. During the last test campaigns the principle of measurement has been investigated and first measurements have been performed. In the presentation the measurement principle will be shown and its implementation into the parabolic flight setup. Pressure measurement results on ground tests of different penetrator and tip configurations will be presented.

  3. Sticky water surfaces: helix-coil transitions suppressed in a cell-penetrating peptide at the air-water interface.

    Schach, Denise; Globisch, Christoph; Roeters, Steven J; Woutersen, Sander; Fuchs, Adrian; Weiss, Clemens K; Backus, Ellen H G; Landfester, Katharina; Bonn, Mischa; Peter, Christine; Weidner, Tobias

    2014-12-14

    GALA is a 30 amino acid synthetic peptide consisting of a Glu-Ala-Leu-Ala repeat and is known to undergo a reversible structural transition from a disordered to an α-helical structure when changing the pH from basic to acidic values. In its helical state GALA can insert into and disintegrate lipid membranes. This effect has generated much interest in GALA as a candidate for pH triggered, targeted drug delivery. GALA also serves as a well-defined model system to understand cell penetration mechanisms and protein folding triggered by external stimuli. Structural transitions of GALA in solution have been studied extensively. However, cell penetration is an interfacial effect and potential biomedical applications of GALA would involve a variety of surfaces, e.g., nanoparticles, lipid membranes, tubing, and liquid-gas interfaces. Despite the apparent importance of interfaces in the functioning of GALA, the effect of surfaces on the reversible folding of GALA has not yet been studied. Here, we use sum frequency generation vibrational spectroscopy (SFG) to probe the structural response of GALA at the air-water interface and IR spectroscopy to follow GALA folding in bulk solution. We combine the SFG data with molecular dynamics simulations to obtain a molecular-level picture of the interaction of GALA with the air-water interface. Surprisingly, while the fully reversible structural transition was observed in solution, at the water-air interface, a large fraction of the GALA population remained helical at high pH. This "stickiness" of the air-water interface can be explained by the stabilizing interactions of hydrophobic leucine and alanine side chains with the water surface. PMID:25494788

  4. Sticky water surfaces: Helix-coil transitions suppressed in a cell-penetrating peptide at the air-water interface

    Schach, Denise; Globisch, Christoph; Roeters, Steven J.; Woutersen, Sander; Fuchs, Adrian; Weiss, Clemens K.; Backus, Ellen H. G.; Landfester, Katharina; Bonn, Mischa; Peter, Christine; Weidner, Tobias

    2014-12-01

    GALA is a 30 amino acid synthetic peptide consisting of a Glu-Ala-Leu-Ala repeat and is known to undergo a reversible structural transition from a disordered to an α-helical structure when changing the pH from basic to acidic values. In its helical state GALA can insert into and disintegrate lipid membranes. This effect has generated much interest in GALA as a candidate for pH triggered, targeted drug delivery. GALA also serves as a well-defined model system to understand cell penetration mechanisms and protein folding triggered by external stimuli. Structural transitions of GALA in solution have been studied extensively. However, cell penetration is an interfacial effect and potential biomedical applications of GALA would involve a variety of surfaces, e.g., nanoparticles, lipid membranes, tubing, and liquid-gas interfaces. Despite the apparent importance of interfaces in the functioning of GALA, the effect of surfaces on the reversible folding of GALA has not yet been studied. Here, we use sum frequency generation vibrational spectroscopy (SFG) to probe the structural response of GALA at the air-water interface and IR spectroscopy to follow GALA folding in bulk solution. We combine the SFG data with molecular dynamics simulations to obtain a molecular-level picture of the interaction of GALA with the air-water interface. Surprisingly, while the fully reversible structural transition was observed in solution, at the water-air interface, a large fraction of the GALA population remained helical at high pH. This "stickiness" of the air-water interface can be explained by the stabilizing interactions of hydrophobic leucine and alanine side chains with the water surface.

  5. Binding characteristics of thrombin-activatable fibrinolysis inhibitor to streptococcal surface collagen-like proteins A and B

    Seron, Mercedes Valls; Plug, Tom; Marquart, J. Arnoud; Marx, Pauline F.; Herwald, Heiko; de Groot, Philip G.; Meijers, Joost C. M.

    2011-01-01

    Streptococcus pyogenes is the causative agent in a wide range of diseases in humans. Thrombin-activatable fibrinolysis inhibitor (TAFI) binds to collagen-like proteins ScIA and ScIB at the surface of S. pyogenes. Activation of TAFI at this surface redirects inflammation from a transient to chronic s

  6. Differential impact of high and low penetrance TNFRSF1A gene mutations on conventional and regulatory CD4+ T cell functions in TNFR1-associated periodic syndrome.

    Pucino, Valentina; Lucherini, Orso Maria; Perna, Francesco; Obici, Laura; Merlini, Giampaolo; Cattalini, Marco; La Torre, Francesco; Maggio, Maria Cristina; Lepore, Maria Teresa; Magnotti, Flora; Galgani, Mario; Galeazzi, Mauro; Marone, Gianni; De Rosa, Veronica; Talarico, Rosaria; Cantarini, Luca; Matarese, Giuseppe

    2016-05-01

    TNFR-associated periodic syndrome is an autoinflammatory disorder caused by autosomal-dominant mutations in TNFRSF1A, the gene encoding for TNFR superfamily 1A. The lack of knowledge in the field of TNFR-associated periodic syndrome biology is clear, particularly in the context of control of immune self-tolerance. We investigated how TNF-α/TNFR superfamily 1A signaling can affect T cell biology, focusing on conventional CD4(+)CD25(-) and regulatory CD4(+)CD25(+) T cell functions in patients with TNFR-associated periodic syndrome carrying either high or low penetrance TNFRSF1A mutations. Specifically, we observed that in high penetrance TNFR-associated periodic syndrome, at the molecular level, these alterations were secondary to a hyperactivation of the ERK1/2, STAT1/3/5, mammalian target of rapamycin, and NF-κB pathways in conventional T cells. In addition, these patients had a lower frequency of peripheral regulatory T cells, which also displayed a defective suppressive phenotype. These alterations were partially found in low penetrance TNFR-associated periodic syndrome, suggesting a specific link between the penetrance of the TNFRSF1A mutation and the observed T cell phenotype. Taken together, our data envision a novel role for adaptive immunity in the pathogenesis of TNFR-associated periodic syndrome involving both CD4(+) conventional T cells and Tregs, suggesting a novel mechanism of inflammation in the context of autoinflammatory disorders. PMID:26598380

  7. Cell penetrating silica nanoparticles doped with two-photon absorbing fluorophores

    Bertazza, Loris; Celotti, Lucia; Fabbrini, Graziano; Loi, Maria Antonietta; Maggini, Michele; Mancin, Fabrizio; Marcuz, Silvia; Menna, Enzo; Muccini, Michele; Tonellato, Umberto

    2006-01-01

    Organosilica nanoparticles, doped with two-photon absorbing distyrylbenzene derivatives, were prepared and studied as cell staining agents. Two dyes were used, bearing either two peripheral dimethylamino groups or one dimethylamino and one cyano group. Due to the internal charge transfer character o

  8. Applications and Challenges for Use of Cell-Penetrating Peptides as Delivery Vectors for Peptide and Protein Cargos

    Mie Kristensen

    2016-01-01

    Full Text Available The hydrophilic nature of peptides and proteins renders them impermeable to cell membranes. Thus, in order to successfully deliver peptide and protein-based therapeutics across the plasma membrane or epithelial and endothelial barriers, a permeation enhancing strategy must be employed. Cell-penetrating peptides (CPPs constitute a promising tool and have shown applications for peptide and protein delivery into cells as well as across various epithelia and the blood-brain barrier (BBB. CPP-mediated delivery of peptides and proteins may be pursued via covalent conjugation of the CPP to the cargo peptide or protein or via physical complexation obtained by simple bulk-mixing of the CPP with its cargo. Both approaches have their pros and cons, and which is the better choice likely relates to the physicochemical properties of the CPP and its cargo as well as the route of administration, the specific barrier and the target cell. Besides the physical barrier, a metabolic barrier must be taken into consideration when applying peptide-based delivery vectors, such as the CPPs, and stability-enhancing strategies are commonly employed to prolong the CPP half-life. The mechanisms by which CPPs translocate cell membranes are believed to involve both endocytosis and direct translocation, but are still widely investigated and discussed. The fact that multiple factors influence the mechanisms responsible for cellular CPP internalization and the lack of sensitive methods for detection of the CPP, and in some cases the cargo, further complicates the design and conduction of conclusive mechanistic studies.

  9. Redoxable heteronanocrystals functioning magnetic relaxation switch for activatable T1 and T2 dual-mode magnetic resonance imaging.

    Kim, Myeong-Hoon; Son, Hye-Young; Kim, Ga-Yun; Park, Kwangyeol; Huh, Yong-Min; Haam, Seungjoo

    2016-09-01

    T1/T2 dual-mode magnetic resonance (MR) contrast agents (DMCAs) have gained much attention because of their ability to improve accuracy by providing two pieces of complementary information with one instrument. However, most of these agents are "always ON" systems that emit MR contrast regardless of their interaction with target cells or biomarkers, which may result in poor target-to-background ratios. Herein, we introduce a rationally designed magnetic relaxation switch (MGRS) for an activatable T1/T2 dual MR imaging system. Redox-responsive heteronanocrystals, consisting of a superparamagnetic Fe3O4 core and a paramagnetic Mn3O4 shell, are synthesized through seed-mediated growth and subsequently surface-modified with polysorbate 80. The Mn3O4 shell acts as both a protector of Fe3O4 in aqueous environments to attenuate T2 relaxation and as a redoxable switch that can be activated in intracellular reducing environments by glutathione. This simultaneously generates large amounts of magnetically decoupled Mn(2+) ions and allows Fe3O4 to interact with the water protons. This smart nanoplatform shows an appropriate hydrodynamic size for the EPR effect (10-100 nm) and demonstrates biocompatibility. Efficient transitions of OFF/ON dual contrast effects are observed by in vitro imaging and MR relaxivity measurements. The ability to use these materials as DMCAs is demonstrated via effective passive tumor targeting for T1- and T2-weighted MR imaging in tumor-bearing mice. PMID:27281684

  10. Titanium Dioxide Nanoparticle Penetration into the Skin and Effects on HaCaT Cells

    Matteo Crosera

    2015-08-01

    Full Text Available Titanium dioxide nanoparticles (TiO2NPs suspensions (concentration 1.0 g/L in synthetic sweat solution were applied on Franz cells for 24 h using intact and needle-abraded human skin. Titanium content into skin and receiving phases was determined. Cytotoxicity (MTT, AlamarBlue® and propidium iodide, PI, uptake assays was evaluated on HaCat keratinocytes after 24 h, 48 h, and seven days of exposure. After 24 h of exposure, no titanium was detectable in receiving solutions for both intact and damaged skin. Titanium was found in the epidermal layer after 24 h of exposure (0.47 ± 0.33 μg/cm2 while in the dermal layer, the concentration was below the limit of detection. Damaged skin, in its whole, has shown a similar concentration (0.53 ± 0.26 μg/cm2. Cytotoxicity studies on HaCaT cells demonstrated that TiO2NPs induced cytotoxic effects only at very high concentrations, reducing cell viability after seven days of exposure with EC50s of 8.8 × 10−4 M (MTT assay, 3.8 × 10−5 M (AlamarBlue® assay, and 7.6 × 10−4 M (PI uptake, index of a necrotic cell death. Our study demonstrated that TiO2NPs cannot permeate intact and damaged skin and can be found only in the stratum corneum and epidermis. Moreover, the low cytotoxic effect observed on human HaCaT keratinocytes suggests that these nano-compounds have a potential toxic effect at the skin level only after long-term exposure.

  11. The use of nanoscale fluorescence microscopic to decipher cell wall modifications during fungal penetration

    Dorothea eEllinger; Christian eVoigt

    2014-01-01

    Plant diseases are one of the most studied subjects in the field of plant science due to their impact on crop yield and food security. Our increased understanding of plant–pathogen interactions was mainly driven by the development of new techniques that facilitated analyses on a subcellular and molecular level. The development of labeling technologies, which allowed the visualization and localization of cellular structures and proteins in live cell imaging, promoted the use of fluorescence an...

  12. Antitumor activity of tripterine via cell-penetrating peptide-coated nanostructured lipid carriers in a prostate cancer model

    Yuan L

    2013-11-01

    Full Text Available Ling Yuan,1 Congyan Liu,2 Yan Chen,2 Zhenhai Zhang,2 Lei Zhou,1 Ding Qu2 1Department of Pharmaceutics, School of Pharmacy, Jiangsu University, Zhenjiang, Jiangsu, 2Key Laboratory of New Drug Delivery System of Chinese Materia Medica, Jiangsu Provincial Academy of Chinese Medicine, Nanjing, Jiangsu, People's Republic of China Background: The purpose of this study was to evaluate the antitumor effect of cell-penetrating peptide-coated tripterine-loaded nanostructured lipid carriers (CT-NLC on prostate tumor cells in vitro and in vivo. Methods: CT-NLC were developed to improve the hydrophilicity of tripterine. The antiproliferative effects of CT-NLC, tripterine-loaded nanostructured lipid carriers (T-NLC, and free tripterine in a human prostatic carcinoma cell line (PC-3 and a mouse prostate carcinoma cell line (RM-1 were evaluated using an MTT assay. The advantage of CT-NLC over T-NLC and free tripterine with regard to antitumor activity in vivo was evaluated in a prostate tumor-bearing mouse model. The induced tumor necrosis factor-alpha and interleukin-6 cytokine content was investigated by enzyme-linked immunosorbent assay to determine the effect of CT-NLC, T-NLC, and free tripterine on immune responses. Histologic and TUNEL assays were carried out to investigate the mechanisms of tumor necrosis and apoptosis. Results: CT-NLC, T-NLC, and free tripterine showed high antiproliferative activity in a dose-dependent manner, with an IC50 of 0.60, 0.81, and 1.02 µg/mL in the PC-3 cell line and 0.41, 0.54, and 0.89 µg/mL in the RM-1 cell line after 36 hours. In vivo, the tumor inhibition rates for cyclophosphamide, high-dose (4 mg/kg and low-dose (2 mg/kg tripterine, high-dose (4 mg/kg and low-dose (2 mg/kg T-NLC, high-dose (4 mg/kg and low-dose (2 mg/kg CT-NLC were 76.51%, 37.07%, 29.53%, 63.56%, 48.25%, 72.68%, and 54.50%, respectively, showing a dose-dependent pattern. The induced tumor necrosis factor-alpha and interleukin-6 cytokine content

  13. Penetration testing

    Zemaníková, Martina

    2010-01-01

    This work focuses on the practical demonstration of design penetration testing. Testing is carried out based on the order of a particular entity/subject which is at their request anonymous. The work is divided into two parts, theoretical and practical. We will be made in first part familiarize with the process and techniques of testing, as is now used in ethical hacking, then we can find in the end appropriate recommendations 6 how to prevent and fight against it in order to protect the...

  14. Improvement on light penetrability and microalgae biomass production by periodically pre-harvesting Chlorella vulgaris cells with culture medium recycling.

    Huang, Yun; Sun, Yahui; Liao, Qiang; Fu, Qian; Xia, Ao; Zhu, Xun

    2016-09-01

    To improve light penetrability and biomass production in batch cultivation, a cultivation mode that periodically pre-harvesting partial microalgae cells from suspension with culture medium recycling was proposed. By daily pre-harvesting 30% microalgae cells from the suspension, the average light intensity in the photobioreactor (PBR) was enhanced by 27.05-122.06%, resulting in a 46.48% increase in total biomass production than that cultivated in batch cultivation without pre-harvesting under an incident light intensity of 160μmolm(-2)s(-1). Compared with the semi-continuous cultivation with 30% microalgae suspension daily replaced with equivalent volume of fresh medium, nutrients and water input was reduced by 60% in the proposed cultivation mode but with slightly decrease (12.82%) in biomass production. No additional nutrient was replenished when culture medium recycling. Furthermore, higher pre-harvesting ratios (40%, 60%) and lower pre-harvesting frequencies (every 2, 2.5days) were not advantageous for the pre-harvesting cultivation mode. PMID:27289058

  15. Recurrent invasive squamous cell carcinoma of the ocular surface requiring penetrating therapeutic sclerokeratoplasty

    Mark J. Mannis

    2012-12-01

    Full Text Available Purpose: We review a case of invasive squamous cell carcinoma invading the cornea to discuss optimal management. Methods:  Observational case report with histopathologic analysis. Results: Histopathology demonstrates corneal invasion by the tumor that appears to have been completely excised with a large therapeutic keratoplasty and adjuvant cryotherapy. Conclusions: Successful management of ocular surface squamous neoplasia (OSSN requires removal of identifiably abnormal tissue without disruption of normal protective architecture, careful histopathologic analysis, and the employment of adjuvant therapy at the time of or subsequent to surgical excision.

  16. HIV Fusion Peptide Penetrates, Disorders, and Softens T-Cell Membrane Mimics

    Tristram-Nagle, Stephanie; Chan, Rob; Kooijman, Edgar; Uppamoochikkal, Pradeep; Qiang, Wei; Weliky, David P.; Nagle, John F.

    2010-01-01

    This work investigates the interaction of N-terminal gp41 fusion peptide (FP) of human immunodeficiency virus type 1 (HIV-1) with model membranes in order to elucidate how FP leads to fusion of HIV and T-cell membranes. FP constructs were (i) wild-type FP23 (23 N-terminal amino acids of gp41), (ii) water-soluble monomeric FP that adds six lysines on the C-terminus of FP23 (FPwsm), and (iii) the C-terminus covalently linked trimeric version (FPtri) of FPwsm. Model membranes were (i) LM3 (a T-c...

  17. Functionalization with C-terminal cysteine enhances transfection efficiency of cell-penetrating peptides through dimer formation

    Highlights: ► Reversible CPP dimerisation is a simple yet efficient strategy to improve delivery. ► Dimer formation enhances peptiplex stability, resulting in increased transfection. ► By dimerisation, the CPP EB1 even gain endosomal escape properties while lowering cytotoxicity. -- Abstract: Cell-penetrating peptides have the ability to stimulate uptake of macromolecular cargo in mammalian cells in a non-toxic manner and therefore hold promise as efficient and well tolerated gene delivery vectors. Non-covalent peptide-DNA complexes (“peptiplexes”) enter cells via endocytosis, but poor peptiplex stability and endosomal entrapment are considered as main barriers to peptide-mediated delivery. We explore a simple, yet highly efficient, strategy to improve the function of peptide-based vectors, by adding one terminal cysteine residue. This allows the peptide to dimerize by disulfide bond formation, increasing its affinity for nucleic acids by the “chelate effect” and, when the bond is reduced intracellularly, letting the complex dissociate to deliver the nucleic acid. By introducing a single C-terminal cysteine in the classical CPP penetratin and the penetratin analogs PenArg and EB1, we show that this minor modification greatly enhances the transfection capacity for plasmid DNA in HEK293T cells. We conclude that this effect is mainly due to enhanced thermodynamic stability of the peptiplexes as endosome-disruptive chloroquine is still required for transfection and the effect is more pronounced for peptides with lower inherent DNA condensation capacity. Interestingly, for EB1, addition of one cysteine makes the peptide able to mediate transfection in absence of chloroquine, indicating that dimerisation can also improve endosomal escape properties. Further, the cytotoxicity of EB1 peptiplexes is considerably reduced, possibly due to lower concentration of free peptide dimer resulting from its stronger binding to DNA.

  18. Functionalization with C-terminal cysteine enhances transfection efficiency of cell-penetrating peptides through dimer formation

    Amand, Helene L., E-mail: helene.amand@chalmers.se [Chalmers University of Technology, Department of Chemical and Biological Engineering/Physical Chemistry, SE-412 96 Gothenburg (Sweden); Norden, Bengt, E-mail: norden@chalmers.se [Chalmers University of Technology, Department of Chemical and Biological Engineering/Physical Chemistry, SE-412 96 Gothenburg (Sweden); Fant, Kristina, E-mail: kristina.fant@sp.se [Chalmers University of Technology, Department of Chemical and Biological Engineering/Physical Chemistry, SE-412 96 Gothenburg (Sweden)

    2012-02-17

    Highlights: Black-Right-Pointing-Pointer Reversible CPP dimerisation is a simple yet efficient strategy to improve delivery. Black-Right-Pointing-Pointer Dimer formation enhances peptiplex stability, resulting in increased transfection. Black-Right-Pointing-Pointer By dimerisation, the CPP EB1 even gain endosomal escape properties while lowering cytotoxicity. -- Abstract: Cell-penetrating peptides have the ability to stimulate uptake of macromolecular cargo in mammalian cells in a non-toxic manner and therefore hold promise as efficient and well tolerated gene delivery vectors. Non-covalent peptide-DNA complexes ('peptiplexes') enter cells via endocytosis, but poor peptiplex stability and endosomal entrapment are considered as main barriers to peptide-mediated delivery. We explore a simple, yet highly efficient, strategy to improve the function of peptide-based vectors, by adding one terminal cysteine residue. This allows the peptide to dimerize by disulfide bond formation, increasing its affinity for nucleic acids by the 'chelate effect' and, when the bond is reduced intracellularly, letting the complex dissociate to deliver the nucleic acid. By introducing a single C-terminal cysteine in the classical CPP penetratin and the penetratin analogs PenArg and EB1, we show that this minor modification greatly enhances the transfection capacity for plasmid DNA in HEK293T cells. We conclude that this effect is mainly due to enhanced thermodynamic stability of the peptiplexes as endosome-disruptive chloroquine is still required for transfection and the effect is more pronounced for peptides with lower inherent DNA condensation capacity. Interestingly, for EB1, addition of one cysteine makes the peptide able to mediate transfection in absence of chloroquine, indicating that dimerisation can also improve endosomal escape properties. Further, the cytotoxicity of EB1 peptiplexes is considerably reduced, possibly due to lower concentration of free peptide

  19. The spacer arm length in cell-penetrating peptides influences chitosan/siRNA nanoparticle delivery for pulmonary inflammation treatment

    Jeong, Eun Ju; Choi, Moonhwan; Lee, Jangwook; Rhim, Taiyoun; Lee, Kuen Yong

    2015-11-01

    Although chitosan and its derivatives have been frequently utilized as delivery vehicles for small interfering RNA (siRNA), it is challenging to improve the gene silencing efficiency of chitosan-based nanoparticles. In this study, we hypothesized that controlling the spacer arm length between a cell-penetrating peptide (CPP) and a nanoparticle could be critical to enhancing the cellular uptake as well as the gene silencing efficiency of conventional chitosan/siRNA nanoparticles. A peptide consisting of nine arginine units (R9) was used as a CPP, and the spacer arm length was controlled by varying the number of glycine units between the peptide (R9Gn) and the nanoparticle (n = 0, 4, and 10). Various physicochemical characteristics of R9Gn-chitosan/siRNA nanoparticles were investigated in vitro. Increasing the spacing arm length did not significantly affect the complex formation between R9Gn-chitosan and siRNA. However, R9G10-chitosan was much more effective in delivering genes both in vitro and in vivo compared with non-modified chitosan (without the peptide) and R9-chitosan (without the spacer arm). Chitosan derivatives modified with oligoarginine containing a spacer arm can be considered as potential delivery vehicles for various genes.Although chitosan and its derivatives have been frequently utilized as delivery vehicles for small interfering RNA (siRNA), it is challenging to improve the gene silencing efficiency of chitosan-based nanoparticles. In this study, we hypothesized that controlling the spacer arm length between a cell-penetrating peptide (CPP) and a nanoparticle could be critical to enhancing the cellular uptake as well as the gene silencing efficiency of conventional chitosan/siRNA nanoparticles. A peptide consisting of nine arginine units (R9) was used as a CPP, and the spacer arm length was controlled by varying the number of glycine units between the peptide (R9Gn) and the nanoparticle (n = 0, 4, and 10). Various physicochemical characteristics of

  20. Intercellular imaging by a polyarginine derived cell penetrating peptide labeled magnetic resonance contrast agent,diethylenetriamine pentaacetic acid gadolinium

    GUO You-min; LIU Min; YANG Jun-le; GUO Xiao-juan; WANG Si-cen; DUAN Xiao-yi; WANG Peng

    2007-01-01

    Background The cellular plasma membrane represents a natural barrier to many exogenous molecules including magnetic resonance (MR) contrast agent. Cell penetrating peptide (CPP) is used to internalize proteins, peptides, and radionuclide. This study was undertaken to assess the value of a new intracellular MR contrast medium, CPP labeled diethylenetriamine pentaacetic acid gadolinium (Gd-DTPA) in molecular imaging in vitro. Methods Fluorescein-5-isothiocyanate (FITC) and Gd-DTPA respectively labeled with CPP (FITC-CPP, Gd-DTPA-CPP) were synthesized by the solid-phase method. Human hepatic cancer cell line-HepG2 was respectively stained by FITC-CPP and FITC to observe the uptake and intracellular distribution. HepG2 was respectively incubated with 100 nmol/ml Gd-DTPA-CPP for 0, 10, 30, 60 minutes, and imaged by MR for studying the relationship between the incubation time and T1WI signal. The cytotoxicity to NIH3T3 fibroblasts cells was measured by 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide reduction assay (MTT). Results The molecular weights of CPP labeled imaging agents, which were determined by MALDI mass spectrometry (FITC-CPP MW=2163.34, Gd-DTPA-CPP MW=2285.99), were similar to the calculated molecular weights. Confocal microscopy suggested HepG2 translocated FITC-CPP in cytoplasm and nucleus independent with the incubation temperature. MR images showed HepG2 uptaken Gd-DTPA-CPP had a higher T1 weighted imaging (T1WI) signal, and that the T1WI signal intensity was increasing in a time-dependent manner (r=0.972, P=0.001), while the signal intensity between the cells incubated by Gd-DTPA for 60 minutes and the controlled cells was not significantly different (P=0.225). By MTT, all concentrations from 50 nmol/ml to 200 nmol/ml had no significant (F=0.006, P=1.000) effect on cell viability of mouse NIH3T3 fibroblasts, compared with the control group. Conclusions The newly constructed CPP based on polyarginine can translocate cells by carrying FITC

  1. Targeting the EGFR/PCNA signaling suppresses tumor growth of triple-negative breast cancer cells with cell-penetrating PCNA peptides.

    Yung-Luen Yu

    Full Text Available Tyrosine 211 (Y211 phosphorylation of proliferation cell nuclear antigen (PCNA coincides with pronounced cancer cell proliferation and correlates with poor survival of breast cancer patients. In epidermal growth factor receptor (EGFR tyrosine kinase inhibitor (TKI-resistant cells, both nuclear EGFR (nEGFR expression and PCNA Y211 phosphorylation are increased. Moreover, the resistance to EGFR TKI is a major clinical problem in treating EGFR-overexpressing triple-negative breast cancer (TNBC. Thus, effective treatment to combat resistance is urgently needed. Here, we show that treatment of cell-penetrating PCNA peptide (CPPP inhibits growth and induces apoptosis of human TNBC cells. The Y211F CPPP specifically targets EGFR and competes directly for PCNA tyrosine Y211 phosphorylation and prevents nEGFR from binding PCNA in vivo; it also suppresses tumor growth by sensitizing EGFR TKI resistant cells, which have enhanced nEGFR function and abrogated classical EGFR membrane signaling. Furthermore, we identify an active motif of CPPP, RFLNFF (RF6 CPPP, which is necessary and sufficient to inhibit TKI-resistant TNBC cell growth of orthotopic implanted tumor in mice. Finally, the activity of its synthetic retro-inverted derivative, D-RF6 CPPP, on an equimolar basis, is more potent than RF6 CPPP. Our study reveals a drug candidate with translational potential for the future development of safe and effective therapeutic for EGFR TKI resistance in TNBC.

  2. The use of nanoscale fluorescence microscopic to decipher cell wall modifications during fungal penetration

    Dorothea eEllinger

    2014-06-01

    Full Text Available Plant diseases are one of the most studied subjects in the field of plant science due to their impact on crop yield and food security. Our increased understanding of plant–pathogen interactions was mainly driven by the development of new techniques that facilitated analyses on a subcellular and molecular level. The development of labeling technologies, which allowed the visualization and localization of cellular structures and proteins in live cell imaging, promoted the use of fluorescence and laser-scanning microscopy in the field of plant–pathogen interactions. Recent advances in new microscopic technologies opened their application in plant science and in the investigation of plant diseases. In this regard, in planta Förster/Fluorescence resonance energy transfer has demonstrated to facilitate the measurement of protein-protein interactions within the living tissue, supporting the analysis of regulatory pathways involved in plant immunity and putative host-pathogen interactions on a nanoscale level. Localization microscopy, an emerging, non-invasive microscopic technology, will allow investigations with a nanoscale resolution leading to new possibilities in the understanding of molecular processes.

  3. Curb Challenges of the “Trojan Horse” Approach: Smart Strategies in Achieving Effective yet Safe Cell-penetrating Peptide-based Drug Delivery

    Huang, Yongzhuo; Jiang, Yifan; Wang, Huiyuan; Wang, Jianxin; Shin, Meong Cheol; Byun, Youngro; He, Huining; Liang, Yanqin; Yang, Victor C.

    2013-01-01

    Cell-penetrating peptide (CPP)-mediated intracellular drug delivery system, often specifically termed as “the Trojan horse approach”, has become the “holy grail” in achieving effective delivery of macromolecular compounds such as proteins, DNA, siRNAs, and drug carriers. It is characterized by the unique cell- (or receptor-), temperature-, and payload-independent mechanisms, therefore offering potent means to improve poor cellular uptake of a variety of macromolecular drugs. Nevertheless, thi...

  4. Development of a market penetration forecasting model for Hydrogen Fuel Cell Vehicles considering infrastructure and cost reduction effects

    In order to cope with climate change, the development and deployment of Hydrogen Fuel Cell Vehicles (HFCVs) is becoming more important. In this study, we developed a forecasting model for HFCVs based on the generalized Bass diffusion model and a simulation model using system dynamics. Through the developed model, we could forecast that the saturation of HFCVs in Korea can be moved up 12 years compared with the US. A sensitivity analysis on external variables such as price reduction rates of HFCVs and number of hydrogen refueling stations is also conducted. The results of this study can give insights on the effects of external variables on the market penetration of HFCVs, and the developed model can also be applied to other studies in analyzing the diffusion effects of HFCVs. - Highlights: → A forecasting model for HFCVs was developed using the generalized Bass diffusion model. → A simulation model using system dynamics was also developed. → The empirical study shows that the infrastructure is an important factor to the initial purchase. → The results of this study can promote research related to the diffusion of innovation.

  5. Cell-penetrating peptides mediated protein cross-membrane delivery and its use in bacterial vector vaccine.

    Ma, Jimei; Xu, Jinmei; Guan, Lingyu; Hu, Tianjian; Liu, Qin; Xiao, Jingfan; Zhang, Yuanxing

    2014-07-01

    It is an attractive strategy to develop a recombinant bacterial vector vaccine by expressing exogenous protective antigen to induce the immune response, and the main concern is how to enhance the cellular internalization of antigen produced by bacterial vector. Cell-penetrating peptides (CPPs) are short cationic/amphipathic peptides which facilitate cellular uptake of various molecular cargoes and therefore have great potentials in vector vaccine design. In this work, eleven different CPPs were fused to the C-terminus of EGFP respectively, and the resultant EGFP-CPP fusion proteins were expressed and purified to assay their cross-membrane transport in macrophage J774 A.1 cells. Among the tested CPPs, TAT showed an excellent capability to deliver the cargo protein EGFP into cytoplasm. In order to establish an efficient antigen delivery system in Escherichia coli, the EGFP-TAT synthesis circuit was combined with an in vivo inducible lysis circuit PviuA-E in E. coli to form an integrated antigen delivery system, the resultant E. coli was proved to be able to lyse upon the induction of a mimic in vivo signal and thus release intracellular EGFP-TAT intensively, which were assumed to undergo a more efficient intracellular delivery by CPP to evoke protective immune responses. Based on the established antigen delivery system, the protective antigen gene flgD from an invasive intracellular fish pathogen Edwardsiella tarda EIB202, was applied to establish an E. coli recombinant vector vaccine. This E. coli vector vaccine presented superior immune protection (RPS = 63%) under the challenge with E. tarda EIB202, suggesting that the novel antigen delivery system had great potential in bacterial vector vaccine applications. PMID:24746937

  6. Cell-penetrable mouse forkhead box protein 3 alleviates experimental arthritis in mice by up-regulating regulatory T cells.

    Liu, Xia; Ji, Baoju; Sun, Mengyi; Wu, Weijiang; Huang, Lili; Sun, Aihua; Zong, Yangyong; Xia, Sheng; Shi, Liyun; Qian, Hui; Xu, Wenrong; Shao, Qixiang

    2015-07-01

    Regulatory T cells (T(regs)) have potential applications in clinical disease therapy, such as autoimmune diseases and transplant rejection. However, their numbers are limited. Forkhead box protein 3 (FoxP3) is a key transcription factor that controls T(reg) development and function. Here, we generated a cell-permeable fusion protein, protein transduction domain (PTD)-conjugated mouse FoxP3 protein (PTD-mFoxP3), and evaluated whether PTD-mFoxp3 can alleviate rheumatoid arthritis (RA) in the collagen-induced arthritis (CIA) mouse model. As expected, PTD-mFoxP3 was transduced into cells effectively, and inhibited T cell activation and attenuated the cell proliferation. It decreased interleukin (IL) 2 and interferon (IFN)-γ expression, and increased IL-10 expression in activated CD4(+)CD25(-) T cells. PTD-mFoxP3-transduced CD4(+)CD25(-) T cells attenuated proliferation of activated CD4(+)CD25(-) T cells. In addition, PTD-mFoxP3 blocked the Th17 differentiation programme in vitro and down-regulated IL-17 production from T cells by modulating induction and levels of retinoid-related orphan receptor gamma t (RORγt). Intra-articular delivery of PTD-mFoxP3 delayed disease incidence remarkably and alleviated autoimmune symptoms of CIA mice. Moreover, protective effects of PTD-mFoxP3 were associated with regulating the balance of T helper type 17 (Th17) and T(regs). These results suggest that PTD-mFoxP3 may be a candidate for RA therapy. PMID:25809415

  7. Tumor penetrating peptides

    ErkkiRuoslahti

    2013-08-01

    Full Text Available Tumor-homing peptides can be used to deliver drugs into tumors. Phage library screening in live mice has recently identified homing peptides that specifically recognize the endothelium of tumor vessels, extravasate, and penetrate deep into the extravascular tumor tissue. The prototypic peptide of this class, iRGD (CRGDKGPDC, contains the integrin-binding RGD motif. RGD mediates tumor homing through binding to αv integrins, which are selectively expressed on various cells in tumors, including tumor endothelial cells. The tumor-penetrating properties of iRGD are mediated by a second sequence motif, R/KXXR/K. This C-end Rule (or CendR motif is active only when the second basic residue is exposed at the C-terminus of the peptide. Proteolytic processing of iRGD in tumors activates the cryptic CendR motif, which then binds to neuropilin-1 activating an endocytic bulk transport pathway through tumor tissue. Phage screening has also yielded tumor-penetrating peptides that function like iRGD in activating the CendR pathway, but bind to a different primary receptor. Moreover, novel tumor-homing peptides can be constructed from tumor-homing motifs, CendR elements and protease cleavage sites. Pathologies other than tumors can be targeted with tissue-penetrating peptides, and the primary receptor can also be a vascular “zip code” of a normal tissue. The CendR technology provides a solution to a major problem in tumor therapy, poor penetration of drugs into tumors. The tumor-penetrating peptides are capable of taking a payload deep into tumor tissue in mice, and they also penetrate into human tumors ex vivo. Targeting with these peptides specifically increases the accumulation in tumors of a variety of drugs and contrast agents, such as doxorubicin, antibodies and nanoparticle-based compounds. Remarkably the drug to be targeted does not have to be coupled to the peptide; the bulk transport system activated by the peptide sweeps along any compound that is

  8. Drug penetration and metabolism in 3D cell cultures treated in a 3D printed fluidic device: assessment of irinotecan via MALDI imaging mass spectrometry.

    LaBonia, Gabriel J; Lockwood, Sarah Y; Heller, Andrew A; Spence, Dana M; Hummon, Amanda B

    2016-06-01

    Realistic in vitro models are critical in the drug development process. In this study, a novel in vitro platform is employed to assess drug penetration and metabolism. This platform, which utilizes a 3D printed fluidic device, allows for dynamic dosing of three dimensional cell cultures, also known as spheroids. The penetration of the chemotherapeutic irinotecan into HCT 116 colon cancer spheroids was examined with MALDI imaging mass spectrometry (IMS). The active metabolite of irinotecan, SN-38, was also detected. After twenty-four hours of treatment, SN-38 was concentrated to the outside of the spheroid, a region of actively dividing cells. The irinotecan prodrug localization contrasted with SN-38 and was concentrated to the necrotic core of the spheroids, a region containing mostly dead and dying cells. These results demonstrate that this unique in vitro platform is an effective means to assess drug penetration and metabolism in 3D cell cultures. This innovative system can have a transformative impact on the preclinical evaluation of drug candidates due to its cost effectiveness and high throughput. PMID:27198560

  9. PREPARATION OF CHEMICAL AND PHYSICAL CONJUGATES OF SELF-ASSEMBLING NANOPARTICLES WITH CELL-PENETRATING PEPTIDE AND DOXORUBICIN

    Zhadyra Sagykyzy Shagyrova

    2015-09-01

    Full Text Available Abstract: Nano-sized carriers can help to reduce toxicity and improve clinical efficacy of drugs. Virus-like particles (VLPs are biocompatible and biodegradable self-assembling nanoparticles, which show great promise as carriers for substances for targeted delivery and controlled release. Either chemical conjugation of physical incorporation without formation of covalent bonds is possible to load substances of interest into VLPs.Objectives: To produce VLPs from recombinant viral capsid protein (HBcAg and test feasibility of methods of formation of chemical and physical conjugates of VLPs with substances of pharmacological interest.Methods: Virus-like particles composed from recombinant hepatitis B core antigen (HBcAg were produced by recombinant expression in E.coli and purified by successive centrifugation through sucrose gradients. Peptide transportan 10 was synthesized and used for carbodiimide (EDC-mediated conjugation to VLPs. Doxorubicin (DOX was loaded into the nucleic acid-containing VLPs to form physical conjugate.Results: VLPs with chemically attached moieties of cell-penetrating peptide transportan 10 were produced. The conjugate was examined in SDS-PAGE to confirm presence of conjugation products. Conjugation efficiency (molar ration peptide/protein in the conjugate reaches 0.5:1 (i.e. 50% of protein chains have one attached peptide moiety. The nucleic acid-containing VLPs can be loaded with the DOX forming stable non-covalent physical conjugate.Conclusion: Recombinantly expressed VLPs allow easy attaching of small molecules making them a convenient platform to develop drug carriers.

  10. Selective Intracellular Delivery of Recombinant Arginine Deiminase (ADI) Using pH-Sensitive Cell Penetrating Peptides To Overcome ADI Resistance in Hypoxic Breast Cancer Cells.

    Yeh, Tzyy-Harn; Chen, Yun-Ru; Chen, Szu-Ying; Shen, Wei-Chiang; Ann, David K; Zaro, Jennica L; Shen, Li-Jiuan

    2016-01-01

    Arginine depletion strategies, such as pegylated recombinant arginine deiminase (ADI-PEG20), offer a promising anticancer treatment. Many tumor cells have suppressed expression of a key enzyme, argininosuccinate synthetase 1 (ASS1), which converts citrulline to arginine. These tumor cells become arginine auxotrophic, as they can no longer synthesize endogenous arginine intracellularly from citrulline, and are therefore sensitive to arginine depletion therapy. However, since ADI-PEG20 only depletes extracellular arginine due to low internalization, ASS1-expressing cells are not susceptible to treatment since they can synthesize arginine intracellularly. Recent studies have found that several factors influence ASS1 expression. In this study, we evaluated the effect of hypoxia, frequently encountered in many solid tumors, on ASS1 expression and its relationship to ADI-resistance in human MDA-MB-231 breast cancer cells. It was found that MDA-MB-231 cells developed ADI resistance in hypoxic conditions with increased ASS1 expression. To restore ADI sensitivity as well as achieve tumor-selective delivery under hypoxia, we constructed a pH-sensitive cell penetrating peptide (CPP)-based delivery system to carry ADI inside cells to deplete both intra- and extracellular arginine. The delivery system was designed to activate the CPP-mediated internalization only at the mildly acidic pH (6.5-7) associated with the microenvironment of hypoxic tumors, thus achieving better selectivity toward tumor cells. The pH sensitivity of the CPP HBHAc was controlled by recombinant fusion to a histidine-glutamine (HE) oligopeptide, generating HBHAc-HE-ADI. The tumor distribution of HBHAc-HE-ADI was comparable to ADI-PEG20 in a mouse xenograft model of human breast cancer cells in vivo. In addition, HBHAc-HE-ADI showed increased in vitro cellular uptake in cells incubated in a mildly acidic pH (hypoxic conditions) compared to normal pH (normoxic conditions), which correlated with p

  11. The effect of "on/off" molecular switching on the photophysical and photochemical properties of axially calixarene substituted activatable silicon(iv)phthalocyanine photosensitizers.

    Güngör, Ömer; Altınbaş Özpınar, Gül; Durmuş, Mahmut; Ahsen, Vefa

    2016-05-01

    Silicon(iv) phthalocyanines ( and ) bearing two calixarene groups as axial ligands were synthesized. Surprisingly, both phthalocyanines were obtained as two different isomers ( and ) depending on the distance between calixarene benzene groups and the phthalocyanine ring. DFT and TD-DFT computations were performed to model plausible structures of these isomers and to simulate electronic absorption spectra. These isomers converted into each other depending on the polarity of the used solvent, temperature and light irradiation. The photophysical and photochemical properties of each isomer were investigated in dimethylsulfoxide (DMSO) for the determination of photodynamic therapy (PDT) activities of these compounds. The more blue-shifted isomers ( and ) showed higher fluorescence quantum yields and singlet oxygen generation compared to more red-shifted counterparts ( and ). This behavior is extremely important for developing activatable photosensitizers for cancer treatment by PDT. Although these photosensitizers produce lower singlet oxygen in normal cells, they produce higher singlet oxygen (six times higher for ) in cancer cells since these photosensitizers converted to more blue-shifted isomers by using light irradiation. PMID:27052992

  12. Differential neuroprotective potential of CRMP2 peptide aptamers conjugated to cationic, hydrophobic, and amphipathic cell penetrating peptides

    Aubin eMoutal

    2015-01-01

    Full Text Available The microtubule-associated axonal specification collapsin response mediator protein 2 (CRMP2 is a novel target for neuroprotection. A CRMP2 peptide (TAT-CBD3 conjugated to the HIV transactivator of transcription (TAT protein’s cationic cell penetrating peptide motif (CPP protected neurons in the face of toxic levels of Ca2+ influx leaked in via N-methyl-D-aspartate receptor (NMDAR hyperactivation. Here we tested whether replacing the hydrophilic TAT motif with alternative cationic (nona-arginine (R9, hydrophobic (membrane transport sequence (MTS of k-fibroblast growth factor or amphipathic (model amphipathic peptide (MAP CPPs could be superior to the neuroprotection bestowed by TAT-CBD3. In giant plasma membrane vesicles (GPMVs derived from cortical neurons, the peptides translocated across plasma membranes with similar efficiencies. Cortical neurons, acutely treated with peptides prior to a toxic glutamate challenge, demonstrated enhanced efflux of R9-CBD3 compared to others. R9-CBD3 inhibited N-methyl-D-aspartate (NMDA-evoked Ca2+ influx to a similar extent as TAT-CBD3 while MTS-CBD3 was ineffective which correlated with the ability of R9- and TAT-CBD3, but not MTS-CBD3, to block NMDAR interaction with CRMP2. Unrestricted Ca2+ influx through NMDARs leading to delayed calcium dysregulation and neuronal cell death was blocked by all peptides but MAP-CBD3. When applied acutely for 10 minutes, R9-CBD3 was more effective than TAT-CBD3 at neuroprotection while MTS- and MAP-CBD3 were ineffective. In contrast, long-term (> 24 hours treatment with MTS-CBD3 conferred neuroprotection where TAT-CBD3 failed. Neither peptide altered surface trafficking of NMDARs. Neuroprotection conferred by MTS-CBD3 peptide is likely due to its increased uptake coupled with decreased efflux when compared to TAT-CBD3. Overall, our results demonstrate that altering CPPs can bestow differential neuroprotective potential onto the CBD3 cargo.

  13. The feasibility of a targeted ultrasound contrast agent carrying genes and cell-penetrating peptides to hypoxic HUVEC

    Objective: To prepare an anti-P-selectin targeted ultrasound contrast agent carrying genes and cell-penetrating peptides (CPP) and to investigate its feasibility of delivery to hypoxic human umbilical vein endothelial cells (HUVEC). Methods: Anti-P-selectin targeted ultrasound contrast agent carrying a green fluorescent protein gene (pEGFP-N1) and CPP was prepared by mechanical vibration and carbodiimide techniques. The appearance, distribution, concentration and diameter of the ultrasound contrast agent were measured. The gene and CPP distribution on the agent was investigated using confocal laser scanning microscopy (CLSM). The efficiency of the ultrasound contrast agent to carry the gene and CPP was investigated by fluorospectrophotometry. HUVEC were cultured in vitro and hypoxic HUVEC were prepared using hydrogen peroxide (H2O2). Hypoxic HUVEC were randomly assigned targeted ultrasound contrast agents and non-targeted ultrasound contrast agents for transfection. The transfection effect of green fluorescent protein in the two groups was observed using fluorescence microscopy and flow cytometry. T-test and linear correlation analysis were used for statistical analysis. Results: The average diameter of anti-P-selectin targeted ultrasound contrast agents carrying gene and CPP was (2.15 ±0.36) μm and the concentration was (1.58 ± 0.23) × 107/ml.The results of CLSM showed that gene and CPP were distributed on the shell of the agent. The gene encapsulation efficiency was 28% (y=0.932x-0.09, r=0.993, P<0.05), and the CPP encapsulation efficiency was 25% (y=5.875x-0.81, r=0.987, P<0.05). EGFP expression was observed using fluorescence microscopy in targeted ultrasound contrast agents and non-targeted ultrasound contrast agents. The average transfection efficiencies of targeted ultrasound contrast agents and non-targeted ultrasound contrast agents were (18.74 ± 0.47) % and (15.34 ± 0.22) % after 24 h (t=10.923, P<0.001). Conclusions: The in vitro studies showed

  14. The current distribution in an electrochemical cell. Part V. The determination of the depth of the current line penetration between the edges of the electrodes and the side walls of the cell

    TANJA M. KOSTIC

    1999-12-01

    Full Text Available A method for the calculation of the depth of the current line penetration between the edges of the electrodes and the side walls of the cell in a cell with plane parallel electrode arrangement is proposed. The method is verified by the calculation of the polarization curves for the cells in which the electrode edges do not touch the side walls of the cell. The agreement between the calculated and the measured values was fair.

  15. Cellular penetration and nuclear importation properties of 111In-labeled and 123I-labeled HIV-1 tat peptide immunoconjugates in BT-474 human breast cancer cells

    Introduction: Our objective was to compare the cell penetration and nuclear importation properties of 111In-labeled and 123I-labeled immunoconjugates (ICs) composed of 16-mer peptides (GRKKRRQRRRPPQGYG) derived from HIV-1 transactivator of transcription (tat) protein and anti-mouse IgG (mIgG) in BT-474 breast cancer (BC) cells. Methods: [111In]tat ICs were constructed by site-specific conjugation of tat peptides to NaIO4--oxidized carbohydrates in the Fc domain of diethylenetriaminepentaacetic-acid-modified anti-mIgG antibodies. Immunoreactivity against mIgG was assessed in a competition assay. The kinetics of the accumulation of [111In]anti-mIgG-tat IC and [123I]anti-mIgG-tat ICs in BT-474 cells and the elimination of radioactivity from cells, cytoplasm or nuclei were determined. The effects of excess tat peptides or NH4Cl (an inhibitor of endosomal acidification) on cellular uptake and nuclear importation of [111In]anti-mIgG-tat were measured. Results: [111In]anti-mIgG-tat was >97% radiochemically pure and exhibited preserved immunoreactivity with mIgG epitopes. [123I]Anti-mIgG-tat penetrated BT-474 cells more rapidly than [111In]anti-mIgG-tat ICs and achieved a 1.5-fold to a 2-fold higher uptake in cells and nuclei. Cell penetration and nuclear uptake of [111In]anti-mIgG-tat were inhibited by excess tat peptides and NH4Cl. Elimination of radioactivity from BT-474 cells and nuclei was more rapid and complete for 123I-labeled than for 111In-labeled anti-mIgG-tat ICs. Conclusion: Tat peptides derived from HIV-1 tat protein promoted the penetration and nuclear uptake of radioactivity following the incubation of 111In-labeled and 123I-labeled anti-mIgG antibodies with BT-474 human BC cells. 111In-labeled tat ICs are feasible for inserting radionuclides into cancer cells with potential for targeting intracellular and, particularly, nuclear epitopes for imaging and/or radiotherapeutic applications

  16. Synthesis of Glycopolymer Containing Cell-Penetrating Peptides as Inducers of Recombinant Protein Expression under the Control of Lactose Operator/Repressor Systems.

