A solid-contact Pb{sup 2+}-selective electrode using poly(2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene) as ion-to-electron transducer

Energy Technology Data Exchange (ETDEWEB)

Yu Shunyang [CAS and Shandong Provincial Key Laboratory of Coastal Zone Environmental Processes, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); Li Fuhai [CAS and Shandong Provincial Key Laboratory of Coastal Zone Environmental Processes, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); Chemistry and Chemical Engineering College, Yantai University, Yantai 264005 (China); Yin Tanji [CAS and Shandong Provincial Key Laboratory of Coastal Zone Environmental Processes, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); Liu Yongming [Chemistry and Chemical Engineering College, Yantai University, Yantai 264005 (China); Pan, Dawei [CAS and Shandong Provincial Key Laboratory of Coastal Zone Environmental Processes, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); Qin Wei, E-mail: wqin@yic.ac.cn [CAS and Shandong Provincial Key Laboratory of Coastal Zone Environmental Processes, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China)

2011-09-30

Highlights: {yields} All reagents used for the electrodes preparation were commercially available. {yields} The lower detection limit of the proposed electrode reached subnanomolar levels. {yields} No water film was observed with conventional commercially available PVC ion-sensing membranes. {yields} This research provides an excellent strategy for fabrication of robust polymeric ion sensors. - Abstract: In this work, a novel all-solid-state polymeric membrane Pb{sup 2+}-selective electrode was developed by using for the first time poly(2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene) (MEH-PPV) as solid contact. To demonstrate the ion-to-electron transducing ability of MEH-PPV, chronopotentiometry and electrochemical impedance spectroscopy measurements were carried out. The proposed electrodes showed a Nernstian response of 29.1 mV decade{sup -1} and a lower detection limit of subnanomolar level. No water film was observed with the conventional plasticized PVC membrane. This work demonstrates a new strategy for the fabrication of robust potentiometric ion sensors.

Multistimuli-responsive benzothiadiazole-cored phenylene vinylene derivative with nanoassembly properties.

Science.gov (United States)

Dou, Chuandong; Chen, Dong; Iqbal, Javed; Yuan, Yang; Zhang, Hongyu; Wang, Yue

2011-05-17

A trifluoromethyl-substituted benzothiadiazole-cored phenylene vinylene fluorophore (1) was synthesized and displayed piezo- and vapochromism and thermo-induced fluorescence variation in solid phase. Grinding could disrupt the crystalline compound 1 with orange emission into amorphous compound 1 with green emission, and heating treatment could change the amorphous compound 1 into crystalline compound 1. Ultraviolet-visible (UV-vis) absorption spectra, (13)C nuclear magnetic resonance (NMR), and powder X-ray diffraction (PXRD) characterizations demonstrated that crystalline and amorphous compound 1 possess different molecular packing. A differential scanning calorimetry (DSC) measurement revealed that the emission switching was due to the exchange between the thermodynamic-stable crystalline and metastable amorphous states. The ground sample exhibited vapochromic fluorescence property. Furthermore, compound 1 showed interesting supramolecular assembly characteristics in solution. Slowly cooling the hot N,N-dimethylformamide (DMF) solution of compound 1 resulted in the formation of orange fluorescent fibers, whereas sonication treatment of the cooling solution led to the generation of organic molecular gel. The field emission scanning electronic microscope (FESEM) and fluorescent microscopy images revealed smooth nano- or microfiber and network morphology properties. The PXRD spectra confirmed that these nano- or microstructures had a similar molecular-packing model with the crystalline state of compound 1. Slow evaporation of the toluene solution of compound 1 could produce green emissive microrods, which exhibited interesting thermo-induced fluorescence variation.

Hydrogen bonding as the origin of the switching behavior in dithiolated phenylene-vinylene oligomers

KAUST Repository

Obodo, Tobechukwu Joshua

2013-08-29

We investigate theoretically the switching behavior of a dithiolated phenylene-vinylene oligomer sandwiched between Au(111) electrodes using self-interaction corrected density-functional theory combined with the nonequilibrium Green\\'s-function method for quantum transport. The molecule presents a configurational bistability, which can be exploited in constructing molecular memories, switches, and sensors. We find that protonation of the terminating thiol groups is at the origin of the change in conductance. H bonding at the thiol group weakens the S-Au bond and reduces by about one order of magnitude the transmission coefficient at the Fermi level, and thus the linear response conductance. Furthermore, protonation downshifts in energy the position of the highest occupied molecular orbital, so that the current of the protonated species is lower than that of the unprotonated one along the entire bias range investigated, from −1.5 to 1.5 V. A second protonation at the opposite thiol group has only minor effects and no further drastic reduction in transmission takes place. Our results allow us to re-interpret the experimental data originally attributing the conductance reduction to H dissociation.

Determination of the trap-assisted recombination strength in polymer light emitting diodes

NARCIS (Netherlands)

Kuik, M.; Nicolai, H.T.; Lenes, M.; Wetzelaer, G.-J.A.H.; Lu, M.; Blom, P.W.M.

2011-01-01

The recombination processes in poly(p -phenylene vinylene) based polymer light-emitting diodes (PLEDs) are investigated. Photogenerated current measurements on PLED device structures reveal that next to the known Langevin recombination also trap-assisted recombination is an important recombination

Effect of Side Chains on Molecular Conformation of Anthracene-Ethynylene-Phenylene-Vinylene Oligomers: A Comparative Density Functional Study With and Without Dispersion Interaction.

Science.gov (United States)

Dong, Chuanding; Hoppe, Harald; Beenken, Wichard J D

2016-06-02

Using density functional calculations with and without dispersion interaction, we studied the effects of linear octyl and branched 2-ethylhexyl side chains on the oligomer conformation of the conjugated copolymer poly(p-anthracene-ethynylene)-alt-poly(p-phenylene-vinylene). With dispersion included, the branched side chains can cause significant bending of the oligomer backbone, while without dispersion they induce mainly torsional disorder. The oligomers with mainly linear side chains keep good planarity when optimized with and without dispersion. Despite their dramatically different conformations, the calculated absorption spectra of the oligomers with various side chain combinations are very similar, indicating that the conformation of the copolymer is not the main reason for the experimentally observed different spectra of ordered and disordered phases.

Block-type architectures for poly(p-Phenylene Vinylene) derivatives: a reality or an illusion?

Science.gov (United States)

Vanderzande, Dirk J. M.; Hontis, Lieve; Palmaerts, Arne; Van Den Berghe, David; Wouters, Jimmy; Lutsen, Laurence; Cleij, Thomas

2005-10-01

Poly(p-Phenylene Vinylene) derivatives are synthesized mostly making use of the polymerization behavior of p-quinodimethane systems. Over the last forty years different synthetic routes have been developed, e.g. Wessling, Gilch, Xanthate and Sulphinyl route. For all these routes mechanistic studies are rather scarce and lead to a controversy between two possible mechanisms: anionic and radical polymerization. In this contribution it becomes clear that high molecular weight materials are associated with a self-initiated radical chain polymerization and low molecular weight materials are obtained via an anionic mechanism. This will be demonstrated for the model system in which a sulphinyl pre-monomer is polymerized in N-Methyl-Pyrrolidone. In this model system both these mechanisms are competing with each other. The observed effects on the product distribution of concentration of reagents, temperature and order in which the reagents are added, are consistent with the conclusion above. The question whether living polymerization can occur will be addressed for the radical mechanism. An experiment with a set of sequential polymerizations gives rise to an evolution of molecular weight consistent with the effect of simple dilution of the reaction medium. The conclusion is that a termination reaction is active, which can be identified as related to traces of oxygen. In these conditions the synthesis of block-type copolymers can not be achieved. For the anionic mechanism an argumentation against such possibility will be presented on the basis of relative acidities.

Synthesis and photophysical and electroluminescent properties of poly(1,4-phenylene–ethynylene)-alt-poly(1,4-phenylene–vinylene)s with various dissymmetric substitution of alkoxy side chains

Czech Academy of Sciences Publication Activity Database

Bouguerra, N.; Růžička, Aleš; Ulbricht, C.; Enengl, C.; Enengl, S.; Pokorná, Veronika; Výprachtický, Drahomír; Tordin, E.; Aitout, R.; Cimrová, Věra; Egbe, D. A. M.

2016-01-01

Roč. 49, č. 2 (2016), s. 455-464 ISSN 0024-9297 R&D Projects: GA ČR(CZ) GA13-26542S; GA ČR(CZ) GAP106/12/0827 Institutional support: RVO:61389013 Keywords : poly(1,4-phenylene-ethynylene)-alt-poly(1,4-phenylene-vinylene)s * dissymmetric side chains * synthesis Subject RIV: CD - Macromolecular Chemistry Impact factor: 5.835, year: 2016

Hole mobility enhancement of MEH-PPV film by heat treatment at T{sub g}

Energy Technology Data Exchange (ETDEWEB)

Kajiya, Daisuke [Natural Science Center for Basic Research and Development (N-BARD), Hiroshima University, 1-3-1 Kagamiyama, Higashi-hiroshima, Hiroshima 739-8526 (Japan); Koganezawa, Tomoyuki [Japan Synchrotron Radiation Research Institute, 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Saitow, Ken-ichi, E-mail: saitow@hiroshima-u.ac.jp [Natural Science Center for Basic Research and Development (N-BARD), Hiroshima University, 1-3-1 Kagamiyama, Higashi-hiroshima, Hiroshima 739-8526 (Japan); Department of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-hiroshima, Hiroshima 739-8526 (Japan)

2015-12-15

The hole mobility of poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene vinylene] (MEH-PPV) film was measured using the time-of-flight method. The hole mobility was enhanced 4-fold after annealing at around the glass transition temperature (T{sub g}). Optical, atomic force, and Kelvin force microscopies, and grazing-incidence X-ray diffraction measurements indicate the enhancement can be attributed to a homogeneous film structure, a homogeneous Fermi level energy, and a face-on oriented structure, all of which were established by annealing at T{sub g}.

Photonic effects in microstructured conjugated polymer films and light emitting diodes

International Nuclear Information System (INIS)

Matterson, B.J.

2002-03-01

This thesis reports an investigation into the photonic effects caused by wavelength scale microstructure patterned onto films of conjugated polymers. The efficiency of light emitting diodes (LEDs) made from conjugated polymers is limited in part by the trapping of light into waveguide modes caused by the high refractive index of these materials. Waveguide modes in films of poly(p,-phenylene vinylene) (PPV) and poly(2-methoxy, 5-(2'ethylhexyloxy)-p-phenylene vinylene) (MEH-PPV) are analysed and the refractive index of these materials is calculated. The photoluminescence of conjugated polymer films that have been spun onto textured substrates is analysed. It is found that the photoluminescence quantum yield of a film spun onto a substrate inscribed with a grating is increased. It is also found that the photoluminescence spectrum of the film is dramatically altered and varies substantially with viewing angle. The features in the spectrum caused by the grating are strongly polarized. These effects are analysed and are attributed to the scattering of waveguided light out of the film. It is found that films spun onto metal gratings exhibit especially strong scattering. The effect of metal gratings with various grating depths is analysed. The possible contribution of band gaps to the photoluminescence spectrum from polymers on strong metal gratings is discussed. LEDs that include grating structures are constructed and analysed. It is found that having grating structures on the metal layers that are used as electrodes in the LED does not adversely affect the electrical properties of the LED. It is demonstrated that grating in the LED is able to substantially increase the light emission without using extra electrical power. The emission spectra from LEDs are observed to vary with angle, and exhibit considerable polarization. (author)

Donor-acceptor random copolyesters containing perylenebisimide (PBI) and oligo(p-phenylene vinylene) (OPV) by melt condensation polymerization: energy transfer studies.

Science.gov (United States)

Nisha, S Kumari; Asha, S K

2013-10-31

Novel copolyesters consisting of oligo(p-phenylene vinylene) (OPV) as donor (D) and perylenebisimide (PBI) as acceptor (A) were synthesized by melt polycondensation. Photoinduced energy transfer and photoinduced charge separation in these polyesters were studied in solution as well as in the solid state. Selective excitation of OPV moiety resulted in the energy transfer with >90% efficiency from OPV to PBI chromophore in the solution state. The direct excitation of PBI in the D-A copolyester resulted in reduced fluorescence emission of acceptor, indicating electron transfer between the D and A moieties. The effect of distance between donor and acceptor on the energy transfer efficiency from donor to acceptor was studied. Compared to a physical mixture of D and A polyesters alone, the energy transfer was 4 times more efficient in the D-A copolyester, highlighting the influence of covalently linking D and A in a single polymer chain. A strong fluorescence quenching (∼ 100%) of both chromophores in solid state indicated an efficient photoinduced charge transfer after photoexcitation of either D or A. Thus, OPV-PBI main chain copolyester is an excellent system for the study of energy- and electron-transfer processes in organic semiconductor. Reactive blend of D/A copolyester was also prepared by the transesterification reaction between D and A alone copolyesters. The energy transfer efficiency from D to A moiety upon selective excitation of D chromophore in the D/A copolyester blend was ∼4 times higher compared to a physical mixture of D and A alone copolyesters, which gave direct proof for the transesterification reaction in polyester/polyester reactive blending.

Effect of dioxan and toluene as solvents on: Polycondensation leading to poly (2.5-furylene vinylene)s

International Nuclear Information System (INIS)

Al-Hariri, S. N.

2008-01-01

This paper describes the influence of two different solvents, on a synthetic route leading to linear poly (2.5-furylene vinylene)s PFV, which involves the polycondensation of 5-methyl furfural in a basic medium, and on the characterization of PFV. The replacement of benzene by dioxan gives a linear polymeric structure possessing a high degree of conjugation, a good degree of polymerization, a remarkable stability to storage under ordinary condition and a partial solubility in common solvents, especially methylene chloride. Casting films from solution polymer gives brittle material, without any mechanical strength. However, the product obtained by using the toluene differs from the expected polymer. The results indicate that the raising of the degree of polymerization was done by increasing the time of reaction and successively introducing the monomer. Monomer, and dimer are isolated and characterized from the sub-product (oligomer) of the reaction. (author)

Molecular Tuning of Phenylene-Vinylene Derivatives for Two-Photon Photosensitized Singlet Oxygen Production

DEFF Research Database (Denmark)

Nielsen, Christian B.; Arnbjerg, Jacob; Johnsen, Mette

2009-01-01

Substituent-dependent features and properties of the sensitizer play an important role in the photosensitized production of singlet oxygen, O2(a1Δg). In this work, we systematically examine the effect of molecular changes in the sensitizer on the efficiency of singlet oxygen production using......, as the sensitizer, oligophenylene-vinylene derivatives designed to optimally absorb light in a nonlinear two-photon process. We demonstrate that one cannot always rely on rule-of-thumb guidelines when attempting to construct efficient two-photon singlet oxygen sensitizers. Rather, as a consequence of behavior...... that can deviate from the norm, a full investigation of the photophysical properties of the system is generally required. For example, it is acknowledged that the introduction of a ketone moiety to the sensitizer chromophore often results in more efficient production of singlet oxygen. However, we show...

Structure-processing-property correlations in thin films of conjugated polymer nanocomposites and blends

Science.gov (United States)

Sreeram, Arvind

Conjugated polymers have found several applications in recent years, in energy conversion and storage devices such as organic light emitting diodes, solar cells, batteries, and super capacitors. Thin films of polymers used for these applications need to be mechanically and thermally stable to withstand the harsh operating conditions. Although there is significant information on the optoelectronic properties of many of these polymers, there are only few studies on their mechanical properties. There is little information in the literature on how processing of these films influence mechanical properties. In the first part of this study, poly(p-phenylene vinylene) (PPV) films were prepared by thermolytic conversion of poly[p -phenylene (tetrahydrothiophenium)ethylene chloride] precursor films, at different temperatures and the kinetics of reaction was investigated using thermogravimetry and Fourier transform infrared (FTIR) spectroscopy. The mechanical properties of the films, studied using nanoindentation, showed a dependence on the extent of conversion and chemical composition of the films. The presence of chemical defects (e.g., carbonyl groups, detected using FTIR spectroscopy), was also found to have a noticeable effect on the modulus and hardness of the films. The storage modulus, E', and plasticity decreased with an increase in conversion, whereas the loss modulus, E", showed the opposite trend. Both the precursor and the fully-converted PPV films were found to have significantly lower E" than E', consistent with the glassy nature of the polymers at room temperature. In the second part of the study, polyacetylene films were synthesized by acid-catalyzed dehydration reaction of poly(vinyl alcohol) (PVA) precursor films. The kinetics of this reaction was monitored by thermogravimetry. The chemical structure of the conjugated polymer films was characterized by Raman and IR spectroscopy. Polyacetylene films incorporated with 1-propyl-3-methylimidazolium ionic liquid

UV and RIR matrix assisted pulsed laser deposition of organic MEH-PPV films

International Nuclear Information System (INIS)

Toftmann, B.; Papantonakis, M.R.; Auyeung, R.C.Y.; Kim, W.; O'Malley, S.M.; Bubb, D.M.; Horwitz, J.S.; Schou, J.; Johansen, P.M.; Haglund, R.F.

2004-01-01

A comparative study of thin film production based on gentle laser-ablation techniques has been carried out with the luminescent polymer poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene]. Using a free-electron laser films were made by resonant infrared pulsed laser deposition (RIR-PLD). For the first time resonant infrared matrix assisted pulsed laser evaporation (RIR-MAPLE) was successfully demonstrated on a luminescent polymer system. In addition to this, an excimer laser has been used for UV-MAPLE depositions at 193 and 248-nm irradiation. Films deposited onto NaCl and quartz substrates were analyzed by Fourier transform infrared spectroscopy, UV-visible absorbance and photoluminescence. Photoluminescent material was deposited by RIR-MAPLE and 248-nm MAPLE, while the RIR-PLD and 193-nm-MAPLE depositions displayed the smoothest surfaces but did not show photoluminescence

UV and RIR matrix assisted pulsed laser deposition of organic MEH-PPV films

DEFF Research Database (Denmark)

Christensen, Bo Toftmann; Papantonalis, M.R.; Auyeung, R.C.Y.

2004-01-01

-PLD). For the first time resonant infrared matrix assisted pulsed laser evaporation (RIR-MAPLE) was successfully demonstrated on a luminescent polymer system. In addition to this, an excimer laser has been used for UV-MAPLE depositions at 193 and 248-nm irradiation. Films deposited onto NaCl and quartz substrates......A comparative study of thin film production based on gentle laser-ablation techniques has been carried out with the luminescent polymer poly [2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene]. Using a free-electron laser films were made by resonant infrared pulsed laser deposition (RIR...... were analyzed by Fourier transform infrared spectroscopy, UV-visible absorbance and photoluminescence. Photoluminescent material was deposited by RIR-MAPLE and 248-nm MAPLE, while the RIR-PLD and 193-nm-MAPLE depositions displayed the smoothest surfaces but did not show photoluminescence. (C) 2003...

Lifetimes of organic photovoltaics: photooxidative degradation of a model compound

DEFF Research Database (Denmark)

Norrman, K.; Alstrup, J.; Jørgensen, M.

2006-01-01

A poly phenylene vinylene (PPV-type) oligomer used in organic photovoltaics was designed to facilitate the interpretation of mass spectral data. A film of the oligomer was subjected to various degrees of illumination (1000 W m(-2), AM1.5) in air resulting in photooxidation of the material...

Cellulose/poly-(m-phenylene isophthalamide) porous film as a tissue-engineered skin bioconstruct

Science.gov (United States)

Lee, Jae Woong; Han, Sung Soo; Zo, Sum Mi; Choi, Soon Mo

2018-06-01

Regarding the porous structure, coagulated cellulose may not provide sufficient voids for cell proliferation, resulting in tissue growth. For this reason, it was blended with poly(m-phenylene isophthalamide) (PMIA), which could produce a porous structure in the resulting construct. The aim of this study was to confirm the potential of a novel cellulose/PMIA porous film as a tissue-engineered bioconstruct for impaired skin. The films were fabricated by a coagulation process added with a peel-off method, and the structural, mechanical properties were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and capillary flow porometry. CRL-2310 human keratinocytes were used to determine the biocompatibility of the prepared films. The attachment and proliferation of cells were investigated by scanning electron microscopy, DAPI staining, and a cell viability assay. The results show that cellulose/PMIA porous films have potential use as wound matrices for skin tissue genesis.

Langmuir-Blodgett film based on MEH-PPV for cholesterol biosensor

International Nuclear Information System (INIS)

Matharu, Zimple; Arya, Sunil K.; Singh, S.P.; Gupta, Vinay; Malhotra, B.D.

2009-01-01

Cholesterol oxidase (ChOx) has been immobilized onto conducting poly[2-methoxy,5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV)/stearic acid (SA) Langmuir-Blodgett film transferred onto octadecanethiol (ODT) modified gold plate. The ChOx/MEH-PPV/SA LB film bioelectrode exhibits has been characterized by FT-IR, contact angle, and atomic force microscopy. The response of the ChOx/MEH-PPV/SA LB film bioelectrode carried out using differential pulse voltammetry (DPV) studies reveal linearity from 1.29 to 12.91 mM of cholesterol concentration and response time as 30 s. This ChOx/MEH-PPV/SA bioelectrode exhibits values of correlation coefficient as 0.9939, standard deviation as 0.0029 μA and limit of detection as 1.66 mM. UV-visible spectrophotometer studies reveal that 5.2 x 10 -3 U of ChOx are actively working per cm 2 area of ChOx/MEH-PPV/SA LB film bioelectrode and this bioelectrode is thermally stable upto 55 deg. C with reusability of about 60 times

Langmuir-Blodgett film based on MEH-PPV for cholesterol biosensor

Energy Technology Data Exchange (ETDEWEB)

Matharu, Zimple [Biomolecular Electronics and Conducting Polymer Research Group, National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi 110012 (India); Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Arya, Sunil K.; Singh, S.P. [Biomolecular Electronics and Conducting Polymer Research Group, National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi 110012 (India); Gupta, Vinay [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Malhotra, B.D. [Biomolecular Electronics and Conducting Polymer Research Group, National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi 110012 (India)], E-mail: bansi.malhotra@gmail.com

2009-02-23

Cholesterol oxidase (ChOx) has been immobilized onto conducting poly[2-methoxy,5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV)/stearic acid (SA) Langmuir-Blodgett film transferred onto octadecanethiol (ODT) modified gold plate. The ChOx/MEH-PPV/SA LB film bioelectrode exhibits has been characterized by FT-IR, contact angle, and atomic force microscopy. The response of the ChOx/MEH-PPV/SA LB film bioelectrode carried out using differential pulse voltammetry (DPV) studies reveal linearity from 1.29 to 12.91 mM of cholesterol concentration and response time as 30 s. This ChOx/MEH-PPV/SA bioelectrode exhibits values of correlation coefficient as 0.9939, standard deviation as 0.0029 {mu}A and limit of detection as 1.66 mM. UV-visible spectrophotometer studies reveal that 5.2 x 10{sup -3} U of ChOx are actively working per cm{sup 2} area of ChOx/MEH-PPV/SA LB film bioelectrode and this bioelectrode is thermally stable upto 55 deg. C with reusability of about 60 times.

Blue shift in the luminescence spectra of MEH-PPV films containing ZnO nanoparticles

International Nuclear Information System (INIS)

Ton-That, Cuong; Phillips, Matthew R.; Nguyen, Thien-Phap

2008-01-01

Luminescence properties of nanocomposites consisting of ZnO nanoparticles in a conjugated polymer, poly [2-methoxy-5-(2'-ethyl hexyloxy)-phenylene vinylene] (MEH-PPV), were investigated. Photoluminescence measurements reveal a blue shift in the emission spectrum of MEH-PPV upon incorporation of ZnO nanoparticles into the polymer film while the emission is increasingly quenched with increasing ZnO concentration. In contrast, the structure of the polymer and its conjugation length are not affected by the presence of ZnO nanoparticles (up to 16 wt% ZnO) as revealed by Raman spectroscopy. The blue shift and photoluminescence quenching are explained by the separation of photogenerated electron-hole pairs at the MEH-PPV/ZnO interface and the charging of the nanoparticles

Investigation of electrical and optical properties of MEH-PPV: ZnO nanocomposite films for OLED applications

Energy Technology Data Exchange (ETDEWEB)

Azhar, N. E. A., E-mail: najwaezira@yahoo.com; Shafura, A. K., E-mail: shafura@ymail.com; Affendi, I. H. H., E-mail: irmahidayanti.halim@gmail.com; Shariffudin, S. S., E-mail: sobihana@gmail.com [NANO-ElecTronic Centre, Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); Saurdi, I., E-mail: saurdy788@gmail.com [Faculty of Electrical Engineering, UiTM Sarawak, Kampus Kota Meranek, Sarawak (Malaysia); Alrokayan, Salman A. H., E-mail: dr.salman@alrokayan.com; Khan, Haseeb A., E-mail: khan-haseeb@yahoo.com [Research Chair of Targeting and Treatment of Cancer Using Nanoparticles Department of Biochemistry, College of Science, King Saud University (KSU), 245 Riyadh 11454 (Saudi Arabia); Rusop, M., E-mail: rusop@salam.uitm.edu.my [NANO-ElecTronic Centre, Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); NANO-SciTech Centre, Institute of Science, Universiti Teknologi MARA (UiTM), Shah Alam, Selangor (Malaysia)

2016-07-06

Recent investigations of the promising materials for optoelectronic have been demonstrated by introducing n-type inorganic material into conjugated polymer. The optical and electrical of nanocomposite films based on poly[2-methoxy-5-(2’-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) and zinc oxide (ZnO) nanostructured of various deposition layers (1 to 3 layers) have been investigated. The MEH-PPV: ZnO nanocomposite films were deposited using spin-coating technique. The surface morphology nanocomposite films were characterized using field emission scanning electron microscope. From surface profiler measurement, we found that the thickness of nanocomposite films increased as deposition time increased. The optical properties were measured using photoluminescence spectroscope. The photoluminescence (PL) spectra showed that two deposition layers is the highest intensity at visible region (green emission) due to high energy transfer from particles to the polymer. The current density for two layers sample is due to aggregation of conjugated polymer chain hence form excited interchain exciton for optical excitation. This study will provide better performance and suitable for optoelectronic device especially OLEDs application.

Weak-link capacitor

Science.gov (United States)

Dirk, Shawn M.; Johnson, Ross S.; Wheeler, David R.; Bogart, Gregory R.

2013-04-23

A process for making a dielectric material where a precursor polymer selected from poly(phenylene vinylene)polyacetylene, poly(p-phenylene), poly(thienylene vinylene), poly(1,4-naphthylene vinylene), and poly(p-pyridine vinylene) is energized said by exposure by radiation or increase in temperature to a level sufficient to eliminate said leaving groups contained within the precursor polymer, thereby transforming the dielectric material into a conductive polymer. The leaving group in the precursor polymer can be a chloride, a bromide, an iodide, a fluoride, an ester, an xanthate, a nitrile, an amine, a nitro group, a carbonate, a dithiocarbamate, a sulfonium group, an oxonium group, an iodonium group, a pyridinium group, an ammonium group, a borate group, a borane group, a sulphinyl group, or a sulfonyl group.

Effect of substituents on electronic properties, thin film structure and device performance of dithienothiophene-phenylene cooligomers

International Nuclear Information System (INIS)

Zhang Shiming; Guo Yunlong; Xi Hongxia; Di Chongan; Yu Jian; Zheng Kai; Liu Ruigang; Zhan Xiaowei; Liu Yunqi

2009-01-01

Dithienothiophene-phenylene cooligomers with n-hexyloxy or n-dodecyloxy substituents have been synthesized and compared to the previously reported unsubstituted parent compound. The effect of substituents on the thermal, electronic, optical, thin film structure and field-effect transistor (OFET) properties was investigated. Structural phase transitions from highly-ordered nanocrystalline to liquid crystalline were observed at 241 and 213 deg. C for n-hexyloxy- and n-dodecyloxy-substituted compounds respectively, different from the parent compound. For the alkoxy-substituted compounds, the absorption spectra in thin film blue shift 50 nm, while the fluorescence spectra in thin film red shift 88-100 nm compared to those in solution. The OFET devices based on the alkoxy-substituted compounds exhibit mobilities as high as ca 0.02 cm 2 V -1 s -1 and their performance is sensitive to the alkoxy substituents and substrate temperatures

Systematic investigation of the effects of organic film structure on light emitting diode performance

Science.gov (United States)

Joswick, M. D.; Campbell, I. H.; Barashkov, N. N.; Ferraris, J. P.

1996-09-01

We present a systematic investigation of the effects of organic film structure on light emitting diode (LED) performance. Metal/organic film/metal LEDs were fabricated using a five ring, poly(phenylene vinylene) related oligomer as the active layer. The structure of the vacuum evaporated oligomer films was varied from amorphous to polycrystalline by changing the substrate temperature during deposition. The intrinsic properties of the oligomer films and the LED performance were measured. The measured intrinsic film properties include: optical absorption, photoluminescence (PL) spectra, PL lifetime, PL efficiency, and effective carrier mobility. The measured device characteristics include current-voltage, capacitance-voltage, electroluminescence (EL) efficiency, and the contact metal/organic film Schottky barrier heights. The optical absorption and PL properties of the films are weakly dependent on film structure but the effective carrier mobility decreases with increasing crystallinity. The EL quantum efficiency decreases by more than one order of magnitude, the drive voltage at a fixed current increases, and the electron Schottky barrier height increases as the crystallinity of the film is increased. The diode current-voltage characteristic is determined by the dominant hole current and the electroluminescence efficiency is controlled by the contact limited electron injection. These results demonstrate significant effects of organic film structure on the performance of organic LEDs.

Investigation on the Optical and Surface Morphology of Conjugated Polymer MEH-PPV:ZnO Nanocomposite Thin Films

Directory of Open Access Journals (Sweden)

Nurul Zayana Yahya

2012-01-01

Full Text Available Thin films of red color poly(2-methoxy-5(2′-ethylhexyloxy-phenylene vinylene (MEH-PPV containing different weight percent of ZnO nanoparticles were obtained by spin-coating techniques. The MEH-PPV:ZnO solutions were spin coated onto silicon and glass substrates. The spun MEH-PPV:ZnO thin films were then used to investigate optical properties by using ultraviolet-visible spectrometer (UV-Vis and photoluminescence spectrophotometer (PL. The morphologies were investigated by using field emission scanning electron microscopy (FESEM, while the identification of ZnO in the final product was determined by using energy-dispersive X-ray spectroscopy (EDS. The UV-Vis absorption band increases, while the optical bandgap decreases when the amount of ZnO nanoparticles increases. ZnO nanoparticles apparently have no effect on the conjugation segments of MEH-PPV. PL spectra show that the emission peak increases and slightly red shift as ZnO concentration increases. Based on SEM images of MEH-PPV:ZnO nanocomposite thin films, ZnO nanoparticles form agglomerated regions.

Systematic investigation of the effects of organic film structure on light emitting diode performance

Energy Technology Data Exchange (ETDEWEB)

Joswick, M.D.; Campbell, I.H. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Barashkov, N.N.; Ferraris, J.P. [The University of Texas at Dallas, Richardson, Texas 75080 (United States)

1996-09-01

We present a systematic investigation of the effects of organic film structure on light emitting diode (LED) performance. Metal/organic film/metal LEDs were fabricated using a five ring, poly(phenylene vinylene) related oligomer as the active layer. The structure of the vacuum evaporated oligomer films was varied from amorphous to polycrystalline by changing the substrate temperature during deposition. The intrinsic properties of the oligomer films and the LED performance were measured. The measured intrinsic film properties include: optical absorption, photoluminescence (PL) spectra, PL lifetime, PL efficiency, and effective carrier mobility. The measured device characteristics include current{endash}voltage, capacitance{endash}voltage, electroluminescence (EL) efficiency, and the contact metal/organic film Schottky barrier heights. The optical absorption and PL properties of the films are weakly dependent on film structure but the effective carrier mobility decreases with increasing crystallinity. The EL quantum efficiency decreases by more than one order of magnitude, the drive voltage at a fixed current increases, and the electron Schottky barrier height increases as the crystallinity of the film is increased. The diode current{endash}voltage characteristic is determined by the dominant hole current and the electroluminescence efficiency is controlled by the contact limited electron injection. These results demonstrate significant effects of organic film structure on the performance of organic LEDs. {copyright} {ital 1996 American Institute of Physics.}

Morphological, structural and optical properties of MEH-PPV: PC70BM nanocomposite film

Science.gov (United States)

Mhamdi, Asya; Sweii, Fatma ben Slama; Saidi, Hamza; Saidi, Faouzi; Bouazizi, Abdelaziz

2018-05-01

In this report, the influence of annealing temperature and spin coating speed on the structural and morphological properties of a blend of poly (2-methoxy-5-(2-ethyl-oxy)-p-phenylene-vinylene) (MEH-PPV) and [6-6]-phenyl-C71-butyric acid methyl ester (PC70BM) layer has been investigated. The photoactive layer (MEH-PPV: PC70BM) was deposited on ZnO film deposited on top of indium tin oxide (ITO) substrate by spin-coating. The effect of spin coating speed via atomic force microscope (AFM) leads to conclude that high speed is favorable for a good homogeneity of the film surface and good aggregates dispersion. The optimized structure was studied by varying the annealing temperatures using X-ray diffraction (XRD). The XRD analysis indicates that annealing treatment promoted the ordered aggregation and crystallization of MEH-PPV: PC70BM films. Indeed, the blend ratio effect on the optical properties of MEH-PPV: PC70BM thin film was investigated. While, the effect of incorporation of PC70BM on the optical properties was studied using UV-Vis and photoluminescence (PL) measurement. We conclude that MEH-PPV: PC70BM (1:3) film leads to high charge transfer rate.

Colorectal polyps

Science.gov (United States)

Intestinal polyps; Polyps - colorectal; Adenomatous polyps; Hyperplastic polyps; Villous adenomas; Serrated polyp; Serrated adenoma; Precancerous polyps; Colon cancer - polyps; Bleeding - colorectal polyps

Origin of Negative Capacitance in Bipolar Organic Diodes

Science.gov (United States)

Niu, Quan; Crǎciun, N. Irina; Wetzelaer, Gert-Jan A. H.; Blom, Paul W. M.

2018-03-01

Negative differential capacitance (NC) occurring at low frequencies in organic light-emitting diodes (OLEDs) is a poorly understood phenomenon. We study the origin of the NC effect by systematically varying the number of electron traps in OLEDs based on the polymeric semiconductor poly(p -phenylene vinylene). Increasing the electron trap density enhances the NC effect. The magnitude and observed decrease of the relaxation time is consistent with the (inverse) rate of trap-assisted recombination. The absence of NC in a nearly trap-free light-emitting diode unambiguously shows that trap-assisted recombination is the responsible mechanism for the negative contribution to the capacitance in bipolar organic diodes. Our results reveal that the NC effect can be exploited to quantitatively determine the number of traps in organic semiconductors in a nondestructive fashion.

Femtosecond dynamics of excitons in π-conjugated oligomers: the role of intrachain two-exciton states in the formation of interchain species

Science.gov (United States)

Klimov, Victor I.; McBranch, Duncan W.; Barashkov, Nikolay N.; Ferraris, John P.

1997-10-01

We report femtosecond transient absorption results for solutions and thin films of a substituted oligomer of poly(para-phenylene vinylene) performed over wide spectral and pump-intensity ranges. Solutions and films exhibit a photoinduced absorption (PA) band with dynamics matching those of the stimulated emission, demonstrating unambiguously that these features originate from intrachain singlet excitons. Thin films exhibit an additional short-wavelength PA band with pump-independent dynamics, indicating the formation of non-emissive interchain excitons. Correlations in the dynamics of the two PA features, as well as the intensity-dependence, provide strong evidence that the formation of interchain excitons is mediated by intrachain two-exciton states.

Tetrafullerene conjugates for all-organic photovoltaics

NARCIS (Netherlands)

Fernández, G.; Sánchez, L.; Veldman, D.; Wienk, M.M.; Atienza, C.M.; Guldi, D.M.; Janssen, R.A.J.; Martin, N.

2008-01-01

The synthesis of two new tetrafullerene nanoconjugates in which four C60 units are covalently connected through different -conjugated oligomers (oligo(p-phenylene ethynylene) and oligo(p-phenylene vinylene)) is described. The photovoltaic (PV) response of these C60-based conjugates was evaluated by

Influence of poly(2-methoxy-5-(2’-ethyl)-hexyloxy-p-phenylene vinylene):(6,6)-phenyl C61 butyric acid methyl ester blend ratio on the performance of inverted type organic solar cells based on Eosin-Y-coated ZnO nanorod arrays

International Nuclear Information System (INIS)

Ginting, Riski Titian; Yap, Chi Chin; Yahaya, Muhammad; Salleh, Muhamad Mat

2013-01-01

The influence of poly(2-methoxy-5-(2’-ethyl)-hexyloxy-p-phenylene vinylene) (MEH-PPV) and (6,6)-phenyl C61 butyric acid methyl ester (PCBM) weight ratio on the photovoltaic performance of inverted type organic solar cell based on Eosin-Y-coated ZnO nanorods has been investigated. Experimental results showed that the photovoltaic performance improved with weight ratio of MEH-PPV:PCBM from 1:1 to 1:3 due to better percolation pathway for electron transport and enhanced infiltration of polymer blend into interspace of Eosin-Y-coated ZnO nanorods. However, the overall performance started to decrease at weight ratio of 1:4 due to the aggregation of PCBM clusters which results in poor polymer blend infiltration. The optimum device at weight ratio of 1:3 exhibited short circuit current density of 3.95 ± 0.10 mA cm −2 , open circuit voltage of 0.53 ± 0.03 V, fill factor of 0.50 ± 0.03, and power conversion efficiency of 1.02 ± 0.07 %. - Highlights: • The device performance increased with donor:acceptor weight ratio up to 1:3. • Aggregation of fullerene-derivative led to poor infiltration at weight ratio of 1:4. • The optimum weight ratio was different from that of conventional device

Influence of poly(2-methoxy-5-(2’-ethyl)-hexyloxy-p-phenylene vinylene):(6,6)-phenyl C61 butyric acid methyl ester blend ratio on the performance of inverted type organic solar cells based on Eosin-Y-coated ZnO nanorod arrays

Energy Technology Data Exchange (ETDEWEB)

Ginting, Riski Titian [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Yap, Chi Chin, E-mail: ccyap@ukm.my [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Yahaya, Muhammad [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Salleh, Muhamad Mat [Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

2013-06-01

The influence of poly(2-methoxy-5-(2’-ethyl)-hexyloxy-p-phenylene vinylene) (MEH-PPV) and (6,6)-phenyl C61 butyric acid methyl ester (PCBM) weight ratio on the photovoltaic performance of inverted type organic solar cell based on Eosin-Y-coated ZnO nanorods has been investigated. Experimental results showed that the photovoltaic performance improved with weight ratio of MEH-PPV:PCBM from 1:1 to 1:3 due to better percolation pathway for electron transport and enhanced infiltration of polymer blend into interspace of Eosin-Y-coated ZnO nanorods. However, the overall performance started to decrease at weight ratio of 1:4 due to the aggregation of PCBM clusters which results in poor polymer blend infiltration. The optimum device at weight ratio of 1:3 exhibited short circuit current density of 3.95 ± 0.10 mA cm{sup −2}, open circuit voltage of 0.53 ± 0.03 V, fill factor of 0.50 ± 0.03, and power conversion efficiency of 1.02 ± 0.07 %. - Highlights: • The device performance increased with donor:acceptor weight ratio up to 1:3. • Aggregation of fullerene-derivative led to poor infiltration at weight ratio of 1:4. • The optimum weight ratio was different from that of conventional device.