    Katagiri, Kei; Takasu, Akinori; Higuchi, Masahiro

    2016-05-01

    We recently reported on newly synthesized S-galactosyl oligo(Arg) conjugates to overcome the serious problem of the passage through the E. coli cell membrane. Following in vivo expression of green fluorescent protein (GFP) induced by each of the S-galactosyl (Arg)n constructs (n = 5, 6, 8) at the T5 promoter in E. coli for 18 h, we visually observed that the cultures fluoresced green light when excited with UV light. The fluorescence intensities for these cultures were greater than that found for a control culture, indicating that the peptides had induced GFP expression. In order to accomplish higher expression efficiency, we investigated the cluster effect and structural fine-tuning of new poly(2-oxazoline) containing CysArgArg as the cell-penetrating peptide (CPP) and S-galactosides when acting as inducers of recombinant protein expression under the control of lac operator/repressor systems in this article. Quantitative fluorescence intensities (calculated per molecule) also supported the observations that the cell-penetrating glyco poly(2-oxazoline)s were better inducers of GFP expression than glyco poly(2-oxazoline) containing no CPP or isopropyl β-d-thiogalactoside. Because the level of GFP expression was directly related to the number of sugar residues in each glyco poly(2-oxazoline), we propose that a cluster effect of the S-galactosides attached to the cell-penetrating poly(2-oxazoline) is responsible for how well the galactosides inhibited the lac repressor to activate the protein expression under the control of the lac operator/repressor system. A similar tendency was observed when the T7 promoter was placed upstream of the gene for an artificial extracellular matrix protein and glyco poly(2-oxazoline)s-CPP conjugates were used as inducers. To assess how the glyco poly(2-oxazoline) penetrate the cell membrane, we labeled the glyco poly(2-oxazoline) using 1-amino pyrene and directly observed the penetration process. Furthermore, we could visualize protein

  17. Biochemical characterization of bovine plasma thrombin-activatable fibrinolysis inhibitor (TAFI

    Kristensen Torsten

    2009-05-01

    Full Text Available Abstract Background TAFI is a plasma protein assumed to be an important link between coagulation and fibrinolysis. The three-dimensional crystal structures of authentic mature bovine TAFI (TAFIa in complex with tick carboxypeptidase inhibitor, authentic full lenght bovine plasma thrombin-activatable fibrinolysis inhibitor (TAFI, and recombinant human TAFI have recently been solved. In light of these recent advances, we have characterized authentic bovine TAFI biochemically and compared it to human TAFI. Results The four N-linked glycosylation sequons within the activation peptide were all occupied in bovine TAFI, similar to human TAFI, while the sequon located within the enzyme moiety of the bovine protein was non-glycosylated. The enzymatic stability and the kinetic constants of TAFIa differed somewhat between the two proteins, as did the isoelectric point of TAFI, but not TAFIa. Equivalent to human TAFI, bovine TAFI was a substrate for transglutaminases and could be proteolytically cleaved by trypsin or thrombin/solulin complex, although small differences in the fragmentation patterns were observed. Furthermore, bovine TAFI exhibited intrinsic activity and TAFIa attenuated tPA-mediated fibrinolysis similar to the human protein. Conclusion The findings presented here suggest that the properties of these two orthologous proteins are similar and that conclusions reached using the bovine TAFI may be extrapolated to the human protein.

  18. Membrane-Bound Dynamic Structure of an Arginine-Rich Cell-Penetrating Peptide, the Protein Transduction Domain of HIV TAT, from Solid-State NMR

    Su, Yongchao; Alan J Waring; Ruchala, Piotr; Hong, Mei

    2010-01-01

    The protein transduction domain of HIV-1 TAT, TAT(48-60), is an efficient cell-penetrating peptide (CPP) that diffuses across the lipid membranes of cells despite eight cationic Arg and Lys residues. To understand its mechanism of membrane translocation against the free energy barrier, we have conducted solid-state NMR experiments to determine the site-specific conformation, dynamics, and lipid interaction of the TAT peptide in anionic lipid bilayers. We found that TAT(48-60) is a highly dyna...

  19. A novel strategy to improve antigen presentation for active immunotherapy in cancer. Fusion of the human papillomavirus type 16 E7 antigen to a cell penetrating peptide

    Facilitating the delivery of exogenous antigens to antigen-presenting cells, ensuing processing and presentation via the major histocompatibility complex class I and induction of an effective immune response are fundamental for an effective therapeutic cancer vaccine. In this regard, we propose the use of cell-penetrating peptides fused to a tumor antigen. To demonstrate this concept we designed a fusion protein comprising a novel cell-penetrating and immunostimulatory peptide corresponding to residues 32 to 51 of the Limulus anti-lipopolysaccharide factor protein (LALF32-51) linked to human papillomavirus 16 E7 antigen (LALF32-51-E7). In this work, we demonstrated that the immunization with LALF32-51-E7 using the TC-1 mouse model induces a potent and long-lasting anti-tumor response supported on an effective E7-specific CD8+T-cell response. The finding that therapeutic immunization with LALF32-51 or E7 alone, or an admixture of LALF32-51 and E7, does not induce significant tumor reduction indicates that covalent linkage between LALF32-51 and E7 is required for the anti-tumor effect. These results support the use of this novel cell-penetrating peptide as an efficient means for delivering therapeutic targets into cellular compartments with the induction of a cytotoxic CD8+T lymphocyte immune response. This approach is promissory for the treatment of tumors associated with the human papillomavirus 16, which is responsible for the 50% of cervical cancer cases worldwide and other malignancies. Furthermore, protein-based vaccines can circumvent the major histocompatibility complex specificity limitation associated with peptide vaccines providing a greater extent in their application

  20. Folic Acid-Targeted and Cell Penetrating Peptide-Mediated Theranostic Nanoplatform for High-Efficiency Tri-Modal Imaging-Guided Synergistic Anticancer Phototherapy.

    Li, Na; Li, Tingting; Liu, Chen; Ye, Shiyi; Liang, Jiangong; Han, Heyou

    2016-05-01

    A novel nanomaterial with precisely-defined size and shape, biocompatible composition, and excellent stability, which can integrate multi modal targeted imaging and therapy into a single system for visualized therapeutics, has recently attracted significant research interest. Here, we developed a multifunctional nanoplatform based on silica-coated 4-mercaptobenzoic acid-modified gold nanorods (Au NRs) decorated with gold nanoclusters rich in the photosensitizer Ce6 (Au-Ce6 NCs). The nanoparticles also comprised folic acid and cell penetrating peptide molecules anchored on the surface, obtaining the Au@SiO2@Au-cell penetrating peptide nanocomposite. The Au-Ce6 NCs enhanced the photophysical stability, provided numerous bonding sites and offered a large surface-area and interior space to achieve a high drug loading efficiency (up to 55%). The anchored folic acid and cell penetrating peptide synergistically enhanced the efficiency of uptake of nanocomposites by HeLa cells (up to 70.7%) and improved therapeutic efficacy. The nanocomposite also has good water-solubility, excellent biocompatibility, and long-term stability against illumination and exposure to pH 3-12, thus facilitating their bioapplications in cancer theranostics. Here, the nanocomposite was established for high-resolution and noninvasive tri-modal surface-enhanced Raman spectrum/dark-field/fluorescence imaging-guided high-efficiency synergistic photodynamic/photothermal therapy of cancer. Our studies demonstrate that the multifunctional nanocomposite has the potential as a novel and sensitive contrast agent for complementary and synergistic theranostics in the clinic. PMID:27305812

  1. Penetration through the Skin Barrier

    Nielsen, Jesper Bo; Benfeldt, Eva; Holmgaard, Rikke

    2016-01-01

    . During recent decades, the latter has received increased attention as a route for intentionally delivering drugs to patients. This has stimulated research in methods for sampling, measuring and predicting percutaneous penetration. Previous chapters have described how different endogenous, genetic and...... exogenous factors may affect barrier characteristics. The present chapter introduces the theory for barrier penetration (Fick's law), and describes and discusses different methods for measuring the kinetics of percutaneous penetration of chemicals, including in vitro methods (static and flow......-through diffusion cells) as well as in vivo methods (microdialysis and microperfusion). Then follows a discussion with examples of how different characteristics of the skin (age, site and integrity) and of the penetrants (size, solubility, ionization, logPow and vehicles) affect the kinetics of percutaneous...

  2. Novel cell-penetrating peptide-loaded nanobubbles synergized with ultrasound irradiation enhance EGFR siRNA delivery for triple negative Breast cancer therapy.

    Jing, Hui; Cheng, Wen; Li, Shouqiang; Wu, Bolin; Leng, Xiaoping; Xu, Shouping; Tian, Jiawei

    2016-10-01

    The lack of safe and effective gene delivery strategies remains a bottleneck for cancer gene therapy. Here, we describe the synthesis, characterization, and application of cell-penetrating peptide (CPP)-loaded nanobubbles (NBs), which are characterized by their safety, strong penetrating power and high gene loading capability for gene delivery. An epidermal growth factor receptor (EGFR)-targeted small interfering RNA (siEGFR) was transfected into triple negative breast cancer (TNBC) cells via prepared CPP-NBs synergized with ultrasound-targeted microbubble destruction (UTMD) technology. Fluorescence microscopy showed that siEGFR and CPP were loaded on the shells of the NBs. The transfection efficiency and cell proliferation levels were evaluated by FACS and MTT assays, respectively. In addition, in vivo experiments showed that the expression of EGFR mRNA and protein could be efficiently downregulated and that the growth of a xenograft tumor derived from TNBC cells could be inhibited. Our results indicate that CPP-NBs carrying siEGFR could potentially be used as a promising non-viral gene vector that can be synergized with UTMD technology for efficient TNBC therapy. PMID:27388967

  3. Identification of a cell-penetrating peptide domain from human beta-defensin 3 and characterization of its anti-inflammatory activity

    Lee JY

    2015-08-01

    Full Text Available Jue Yeon Lee,1,* Jin Sook Suh,2,* Jung Min Kim,1 Jeong Hwa Kim,1 Hyun Jung Park,1 Yoon Jeong Park,1,2 Chong Pyoung Chung1 1Central Research Institute, Nano Intelligent Biomedical Engineering Corporation (NIBEC, Chungcheongbuk-do, Republic of Korea; 2Dental Regenerative Biotechnology, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea *These authors contributed equally to this work Abstract: Human beta-defensins (hBDs are crucial factors of intrinsic immunity that function in the immunologic response to a variety of invading enveloped viruses, bacteria, and fungi. hBDs can cause membrane depolarization and cell lysis due to their highly cationic nature. These molecules participate in antimicrobial defenses and the control of adaptive and innate immunity in every mammalian species and are produced by various cell types. The C-terminal 15-mer peptide within hBD3, designated as hBD3-3, was selected for study due to its cell- and skin-penetrating activity, which can induce anti-inflammatory activity in lipopolysaccharide-treated RAW 264.7 macrophages. hBD3-3 penetrated both the outer membrane of the cells and mouse skin within a short treatment period. Two other peptide fragments showed poorer penetration activity compared to hBD3-3. hBD3-3 inhibited the lipopolysaccharide-induced production of inducible nitric oxide synthase, nitric oxide, and secretory cytokines, such as interleukin-6 and tumor necrosis factor in a concentration-dependent manner. Moreover, hBD3-3 reduced the interstitial infiltration of polymorphonuclear leukocytes in a lung inflammation model. Further investigation also revealed that hBD3-3 downregulated nuclear factor kappa B-dependent inflammation by directly suppressing the degradation of phosphorylated-IκBα and by downregulating active nuclear factor kappa B p65. Our findings indicate that hBD3-3 may be conjugated with drugs of interest to ensure their proper translocation to

  4. Transition-Metal-Free CO-Releasing BODIPY Derivatives Activatable by Visible to NIR Light as Promising Bioactive Molecules.

    Palao, Eduardo; Slanina, Tomáš; Muchová, Lucie; Šolomek, Tomáš; Vítek, Libor; Klán, Petr

    2016-01-13

    Carbon monoxide-releasing molecules (CORMs) are chemical agents used to administer CO as an endogenous, biologically active molecule. A precise spatial and temporal control over the CO release is the major requirement for their applications. Here, we report the synthesis and properties of a new generation of transition-metal-free carbon monoxide-releasing molecules based on BODIPY chromophores (COR-BDPs) activatable by visible-to-NIR (up to 730 nm) light. We demonstrate their performance for both in vitro and in vivo experimental settings, and we propose the mechanism of the CO release based on steady-state and transient spectroscopy experiments and quantum chemical calculations. PMID:26697725

  5. Penetration of Rifampin through Staphylococcus epidermidis Biofilms

    Zheng, Zhilan; Philip S. Stewart

    2002-01-01

    Rifampin penetrated biofilms formed by Staphylococcus epidermidis but failed to effectively kill the bacteria. Penetration was demonstrated by a simple diffusion cell bioassay and by transmission electron microscopic observation of antibiotic-affected cells at the distal edge of the biofilm.

  6. Design and synthesis of phospholipase C and A2-activatable near-infrared fluorescent smart probes.

    Popov, Anatoliy V; Mawn, Theresa M; Kim, Soungkyoo; Zheng, Gang; Delikatny, E James

    2010-10-20

    The primary focus of this work was to develop activatable probes suitable for in vivo detection of phospholipase activity. Phospholipases (PLs) are ubiquitous enzymes that perform a number of critical regulatory functions. They catalyze phospholipid breakdown and are categorized as A(1), A(2) (PLA(2)), C (PLC), and D (PLD) based on their site of action. Here, we report the design, synthesis, and characterization of self-quenching reporter probes that release fluorescent moieties upon cleavage with PLA(2) or PLC. A series of phospholipids were synthesized bearing the NIR fluorophore pyropheophorbide a (Pyro) at the sn-2 position. Fluorescence quenching was achieved by attachment of either a positively charged black hole quencher-3 (BHQ-3) to the phospholipid headgroup or another neutral Pyro moiety at the sn-1 position. The specificity to different phospholipases was modulated by insertion of spacers (C(6), C(12)) between Pyro and the lipid backbone. The specificity of the quenched fluorescent phospholipids was assayed on a plate reader against a number of phospholipases and compared with two commercial probes bearing the visible fluorophore BODIPY. While PyroC(6)-PyroC(6)-PtdCho revealed significant background fluorescence, and a 10% fluorescence increase under the action of PLA(2), Pyro-PtdEtn-BHQ demonstrated high selective sensitivity to PLC, particularly to the PC-PLC isoform, and its sensitivity to PLA(2) was negligible due to steric hindrance at the sn-2 position. In contrast, the C(12)-spacered PyroC(12)-PtdEtn-BHQ demonstrated a remarkable selectivity for PLA(2) and the best relative PLA(2)/PLC sensitivity, significantly outperforming previously known probes. These results open an avenue for future in vivo experiments and for new probes to detect PL activity. PMID:20882956

  7. Combined HLA matched limbal stem cells allograft with amniotic membrane transplantation as a prophylactic surgical procedure to prevent corneal graft rejection after penetrating keratoplasty: case report

    Paolo Capozzi

    2014-09-01

    Full Text Available Purpose. To determine if the use of combined HLA matched limbal stem cells allograft with amniotic membrane transplantation (AMT is a safe and effective prophylactic surgical procedure to prevent corneal graft after penetrating keratoplasty (PK. Methods. We report the case of a 17 years old patient with a history of congenital glaucoma, trabeculectomy and multiple corneal graft rejections, presenting total limbal cell deficiency. To reduce the possibility of graft rejection in the left eye after a new PK, a two step procedure was performed. At first the patient underwent a combined HLA matched limbal stem cells allograft (LAT and AMT and then, 10 months later, a new PK. Results. During 12 months of follow-up, the corneal graft remained stable and smooth, with no sign of graft rejection. Conclusions. In our patient, the prophylactic use of LAT from HLA-matched donors and AMT before PK, may result in a better prognosis of corneal graft survival.

  8. Penetration through the Skin Barrier.

    Nielsen, Jesper Bo; Benfeldt, Eva; Holmgaard, Rikke

    2016-01-01

    The skin is a strong and flexible organ with barrier properties essential for maintaining homeostasis and thereby human life. Characterizing this barrier is the ability to prevent some chemicals from crossing the barrier while allowing others, including medicinal products, to pass at varying rates. During recent decades, the latter has received increased attention as a route for intentionally delivering drugs to patients. This has stimulated research in methods for sampling, measuring and predicting percutaneous penetration. Previous chapters have described how different endogenous, genetic and exogenous factors may affect barrier characteristics. The present chapter introduces the theory for barrier penetration (Fick's law), and describes and discusses different methods for measuring the kinetics of percutaneous penetration of chemicals, including in vitro methods (static and flow-through diffusion cells) as well as in vivo methods (microdialysis and microperfusion). Then follows a discussion with examples of how different characteristics of the skin (age, site and integrity) and of the penetrants (size, solubility, ionization, logPow and vehicles) affect the kinetics of percutaneous penetration. Finally, a short discussion of the advantages and challenges of each method is provided, which will hopefully allow the reader to improve decision making and treatment planning, as well as the evaluation of experimental studies of percutaneous penetration of chemicals. PMID:26844902

  9. Fusion of cell-penetrating peptides to thermally responsive biopolymer improves tumor accumulation of p21 peptide in a mouse model of pancreatic cancer

    Walker LR

    2014-10-01

    Full Text Available Leslie R Walker,1 Jung Su Ryu,1 Eddie Perkins,2 Lacey R McNally,3 Drazen Raucher1 1Department of Biochemistry, 2Department of Neurosurgery, University of Mississippi Medical Center, Jackson, MS, USA; 3Division of Hematology and Oncology, University of Louisville, Louisville, KY, USAAbstract: Current therapies for the treatment of pancreatic cancer are limited. The limitations of this type of treatment are abundant. The majority of chemotherapeutic agents used in clinics are highly toxic to both tumor cells and normal tissues due to the lack of specificity. Resistance can develop due to overexposure of these agents. To address these issues, these agents must be made more exclusive toward the tumor site. We have developed a macromolecular carrier based on the sequence of the biopolymer elastin-like polypeptide (ELP that is able to aggregate upon reaching the externally heated tumor environment. This carrier is specific to the tumor as it only aggregates at the heated tumor site. ELP is soluble below its transition temperature but will aggregate when the temperature is raised above its transition temperature. ELP was modified by p21, a cell cycle inhibitory peptide, and the addition of Bac, a cell-penetrating peptide with nuclear localization capabilities. In this study, p21-ELP-Bac and its control, ELP-p21, were used in cell proliferation studies using the pancreatic cancer cell lines Panc-1, MiaPaca-2, and S2013. ELP-p21 had little effect on proliferation, while the half maximal inhibitory concentration of p21-ELP-Bac was ~30 µM. As translocation across the plasma membrane is a limiting step for delivery of macromolecules, these polypeptides were utilized in a pancreatic xenograft model to study the plasma clearance, biodistribution, tumor accumulation, and tumor reduction capabilities of the polypeptide with and without a cell-penetrating peptide.Keywords: elastin-like polypeptide, peptide, targeted drug delivery, macromolecule

  10. Activatable albumin-photosensitizer nanoassemblies for triple-modal imaging and thermal-modulated photodynamic therapy of cancer.

    Hu, Dehong; Sheng, Zonghai; Gao, Guanhui; Siu, Fungming; Liu, Chengbo; Wan, Qian; Gong, Ping; Zheng, Hairong; Ma, Yifan; Cai, Lintao

    2016-07-01

    Photodynamic therapy (PDT) is a noninvasive and effective approach for cancer treatment. The main bottlenecks of clinical PDT are poor selectivity of photosensitizer and inadequate oxygen supply resulting in serious side effects and low therapeutic efficiency. Herein, a thermal-modulated reactive oxygen species (ROS) strategy using activatable human serum albumin-chlorin e6 nanoassemblies (HSA-Ce6 NAs) for promoting PDT against cancer is developed. Through intermolecular disulfide bond crosslinking and hydrophobic interaction, Ce6 photosensitizer is effectively loaded into the HSA NAs, and the obtained HSA-Ce6 NAs exhibit excellent reduction response, as well as enhanced tumor accumulation and retention. By the precision control of the overall body temperature instead of local tumor temperature increasing from 37 °C to 43 °C, the photosensitization reaction rate of HSA-Ce6 NAs increases 20%, and the oxygen saturation of tumor tissue raise 52%, significantly enhancing the generation of ROS for promoting PDT. Meanwhile, the intrinsic fluorescence and photoacoustic properties, and the chelating characteristic of porphyrin ring can endow the HSA-Ce6 NAs with fluorescence, photoacoustic and magnetic resonance triple-modal imaging functions. Upon irradiation of low-energy near-infrared laser, the tumors are completely suppressed without tumor recurrence and therapy-induced side effects. The robust thermal-modulated ROS strategy combined with albumin-based activatable nanophotosensitizer is highly potential for multi-modal imaging-guided PDT and clinical translation. PMID:27061266

  11. The potent antimicrobial properties of cell penetrating peptide-conjugated silver nanoparticles with excellent selectivity for Gram-positive bacteria over erythrocytes

    Liu, Lihong; Yang, Jun; Xie, Jianping; Luo, Zhentao; Jiang, Jiang; Yang, Yi Yan; Liu, Shaomin

    2013-04-01

    Silver nanoparticles are of great interest for use as antimicrobial agents. Studies aimed at producing potent nano-silver biocides have focused on manipulation of particle size, shape, composition and surface charge. Here, we report the cell penetrating peptide catalyzed formation of antimicrobial silver nanoparticles in N,N-dimethylformamide. The novel nano-composite demonstrated a distinctly enhanced biocidal effect toward bacteria (Gram-positive Bacillus subtilis, Gram-negative Escherichia coli) and pathogenic yeast (Candida albicans), as compared to triangular and extremely small silver nanoparticles. In addition, a satisfactory biocompatibility was verified by a haemolysis test. Our results provide a paradigm in developing strategies that can maximize the silver nanoparticle application potentials while minimizing the toxic effects.Silver nanoparticles are of great interest for use as antimicrobial agents. Studies aimed at producing potent nano-silver biocides have focused on manipulation of particle size, shape, composition and surface charge. Here, we report the cell penetrating peptide catalyzed formation of antimicrobial silver nanoparticles in N,N-dimethylformamide. The novel nano-composite demonstrated a distinctly enhanced biocidal effect toward bacteria (Gram-positive Bacillus subtilis, Gram-negative Escherichia coli) and pathogenic yeast (Candida albicans), as compared to triangular and extremely small silver nanoparticles. In addition, a satisfactory biocompatibility was verified by a haemolysis test. Our results provide a paradigm in developing strategies that can maximize the silver nanoparticle application potentials while minimizing the toxic effects. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr34254a

  12. Fusion of EBV with the surface of receptor-negative human hepatoma cell line Li7A permits virus penetration and infection.

    Lisi, A; Pozzi, D; Carloni, G; Da Villa, G; Iacovacci, S; Valli, M B; Grimaldi, S

    1995-01-01

    Our preliminary data suggest that Epstein-Barr virus (EBV) is able to bind to and fuse with the surface membranes of hepatoma cell line Li7A. In order to obtain further evidence, we utilized the relief of rhodamine fluorescence to monitor whether fusion would also take place when Li7A cells were exposed to experimental conditions such as neutral or low pH. It is well known that for some viruses, protonation in the endosomal compartment is needed to trigger the fusion. We show, furthermore, that the rate and extent of fusion are not affected by pretreatment of the cells with agents known to elevate the lysosomal and ensodomal pH, such as chloroquine or NH4Cl (lysosomotropic agent). By indirect immunofluorescence assay, in addition, we confirmed the binding of the EBV to the Li7A cell surface membrane. We attempted finally to correlate the above processes with successful infection of Li7A cells by EBV detected using the polymerase chain reaction technique. In spite of the apparent lack of viral receptor CD21, these nonlymphoid cells appeared susceptible to EBV penetration and infection through fusion with the plasma membrane at the surface of the cells. PMID:8539493

  13. An efficient PEGylated liposomal nanocarrier containing cell-penetrating peptide and pH-sensitive hydrazone bond for enhancing tumor-targeted drug delivery

    Ding Y

    2015-10-01

    Full Text Available Yuan Ding,1,* Dan Sun,1,* Gui-Ling Wang,1 Hong-Ge Yang,1 Hai-Feng Xu,1 Jian-Hua Chen,2 Ying Xie,1,3 Zhi-Qiang Wang4 1Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, School of Pharmaceutical Sciences, Peking University, Beijing, 2School of Medicine, Jianghan University, Wuhan, 3State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing, People’s Republic of China; 4Department of Chemistry and Biochemistry, Kent State University Geauga, Burton, OH, USA *These authors contributed equally to this work Abstract: Cell-penetrating peptides (CPPs as small molecular transporters with abilities of cell penetrating, internalization, and endosomal escape have potential prospect in drug delivery systems. However, a bottleneck hampering their application is the poor specificity for cells. By utilizing the function of hydration shell of polyethylene glycol (PEG and acid sensitivity of hydrazone bond, we constructed a kind of CPP-modified pH-sensitive PEGylated liposomes (CPPL to improve the selectivity of these peptides for tumor targeting. In CPPL, CPP was directly attached to liposome surfaces via coupling with stearate (STR to avoid the hindrance of PEG as a linker on the penetrating efficiency of CPP. A PEG derivative by conjugating PEG with STR via acid-degradable hydrazone bond (PEG2000-Hz-STR, PHS was synthesized. High-performance liquid chromatography and flow cytometry demonstrated that PHS was stable at normal neutral conditions and PEG could be completely cleaved from liposome surface to expose CPP under acidic environments in tumor. An optimal CPP density on liposomes was screened to guaranty a maximum targeting efficiency on tumor cells as well as not being captured by normal cells that consequently lead to a long circulation in blood. In vitro and in vivo studies indicated, in 4 mol% CPP of lipid modified system, that CPP exerted higher efficiency on internalizing the liposomes into

  14. Cell-Penetrating Poly(disulfide) Assisted Intracellular Delivery of Mesoporous Silica Nanoparticles for Inhibition of miR-21 Function and Detection of Subsequent Therapeutic Effects.

    Yu, Changmin; Qian, Linghui; Ge, Jingyan; Fu, Jiaqi; Yuan, Peiyan; Yao, Samantha C L; Yao, Shao Q

    2016-08-01

    The design of drug delivery systems capable of minimal endolysosomal trapping, controlled drug release, and real-time monitoring of drug effect is highly desirable for personalized medicine. Herein, by using mesoporous silica nanoparticles (MSNs) coated with cell-penetrating poly(disulfide)s and a fluorogenic apoptosis-detecting peptide (DEVD-AAN), we have developed a platform that could be uptaken rapidly by mammalian cells via endocytosis-independent pathways. Subsequent loading of these MSNs with small molecule inhibitors and antisense oligonucleotides resulted in intracellular release of these drugs, leading to combination inhibition of endogenous miR-21 activities which was immediately detectable by the MSN surface-coated peptide using two-photon fluorescence microscopy. PMID:27325284

  15. Cell-penetrating superoxide dismutase attenuates oxidative stress-induced senescence by regulating the p53-p21Cip1 pathway and restores osteoblastic differentiation in human dental pulp stem cells

    Park YJ

    2012-09-01

    Full Text Available Yoon Jung Choi,1,* Jue Yeon Lee,2,* Chong Pyoung Chung,2 Yoon Jeong Park,1,21Craniomaxillofacial Reconstructive Sciences, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea; 2Research Institute, Nano Intelligent Biomedical Engineering, Seoul, Republic of Korea*These authors contributed equally to this workBackground: Human dental pulp stem cells (DPSCs have potential applications in tissue regeneration because of their convenient cell harvesting procedures and multipotent capacity. However, the tissue regenerative potential of DPSCs is known to be negatively regulated by aging in long-term culture and under oxidative stress. With an aim of reducing cellular senescence and oxidative stress in DPSCs, an intracellular delivery system for superoxide dismutase 1 (SOD1 was developed. We conjugated SOD1 with a cell-penetrating peptide known as low-molecular weight protamine (LMWP, and investigated the effect of LMWP-SOD1 conjugates on hydrogen peroxide-induced cellular senescence and osteoblastic differentiation.Results: LMWP-SOD1 significantly attenuated enlarged and flattened cell morphology and increased senescence-associated β-galactosidase activity. Under the same conditions, LMWP-SOD1 abolished activation of the cell cycle regulator proteins, p53 and p21Cip1, induced by hydrogen peroxide. In addition, LMWP-SOD1 reversed the inhibition of osteoblastic differentiation and downregulation of osteogenic gene markers induced by hydrogen peroxide. However, LMWP-SOD1 could not reverse the decrease in odontogenesis caused by hydrogen peroxide.Conclusion: Overall, cell-penetrating LMWP-SOD1 conjugates are effective for attenuation of cellular senescence and reversal of osteoblastic differentiation of DPSCs caused by oxidative stress inhibition. This result suggests potential application in the field of antiaging and tissue engineering to overcome the limitations of senescent stem cells.Keywords: superoxide

  16. Intestinal Cell Tight Junctions Limit Invasion of Candida albicans through Active Penetration and Endocytosis in the Early Stages of the Interaction of the Fungus with the Intestinal Barrier.

    Marianne Goyer

    Full Text Available C. albicans is a commensal yeast of the mucous membranes in healthy humans that can also cause disseminated candidiasis, mainly originating from the digestive tract, in vulnerable patients. It is necessary to understand the cellular and molecular mechanisms of the interaction of C. albicans with enterocytes to better understand the basis of commensalism and pathogenicity of the yeast and to improve the management of disseminated candidiasis. In this study, we investigated the kinetics of tight junction (TJ formation in parallel with the invasion of C. albicans into the Caco-2 intestinal cell line. Using invasiveness assays on Caco-2 cells displaying pharmacologically altered TJ (i.e. differentiated epithelial cells treated with EGTA or patulin, we were able to demonstrate that TJ protect enterocytes against invasion of C. albicans. Moreover, treatment with a pharmacological inhibitor of endocytosis decreased invasion of the fungus into Caco-2 cells displaying altered TJ, suggesting that facilitating access of the yeast to the basolateral side of intestinal cells promotes endocytosis of C. albicans in its hyphal form. These data were supported by SEM observations of differentiated Caco-2 cells displaying altered TJ, which highlighted membrane protrusions engulfing C. albicans hyphae. We furthermore demonstrated that Als3, a hypha-specific C. albicans invasin, facilitates internalization of the fungus by active penetration and induced endocytosis by differentiated Caco-2 cells displaying altered TJ. However, our observations failed to demonstrate binding of Als3 to E-cadherin as the trigger mechanism of endocytosis of C. albicans into differentiated Caco-2 cells displaying altered TJ.

  17. Penetrating abdominal trauma.

    Henneman, P L

    1989-08-01

    The management of patients with penetrating abdominal trauma is outlined in Figure 1. Patients with hemodynamic instability, evisceration, significant gastrointestinal bleeding, peritoneal signs, gunshot wounds with peritoneal violation, and type 2 and 3 shotgun wounds should undergo emergency laparotomy. The initial ED management of these patients includes airway management, monitoring of cardiac rhythm and vital signs, history, physical examination, and placement of intravenous lines. Blood should be obtained for initial hematocrit, type and cross-matching, electrolytes, and an alcohol level or drug screen as needed. Initial resuscitation should utilize crystalloid fluid replacement. If more than 2 liters of crystalloid are needed to stabilize an adult (less in a child), blood should be given. Group O Rh-negative packed red blood cells should be immediately available for a patient in impending arrest or massive hemorrhage. Type-specific blood should be available within 15 minutes. A patient with penetrating thoracic and high abdominal trauma should receive a portable chest x-ray, and a hemo- or pneumothorax should be treated with tube thoracostomy. An unstable patient with clinical signs consistent with a pneumothorax, however, should receive a tube thoracostomy prior to obtaining roentgenographic confirmation. If time permits, a nasogastric tube and Foley catheter should be placed, and the urine evaluated for blood (these procedures can be performed in the operating room). If kidney involvement is suspected because of hematuria or penetrating trauma in the area of a kidney or ureter in a patient requiring surgery, a single-shot IVP should be performed either in the ED or the operating room. An ECG is important in patients with possible cardiac involvement and in patients over the age of 40 going to the operating room. Tetanus status should be updated, and appropriate antibiotics covering bowel flora should be given. Operative management should rarely be delayed

  18. Polypyrrole-based nanotheranostics for activatable fluorescence imaging and chemo/photothermal dual therapy of triple-negative breast cancer

    Park, Dongjin; Ahn, Kyung-Ohk; Jeong, Kyung-Chae; Choi, Yongdoo

    2016-05-01

    Here, we fabricated polypyrrole nanoparticles (PPys) (termed HA10-PPy, HA20-PPy, and HA40-PPy) doped with different average molecular weight hyaluronic acids (HAs) (10, 20, and 40 kDa, respectively), and evaluated the effect of molecular weight of doped HA on photothermal induction, fluorescence quenching, and drug loading efficiencies. Doxorubicin-loaded HA-doped PPys (DOX@HA-PPys) could be used for imaging and therapy of triple-negative breast cancer (TNBC). Fluorescence turn-on, stimuli-responsive drug release, and photo-induced heating of DOX@HA-PPys enabled not only activatable fluorescence imaging but also subsequent chemo/photothermal dual therapy for TNBC. In particular, we illustrated the potential usefulness of the photothermal effect of the nanoparticles for overcoming chemoresistance in TNBC.

  19. Thiol-Activatable Triplet-Triplet Annihilation Upconversion with Maleimide-Perylene as the Caged Triplet Acceptor/Emitter.

    Mahmood, Zafar; Zhao, Jianzhang

    2016-01-15

    Efficient thiol-activated triplet-triplet annihilation (TTA) upconversion system was devised with maleimide-caged perylene (Py-M) as the thiol-activatable triplet acceptor/emitter and with diiodoBodipy as the triplet photosensitizer. The photophysical processes were studied with steady-state UV-vis absorption spectroscopy, fluorescence spectroscopy, electrochemical properties, and nanosecond transient absorption spectroscopy. The triplet acceptor/emitter Py-M shows week fluorescence (ΦF = 0.8%), and no upconversion (ΦUC = 0%) was observed. The quenching of fluorescence of Py-M is due to photoinduced electron-transfer (PET) process from perylene to maleimide-caging unit, which quenches the singlet excited state of perylene. The fluorescence of Py-M was enhanced by 200-fold (ΦF = 97%) upon addition of thiols such as 2-mercaptoethanol, and the ΦUC was increased to 5.9%. The unique feature of this thiol-activated TTA upconversion is that the activation is based on addition reaction of the thiols with the caged acceptor/emitter, and no side products were formed. The previously reported cleavage approach gives side products which are detrimental to the TTA upconversion. With nanosecond transient absorption spectroscopy, we found that the triplet excited state of Py-M was not quenched by any PET process, which is different from singlet excited state (fluorescence) of Py-M. The results are useful for study of the triplet excited states of organic chromophores and for activatable TTA upconversion. PMID:26694534

  20. Combinative effect of medium physical and chemical factors on the penetration and localization of some radionuclides in water plant cells

    As a result of the experiments, carried out with the charophytes algae Nitellopsis obtusa, gathered from lake Drukshyaj (the North-East part of the Lithuanian SSR) in 1985, it has been determined that the 90Sr, 144Ce and 137Cs radionuclides accumulation by water plant cell constituents (wall, protoplasm, vacuole) is substantially influenced by the water temperature, the chemical substances, which change the water structure, as well as the combinative effect of these factors. An identical character of the changes of the accumulation factors of 90Sr and 137Cs, which are found in the water solutions in an ionic form, and slightly different character in the case of 144Ce, which exists by 85% in the form of colloid particles, have been noted. In the case of 144Ce the influence of the physical as well as chamical factors on the cell walls is felt stronger than on the inner cell membranes

  1. Fusion of a Short HA2-Derived Peptide Sequence to Cell-Penetrating Peptides Improves Cytosolic Uptake, but Enhances Cytotoxic Activity

    Igor Kitanovic

    2009-09-01

    Full Text Available Cell-penetrating peptides (CPP have become a widely used tool for efficient cargo delivery into cells. However, one limiting fact is their uptake by endocytosis causing the enclosure of the CPP-cargo construct within endosomes. One often used method to enhance the outflow into the cytosol is the fusion of endosome-disruptive peptide or protein sequences to CPP. But, until now, no studies exist investigating the effects of the fusion peptide to the cellular distribution, structural arrangements and cytotoxic behaviour of the CPP. In this study, we attached a short modified sequence of hemagglutinin subunit HA2 to different CPP and analysed the biologic activity of the new designed peptides. Interestingly, we observed an increased cytosolic distribution but also highly toxic activities in the micromolar range against several cell lines. Structural analysis revealed that attachment of the fusion peptide had profound implications on the whole conformation of the peptide, which might be responsible for membrane interaction and endosome disruption.

  2. Arginine-rich peptides destabilize the plasma membrane, consistent with a pore formation translocation mechanism of cell-penetrating peptides.

    Herce, H D; Garcia, A E; Litt, J; Kane, R S; Martin, P; Enrique, N; Rebolledo, A; Milesi, V

    2009-10-01

    Recent molecular-dynamics simulations have suggested that the arginine-rich HIV Tat peptides translocate by destabilizing and inducing transient pores in phospholipid bilayers. In this pathway for peptide translocation, Arg residues play a fundamental role not only in the binding of the peptide to the surface of the membrane, but also in the destabilization and nucleation of transient pores across the bilayer. Here we present a molecular-dynamics simulation of a peptide composed of nine Args (Arg-9) that shows that this peptide follows the same translocation pathway previously found for the Tat peptide. We test experimentally the hypothesis that transient pores open by measuring ionic currents across phospholipid bilayers and cell membranes through the pores induced by Arg-9 peptides. We find that Arg-9 peptides, in the presence of an electrostatic potential gradient, induce ionic currents across planar phospholipid bilayers, as well as in cultured osteosarcoma cells and human smooth muscle cells. Our results suggest that the mechanism of action of Arg-9 peptides involves the creation of transient pores in lipid bilayers and cell membranes. PMID:19804722

  3. Hair follicle targeting, penetration enhancement and Langerhans cell activation make cyanoacrylate skin surface stripping a promising delivery technique for transcutaneous immunization with large molecules and particle-based vaccines.

    Vogt, Annika; Hadam, Sabrina; Deckert, Iliane; Schmidt, Julia; Stroux, Andrea; Afraz, Zahra; Rancan, Fiorenza; Lademann, Jürgen; Combadiere, Behazine; Blume-Peytavi, Ulrike

    2015-01-01

    Transcutaneous immunization (TCI) requires targeting of a maximum number of skin antigen-presenting cells as non-invasive as possible on small skin areas. In two clinical trials, we introduced cyanoacrylate skin surface stripping (CSSS) as a safe method for TCI. Here, using ex vivo human skin, we demonstrate that one CSSS procedure removed only 30% of stratum corneum, but significantly increased the penetration of 200 nm polystyrene particles deep into vellus and intermediate hair follicles from where they could not been retrieved by conventional tape stripping. Two subsequent CSSS had no striking additional effect. CSSS increased particle penetration in superficial stratum corneum and induced Langerhans cell activation. Formulation in amphiphilic ointment or massage did not substantially influences the interfollicular penetration profiles. Hair follicle (HF) targeting by CSSS could become a highly effective tool for TCI when combined with carrier-based delivery and is gaining new attention as our understanding on the HF immune system increases. PMID:25382068

  4. The cell-penetrating peptide domain from human heparin-binding epidermal growth factor-like growth factor (HB-EGF) has anti-inflammatory activity in vitro and in vivo

    Highlights: ► HBP sequence identified from HB-EGF has cell penetration activity. ► HBP inhibits the NF-κB dependent inflammatory responses. ► HBP directly blocks phosphorylation and degradation of IκBα. ► HBP inhibits nuclear translocation of NF-κB p65 subunit. -- Abstract: A heparin-binding peptide (HBP) sequence from human heparin-binding epidermal growth factor-like growth factor (HB-EGF) was identified and was shown to exhibit cell penetration activity. This cell penetration induced an anti-inflammatory reaction in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages. HBP penetrated the cell membrane during the 10 min treatment and reduced the LPS-induced production of nitric oxide (NO), inducible nitric oxide synthase (iNOS), and cytokines (TNF-α and IL-6) in a concentration-dependent manner. Additionally, HBP inhibited the LPS-induced upregulation of cytokines, including TNF-α and IL-6, and decreased the interstitial infiltration of polymorphonuclear leukocytes in a lung inflammation model. HBP inhibited NF-κB-dependent inflammatory responses by directly blocking the phosphorylation and degradation of IκBα and by subsequently inhibiting the nuclear translocation of the p65 subunit of NF-κB. Taken together, this novel HBP may be potentially useful candidate for anti-inflammatory treatments and can be combined with other drugs of interest to transport attached molecules into cells.

  5. Parallel Synthesis of Cell-Penetrating Peptide Conjugates of PMO Toward Exon Skipping Enhancement in Duchenne Muscular Dystrophy

    O'Donovan, Liz; Okamoto, Itaru; Arzumanov, Andrey A; Williams, Donna L.; Deuss, Peter; Gait, Michael J.

    2015-01-01

    We describe two new methods of parallel chemical synthesis of libraries of peptide conjugates of phosphorodiamidate morpholino oligonucleotide (PMO) cargoes on a scale suitable for cell screening prior to in vivo analysis for therapeutic development. The methods represent an extension of the SELection of PEPtide CONjugates (SELPEPCON) approach previously developed for parallel peptide-peptide nucleic acid (PNA) synthesis. However, these new methods allow for the utilization of commercial PMO ...

  6. A Multilayered Cell Culture Model for Transport Study in Solid Tumors: Evaluation of Tissue Penetration of Polyethyleneimine Based Cationic Micelles

    Miura, Seiji; Suzuki, Hidenori; Bae, You Han

    2014-01-01

    Limited drug distribution is partially responsible for the efficacy gap between preclinical and clinical studies of nano-sized drug carriers for cancer therapy. In this study, we examined the transport behavior of cationic micelles formed from a triblock copolymer of poly(D,L-lactide-co-glycolide)-block-branched polyethyleneimine-block-poly(D,L-lactide-co-glycolide) using a unique in vitro tumor model composed of a multilayered cell culture (MCC) and an Ussing chamber system. The Cy3-labeled ...

  7. A mouse model for inducible overexpression of Prdm14 results in rapid-onset and highly penetrant T-cell acute lymphoblastic leukemia (T-ALL

    Brandi L. Carofino

    2013-11-01

    PRDM14 functions in embryonic stem cell (ESC maintenance to promote the expression of pluripotency-associated genes while suppressing differentiation genes. Expression of PRDM14 is tightly regulated and typically limited to ESCs and primordial germ cells; however, aberrant expression is associated with tumor initiation in a wide variety of human cancers, including breast cancer and leukemia. Here, we describe the generation of a Cre-recombinase-inducible mouse model for the spatial and temporal control of Prdm14 misexpression [ROSA26 floxed-stop Prdm14 (R26PR]. When R26PR is mated to either of two Cre lines, Mx1-cre or MMTV-cre, mice develop early-onset T-cell acute lymphoblastic leukemia (T-ALL with median overall survival of 41 and 64 days for R26PR;Mx1-cre and R26PR;MMTV-cre, respectively. T-ALL is characterized by the accumulation of immature single-positive CD8 cells and their widespread infiltration. Leukemia is preceded by a dramatic expansion of cells resembling hematopoietic stem cells and lymphoid-committed progenitors prior to disease onset, accompanied by a blockage in B-cell differentiation at the early pro-B stage. Rapid-onset PRDM14-induced T-ALL requires factors that are present in stem and progenitor cells: R26PR;dLck-cre animals, which express Prdm14 starting at the double-positive stage of thymocyte development, do not develop disease. PRDM14-induced leukemic cells contain high levels of activated NOTCH1 and downstream NOTCH1 targets, including MYC and HES1, and are sensitive to pharmacological inhibition of NOTCH1 with the γ-secretase inhibitor DAPT. Greater than 50% of human T-ALLs harbor activating mutations in NOTCH1; thus, our model carries clinically relevant molecular aberrations. The penetrance, short latency and involvement of the NOTCH1 pathway will make this hematopoietic R26PR mouse model ideal for future studies on disease initiation, relapse and novel therapeutic drug combinations. Furthermore, breeding R26PR to additional Cre

  8. Conformational changes in Sindbis virions resulting from exposure to low pH and interactions with cells suggest that cell penetration may occur at the cell surface in the absence of membrane fusion

    Alphaviruses have the ability to induce cell-cell fusion after exposure to acid pH. This observation has served as an article of proof that these membrane-containing viruses infect cells by fusion of the virus membrane with a host cell membrane upon exposure to acid pH after incorporation into a cell endosome. We have investigated the requirements for the induction of virus-mediated, low pH-induced cell-cell fusion and cell-virus fusion. We have correlated the pH requirements for this process to structural changes they produce in the virus by electron cryo-microscopy. We found that exposure to acid pH was required to establish conditions for membrane fusion but that membrane fusion did not occur until return to neutral pH. Electron cryo-microscopy revealed dramatic changes in the structure of the virion as it was moved to acid pH and then returned to neutral pH. None of these treatments resulted in the disassembly of the virus protein icosahedral shell that is a requisite for the process of virus membrane-cell membrane fusion. The appearance of a prominent protruding structure upon exposure to acid pH and its disappearance upon return to neutral pH suggested that the production of a 'pore'-like structure at the fivefold axis may facilitate cell penetration as has been proposed for polio (J. Virol. 74 (2000) 1342) and human rhino virus (Mol. Cell 10 (2002) 317). This transient structural change also provided an explanation for how membrane fusion occurs after return to neutral pH. Examination of virus-cell complexes at neutral pH supported the contention that infection occurs at the cell surface at neutral pH by the production of a virus structure that breaches the plasma membrane bilayer. These data suggest an alternative route of infection for Sindbis virus that occurs by a process that does not involve membrane fusion and does not require disassembly of the virus protein shell

  9. Cell-penetrating peptide and antibiotic combination therapy: a potential alternative to combat drug resistance in methicillin-resistant Staphylococcus aureus.

    Randhawa, Harmandeep Kaur; Gautam, Ankur; Sharma, Minakshi; Bhatia, Rakesh; Varshney, Grish C; Raghava, Gajendra Pal Singh; Nandanwar, Hemraj

    2016-05-01

    The diverse pattern of resistance by methicillin-resistant Staphylococcus aureus (MRSA) is the major obstacle in the treatment of its infections. The key reason of resistance is the poor membrane permeability of drug molecules. Over the last decade, cell-penetrating peptides (CPPs) have emerged as efficient drug delivery vehicles and have been exploited to improve the intracellular delivery of numerous therapeutic molecules in preclinical studies. Therefore, to overcome the drug resistance, we have investigated for the first time the effects of two CPPs (P3 and P8) in combination with four antibiotics (viz. oxacillin, erythromycin, norfloxacin, and vancomycin) against MRSA strains. We found that both CPPs internalized into the MRSA efficiently at very low concentration (oxacillin, norfloxacin, and vancomycin to susceptible levels (generally <1 μg/mL) for almost all five clinical isolates. Further, the bacterial cell death was confirmed by scanning electron microscopy as well as propidium iodide uptake assay. Simultaneously, time-kill kinetics revealed the increased uptake of antibiotics. In summary, CPPs assist to restore the effectiveness of antibiotics at much lower concentration, eliminate the antibiotic toxicity, and represent the CPP-antibiotic combination therapy as a potential novel weapon to combat MRSA infections. PMID:26837216

  10. Enhanced oral bioavailability of insulin using PLGA nanoparticles co-modified with cell-penetrating peptides and Engrailed secretion peptide (Sec).

    Zhu, Siqi; Chen, Shuangxi; Gao, Yuan; Guo, Feng; Li, Fengying; Xie, Baogang; Zhou, Jianliang; Zhong, Haijun

    2016-07-01

    Biodegradable polymer nanoparticle drug carriers are an attractive strategy for oral delivery of peptide and protein drugs. However, their ability to cross the intestinal epithelium membrane is largely limited. Therefore, in the present study, cell-penetrating peptides (R8, Tat, penetratin) and a secretion peptide (Sec) with N-terminal stearylation were introduced to modify nanoparticles (NPs) on the surface to improve oral bioavailability of peptide and protein drugs. In vitro studies conducted in Caco-2 cells showed the value of the apparent permeability coefficient (Papp) of the nanoparticles co-modified with Sec and penetratin (Sec-Pen-NPs) was about two-times greater than that of the nanoparticles modified with only penetratin (Pen-NPs), while the increase of transcellular transport of nanoparticles modified together with Sec and R8 (Sec-R8-NPs), or Sec and Tat (Sec-Tat-NPs), was not significant compared with nanoparticles modified with only R8 (R8-NPs) or Tat (Tat-NPs). Using insulin as the model drug, in vivo studies performed on rats indicated that compared to Pen-NPs, the relative bioavailability of insulin for Sec-Pen-NPs was 1.71-times increased after ileal segments administration, and stronger hypoglycemic effects was also observed. Therefore, the nanoparticles co-modified with penetratin and Sec could act as attractive carriers for oral delivery of insulin. PMID:26181841

  11. Photoacoustic Imaging: Semiconducting Oligomer Nanoparticles as an Activatable Photoacoustic Probe with Amplified Brightness for In Vivo Imaging of pH (Adv. Mater. 19/2016).

    Miao, Qingqing; Lyu, Yan; Ding, Dan; Pu, Kanyi

    2016-05-01

    Despite the great potential of photoacoustic imaging in the life sciences, the development of smart activatable photoacoustic probes remains elusive. On page 3662, K. Pu and co-workers report a facile nanoengineering approach based on semiconducting oligomer nano-particles to develop ratiometric photoacoustic probes with amplified brightness and enhanced sensing capability for accurate photoacoustic mapping of pH in the tumors of living mice. PMID:27167028

  12. Parallel synthesis of cell-penetrating peptide conjugates of PMO toward exon skipping enhancement in Duchenne muscular dystrophy.

    O'Donovan, Liz; Okamoto, Itaru; Arzumanov, Andrey A; Williams, Donna L; Deuss, Peter; Gait, Michael J

    2015-02-01

    We describe two new methods of parallel chemical synthesis of libraries of peptide conjugates of phosphorodiamidate morpholino oligonucleotide (PMO) cargoes on a scale suitable for cell screening prior to in vivo analysis for therapeutic development. The methods represent an extension of the SELection of PEPtide CONjugates (SELPEPCON) approach previously developed for parallel peptide-peptide nucleic acid (PNA) synthesis. However, these new methods allow for the utilization of commercial PMO as cargo with both C- and N-termini unfunctionalized. The synthetic methods involve conjugation in solution phase, followed by rapid purification via biotin-streptavidin immobilization and subsequent reductive release into solution, avoiding the need for painstaking high-performance liquid chromatography purifications. The synthesis methods were applied for screening of PMO conjugates of a 16-member library of variants of a 10-residue ApoE peptide, which was suggested for blood-brain barrier crossing. In this work the conjugate library was tested in an exon skipping assay using skeletal mouse mdx cells, a model of Duchene's muscular dystrophy where higher activity peptide-PMO conjugates were identified compared with the starting peptide-PMO. The results demonstrate the power of the parallel synthesis methods for increasing the speed of optimization of peptide sequences in conjugates of PMO for therapeutic screening. PMID:25412073

  13. Metasploit penetration testing cookbook

    Agarwal, Monika

    2013-01-01

    This book follows a Cookbook style with recipes explaining the steps for penetration testing with WLAN, VOIP, and even cloud computing. There is plenty of code and commands used to make your learning curve easy and quick.This book targets both professional penetration testers as well as new users of Metasploit, who wish to gain expertise over the framework and learn an additional skill of penetration testing, not limited to a particular OS. The book requires basic knowledge of scanning, exploitation, and the Ruby language.

  14. Penetration testing with Perl

    Berdeaux, Douglas

    2014-01-01

    If you are an expert Perl programmer interested in penetration testing or information security, this guide is designed for you. However, it will also be helpful for you even if you have little or no Linux shell experience.

  15. Guanidinium-rich, glycerol-derived oligocarbonates: a new class of cell-penetrating molecular transporters that complex, deliver, and release siRNA.

    Wender, Paul A; Huttner, Melanie A; Staveness, Daryl; Vargas, Jessica R; Xu, Adele F

    2015-03-01

    A highly versatile and step-economical route to a new class of guanidinium-rich molecular transporters and evaluation of their ability to complex, deliver, and release siRNA are described. These new drug/probe delivery systems are prepared in only two steps, irrespective of length or composition, using an organocatalytic ring-opening co-oligomerization of glycerol-derived cyclic carbonate monomers incorporating either protected guanidine or lipid side chains. The resultant amphipathic co-oligomers are highly effective vehicles for siRNA delivery, providing an excellent level of target protein suppression (>85%). These new oligocarbonates are nontoxic at levels required for cell penetration and can be tuned for particle size. Relative to the previously reported methyl(trimethylene)carbonate (MTC) scaffold, the ether linkage at C2 in the new transporters markedly enhances the stability of the siRNA/co-oligomer complexes. Both hybrid co-oligomers, containing a mixture of glycerol- and MTC-derived monomers, and co-oligomers containing only glycerol monomers are found to provide tunable control over siRNA complex stability. On the basis of a glycerol and CO2 backbone, these new co-oligomers represent a rapidly tunable and biocompatible siRNA delivery system that is highly effective in suppressing target protein synthesis. PMID:25588140

  16. Inhibiting α-synuclein oligomerization by stable cell-penetrating β-synuclein fragments recovers phenotype of Parkinson's disease model flies.

    Ronit Shaltiel-Karyo

    Full Text Available The intracellular oligomerization of α-synuclein is associated with Parkinson's disease and appears to be an important target for disease-modifying treatment. Yet, to date, there is no specific inhibitor for this aggregation process. Using unbiased systematic peptide array analysis, we identified molecular interaction domains within the β-synuclein polypeptide that specifically binds α-synuclein. Adding such peptide fragments to α-synuclein significantly reduced both amyloid fibrils and soluble oligomer formation in vitro. A retro-inverso analogue of the best peptide inhibitor was designed to develop the identified molecular recognition module into a drug candidate. While this peptide shows indistinguishable activity as compared to the native peptide, it is stable in mouse serum and penetrates α-synuclein over-expressing cells. The interaction interface between the D-amino acid peptide and α-synuclein was mapped by Nuclear Magnetic Resonance spectroscopy. Finally, administering the retro-inverso peptide to a Drosophila model expressing mutant A53T α-synuclein in the nervous system, resulted in a significant recovery of the behavioral abnormalities of the treated flies and in a significant reduction in α-synuclein accumulation in the brains of the flies. The engineered retro-inverso peptide can serve as a lead for developing a novel class of therapeutic agents to treat Parkinson's disease.

  17. Large-scale preparation of active caspase-3 in E. coli by designing its thrombin-activatable precursors

    Park Sung

    2008-12-01

    Full Text Available Abstract Background Caspase-3, a principal apoptotic effector that cleaves the majority of cellular substrates, is an important medicinal target for the treatment of cancers and neurodegenerative diseases. Large amounts of the protein are required for drug discovery research. However, previous efforts to express the full-length caspase-3 gene in E. coli have been unsuccessful. Results Overproducers of thrombin-activatable full-length caspase-3 precursors were prepared by engineering the auto-activation sites of caspase-3 precursor into a sequence susceptible to thrombin hydrolysis. The engineered precursors were highly expressed as soluble proteins in E. coli and easily purified by affinity chromatography, to levels of 10–15 mg from 1 L of E. coli culture, and readily activated by thrombin digestion. Kinetic evaluation disclosed that thrombin digestion enhanced catalytic activity (kcat/KM of the precursor proteins by two orders of magnitude. Conclusion A novel method for a large-scale preparation of active caspase-3 was developed by a strategic engineering to lack auto-activation during expression with amino acid sequences susceptible to thrombin, facilitating high-level expression in E. coli. The precursor protein was easily purified and activated through specific cleavage at the engineered sites by thrombin, generating active caspase-3 in high yields.

  18. Ground penetrating radar

    Daniels, David J

    2004-01-01

    Ground-penetrating radar has come to public attention in recent criminal investigations, but has actually been a developing and maturing remote sensing field for some time. In the light of recent expansion of the technique to a wide range of applications, the need for an up-to-date reference has become pressing. This fully revised and expanded edition of the best-selling Surface-Penetrating Radar (IEE, 1996) presents, for the non-specialist user or engineer, all the key elements of this technique, which span several disciplines including electromagnetics, geophysics and signal processing. The

  19. Session: Hard Rock Penetration

    Tennyson, George P. Jr.; Dunn, James C.; Drumheller, Douglas S.; Glowka, David A.; Lysne, Peter

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five presentations: ''Hard Rock Penetration - Summary'' by George P. Tennyson, Jr.; ''Overview - Hard Rock Penetration'' by James C. Dunn; ''An Overview of Acoustic Telemetry'' by Douglas S. Drumheller; ''Lost Circulation Technology Development Status'' by David A. Glowka; ''Downhole Memory-Logging Tools'' by Peter Lysne.

  20. Prevention of Escherichia coli K1 Penetration of the Blood-Brain Barrier by Counteracting the Host Cell Receptor and Signaling Molecule Involved in E. coli Invasion of Human Brain Microvascular Endothelial Cells▿

    Zhu, Longkun; Pearce, Donna; Kim, Kwang Sik

    2010-01-01

    Escherichia coli meningitis is an important cause of mortality and morbidity, and a key contributing factor is our incomplete understanding of the pathogenesis of E. coli meningitis. We have shown that E. coli penetration into the brain requires E. coli invasion of human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier. E. coli invasion of HBMEC involves its interaction with HBMEC receptors, such as E. coli cytotoxic necrotizing factor 1 (CNF1) interacti...

  1. Penetration of erythromycin through Staphylococcus epidermidis biofilm

    LIN Mao-hu; HE Lei; GAO Jie; LIU Yun-xi; SUO Ji-jiang; XING Yu-bin; JIA Ning

    2013-01-01

    Background The catheter related infection caused by Staphylococcus epiderrnidis biofilm is increasing and difficult to treat by antimicrobial chemotherapy.The properties of biofilms that give rise to antibiotic resistance are only partially understood.This study aimed to elucidate the penetration of erythromycin through Staphylococcus epidermidis biofilm.Methods The penetration ratio of erythromycin through Staphylococcus epidermidis biofilms of 1457,1457-msrA,and wild isolate S68 was detected by biofilm penetration model at different time points according to the standard regression curve.The RNNDNA ratio and the cell density within the biofilms were observed by confocal laser microscope and transmission electromicroscope,respectively.Results The penetration ratios of erythromycin through the biofilms of 1457,1457-msrA,and S68 after cultivation for 36 hours were 0.93,0.55 and 0.4,respectively.The erythromycin penetration ratio through 1457 biofilm (0.58 after 8 hours)was higher than that through the other two (0.499 and 0.31 after 24 hours).Lower growth rate of the cells in biofilm was shown,with reduction of RNA/DNA proportion observed by confocal laser microscope through acridine orange stain.Compared with the control group observed by transmission electrmicroscope,the cell density of biofilm air face was lower than that of agar face,with more cell debris.Conclusions Erythromycin could penetrate to the Staphylococcus epidermidis biofilm,but could not kill the cells thoroughly.The lower growth rate of the cells within biofilm could help decreasing the erythromycin susceptibility.

  2. Design and study of activatable ("OFF/ON") quantum dots (Qdots): ligand selection for Qdot surface modification for controlling Qdot fluorescence quenching and restoration

    Teblum, Andrew; Basumallick, Srijita; Shah, Rikhav; Mitra, Rajendra N.; Banerjee, Subhash; Santra, Swadeshmukul

    2012-03-01

    We report design and synthesis of a series of activatable "OFF/ON" CdS:Mn/ZnS quantum dot (Qdot) based sensing probes. The Qdot "OFF" state represent the "quenched state" where the Qdot fluorescence is quenched by ligands attached to Qdot surface. Fluorescence quenching is likely due to ligand assisted electron transfer process. Qdot fluorescence is restored when the electron transfer process is stopped. Using this activatable Qdots, we have successfully demonstrated usefulness of these Qdot probes for reliable detection of toxic cadmium ions in solution, selective detection of glutathione and sensitive detection of intracellular cancer drug release event. In this paper, we will discuss a simple but robust method of making water-soluble CdS:Mn/ZnS Qdots at the room-temperature. Two different water-soluble biomolecules, the N-acetyl cysteine (NAC) and the glutathione (GSH) were used as surface coating ligands. This is a singlestep, one-pot synthesis where the Qdot nanocrystals were grown in the presence of the biomolecules. These Qdots were characterized by fluorescence spectroscopy. Stability of the GSH coated Qdots and the NAC coated Qdots were studied by treating with ethylenediaminetetraacetic acid (EDTA, a strong chelating agent for Zn and Cd ions). Our results show that fluorescence properties of Qdots are affected by the type of surface coated ligands. In comparison to the GSH coated Qdots, the NAC coated Qdots show broad but strong emission towards near infra-red region. When treated with EDTA, fluorescence property of the GSH coated Qdot was affected less than the NAC coated Qdots. This preliminary study shows that NAC coated Qdots could potentially be used to develop activatable ("OFF/ON") probes for potential deep-tissue imaging applications. Similarly, the GSH coated Qdots could be applied for probing desired analytes or for bioimaging purposes in environmentally harsh conditions.

  3. Cellular penetration and nuclear importation properties of {sup 111}In-labeled and {sup 123}I-labeled HIV-1 tat peptide immunoconjugates in BT-474 human breast cancer cells

    Cornelissen, Bart [Division of Nuclear Medicine, University Health Network, Toronto, ON, M5S 3M2 (Canada); Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, M5S 3M2 (Canada); Hu, Meiduo [Division of Nuclear Medicine, University Health Network, Toronto, ON, M5S 3M2 (Canada); Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, M5S 3M2 (Canada); McLarty, Kristin [Division of Nuclear Medicine, University Health Network, Toronto, ON, M5S 3M2 (Canada); Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, M5S 3M2 (Canada); Costantini, Dan [Division of Nuclear Medicine, University Health Network, Toronto, ON, M5S 3M2 (Canada); Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, M5S 3M2 (Canada); Reilly, Raymond M. [Division of Nuclear Medicine, University Health Network, Toronto, ON, M5S 3M2 (Canada) and Department of Medical Imaging, University of Toronto, Toronto, ON, M5S 3M2 (Canada) and Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, M5S 3M2 (Canada) and Toronto General Research Institute, University Health Network, Toronto, ON, M5S 3M2 (Canada)]. E-mail: raymond.reilly@utoronto.ca

    2007-01-15

    Introduction: Our objective was to compare the cell penetration and nuclear importation properties of {sup 111}In-labeled and {sup 123}I-labeled immunoconjugates (ICs) composed of 16-mer peptides (GRKKRRQRRRPPQGYG) derived from HIV-1 transactivator of transcription (tat) protein and anti-mouse IgG (mIgG) in BT-474 breast cancer (BC) cells. Methods: [{sup 111}In]tat ICs were constructed by site-specific conjugation of tat peptides to NaIO{sub 4} {sup -}-oxidized carbohydrates in the Fc domain of diethylenetriaminepentaacetic-acid-modified anti-mIgG antibodies. Immunoreactivity against mIgG was assessed in a competition assay. The kinetics of the accumulation of [{sup 111}In]anti-mIgG-tat IC and [{sup 123}I]anti-mIgG-tat ICs in BT-474 cells and the elimination of radioactivity from cells, cytoplasm or nuclei were determined. The effects of excess tat peptides or NH{sub 4}Cl (an inhibitor of endosomal acidification) on cellular uptake and nuclear importation of [{sup 111}In]anti-mIgG-tat were measured. Results: [{sup 111}In]anti-mIgG-tat was >97% radiochemically pure and exhibited preserved immunoreactivity with mIgG epitopes. [{sup 123}I]Anti-mIgG-tat penetrated BT-474 cells more rapidly than [{sup 111}In]anti-mIgG-tat ICs and achieved a 1.5-fold to a 2-fold higher uptake in cells and nuclei. Cell penetration and nuclear uptake of [{sup 111}In]anti-mIgG-tat were inhibited by excess tat peptides and NH{sub 4}Cl. Elimination of radioactivity from BT-474 cells and nuclei was more rapid and complete for {sup 123}I-labeled than for {sup 111}In-labeled anti-mIgG-tat ICs. Conclusion: Tat peptides derived from HIV-1 tat protein promoted the penetration and nuclear uptake of radioactivity following the incubation of {sup 111}In-labeled and {sup 123}I-labeled anti-mIgG antibodies with BT-474 human BC cells. {sup 111}In-labeled tat ICs are feasible for inserting radionuclides into cancer cells with potential for targeting intracellular and, particularly, nuclear epitopes for

  4. Au@Ag/Au nanoparticles assembled with activatable aptamer probes as smart ``nano-doctors'' for image-guided cancer thermotherapy

    Shi, Hui; Ye, Xiaosheng; He, Xiaoxiao; Wang, Kemin; Cui, Wensi; He, Dinggeng; Li, Duo; Jia, Xuekun

    2014-07-01

    Although nanomaterial-based theranostics have increased positive expectations from cancer treatment, it remains challenging to develop in vivo ``nano-doctors'' that provide high-contrast image-guided site-specific therapy. Here we designed an activatable theranostic nanoprobe (ATNP) via self-assembly of activatable aptamer probes (AAPs) on Au@Ag/Au nanoparticles (NPs). As both quenchers and heaters, novel Au@Ag/Au NPs were prepared, showing excellent fluorescence quenching and more effective near-infrared photothermal therapy than Au nanorods. The AAP comprised a thiolated aptamer and a fluorophore-labeled complementary DNA; thus, the ATNP with quenched fluorescence in the free state could realize signal activation through target binding-induced conformational change of the AAP, and then achieve on-demand treatment under image-guided irradiation. By using S6 aptamer as the model, in vitro and in vivo studies of A549 lung cancer verified that the ATNP greatly improved imaging contrast and specific destruction, suggesting a robust and versatile theranostic strategy for personalized medicine in future.Although nanomaterial-based theranostics have increased positive expectations from cancer treatment, it remains challenging to develop in vivo ``nano-doctors'' that provide high-contrast image-guided site-specific therapy. Here we designed an activatable theranostic nanoprobe (ATNP) via self-assembly of activatable aptamer probes (AAPs) on Au@Ag/Au nanoparticles (NPs). As both quenchers and heaters, novel Au@Ag/Au NPs were prepared, showing excellent fluorescence quenching and more effective near-infrared photothermal therapy than Au nanorods. The AAP comprised a thiolated aptamer and a fluorophore-labeled complementary DNA; thus, the ATNP with quenched fluorescence in the free state could realize signal activation through target binding-induced conformational change of the AAP, and then achieve on-demand treatment under image-guided irradiation. By using S6 aptamer as

  5. Association between thrombin-activatable fibrinolysis inhibitor gene polymorphisms and venous thrombosis risk: a meta-analysis.

    Wang, Wei; Ma, He; Lu, Lili; Sun, Guixiang; Liu, Dang; Zhou, Yunti; Tong, Yue; Lu, Zhaojun

    2016-06-01

    Thrombin-activatable fibrinolysis inhibitor (TAFI) is an important antifibrinolytic factor that has been shown in increased concentrations to be associated with an increased risk for venous thrombosis. However, the effect of TAFI gene polymorphisms on the risk of venous thrombosis remains debatable. The aim of the current study was to evaluate the association of three single nucleotide polymorphisms: 505G>A (rs3742264), 1040 C>T (rs1926447) and -438G>A (rs2146881) with venous thrombosis risk using a meta-analysis. A systematic literature search for eligible studies published before 20 January 2015 was conducted in PubMed, EMBASE, Web of Science, WanFang database and Chinese National Knowledge Infrastructure. We assessed the possible association by pooled odds ratio and its 95% confidence interval. A total of 14 independent case-control studies including 2970 cases and 3049 controls were enrolled in the final meta-analysis. A significant reduction of venous thrombosis risk in the 505G>A polymorphism was observed under allele comparison, homozygote comparison and recessive models, but opposite results were seen in Asians. Likewise, there was a significant decreased susceptibility to venous thrombosis in the 1040C>T polymorphism in homozygote comparison and recessive models. In the subgroup analysis, the nonvenous thromboembolism disease group showed a significantly increased venous thrombosis risk. Pooled estimates did not show evidence of association between -438G>A and venous thrombosis risk in any genetic model. This meta-analysis suggested that although the -438G>T polymorphism is not correlated with venous thrombosis risk in all models, a trend toward reduced risk still could be observed. The A allele and AA genotype of 505G>A in whites and the TT genotype of 1040C>T were significantly associated with a decreased risk of venous thrombosis, except in the non-venous thromboembolism group. PMID:26656901

  6. Pitfalls in penetrating trauma.

    van Vugt, A B

    2003-08-01

    In Western Europe the most frequent cause of multiple injuries is blunt trauma. Only few of us have experience with penetrating trauma, without exception far less than in the USA or South-Africa. In Rotterdam, the Erasmus Medical Centre is a level I trauma centre, situated directly in the town centre. All penetrating traumas are directly presented to our emergency department by a well organized ambulance service supported by a mobile medical team if necessary. The delay with scoop and run principles is very short for these cases, resulting in severely injured reaching the hospital alive in increasing frequency. Although the basic principles of trauma care according to the guidelines of the Advanced Trauma Life Support (ATLS) (1-2) are the same for blunt and penetrating trauma with regard to priorities, diagnostics and primary therapy, there are some pitfalls in the strategy of management in penetrating trauma one should be aware of. Simple algorithms can be helpful, especially in case of limited experience (3). In case of life-saving procedures, the principles of Damage Control Surgery (DCS) must be followed (4-5). This approach is somewhat different from "traditional" surgical treatment. In the Ist phase prompt interventions by emergency thoracotomy and laparotomy are carried out, with only two goals to achieve: surgical control of haemorrhage and contamination. After temporary life-saving procedures, the 2nd phase is characterized by intensive care treatment, dealing with hypothermia, metabolic acidosis and clotting disturbances. Finally in the 3rd phase, within 6-24 hours, definitive surgical care takes place. In this overview, penetrating injuries of neck, thorax, abdomen and extremities will be outlined. Penetrating cranial injuries, as a neurosurgical emergency with poor prognosis, are not discussed. History and physical examination remain the corner stones of good medical praxis. In a work-up according to ATLS principles airway, breathing and circulation

  7. Conjugation of cell-penetrating peptides with poly(lactic-co-glycolic acid-polyethylene glycol nanoparticles improves ocular drug delivery

    Vasconcelos A

    2015-01-01

    Full Text Available Aimee Vasconcelos,1 Estefania Vega,2 Yolanda Pérez,3 María J Gómara,1 María Luisa García,2 Isabel Haro1 1Unit of Synthesis and Biomedical Applications of Peptides, Department of Biomedical Chemistry, Institute for Advanced Chemistry of Catalonia, Consejo Superior de Investigaciones Científicas (IQAC-CSIC, 2Department of Physical Chemistry, Institute of Nanoscience and Nanotechnology, Faculty of Pharmacy, University of Barcelona, 3Nuclear Magnetic Resonance Unit, IQAC-CSIC, Barcelona, Spain Abstract: In this work, a peptide for ocular delivery (POD and human immunodeficiency virus transactivator were conjugated with biodegradable poly(lactic-co-glycolic acid (PGLA–polyethylene glycol (PEG-nanoparticles (NPs in an attempt to improve ocular drug bioavailability. The NPs were prepared by the solvent displacement method following two different pathways. One involved preparation of PLGA NPs followed by PEG and peptide conjugation (PLGA-NPs-PEG-peptide; the other involved self-assembly of PLGA-PEG and the PLGA-PEG-peptide copolymer followed by NP formulation. The conjugation of the PEG and the peptide was confirmed by a colorimetric test and proton nuclear magnetic resonance spectroscopy. Flurbiprofen was used as an example of an anti-inflammatory drug. The physicochemical properties of the resulting NPs (morphology, in vitro release, cell viability, and ocular tolerance were studied. In vivo anti-inflammatory efficacy was assessed in rabbit eyes after topical instillation of sodium arachidonate. Of the formulations developed, the PLGA-PEG-POD NPs were the smaller particles and exhibited greater entrapment efficiency and more sustained release. The positive charge on the surface of these NPs, due to the conjugation with the positively charged peptide, facilitated penetration into the corneal epithelium, resulting in more effective prevention of ocular inflammation. The in vitro toxicity of the NPs developed was very low; no ocular irritation

  8. Ground-penetrating rada

    Thuma, W. R.

    The theory and applications of digital Ground-Penetrating Radar were discussed at a 5-day seminar held at the China University of Geosciences in Wuhan, People's Republic of China, in April. Cohosted by the Department of Applied Geophysics and Canada-China Geoscience, more than 60 senior geophysicists, engineers, technical specialists, university professors and researchers attended.Focus of the meeting was the expanded uses of the new deep-penetrating fully digital PulseEKKO, which is gaining wide acceptance around the world. Attendees showed intense interest in this new and unique technology. Applications covered were groundwater and mineral exploration; engineering, construction and toxic waste site surveying; tunnel and underground mine probing for potential geological hazards, blind ore zones, karst cavities and solution pathways; and locating buried objects such as petroleum storage tanks, unexploded bombs and archeological remains.

  9. Percutaneous Penetration - Methodological Considerations

    Holmgaard, Rikke; Benfeldt, Eva; Nielsen, Jesper B

    2014-01-01

    developed to replace methods involving experimental animals. The results obtained from these methods are decided not only by the chemical or product tested, but to a significant degree also by the experimental set-up and decisions made by the investigator during the planning phase. The present Mini......Studies on percutaneous penetration are needed to assess the hazards after unintended occupational skin exposures to industrial products as well as the efficacy after intended consumer exposure to topically applied medicinal or cosmetic products. During recent decades, a number of methods have been......Review discusses some of the existing and well-known experimental in vitro and in vivo methods for studies of percutaneous penetration together with some more recent and promising methods. After this, some considerations and recommendations about advantages and limitations of the different methods and their...

  10. Python penetration testing essentials

    Mohit

    2015-01-01

    If you are a Python programmer or a security researcher who has basic knowledge of Python programming and want to learn about penetration testing with the help of Python, this book is ideal for you. Even if you are new to the field of ethical hacking, this book can help you find the vulnerabilities in your system so that you are ready to tackle any kind of attack or intrusion.

  11. Penetrating Cardiac Injuries

    ÖZYAZICIOĞLU, Ahmet

    2002-01-01

    Objectives: To present our experience of penetrating cardiac injuries treated at Atatürk University hospital; in 17 years 38 patients were analyzed. Methods: Patients were classified into three groups: group A (stable), 12; group B (shock), 21; and group C (agonal), five. Five patients were treated by pericardial window and three by pericardiocentesis. Two patients in group C, 19 patients in group B and five patients in group A underwent median sternotomy or thoracotomy in the operating room...

  12. Market penetration of biodiesel

    Kenneth R. Szulczyk, Bruce A. McCarl

    2010-01-01

    Full Text Available This research examines in detail the technology and economics of substituting biodiesel for diesel #2. This endeavor examines three areas. First, the benefits of biodiesel are examined, and the technical problems of large-scale implementation. Second, the biodiesel production possibilities are examined for soybean oil, corn oil, tallow, and yellow grease, which are the largest sources of feedstocks for the United States. Examining in detail the production possibilities allows to identity the extent of technological change, production costs, byproducts, and greenhouse gas (GHG emissions. Finally, a U.S. agricultural model, FASOMGHG was used to predict market penetration of biodiesel, given technological progress, variety of technologies and feedstocks, market interactions, energy prices, and carbon dioxide equivalent prices. FASOMGHG has several interesting results. First, diesel fuel prices have an expansionary impact on the biodiesel industry. The higher the diesel fuel prices, the more biodiesel is produced. However, given the most favorable circumstances, the maximum biodiesel market penetration is 9% in 2030 with a wholesale diesel price of $4 per gallon. Second, the two dominant sources of biodiesel are from corn and soybeans. Sources like tallow and yellow grease are more limited, because they are byproducts of other industries. Third, GHG prices have an expansionary impact on the biodiesel prices, because biodiesel is quite GHG efficient. Finally, U.S. government subsidies on biofuels have an expansionary impact on biodiesel production, and increase market penetration at least an additional 3%.

  13. pH-activatable nanoparticles for tumor-specific drug delivery

    Liu, Karen C.

    To address the need for a tumor-specific drug delivery system that can achieve both prolonged circulation and cellular retention at the tumor site, nanocomplexes of Zwitterionic Chitosan (ZWC) and Polyamidoamine (PAMAM) generation 5 were designed. Polyamidoamine (PAMAM) dendrimers have been widely explored as carriers of therapeutics and imaging agents, however, amine-terminated PAMAM dendrimers are rarely utilized in systemic applications due to its cytotoxicity and risk of opsonization, caused by its cationic charge. Such undesirable effects may be mitigated by shielding the PAMAM dendrimer surface with polymers that reduce the charges. However, this shielding may also interfere with PAMAM dendrimers' ability to interact with target cells, thus reducing cellular uptake and overall efficacy of the delivery system. ZWC, a new chitosan derivative, has a unique pH-sensitive charge profile and can shield the cationic surface of PAMAM dendrimers and block adsorption of serum proteins to allow for prolonged circulation. The hypothesis of this approach is that ZWC is anionic and able to coat PAMAM in neutral pH but becomes positive in the acidic tumor microenvironment, revealing the polycationic drug carrier. We expect that ZWC will provide (i) stealth coating for PAMAM drug carrier during circulation (pH 7.4) and (ii) be removed from the PAMAM drug carrier at acidic pH (pH ~6.3), allowing for cellular interaction. The cationic charge of PAMAM has been demonstrated to facilitate uptake and drug delivery to tumor cells via interactions with the negatively charged cell surface. Stable electrostatic complexes of ZWC and PAMAM dendrimers were formed at pH 7.4, as demonstrated by fluorescence spectroscopy and transmission electron microscopy. The presence of ZWC coating protected red blood cells and fibroblast cells from hemolytic and cytotoxic activities of PAMAM dendrimers, respectively. Confocal microscopy showed that the protective effect of ZWC disappeared at low pH as

  14. Imaging Primary Mouse Sarcomas After Radiation Therapy Using Cathepsin-Activatable Fluorescent Imaging Agents

    Cuneo, Kyle C. [Department of Radiation Oncology, Duke University School of Medicine, Durham, North Carolina (United States); Mito, Jeffrey K.; Javid, Melodi P. [Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina (United States); Ferrer, Jorge M. [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Kim, Yongbaek [Department of Clinical Pathology, College of Veterinary Medicine, Seoul National University, Seoul (Korea, Republic of); Lee, W. David [The David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Bawendi, Moungi G. [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Brigman, Brian E. [Department of Orthopedic Surgery, Duke University School of Medicine, Durham, North Carolina (United States); Kirsch, David G., E-mail: david.kirsch@duke.edu [Department of Radiation Oncology, Duke University School of Medicine, Durham, North Carolina (United States); Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina (United States)

    2013-05-01

    Purpose: Cathepsin-activated fluorescent probes can detect tumors in mice and in canine patients. We previously showed that these probes can detect microscopic residual sarcoma in the tumor bed of mice during gross total resection. Many patients with soft tissue sarcoma (STS) and other tumors undergo radiation therapy (RT) before surgery. This study assesses the effect of RT on the ability of cathepsin-activated probes to differentiate between normal and cancerous tissue. Methods and Materials: A genetically engineered mouse model of STS was used to generate primary hind limb sarcomas that were treated with hypofractionated RT. Mice were injected intravenously with cathepsin-activated fluorescent probes, and various tissues, including the tumor, were imaged using a hand-held imaging device. Resected tumor and normal muscle samples were harvested to assess cathepsin expression by Western blot. Uptake of activated probe was analyzed by flow cytometry and confocal microscopy. Parallel in vitro studies using mouse sarcoma cells were performed. Results: RT of primary STS in mice and mouse sarcoma cell lines caused no change in probe activation or cathepsin protease expression. Increasing radiation dose resulted in an upward trend in probe activation. Flow cytometry and immunofluorescence showed that a substantial proportion of probe-labeled cells were CD11b-positive tumor-associated immune cells. Conclusions: In this primary murine model of STS, RT did not affect the ability of cathepsin-activated probes to differentiate between tumor and normal muscle. Cathepsin-activated probes labeled tumor cells and tumor-associated macrophages. Our results suggest that it would be feasible to include patients who have received preoperative RT in clinical studies evaluating cathepsin-activated imaging probes.

  15. Analysis program for SCV penetration

    Background: Steel Containment Vessel (SCV) penetrations are special parts in nuclear plant. The analysis method and acceptance criteria of SCV penetration are different from piping. The analysis method and acceptance criteria for SCV penetration of CAP1000 plant are required. Purpose: To set the analysis method and acceptance criteria for SCV penetration. And base on these calculation and evaluation method, make a program for the penetration calculation and evaluation that is automatic, rapid and easy to use. Methods: The development of this program is based on the research and contrast. The axisymmetric penetration model with nonaxisymmetric loading is established in this program. The two sides loads combination of penetration is considered in this program. The stress is calculated by ANSYS 11.0; pre-process is developed by VB and post-process is done by Excel. Results: The analysis method and acceptance criteria of SCV penetration are established, and a program for the penetration calculation and evaluation is developed which is automatic, rapid and easy to use, Conclusions: The analysis method and acceptance criteria of SCV penetration and the program for the penetration calculation and evaluation in this paper are reliable. By this program, the high speed and accurate penetration analysis will be expected. (authors)

  16. Enhancing Targeted Tumor Treatment by Near IR Light-Activatable Photodynamic–Photothermal Synergistic Therapy

    Fan, Zhen; Dai, Xuemei; Lu, Yuefeng; Yu, Eugene; Brahmbatt, Nupur; Carter, NaTasha; Tchouwou, Christine; Singh, Anant Kumar; Jones, Yolanda; Yu, Hongtao; Ray, Paresh Chandra

    2014-01-01

    For several decades, cancer has been one of the most life-threatening diseases. For enhancing anticancer efficiency with minimum side effects, combination therapy is envisioned. The current manuscript reports for the first time the development of a methylene blue (MB) bound nanoplatform, which is capable of delivering targeted diagnostic and combined synergistic photothermal and photodynamic treatment of cancer. Experimental data found that, once the nanoparticle binds with the target cell su...

  17. An albumin nanocomplex-based endosomal pH-activatable on/off probe system.

    Lee, Changkyu; Lee, Seunghyun; Thao, Le Quang; Hwang, Ha Shin; Kim, Jong Oh; Lee, Eun Seong; Oh, Kyung Taek; Shin, Beom Soo; Choi, Han-Gon; Youn, Yu Seok

    2016-08-01

    Albumin has gained considerable interest as a material for fabricating nanoparticulate systems due to its biomedical advantages, such as biocompatibility and chemical functionality. Here, we report a new pH-sensitive albumin nanocomplex prototype with a zinc-imidazole coordination bond. Albumin was conjugated with 1-(3-aminopropyl)imidazole and mPEG10kDa-NHS, and the resulting albumin conjugate (PBI) was then modified with either Cy5.5 or BHQ-3. The newly formed albumin nanocomplex (C/BQ-PBI Zn NCs: ∼116nm) system was facilely self-assembled around pH 7.4 in the presence of Zn(2+), but it quickly disassembled in an acidic environment (∼pH 5.0). Based on this pH-sensitivity, C/BQ-PBI Zn NCs emitted strong near-infrared fluorescence and released Zn(2+), turning "off" at pH ∼7.4 (e.g., plasma) and "on" at pH ∼5.0 (e.g., endo/lysosomes in tumor cells) on account of fluorescence resonance energy transfer. C/BQ-PBI Zn NCs displayed significant cytotoxicity due to an increase in cellular Zn(2+) in response to endosomal pH (∼5.0) in breast cancer MCF-7 cells and lung adenocarcinoma A549 cells. Particularly, confocal laser scanning microscopic images showed a strong fluorescence signal caused by the disassembly of C/BQ-PBI Zn NCs in the endosomal region of MCF-7 cells. Based on these results, we believe that this albumin nanocomplex is an attractive biocompatible tumor targeting probe carrier for the theranostic purpose. PMID:27108210

  18. Microbial Penetration through Nutrient-Saturated Berea Sandstone.

    Jenneman, G E; McInerney, M J; Knapp, R M

    1985-08-01

    Penetration times and penetration rates for a motile Bacillus strain growing in nutrient-saturated Berea sandstone cores were determined. The rate of penetration was essentially independent of permeabilities above 100 mdarcys and rapidly declined for permeabilities below 100 mdarcys. It was found that these penetration rates could be grouped into two statistically distinct classes consisting of rates for permeabilities above 100 mdarcys and rates for those below 100 mdarcys. Instantaneous penetration rates were found to be zero order with respect to core length for cores with permeabilities above 100 mdarcys and first order with respect to core length for cores with permeabilities below 100 mdarcys. The maximum observed penetration rate was 0.47 cm . h, and the slowest was 0.06 cm . h; however, these rates may be underestimates of the true penetration rate, since the observed rates included the time required for growth in the flask as well as the core. The relationship of penetration time to the square of the length of the core suggested that cells penetrated high-permeability cores as a band and low-permeability cores in a diffuse fashion. The motile Enterobacter aerogenes strain penetrated Berea sandstone cores three to eight times faster than did the nonmotile Klebsiella pneumoniae strain when cores of comparable length and permeability were used. A penetration mechanism based entirely on motility predicted penetration times that were in agreement with the observed penetration times for motile strains. The fact that nonmotile strains penetrated the cores suggested that filamentous or unrestricted growth, or both, may also be important. PMID:16346858

  19. Market penetration of ethanol

    This research examines in detail the technology and economics of substituting ethanol for gasoline. This endeavor examines three issues. First, the benefits of ethanol/gasoline blends are examined, and then the technical problems of large-scale implementation of ethanol. Second, ethanol production possibilities are examined in detail from a variety of feedstocks and technologies. The feedstocks are the starch/sugar crops and crop residues, while the technologies are corn wet mill, dry grind, and lignocellulosic fermentation. Examining in detail the production possibilities allows the researchers to identity the extent of technological change, production costs, byproducts, and GHG emissions. Finally, a U.S. agricultural model, FASOMGHG, is updated which predicts the market penetration of ethanol given technological progress, variety of technologies and feedstocks, market interactions, energy prices, and GHG prices. FASOMGHG has several interesting results. First, gasoline prices have a small expansionary impact on the U.S. ethanol industry. Both agricultural producers' income and cost both increase with higher energy prices. If wholesale gasoline is $4 per gallon, the predicted ethanol market penetration attains 53% of U.S. gasoline consumption in 2030. Second, the corn wet mill remains an important industry for ethanol production, because this industry also produces corn oil, which could be converted to biodiesel. Third, GHG prices expand the ethanol industry. However, the GHG price expands the corn wet mill, but has an ambiguous impact on lignocellulosic ethanol. Feedstocks for lignocellulosic fermentation can also be burned with coal to generate electricity. Both industries are quite GHG efficient. Finally, U.S. government subsidies on biofuels have an expansionary impact on ethanol production, but may only increase market penetration by an additional 1% in 2030, which is approximately 6 billion gallons. (author)

  20. Deep penetration calculations

    Several Monte Carlo techniques are compared in the transport of neutrons of different source energies through two different deep-penetration problems each with two parts. The first problem involves transmission through a 200-cm concrete slab. The second problem is a 900 bent pipe jacketed by concrete. In one case the pipe is void, and in the other it is filled with liquid sodium. Calculations are made with two different Los Alamos Monte Carlo codes: the continuous-energy code MCNP and the multigroup code MCMG

  1. Different patterns of nuclear and mitochondrial penetration by the G3 PAMAM dendrimer and its biotin–pyridoxal bioconjugate BC-PAMAM in normal and cancer cells in vitro

    Uram, Łukasz; Szuster, Magdalena; Filipowicz, Aleksandra; Gargasz, Krzysztof; Wołowiec, Stanisław; Wałajtys-Rode, Elżbieta

    2015-01-01

    The intracellular localization and colocalization of a fluorescently labeled G3 amine-terminated cationic polyamidoamine (PAMAM) dendrimer and its biotin–pyridoxal (BC-PAMAM) bioconjugate were investigated in a concentration-dependent manner in normal human fibroblast (BJ) and squamous epithelial carcinoma (SCC-15) cell lines. After 24 hours treatment, both cell lines revealed different patterns of intracellular dendrimer accumulation depending on their cytotoxic effects. Cancer cells exhibited much higher (20-fold) tolerance for native PAMAM treatment than fibroblasts, whereas BC-PAMAM was significantly toxic only for fibroblasts at 50 µM concentration. Fibroblasts accumulated the native and bioconjugated dendrimers in a concentration-dependent manner at nontoxic range of concentration, with significantly lower bioconjugate loading. After reaching the cytotoxicity level, fluorescein isothiocyanate-PAMAM accumulation remains at high, comparable level. In cancer cells, native PAMAM loading at higher, but not cytotoxic concentrations, was kept at constant level with a sharp increase at toxic concentration. Mander’s coefficient calculated for fibroblasts and cancer cells confirmed more efficient native PAMAM penetration as compared to BC-PAMAM. Significant differences in nuclear dendrimer penetration were observed for both cell lines. In cancer cells, PAMAM signals amounted to ~25%–35% of the total nuclei area at all investigated concentrations, with lower level (15%–25%) observed for BC-PAMAM. In fibroblasts, the dendrimer nuclear signal amounted to 15% at nontoxic and up to 70% at toxic concentrations, whereas BC-PAMAM remained at a lower concentration-dependent level (0.3%–20%). Mitochondrial localization of PAMAM and BC-PAMAM revealed similar patterns in both cell lines, depending on the extracellular dendrimer concentration, and presented significantly lower signals from BC-PAMAM, which correlated well with the cytotoxicity. PMID:26379435

  2. Subphthalocyanines: addressing water-solubility, nano-encapsulation, and activation for optical imaging of B16 melanoma cells.

    Bernhard, Yann; Winckler, Pascale; Chassagnon, Remi; Richard, Philippe; Gigot, Élodie; Perrier-Cornet, Jean-Marie; Decréau, Richard A

    2014-11-21

    Water-soluble disulfonato-subphthalocyanines (SubPcs) or hydrophobic nano-encapsulated SubPcs are efficient probes for the fluorescence imaging of cells. 20 nm large liposomes (TEM and DLS) incorporated about 13% SubPc. Moreover, some of these fluorophores were found to be pH activatable. PMID:25266256

  3. Thrombin-activatable fibrinolysis inhibitor Thr325Ile polymorphism and plasma level in breast cancer: A pilot study

    Manal S. Fawzy

    2015-06-01

    Full Text Available This study aimed to investigate thrombin-activatable fibrinolysis inhibitor (TAFI Thr325Ile polymorphism and TAFI antigen (Ag levels in breast cancer (BC in the Egyptian population to clarify their role in relation to BC. A group of 300 females was recruited in this study; of these 150 unrelated patients with different stages of BC and 150 age-matched healthy controls. Plasma TAFI Ag was measured by ELISA and TAFI Thr325Ile (rs1926447 polymorphism was genotyped using TaqMan single nucleotide polymorphism (SNP genotyping assay. The results showed the genotypes of the minor allele; Thr/Ile (CT and Ile/Ile (TT were significantly more frequent in patients compared to control group (50.0% and 22.0% vs. 42.0% and 13.3%, respectively and were also associated with BC susceptibility [OR = 1.9 and 2.6; 95% CI: (1.1–3.3 and (1.3–5.5, respectively P = 0.01]. Ile325 allele carriers were more frequent in cases than in controls (47.0% vs. 34.0% [OR = 1.7, (95% CI = 1.2–2.4, P = 0.001]. However, TAFI Thr325Ile polymorphism was not associated with BC stage or other clincopathological characteristics. TAFI Ag levels were correlated with advanced stages of BC, poor prognosis and risk of recurrence (P = 0.02, P = 0.04 and P  < 0.001, respectively and Thr325Ile SNP was significantly correlated with TAFI antigen levels with the C/C genotype corresponding to the highest and the T/T genotype to the lowest TAFI antigen levels (P < 0.001 in the study groups. In conclusion, this study showed for the first time that TAFI Thr325Ile polymorphism could have a contribution to BC susceptibility in our population. Furthermore, high TAFI plasma levels may serve as a predictor of poor prognosis in patients with BC.

  4. Overview: Hard Rock Penetration

    Dunn, J.C.

    1992-08-01

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  5. Overview: Hard Rock Penetration

    Dunn, J.C.

    1992-01-01

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  6. Overview - Hard Rock Penetration

    Dunn, James C.

    1992-03-24

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling Organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  7. Penetration Testing: A Review

    Kumar Shravan

    2014-04-01

    Full Text Available : Network Security is becoming more and more crucial as the volume of data being exchanged on the Internet increases. When people use Internet, they have certain expectations. They expect confidentiality, data integrity and authentication (CIA Standards. In 1980’s most organizations had only a physical boundary that needed protection of the assets. Today, due to the changes in the way resources are made available Organizations are forced to verify that their assets are protected from both the external and internal threats that our working environment has enabled. Due to the increasing dependency of our society on networked information system the overall security of these systems should be measured and improved. The most accurate method to evaluate organization’s information security stance is to observe how it stands up against an attack. Network administrators have often tried their best by improving their network security, however with rapid surface of new exploits; the best way of ensuring that the system is secure is to attempt penetration testing. This would be the most effective way to find exploits and to proof whether a system is vulnerable. Penetration test ing often allows the security analyst to find new vulnerabilities.

  8. Membrane damage as first and DNA as the secondary target for anti-candidal activity of antimicrobial peptide P7 derived from cell-penetrating peptide ppTG20 against Candida albicans.

    Li, Lirong; Song, Fengxia; Sun, Jin; Tian, Xu; Xia, Shufang; Le, Guowei

    2016-06-01

    P7, a peptide analogue derived from cell-penetrating peptide ppTG20, possesses antibacterial and antitumor activities without significant hemolytic activity. In this study, we investigated the antifungal effect of P7 and its anti-Candida acting mode in Candida albicans. P7 displayed antifungal activity against the reference C. albicans (MIC = 4 μM), Aspergilla niger (MIC = 32 μM), Aspergillus flavus (MIC = 8 μM), and Trichopyton rubrum (MIC = 16 μM). The effect of P7 on the C. albicans cell membrane was examined by investigating the calcein leakage from fungal membrane models made of egg yolk l-phosphatidylcholine/ergosterol (10 : 1, w/w) liposomes. P7 showed potent leakage effects against fungal liposomes similar to Melittin-treated cells. C. albicans protoplast regeneration assay demonstrated that P7 interacted with the C. albicans plasma membrane. Flow cytometry of the plasma membrane potential and integrity of C. albicans showed that P7 caused 60.9 ± 1.8% depolarization of the membrane potential of intact C. albicans cells and caused 58.1 ± 3.2% C. albicans cell membrane damage. Confocal laser scanning microscopy demonstrated that part of FITC-P7 accumulated in the cytoplasm. DNA retardation analysis was also performed, which showed that P7 interacted with C. albicans genomic DNA after penetrating the cell membrane, completely inhibiting the migration of genomic DNA above the weight ratio (peptide : DNA) of 6. Our results indicated that the plasma membrane was the primary target, and DNA was the secondary intracellular target of the mode of action of P7 against C. albicans. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. PMID:27197902

  9. Liquid Crystalline Nanodispersions Functionalized with Cell-Penetrating Peptides for Topical Delivery of Short-Interfering RNAs: A Proposal for Silencing a Pro-Inflammatory Cytokine in Cutaneous Diseases.

    Petrilli, R; Eloy, J O; Praça, F S G; Del Ciampo, J O; Fantini, M A C; Fonseca, M J V; Bentley, M V L B

    2016-05-01

    Short-interfering RNAs (siRNAs) are a potential strategy for the treatment of cutaneous diseases. In this context, liquid crystalline nanoparticles functionalized with specific proteins and peptide-transduction domains (PTDs), which act as penetration enhancers, are a promising carrier for siRNA delivery through the skin. Herein, hexagonal phase liquid crystal nanoparticles based on monoolein (MO) and/or oleic acid (OA) containing (or lacking) the cationic polymer polyethylenimine (PEI) and the cationic lipid oleylamine (OAM) were functionalized with the membrane transduction peptides transcriptional activator (TAT) or penetratin (PNT). These nanoparticles were complexed with siRNA and characterized by particle size, polydispersity, zeta potential, complexation efficiency and siRNA release. The formulations containing cationic agents presented positive zeta potentials, sizes on the nanometer scale, and complexed siRNAs at concentrations of 10 μM; these agents were successfully released in a heparin competition assay. Cell culture studies demonstrated that nanoparticles composed of MO:OA:PEI functionalized with TAT were the most efficient at transfecting L929 cells, and the uptake efficiency was enhanced by TAT peptide functionalization. Thereafter, the selected formulations were evaluated for in vivo skin irritation, penetration and in vivo efficacy using a chemically induced inflammatory animal model. These nanoparticles did not irritate the skin and provided higher siRNA penetration and delivery into the skin than control formulations. Additionally, efficacy studies in the animal model showed that the association of TAT with the nanodispersion provided higher suppression of tumor necrosis factor (TNF)-α. Thus, the development of liquid crystalline nanodispersions containing TAT may lead to improved topical siRNA delivery for the treatment of inflammatory skin diseases. PMID:27305826

  10. Cognitive penetrability and ethical perception

    Cowan, Robert

    2014-01-01

    In recent years there has been renewed philosophical interest in the thesis that perceptual experience is cognitively penetrable, i.e., roughly, the view that the contents and/or character of a subject's perceptual experience can be modified by what a subject believes and desires. As has been widely noted, it is plausible that cognitive penetration has implications for perception's epistemic role. On the one hand, penetration could make agents insensitive to the world in a way which epistemic...

  11. Conjugated primary bile salts reduce permeability of endotoxin through bacteria-stimulated intestinal epithelial cells and synergize with lecithin in suppression of inflammatory cytokine production

    Parlesak, Alexandr; Schaeckeler, Simone; Moser, Lydia;

    2007-01-01

    Objective: Endotoxemia was shown to be integral in the pathophysiology of obstructive jaundice. In the current study, the role of conjugated primary bile salts (CPBS) and phosphatidylcholine on the permeability of endotoxin through a layer of intestinal epithelial cells and the consequent activat...

  12. Penetration Tester's Open Source Toolkit

    Faircloth, Jeremy

    2011-01-01

    Great commercial penetration testing tools can be very expensive and sometimes hard to use or of questionable accuracy. This book helps solve both of these problems. The open source, no-cost penetration testing tools presented do a great job and can be modified by the user for each situation. Many tools, even ones that cost thousands of dollars, do not come with any type of instruction on how and in which situations the penetration tester can best use them. Penetration Tester's Open Source Toolkit, Third Edition, expands upon existing instructions so that a professional can get the most accura

  13. Endophthalmitis after penetrating keratoplasty.

    Guss, R B; Koenig, S; De La Pena, W; Marx, M; Kaufman, H E

    1983-05-01

    Of 445 eyes (305 of which were aphakic) that underwent penetrating keratoplasty, 11 developed endophthalmitis, three immediately after surgery, two after subsequent secondary surgery, and six after late ulceration of the transplanted cornea. The diagnosis was based clinically on the loss of the red reflex and vitreous opacification, and was confirmed by culture of vitreous aspirate. All patients who developed endophthalmitis were aphakic and had received corticosteroids at the time of infection; most had undergone previous ocular surgery. These patients differed from those previously described with this condition because neither the donor tissue nor the storage medium was the source of infection. Treatment included intracameral, systemic, and topical administration of antibiotics. When the endophthalmitis originated from a corneal ulcer in a graft, the infected tissue was replaced with a new transplant. Despite treatment, the final visual outcomes were not good. One eye had a final visual acuity of 20/200 and one eye had a final visual acuity of 20/400. Three eyes had light perception and six eyes had no light perception. One eye was eventually enucleated. PMID:6342401

  14. Ground-penetrating radar methods

    Ground-penetrating radar geophysical methods are finding greater and greater use in agriculture. With the ground-penetrating radar (GPR) method, an electromagnetic radio energy (radar) pulse is directed into the subsurface, followed by measurement of the elapsed time taken by the radar signal as it ...