Thermally switchable dielectrics

Science.gov (United States)

Dirk, Shawn M.; Johnson, Ross S.

2013-04-30

Precursor polymers to conjugated polymers, such as poly(phenylene vinylene), poly(poly(thiophene vinylene), poly(aniline vinylene), and poly(pyrrole vinylene), can be used as thermally switchable capacitor dielectrics that fail at a specific temperature due to the non-conjugated precursor polymer irreversibly switching from an insulator to the conjugated polymer, which serves as a bleed resistor. The precursor polymer is a good dielectric until it reaches a specific temperature determined by the stability of the leaving groups. Conjugation of the polymer backbone at high temperature effectively disables the capacitor, providing a `built-in` safety mechanism for electronic devices.

Boltorn-Modified Poly(2,6-dimethyl-1,4,phenylene oxide) Gas Separation Membranes

NARCIS (Netherlands)

Sterescu, D.M.; Stamatialis, Dimitrios; Mendes, Eduardo; Kruse, Jan; Rätzke, Klaus; Faupel, Franz; Wessling, Matthias

2007-01-01

This paper describes the preparation, characterization and the permeation properties of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) dense polymer films containing aliphatic hyperbranched polyesters, Boltorn (H20, H30, and H40). The Boltorn are dispersed in PPO at various concentrations. The gas

Dynamics of the central phenylene ring torsional motion in halogenated phenylene ethynylene oligomers

Energy Technology Data Exchange (ETDEWEB)

Pejov, Ljupco [Institute of Chemistry, Department of Physical Chemistry, SS. Cyril and Methodius University, Arhimedova 5, P.O. Box 162, 1000 Skopje(Macedonia, The Former Yugoslav Republic of)], E-mail: ljupcop@iunona.pmf.ukim.edu.mk; La Rosa, Manuela [PST Group- M6, STMicroelectronics, Stradale Primosole 50, 95121 Catania (Italy); Kocarev, Ljupco [Institute for Nonlinear Science, University of California, San Diego 9500 Gilman, Drive, La Jolla, CA 92093-0402 (United States); Macedonian Academy of Sciences and Arts, bul. Krste Misirkov 2, P.O. Box 428, 1000 Skopje (Macedonia, The Former Yugoslav Republic of)

2007-11-09

The dynamics of intramolecular torsional motion of central phenylene ring in a series of phenylene ethynylene oligomer derivatives was investigated. On the basis of calculated hindered rotational potentials corresponding to this motion, the torsional energy levels were obtained by solving the torsional Schroedinger equation. Subsequently, the torsional correlation time and transition probability was computed within the Bloembergen-Purcell-Pound (BPP) formalism, considering both the classical and quantum mechanical tunneling contributions to the intramolecular rotation. The results were interpreted in the context of molecular conductivity switching behavior of the considered series of compounds. Also some other parameters relevant to molecular admittance were calculated, such as the HOMO-LUMO energy difference and the spatial extent of the frontier molecular orbitals. Classical electrostatic arguments were applied to understand the physical basis of the conformational stability differences in the studied compounds. It was found that halogenation of the central phenylene ring may be used for fine-tuning of molecular conduction behavior, in the sense of modulating the HOMO-LUMO energy difference, the spatial extent of frontier MOs, as well as the barrier height to torsional motion of the central phenylene ring. The time scale of the temperature induced stochastic conformational switching between the 'on' and 'off' states, along with the corresponding transition probability could be varied by an order of magnitude upon halogenation of the central phenylene ring. The tunneling contributions to the torsional correlation time were found to be of minor importance in this context, and this quantity may be quite correctly estimated with the classical BPP approach.

Dynamics of the central phenylene ring torsional motion in halogenated phenylene ethynylene oligomers

International Nuclear Information System (INIS)

Pejov, Ljupco; La Rosa, Manuela; Kocarev, Ljupco

2007-01-01

The dynamics of intramolecular torsional motion of central phenylene ring in a series of phenylene ethynylene oligomer derivatives was investigated. On the basis of calculated hindered rotational potentials corresponding to this motion, the torsional energy levels were obtained by solving the torsional Schroedinger equation. Subsequently, the torsional correlation time and transition probability was computed within the Bloembergen-Purcell-Pound (BPP) formalism, considering both the classical and quantum mechanical tunneling contributions to the intramolecular rotation. The results were interpreted in the context of molecular conductivity switching behavior of the considered series of compounds. Also some other parameters relevant to molecular admittance were calculated, such as the HOMO-LUMO energy difference and the spatial extent of the frontier molecular orbitals. Classical electrostatic arguments were applied to understand the physical basis of the conformational stability differences in the studied compounds. It was found that halogenation of the central phenylene ring may be used for fine-tuning of molecular conduction behavior, in the sense of modulating the HOMO-LUMO energy difference, the spatial extent of frontier MOs, as well as the barrier height to torsional motion of the central phenylene ring. The time scale of the temperature induced stochastic conformational switching between the 'on' and 'off' states, along with the corresponding transition probability could be varied by an order of magnitude upon halogenation of the central phenylene ring. The tunneling contributions to the torsional correlation time were found to be of minor importance in this context, and this quantity may be quite correctly estimated with the classical BPP approach

Research and development of basic technologies for next generation industries, 'electrically conductive polymeric material'. Evaluation on second term research and development; Jisedai sangyo kiban gijutsu kenkyu kaihatsu. Dodensei kobunshi zairyo (dainiki kenkyu kaihatsu hyoka)

Energy Technology Data Exchange (ETDEWEB)

NONE

1988-03-01

The research and development in the second term included development of raw materials, elucidation of electricity conduction mechanism, and development of methods to improve stability and a new processing method. Crystals of a large number of charge migrating complexes were grown to elucidate their electron properties and structures. A theoretical model was structured for the superconduction mechanism in the charge migrating complexes. Poly-p-phenylene vinylene-based polymers achieved {sigma}=1.1 times 10{sup 4}s/cm as a result of extension of soluble reaction intermediates. Poly-2, 5-phenylene vinylene doped with FeCl{sub 3} retained 10{sup 3}s/m for 165 days in nitrogen. Polypyrrole achieved 3.0 times 10{sup 3}s/cm in constant potential electrolytically oxidizing polymerization and extension at low temperatures. Polypyrrole doped with ClO{sub 4}{sup -} retained electric conductivity of 85% for 400 days in nitrogen. Electric conductivity of higher than 10{sup 5}s/cm was obtained by applying different kinds of doping into thin film and fiber formed graphite. The world's highest conductivity of 9 times 10{sup 5}s/cm was achieved particularly with discharge laminated and polymerized graphite doped with AsF{sub 5}. (NEDO)

Improvement in carrier mobility and photovoltaic performance through random distribution of segments of linear and branched side chains

Czech Academy of Sciences Publication Activity Database

Egbe, D. A. M.; Adam, G.; Pivrikas, A.; Ramil, A. M.; Birckner, E.; Cimrová, Věra; Hoppe, H.; Sariciftci, N. S.

2010-01-01

Roč. 20, č. 43 (2010), s. 9726-9734 ISSN 0959-9428 R&D Projects: GA MŠk(CZ) 1M06031 Institutional research plan: CEZ:AV0Z40500505 Keywords : poly(p-phenylene-ethynylene)-alt-poly(p-phenylene-vinylene) * solar cells * charge carrier mobility Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 5.101, year: 2010

Lifetimes of organic photovoltaics: Design and synthesis of single oligomer molecules in order to study chemical degradation mechanisms

DEFF Research Database (Denmark)

Alstrup, J.; Norrman, K.; Jørgensen, M.

2006-01-01

Degradation mechanisms in organic and polymer photovoltaics are addressed through the study of an organic photovoltaic molecule based on a single phenylene-vinylene-type oligomer molecule. The synthesis of such a model compound with different end-groups is presented that allows for assignment...... of degradation products from different parts of the molecule. Photovoltaic devices with and without C(60) have been prepared and their characteristics under AM1.5 conditions are reported. The degradation of the active phenylene-vinylene compound in darkness and after 20h of illumination were investigated using...... a mass spectrometric technique (time-of-flight secondary ion mass spectrometry) allowing elucidation of the oxidative degradation pathways. (c) 2006 Elsevier B.V. All rights reserved....

Optical constants and self-assembly of phenylene ethynylene oligomer monolayers

DEFF Research Database (Denmark)

Marx, E.; Walzer, Karsten; Less, R.J.

2004-01-01

This paper studies the self-assembly on gold surfaces of 1,4-ethynylphenyl-4'-ethynylphenyl-2'-nitro-1-benzenedithiolate (EP2NO(2)), a substituted phenylene ethynylene trimer with applications in molecular electronics. We develop an ellipsometric technique to measure the optical constants...... of these self-assembled monolayers, and we also use attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and scanning tunneling microscopy (STM) to confirm the structure of the films....

Clinical and radiographic characteristics of ureteral polyps in children

International Nuclear Information System (INIS)

Niu Zhibing; Wang Changlin; Yang Qi; Hou Ying

2007-01-01

Objective: To analyze the clinical and radiographic characterstics of ureteral polyps with hydronephrosis in children. Methods: Thirteen patients with ureteral polyps and hydronephrosis were studied retrospectively. All patients underwent abdominal plain film, intravenous pyelogram (IVP) and ultrasound (US) examinations,contrast-enhanced CT scan was performed in 10 cases. Results: Intermittent or recurrent abdominal pain with painless hematuria was presented in most cases. Hydronephrosis was demonstrated in radiographic images. IVP delineated the dilatation of the ureter and filling defects within the ureteral lumen in 5 cases. Computed tomography (CT) showed all abnormal changes of ureter and irregular intraluminal soft tissue masses in 6 cases. Moderate and low echoic structures were showed in ureters by US in 2 cases. Conclusion: US and CT, as an important imaging modalities, can improve the diagnostic accuracy for ureteral polyps. (authors)

Short-time dynamics of phenylene-rings in bisphenol based engineering thermoplastics

International Nuclear Information System (INIS)

Arrese-Igor, S.; Arbe, A.; Alegria, A.; Colmenero, J.; Frick, B.

2003-01-01

We have recently performed one of the first approaches by means of quasielastic neutron scattering (QENS) to the problem of identifying the molecular motions giving rise to the secondary relaxations of engineering thermoplastics. Preliminary results point to phenylene ring π-flips as the main motion causing the observed quasielastic broadening in the ∼10 -10 -10 -9 s time scale below the glass transition temperature T g . Continuing our study of sub-T g dynamics in these systems by QENS, measurements on polycarbonate (PC) and polysulfone (PSF) with deuterated methyl groups (d6) in the ∼10 -13 -10 -11 s time scale have been performed. The intermediate scattering function shows a smooth second decay in addition to that of vibrations and 'fast dynamics' at T > or approx. 200 K. The extrapolation of phenylene π-flip motion to faster times does not explain the decay observed. However, a non-negligible contribution of π-flips at T≥350 K in PCd6 is noticeable, whereas for PSFd6 some effect can be inferred above ∼450 K. In the temperature region where the π-flips do not contribute to the spectra we have characterised the signal by assuming a temperature dependent distribution of small angle oscillations of phenylene rings leading to an activation energy of 0.18 eV

Density Functional Study of Stacking Structures and Electronic Behaviors of AnE-PV Copolymer.

Science.gov (United States)

Dong, Chuan-Ding; Beenken, Wichard J D

2016-10-10

In this work, we report an in-depth investigation on the π-stacking and interdigitating structures of poly(p-anthracene-ethynylene)-alt-poly(p-phenylene-vinylene) copolymer with octyl and ethyl-hexyl side chains and the resulting electronic band structures using density functional theory calculations. We found that in the π-stacking direction, the preferred stacking structure, determined by the steric effect of the branched ethyl-hexyl side chains, is featured by the anthracene-ethynylene units stacking on the phenylene-vinylene units of the neighboring chains and vice versa. This stacking structure, combined with the interdigitating structure where the branched side chains of the laterally neighboring chains are isolated, defines the energetically favorable structure of the ordered copolymer phase, which provides a good compromise between light absorption and charge-carrier transport.

Organic solar cells based on anthracene-containing PPE–PPVs and non-fullerene acceptors

KAUST Repository

Alam, Shahidul

2018-04-13

Lately, non-fullerene acceptors (NFAs) have received increasing attention for use in polymer-based bulk-heterojunction (BHJ) organic solar cells (OSCs), as improved photovoltaic performance compared to classical polymer–fullerene blends could be demonstrated. In this study, polymer solar cells based on a statistically substituted anthracene-containing poly(p-phenylene ethynylene)-alt-poly(p-phenylene vinylene)s (PPE–PPVs) copolymer (AnE-PVstat) as donor in combination with a number of different electron accepting materials were investigated. Strong photoluminescence quenching of the polymer donor indicates intimate intermixing of both materials. However, the photovoltaic performances were found to be poor compared to blends that use fullerene as acceptor. Time-delayed collection field (TDCF) measurements demonstrate: charge generation is field-independent, but bimolecular recombination processes limit the fill factor and thus the efficiency of devices.

Organic solar cells based on anthracene-containing PPE–PPVs and non-fullerene acceptors

KAUST Repository

Alam, Shahidul; Meitzner, Rico; Nwadiaru, Ogechi V.; Friebe, Christian; Cann, Jonathan; Ahner, Johannes; Ulbricht, Christoph; Kan, Zhipeng; Hö ppener, Stephanie; Hager, Martin D.; Egbe, Daniel A. M.; Welch, Gregory C.; Laquai, Fré dé ric; Schubert, Ulrich S.; Hoppe, Harald

2018-01-01

Lately, non-fullerene acceptors (NFAs) have received increasing attention for use in polymer-based bulk-heterojunction (BHJ) organic solar cells (OSCs), as improved photovoltaic performance compared to classical polymer–fullerene blends could be demonstrated. In this study, polymer solar cells based on a statistically substituted anthracene-containing poly(p-phenylene ethynylene)-alt-poly(p-phenylene vinylene)s (PPE–PPVs) copolymer (AnE-PVstat) as donor in combination with a number of different electron accepting materials were investigated. Strong photoluminescence quenching of the polymer donor indicates intimate intermixing of both materials. However, the photovoltaic performances were found to be poor compared to blends that use fullerene as acceptor. Time-delayed collection field (TDCF) measurements demonstrate: charge generation is field-independent, but bimolecular recombination processes limit the fill factor and thus the efficiency of devices.

Efficient Naphthalenediimide-Based Hole Semiconducting Polymer with Vinylene Linkers between Donor and Acceptor Units

KAUST Repository

Zhang, Lei

2016-11-04

We demonstrate a new method to reverse the polarity and charge transport behavior of naphthalenediimide (NDI)-based copolymers by inserting a vinylene linker between the donor and acceptor units. The vinylene linkers minimize the intrinsic steric congestion between the NDI and thiophene moieties to prompt backbone planarity. The polymers with vinylene linkers exhibit electron n-channel transport characteristics under vacuum, similar to the benchmark polymer, P(NDI2OD-T2). To our surprise, when the polymers are measured in air, the dominant carrier type switches from n- to p-type and yield hole mobilities up to 0.45 cm(2) s(-1) with hole to electron mobility ratio of three (mu(h)/mu(e), similar to 3), which indicates that the hole density in the active layer can be significantly increased by exposure to air. This increase is consistent with the intrinsic more delocalized nature of the highest occupied molecular orbital of the charged vinylene polymer, as estimated by density functional theory (DFT) calculations, which facilitates hole transport within the polymer chains. This is the first demonstration of an efficient NDI-based hole semiconducting polymer, which will enable new developments in all-polymer solar cells, complementary circuits, and dopable polymers for use in thermoelectrics.

Efficient Naphthalenediimide-Based Hole Semiconducting Polymer with Vinylene Linkers between Donor and Acceptor Units

KAUST Repository

Zhang, Lei; Rose, Bradley Daniel; Liu, Yao; Nahid, Masrur M.; Gann, Eliot; Ly, Jack; Zhao, Wei; Rosa, Stephen J.; Russell, Thomas P.; Facchetti, Antonio; McNei, Christopher R.; Bredas, Jean-Luc; Briseno, Alejandro L.

2016-01-01

We demonstrate a new method to reverse the polarity and charge transport behavior of naphthalenediimide (NDI)-based copolymers by inserting a vinylene linker between the donor and acceptor units. The vinylene linkers minimize the intrinsic steric congestion between the NDI and thiophene moieties to prompt backbone planarity. The polymers with vinylene linkers exhibit electron n-channel transport characteristics under vacuum, similar to the benchmark polymer, P(NDI2OD-T2). To our surprise, when the polymers are measured in air, the dominant carrier type switches from n- to p-type and yield hole mobilities up to 0.45 cm(2) s(-1) with hole to electron mobility ratio of three (mu(h)/mu(e), similar to 3), which indicates that the hole density in the active layer can be significantly increased by exposure to air. This increase is consistent with the intrinsic more delocalized nature of the highest occupied molecular orbital of the charged vinylene polymer, as estimated by density functional theory (DFT) calculations, which facilitates hole transport within the polymer chains. This is the first demonstration of an efficient NDI-based hole semiconducting polymer, which will enable new developments in all-polymer solar cells, complementary circuits, and dopable polymers for use in thermoelectrics.

Understanding triplet formation pathways in bulk heterojunction polymer : fullerene photovoltaic devices

NARCIS (Netherlands)

Tedla, B.; Zhu, F.; Cox, M.; Drijkoningen, J.; Manca, J.V.; Koopmans, B.; Goovaerts, E.

2015-01-01

Triplet exciton (TE) formation pathways are systematically investigated in prototype bulk heterojunction (BHJ) "super yellow" poly(p-phenylene vinylene) (SY-PPV) solar cell devices with varying fullerene compositions using complementary optoelectrical and electrically detected magnetic resonance

21 CFR 177.1345 - Ethylene/1,3-phenylene oxyethylene isophthalate/ terephthalate copolymer.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene/1,3-phenylene oxyethylene isophthalate... Ethylene/1,3-phenylene oxyethylene isophthalate/ terephthalate copolymer. Ethylene/1, 3-phenylene... polymers complying with § 177.1630. (a) Identity. For the purpose of this section, ethylene/1,3-phenylene...

Inflammatory myoglandular polyp--a rare but distinct type of colorectal polyps.

Science.gov (United States)

Becheanu, Gabriel; Stamm, Bernhard

2003-01-01

The aim of this paper was to report another example of a rare type of colorectal polyps, the inflammatory myoglandular polyp, and to reaffirm this type of polyp as a distinct entity. This solitary pedunculated polyp was detected after a single episode of rectal bleeding. It was situated in the sigmoid colon, measured 2.5 cm in greatest diameter, and was composed almost exclusively of smooth muscles and hyperplastic glands. The patient had neither chronic colitis nor diverticula. Clinical presentation, localization, and histology give this type of polyp a unique appearance and justify its designation as a separate entity.

Electrical characterization of single molecule and Langmuir–Blodgett monomolecular films of a pyridine-terminated oligo(phenylene-ethynylene derivative

Directory of Open Access Journals (Sweden)

Henrry M. Osorio

2015-05-01

Full Text Available Monolayer Langmuir–Blodgett (LB films of 1,4-bis(pyridin-4-ylethynylbenzene (1 together with the “STM touch-to-contact” method have been used to study the nature of metal–monolayer–metal junctions in which the pyridyl group provides the contact at both molecule–surface interfaces. Surface pressure vs area per molecule isotherms and Brewster angle microscopy images indicate that 1 forms true monolayers at the air–water interface. LB films of 1 were fabricated by deposition of the Langmuir films onto solid supports resulting in monolayers with surface coverage of 0.98 × 10−9 mol·cm−2. The morphology of the LB films that incorporate compound 1 was studied using atomic force microscopy (AFM. AFM images indicate the formation of homogeneous, monomolecular films at a surface pressure of transference of 16 mN·m−1. The UV–vis spectra of the Langmuir and LB films reveal that 1 forms two dimensional J-aggregates. Scanning tunneling microscopy (STM, in particular the “STM touch-to-contact” method, was used to determine the electrical properties of LB films of 1. From these STM studies symmetrical I–V curves were obtained. A junction conductance of 5.17 × 10−5 G0 results from the analysis of the pseudolinear (ohmic region of the I–V curves. This value is higher than that of the conductance values of LB films of phenylene-ethynylene derivatives contacted by amines, thiols, carboxylate, trimethylsilylethynyl or acetylide groups. In addition, the single molecule I–V curve of 1 determined using the I(s method is in good agreement with the I–V curve obtained for the LB film, and both curves fit well with the Simmons model. Together, these results not only indicate that the mechanism of transport through these metal–molecule–metal junctions is non-resonant tunneling, but that lateral interactions between molecules within the LB film do not strongly influence the molecule conductance. The results presented here

Optical properties of poly(2,6-dimethyl-1,4-phenylene oxide) film and its potential for a long-term solar ultraviolet dosimeter

International Nuclear Information System (INIS)

Lester, R A; Parisi, A V; Kimlin, M G; Sabburg, J

2003-01-01

The optical properties of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) film have been characterized in order to develop an alternative method for UV dosimetry with a focus on long-term human exposure measurements. The dynamic range of PPO film was found to extend to 2 MJ m -2 of broadband UV exposure independently of film thickness, providing an exposure range of roughly four summer days at subtropical latitudes. The sensitivity of the film to UV exposure was positively related to film thickness in the 20-40 μm range. Films of 40 μm thickness proved to be the most suitable for long-term human UV exposure measurements. The temperature independence of the response of 40 μm PPO film was established from 1.5 deg. C to 50 deg. C within a dosimeter response uncertainty of 6.5%. Dose-rate independence was also demonstrated within 8% of the mean dosimeter response. The spectral response approximates the CIE erythemal action spectrum between 300 and 340 nm, with a peak response at 305 nm. A large deviation from this action spectrum was observed at shorter wavelengths. Investigation of the angular response in both the azimuth and altitude planes showed a cosine error of less than 6.2% between 0 deg. and 40 deg., and did not exceed 13.3% at any angle greater than 40 deg. These results indicate that PPO film satisfies the requirements for use as a UV dosimeter, and may be employed in long-term human exposure measurements

Novel Electroactive Polymers as Environmentally Compliant Coatings for Corrosion Control

National Research Council Canada - National Science Library

Zarras, Peter; Mansfeld, Florian; Wynne, Kenneth, J; Tallman, Dennis E; Benicewicz, Brian C; Xu, Jun; Kendall, Gay

2006-01-01

The objectives of this SERDP program (WP 1148) have been completed successfully. The synthesis, scale-up and characterization of new monomers based on a bis-amino derivative of poly-p-phenylene vinylene (PPV) called poly(2,5-bis...

Vinylene carbonate and tris(trimethylsilyl) phosphite hybrid additives to improve the electrochemical performance of spinel lithium manganese oxide/graphite cells at 60 °C

International Nuclear Information System (INIS)

Koo, Bonjae; Lee, Jeongmin; Lee, Yongwon; Kim, Jun Ki; Choi, Nam-Soon

2015-01-01

Highlights: •The combination of tris(trimethylsilyl) phosphite and vinylene carbonate improves the electrochemical performance of lithium manganese oxide/graphite cells at 60 °C. •Removal of hydrogen fluoride and water by tris(trimethylsilyl) phosphite suppresses manganese dissolution from lithium manganese oxide. -- Abstract: The organophosphorus compounds tris(trimethylsilyl) phosphite (TMSP) and vinylene carbonate (VC) have been considered for use as functional additives to improve the electrochemical performance of Li 1.1 Mn 1.86 Mg 0.04 O 4 (LMO)/graphite full cells. Our investigation reveals that the combination of VC and TMSP as additives enhances the cycling properties and storage performance of full cells at 60 °C. The unique functions of the TMSP additive in the VC electrolyte are investigated via ex situ X-ray photoelectron spectroscopy (XPS) and 19 F nuclear magnetic resonance (NMR) measurements. The TMSP additive effectively eliminates trace water and hydrogen fluoride (HF) and produces a protective film on the LMO cathode that alleviates manganese dissolution at 60 °C

Determination of the trap-assisted recombination strength in polymer light emitting diodes

NARCIS (Netherlands)

Kuik, Martijn; Nicolai, Herman T.; Lenes, Martijn; Wetzelaer, Gert-Jan A. H.; Lu, Mingtao; Blom, Paul W. M.

2011-01-01

The recombination processes in poly(p-phenylene vinylene) based polymer light-emitting diodes (PLEDs) are investigated. Photogenerated current measurements on PLED device structures reveal that next to the known Langevin recombination also trap-assisted recombination is an important recombination

Stomach Polyps

Science.gov (United States)

... pylori) bacteria are a common cause of the gastritis that contributes to hyperplastic polyps and adenomas. Familial adenomatous polyposis. This rare, inherited syndrome increases the risk of colon cancer and other conditions, including stomach polyps. Certain medications. ...

Anionic PPV polymerization from the sulfinyl precursor route : Block copolymer formation from sequential addition of monomers

NARCIS (Netherlands)

Cosemans, Inge; Vandenbergh, Joke; Voet, Vincent S. D.; Loos, Katja; Lutsen, Laurence; Vanderzande, Dirk; Junkers, Thomas

2013-01-01

The sulfinyl precursor route for the synthesis of poly(p-phenylene vinylene) (PPV) materials via an anionic polymerization procedure employing dedicated initiators is evaluated in depth. Reaction kinetics are investigated to gain more control over the polymerization, since polymerization proceeds to

High-performance solution-processed polymer ferroelectric field-effect transistors

NARCIS (Netherlands)

Naber, RCG; Tanase, C; Blom, PWM; Gelinck, GH; Marsman, AW; Touwslager, FJ; Setayesh, S; De Leeuw, DM; Naber, Ronald C.G.; Gelinck, Gerwin H.; Marsman, Albert W.; Touwslager, Fred J.

We demonstrate a rewritable, non-volatile memory device with flexible plastic active layers deposited from solution. The memory device is a ferroelectric field-effect transistor (FeFET) made with a ferroelectric fluoropolymer and a bisalkoxy-substituted poly(p-phenylene vinylene) semiconductor

SPHENOCHOANAL POLYP: A CASE STUDY

Directory of Open Access Journals (Sweden)

Gaurav

2015-09-01

Full Text Available Sphenochoanal polyp is a rare clinical occurrence as compared to the much common antro - choanal polyp. It originates from the sphenoid sinus and extends into the choana via the sphenoid ostium. We present a case of spheno - choanal polyp and its clinical features and surgical management is discussed. Our aim in this case was to properly d elineate the origin of the polyp and differentiate it from other lesions such as the antro - choanal polyp and meningocele, followed by meticulous endoscopic excision of the polyp

Detection of colonic polyps in the elderly: Optimization of the single-contrast barium enema examination

International Nuclear Information System (INIS)

Gelfand, D.W.; Chen, Y.M.; Ott, D.J.; Munitz, H.A.

1986-01-01

Single-contrast studies account for 75% of barium enema examinations and are often performed in the elderly. By optimizing all factors, the following results were obtained: for polyps of less than 1 cm, 40 of 57 were detected (sensitivity, 70.2%); for polyps of 1 cm or larger, 33 of 35 were detected (sensitivity, 94%). Overall, 73 of 92 polyps were detected (sensitivity, 79.3%). These sensitivities result from meticulous preparation and the use of compression filming, low-density barium, moderate kilovoltages, high-resolution screens, remote control apparatus, and high-bandpass TV fluoroscopy. The authors conclude that an optimal single-contrast barium enema examination detects colonic polyps with a sensitivity approaching that of the double-contrast study and may be employed in elderly patients who cannot undergo the double-contrast study

Photoinduced electron-transfer from pi-conjugated polymers onto buckminsterfullerene, fulleroids, and methanofullerenes

NARCIS (Netherlands)

Janssen, R. A. J.; Hummelen, J. C.; Lee, Kwanghee; Pakbaz, K.; Sariciftci, N. S.; Heeger, A. J.; Wudl, F

1995-01-01

We present near-steady-state photoinduced absorption (PIA), photoluminescence, and light-induced electron spin resonance (LESR) studies on photoinduced electron transfer reactions from poly(bis-2,5-epi-cholestanoxy-1,4-phenylene vinylene) (BeCHA-PPV) as a donor to Buckminsterfullerene (C60) and a

A Nanoparticle Approach towards Morphology Controlled Organic Photovoltaics (OPV)

DEFF Research Database (Denmark)

Andersen, Thomas Rieks; Yan, Quanxiang; Larsen-Olsen, Thue Trofod

2012-01-01

Silicon nano-particles grafted with two different organic oligomers were prepared; the oligomers used were a phenylene-vinylene (PV) oligomer and a 3,3'''-didodecylquaterthiophene. The graftings were performed by the use of two different functional groups, the PV oligomer was grafted by a hydroxy...

Electron traps in semiconducting polymers : Exponential versus Gaussian trap distribution

NARCIS (Netherlands)

Nicolai, H. T.; Mandoc, M. M.; Blom, P. W. M.

2011-01-01

The low electron currents in poly(dialkoxy-p-phenylene vinylene) (PPV) derivatives and their steep voltage dependence are generally explained by trap-limited conduction in the presence of an exponential trap distribution. Here we demonstrate that the electron transport of several PPV derivatives can

Electron traps in semiconducting polymers: exponential versus Gaussian trap distribution

NARCIS (Netherlands)

Nicolai, H.T.; Mandoc, M.M.; Blom, P.W.M.

2011-01-01

The low electron currents in poly(dialkoxy-p-phenylene vinylene) (PPV) derivatives and their steep voltage dependence are generally explained by trap-limited conduction in the presence of an exponential trap distribution. Here we demonstrate that the electron transport of several PPV derivatives can

Supramolecular self-assembly and opto-electronic properties of semiconducting block copolymers

NARCIS (Netherlands)

Boer, Bert de; Stalmach, Ulf; Hutten, Paul F. van; Melzer, Christian; Krasnikov, Victor V.; Hadziioannou, Georges

2001-01-01

With continuous and nanometre-scale interpenetrating phases of electron donor and acceptor components, a novel diblock copolymer, in which one block is poly(p-phenylene vinylene) (PPV) and the other is a C60-functionalized polystyrene, is designed to be an efficient photovoltaic material. The

Influence of the polymer architecture on morphology and device properties of polymer bulk heterojunction photovoltaic cells

NARCIS (Netherlands)

Koetse, M.M.; Sweelssen, J.; Franse, T.; Veenstra, S.C.; Kroon, J.M.; Yang, X.N.; Alexeev, A.A.; Loos, J.; Schubert, U.S.; Schoo, H.F.M.; Kafafi, Z.H.; Lane, P.A.

2004-01-01

Polymer bulk hetero junction solar cells were made from poly(2-methoxy-5-(3,7-dimethyloctyloxy)-1,4-phenylene-vinylene) (MDMO-PPV) as donor and poly(cyanoetherphenylenevinylene) (PCNEPV) derivatives as acceptor material. In this paper we start out with discussing the synthesis of the materials.

Transient optical studies of charge recombination dynamics in a polymer/fullerene composite at room temperature

NARCIS (Netherlands)

Montanari, Ivan; Nogueira, Ana F.; Nelson, Jenny; Durrant, James R.; Winder, Christoph; Loi, Maria Antonietta; Sariciftci, Niyazi Serdar; Brabec, Christoph

2002-01-01

The recombination kinetics of photogenerated charge carriers in a composite of poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1-4-phenylene vinylene], (MDMO–PPV) and the functionalised fullerene 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C61 are investigated at room temperature by transient absorption

Electro-optical properties of a polymer light-emitting diode with an injection-limited hole contact

NARCIS (Netherlands)

van Woudenbergh, T; Blom, PWM; Huiberts, JN

2003-01-01

The electro-optical characteristics of a polymer light-emitting diode with a strongly reduced hole injection have been investigated. A silver contact on poly-dialkoxy-p-phenylene vinylene decreases the hole injection by five orders of magnitude, resulting in both a highly reduced light output and

Photoluminescence quenching through resonant energy transfer in blends of conjugated polymer with low-molecular acceptor

International Nuclear Information System (INIS)

Zapunidi, S. A.; Paraschuk, D. Yu.

2008-01-01

A model is proposed for photoluminescence quenching due to resonant energy transfer in a blend of a conjugated polymer and a low-molecular energy acceptor. An analytical dependence of the normalized photoluminescence intensity on the acceptor concentration is derived for the case of a homogeneous blend. This dependence can be described by two fitting parameters related to the Foerster radii for energy transfer between conjugated segments of the polymer and between the conjugated polymer segment and the energy acceptor. Asymptotic approximations are obtained for the model dependence that make it possible to estimate the contribution from the spatial migration of excitons to the photoluminescence quenching. The proposed model is used to analyze experimental data on the photoluminescence quenching in a blend of the soluble derivative of poly(p-phenylene vinylene) and trinitrofluorenone [13]. The Foerster radius for resonant energy transfer between the characteristic conjugated segment of poly(p-phenylene vinylene) and the energy acceptor is determined to be r F = 2.6 ± 0.3 nm

Angiomatous nasal polyp: Clinical diagnostic dilemma

Directory of Open Access Journals (Sweden)

Sunder Goyal

2015-03-01

Full Text Available Angiomatous polyp (Angiectatic nasal polyps is rare and its incidence is 4-5% of all nasal polyps. As it occurs with variable clinical features and there is no confirmatory preoperative investigation, clinical diagnosis can be a dilemma. Clinical picture of angiofibroma, simple antrochoanal polyp and inverted papilloma may resemble with each other. As polyps invade surrounding bone, these should be distinguished from a malignant mass. We present an interesting case of an infarcted angiectatic nasal polyp with extensive surrounding bony destruction. Correct preoperative radiological diagnosis is important to avoid unnecessary extensive surgery. Histopathological evaluation of polyps is mandatory since they require different treatment due to difference in the prognosis.

Injection-limited electron current in a methanofullerene

NARCIS (Netherlands)

Duren, J.K.J. van; Mihailetchi, V.D.; Blom, P.W.M.; Woudenbergh, T. van; Hummelen, J.C.; Rispens, M.T.; Janssen, R.A.J.; Wienk, M.M.

2003-01-01

The dark current of bulk-heterojunction photodiodes consisting of a blend of a methanofullerene (PCBM) as n-type electron acceptor and a dialkoxy-(p-phenylene vinylene) (OC1C10-PPV) as a p-type electron donor sandwiched between electrodes with different work functions has been investigated. With

Stability and photodegradation mechanisms of conjugated polymer/fullerene plastic solar cells

NARCIS (Netherlands)

Neugebauer, H.; Brabec, C.; Hummelen, J.C.; Sariciftci, N.S.

2000-01-01

Degradation studies of poly(2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene-vinylene) (MDMO-PPV), fullerenes ((6,6)-phenyl C-61-butyric acid methyl ester (PCBM) and C-60), and mixtures, which are the photoactive components in plastic solar cells, are shown. The degradation processes of the

Performance of injection-limited polymer light-emitting diodes

NARCIS (Netherlands)

Blom, P.W.M.; Woudenberg, T.V.; Huiberts, H.; Jabbour, GE; Carter, SA; Kido, J; Lee, ST; Sariciftci, NS

2002-01-01

The electro-optical characteristics of a polymer light emitting diode (PLED) with a strongly reduced hole injection have been investigated. The device consists of a poly-p-phenylene vinylene semiconductor with a Ag hole injecting contact, which has an injection barrier of about 1 eV. It is observed

Photoacoustic imaging for differential diagnosis of benign polyps versus malignant polyps of the gallbladder: A preliminary study

Energy Technology Data Exchange (ETDEWEB)

Chae, Hee Dong; Lee, Jae Young; Han, Joon Koo [Dept. of Radiology and Institute of Radiation Medicine, Seoul National University College of Medicine, Clinical Research Institute, Seoul National University Hospital, Seoul (Korea, Republic of); Jang, Jin Young; Kang, Mee Joo [Div. of Hepatobiliary-Pancreatic Surgery, Department of Surgery, Seoul National University College of Medicine, Seoul (Korea, Republic of); Chang, Jin Ho; Kang, Jeeun [Sogang University, Seoul (Korea, Republic of)

2017-09-15

To investigate the feasibility of ex vivo multispectral photoacoustic (PA) imaging in differentiating cholesterol versus neoplastic polyps, and benign versus malignant polyps, of the gallbladder. A total of 38 surgically confirmed gallbladder polyps (24 cholesterol polyps, 4 adenomas, and 10 adenocarcinomas) from 38 patients were prospectively included in this study. The surgical specimens were set on a gel pad immersed in a saline-filled container. The PA intensities of polyps were then measured, using two separate wavelength intervals (421–647 nm and 692–917 nm). Mann-Whitney U test was performed for the comparison of normalized PA intensities between the cholesterol and neoplastic polyps, and between the benign and malignant polyps. Kruskal-Wallis test was conducted for the comparison of normalized PA intensities among the cholesterol polyps, adenomas, and adenocarcinomas. A significant difference was observed in the normalized PA intensities between the cholesterol and neoplastic polyps at 459 nm (median, 1.00 vs. 0.73; p = 0.032). Comparing the benign and malignant polyps, there were significant differences in the normalized PA intensities at 765 nm (median, 0.67 vs. 0.78; p = 0.013), 787 nm (median, 0.65 vs. 0.77; p = 0.034), and 853 nm (median, 0.59 vs. 0.85; p = 0.028). The comparison of the normalized PA intensities among cholesterol polyps, adenomas, and adenocarcinomas demonstrated marginally significant differences at 765 nm (median, 0.67 vs. 0.66 vs. 0.78, respectively; p = 0.049). These preliminary results indicate that benign versus malignant gallbladder polyps might exhibit different spectral patterns on multispectral PA imaging.