  15. Different patterns of nuclear and mitochondrial penetration by the G3 PAMAM dendrimer and its biotin–pyridoxal bioconjugate BC-PAMAM in normal and cancer cells in vitro

    Uram Ł

    2015-09-01

    Full Text Available Łukasz Uram,1 Magdalena Szuster,1 Aleksandra Filipowicz,2 Krzysztof Gargasz,3 Stanisław Wołowiec,3 Elżbieta Wałajtys-Rode4 1Bioorganic Chemistry Laboratory, Faculty of Chemistry, Rzeszow University of Technology, 2Cosmetology Department, University of Information Technology and Management in Rzeszow, 3Institute of Nursery and Health Sciences, Faculty of Medicine, University of Rzeszow, Rzeszow, 4Department of Drug Technology and Biotechnology, Faculty of Chemistry, Warsaw University of Technology, Warsaw, Poland Abstract: The intracellular localization and colocalization of a fluorescently labeled G3 amine-terminated cationic polyamidoamine (PAMAM dendrimer and its biotin–pyridoxal (BC-PAMAM bioconjugate were investigated in a concentration-dependent manner in normal human fibroblast (BJ and squamous epithelial carcinoma (SCC-15 cell lines. After 24 hours treatment, both cell lines revealed different patterns of intracellular dendrimer accumulation depending on their cytotoxic effects. Cancer cells exhibited much higher (20-fold tolerance for native PAMAM treatment than fibroblasts, whereas BC-PAMAM was significantly toxic only for fibroblasts at 50 µM concentration. Fibroblasts accumulated the native and bioconjugated dendrimers in a concentration-dependent manner at nontoxic range of concentration, with significantly lower bioconjugate loading. After reaching the cytotoxicity level, fluorescein isothiocyanate-PAMAM accumulation remains at high, comparable level. In cancer cells, native PAMAM loading at higher, but not cytotoxic concentrations, was kept at constant level with a sharp increase at toxic concentration. Mander’s coefficient calculated for fibroblasts and cancer cells confirmed more efficient native PAMAM penetration as compared to BC-PAMAM. Significant differences in nuclear dendrimer penetration were observed for both cell lines. In cancer cells, PAMAM signals amounted to ~25%–35% of the total nuclei area at all

  16. Penetration of Photovoltaics in Greece

    Eugenia Giannini

    2015-06-01

    Full Text Available Recently, an interesting experiment was completed in Greece concerning photovoltaic penetration into the electricity production sector. Based on the relevant laws and in accordance to the related European directives, an explosive penetration process was completed in less than three years, resulting in a 7% share of photovoltaics in electricity production instead of the previous negligible share. The legislation was based on licensing simplification and generous feed-in-tariffs. This approach transformed photovoltaic technology from a prohibitively expensive to a competitive one. This work aims to summarize the relevant legislation and illustrate its effect on the resulting penetration. A sigmoid-shape penetration was observed which was explained by a pulse-type driving force. The return on investment indicator was proposed as an appropriate driving force, which incorporates feed-in-tariffs and turnkey-cost. Furthermore, the resulting surcharge on the electricity price due to photovoltaic penetration was also analyzed.

  17. An Earth Penetrating Modeling Assessment

    Stokes, E; Yarrington, P; Glenn, L

    2005-06-21

    Documentation of a study to assess the capability of computer codes to predict lateral loads on earth penetrating projectiles under conditions of non-normal impact. Calculations simulated a set of small scale penetration tests into concrete targets with oblique faces at angles of 15 and 30 degrees to the line-of-flight. Predictive codes used by the various calculational teams cover a wide range of modeling approaches from approximate techniques, such as cavity expansion, to numerical methods, such as finite element codes. The modeling assessment was performed under the auspices of the Phenomenology Integrated Product Team (PIPT) for the Robust Nuclear Earth Penetrator Program (RNEP). Funding for the penetration experiments and modeling was provided by multiple earth penetrator programs.

  18. Comparison of mechanisms and cellular uptake of cell-penetrating peptide on different cell lines%不同细胞系对细胞穿透肽的摄取和机制比较

    马冬旭; 齐宪荣

    2010-01-01

    细胞穿透肽(cell-penetrating peptide,CPP)作为一种潜在的药物输送高效转运载体一直得到研究者的广泛关注.本文中采用4种肿瘤细胞系(MCF-7、MDA-MB-231、C6和B16F10)分别摄取异硫氰酸荧光素(fluorescein isothiocyanate,FITC)标记的CPP,观察到CPP入胞,并具有时间和浓度的依赖性,同时发现了C6细胞对CPP的胞吐作用,其胞吐动力学符合零级方程;在低温(4℃)和内吞抑制剂存在条件下探讨了CPP入胞的机制.低温条件对CPP的入胞未产生抑制作用;肝素钠作为细胞表面硫酸糖蛋白受体抑制剂对CPP的入胞有较强抑制作用,肝素组对CPP的摄取只达到对照组的3%~10%;而氯丙嗪、氯喹和N-乙酰基-N-异丙基阿米洛利[5-(N-ethyL-N-isopropyl)-amiloride,EIPA]对CPP的入胞影响不大.本研究表明,CPP穿透细胞没有选择性,即缺乏细胞特异性,但CPP的摄取量与细胞种类有关.硫酸蛋白聚糖的吸附介导在CPP穿透细胞中发挥了重要作用.

  19. Cooperative Transmembrane Penetration of Nanoparticles

    Zhang, Haizhen; Ji, Qiuju; Huang, Changjin; Zhang, Sulin; Yuan, Bing; Yang, Kai; Ma, Yu-qiang

    2015-01-01

    Physical penetration of lipid bilayer membranes presents an alternative pathway for cellular delivery of nanoparticles (NPs) besides endocytosis. NPs delivered through this pathway could reach the cytoplasm, thereby opening the possibility of organelle-specific targeting. Herein we perform dissipative particle dynamics simulations to elucidate the transmembrane penetration mechanisms of multiple NPs. Our simulations demonstrate that NPs’ translocation proceeds in a cooperative manner, where the interplay of the quantity and surface chemistry of the NPs regulates the translocation efficiency. For NPs with hydrophilic surfaces, the increase of particle quantity facilitates penetration, while for NPs with partly or totally hydrophobic surfaces, the opposite highly possibly holds. Moreover, a set of interesting cooperative ways, such as aggregation, aggregation-dispersion, and aggregation-dispersion-reaggregation of the NPs, are observed during the penetration process. We find that the penetration behaviors of multiple NPs are mostly dominated by the changes of the NP-membrane force components in the membrane plane direction, in addition to that in the penetration direction, suggesting a different interaction mechanism between the multiple NPs and the membrane compared with the one-NP case. These results provide a fundamental understanding in the underlying mechanisms of cooperative penetration of NPs, and shed light on the NP-based drug and gene delivery. PMID:26013284

  20. Deep ocean model penetrator experiments

    Preliminary trials of experimental model penetrators in the deep ocean have been conducted as an international collaborative exercise by participating members (national bodies and the CEC) of the Engineering Studies Task Group of the Nuclear Energy Agency's Seabed Working Group. This report describes and gives the results of these experiments, which were conducted at two deep ocean study areas in the Atlantic: Great Meteor East and the Nares Abyssal Plain. Velocity profiles of penetrators of differing dimensions and weights have been determined as they free-fell through the water column and impacted the sediment. These velocity profiles are used to determine the final embedment depth of the penetrators and the resistance to penetration offered by the sediment. The results are compared with predictions of embedment depth derived from elementary models of a penetrator impacting with a sediment. It is tentatively concluded that once the resistance to penetration offered by a sediment at a particular site has been determined, this quantity can be used to sucessfully predict the embedment that penetrators of differing sizes and weights would achieve at the same site

  1. Cement penetration after patella venting.

    Jones, Christopher W; Lam, Li-On; Butler, Adam; Wood, David J; Walsh, William R

    2009-01-01

    There is a high rate of patellofemoral complications following total knee arthroplasty. Optimization of the cement-bone interface by venting and suction of the tibial plateau has been shown to improve cement penetration. Our study was designed to investigate if venting the patella prior to cementing improved cement penetration. Ten paired cadaver patellae were allocated prior to resurfacing to be vented or non-vented. Bone mineral density (BMD) was measured by DEXA scanning. In vented specimens, a 1.6 mm Kirschner wire was used to breach the anterior cortex at the center. Specimens were resurfaced with standard Profix instrumentation and Versabond bone cement (Smith and Nephew PLC, UK). Cement penetration was assessed from Faxitron and sectioned images by a digital image software package (ImageJ V1.38, NIH, USA). Wilcoxon rank sum test was used to assess the difference in cement penetration between groups. The relationship between BMD and cement penetration was analyzed by Pearson correlation coefficient. There was a strong negative correlation between peak BMD and cement penetration when analyzed independent of experimental grouping (r(2)=-0.812, p=0.004). Wilcoxon rank sum testing demonstrated no significant difference (rank sum statistic W=27, p=0.579) in cement penetration between vented (10.53%+/-4.66; mean+/-std dev) and non-vented patellae (11.51%+/-6.23; mean+/-std dev). Venting the patella using a Kirschner wire does not have a significant effect on the amount of cement penetration achieved in vitro using Profix instrumentation and Versabond cement. PMID:19010682

  2. Novel approach for characterizing the specific shunt resistance caused by the penetration of the front contact through the p-n junction in solar cell

    Zhang Lucheng; Shen Hui

    2009-01-01

    on process was completely compatible with the industrial silicon fabrication sequence, which was of great convenience. The measurement results give informations on the solar cell structure, material ingredients, and process parameters.

  3. Cell-penetrating DNA-binding protein as a safe and efficient naked DNA delivery carrier in vitro and in vivo

    Kim, Eun-Sung; Yang, Seung-Woo [Department of Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Hong, Dong-Ki; Kim, Woo-Taek [Department of Biology, Yonsei University, Seoul 120-749 (Korea, Republic of); Kim, Ho-Guen [Department of Pathology, Yonsei Medical School, Seoul 120-752 (Korea, Republic of); Lee, Sang-Kyou, E-mail: sjrlee@yonsei.ac.kr [Department of Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2010-01-29

    Non-viral gene delivery is a safe and suitable alternative to viral vector-mediated delivery to overcome the immunogenicity and tumorigenesis associated with viral vectors. Using the novel, human-origin Hph-1 protein transduction domain that can facilitate the transduction of protein into cells, we developed a new strategy to deliver naked DNA in vitro and in vivo. The new DNA delivery system contains Hph-1-GAL4 DNA-binding domain (DBD) fusion protein and enhanced green fluorescent protein (EGFP) reporter plasmid that includes the five repeats of GAL4 upstream activating sequence (UAS). Hph-1-GAL4-DBD protein formed complex with plasmid DNA through the specific interaction between GAL4-DBD and UAS, and delivered into the cells via the Hph-1-PTD. The pEGFP DNA was successfully delivered by the Hph-1-GAL4 system, and the EGFP was effectively expressed in mammalian cells such as HeLa and Jurkat, as well as in Bright Yellow-2 (BY-2) plant cells. When 10 {mu}g of pEGFP DNA was intranasally administered to mice using Hph-1-GAL4 protein, a high level of EGFP expression was detected throughout the lung tissue for 7 days. These results suggest that an Hph-1-PTD-mediated DNA delivery strategy may be an useful non-viral DNA delivery system for gene therapy and DNA vaccines.

  4. Macrophage Activation Redirects Yersinia-Infected Host Cell Death from Apoptosis to Caspase-1-Dependent Pyroptosis

    Bergsbaken, Tessa; Cookson, Brad T.

    2007-01-01

    Infection of macrophages by Yersinia species results in YopJ-dependent apoptosis, and naïve macrophages are highly susceptible to this form of cell death. Previous studies have demonstrated that macrophages activated with lipopolysaccharide (LPS) prior to infection are resistant to YopJ-dependent cell death; we found this simultaneously renders macrophages susceptible to killing by YopJ− Yersinia pseudotuberculosis (Yptb). YopJ− Yptb-induced macrophage death was dependent on caspase-1 activat...

  5. Plutonium in depleted uranium penetrators

    Depleted Uranium (DU) penetrators used in the recent Balkan conflicts have been found to be contaminated with trace amounts of transuranic materials such as plutonium. This contamination is usually a consequence of DU fabrication being carried out in facilities also using uranium recycled from spent military and civilian nuclear reactor fuel. Specific activities of 239+240 Plutonium generally in the range 1 to 12 Bq/kg have been found to be present in DU penetrators recovered from the attack sites of the 1999 NATO bombardment of Kosovo. A DU penetrator recovered from a May 1999 attack site at Bratoselce in southern Serbia and analysed by University College Dublin was found to contain 43.7 +/- 1.9 Bq/kg of 239+240 Plutonium. This analysis is described. An account is also given of the general population radiation dose implications arising from both the DU itself and from the presence of plutonium in the penetrators. According to current dosimetric models, in all scenarios considered likely ,the dose from the plutonium is estimated to be much smaller than that due to the uranium isotopes present in the penetrators. (author)

  6. Expression and purification of Tat-GFP fusion protein and its cell membrane penetrating activity%Tat-GFP融合蛋白的表达纯化及其穿膜活性

    关新刚; 苏维恒; 于欣; 佟海滨; 孙新

    2014-01-01

    Objective To obtain the Tat-GFP fusion proteins with penetrating activity and labeled with green fluorescence protein (GFP), and to explore the cell membrane penetrating activity of Tat-GFP in MCF-7 cells. Methods The plasmid pET-24a-Tat-GFP was transformed into Escherichia coli BL21 cells. Different concentrations (0.5 and 1.0 mmol · L-1 ) of isopropyl-β-D-thiogalactopyranoside (IPTG ) and cell culture temperatures (22℃ and 37℃)were used to optimize the protein expression.The Tat-GFP proteins in supernatant were purified using Ni-IDA resins. Western blotting analysis was used to identify the Tat-GFP protein, and confocal laser scanning microscope (CLSM ) was used to examine the cell penetration of Tat-GFP protein. Results There was no significant difference in the Tat-GFP protein production induced by 0.5 and 1.0 mmol·L-1 IPTG;however,the low temperature (22℃)-induced BL21 cells expressed more Tat-GFP proteins than that at 37℃ induction.The Western blotting analysis results showed that GFP antibody could specifically recognize the proteins in PVDF membranes in dose-dependent manner;the CLSM results indicated the distribution of green fluorescence in cytoplasm and nucleus of MCF-7 cells.Conclusion The Tat-GFP protein highly expresses in the supenatant of Escherichia coli i BL2 1 cells at low temperature;the obtained Tat-GFP protein with green fluorescence preserves the cell penetrating activity.%目的:获得具备穿膜活性与绿色荧光蛋白(GFP)标记的 Tat-GFP 融合蛋白,探讨 Tat-GFP 在MCF-7细胞中的跨膜转运特性。方法:应用 pET-24a-Tat-GFP质粒转化大肠杆菌 BL21感受态细胞,检测不同异丙基硫代半乳糖苷(IPTG)浓度(0.5和1.0 mmol·L-1)和不同温度(22℃和37℃)诱导融合蛋白的表达情况;利用 Ni-IDA树脂亲和纯化Tat-GFP蛋白,利用 GFP特异性抗体采用 Western blotting法分析洗脱液中的蛋白;激光共聚焦荧光显微镜下检测Tat-GFP融合蛋白

  7. Isolation, Co-Crystallization and Structure-Based Characterization of Anabaenopeptins as Highly Potent Inhibitors of Activated Thrombin Activatable Fibrinolysis Inhibitor (TAFIa).

    Schreuder, Herman; Liesum, Alexander; Lönze, Petra; Stump, Heike; Hoffmann, Holger; Schiell, Matthias; Kurz, Michael; Toti, Luigi; Bauer, Armin; Kallus, Christopher; Klemke-Jahn, Christine; Czech, Jörg; Kramer, Dan; Enke, Heike; Niedermeyer, Timo H J; Morrison, Vincent; Kumar, Vasant; Brönstrup, Mark

    2016-01-01

    Mature thrombin activatable fibrinolysis inhibitor (TAFIa) is a carboxypeptidase that stabilizes fibrin clots by removing C-terminal arginines and lysines from partially degraded fibrin. Inhibition of TAFIa stimulates the degradation of fibrin clots and may help to prevent thrombosis. Applying a lead finding approach based on literature-mining, we discovered that anabaenopeptins, cyclic peptides produced by cyanobacteria, were potent inhibitors of TAFIa with IC50 values as low as 1.5 nM. We describe the isolation and structure elucidation of 20 anabaenopeptins, including 13 novel congeners, as well as their pronounced structure-activity relationships (SAR) with respect to inhibition of TAFIa. Crystal structures of the anabaenopeptins B, C and F bound to the surrogate protease carboxypeptidase B revealed the binding modes of these large (~850 Da) compounds in detail and explained the observed SAR, i.e. the strong dependence of the potency on a basic (Arg, Lys) exocyclic residue that addressed the S1' binding pocket, and a broad tolerance towards substitutions in the pentacyclic ring that acted as a plug of the active site. PMID:27604544

  8. Resuscitative thoracotomy in penetrating trauma.

    Fairfax, Lindsay M; Hsee, Li; Civil, Ian D

    2015-06-01

    The resuscitative thoracotomy (RT) is an important procedure in the management of penetrating trauma. As it is performed only in patients with peri-arrest physiology or overt cardiac arrest, survival is low. Experience is also quite variable depending on volume of penetrating trauma in a particular region. Survival ranges from 0% to as high as 89% depending on patient selection, available resources, and location of RT (operating or emergency rooms). In this article, published guidelines are reviewed as well as outcomes. Technical considerations of RT and well as proper training, personnel, and location are also discussed. PMID:25342073

  9. Projectile penetration into ballistic gelatin.

    Swain, M V; Kieser, D C; Shah, S; Kieser, J A

    2014-01-01

    Ballistic gelatin is frequently used as a model for soft biological tissues that experience projectile impact. In this paper we investigate the response of a number of gelatin materials to the penetration of spherical steel projectiles (7 to 11mm diameter) with a range of lower impacting velocities (number of predictive relationships available in the literature, it is found that over the range of projectiles and compositions used, the results fit a simple relationship that takes into account the projectile diameter, the threshold velocity for penetration into the gelatin and a value of the shear modulus of the gelatin estimated from the threshold velocity for penetration. The normalised depth is found to fit the elastic Froude number when this is modified to allow for a threshold impact velocity. The normalised penetration data are found to best fit this modified elastic Froude number with a slope of 1/2 instead of 1/3 as suggested by Akers and Belmonte (2006). Possible explanations for this difference are discussed. PMID:24184862

  10. Industrial Penetration and Internet Intensity

    C-L. Chang (Chia-Lin); M.J. McAleer (Michael); Y-C. Wu (Yu-Chieh)

    2016-01-01

    textabstractThis paper investigates the effect of industrial penetration and internet intensity for Taiwan manufacturing firms, and analyses whether the relationships are substitutes or complements. The sample observations are based on 153,081 manufacturing plants, and covers 26 two-digit industry c

  11. The Penetration of Shaped Charges

    Wu Mingde

    1996-01-01

    @@ In order to get the best perforating effect, many facts have to be considered. Perforating job is often design by computer. A perforating engineer has to decide the perforating technology and procedure, the gun and charge system, the shot density and phasing, the penetration and hole size, etc.

  12. FAA Fluorescent Penetrant Laboratory Inspections

    WINDES,CONNOR L.; MOORE,DAVID G.

    2000-08-02

    The Federal Aviation Administration Airworthiness Assurance NDI Validation Center currently assesses the capability of various non-destructive inspection (NDI) methods used for analyzing aircraft components. The focus of one such exercise is to evaluate the sensitivity of fluorescent liquid penetrant inspection. A baseline procedure using the water-washable fluorescent penetrant method defines a foundation for comparing the brightness of low cycle fatigue cracks in titanium test panels. The analysis of deviations in the baseline procedure will determine an acceptable range of operation for the steps in the inspection process. The data also gives insight into the depth of each crack and which step(s) of the inspection process most affect penetrant sensitivities. A set of six low cycle fatigue cracks produced in 6.35-mm thick Ti-6Al-4V specimens was used to conduct the experiments to produce sensitivity data. The results will document the consistency of the crack readings and compare previous experiments to find the best parameters for water-washable penetrant.

  13. Simulation of laser penetration efficiency

    Semak, V. V.; Miller, T. F.

    2013-09-01

    The results of numerical simulation of laser beam interaction with a hypothetical metallic material with properties similar to a steel alloy are reported. The numerical simulation was performed using a physical model that includes detailed consideration of surface evaporation, evaporative cooling of the surface and evaporation recoil induced melt ejection. The laser beam ‘penetration’ is considered in terms of melting through the sample or drilling through the sample due to both evaporation and recoil ejection of material. As a demonstration of the predictive capabilities of the model, the average velocity of penetration through a material with steel-like properties is numerically predicted for various laser interaction parameters such as, laser beam radius, laser pulse duration (including CW regime), laser pulse energy and pulse repetition. In particular, the average penetration velocities through a sample due to melting are compared for pulsed and CW lasers of the same power. For the sake of another demonstration of penetration simulation, the temporal dynamics of the position of melt front relative to the sample surface irradiated by a laser beam was computed for different laser pulse repetition rates and constant average laser power. An illustration of the penetration efficiency (W parameter) defined as the amount of energy per unit volume delivered into a target in order to achieve either melting of drilling through a target wall is shown in a wide range of laser pulse parameters covering regimes corresponding to domination of melting through and drilling through.

  14. Simulation of laser penetration efficiency

    The results of numerical simulation of laser beam interaction with a hypothetical metallic material with properties similar to a steel alloy are reported. The numerical simulation was performed using a physical model that includes detailed consideration of surface evaporation, evaporative cooling of the surface and evaporation recoil induced melt ejection. The laser beam ‘penetration’ is considered in terms of melting through the sample or drilling through the sample due to both evaporation and recoil ejection of material. As a demonstration of the predictive capabilities of the model, the average velocity of penetration through a material with steel-like properties is numerically predicted for various laser interaction parameters such as, laser beam radius, laser pulse duration (including CW regime), laser pulse energy and pulse repetition. In particular, the average penetration velocities through a sample due to melting are compared for pulsed and CW lasers of the same power. For the sake of another demonstration of penetration simulation, the temporal dynamics of the position of melt front relative to the sample surface irradiated by a laser beam was computed for different laser pulse repetition rates and constant average laser power. An illustration of the penetration efficiency (W parameter) defined as the amount of energy per unit volume delivered into a target in order to achieve either melting of drilling through a target wall is shown in a wide range of laser pulse parameters covering regimes corresponding to domination of melting through and drilling through. (paper)

  15. Akon - A Penetrator for Europa

    Jones, Geraint

    2016-04-01

    Jupiter's moon Europa is one of the most intriguing objects in our Solar System. This 2000km-wide body has a geologically young solid water ice crust that is believed to cover a global ocean of liquid water. The presence of this ocean, together with a source of heating through tidal forces, make Europa a conceivable location for extraterrestrial life. The science case for exploring all aspects of this icy world is compelling. NASA has selected the Europa Mission (formerly Europa Clipper) to study Europa in detail in the 2020s through multiple flybys, and ESA's JUICE mission will perform two flybys of the body in the 2030s. The US agency has extended to the European Space Agency an invitation to provide a contribution to their mission. European scientists interested in Europa science and exploration are currently organizing themselves, in the framework of a coordinated Europa M5 Inititative to study concurrently the main options for this ESA contribution, from a simple addition of individual instruments to the NASA spacecraft, to a lander to investigate Europa's surface in situ. A high speed lander - a penetrator - is by far the most promising technology to achieve this latter option within the anticipated mass constraints, and studies of such a hard lander, many funded by ESA, are now at an advanced level. An international team to formally propose an Europa penetrator to ESA in response to the anticipated ESA M5 call is growing. The working title of this proposal is Akon (Άκων), named after the highly accurate javelin gifted to Europa by Zeus in ancient Greek mythology. We present plans for the Akon penetrator, which would impact Europa's surface at several hundred metres per second, and travel up to several metres into the moon's subsurface. To achieve this, the penetrator would be delivered to the surface by a dedicated descent module, to be destroyed on impact following release of the penetrator above the surface. It is planned that the instruments to be

  16. 经穿膜肽与PEG修饰的核糖体失活蛋白Gelonin抗肿瘤作用的研究%Study on cell-penetrating peptide modified and PEGylated ribosome inactive protein Gelonin

    张娅洁; 王慧媛; 陈应之; 汤懿斯; 杨志民; 黄永焯

    2015-01-01

    Objective:To improve anti-tumor effect of Gelonin, the plant-sourced RIP is modified by chemically conjugating a cell-penetrating peptide and polyethylene glycol (PEG). Methods:Purified protein was obtained after being performed on FPLC (fast protein liquid chromatography) Superdex75 column. Cytotoxicity was detected by MTT assay. The cellular uptake by HT1080 cells was studied by using inverted fluorescence microscopy and flow cytometry. In-vivo imaging technology was utilized for investigation of the in-vivo drug distribution in the HT1080 tumor-bearing mice. Results:The modified product was purified by using gel filtration chromatergraphy. Moreover, compared with native Gelonin, the cytotoxicity of modified protein was increased, especially in HT1080, presumably due to the enhanced cellular uptake. The in-vivo imaging results suggested that drug accumulation in tumor was improved by PEGylation. Conclusion:Modified Gelonin can improve cell penetration and cytotoxicity in tumor cells. PEGylation can increase tumor accumulation of the protein drug, and thereby enhance its anti-tumor effect.%目的:通过对核糖体失活蛋白Gelonin进行化学修饰,利用穿膜肽和聚乙二醇(PEG)偶联来提高其到达肿瘤部位和进入肿瘤细胞的能力,使Gelonin更高效地发挥抑瘤作用. 方法:利用FPLC Superdex75分子筛预装柱纯化系统对所修饰的Gelonin进行纯化后,在不同细胞系测试细胞毒性;通过倒置荧光显微镜、流式细胞分析技术等对药物进入纤维肉瘤细胞HT1080的能力进行评价;采用小动物活体成像技术考察药物体系在荷瘤动物体内的分布情况. 结果:采用分子筛色谱纯化可以得到纯度相对较高的修饰产物,其毒性较无修饰的Gelonin强,且在HT1080细胞系作用最明显;细胞摄取结果显示,与未修饰的Gelonin相比,该药物体系具有更高的细胞摄取效率;动物成像结果表明,PEG5000修饰可以改变Gelonin在动物体内的分布情况,

  17. Evaluation of drug penetration with cationic micelles and their penetration mechanism using an in vitro tumor model.

    Suzuki, Hidenori; Bae, You Han

    2016-08-01

    Elevated interstitial fluid pressure (IFP) and abnormal extracellular matrix (ECM) are major factors causing significant barriers to penetration of nanomedicines in solid tumors. To better understand the barriers, various in vitro tumor models including multicellular spheroids and multilayered cell cultures (MCCs) have been developing. Recently, we have established a unique in vitro tumor model composed of a MCC and an Ussing chamber system which is modified to add a hydraulic pressure gradient through the MCC. In this study, we evaluated the drug penetration ability of cationic micelles using the unique in vitro tumor model. The doxorubicin (DOX)-loaded cationic micelles, which are formed from a triblock copolymer of poly(d,l-lactide-co-glycolide)-block-branched polyethyleneimine-block-poly(d,l-lactide-co-glycolide), deeply penetrated and released the DOX throughout the MCC against convectional flow caused by a hydraulic pressure gradient. The studies using endocytosis markers and inhibitors showed that the micelles utilized mainly macropinocytosis as an internalization pathway. Furthermore, the penetration was apparently inhibited by treatment with exocytosis inhibitor Exo1. These results suggest that the active penetration of the cationic micelles is induced by iterative transcytosis via macropinocytosis and exocytosis. Our findings could be beneficial information to improve intratumoral penetration in new nanomedicines for solid tumors. PMID:27182814

  18. Assessing high wind energy penetration

    Tande, J.O.

    In order to convincingly promote installing wind power capacity as a substantial part of the energy supply system, a set of careful analyses must be undertaken. This paper applies a case study concentrated on assessing the cost/benefit of high wind energy penetration. The case study considers...... expanding the grid connected wind power capacity in Praia, the capital of Cape Verde. The currently installed 1 MW of wind power is estimated to supply close to 10% of the electric energy consumption in 1996. Increasing the wind energy penetration to a higher level is considered viable as the project...... existing wind power, supply over 30% of the electric consumption in 1996. Applying the recommended practices for estimating the cost of wind energy, the life-cycle cost of this 2.4 MW investment is estimated at a 7% discount rate and a 20 year lifetime to 0.26 DKK/kW h....

  19. PENETRATION ENHANCEMENT OF MEDICINAL AGENTS

    Sharma Ganesh N.; Sanadya Jyotsana; Kaushik Avinash; Dwivedi Abha

    2012-01-01

    Many current therapeutic agents like antibiotics, ionizable and peptide drugs are impermeable or do not possess the requisite physicochemical properties for efficient transport through outer tissue barrier to attain therapeutic blood level. For this reason the delivery of such drugs through barriers is currently one of the major interests in pharmaceutical research. Penetration enhancers or promoters are agents that have no therapeutic properties of their own but can transport the sorption of...

  20. Penetration enhancing effect of phytoceramides

    Veryser, Lieselotte; Boonen, Jente; Guillaume, Joren; Risseeuw, Martijn; Van Calenbergh, Serge; De Spiegeleer, Bart

    2012-01-01

    Ceramides are essential components in the stratum corneum barrier function. Different classes of ceramides are present in human skin, differing in the nature of sphingosine and acyl moieties with respect to chain length, degree of saturation and the presence of an OH group [1]. Ceramides with a saturated sphingosine base containing a hydroxyl function at C4 are known as phytoceramides. A few studies demonstrated the penetration enhancing properties of ceramides [2-5], however, systematic...

  1. Cardiac Penetrating Injuries and Pseudoaneurysm

    CHEN Shifeng

    2002-01-01

    Objective To discuss the early diagnosis and treatment of cardiac penetrating injuries and pseudoaneurysm. Methods 18 cases of cardiac penetrating injuries, in which 2 cases were complicated with pseudoaneurysm, were diagnosed by emergency operation and color Doppler echocardiography between May 1973 and Dec. 2001 in our hospital. The basis for emergency operation is the injured path locating in cardiac dangerous zone, severe shock or pericardial tamponade. ResultsAmong 18 cases of this study, 17 cases underwent emergency operation. During the operation, 11 cases were found injured in right ventricle, 2 cases were found injured in right atrium, 1 case was found injured in pulmonary artery,4 cases were found injured in left ventricle, 2 cases were found complicated with pseudoaneurysm. 17cases underwent cardiac repair including 1 case of rupture of aneurysm. 1 case underwent elective aneurysm resection. In whole group, 15 cases survived(83.33% ), 3 cases died( 16.67%). The cause of death is mainly hemorrhagic shock. Conclusion Highly suspicious cardiac penetrating injuries or hemopericaridium should undergo direct operative exploration. Pseudoaneurysm should be resected early,which can prevent severe complications.

  2. Combined logging/penetration methods

    A method is described for studying important soil and rock properties by simultaneous penetration and logging measurements. In penetration measurements, a BORROS Co. probe with a coned tip, 35.6 mm in diameter, a point angle of 60 deg, and with a friction roller 150 cm2 in area was dipped in the soil at a constant speed. Tip resistance and skin friction were measured. At the same time, gamma logging was carried out to determine natural radioactivity, gamma-gamma logging to determine bulk density, neutron-neutron logging to determine bulk density and porosity, and inclinometry. An original probe fitted with a NaI(Tl) scintillation detector with a crystal 25 mm in diameter and 100 mm in length was developed for gamma logging. For gamma-gamma logging, a 137Cs emitter probe was used with the emitter/detector distance of 45 cm. A NaI(Tl) crystal 18 mm in diameter and 50 mm in length was used for radiation detection. For neutron-neutron logging, a NIV 2 probe was purchased in the USSR and modified for simultaneous penetration measurements. A Soviet-made UMI 30 inclinometer with a modified case was used for inclinometry. (Ha)

  3. Site-specific conjugation of the quencher on peptide's N-terminal for the synthesis of a targeted non-spreading activatable optical probe.

    Simard, Bryan; Mironov, Gleb G; Tomanek, Boguslaw; van Veggel, Frank C J M; Abulrob, Abedelnasser

    2016-06-01

    Optical imaging offers high sensitivity and portability at low cost. The design of 'smart' or 'activatable' probes can decrease the background noise and increase the specificity of the signal. By conjugating a fluorescent dye and a compatible quencher on each side of an enzyme's substrate, the signal remains in its 'off ' state until it reaches the area where a specific enzyme is expressed. However, the signal can leak from that area unless the dye is attached to a molecule able to bind to a specific target also presented in that area. The aim of this study was to (i) specifically conjugate the quencher on the α-amino group of the peptide's N-terminus, (ii) conjugate the dye on the ε-amino group of a lysine in C-terminus, and (iii) conjugate the carboxyl group of the peptide's C-terminus to an amino group present on an antibody, using carbodiimide chemistry. The use of protecting groups, such as Boc or Fmoc, to allow site-specific conjugation, presents several drawbacks including 'on beads labeling', additional steps required for deprotection and removal from the resin, decreased yield, and dye degradation. A method of preferential labeling of α-amino N-terminal group in slightly acidic solution, proposed by Selo et al. (1996) has partially solved the problem. The present study reports improvements of the method allowing to (i) avoid the homo-bilabeling, (ii) increase the yield of the N-terminal labeling by two folds, and (iii) decrease the cost by 44-fold. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. PMID:27282138

  4. Network Penetration Testing and Research

    Murphy, Brandon F.

    2013-01-01

    This paper will focus the on research and testing done on penetrating a network for security purposes. This research will provide the IT security office new methods of attacks across and against a company's network as well as introduce them to new platforms and software that can be used to better assist with protecting against such attacks. Throughout this paper testing and research has been done on two different Linux based operating systems, for attacking and compromising a Windows based host computer. Backtrack 5 and BlackBuntu (Linux based penetration testing operating systems) are two different "attacker'' computers that will attempt to plant viruses and or NASA USRP - Internship Final Report exploits on a host Windows 7 operating system, as well as try to retrieve information from the host. On each Linux OS (Backtrack 5 and BlackBuntu) there is penetration testing software which provides the necessary tools to create exploits that can compromise a windows system as well as other operating systems. This paper will focus on two main methods of deploying exploits 1 onto a host computer in order to retrieve information from a compromised system. One method of deployment for an exploit that was tested is known as a "social engineering" exploit. This type of method requires interaction from unsuspecting user. With this user interaction, a deployed exploit may allow a malicious user to gain access to the unsuspecting user's computer as well as the network that such computer is connected to. Due to more advance security setting and antivirus protection and detection, this method is easily identified and defended against. The second method of exploit deployment is the method mainly focused upon within this paper. This method required extensive research on the best way to compromise a security enabled protected network. Once a network has been compromised, then any and all devices connected to such network has the potential to be compromised as well. With a compromised

  5. The production process for water penetrated brick

    SunGuofeng

    2005-01-01

    Waste penetrated brick, which is a green building material with good water penetration, high strength, lower firing temperature, lower production cost, good appearance and good structure, can holding ground water lever. This article analysis the production process and related factor for water penetrated brick:proper particle size distribution, proper shaping method, proper press and proper firing can ensure to produce good quality water penetrated brick.

  6. Penetration Testing: A Roadmap to Network Security

    Naik, Nitin A.; Gajanan D. Kurundkar; Khamitkar, Santosh D.; Kalyankar, Namdeo V.

    2009-01-01

    Network penetration testing identifies the exploits and vulnerabilities those exist within computer network infrastructure and help to confirm the security measures. The objective of this paper is to explain methodology and methods behind penetration testing and illustrate remedies over it, which will provide substantial value for network security Penetration testing should model real world attacks as closely as possible. An authorized and scheduled penetration testing will probably detected ...

  7. Beyond Cell Penetrating Peptides: Designed Molecular Transporters

    Wender, Paul A.; Cooley, Christina B.; Geihe, Erika I.

    2012-01-01

    Inspired originally by peptides that traverse biological barriers, research on molecular transporters has since identified the key structural requirements that govern cellular entry, leading to new, significantly more effective and more readily available agents. These new drug delivery systems enable or enhance cellular and tissue uptake, can be targeted, and provide numerous additional advantages of significance in imaging, diagnostics and therapy.

  8. Daptomycin Rapidly Penetrates a Staphylococcus epidermidis Biofilm▿ †

    Stewart, Philip S.; Davison, William M.; Steenbergen, Judith N.

    2009-01-01

    Fluorescently tagged daptomycin accessed the interior of Staphylococcus epidermidis biofilm cell clusters within minutes. The diffusion coefficient of daptomycin in the biofilm was 28% of its value in pure water. Daptomycin activity against staphylococci embedded in biofilms is unlikely to be limited by penetration of the antibiotic into the biofilm.

  9. Kali Linux wireless penetration testing essentials

    Alamanni, Marco

    2015-01-01

    This book is targeted at information security professionals, penetration testers and network/system administrators who want to get started with wireless penetration testing. No prior experience with Kali Linux and wireless penetration testing is required, but familiarity with Linux and basic networking concepts is recommended.

  10. In vitro dermal penetration study of carbofuran, carbosulfan, and furathiocarb

    Liu, Kwang-Hyeon [Department of Pharmacology, Inje University, College of Medicine, 614-735, Busan (Korea); Kim, Jeong-Han [School of Agricultural Biotechnology, Seoul National University, 441-744, Suwon (Korea)

    2003-05-01

    In this study, the dermal penetration rate of carbofuran, carbosulfan, and furathiocarb has been measured with rat abdominal skin using the static diffusion cell. The technical grades of three compounds were applied at different doses on skin surface mounted in static diffusion cell and incubated at 32 C for 48 h with shaking. The same procedures were carried out with furathiocarb EC (emulsifiable concentrate) and WP (wettable powder). At regular intervals, the receptor fluid in cell was sampled and analyzed by HPLC. Only carbofuran was found in carbosulfan- or furathiocarb-treated samples, suggesting they converted into carbofuran while passing through the skin layer. The quantity of insecticide penetrating skin increased with time and applied dose. The skin penetration rate increased with the water solubility of insecticides. The dermal penetration rates of carbofuran, furathiocarb, and carbosulfan were determined as 1.05 {mu}g/cm{sup 2} per h (r{sup 2}=0.991), 0.46 {mu}g/cm{sup 2} per h (r{sup 2}=0.984) and 0.14 {mu}g/cm{sup 2} per h (r{sup 2}=0.967), respectively. There was no significant difference in rate of skin penetration between furathiocarb EC (1.42 {mu}g/cm{sup 2} per h, r{sup 2}=0.988) and WP (1.35 {mu}g/cm{sup 2} per h, r{sup 2}=0.982), while furathiocarb technical grade showed a lower skin penetration rate. In vitro models may be used to predict percutaneous absorption and are useful in selecting safer formulations for field application of pesticide. (orig.)

  11. Correlation Between Cone Penetration Rate And Measured Cone Penetration Parameters In Silty Soils

    Poulsen, Rikke; Nielsen, Benjaminn Nordahl; Ibsen, Lars Bo

    2013-01-01

    This paper shows, how a change in cone penetration rate affects the cone penetration measurements, hence the cone resistance, pore pressure, and sleeve friction in silty soil. The standard rate of penetration is 20 mm/s, and it is generally accepted that undrained penetration occurs in clay while...

  12. FAA Fluorescent Penetrant Activities - An Update

    Moore, D.G.

    1998-10-20

    The Federal Aviation Administration's Airworthiness Assurance NDI Validation Center (AANC) is currently characterizing low cycle fatigue specimens that will support the needs of penetrant manufacturers, commercial airline industry and the Federal Aviation Administration. The main focus of this characterization is to maintain and enhance the evaluation of penetrant inspection materials and apply resources to support the aircraft community needs. This paper discusses efforts to-date to document the Wright Laboratory penetrant evaluation process and characterize penetrant brightness readings in the initial set of sample calibration panels using Type 1 penetrant.

  13. Web penetration testing with Kali Linux

    Muniz, Joseph

    2013-01-01

    Web Penetration Testing with Kali Linux contains various penetration testing methods using BackTrack that will be used by the reader. It contains clear step-by-step instructions with lot of screenshots. It is written in an easy to understand language which will further simplify the understanding for the user.""Web Penetration Testing with Kali Linux"" is ideal for anyone who is interested in learning how to become a penetration tester. It will also help the users who are new to Kali Linux and want to learn the features and differences in Kali versus Backtrack, and seasoned penetration testers

  14. Penetration testing with Raspberry Pi

    Muniz, Joseph

    2015-01-01

    If you are looking for a low budget, small form-factor remotely accessible hacking tool, then the concepts in this book are ideal for you. If you are a penetration tester who wants to save on travel costs by placing a low-cost node on a target network, you will save thousands by using the methods covered in this book. You do not have to be a skilled hacker or programmer to use this book. It will be beneficial to have some networking experience; however, it is not required to follow the concepts covered in this book.

  15. Probing intra-cellular drug release event using activatable (OFF/ON) CdS:Mn/ZnS quantum dots (Qdots): spectroscopic studies to investigate interaction of Qdots with quencher

    Tharkur, Jeremy; Teblum, Andrew; Basumallick, Srijita; Shah, Rikhav; Cantarero, Karishma; Maity, Niharika; Rifai, Sara; Doshi, Mona; Gesquiere, Andre J.; Santra, Swadeshmukul

    2013-02-01

    In recent years, activatable Quantum Dots (AQdots) are gaining popularity in a number of chemical and biological sensing applications. A basic design of AQdot probes involves a suitable quencher which is capable of altering optical properties of the Qdots. In our previous studies we have shown that CdS:Mn/ZnS fluorescence can be effectively quenched using small molecule quenchers (such as dopamine, chemotherapeutic drug) as well as iron oxide nanoparticle via electron/energy transfer process. We have also shown that the quenched Qdot fluorescence can be restored when the Qdots are separated from the quencher. Using Qdot based activatable probes, we detected intracellular drug release event. Qdot fluorescence was restored upon interaction with the intracellular glutathione (GSH). In this paper, we report a GSH induced quenching of water-soluble N-Acetyl Cysteine (NAC) surface-conjugated Cds:Mn/ZnS Qdots. Quenching of NAC-Qdots was due to aggregation of Qdots in solution. This aggregation induced fluorescence quenching phenomenon resembles with the self-quenching phenomenon of traditional organic fluorescence dyes at high concentrations. UV-VIS and fluorescence emission spectroscopy data support the interaction and binding of GSH with the NAC-Qdots. Increase in particle size due to GSH induced aggregation of NAC-Qdots was confirmed by the Dynamic Light Scattering (DLS) data.

  16. An electrochemical modeling of lithium-ion battery nail penetration

    Chiu, Kuan-Cheng; Lin, Chi-Hao; Yeh, Sheng-Fa; Lin, Yu-Han; Chen, Kuo-Ching

    2014-04-01

    Nail penetration into a battery pack, resulting in a state of short-circuit and thus burning, is likely to occur in electric car collisions. To demonstrate the behavior of a specific battery when subject to such incidents, a standard nail penetration test is usually performed; however, conducting such an experiment is money consuming. The purpose of this study is to propose a numerical electrochemical model that can simulate the test accurately. This simulation makes two accurate predictions. First, we are able to model short-circuited lithium-ion batteries (LIBs) via electrochemical governing equations so that the mass and charge transfer effect could be considered. Second, the temperature variation of the cell during and after nail penetration is accurately predicted with the help of simulating the temperature distribution of thermal runaway cells by thermal abuse equations. According to this nail penetration model, both the onset of battery thermal runaway and the cell temperature profile of the test are obtained, both of which are well fitted with our experimental results.

  17. Evaluation of nicotinamide microemulsion on the skin penetration enhancement.

    Boonme, Prapaporn; Boonthongchuay, Chalida; Wongpoowarak, Wibul; Amnuaikit, Thanaporn

    2016-01-01

    This study purposed to evaluate a microemulsion containing nicotinamide for its characteristics, stability, and skin penetration and retention comparing with a solution of nicotinamide in 2:1 mixture of water and isopropyl alcohol (IPA). The microemulsion system was composed of 1:1 mixture of Span80 and Tween80 as a surfactant mixture, isopropyl palmitate (IPP) as an oil phase, and 2:1 mixture of water and IPA as an aqueous phase. Nicotinamide microemulsion was prepared by dissolving the active in the aqueous phase before simply mixing with the other components. It was determined for its characteristics and stability under various conditions. The skin penetration and retention studies of nicotinamide microemulsion and solution were performed by modified Franz diffusion cells, using newborn pig skin as the membrane. The results showed that nicotinamide microemulsion could be obtained as clear yellowish liquid, was water-in-oil (w/o) type, possessed Newtonian flow, and exhibited physicochemical stability when kept at 4 °C and room temperature (≈30 ± 2 °C) during 3 months. From the skin penetration data, the microemulsion could enhance the skin penetration of nicotinamide comparing with the solution. Additionally, nicotinamide microemulsion could provide much higher amount of skin retention than that of skin penetration, resulting in suitability for a cosmeceutical product. PMID:25318786

  18. High-pressure-induced water penetration into 3-isopropylmalate dehydrogenase

    Structures of 3-isopropylmalate dehydrogenase were determined at pressures ranging from 0.1 to 650 MPa. Comparison of these structures gives a detailed picture of the swelling of a cavity at the dimer interface and the generation of a new cleft on the molecular surface, which are accompanied by water penetration. Hydrostatic pressure induces structural changes in proteins, including denaturation, the mechanism of which has been attributed to water penetration into the protein interior. In this study, structures of 3-isopropylmalate dehydrogenase (IPMDH) from Shewanella oneidensis MR-1 were determined at about 2 Å resolution under pressures ranging from 0.1 to 650 MPa using a diamond anvil cell (DAC). Although most of the protein cavities are monotonically compressed as the pressure increases, the volume of one particular cavity at the dimer interface increases at pressures over 340 MPa. In parallel with this volume increase, water penetration into the cavity could be observed at pressures over 410 MPa. In addition, the generation of a new cleft on the molecular surface accompanied by water penetration could also be observed at pressures over 580 MPa. These water-penetration phenomena are considered to be initial steps in the pressure-denaturation process of IPMDH

  19. High-pressure-induced water penetration into 3-isopropylmalate dehydrogenase

    Nagae, Takayuki; Kawamura, Takashi [Nagoya University, (Japan); Chavas, Leonard M. G. [High Energy Research Organization (KEK), (Japan); Niwa, Ken; Hasegawa, Masashi [Nagoya University, (Japan); Kato, Chiaki [Japan Agency for Marine-Earth Science and Technology (JAMSTEC), (Japan); Watanabe, Nobuhisa, E-mail: nobuhisa@nagoya-u.jp [Nagoya University, (Japan); Nagoya University, (Japan)

    2012-03-01

    Structures of 3-isopropylmalate dehydrogenase were determined at pressures ranging from 0.1 to 650 MPa. Comparison of these structures gives a detailed picture of the swelling of a cavity at the dimer interface and the generation of a new cleft on the molecular surface, which are accompanied by water penetration. Hydrostatic pressure induces structural changes in proteins, including denaturation, the mechanism of which has been attributed to water penetration into the protein interior. In this study, structures of 3-isopropylmalate dehydrogenase (IPMDH) from Shewanella oneidensis MR-1 were determined at about 2 Å resolution under pressures ranging from 0.1 to 650 MPa using a diamond anvil cell (DAC). Although most of the protein cavities are monotonically compressed as the pressure increases, the volume of one particular cavity at the dimer interface increases at pressures over 340 MPa. In parallel with this volume increase, water penetration into the cavity could be observed at pressures over 410 MPa. In addition, the generation of a new cleft on the molecular surface accompanied by water penetration could also be observed at pressures over 580 MPa. These water-penetration phenomena are considered to be initial steps in the pressure-denaturation process of IPMDH.

  20. Influence of massage and occlusion on the ex vivo skin penetration of rigid liposomes and invasomes

    Trauer, S.; Richter, H.; Kuntsche, Judith;

    2014-01-01

    Liposomes are frequently described as drug delivery systems for dermal and transdermal applications. Recently, it has been shown that particulate substances penetrate effectively into hair follicles and that the follicular penetration depth can be increased by massaging the skin, which simulates...... the in vivo movement of hairs in the hair follicles. In the present study, massage was applied to skin mounted to Franz diffusion cells. By means of confocal laser scanning microscopy, the influence of massage and occlusion on the follicular penetration depths of rigid and flexible liposomes loaded...... with a hydrophilic and lipophilic dye was investigated. The application of massage increased follicular penetration significantly. Occlusion resulted in an increased follicular penetration depth only for rigid liposomes, whereas invasomes did not penetrate more effectively if occlusion was applied. The...

  1. Effects of soap-water wash on human epidermal penetration.

    Zhu, Hanjiang; Jung, Eui-Chang; Phuong, Christina; Hui, Xiaoying; Maibach, Howard

    2016-08-01

    Skin decontamination is a primary interventional method used to decrease dermal absorption of hazardous contaminants, including chemical warfare agents, pesticides and industrial pollutants. Soap and water wash, the most common and readily available decontamination system, may enhance percutaneous absorption through the "wash-in effect." To understand better the effect of soap-water wash on percutaneous penetration, and provide insight to improving skin decontamination methods, in vitro human epidermal penetration rates of four C(14) -labeled model chemicals (hydroquinone, clonidine, benzoic acid and paraoxon) were assayed using flow-through diffusion cells. Stratum corneum (SC) absorption rates of these chemicals at various hydration levels (0-295% of the dry SC weights) were determined and compared with the results of the epidermal penetration study to clarify the effect of SC hydration on skin permeability. Results showed accelerated penetration curves of benzoic acid and paraoxon after surface wash at 30 min postdosing. Thirty minutes after washing (60 min postdosing), penetration rates of hydroquinone and benzoic acid decreased due to reduced amounts of chemical on the skin surface and in the SC. At the end of the experiment (90 min postdosing), a soap-water wash resulted in lower hydroquinone penetration, greater paraoxon penetration and similar levels of benzoic acid and clonidine penetration compared to penetration levels in the non-wash groups. The observed wash-in effect agrees with the enhancement effect of SC hydration on the SC chemical absorption rate. These results suggest SC hydration derived from surface wash to be one cause of the wash-in effect. Further, the occurrence of a wash-in effect is dependent on chemical identity and elapsed time between exposure and onset of decontamination. By reducing chemical residue quantity on skin surface and in the SC reservoir, the soap-water wash may decrease the total quantity of chemical absorbed in the

  2. Microbial light-activatable proton pumps as neuronal inhibitors to functionally dissect neuronal networks in C. elegans.

    Steven J Husson

    Full Text Available Essentially any behavior in simple and complex animals depends on neuronal network function. Currently, the best-defined system to study neuronal circuits is the nematode Caenorhabditis elegans, as the connectivity of its 302 neurons is exactly known. Individual neurons can be activated by photostimulation of Channelrhodopsin-2 (ChR2 using blue light, allowing to directly probe the importance of a particular neuron for the respective behavioral output of the network under study. In analogy, other excitable cells can be inhibited by expressing Halorhodopsin from Natronomonas pharaonis (NpHR and subsequent illumination with yellow light. However, inhibiting C. elegans neurons using NpHR is difficult. Recently, proton pumps from various sources were established as valuable alternative hyperpolarizers. Here we show that archaerhodopsin-3 (Arch from Halorubrum sodomense and a proton pump from the fungus Leptosphaeria maculans (Mac can be utilized to effectively inhibit excitable cells in C. elegans. Arch is the most powerful hyperpolarizer when illuminated with yellow or green light while the action spectrum of Mac is more blue-shifted, as analyzed by light-evoked behaviors and electrophysiology. This allows these tools to be combined in various ways with ChR2 to analyze different subsets of neurons within a circuit. We exemplify this by means of the polymodal aversive sensory ASH neurons, and the downstream command interneurons to which ASH neurons signal to trigger a reversal followed by a directional turn. Photostimulating ASH and subsequently inhibiting command interneurons using two-color illumination of different body segments, allows investigating temporal aspects of signaling downstream of ASH.