Photoacoustic imaging for differential diagnosis of benign polyps versus malignant polyps of the gallbladder: A preliminary study

International Nuclear Information System (INIS)

Chae, Hee Dong; Lee, Jae Young; Han, Joon Koo; Jang, Jin Young; Kang, Mee Joo; Chang, Jin Ho; Kang, Jeeun

2017-01-01

To investigate the feasibility of ex vivo multispectral photoacoustic (PA) imaging in differentiating cholesterol versus neoplastic polyps, and benign versus malignant polyps, of the gallbladder. A total of 38 surgically confirmed gallbladder polyps (24 cholesterol polyps, 4 adenomas, and 10 adenocarcinomas) from 38 patients were prospectively included in this study. The surgical specimens were set on a gel pad immersed in a saline-filled container. The PA intensities of polyps were then measured, using two separate wavelength intervals (421–647 nm and 692–917 nm). Mann-Whitney U test was performed for the comparison of normalized PA intensities between the cholesterol and neoplastic polyps, and between the benign and malignant polyps. Kruskal-Wallis test was conducted for the comparison of normalized PA intensities among the cholesterol polyps, adenomas, and adenocarcinomas. A significant difference was observed in the normalized PA intensities between the cholesterol and neoplastic polyps at 459 nm (median, 1.00 vs. 0.73; p = 0.032). Comparing the benign and malignant polyps, there were significant differences in the normalized PA intensities at 765 nm (median, 0.67 vs. 0.78; p = 0.013), 787 nm (median, 0.65 vs. 0.77; p = 0.034), and 853 nm (median, 0.59 vs. 0.85; p = 0.028). The comparison of the normalized PA intensities among cholesterol polyps, adenomas, and adenocarcinomas demonstrated marginally significant differences at 765 nm (median, 0.67 vs. 0.66 vs. 0.78, respectively; p = 0.049). These preliminary results indicate that benign versus malignant gallbladder polyps might exhibit different spectral patterns on multispectral PA imaging

Crystallinity and the effect of ionizing radiation in polyethylene. V. Distribution of trans-vinylene and trans, trans conjugated double bonds in linear polyethylene

International Nuclear Information System (INIS)

Patel, G.N.

1975-01-01

Freeze-dried chain folded single crystals and the single crystals without amorphous surface layers (crystalline cores) of different thicknesses of linear polyethylene were irradiated with 60 Co γ-rays up to 600 Mrad. Concentration of trans-vinylene double bonds and conjugated diene produced during irradiation of the crystals was measured by infrared. Concentrations of trans-vinylene and of the conjugated diene were independent of thickness of crystalline core which suggest that the double bonds were randomly distributed in the crystalline parts of the crystals. Concentrations of trans-vinylene and of conjugated double bonds were lower in chain-folded crystals than in the crystalline cores and this suggests that the folds (amorphous surface layers) are less preferential sites for formation of the double bonds. The zero-order growth and first-order decay kinetics of trans-vinylene double bonds was studied by the equation derived by Dole et al. The equation is strictly obeyed up to 300 Mrad and the results then deviate. Since there is the decay of trans-vinylene double bonds and though there are no crosslinks in the crystalline cores, it has been suggested that the decay of the double bond does not result in the crosslinks

Microneedle crystals of cyano-substituted thiophene/phenylene co-oligomer epitaxially grown on KCl surface

Science.gov (United States)

Torii, Kazuki; Dokiya, Shohei; Tanaka, Yosuke; Yoshinaga, Shohei; Yanagi, Hisao

2017-06-01

A cyno-substituted thiophene/phenylene co-oligomer (TPCO), 5,5‧-bis(4‧-cyanobiphenyl-4-yl)-2,2‧-bithiophene (BP2T-CN), is vapor-deposited on KCl (001) surface kept at 220 °C by the mask-shadowing method. Transmission electron microscopy and fluorescence microscopy reveal that the deposited BP2T-CN crystallizes in two types of morphologies: microneedles and thin film crystallites. In particular, the predominant microneedles epitaxially grow in four directions in the manner that the BP2T-CN molecules align along the [110]KCl or [-110]KCl. X-ray diffraction patterns indicate that the BP2T-CN molecules in the microneedle lie parallel while those in the thin film crystallite obliquely stand on the KCl surface.

Hybrid TiO2: polymer photovoltaic cells made from a titanium oxide precursor

NARCIS (Netherlands)

Slooff, L.H.; Wienk, M.M.; Kroon, J.M.

2004-01-01

Hybrid TiO2:polymer photovoltaic cells were made from mixtures of titanium(IV) isopropoxide and poly[2-methoxy-5-(3',7'-dimethyloctyl)-p-phenylene vinylene] (MDMO-PPV) or poly(3-octyl thiophene) (P3OT) via hydrolysis in air. Cells were made with varying titanium(IV) isopropoxide:polymer ratios.

Enhanced Efficiency of Polymer Light-Emitting Diodes by Dispersing Dehydrated Nanotube Titanic Acid in the Hole-buffer Layer

Energy Technology Data Exchange (ETDEWEB)

Qian, L., E-mail: qian_lei@126.com; Xu, Z.; Teng, F.; Duan, X.-X. [Beijing Jiaotong University, Institute of Optoelectronic Technology (China); Jin, Z.-S.; Du, Z.-L. [Henan University, Key Laboratory on special functional materials (China); Li, F.-S.; Zheng, M.-J. [State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, Peking University, Department of Physics (China); Wang, Y.-S. [Beijing Jiaotong University, Institute of Optoelectronic Technology (China)

2007-06-15

Efficiency of polymer light-emitting diodes (PLEDs) with poly(2-methoxy-5-(2-ethyl hexyloxy)-p-phenylene vinylene) (MEH-PPV) as an emitting layer was improved if a dehydrated nanotubed titanic acid (DNTA) doped hole-buffer layer polyethylene dioxythiophene (PEDOT) was used. Photoluminescence (PL) and Raman spectra indicated a stronger interaction between DNTA and sulfur atom in thiophene of PEDOT, which suppresses the chemical interaction between vinylene of MEH-PPV and thiophene of PEDOT. The interaction decreases the defect states in an interface region to result in enhancement in device efficiency, even though the hole transporting ability of PEDOT was decreased.

Enhanced Efficiency of Polymer Light-Emitting Diodes by Dispersing Dehydrated Nanotube Titanic Acid in the Hole-buffer Layer

Science.gov (United States)

Qian, L.; Xu, Z.; Teng, F.; Duan, X.-X.; Jin, Z.-S.; Du, Z.-L.; Li, F.-S.; Zheng, M.-J.; Wang, Y.-S.

2007-06-01

Efficiency of polymer light-emitting diodes (PLEDs) with poly(2-methoxy-5-(2-ethyl hexyloxy)- p-phenylene vinylene) (MEH-PPV) as an emitting layer was improved if a dehydrated nanotubed titanic acid (DNTA) doped hole-buffer layer polyethylene dioxythiophene (PEDOT) was used. Photoluminescence (PL) and Raman spectra indicated a stronger interaction between DNTA and sulfur atom in thiophene of PEDOT, which suppresses the chemical interaction between vinylene of MEH-PPV and thiophene of PEDOT. The interaction decreases the defect states in an interface region to result in enhancement in device efficiency, even though the hole transporting ability of PEDOT was decreased.

Biexcitons in π-conjugated oligomers: Intensity-dependent femtosecond transient-absorption study

Science.gov (United States)

Klimov, V. I.; McBranch, D. W.; Barashkov, N.; Ferraris, J.

1998-09-01

We report femtosecond transient-absorption (TA) studies of a five-ring oligomer of poly(para-phenylene vinylene) prepared in two different forms: solid-state films and dilute solutions. At high pump fluences, in both types of samples, we observe generation of two-exciton states, which are detected by the evolution of TA spectra and dynamics with increasing pump intensity. In solutions, double excitation of molecules results in the formation of stable biexcitons with enhanced oscillator strength, leading to an increased efficiency of the radiative decay and a superlinear pump dependence of the stimulated emission. In solid-state samples, the two-exciton states are unstable and decay on the subpicosecond time scale due to ultrafast charge transfer, accompanied by generation of interchain excitons.

Tuning of metal work functions with self-assembled monolayers

NARCIS (Netherlands)

de Boer, B; Hadipour, A; Mandoc, MM; van Woudenbergh, T; Blom, PWM

2005-01-01

Work functions of gold and silver are varied by over 1.4 and 1.7 eV, respectively, by using self-assembled monolayers. Using these modified electrodes, the hole current in a poly(2-methoxy-5-(2'-ethylhexyloxy)- 1,4-phenylene vinylene) light-emitting diode is tuned by more than six orders of

Sporadic colorectal polyps and mismatch repair proteins

Directory of Open Access Journals (Sweden)

Mahsa Molaei

2011-01-01

Full Text Available Background: Colorectal cancers often arise from benign polyps. Adenomatous polyps and serrated polyps progress step by step to adenocarcinoma and change into malignant cancers. Genetic and epigenetic changes have correlation with specific stages of polyp-adenocarcinoma progression and colorectal cancer histopathological changes. Aims: In this study we used immunohistochemistry (IHC staining in sporadic colorectal polyps to assay functional status of MLH1, MSH2, MSH6, and PMS2 proteins, to track genetic/epigenetic roles of this issue in our patients. Materials and Methods: In this cross-sectional study we assessed all patients who were admitted with sporadic colorectal polyps and underwent polypectomy in endoscopy department during 2004-2008. Result: IHC results were abnormal in 6.8% cases for MLH1, in 4.5% cases for MSH2, in 3% for MSH6, and in 4.8% for PMS2. In all cases with abnormal PMS2, MLH1 was also reported as abnormal. Same results were reported for abnormal MSH2, which is accompanied with abnormal MSH6 in all cases (P values < 0.001. There is no significant difference between IHC staining results, gender, dysplasia grade, adenomatous type, and invasion. On the other hand, there was significant difference between IHC staining results, polyp location, and mean age of patients. The same significant difference was between adenomatous polyps and serrated adenoma polyps by MLH1 and PMS2 (P values < 0.05. Conclusion: According to our findings, maybe MMR dysfunction is the cause of sporadic colorectal polyps in younger age and its increasing risk of dysplasia progression and malignancy progression is only in serrated adenoma. Sporadic polyps in left colon had a higher risk to progress to malignancies, and abnormal IHC staining for MLH1 and PMS2 in serrated polyps is much more than in other adenomatous polyps.

Giant fibrovascular polyp of esophagus

Directory of Open Access Journals (Sweden)

Ramakanth Sannidi

2016-01-01

Full Text Available Benign tumors of esophagus are uncommon and account for only 3% of all esophageal neoplasms. Fibrovascular polyps (FVP are rare intraluminal tumors of esophagus. They are composed of fibrous tissue, vascular structures and covered with normal Squamous epithelium. Here we present a case of a 45 yr old gentleman with progressive dysphagia since 3 months. UGI endoscopy showed a long, linear, compressible mass extending from cricoid area to gastro-esophageal junction (GEJ. Patient was operated, through cervical incision esophgectomy done and polyp of size 16 × 7 cm was removed. Histopathology of polyp was suggestive of fibrovascular polyp. Post surgery patient was asymptomatic and doing well.

Device operation of conjugated polymer/zinc oxide bulk heterojunction solar cells

NARCIS (Netherlands)

Koster, L. Jan Anton; van Strien, Wouter J.; Beek, Waldo J. E.; Blom, Paul W. M.

2007-01-01

Solar cells based on a poly (p-phenylene vinylene) (PPV) derivative and zinc oxide nanoparticles can reach a power conversion efficiency of 1.6%. The transport of electrons and holes in these promising devices is characterized and it is found that the electron mobility is equal to 2.8 x 10(-9) m(2)

Evaluation of patients with gastric polyps.

Science.gov (United States)

Olmez, Sehmus; Sayar, Suleyman; Saritas, Bunyamin; Savas, Ayla Yildiz; Avcioglu, Ufuk; Tenlik, Ilyas; Ozaslan, Ersan; Koseoglu, Hasan Tankut; Altiparmak, Emin

2018-01-01

The incidence of gastric polyps (GPs) greatly differs according to study populations and was found to be 0.33%-6.7% in various studies. The majority of GPs are composed of hyperplastic polyps (HPs), fundic gland polyps (FGPs), and adenomatous polyps (APs). Although APs have a high risk of malignant potential, sporadic FGPs have no malignant potential. Conversely, HPs have a low risk of malignant potential. It is not sufficient to perform a biopsy to identify the polyp type and the presence of dysplasia; thus, some polyps may require multiple biopsies or total excision. This retrospective study included patients with GPs or polypoid lesions found on esophagogastroscopy with polyp or malignant histology on biopsy at Ankara Numune Training and Research Hospital Endoscopy Unit between 2005 and 2011. In a series of 56.300 upper endoscopies, 192 patients (0.34%) were found to have GPs. Among the patients, 51 (26.6%) were men and 151 (73.4%) were women. The average age of the patients was 61.9±13.3 (14-90) years. The frequency of HPs, APs, and FGPs were 88%, 2.6%, and 1.6%, respectively. The size of the polyps was ≤1 cm in 137 (70%) patients. One polyp was determined in 141 (73.4%) patients. The most common localizations of polyps were the antrum and corpus. Endoscopic snare polypectomy was performed in 64 patients. One bleeding episode was observed, which required endoscopic treatment after ESP. In our study, the GP frequency was low (0.34%), whereas the frequency of HP maybe high due to the high frequency of Helicobacter pylori (HPy) infection in our country. The frequency of FGP is probably low due to the high frequency of HPy infection and the short-term use of proton-pump inhibitors.

Automatic polyp detection in colonoscopy videos

Science.gov (United States)

Yuan, Zijie; IzadyYazdanabadi, Mohammadhassan; Mokkapati, Divya; Panvalkar, Rujuta; Shin, Jae Y.; Tajbakhsh, Nima; Gurudu, Suryakanth; Liang, Jianming

2017-02-01

Colon cancer is the second cancer killer in the US [1]. Colonoscopy is the primary method for screening and prevention of colon cancer, but during colonoscopy, a significant number (25% [2]) of polyps (precancerous abnormal growths inside of the colon) are missed; therefore, the goal of our research is to reduce the polyp miss-rate of colonoscopy. This paper presents a method to detect polyp automatically in a colonoscopy video. Our system has two stages: Candidate generation and candidate classification. In candidate generation (stage 1), we chose 3,463 frames (including 1,718 with-polyp frames) from real-time colonoscopy video database. We first applied processing procedures, namely intensity adjustment, edge detection and morphology operations, as pre-preparation. We extracted each connected component (edge contour) as one candidate patch from the pre-processed image. With the help of ground truth (GT) images, 2 constraints were implemented on each candidate patch, dividing and saving them into polyp group and non-polyp group. In candidate classification (stage 2), we trained and tested convolutional neural networks (CNNs) with AlexNet architecture [3] to classify each candidate into with-polyp or non-polyp class. Each with-polyp patch was processed by rotation, translation and scaling for invariant to get a much robust CNNs system. We applied leave-2-patients-out cross-validation on this model (4 of 6 cases were chosen as training set and the rest 2 were as testing set). The system accuracy and sensitivity are 91.47% and 91.76%, respectively.

Inappropriate colonoscopic surveillance of hyperplastic polyps.

LENUS (Irish Health Repository)

Keane, R A

2011-11-15

Colonoscopic surveillance of hyperplastic polyps alone is controversial and may be inappropriate. The colonoscopy surveillance register at a university teaching hospital was audited to determine the extent of such hyperplastic polyp surveillance. The surveillance endoscopy records were reviewed, those patients with hyperplastic polyps were identified, their clinical records were examined and contact was made with each patient. Of the 483 patients undergoing surveillance for colonic polyps 113 (23%) had hyperplastic polyps alone on last colonoscopy. 104 patients remained after exclusion of those under appropriate surveillance. 87 of the 104 patients (84%) were successfully contacted. 37 patients (8%) were under appropriate colonoscopic surveillance for a significant family history of colorectal carcinoma. 50 (10%) patients with hyperplastic polyps alone and no other clinical indication for colonoscopic surveillance were booked for follow up colonoscopy. This represents not only a budgetary but more importantly a clinical opportunity cost the removal of which could liberate valuable colonoscopy time for more appropriate indications.

Determinants of polyp Size in patients undergoing screening colonoscopy

Directory of Open Access Journals (Sweden)

Maisonneuve Patrick

2011-09-01

Full Text Available Abstract Background Pre-existing polyps, especially large polyps, are known to be the major source for colorectal cancer, but there is limited available information about factors that are associated with polyp size and polyp growth. We aim to determine factors associated with polyp size in different age groups. Methods Colonoscopy data were prospectively collected from 67 adult gastrointestinal practice sites in the United States between 2002 and 2007 using a computer-generated endoscopic report form. Data were transmitted to and stored in a central data repository, where all asymptomatic white (n = 78352 and black (n = 4289 patients who had a polyp finding on screening colonoscopy were identified. Univariate and multivariate analysis of age, gender, performance site, race, polyp location, number of polyps, and family history as risk factors associated with the size of the largest polyp detected at colonoscopy. Results In both genders, size of the largest polyp increased progressively with age in all age groups (P P Conclusions In both genders there is a significant increase in polyp size detected during screening colonoscopy with increasing age. Important additional risk factors associated with increasing polyp size are gender, race, polyp location, and number of polyps, with polyp multiplicity being the strongest risk factor. Previous family history of bowel cancer was not a risk factor.

Inflammatory fibroid polyp of sigmoid colon.

Science.gov (United States)

Lifschitz, O; Lew, S; Witz, M; Reiss, R; Griffel, B

1979-01-01

A case of inflammatory fibroid polyp of the sigmoid colon is presented. This is the eight case of this type of polyp in the colon and, to the best of our knowledge, the first one involving the sigmoid and producing intussusception. Symptomatology of the inflamed fibroid polyp in this part of the gut closely simulates gastrointestinal malignancy. The treatment is surgical excision of the polyp, or colonoscopic resection when it is possible. Intraoperative colonoscopy helps the surgeon to localize the lesion and to role out the existence of other lesions.

Photoelectrochemical properties of ZnO nanocrystals/MEH-PPV composite: The effects of nanocrystals synthetic route, film deposition and electrolyte composition

Energy Technology Data Exchange (ETDEWEB)

Petrella, A. [Dipartimento di Ingegneria Civile, Ambientale, del Territorio, Edile e Chimica, Politecnico di Bari, Via Orabona 4, 70125 Bari (Italy); Curri, M.L.; Striccoli, M. [CNR IPCF Sez. Bari c/o Dip. Chimica, Università di Bari, Via Orabona 4, 70126 Bari (Italy); Agostiano, A. [Dipartimento di Chimica, Università di Bari, via Orabona 4, 70126 Bari (Italy); CNR IPCF Sez. Bari c/o Dip. Chimica, Università di Bari, Via Orabona 4, 70126 Bari (Italy); Cosma, P., E-mail: pinalysa.cosma@uniba.it [Dipartimento di Chimica, Università di Bari, via Orabona 4, 70126 Bari (Italy); CNR IPCF Sez. Bari c/o Dip. Chimica, Università di Bari, Via Orabona 4, 70126 Bari (Italy)

2015-11-30

This paper reports a study on the photoelectrochemical processes occurring at the interface of ZnO nanocrystals/MEH-PPV composites. Colloidal chemical routes were used to obtain size controlled non-hydrolytic ZnO nanocrystals (NCs) dispersible in organic solvents, while a low molecular weight poly[2-methoxy-5-(2′-ethyl-hexyloxy)phenylene vinylene] (MEH-PPV), characterized by high degree of structural order, was synthesized via an organometallic method. The optical properties of the nanocomposite material were comprehensively investigated on solution and on films deposited by spin coating. Remarkably, a significant fluorescence quenching of the polymer at the MEH-PPV/ZnO junction was observed. Photoelectrochemical measurements demonstrated that the photoactivity of the composite material was significantly improved in the case of non-hydrolytic NCs with respect to hydrolytic route prepared ZnO. Moreover, the effective role of the organic/inorganic blend to improve the charge transfer with respect to the double layer hetero-junction was confirmed, thanks to the extended interfaces which enable an effective electron transfer between the hetero-junction components. The system was also studied at different film thicknesses and electrolyte compositions. The results indicated that film photoactivity increased with film thickness up to 300 nm due to the presence of a large number of interfaces, while the change of cation size influenced the ionic conductivity through the nanocomposite film. It was shown that efficient photoconductivity requires not only efficient charge separation, but also efficient transport of the carriers to the electrodes without recombination. - Highlights: • The photoelectrochemical processes at ZnO nanocrystals/MEH-PPV hetero-junction were studied. • Fluorescence quenching of the polymer at the MEH-PPV/ZnO interface was observed. • Non-hydrolytic ZnO junction showed higher photocurrents than hydrolytic equivalent. • The blends showed

Photoelectrochemical properties of ZnO nanocrystals/MEH-PPV composite: The effects of nanocrystals synthetic route, film deposition and electrolyte composition

International Nuclear Information System (INIS)

Petrella, A.; Curri, M.L.; Striccoli, M.; Agostiano, A.; Cosma, P.

2015-01-01

This paper reports a study on the photoelectrochemical processes occurring at the interface of ZnO nanocrystals/MEH-PPV composites. Colloidal chemical routes were used to obtain size controlled non-hydrolytic ZnO nanocrystals (NCs) dispersible in organic solvents, while a low molecular weight poly[2-methoxy-5-(2′-ethyl-hexyloxy)phenylene vinylene] (MEH-PPV), characterized by high degree of structural order, was synthesized via an organometallic method. The optical properties of the nanocomposite material were comprehensively investigated on solution and on films deposited by spin coating. Remarkably, a significant fluorescence quenching of the polymer at the MEH-PPV/ZnO junction was observed. Photoelectrochemical measurements demonstrated that the photoactivity of the composite material was significantly improved in the case of non-hydrolytic NCs with respect to hydrolytic route prepared ZnO. Moreover, the effective role of the organic/inorganic blend to improve the charge transfer with respect to the double layer hetero-junction was confirmed, thanks to the extended interfaces which enable an effective electron transfer between the hetero-junction components. The system was also studied at different film thicknesses and electrolyte compositions. The results indicated that film photoactivity increased with film thickness up to 300 nm due to the presence of a large number of interfaces, while the change of cation size influenced the ionic conductivity through the nanocomposite film. It was shown that efficient photoconductivity requires not only efficient charge separation, but also efficient transport of the carriers to the electrodes without recombination. - Highlights: • The photoelectrochemical processes at ZnO nanocrystals/MEH-PPV hetero-junction were studied. • Fluorescence quenching of the polymer at the MEH-PPV/ZnO interface was observed. • Non-hydrolytic ZnO junction showed higher photocurrents than hydrolytic equivalent. • The blends showed

Writable and erasable PPV medium by irradiation at 365 nm

Energy Technology Data Exchange (ETDEWEB)

Mochizuki, Hiroyuki [Photonics Research Institutes, National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan)], E-mail: h-mochizuki@aist.go.jp; Mizokuro, Toshiko; Tanigaki, Nobutaka; Hiraga, Takashi [Photonics Research Institutes, National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan)

2008-03-03

Dopings of vaporized cis-1,2-dicyano-1,2-bis(2,4,5-trimethyl-3-thienyl) ethane (CMTE) into poly(methyl methacrylate) (PMMA), polystyrene, and polycarbonate were performed by a vacuum process, and the doping behaviors of CMTE were evaluated. Among the matrix polymers, PMMA was dispersed CMTE densely in its surface region. By using the CMTE-doped PMMA, we could fabricate a novel rewritable medium: a multi-layered film was prepared from over-coating of CMTE-doped PMMA onto poly(p-phenylene vinylene) (PPV) film, which set on a transparent substrate. Image storage could be performed upon irradiation at 365 nm at the side of CMTE/PMMA layer: color of the irradiated area changed a light yellow to a red due to photo-isomerization of CMTE. Next, upon irradiation at 365 nm at the side of the transparent substrate, PPV emitted a green fluorescence at around 530 nm, and the CMTE absorbed the emission from PPV causing image-erasure based on back-isomerization of CMTE.

Multilayer polymer light-emitting diodes by blade coating method

Science.gov (United States)

Tseng, Shin-Rong; Meng, Hsin-Fei; Lee, Kuan-Chen; Horng, Sheng-Fu

2008-10-01

Multilayer polymer light-emitting diodes fabricated by blade coating are presented. Multilayer of polymers can be easily deposited by blade coating on a hot plate. The multilayer structure is confirmed by the total thickness and the cross section view in the scanning electron microscope. The film thickness variation is only 3.3% in 10cm scale and the film roughness is about 0.3nm in the micron scale. The efficiency of single layer poly(para-phenylene vinylene) copolymer Super Yellow and poly(9,9-dioctylfluorene) (PFO, deep blue) devices are 9 and 1.7cd/A, respectively, by blade coating. The efficiency of the PFO device is raised to 2.9cd/A with a 2-(4-tert-butylphenyl)-5-(4-biphenylyl)-1,3,4-oxadiazole (PBD) hole-blocking layer and to 2.3cd/A with a poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl))diphenylamine)] elec-tron-blocking layer added by blade coating.

Biexcitons in {pi}-conjugated oligomers: Intensity-dependent femtosecond transient-absorption study

Energy Technology Data Exchange (ETDEWEB)

Klimov, V.I.; McBranch, D.W. [Chemical Science and Technology Division, CST-6, Mail Stop J585, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Barashkov, N.; Ferraris, J. [Chemistry Department, University of Texas, Dallas, Texas 75083 (United States)

1998-09-01

We report femtosecond transient-absorption (TA) studies of a five-ring oligomer of poly({ital para}-phenylene vinylene) prepared in two different forms: solid-state films and dilute solutions. At high pump fluences, in both types of samples, we observe generation of two-exciton states, which are detected by the evolution of TA spectra and dynamics with increasing pump intensity. In solutions, double excitation of molecules results in the formation of stable biexcitons with enhanced oscillator strength, leading to an increased efficiency of the radiative decay and a superlinear pump dependence of the stimulated emission. In solid-state samples, the two-exciton states are unstable and decay on the subpicosecond time scale due to ultrafast charge transfer, accompanied by generation of interchain excitons. {copyright} {ital 1998} {ital The American Physical Society}

The Polyp Manager: a new tool for optimal polyp documentation during colonoscopy. A pilot study.

Science.gov (United States)

van de Meeberg, Maartje M.; Ouwendijk, Rob J. Th.; ter Borg, Pieter C. J.; van den Hazel, Sven J.; van de Meeberg, Paul C.

2016-01-01

Background and study aims: Conventional reporting of polyps is often incomplete. We tested the Polyp Manager (PM), a new software application permitting the endoscopist to document polyps in real time during colonoscopy. We studied completeness of polyp descriptions, user-friendliness and the potential time benefit. Patients and methods: In two Dutch hospitals colonoscopies were performed with PM (as a touchscreen endoscopist-operated device or nurse-operated desktop application). Completeness of polyp descriptions was compared to a historical group with conventional reporting (CRH). Prospectively, we compared user-friendliness (VAS-scores) and time benefit of the endoscopist-operated PM to conventional reporting (CR) in one hospital. Duration of colonoscopy and time needed to report polyps and provide a pathology request were measured. Provided that using PM does not prolong colonoscopy, the sum of the latter two was considered as a potential time-benefit if the PM were fully integrated into a digital reporting system. Results: A total of 144 regular colonoscopies were included in the study. Both groups were comparable with regard to patient characteristics, duration of colonoscopy and number of polyps. Using the PM did reduce incomplete documentation of the following items in CRH-reports: location (96 % vs 82 %, P = 0.01), size (95 % vs 89 %, P = 0.03), aspect (71 % vs 36 %, P < 0.001) and completeness of removal (61 % vs 37 %, P < 0.001). In the prospective study 23 PM-colonoscopies where compared to 28 CR-colonoscopies. VAS-scores were significantly higher in the endoscopist-operated PM group. Time to report was 01:27 ± 01:43 minutes (median + interquartile range) in the entire group (PM as CR), reflecting potential time benefit per colonoscopy. Conclusions: The PM is a user-friendly tool that seems to improve completeness of polyp reporting. Once integrated with digital reporting systems, it is probably time saving as

Sonographic diagnosis of juvenile polyps in children.

Science.gov (United States)

Zhang, Yao; Li, Shi-Xing; Xie, Li-Mei; Shi, Bo; Ju, Hao; Bai, Yu-Zuo; Zhang, Shu-Cheng

2012-09-01

The aim of this study was to assess the diagnostic value of ultrasonography for juvenile polyps in children and their sonographic characteristics. A retrospective analysis was performed of the ultrasound findings in 27 children who were diagnosed preoperatively with juvenile polyp within the intestinal tract by ultrasonography and then confirmed by colonoscopy, laparotomy and histopathology. The ultrasonic finding common to all polyps was an isolated intraluminal nodular or massive protrusion, associated with multiple mesh-like fluid areas of different sizes. In 25 children, surrounding pedicle-like low echoes of varying lengths were seen connecting with the polyps to form "mushroom" sign. The color Doppler showed abundant blood flow signals within all polyps and pedicles in a shape of a branch or an umbrella. For seven children with an intussusception, the polyp shadow was detected in the cervical part or interior of the intussusception. Ultrasonography is, thus, considered to be a feasible method for diagnosing intestinal juvenile polyp. Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Phenylene ring dynamics in bisphenol-A-polysulfone by neutron scattering

International Nuclear Information System (INIS)

Arrese-Igor, S.; Arbe, A.; Alegria, A.; Colmenero, J.; Frick, B.

2004-01-01

We have investigated the dynamics of phenylene rings in a glassy polysulfone (bisphenol-A-polysulfone) by means of quasielastic neutron scattering. Nowadays it is well known that these molecular motions are directly connected with the mechanical properties of engineering thermoplastics in general. The particular system investigated by us has the advantage that by selective deuteration of the methyl groups, the neutron scattering measured is dominated by the incoherent contribution from the protons in the phenylene rings. In this way, the dynamics of such molecular groups can be experimentally isolated. Two different types of neutron spectrometers: time of flight and backscattering, were used in order to cover a wide dynamic range, which extends from microscopic (10 -13 s) to mesoscopic (10 -9 s) times. Moreover, neutron diffraction experiments with polarization analysis were also carried out in order to characterize the structural features of the sample investigated. Fast oscillations of increasing amplitude with temperature and π-flips are identified for phenylene rings motions. Due to the structural disorder characteristic of the amorphous state, both molecular motions display a broad distribution of relaxation times, which spreads over several orders of magnitude. Based on the results obtained, we propose a model for phenylene rings dynamics, which combines the two kinds of molecular motions identified. This model nicely describes the neutron scattering results in the whole dynamic range investigated

IR Laser Ablative Degradation of Poly(phenylene ether sulfone): Deposition of Films Containing Sulfone, Sulfoxide and Sulfide Groups

Czech Academy of Sciences Publication Activity Database

Blazevska-Gilev, J.; Bastl, Zdeněk; Šubrt, Jan; Stopka, Pavel; Pola, Josef

2009-01-01

Roč. 94, č. 2 (2009), s. 196-200 ISSN 0141-3910 R&D Projects: GA AV ČR IAA400720619 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z40400503; CEZ:AV0Z40320502 Keywords : laser ablation * laser-induced degradation * poly(1,4-phenylene ether-sulfone) Subject RIV: CH - Nuclear ; Quantum Chemistry Impact factor: 2.154, year: 2009

Effect of the morphology in the electrical conductivity of poly (phenylene sulfide)

International Nuclear Information System (INIS)

Lunardi, G.J.; Bretas, R.E.S.

1988-01-01

Poly (phenylene sulfide), PPS, is a polymer that can become electrically conducally condutive after treated with strong oxidizing agents, such as AsF 5 AlCl 3 and SO 3 . A study of the influence of morphology on the PPS electrical conductivity was carried out, in which specimens (films) made by different processing conditions were employed. Specimens were characterized by Polarized Light Microscopy, Electron Scanning Microscopy and wide angle X-Ray Diffraction. doping of PPS with a solution of AlCl 3 in CH 2 Cl 2 (saturated) reveals that conductivity drops when crystallinity roses. Doping of PPS specimens with a gaseous mixture of AlCl 3 and dry HCl yields a conductivity value independent of the initial crystallinity. (author) [pt

Frequency of Thyroid Nodules among Patients with Colonic Polyps

Directory of Open Access Journals (Sweden)

Cevdet Duran

2012-01-01

Full Text Available Aim. Colonic polyps and thyroid nodules are common diseases and their frequency increases with age. In the literature, there is no study investigating the coexistence of colonic polyps and thyroid nodules. Therefore, this study was designed to investigate thyroid nodule prevalence in patients with colonic polyps. Material and Methods. Sixty-six patients with colonic polyps and 146 patients without colonic polyps enrolled into the study. Age and sex matched control group was composed from patients without colonic polyps. Colonoscopic examinations, thyroid ultrasonographies were performed in all patients, and TSH were measured. Results. Male/female ratio in polyp and control groups were 40/26 versus 68/78, respectively (P=0.058. Mean ages were similar in both groups (53.3±11.4 versus, 51.8±11.4, P=0.373. Thyroid nodule was detected in 44 (66.7% patients with polyps and in 61 (41.8% controls (P=0.001. Patients with adenomatous polyps had 5 or more thyroid nodules compared to patients with hyperplastic polyps (P=0.03. Thyroid nodules were more prevalent among patients aged 50 or older compared to 50 years or less (P=0.023. Conclusion. Thyroid nodules were detected more common in patients with colonic polyps. Further studies are needed to clarify this coexistence.

Solid polymer electrolytes based on alternating copolymers of vinyl ethers with methoxy oligo(ethyleneoxy)ethyl groups and vinylene carbonate

International Nuclear Information System (INIS)

Itoh, Takahito; Fujita, Katsuhito; Inoue, Kentaro; Iwama, Hiroki; Kondoh, Kensaku; Uno, Takahiro; Kubo, Masataka

2013-01-01

Graphical abstract: - Highlights: • Synthesis of alternating copolymers of vinyl ethers and vinylene carbonate. • Preparation of polymer electrolytes based on the alternating copolymers with LiTFSI. • Structure-property relationship for alternating copolymers-based electrolytes. • Interfacial stability between polymer electrolytes with lithium metal electrode. - Abstract: Alternating copolymers (poly(1a-g-alt-VC)) of vinyl ethers with various methoxy oligo(ethyleneoxy)ethyl groups and vinylene carbonate (VC) were prepared, and the thermal and electrochemical properties of their polymer electrolytes with LiTFSI and interfacial stability between the polymer electrolyte and Li metal electrode were investigated. T g 's increased linearly with salt contents, and decreased with an increase in the chain length of methoxy oligo(ethyleneoxy)ethyl groups in the vinyl ethers at constant salt concentration. The slopes of T g vs. [Li]/[O] were identical, independent of the polymer structure. The ionic conductivities of the polymer electrolytes increased with increasing the side-chain ethyleneoxy (EO) unit length of the vinyl ether unit in the alternating copolymers, and also their temperature dependences became relatively smaller in the polymer electrolytes having longer EO units in the vinyl ethers. The highest ionic conductivity, 1.2 × 10 −4 S/cm at 30 °C, was obtained in the alternating copolymer with a side-chain EO unit length of 23.5 in the vinyl ether unit. Ion transport coupled with the segmental motion of the polymer is dominant in these polymer electrolytes. Interfacial resistance increased gradually with contact time, indicative of the formation of passivation films on the Li metal electrode. These polymer electrolytes are thermally stable and have large electrochemical windows of use

Photophysical, electrochemical and photovoltaic properties of thiophene-containing arylene-ethynylene/arylene-vinylene polymers

International Nuclear Information System (INIS)

Egbe, Daniel Ayuk Mbi; Huong Nguyen, Le; Muehlbacher, David; Hoppe, Harald; Schmidtke, Kathy; Serdar Sariciftci, Niyazi

2006-01-01

This work reports the properties of two types of thiophene-containing poly(arylene-ethynylene)-alt-poly(arylene-vinylene)s polymers, whose repeating units (-Ph-C≡C-Th-CH=CH-Ph-CH=CH-) n , 1, and (-Th-C≡C-Ph-C≡C-Th-CH=CH-Ph-CH=CH-) n , 2, consist respectively of a 1 : 2 and a 2 : 2 ratio of -C≡C-/-CH=CH- moieties. Although similar electrochemical data (HOMO: - 5.43 eV, LUMO: ∼- 3.15 eV, E g ec = 2.28 eV) as well as identical thin film absorption behaviour (λ a = 501 nm, E g opt = 2.10 eV) were obtained for both types of materials, significant differences in their thin film photoluminescence behaviour and photovoltaic properties were observed. While polymer 1 shows a fluorescence maximum at λ e = 568 nm (with a fluorescence quantum yield of Φ f = 7%), a total fluorescence quenching was observed in 2. Solar cells (set up: ITO/PEDOT : PSS/active layer/LiF/Al; active layer consisting of 1 or 2 as donor and PCBM as acceptor in a 1 : 3 ratio by weight) designed from 1 (best cell: V OC = 900 mV, I SC = 2.51 mA.cm -2 , FF = 53.7%, η AM1.5 = 1.21%) show far better photovoltaic performance than those from 2 (best cell: V OC = 500 mV, I SC = 1.44 mA.cm -2 , FF = 37.1%, η AM1.5 = 0.27%)

Solid-state deep blue and UV fluorescent dyes based on para-bis(2-thienyl)phenylene

Energy Technology Data Exchange (ETDEWEB)

Krajčovič, Jozef; Kovalenko, Alexander, E-mail: kovalenko.alx@gmail.com; Heinrichová, Patricie; Vala, Martin; Weiter, Martin

2015-11-15

Despite the general rule of strong acceptor substituents having a tendency to quench fluorescence due to molecular stacking, it is shown how tetra-fluorination of the central phenylene unit of para-bis(2-thienyl)phenylene can augment the quantum yields of solid state fluorescent dyes. Another significant part of the present research was the study of the influence of the position of the solubilization alkyl chains position on the fluorescent properties of the abovementioned non- and tetra-fluorinated materials. Tenfold augmentation of quantum yields, depending on the position of the alkyl chains is reported. - Highlights: • Solid state luminescence was observed in para-bis(2-thienyl)phenylene molecules. • Quantum yields was augmented by polyfluorination of the central phenylene unit. • Tenfold augmentation of luminescence was observed by changing alkyls position. • Possibilities of steric hindrance and charge transfer were studied.

Nasal polyps

Science.gov (United States)

... shrink polyps, and can reduce swelling and nasal congestion. The effect lasts a few months in most ... this procedure, your doctor uses a thin, lighted tube with instruments at the end. The tube is ...

A Rare Complication of Hyperplastic Gastric Polyp

Directory of Open Access Journals (Sweden)

Suresh Kumar Nayudu

2013-01-01

Full Text Available Hyperplastic gastric polyps are incidentally diagnosed during upper gastrointestinal endoscopy. They are known to cause gastric outlet obstruction and chronic blood loss leading to iron deficiency anemia. However, hyperplastic gastric polyp presenting as acute severe upper gastrointestinal bleeding is very rare. To the best of our knowledge, there have been two cases of hyperplastic gastric polyps presenting as acute gastrointestinal bleeding in the medical literature. We present a case of a 56-year-old African American woman who was admitted to our hospital with symptomatic anemia and sepsis. The patient developed acute upper gastrointestinal bleeding during her hospital stay. She underwent emergent endoscopy, but bleeding could not be controlled. She underwent emergent laparotomy and wedge resection to control the bleeding. Biopsy of surgical specimen was reported as hyperplastic gastric polyp. We recommend that physicians should be aware of this rare serious complication of hyperplastic gastric polyps as endoscopic polypectomy has diagnostic and therapeutic benefits in preventing future complications including bleeding.