  3. Microbial light-activatable proton pumps as neuronal inhibitors to functionally dissect neuronal networks in C. elegans.

    Husson, Steven J; Liewald, Jana F; Schultheis, Christian; Stirman, Jeffrey N; Lu, Hang; Gottschalk, Alexander

    2012-01-01

    Essentially any behavior in simple and complex animals depends on neuronal network function. Currently, the best-defined system to study neuronal circuits is the nematode Caenorhabditis elegans, as the connectivity of its 302 neurons is exactly known. Individual neurons can be activated by photostimulation of Channelrhodopsin-2 (ChR2) using blue light, allowing to directly probe the importance of a particular neuron for the respective behavioral output of the network under study. In analogy, other excitable cells can be inhibited by expressing Halorhodopsin from Natronomonas pharaonis (NpHR) and subsequent illumination with yellow light. However, inhibiting C. elegans neurons using NpHR is difficult. Recently, proton pumps from various sources were established as valuable alternative hyperpolarizers. Here we show that archaerhodopsin-3 (Arch) from Halorubrum sodomense and a proton pump from the fungus Leptosphaeria maculans (Mac) can be utilized to effectively inhibit excitable cells in C. elegans. Arch is the most powerful hyperpolarizer when illuminated with yellow or green light while the action spectrum of Mac is more blue-shifted, as analyzed by light-evoked behaviors and electrophysiology. This allows these tools to be combined in various ways with ChR2 to analyze different subsets of neurons within a circuit. We exemplify this by means of the polymodal aversive sensory ASH neurons, and the downstream command interneurons to which ASH neurons signal to trigger a reversal followed by a directional turn. Photostimulating ASH and subsequently inhibiting command interneurons using two-color illumination of different body segments, allows investigating temporal aspects of signaling downstream of ASH. PMID:22815873

  4. Cable Braid Electromagnetic Penetration Model.

    Warne, Larry K. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Langston, William L. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Basilio, Lorena I. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Johnson, W. A. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-06-01

    The model for penetration of a wire braid is rigorously formulated. Integral formulas are developed from energy principles and reciprocity for both self and transfer immittances in terms of potentials for the fields. The detailed boundary value problem for the wire braid is also setup in a very efficient manner; the braid wires act as sources for the potentials in the form of a sequence of line multipoles with unknown coefficients that are determined by means of conditions arising from the wire surface boundary conditions. Approximations are introduced to relate the local properties of the braid wires to a simplified infinite periodic planar geometry. This is used in a simplified application of reciprocity to be able to treat nonuniform coaxial geometries including eccentric interior coaxial arrangements and an exterior ground plane.

  5. A lightweight ground penetrating radar

    Koppenjan, S.K.; Allen, C.M.; Gardner, D.; Wong, H.R.

    1998-12-31

    The detection of buried objects, particularly unexploded ordnance (UXO), has gained significant interest in the US in the late 1990s. The desire to remediate the thousands of sites worldwide has become an increasing humanitarian concern. The application of radar to this problem has received renewed attention. Bechtel Nevada, Special Technologies Laboratory (STL) has developed several frequency modulated, continuous wave (FM-CW) ground penetrating radar (GPR) units for the US Department of Energy since 1984. To meet these new technical requirements for high resolution data and UXO detection, STL is moving forward with advances to GPR technology, signal processing, and imaging with the development of an innovative system. The goal is to design and fabricate a lightweight, battery operated unit that does not require surface contact and can be operated by a novice user.

  6. Assessing high wind energy penetration

    In order to convincingly promote installing wind power capacity as a substantial part of the energy supply system, a set of careful analyses must be undertaken. This paper applies a case study concentrated on assessing the cost/benefit of high wind energy penetration. The case study considers expanding the grid connected wind power capacity in Praia, the capital of Cape Verde. The currently installed 1 MW of wind power is estimated to supply close to 10% of the electric energy consumption in 1996. Increasing the wind energy penetration to a higher level is considered viable as the project settings are close to ideal, including a very capable national utility company, Electra, a conventional power supply system based on imported heavy fuel and gas oil, and favourable wind conditions with an estimated annual average of 9.3 m/s at the hub height of the wind turbines. With the applied case study assumptions, simulations with WINSYS over the lifetime of the assessed wind power investment show that investments up to 4.2 MW are economically viable. The economic optimum is found at 2.4 MW reaching an internal rate of return of almost 8% p.a. This 2.4 MW of wind power would, together with the existing wind power, supply over 30% of the electric consumption in 1996. Applying the recommended practices for estimating the cost of wind energy, the life-cycle cost of this 2.4 MW investment is estimated at a 7% discount rate and a 20 year lifetime to 0.26 DKK/kW h. (Author)

  7. Ethical hacking and penetration testing guide

    Baloch, Rafay

    2014-01-01

    Requiring no prior hacking experience, Ethical Hacking and Penetration Testing Guide supplies a complete introduction to the steps required to complete a penetration test, or ethical hack, from beginning to end. You will learn how to properly utilize and interpret the results of modern-day hacking tools, which are required to complete a penetration test. The book covers a wide range of tools, including Backtrack Linux, Google reconnaissance, MetaGooFil, dig, Nmap, Nessus, Metasploit, Fast Track Autopwn, Netcat, and Hacker Defender rootkit. Supplying a simple and clean explanation of how to effectively utilize these tools, it details a four-step methodology for conducting an effective penetration test or hack.Providing an accessible introduction to penetration testing and hacking, the book supplies you with a fundamental understanding of offensive security. After completing the book you will be prepared to take on in-depth and advanced topics in hacking and penetration testing. The book walks you through each ...

  8. Complementary optical and nuclear imaging of caspase-3 activity using combined activatable and radio-labeled multimodality molecular probe

    Lee, Hyeran; Akers, Walter J.; Cheney, Philip P.; Edwards, W. Barry; Liang, Kexian; Culver, Joseph P.; Achilefu, Samuel

    2009-07-01

    Based on the capability of modulating fluorescence intensity by specific molecular events, we report a new multimodal optical-nuclear molecular probe with complementary reporting strategies. The molecular probe (LS498) consists of tetraazacyclododecanetetraacetic acid (DOTA) for chelating a radionuclide, a near-infrared fluorescent dye, and an efficient quencher dye. The two dyes are separated by a cleavable peptide substrate for caspase-3, a diagnostic enzyme that is upregulated in dying cells. LS498 is radiolabeled with 64Cu, a radionuclide used in positron emission tomography. In the native form, LS498 fluorescence is quenched until caspase-3 cleavage of the peptide substrate. Enzyme kinetics assay shows that LS498 is readily cleaved by caspase-3, with excellent enzyme kinetic parameters kcat and KM of 0.55+/-0.01 s-1 and 1.12+/-0.06 μM, respectively. In mice, the initial fluorescence of LS498 is ten-fold less than control. Using radiolabeled 64Cu-LS498 in a controlled and localized in-vivo model of caspase-3 activation, a time-dependent five-fold NIR fluorescence enhancement is observed, but radioactivity remains identical in caspase-3 positive and negative controls. These results demonstrate the feasibility of using radionuclide imaging for localizing and quantifying the distribution of molecular probes and optical imaging for reporting the functional status of diagnostic enzymes.

  9. Proniosomes for Penetration Enhancement in Transdermal System

    Samita Singla; S. L. Harikumar; Geeta Aggarwal

    2012-01-01

    Over the last few years an inclusive research has been done over provesicular approach for transdermal drug delivery. Skin has a very tough diffusion barrier inhibiting penetration of drug moiety which is rate limiting barrier for penetration of drugs. There are several approaches that deal with penetration enhancement across the skin. Vesicular and provesicular systems are promising amongst them. Vesicular systems including (niosomes, ethosomes, transfersomes and liposomes) are promising sys...

  10. Cognitive Penetration, Perceptual Learning and Neural Plasticity

    Cecchi, Ariel Sebastianos

    2014-01-01

    Cognitive penetration of perception, broadly understood, is the influence that the cognitive system has on a perceptual system (e.g., visual, auditory, haptic). The paper shows a form of cognitive penetration in the visual system (defined as early vision) which I call ‘architectural’. Architectural cognitive penetration is the process whereby the behaviour or the structure of the perceptual system is influenced by the cognitive system, which consequently may have an impact on the content of t...

  11. In-place HEPA filter penetration test

    Bergman, W.; Wilson, K.; Elliott, J. [Lawrence Livermore National Lab., CA (United States)] [and others

    1997-08-01

    We have demonstrated the feasibility of conducting penetration tests on high efficiency particulate air (HEPA) filters as installed in nuclear ventilation systems. The in-place penetration test, which is designed to yield equivalent penetration measurements as the standard DOP efficiency test, is based on measuring the aerosol penetration of the filter installation as a function of particle size using a portable laser particle counter. This in-place penetration test is compared to the current in-place leak test using light scattering photometers for single HEPA filter installations and for HEPA filter plenums using the shroud method. Test results show the in-place penetration test is more sensitive than the in-place leak test, has a similar operating procedure, but takes longer to conduct. Additional tests are required to confirm that the in-place penetration test yields identical results as the standard dioctyl phthalate (DOP) penetration test for HEPA filters with controlled leaks in the filter and gasket and duct by-pass leaks. Further development of the procedure is also required to reduce the test time before the in-place penetration test is practical. 14 refs., 14 figs., 3 tabs.

  12. Penetration depth time history measurement method

    Liu, C; Ahrens, T. J.

    2000-01-01

    A new method for measuring the depth time history of rigid body penetration into brittle materials under a deceleration of ~10^5 g. The method includes: sabot-projectile, sabot-projectile separation and penetration depth detection systems. Relatively small intrinsic time error (3%) and depth error (0.3–0.7 mm) results. Penetration depth time history in a series of 4140 steel projectile penetrations into a mortar are measured at velocities of 100 to 500 m/sec with sufficient accuracy such that...

  13. Market penetration rates of new energy technologies

    The market penetration rates of 11 different new energy technologies were studied covering energy production and end-use technologies. The penetration rates were determined by fitting observed market data to an epidemical diffusion model. The analyses show that the exponential penetration rates of new energy technologies may vary from 4 up to over 40%/yr. The corresponding take-over times from a 1% to 50% share of the estimated market potential may vary from less than 10 to 70 years. The lower rate is often associated with larger energy impacts. Short take-over times less than 25 years seem to be mainly associated with end-use technologies. Public policies and subsides have an important effect on the penetration. Some technologies penetrate fast without major support explained by technology maturity and competitive prices, e.g. compact fluorescent lamps show a 24.2%/yr growth rate globally. The penetration rates determined exhibit some uncertainty as penetration has not always proceeded close to saturation. The study indicates a decreasing penetration rate with increasing time or market share. If the market history is short, a temporally decreasing functional form for the penetration rate coefficient could be used to anticipate the probable behavior

  14. In-place HEPA filter penetration test

    We have demonstrated the feasibility of conducting penetration tests on high efficiency particulate air (HEPA) filters as installed in nuclear ventilation systems. The in-place penetration test, which is designed to yield equivalent penetration measurements as the standard DOP efficiency test, is based on measuring the aerosol penetration of the filter installation as a function of particle size using a portable laser particle counter. This in-place penetration test is compared to the current in-place leak test using light scattering photometers for single HEPA filter installations and for HEPA filter plenums using the shroud method. Test results show the in-place penetration test is more sensitive than the in-place leak test, has a similar operating procedure, but takes longer to conduct. Additional tests are required to confirm that the in-place penetration test yields identical results as the standard dioctyl phthalate (DOP) penetration test for HEPA filters with controlled leaks in the filter and gasket and duct by-pass leaks. Further development of the procedure is also required to reduce the test time before the in- place penetration test is practical

  15. The equine herpesvirus 1 glycoprotein gp21/22a, the herpes simplex virus type 1 gM homolog, is involved in virus penetration and cell-to-cell spread of virions.

    Osterrieder, N.; Neubauer, A.; Brandmuller, C; Braun, B.; Kaaden, O R; Baines, J D

    1996-01-01

    Experiments to analyze the function of the equine herpesvirus 1 (EHV-1) glycoprotein gM homolog were conducted. To this end, an Rk13 cell line (TCgM) that stably expressed EHV-1 gM was constructed. Proteins with apparent M(r)s of 46,000 to 48,000 and 50,000 to 55,000 were detected in TCgM cells with specific anti-gM antibodies, and the gM protein pattern was indistinguishable from that in cells infected with EHV-1 strain RacL11. A viral mutant (L11deltagM) bearing an Escherichia coli lacZ gen...

  16. Ultrasonic/Sonic Impacting Penetrators

    Bao, Xiaoqi; Bar-Cohen, Yoseph; Chang, Zensheu; Sherrit, Stewart; Stark, Randall A.

    2008-01-01

    Ultrasonic/sonic impacting penetrators (USIPs) are recent additions to the series of apparatuses based on ultrasonic/sonic drill corers (USDCs). A USIP enables a rod probe to penetrate packed soil or another substance of similar consistency, without need to apply a large axial force that could result in buckling of the probe or in damage to some buried objects. USIPs were conceived for use in probing and analyzing soil to depths of tens of centimeters in the vicinity of buried barrels containing toxic waste, without causing rupture of the barrels. USIPs could also be used for other purposes, including, for example, searching for pipes, barrels, or other hard objects buried in soil; and detecting land mines. USDCs and other apparatuses based on USDCs have been described in numerous previous NASA Tech Briefs articles. The ones reported previously were designed, variously, for boring into, and/or acquiring samples of, rock or other hard, brittle materials of geological interest. To recapitulate: A USDC can be characterized as a lightweight, low-power, piezoelectrically driven jackhammer in which ultrasonic and sonic vibrations are generated and coupled to a tool bit. As shown in the figure, a basic USDC includes a piezoelectric stack, a backing and a horn connected to the stack, a free mass (free in the sense that it can slide axially a short distance between the horn and the shoulder of tool bit), and a tool bit, i.e., probe for USIP. The piezoelectric stack is driven at the resonance frequency of the stack/horn/backing assembly to create ultrasonic vibrations that are mechanically amplified by the horn. To prevent fracture during operation, the piezoelectric stack is held in compression by a bolt. The bouncing of the free mass between the horn and the tool bit at sonic frequencies generates hammering actions to the bit that are more effective for drilling than is the microhammering action of ultrasonic vibrations in ordinary ultrasonic drills. The hammering actions

  17. RELATIONSHIP BETWEEN PLASMA OPTIC SIGNAL AND PENETRATION DEPTH FOR PARTIAL-PENETRATION LASER WELDING

    2006-01-01

    Through sampling and analyzing of plasma optic signals of 400~600 nm emitted from partial-penetration laser welding processes, how the penetration depth is related to the welding parameter and the plasma optic signal is studied. Under the experimental conditions, the plasma optic signal has good response to variety of the weld penetration, and the signal's RMS value increases with the penetration in a quadratic curve mode. The inherent relation between the plasma optic signal and the penetration depth is also analyzed. It is also found that, between the two common parameters of laser power and welding speed, laser power has more influence on penetration while welding speed has more influence on weld width. The research results provide theoretic and practical bases for penetration real-time monitoring or predicting in partial-penetration laser welding.

  18. Instability of a penetrating blade

    Bigoni, D.; Bosi, F.; Dal Corso, F.; Misseroni, D.

    2014-03-01

    Application of a dead compressive load at the free end of an elastic rod (the ‘blade') induces its penetration into a sliding sleeve ending with a linear elastic spring. Bifurcation and stability analysis of this simple elastic system shows a variety of unexpected behaviors: (i) an increase of buckling load at decreasing of elastic stiffness; (ii) a finite number of buckling loads for a system with infinite degrees of freedom (leading to a non-standard Sturm-Liouville problem); (iii) more than one bifurcation load associated to each bifurcation mode; (iv) a restabilization of the straight configuration after the second bifurcation load associated to the first instability mode; (v) the presence of an Eshelby-like (or configurational) force, deeply influencing stability. Only the first of these behaviors was previously known, the second and third ones disprove common beliefs, the fourth highlights a sort of ‘island of instability', and the last one shows surprising phenomena and effects on stability.

  19. Endoscopic biopsy: Duodenal ulcer penetrating into liver

    Baybora Kircali; Tülay Saricam; Aysegul Ozakyol; Eser Vardareli

    2005-01-01

    @@ TO THE EDITOR We have read with interest the recent report by E Kayacetin and S Kayacetin of Gastric ulcer penetrating to liver diagnosed by endoscopic biopsy[1] since we diagnosed the duodenal ulcer which penetrated into liver similarly. This is a rather unusual case because of the fifth case in the literature and responding to medical therapy.

  20. An Observational Investigation of Penetrative Convection

    Jensen, Niels Otto; Lenschow, D. H.

    1978-01-01

    Data taken during the Air Mass Transformation Experiment (AMTEX) by the NCAR Electra aircraft have proven useful for investigating the structure of thermals penetrating into the turbulent inversion layer which caps the convective mixed layer. Variances, covariances, spectra and cospectra......, which seems to be related to the characteristic size of a penetrating thermal...

  1. A study of the penetration of projectiles into marine sediments

    The work described in this document consists of three main parts: - Application, after having reviewed calculation methods and known codes, of a dynamic plasticity model based on the upper bound-method (with dissipated energy calculations by plastic deformations). The soil model used for this calculation is the Cambridge Clay Model. - Carrying out a programme of tests with instrumented small scale penetrators in centrifuge on a consolidated clay-target. The trials are done under 50 g, with projectiles, fired with an airgun at high impact velocity (50 m/s). The penetrators' instrumentation consists of either measuring acceleration, or tip force with strain gauges. - The mounting of a small instrumented penetrator for shallow water depth experimentations, with an accelerometer, and a local cell for tip resistance. A rapid electronic data acquisition system has been developed for these experimentations. The preliminary tests are done in a large tank filled with clay. The geotechnical characteristics of the clay are perfectly controlled. The tests performed under these conditions have shown the following observations: the rapid electronic data acquisition system works perfectly and could be used as a basic component for a deep water instrumentated penetrator; the results, obtained in these particular test conditions, are in a perfect agreement with the predictions of the model developed in the frame of this contract

  2. Diesel spray penetration studied by simultaneous Mie and shadowgraphy measurements

    Bougie, B.; Tulej, M.; Beaud, P.; Knopp, G.; Radi, P.; Gerber, T.

    2003-03-01

    The influence of gas density and vaporization on penetration and dispersion of Diesel sprays were investigated in a High Temperature High Pressure Cell (HTDZ) within the range of typical Diesel engine injection parameters. The temporal evolution of cold and vaporizing Diesel sprays were probed simultaneously by laser elastic scattering- and shadowgraphy-techniques. The experimental results were used to verify recently proposed Diesel spray models. (author)

  3. MDCT diagnosis of penetrating diaphragm injury

    Bodanapally, Uttam K.; Shanmuganathan, Kathirkamanathan; Mirvis, Stuart E.; Sliker, Clint W.; Fleiter, Thorsten R.; Sarada, Kamal; Miller, Lisa A. [University of Maryland School of Medicine, Department of Diagnostic Radiology, Baltimore, MD (United States); Stein, Deborah M. [University of Maryland, Department of Surgery, Shock Trauma Center, Baltimore, MD (United States); Alexander, Melvin [National Study Center for Trauma and Emergency Medical Systems, Baltimore, MD (United States)

    2009-08-15

    The purpose of the study was to determine the diagnostic sensitivity and specificity of multidetector CT (MDCT) in detection of diaphragmatic injury following penetrating trauma. Chest and abdominal CT examinations performed preoperatively in 136 patients after penetrating trauma to the torso with injury trajectory in close proximity to the diaphragm were reviewed by radiologists unaware of surgical findings. Signs associated with diaphragmatic injuries in penetrating trauma were noted. These signs were correlated with surgical diagnoses, and their sensitivity and specificity in assisting the diagnosis were calculated. CT confirmed diaphragmatic injury in 41 of 47 injuries (sensitivity, 87.2%), and an intact diaphragm in 71 of 98 patients (specificity, 72.4%). The overall accuracy of MDCT was 77%. The most accurate sign helping the diagnosis was contiguous injury on either side of the diaphragm in single-entry penetrating trauma (sensitivity, 88%; specificity, 82%). Thus MDCT has high sensitivity and good specificity in detecting penetrating diaphragmatic injuries. (orig.)

  4. Transconjunctival penetration of mitomycin C

    Velpandian T

    2008-01-01

    Full Text Available Aims: The study was performed to estimate transconjunctival penetration of mitomycin C (MMC to Tenon′s tissue following application over the intact conjunctiva before routine trabeculectomy. Settings and Design: Institution-based case series. Materials and Methods: In 41 eyes of 41 patients, MMC (0.4 mg/ml for 3 min was applied over the intact conjunctiva before beginning trabeculectomy. Tenon′s capsule directly beneath the site of application was excised during trabeculectomy and was homogenized, centrifuged and MMC concentrations were analyzed using high-performance liquid chromatography (HPLC. Statistical Analysis Used: Statistical analysis was performed using stata0 8.0 version software (STATA Corporation, Houston, TX, USA. In this study, P -values less than 0.05 were considered as statistically significant. Results: The average weight of the sample of Tenon′s tissue excised was 5.51 ± 4.42 mg (range: 0.9-17.1 and the average estimated MMC concentration found to be present in Tenon′s tissue using HPLC was 18.67 ± 32.36 x 10−6 moles/kg of the tissue (range: 0.38-197.05 x 10−6 . In 36 of the 41 patients (87.80%, the MMC concentration reached above 2 x 10−6 moles/kg of the tissue concentration required to inhibit human conjunctival fibroblasts. Conclusions: Mitomycin C does permeate into the subconjunctival tissue after supraconjunctival application for 3 min. Application of MMC over the conjunctiva may be a useful alternative to subconjunctival or subscleral application during routine trabeculectomy and as an adjunct for failing blebs.

  5. Characterization of TFTR shielding penetrations of ITER-relevance in D-T neutron field

    D-T operation of TFTR began successfully with trace tritium discharges in mid-November 1993. During the next year, the TFTR plasma tritium fraction is scheduled to be increased to at least 50%. The availability of larger amounts of D-T fusion neutrons in the high power D-T plasma phase of TFTR provides a useful opportunity to characterize tokamak shielding-penetration geometries of potential interest to ITER. These types of measurements can provide direct experimental data on the degree of enhancement of transmitted neutron flux along or across a realistic penetration and, as such, can be used to validate, calculational methods and to meet fusion reactor licensing requirements. The enhancement of neutron streaming in the shielding penetrations has the following significant consequences from the ITER viewpoint: (1) increased radiation damage to plasma diagnostics/detectors, (2) increased biological dose rates behind the shield, (3) increased radiation damage to the superconducting magnet on the inboard side. TFTR has penetrations of different varieties inside the vacuum vessel, the test cell, and the adjoining hot cell. In the initial stage, the authors have chosen to characterize three different types of penetrations in and around the TFTR test cell: (1) a straight hollow pipe coming out of the test cell concrete wall on east side of the test cell into the hot cell, (2) a bent pipe coming out of the test cell through the north concrete wall, and (3) a labyrinth in the north-west end of the test cell

  6. Penetration monitoring as a potential safeguards measure

    Penetration Monitoring is a form of extended Containment/Surveillance which is designed to detect bypassing of flow Key Measurement Points. This would be achieved in practice by providing a containment structure surrounding the Material Balance Area and monitoring all penetrations of the containment which present realistic diversion routes. The performance of a penetration monitoring system may be quantified in terms of detection probability and false alarm probability. The validity of the quantification of system performance depends in turn on: the quantifiability of the performance of individual detection devices; the independence of performance between individual devices; the completeness of coverage of all realistic diversion routes by the penetration monitoring system; the assurance that the integrity of the containment itself remains unimpaired. A sub-group of the International Working Group on Reprocessing Plant Safeguards carried out an appreciation of penetration monitoring as applied to this type of facility, discussing in some detail aspects of system performance including quantification of performance of types of detection devices. Since this study little further work has been reported. Problem areas remaining to be tackled include: (a) An investigation to ascertain which facilities or parts of facilities would lend themselves to the application of penetration monitoring, bearing in mind the needs of the Agency. (b) Design of penetration monitoring systems which do not involve an excessive number of detection devices; the solution of this problem depends very much on the choice of containment boundaries and the penetrations thereof which constitute realistic diversion routes. (c) Specification of performance requirements for detection devices, including those for demonstrating the integrity of the containment itself. (d) Formulation of appropriate response procedures to anomalies generated by a penetration monitoring system. (author)

  7. Development of coring, consolidating, subterrene penetrators

    Murphy, H.D.; Neudecker, J.W.; Cort, G.E.; Turner, W.C.; McFarland, R.D.; Griggs, J.E.

    1976-02-01

    Coring penetrators offer two advantages over full face-melting penetrators, i.e., formation of larger boreholes with no increase in power and the production of glass-lined, structurally undisturbed cores which can be recovered with conventional core-retrieval systems. These cores are of significant value in geological exploratory drilling programs. The initial design details and fabrication features of a 114-mm-diam coring penetrator are discussed; significant factors for design optimization are also presented. Results of laboratory testing are reported and compared with performance predictions, and an initial field trial is described.

  8. Development of coring, consolidating, subterrene penetrators

    Coring penetrators offer two advantages over full face-melting penetrators, i.e., formation of larger boreholes with no increase in power and the production of glass-lined, structurally undisturbed cores which can be recovered with conventional core-retrieval systems. These cores are of significant value in geological exploratory drilling programs. The initial design details and fabrication features of a 114-mm-diam coring penetrator are discussed; significant factors for design optimization are also presented. Results of laboratory testing are reported and compared with performance predictions, and an initial field trial is described

  9. Sphere impact and penetration into wet sand

    Marston, J. O.

    2012-08-07

    We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

  10. A Mass Loss Penetration Model to Investigate the Dynamic Response of a Projectile Penetrating Concrete considering Mass Abrasion

    NianSong Zhang

    2015-01-01

    Full Text Available A study on the dynamic response of a projectile penetrating concrete is conducted. The evolutional process of projectile mass loss and the effect of mass loss on penetration resistance are investigated using theoretical methods. A projectile penetration model considering projectile mass loss is established in three stages, namely, cratering phase, mass loss penetration phase, and remainder rigid projectile penetration phase.

  11. Increased in vivo skin penetration of quantum dots with UVR and in vitro quantum dot cytotoxicity

    Mortensen, Luke; Zheng, Hong; Faulknor, Renea; De Benedetto, Anna; Beck, Lisa; DeLouise, Lisa A.

    2009-02-01

    The growing presence of quantum dots (QD) in a variety of biological, medical, and electronics applications means an increased risk of human exposure in manufacturing, research, and consumer use. However, very few studies have investigated the susceptibility of skin to penetration of QD - the most common exposure route- and the results of those that exist are conflicting. This suggests that a technique allowing determination of skin barrier status and prediction of skin permeability to QD would be of crucial interest as recent findings have provided evidence of in vitro cytotoxicity and long-term in vivo retention in the body for most QD surface chemistries. Our research focuses on barrier status of the skin (intact and with ultraviolet radiation induced barrier defect) and its impact on QD skin penetration. These model studies are particularly relevant to the common application condition of NP containing sunscreen and SPF cosmetics to UV exposed skin. Herein we present our initial efforts to develop an in vivo model of nanoparticle skin penetration using the SKH-1 hairless mouse with transepidermal water loss (TEWL) to evaluate skin barrier status and determine its ability to predict QD penetration. Our results show that ultraviolet radiation increases both TEWL and skin penetration of QD. Additionally, we demonstrate cytotoxic potential of QD to skin cells using a metastatic melanoma cell line. Our research suggests future work in specific targeting of nanoparticles, to prevent or enhance penetration. This knowledge will be used to develop powerful therapeutic agents, decreased penetration cosmetic nanoparticles, and precise skin cancer imaging modalities.

  12. Penetration testing protecting networks and systems

    Henry, Kevin M

    2012-01-01

    This book is a preparation guide for the CPTE examination, yet is also a general reference for experienced penetration testers, ethical hackers, auditors, security personnel and anyone else involved in the security of an organization's computer systems.

  13. Prediction of weld penetration extent in GTAW

    Zhao Ming; Zhai Lei

    2008-01-01

    The governing equations of surface-deformation in fully-penetrated GTA W weld pool are derived. The solution scheme of the Lagrange multiplier, which makes the top sutface-deformation equation be coupled with that for the bottomsurface of a single weld pool, is given out. Through numerical analysis of weld pool surface-deformation in GTA W,it is found that there is clear correlation between the penetration extent and the Lagrange multiplier, in addition to the relationship between the penetration extent and the maximum depression and hump as well as the depressed volume of the top surface of weld pool. It lays good foundation for top-side sensing based weld penetration control.

  14. Kali Linux wireless penetration testing beginner's guide

    Ramachandran, Vivek

    2015-01-01

    If you are a security professional, pentester, or anyone interested in getting to grips with wireless penetration testing, this is the book for you. Some familiarity with Kali Linux and wireless concepts is beneficial.

  15. Temporary fire sealing of penetrations on TFTR

    The radiation shielding provided for TFTR for D-D and D-T operation will be penetrated by numerous electrical and mechanical services. Eventually, these penetrations will have to be sealed to provide the required fire resistance, tritium sealability, pressure integrity and radiation attenuation. For the initial hydrogen operation, however, fire sealing of the penetrations in the walls and floor is the primary concern. This report provides a discussion of the required and desirable properties of a temporary seal which can be used to seal these penetrations for the hydrogen operation and then subsequently be removed and replaced as required for the D-D and D-T operations. Several candidate designs are discussed and evaluated and recommendations are made for specific applications

  16. Penetration of amalgam constituents into dentine

    Scholtanus, J.D.; Özcan, M; Huysmans, M.C.D.N.J.M.

    2009-01-01

    OBJECTIVES: Amalgam restorations are replaced by adhesively placed composite resin restorations at an increasing rate. After the removal of amalgam dentine often shows marked dark discoloration that is attributed to the penetration of corrosion products from overlying amalgams. It is questioned whether penetration of metals into dentine affects the dentine as a substrate for adhesive procedures. This study has been performed to clarify the origin of dark discoloration of dentine by metals fro...

  17. Low Force Penetration of Icy Regolith

    Mantovani, J. G.; Galloway, G. M.; Zacny, K.

    2016-01-01

    A percussive cone penetrometer measures the strength of granular material by using percussion to deliver mechanical energy into the material. A percussive cone penetrometer was used in this study to penetrate a regolith ice mixture by breaking up ice and decompacting the regolith. As compared to a static cone penetrometer, percussion allows low reaction forces to push a penetrometer probe tip more easily into dry regolith in a low gravity environment from a planetary surface rover or a landed spacecraft. A percussive cone penetrates icy regolith at ice concentrations that a static cone cannot penetrate. In this study, the percussive penetrator was able to penetrate material under 65 N of down-force which could not be penetrated using a static cone under full body weight. This paper discusses using a percussive cone penetrometer to discern changes in the concentration of water-ice in a mixture of lunar regolith simulant and ice to a depth of one meter. The rate of penetration was found to be a function of the ice content and was not significantly affected by the down-force. The test results demonstrate that this method may be ideal for a small platform in a reduced gravity environment. However, there are some cases where the system may not be able to penetrate the icy regolith, and there is some risk of the probe tip becoming stuck so that it cannot be retracted. It is also shown that a percussive cone penetrometer could be used to prospect for water ice in regolith at concentrations as high as 8 by weight.

  18. DRUG VEHICLE BASED APPROACHES OF PENETRATION ENHANCEMENT

    Swaroop R Lahoti; MOHD. HASSAN G DEHGHAN; Dinesh L Dhamecha; AMIT A RATHI; MARIA SAIFEE

    2009-01-01

    Transdermal delivery of drugs through the skin to the systemic circulation provides a convenient route of administration for a variety of clinical indications. For transdermal delivery of drugs, stratum corneum is the main barrier layer for permeation of drug. So to circumvent the stratum corneum and to increase the flux through skin membrane, different approaches of penetration enhancement are used. Many reviews had described regarding the chemical penetration enhancement but vehicle based e...

  19. Effect of penetrants on the aramid Nomex

    Anjana Jain; Kalyani Vijayan

    2000-06-01

    The response of Nomex sheets to some penetrants has been analyzed. The process of moisture uptake depends on the relative humidity (RH) of the ambient atmosphere and the initial characteristics of the polymer. In the case of common laboratory solvents, the uptake by the polymer shows an inverse dependence on the molar volume of the former. Although the calendered and the uncalendered Nomex sheets exhibit an overall similarity in their response to various penetrants, quantitative comparison reveals distinct differences.

  20. Evaluation of penetrating cardiac stab wounds

    Bamous, Mehdi; Abdessamad, Abdou; Tadili, Jawad; Kettani, Ali; Faroudy, Mamoun

    2016-01-01

    Background The purpose of this study was to identify factors associated with unfavourable outcome following stab wounds to the heart in order to improve selection of patients who may benefit from resuscitative effort. Methods From February to March, variables were collected from medical records of patients sustaining cardiac trauma. The inclusion criterion was the presence of a penetrating cardiac injury confirmed intraoperatively. Results Ninety-eight patients were admitted with penetrating ...

  1. Penetrating cardiac injury by a metallic fragment

    An adult male had a penetrating injury of the chest resulting in cardiac tamponade. The injury resulted as a consequence of a detached iron piece from an iron bar in a steel mill. Emergency sternotomy and percardiotomy revealed blood in the pericardial cavity and full thickness penetration of the right ventricle. The defect was repaired following the removal of the iron fragment. Postoperative recovery was uneventful. (author)

  2. A method for sealing a penetration unit and thus obtained penetration

    The method is characterized in that it consists in achieving an area/volume ratio of the rain cast part for forming an exothermic core that shrinks inwardly while hardening, and in placing at least one penetration member in that exothermic core the shrinking of which providing a compression-joint between the resin compound and said penetration member. The invention can be applied, in particular, to the sealed penetrations for the electric equipment of nuclear reactors

  3. In vitro penetration of bleaching agents into the pulp chamber

    Benetti, Ana Raquel; Valera, M C; Mancini, M N G;

    2004-01-01

    To investigate pulp chamber penetration of bleaching agents in teeth following restorative procedures.......To investigate pulp chamber penetration of bleaching agents in teeth following restorative procedures....

  4. Rapid penetration into granular media visualizing the fundamental physics of rapid earth penetration

    Iskander, Magued

    2015-01-01

    Rapid Penetration into Granular Media: Visualizing the Fundamental Physics of Rapid Earth Penetration introduces readers to the variety of methods and techniques used to visualize, observe, and model the rapid penetration of natural and man-made projectiles into earth materials. It provides seasoned practitioners with a standard reference that showcases the topic's most recent developments in research and application. The text compiles the findings of new research developments on the subject, outlines the fundamental physics of rapid penetration into granular media, and assembles a com

  5. Coagulation factor Va binds to human umbilical vein endothelial cells and accelerates protein C activation.

    Maruyama, I.; Salem, H H; Majerus, P W

    1984-01-01

    In vitro the rate of protein C activation by thrombin is significantly accelerated by two distinct cofactors (a) the endothelial cell surface protein, thrombomodulin, and (b) human coagulation Factor Va. We have recently reported that the activity of Factor Va is contained in the 78,000-D light chain. In this study we have investigated the effects of Factor Va and its light chain on the activation of protein C in the presence of cultured endothelial cells. Thrombin-catalyzed protein C activat...

  6. Overcoming the nail barrier: A systematic investigation of ungual chemical penetration enhancement.

    Brown, M B; Khengar, R H; Turner, R B; Forbes, B; Traynor, M J; Evans, C R G; Jones, S A

    2009-03-31

    This study investigated the in vitro nail permeability of penetrants of varying lipophilicity-caffeine (CF, logP -0.07), methylparaben (MP, logP 1.96) and terbinafine (TBF, logP 3.3) and the effect of 2 novel penetration enhancers (PEs), thioglycolic acid (TA) and urea hydrogen peroxide (urea H(2)O(2)) on their permeation. Studies were conducted using full thickness human nail clippings and ChubTur((R)) diffusion cells and penetrants were applied as saturated solutions. The rank order of steady-state penetrant flux through nails without PE application (MP>CF>TBF) suggested a greater sensitivity to penetrant molecular weight rather than logP. TA increased the flux of CF and MP approximately 4- and approximately 2-fold, respectively, whilst urea H(2)O(2) proved ineffective at enhancing permeability. The sequential application of TA followed by urea H(2)O(2) increased TBF and CF flux ( approximately 19- and approximately 4-fold, respectively) but reversing the application order of the PEs was only mildly effective at increasing just MP flux ( approximately 2-fold). Both nail PEs are likely to function via disruption of keratin disulphide bonds and the associated formation of pores that provide more 'open' drug transport channels. Effects of the PEs were penetrant specific, but the use of a reducing agent (TA) followed by an oxidising agent (urea H(2)O(2)) dramatically improved human nail penetration. PMID:19071202

  7. Study of aerosol penetration into filtering layers

    In this work a radio-active aerosol is used to study the penetration of particles inside various filtering media by a layer technique. First of all the penetration of the active thoron deposit fixed on the atmospheric dust was examined for a series of filters which were considered to be representative of the various filtering materials used. From this series of tests it appears that the penetration of an ultrafine aerosol in a filter made up of fibrous matter involves two successive, different processes: the first part of the curve characterizes the surface effect, the second part which is practically exponential in form has a slope which depends on the test conditions and on the nature of the filter. The changes in the penetration as a function either of the porosity or of the rate of filtration yield only a qualitative check of the theory; in all cases the penetration is much greater than predicted. The last part of the work is devoted to an examination and a discussion of results obtained, and to various applications of the method, especially concerning the determination of the absorption coefficient for α particles by the matter. The changes in the absorption factor with filtering speed are particularly studied. (author)

  8. Penetrators (penetrating sondes) and new possibilities for study of the planets

    Davydov, V. D.; Skuridin, G. A.

    1979-01-01

    The fields of possible use of penetrators in space research are considered. A survey of the condition of development and plans for use of penetrators abroad is presented and an analysis is given of the significance of scientific problems when probing planets.

  9. Opportunities for high wind energy penetration

    Tande, J.O.; Hansen, J.C.

    1997-01-01

    Wind power is today a mature technology, which at windy locations, is economically competitive to conventional power generation technologies. This and growing global environmental concerns have led governments to encourage and plan for wind energy development, a typical aim being 10% of electricity...... consumption. The successful operation of the three major power systems of Cape Verde, with a total wind energy penetration of about 15% since December 1994, demonstrates that power systems can be operated with high penetration of wind energy by adding simple control and monitoring systems only. Thorough...... analyses conclude that expanding to even above 15% wind energy penetration in the Cape Verde power systems is economical. Worldwide, numerous locations with favorable wind conditions and power systems similar to the Capeverdean provide good opportunities for installing wind farms and achieving high wind...

  10. Proniosomes for Penetration Enhancement in Transdermal System

    Samita Singla

    2012-06-01

    Full Text Available Over the last few years an inclusive research has been done over provesicular approach for transdermal drug delivery. Skin has a very tough diffusion barrier inhibiting penetration of drug moiety which is rate limiting barrier for penetration of drugs. There are several approaches that deal with penetration enhancement across the skin. Vesicular and provesicular systems are promising amongst them. Vesicular systems including (niosomes, ethosomes, transfersomes and liposomes are promising systems to cross this permeation barrier. But their major drawback is their unstability, which can be overcome by using provesicular approaches like proniosomes, protransfersomes and proliposomes. Provesicular approaches have been proposed to enhance the stability of vesicles. These approaches may overcome skin barrier properties and enhance percutaneous absorption. In these systems both type of drugs, hydrophilic and lipophillic drugs can be incorporated. The focus of this review is to bring together different aspects related to mechanism of skin permeation of provesicular system, proniosomes preparation and its applications as a carrier system

  11. Nondestructive examination of vessel bottom head penetrations

    Vessel bottom Head penetration of French PWR units are made of Inconel 600 alloy which is known to be sensitive to stress corrosion cracking and so, need to be inspected. FRAMATOME has developed different complementary non destructive examination methods and a tooling to perform this inspection. These methods are able to detect, from the inside of the penetration, axially or circumferential oriented defects. For defects initiated in the inner surface, Eddy Current examination and TV inspection are used. If they are initiated in the outer surface, ultrasonic examination is used. In addition, ultrasonic examination enables the sensitive stress area of the penetration/vessel bottom head weld joint to be located to the detected defects. The use of fully numerical electronics allows extensive post-processing of ultrasonic and Eddy Current Data. In this paper, the nondestructive examination methods and associated tooling are presented. The accuracy of detection, location and sizing defects is also discussed

  12. Diagnosis and treatment of penetrating anorectal wounds

    LIU Xin-sheng; HUI Xi-zeng; ZHANG Yang-de; LI Kun

    2006-01-01

    Objective:To research the diagnosis and effective treatment of penetrating anorectal wounds.Methods: Retrospective analysis was done in 16 cases of penetrating anorectal wounds from 1985 to 2004.Debridement and suture of anorectal and vesical wounds,effective diversion of fecal and urinary stream and sufficient presacral drainage were performed in all cases.Results: All the 16 cases were cured. Among them, 2cases with infection in presacral space were cured by sufficient drainage after operation, one case was cured by secondary repair after anal sphincter was repaired unsuccessfully and one case with rectovesical fistula was cured with conservative treatment. None of them suffered from complications such as anal stenosis, dysuria or importence etc.Conclusions: For penetrating anorectal wound, to master early recognition of concomitant injures, to select appropriate surgical intervention and to strengthen perioperative treatment are the keys to improve the curative effects.

  13. WAPTT - Web Application Penetration Testing Tool

    DURIC, Z.

    2014-02-01

    Full Text Available Web applications vulnerabilities allow attackers to perform malicious actions that range from gaining unauthorized account access to obtaining sensitive data. The number of reported web application vulnerabilities in last decade is increasing dramatically. The most of vulnerabilities result from improper input validation and sanitization. The most important of these vulnerabilities based on improper input validation and sanitization are: SQL injection (SQLI, Cross-Site Scripting (XSS and Buffer Overflow (BOF. In order to address these vulnerabilities we designed and developed the WAPTT (Web Application Penetration Testing Tool tool - web application penetration testing tool. Unlike other web application penetration testing tools, this tool is modular, and can be easily extended by end-user. In order to improve efficiency of SQLI vulnerability detection, WAPTT uses an efficient algorithm for page similarity detection. The proposed tool showed promising results as compared to six well-known web application scanners in detecting various web application vulnerabilities.

  14. Development Of The Nuclear Optical Penetration

    Inoue, K.; Koike, K.; Imada, Y.

    1984-10-01

    We have developed the nuclear optical penetration to be incorporated in the wall penetration of the shell to introduce a data transmission system using optical fibers into a nuclear power plant with a pressurized water reactor. Radiation-induced coloration in optical glass seriously affects transmission characteristics of optical fibers, whereas it has been revealed that the pure-silica core optical fiber without any dopant in the core has wide applicability in radiation fields thanks to its very low radiation-induced attenuation. The wall penetration of the shell should have airtightness and resistivity to heat, vibration, and pressure, let alone radiation, excellent enough to be invariable in data transmission efficiency even when subjected to severe environmental tests. The sealing modules of this newly developed nuclear optical penetration are hermetically sealed. The gap between the optical fiber rod (100 pm in core diameter and 5 mm in rod diameter) and stainless steel tube is sealed with lamingted glass layer. As the result of He gas leakage test, high airtightness of less than 10 cc/sec was achieved. No thermal deformation of the core was caused by sealing with laminated glass layer, nor was observed transmission loss. Then the sealiing modules were subjected to the irradiation test using 60 Co gamma ray exposure of 2 x 10 rads. Though silica glass layer supporting the fiber rod and sealing glass portion turned blackish purple, transparency of the fiber was not affected. Only less than 0.5 dB of connecting loss was observed at the connecting point with the optical fiber cable. The sealing modules were also found to have resistivity to vibration and pressure as excellent as that of existing nuclear electric penetrations. We expect the nuclear optical fiber penetration will be much effective in improving reliability of data transmission systems using optical fibers in radiation fields.

  15. Ex vivo penetration of low-level laser light through equine skin and flexor tendons.

    Duesterdieck-Zellmer, Katja F; Larson, Maureen K; Plant, Thomas K; Sundholm-Tepper, Andrea; Payton, Mark E

    2016-09-01

    OBJECTIVE To measure penetration efficiencies of low-level laser light energy through equine skin and to determine the fraction of laser energy absorbed by equine digital flexor tendons (superficial [SDFT] and deep [DDFT]). SAMPLE Samples of skin, SDFTs, and DDFTs from 1 metacarpal area of each of 19 equine cadavers. PROCEDURES A therapeutic laser with wavelength capabilities of 800 and 970 nm was used. The percentage of energy penetration for each wavelength was determined through skin before and after clipping and then shaving of hair, through shaved skin over SDFTs, and through shaved skin, SDFTs, and DDFTs (positioned in anatomically correct orientation). Influence of hair color; skin preparation, color, and thickness; and wavelength on energy penetration were assessed. RESULTS For haired skin, energy penetration was greatest for light-colored hair and least for dark-colored hair. Clipping or shaving of skin improved energy penetration. Light-colored skin allowed greatest energy penetration, followed by medium-colored skin and dark-colored skin. Greatest penetration of light-colored skin occurred with the 800-nm wavelength, whereas greatest penetration of medium- and dark-colored skin occurred with the 970-nm wavelength. As skin thickness increased, energy penetration of samples decreased. Only 1% to 20% and 0.1% to 4% of energy were absorbed by SDFTs and DDFTs, respectively, depending on skin color, skin thickness, and applied wavelength. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that most laser energy directed through equine skin was absorbed or scattered by the skin. To achieve delivery of energy doses known to positively affect cells in vitro to equine SDFTs and DDFTs, skin preparation, color, and thickness and applied wavelength must be considered. PMID:27580111

  16. Effects of Penetrative Convection on Solar Dynamo

    Masada, Youhei; Kageyama, Akira

    2013-01-01

    Spherical solar dynamo simulations are performed. Self-consistent, fully compressible magnetohydrodynamic system with a stably stratified layer below the convection zone are numerically solved with a newly developed simulation code based on the Yin-Yang grid. The effects of penetrative convection are studied by comparing two models with and without the stable layer. A solar-like differential rotation profile is established when the penetrative convection is taken into account without assuming any forcing. A large-scale magnetic field is also spontaneously organized in the underlying stable layer. The embedded field has a dipole symmetry about the equator and it shows polarity reversals in time.

  17. HMO penetration: has it hurt public hospitals?

    Clement, J P; Grazier, K L

    2001-01-01

    The purpose of this study is to determine the extent to which health maintenance organization (HMO) penetration within the public hospitals' market area affects the financial performance and viability of these institutions, relative to private hospitals. Hospital- and market-specific measures are examined in a fully interacted model of over 2,300 hospitals in 321 metropolitan statistical areas (MSAs) in 1995. Although hospitals located in markets with higher HMO penetration have lower financial performance as reflected in revenues, expenses and operating margin, public hospitals are not more disadvantaged than other hospitals by managed care. PMID:11669291

  18. Hybrid treatment of penetrating aortic ulcer

    Lara, Juan Antonio Herrero; Martins-Romeo, Daniela de Araujo; Escudero, Carlos Caparros; Falcon, Maria del Carmen Prieto; Batista, Vinicius Bianchi, E-mail: jaherrero5@hotmail.com [Unidade de Gestao Clinica (UGC) de Diagnostico por Imagem - Hosppital Universitario Virgen Macarena, Sevilha (Spain); Vazquez, Rosa Maria Lepe [Unit of Radiodiagnosis - Hospital Nuestra Senora de la Merced, Osuna, Sevilha (Spain)

    2015-05-15

    Penetrating atherosclerotic aortic ulcer is a rare entity with poor prognosis in the setting of acute aortic syndrome. In the literature, cases like the present one, located in the aortic arch, starting with chest pain and evolving with dysphonia, are even rarer. The present report emphasizes the role played by computed tomography in the diagnosis of penetrating atherosclerotic ulcer as well as in the differentiation of this condition from other acute aortic syndromes. Additionally, the authors describe a new therapeutic approach represented by a hybrid endovascular surgical procedure for treatment of the disease. (author)

  19. Depleted Uranium Penetrators : Hazards and Safety

    Rao, S S; T. Balakrishna Bhat

    1997-01-01

    The depleted uranium (DU) alloy is a state-of-the-art material for kinetic energy penetrators due to its superior ballistic performance. Several countries use DU penetrators in their main battle tanks. There is no gamma radiation hazard to the crew members from stowage of DO rounds. Open air firing can result in environmental contamination and associated hazards due to airborne particles containing essentially U/sub 3/0/sub 8/ and UO/sub 2/. Inhalation of polluted air only through resp...

  20. METHOD ON ESTIMATION OF DRUG'S PENETRATED PARAMETERS

    刘宇红; 曾衍钧; 许景锋; 张梅

    2004-01-01

    Transdermal drug delivery system (TDDS) is a new method for drug delivery. The analysis of plenty of experiments in vitro can lead to a suitable mathematical model for the description of the process of the drug's penetration through the skin, together with the important parameters that are related to the characters of the drugs.After the research work of the experiments data,a suitable nonlinear regression model was selected. Using this model, the most important parameter-penetrated coefficient of 20 drugs was computed.In the result one can find, this work supports the theory that the skin can be regarded as singular membrane.

  1. Roentgenologic image of penetrating duodenal bulb ulcer

    When studying a series of aimed roentgenograms in patients with peptic ulcer a gas bubble of irregular spherical configuration or two-layer niche were determined near the bulb medial contour. Gas bubble was from 0.5-0.7 to 3.5 cm in diameter. In such cases penetrating ulcers were determined in operations. Along with other signs gas bubble symptom, sometimes two-layer signs may be used for timely and exact roentgenological diagnosis of penetrating duodenal bulb ulcer in peptic ulcer disease

  2. FREEFALL: A seabed penetrator flight code

    This report presents a one-dimensional model and computer program for predicting the motion of seabed penetrators. The program calculates the acceleration, velocity, and depth of a penetrator as a function of time from the moment of launch until the vehicle comes to rest in the sediment. The code is written in Pascal language for use on a small personal computer. Results are presented as printed tables and graphs. A comparison with experimental data is given which indicates that the accuracy of the code is perhaps as good as current techniques for measuring vehicle performance. 31 refs., 12 figs., 5 tabs

  3. Generic Penetration of the SSRI Market

    Cascade, Elisa F.; Kalali, Amir H.