ETIOLOGICAL FACTORS FOR VOCAL FOLD POLYP FORMATION

Directory of Open Access Journals (Sweden)

DAŠA GLUVAJIĆ

2016-05-01

Full Text Available Background: Vocal fold polyp is one of the most common causes for hoarseness. Many different etiological factors contribute to vocal fold polyp formation. The aim of the study was to find out whether the etiological factors for polyp formation have changed in the last 30 years.Methods: Eighty-one patients with unilateral vocal fold polyp were included in the study. A control group was composed of 50 volunteers without voice problems who matched the patients by age and gender. The data about etiological factors and the findings of phoniatric examination were obtained from the patients' medical documentation and from the questionnaires for the control group. The incidence of etiological factors was compared between the two groups. The program SPSS, Version 18 was used for statistical analysis.Results: The most frequent etiological factors were occupational voice load, GER, allergy and smoking. In 79% of patients 2 – 6 contemporary acting risk factors were found. Occupational voice load (p=0,018 and GER (p=0,004 were significantly more frequent in the patients than in the controls. The other factors did not significantly influence the polyp formation.Conclusions: There are several factors involved simultaneously in the formation of vocal fold polyps both nowadays and 30 years ago. Some of the most common factors remain the same (voice load, smoking, others are new (GER, allergy, which is probably due to the different lifestyle and working conditions than 30 years ago. Occupational voice load and GER were significantly more frequently present in the patients with polyp than in the control group. Regarding the given results it is important to instruct workers with professional vocal load about etiological factors for vocal fold polyp formation.

Epidemiology of goblet cell and microvesicular hyperplastic polyps.

Science.gov (United States)

Qazi, Taha M; O'Brien, Michael J; Farraye, Francis A; Gould, Ryan W; Chen, Clara A; Schroy, Paul C

2014-12-01

Serrated polyps compromise both typical hyperplastic polyps as well as sessile serrated adenomas and dysplastic serrated polyps. Hyperplastic polyps exhibit two histological patterns: microvesicular hyperplastic polyps (MVHPs) and goblet cell hyperplastic polyps (GCHPs). MVHPs and GCHPs differ in their molecular signature. MVHPs have been frequently found to have the BRAF(V600E) mutation as well as aberrant methylation. In contrast, GCHPs have been associated with the KRAS mutation (KRAS-mut), which are infrequently seen in dysplastic serrated sessile adenomas. The particular risk factors that are associated with development of the types of hyperplastic polyps have not been previously studied. The purpose of this study is to characterize the associations between particular risk factors and the development of goblet cell or microvesicular hyperplastic polyps. We conducted a cross-sectional analysis of 3,543 asymptomatic, mostly average risk patients 50 and 79 years of age undergoing open-access screening colonoscopy between March 2005 and January 2012. Each patient was given a survey regarding 25 reputed risk factors for colorectal neoplasia and the responses were correlated with findings at colonoscopy. Associations between putative risk factors for colorectal neoplasia and MVHPs and GSHPs were examined using multiple logistic regression. MVHPS and GCHPs were identified in 5.3% and 8.7% of patients, respectively. The results of the statistical analysis indicate that a history of smoking greater than 20 years is associated with an increased risk of MVHPs (P30 kg/m(2) was also associated with the presence of MVHP at colonoscopy (PGCHP at colonoscopy in blacks. The study suggests that the development of the distinct histological types of hyperplastic polyps are associated with distinct modifiable and non-modifiable lifestyle factors.

Chain-length dependent para-phenyelene film- and needle-growth on dielectrics

DEFF Research Database (Denmark)

Balzer, Frank; Rubahn, Horst-Günter

2004-01-01

Surface unit cells of vacuum grown ultrathin films of blue-light emitting para-phenylene oligomers on alkali halides and on muscovite mica have been determined using low energy electron diffraction. Both, films from upright and from laying molecules are grown on alkali halide (1 0 0) and mica (0 ...

Antiferromagnetic exchange in meta-phenylene bridged bis(tris-o-iminosemiquinonato)metal complexes

International Nuclear Information System (INIS)

Dei, A.; Gatteschi, D.; Sangregorio, C.; Sorace, L.; Vaz, M.G.F.

2004-01-01

By reaction of the ligand N,N' bis(3,5-di-tert-butyl-2-hydroxyphenyl)-1,3-phenylenediamine (1), with Fe, Co or Mn salts, three complexes were synthesized where the bis-bidentate ligand is in the bis-semiquinonato oxidation state. Although the m-phenylene linker is known to afford ferromagnetic coupling in diradicals, the antiferromagnetic interaction of intramolecular origin we observed is not unexpected, given the large torsion angles between the semiquinonato and the m-phenylene planes

Antiferromagnetic exchange in meta-phenylene bridged bis(tris-o-iminosemiquinonato)metal complexes

Energy Technology Data Exchange (ETDEWEB)

Dei, A. E-mail: andrea.dei@unifi.it; Gatteschi, D.; Sangregorio, C.; Sorace, L.; Vaz, M.G.F

2004-05-01

By reaction of the ligand N,N' bis(3,5-di-tert-butyl-2-hydroxyphenyl)-1,3-phenylenediamine (1), with Fe, Co or Mn salts, three complexes were synthesized where the bis-bidentate ligand is in the bis-semiquinonato oxidation state. Although the m-phenylene linker is known to afford ferromagnetic coupling in diradicals, the antiferromagnetic interaction of intramolecular origin we observed is not unexpected, given the large torsion angles between the semiquinonato and the m-phenylene planes.

Association between colonic polyps and diverticular disease

Institute of Scientific and Technical Information of China (English)

Tetsuo Hirata; Yuko Kawakami; Nagisa Kinjo; Susumu Arakald; Tetsu Arakaki; Akira Hokama; Fukunori Kinjo; Jim Fujita

2008-01-01

AIM: TO evaluate the association between colonic polyps and diverticular disease in Japan.METHODS: We retrospectively reviewed the medical records of 672 consecutive patients who underwent total colonoscopy between August 2006 and April 2007 at Nishinjo Hospital, Okinawa, Japan. Patients with ahistory of any of the following were excluded from the study: previous polypectomy, colonic resection, and inflammatory bowel diseases. The association between colonic polyps and diverticular disease was analyzed by logistic regression analysis, adjusted for age and sex.RESULTS: Prevalence of colonic polyps in all patients with diverticular disease was significantly higher than that in those without diverticular disease (adjusted odds ratio 1.7).CONCLUSION: Our data showed that patients with diverticular disease have a higher risk of colonic polyps compared to those without.

Recurrent giant fibrovascular polyp of the esophagus

OpenAIRE

Lee, Ser Yee; Chan, Weng Hoong; Sivanandan, Ranjiv; Lim, Dennis Teck Hock; Wong, Wai Keong

2009-01-01

Giant fibrovascular polyps of the esophagus and hypopharynx are rare benign esophageal tumors. They arise most commonly in the upper esophagus and may, rarely, originate in the hypopharynx. They can vary significantly in size. Even though they are benign, they may be lethal due to either bleeding or, rarely, asphyxiation if a large polyp is regurgitated. Patients commonly present with dysphagia or hematemesis. The polyps may not be well visualized on endoscopy and imaging plays a vital role i...

Mechanism of trans-vinylene groups formation in the radiolysis of polyethylene and n-alkanes

International Nuclear Information System (INIS)

Borzov, S.M.; Sukhov, F.F.; Slovokhotova, N.A.

1984-01-01

Infrared spectra of polyethylene and some n-alkanes were studied after their irradiation at 20 K with 1-MeV electrons and subsequent heating to 160 K. The mechanism of trans-vinylene groups formation is suggested, which takes into account the decay of excited states of molecules in primary processes and the intra-chain recombination of free radicals in post-irradiation reactions. (author)

Hamartomatous polyps - a clinical and molecular genetic study

DEFF Research Database (Denmark)

Jelsig, Anne Marie

2016-01-01

the knowledge on clinical course and molecular genetics in patients with HPs and HPS, and to investigate research participants' attitude towards the results of extensive genetic testing. Paper I: In the first paper we investigated the occurrence, anatomic distribution, and other demographics of juvenile polyps...... appearance. Patients with one or a few juvenile polyps are usually not offered clinical follow-up as the polyp(s) are considered not to harbour any malignant potential. Nevertheless, it is important to note that juvenile polyps and HPs are also found in patients with hereditary hamartomatous polyposis......-Jeghers syndrome, and the PTEN hamartoma tumour syndrome. Currently, the HPS diagnoses are based on clinical criteria and are often assisted with genetic testing as candidate genes have been described for each syndrome. This thesis is based on six scientific papers. The overall aim of the studies was to expand...

Molecular features of colorectal hyperplastic polyps and sessile serrated adenoma/polyps from Korea.

Science.gov (United States)

Kim, Kyoung-Mee; Lee, Eui Jin; Ha, Sangyun; Kang, So Young; Jang, Kee-Taek; Park, Cheol Keun; Kim, Jin Yong; Kim, Young Ho; Chang, Dong Kyung; Odze, Robert Daniel

2011-09-01

Abundant recent data suggest that sessile serrated adenoma/polyp (SSA/P) is an early precursor lesion in the serrated pathway of carcinogenesis. It is believed that SSA/Ps develop cancer by an SSA/P-dysplasia-carcinoma sequence. Hyperplastic polyps (HPs) share some histologic and molecular characteristics with SSA/P, but it is unclear whether SSA/Ps are derived from HPs or whether they develop by a different pathogenetic pathway. Previous studies have shown that serrated polyps from Korean patients show different prevalence rates of certain molecular abnormalities compared with similar lesions from American patients, and this suggests that lifestyle and dietary factors may influence the serrated neoplasia pathway. The purpose of this study was to evaluate the molecular features of HPs and SSA/Ps, the latter both with and without dysplasia, from Korean patients and to compare the findings with similar lesions from American patients. One hundred and eleven serrated polyps, consisting of 45 HPs (30 microvesicular, 11 goblet cell, 4 mucin depleted) and 56 SSA/Ps (36 with dysplasia, 20 without dysplasia), were retrieved from the pathology files of a large medical center in Korea and 38 SSA/P from American patients were evaluated for BRAF and KRAS mutations, microsatellite instability, and hypermethylation of O6-methylguanine-DNA methyltransferase (MGMT), hMLH1, adenomatous polyposis coli (APC), p16, methylated in tumor-1 (MINT-1), MINT2, and MINT31. Methylation of hMLH1 was performed using 2 different sets of primers. Twenty-three conventional adenomas from Korean patients were included as controls. The data were compared between polyp subtypes and between polyps in the right versus the left colon. With regard to HP, KRAS mutations were present in 31.1% of polyps and BRAF mutations in 46.7% of polyps. KRAS mutations were significantly more common in goblet cell HP and BRAF in microvesicular HP (MVHP). Methylation of MGMT, hMLH1, APC, p16, MINT1, MINT2, and MINT31 were

Giant fibroepithelial polyp of the vulva

Directory of Open Access Journals (Sweden)

Selma Korkmaz

2014-12-01

Full Text Available Fibroepithelial polyps are among common benign skin lesions. They are usually small and skin-colored lesions and are located frequently in the axilla and neck. They are rarely seen in the vulva. There is a small number of cases that reach the giant sizes in this area in the literature. A 20-year-old female patient presented with a pedunculated mass measuring 25 cm in diameter, localized to the right labium majus. The lesion was excised and the histopathological diagnosis was fibroepithelial polyp. We present this case because of it is the largest reported fibroepithelial polyp of the vulva in the literature.

Microwave-assisted McMurry polymerization utilizing low-valent titanium for the synthesis of poly 2,6-[1,5-bis(dodecyloxy)naphthylene vinylene] (PNV)

DEFF Research Database (Denmark)

Thomas, Henrik; Stuhr-Hansen, Nicolai; Westerlund, Fredrik

2009-01-01

Poly 2,6-[1,5-bis(dodecyloxy)naphthylene vinylene] is synthesized by microwave-assisted McMurry polymerization utilizing low-valent titanium generated from titanium tetrachloride and zinc. The obtained polymer is fluorescent with an average molecular weight of approximately 65,000 g/mol and a pol......Poly 2,6-[1,5-bis(dodecyloxy)naphthylene vinylene] is synthesized by microwave-assisted McMurry polymerization utilizing low-valent titanium generated from titanium tetrachloride and zinc. The obtained polymer is fluorescent with an average molecular weight of approximately 65,000 g...

Association between colonic polyps and diverticular disease

Science.gov (United States)

Hirata, Tetsuo; Kawakami, Yuko; Kinjo, Nagisa; Arakaki, Susumu; Arakaki, Tetsu; Hokama, Akira; Kinjo, Fukunori; Fujita, Jiro

2008-01-01

AIM: To evaluate the association between colonic polyps and diverticular disease in Japan. METHODS: We retrospectively reviewed the medical records of 672 consecutive patients who underwent total colonoscopy between August 2006 and April 2007 at Nishinjo Hospital, Okinawa, Japan. Patients with a history of any of the following were excluded from the study: previous polypectomy, colonic resection, and inflammatory bowel diseases. The association between colonic polyps and diverticular disease was analyzed by logistic regression analysis, adjusted for age and sex. RESULTS: Prevalence of colonic polyps in all patients with diverticular disease was significantly higher than that in those without diverticular disease (adjusted odds ratio 1.7). CONCLUSION: Our data showed that patients with diverticular disease have a higher risk of colonic polyps compared to those without. PMID:18416471

Cyclooxygenase-2 overexpression is common in serrated and non-serrated colorectal adenoma, but uncommon in hyperplastic polyp and sessile serrated polyp/adenoma

Directory of Open Access Journals (Sweden)

Kirkner Gregory J

2008-01-01

Full Text Available Abstract Background Cyclooxygenase-2 (COX-2, PTGS2 plays an important role in colorectal carcinogenesis. COX-2 overexpression in colorectal cancer is inversely associated with microsatellite instability (MSI and the CpG island methylator phenotype (CIMP. Evidence suggests that MSI/CIMP+ colorectal cancer may arise through the serrated tumorigenic pathway through various forms of serrated neoplasias. Therefore, we hypothesized that COX-2 may play a less important role in the serrated pathway. Methods By immunohistochemistry, we assessed COX-2 expression in 24 hyperplastic polyps, 7 sessile serrated polyp/adenomas (SSA, 5 mixed polyps with SSA and adenoma, 27 traditional serrated adenomas, 515 non-serrated adenomas (tubular adenoma, tubulovillous adenoma and villous adenoma, 33 adenomas with intramucosal carcinomas, 96 adenocarcinomas with serration (corkscrew gland and 111 adenocarcinomas without serration. Results Strong (2+ COX-2 overexpression was more common in non-serrated adenomas (28% = 143/515 than in hyperplastic polyps (4.2% = 1/24, p = 0.008 and serrated polyps (7 SSAs and 5 mixed polyps (0% = 0/12, p = 0.04. Furthermore, any (1+/2+ COX-2 overexpression was more frequent in non-serrated adenomas (60% = 307/515 than in hyperplastic polyps (13% = 3/24, p Conclusion COX-2 overexpression is infrequent in hyperplastic polyp, SSA and mixed polyp with SSA and adenoma, compared to non-serrated and serrated adenoma. COX-2 overexpression becomes more frequent as tumors progress to higher grade neoplasias. Our observations suggest that COX-2 may play a less significant role in the serrated pathway of tumorigenesis; however, COX-2 may still play a role in later stage of the serrated pathway.

Prevalence and risk factors of the gallbladder polyps diagnosed by ultrasound

International Nuclear Information System (INIS)

Lee, Mi Hwa; Cho, Pyong Kon; Kwon, Duck Moon

2015-01-01

This study was designed to determine the prevalence of gallstones in the last three years and evaluate the associated risk factors in the population who underwent health screening. Although there are many studies reporting the prevalence and risk factors of GB polyp, the results varied among each report. The aims of this study were to evaluate the prevalence rate and risk factors of GB polyp, colon polyp and fatty liver in the population who underwent health screening. The study population consisted of 4,877 visited the health promotion center in Dalseogu, Daegu in Korea from January 2011 to December 2013. Each participant in the study had their biliary system gallbladder examined using ultrasonography. The prevalence of GB polyp was evaluated along with age, gender, metabolic syndrom, body mass index (BMI), Fatty liver, Colon polyp. A showed of total 383 (7.9%) people were found to have GB polyps. The prevalence of sex among 256 (9.8%) patients men and 127 (5.6%) women which showed significantly higher in male than in female subjects(p=0.001). The mean size of the GB polyps 4.92 mm (1.6-17 mm). The sizes of most GB polyps (73.6%) were less than 10 mm in diameter. 122 subjects (31.28%) had multiple GB polyps which 2 or more polyps and 261 subjects (68.2%) had single polyp. Independent risk factors related with GB polyp were male gender (OR 0.551, p<0.001), overweight that BMI above 23 kg/m"2 (OR 0.713, p=0.002) triglyceride (OR 0.571, p<0.001), metabolic syndrome (OR 0.049, p=0.033) and colon polyp (OR 1.409, p=0.002). In spite of the conclusion, the prevalence GB polyp was higher than previous Korea and other country reports. The GB polyp in a healthy population was results as 7.9%. The risk factors of GB polyps were found to be male, being overweight, triglyceride, metabolic syndrome and colon polyp. Not only the subject of a health examination is needed but, a further study of the general public when possible

Prevalence and risk factors of the gallbladder polyps diagnosed by ultrasound

Energy Technology Data Exchange (ETDEWEB)

Lee, Mi Hwa; Cho, Pyong Kon [Dept. of Radiological science, Catholic University of Daegu, Daegu (Korea, Republic of); Kwon, Duck Moon [Dept. of Diagnostic Radiology, Daegu Health College, Daegu (Korea, Republic of)

2015-06-15

This study was designed to determine the prevalence of gallstones in the last three years and evaluate the associated risk factors in the population who underwent health screening. Although there are many studies reporting the prevalence and risk factors of GB polyp, the results varied among each report. The aims of this study were to evaluate the prevalence rate and risk factors of GB polyp, colon polyp and fatty liver in the population who underwent health screening. The study population consisted of 4,877 visited the health promotion center in Dalseogu, Daegu in Korea from January 2011 to December 2013. Each participant in the study had their biliary system gallbladder examined using ultrasonography. The prevalence of GB polyp was evaluated along with age, gender, metabolic syndrom, body mass index (BMI), Fatty liver, Colon polyp. A showed of total 383 (7.9%) people were found to have GB polyps. The prevalence of sex among 256 (9.8%) patients men and 127 (5.6%) women which showed significantly higher in male than in female subjects(p=0.001). The mean size of the GB polyps 4.92 mm (1.6-17 mm). The sizes of most GB polyps (73.6%) were less than 10 mm in diameter. 122 subjects (31.28%) had multiple GB polyps which 2 or more polyps and 261 subjects (68.2%) had single polyp. Independent risk factors related with GB polyp were male gender (OR 0.551, p<0.001), overweight that BMI above 23 kg/m{sup 2} (OR 0.713, p=0.002) triglyceride (OR 0.571, p<0.001), metabolic syndrome (OR 0.049, p=0.033) and colon polyp (OR 1.409, p=0.002). In spite of the conclusion, the prevalence GB polyp was higher than previous Korea and other country reports. The GB polyp in a healthy population was results as 7.9%. The risk factors of GB polyps were found to be male, being overweight, triglyceride, metabolic syndrome and colon polyp. Not only the subject of a health examination is needed but, a further study of the general public when possible.

Evaluating success of curettage in the surgical treatment of endometrial polyps.

Science.gov (United States)

Hafizi, Leili; Mousavifar, Nezhat; Zirak, Nahid; Khadem, Nayereh; Davarpanah, Sousan; Akhondi, Mohsen

2015-02-01

To determine treatment efficacy of curettage on endometrial polyp. The quasi-experimental pre-and-post study was conducted in 2011-12 at the gynaecology department of Imam Reza Hospital, Mashhad, Iran, and comprised patients who underwent hysteroscopy for endometrial polyp. Location, size, number and base condition of the polyps were recorded before the patient underwent curettage. Hysteroscopy was then performed and the condition of the remaining polyps was compared with initial findings. Also, the remaining polyps were resected. SPSS 13 was used for statistical analysis. There were 51 patients in the study with a mean age of 33.14 ± 8.19 years (range: 23-59 years)Besides, there were 82 polyps; 38(46.3%) having a narrow base, and 44(53.7%) having a wide base. The mean polyp size was 2.39 ± 2.63cm.After performing curettage, 23 (28.0%) polyps were removed completely, 39(47.6%) had size reduction, and 20(24.4%) had no change in size. Curettage could not significantly remove polyps (p < 0.001). Polyps smaller than 2cm were more likely to have been removed compared to the bigger ones (p = 0.003).Polyps with wide base were more significantly removed than those with narrow base (p < 0.001).Further, those with wide base and also smaller than 2 cm were removed more significantly than others (p < 0.001).The location of polyps had no effect on removal probability by curettage (p = 0.114). Curettage was not found to be a reliable method for endometrial polyp removal. If hysteroscopy is not accessible, the size of the polyp should be determined by vaginal sonograghy to estimate the probability of its removal by curettage.

Factors Influencing the Recurrence Potential of Benign Endometrial Polyps after Hysteroscopic Polypectomy.

Directory of Open Access Journals (Sweden)

Jehn-Hsiahn Yang

Full Text Available An endometrial polyp is a frequently encountered gynecologic disease with abnormal uterine bleeding and infertility being the two common presenting problems, and hysteroscopic polypectomy is an effective method to remove them. The postoperative polyp recurrence might result in reappearance of abnormal uterine bleeding or infertility, whereas factors influencing the postoperative recurrence potential have limited data.This case-series report included 168 premenopausal women who suffered from endometrial polyps and underwent hysteroscopic polypectomy. All of them were awaiting a future pregnancy. Office hysteroscopy was done before and after hysteroscopic polypectomy, in which preoperative hysteroscopy examined the number, type, and location of endometrial polyps, and postoperative hysteroscopy checked the polyp recurrence. Surgical indications, either infertility or the presentation of abnormal uterine bleeding, and follow-up duration were recorded.Seventy-three out of 168 (43% women had polyp recurrence after hysteroscopic polypectomy. Multivariate logistic regression analysis revealed that more endometrial polyps (P = 0.015 and longer duration of follow-up (P = 0.004 were significantly associated with an increased risk of postoperative polyp recurrence. The type of endometrial polyps was not correlated with polyp recurrence potential, whereas pedunculated type endometrial polyps were closely related to the presentation of abnormal uterine bleeding (P = 0.001.A higher number of endometrial polyps and longer follow-up duration are associated with a greater potential of polyp recurrence after hysteroscopic polypectomy.

Dependency of non-homogeneity energy dispersion on absorbance line-shape of luminescent polymers

Energy Technology Data Exchange (ETDEWEB)

Silva, Marcelo Castanheira da, E-mail: mar_castanheira@yahoo.com.br [Centro de Ciências Biológicas e da Natureza, Universidade Federal do Acre, CP 500, 69915-900 Rio Branco, AC (Brazil); Instituto de Física, Universidade Federal de Uberlândia, CP 593, 38400-902 Uberlândia, MG (Brazil); Santos Silva, H.; Silva, R.A.; Marletta, Alexandre [Instituto de Física, Universidade Federal de Uberlândia, CP 593, 38400-902 Uberlândia, MG (Brazil)

2013-01-16

In this paper, we study the importance of the non-homogeneity energy dispersion on absorption line-shape of luminescent polymers. The optical transition probability was calculated based on the molecular exciton model, Franck–Condon states, Gaussian distribution of non-entangled chains with conjugate degree n, semi-empirical parameterization of energy gap, electric dipole moment, and electron-vibrational mode coupling. Based on the approach of the energy gap functional dependence 1/n, the inclusion of the non-homogeneity energy dispersion 1/n{sup 2} is essential to obtain good experimental data agreement, mainly, where the absorption spectra display peaks width of about 65 meV. For unresolved absorption spectra, such as those observed for a large number of conjugated polymers processed via spin-coating technique, for example, the non-homogeneity energy dispersion parameterization is not significant. Results were supported by the application of the model for poly (p-phenylene vinylene) films.

Endometrial Intraepithelial Neoplasia (EIN In An Endometrial Polyp

Directory of Open Access Journals (Sweden)

Devic Ana

2015-12-01

Full Text Available Endometrial intraepithelial neoplasia (EIN is a monoclonal neoplastic cell proliferation of the endometrium associated with a significantly increased risk of endometrioid endometrial adenocarcinoma. We herein present the case of a 58-year-old female patient who underwent a hysterectomy with bilateral salpingo-oophorectomy because of the existence of endometrial intraepithelial neoplasia in an endometrial polyp. The patient had irregular uterine bleeding, which lasted 10 days. An endometrial polyp was diagnosed by ultrasound examination. The polyp was located in the isthmus of the uterus, on the back wall, and measured 32 mm × 25 mm. The patient underwent fractional dilation and curettage, and the specimens were subjected to a histopathological examination. The histopathological findings were EIN, endometrioid type, a focus of which was found within the endometrial polyps, as well as the endometrial polyp and proliferative endometrium. The endocervical tissue was normal. Given the age of the patient and the histopathological findings, she underwent a total abdominal hysterectomy with bilateral salpingo-oophorectomy. The final histopathological findings were EIN, endometrioid type with a focus found within the endometrial polyp; endometrial polyp; simple hyperplasia; chronic inflammation of the uterine cervix; hyperkeratosis of the cervical squamous epithelium; and cervicitis chronica. There was also hydrosalpinx of the left fallopian tube, and cystic follicles in the left ovary. There was no significant morphological change in the right ovary or fallopian tube. The surgical and postoperative course were normal. The patient was sent home on the fifth postoperative day in good general condition. A check-up performed one month after surgery showed normal findings.

Prolapsing Gastric Polyp Causing Intermittent Gastric Outlet Obstruction.

Science.gov (United States)

Kosai, Nik Ritza; Gendeh, Hardip Singh; Norfaezan, Abdul Rashid; Razman, Jamin; Sutton, Paul Anthony; Das, Srijit

2015-06-01

Gastric polyps are often an incidental finding on upper gastrointestinal endoscopy, with an incidence up to 5%. The majority of gastric polyps are asymptomatic, occurring secondary to inflammation. Prior reviews discussed Helicobacter pylori (H pylori)-associated singular gastric polyposis; however, we present a rare and unusual case of recurrent multiple benign gastric polyposis post H pylori eradication resulting in intermittent gastric outlet obstruction. A 70-year-old independent male, Chinese in ethnicity, with a background of diabetes mellitus, hypertension, and a simple renal cyst presented with a combination of melena, anemia, and intermittent vomiting of partially digested food after meals. Initial gastroscopy was positive for H pylori; thus he was treated with H pylori eradication and proton pump inhibitors. Serial gastroscopy demonstrated multiple sessile gastric antral polyps, the largest measuring 4 cm. Histopathologic examination confirmed a benign hyperplastic lesion. Computed tomography identified a pyloric mass with absent surrounding infiltration or metastasis. A distal gastrectomy was performed, whereby multiple small pyloric polyps were found, the largest prolapsing into the pyloric opening, thus explaining the intermittent nature of gastric outlet obstruction. Such polyps often develop from gastric ulcers and, if left untreated, may undergo neoplasia to form malignant cells. A distal gastrectomy was an effective choice of treatment, taking into account the polyp size, quantity, and potential for malignancy as opposed to an endoscopic approach, which may not guarantee a complete removal of safer margins and depth. Therefore, surgical excision is favorable for multiple large gastric polyps with risk of malignancy.

Natural history of diminutive colorectal polyps: long-term prospective observation by colonoscopy.

Science.gov (United States)

Mizuno, Ken-Ichi; Suzuki, Yutaka; Takeuchi, Manabu; Kobayashi, Masaaki; Aoyagi, Yutaka

2014-04-01

Endoscopic removal of colorectal adenomatous polyps effectively prevents cancer. However, the treatment strategy for diminutive polyps (diameter ≤ 5 mm) remains controversial. Understanding the natural history of diminutive polyps is a prerequisite to their effective management. We prospectively examined the natural history of diminutive polyps by long-term surveillance colonoscopy. A total of 207 polyps detected in 112 patients from December 1991 through March 2002 were studied. To avoid potential effects on size and morphological characteristics, all polyps were selected randomly and were followed without biopsy. Polyp size was estimated by comparing the lesion with the diameter of a biopsy forceps. Mean follow up was 7.8 years (SD, 4.8; range, 1.0-18.6; median, 7.5; interquartile range 3.4-11.2). Twenty-four polyps were resected endoscopically, and the histopathological diagnosis was mucosal high-grade neoplasia (Category 4) for one polyp, and mucosal low-grade neoplasia (Category 3) for 23 polyps. Mean linear size of the polyps was 3.2 mm (SD, 1.0; range, 1.3-5.0) at initial colonoscopy and 3.8 mm (SD 1.6; range 1.3-10.0) at final colonoscopy (Ppit pattern was associated with a lower growth rate than a type IIIL1 pattern. We clarified the natural history of diminutive polyps by long-term follow-up colonoscopy. The benign course of diminutive polyps should be considered in the design of treatment strategies. © 2014 The Authors. Digestive Endoscopy © 2014 Japan Gastroenterological Endoscopy Society.

Diagnostic Performance of CT Colonography for the Detection of Colorectal Polyps

International Nuclear Information System (INIS)

Yun, Ji Young; Ro, Hee Jeong; Choi, Jung Bin; Chung, Ji Eun; Kim, Yong Jin; Suh, Won Hyuck; Lee, Jong Kyun; Park, Jong Beom

2007-01-01

To investigate the diagnostic value of CT colonography for the detection of colorectal polyps. From December 2004 to December 2005, 399 patients underwent CT colonography and follow-up conventional colonoscopy. We excluded cases of advanced colorectal cancer. We retrospectively analyzed the CT colonography findings and follow-up conventional colonoscopy findings of 113 patients who had polyps more than 6 mm in diameter. Radiologists using 3D and 2D computer generated displays interpreted the CT colonography images. The colonoscopists were aware of the CT colonography findings before the procedure. CT colonography detected 132 polyps in 107 of the 113 patients and conventional colonoscopy detected 114 colorectal polyps more than 6 mm in diameter in 87 of the 113 patients. The sensitivity of CT colonography analyzed per polyp was 91% (41/45) for polyps more than 10 mm in diameter and 89% (101/114) for polyps more than 6 mm in diameter. Thirteen polyps were missed by CT colonography and were detected on follow-up conventional colonoscopy. CT colonography is a sensitive diagnostic tool for the detection of colorectal polyps and adequate bowel preparation, optimal bowel distention and clinical experience are needed to reduce the rate of missing appropriate lesions

Antral hyperplastic polyp: A rare cause of gastric outlet obstruction.

Science.gov (United States)

Aydin, Ibrahim; Ozer, Ender; Rakici, Halil; Sehitoglu, Ibrahim; Yucel, Ahmet Fikret; Pergel, Ahmet; Sahin, Dursun Ali

2014-01-01

Gastric polyps are usually found incidentally during upper gastrointestinal endoscopic examinations. These polyps are generally benign, with hyperplasia being the most common. While gastric polyps are often asymptomatic, they can cause gastric outlet obstruction. A 64 years-old female patient presented to our polyclinic with a history of approximately 2 months of weakness, occasional early nausea, vomiting after meals and epigastric pain. A polypoid lesion of approximately 25mm in diameter was detected in the antral area of the stomach, which prolapsed through the pylorus into the duodenal bulbus, and subsequently caused gastric outlet obstruction, as revealed by upper gastrointestinal endoscopy of the patient. The polyp was retrieved from the pyloric canal into the stomach with the aid of a tripod, and snare polypectomy was performed. Currently, widespread use of endoscopy has led to an increase in the frequency of detecting hyperplastic polyps. While most gastric polyps are asymptomatic, they can cause iron deficiency anemia, acute pancreatitis and more commonly, gastric outlet obstruction because of their antral location. Although there are no precise principles in the treatment of asymptomatic polyps, polyps >5mm should be removed due to the possibility of malignant transformation. According to the medical evidence, polypectomy is required for gastric hyperplastic polyps because of the risks of complication and malignancy. These cases can be successfully treated endoscopically. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Relation between obesity and adenomatous polyps of the large bowel.

Science.gov (United States)

Sato, Yumi; Nozaki, Ryoichi; Yamada, Kazutaka; Takano, Masahiro; Haruma, Ken

2009-07-01

We compared the prevalence of colorectal adenoma (polyps) in men and women and examined the role of body mass index (BMI) on polyp risk according to patient age and gender. The risk of developing colorectal polyps was studied in 15 380 subjects (7155 men and 8225 women) who underwent colonoscopy for the first time from April 1998 to March 2006 at our 'Human Dry Dock', which is the check-up service provided in Japan. Eligible subjects were 20-86 years old (mean age +/- SD, 47.3 +/- 8.5) and were free of invasive cancer, hyperplastic polyps and familial polyposis. Polyps were found in 1590 subjects (1062 men and 528 women). The odds ratio (OR) of detection of polyps in relation to obesity was determined in all cases by multivariate logistic regression analysis after making an adjustment for gender and age. The OR of polyp detection in obese subjects (BMI >or= 25) versus non-obese subjects (BMI women. As the BMI increased in increments of one, the OR in men increased significantly to 1.01 (P women was unchanged at 1.00 (P = 0.23), which was without significance. We conclude that obesity in men is a risk factor for the development of polyps. These results must be confirmed by additional epidemiological studies.

Association between Obesity, Serum Lipids, and Colorectal Polyps in Old Chinese People

Directory of Open Access Journals (Sweden)

Wen Yang

2013-01-01

Full Text Available Background. Colorectal cancer mostly arises from the polyps of colon. The aim of our study was to examine the association of body mass index (BMI and serum lipids with the colorectal polyps in old Chinese people. Methods. The risk of developing colorectal polyps was studied in 244 subjects (212 men and 32 women, 74.63 ± 11.63 years old who underwent colonoscopy for the first time from January 2008 to July 2012 at the Navy General Hospital, Beijing, China. According to the results of colonoscopy, all the subjects were divided into 112 normal control, 38 right colorectal polyps, 53 left colorectal polyps, and 41 both right and left colorectal polyps groups. The total plasma cholesterol, plasma triglyceride, plasma creatinine concentration, blood urinary nitrogen, and fasting glucose were determined using a multichannel analyzer. Results. There were significant differences among normal control, right colorectal polyps, left colorectal polyps, and both right and left polyps groups, which were the BMI, total cholesterol, triglycerides, creatinine, and urinary nitrogen. In binary logistic regression analysis, there were two risk factors associated with the occurrence of colorectal polyps, which included BMI and systolic blood pressure. Conclusions. Colorectal polyps were significantly associated with increased BMI, total cholesterol, and triglycerides levels.

The patient with multiple intestinal polyps.

Science.gov (United States)

Schulmann, Karsten; Pox, Christian; Tannapfel, Andrea; Schmiegel, Wolff

2007-01-01

The management of patients with multiple intestinal polyps may be difficult and greatly depends on the correct classification. Polyposis syndromes account for less than 1% of newly diagnosed colorectal cancers. In addition the risk for extracolonic cancer is increased in most syndromes. Here we report the case of a difficult patient with severe gastric polyposis and we present a review of polyposis syndromes such as classical and attenuated familial adenomatous polyposis (FAP), MYH-associated polyposis, Peutz-Jeghers syndrome, juvenile polyposis as well as rare polyposis syndromes. The most practical approach for the diagnostic workup in patients with newly diagnosed gastrointestinal polyposis is based on the histological typing of polyps. In addition, a detailed family history regarding cancer, polyps and congenital abnormalities should be obtained from every polyposis patient. Patients with multiple adenomas are most likely to suffer from FAP, AFAP or MAP. Of these, younger age and higher polyp count are most likely a diagnosis of typical FAP. Older age and fewer polyps favour a diagnosis of AFAP or MAP. Germline testing of the APC gene is suggested, and if negative, MYH gene testing should be done. In patients with hamartomas, extraintestinal features should be evaluated and reference histology should be initiated. In addition panintestinal imaging should be performed with EGD, colonoscopy and small bowel imaging (PE, CE, and MR) enteroclysis. For diagnostic and therapeutic problems a familial colorectal cancer center should be consulted. Using this algorithm, correct classification and adequate treatment should be possible for every polyposis patient.

Intravenous contrast enhanced computed tomography colonoscopy in children with suspected colonic polyps

International Nuclear Information System (INIS)

Bhatia, Anmol; Saxena, Akshay K.; Kalra, Naveen; Sodhi, Kushaljit S.; Thapa, Babu R.; Rao, Katragadda L.N.; Khandelwal, Niranjan

2013-01-01

Objective: The purpose of this study was to evaluate the diagnostic performance of intravenous contrast enhanced computed tomographic colonoscopy (IVCTC) in the diagnosis of clinically suspected colorectal polyps in children, using conventional colonoscopy (CC) as the gold standard. Methods: This was a prospective study conducted between July 2008 and June 2010. 30 pediatric patients with history of rectal bleeding and clinically suspected to have colorectal polyps were enrolled. All of the patients underwent IVCTC followed by CC. 30 IVCTC and 31 CC were performed in 30 patients. The findings of IVCTC were compared with those of CC. Statistical analysis was performed to obtain diagnostic performance values of IVCTC on per polyp (sensitivity and positive predictive value) and per patient (sensitivity, specificity, positive predictive value and negative predictive value) basis. Results: By IVCTC, 63 polyps were detected in 28 patients of which 53 polyps were eligible for inclusion in the statistical analysis. 60 polyps were detected by CC in 28 patients of which 50 polyps were eligible for inclusion in the statistical analysis. The per polyp sensitivity and positive predictive values were 94% and 88.6% respectively. The per patient sensitivity, specificity, positive predictive value, and negative predictive values were 96.4, 50, 96.4, and 50% respectively. Twenty polyps, in 10 patients, were visualized only after intravenous contrast administration of which 5 polyps, in 5 patients, were likely to have been missed in the absence of the intravenous contrast injection as these polyps were submerged in fluid. Four patients would have had a false negative CTC examination if the intravenous contrast had not been injected; while in another patient, the number of polyps would have been underestimated. Conclusion: CTC is capable of serving as a safe and efficient non-invasive tool for evaluating children with clinically suspected colorectal polyps. Administration of

Diffuse benign gastric inflammatory hyperplastic polyps presenting ...

African Journals Online (AJOL)

Benign gastric inflammatory hyperplasic polyps are benign lesions that rarely occur in young age. We report a case of diffuse benign gastric inflammatory hyperplastic polyps in a 19 year old boy who presented with cough, nausea, and hematamesis. In the presented case symptoms such as nausea and vomiting are non ...

Characterization and electrochemical application of carbon materials based on poly(phenylene oxide)

Science.gov (United States)

Gray, Hunter

Carbon materials possess excellent electrical and surface properties for the next generation of energy storage devices. Polymers provide a carbon rich and tailorable precursor for the production of carbon materials. Therefore, activated carbons were prepared from poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) via a three step process: thermal oxidation, carbonization, and activation with KOH. The activated carbons are predominately microporous with BET specific surface areas up to 2638 m2/g. Impedance spectroscopy revealed these carbons possess electrical conductivities comparable to commercial carbon blacks and consequently were employed in thin-film composite electrodes in electrochemical double-layer capacitors. Cyclic voltammetry confirmed maximum specific capacitances of 13.23 F/g and 2.848 F/g for aqueous and organic electrolyte systems, respectively. Additionally, carbon nanotubes were synthesized from PPO and other polymers with a nickel catalyst via chemical vapor deposition as revealed by transmission electron microscopy. This is the first report of carbon nanotubes produced from PPO.