    2008-01-01

    In this article, we investigate the penetration of generic selective serotonin reuptake inhibitors (SSRIs) in the US market and the implications for patient out-of-pocket expense. The data suggest that generic penetration into the SSRI market has grown from approximately nine percent in 2000, the year that the patent for Prozac® expired, to 72 percent in 2007. For December, 2007, the difference in patient out-of-pocket expense for branded vs. generic agents was, on average, $55.42 for patient...

  4. Enhancement of skin penetration of nonsteroidal anti-inflammatory drugs from extemporaneously compounded topical-gel formulations.

    Goodwin, D A; Fuhrman, L C

    1999-01-01

    Ketoprofen and ibuprofen topical gels were compounded with decyl methyl sulfoxide and the terpenes d-limonene, (-)-menthone, terpinen-4-ol, and a-terpineol as penetration enhancers. Transdermal penetration profiles for both ketoprofen and ibuprofen were determined using full-thickness human skin, modified Franz diffusion cells and an isotonic (pH7.4) phosphate buffer solution. Human skin was used in these experiments to approximate the therapeutic use of these gels. Ibuprofen was found to have superior transdermal kinetics when compared to ketoprofen. Ibuprofen is a smaller and more lipophilic molecule than ketoprofen, which gives it better penetration properties. All enhancers tested significantly increased the penetration (except (-)-menthone) and skin retention (except terpinen-4-ol) of ketoprofen. None of the enhancers tested significantly increased the penetration or retention of ibuprofen. Despite the lack of enhancer activity, ibuprofen still demonstrated higher skin penetration and retention than enhanced delivery of ketoproen. The results of these studies suggest that the addition of penetration enhancers can significantly increase the amount of ketoprofen penetration, while enhancers demonstrated no significant increase (and can actually decrease) the amount of ibuprofen penetrating into and through the skin. PMID:23985822

  5. Design of Fire/Gas Penetration Seals and fire exposure tests for Tokamak Fusion Test Reactor experimental areas

    A Fire/Gas Penetration Seal is required in every penetration through the walls and ceilings into the Test Cell housing the Tokamak Fusion Test Reactor (TFTR), as well as other adjacent areas to protect the TFTR from fire damage. The penetrations are used for field coil lead stems, diagnostics systems, utilities, cables, trays, mechanical devices, electrical conduits, vacuum liner, air conditioning ducts, water pipes, and gas pipes. The function of the Fire/Gas Penetration Seals is to prevent the passage of fire and products of combustion through penetrations for a period of time up to three hours and remain structurally intact during fire exposure. The Penetration Seal must withstand, without rupture, a fire hose water stream directed at the hot surface. There are over 3000 penetrations ranging in size from several square inches to 100 square feet, and classified into 90 different types. The material used to construct the Fire/Gas Penetration Seals consist of a single and a two-component room temperature vulcanizing (RTV) silicone rubber compound. Miscellaneous materials such as alumina silica refractory fibers in board, blanket and fiber forms are also used in the construction and assembly of the Seals. This paper describes some of the penetration seals and the test procedures used to perform the three-hour fire exposure tests to demonstrate the adequacy of the seals

  6. Penetration resistance according to penetration rate, cone base size and different soil conditions

    Daniel Dias Valadão Junior

    2014-06-01

    Full Text Available This study aimed to evaluate the effect of penetration rate and the size of the cone base on the resistance to penetration under different soil moistures and soil bulk density. The experimental design was completely randomized in a 4x2x2x2 factorial arrangement, with the factors, soil bulk density of 1.0; 1.2; 1.4 and 1.6 Mg m-3, soil moisture at the evaluation of 0.16 and 0.22 kg kg-1, penetration rates of 0.166 and 30 mm s-1 and areas of the cone base of 10.98 and 129.28 mm² resulting in 32 treatments with 8 replicates. To ensure greater uniformity and similarity to field conditions, samples passed through cycles of wetting and drying. Only the interaction of the four factors was not significant. Resistance values varied with the density of the soil, regardless of moisture and penetration rate. Soil penetration resistance was influenced by the size of the cone base, with higher values for the smallest base independent of moisture and soil bulk density. The relationship between resistance to penetration and moisture is not always linear, once it is influenced by soil bulk density. Reduction in the area of the cone leads to an increase in the soil resistance to penetration.

  7. Penetration of electronic beams in ionizing media

    It is studied the penetration of an electron beam in an ionizable medium by means of a generalized kinetic equation. This equation is related to elastic collisions, processes of creation and destruction of particles. By integrating numerically the transport equation, it can be evaluated the relative effects of all the processes involved in the evolution of the system. (A.C.A.S.)

  8. Computed tomographic findings in penetrating peptic ulcer

    Four cases of peptic ulcer penetrating the head of the pancreas were diagnosed by computed tomography (CT). Findings common to 3 cases included (a) an ulcer crater, (b) a sinus tract, and (c) enlargement of the head of the pancreas. Unlike other modalities, the inherent spatial resolution of CT allows a convenient diagnosis of this important complication of peptic ulcer disease

  9. Effects of Sizes and Conformations of Fish-Scale Collagen Peptides on Facial Skin Qualities and Transdermal Penetration Efficiency

    Huey-Jine Chai; Jing-Hua Li; Han-Ning Huang; Tsung-Lin Li; Yi-Lin Chan; Chyuan-Yuan Shiau; Chang-Jer Wu

    2010-01-01

    Fish-scale collagen peptides (FSCPs) were prepared using a given combination of proteases to hydrolyze tilapia (Oreochromis sp.) scales. FSCPs were determined to stimulate fibroblast cells proliferation and procollagen synthesis in a time- and dose-dependent manner. The transdermal penetration capabilities of the fractionationed FSCPs were evaluated using the Franz-type diffusion cell model. The heavier FSCPs, 3500 and 4500 Da, showed higher cumulative penetration capability as opposed to the...

  10. The Basics of Hacking and Penetration Testing Ethical Hacking and Penetration Testing Made Easy

    Engebretson, Patrick

    2011-01-01

    The Basics of Hacking and Penetration Testing serves as an introduction to the steps required to complete a penetration test or perform an ethical hack. You learn how to properly utilize and interpret the results of modern day hacking tools; which are required to complete a penetration test. Tool coverage will include, Backtrack Linux, Google, Whois, Nmap, Nessus, Metasploit, Netcat, Netbus, and more. A simple and clean explanation of how to utilize these tools will allow you  to gain a solid understanding of each of the four phases and prepare them to take on more in-depth texts and topi

  11. Quantification of quantum dot murine skin penetration with UVR barrier impairment.

    Mortensen, Luke J; Jatana, Samreen; Gelein, Robert; De Benedetto, Anna; De Mesy Bentley, Karen L; Beck, Lisa A; Elder, Alison; Delouise, Lisa A

    2013-12-01

    Ultraviolet radiation (UVR) skin exposure is a common exogenous insult that can alter skin barrier and immune functions. With the growing presence of nanoparticles (NPs) in consumer goods and technological applications the potential for NPs to contact UVR-exposed skin is increasing. Therefore it is important to understand the effect of UVR on NP skin penetration and the potential for systemic translocation. Previous studies qualitatively showed that UVR skin exposure can increase the penetration of NPs below the stratum corneum. In this work, an in vivo mouse model was used to quantitatively examine the skin penetration of carboxylated (CdSe/ZnS, core/shell) quantum dots (QDs) through intact and UVR barrier-disrupted murine skin by organ Cd mass analysis. Transepidermal water loss was used to measure the magnitude of the skin barrier defect as a function of UVR dose and time post-UVR exposure. QDs were applied to mice 3-4 days post-UVR exposure at the peak of the skin barrier disruption. Our results reveal unexpected trends that suggest these negative-charged QDs can penetrate barrier intact skin and that penetration and systemic transport depends on the QD application time post-UVR exposure. The effect of UVR on skin-resident dendritic cells and their role in the systemic translocation of these QDs are described. Our results suggest that NP skin penetration and translocation may depend on the specific barrier insult and the inflammatory status of the skin. PMID:23078247

  12. Common gene therapy viral vectors do not efficiently penetrate sputum from cystic fibrosis patients.

    Kaoru Hida

    Full Text Available Norwalk virus and human papilloma virus, two viruses that infect humans at mucosal surfaces, have been found capable of rapidly penetrating human mucus secretions. Viral vectors for gene therapy of Cystic Fibrosis (CF must similarly penetrate purulent lung airway mucus (sputum to deliver DNA to airway epithelial cells. However, surprisingly little is known about the rates at which gene delivery vehicles penetrate sputum, including viral vectors used in clinical trials for CF gene therapy. We find that sputum spontaneously expectorated by CF patients efficiently traps two viral vectors commonly used in CF gene therapy trials, adenovirus (d∼80 nm and adeno-associated virus (AAV serotype 5; d∼20 nm, leading to average effective diffusivities that are ∼3,000-fold and 12,000-fold slower than their theoretical speeds in water, respectively. Both viral vectors are slowed by adhesion, as engineered muco-inert nanoparticles with diameters as large as 200 nm penetrate the same sputum samples at rates only ∼40-fold reduced compared to in pure water. A limited fraction of AAV exhibit sufficiently fast mobility to penetrate physiologically thick sputum layers, likely because of the lower viscous drag and smaller surface area for adhesion to sputum constituents. Nevertheless, poor penetration of CF sputum is likely a major contributor to the ineffectiveness of viral vector based gene therapy in the lungs of CF patients observed to date.

  13. Dynamic Cone Penetration Test (DCPT) for Subgrade Assessment

    Salgado, Rodrigo; Yoon, Sungmin

    2003-01-01

    In-situ penetration tests have been widely used in geotechnical and foundation engineering for site investigation in support of analysis and design. The standard penetration test (SPT) and the cone penetration test (CPT) are two typical in-situ penetration tests. The dynamic cone penetration test shows features of both the CPT and the SPT. The DCPT is performed by dropping a hammer from a certain fall height and measuring penetration depth per blow for each tested depth. The DCPT is a quick t...

  14. CNS Active O-Linked Glycopeptides that Penetrate the BBB

    Evan M Jones

    2015-06-01

    Full Text Available Naturally occurring glycopeptides and glycoproteins play important roles in biological processes. Glycosylation is one of the most common post-translational modifications in vivo. Glycopeptides are involved in cell signaling and sorting, providing cell surface markers for recognition. From the drug design and synthesis perspective, modification of a peptide through glycosylation results in increased bioavailability and bioactivity of glycopeptides in living systems with negligible toxicity of degradation products. Glycopeptide synthesis can be accomplished through incorporation of a glycosylated amino acid in solid phase peptide synthesis (SPPS to form the desired peptide, or via incorporation of sugar-amino acid moieties. Additionally, research indicates that glycosylation increases penetration of the blood-brain barrier (BBB by peptides, which may lead to novel therapeutics for neurological disorders. Recent applications of glycopeptides have focused on the in vivo central nervous system effects after peripheral administration of centrally active peptides modified with various carbohydrates.

  15. CNS Active O-Linked Glycopeptides that Penetrate the BBB

    Jones, Evan; Polt, Robin

    2015-06-01

    Naturally occurring glycopeptides and glycoproteins play important roles in biological processes. Glycosylation is one of the most common post-translational modifications in vivo. Glycopeptides are involved in cell signaling and sorting, providing cell surface markers for recognition. From the drug design and synthesis perspective, modification of a peptide through glycosylation results in increased bioavailability and bioactivity of glycopeptides in living systems with negligible toxicity of degradation products. Glycopeptide synthesis can be accomplished through incorporation of a glycosylated amino acid in solid phase peptide synthesis (SPPS) to form the desired peptide, or via incorporation of sugar-amino acid moieties. Additionally, research indicates that glycosylation increases penetration of the blood-brain barrier (BBB) by peptides, which may lead to novel therapeutics for neurological disorders. Recent applications of glycopeptides have focused on the in vivo central nervous system effects after peripheral administration of centrally active peptides modified with various carbohydrates.

  16. Lipid peroxidation and water penetration in lipid bilayers

    Conte, Elena; Megli, Francesco Maria; Khandelia, Himanshu;

    2012-01-01

    Lipid peroxidation plays a key role in the alteration of cell membrane's properties. Here we used as model systems multilamellar vesicles (MLVs) made of the first two products in the oxidative cascade of linoleoyl lecithin, namely 1-palmitoyl-2-(13-hydroperoxy-9,11-octadecanedienoyl)-lecithin (Hp......(zz) parameters revealed that OHPLPC, but mostly HpPLPC, induced a measurable increase in polarity and H-bonding propensity in the central region of the bilayer. Molecular dynamics simulation performed on 16-DSA in the PLPC-HpPLPC bilayer revealed that water molecules are statistically favored with respect to the...... hydroperoxide groups to interact with the nitroxide at the methyl-terminal, confirming that the H-bonds experimentally observed are due to increased water penetration in the bilayer. The EPR and MD data on model membranes demonstrate that cell membrane damage by oxidative stress cause alteration of water...

  17. Dynamic behavior of novel tungsten penetrator materials

    The scope of the investigations was to find criteria which are related to the terminal ballistic performance of high strength tungsten KE-penetrator materials. The study comprised three tungsten alloys having densities above 17.1 g/cm3 and comparable static material strengths. For this purpose the authors investigated the dynamic material behavior by means of the instrumented Taylor-test. The influence of the strain rate on the yield strength and the maximum strain when cracking occurred were determined. The measured dynamic strength data were compared with the terminal ballistic efficiency of rods penetrating a semi-infinite RHA-target. Furthermore, the structural properties of the alloys were discussed with respect to their behavior in the regime of hydrodynamic flow

  18. Suicide bomb attack causing penetrating craniocerebral injury

    Hussain Manzar

    2013-02-01

    Full Text Available 【Abstract】Penetrating cerebral injuries caused by foreign bodies are rare in civilian neurosurgical trauma, al-though there are various reports of blast or gunshot inju-ries in warfare due to multiple foreign bodies like pellets and nails. In our case, a 30-year-old man presented to neurosur-gery clinic with signs and symptoms of right-sided weak-ness after suicide bomb attack. The skull X-ray showed a single intracranial nail. Small craniotomy was done and the nail was removed with caution to avoid injury to surround-ing normal brain tissue. At 6 months’ follow-up his right-sided power improved to against gravity. Key words: Head injury, penetrating; Bombs; Nails

  19. Eddy current testing with high penetration

    The low-frequency eddy current testing method is used when penetration into very deep layers is required. The achievable penetration depth is determined among other parameters by the lowest testing frequency that can be realised together with the eddy current sensor. When using inductive sensors, the measuring effect declines proportional to the lowering frequency (induction effect). Further reduction of testing frequency requires other types of sensors, as e.g. the GMR (Giant Magnetic Resistance), which achieves a constant measuring sensitivity down to the steady field. The multi-frequency eddy current testing method MFEC 3 of IZFP described here can be operated using three different scanning frequencies at a time. Two variants of eddy current probes are used in this case. Both have an inductive winding at their emitters, of the type of a measuring probe. The receiver end is either also an inductive winding, or a magnetic field-responsive resistance (GMR). (orig./CB)

  20. Containment penetration elastomer seal leak rate tests

    Tests were performed on three elastomer seal designs commonly used for nuclear plant containment mechanical penetrations. The objective of this research project is to obtain an understanding of the integrity and leakage behavior of these seal designs under severe accident temperature and pressure conditions. The three designs tested and the seal materials used in the tests were: (1) double tongue-and-groove design with silicone rubber seals, (2) double-O-ring design with neoprene and ethylene-propylene (EPDM) seals, and (3) double gumdrop design with neoprene and EPDM seals. The effects of thermal aging and angular rotations of flange mating surfaces were determined. The test results provide information required to characterize the leakage behavior of penetrations under severe accident conditions. 3 refs., 10 figs., 12 tabs

  1. Depleted Uranium Penetrators : Hazards and Safety

    S. S. Rao

    1997-01-01

    Full Text Available The depleted uranium (DU alloy is a state-of-the-art material for kinetic energy penetrators due to its superior ballistic performance. Several countries use DU penetrators in their main battle tanks. There is no gamma radiation hazard to the crew members from stowage of DO rounds. Open air firing can result in environmental contamination and associated hazards due to airborne particles containing essentially U/sub 3/0/sub 8/ and UO/sub 2/. Inhalation of polluted air only through respirators or nose masks and refraining form ingestion of water or food materials from contaminated environment are safety measures for avoiding exposure to uranium and its toxicity. Infusion of sodium bicarbonate helps in urinary excretion of uranium that may have entered the body.

  2. Simulation of penetration into porous geologic media

    Vorobiev, O Y; Liu, B T; Lomov, I N; Antoun, T

    2005-05-31

    We present a computational study on the penetration of steel projectiles into porous geologic materials. The purpose of the study is to extend the range of applicability of a recently developed constitutive model to simulations involving projectile penetration into geologic media. The constitutive model is non-linear, thermodynamically consistent, and properly invariant under superposed rigid body motions. The equations are valid for large deformations and they are hyperelastic in the sense that the stress tensor is related to a derivative of the Helmholtz free energy. The model uses the mathematical structure of plasticity theory to capture the basic features of the mechanical response of geological materials including the effects of bulking, yielding, damage, porous compaction and loading rate on the material response. The new constitutive model has been successfully used to simulate static laboratory tests under a wide range of triaxial loading conditions, and dynamic spherical wave propagation tests in both dry and saturated geologic media.

  3. Large scale wind power penetration in Denmark

    Karnøe, Peter

    2013-01-01

    he Danish electricity generating system prepared to adopt nuclear power in the 1970s, yet has become the world's front runner in wind power with a national plan for 50% wind power penetration by 2020. This paper deploys a sociotechnical perspective to explain the historical transformation of...... "networks of power" via the interactions of politics, the techno-physics of electrons, and the market setting. The Danish case is about how an assemblage of new agencies has reorganized and reshaped society by building a new sociotechnical network. This has rendered developments highly unpredictable and...... highly experimental. The transformation process can be followed through the way successive technical engineering reports have represented the challenges associated with the penetration of wind power. The iteration shows how novel technical phenomena emerge and are assimilated, and how new engineering...

  4. Benchmark field study of deep neutron penetration

    Morgan, J. F.; Sale, K.; Gold, R.; Roberts, J. H.; Preston, C. C.

    1991-06-01

    A unique benchmark neutron field has been established at the Lawrence Livermore National Laboratory (LLNL) to study deep penetration neutron transport. At LLNL, a tandem accelerator is used to generate a monoenergetic neutron source that permits investigation of deep neutron penetration under conditions that are virtually ideal to model, namely the transport of mono-energetic neutrons through a single material in a simple geometry. General features of the Lawrence Tandem (LATAN) benchmark field are described with emphasis on neutron source characteristics and room return background. The single material chosen for the first benchmark, LATAN-1, is a steel representative of Light Water Reactor (LWR) Pressure Vessels (PV). Also included is a brief description of the Little Boy replica, a critical reactor assembly designed to mimic the radiation doses from the atomic bomb dropped on Hiroshima, and its us in neutron spectrometry.

  5. Ultrastructure and penetration of cell co-culture model of human skin equivalent%细胞共培养人体皮肤类似物超微结构观察及其渗透性测试

    李辉; 王景雁; 林红梅; 于竞新; 章烨雯; 毛颖秋; 吴清

    2016-01-01

    目的:观察人体皮肤类似物模型形态结构,对其屏障功能进行初步评价。方法通过胶原蛋白包被成纤维细胞,制备真皮层,真皮层表面接种角质细胞,浸没培养1周后,气-液界面培养以促进角质细胞的分化形成角质层,3周后收获皮肤模型;通过肉眼观察、电镜观察皮肤类似物的宏观结构和超微结构;以吲哚美辛作为模型药物,进行体外透皮实验考察细胞共培养皮肤类似物模型的屏障功能。结果皮肤类似物形成与人类皮肤相似的真皮层和表皮层,表皮层表面形成完整的角质层,具有与人类皮肤类似的超微结构;24 h 内渗透性实验结果显示皮肤类似物屏障功能略低于大鼠腹部皮肤,但22~24 h,皮肤类似物对模型药的透过速率远小于大鼠腹部皮肤(约为其28%),且2种皮肤模型对吲哚美辛经皮渗透的稳态流速没有显著性差异(P >0.05)。结论皮肤类似物有与人体皮肤相类似的形态结构特征,与大鼠腹部皮肤相比对吲哚美辛有相似的屏障作用,有望替代动物皮肤成为经皮给药系统评价的新型皮肤模型。%Abatract:Objective To observe the structure of human skin equivalent (HSE)model in vitro,and to preliminarily assess the barrier function of HSE.Methods The HSE model was established by two steps:preparation of dermal layer and preparation of full-thickness skin.Keratinocytes were inoculated on the surface of dermal layer prepared by type 1 collagen coating fibroblasts.After submerged cultured for one week,air-liquid interface cultured for three weeks to enhance the proliferation of keratinocytes,the HSE model was obtained.Then the macroscopical structure and electon microscopical structure of HSE were studied.To investigate the barrier function of HSE model,indometacin was selected as the model drug for the penetration testing in vitro.Results The structures similar to dermal layer and

  6. CRM approach penetration in a service organization

    Mäyry, Asko

    2012-01-01

    The purpose was to develop CRM (Customer Relationship Management) system user commitment and CRM results for a service organization. The CRM approach penetration was used as an indicator to measure and explain the success of the CRM introduction. CRM related research questions and hypotheses were created. 21 respondents (95 %) answered the questionnaires before and after development activities. After both surveys, interviews were conducted to collect additional research data. A new method...

  7. Thyroid Emphysema Following Penetrating Neck Trauma

    Karadağ, Demet; Doner, Egemen; Adapınar, Baki

    2011-01-01

    Although traumatic thyroid gland rupture or hemorrhage is usually seen in goitrous glands, injuries of the normal thyroid gland after neck trauma have rarely been described in the literature. We describe a 44-year-old man who presented with thyroid emphysema and subcutaneous emphysema (SCE) that occurred after penetrating neck trauma. CT images showed complete resolution of thyroid emphysema and subcutaneous emphysema at follow-up examination. Neck injuries can be life threatening. After pene...

  8. Corrosion Inhibitors as Penetrant Dyes for Radiography

    Novak, Howard L.; Hall, Phillip B.

    2003-01-01

    Liquid/vapor-phase corrosion inhibitors (LVCIs) have been found to be additionally useful as penetrant dyes for neutron radiography (and perhaps also x-radiography). Enhancement of radiographic contrasts by use of LVCIs can reveal cracks, corrosion, and other defects that may be undetectable by ultrasonic inspection, that are hidden from direct optical inspection, and/or that are difficult or impossible to detect in radiographs made without dyes.

  9. Penetration of minocycline into lung tissues.

    Naline, E.; Sanceaume, M; Toty, L; Bakdach, H; Pays, M; Advenier, C

    1991-01-01

    The penetration of minocycline into different lung tissues and bronchial mucus was studied in 17 patients undergoing pulmonary surgery for cancer. The patients received oral minocycline 100 mg at night for 3 days preceding surgery. Minocycline concentrations were measured in plasma samples collected before the operation and in tissues and mucus taken from in and around the part of the lung that was surgically removed. Mean tissue or mucus concentration to plasma concentration ratios were 3.78...

  10. Penetration of Candida Biofilms by Antifungal Agents

    Al-Fattani, Mohammed A.; Douglas, L. Julia

    2004-01-01

    A filter disk assay was used to investigate the penetration of antifungal agents through biofilms containing single and mixed-species biofilms containing Candida. Fluconazole permeated all single-species Candida biofilms more rapidly than flucytosine. The rates of diffusion of either drug through biofilms of three strains of Candida albicans were similar. However, the rates of drug diffusion through biofilms of C. glabrata or C. krusei were faster than those through biofilms of C. parapsilosi...

  11. Market penetration of new energy technologies

    Packey, D.J.

    1993-02-01

    This report examines the characteristics, advantages, disadvantages, and, for some, the mathematical formulas of forecasting methods that can be used to forecast the market penetration of renewable energy technologies. Among the methods studied are subjective estimation, market surveys, historical analogy models, cost models, diffusion models, time-series models, and econometric models. Some of these forecasting methods are more effective than others at different developmental stages of new technologies.

  12. Two-step LASIK after penetrating keratoplasty

    Kollias, Aris

    2009-01-01

    Aris N Kollias, Markus M Schaumberger, Thomas C Kreutzer, Michael W Ulbig, Carlo A LackerbauerUniversity Eye Hospital, Ludwig-Maximilians University, Munich, GermanyPurpose: The point of interest of this retrospective case review is to study refractive changes caused by the hinged lamellar keratotomy and the refractive outcome after laser ablation in a second step within the scope of laser in situ keratomileusis (LASIK) in patients with penetrating keratoplasty.Methods: Data...

  13. Two-step LASIK after penetrating keratoplasty

    Kollias, Aris N.; Schaumberger, Markus M; Kreutzer, Thomas C.; Ulbig, Michael W; Lackerbauer, Carlo A.

    2009-01-01

    Purpose: The point of interest of this retrospective case review is to study refractive changes caused by the hinged lamellar keratotomy and the refractive outcome after laser ablation in a second step within the scope of laser in situ keratomileusis (LASIK) in patients with penetrating keratoplasty. Methods: Data from eight patients obtained before lamellar keratotomy, before laser ablation, and three months later were evaluated. Keratotomies were performed with the Moria® LSK one and the Am...

  14. Surfactant improves irrigant penetration into unoperated sinuses

    Rohrer, Joseph W.; Dion, Greg R.; Brenner, Pryor S.; Abadie, Wesley M.; McMains, Kevin C.; Thomas, Roy F.; Weitzel, Erik K.

    2012-01-01

    Background: Saline irrigations are proving to be a valuable intervention in the treatment of chronic sinusitis. The use of surfactants is a well established additive to topical treatments known to reduce surface tension and may prove to be a simple, nonoperative intervention to improve intrasinus douching penetration. Methods: Six 30-mL, flat-bottomed medicine cups with circular holes cut through the bottom center and varying in diameter from 1 to 6 mm were created with punch biopsies. Water,...

  15. Essential fatty acids as transdermal penetration enhancers

    Van Zyl, Lindi; du Preez, Jan; Gerber, Minja; Du Plessis, Jeanetta; Viljoen, Joe

    2015-01-01

    The aim of this study was to investigate the effect of different penetration enhancers, containing essential fatty acids (EFAs), on the transdermal delivery of flurbiprofen. Evening primrose oil (EPO), vitamin F and Pheroid™ technology all contain fatty acids and were compared using a cream-based formulation. This selection was to ascertain whether EFAs solely, or EFAs in a Pheroid™ delivery system, would have a significant increase in the transdermal delivery of a compound. Membrane release ...

  16. Penetrating ocular trauma associated with blank cartridge

    Moon, Sunghyuk; Lim, Su-Ho

    2014-01-01

    Background Blank cartridge guns are generally regarded as being harmless and relative safe. However recent published articles demonstrated that the gas pressure from the exploding propellant of blank cartridge is powerful enough to penetrate the thoracic wall, abdominal muscle, small intestine and the skull. And there has been a limited number of case reports of ocular trauma associated with blank cartridge injury. In addition, no report on case with split extraocular muscle injury with traum...

  17. Results of Thoracotomy in Penetrating Chest Trauma

    Mahmood Aghaei-Afshar; Foroogh Mangeli; Sara Farifteh

    2012-01-01

    Background: Thoracotomy is a surgical procedure to access the chest components, which is often performed after severe bleeding caused by heart damage, lung laceration and other similar injuries.Materials and Methods: This is a cross-sectional study which was conducted on all patients with penetrating chest trauma during April 2000 to October 2008.Results: In 5% of cases, thoracotomy was used for treatment in which severe bleeding was the main surgical indication. It was the most common findin...

  18. Simultaneous Penetrating Keratoplasty and Cataract Surgery

    Mohammad-Ali Javadi; Sepehr Feizi; Hamid-Reza Moein

    2013-01-01

    Purpose: To determine the clinical outcomes of simultaneous penetrating keratoplasty (PK), cataract removal and intraocular lens implantation (triple procedure), and to compare the safety and efficacy of two different cataract extraction techniques during the course of PK. Methods: This retrospective comparative study was conducted on patients who had undergone a triple procedure. The technique of cataract extraction was either opensky extracapsular cataract extraction (ECCE) or phacoemul...

  19. Aerosol penetration inside HEPA filtration media

    Attempts made to modelize changes in high-efficiency particulate air (HEPA) filter pressure drop as a function of such parameters as the amount of aerosol collected, which also take account of filtering medium characteristics, those of the filtered aerosol and the filtration velocity, have always been limited by a lack of knowledge of the distribution of particles within the medium. For the last few years, a method, developed over 25 years ago to study the distribution of Radon daughters within filter media made of cellulose fibers, has been reused and applied to radioactive and fluorescent aerosols penetration studies. This method enables determination of aerosol distribution on the surface and inside the filter medium by peeling away successive layers using an adhesive tape and measuring the specific amounts removed each time. Knowledge of aerosol penetration within the filter has revealed that, for a give aerosol, particle distribution inside the filter rapidly decreased exponentially and that fixation on the filter's front surface rapidly superseded penetration inside the medium. The deposit profiles thus measured have made it possible to propose a model for determining the rate of filter pressure drop increase that closely agrees with experimental results

  20. Spanish RPV head penetrations. Regulatory status

    The paper presents the actual status of inspection results on the Spanish PWR RPV CRD head penetrations (CRDH's), after two years of a whole program of inspections in all affected plants. Actual situation of penetrations pertaining to ALMARAZ 1 and 2, ASCO 1 and 2 and VANDELLOS 2 NPP's show any damage in those CRDH's inspected in 1993 and 1994 (roughly 20 out of 65 CRDH's at each unit). The paper presents a summary of CRDH characteristics, inspection methods and results obtained in each plant. TRILLO NPP has a different CRDH design (KWU-SIEMENS type) and for that reason is not considered an affected plant nor has conducted any inspection up to now. JOSE CABRERA (ZORITA) NPP has shown extensive damage, both in the lower side (weldment to the vessel) and in the upper free span area, near bimetallic weldment to SS 304, in active and nonactive penetrations and also in the vent nozzle. The paper comments extensively on the CRDH materials general data, root-cause analysis and structural analysis of degraded zones, inspection results, repair actions and other additional actions applied up to now. Finally, the paper deals with the regulatory actions taken by CSN on this topic, both for those NPP's actually non affected by the IGSCC phenomenon in the RPV CRDH's and for the specific safety case of ZORITA NPP. (author)

  1. Essential Fatty Acids as Transdermal Penetration Enhancers.

    van Zyl, Lindi; du Preez, Jan; Gerber, Minja; du Plessis, Jeanetta; Viljoen, Joe

    2016-01-01

    The aim of this study was to investigate the effect of different penetration enhancers, containing essential fatty acids (EFAs), on the transdermal delivery of flurbiprofen. Evening primrose oil (EPO), vitamin F, and Pheroid technology all contain fatty acids and were compared using a cream-based formulation. This selection was to ascertain whether EFAs solely, or EFAs in a Pheroid delivery system, would have a significant increase in the transdermal delivery of a compound. Membrane release studies were performed, and the results indicated the following rank order for flurbiprofen release from the different formulations: vitamin F > control > EPO > Pheroid. Topical skin delivery results indicated that flurbiprofen was present in the stratum corneum-epidermis and the epidermis-dermis. The average percentage flurbiprofen diffused to the receptor phase (representing human blood) indicated that the EPO formulation showed the highest average percentage diffused. The Pheroid formulation delivered the lowest concentration with a statistical significant difference (p < 0.05) compared with the control formulation (containing 1% flurbiprofen and no penetration enhancers). The control formulation presented the highest average flux, with the EPO formulation following the closest. It could, thus, be concluded that EPO is the most favorable chemical penetration enhancer when used in this formulation. PMID:26852854

  2. Inspection and repair technology for BMI penetrations

    Historically, United States (US) nuclear power plant inspections of the reactor vessel bottom-mounted-instrument (BMI) penetrations have been limited to visual verification via a combination of walk-downs and pressure tests. However in France, more than 18 ultrasonic examination (UT) and weld-surface visual test (VT) campaigns had been performed to inspect the BMI penetration nozzles and welds since 1992 with no observed failures through 2002. In April 2003, South Texas Project Unit 1 discovered apparent leakage from two nozzles during a bare-metal examination. Based on the French inspection experience, Framatome-ANP was selected for inspection and repair services to address the leaking nozzles. Inspection activities included ultrasonic examination of the tube, enhanced visual test and eddy current testing (ECT) of the J-groove weld, bobbin ECT and profile measurement of the tube inside, helium leak test, phased-array UT, borescope VT, and boat-sample removal with destructive metallurgical analysis. Repair activities included sealing the top portion of the penetration, cutting out the old nozzles, and welding in new nozzles. This presentation discusses BMI inspection and repair technology focused particularly on the South Texas Project experience. (authors)

  3. Penetration Testing Curriculum Development in Practice

    Chengcheng Li

    2015-04-01

    Full Text Available As both the frequency and the severity of network breaches have increased in recent years, it is essential that cybersecurity is incorporated into the core of business operations. Evidence from the U.S. Bureau of Labor Statistics (Bureau of Labor Statistics, 2012 indicates that there is, and will continue to be, a severe shortage of cybersecurity professionals nationwide throughout the next decade. To fill this job shortage we need a workforce with strong hands-on experience in the latest technologies and software tools to catch up with the rapid evolution of network technologies. It is vital that the IT professionals possess up-to-date technical skills and think and act one step ahead of the cyber criminals who are constantly probing and exploring system vulnerabilities. There is no perfect security mechanism that can defeat all the cyber-attacks; the traditional defensive security mechanism will eventually fail to the pervasive zero-day attacks. However, there are steps to follow to reduce an organization’s vulnerability to cyber-attacks and to mitigate damages. Active security tests of the network from a cyber-criminal’s perspective can identify system vulnerabilities that may lead to future breaches. “If you know yourself but not the enemy, for every victory gained you will also suffer a defeat. But if you know the enemy and know yourself, you need not fear the result of hundred battles” (Sun, 2013. Penetration testing is a discipline within cybersecurity that focuses on identifying and exploiting the vulnerabilities of a network, eventually obtaining access to the critical business information. The pentesters, the security professionals who perform penetration testing, or ethical hackers, break the triad of information security - Confidentiality, Integrity, and Accountability (CIA - as if they were a cyber-criminal. The purpose of ethical hacking or penetration testing is to know what the “enemy” can do and then generate a

  4. Capillary Penetration into Inclined Circular Glass Tubes.

    Trabi, Christophe L; Ouali, F Fouzia; McHale, Glen; Javed, Haadi; Morris, Robert H; Newton, Michael I

    2016-02-01

    The spontaneous penetration of a wetting liquid into a vertical tube against the force of gravity and the imbibition of the same liquid into a horizontal tube (or channel) are both driven by capillary forces and described by the same fundamental equations. However, there have been few experimental studies of the transition from one orientation to the other. We report systematic measurements of capillary penetration of polydimethylsiloxane oils of viscosities 9.6, 19.2, and 48.0 mPa·s into glass capillary tubes. We first report the effect of tube radii R between 140 and 675 μm on the dynamics of spontaneous imbibition. We show that the data can be fitted using the exact numerical solution to the governing equations and that these are similar to fits using the analytical viscogravitational approximation. However, larger diameter tubes show a rate of penetration slower than expected using an equilibrium contact angle and the known value of liquid viscosity. To account for the slowness, an increase in viscosity by a factor (η/ρ)scaling is needed. We show full agreement with theory requires the ratio R/κ(-1) ∼ 0.1 or less, where κ(-1) is the capillary length. In addition, we propose an experimental method that enables the determination of the dynamic contact angle during imbibition, which gives values that agree with the literature values. We then report measurements of dynamic penetration into the tubes of R = 190 and 650 μm for a range of inclination angles to the horizontal, φ, from 5 to 90°. We show that capillary penetration can still be fitted using the viscogravitational solution, rather than the Bosanquet solution which describes imbibition without gravity, even for inclination angles as low as 10°. Moreover, at these low angles, the effect of the tube radius is found to diminish and this appears to relate to an effective capillary length, κ(-1)(φ) = (γLV/ρg sin φ)(1/2). PMID:26738739

  5. Penetration Testing Professional Ethics: a conceptual model and taxonomy

    Justin Pierce; Ashley Jones; Matthew Warren

    2006-01-01

    In an environment where commercial software is continually patched to correct security flaws, penetration testing can provide organisations with a realistic assessment of their security posture. Penetration testing uses the same principles as criminal hackers to penetrate corporate networks and thereby verify the presence of software vulnerabilities. Network administrators can use the results of a penetration test to correct flaws and improve overall security. The use of hacking techniques...

  6. Microbial Penetration through Nutrient-Saturated Berea Sandstone

    Jenneman, Gary E.; McInerney, Michael J.; Knapp, Roy M.

    1985-01-01

    Penetration times and penetration rates for a motile Bacillus strain growing in nutrient-saturated Berea sandstone cores were determined. The rate of penetration was essentially independent of permeabilities above 100 mdarcys and rapidly declined for permeabilities below 100 mdarcys. It was found that these penetration rates could be grouped into two statistically distinct classes consisting of rates for permeabilities above 100 mdarcys and rates for those below 100 mdarcys. Instantaneous pen...

  7. A SNARE-protein has opposing functions in penetration resistance and defence signalling pathways

    Zhang, Ziguo; Feechan, Angela; Pedersen, Carsten;

    2007-01-01

    Penetration resistance is often the first line of defence against fungal pathogens. Subsequently induced defences are mediated by the programmed cell death (PCD) reaction pathway and the salicylic acid (SA), jasmonic acid (JA) and ethylene (ET) signalling pathways. We previously demonstrated...

  8. Verifying Removal Of Red Penetrant Dye From Inspected Welds

    Torkelson, Jan R.

    1996-01-01

    Clean surface assured for more sensitive inspection with fluorescent penetrant dye. Simple procedure devised to ensure visible (red) penetrant dye used to identify flaws in welded surface completely removed from surface. Consists in applying reversible penetrant developer to surface to be inspected.

  9. Diffusion of radioactively tagged penetrants through rubbery polymers. II. Dependence on molecular length of penetrant

    The diffusion of radioactively tagged n-hexadecane, n-dotriacontane, and a polybutadiene oligomer with molecular weight 1600 has been studied in 12 rubbery polymers. Diffusion coefficients were obtained from the theory for the thin smear method: for n-hexadecane and for n-dotriacontane (with one exception), in the form appropriate for a completely miscible polymer-penetrant pair, and for the oligomer in the form appropriate for slow entry of the pentrant across the penetrant-polymer interface. For the four flexible linear penetrants, n-dodecane, n-hexadecane, n-dotriacontane, and oligomer, the ratios of diffusion coefficients (or translational friction coefficients) are nearly the same in every polymer. It is concluded that these penetrants travel with similar segmentwise motions, although that is not the case with bulkier, more rigid penetrants. For the three normal paraffins, the friction coefficient is approximately proportional to molecular weight, but that for the oligomer is smaller than would be predicted on this basis

  10. Radon penetration of concrete slab cracks, joints, pipe penetrations, and sealants.

    Nielson, K K; Rogers, V C; Holt, R B; Pugh, T D; Grondzik, W A; de Meijer, R J

    1997-10-01

    Radon movement through 12 test slabs with different cracks, pipe penetrations, cold joints, masonry blocks, sealants, and tensile stresses characterized the importance of these anomalous structural domains. Diffusive and advective radon transport were measured with steady-state air pressure differences controlled throughout the deltaP = 0 to 60 Pa range. Diffusion coefficients (deltaP = 0) initially averaged 6.5 x 10(-8) m2 s(-1) among nine slabs with only 8% standard deviation, but increased due to drying by 0.16% per day over a 2-y period to an average of 2.0 x 10(-7) m2 s(-1). An asphalt coating reduced diffusion sixfold but an acrylic surface sealant had no effect. Diffusion was 42 times higher in solid masonry blocks than in concrete and was not affected by small cracks. Advective transport (deltaP pipe penetrations, and caulked gaps, but was significant for cracks, disturbed pipe penetrations, cold joints, masonry blocks, and concrete under tensile stress. Crack areas calculated to be as small as 10(-7) m2 significantly increased radon advection. Algebraic expressions predict air velocity and effective crack width from enhanced radon transport and air pressures. Masonry blocks, open cracks, and slab cold joints enhance radon penetration but stressed slabs, undisturbed pipe penetrations, and sealed cracks may not. PMID:9314229

  11. Effects of Sizes and Conformations of Fish-Scale Collagen Peptides on Facial Skin Qualities and Transdermal Penetration Efficiency

    Huey-Jine Chai

    2010-01-01

    Full Text Available Fish-scale collagen peptides (FSCPs were prepared using a given combination of proteases to hydrolyze tilapia (Oreochromis sp. scales. FSCPs were determined to stimulate fibroblast cells proliferation and procollagen synthesis in a time- and dose-dependent manner. The transdermal penetration capabilities of the fractionationed FSCPs were evaluated using the Franz-type diffusion cell model. The heavier FSCPs, 3500 and 4500 Da, showed higher cumulative penetration capability as opposed to the lighter FSCPs, 2000 and 1300 Da. In addition, the heavier seemed to preserve favorable coiled structures comparing to the lighter that presents mainly as linear under confocal scanning laser microscopy. FSCPs, particularly the heavier, were concluded to efficiently penetrate stratum corneum to epidermis and dermis, activate fibroblasts, and accelerate collagen synthesis. The heavier outweighs the lighter in transdermal penetration likely as a result of preserving the given desired structure feature.

  12. Effects of sizes and conformations of fish-scale collagen peptides on facial skin qualities and transdermal penetration efficiency.

    Chai, Huey-Jine; Li, Jing-Hua; Huang, Han-Ning; Li, Tsung-Lin; Chan, Yi-Lin; Shiau, Chyuan-Yuan; Wu, Chang-Jer

    2010-01-01

    Fish-scale collagen peptides (FSCPs) were prepared using a given combination of proteases to hydrolyze tilapia (Oreochromis sp.) scales. FSCPs were determined to stimulate fibroblast cells proliferation and procollagen synthesis in a time- and dose-dependent manner. The transdermal penetration capabilities of the fractionationed FSCPs were evaluated using the Franz-type diffusion cell model. The heavier FSCPs, 3500 and 4500 Da, showed higher cumulative penetration capability as opposed to the lighter FSCPs, 2000 and 1300 Da. In addition, the heavier seemed to preserve favorable coiled structures comparing to the lighter that presents mainly as linear under confocal scanning laser microscopy. FSCPs, particularly the heavier, were concluded to efficiently penetrate stratum corneum to epidermis and dermis, activate fibroblasts, and accelerate collagen synthesis. The heavier outweighs the lighter in transdermal penetration likely as a result of preserving the given desired structure feature. PMID:20625414

  13. Strategies to increase drug penetration in solid tumors

    AndreLieber

    2013-07-01

    Full Text Available Despite significant improvement in modalities for treatment of cancer that led to a longer survival period, the death rate of patients with solid tumors has not changed during the last decades. Emerging studies have identified several physical barriers that limit the therapeutic efficacy of cancer therapeutic agents such as monoclonal antibodies, chemotherapeutic agents, antitumor immune cells, and gene therapeutics. Most solid tumors are of epithelial origin and, although malignant cells are de-differentiated, they maintain intercellular junctions, a key feature of epithelial cells, both in the primary tumor as well as in metastatic lesions. Furthermore, nests of malignant epithelial tumor cells are shielded by layers of extracellular matrix (ECM proteins (e.g. collagen, elastin, fibronectin, laminin whereby tumor vasculature rarely penetrates into the tumor nests. In this chapter, we will review potential strategies to modulate the ECM and epithelial junctions to enhance the intratumoral diffusion and/or to remove physical masking of target receptors on malignant cells. We will focus on peptides that bind to the junction protein desmoglein 2 (DSG2 and trigger intracellular signaling, resulting in the transient opening of intercellular junctions. Intravenous injection of these junction openers increased the efficacy and safety of therapies with monoclonal antibodies, chemotherapeutics, and T-cells in mouse tumor models and was safe in non-human primates. Furthermore, we will summarize approaches to transiently degrade ECM proteins or downregulate their expression. Among these approaches is the intratumoral expression of relaxin or decorin after adenovirus (Ad- or stem cell-mediated gene transfer. We will provide examples that relaxin- based approaches increase the antitumor efficacy of oncolytic viruses, monoclonal antibodies, and T-cells.

  14. Differential penetration of targeting agents into multicellular spheroids derived from human neuroblastoma

    The authors have used a multicellular tumour spheroid model for determination of the penetration of various targeting agents of potential use in the treatment of neuroblastoma. Both the radiopharmaceutical meta-iodobenzylguanidine (mIBG) and the β subunit of nerve growth factor (β-NGF) distributed uniformly throughout spheroids, though the latter was poorly concentrated relative to mIBG. In contrast, the anti-neuroectodermal monoclonal antibody. UJ13A bound only to peripheral cell layers with little accumulation in the spheroid interior. Differential penetration of targeting agents may influence the choice of conjugated radionuclide which is likely to achieve maximum therapeutic benefit

  15. Glove material, reservoir formation, and dose affect glove permeation and subsequent skin penetration

    Nielsen, Jesper Bo; Sørensen, Jens Ahm

    2012-01-01

    cell to evaluate overall penetration through glove and skin as well as the deposition in the different reservoirs. Benzoic acid was applied on latex or nitrile gloves placed on top of human skin. The amounts of chemical were quantified in the glove material, between glove and skin, within the skin, and...... in the receptor chamber. Both glove materials reduce total penetration of benzoic acid, but nitrile gloves offer a significantly better protection than latex gloves. This difference was less pronounced at the higher of the two concentrations of benzoic acid applied. Thus, glove types that offer...

  16. Development of fluorescent penetrant testing system for turbine rotor

    This paper outlines the development of fluorescent penetrant testing system for turbine rotors. At TEPCO's nuclear power plants, the inspection for turbine rotors implements dye penetrant testing, the inspection for turbine rotors using dye penetrant testing often needs many workers and work hours from our previous experience. We succeeded in the development of fluorescent penetrant testing system for turbine rotors, which can implement the inspection automatically and shortly. This paper also outlines various element test results which apply to this fluorescent penetrant testing system. (author)

  17. Penetration Testing Professional Ethics: a conceptual model and taxonomy

    Justin Pierce

    2006-05-01

    Full Text Available In an environment where commercial software is continually patched to correct security flaws, penetration testing can provide organisations with a realistic assessment of their security posture. Penetration testing uses the same principles as criminal hackers to penetrate corporate networks and thereby verify the presence of software vulnerabilities. Network administrators can use the results of a penetration test to correct flaws and improve overall security. The use of hacking techniques, however, raises several ethical questions that centre on the integrity of the tester to maintain professional distance and uphold the profession. This paper discusses the ethics of penetration testing and presents our conceptual model and revised taxonomy.

  18. A penetrative addictive for water infusion in coal seams

    2003-01-01

    The manufacturing process, characteristics, and application results of a rod-like penetrative additive (the penetrative rod)were discussed. The components and functions of the penetrative rod were studied carefully. A large number of orthogonal combinedtests were carried out and over 100 sample molds were made. Ultimately the components were decided after careful selection amongthese molds, mainly including hygroscopic major components and auxiliary material. The results of on-site practical applicationshow that such an addictive can increase the water penetrative ability effectively and has a remarkable effect on preventing dust pro-duction during coal seam excavation. The penetrating radius, the infusing velocity and the dust-preventive effect were systematicallystudied.

  19. Suicide bomb attack causing penetrating craniocerebral injury

    Manzar Hussain; Muhammad Ehsan Bari

    2013-01-01

    Penetrating cerebral injuries caused by foreign bodies are rare in civilian neurosurgical trauma,although there are various reports of blast or gunshot injuries in warfare due to multiple foreign bodies like pellets and nails.In our case,a 30-year-old man presented to neurosurgery clinic with signs and symptoms of right-sided weakness after suicide bomb attack.The skull X-ray showed a single intracranial nail.Small craniotomy was done and the nail was removed with caution to avoid injury to surrounding normal brain tissue.At 6 months' follow-up his right-sided power improved to against gravity.

  20. Penetration of ceftibuten into middle ear fluid.

    Lin, C.; Kumari, P; Perrotta, R J; Reidenberg, B E

    1996-01-01

    The penetration of ceftibuten, an extended-spectrum oral cephalosporin, into middle ear fluid (MEF) was evaluated in pediatric patients during a course of daily oral doses of 9 mg/kg of body weight for 10 days. Plasma and MEF collected at 2, 4, 6, or 12 h after at least 3 days of dosing were analyzed for ceftibuten by a high-pressure liquid chromatography method, and the data were used to calculate pharmacokinetic parameters. Plasma and MEF had almost identical maximum concentrations (Cmax) o...

  1. Premium Efficiency Motors And Market Penetration Policy

    Benhaddadi, Mohamed; Olivier, Guy

    2010-09-15

    This paper illustrates the induced enormous energy saving potential, permitted by using high-efficiency motors. Furthermore, the most important barriers to larger high-efficiency motors utilization are identified, and some incentives recommendations are given to overcome identified impediments. The authors consider that there is a strong case to enhance incentives policies for larger market penetration. The US Energy Policy Act and the Canadian Energy Efficient Act have lead to North American leadership on motor efficiency implementation. North America is not on the leading edge for energy saving and conservation. Motor efficiency is an exception that should be at least maintained.

  2. Kali Linux assuring security by penetration testing

    Ali, Shakeel; Allen, Lee

    2014-01-01

    Written as an interactive tutorial, this book covers the core of Kali Linux with real-world examples and step-by-step instructions to provide professional guidelines and recommendations for you. The book is designed in a simple and intuitive manner that allows you to explore the whole Kali Linux testing process or study parts of it individually.If you are an IT security professional who has a basic knowledge of Unix/Linux operating systems, including an awareness of information security factors, and want to use Kali Linux for penetration testing, then this book is for you.