Polyp Detection and Segmentation from Video Capsule Endoscopy: A Review

Directory of Open Access Journals (Sweden)

V. B. Surya Prasath

2016-12-01

Full Text Available Video capsule endoscopy (VCE is used widely nowadays for visualizing the gastrointestinal (GI tract. Capsule endoscopy exams are prescribed usually as an additional monitoring mechanism and can help in identifying polyps, bleeding, etc. To analyze the large scale video data produced by VCE exams, automatic image processing, computer vision, and learning algorithms are required. Recently, automatic polyp detection algorithms have been proposed with various degrees of success. Though polyp detection in colonoscopy and other traditional endoscopy procedure based images is becoming a mature field, due to its unique imaging characteristics, detecting polyps automatically in VCE is a hard problem. We review different polyp detection approaches for VCE imagery and provide systematic analysis with challenges faced by standard image processing and computer vision methods.

Charge transport and recombination in bulk heterojunction solar cells studied by the photoinduced charge extraction in linearly increasing voltage technique

OpenAIRE

Mozer, AJ; Sariciftci, NS; Osterbacka, R; Westerling, M; Juska, G; LUTSEN, Laurence; VANDERZANDE, Dirk

2005-01-01

Charge carrier mobility and recombination in a bulk heterojunction solar cell based on the mixture of poly[2-methoxy-5-(3,7-dimethyloctyloxy)-phenylene vinylene] (MDMO-PPV) and 1-(3-methoxycarbonyl)propyl-1-phenyl-(6,6)-C-61 (PCBM) has been studied using the novel technique of photoinduced charge carrier extraction in a linearly increasing voltage (Photo-CELIV). In this technique, charge carriers are photogenerated by a short laser flash, and extracted under a reverse bias voltage ramp after ...

Lymphangiomatous Polyp of Tonsil: A Case Report.

Science.gov (United States)

Sayar, Hamide; Sayar, Çağdaş; Adamhasan, Fulya; Uğuz, Aysun

2016-01-01

Lymphangiomatous polyps of the palatine tonsils are uncommon hamartomatous proliferations that could be clinically misdiagnosed as malignant neoplasms. These polyps consist of dilated lymphatic vessels located inside fibrous and/or adipose tissue. In this paper, a 27-year-old man who presented to the outpatient clinic with a complaint of dysphagia is presented. On physical examination, the patient had a smooth, polypoid mass extending from the posterior section of the right palatine tonsil into the oropharynx. The patient underwent right tonsillectomy. Histopathological examination of the specimen showed typical features of a lymphangiomatous polyp of the tonsil. The case is reported with the accompanying literature to avoid the possibility of misdiagnosing it as a malignant lesion clinically.

Gallbladder stones and gallbladder polyps associated with increased risk of colorectal adenoma in men.

Science.gov (United States)

Liu, Yen-Ling; Wu, Jin-Shang; Yang, Yi-Ching; Lu, Feng-Hwa; Lee, Chih-Ting; Lin, Wan-Ju; Chang, Chih-Jen

2018-04-01

Most cases of colorectal cancer develop via an adenoma to carcinoma sequence. Gallbladder polyps share some risk factors with colorectal polyps. Little is known about the relationship between gallbladder diseases and different status of colorectal polyps by gender. This study was to investigate the association of gallbladder stones and polyps with colorectal adenomas by gender in a Taiwanese population. A total of 7066 eligible subjects who underwent a total colonoscopy as a part of health check-up between January 2001 and August 2009 were recruited. Colonoscopic findings were classified into polyp-free, non-neoplastic polyps and colorectal adenomas. Gallbladder stones and gallbladder polyps were diagnosed based on ultrasonographic findings. There was a significant difference in the status of colon polyps between subjects with and without gallbladder polyps. However, the status of colon polyps was not significantly different between subjects with or without gallbladder stones. After adjusting obesity, fasting plasma glucose, and other variables, there was a positive relationship between gallbladder polyps and colorectal adenomas (odds ratio [OR]: 1.396, 95% confidence interval [CI]: 1.115-1.747) but not non-neoplastic polyps in all subjects. In men, gallbladder polyps (OR: 1.560, 95% CI: 1.204-2.019) and gallbladder stones (OR: 1.465, 95% CI 1.081-1.984) were positively associated with colorectal adenomas. In women, neither gallbladder polyps nor gallbladder stones were significantly related to colon polyps. Both gallbladder polyps and gallbladder stones were associated with an increased risk of colorectal adenomas in men but not in women. Gender difference was significant for the association between gallbladder lesions and colorectal polyps. © 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

Substituent effects on furan-phenylene copolymer for photovoltaic improvement: A density functional study

Science.gov (United States)

Janprapa, Nuttaporn; Vchirawongkwin, Viwat; Kritayakornupong, Chinapong

2018-06-01

The structural, electronic and photovoltaic properties of furan-phenylene copolymer ((Fu-co-Ph)4) and its derivatives were evaluated using density functional theory (DFT) and time-dependent density functional theory (TD-DFT). The calculated band gaps of pristine furan and phenylene are in good agreement with the available experimental data. The lower band gap value of 2.72 eV was obtained from -NO2 and -NHCH3 substituents, leading to broader solar absorption range. With respected to the reorganization energy, -OCH3, -NHCH3, -OH, -SCH3, -CH3, -CF3, -NO2, and -F substituted (Fu-co-Ph)4 structures were classified as better electron donor materials. For combination with PC61BM, -NO2, -CN, -CF3 and -F functionalized copolymers demonstrated significantly higher open circuit voltage (Voc) values ranging from 1.07 to 2.10 eV. Our results revealed that electron withdrawing group substitution on furan-phenylene copolymers was an effective way for improving electronic and optical properties of donor materials used in photovoltaic applications.

The Colonoscopist's Expertise Affects the Characteristics of Detected Polyps

Directory of Open Access Journals (Sweden)

Da Kyoung Jung

2016-01-01

Full Text Available Background/Aims: The influence of the endoscopist on the polyp detection rate (PDR is underappreciated in clinical practice. Moreover, flat lesions or lesions of the proximal colon are more difficult to detect. Here, we evaluated the differences in the PDR and the characteristics of detected polyps according to the experience of the colonoscopist. Methods: We collected data on 2,549 patients who underwent screening colonoscopy performed by three fellows. The PDR was calculated according to the percentage of patients who had at least one polyp (method A and according to the percentage of detected lesions (method B. The primary outcome included the change in the PDR, and the secondary outcome included the change in the characteristics of the detected polyps with increasing experience of the colonoscopist. Results: No proportional correlation was found between the PDR and increasing experience in colonoscopy with method A; however, with method B, the PDR increased after 400 colonoscopies (p=0.0209. With method B, the detection rates of small polyps (<5 mm (p=0.0015 and polyps in proximal sites (p=0.0050 increased after 300 colonoscopies. Conclusions: Our study demonstrated that the quality of a colonoscopy, measured by using the PDR, may increase when performed by experienced fellows.

Multi-Functional pi-Conjugated Macromolecules Based on Poly(Phenylene Vinylene)

Science.gov (United States)

1994-03-14

methacrylate-co-4-vinylpyridine)" (in press). 43. J . Polym. Sci., (with R. Vukovic , G. Bogdanic, V. Kuresevic, M. Tomaskovic and W.J. MacKnight) "Phase...Sokolik I Dr. Zhou Yang Dr. Iwao Teraoka IV. JUNIOR RESEARCH PERSONNEL: J . Neill B. Ma. S.L I U i I I i 5 VI. ABSTRACT OF ACCOMPLISHMENTS This report is...chains. I I U I * 14 I VIII. PUBLICATIONS IN PERIOD WITH AFOSR SUPPORT 1. J . Chem. Phys. 98, 712-716 (1993) (with G. Mao, J.E. Fischer and M.J. Winokur

Automated polyp measurement based on colon structure decomposition for CT colonography

Science.gov (United States)

Wang, Huafeng; Li, Lihong C.; Han, Hao; Peng, Hao; Song, Bowen; Wei, Xinzhou; Liang, Zhengrong

2014-03-01

Accurate assessment of colorectal polyp size is of great significance for early diagnosis and management of colorectal cancers. Due to the complexity of colon structure, polyps with diverse geometric characteristics grow from different landform surfaces. In this paper, we present a new colon decomposition approach for polyp measurement. We first apply an efficient maximum a posteriori expectation-maximization (MAP-EM) partial volume segmentation algorithm to achieve an effective electronic cleansing on colon. The global colon structure is then decomposed into different kinds of morphological shapes, e.g. haustral folds or haustral wall. Meanwhile, the polyp location is identified by an automatic computer aided detection algorithm. By integrating the colon structure decomposition with the computer aided detection system, a patch volume of colon polyps is extracted. Thus, polyp size assessment can be achieved by finding abnormal protrusion on a relative uniform morphological surface from the decomposed colon landform. We evaluated our method via physical phantom and clinical datasets. Experiment results demonstrate the feasibility of our method in consistently quantifying the size of polyp volume and, therefore, facilitating characterizing for clinical management.

Analysis of mtDNA sequence variants in colorectal adenomatous polyps

Directory of Open Access Journals (Sweden)

Grizzle William

2010-10-01

Full Text Available Abstract Colorectal tumors mostly arise from sporadic adenomatous polyps. Polyps are defined as a mass of cells that protrudes into the lumen of the colon. Adenomatous polyps are benign neoplasms that, by definition display some characteristics of dysplasia. It has been shown that polyps were benign tumors which may undergo malignant transformation. Adenomatous polyps have been classified into three histologic types; tubular, tubulovillous, and villous with increasing malignant potential. The ability to differentially diagnose these colorectal adenomatous polyps is important for therapeutic intervention. To date, little efforts have been directed to identifying genetic changes involved in adenomatous polyps. This study was designed to examine the relevance of mitochondrial genome alterations in the three adenomatous polyps. Using high resolution restriction endonucleases and PCR-based sequencing, fifty-seven primary fresh frozen tissues of adenomatous polyps (37 tumors and 20 matched surrounding normal tissues obtained from the southern regional Cooperative Human Tissue Network (CHTN and Grady Memorial Hospital at Atlanta were screened with three mtDNA regional primer pairs that spanned 5.9 kbp. Results from our data analyses revealed the presence of forty-four variants in some of these mitochondrial genes that the primers spanned; COX I, II, III, ATP 6, 8, CYT b, ND 5, 6 and tRNAs. Based on the MITODAT database as a sequence reference, 25 of the 44 (57% variants observed were unreported. Notably, a heteroplasmic variant C8515G/T in the MT-ATP 8 gene and a germline variant 8327delA in the tRNAlys was observed in all the tissue samples of the three adenomatous polyps in comparison to the referenced database sequence. A germline variant G9055A in the MT-ATP 6 gene had a frequency of 100% (17/17 in tubular and 57% (13/23 in villous adenomas; no corresponding variant was in tubulovillous adenomas. Furthermore, A9006G variant at MT-ATP 6 gene was

Controlled Aloin Release from Crosslinked Polyacrylamide Hydrogels: Effects of Mesh Size, Electric Field Strength and a Conductive Polymer

Directory of Open Access Journals (Sweden)

Anuvat Sirivat

2013-10-01

Full Text Available The aim of this paper is to investigate the effects of hydrogel mesh size, a conductive polymer, and electric field strength on controlled drug delivery phenomena using drug-loaded polyacrylamide hydrogels prepared at various crosslinking ratios both with and without a conductive polymer system. Poly(p-phenylene vinylene, PPV, as the model conductive polymer, was used to study its ability to control aloin released from aloin-doped poly(p-phenylene vinylene/polyacrylamide hydrogel (aloin-doped PPV/PAAM. In the passive release, the diffusion of aloin from five aloin-doped PPV/PAAM hydrogel systems each was delayed ranging from during the first three hours to during the first 14 h due to the ionic interaction between the anionic drug and PPV. After the delayed periods, aloin could diffuse continuously into the buffer solution through the PAAM matrix. The amount of aloin released from the aloin-doped PPV/PAAM rose with increasing electric field strength as a result of the three mechanisms: the expansion of PPV chains inside the hydrogel, iontophoresis, and the electroporation of the matrix pore size, combined. Furthermore, the conductive polymer and the electric field could be used in combination to regulate the amount of release drug to a desired level, to control the release rate, and to switch the drug delivery on/off.

Endometrial polyps and associated factors in Danish women aged 36-74 years

DEFF Research Database (Denmark)

Dreisler, Eva; Sorensen, Soren Stampe; Lose, Gunnar

2008-01-01

, the following was positively associated with endometrial polyps: current use of hormone therapy (odds ratio, 2.81; 95% CI, 1.29-6.13) and being overweight (body mass index > 25 kg/m(2)) (odds ratio, 2.06; 95% CI, 1.12-3.79) (postmenopausal women). Negatively associated was use of oral contraceptive pills (odds...... women were positively associated, whereas the use of oral contraceptive pills was negatively associated with endometrial polyps. Hypertension and cervical polyps were not associated with endometrial polyps. Endometrial polyps were infrequently related to premalignant and malignant disease....

An umbilical polyp in an infant.

Science.gov (United States)

Swanson, David L; Pakzad, Betty

2005-10-01

The persistence at birth of the omphalomesenteric (vitelline) duct may result in life-threatening consequences. Early identification of this congenital anomaly is essential for prompt surgical treatment to eliminate the risk of prolapse and herniation. A neonatal umbilical polyp may indicate the presence of an omphalomesenteric duct remnant. We describe the diagnosis and surgical treatment of an infant with an umbilical polyp. We also present an overview of the diagnosis and treatment of vitelline duct remnants and their associated anomalies.

Computer-assisted polyp matching between optical colonoscopy and CT colonography: a phantom study

Science.gov (United States)

Roth, Holger R.; Hampshire, Thomas E.; Helbren, Emma; Hu, Mingxing; Vega, Roser; Halligan, Steve; Hawkes, David J.

2014-03-01

Potentially precancerous polyps detected with CT colonography (CTC) need to be removed subsequently, using an optical colonoscope (OC). Due to large colonic deformations induced by the colonoscope, even very experienced colonoscopists find it difficult to pinpoint the exact location of the colonoscope tip in relation to polyps reported on CTC. This can cause unduly prolonged OC examinations that are stressful for the patient, colonoscopist and supporting staff. We developed a method, based on monocular 3D reconstruction from OC images, that automatically matches polyps observed in OC with polyps reported on prior CTC. A matching cost is computed, using rigid point-based registration between surface point clouds extracted from both modalities. A 3D printed and painted phantom of a 25 cm long transverse colon segment was used to validate the method on two medium sized polyps. Results indicate that the matching cost is smaller at the correct corresponding polyp between OC and CTC: the value is 3.9 times higher at the incorrect polyp, comparing the correct match between polyps to the incorrect match. Furthermore, we evaluate the matching of the reconstructed polyp from OC with other colonic endoluminal surface structures such as haustral folds and show that there is a minimum at the correct polyp from CTC. Automated matching between polyps observed at OC and prior CTC would facilitate the biopsy or removal of true-positive pathology or exclusion of false-positive CTC findings, and would reduce colonoscopy false-negative (missed) polyps. Ultimately, such a method might reduce healthcare costs, patient inconvenience and discomfort.

Spontaneous resolution of hemorrhagic polyps of the true vocal fold.

Science.gov (United States)

Klein, Adam M; Lehmann, Marcus; Hapner, Edie R; Johns, Michael M

2009-01-01

Hemorrhagic polyps are the most common benign lesions surgically removed from the vocal folds. Although this modality does offer satisfactory results in most of the cases, there is a subset of polyps that seems to resolve with conservative therapy. This study was performed to examine this subset of polyps. Thirty-four consecutive subjects diagnosed with hemorrhagic polyps of the true vocal fold were retrospectively reviewed to determine the incidence of spontaneous resolution of the lesions with nonsurgical therapy. Sixteen subjects began conservative therapy, consisting of voice therapy and proper vocal hygiene, often while awaiting an optimal personal time for surgical intervention. Of these subjects, nine (56.3%) experienced a resolution of their lesion and symptoms without undergoing surgical therapy. Surgical removal of hemorrhagic polyps is often considered the standard of treatment for these benign lesions. However, these observations support a regimen of voice therapy and observation in select cases.

Congenital urethral polyps: a report of two cases

International Nuclear Information System (INIS)

Cano, D.; Vivas, I.; Torres, E.; Garcia, L.; Fernandez-Villa, T.

1999-01-01

Congenital urethral polyps are uncommon lesions, very few cases of which have been previously reported in the literature. We present two cases of congenital urethral polyps in children, describing the clinical and radiological features and the diagnostic method employed, as well as reviewing the literature. (Author) 6 refs

An evidence-based treatment algorithm for colorectal polyp cancers: results from the Scottish Screen-detected Polyp Cancer Study (SSPoCS).

Science.gov (United States)

Richards, C H; Ventham, N T; Mansouri, D; Wilson, M; Ramsay, G; Mackay, C D; Parnaby, C N; Smith, D; On, J; Speake, D; McFarlane, G; Neo, Y N; Aitken, E; Forrest, C; Knight, K; McKay, A; Nair, H; Mulholland, C; Robertson, J H; Carey, F A; Steele, Rjc

2018-02-01

Colorectal polyp cancers present clinicians with a treatment dilemma. Decisions regarding whether to offer segmental resection or endoscopic surveillance are often taken without reference to good quality evidence. The aim of this study was to develop a treatment algorithm for patients with screen-detected polyp cancers. This national cohort study included all patients with a polyp cancer identified through the Scottish Bowel Screening Programme between 2000 and 2012. Multivariate regression analysis was used to assess the impact of clinical, endoscopic and pathological variables on the rate of adverse events (residual tumour in patients undergoing segmental resection or cancer-related death or disease recurrence in any patient). These data were used to develop a clinically relevant treatment algorithm. 485 patients with polyp cancers were included. 186/485 (38%) underwent segmental resection and residual tumour was identified in 41/186 (22%). The only factor associated with an increased risk of residual tumour in the bowel wall was incomplete excision of the original polyp (OR 5.61, p=0.001), while only lymphovascular invasion was associated with an increased risk of lymph node metastases (OR 5.95, p=0.002). When patients undergoing segmental resection or endoscopic surveillance were considered together, the risk of adverse events was significantly higher in patients with incomplete excision (OR 10.23, p<0.001) or lymphovascular invasion (OR 2.65, p=0.023). A policy of surveillance is adequate for the majority of patients with screen-detected colorectal polyp cancers. Consideration of segmental resection should be reserved for those with incomplete excision or evidence of lymphovascular invasion. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Posterior urethral polyps and review of literature

Directory of Open Access Journals (Sweden)

Prashant Jain

2007-01-01

Full Text Available Urethral polyp is a rare finding in young children. Fibroepithelial polyps of the urethra are usually diagnosed during the first decade of life. They present with obstruction, voiding dysfunction and hematuria. They can be associated with other congenital urinary tract anomalies. They are usually benign fibroepithelial lesions with no tendency to recur and are treated by surgical ablation, fulguration or laser therapy.

Application of poly (p-phenylene oxide) as blocking layer to reduce self-discharge in supercapacitors

Science.gov (United States)

Tevi, Tete; Yaghoubi, Houman; Wang, Jing; Takshi, Arash

2013-11-01

Supercapacitors are electrochemical energy storage devices with high power density. However, application of supercapacitors is limited mainly due to their high leakage current. In this work, application of an ultra-thin layer of electrodeposited poly (p-phenylene oxide) (PPO) has been investigated as a blocking layer to reduce the leakage current. The polymer was first deposited on a glassy carbon electrode. The morphology of the film was studied by atomic force microscopy (AFM), and the film thickness was estimated to be ˜1.5 nm by using the electrochemical impedance spectroscopy (EIS) technique. The same deposition method was applied to coat the surface of the activated carbon electrodes of a supercapacitor with PPO. The specific capacitance, the leakage current, and the series resistance were measured in two devices with and without the blocking layer. The results demonstrate that the application of the PPO layer reduced the leakage current by ˜78%. However, the specific capacitance was decreased by ˜56%, when the blocking layer was applied. Due to the lower rate of self-discharge, the suggested approach can be applied to fabricate devices with longer charge storage time.

Appendiceal Adenocarcinoma Presenting as a Rectal Polyp

Directory of Open Access Journals (Sweden)

Erin Fitzgerald

2016-02-01

Full Text Available Appendiceal adenocarcinoma typically presents as an incidentally noted appendiceal mass, or with symptoms of right lower quadrant pain that can mimic appendicitis, but local involvement of adjacent organs is uncommon, particularly as the presenting sign. We report on a case of a primary appendiceal cancer initially diagnosed as a rectal polyp based on its appearance in the rectal lumen. The management of the patient was in keeping with standard practice for a rectal polyp, and the diagnosis of appendiceal adenocarcinoma was made intraoperatively. The operative strategy had to be adjusted due to this unexpected finding. Although there are published cases of appendiceal adenocarcinoma inducing intussusception and thus mimicking a cecal polyp, there are no reports in the literature describing invasion of the appendix through the rectal wall and thus mimicking a rectal polyp. The patient is a 75-year-old female who presented with spontaneous hematochezia and, on colonoscopy, was noted to have a rectal polyp that appeared to be located within a diverticulum. When endoscopic mucosal resection was not successful, she was referred to colorectal surgery for a low anterior resection. Preoperative imaging was notable for an enlarged appendix adjacent to the rectum. Intraoperatively, the appendix was found to be densely adherent to the right lateral rectal wall. An en bloc resection of the distal sigmoid colon, proximal rectum and appendix was performed, with pathology demonstrating appendiceal adenocarcinoma that invaded through the rectal wall. The prognosis in this type of malignancy weighs heavily on whether or not perforation and spread throughout the peritoneal cavity have occurred. In this unusual presentation, an en bloc resection is required for a complete resection and to minimize the risk of peritoneal spread. Unusual appearing polyps do not always originate from the bowel wall. Abnormal radiographic findings adjacent to an area of

First-principles calculation of optical absorption spectra in conjugated polymers: Role of electron-hole interaction

International Nuclear Information System (INIS)

Rohlfing, Michael; Tiago, M.L.; Louie, Steven G.

2000-01-01

Experimental and theoretical studies have shown that excitonic effects play an important role in the optical properties of conjugated polymers. The optical absorption spectrum of trans-polyacetylene, for example, can be understood as completely dominated by the formation of exciton bound states. We review a recently developed first-principles method for computing the excitonic effects and optical spectrum, with no adjustable parameters. This theory is used to study the absorption spectrum of two conjugated polymers: trans-polyacetylene and poly-phenylene-vinylene(PPV)

First-principles calculation of optical absorption spectra in conjugated polymers: Role of electron-hole interaction

Energy Technology Data Exchange (ETDEWEB)

Rohlfing, Michael; Tiago, M.L.; Louie, Steven G.

2000-03-20

Experimental and theoretical studies have shown that excitonic effects play an important role in the optical properties of conjugated polymers. The optical absorption spectrum of trans-polyacetylene, for example, can be understood as completely dominated by the formation of exciton bound states. We review a recently developed first-principles method for computing the excitonic effects and optical spectrum, with no adjustable parameters. This theory is used to study the absorption spectrum of two conjugated polymers: trans-polyacetylene and poly-phenylene-vinylene(PPV).

Enhanced luminescence of MEH-PPV through the reduction of chain aggregations by blending 4-cyano-4′-N-heptylbiphenyl

Energy Technology Data Exchange (ETDEWEB)

Hsu, Kuei-Ting [Institute of Organic and Polymeric Materials, National Taipei University of Technology, No.1, Section 3, Zhongxiao E. Rd., Da’an Dist., Taipei City 106, Taiwan (R.O.C.) (China); Department of Chemical Engineering, Army Academy, No.750, Longdong Rd., Chung-Li 320, Taiwan (R.O.C.) (China); Chang, Shu-Mei; Li, Guo-Yuan [Institute of Organic and Polymeric Materials, National Taipei University of Technology, No.1, Section 3, Zhongxiao E. Rd., Da’an Dist., Taipei City 106, Taiwan (R.O.C.) (China); Liu, Wei-Ren, E-mail: WRLiu1203@gmail.com [Department of Chemical Engineering, R and D Center for Membrane Center, Chung Yuan Christian University, Chung Li, Taiwan (China)

2015-02-15

In this study, we report the electroluminescence and photoluminescence of poly[2-methoxy-5-(2-ethylhexyloxy)-p-phenylene vinylene] (MEH-PPV) and 4-cyano-4′-N-heptylbiphenyl (7CB) blends in the ratios of 0–90 wt% by drop-coating processes. The corresponding characterization of polarized optical microscope, electroluminescence, photoluminescence and atomic force microscope of different blending ratios of MEH-PPV/7CB are systematically carried out in this study. The optimal composition of 6/4 ratio in MEH-PPV/7CB exhibit the highest luminescence, which is almost ten times than that of pure MEH-PPV due to the fact that 7CB could be a barrier to avoid the aggression of MEH-PPV. The novel blending system demonstrate a potential approach for synthesizing the MEH-PPV/7CB composite film for electroluminescent device applications. - Highlights: • We propose a novel blending system of MEH-PPV/7CB system. • Controlling the alignment of polymer. • Avoid the aggression of MEH-PPV. • The luminescence intensity of blend film can be enhanced by 10 times. • A potential approach for electroluminescent device applications.

Clinical and pathological characteristics of colorectal polyps in ...

African Journals Online (AJOL)

Background & Aim: Colon polyps are important lesions and a concern because of the potential for colorectal cancer. Colorectal carcinoma is one of the most common causes of cancer-related deaths in Iranian population. The distribution of polyps in the colon may affect the efficacy of a screening modality. The aim of this ...

Tuning the Optoelectronic Properties of Vinylene-Linked Donor−Acceptor Copolymers for Organic Photovoltaics

KAUST Repository

Ko, Sangwon

2010-08-24

Five new donor-acceptor copolymers containing the electron acceptor benzothiadiazole (BTZ) linked to the electron donors fluorene (FL) or cyclopentadithiophene (CPDT) via vinylene units were synthesized to study polymer structure-property relationships in organic photovoltaic devices. Both alternating (P) and random copolymers (P1-P4) were prepared via Suzuki and Stille polycondensations, respectively. The cyclopentadithiophene copolymers (P2 and P4) have smaller electrochemical band gaps (1.79 and 1.64 eV) compared to the fluorene-containing copolymers (2.08 and 1.95 eV for P1 and P3). However, the presence of CPDT raises the electrochemical HOMO energy levels (-4.83 and-4.91 eV for P2 and P4) compared to the FL copolymers (-5.06 and-5.15 eV for P1 and P3) leading to small open circuit voltages (Voc) in solar cells. The primary solution and thin-film UV-vis absorption peaks of P3 and P4, which do not contain alkylated thiophenes appended to the BTZ unit, are at lower energy and have larger absorption coefficients than their P1 and P2 counterparts. Detailed theoretical analyses of the geometric structure, electronic structure, and excited-state vertical transitions using density functional theory provide direct insight into the interplay between the structural modifications and resulting electronic and optical changes. A high molecular weight (Mn = 25 kg/mol) polymer with a large degree of polymerization (DPn = 21) was easily achieved for the random copolymer P1, leading to thin films with both a larger absorption coefficient and a larger hole mobility compared to the analogous alternating polymer P (Mn = 22 kg/mol, DPn = 18). An improved short circuit current and a power conversion efficiency up to 1.42% (Jsc = 5.82 mA/cm2, Voc = 0.765 V, and FF = 0.32) were achieved in bulk heterojunction solar cells based on P1. © 2010 American Chemical Society.

New Copolymers Containing Charge Carriers for Organic Devices with ITO Films Treated by UV-Ozone Using High Intensity Discharge Lamp

Directory of Open Access Journals (Sweden)

Emerson Roberto SANTOS

2009-02-01

Full Text Available For electroluminescent devices new copolymers were synthesized using a Suzuki cross-coupling reaction based on monomers (fluorine-alt-phenylene in conjugation with quinoline-alt-phenylene units. They were characterized by 1H NMR, 13C NMR and FTIR. TGA measurements indicated that the copolymers have good thermal properties and no weight loss was observed up to 250 °C. The UV-Vis spectra were characterized by absorptions from the fluorene-alt-phenylene and quinoline-alt-phenylene segments in the backbone, while their photoluminescence (PL spectra dominated by emissions from the fluorene excimer. For devices assembly ITO films were treated using a High Intensity Discharge Lamp (HPMVL without outer bulb presenting high ozone concentration than that conventional germicidal lamp. The device with ITO treated revealed significant decrease of threshold voltage (or turn-on voltage compared by untreated with I-V curves. This decrease can be related by water and carbon dioxide extracted on surface after UV-Ozone treatment revealed by DRIFT measurements.

Association between Laryngeal Pepsin Levels and the Presence of Vocal Fold Polyps.

Science.gov (United States)

Wang, Lu; Tan, Jia-Jie; Wu, Ting; Zhang, Rui; Wu, Jia-Nuan; Zeng, Fang-Fang; Liu, You-Li; Han, Xiao-Yan; Li, Yan-Fei; Li, Xiang-Ping

2017-01-01

Objective To determine whether pepsin, the main component of refluxed gastric contents, is significantly associated with vocal fold polyps and to evaluate the diagnostic value of pepsin in vocal fold polyps' tissues. Study Design Cross-sectional study. Setting Nanfang Hospital of Southern Medical University. Subjects and Methods The study included 32 patients with vocal fold polyps and 16 healthy controls between 2011 and 2012. Reflux symptom index and reflux finding score assessments, 24-hour combined multichannel intraluminal impedance and pH monitoring, and biopsy of the vocal fold polyp tissues or posterior laryngeal mucosa (healthy controls) for immunohistochemical pepsin staining were performed. Results The expression of pepsin was significantly higher in patients with vocal fold polyps than in controls (28/32, 75% vs 5/16, 31.25%; P vocal fold polyps formation. In addition, pepsin immunohistochemical analysis of polyp biopsy samples appears to be a more sensitive and effective test for diagnosing laryngopharyngeal reflux than the reflux symptom index, the reflux finding score, and 24-hour pH monitoring in a clinical setting.

Antral hyperplastic polyp causing intermittent gastric outlet obstruction: Case report

Directory of Open Access Journals (Sweden)

Kurtkaya-Yapicier Ozlem

2003-06-01

Full Text Available Abstract Background Hyperplastic polyps are the most common polypoid lesions of the stomach. Rarely, they cause gastric outlet obstruction by prolapsing through the pyloric channel, when they arise in the prepyloric antrum. Case presentation A 62-year-old woman presented with intermittent nausea and vomiting of 4 months duration. Upper gastrointestinal endoscopy revealed a 30 mm prepyloric sessile polyp causing intermittent gastric outlet obstruction. Following submucosal injection of diluted adrenaline solution, the polyp was removed with a snare. Multiple biopsies were taken from the greater curvature of the antrum and the corpus. Rapid urease test for Helicobacter pylori yielded a negative result. Histopathologic examination showed a hyperplastic polyp without any evidence of malignancy. Biopsies of the antrum and the corpus revealed gastritis with neither atrophic changes nor Helicobacter pylori infection. Follow-up endoscopy after a 12-week course of proton pomp inhibitor therapy showed a complete healing without any remnant tissue at the polypectomy site. The patient has been symptom-free during 8 months of follow-up. Conclusions Symptomatic gastric polyps should be removed preferentially when they are detected at the initial diagnostic endoscopy. Polypectomy not only provides tissue to determine the exact histopathologic type of the polyp, but also achieves radical treatment.

Multi-block sulfonated poly(phenylene) copolymer proton exchange membranes

Science.gov (United States)

Fujimoto, Cy H [Albuquerque, NM; Hibbs, Michael [Albuquerque, NM; Ambrosini, Andrea [Albuquerque, NM

2012-02-07

Improved multi-block sulfonated poly(phenylene) copolymer compositions, methods of making the same, and their use as proton exchange membranes (PEM) in hydrogen fuel cells, direct methanol fuel cells, in electrode casting solutions and electrodes. The multi-block architecture has defined, controllable hydrophobic and hydrophilic segments. These improved membranes have better ion transport (proton conductivity) and water swelling properties.

Seasonality in polyps of a tropical cubozoan: A latina nr mordens.

Directory of Open Access Journals (Sweden)

Robert Courtney

Full Text Available A latina nr mordens have been located in large predictable spawning aggregations near Osprey Reef in the Coral Sea eight to ten days after a full moon; however, polyps have never been located in-situ. The polyp stage contributes to the abundance of medusae through asexual reproduction and metamorphosis, and may influence the periodicity of medusae by metamorphosis of the polyp. To elucidate the relationship between medusae periodicity and polyp ecology, polyps were exposed to thermal and osmotic treatments in order to determine the theoretical environmental limits to their distribution. Maximum fecundity occurred in thermal treatments of 21 to 25ºC and the theoretical minimum thermal requirement for population stability was approximately 17ºC. Polyps were also exposed to five feeding regimes and fecundity was found to be positively correlated with feeding frequency. Thermal and osmotic variations did not induce metamorphosis in this species, however, reduced food did. The implications of asexual reproduction and cues for metamorphosis in relation to population dynamics of this species are discussed.

Unraveling the Solution-State Supramolecular Structures of Donor-Acceptor Polymers and their Influence on Solid-State Morphology and Charge-Transport Properties.

Science.gov (United States)

Zheng, Yu-Qing; Yao, Ze-Fan; Lei, Ting; Dou, Jin-Hu; Yang, Chi-Yuan; Zou, Lin; Meng, Xiangyi; Ma, Wei; Wang, Jie-Yu; Pei, Jian

2017-11-01

Polymer self-assembly in solution prior to film fabrication makes solution-state structures critical for their solid-state packing and optoelectronic properties. However, unraveling the solution-state supramolecular structures is challenging, not to mention establishing a clear relationship between the solution-state structure and the charge-transport properties in field-effect transistors. Here, for the first time, it is revealed that the thin-film morphology of a conjugated polymer inherits the features of its solution-state supramolecular structures. A "solution-state supramolecular structure control" strategy is proposed to increase the electron mobility of a benzodifurandione-based oligo(p-phenylene vinylene) (BDOPV)-based polymer. It is shown that the solution-state structures of the BDOPV-based conjugated polymer can be tuned such that it forms a 1D rod-like structure in good solvent and a 2D lamellar structure in poor solvent. By tuning the solution-state structure, films with high crystallinity and good interdomain connectivity are obtained. The electron mobility significantly increases from the original value of 1.8 to 3.2 cm 2 V -1 s -1 . This work demonstrates that "solution-state supramolecular structure" control is critical for understanding and optimization of the thin-film morphology and charge-transport properties of conjugated polymers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Structure and signaling at hydroid polyp-stolon junctions, revisited

Directory of Open Access Journals (Sweden)

Katherine L. Harmata

2015-09-01

Full Text Available The gastrovascular system of colonial hydroids is central to homeostasis, yet its functional biology remains poorly understood. A probe (2′,7′-dichlorodihydrofluorescein diacetate for reactive oxygen species (ROS identified fluorescent objects at polyp-stolon junctions that emit high levels of ROS. A nuclear probe (Hoechst 33342 does not co-localize with these objects, while a mitochondrial probe (rhodamine 123 does. We interpret these objects as mitochondrion-rich cells. Confocal microscopy showed that this fluorescence is situated in large columnar cells. Treatment with an uncoupler (2,4-dinitrophenol diminished the ROS levels of these cells relative to background fluorescence, as did removing the stolons connecting to a polyp-stolon junction. These observations support the hypothesis that the ROS emanate from mitochondrion-rich cells, which function by pulling open a valve at the base of the polyp. The open valve allows gastrovascular fluid from the polyp to enter the stolons and vice versa. The uncoupler shifts the mitochondrial redox state in the direction of oxidation, lowering ROS levels. By removing the stolons, the valve is not pulled open, metabolic demand is lowered, and the mitochondrion-rich cells slowly regress. Transmission electron microscopy identified mitochondrion-rich cells adjacent to a thick layer of mesoglea at polyp-stolon junctions. The myonemes of these myoepithelial cells extend from the thickened mesoglea to the rigid perisarc on the outside of the colony. The perisarc thus anchors the myoepithelial cells and allows them to pull against the mesoglea and open the lumen of the polyp-stolon junction, while relaxation of these cells closes the lumen.

Inverted Lymphoglandular Polyp in Descending Colon

Directory of Open Access Journals (Sweden)

Shengmei Zhou

2015-01-01

Full Text Available A 47-year-old male with a history of left colon cancer, status post left colon resection for 12 years, presented with rectal bleeding. Colonoscopic examination revealed an 8 mm sessile polyp in the proximal descending colon. Microscopic examination showed that the surface of this polyp was covered with a layer of normal colonic mucosa with focal surface erosion. In the submucosal layer, an intimate admixture of multiple cystically dilated glands and prominent lymphoid aggregates with germinal centers was seen. The glands were lined by columnar epithelium. Immunohistochemical staining showed the glands were positive for CK20 and CDX2 and negative for CK7, with a low proliferative index, mostly consistent with reactive colonic glands. The patient remained asymptomatic after one-year follow-up. A review of the literature shows very rare descriptions of similar lesions, but none fits exactly this pattern. We would designate this inverted lymphoglandular polyp and present this case to raise the awareness of recognizing this unusual histological entity.

Antifungal Properties of Cationic Phenylene Ethynylenes and Their Impact on β-Glucan Exposure.

Science.gov (United States)

Pappas, Harry C; Sylejmani, Rina; Graus, Matthew S; Donabedian, Patrick L; Whitten, David G; Neumann, Aaron K

2016-08-01

Candida species are the cause of many bloodstream infections through contamination of indwelling medical devices. These infections account for a 40% mortality rate, posing a significant risk to immunocompromised patients. Traditional treatments against Candida infections include amphotericin B and various azole treatments. Unfortunately, these treatments are associated with high toxicity, and resistant strains have become more prevalent. As a new frontier, light-activated phenylene ethynylenes have shown promising biocidal activity against Gram-positive and -negative bacterial pathogens, as well as the environmental yeast Saccharomyces cerevisiae In this study, we monitored the viability of Candida species after treatment with a cationic conjugated polymer [poly(p-phenylene ethynylene); PPE] or oligomer ["end-only" oligo(p-phenylene ethynylene); EO-OPE] by flow cytometry in order to explore the antifungal properties of these compounds. The oligomer was found to disrupt Candida albicans yeast membrane integrity independent of light activation, while PPE is able to do so only in the presence of light, allowing for some control as to the manner in which cytotoxic effects are induced. The contrast in killing efficacy between the two compounds is likely related to their size difference and their intrinsic abilities to penetrate the fungal cell wall. Unlike EO-OPE-DABCO (where DABCO is quaternized diazabicyclo[2,2,2]octane), PPE-DABCO displayed a strong propensity to associate with soluble β-glucan, which is expected to inhibit its ability to access and perturb the inner cell membrane of Candida yeast. Furthermore, treatment with PPE-DABCO unmasked Candida albicans β-glucan and increased phagocytosis by Dectin-1-expressing HEK-293 cells. In summary, cationic phenylene ethynylenes show promising biocidal activity against pathogenic Candida yeast cells while also exhibiting immunostimulatory effects. Copyright © 2016, American Society for Microbiology. All Rights

Transanal endoscopic microsurgery for giant polyps of the rectum

DEFF Research Database (Denmark)

Levic, K; Bulut, O; Hesselfeldt, P

2014-01-01

in the rectum. We present our results with TEM in the removal of giant polyps equal or greater than 4 cm in diameter. METHODS: In the period between 1998 and 2012, TEM was performed in 39 patients with rectal polyps measuring at least 4 cm in diameter. Transrectal ultrasound and/or magnetic resonance imaging......, these recurrences were treated with endoscopic removal or re-TEM. The remaining 5 underwent total mesorectal excision and/or chemotherapy. CONCLUSIONS: Full-thickness TEM provides a safe and efficient treatment for excision of giant polyps. In case of unexpected cancer, TEM can be curative. Local recurrence can...

Epoxy-crosslinked sulfonated poly (phenylene) copolymer proton exchange membranes

Science.gov (United States)

Hibbs, Michael; Fujimoto, Cy H.; Norman, Kirsten; Hickner, Michael A.

2010-10-19

An epoxy-crosslinked sulfonated poly(phenylene) copolymer composition used as proton exchange membranes, methods of making the same, and their use as proton exchange membranes (PEM) in hydrogen fuel cells, direct methanol fuel cell, in electrode casting solutions and electrodes, and in sulfur dioxide electrolyzers. These improved membranes are tougher, have higher temperature capability, and lower SO.sub.2 crossover rates.

Prevalence of colonic polyp and its predictors in patients with acromegaly

Directory of Open Access Journals (Sweden)

Purnima Agarwal

2016-01-01

Full Text Available Background: There are conflicting data regarding the prevalence of colorectal polyp in patients with acromegaly. Subjects and Methods: Consecutive forty-seven acromegalic patients (21 men, 26 women, with a mean age of (40 ± 12 years attending endocrinology outpatient department underwent full colonoscopy. All the patients underwent clinical and biochemical evaluation (glucose suppressed growth hormone (GH, Insulin-like growth factor-1 [IGF-1], fasting insulin, and glucose. The control group (n = 120 for colonoscopy was adult subjects undergoing evaluation for symptoms of irritable bowel syndrome. Clinical and biochemical parameters in acromegalic patients with colonic polyp were compared to those without a polyp. Results: Patients with acromegaly had significantly higher prevalence of colonic polyp as compared to control subjects (10.6% vs. 0.8%. None of the patients with polyp had skin tags. There was no significant difference between subjects with and without colonic polyp in duration of illness, basal, and glucose-suppressed GH and most recent IGF-1. Fasting blood sugar was significantly higher (P < 0.05 in adenoma group after adjusting for age, body mass index (BMI, and insulin levels. Patients in adenoma group showed a trend toward male gender and younger age as compared to those without adenoma. Conclusions: Subjects with acromegaly as compared to control have a higher prevalence of colonic polyps. There was no association of polyps seen with age, BMI, skin tags, homeostasis model assessment of insulin resistance index, duration of disease, and basal and glucose-suppressed GH and IGF-1 levels. There were no specific predictive factors detected. Screening full colonoscopy is recommended in all cases with acromegaly.

Treatment of Hemorrhagic Vocal Polyps by Pulsed Dye Laser-Assisted Laryngomicrosurgery

Directory of Open Access Journals (Sweden)

Hyung Kwon Byeon

2015-01-01

Full Text Available Objective. Conventional surgical techniques of laryngomicrosurgery (LMS on hemorrhagic vocal polyps are often difficult due to obscuration of the surgical field by inadvertent bleeding from the lesion, and there are often significant amounts of mucosal epithelium loss. Here, we introduce our surgical technique using pulsed dye laser (PDL, which can effectively resect the polyp with vocal fold mucosa preservation. Methods. Patients who were diagnosed with hemorrhagic vocal polyp and who were surgically managed using PDL from March 2013 to October 2014 were retrospectively reviewed. Preoperative and postoperative clinical outcomes and surgical findings were evaluated. Results. A total of 39 patients were treated with PDL-assisted enucleation LMS. The average age was 43.7 years (range 20–73, and there were 20 males and 19 females (17 professional voice users. In all cases, the hemorrhagic polyp was successfully enucleated after application of PDL, thereby preserving the overlying epithelium. Postoperative voice outcomes were favorable with clear preservation of the vocal fold mucosal wave. Conclusion. PDL-assisted enucleation LMS for the treatment of hemorrhagic vocal polyps can be a safe and effective surgical technique. It can be considered a promising treatment option for hemorrhagic vocal polyps.

Dysphagia caused by a fibrovascular polyp: a case report.

NARCIS (Netherlands)

Blacha, M.M.; Sloots, C.E.J.; Munster, I.P. van; Wobbes, T.

2008-01-01

ABSTRACT: A 73-year old man presented with dysphagia for liquid and solid food. Barium contrast study of the esophagus and esophagoscopy demonstrated a fibrovascular polyp. This, almost 10 cm benign esophageal tumor, was removed surgically by a cervical esophagotomy. A fibrovascular polyp is a rare

Deep learning of contrast-coated serrated polyps for computer-aided detection in CT colonography

Science.gov (United States)

Näppi, Janne J.; Pickhardt, Perry; Kim, David H.; Hironaka, Toru; Yoshida, Hiroyuki

2017-03-01

Serrated polyps were previously believed to be benign lesions with no cancer potential. However, recent studies have revealed a novel molecular pathway where also serrated polyps can develop into colorectal cancer. CT colonography (CTC) can detect serrated polyps using the radiomic biomarker of contrast coating, but this requires expertise from the reader and current computer-aided detection (CADe) systems have not been designed to detect the contrast coating. The purpose of this study was to develop a novel CADe method that makes use of deep learning to detect serrated polyps based on their contrast-coating biomarker in CTC. In the method, volumetric shape-based features are used to detect polyp sites over soft-tissue and fecal-tagging surfaces of the colon. The detected sites are imaged using multi-angular 2D image patches. A deep convolutional neural network (DCNN) is used to review the image patches for the presence of polyps. The DCNN-based polyp-likelihood estimates are merged into an aggregate likelihood index where highest values indicate the presence of a polyp. For pilot evaluation, the proposed DCNN-CADe method was evaluated with a 10-fold cross-validation scheme using 101 colonoscopy-confirmed cases with 144 biopsy-confirmed serrated polyps from a CTC screening program, where the patients had been prepared for CTC with saline laxative and fecal tagging by barium and iodine-based diatrizoate. The average per-polyp sensitivity for serrated polyps >=6 mm in size was 93+/-7% at 0:8+/-1:8 false positives per patient on average. The detection accuracy was substantially higher that of a conventional CADe system. Our results indicate that serrated polyps can be detected automatically at high accuracy in CTC.

Syndromic Gastric Polyps : At the Crossroads of Genetic and Environmental Cancer Predisposition

NARCIS (Netherlands)

Brosens, Lodewijk A A; Giardiello, Francis M; Offerhaus, G Johan; Montgomery, Elizabeth A

2016-01-01

Gastric polyps occur in 1-4 % of patients undergoing gastroscopy. Although most are sporadic, some gastric polyps are part of an underlying hereditary syndrome. Gastric polyps can be seen in each of the well-known gastrointestinal polyposis syndromes, but also in Lynch syndrome and in several rare

Fluorescence blinking in MEH-PPV single molecules at low temperature

International Nuclear Information System (INIS)

Mirzov, O.; Cichos, F.; Borczyskowski, C. von; Scheblykin, I.

2005-01-01

Fluorescence intensity transients of single molecules of the conjugated polymer poly[2-methoxy,5-(2'-ethylhexyloxy)-p-phenylene-vinylene] (MEH-PPV) were studied at 15 K. Fluorescence blinking behavior was observed despite the expected low-temperature suppression of energy migration in such disordered molecular systems. Presence of the fluorescence blinking effect at 15 K indicates that the single molecules possess a collapsed conformation with characteristic size of not more than several nanometers, which corresponds to only a few exciton hops over a polymer chain

Polyp Removal of a Bloom Forming Jellyfish, Aurelia coerulea, in Korean Waters and Its Value Evaluation

Science.gov (United States)

Yoon, Wonduk; Chae, Jinho; Koh, Byoung-Seol; Han, Changhoon

2018-04-01

Aurelia coerulea is a bloom forming jellyfish that first appeared before 1980 in the western and southern Korean seas and which has been blamed for huge economical losses in all fields of marine activities. As a preventive measure to reduce economical losses, polyp removal was undertaken at Lake Shihwa, Lake Saemangeum, and Masan Bay, Korea. In the course of efforts during 2 years to remove polyps, polyps were surveyed, quantified, and removed. In these areas, the initial total polyp abundance was 5.04 × 109 and 46.25% of them were removed; Lake Shihwa the highest rates of removal and Lake Saemangeum the lowest. These efforts to remove polyps prevented the appearance of 1.20 × 109 medusae, corresponding to 78.28 × 106 kg. The cost of polyp removal was evaluated and compared with that of medusae removal. The ratio between the cost of polyp removal and that of medusae removal ranged between 0.78-3.14%, indicating large cost savings for polyp removal undertakings. However, the effect of polyp removal varied from positive to none, and we assumed that the cleared surface for polyp removal, quantity of removed polyp, and existence of polyps' hotspots in neighboring areas were the causes of the non-effectiveness of polyp removal undertakings.

Selective suppression of in situ proliferation of scyphozoan polyps by biofouling

International Nuclear Information System (INIS)

Feng, Song; Wang, Shi-Wei; Zhang, Guang-Tao; Sun, Song; Zhang, Fang

2017-01-01

An increase in marine artificial constructions has been proposed as a major cause of jellyfish blooms, because these constructions provide additional substrates for organisms at the benthic stage (polyps), which proliferate asexually and release a large amount of free-swimming medusae. These hard surfaces are normally covered by fouling communities, the components of which have the potential to impede the proliferation of polyps. In this study, we report an in situ experiment of polyp survival of four large scyphozoan species found in East Asian marginal seas that were exposed to biofouling, a universal phenomenon occurring on marine artificial constructions. Our results showed that the polyps of three species (Nemopilema nomurai, Cyanea nozaki, and Rhopilema esculentum) attached to the artificial surfaces were completely eliminated by biofouling within 7–8 months, and only those of moon jellyfish (Aurelia sp.1) in the upper layers could multiply on both artificial materials and other organisms (e.g., ascidians and bryozoans). Fouling-associated competition and predation and suppressed asexual reproduction of podocysts were observed to contribute to the loss of polyps. This study shows that the natural distribution of polyps is defined by the biofouling community that colonizes the surfaces of artificial constructions. Consequently, the contribution of marine constructions to jellyfish bloom is limited only to the ability of the jellyfish species to reproduce asexually through budding and inhabit solid surfaces of fouling organisms in addition to inhabiting original artificial materials. We anticipate that fragile polyps will colonize and proliferate in harsh environments that are deleterious to biofouling, and we propose special attention to polyps in antifouling practices for excluding the possibility that they occupy the available ecological space. - Highlights: • Biofouling selectively controls in situ proliferation of scyphozoan polyps • The contribution

The Effects of Size and Type of Vocal Fold Polyp on Some Acoustic Voice Parameters

Directory of Open Access Journals (Sweden)

Elaheh Akbari

2018-03-01

Full Text Available Background: Vocal abuse and misuse would result in vocal fold polyp. Certain features define the extent of vocal folds polyp effects on voice acoustic parameters. The present study aimed to define the effects of polyp size on acoustic voice parameters, and compare these parameters in hemorrhagic and non-hemorrhagic polyps. Methods: In the present retrospective study, 28 individuals with hemorrhagic or non-hemorrhagic polyps of the true vocal folds were recruited to investigate acoustic voice parameters of vowel/ æ/ computed by the Praat software. The data were analyzed using the SPSS software, version 17.0. According to the type and size of polyps, mean acoustic differences and correlations were analyzed by the statistical t test and Pearson correlation test, respectively; with significance level below 0.05. Results: The results indicated that jitter and the harmonics-to-noise ratio had a significant positive and negative correlation with the polyp size (P=0.01, respectively. In addition, both mentioned parameters were significantly different between the two types of the investigated polyps. Conclusion: Both the type and size of polyps have effects on acoustic voice characteristics. In the present study, a novel method to measure polyp size was introduced. Further confirmation of this method as a tool to compare polyp sizes requires additional investigations.

Localization by immunoperoxidase and estimation by radioimmunoassay of carcinoembryonic antigen on colonic polyp

International Nuclear Information System (INIS)

Sharkey, R.M.; Hagihara, P.F.; Goldenberg, D.M.

1977-01-01

A 3-layer immunoperoxidase technique was used to demonstrate carcinoembryonic antigen (CEA) in colonic polyps from patients with or without previous or concurrent malignancy. CEA was demonstrated in a higher percentage of the polyps received as fresh specimens that were rapidly frozen and fixed in ethanol, than in formalin-fixed, paraffin-embedded sections. Tissue CEA content of both colonic carcinomas and polyps was determined by radioimmunoassay, and it was found that benign colonic tumours had levels of tissue CEA comparable to colonic cancer, indicating that CEA concentration in a tumour does not reflect its grade of malignancy. In fact, in one case in which both colonic cancer and polyps were removed, the polyps has the higher quantities of tissue CEA. Further, tissue CEA concentration of a polyp was not dependent on its size or location. Studying the titres of circulating CEA in these patients revealed an elevation of plasma CEA in one-third of the patients with only colonic polyps, whilst the patients with cancer all had increased titres. (author)

Selective suppression of in situ proliferation of scyphozoan polyps by biofouling.

Science.gov (United States)

Feng, Song; Wang, Shi-Wei; Zhang, Guang-Tao; Sun, Song; Zhang, Fang

2017-01-30

An increase in marine artificial constructions has been proposed as a major cause of jellyfish blooms, because these constructions provide additional substrates for organisms at the benthic stage (polyps), which proliferate asexually and release a large amount of free-swimming medusae. These hard surfaces are normally covered by fouling communities, the components of which have the potential to impede the proliferation of polyps. In this study, we report an in situ experiment of polyp survival of four large scyphozoan species found in East Asian marginal seas that were exposed to biofouling, a universal phenomenon occurring on marine artificial constructions. Our results showed that the polyps of three species (Nemopilema nomurai, Cyanea nozaki, and Rhopilema esculentum) attached to the artificial surfaces were completely eliminated by biofouling within 7-8months, and only those of moon jellyfish (Aurelia sp.1) in the upper layers could multiply on both artificial materials and other organisms (e.g., ascidians and bryozoans). Fouling-associated competition and predation and suppressed asexual reproduction of podocysts were observed to contribute to the loss of polyps. This study shows that the natural distribution of polyps is defined by the biofouling community that colonizes the surfaces of artificial constructions. Consequently, the contribution of marine constructions to jellyfish bloom is limited only to the ability of the jellyfish species to reproduce asexually through budding and inhabit solid surfaces of fouling organisms in addition to inhabiting original artificial materials. We anticipate that fragile polyps will colonize and proliferate in harsh environments that are deleterious to biofouling, and we propose special attention to polyps in antifouling practices for excluding the possibility that they occupy the available ecological space. Copyright © 2016 Elsevier Ltd. All rights reserved.

Improving Polyp Detection Algorithms for CT Colonography: Pareto Front Approach.

Science.gov (United States)

Huang, Adam; Li, Jiang; Summers, Ronald M; Petrick, Nicholas; Hara, Amy K

2010-03-21

We investigated a Pareto front approach to improving polyp detection algorithms for CT colonography (CTC). A dataset of 56 CTC colon surfaces with 87 proven positive detections of 53 polyps sized 4 to 60 mm was used to evaluate the performance of a one-step and a two-step curvature-based region growing algorithm. The algorithmic performance was statistically evaluated and compared based on the Pareto optimal solutions from 20 experiments by evolutionary algorithms. The false positive rate was lower (pPareto optimization process can effectively help in fine-tuning and redesigning polyp detection algorithms.

Giant fibrovascular polyp of the esophagus: a case report

International Nuclear Information System (INIS)

Ryoo, Jae Wook; Kim, Jeung Sook; Lee, Kyung Soo; Lim, Jae Hoon; Shim, Young Mog; Han, Joung Ho

1995-01-01

Fibrovascular polyp of the esophagus is a rare and benign pedunculated intraluminal tumor. The tumor consists of varying amount of vascular fibrous and adipose tissue that arises in the submucosa and is covered by squamous epithelium. We report the typical radiographic, CT and MR findings of a case of giant fibrovascular polyp of the esophagus

Increased Prevalence of Colorectal Polyp in Acromegaly Patients: A Case-Control Study

Directory of Open Access Journals (Sweden)

Ali Riza Koksal

2014-01-01

Full Text Available An increase in the prevalence of colorectal polyps and cancer is reported in patients with acromegaly. This trial is designed to determine whether there is an increase in the prevalence of colorectal polyps/cancer in Turkish acromegaly patients. Sixty-six patients, who were under follow-up with the diagnosis of acromegaly and underwent total colonoscopic examination, were enrolled in the study. Sixty-five age- and gender-matched patients with nonspecific complaints were selected as control. The mean age of acromegalic patients was 51.5±12.8 years of whom 27 (40.9% were females. In 20 (30.3% of the patients with acromegaly a total of 65 colorectal polyps were detected. Forty-seven (72.3% of the polyps were detected at the rectosigmoid region. In 8 (12.3% of the 65 control patients a total of 17 polyps were found. There was a statistically significant difference between the groups (P=0.018. At the logistic regression analysis we found that the risk for colon polyps increased 3.2-fold in the presence of acromegaly, irrespective of age and gender (OR: 3.191, 95% CI: 1.25–8.13. In conclusion, patients who were followed up with the diagnosis of acromegaly should be taken to the colonoscopic surveillance program and all polyps detected should be excised in order to protect them from colorectal cancer.

Measurement of smaller colon polyp in CT colonography images using morphological image processing.

Science.gov (United States)

Manjunath, K N; Siddalingaswamy, P C; Prabhu, G K

2017-11-01

Automated measurement of the size and shape of colon polyps is one of the challenges in Computed tomography colonography (CTC). The objective of this retrospective study was to improve the sensitivity and specificity of smaller polyp measurement in CTC using image processing techniques. A domain knowledge-based method has been implemented with hybrid method of colon segmentation, morphological image processing operators for detecting the colonic structures, and the decision-making system for delineating the smaller polyp-based on a priori knowledge. The method was applied on 45 CTC dataset. The key finding was that the smaller polyps were accurately measured. In addition to 6-9 mm range, polyps of even processing. It takes [Formula: see text] min for measuring the smaller polyp in a dataset of 500 CTC images. With this method, [Formula: see text] and [Formula: see text] were achieved. The domain-based approach with morphological image processing has given good results. The smaller polyps were measured accurately which helps in making right clinical decisions. Qualitatively and quantitatively the results were acceptable when compared to the ground truth at [Formula: see text].

Glycoprotein expression by adenomatous polyps of the colon

Science.gov (United States)

Roney, Celeste A.; Xie, Jianwu; Xu, Biying; Jabour, Paul; Griffiths, Gary; Summers, Ronald M.

2008-03-01

Colon cancer is the second leading cause of cancer related deaths in the United States. Specificity in diagnostic imaging for detecting colorectal adenomas, which have a propensity towards malignancy, is desired. Adenomatous polyp specimens of the colon were obtained from the mouse model of colorectal cancer called adenomatous polyposis coli-multiple intestinal neoplasia (APC Min). Histological evaluation, by the legume protein Ulex europaeus agglutinin I (UEA-1), determined expression of the glycoprotein α-L-fucose. FITC-labelled UEA-1 confirmed overexpression of the glycoprotein by the polyps on fluorescence microscopy in 17/17 cases, of which 13/17 included paraffin-fixed mouse polyp specimens. In addition, FITC-UEA-1 ex vivo multispectral optical imaging of 4/17 colonic specimens displayed over-expression of the glycoprotein by the polyps, as compared to non-neoplastic mucosa. Here, we report the surface expression of α-L-fucosyl terminal residues by neoplastic mucosal cells of APC specimens of the mouse. Glycoprotein expression was validated by the carbohydrate binding protein UEA-1. Future applications of this method are the development of agents used to diagnose cancers by biomedical imaging modalities, including computed tomographic colonography (CTC). UEA-1 targeting to colonic adenomas may provide a new avenue for the diagnosis of colorectal carcinoma by CT imaging.

Molecular junctions based on SAMs of cruciform oligo(phenylene ethynylene)s

DEFF Research Database (Denmark)

Wei, Zhongming; Li, Tao; Jennum, Karsten Stein

2012-01-01

Cruciform oligo(phenylene ethynylene)s (OPEs) with an extended tetrathiafulvalene (TTF) donor moiety (OPE5-TTF and OPE3-TTF) and their simple analogues (OPE5-S and OPE3) without conjugated substituents were used to form high quality self-assembled monolayers (SAMs) on ultra-flat gold substrates...

Further refinements of the polyp snare for interuterine surgery--a new modality for treatment of myomas and polyps.

Science.gov (United States)

McLucas, B

1995-01-01

Hysteroscopic treatment of 30 patients suffering from menorrhagia or post-partum complications was accomplished using an electrosurgical polyp snare. Using this method, 18 polyps and 12 myomas were successfully removed in less than twenty minutes without complications. Local anaesthesia was used in 12 patients. Three patients have presented with recurrence of menorrhagia, with a minimum of six months follow-up. Benefits of this technique compared to uterine resectoscopy include shorter operative time, decreased risk of fluid overload, and less risk of uterine perforation. The snare is difficult to use and a learning curve exists. Higher currents than that used for resection are required.

Photoresponse of poly(para-phenylenevinylene) light-emitting diodes

International Nuclear Information System (INIS)

Wei, X.; Raikh, M.; Vardeny, Z.V.; Yang, Y.; Moses, D.

1994-01-01

We have studied the photoresponses of poly(para-phenylene vinylene) (PPV) light-emitting diodes (LED's) with PPV derivatives sandwiched between tin oxide (ITO) and metals including calcium, aluminum, and copper. Under illumination all diodes exhibit relatively large photoconductive I(V) responses which cross the dark I(V) curve at a forward-bias voltage V 0 that scales with the difference in work functions between the ITO and metal electrodes, the open-circuit voltage saturates at V 0 and is temperature independent, and the enhanced electroluminescence intensity of the illuminated LED's correlates with the photocurrent

A Giant Pedunculated Urothelial Polyp Mimicking Bladder Mass in a Child: A Rare Case

Directory of Open Access Journals (Sweden)

Mehmet Kaba

2014-01-01

Full Text Available Ureteral fibroepithelial polyps are rarely seen benign tumors with mesodermal origin. These polyps can involve kidney, pelvis, ureter, bladder, and urethra. The most common symptoms are hematuria and flank pain. The choice of treatment is either endoscopic or surgical resection of polyp by sparing kidney. Here, we presented a pediatric case with giant, fibroepithelial polyp that mimics bladder tumor, originating from middle segment of the ureter.

Male and female stem cells and sex reversal in Hydra polyps

OpenAIRE

Bosch, Thomas C. G.; David, Charles N.

1986-01-01

Single interstitial stem cells of male polyps of Hydra magnipapillata give rise to clones that differentiate either male or female gametes. To test the sexual stability of these clones, stem cells were recloned. The results indicate that stem cells from female clones are stable in their sexual differentiation capacity; male stem cells, by comparison, switch sexual phenotype at the rate of 10-2 per cell per generation. As a result, female polyps contain only female stem cells; male polyps cont...

Giant fibrovascular esophageal polyp misdiagnosed as achalasia.

Science.gov (United States)

Cordoş, I; Istrate, A; Codreşi, M; Bolca, C

2012-01-01

A 59 years old woman was admitted in our unit accusing longtime dysphagia and regurgitation. On admission, the patient was wearing a 3 month old definitive feeding gastrostomy tube. The contrast swallow, endoscopy and esophageal manometry established the diagnostic--achalasia. We removed the gastrostomy tube and we performed an open Heller myotomy. The postoperative period was uneventful and the patient was discharged one week later with affirmatively unimpaired deglutition. One month later, the patient was admitted via emergency with a giant fibrous tumor arising from her mouth after an episode of strong coughing and vomiting. The repeated endoscopy showed a giant esophageal polyp that was missed by the previous investigations, originating from pharingoesophageal junction. The esophageal polyp was resected by cervical approach with good postoperative outcome. The polyp's particular extreme dimensions (27 cm) prevented the acute asphyxia by blockage at the laryngeal level, possibly provoked by smaller tumors. As postoperative one month barium swallow showed a normal esophageal aspect, a final question remains--was achalasia real or an erroneous diagnosis was established the second time too?

Clinical Significance of Colonoscopy in Patients with Upper Gastrointestinal Polyps and Neoplasms: A Meta-Analysis

Science.gov (United States)

Wu, Zhen-Jie; Lin, Yuan; Xiao, Jun; Wu, Liu-Cheng; Liu, Jun-Gang

2014-01-01

Background Some authors have studied the relationship between the presence of polyps, adenomas and cancers of upper gastrointestinal tract (stomach and duodenum) and risk of colorectal polyps and neoplasms; however, the results are controversial, which may be due to study sample size, populations, design, clinical features, and so on. No meta-analysis, which can be generalized to a larger population and could provide a quantitative pooled risk estimate of the relationship, of this issue existed so far. Methods We performed a meta-analysis to evaluate risk of colorectal polyps or neoplasms in patients with polyps, adenomas or cancers in upper gastrointestinal tract comparing with controls. A search was conducted through PubMed, EMBASE, reference lists of potentially relevant papers, and practice guidelines up to 27 November 2013 without languages restriction. Odd ratios (ORs) were pooled using random-effects models. Results The search yielded 3 prospective and 21 retrospective case-control studies (n = 37152 participants). The principal findings included: (1) OR for colorectal polyps was 1.15 (95% CI, 1.04–1.26) in the gastric polyps group comparing with control groups; (2) Patients with gastric polyps and neoplasms have higher risk (OR, 1.31 [95% CI, 1.06–1.62], and 1.72 [95% CI, 1.42–2.09], respectively) of colorectal neoplasms comparing with their controls; and (3) Positive association was found between the presence of colorectal neoplasms and sporadic duodenal neoplasms (OR, 2.59; 95% CI, 1.64–4.11). Conclusions Findings from present meta-analysis of 24 case-control studies suggest that the prevalence of colorectal polyps was higher in patients with gastric polyps than in those without gastric polyps, and the risk of colorectal neoplasms increases significantly in patients with gastric polyps, neoplasms, and duodenal neoplasms. Therefore, screening colonoscopy should be considered for patients with upper gastrointestinal polyps and neoplasms. PMID

New Polyamides Based on Bis(p-amidobenzoic acid)-p-phenylene diacrylic acid and Hydantoin Derivatives: Synthesis and Characterization

OpenAIRE

FAGHIHI, Khalil

2008-01-01

Bis(p-amidobenzoic acid)-p-phenylene diacrylic acid (6) as a new monomer containing p-phenylenediacryloyl moiety was synthesized by using a 3-step reaction. At first p-phenylenediacrylic acid (3) was prepared by reaction of terephthal aldehyde (1) with malonic acid (2) in the presence of pyridine, and then diacid 3 was converted to p-phenylenediacryloyl chloride (4) by reaction with thionyl chloride. Finally bis(p-amidobenzoic acid)-p-phenylene diacrylic acid (6) was prepared by the ...

Detection of helicobacter pylori in nasal polyps using rapid urease test and ELISA

Directory of Open Access Journals (Sweden)

Masood Kaviani

2009-01-01

Full Text Available Introduction: Nasal polyposis is an inflammatory condition of unknown etiology. Recently concerns regarding gastroesophageal reflux or helicobacter pylori as a possible pathologic cause of nasal polyps have been increasing. The present study was planned to investigate the presence of helicobacter pylori in nasal polyps. Materials and Methods: This case-control study was undertaken enrolling 37 patients with nasal polyps who had undergone nasal endoscopic sinus surgery and 38 control subjects. Biopsy specimens of nasal polyps and inferior turbinates were assessed by rapid urease test. Blood samples of both study and control subjects were evaluated for anti H.pylori IgG by ELISA. H. pylori status was regarded positive, if both tests were positive. Results: Seropositivity was more common in the patients with nasal polyps (66.2% than control subjects (36.8% (P

Associations between dietary fiber and colorectal polyp risk differ by polyp type and smoking status.

Science.gov (United States)

Fu, Zhenming; Shrubsole, Martha J; Smalley, Walter E; Ness, Reid M; Zheng, Wei

2014-05-01

The association of dietary fiber intake with colorectal cancer risk is established. However, the association may differ between cigarette smokers and nonsmokers. We evaluated this hypothesis in a large colonoscopy-based case-control study. Dietary fiber intakes were estimated by self-administered food frequency questionnaire. Unconditional logistic regression analysis was used to estimate ORs and 95% CIs with adjustment for potential confounders. Analysis also was stratified by cigarette smoking and sex. High dietary fiber intake was associated with reduced risk of colorectal polyps (P-trend = 0.003). This association was found to be stronger among cigarette smokers (P-trend = 0.006) than nonsmokers (P-trend = 0.21), although the test for multiplicative interaction was not statistically significant (P = 0.11). This pattern of association was more evident for high-risk adenomatous polyps (ADs), defined as advanced or multiple ADs (P-interaction smoking and dietary fiber intake = 0.09). Among cigarette smokers who smoked ≥23 y, a 38% reduced risk of high-risk ADs was found to be associated with high intake of dietary fiber compared with those in the lowest quartile fiber intake group (P-trend = 0.004). No inverse association with dietary fiber intake was observed for low-risk ADs, defined as single nonadvanced ADs. Cigarette smoking may modify the association of dietary fiber intake with the risk of colorectal polyps, especially high-risk ADs, a well-established precursor of colorectal cancer.

Growth of Optically Active p-Phenylene Needles on Mica

DEFF Research Database (Denmark)

Balzer, F.; Rubahn, Horst-Günter

2002-01-01

Structural and optical properties of p-phenylene oligomers (p-nP, n=4, 5, 6) grown on mica (0 0 0 1) are investigated via low energy electron diffraction (LEED) using a multi-channelplate LEED as well as linear absorption spectroscopy and fluorescence microscopy. Single-crystalline fibres of laying...

Fibroepithelial ureteral polyps presenting as ureteropelvic obstruction

Science.gov (United States)

Cusano, Antonio; Abarzua-Cabezas, Fernando; Kesler, Stuart

2014-01-01

A 57-year-old woman presented with bilateral abdominal pain and flank discomfort. Imaging studies, consisting of CT scan, diethylene triamine pentaacetic acid renal scan with Lasix and a retrograde pyelogram, indicated an obstruction at the uteropelvic junction (UPJ), possibly due to fibroepithelial polyps within the ureter. A robotic pyeloplasty revealed a ureteral diverticulum and a thin, still-attached fibroepithelial polyp of approximately 2 cm in length. The patient tolerated the procedure well and was discharged one day postpyeloplasty with no reported complications. This rare clinical scenario should be considered when formulating a diagnosis for a UPJ obstruction. PMID:24759168

Predictors of Colorectal Polyp Recurrence after the First Polypectomy in Private Practice Settings: A Cohort Study

Science.gov (United States)

Viel, Jean-François; Studer, Jean-Marie; Ottignon, Yves; Hirsch, Jean-Pierre

2012-01-01

Background Supplementary observational data in the community setting are required to better assess the predictors of colorectal polyp recurrence and the effectiveness of colonoscopy surveillance under real circumstances. Aim The goal of this study was to identify patient characteristics and polyp features at baseline colonoscopy that are associated with the recurrence of colorectal polyps (including hyperplastic polyps) among patients consulting private practice physicians. Patients and Methods This cohort study was conducted from March 2004 to December 2010 in 26 private gastroenterology practices (France). It included 1023 patients with a first-time diagnosis of histologically confirmed polyp removed during a diagnostic or screening colonoscopy. At enrollment, interviews were conducted to obtain data on socio-demographic variables and risk factors. Pathology reports were reviewed to abstract data on polyp features at baseline colonoscopy. Colorectal polyps diagnosed at the surveillance colonoscopy were considered as end points. The time to event was analyzed with an accelerated failure time model assuming a Weibull distribution. Results Among the 1023 patients with colorectal polyp at baseline, 553 underwent a surveillance colonoscopy. The mean time interval from baseline colonoscopy to first surveillance examination was 3.42 (standard deviation, 1.45) years. The recurrence rates were 50.5% and 32.9% for all polyps and adenomas, respectively. In multivariate models, the number of polyps at baseline was the only significant predictor for both polyp recurrence (hazard ratio [HR] 1.19, 95% CI 1.06 to 1.33), and adenoma recurrence (HR 1.17, 95% CI 1.03 to 1.34). Conclusion The efficacy of surveillance colonoscopy in community gastroenterology practice compared favorably with academic settings. This study provides further evidence that the number of initial colorectal polyps is useful for predicting the risk of polyp recurrence, even in the community setting. PMID

Modelling the effect of nonplanarity on charge transport along conjugated polymer chains

International Nuclear Information System (INIS)

Correia, Helena M.G.; Ramos, Marta M.D.

2007-01-01

Conjugated polymers show interesting properties that make them appropriated for nanoelectronics. Several studies of poly(p-phenylene vinylene) (PPV) have suggested that each polymer chain consists of several planar segments, with conjugation length of nanoscale dimension, linked by twists or kinks. A pronounced twist between two planar segments in a PPV chain not only causes loss of main-chain conjugation but it may also alter electron and hole mobility along the chain, which has further implications for the percolation of charge through the polymer film. We used self-consistent quantum molecular dynamics calculations to provide information on the electric field needed to move the injected charges (either electrons or holes) along the planar segments of PPV and to cross the twist between two planar segments perpendicular to each other. Field-dependent charge mobility was also estimated for conjugated segments of various lengths. Our results suggest that electrons can cross the twist between adjacent planar segments for lower applied electric fields than holes if there is no more than one electronic charge (electron or hole) on the PPV chain, otherwise similar fields are needed

Flexible Synthetic Semiconductor Applied in Optoelectronic Organic Sensor

Directory of Open Access Journals (Sweden)

Andre F. S. Guedes

2017-06-01

Full Text Available The synthesis and application of new nanostructured organic materials, for the development of technology based on organic devices, have taken great interest from the scientific community. The greatest interest in studying organic semiconductor materials has been connected to its already known potential applications, such as: batteries, organic solar cells, flexible organic solar cells, organic light emitting diodes, organic sensors and others. Phototherapy makes use of different radiation sources, and the treatment of hyperbilirubinemia the most common therapeutic intervention occurs in the neonatal period. In this work we developed an organic optoelectronic sensor capable of detecting and determining the radiation dose rate emitted by the radiation source of neonatal phototherapy equipment. The sensors were developed using optically transparent substrate with Nanostructured thin film layers of Poly(9-Vinylcarbazole covered by a layer of Poly(P-Phenylene Vinylene. The samples were characterized by UV-Vis Spectroscopy, Electrical Measurements and SEM. With the results obtained from this study can be developed dosimeters organics to the neonatal phototherapy equipment.

Prevalence of colon polyps detected by colonoscopy screening in asymptomatic black and white patients

Science.gov (United States)

Lieberman, David; Holub, Jennifer; Moravec, Matthew; Eisen, Glenn; Peters, Dawn; Morris, Cynthia

2013-01-01

Context Compared to whites, Black men and women have a higher incidence and mortality from colorectal cancer and may develop cancer at a younger age. Colorectal cancer screening might be less effective in Blacks, if there are racial differences in the age-adjusted prevalence and location of cancer precursor lesions. Objectives To determine and compare the prevalence rates and location of polyp(s) >9mm in asymptomatic Blacks and whites who receive colonoscopy screening. Design, Setting, and Patients Colonoscopy data were prospectively collected from 67 practice sites in the United States using a computerized endoscopic report generator from 2004–2005. Data were transmitted to a central data repository, where all asymptomatic whites (n = 80,061) and Blacks (n = 5464) who received screening colonoscopy were identified. Main outcome measures Prevalence and location of polyp(s) >9mm, adjusted for age, gender, and family history of colorectal cancer in a multivariate analysis. Results Both Black men and women had a higher prevalence of polyp(s) >9mm (7.7 versus 6.2%; p 9mm (OR 1.133; 95% CI 0.93,1.38). However, in a sub-analysis of patients over age 60 years, proximal polyps >9mm were more likely in Black men (p = 0.026) and women (p9mm, and Black over age 60 years are more likely to proximal polyps >9mm. PMID:18812532

Comparison of polyp size and volume at CT colonography: implications for follow-up CT colonography.

Science.gov (United States)

Bethea, Emily; Nwawka, Ogonna K; Dachman, Abraham H

2009-12-01

The purpose of this study was to evaluate the reliability of polyp measurements at CT colonography and the factors that affect the measurements. Fifty colonoscopically proven cases of polyps 6 mm in diameter or larger were analyzed by two observers who measured each polyp in supine and prone views. Manual measurements of 2D volume by summation of areas, 2D maximum diameter, and 3D maximum diameter and automated measurements of 3D maximum diameter and volume were recorded for each observer and were repeated for one of the observers. Intraobserver and interobserver agreement was calculated. Analysis was performed to determine the measurement parameter that correlated most with summation-of-areas volume. Supine and prone measurements as a surrogate for tracking change in polyp size over time were analyzed to determine the measurement parameter with the least variation. Maximum diameter measured manually on 3D images had the highest correlation with summation-of-areas volume. Manual summation-of-areas volume was found to have the least variation between supine and prone measurements. Linear polyp measurement in the 3D endoluminal view appears to be the most reliable parameter for use in the decision to excise a polyp according to current guidelines. In our study, manual calculation of volume with summation of areas was found to be the most reliable measurement parameter for observing polyp growth over serial examinations. High reliability of polyp measurements is essential for adequate assessment of change in polyp size over serial examinations because many patients with intermediate-size polyps are expected to choose surveillance.

Photoinduced electron transfer and photocurrent in multicomponent organic molecular films containing oriented porphyrin-fullerene dyad

NARCIS (Netherlands)

Kaunisto, Kimmo; Vuorinen, Tommi; Vahasalo, Heidi; Chukharev, Vladimir; Tkachenko, Nikolai V.; Efimov, Alexander; Tolkki, Antti; Lehtivuori, Heli; Lemmetyinen, Helge

2008-01-01

Layers of poly(3-hexylthiophene), PHT, phenyl vinyl thiophene, PVT3, poly(p-phenylene-2,3′-bis(3,2′-diphenyl)-quinoxaline-7-7′- diyl), PPQ, and covalently linked porphyrin-fullerene donor-acceptor dyad, P-F, were deposited as various multilayer films, which then were used to study photoinduced

Chemical potential pinning due to equilibrium electron transfer at metal/C60-doped polymer interfaces

Science.gov (United States)

Heller, C. M.; Campbell, I. H.; Smith, D. L.; Barashkov, N. N.; Ferraris, J. P.