  3. Cephradine (Velosef) penetration of mandibular bone.

    Middlehurst, R J; Rood, J P

    1990-04-01

    The concentration of cephradine in serum and mandibular bone was assayed in 28 patients undergoing 3rd molar surgery following a single 1 g intravenous injection. Serum and cortical bone samples taken simultaneously, contained mean cephradine concentrations of 42.11 micrograms/ml and 2.61 micrograms/g respectively. These results, when compared with those reported for other bony sites including the femoral head and knee, show a reduced bone penetration with a bone-to-serum ratio of approximately 0.06:1. PMID:2111359

  4. Mastering Kali Linux for advanced penetration testing

    Beggs, Robert W

    2014-01-01

    This book provides an overview of the kill chain approach to penetration testing, and then focuses on using Kali Linux to provide examples of how this methodology is applied in the real world. After describing the underlying concepts, step-by-step examples are provided that use selected tools to demonstrate the techniques. If you are an IT professional or a security consultant who wants to maximize the success of your network testing using some of the advanced features of Kali Linux, then this book is for you. This book will teach you how to become an expert in the pre-engagement, management,

  5. Hacking with Kali practical penetration testing techniques

    Broad, James

    2013-01-01

    Hacking with Kali introduces you the most current distribution of the de facto standard tool for Linux pen testing. Starting with use of the Kali live CD and progressing through installation on hard drives, thumb drives and SD cards, author James Broad walks you through creating a custom version of the Kali live distribution. You'll learn how to configure networking components, storage devices and system services such as DHCP and web services. Once you're familiar with the basic components of the software, you'll learn how to use Kali through the phases of the penetration testing lifecycle

  6. Penetrating the markets: biomass and commercial distribution

    Although biomass accounts for a significant proportion of renewable energy in Europe, its market penetration could be increased if certain barriers can be surmounted. Some of those barriers are identified and suggestions made as to how they may be overcome through improved 'distribution' in various sectors. To integrate biomass into the electricity distribution system, the commercial distribution of liquid biofuels, and in the commercial distribution of biomass in the heat sector, certain rewards and penalties could be introduced and these are discussed. The low temperature heat market is seen as very important for the further development of bioenergy in Europe. (UK)

  7. Opportunities for high wind energy penetration

    Tande, J.O.; Hansen, J.C.

    1997-01-01

    Wind power is today a mature technology, which at windy locations, is economically competitive to conventional power generation technologies. This and growing global environmental concerns have led governments to encourage and plan for wind energy development, a typical aim being 10% of electricity...... analyses conclude that expanding to even above 15% wind energy penetration in the Cape Verde power systems is economical. Worldwide, numerous locations with favorable wind conditions and power systems similar to the Capeverdean provide good opportunities for installing wind farms and achieving high wind...

  8. Variant haploinsufficiency and phenotypic non-penetrance in PRPF31-associated retinitis pigmentosa.

    Rose, A M; Bhattacharya, S S

    2016-08-01

    Retinitis pigmentosa (RP) is a genetically heterogenous group of inherited disorders, characterized by death of the retinal photoreceptor cells, leading to progressive visual impairment. One form of RP is caused by mutations in the ubiquitously expressed splicing factor, PRPF31, this form being known as RP11. An intriguing feature of RP11 is the presence of non-penetrance, which has been observed in the majority of PRPF31 mutation-carrying families. In contrast to variable expressivity, which is highly pervasive, true non-penetrance is a very rare phenomenon in Mendelian disorders. In this article, the molecular mechanisms underlying phenotypic non-penetrance in RP11 are explored. It is an elegant example of how our understanding of monogenic disorders has evolved from studying only the disease gene, to considering a mutation on the genetic background of the individual - the logical evolution in this genomic era. PMID:26853529

  9. Independent regulation of reovirus membrane penetration and apoptosis by the mu1 phi domain.

    Pranav Danthi

    2008-12-01

    Full Text Available Apoptosis plays an important role in the pathogenesis of reovirus encephalitis. Reovirus outer-capsid protein mu1, which functions to penetrate host cell membranes during viral entry, is the primary regulator of apoptosis following reovirus infection. Ectopic expression of full-length and truncated forms of mu1 indicates that the mu1 phi domain is sufficient to elicit a cell death response. To evaluate the contribution of the mu1 phi domain to the induction of apoptosis following reovirus infection, phi mutant viruses were generated by reverse genetics and analyzed for the capacity to penetrate cell membranes and elicit apoptosis. We found that mutations in phi diminish reovirus membrane penetration efficiency by preventing conformational changes that lead to generation of key reovirus entry intermediates. Independent of effects on membrane penetration, amino acid substitutions in phi affect the apoptotic potential of reovirus, suggesting that phi initiates apoptosis subsequent to cytosolic delivery. In comparison to wild-type virus, apoptosis-defective phi mutant viruses display diminished neurovirulence following intracranial inoculation of newborn mice. These results indicate that the phi domain of mu1 plays an important regulatory role in reovirus-induced apoptosis and disease.

  10. Penetrating eye injuries from writing instruments

    Kelly SP

    2011-12-01

    Full Text Available Simon P Kelly, Graham MB ReevesThe Royal Bolton Hospital, Bolton, UKPurpose: To consider the potential for ocular injury from writing implements by presenting four such cases, and to consider the incidence of such eye injuries from analysis of a national trauma database.Methods: The Home and Leisure Accident Surveillance System was searched for records of eye injuries from writing instruments to provide UK estimates of such injuries. Four patients with ocular penetrating injury from pens or pencils (especially when caused by children, and examined by the authors, are described which illustrate mechanisms of injury.Results: It is estimated that around 748 ocular pen injuries and 892 ocular pencil injuries of undetermined severity occurred annually in the UK during the database surveillance period 2000–2002. No eye injuries from swords, including toy swords and fencing foils, were reported.Conclusion: Ocular perforation sometimes occur from writing instruments that are thrown in the community, especially by children. Implications for policy and prevention are discussed. Non-specialists should have a low threshold for referring patients with eye injuries if suspicious of ocular penetration, even where caused by everyday objects, such as writing instruments.Keywords: eye injury, eye, children, mechanism, writing instruments, prevention

  11. More on the penetration of yawed rods

    Rosenberg, Z.; Dekel, E.; Ashuach, Y.

    2006-08-01

    One of the most complex processes, in the field of terminal ballistics, is that of yawed impact of long rods. In spite of many experimental observations, and some analytical modeling, a clear picture of this issue is still lacking. In order to gain some insight into the operating mechanisms, we developed a simple engineering model which considers the yawed rod as a series of small disks. We then define the effective length and diameter of the rod by considering those disks which are going to hit the initial crater which is opened by the impact. We also performed a series of 3D numerical simulations with various L/D tungsten alloy rods impacting a steel target, at yaws in the full range of 0-90^circ. We analyzed the results of these simulations in terms of the normalized penetration (P/D), where D is the rod diameter, and looked for systematic trends in the results for the various rods. The agreement between our model predictions and both experimental data and simulation results is quite good. Based on this agreement we can highlight some new features of the penetration process of yawed rods.

  12. High Penetration Photovoltaic Case Study Report

    Bank, J.; Mather, B.; Keller, J.; Coddington, M.

    2013-01-01

    Technical concerns with integrating higher penetrations of photovoltaic (PV) systems include grid stability, voltage regulation, power quality (voltage rise, sags, flicker, and frequency fluctuations), and protection and coordination. The current utility grid was designed to accommodate power flows from the central generation source to the transmission system and eventually to the distribution feeders. At the distribution level, the system was designed to carry power from the substation toward the load. Renewable distributed generation, particularly solar PV, provides power at the distribution level challenging this classical paradigm. As these resources become more commonplace the nature of the distribution network and its operation is changing to handle power flow in both directions. This report is focused on large PV installations in which penetration is significantly greater than 15% of maximum daytime feeder load. These case studies are intended to demonstrate success stories with integration of large PV plants at the distribution level as well as some of the solutions used by the utility to ensure safe, reliable operation of both the PV system and the distribution network.

  13. Simulation of Hypervelocity Penetration in Limestone

    Antoun, T; Glenn, L; Walton, O; Goldstein, P; Lomov, I; Liu, B

    2005-05-31

    A parameter study was performed to examine the (shock) damage obtained with long-rod and spherical mono-material penetrators impacting two varieties of limestone. In all cases, the impacts were assumed to be normal to the plane of the rock and at zero angle of attack (in the case of the rods). Impact velocities ranged to 15 km/s but most calculations were performed at 4 and 6 km/s and the penetrator mass was fixed at 1000 kg. For unlined underground structures, incipient damage was defined to occur when the peak stress, {sigma}{sub pk}, exceeds 1 kb (100 MPa) and the applied impulse per unit area, I{sub pk}, exceeds 1 ktap (1 kb-{micro}s). Severe damage was assumed to occur when {sigma}{sub pk} exceeds 1 kb and I{sub pk} exceeds 1000 ktaps. Using the latter definition it was found that severe damage in hard, non-porous limestone with spherical impactors extended to a depth of 9 m on-axis for an impact velocity of 4 km/s and 12 m at 6 km/s. Cylinders with length-to-diameter (L/D) ratio of 8.75 achieved depth to severe damage of 23 m and 40 m, respectively under the same conditions. For a limestone medium with 2% initial gas porosity, the latter numbers were reduced to 12 m and 18 m.

  14. Penetration of projectiles into granular targets

    Ruiz-Suárez, J. C.

    2013-06-01

    Energetic collisions of subatomic particles with fixed or moving targets have been very valuable to penetrate into the mysteries of nature. But the mysteries are quite intriguing when projectiles and targets are macroscopically immense. We know that countless debris wandering in space impacted (and still do) large asteroids, moons and planets; and that millions of craters on their surfaces are traces of such collisions. By classifying and studying the morphology of such craters, geologists and astrophysicists obtain important clues to understand the origin and evolution of the Solar System. This review surveys knowledge about crater phenomena in the planetary science context, avoiding detailed descriptions already found in excellent papers on the subject. Then, it examines the most important results reported in the literature related to impact and penetration phenomena in granular targets obtained by doing simple experiments. The main goal is to discern whether both schools, one that takes into account the right ingredients (planetary bodies and very high energies) but cannot physically reproduce the collisions, and the other that easily carries out the collisions but uses laboratory ingredients (small projectiles and low energies), can arrive at a synergistic intersection point.

  15. Energetic particle penetrations into the inner magnetosphere

    Data from Explorer 45 (S3- A) instruments have revealed characteristics of magnetospheric storm or substorm time energetic particle enhancements in the inner magnetosphere (L< or approx. =5). The properties of the ion 'nose' structure in the dusk hemisphere are examined in detail. A statistical study of the local time dependence of noses places the highest probability of occurrence around 2000 MLT, but hey can be observed even near the noon meridian. It also appears that most noses are not isolated events but will appear on successive passes. A geoelectric field enhancement corresponding to a minimum value of AE of about 205 γ seems to be required to convect the particles within the apogee of Explorer 45. The dynamical behavior of the nose characteristics observed along successive orbits is then explained quantitatively by the time-dependent convection theory in a Volland-Stern type geoelectric field (γ=2). These calculations of adiabatic charged particle motions are also applied to expalin the energy spectra and dispersion in penetration distances for both electrons and ions observed in the postmidnight to morning hours. Finally, useful descriptions are given of the dispersion properties of particles penetrating the inter magnetosphere at all local times as a function of time after a sudden enhancement of the geoelectric field

  16. Penetration through a wall: Is it reality?

    Ivlev, B

    2011-01-01

    A tennis ball is not expected to penetrate through a brick wall since a motion under a barrier is impossible in classical mechanics. With quantum effects a motion of a particle through a barrier is allowed due to quantum tunneling. According to usual theories of tunneling, the particle density decays inside a classical barrier resulting in an extremely slow pentration process. However, there are no general laws forbidding fast motion through classical barriers. The problem addressed is investigation of unusual features o quantum tunneling through a classic static barrier which is at least two-dimensional. Here we show that penetration through such barrier can be not slow. When the barrier satisfies the certain conditions, a regime of quantum lens is possible with formation of caustics. De Broglie waves are reflected from the caustics, interfere, and result in a not small flux from under the barrier. This strongly contrasts to the usual scenario with a decaying under-barrier density. We construct a particular ...

  17. Ground penetrating radar for asparagus detection

    Seyfried, Daniel; Schoebel, Joerg

    2016-03-01

    Ground penetrating radar is a promising technique for detection of buried objects. Recently, radar has more and more been identified to provide benefits for a plurality of applications, where it can increase efficiency of operation. One of these fields is the industrial automatic harvesting process of asparagus, which is performed so far by cutting the soil ridge at a certain height including all the asparagus spears and subsequently sieving the latter out of the soil. However, the height where the soil is cut is a critical parameter, since a wrong value leads to either damage of the roots of the asparagus plants or to a reduced crop yield as a consequence of too much biomass remaining in the soil. In this paper we present a new approach which utilizes ground penetrating radar for non-invasive sensing in order to obtain information on the optimal height for cutting the soil. Hence, asparagus spears of maximal length can be obtained, while keeping the roots at the same time undamaged. We describe our radar system as well as the subsequent digital signal processing steps utilized for extracting the information required from the recorded radar data, which then can be fed into some harvesting unit for setting up the optimal cutting height.

  18. Visual outcome in patients undergoing penetrating keratoplasty

    Gurpal Singh

    2015-01-01

    Methods: Thirty patients were selected from department of ophthalmology, Guru Gobind Singh medical college and hospital, Faridkot for penetrating keratoplasty. Results: Visual acuity of 6/12 was seen in 1 case, 6/18 in 4 cases, 6/36 in 5 cases, 6/60 in 5 cases, 3/60 in 4 cases, hand movements in 4 cases, PL+PR+ in 2 cases and no perception of light in 2 cases. Final vision at 6 months of follow up was >6/60 in 10 cases (33.33%. 5 cases (16.67% had vision between 6/60-4/60. 13 cases (43.33% had vision of 3/60 or less. While in 2 cases (6.67% there was no vision at the end of follow up. Conclusion: Penetrating keratoplasty helps patients in regaining vision which makes them able to move independently. Although in our study visual outcome of more than 3/60 was present in only 50% cases. [Int J Res Med Sci 2015; 3(1.000: 244-249

  19. Bone marrow-specific knock-in of a non-activatable Ikkα kinase mutant influences haematopoiesis but not atherosclerosis in Apoe-deficient mice.

    Pathricia V Tilstam

    Full Text Available BACKGROUND: The Ikkα kinase, a subunit of the NF-κB-activating IKK complex, has emerged as an important regulator of inflammatory gene expression. However, the role of Ikkα-mediated phosphorylation in haematopoiesis and atherogenesis remains unexplored. In this study, we investigated the effect of a bone marrow (BM-specific activation-resistant Ikkα mutant knock-in on haematopoiesis and atherosclerosis in mice. METHODS AND RESULTS: Apolipoprotein E (Apoe-deficient mice were transplanted with BM carrying an activation-resistant Ikkα gene (Ikkα(AA/AAApoe(-/- or with Ikkα(+/+Apoe(-/- BM as control and were fed a high-cholesterol diet for 8 or 13 weeks. Interestingly, haematopoietic profiling by flow cytometry revealed a significant decrease in B-cells, regulatory T-cells and effector memory T-cells in Ikkα(AA/AAApoe(-/- BM-chimeras, whereas the naive T-cell population was increased. Surprisingly, no differences were observed in the size, stage or cellular composition of atherosclerotic lesions in the aorta and aortic root of Ikkα(AA/AAApoe(-/- vs Ikkα(+/+Apoe(-/- BM-transplanted mice, as shown by histological and immunofluorescent stainings. Necrotic core sizes, apoptosis, and intracellular lipid deposits in aortic root lesions were unaltered. In vitro, BM-derived macrophages from Ikkα(AA/AAApoe(-/- vs Ikkα(+/+Apoe(-/- mice did not show significant differences in the uptake of oxidized low-density lipoproteins (oxLDL, and, with the exception of Il-12, the secretion of inflammatory proteins in conditions of Tnf-α or oxLDL stimulation was not significantly altered. Furthermore, serum levels of inflammatory proteins as measured with a cytokine bead array were comparable. CONCLUSION: Our data reveal an important and previously unrecognized role of haematopoietic Ikkα kinase activation in the homeostasis of B-cells and regulatory T-cells. However, transplantation of Ikkα(AA mutant BM did not affect atherosclerosis in Apoe(-/- mice. This

  20. Electromagnetic modelling of Ground Penetrating Radar responses to complex targets

    Pajewski, Lara; Giannopoulos, Antonis

    2014-05-01

    This work deals with the electromagnetic modelling of composite structures for Ground Penetrating Radar (GPR) applications. It was developed within the Short-Term Scientific Mission ECOST-STSM-TU1208-211013-035660, funded by COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar". The Authors define a set of test concrete structures, hereinafter called cells. The size of each cell is 60 x 100 x 18 cm and the content varies with growing complexity, from a simple cell with few rebars of different diameters embedded in concrete at increasing depths, to a final cell with a quite complicated pattern, including a layer of tendons between two overlying meshes of rebars. Other cells, of intermediate complexity, contain pvc ducts (air filled or hosting rebars), steel objects commonly used in civil engineering (as a pipe, an angle bar, a box section and an u-channel), as well as void and honeycombing defects. One of the cells has a steel mesh embedded in it, overlying two rebars placed diagonally across the comers of the structure. Two cells include a couple of rebars bent into a right angle and placed on top of each other, with a square/round circle lying at the base of the concrete slab. Inspiration for some of these cells is taken from the very interesting experimental work presented in Ref. [1]. For each cell, a subset of models with growing complexity is defined, starting from a simple representation of the cell and ending with a more realistic one. In particular, the model's complexity increases from the geometrical point of view, as well as in terms of how the constitutive parameters of involved media and GPR antennas are described. Some cells can be simulated in both two and three dimensions; the concrete slab can be approximated as a finite-thickness layer having infinite extension on the transverse plane, thus neglecting how edges affect radargrams, or else its finite size can be fully taken into account. The permittivity of concrete can be

  1. Diffusion of radioactively tagged penetrants through rubbery polymers. I. Penetrants with very low solubility

    The diffusion of radioactively tagged n-hexadecane, 1,7-heptanediol, and ethylene glycol has been studied in one polar and six nonpolar rubbery polymers. The penetrant-polymer pairs included some in which the two components were miscible in all proportions and some in which they were nearly incompatible (solubility of penetrant in polymer of the order of 1 percent). The theory for the thin smear method for measuring the diffusion coefficient was evaluated for incompatible pairs with two cases: case 2, when the rate-limiting step is diffusion through the polymer; and case 3, when the rate-limiting step is entry into the polymer across the penetrant-polymer interface. They are easily distinguished experimentally from each other and from case 1, which refers to completely miscible pairs. The diffusion coefficients, when compared in four hydrocarbon rubbers, of n-hexadecane and 1,7-heptanediol were similar in magnitude even though in each rubber the hexadecane was soluble in all proportions and the diol only very slightly. The diffusion coefficient of ethylene glycol, despite its extreme thermodynamic incompatibility, appeared to be somewhat larger than those of the other penetrants

  2. Intraductal Papillary-Mucinous Neoplasm of the Pancreas Penetrating to the Stomach and the Common Bile Duct

    Norihiro Goto

    2012-01-01

    Full Text Available Context Intraductal papillary mucinous neoplasm (IPMN of the pancreas occasionally penetrates to others organs. We present a case of IPMN penetrating to the stomach and the common bile duct. Case report A 75-year-old man was admitted to the hospital because of epigastric pain. Computed tomography (CT showed a papillary tumor protruding into the markedly dilated main pancreatic duct and splenic vein obstruction. The tumor was diagnosed as IPMN arising in the main duct, but he rejected surgery and he was followed without treatment. One year later, gastroduodenoscopy revealed gastropancreatic fistula and we were able to pass an endoscope through the fistula and directly examine the lumen of the main pancreatic duct and the papillary tumor adjacent to the fistula. Absence of malignant cells on histopathology suggested mechanical penetration rather than invasive penetration. CT showed splenic vein reperfusion due to decreased inner pressure of the main pancreatic duct. Two and a half years later, CT revealed biliopancreatic fistula formation. Endoscope biliary drainage was performed but failed. Despite jaundice, he is still ambulatory and seen in the clinic three years after the first admission. Conclusions We have experienced a case of IPMN penetrating to the stomach and the common bile duct that has taken a slow course. It represents the importance of distinguishing mechanical penetration from invasive penetration as well as mechanical splenic vein obstruction from splenic vein invasion.

  3. Penetration resistance of reinforced concrete containment structures

    Containment structures not only provide a leak tight barrier, but also play a role in ensuring that the structures can withstand the impact load from projectile impacts or internal plant accidents. In assessing the containment structures of nuclear power plants, predicting the characteristics of impact resistance in relation to design and safety considerations is relevant. This investigation proposes a simple but effective method of performing numerical analysis on perforation resistance of reinforced concrete containment structures. In this work, normal and oblique impacting is considered to examine the residual velocity and impact phenomena of an ogive-nose steel projectile with various impact velocities against a reinforced concrete slab. Additionally, a phase diagram is devised to describe the ballistic terminal phenomena of projectile and target. This model could assess the resistance to penetration to results in the optimum design of the containment structures in nuclear power plants

  4. Results of Thoracotomy in Penetrating Chest Trauma

    Mahmood Aghaei-Afshar

    2012-04-01

    Full Text Available Background: Thoracotomy is a surgical procedure to access the chest components, which is often performed after severe bleeding caused by heart damage, lung laceration and other similar injuries.Materials and Methods: This is a cross-sectional study which was conducted on all patients with penetrating chest trauma during April 2000 to October 2008.Results: In 5% of cases, thoracotomy was used for treatment in which severe bleeding was the main surgical indication. It was the most common finding followed by lung laceration thoracotomy.Conclusion: Most urban injuries are treatable by chest tube. About 3 to 10 percent of cases may require a thoracotomy in which severe bleeding is the most common indication of surgery.

  5. Obstacle penetrating dynamic radar imaging system

    Romero, Carlos E.; Zumstein, James E.; Chang, John T.; Leach, Jr.. Richard R.

    2006-12-12

    An obstacle penetrating dynamic radar imaging system for the detection, tracking, and imaging of an individual, animal, or object comprising a multiplicity of low power ultra wideband radar units that produce a set of return radar signals from the individual, animal, or object, and a processing system for said set of return radar signals for detection, tracking, and imaging of the individual, animal, or object. The system provides a radar video system for detecting and tracking an individual, animal, or object by producing a set of return radar signals from the individual, animal, or object with a multiplicity of low power ultra wideband radar units, and processing said set of return radar signals for detecting and tracking of the individual, animal, or object.

  6. Civil engineering applications of ground penetrating radar

    Pajewski, Lara

    2015-01-01

    This book, based on Transport and Urban Development COST Action TU1208, presents the most advanced applications of ground penetrating radar (GPR) in a civil engineering context, with documentation of instrumentation, methods, and results. It explains clearly how GPR can be employed for the surveying of critical transport infrastructure, such as roads, pavements, bridges, and tunnels, and for the sensing and mapping of underground utilities and voids. Detailed attention is also devoted to use of GPR in the inspection of geological structures and of construction materials and structures, including reinforced concrete, steel reinforcing bars, and pre/post-tensioned stressing ducts. Advanced methods for solution of electromagnetic scattering problems and new data processing techniques are also presented. Readers will come to appreciate that GPR is a safe, advanced, nondestructive, and noninvasive imaging technique that can be effectively used for the inspection of composite structures and the performance of diagn...

  7. Cephalic Tetanus from Penetrating Orbital Wound

    Eloïse Guyennet

    2009-01-01

    Full Text Available Tetanus is a neurologic disorder caused by tetanospasmin, a protein toxin elaborated by Clostridium tetani. Cephalic tetanus is a localized form of the disease causing trismus and dysfunction of cranial nerves. We report the case of a man who presented with facial trauma, complete ophthalmoplegia, exophthalmos, areactive mydriasis, and periorbital hematoma. An orbital CT revealed air bubbles in the right orbital apex. The patient was given a tetanus toxoid booster and antibiotherapy. After extraction of a wooden foreign body, the patient developed right facial nerve palsy, disorders of swallowing, contralateral III cranial nerve palsy, and trismus. Only one case of cephalic tetanus from penetrating orbital wound has been reported in literature 20 years ago. When a patient presents with an orbital wound with ophthalmoplegia and signs of anaerobic infection, cephalic tetanus should be ruled out.

  8. Fungal penetration of defensive barriers of plants

    Plants, like all other living organisms, are packaged in an outer envelope which acts as the barrier between the plant and its environment. The outer envelop of the aerial parts of plants (the cuticle) consists of a polyester, called cutin, which is embedded in a soluble mixture of relatively nonpolar lipids, collectively called waxes. The insoluble structural polymer, cutin, constitutes the major barrier to invasion by pathogenic microbes. The underground parts and aerially formed periderms and barks are protected by a different type of insoluble polymeric material called suberin. This polymer is also associated with waxes which make this layer resistant to diffusion. It has been known for a long period of time that these protective barriers are breached by pathogenic fungi. In this chapter, the nature of these barriers and how pathogenic fungi penetrate such barriers during infection are discussed. Topics include the composition, location and ultrastructure of cutin and suberin; and the isolation and properties of cutinase

  9. Delineate subsurface structures with ground penetrating radar

    High resolution ground penetrating radar (GPR) surveys were conducted at the Savannah River Site in South Carolina in late 1991 to demonstrate the radar techniques in imaging shallow utility and soil structures. Targets of interest at two selected sites, designated as H- and D-areas, were a buried backfilled trench, buried drums, geologic stratas, and water table. Multiple offset 2-D and single offset 3-D survey methods were used to acquire high resolution radar data. This digital data was processed using standard seismic processing software to enhance signal quality and improve resolution. Finally, using a graphics workstation, the 3D data was interpreted. In addition, a small 3D survey was acquired in The Woodlands, Texas, with very dense spatial sampling. This data set adequately demonstrated the potential of this technology in imaging subsurface features

  10. Computational benchmark for deep penetration in iron

    A benchmark for calculation of neutron transport through iron is now available based upon a rigorous Monte Carlo treatment of ENDF/B-IV and ENDF/B-V cross sections. The currents, flux, and dose (from monoenergetic 2, 14, and 40 MeV sources) have been tabulated at various distances through the slab using a standard energy group structure. This tabulation is available in a Los Alamos Scientific Laboratory report. The benchmark is simple to model and should be useful for verifying the adequacy of one-dimensional transport codes and multigroup libraries for iron. This benchmark also provides useful insights regarding neutron penetration through iron and displays differences in fluxes calculated with ENDF/B-IV and ENDF/B-V data bases

  11. Penetrating injuries to the thoracic great vessels.

    Demetriades, D

    1997-01-01

    Penetrating injuries to the thoracic great vessels have been diagnosed with increased frequency because of the escalating use of automatic weapons. The overall incidence is 5.3% of gunshot wounds and 2% of stab wounds to the chest. Most of these patients reach the hospital dead or in severe shock. The overall mortality of thoracic aortic injuries is higher than 90% and in subclavian vascular injuries higher than 65%. In the prehospital phase, the "scoop and run" policy offers the best chances of survival and no attempts should be made for any form of stabilization. Investigations should be reserved only for fairly stable patients. Angiography, color flow Doppler, and transesophageal echocardiography may be useful in selected cases. Patients in cardiac arrest or imminent cardiac arrest may benefit from an emergency room thoracotomy. The surgical approach to specific thoracic great vessels is described. PMID:9271743

  12. Two-step LASIK after penetrating keratoplasty

    Aris N Kollias

    2009-10-01

    Full Text Available Aris N Kollias, Markus M Schaumberger, Thomas C Kreutzer, Michael W Ulbig, Carlo A LackerbauerUniversity Eye Hospital, Ludwig-Maximilians University, Munich, GermanyPurpose: The point of interest of this retrospective case review is to study refractive changes caused by the hinged lamellar keratotomy and the refractive outcome after laser ablation in a second step within the scope of laser in situ keratomileusis (LASIK in patients with penetrating keratoplasty.Methods: Data from eight patients obtained before lamellar keratotomy, before laser ablation, and three months later were evaluated. Keratotomies were performed with the Moria® LSK one and the Amadeus® 2 microkeratome, laser ablation was performed with the Schwind® Keratome I and the Wavelight® Allegretto WaveEyeQ. Results: Uncorrected visual acuity (UCVA improved significantly from 1 [logMar] to 0.4 [logMar] at the last visit. Median gain of UCVA was 7.38 ± 2.96 Snellen lines. Best spectacle-corrected visual acuity did not change significantly. Preoperative manifest refraction spherical equivalent decreased from -4.02 ± 4.77 diopters (D to -1.11 ± 2.45 D after laser ablation. Mean preoperative manifest astigmatism was -7.27 ± 3.65 D, after lamellar keratotomy -6.72 ± 3.68 D, and after laser ablation -2.08 ± 1.80 D. Manifest astigmatism did not change significantly after the keratotomy.Conclusions: Lamellar keratotomy causes biomechanical changes to the cornea. We favor a two-step LASIK in penetrating keratoplasty patients in order to improve precision and predictability of the refractive outcome.Keywords: two-step, cornea, LASIK, keratoplasty, astigmatism

  13. The full penetration hole as a stochastic process: controlling penetration depth in keyhole laser-welding processes

    Blug, A.; Abt, F.; Nicolosi, L.; Heider, A.; Weber, R.; Carl, D.; Höfler, H.; Tetzlaff, R.

    2012-07-01

    Although laser-welding processes are frequently used in industrial production the quality control of these processes is not satisfactory yet. Until recently, the "full penetration hole" was presumed as an image feature which appears when the keyhole opens at the bottom of the work piece. Therefore it was used as an indicator for full penetration only. We used a novel camera based on "cellular neural networks" which enables measurements at frame rates up to 14 kHz. The results show that the occurrence of the full penetration hole can be described as a stochastic process. The probability to observe it increases near the full penetration state. In overlap joints, a very similar image feature appears when the penetration depth reaches the gap between the sheets. This stochastic process is exploited by a closed-loop system which controls penetration depth near the bottom of the work piece ("full penetration") or near the gap in overlap joints ("partial penetration"). It guides the welding process at the minimum laser power necessary for the required penetration depth. As a result, defects like spatters are reduced considerably and the penetration depth becomes independent of process drifts such as feeding rate or pollution on protection glasses.

  14. Spatial resolution of MFM measurements of penetration depth

    Spanton, Eric; Luan, Lan; Kirtley, John; Moler, Kathryn

    2012-02-01

    The penetration depth and its temperature dependence are key ways to characterize superconductors. Measurements of the local Meissner response of a superconductor can determine the local penetration depth. To quantify the spatial resolution of such measurements, we seek to characterize the point spread function of magnetic force microscope (MFM) measurements of the penetration depth both numerically and experimentally. Modeling various geometries of MFM tips (pyramid, dipole, and long thin cylinder) in the presence of various geometries of spatial variation in the penetration depth (point variation, columnar defects, and planar defects or twin boundaries) shows the importance of the MFM tip geometry to achieving both excellent spatial resolution and quantitatively interpretable results. We compare these models to experimental data on pnictides and cuprates to set upper limits on the sub-micron-scale variation of the penetration depth. These results demonstrate both the feasibility and the technical challenges of submicron penetration depth mapping.

  15. Penetration, distribution and kinetics of 2,3,7,8-tetrachlorodibenzo-p-dioxin in human skin in vitro

    The in vitro penetration of 3H-labeled 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) into human cadaver skin was studied at concentrations of 65 and 6.5 ng TCDD per cm2 of skin surface. Vehicles used were acetone to simulate exposure to TCDD as a dry material, and mineral oil to simulate exposure to TCDD in an oily medium. Penetration was performed for 30, 100, 300, and 1000 min in improved Franz cells. Skin was used either intact, or with stripped horny layer. Skin was sectioned along its natural layers and radioactivity determined in epidermis and dermis. TCDD did not readily penetrate into human skin in vitro. The vehicle of exposure to TCDD played an important role in dermal penetration. The rapidly evaporating acetone allowed TCDD to penetrate deeply into the loose surface lamellae of the horny layer, but then appeared to be poorly available for further penetration. Mineral oil as the vehicle showed its penetration even more. The stratum corneum acted as a protective barrier, as its removal increased the amount of TCDD absorbed into layers of the skin. Hourly rates of adsorption of TCDD per unit area of skin were calculated in two ways: a worst case scenario where TCDD absorbed into any layer of skin including the stratum corneum and a physiological approach where only that amount of TCDD was considered absorbed which had penetrated beyond the epidermis. Under worst case scenario conditions the stratum corneum appeared to mediate dermal absorption of TCDD. This was, however, not the case with the physiological approach. There was a consistent relationship between concentration of TCDD applied and concentration of TCDD found in skin. Also, a clear-cut correlation was found between the amount of TCDD that penetrated and the time of exposure. (orig./MG)

  16. Penetration of tamoxifen citrate loaded ethosomes and liposomes across human skin: a comparative study with confocal laser scanning microscopy.

    Sarwa, Khomendra K; Suresh, Preeti K; Rudrapal, Mithun; Verma, Vinod K

    2014-01-01

    In the present study, ethosomal and liposomal formulations containing tamoxifen citrate were prepared and evaluated for their penetration properties in human cadaver skin using Franz diffusion cell and confocal laser scanning microscope (CLSM). The results clearly revealed that ethosomal vesicles showed a better drug permeation profile than that of liposomal vesicles. In addition, low fluorescence intensity in CLSM was recorded with liposomes as compared to ethosomes, indicating lower cumulative amount of drug permeation from liposomal vesicles. Furthermore, CLSM showed uniform fluorescence intensity across the entire depth of skin in ethosomal treatment, indicating high penetrability of ethosomal vesicles through human cadaver skin. In contrast, low penetrability of conventional liposomal vesicles was recorded as penetration was limited to the 7(th) section (i.e. upper epidermis layer) of skin as evident from visualization of intact liposomal vesicles in CLSM. PMID:24428443

  17. Depletion-induced forces and crowding in polymer-nanoparticle mixtures: Role of polymer shape fluctuations and penetrability

    Lim, Wei Kang; Denton, Alan R.

    2016-01-01

    Depletion forces and macromolecular crowding govern the structure and function of biopolymers in biological cells and the properties of polymer nanocomposite materials. To isolate and analyze the influence of polymer shape fluctuations and penetrability on depletion-induced interactions and crowding by nanoparticles, we model polymers as effective penetrable ellipsoids, whose shapes fluctuate according to the probability distributions of the eigenvalues of the gyration tensor of an ideal random walk. Within this model, we apply Monte Carlo simulation methods to compute the depletion-induced potential of mean force between hard nanospheres and crowding-induced shape distributions of polymers in the protein limit, in which polymer coils can be easily penetrated by smaller nanospheres. By comparing depletion potentials from simulations of ellipsoidal and spherical polymer models with predictions of polymer field theory and free-volume theory, we show that polymer depletion-induced interactions and crowding depend sensitively on polymer shapes and penetrability, with important implications for bulk thermodynamic phase behavior.

  18. Seasonal changes in radiation penetration within mustard crop canopy

    Adak, Tarun; Chakravarty, NVK

    2012-01-01

    Green leaf area index, dry matter production and economic seed yield are significantly influenced by dynamics of radiation penetration within oilseed crop canopy. Keeping this in view, following a two years field experiment with Indian mustard cultivars in IARI research farm, it was revealed that the radiation penetration at the early crop growth stage was high and then decreased within the canopy as the leaf area developed. The study indicated significant seasonal changes in radiation penetr...

  19. The Effect of Soil Parameters on Earth Penetration of Projectiles

    Thompson, L J; Ferguson, III, G H; Murff, J D; Cetiner, A

    1969-07-01

    The purpose of this study can be divided into the three following parts: 1) to present complete sets of data obtained for projectile penetration into soil targets of precisely known properties, and to describe how to build and test these targets; 2) to present a numerical method of data analysis for empirically determining the force on a projectile, during penetration; and 3) to demonstrate how physical soil parameters, as well as impact velocity and a projectile property influence penetration.

  20. PENETRATION ENHANCERS: A NOVEL STRATEGY FOR ENHANCING TRANSDERMAL DRUG DELIVERY

    Singla Vikas; Saini Seema; Singh Gurpreet; Rana A.C.; Joshi Baibhav

    2011-01-01

    Skin penetration enhancers have been used to improve bioavailability and increase the range of drugs to be administered by topical and transdermal route. Enhancement in skin penetration via modification of the stratum corneum by hydration, or via use of chemical enhancers acting on the structure of the stratum corneum lipids and keratin, partitioning and solubility effects. The mechanism of action of penetration enhancers are used as an aid in potential clinical applications. Synthetic chemic...

  1. Building virtual pentesting labs for advanced penetration testing

    Cardwell, Kevin

    2014-01-01

    Written in an easy-to-follow approach using hands-on examples, this book helps you create virtual environments for advanced penetration testing, enabling you to build a multi-layered architecture to include firewalls, IDS/IPS, web application firewalls, and endpoint protection, which is essential in the penetration testing world. If you are a penetration tester, security consultant, security test engineer, or analyst who wants to practice and perfect penetration testing skills by building virtual pen testing labs in varying industry scenarios, this is the book for you. This book is ideal if yo

  2. Hacking and penetration testing with low power devices

    Polstra, Philip

    2014-01-01

    Hacking and Penetration Testing with Low Power Devices shows you how to perform penetration tests using small, low-powered devices that are easily hidden and may be battery-powered. It shows how to use an army of devices, costing less than you might spend on a laptop, from distances of a mile or more. Hacking and Penetration Testing with Low Power Devices shows how to use devices running a version of The Deck, a full-featured penetration testing and forensics Linux distribution, and can run for days or weeks on batteries due to their low power consumption. Author Philip Polstra shows how to

  3. Effect of Liquid Penetrant Sensitivity on Probability of Detection

    Parker, Bradford H.

    2011-01-01

    The objective of the task is to investigate the effect of liquid penetrant sensitivity level on probability of detection (POD) of cracks in various metals. NASA-STD-5009 currently requires the use of only sensitivity level 4 liquid penetrants for NASA Standard Level inspections. This requirement is based on the fact that the data used to establish the reliably detectable flaw sizes penetrant inspection was from studies performed in the 1970s using penetrant deemed to be equivalent only to modern day sensitivity level 4 penetrants. However, many NDE contractors supporting NASA Centers routinely use sensitivity level 3 penetrants. Because of the new NASA-STD-5009 requirement, these contractors will have to either shift to sensitivity level 4 penetrants or perform formal POD demonstration tests to qualify their existing process. We propose a study to compare the POD generated for two penetrant manufactures, Sherwin and Magnaflux, and for the two most common penetrant inspection methods, water washable and post emulsifiable, hydrophilic. NDE vendors local to GSFC will be employed. A total of six inspectors will inspect a set of crack panels with a broad range of fatigue crack sizes. Each inspector will perform eight inspections of the panel set using the combination of methods and sensitivity levels described above. At least one inspector will also perform multiple inspections using a fixed technique to investigate repeatability. The hit/miss data sets will be evaluated using both the NASA generated DOEPOD software and the MIL-STD-1823 software.

  4. Prevention of serious impurity penetration into water-steam circuits

    In consequence of reports from several power Plants concerning heavy damages due to penetrations of impurities into the water-steam circuit, the VGB Sub-Committee 'Water Chemistry in Thermal Power Plants' has established a working group to check-up how serious impurity penetration can be avoided. The lecture describes possible danger points. Suitable technical arrangements for the avoidance of penetrations, and possibilities for monitoring will be discussed. Penetration of impurities cannot be avoided with absolute reliability, even when the recommended arrangements and usual monitoring are realized. Additional measures for the protection of water steam circuits will be suggested. (orig.)

  5. Penetrance of Hypertrophic Cardiomyopathy in Children and Adolescents

    Jensen, Morten K; Havndrup, Ole; Christiansen, Michael;

    2013-01-01

    The penetrance of hypertrophic cardiomyopathy (HCM) during childhood and adolescence has been only sparsely described. We studied the penetrance of HCM and the short- and long-term outcomes of clinical screening and predictive genetic testing of child relatives of patients with HCM.......The penetrance of hypertrophic cardiomyopathy (HCM) during childhood and adolescence has been only sparsely described. We studied the penetrance of HCM and the short- and long-term outcomes of clinical screening and predictive genetic testing of child relatives of patients with HCM....

  6. Characterization of nuclear reactor containment penetrations. Preliminary report

    This report summarizes the survey work conducted by Argonne National Laboratory on the design and details of major penetrations in 22 nuclear power plants. The survey includes all containment types and materials in current use. It also includes details of all types of penetrations (except for electrical penetration assemblies and valves) and the seals and gaskets used in them. The report provides a test matrix for testing major penetrations and for testing seals and gaskets in order to evaluate their leakage potential under severe accident conditions

  7. Consistent constitutive modeling of metallic target penetration using empirical, analytical, and numerical penetration models

    John (Jack) P. Riegel III; David Davison

    2016-01-01

    Historically, there has been little correlation between the material properties used in (1) empirical formulae, (2) analytical formulations, and (3) numerical models. The various regressions and models may each provide excellent agreement for the depth of penetration into semi-infinite targets. But the input parameters for the empirically based procedures may have little in common with either the analytical model or the numerical model. This paper builds on previous work by Riegel and Anderso...

  8. Evaluating and Comparing of Three Penetrability Measuring Devices : Modified Filter Pump, Modified Penetrability Meter, and Short Slot

    Ali Akbar, Saman; Al-Naddaf, Manar

    2015-01-01

    Rock grouting is a commonly used process for sealing rocks in tunnels to reduce water ingress. In order to achieve sufficient sealing level the grout must effectively penetrate into rock fractures while the limiting factor is filtration of cement based grout. Many devices and measuring methods have been developed to study filtration and to measure the penetrability. The filter pump and the penetrability meter are two of the most commonly used instruments for measuring filtration tendency in t...

  9. Ground Penetrating Radar Technologies in Ukraine

    Pochanin, Gennadiy P.; Masalov, Sergey A.

    2014-05-01

    Transient electromagnetic fields are of great interest in Ukraine. The following topics are studied by research teams, with high-level achievements all over the world: (i) Ultra-Wide Band/Short-pulse radar techniques (IRE and LLC "Transient Technologies", for more information please visit http://applied.ire.kharkov.ua/radar%20systems_their%20components%20and%20relevant%20technologies_e.html and http://viy.ua); (ii) Ground Penetrating Radar (GPR) with stepped frequency sounding signals (IRE); (iii) Continuous-Wave (CW) radar with phase-shift keying signals (IRE); and (iv) Radio-wave interference investigation (Scientific and Technical Centre of The Subsurface Investigation, http://geophysics.ua). GPR applications are mainly in search works, for example GPR is often used to search for treasures. It is also used to identify leaks and diffusion of petroleum in soil, in storage areas, as well as for fault location of pipelines. Furthermore, GPR is used for the localization of underground utilities and for diagnostics of the technical state of hydro dams. Deeper GPR probing was performed to identify landslides in Crimea. Rescue radar with CW signal was designed in IRE to search for living people trapped under the rubble of collapsed buildings. The fourth version of this radar has been recently created, showing higher stability and noise immunity. Radio-wave interference investigation allows studying the soil down to tens of meters. It is possible to identify areas with increased conductivity (moisture) of the soil. LLC "Transient Technologies" is currently working with Shevchenko Kyiv University on a cooperation program in which the construction of a test site is one of the planned tasks. In the framework of this program, a GPR with a 300 MHz antenna was handed to the geological Faculty of the University. Employees of "Transient Technologies" held introductory lectures with a practical demonstration for students majoring in geophysics. The authors participated to GPR

  10. GSTAMIDS ground-penetrating radar: hardware description

    Sower, Gary D.; Eberly, John; Christy, Ed

    2001-10-01

    The Ground Standoff Mine Detection System (GSTAMIDS) is now in the Engineering, Manufacturing and Development (EMD) Block 0 phase for USA CECOM. The Mine Detection Subsystem (MDS) presently utilizes three different sensor technologies to detect buried anti-tank (AT) land mines; Ground Penetrating Radar (GPR), Pulsed Magnetic Induction (PMI), and passive infrared (IR). The GSTAMIDS hardware and software architectures are designed so that other technologies can readily be incorporated when and if they prove viable. Each sensor suite is designed to detect the buried mines and to discriminate against various clutter and background objects. Sensor data fusion of the outputs of the individual sensor suites then enhances the detection probability while reducing the false alarm rate from clutter objects. The metal detector is an essential tool for buried mine detection, as metal land mines still account for a large percentage of land mines. Technologies such as nuclear quadrupole resonance (NQR or QR) are presently being developed to detect or confirm the presence of explosive material in buried land mines, particularly the so-called plastic mines; unfortunately, the radio frequency signals required cannot penetrate into a metal land mine. The limitation of the metal detector is not in detection of the metal mines, but in the additional detection of metal clutter. A metal detector has been developed using singular value decomposition (SVD) extraction techniques to discriminate the mines from the clutter, thereby greatly reducing false alarm rates. This mine detector is designed to characterize the impulse response function of the metal objects, based on a parametric three-pole model of the response, and to use pattern recognition to determine the match of the responses to known mines. In addition to discrimination against clutter, the system can also generally tell one mine type from another. This paper describes the PMI sensor suite hardware and its physical incorporation

  11. Ice-Penetrating Robot for Scientific Exploration

    Zimmerman, Wayne; Carsey, Frank; French, Lloyd

    2007-01-01

    The cryo-hydro integrated robotic penetrator system (CHIRPS) is a partially developed instrumentation system that includes a probe designed to deeply penetrate the European ice sheet in a search for signs of life. The CHIRPS could also be used on Earth for similar exploration of the polar ice caps especially at Lake Vostok in Antarctica. The CHIRPS probe advances downward by a combination of simple melting of ice (typically for upper, non-compacted layers of an ice sheet) or by a combination of melting of ice and pumping of meltwater (typically, for deeper, compacted layers). The heat and electric power for melting, pumping, and operating all of the onboard instrumentation and electronic circuitry are supplied by radioisotope power sources (RPSs) and thermoelectric converters energized by the RPSs. The instrumentation and electronic circuitry includes miniature guidance and control sensors and an advanced autonomous control system that has fault-management capabilities. The CHIRPS probe is about 1 m long and 15 cm in diameter. The RPSs generate a total thermal power of 1.8 kW. Initially, as this power melts the surrounding ice, a meltwater jacket about 1 mm thick forms around the probe. The center of gravity of the probe is well forward (down), so that the probe is vertically stabilized like a pendulum. Heat is circulated to the nose by means of miniature pumps and heat pipes. The probe melts ice to advance in a step-wise manner: Heat is applied to the nose to open up a melt void, then heat is applied to the side to allow the probe to slip down into the melt void. The melt void behind the probe is allowed to re-freeze. Four quadrant heaters on the nose and another four quadrant heaters on the rear (upper) surface of the probe are individually controllable for steering: Turning on two adjacent nose heaters on the nose and two adjacent heaters on the opposite side at the rear causes melt voids to form on opposing sides, such that the probe descends at an angle from

  12. Polymer drug carriers with enhanced penetration into tumor cells

    Pola, Robert; Pechar, Michal; Hoecherl, Anita; Janoušková, Olga; Ulbrich, Karel

    2015-01-01

    Roč. 6, Proceedings (2015), s. 28. ISSN 2153-2435. [International Conference and Exhibition on Pharmaceutics & Novel Drug Delivery Systems /5./ - Pharmaceutica 2015. 16.03.2015-18.03.2015, Dubai ] R&D Projects: GA MŠk(CZ) EE2.3.30.0029 Institutional support: RVO:61389013 Keywords : HPMA polymers * peptides * targeting Subject RIV: CE - Biochemistry

  13. Target cell specific antibody-based photosensitizers for photodynamic therapy

    Rosenblum, Lauren T.; Mitsunaga, Makoto; Kakareka, John W.; Morgan, Nicole Y.; Pohida, Thomas J.; Choyke, Peter L.; Kobayashi, Hisataka

    2011-03-01

    In photodynamic therapy (PDT), localized monochromatic light is used to activate targeted photosensitizers (PS) to induce cellular damage through the generation of cytotoxic species such as singlet oxygen. While first-generation PS passively targeted malignancies, a variety of targeting mechanisms have since been studied, including specifically activatable agents. Antibody internalization has previously been employed as a fluorescence activation system and could potentially enable similar activation of PS. TAMRA, Rhodamine-B and Rhodamine-6G were conjugated to trastuzumab (brand name Herceptin), a humanized monoclonal antibody with specificity for the human epidermal growth factor receptor 2 (HER2), to create quenched PS (Tra-TAM, Tra-RhoB, and Tra-Rho6G). Specific PDT with Tra-TAM and Tra-Rho6G, which formed covalently bound H-dimers, was demonstrated in HER2+ cells: Minimal cell death (SDS-PAGE).

  14. Surface-Adaptive, Antimicrobially Loaded, Micellar Nanocarriers with Enhanced Penetration and Killing Efficiency in Staphylococcal Biofilms.

    Liu, Yong; Busscher, Henk J; Zhao, Bingran; Li, Yuanfeng; Zhang, Zhenkun; van der Mei, Henny C; Ren, Yijin; Shi, Linqi

    2016-04-26

    Biofilms cause persistent bacterial infections and are extremely recalcitrant to antimicrobials, due in part to reduced penetration of antimicrobials into biofilms that allows bacteria residing in the depth of a biofilm to survive antimicrobial treatment. Here, we describe the preparation of surface-adaptive, Triclosan-loaded micellar nanocarriers showing (1) enhanced biofilm penetration and accumulation, (2) electrostatic targeting at acidic pH toward negatively charged bacterial cell surfaces in a biofilm, and (3) antimicrobial release due to degradation of the micelle core by bacterial lipases. First, it was established that mixed-shell-polymeric-micelles (MSPM) consisting of a hydrophilic poly(ethylene glycol) (PEG)-shell and pH-responsive poly(β-amino ester) become positively charged at pH 5.0, while being negatively charged at physiological pH. This is opposite to single-shell-polymeric-micelles (SSPM) possessing only a PEG-shell and remaining negatively charged at pH 5.0. The stealth properties of the PEG-shell combined with its surface-adaptive charge allow MSPMs to penetrate and accumulate in staphylococcal biofilms, as demonstrated for fluorescent Nile red loaded micelles using confocal-laser-scanning-microscopy. SSPMs, not adapting a positive charge at pH 5.0, could not be demonstrated to penetrate and accumulate in a biofilm. Once micellar nanocarriers are bound to a staphylococcal cell surface, bacterial enzymes degrade the MSPM core to release its antimicrobial content and kill bacteria over the depth of a biofilm. This constitutes a highly effective pathway to control blood-accessible staphylococcal biofilms using antimicrobials, bypassing biofilm recalcitrance to antimicrobial penetration. PMID:26998731

  15. FINITE ELEMENT METHOD ON NUMERICAL SIMULATION OF STRATUM CORNEUM'S PENETRATION PROPERTY

    2006-01-01

    How the outer substance could penetrate through the skin lies in the stratum corneum, because it is the main barrier in the multi-layers of the skin. Supposing the keratin cell with a special geometry as tetrakaidecahedron, the penetration property of stratum corneum was the key problem which was numerically simulated with finite element method. At first the discretization of the stratum corneum region was given in two steps: first, the discretization of the keratin cell; second, the discretization of fattiness that surrounds the keratin. Then there was the work of numerical simulation. In this procedure, the finite element method and the multi-grid method were used. The former was to obtain the discretization of basic elements; the latter was to decrease the high frequency error. At last the visualization of the numerical simulation was shown.