1997-04-01

We report electroabsorption measurements of the built-in electrostatic potential in metal/C60-doped polymer/metal structures to investigate chemical potential pinning due to equilibrium electron transfer from a metal contact to the electron acceptor energy level of C60 molecules in the polymer film. The built-in potentials of a series of structures employing thin films of both undoped and C60-doped poly[2-methoxy, 5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) were measured. For undoped MEH-PPV, which has an energy gap of about 2.4 eV, the maximum built-in potential is about 2.1 eV, whereas for C60-doped MEH-PPV the maximum built-in potential decreases to 1.5 eV. Electron transfer to the C60 molecules close to the metal interface pins the chemical potential of the metal contact near the electron acceptor energy level of C60 and decreases the built-in potential of the structure. From the systematic dependence of the built-in potential on the metal work function we find that the electron acceptor energy level of C60 in MEH-PPV is about 1.7 eV above the hole polaron energy level of MEH-PPV.

Thermodynamic properties of poly(phenylene-pyridyl) dendrons of the second and the third generations

International Nuclear Information System (INIS)

Smirnova, Natalia N.; Samosudova, Yanina S.; Markin, Alexey V.; Serkova, Elena S.; Kuchkina, Nina V.; Shifrina, Zinaida B.

2017-01-01

Highlights: • We report thermodynamic properties for poly(phenylene-pyridyl) dendrons of the second and the third generations. • The thermodynamic quantities of devitrification and fusion have been determined. • Thermodynamic functions for the temperature range from T → 0 to 520 K for different physical states were calculated. • The dependences of thermodynamic properties of the dendrons on their composition and structure have been obtained. - Abstract: The temperature dependence of the heat capacity of poly(phenylene-pyridyl) dendrons of the second and the third generations have been measured by the method of adiabatic vacuum and differential scanning calorimetry over the range from 6 K to (500–520) K in the present research. Phase transformations have been detected and their thermodynamic characteristics have been estimated and analysed in the above temperature range. The standard thermodynamic functions, namely, the heat capacity C p 0 (T), enthalpy H°(T) − H°(0), entropy S°(T) − S°(0) and potential Φ m °, for the range from T → 0 K to (500–520) K and the standard entropy of formation of the dendrons in different physical states at T = 298.15 K have been calculated based on the experimental results. The thermodynamic characteristics of the samples under study and investigated earlier, poly(phenylene-pyridyl) dendrons decorated with dodecyl groups of the same generations have been compared and discussed.

Inflammatory myoglandular colorectal polyps: a series of seven cases and review of literature.

Science.gov (United States)

Becheanu, G; Gheorghe, C; Dumbravă, M; Serban-Barbu, V; Diculescu, M

2011-01-01

Inflammatory myoglandular polyp is an unusual but distinct, non-neoplastic type of colorectal polyp, commonly with a distal localization at the recto-sigmoidian level. It was first described in 1992 by Nakamura and his colleagues and it is considered to have few particular histological features. We report a series of seven cases (two male and five female patients) of myoglandular polyps with different localization from 15 to 40 cm from anus. Only four out of seven cases presented with rectal bleeding, the others polyps we incidentally discovered. The polyps varied between 4 and 30 mm in the maximum diameter. Grossly, they had firm consistency and smooth reddish surface. Histological examination of the specimens revealed hyperplastic glands with occasional cystic dilatation, proliferation of smooth muscle with no regular distribution, a variable amount of granulation tissue (usually minimal) and no evidence of epithelial dysplasia. All the lesions were removed endoscopically without any complications. Inflammatory myoglandular polyps are distinct histopathological entities, with insufficiently investigated pathogenesis that can include local trauma, mucosal prolapse or ischemia. Being benign they can be removed endoscopically, surgical treatment being reserved in selected cases.

Low lymphatic vessel density associates with chronic rhinosinusitis with nasal polyps.

Science.gov (United States)

Luukkainen, A; Seppälä, M; Renkonen, J; Renkonen, R; Hagstrő M, J; Huhtala, H; Rautiainen, M; Myller, J; Paavonen, T; Ranta, A; Torkkeli, T; Toppila-Salmi, S

2017-06-01

Chronic rhinosinusitis with and without nasal polyps (CRSwNP and CRSsNP) and antrochoanal polyps (ACP) are different upper airway inflammation phenotypes with different pathomechanisms. In order to understand the development of tissue edema, the present study aimed to evaluate lymphatic vessel density in CRSsNP, CRSwNP and ACP. 120 retrospective nasal and maxillary sinus specimens were stained immunohistochemically with a von Willebrand factor polyclonal antibody recognizing vascular and lymphatic endothelium, and with a podoplanin monoclonal antibody recognizing lymphatic endothelium. Vessels were studied by microscopy in a blinded fashion, and the vessel density and the relative density of lymphatic vessels were calculated. Patient characteristic factors and follow-up data of in average 9 years were collected from patient records. In the nasal cavity, the low absolute and relative density of vessels and of lymphatic vessels was associated with CRSwNP and ACP tissues compared to control inferior turbinate. This was observed also in the inflammatory hotspot area. In the maxillary sinus, lower absolute and relative density of lymphatic vessels associated with the CRSwNP phenotype. High lymphatic vessel density in polyp tissue associated with the need for revision CRS-surgery. As a conclusion, low density of lymphatic vessels distinguished patients with CRSwNP not only in the hotspot area of polyp tissue, but also in maxillary sinus mucosa. Yet, higher lymphatic vessel density seems to associate with polyp recurrence. Further studies are still needed to explore if formation of nasal polyps could be diminished by intranasal therapeutics affecting lymphangiogenesis.

Needle knife-assisted polypectomy in hot snare-resistant fibrotic inflammatory polyps

Directory of Open Access Journals (Sweden)

Xian-rui Wu

2014-01-01

Full Text Available Background: Inflammatory polyps are common sequelae in patients with inflammatory bowel diseases (IBD. Those polyps can usually be removed with snare polypectomy. There were limited data evaluating the management of hot snare-resistant inflammatory polyps. Methods: We reported on two cases with hot snare-resistant inflammatory polyps, one was a Crohn's disease (CD patient with the polyp at the ileo-colonic anastomosis (ICA and the other one was an ulcerative colitis (UC patient with polyp at the pouch inlet. Results: Sedated endoscopy was performed, which showed a large 2.5 cm pedunculated polyp at the ICA in the first patient and a large 5 cm pedunculated polyp at the pouch inlet in the second patient. Hot snare polypectomy was initially attempted, but failed in both pa- tients. Then endoscopic needle knife polypectomy was performed, which helped complete polypectomy. Both procedures took approximately 25 minutes each. The patients tolerated the procedure well and continued to do well after the procedure. The final pathological diagnoses for both patients were inflammatory polyps with extensive fibrosis. Conclusions: Endoscopic needle knife-assisted polypectomy appeared to be an effective technique for the management of hot snare-resistant inflammatory polyps. Resumo: Experiência: Pólipos inflamatórios são sequelas comuns em pacientes com doença intestinal inflamatória (DII. Geralmente esses pólipos podem ser removidos pela polipectomia por cauterização com laço. São limitados os dados que avaliam o tratamento de pólipos infla- matórios resistentes à cauterização por laço. Métodos: Descrevemos dois casos com pólipos inflamatórios resistentes à cauterização por laço; um deles se tratava de paciente com doença de Crohn (DC com o pólipo na anas-tomose íleo-colônica (AIC, e o outro era paciente de colite ulcerativa (CU com pólipo na entrada da bolsa. Resultados: Foi efetuada uma endoscopia com o paciente sedado

[Colonic polyps diagnosis by conventional video colonoscopes and chromoscopy with indigo carmine dye solution].

Science.gov (United States)

Nakao, Frank Shigueo; Araújo, Isabella Saraiva; Ornellas, Laura Cotta; Cury, Marcelo de Sousa; Ferrari, Angelo Paulo

2002-01-01

Magnification colonoscopy and contrast chromoscopy with indigo carmine dye solution have been used to differentiate neoplastic polyps (adenomas and adenocarcinomas) from non-neoplastic (hyperplastic, inflammatory, juvenile) in an attempt to obviate endoscopic polypectomy. On the other hand, little published information exists concerning conventional video colonoscopes and chromoscopy for polyp histology prediction. Aim - To assess usefullness of conventional video colonoscopes and contrast chromoscopy with indigo carmine solution for differential diagnosis of colon polyps. In a routine colonoscopy series, we performed chromoscopy with conventional video colonoscopes before endoscopic excision of detected polyps. If a sulcus pattern was observed on the surface of the lesion, it was classified as neoplastic. Polyps were classified as non-neoplastic if no sulcus was detected on its surface. These observations were then compared with histology. In the study period (18 months), we detected 133 polyps in 53 patients. We were able to compare results of histology and chromoscopy in 126 lesions. The sensitivity, specificity, diagnostic accuracy, negative predictive value, and positive predictive value were 56,4%, 79,2%, 65,1%, 52,8%, and 81,5%, respectively. On the base of the presented data, we concluded that conventional video colonoscopes and contrast chromoscopy with indigo carmine solution is not a good technique for differential diagnosis of colon polyps.

Endoscopic mucosal resection for middle and large colorectal polyps with a double-loop snare.

Science.gov (United States)

Yoshida, Naohisa; Saito, Yutaka; Hirose, Ryohei; Ogiso, Kiyoshi; Inada, Yutaka; Yagi, Nobuaki; Naito, Yuji; Otake, Yosuke; Nakajima, Takeshi; Matsuda, Takahisa; Yanagisawa, Akio; Itoh, Yoshito

2014-01-01

This study aimed to analyze the endoscopic mucosal resection (EMR) with a novel uniquely shaped, double-loop snare (Dualoop, Medico's Hirata Inc., Tokyo, Japan) for colorectal polyps. This was a clinical trial conducted in two referral centers, Kyoto Prefectural University of Medicine and National Cancer Center Hospital in Japan. First, the firmness of various snares including 'Dualoop' was experimentally analyzed with a pressure gauge. Five hundred and eighty nine consecutive polyps that underwent EMR with 'Dualoop' were compared to 339 polyps with the standard round snare. Lesion characteristics, en bloc resection, and complications were analyzed. 'Dualoop' had the most firmness among the various snares. The average tumor size was 9.3 mm (5-30), and en bloc resection was achieved in 95.4%. The rate of en bloc resection for middle polyps 15-19 mm in diameter was significantly higher with the 'Dualoop' than that with the round snare (97.9 vs. 80.0%, p < 0.05). The rate of en bloc resection was 64.7% for large polyps ≥20 mm in diameter using 'Dualoop'. Higher age, larger tumor size, and superficial polyps were associated with the failure of en bloc resection. EMR with 'Dualoop' was effective for resecting both middle and large polyps en-bloc. © 2014 S. Karger AG, Basel.

Risk and protective factors for development of colorectal polyps and cancer (Bulgarian experience).

Science.gov (United States)

Kotzev, I; Mirchev, M; Manevska, B; Ivanova, I; Kaneva, M

2008-01-01

Colorectal cancer takes third place among all malignancies in the Varna region. The present study aims to determine the typical and distinguishing risk and protective factors for colorectal polyps and cancer formation. 166 patients with large bowel polyps and 107 patients with colorectal cancer were questioned, examined endoscopically and histologically. Logistic regression analysis was used to find a possible correlation between alimentary habits, way of life, and risk for colorectal polyps and cancer formation. The latter have been used to define a strategy for their prevention. Our results showed that fried, preserved, and grilled meat, consumption of animal fats, sugar, and being overweight are positively associated with colorectal polyps. In contrast, consumption of fruit, vegetables, rye- and brown bread, green tea, vegetable food, yoghourt, vegetarian food, fish, lamb, hare, garlic, boiled food, and mineral water, have strong protective effect against large bowel polyps. We have confirmed the role of the well-known risk factors for colorectal cancer, and discovered an association between H. pylori infection, age, villous component in the adenomatous polyps, and family history for any neoplasia and large bowel carcinoma. We suggest the following protective factors for CRC: vegetarian food, plant oil, rural life, aspirin intake, legumes, fish, fruit and vegetable consumption. We observe a similarity between the risk factors for colorectal polyps and cancer formation. They act simultaneously and depend on genetic predisposition. A combination of endoscopic treatment and correction of the alimentary factors could be used as a means of cancer prevention.

Heterogeneous ion-exchange membranes based on sulfonated poly(1,4-phenylene sulfide)

Czech Academy of Sciences Publication Activity Database

Schauer, Jan; Kůdela, Vlastimil; Richau, K.; Mohr, R.

2006-01-01

Roč. 198, 1-3 (2006), s. 256-264 ISSN 0011-9164 R&D Projects: GA ČR GA203/05/0080 Institutional research plan: CEZ:AV0Z40500505 Keywords : poly(1,4-phenylene sulfide) sulfonated * ion-exchange membrane Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.917, year: 2006

Nilotinib Induced Recurrent Gastric Polyps: Case Report and Review of Literature.

Science.gov (United States)

Kassem, Nancy; Ismail, Omar M; Elomri, Halima; Yassin, Mohamad A

2017-07-14

BACKGROUND Tyrosine kinase inhibitors (TKIs) are currently an important targeted drug class in the treatment of chronic myeloid leukemia (CML). Imatinib was the first approved TKI for CML in 2001. Nilotinib is a second-generation TKI, approved in 2007; it inhibits BCR-ABL, PDGFR, and c-KIT, and is 30 times more potent than imatinib. Tyrosine kinase enzymes are expressed in multiple tissues and are involved in several signaling pathways; they have been shown to have several off-target side effects. CASE REPORT We report a case of an elderly male with CML and no history of gastrointestinal diseases, treated with nilotinib, and developed recurrent gastric polyps after three years of treatment. We excluded common causes of gastric polyps and therefore considered nilotinib as a probable cause of recurrent gastric polyps. CONCLUSIONS Recurrent gastric polyps could be a potential side effect of nilotinib treatment. Careful long-term monitoring of patients on TKI therapy is necessary and further long-term studies of TKI side effects are needed.

How does the serrated polyp pathway alter CRC screening and surveillance?

Science.gov (United States)

Kahi, Charles J

2015-03-01

Screening and surveillance for colorectal cancer (CRC) reduces mortality through the detection of early-stage adenocarcinoma, and more importantly the detection and removal of premalignant polyps. While adenomas have historically been considered the most common and screening-relevant precursor lesions, there is accumulating evidence showing that the serrated pathway is an important contributor to CRC, and a disproportionate contributor to interval or postcolonoscopy CRC, particularly in the proximal colon. The serrated pathway is characterized by mutations in the BRAF gene, high levels of methylation of promoter CpG islands (CIMP-high), and the sessile serrated adenoma/polyp (SSA/P) is the most important precursor lesion. The study of serrated polyps has been complicated by evolving nomenclature, substantial variation among pathologists in the identification of SSA/Ps, high variability in endoscopic detection rates, and uncertainty regarding the relation to synchronous and metachronous colonic neoplasia. This paper presents an overview of the serrated polyp pathway and discusses its clinical implications including its impact on CRC screening.

[Application of metal hemoclip for endoscopic polypectomy in children with thick-pedunculated intestinal polyps].

Science.gov (United States)

Deng, Zhao-hui; Xu, Chun-di; Zhong, Jie; Chen, Shun-nian; Yao, Wei-jiong

2004-03-01

With the development of endoscopic therapy in children, endoscopic electrocoagulation polypectomy had gradually replaced surgery and became an important method to resect gastrointestinal polyps in children. Simple electrocoagulation polypectomy could often bring some complications of gastrointestinal bleeding and perforation because of incomplete electrocoagulation or mechanical incision, especially in gastrointestinal thick-pedunculated polyps which always have thick nutrient blood vessel. Hemoclips can successfully interdict arteriovenous blood because it can clamp tissue firmly without causing necrosis around the target area. Based on its good mechanical hemostasis, hemoclips are not only widely used in treating bleeding like from ulcer, tumor and variceal ligation but also used in removal of thick-pedunculated gastrointestinal polyps in adults. This paper describes the application of endoscopic electrocoagulation with metal hemoclips to remove thick-pedunculated intestinal polpys in children for the first time, sums up the experience and evaluates its efficacy and safety. Between October, 2001 and December, 2002, 5 cases with thick-pedunculated intestinal polpys were presented. The age of the patients ranged from 3 to 5 years. The clinical features were gastrointestinal bleeding or abdominal pain. The longest course of disease was 2 years. Enough preparations for alimentary tract were necessary for polypectomy. The procedures were performed under general anesthesia in order to avoid the risk of bleeding aspiration. Endoscopy was performed in the standard fashion. The apparatus included electronic colonic endoscope (XQ 200, Fuji Corp, Tokyo, Japan), snare (XQ200, Fuji Corp, Tokyo, Japan), impeller of the clip (HX-5QR-1) and hemoclip (MD850) which could be passed through the biopsy channel of endoscope. The clip was completely covered with a hood avoiding any injury to the mucous membrane. The pedicel with diameter of more than 1.0 cm underwent endoscopic

Low-Dissipation Thermosets Derived from Oligo(2,6-Dimethyl Phenylene Oxide-Containing Benzoxazines

Directory of Open Access Journals (Sweden)

Chien-Han Chen

2018-04-01

Full Text Available Poly(2,6-dimethyl phenyl oxide (PPO is known for its low dissipation factor. To achieve insulating materials with low dissipation factors for high-frequency communication applications, a telechelic oligomer-type benzoxazine (P-APPO and a main-chain type benzoxazine polymer (BPA-APPO were prepared from an amine end-capped oligo (2,6-dimethyl phenylene oxide (APPO. The APPO was prepared from a nucleophilic substitution of a phenol-end capped oligo (2,6-dimethyl phenylene oxide (a commercial product, SA 90 with fluoronitrobenzene, and followed by catalytic hydrogenation. After self-curing or curing with a dicyclopentadiene-phenol epoxy (HP 7200, thermosets with high-Tg and low-dissipation factor can be achieved. Furthermore, the resulting epoxy thermosets show better thermal and dielectric properties than those of epoxy thermoset cured from its precursor SA90, demonstrating it is a successful modification in simultaneously enhancing the thermal and dielectric properties.

Hydration effect on the electronic transport properties of oligomeric phenylene ethynylene molecular junctions

International Nuclear Information System (INIS)

Zong-Liang, Li; Huai-Zhi, Li; Yong, Ma; Guang-Ping, Zhang; Chuan-Kui, Wang

2010-01-01

A first-principles computational method based on the hybrid density functional theory is developed to simulate the electronic transport properties of oligomeric phenylene ethynylene molecular junctions with H 2 O molecules accumulated in the vicinity as recently reported by Na et al. [Nanotechnology 18 424001 (2007)]. The numerical results show that the hydrogen bonds between the oxygen atoms of the oligomeric phenylene ethynylene molecule and H 2 O molecules result in the localisation of the molecular orbitals and lead to the lower transition peaks. The H 2 O molecular chains accumulated in the vicinity of the molecular junction can not only change the electronic structure of the molecular junctions, but also open additional electronic transport pathways. The obvious influence of H 2 O molecules on the electronic structure of the molecular junction and its electronic transport properties is thus demonstrated. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Unified picture of the photoexcitations in phenylene-based conjugated polymers: Universal spectral and dynamical features in subpicosecond transient absorption

International Nuclear Information System (INIS)

Kraabel, B.; Klimov, V. I.; Kohlman, R.; Xu, S.; Wang, H-L.; McBranch, D. W.

2000-01-01

Using subpicosecond transient absorption spectroscopy, we investigate the primary photoexcitations in thin films and solutions of several phenylene-based conjugated polymers and an oligomer. We identify several features in the transient absorption spectra and dynamics that are common to all of the materials which we studied from this family. The first spectral feature is a photoinduced absorption (PA) band peaking near 1 eV that has intensity-dependent dynamics that match the stimulated emission dynamics exactly over two orders of magnitude in excitation density. This band is associated with singlet intrachain excitons. The second spectral feature (observed only in thin films and aggregated solutions) is a PA band peaking near 1.8 eV, that is longer lived than the 1 eV exciton PA band, and that has dynamics that are independent (or weakly dependent) on excitation density. This feature is attributed to polarons, generated through a mechanism that is sample dependent. In pristine samples, polarons are generated via a mechanism that is quadratic in exciton density, whereas in photodegraded samples or samples doped with electron acceptors, the generation mechanism becomes linear in exciton density. (c) 2000 The American Physical Society

A large hymenal polyp in a 21-year-old virgin:

OpenAIRE

Borko, Elko; Došen, Marko; Kavalar, Rajko; Pivec, Gregor; Žebeljan, Ivan

2009-01-01

Pathological conditions of the hymen are rare in everyday medical practice. They are usually encountered in the pediatric patient population and are sometimes a matter of forensic interest. We report an interesting case of a large hymenal polyp in an adolescent virgin that presented only a cosmetic problem. The polyp was excised, the hymenal ring was preserved, and the sample was histologically verified.

Facile Synthesis of Well-Defined MDMO-PPV Containing (TriBlock—Copolymers via Controlled Radical Polymerization and CuAAC Conjugation

Directory of Open Access Journals (Sweden)

Neomy Zaquen

2015-02-01

Full Text Available A systematic investigation into the chain transfer polymerization of the so-called radical precursor polymerization of poly(p-phenylene vinylene (PPV materials is presented. Polymerizations are characterized by systematic variation of chain transfer agent (CTA concentration and reaction temperature. For the chain transfer constant, a negative activation energy of −12.8 kJ·mol−1 was deduced. Good control over molecular weight is achieved for both the sulfinyl and the dithiocarbamate route (DTC. PPVs with molecular weights ranging from thousands to ten thousands g·mol−1 were obtained. To allow for a meaningful analysis of the CTA influence, Mark–Houwink–Kuhn–Sakurada (MHKS parameters were determined for conjugated MDMO-PPV ([2-methoxy-5-(3',7'-dimethyloctyloxy]-1,4-phenylenevinylene to α = 0.809 and k = 0.00002 mL·g−1. Further, high-endgroup fidelity of the CBr4-derived PPVs was proven via chain extension experiments. MDMO-PPV-Br was successfully used as macroinitiator in atom transfer radical polymerization (ATRP with acrylates and styrene. A more polar PPV counterpart was chain extended by an acrylate in single-electron transfer living radical polymerization (SET-LRP. In a last step, copper-catalyzed azide alkyne cycloaddition (CuAAC was used to synthesize block copolymer structures. Direct azidation followed by macromolecular conjugation showed only partial success, while the successive chain extension via ATRP followed by CuAAC afforded triblock copolymers of the poly(p-phenylene vinylene-block-poly(tert-butyl acrylate-block-poly(ethylene glycol (PPV-b-PtBuA-b-PEG.

Nonadiabatic excited-state molecular dynamics: On-the-fly limiting of essential excited states

Energy Technology Data Exchange (ETDEWEB)

Nelson, Tammie [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Naumov, Artem [Skolkovo Institute of Science and Technology, Moscow 143026 (Russian Federation); Fernandez-Alberti, Sebastian [Universidad Nacional de Quilmes, Roque Saenz Pea 352, B1876BXD Bernal (Argentina); Tretiak, Sergei, E-mail: serg@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2016-12-20

The simulation of nonadiabatic dynamics in extended molecular systems involving hundreds of atoms and large densities of states is particularly challenging. Nonadiabatic coupling terms (NACTs) represent a significant numerical bottleneck in surface hopping approaches. Rather than using unreliable NACT cutting schemes, here we develop “on-the-fly” state limiting methods to eliminate states that are no longer essential for the non-radiative relaxation dynamics as a trajectory proceeds. We propose a state number criteria and an energy-based state limit. The latter is more physically relevant by requiring a user-imposed energy threshold. For this purpose, we introduce a local kinetic energy gauge by summing contributions from atoms within the spatial localization of the electronic wavefunction to define the energy available for upward hops. The proposed state limiting schemes are implemented within the nonadiabatic excited-state molecular dynamics framework to simulate photoinduced relaxation in poly-phenylene vinylene (PPV) and branched poly-phenylene ethynylene (PPE) oligomers for benchmark evaluation.

Nasal polyps. A clinical radiological histopathological and mycological study

Energy Technology Data Exchange (ETDEWEB)

Babiker, Babiker Eltayeb [Faculty of Medicine, University of Khartoum, Khartoum (Sudan)

1997-12-01

Forty patients with nasal polyposis were studied. This study included clinical, haematological and mycological aspects. There were 24 females (60% of patients) and 16 males (40%). We found that all patients presented with nasal obstruction and nasal tone and the majority of them had allergic nasal symptoms such as sneezing and watery discharge. Thirty five percent of the patients were recurrent cases, being operated before for nasal polyps. Radiological investigations showed high of sinusitis and that 10% of the patients had complicated disease with orbital or intracranial extensions. Mycological studies revealed the presence of fungal infection in 4 patient (10%) and it was caused by Aspergillus flavus. Histological studies identified the allergic nature of the polyps in all patients. Surgical treatment was carried out in all patients and operations varied from simple intranasal polypectomy, intranasal ethmiodectomy, external ethmoidectomy to Caldwell-Luc operation for patients with antrochanal polyps.(Author)

Thermal and Osmotic Tolerance of 'Irukandji' Polyps: Cubozoa; Carukia barnesi.

Directory of Open Access Journals (Sweden)

Robert Courtney

Full Text Available This research explores the thermal and osmotic tolerance of the polyp stage of the Irukandji jellyfish Carukia barnesi, which provides new insights into potential polyp habitat suitability. The research also targets temperature, salinity, feeding frequency, and combinations thereof, as cues for synchronous medusae production. Primary findings revealed 100% survivorship in osmotic treatments between 19 and 46‰, with the highest proliferation at 26‰. As salinity levels of 26‰ do not occur within the waters of the Great Barrier Reef or Coral Sea, we conclude that the polyp stage of C. barnesi is probably found in estuarine environments, where these lower salinity conditions commonly occur, in comparison to the medusa stage, which is oceanic. Population stability was achieved at temperatures between 18 and 31°C, with an optimum temperature of 22.9°C. We surmise that C. barnesi polyps may be restricted to warmer estuarine areas where water temperatures do not drop below 18°C. Asexual reproduction was also positively correlated with feeding frequency. Temperature, salinity, feeding frequency, and combinations thereof did not induce medusae production, suggesting that this species may use a different cue, possibly photoperiod, to initiate medusae production.

Computer-aided diagnosis of colonic polyp by CT colonography

International Nuclear Information System (INIS)

Yoshida, Hiroyuki

2007-01-01

The outcome of National CT Colonography Trial, by American College of Radiology Imaging Network, 2006 (www.acrin.org/6664 protocol), possibly leads to the introduction of colorectal cancer screening in the US because CT colonography (CTCG) has been approved in the health insurance system. This paper describes the outline of computer-aided diagnosis (CAD) of colonic polyp by CTCG, its polyp detectability and future aspects. CTCG essentially derives from the virtual, abdominal 3D CT images and gives as many as about 500 images/patient, in the reading of which CAD support the expert. CAD technology in CTCG is said to have been essentially established in the first half of 2000s, which involves the cleansing of fecal tagging effect, extraction of the colonal wall from the image, detection of suspicious polyp, reduction of false-positive findings and displaying of the detected polyp. The detectability is thought to be at comparable level to expert's. The last displaying is done on the user-interface like Colon CAD Workstation. More efficient expert's reading with CAD, imaging without previous gut cleansing, detection of the flat lesion and further reduction of false-positive are the forthcoming tasks in clinical practice. Significance of CTCG is becoming in realization and its usage with CAD is thought to be more popular in Japan. (R.T.)

Controlling charge injection in organic electronic devices using self-assembled monolayers

Science.gov (United States)

Campbell, I. H.; Kress, J. D.; Martin, R. L.; Smith, D. L.; Barashkov, N. N.; Ferraris, J. P.

1997-12-01

We demonstrate control and improvement of charge injection in organic electronic devices by utilizing self-assembled monolayers (SAMs) to manipulate the Schottky energy barrier between a metal electrode and the organic electronic material. Hole injection from Cu electrodes into the electroluminescent conjugated polymer poly[2-methoxy,5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] was varied by using two conjugated-thiol based SAMs. The chemically modified electrodes were incorporated in organic diode structures and changes in the metal/polymer Schottky energy barriers and current-voltage characteristics were measured. Decreasing (increasing) the Schottky energy barrier improves (degrades) charge injection into the polymer.

Phenylene ring dynamics in phenoxy and the effect of intramolecular linkages on the dynamics of some engineering thermoplastics below the glass transition temperature

International Nuclear Information System (INIS)

Arrese-Igor, Silvia; Arbe, Arantxa; Alegria, Angel; Colmenero, Juan; Frick, Bernhard

2007-01-01

We have investigated the dynamics of phenylene rings in the engineering thermoplastic bisphenol-A poly(hydroxyether)--phenoxy--below its glass transition temperature by means of neutron scattering techniques. A relatively wide dynamic range has been covered thanks to the combination of two different types of neutron spectrometers, time of flight and backscattering. Partially deuterated samples have been used in order to isolate the phenylene ring dynamics. The resulting neutron scattering signal of phenoxy has been described by a model that considers π flips and oscillation motions for phenylene rings. The associated time scales are broadly distributed with mean activation energies equal to 0.41 and 0.21 eV, respectively. Finally, a comparative study with the literature shows that the dielectric and mechanical γ relaxation in phenoxy exhibit good correlation with the characteristic times of the aliphatic chain published elsewhere and with the characteristic times observed for the motion of phenylene rings by neutron scattering. These findings are discussed in a more general framework that considers, in addition, previous results on other polymers, which also contain the bisphenol-A unit

Double-contrast gastrography and gastroscopy in the diagnosis of gastric polyps. Personal experience

Energy Technology Data Exchange (ETDEWEB)

Biscarini, R; Giorgi, G; Lazzari, G and others

1986-01-01

Gastric polyps are benign tumors which have been less uncommonly detected in recent years, due to the refinement of both radiologic and endoscopic investigations. From 1981 through 1985 gastric polyps were detected in 102 patients (1,9%) out of 5368 radiologic examination. In the same period, 98 cases (3,3%) were detected out of 2942 endoscopic examination. The comparison of data in these two series shows a superimposition. Despite an increased percentage of endoscopic findings (to some extent due to previous radiologic reports), the authors assert the diagnostic efficacy of double contrast radiologic investigation as a first approach to benign polypous lesions of the stomach. As far as histology is concerned, a clear prevalence is shown of hyperplastic versus adenomatous polyps (90 and 8 cases repectively).

Polyp bailout in Pocillopora damicornis following thermal stress [version 2; referees: 2 approved

Directory of Open Access Journals (Sweden)

Alexander J Fordyce

2017-08-01

Full Text Available Polyp bailout is an established but understudied coral stress response that involves the detachment of individual polyps from the colonial form as a means of escaping unfavourable conditions. This may influence both the mortality and asexual recruitment of coral genotypes across a range of species. It has been observed in response to numerous stressors including high salinity and low pH. Polyp expulsion in association with thermal stress has once been described in a geographically restricted, temperate species. We therefore cannot reliably apply this observation to tropical coral reefs around the world, which are increasingly under threat from thermal stress events. We present the first qualitative observation of polyp bailout following acute temperature shock  in a near-natural mesocosm experiment. Detached polyps show similar characteristics to those described in previous studies, including the retention of endosymbiotic zooxanthellae and the ability to disperse across short distances. This finding strongly suggests that polyp bailout occurs in tropical coral reef environments and warrants further detailed research into the implication of this response in terms of individual survival, rapid migration into cooler micro-habitats and local recruitment within the reef environment and its coral community.

Computer-aided polyp detection on CT colonography: Comparison of three systems in a high-risk human population

International Nuclear Information System (INIS)

Park, Hee Sun; Kim, Se Hyung; Kim, Jong Hyo; Lee, June-Goo; Kim, Sang Gyun; Lee, Jeong Min; Lee, Jae Young; Han, Joon Koo; Choi, Byung Ihn

2010-01-01

Purpose: To compare the detection performances of two commercial and one academic computer-aided diagnosis (CAD) systems for polyp detection on CT colonography (CTC) in a high-risk human population and to assess their detection characteristics. Materials and methods: This retrospective study had institutional review board approval, but informed consent was waived. Sixty-eight patients who were suspected of having colonic polyps and scheduled for colonoscopic polyp removal were included. After CTC was performed using a 64-row MDCT, two commercial (PEV, CAR) and one academic (Hessian matrix-based) CAD systems were applied to each CTC dataset. Colonoscopy using the segmental unblinded technique was performed as a standard of reference. Per-polyp and per-patient sensitivities were calculated and compared for each CAD system. The mean number of false-positives (FPs) and false-negatives (FNs) was computed and the causes of all FPs and FNs were analyzed. Results: A total of 151 polyps in 61 patients were detected (77 polyps <6 mm, 48 6-9.9 mm, 26 ≥ 10 mm). Per-polyp sensitivity for PEV, CAR, and Hessian matrix-based CAD were: 71.6%, 78.4%, and 83.8% for polyps ≥6 mm, and 88.5%, 96.2%, and 96.2% for polyps ≥10 mm. Per-patient sensitivity for polyps ≥6 mm was 80.4%, 89.1%, and 93.5%, and 87%, 95.7%, and 95.7% for polyps ≥10 mm, respectively. Per-polyp and per-patient sensitivities were not significantly different among the three CAD systems regardless of size threshold. Mean number of FPs was 6.9 for PEV, 7.3 for CAR, and 14 for Hessian matrix-based CAD. The most common cause of FPs were feces, followed by extracolonic findings, prominent folds and ileocecal valve, and rectal tube. The distribution of the causes of FPs was significantly different among the three systems. Conclusion: Sensitivity of the three CAD systems for polyp detection was comparable regardless of the polyp size threshold; however, the number of FPs was higher in the Hessian matrix-based CAD

Cytogenetic comparisons of synchronous carcinomas and polyps in patients with colorectal cancer

DEFF Research Database (Denmark)

Bardi, G; Parada, L A; Bomme, L

1997-01-01

Thirty tumorous lesions from seven patients with colorectal cancer were short-term cultured and cytogenetically analysed: 16 non-adenomatous polyps, six adenomas, seven carcinomas, including one in polyp, and one lymph node metastasis. Clonal chromosome aberrations were found in 20 samples in 100...

Improvement in carrier mobility and photovoltaic performance through random distribution of segments of linear and branched side chains

Energy Technology Data Exchange (ETDEWEB)

Egbe, Daniel A.M.; Adam, Getachew; Pivrikas, Almantas; Ulbricht, Christoph; Ramil, Alberto M.; Sariciftci, Niyazi Serdar [Johannes Kepler Univ., Linz (AT). Linz Inst. for Organic Solar Cells (LIOS); Hoppe, Harald [Technische Univ. Ilmenau (Germany). Inst. of Physics and Inst. of Micro- and Nanotechnologies; Rathgeber, Silke [Mainz Univ. (Germany). Inst. of Physics

2010-07-01

The random distribution of segments of linear octyloxy side chains and of branched 2-ethylhexyloxy side chains, on the backbone of anthracene containing poly(p-phenylene-ethynylene)-alt-poly(p-phenylene-vinylene) (PPE-PPV) has resulted in a side chain based statistical copolymer, denoted AnE-PVstat, showing optimized features as compared to the well defined homologues AnE-PVaa, -ab, -ba and -bb, whose constitutional units are incorporated into its backbone. WAXS studies on AnE-P's demonstrate the highest degree of order at the self-assembly state of AnE-PVstat, which is confirmed by its highly structured thin film absorption band. Electric field independent charge carrier mobility ({mu}{sub hole}) for AnE-PVstat was demonstrated by CELIV and OFET measurements, both methods resulting in similar {mu}{sub hole} values of up to 5.43 x 10{sup -4} cm{sup 2}/Vs. Upon comparison, our results show that charge carrier mobility as measured by CELIV technique is predominantly an intrachain process and less an interchain one, which is in line with past photoconductivity results from PPE-PPV based materials. The present side chain distribution favors efficient solar cell active layer phase separation. As a result, a smaller amount of PC{sub 60}BM is needed to achieve relatively high energy conversion efficiencies above 3 %. The efficiency of {eta}{sub AM1.5} {approx} 3.8 % obtained for AnE-PVstat:PC{sub 60}BM blend is presently the state-of-art value for PPV-based materials. (orig.)

Placental polyp: a rare cause of iron deficiency anemia

Directory of Open Access Journals (Sweden)

Fernando Peixoto Ferraz de Campos

2011-12-01

Full Text Available Placental polyps are defined as pedunculated or polypoid fragments of placentaor ovular membranes retained for an indefinite period of time into the uterus afterabortion or child birth. An important cause of retention is placental accretism, anabnormal adherence of the placenta into the uterine wall. Chronic cases are rarelyreported in the literature. In these cases, the placental retention in the immediatepostpartum is not followed by heavy bleeding what makes the diagnosischallenging. We report a rare case of iron-deficiency anemia in a multiparous29-year-old female patient two years after the last delivery. She sought medicalcare with clinical symptoms of anemia and recent menses alterations. Therewas no history of abortion. On gynecological examination, there was a twofoldenlarged uterus, and the pelvic ultrasound revealed an image compatible with anendometrial polyp. She underwent open hysterectomy because of uncontrollablebleeding followed by hypotension after curettage. The histolopathologicexamination revealed a partially hyalinized and necrotic placental polyp.

[Fibroepithelial polyp of the ureter. Report of one case].

Science.gov (United States)

Morales, Raúl; Manrique, Eduardo; Casanova, Rubén; Molina, Pedro; Falcón, Ramón

2004-05-01

To report the rare case of a patient with a ureteral polyp. We describe the case of a 55-year-old female patient receiving care at the Celia Sanchez Manduley University Hospital in Manzanillo, Cuba, who was fortuitously diagnosed of a fibroepithelial polyp of the right ureter during the work up and treatment of an ovarian tumor. This case is the first of its kind in this hospital after 22 years, which confirms the rarity of ureteral tumors, specifically those of benign etiology. The absence of symptoms, specifically hematuria and pain, does not correspond to the reviewed articles. The chosen treatment was exeresis of the polyp at its base and frozen biopsy, followed by re-establishment of the urinary passage, as various authors recommend. Currently the endoscopical approach is recommended for its multiple advantages. We conclude that this disease is very rare, may have a symptomatic course and the treatment of choice is surgery with very good results.