  16. Spontaneous wound dehiscence after penetrating keratoplasty

    Foroutan, Alireza; Tabatabaei, Seyed Ali; Behrouz, Mahmoud Jabbarvand; Zarei, Reza; Soleimani, Mohammad

    2014-01-01

    Spontaneous wound separation may be developed even months after suture removal especially in the context of long-term corticosteroid therapy. A 68-year-old Caucasian woman presented to our cornea clinic with spontaneous wound dehiscence after her third penetrating keratoplasty (PKP) which was performed three years ago. An Ahmed glaucoma valve (New World Medical, Ranchos Cucamonga, CA) was inserted ten months after the third PKP, which successfully controlled intraocular pressure (IOP). At the examination, the last sutures were removed eight months ago and she was using flourometholone 0.1 % (Sina Darou, Tehran, Iran) with a dose of once a day. There was one quadrant of wound dehiscence from 8 to 11 òclock associated with anterior wound gape and severe corneal edema. Resuturing was performed for the patient. At the one month examination, the corneal edema was resolved and best corrected visual acuity was 20/200 mainly due to previous glaucomatous optic neuropathy. Caution about the prolonged use of corticosteroids is necessary. Topical immunosuppressives could be a promising choice in this field. PMID:25349814

  17. Low Force Icy Regolith Penetration Technology

    Metzger, P. T.; Galloway, G. M.; Mantovani, J. G.; Zacny, K.; Zacny, Kris; Craft, Jack

    2011-01-01

    Recent data from the Moon, including LCROSS data, indicate large quantities of water ice and other volatiles frozen into the soil in the permanently shadowed craters near the poles. If verified and exploited, these volatiles will revolutionize spaceflight as an inexpensive source of propellants and other consumables outside Earth's gravity well. This report discusses a preliminary investigation of a method to insert a sensor through such a soiVice mixture to verify the presence, nature, and concentration of the ice. It uses percussion to deliver mechanical energy into the frozen mixture, breaking up the ice and decompacting the soil so that only low reaction forces are required from a rover or spacecraft to push the sensor downward. The tests demonstrate that this method may be ideal for a small platform in lunar gravity. However, there are some cases where the system may not be able to penetrate the icy soil, and there is some risk ofthe sensor becoming stuck so that it cannot be retracted, so further work is needed. A companion project (ISDS for Water Detection on the Lunar Surface) has performed preliminary investigation of a dielectric/thermal sensor for use with this system.

  18. Investigating hydrocarbon contamination using ground penetrating radar

    The increasing costs of remediating contaminated sites has stimulated research for cost reducing techniques in soil investigation and clean-up techniques. Under the traditional approach soil borings and groundwater wells are used to investigate contaminated soil. These are useful tools to determine the amount and characteristics of the contamination, but they are inefficient and costly in providing information on the location and extent of contamination as they only give information on one point. This often leads to uncertainty in estimating clean-up costs or, even worse, to unsuccessful clean-ups. MAP Environmental Research has developed a technology using Ground Penetrating Radar (GPR) in combination with in-house developed software to locate and define the extent of hydrocarbon contamination. With this technology, the quality of site investigation is increased while costs are reduced. Since 1994 MAP has been improving its technology and has applied it to over 100 projects, which all have been checked afterwards by conventional drilling. This paper gives some general characteristics of the method and presents a case study. The emphasis of this paper lies on the practical application of GPR to hydrocarbon contamination detection

  19. Occult celiac disease prevents penetrance of hemochromatosis

    Andreas Geier; Siegfried Matern; Carsten Gartung; Igor Theurl; Guenter Weiss; Frank Lammert; Christoph G. Dietrich; Ralf Weiskirchen; Heinz Zoller; Benita Hermanns

    2005-01-01

    AIM: To report a patient with C282Y homozygocity, depleted body iron and intestinal atrophy caused by celiac disease (CD) who experienced resolution of the enteropathy with subsequent normalization of iron metabolism upon glutenfree diet.METHODS: To obtain information on the tissue distribution and quantitative expression of proteins involved in duodenal iron trafficking, we determined the expression of divalent-metal transporter 1 (DMT1), ferroportin 1 (FP1) and transferrin receptor (TfR1) by means of immunohistochemistry and real-time PCR in duodenal biopsies of this patient.RESULTS: Whereas in hereditary hemochromatosis patients without CD, DMT1 expression was up-regulated leading to excessive uptake of iron, we identified a significant reduction in protein and mRNA expression of DMT1 as acompensatory mechanism in this patient with HH and CD.CONCLUSION: Occult CD may compensate tot increased DMT1 expression in a specific subset of individuals withhomozygous C282Y mutations in the hemochromatosis(HFE) gene, thus contributing to the low penetrance of HH.

  20. Improving Web Application Security Using Penetration Testing

    D. SriNithi

    2014-08-01

    Full Text Available The main issues of current web application is easily hacking the user information by unauthorized person. The development of entire web application depends on scripting languages that easily displays the user authentication code to the web browser. All code must be transferred through query string parameter (URL of the web application. This kind of application security fails when verifying it by penetration testing which is based on XSS languages. This study overcomes the security issues by developing a web application based on cross site scripting technique which the user codes are encrypted using RSA algorithm and cookies, cross domain verification based on encrypted use code. XSS vulnerabilities come in different forms and may be categorized into two varieties: reflected and stored. Reflected is on type of attack which can be performed against applications that employ a dynamic page error message to users. Stored XSS vulnerability appears when data submitted by one user is store in the application or in the back-end database. The user cookies of the web browser store only the encrypted key values. These techniques applied in Enterprise web application it support multiple organization for processing product purchase order, sales order and invoice details.

  1. Spontaneous wound dehiscence after penetrating keratoplasty.

    Foroutan, Alireza; Tabatabaei, Seyed Ali; Behrouz, Mahmoud Jabbarvand; Zarei, Reza; Soleimani, Mohammad

    2014-01-01

    Spontaneous wound separation may be developed even months after suture removal especially in the context of long-term corticosteroid therapy. A 68-year-old Caucasian woman presented to our cornea clinic with spontaneous wound dehiscence after her third penetrating keratoplasty (PKP) which was performed three years ago. An Ahmed glaucoma valve (New World Medical, Ranchos Cucamonga, CA) was inserted ten months after the third PKP, which successfully controlled intraocular pressure (IOP). At the examination, the last sutures were removed eight months ago and she was using flourometholone 0.1 % (Sina Darou, Tehran, Iran) with a dose of once a day. There was one quadrant of wound dehiscence from 8 to 11 òclock associated with anterior wound gape and severe corneal edema. Resuturing was performed for the patient. At the one month examination, the corneal edema was resolved and best corrected visual acuity was 20/200 mainly due to previous glaucomatous optic neuropathy. Caution about the prolonged use of corticosteroids is necessary. Topical immunosuppressives could be a promising choice in this field. PMID:25349814

  2. Spatial Variability of Penetration Resistance on Pseudogley

    Igor Bogunovic

    2016-01-01

    Full Text Available Usually large numbers of measurements are required to describe spatial variability of soil resistance but GIS technology with interpolations methods make it possible to estimate data from unsampled locations. In this paper cone index (CI measurements were made in two occasions in 2.88 ha field in central Croatia to present soil condition. A commonly used tillage operation consists of ploughing (about 30 cm depth and disc harrowing (12 - 15 cm, and they are practiced on annual basis. Measurements (240 were taken according sample grid in 48 different 24 x 25 m2 fields. Cone index (CI data were interpolated using geostatistical techniques (ordinary kriging to produce the maps of soil resistance. These maps combined with expert knowledge can provide good direction for applying appropriate soil management. Our results demonstrate that the investigated layers had variable spatial structures in terms of their linear trends. This suggests that each layer has a unique spatial structure possibly as consequence of pedogenetic processes, tillage operations and changes influenced by drainage and leveling operations. The results presented here describe spatial variability of soil resistance of a drained Pseudogley of Central Croatia, measured as CI in a field conditions. Tillage practices caused the formation of a plow pan at a depth 30 – 40 cm where the maximum CI values were obtained. According to the values of penetration resistance the tillage practices should be changed if we consider improved conditions for plant roots development.

  3. Pavement thickness evaluation using ground penetrating radar

    Harris, Dwayne Arthur

    Accurate knowledge of pavement thickness is important information to have both at a network and project level. This information aids in pavement management and design. Much of the time this information is missing, out of date, or unknown for highway sections. Current technologies for determining pavement thickness are core drilling, falling weight deflectometer (FWD), and ground penetrating radar (GPR). Core drilling provides very accurate pin point pavement thickness information; however, it is also time consuming, labor intensive, intrusive to traffic, destructive, and limited in coverage. FWD provides nondestructive estimates of both a surface thickness and total pavement structure thickness, including pavement, base and sub-base. On the other hand, FWD is intrusive to traffic and affected by the limitations and assumptions the method used to estimate thickness. GPR provides pavement surface course thickness estimates with excellent data coverage at highway speed. Yet, disadvantages include the pavement thickness estimation being affected by the electrical properties of the pavement, limitations of the system utilized, and heavy post processing of the data. Nevertheless, GPR has been successfully utilized by a number of departments of transportation (DOTs) for pavement thickness evaluation. This research presents the GPR thickness evaluation methods, develops GPRPAVZ the software used to implement the methodologies, and addresses the quality of GPR pavement thickness evaluation.

  4. Irradiated survival effect of melanoma B16 cells at different penetration depths of intermediate energy heavy-ion beams%中能碳离子束对不同贯穿深度上黑色素瘤B16细胞的辐照存活效应

    李强; 周光明; 王菊芳; 李文建; 温小琼; 党秉荣; 颉红梅; 卫增泉

    2001-01-01

    Survival fractions of melanoma B16 cells at different penetrationdepths exposed to 49.30MeV/u 12C ion beam and modulated 74.55MeV/u 12C ion beam with a ridge filter to form a spread-out Bragg peak (SOBP) were measured. The results show the survival response of B16 cells as the biological endpoint to heavy ions increases synchronously with the deposited energy along the beam traversal, that is, the survival fraction near or at the Bragg peak or SOBP is far lower than that at the beam's entrance or exit channel. Comparisons of the experimental data with calculated survival fractions at different depths predicted by the linear-quadratic survival model combined with dose-averaged LET display a good agreement within the experimental errors. It is prompted that the linear-quadratic model combined with dose-averaged LET possibly is a valid way to calculate the survival effect of B16 cells along the beam penetration under the exposure of the intermediate energy heavy-ion beam.%测量了49.30MeV/u及经脊形过滤器展宽的Bragg峰的74.55MeV/u12C离子束在不同贯穿深度上辐射后黑色素瘤B16细胞的存活率。结果显示,以存活为终点的B16细胞生物学效应与碳离子束能量沉积同步增大,即Bragg或展宽的Bragg峰区内细胞存活率远低于离子束入射或出射通道处的细胞存活率。通过实验测量与剂量平均LET结合的线性平方模型理论计算存活曲线的比较,发现在实验测量误差范围内两者符合较好。提示:剂量平均LET结合线性平方模型可能是预测中能重离子束贯穿深度上B16细胞存活效应的一种有效的方法。

  5. Gastroscopic treatment of gastric band penetrating the gastric wall

    Jess, Per; Fonnest, G

    1999-01-01

    Gastric wall penetration of a gastric band after operation for morbid obesity is a well known late complication. The treatment is usually reoperation. In this case report we show that a band penetrating the gastric wall can be successfully treated by gastroscopic operation. This technique is more...... simple than reoperation, especially in case of morbid obesity at the time of the complication....

  6. 3D Numerical Simulation of Projectile Penetration into Concrete Target

    2008-01-01

    Basing on the explicit instantaneous dynamics software MSC-Dytran and the general coupling arithmetic, the process of the projectile penetration into concrete target was simulated with the point-line-surface-body modeling method. Simulation results are in agreement with experimental results. The simulated data could provide design reference for the defense engineering construction and penetrator design.

  7. A Study on Factors Affecting Airborne LiDAR Penetration

    Wei-Chen Hsu

    2015-01-01

    Full Text Available This study uses data from different periods, areas and parameters of airborne LiDAR (light detection and ranging surveys to understand the factors that influence airborne LiDAR penetration rate. A discussion is presented on the relationships between these factors and LiDAR penetration rate. The results show that the flight height above ground level (AGL does not have any relationship with the penetration rate. There are some factors that should have larger influence. For example, the laser is affected by a wet ground surface by reducing the number of return echoes. The field of view (FOV has a slightly negative correlation with the penetration rate, which indicates that the laser incidence angle close to zero should achieve the best penetration. The vegetation cover rate also shows a negative correlation with the penetration rate, thus bare ground and reduced vegetation in the aftermath of a typhoon also cause high penetration rate. More return echoes could be extracted from the full-waveform system, thereby effectively improving the penetration rate. This study shows that full-waveform LiDAR is an effective method for increasing the number of surface reflected echoes. This study suggests avoiding LiDAR survey employment directly following precipitation to prevent laser echo reduction.

  8. 40 CFR 1065.376 - Chiller NO2 penetration.

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Chiller NO2 penetration. 1065.376... Chiller NO2 penetration. (a) Scope and frequency. If you use a chiller to dry a sample upstream of a NOX measurement instrument, but you don't use an NO2-to-NO converter upstream of the chiller, you must...

  9. Radionuclide transport through penetrations in nuclear waste containers

    Penetrations may result from corrosion or cracking and may be through the container material or through deposits of corrosion products. The analysis deals with the resultant radionuclide transport, but not with how these penetrations occur. We provide numerical illustrations for diffusive nuclide flux through these apertures from mathematical expressions. 2 refs., 2 figs

  10. The Impact of IPv6 on Penetration Testing

    Ottow, Christiaan; Vliet, van Frank; Boer, de Pieter-Tjerk; Pras, Aiko

    2012-01-01

    In this paper we discuss the impact the use of IPv6 has on remote penetration testing of servers and web applications. Several modifications to the penetration testing process are proposed to accommodate IPv6. Among these modifications are ways of performing fragmentation attacks, host discovery and

  11. Flux penetrations into two- and three-dimensional nanostructured superconductors

    Highlights: • Flux penetrations into two- and three-dimensional nanostructured superconductors are observed by magneto-optical imaging. • In two-dimensional superconducting networks with square holes on square lattice, anomalous diagonal penetrations are observed. • In three-dimensional superconducting shifted strip arrays, various forms of vortex avalanches are observed. - Abstract: We have fabricated two- and three-dimensional nanostructured superconductors, and observed vortex penetrations by magneto-optical imaging. In the case of two-dimensional superconducting networks with square holes on a square lattice, anomalous diagonal penetrations are widely observed. Two kinds of diagonal vortex penetrations at high and low temperatures have been interpreted as originating from the repulsive interaction of vortices and sharp fan-shaped vortex penetration from the corners of the square holes, respectively. In the case of three-dimensional stack of superconducting strip arrays with double and triple layers, vortex avalanches have been observed in a wide temperature and dimension ranges due to enhanced demagnetization effect. While spotlike avalanches are observed when the overlap of strips is small, anomalous linear avalanches traversing many strips in different layers are observed when the overlap is large. In triple-layer strip arrays, in addition to the spotlike and linear avalanches, vortex penetrations along the line of strips are also observed. Origins of the anomalous diagonal penetration and vortex avalanches are discussed

  12. Uptake of macromolecules by cercariae during skin penetration and transformation to schistosomula (Schistosoma mansoni)

    Joyce Thornhill; John Kusel; Fabricia Alvisi de Oliviera; Fabio Ribeiro; Symone Fulgêncio Lima; Paulo Marcos Zech Coelho; Paul McVeigh; Ana Carolina Alves de Mattos

    2010-01-01

    Here, we observed the uptake of membrane-impermeant molecules by cercariae as they penetrate the skin and are transformed into schistosomula. We propose that membrane-impermeant molecules, Lucifer Yellow, Propidium iodide and Hoechst 33258 enter the parasite through both thenephridiopore and the surface membrane and then diffuse throughout the body of the parasite. We present a hypothesis that the internal cells of the body of the schistosomulum represent a new host-parasite interface, at whi...

  13. Dermal in vitro penetration of methiocarb, paclobutrazol, and pirimicarb: effect of nonylphenolethoxylate and protective gloves.

    Nielsen, J. B.; Andersen, H R

    2001-01-01

    Dermal exposure has become the major route of human occupational exposure to pesticides. Detergents are used as part of formulated pesticide products and are known to change the barrier properties of human skin in vitro. However, studies on the influence of detergents as well as protective glove materials on dermal penetration of pesticides are scarce. In an experiment using in vitro static diffusion cells mounted with human skin, we evaluated the effect of nonylphenol-ethoxylate on dermal pe...

  14. Albumin-bound nanoparticle (nab) paclitaxel exhibits enhanced paclitaxel tissue distribution and tumor penetration

    Chen, Nianhang; Brachmann, Carrie; Liu, Xiping; Pierce, Daniel W.; Dey, Joyoti; William S Kerwin; Li, Yan; Zhou, Simon; Hou, Shihe; Carleton, Michael; Klinghoffer, Richard A.; Palmisano, Maria; Chopra, Rajesh

    2015-01-01

    Purpose nab-paclitaxel demonstrates improved clinical efficacy compared with conventional Cremophor EL (CrEL)-paclitaxel in multiple tumor types. This study explored the distinctions in drug distribution between nab-paclitaxel and CrEL-paclitaxel and the underlying mechanisms. Methods Uptake and transcytosis of paclitaxel were analyzed by vascular permeability assay across human endothelial cell monolayers. The tissue penetration of paclitaxel within tumors was evaluated by local injections i...

  15. Evaporation and skin penetration characteristics of mosquito repellent formulations

    Reifenrath, W.G.; Hawkins, G.S.; Kurtz, M.S.

    1989-03-01

    Formulations of the mosquito repellent N,N-diethyl-3-methylbenzamide (deet) in combination with a variety of additives were developed to control repellent evaporation and percutaneous penetration. Deet was also formulated with the repellent dimethyl phthalate to study the interaction of the two compounds on the skin. The evaporation and penetration processes were evaluated on whole and split-thickness pig skin using radiolabeled repellents with an in vitro apparatus. Under essentially still air and air flow conditions, one of the deet formulations resulted in significantly reduced total evaporation and percutaneous penetration of deet as compared to unformulated repellent. When deet and dimethyl phthalate were combined, neither repellent affected the total amount of evaporation and penetration of the other compound. However, initial percutaneous penetration and evaporation rates were slightly less and decayed less rapidly than when both chemicals were tested separately at the same dose. These results indicated a degree of competition of the two compounds for the same avenues of loss.

  16. Standard practice for liquid penetrant examination for general industry

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This practice covers procedures for penetrant examination of materials. Penetrant testing is a nondestructive testing method for detecting discontinuities that are open to the surface such as cracks, seams, laps, cold shuts, shrinkage, laminations, through leaks, or lack of fusion and is applicable to in-process, final, and maintenance testing. It can be effectively used in the examination of nonporous, metallic materials, ferrous and nonferrous metals, and of nonmetallic materials such as nonporous glazed or fully densified ceramics, as well as certain nonporous plastics, and glass. 1.2 This practice also provides a reference: 1.2.1 By which a liquid penetrant examination process recommended or required by individual organizations can be reviewed to ascertain its applicability and completeness. 1.2.2 For use in the preparation of process specifications and procedures dealing with the liquid penetrant testing of parts and materials. Agreement by the customer requesting penetrant inspection is strongly rec...

  17. Evaporation and skin penetration characteristics of mosquito repellent formulations

    Formulations of the mosquito repellent N,N-diethyl-3-methylbenzamide (deet) in combination with a variety of additives were developed to control repellent evaporation and percutaneous penetration. Deet was also formulated with the repellent dimethyl phthalate to study the interaction of the two compounds on the skin. The evaporation and penetration processes were evaluated on whole and split-thickness pig skin using radiolabeled repellents with an in vitro apparatus. Under essentially still air and air flow conditions, one of the deet formulations resulted in significantly reduced total evaporation and percutaneous penetration of deet as compared to unformulated repellent. When deet and dimethyl phthalate were combined, neither repellent affected the total amount of evaporation and penetration of the other compound. However, initial percutaneous penetration and evaporation rates were slightly less and decayed less rapidly than when both chemicals were tested separately at the same dose. These results indicated a degree of competition of the two compounds for the same avenues of loss

  18. The aerosol penetration through an electret fibrous filter

    Jiang Wei; Cheung Chun-Shun; Chan Cheong-Ki; Zhu Chao

    2006-01-01

    The aim of this paper is to present a theoretical study of the aerosol penetration through an electret fibrous filter, using a numerical approach. The aerosol sizes considered in this study were in the submicron range, and in the numerical model, the conventional mechanical mechanisms (impaction, interception, diffusion and gravitationally settling) were taken into consideration along with the electrostatic mechanisms, including the Coulombic and dielectrophoretic effects. The aerosol penetration through an electret fibrous filter is heavily dependent on the aerosol penetration of a single fibre. The aerosol penetration through a single electret fibre under various filtration conditions was calculated. The effects of aerosol diameter, aerosol and fibre charge state, face velocity, packing density and aerosol dielectric constant on the aerosol penetration were investigated.

  19. PENETRATION ENHANCERS: A NOVEL STRATEGY FOR ENHANCING TRANSDERMAL DRUG DELIVERY

    Singla Vikas

    2011-12-01

    Full Text Available Skin penetration enhancers have been used to improve bioavailability and increase the range of drugs to be administered by topical and transdermal route. Enhancement in skin penetration via modification of the stratum corneum by hydration, or via use of chemical enhancers acting on the structure of the stratum corneum lipids and keratin, partitioning and solubility effects. The mechanism of action of penetration enhancers are used as an aid in potential clinical applications. Synthetic chemicals generally used for this purposes are rapidly losing their value in transdermal patches due to reports of their absorption into the systemic circulation and subsequent possible toxic effect upon long term application. Terpenes are included in the list of Generally Recognized as Safe (GRAS substances and have low irritancy potential. In this review, we have discussed the chemical penetration as well as natural penetration enhancement technology for transdermal drug delivery as well as the probable mechanisms of action.

  20. Assessment of the percutaneous penetration of indomethacin from soybean oil microemulsion: effects of the HLB value of mixed surfactants.

    Chen, Liangmei; Tan, Fengping; Wang, Jinfeng; Liu, Feng

    2012-01-01

    The objective of this study was to evaluate the influence of the ratios or the hydrophile-lipophile balance (HLB) values of Cremophor EL and Span 80 on the phase behavior of the O/W microemulsions and the percutaneous absorption and penetration of indomethacin microemulsions. The existence of microemulsion regions is investigated in quaternary systems composed of soybean oil/Cremophor EL and Span 80 (mixed surfactants)/diethylene glycol monoethyl ether (cosurfactant)/water by constructing pseudo-ternary phase diagrams at various Cremophor EL/Span 80 ratios. In addition, five microemulsion formulations with various mixed surfactants HLB values were evaluated by in vitro penetration experiments using mouse skin and Franz diffusion cells. The flux and amount of indomethacin penetration from 5 microemulsion formulations were significantly different from the control, and the enhance ratios ranged from 2.38 to 4.68 and 2.11 to 4.23, respectively. The HLB value of mixed surfactants in the formulations was a principal factor in determining the percutaneous penetration of the drug. The flux and amount of drug penetration increased gradually with increasing content of the lipophilic surfactant Span 80 and skin retention was highest for mixed surfactants with a HLB value of 7.6. Therefore, it is suggested that the presence of mixed surfactants was beneficial in the formation of O/W microemulsions and enhanced percutaneous penetration of indomethacin. PMID:22393828

  1. Investigation of the Efficacy of Transdermal Penetration Enhancers Through the Use of Human Skin and a Skin Mimic Artificial Membrane.

    Balázs, Boglárka; Vizserálek, Gábor; Berkó, Szilvia; Budai-Szűcs, Mária; Kelemen, András; Sinkó, Bálint; Takács-Novák, Krisztina; Szabó-Révész, Piroska; Csányi, Erzsébet

    2016-03-01

    The aim of this study was to investigate the behavior of promising penetration enhancers through the use of 2 different skin test systems. Hydrogel-based transdermal formulations were developed with ibuprofen as a nonsteroidal anti-inflammatory drug. Transcutol and sucrose esters were used as biocompatible penetration enhancers. The permeability measurements were performed with ex vivo Franz diffusion cell methods and a newly developed Skin Parallel Artificial Membrane Permeability Assays (PAMPA) model. Franz diffusion measurement is commonly used as a research tool in studies of diffusion through synthetic membranes in vitro or penetration through ex vivo human skin, whereas Skin PAMPA involves recently published artificial membrane-based technology for the fast prediction of skin penetration. It is a 96-well plate-based model with optimized artificial membrane structure containing free fatty acid, cholesterol, and synthetic ceramide analog compounds to mimic the stratum corneum barrier function. Transdermal preparations containing 2.64% of different sucrose esters and/or Transcutol and a constant (5%) of ibuprofen were investigated to determine the effects of these penetration enhancers. The study demonstrated the good correlation of the permeability data obtained through use of human skin membrane and the in vitro Skin PAMPA system. The Skin PAMPA artificial membrane serves as quick and relatively deep tool in the early stages of transdermal delivery systems, through which the enhancing efficacy of excipients can be screened so as to facilitate the choice of effective penetration components. PMID:26886318

  2. Tumor-penetrating peptide functionalization enhances the anti-glioblastoma effect of doxorubicin liposomes

    The targeted therapeutic effect of nano drug delivery system for glioblastoma has been hampered by the weak enhanced permeability and retention (EPR) effect of glioblastoma and the low delivering efficiency of NDDS in glioblastoma tissue. In this study, a tumor-penetrating peptide (RGERPPR), the specific ligand of neuropilin-1 overexpressed on glioblastoma and endothelial cells, was used as a targeting moiety to enhance the anti-glioblastoma effect of doxorubicin liposomes. Firstly, RGERPPR-PEG-DSPE was synthesized and used to prepare the RGERPPR peptide-functionalized liposomes (RGE-LS), which showed vesicle sizes of around 90 nm and narrow size distributions. The cellular uptake and in vivo near-infrared fluorescence imaging test displayed that RGE-LS exhibited increased uptake by glioblastoma cells and intracranial glioblastoma tissues. The cytotoxicity assay and anti-glioblastoma study proved that RGERPPR functionalization significantly enhanced the in vitro inhibitory effect of doxorubicin liposomes on glioblastoma cells and prolonged the median survival time of nude mice bearing intracranial glioblastoma. Finally, the immunofluorescence analysis evidenced that RGE-LS were able to penetrate through tumor vessels and stroma and deep into the whole tumor tissue. The results indicated that tumor-penetrating peptide functionalization is an effective strategy for enhancing the anti-glioblastoma effect of doxorubicin liposomes. (paper)

  3. Bioconjugated Gold Nanoparticles Penetrate Into Spermatozoa Depending on Plasma Membrane Status.

    Barchanski, Annette; Taylor, Ulrike; Sajti, Csaba L; Gamrad, Lisa; Kues, Wilfried A; Rath, Detlef; Barcikowski, Stephan

    2015-09-01

    Spermatozoa are not only essential for animal reproduction they also represent important tools for the manipulation of animal genetics. For instance, the genetic labeling and analysis of spermatozoa could provide a prospective complementation of pre-fertilization diagnosis and could help to prevent the inheritance of defective alleles during artificial insemination or to select beneficial traits in livestock. Spermatozoa feature extremely specialized membrane organization and restricted transport mechanisms making the labeling of genetically interesting DNA-sequences, e.g., with gold nanoparticles, a particular challenge. Here, we present a systematic study on the size-related internalization of ligand-free, monovalent and bivalent polydisperse gold nanoparticles, depending on spermatozoa membrane status. While monovalent conjugates were coupled solely to either negatively-charged oligonucleotides or positively-charged cell-penetrating peptides, bivalent conjugates were functionalized with both molecules simultaneously. The results clearly indicate that the cell membrane of acrosome-intact, bovine spermatozoa was neither permeable to ligand-free or oligonucleotide-conjugated nanoparticles, nor responsive to the mechanisms of cell-penetrating peptides. Interestingly, after acrosome reaction, which comprises major changes in sperm membrane composition, fluidity and charge, high numbers of monovalent and bivalent nanoparticles were found in the postequatorial segment, depicting a close and complex correlation between particle internalization and membrane organization. Additionally, depending on the applied peptide and for nanoparticle sizes < 10 nm even a successive nuclear penetration was observed, making the bivalent conjugates promising for future genetic delivery and sorting issues. PMID:26485929

  4. Consistent constitutive modeling of metallic target penetration using empirical, analytical, and numerical penetration models

    John (Jack P. Riegel III

    2016-04-01

    Full Text Available Historically, there has been little correlation between the material properties used in (1 empirical formulae, (2 analytical formulations, and (3 numerical models. The various regressions and models may each provide excellent agreement for the depth of penetration into semi-infinite targets. But the input parameters for the empirically based procedures may have little in common with either the analytical model or the numerical model. This paper builds on previous work by Riegel and Anderson (2014 to show how the Effective Flow Stress (EFS strength model, based on empirical data, can be used as the average flow stress in the analytical Walker–Anderson Penetration model (WAPEN (Anderson and Walker, 1991 and how the same value may be utilized as an effective von Mises yield strength in numerical hydrocode simulations to predict the depth of penetration for eroding projectiles at impact velocities in the mechanical response regime of the materials. The method has the benefit of allowing the three techniques (empirical, analytical, and numerical to work in tandem. The empirical method can be used for many shot line calculations, but more advanced analytical or numerical models can be employed when necessary to address specific geometries such as edge effects or layering that are not treated by the simpler methods. Developing complete constitutive relationships for a material can be costly. If the only concern is depth of penetration, such a level of detail may not be required. The effective flow stress can be determined from a small set of depth of penetration experiments in many cases, especially for long penetrators such as the L/D = 10 ones considered here, making it a very practical approach. In the process of performing this effort, the authors considered numerical simulations by other researchers based on the same set of experimental data that the authors used for their empirical and analytical assessment. The goals were to establish a

  5. Consistent constitutive modeling of metallic target penetration using empirical, analytical, and numerical penetration models

    John Jack P. RIEGEL III; David DAVISON

    2016-01-01

    Historically, there has been little correlation between the material properties used in (1) empirical formulae, (2) analytical formulations, and (3) numerical models. The various regressions and models may each provide excellent agreement for the depth of penetration into semi-infinite targets. But the input parameters for the empirically based procedures may have little in common with either the analytical model or the numerical model. This paper builds on previous work by Riegel and Anderson (2014) to show how the Effective Flow Stress (EFS) strength model, based on empirical data, can be used as the average flow stress in the analytical Walker–Anderson Penetration model (WAPEN) (Anderson and Walker, 1991) and how the same value may be utilized as an effective von Mises yield strength in numerical hydrocode simulations to predict the depth of penetration for eroding projectiles at impact velocities in the mechanical response regime of the materials. The method has the benefit of allowing the three techniques (empirical, analytical, and numerical) to work in tandem. The empirical method can be used for many shot line calculations, but more advanced analytical or numerical models can be employed when necessary to address specific geometries such as edge effects or layering that are not treated by the simpler methods. Developing complete constitutive relationships for a material can be costly. If the only concern is depth of penetration, such a level of detail may not be required. The effective flow stress can be determined from a small set of depth of penetration experiments in many cases, especially for long penetrators such as the L/D=10 ones considered here, making it a very practical approach. In the process of performing this effort, the authors considered numerical simulations by other researchers based on the same set of experimental data that the authors used for their empirical and analytical assessment. The goals were to establish a baseline with a full

  6. Market penetration of biodiesel and ethanol

    Szulczyk, Kenneth Ray

    This dissertation examines the influence that economic and technological factors have on the penetration of biodiesel and ethanol into the transportation fuels market. This dissertation focuses on four aspects. The first involves the influence of fossil fuel prices, because biofuels are substitutes and have to compete in price. The second involves biofuel manufacturing technology, principally the feedstock-to-biofuel conversion rates, and the biofuel manufacturing costs. The third involves prices for greenhouse gas offsets. The fourth involves the agricultural commodity markets for feedstocks, and biofuel byproducts. This dissertation uses the Forest and Agricultural Sector Optimization Model-Greenhouse Gas (FASOM-GHG) to quantitatively examine these issues and calculates equilibrium prices and quantities, given market interactions, fossil fuel prices, carbon dioxide equivalent prices, government biofuel subsidies, technological improvement, and crop yield gains. The results indicate that for the ranges studied, gasoline prices have a major impact on aggregate ethanol production but only at low prices. At higher prices, one runs into a capacity constraint that limits expansion on the capacity of ethanol production. Aggregate biodiesel production is highly responsive to gasoline prices and increases over time. (Diesel fuel price is proportional to the gasoline price). Carbon dioxide equivalent prices expand the biodiesel industry, but have no impact on ethanol aggregate production when gasoline prices are high again because of refinery capacity expansion. Improvement of crop yields shows a similar pattern, expanding ethanol production when the gasoline price is low and expanding biodiesel. Technological improvement, where biorefinery production costs decrease over time, had minimal impact on aggregate ethanol and biodiesel production. Finally, U.S. government subsidies have a large expansionary impact on aggregate biodiesel production. Finally, U.S. government

  7. Ground penetrating radar field evaluation in Angola

    Walls, Richard; Brown, Todd; Clodfelter, Fred; Coors, Jeff; Laudato, Stephen; Lauziere, Steve; Patrikar, Ajay; Poole, Michael; Price, Mike

    2006-05-01

    Deminers around the globe are still using handheld metal detectors that lack the capability to distinguish mines from clutter, detect mines containing very little metal, or find mines buried at deeper depths. In the southern African country of Angola, many areas and roads are impassable due to the threat of anti-tank landmines. Some of these mines are undetectable using current metal detector technology. The US Army has funded the development of the NIITEK ground penetrating radar (GPR) for detection of anti-tank (AT) landmines. This radar detects metal and plastic mines as well as mines that are buried too deep for handheld metal detectors to find. The US Department of Defense Humanitarian Demining (HD) Research & Development Program focuses on developing, testing, demonstrating, and validating new technology for immediate use in humanitarian demining operations around the globe. The HD team provided funding and guidance to NIITEK Incorporated for development of a prototype system called Mine Stalker - a relatively light-weight, remote-controlled vehicle outfitted with the NIITEK GPR, detection algorithms, and a marking system. Individuals from the HD team, NIITEK Inc, and the non-governmental organization Meschen Gegen Minen (MgM) participated in a field evaluation of the Mine Stalker in Angola. The primary aim was to evaluate the effectiveness and reliability of the NIITEK GPR under field conditions. The Mine Stalker was extremely reliable during the evaluation with no significant maintenance issues. All AT mines used to verify GPR performance were detected, even when buried to depths as deep as 25-33cm.

  8. Simultaneous Penetrating Keratoplasty and Cataract Surgery

    Mohammad-Ali Javadi

    2013-01-01

    Full Text Available Purpose: To determine the clinical outcomes of simultaneous penetrating keratoplasty (PK, cataract removal and intraocular lens implantation (triple procedure, and to compare the safety and efficacy of two different cataract extraction techniques during the course of PK. Methods: This retrospective comparative study was conducted on patients who had undergone a triple procedure. The technique of cataract extraction was either opensky extracapsular cataract extraction (ECCE or phacoemulsification (PE. In the ECCE group, the posterior chamber intraocular lens (PCIOL was implanted in the ciliary sulcus, while in the PE group PCIOLs were fixated within the capsular bag. Outcome measures included best spectacle corrected visual acuity (BSCVA, refractive results, graft clarity and complications. Results: Seventy-six eyes of 69 consecutive patients with mean age of 61.4±14.2 years were enrolled. Mean follow-up period was 61.4±37.2 months over which mean BSCVA was significantly improved from 1.40±0.68 to 0.44±0.33 LogMAR (P<0.001. Mean postoperative spherical equivalent refractive error was -2.13±3.02 D, which significantly differed from the target refraction (-0.73±0.29 D, P=0.004. At final follow-up, 89.5% of the corneal grafts remained clear. Conclusion: The triple procedure is a safe and effective approach to restore vision in patients with coexisting corneal pathologies and cataracts. However, unacceptable postoperative refractive error can be anticipated.

  9. Severe accident testing of electrical penetration assemblies

    This report describes the results of tests conducted on three different designs of full-size electrical penetration assemblies (EPAs) that are used in the containment buildings of nuclear power plants. The objective of the tests was to evaluate the behavior of the EPAs under simulated severe accident conditions using steam at elevated temperature and pressure. Leakage, temperature, and cable insulation resistance were monitored throughout the tests. Nuclear-qualified EPAs were produced from D. G. O'Brien, Westinghouse, and Conax. Severe-accident-sequence analysis was used to generate the severe accident conditions (SAC) for a large dry pressurized-water reactor (PWR), a boiling-water reactor (BWR) Mark I drywell, and a BWR Mark III wetwell. Based on a survey conducted by Sandia, each EPA was matched with the severe accident conditions for a specific reactor type. This included the type of containment that a particular EPA design was used in most frequently. Thus, the D. G. O'Brien EPA was chosen for the PWR SAC test, the Westinghouse was chosen for the Mark III test, and the Conax was chosen for the Mark I test. The EPAs were radiation and thermal aged to simulate the effects of a 40-year service life and loss-of-coolant accident (LOCA) before the SAC tests were conducted. The design, test preparations, conduct of the severe accident test, experimental results, posttest observations, and conclusions about the integrity and electrical performance of each EPA tested in this program are described in this report. In general, the leak integrity of the EPAs tested in this program was not compromised by severe accident loads. However, there was significant degradation in the insulation resistance of the cables, which could affect the electrical performance of equipment and devices inside containment at some point during the progression of a severe accident. 10 refs., 165 figs., 16 tabs

  10. Severe accident testing of electrical penetration assemblies

    Clauss, D.B. (Sandia National Labs., Albuquerque, NM (USA))

    1989-11-01

    This report describes the results of tests conducted on three different designs of full-size electrical penetration assemblies (EPAs) that are used in the containment buildings of nuclear power plants. The objective of the tests was to evaluate the behavior of the EPAs under simulated severe accident conditions using steam at elevated temperature and pressure. Leakage, temperature, and cable insulation resistance were monitored throughout the tests. Nuclear-qualified EPAs were produced from D. G. O'Brien, Westinghouse, and Conax. Severe-accident-sequence analysis was used to generate the severe accident conditions (SAC) for a large dry pressurized-water reactor (PWR), a boiling-water reactor (BWR) Mark I drywell, and a BWR Mark III wetwell. Based on a survey conducted by Sandia, each EPA was matched with the severe accident conditions for a specific reactor type. This included the type of containment that a particular EPA design was used in most frequently. Thus, the D. G. O'Brien EPA was chosen for the PWR SAC test, the Westinghouse was chosen for the Mark III test, and the Conax was chosen for the Mark I test. The EPAs were radiation and thermal aged to simulate the effects of a 40-year service life and loss-of-coolant accident (LOCA) before the SAC tests were conducted. The design, test preparations, conduct of the severe accident test, experimental results, posttest observations, and conclusions about the integrity and electrical performance of each EPA tested in this program are described in this report. In general, the leak integrity of the EPAs tested in this program was not compromised by severe accident loads. However, there was significant degradation in the insulation resistance of the cables, which could affect the electrical performance of equipment and devices inside containment at some point during the progression of a severe accident. 10 refs., 165 figs., 16 tabs.

  11. Groundwater contamination downstream of a contaminant penetration site. II. Horizontal penetration of the contaminant plume

    Rubin, H.; Buddemeier, R.W.

    2002-01-01

    Part I of this study (Rubin, H.; Buddemeier, R.W. Groundwater Contamination Downstream of a Contaminant Penetration Site Part 1: Extension-Expansion of the Contaminant Plume. J. of Environmental Science and Health Part A (in press).) addressed cases, in which a comparatively thin contaminated region represented by boundary layers (BLs) developed within the freshwater aquifer close to contaminant penetration site. However, at some distance downstream from the penetration site, the top of the contaminant plume reaches the top or bottom of the aquifer. This is the location of the "attachment point," which comprises the entrance cross section of the domain evaluated by the present part of the study. It is shown that downstream from the entrance cross section, a set of two BLs develop in the aquifer, termed inner and outer BLs. It is assumed that the evaluated domain, in which the contaminant distribution gradually becomes uniform, can be divided into two sections, designated: (a) the restructuring section, and (b) the establishment section. In the restructuring section, the vertical concentration gradient leads to expansion of the inner BL at the expense of the outer BL, and there is almost no transfer of contaminant mass between the two layers. In the establishment section, each of the BLs occupies half of the aquifer thickness, and the vertical concentration gradient leads to transfer of contaminant mass from the inner to the outer BL. By use of BL approximations, changes of salinity distribution in the aquifer are calculated and evaluated. The establishment section ends at the uniformity point, downstream from which the contaminant concentration profile is practically uniform. The length of the restructuring section, as well as that of the establishment section, is approximately proportional to the aquifer thickness squared, and is inversely proportional to the transverse dispersivity. The study provides a convenient set of definitions and terminology that are

  12. Proton Radiography of Shape Charge Jets Penetrating Teflon and Explosive

    Ferm, Eric N.; Burkett, Michael W.; Hull, Larry M.; Marr-Lyon, Mark; McNeil, Wendy V.; Morris, Chris L.; Rightley, Paul M.; Lansce Proton Radiography Team

    2011-06-01

    We have used proton radiography at the Los Alamos Neutron Science Center to observe viper shaped charge jets penetrating inert and explosive materials. A viper jet was observed penetrating both Teflon and PBX 9501. Radiographs captured the penetration events at several times and are analyzed to determine the density of the materials imaged at each time. The interfaces and shock waves in the flow are clearly evident in the images. Multiple time images allow the determination of the velocities of the interfaces and shock waves. Comparisons are made in the Teflon case with estimates of penetration rates and densities using the quasi-steady approximation analysis used in many terminal ballistics models. The PBX 9501 clearly detonated from the impact of the shape charge jet tip traveling at 9.1 mm/s. The detonation wave is examined to see what support it obtains from the pursing jet and the jet is examined to find the influence of the explosive products on penetration velocity. This experiment gives us experimental results of in-situ penetration process that can be used to verify common modeling techniques and fluid mechanic calculations of the penetration process.

  13. Penetration of Mathematics Teaching and Thinking in Junior High School

    Anyong Liu

    2013-06-01

    Full Text Available Mathematical thinking is the essence of the mathematics in the phase of middle school, in which penetration mathematical thinking method contributes to the teaching efficiency in practice. This paper has listed some thinking methods, such as, penetration symbolic method that improves students’ adaptive ability on the transformation from arithmetic to algebra; penetration normalization method that contributes to the problem-solving ability; penetration of the combination of characters and graphics method that improves the competence both on the transformation between characters and graphics, and knowledge migration; penetration inductive method that strengthens their innovation both on thought and practical ability; penetration equation and function that is responsible for the cultivation of their modeling ability; and penetration classified discussion method that is conductive to the competence on observation all-round and handling problem flexibly. It is of much significance to propel the application of mathematical thinking in teaching practice for the goal of improved teaching quality and the cultivation of highly competent talent.

  14. Investigation on penetration model of shaped charge jet in water

    Shi, Jinwei; Luo, Xingbai; Li, Jinming; Jiang, Jianwei

    2016-01-01

    To analyze the process of jet penetration in water medium quantitatively, the properties of jet penetration spaced target with water interlayer were studied through test and numerical simulation. Two theoretical models of jet penetration in water were proposed. The theoretical model 1 was established considering the impact of the shock wave, combined with the shock equation Rankine-Hugoniot and the virtual origin calculation method. The theoretical model 2 was obtained by fitting theoretical analysis and numerical simulation results. The effectiveness and universality of the two theoretical models were compared through the numerical simulation results. Both the models can reflect the relationship between the penetration velocity and the penetration distance in water well, and both the deviation and stability of theoretical model 1 are better than 2, the lower penetration velocity, and the larger deviation of the theoretical model 2. Therefore, the theoretical model 1 can reflect the properties of jet penetration in water effectively, and provide the reference of model simulation and theoretical research.

  15. Counselling framework for moderate-penetrance cancer-susceptibility mutations.

    Tung, Nadine; Domchek, Susan M; Stadler, Zsofia; Nathanson, Katherine L; Couch, Fergus; Garber, Judy E; Offit, Kenneth; Robson, Mark E

    2016-09-01

    The use of multigene panels for the assessment of cancer susceptibility is expanding rapidly in clinical practice, particularly in the USA, despite concerns regarding the uncertain clinical validity for some gene variants and the uncertain clinical utility of most multigene panels. So-called 'moderate-penetrance' gene mutations associated with cancer susceptibility are identified in approximately 2-5% of individuals referred for clinical testing; some of these mutations are potentially actionable. Nevertheless, the appropriate management of individuals harbouring such moderate-penetrance genetic variants is unclear. The cancer risks associated with mutations in moderate-penetrance genes are lower and different than those reported for high-penetrance gene mutations (such as mutations in BRCA1 and BRCA2, and those associated with Lynch syndrome). The extrapolation of guidelines for the management of individuals with high-penetrance variants of cancer-susceptibility genes to the clinical care of patients with moderate-penetrance gene mutations could result in substantial harm. Thus, we provide a framework for clinical decision-making pending the development of a sufficient evidence base to document the clinical utility of the interventions for individuals with inherited moderate-penetrance gene mutations associated with an increased risk of cancer. PMID:27296296

  16. Temperature-sensitive RB mutations linked to incomplete penetrance of familial retinoblastoma in 12 families.

    Otterson, G A; Modi, S; Nguyen, K; Coxon, A B; Kaye, F J

    1999-10-01

    The tumor-suppressor activity of the retinoblastoma protein (RB) is encoded within a protein-binding ("pocket") domain that is targeted for mutations in all cases of familial retinoblastoma and in many common adult cancers. Although familial retinoblastoma is a paradigm for a highly penetrant, recessive model of tumorigenesis, the molecular basis for the phenotype of incomplete penetrance of familial retinoblastoma is undefined. We studied the RB pocket-binding properties of three independent, mutant RB alleles that are present in the germline of 12 kindreds with the phenotype of incomplete penetrance of familial retinoblastoma. Each arises from alterations of single codons within the RB pocket domain (designated "delta 480," "661W," or "712R"). Under the same conditions, we studied the properties of wild-type (WT) RB, an RB point mutant isolated from a lung carcinoma sample (706F) and an adjacent, in vitro-generated point mutant (707W). The delta 480, 661W, and 712R mutants lack pocket protein-binding activity in vitro but retain the WT ability to undergo cyclin-mediated phosphorylation in vivo. Each of the low-penetrant RB mutants exhibits marked enhancement of pocket protein binding when the cells are grown at reduced temperature. In contrast, in this temperature range, no change in binding activity is seen with WT RB, the 706F mutant, or the 707W mutant. We have demonstrated that many families with incomplete penetrance of familial retinoblastoma carry unstable, mutant RB alleles with temperature-sensitive pocket protein-binding activity. The variable frequency for tumor development in these families may result from reversible fluctuations in a threshold level of RB pocket-binding activity. PMID:10486322

  17. Conducting network penetration and espionage in a global environment

    Middleton, Bruce

    2014-01-01

    When it's all said and done, penetration testing remains the most effective way to identify security vulnerabilities in computer networks. Conducting Network Penetration and Espionage in a Global Environment provides detailed guidance on how to perform effective penetration testing of computer networks-using free, open source, and commercially available tools, including Backtrack, Metasploit, Wireshark, Nmap, Netcat, and Nessus. It also considers exploits and other programs using Python, PERL, BASH, PHP, Ruby, and Windows PowerShell.The book taps into Bruce Middleton's decades of experience wi

  18. Preferential diagonal penetration of vortices into square superconducting networks

    We have observed vortex penetration into Nb thin films with square arrays of square holes with variable sizes and lattice constants. We find that when the lattice spacing is large and the width of superconducting line is narrow, vortices penetrate diagonally rather than parallel to the nearest neighbor direction. This phenomenon is also confirmed in NbTiN samples with the same geometry. We also confirm that the direction of edge relative to that of hole array is not relevant. Possible origin of such a preferential penetration is proposed.

  19. Unusual orbitocranial penetrating injury by a grinding wheel: case report

    Murat Vural; Yakup Karabagli; Hikmet Basmak; Baki Adapinar; Ramazan Durmaz; Metin Ant Atasoy

    2009-01-01

    @@ Orbitocranial penetrating injuries are uncommon and usually life threatening, which constitute about 0.4% of all head injuries, 24% of penetrating head trauma in adults, and 45% in children.1,2,3They may occur accidentally or due to an assault and may have serious consequences and can be potentially fatal.4,5 Immediate plastic and reconstructive surgery, ophthalmology and radiology consultations are essential for the proper diagnosis and treatment. We reported an adult patient with a transorbital cerebral injury by an unusual material---grinding wheel. To our knowledge, this is the first reported case of transorbital penetrating injury by a grinding wheel in the literature.

  20. Simulation of armor penetration by tungsten rods: ALEGRA validation report

    Carroll, D.E.; Hertel, E.S. Jr.; Trucano, T.G.

    1997-11-01

    Results from simulations of the impact and penetration of tungsten alloy rods into thick rolled armor plates are presented. The calculations were performed with the CTH and ALEGRA computer codes using the DOE massively parallel TFLOPS computer co-developed by Sandia National Laboratory and Intel Corporation. Comparisons with experimental results are presented. Agreement of the two codes with each other and with the empirical results for penetration channel depth and radius is very close. Other shock physics and penetration features are also compared to simulation results.