Crystal structure and thin film morphology of BBL ladder polymer

Energy Technology Data Exchange (ETDEWEB)

Song, H H [Department of Macromolecular Science, Han Nam University, Taejon (Korea, Republic of); Fratini, A V [Department of Chemistry, University of Dayton, Dayton, OH (United States); Chabinyc, M [Department of Chemistry, University of Dayton, Dayton, OH (United States); Price, G E [University of Dayton Research, Dayton, OH (United States); Agrawal, A K [Systran Corporation, Dayton, OH (United States); Wang, C S [University of Dayton Research, Dayton, OH (United States); Burkette, J [University of Dayton Research, Dayton, OH (United States); Dudis, D S [Materials Directorate, Wright Laboratory, Wright-Patterson Air Force Base, OH (United States); Arnold, F E [Materials Directorate, Wright Laboratory, Wright-Patterson Air Force Base, OH (United States)

1995-03-01

Crystal structure and morphology of poly[7-oxo-7H-benz(d,e)imidazo(4`,5`:5,6)-benzimidazo(2,1-a)isoquinoline-3,4:10,11-tetrayl-10-carbonyl] (BBL) ladder-like polymer were studied. The polymer forms a two-dimensional lattice of nematic liquid crystalline structure. An orthorhombic unit cell with cell parameters of a=7.87 b=3.37 c=11.97A was determined from the fiber diffraction pattern. In thin films, the rigid chains spontaneously form a layered structure across the film thickness, but in a very unusual manner, i.e. the very large molecular plane is standing perpendicularly to the film surface plane. The results are identical to our recent results of poly(p-phenylene benzobisthiazole) (PBT) film [7]. The polymer, however, lost its anisotropic order upon extrusion into a film and resulted in a fiber-like structure. (orig.)

Star-shaped ladder-type ter(p-phenylene)s for efficient multiphoton absorption.

Science.gov (United States)

Guo, Lei; Li, King Fai; Wong, Man Shing; Cheah, Kok Wai

2013-05-04

Star-shaped ladder-type ter(p-phenylene)s exhibit remarkably efficient multiphoton absorption properties with 2PA cross-section up to 2579 GM at 700 nm and 3PA cross-section up to 3.35 × 10(-76) cm(6) s(2) in the femtosecond regime for a blue-emissive molecule despite having such a short π-conjugated framework.

Respiratory response to temperature of three populations of Aurelia aurita polyps in northern Europe.

Directory of Open Access Journals (Sweden)

Danja P Höhn

Full Text Available The benthic life stage (polyp or scyphistoma of the bloom-forming jellyfish, Aurelia aurita (Linnaeus, 1759, also known as the moon jellyfish, contributes to the seasonal occurrence and abundance of medusa blooms via asexual reproduction. A. aurita is widely distributed in coastal areas in northern Europe, and one of the most studied jellyfish species. While the physiology of the visible medusa is largely understood, understanding of the physiology of the perennial benthic life-stage is scarce. To measure the physiological tolerance of A. aurita, the scyphistoma's temperature sensitivity across its distributional range was investigated. Respiration rates of polyps from three northern European locations exposed to 11 temperatures between 2 and 22°C were measured. There was a significant difference in respiration rate among the three polyp populations, which may reflect on differences in their thermal tolerance window. A critical temperature was reached at 14°C with the metabolic rate decreasing below and above that temperature. This pattern was less pronounced in the Norwegian population but polyps were able to survive, at least temporarily, those temperatures exceeding their natural range. While polyps collected from northern Norway, with a narrow environmental thermal window, displayed a low baseline metabolism with a Q10 value of 1.2, polyps from southern England and Scotland had Q10 values of 1.6 and 2.5, respectively. Differences in polyps' respiration rates across their distributional range suggest that populations have evolved adaptations to local environmental thermal conditions.

Three-dimensional laryngeal flow fields induced by a model vocal fold polyp

Energy Technology Data Exchange (ETDEWEB)

Erath, Byron D., E-mail: erath@gwu.edu [Department of Mechanical and Aerospace Engineering, George Washington University, 801 22nd Street NW, 739 Phillips Hall, Washington, DC 20052 (United States); Plesniak, Michael W., E-mail: plesniak@gwu.edu [Department of Mechanical and Aerospace Engineering, George Washington University, 801 22nd Street NW, 739 Phillips Hall, Washington, DC 20052 (United States)

2012-06-15

Highlights: Black-Right-Pointing-Pointer Pathological speech with a unilateral polyp is modeled in a scaled-up flow facility. Black-Right-Pointing-Pointer Vortex shedding from the polyp disrupts normal flow behavior. Black-Right-Pointing-Pointer Hairpin vortices create spatial velocity asymmetries in the glottal flow. - Abstract: Pathological laryngeal flow fields are investigated in a dynamically-driven, scaled-up model of the vocal folds. Disruption of the flow field due to the presence of a geometric protuberance, representative of a sessile unilateral polyp, is investigated in both the streamwise and transverse flow directions using phase-averaged particle image velocimetry. It is shown that the protuberance disrupts the normal flow behavior of the glottal jet throughout the phonatory cycle. During the divergent portions of the glottal cycle, the flow is characterized by the formation of hairpin vortices downstream of the protuberance. The protuberance also introduces significant velocity gradients in the anterior-posterior direction, which cover {approx}30 - 40% of the vocal fold length. It is proposed that the disruption of the normal velocity behavior owing to the presence of a polyp will adversely impact the aerodynamic loadings that drive vocal fold motion, contributing to the temporal and spatial vocal fold asymmetries that are clinically-observed in patients with unilateral polyps.

Three-dimensional laryngeal flow fields induced by a model vocal fold polyp

International Nuclear Information System (INIS)

Erath, Byron D.; Plesniak, Michael W.

2012-01-01

Highlights: ► Pathological speech with a unilateral polyp is modeled in a scaled-up flow facility. ► Vortex shedding from the polyp disrupts normal flow behavior. ► Hairpin vortices create spatial velocity asymmetries in the glottal flow. - Abstract: Pathological laryngeal flow fields are investigated in a dynamically-driven, scaled-up model of the vocal folds. Disruption of the flow field due to the presence of a geometric protuberance, representative of a sessile unilateral polyp, is investigated in both the streamwise and transverse flow directions using phase-averaged particle image velocimetry. It is shown that the protuberance disrupts the normal flow behavior of the glottal jet throughout the phonatory cycle. During the divergent portions of the glottal cycle, the flow is characterized by the formation of hairpin vortices downstream of the protuberance. The protuberance also introduces significant velocity gradients in the anterior-posterior direction, which cover ∼30 − 40% of the vocal fold length. It is proposed that the disruption of the normal velocity behavior owing to the presence of a polyp will adversely impact the aerodynamic loadings that drive vocal fold motion, contributing to the temporal and spatial vocal fold asymmetries that are clinically-observed in patients with unilateral polyps.

Biodegradable Oxamide-Phenylene-Based Mesoporous Organosilica Nanoparticles with Unprecedented Drug Payloads for Delivery in Cells

KAUST Repository

Croissant, Jonas; Fatieiev, Yevhen; Julfakyan, Khachatur; Lu, Jie; Emwas, Abdelhamid; Anjum, Dalaver; Omar, Haneen; Tamanoi, Fuyuhiko; Zink, Jeffrey; Khashab, Niveen M.

2016-01-01

We describe biodegradable mesoporous hybrid NPs in the presence of proteins, and its application for drug delivery. We synthesized oxamide-phenylene-based mesoporous organosilica nanoparticles (MON) in the absence of silica source which had a

THE PREVALENCE OF COLONIC POLYPS IN PATIENTS WITH ACROMEGALY: A CASE-CONTROL, NESTED IN A COHORT COLONOSCOPIC STUDY.

Science.gov (United States)

Gonzalez, Baldomero; Vargas, Guadalupe; Mendoza, Victoria; Nava, Mariana; Rojas, Moisés; Mercado, Moisés

2017-05-01

Acromegaly is associated with an increased risk of colonic polyps. The magnitude of such risk is controversial, and the characteristics that distinguish patients who develop polyps from those who do not are not well established. This study was performed to determine the prevalence of colonic polyps upon the diagnosis of acromegaly and to compare the clinical and biochemical features of patients with and without polyps. Out of 165 patients who underwent a full colonoscopy upon diagnosis of acromegaly, 53 were found to harbor colonic lesions (cases), whereas the remaining 112 were used as controls. Demographic, clinical, and biochemical characteristics were compared between the 2 groups. The prevalence of colonic polyps was 32%, with an estimated relative risk of 6.21 (95% confidence interval [CI] 4.08-9.48). Adenomatous and nonadenomatous polyps were found in 22 and 31 patients, respectively. The most common location was the descending colon. Compared to patients without polyps, subjects with polyps were somewhat older and had significantly higher insulin-like growth factor-1 (IGF-1) levels and a higher prevalence of diabetes. Upon multivariate analysis, only IGF-1 level at diagnosis remained significantly associated with colonic polyps in general and with hyperplastic polyps in particular. Acromegaly is associated with an elevated risk of developing colonic polyps, particularly, distally located hyperplastic lesions. Except for a higher IGF-1 level at diagnosis, no distinctive clinical or biochemical features can be found among those who develop polyps compared to those who do not. CI = confidence interval GH = growth hormone IGF-1 = insulin-like growth factor 1 IQR = inter-quartile range RR = relative risk ULN = upper limit of normal.

PET/CT colonography in patients with colorectal polyps: a feasibility study

International Nuclear Information System (INIS)

Mainenti, Pier P.; Pace, Leonardo; Salvatore, Marco; Salvatore, Barbara; D'Antonio, Dario; Bucci, Luigi; De Falco, Teresa; De Palma, Giovanni D.; D'Armiento, Francesco P.

2007-01-01

To examine: (1) the feasibility of PET/CT colonography (PET/CTc) in patients with colorectal polyps; (2) the impact of metabolic information on CTc interpretation and, conversely, the impact of morphological information on PET characterisation of focal colorectal uptake. Ten patients with colorectal polyps underwent PET/CTc, followed within 3 h by therapeutic conventional colonoscopy (CC). A radiologist and a nuclear medicine physician analysed the PET/CTc images. The agreement of morphological and metabolic information in the colon and rectum was evaluated. The sensitivity and specificity of PET, CT and PET/CT were calculated for colorectal polyps. Seventeen polypoid lesions were identified at CC: six≤5 mm, six between 6 and 9 mm, and five ≥10 mm (four hyperplastic polyps, 11 tubular adenomas, one adenocarcinoma and one submucosal lipoma). A total of 20 scans (supine and prone) were performed in the ten patients: the agreement of morphological and metabolic information was excellent in 17 scans, good in two and moderate in one. PET/CTc showed a sensitivity of 91% for lesions ≥6 mm and a specificity of 100%. The metabolic information did not disclose any further polyps missed on CTc. The morphological information permitted correct classification of all eight instances of focal radiotracer uptake. PET/CTc is a feasible study. Adding a colonographic protocol to PET/CT images seems to allow correct characterisation of all cases of colorectal focal radiotracer uptake. The metabolic information does not seem to increase the accuracy of CTc. (orig.)

Aragonite precipitation by "proto-polyps" in coral cell cultures.

Directory of Open Access Journals (Sweden)

Tali Mass

Full Text Available The mechanisms of coral calcification at the molecular, cellular and tissue levels are poorly understood. In this study, we examine calcium carbonate precipitation using novel coral tissue cultures that aggregate to form "proto-polyps". Our goal is to establish an experimental system in which calcification is facilitated at the cellular level, while simultaneously allowing in vitro manipulations of the calcifying fluid. This novel coral culturing technique enables us to study the mechanisms of biomineralization and their implications for geochemical proxies. Viable cell cultures of the hermatypic, zooxanthellate coral, Stylophora pistillata, have been maintained for 6 to 8 weeks. Using an enriched seawater medium with aragonite saturation state similar to open ocean surface waters (Ω(arag~4, the primary cell cultures assemble into "proto-polyps" which form an extracellular organic matrix (ECM and precipitate aragonite crystals. These extracellular aragonite crystals, about 10 µm in length, are formed on the external face of the proto-polyps and are identified by their distinctive elongated crystallography and X-ray diffraction pattern. The precipitation of aragonite is independent of photosynthesis by the zooxanthellae, and does not occur in control experiments lacking coral cells or when the coral cells are poisoned with sodium azide. Our results demonstrate that proto-polyps, aggregated from primary coral tissue culture, function (from a biomineralization perspective similarly to whole corals. This approach provides a novel tool for investigating the biophysical mechanism of calcification in these organisms.

Germline variants in Hamartomatous Polyposis Syndrome-associated genes from patients with one or few hamartomatous polyps

DEFF Research Database (Denmark)

Jelsig, Anne Marie; Brusgaard, Klaus; Hansen, Tine Plato

2016-01-01

OBJECTIVE: A subgroup of patients with hamartomatous polyps in the GI tract has a hereditary Hamartomatous Polyposis Syndrome with an increased risk of cancer. The distinction between patients with one or few polyps and patients with a syndrome can be difficult. A pathogenic germline mutation can...... significance of genetic variants can be difficult to interpret. A family history of polyps, cancer, or extraintestinal findings or a minimum of 3-5 polyps seems to be relevant information to include before genetic testing....

CT findings of the angiomatous polyp in the nasal cavity and paranasal sinus

Energy Technology Data Exchange (ETDEWEB)

Jang, Young Sim; Youm, Dong Ho; Lee, Myeong Sub; Kang, In Goo; Lee, Jun Ha; Sung, Ki Joon; Cho, Mee Yon; Yang, Suk Woo [Yonsei Univ. College of Medicine, Wonju (Korea, Republic of)

1999-06-01

To assess the characteristic CT findings of the angiomatous polyp. Five cases of pathologically-proven angiomatous polyp were retrospectively evaluated. All underwent CT scanning, but in only four cases were postcontrast CT scans obtained. In analysing CT findings we focused on adjacent bony change, and the extent and enhancement pattern of the mass. All but one case involved the maxillary sinus, showing thickening of the posterolateral wall and erosion or destruction of the medial wall. As for involvement of the anterior wall of this sinus, bony destruction was seen in one case, and thickening in three. In four cases the tumor involved the maxillary sinus and nasal cavity, and two cases showed nasopharyngeal extension. No case involved the pterygopalatine fossa, however. On contrast enhanced CT scans(n=4), all cases showed enhancement as strong as blood vessels, and a multiple focal punctate or tubular pattern. Angiomatous polyp tends to show bone thickening rather than bone destruction, not to involve the pterygopalatine fossa, and to reveal a strong punctate or tubular enhancement pattern. These findings may be helpful in the differential diagnosis of angiomatous polyp from other tumors such as maxillary cancer, angiofibroma and nasal polyp.

CT colonography: Diagnostic role of contrast enhancement of benign polyps and colorectal carcinoma

International Nuclear Information System (INIS)

Stoinova, V.; Nedevska, M.

2006-01-01

Full text: The aim of this study was to compare pre- and postcontrast CT attenuation values of benign colorectal polyps and carcinoma lesions detected by CT colonography, and to investigate whether contrast enhancement of these lesions can be potentially used for differentiation from residual fluid and feces. We retrospectively reviewed CT colonographic dataset of 120 patients. 35 benign polyps and 22 colorectal carcinomas were included in our study. All lesions were confirmed by colonoscopic biopsy or surgery. The difference in attenuation value between precontrast and postcontrast studies of polyps was statistically significant; the same was true for colorectal cancers. In the precontrast phase no statistically significant difference was observed between stool, polyps and cancers. The mean attenuation value of solid fecal residuals was 37 HU before and after contrast enhancement. Residual fluid do not take up contrast and the density does not change in the contrast-enhanced phase. The difference between postcontrast density of polyps and cancers with respect to density of stools and residual fluid was significant. The use of contrast medium could be helpful in CT colonography for discriminating polypoid benign lesions and colorectal cancer from fecal and fluid residuals

Two cases of benign polyps of the posterior urethra (ectopic prostatic tissue)

OpenAIRE

多田, 晃司; 山羽, 正義; 田村, 公一; 藤広, 茂; 河田, 幸道

1990-01-01

We report two cases of benign polyps of the posterior urethra. Their first symptoms were gross hematuria and urinary frequency. Both specimens obtained by transurethral resection were histologically identified as prostatic tissue. Discussion on benign polyps of the posterior urethra as ectopic prostatic tissue was done with review of literature.

Synthesis of Poly(para-phenylene terephthalamide and Preparation of Short Fibers: Effect of Sodium Sulphate on the Fibers

Directory of Open Access Journals (Sweden)

mohammad ali Semsarzadeh

2012-12-01

Full Text Available Kevlar is one of the fbers which is used in heavy industrial productions such as, shipping, military and weaving for reinforcement of composites. Initial polymer of Kevlar or poly(para-phenylene terephthalamide is an oriented liquid crystal polymer. Existence of aromatic group in the main chain leads to formation of rigid-rod molecules in the polymer, high strength and high modulus in it is fbers. Impurities in the polymer lead to decrease in fbers performance. In this research, poly(para - phenylene terephthalamide was synthesized from polycondensation of phenylene diamine and terephthaloyl dichloride in n-methyl pyrrolidone and calcium chloride (NMP-CaCl2 solution. Fourier transform infrared spectroscopy (FTIR and X-ray diffraction (XRD tests were carried out to characterize chemical bonds and crystalline plates of the polymer, respectively. Concentrated sulfuric acid is a solvent of poly(phenylene terephthalate therefore, this polymer was dissolved in concentreated sulfuric acid (96% and  the polymer solution was  injected  into  the cylindrical tank contain water. Sulfuric acid was transferred into water and the polymer was solidifed. After solidifcation,  tensile  force of vortex  led  to orientation of  rigid-rod polymer molecules  in direction of water rotation and  long fbers were formed from the polymer. The fbers were broken to short fbers by the same force of vortex. The short fbers were dried. SEM  images showed  the regular particles on  the surface of fbers. Results of FTIR and XRD proved that the regular particles are sodium sulphate salt. The effect of sodium sulphate salt as an impurity on the short fbers was studied.

Colonic polyp detection method from 3D abdominal CT images based on local intensity analysis

International Nuclear Information System (INIS)

Oda, M.; Nakada, Y.; Kitasaka, T.; Mori, K.; Suenaga, Y.; Takayama, T.; Takabatake, H.; Mori, M.; Natori, H.; Nawano, S.

2007-01-01

This paper presents a detection method of colonic polyps from 3D abdominal CT images based on local intensity analysis. Recently, virtual colonoscopy (VC) has widely received attention as a new colon diagnostic method. VC is considered as a less-invasive inspection method which reduces patient load. However, since the colon has many haustra and its shape is long and convoluted, a physician has to change the viewpoint and the viewing direction of the virtual camera of VC many times while diagnosis. Additionally, there is a risk to overlook lesions existing in blinded areas caused by haustra. This paper proposes an automated colonic polyp detection method from 3D abdominal CT images. Colonic polyps are located on the colonic wall. Their CT values are higher than those of colonic lumen regions and lower than those of fecal materials tagged by an X-ray opaque contrast agent. CT values inside polyps which exist outside the tagged fecal materials tend to gradually increase from outward to inward (blob-like structure). CT values inside polyps that exist inside the tagged fecal materials tend to gradually decrease from outward to inward (inv-blob-like structure). We employ the blob and the inv-blob structure enhancement filters based on the eigenvalues of the Hessian matrix to detect polyps using intensity characteristic of polyps. Connected components with low output values of the enhancement filter are eliminated in false positive reduction process. Small connected components are also eliminated. We applied the proposed method to 44 cases of abdominal CT images. Sensitivity for polyps of 6 mm or larger was 80% with 4.7 false positives per case. (orig.)

Prevalence of advanced adenomas in small and diminutive colon polyps using direct measurement of size.

Science.gov (United States)

Tsai, Franklin C; Strum, Williamson B

2011-08-01

Most studies reporting polyp size use visual estimates. Determining the prevalence of advanced histology based on direct measurement of polyp size may help guide the management of polyps found at optical colonoscopy (OC) and CT colonography (CTC). We designed a large, prospective study to assess the prevalence of advanced adenomas based on direct measurement of polyp size by a certified pathologists' assistant as reported in the pathology report. Patients between 40 and 89 years of age who presented for screening colonoscopy were included in our study. Advanced adenomas were defined as ≥10 mm or ≥25% villous features, high grade dysplasia or cancer. Polyps were divided by size into three groups: diminutive (≤5 mm), small (6-9 mm) and large (≥10 mm). If more than one adenoma was present, the most advanced was used for analysis. We evaluated 6,905 consecutive patients referred for colonoscopy between January 2005 and December 2006. Of the 4,967 who met the inclusion criteria, the mean age was 58.8 and consisted of 59% women. Overall, 930 (18.7%) had an adenoma; 248 (5%) were advanced adenomas including 8 (0.16%) cancers. Of 89 polyps≥10 mm, 76 (85%) had advanced histology; of 247 polyps 6-9 mm, 67 (27%) were advanced; of 1,025 polyps ≤5 mm, 105 (10%) were advanced. Thus, 172 of 248 (69%) patients with advanced adenomas had small or diminutive adenomas. Our data indicate the majority (69%) of advanced adenomas are advanced adenomas (10%). These findings may help guide the management of sub-centimeter colon polyps found by OC or CTC.

Prevalence of endometrial polyps and abnormal uterine bleeding in a Danish population aged 20-74 years

DEFF Research Database (Denmark)

Dreisler, E; Stampe Sorensen, S; Ibsen, P H

2009-01-01

OBJECTIVE: To estimate the prevalence of endometrial polyps and to investigate associated abnormal uterine bleeding in a Danish population aged 20-74 years. METHODS: This was a study of a random selection of women from the Danish Civil Registration System: 1660 women were invited of whom 686 were...... verified polyps were asymptomatic. In asymptomatic premenopausal women the prevalence of polyps was 7.6%, while it was 13% in asymptomatic postmenopausal women. AUB, in particular intermenstrual bleeding, was more frequent among women without polyps (38%). By ultrasound examination, submucosal myomas were...

Metachronous colon polyps in younger versus older adults: a case-control study.

Science.gov (United States)

Nagpal, Sajan Jiv Singh; Mukhija, Dhruvika; Sanaka, Madhusudhan; Lopez, Rocio; Burke, Carol A

2018-03-01

The incidence of colorectal cancer in the United States has decreased substantially in individuals aged 50 and older. In contrast, it is increasing in young adults. The polyp characteristics on baseline and follow-up colonoscopy in young adults are not well characterized. We describe the polyp characteristics on baseline and follow-up colonoscopy in adults 1 polyp removed on colonoscopy followed by a postpolypectomy colonoscopy were eligible. The primary outcome was the occurrence of advanced neoplasia or HR polyp features on follow-up colonoscopy. Secondary endpoints included factors associated with metachronous advanced neoplasia in young adults. The occurrence of metachronous advanced neoplasia in young adults was compared with a cohort of patients aged 50 years and older. Included were 128 patients with a mean age of 34.9 years; 124 patients (97%) had adenomas and 7% had sessile serrated polyps (SSPs). Advanced neoplasia was seen in 35% of patients at baseline. The median follow-up time was 33.6 months. Metachronous advanced neoplasia was identified in 7% of patients on follow-up colonoscopy. Baseline factors associated with metachronous advanced neoplasia included the presence of an SSP (hazard ratio, 7.8; 95% CI, 1.09-56.3; P = .041) with a trend in those with advanced neoplasia (hazard ratio, 3.4; 95% confidence interval, .89-12.8; P = .072). The occurrence of metachronous advanced neoplasia did not differ between the young and older cohorts (7% vs 12.2%, P = .58); however, young adults were less likely to have HR polyp features on follow-up (8.6% vs 20.3%, P = .008). More than 1 in 3 adults <40 years old undergoing colonoscopy had advanced neoplasia on baseline colonoscopy. The occurrence of metachronous advanced neoplasia in young adults is similar to older adults and appears to be associated with the size, pathology, and number of baseline polyps. Our data suggest young polyp-bearing adults may undergo postpolypectomy colonoscopy at intervals

Synthesis and characterization of sulfonated bromo-poly(2,6-dimethyl-1,4-phenylene oxide)-co-(2,6-diphenyl-1,4-phenylene oxide) copolymer as proton exchange membrane

Energy Technology Data Exchange (ETDEWEB)

Jeong, Young-Gi; Seo, Dong-Wan; Lim, Young-Don; Jin, Hyun-Mi; Islam Mollah, M.S. [Department of Applied Chemistry, Konkuk University/RIC-ReSEM Chungju, 322 Danwol-dong, Chungbuk 380-701 (Korea, Republic of); Ur, Soon-Chul [Department of Materials Science and Engineering/RIC-ReSEM, Chungju National University, Chungju, Chungbuk 380-702 (Korea, Republic of); Pyun, Sang-Yong [Department of Chemistry, Pukyong National University, Pusan 608-737 (Korea, Republic of); Kim, Whan-Gi, E-mail: wgkim@kku.ac.k [Department of Applied Chemistry, Konkuk University/RIC-ReSEM Chungju, 322 Danwol-dong, Chungbuk 380-701 (Korea, Republic of)

2010-01-25

Novel polymer electrolyte membranes containing the sulfonic acid groups attached on polymer backbone and side group simultaneously were synthesized. The bromo-poly(2,6-dimethyl-1,4-phenylene oxide)-co-(2,6-diphenyl-1,4-phenylene oxide) copolymer (BrcoPPO) was prepared by oxidative coupling polymerization with 2,6-dimethyl phenol, 2,6-diphenyl phenol, CuCl(I) and pyridine, and followed by bromination with bromine. Copolymer was maintained in 2,6-diphenyl phenol 10 mol% and 2,6-dimethyl phenol 90 mol%. Sulfonation of BrcoPPO (S-BrcoPPO) was carried out in a chlorobenzene solvent using chlorosulfonic acid. The polymeric membranes were cast from dimethylsulfoxide solution. The membranes were studied by nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymers with water and methanol. S-BrcoPPO membranes exhibited proton conductivities from 2.3 x 10{sup -3} to 1.4 x 10{sup -2} S/cm, water uptake from 7.00 to 49.43%, IEC from 0.58 to 1.38 mequiv./g, methanol permeability from 1.9 x 10{sup -7} to 3.5 x 10{sup -7} cm{sup 2}/S.

Automatic Polyp Detection via A Novel Unified Bottom-up and Top-down Saliency Approach.

Science.gov (United States)

Yuan, Yixuan; Li, Dengwang; Meng, Max Q-H

2017-07-31

In this paper, we propose a novel automatic computer-aided method to detect polyps for colonoscopy videos. To find the perceptually and semantically meaningful salient polyp regions, we first segment images into multilevel superpixels. Each level corresponds to different sizes of superpixels. Rather than adopting hand-designed features to describe these superpixels in images, we employ sparse autoencoder (SAE) to learn discriminative features in an unsupervised way. Then a novel unified bottom-up and top-down saliency method is proposed to detect polyps. In the first stage, we propose a weak bottom-up (WBU) saliency map by fusing the contrast based saliency and object-center based saliency together. The contrast based saliency map highlights image parts that show different appearances compared with surrounding areas while the object-center based saliency map emphasizes the center of the salient object. In the second stage, a strong classifier with Multiple Kernel Boosting (MKB) is learned to calculate the strong top-down (STD) saliency map based on samples directly from the obtained multi-level WBU saliency maps. We finally integrate these two stage saliency maps from all levels together to highlight polyps. Experiment results achieve 0.818 recall for saliency calculation, validating the effectiveness of our method. Extensive experiments on public polyp datasets demonstrate that the proposed saliency algorithm performs favorably against state-of-the-art saliency methods to detect polyps.

Combining heterogeneous features for colonic polyp detection in CTC based on semi-definite programming

Science.gov (United States)

Wang, Shijun; Yao, Jianhua; Petrick, Nicholas A.; Summers, Ronald M.

2009-02-01

Colon cancer is the second leading cause of cancer-related deaths in the United States. Computed tomographic colonography (CTC) combined with a computer aided detection system provides a feasible combination for improving colonic polyps detection and increasing the use of CTC for colon cancer screening. To distinguish true polyps from false positives, various features extracted from polyp candidates have been proposed. Most of these features try to capture the shape information of polyp candidates or neighborhood knowledge about the surrounding structures (fold, colon wall, etc.). In this paper, we propose a new set of shape descriptors for polyp candidates based on statistical curvature information. These features, called histogram of curvature features, are rotation, translation and scale invariant and can be treated as complementing our existing feature set. Then in order to make full use of the traditional features (defined as group A) and the new features (group B) which are highly heterogeneous, we employed a multiple kernel learning method based on semi-definite programming to identify an optimized classification kernel based on the combined set of features. We did leave-one-patient-out test on a CTC dataset which contained scans from 50 patients (with 90 6-9mm polyp detections). Experimental results show that a support vector machine (SVM) based on the combined feature set and the semi-definite optimization kernel achieved higher FROC performance compared to SVMs using the two groups of features separately. At a false positive per patient rate of 7, the sensitivity on 6-9mm polyps using the combined features improved from 0.78 (Group A) and 0.73 (Group B) to 0.82 (p<=0.01).

Electrochemical stability and transformations of fluorinated poly(2,6-dimethyl-1,4-phenylene oxide)

NARCIS (Netherlands)

Pud, A.A.; Rogalsky, S.P.; Ghapoval, G.S.; Kharitonov, A.P.; Kemperman, Antonius J.B.

2000-01-01

Fluorination of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) leads to narrowing of its window of electrochemical stability in a cathodic range of potentials. It is found this is connected with appearance of both perfluorinated and incompletely fluorinated units in the polymer. The former units are

CLINICAL, EPIDEMIOLOGIC, AND ENDOSCOPIC PROFILE IN CHILDREN AND ADOLESCENTS WITH COLONIC POLYPS IN TWO REFERENCE CENTERS

Directory of Open Access Journals (Sweden)

Denise O ANDRADE

2015-12-01

Full Text Available Background - The main goal of this paper is to investigate the frequency, clinical profile, and endoscopic findings of children and teenagers submitted to colonoscopies. Methods - Patients of below 18 years of age, diagnosed with polyps by means of colonoscopies at two reference centers of pediatric endoscopy were followed-up between 2002 and 2012. The clinical variables evaluated in this study included: gender, recommendation of colonoscopy, associated signs and symptoms, age of onset of symptoms, age at identification of the polyp, interval of time between the onset of symptoms and the endoscopic diagnosis of colonic polyps, and family history of intestinal polyposis and/or colorectal cancer. The characteristics of the polyps also included: number, morphological type, histology, and distribution. Polyposis syndromes were also investigated. Results - From the 233 patients submitted to colonoscopies, polyps were found in 74 (31.7% patients, with a median age of 6.6 years, of which 61% were male. Juvenile polyps were identified in 55 (74% patients, with 7 (9% characterized within the criteria for juvenile polyposis. Patients with intestinal polyposis syndromes were diagnosed in 35% of the patients. The most frequent clinical presentation was hematochezia. Abdominal pain with acute episodes of intestinal partial obstruction or intussusception with emergency laparotomy was observed in the majority of Peutz-Jeghers syndrome patients leading to an increased morbidity. Conclusions - Even though juvenile colonic polyps are the most frequent type of diagnosed polyps, the present study identified a significant level of children with polyposis syndromes (35%, associated with a higher morbidity of these individuals.

Omalizumab is effective in allergic and nonallergic patients with nasal polyps and asthma

NARCIS (Netherlands)

Gevaert, Philippe; Calus, Lien; van Zele, Thibaut; Blomme, Katrien; de Ruyck, Natalie; Bauters, Wouter; Hellings, Peter; Brusselle, Guy; de Bacquer, Dirk; van Cauwenberge, Paul; Bachert, Claus

2013-01-01

Background: Adult patients with nasal polyps often have comorbid asthma, adding to the serious effect on the quality of life of these patients. Nasal polyps and asthma might represent a therapeutic challenge; inflammation in both diseases shares many features, such as airway eosinophilia, local IgE

Knife-assisted snare resection: a novel technique for resection of scarred polyps in the colon.

Science.gov (United States)

Chedgy, Fergus J Q; Bhattacharyya, Rupam; Kandiah, Kesavan; Longcroft-Wheaton, Gaius; Bhandari, Pradeep

2016-03-01

There have been significant advances in the management of complex colorectal polyps. Previous failed resection or polyp recurrence is associated with significant fibrosis, making endoscopic resection extremely challenging; the traditional approach to these lesions is surgery. The aim of this study was to evaluate the efficacy of a novel, knife-assisted snare resection (KAR) technique in the resection of scarred colonic polyps. This was a prospective cohort study of patients, in whom the KAR technique was used to resect scarred colonic polyps > 2  cm in size. Patients had previously undergone endoscopic mucosal resection (EMR) and developed recurrence, or EMR had been attempted but was aborted as a result of technical difficulty. A total of 42 patients underwent KAR of large (median 40  mm) scarred polyps. Surgery for benign disease was avoided in 38 of 41 patients (93 %). No life-threatening complications occurred. Recurrence was seen in six patients (16 %), five of whom underwent further endoscopic resection. The overall cure rate for KAR in complex scarred colonic polyps was 90 %. KAR of scarred colonic polyps by an expert endoscopist was an effective and safe technique with low recurrence rates. © Georg Thieme Verlag KG Stuttgart · New York.

Controlling morphology and chain aggregation in semiconducting conjugated polymers: the role of solvent on optical gain in MEH-PPV.

Science.gov (United States)

Lampert, Zach E; Reynolds, C Lewis; Papanikolas, John M; Aboelfotoh, M Osama

2012-10-25

We report the results of a detailed investigation that addresses the influence of polymer morphology and chain aggregation, as controlled by the chemical nature of the solvent, on the optical gain properties of the conjugated polymer poly[2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene] (MEH-PPV). Using the variable stripe length technique in the picosecond regime, we have extensively studied the optical gain performance of asymmetric planar waveguides formed with thin MEH-PPV films spin-cast from concentrated chlorobenzene (CB) and tetrahydrofuran (THF) solutions onto thermally oxidized silicon substrates. CB and THF solvents were chosen based on their known ability to promote and effectively limit aggregate formation, respectively. Very large net gain coefficients are demonstrated, reaching values of 330 and 365 cm(-1), respectively, when optically pumping the waveguides with a maximum energy density of 85 μJ/cm(2). Our results clearly demonstrate that polymer morphology, and hence, the chain conformation dependence of the degree of aggregation in the films as controlled by the solvent, has minimal impact on the net gain. Moreover, the waveguides exhibit low loss coefficients of 10-20 cm(-1) at the ASE wavelength. These results question the importance of polymer morphology and aggregate formation in polymer-based optical devices operating at high excitation densities in the stimulated emission regime as would be characteristic of lasers and optical amplifiers.

Chemical potential pinning due to equilibrium electron transfer at metal/C{sub 60}-doped polymer interfaces

Energy Technology Data Exchange (ETDEWEB)

Heller, C.M.; Campbell, I.H.; Smith, D.L. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Barashkov, N.N.; Ferraris, J.P. [The University of Texas at Dallas, Richardson, Texas 75080 (United States)

1997-04-01

We report electroabsorption measurements of the built-in electrostatic potential in metal/C{sub 60}-doped polymer/metal structures to investigate chemical potential pinning due to equilibrium electron transfer from a metal contact to the electron acceptor energy level of C{sub 60} molecules in the polymer film. The built-in potentials of a series of structures employing thin films of both undoped and C{sub 60}-doped poly[2-methoxy, 5-(2{sup {prime}}-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) were measured. For undoped MEH-PPV, which has an energy gap of about 2.4 eV, the maximum built-in potential is about 2.1 eV, whereas for C{sub 60}-doped MEH-PPV the maximum built-in potential decreases to 1.5 eV. Electron transfer to the C{sub 60} molecules close to the metal interface pins the chemical potential of the metal contact near the electron acceptor energy level of C{sub 60} and decreases the built-in potential of the structure. From the systematic dependence of the built-in potential on the metal work function we find that the electron acceptor energy level of C{sub 60} in MEH-PPV is about 1.7 eV above the hole polaron energy level of MEH-PPV. {copyright} {ital 1997 American Institute of Physics.}

Next-generation narrow band imaging system for colonic polyp detection: a prospective multicenter randomized trial.

Science.gov (United States)

Horimatsu, Takahiro; Sano, Yasushi; Tanaka, Shinji; Kawamura, Takuji; Saito, Shoichi; Iwatate, Mineo; Oka, Shiro; Uno, Koji; Yoshimura, Kenichi; Ishikawa, Hideki; Muto, Manabu; Tajiri, Hisao

2015-07-01

Previous studies have yielded conflicting results on the colonic polyp detection rate with narrow-band imaging (NBI) compared with white-light imaging (WLI). We compared the mean number of colonic polyps detected per patient for NBI versus WLI using a next-generation NBI system (EVIS LUCERA ELITE; Olympus Medical Systems) used with standard-definition (SD) colonoscopy and wide-angle (WA) colonoscopy. this study is a 2 × 2 factorial, prospective, multicenter randomized controlled trial. this study was conducted at five academic centers in Japan. patients were allocated to one of four groups: (1) WLI with SD colonoscopy (H260AZI), (2) NBI with SD colonoscopy (H260AZI), (3) WLI with WA colonoscopy (CF-HQ290), and (4) NBI with WA colonoscopy (CF-HQ290). the mean numbers of polyps detected per patient were compared between the four groups: WLI with/without WA colonoscopy and NBI with/without WA colonoscopy. Of the 454 patients recruited, 431 patients were enrolled. The total numbers of polyps detected by WLI with SD, NBI with SD, WLI with WA, and NBI with WA were 164, 176, 188, and 241, respectively. The mean number of polyps detected per patient was significantly higher in the NBI group than in the WLI group (2.01 vs 1.56; P = 0.032). The rate was not higher in the WA group than in the SD group (1.97 vs 1.61; P = 0.089). Although WA colonoscopy did not improve the polyp detection, next-generation NBI colonoscopy represents a significant improvement in the detection of colonic polyps.

Nattokinase, profibrinolytic enzyme, effectively shrinks the nasal polyp tissue and decreases viscosity of mucus.

Science.gov (United States)

Takabayashi, Tetsuji; Imoto, Yoshimasa; Sakashita, Masafumi; Kato, Yukinori; Tokunaga, Takahiro; Yoshida, Kanako; Narita, Norihiko; Ishizuka, Tamotsu; Fujieda, Shigeharu

2017-10-01

Chronic rhinosinusitis with nasal polyps (CRSwNP) is often comorbid with asthma and resistant to therapeutic interventions. We recently reported that excessive fibrin deposition caused by impairment of fibrinolysis might play pivotal role in forming nasal polyp. Nattokinase (NK), a serine protease produced by Bacillus subtilis, has been reported to be a strong fibrinolytic enzyme. NK could be a promising drug candidate for use in the treatment of both CRSwNP and asthma. The objective of this study was to investigate the effects of NK on nasal polyp tissues from patients with CRSwNP. The nasal discharge from patients with CRSwNP and sputum from subjects with asthma were also used to investigate whether NK influences the viscosity of mucus. To examine the effects on NK on nasal polyp tissues, pieces of nasal polyps were incubated either with saline or NK (10-1000 FU/ml) at 37 °C for 24 h. We assessed the presence of fibrin in nasal polyp tissue incubated with NK by means of immunohistochemistry. To examine the effects of NK on nasal discharge and sputum from patients with CRSwNP and asthma, respectively, were incubated with NK solution at 37 °C for 1 h. NK effectively shrinks the nasal polyp tissue through fibrin degradation. We also found that the viscosity of the nasal discharge and sputum from patients with CRSwNP and asthma, respectively, was significantly reduced by incubation with NK solution. NK may be an effective alternative therapeutic option in patients with CRSwNP and comorbid asthma by causing fibrin degradation. Copyright © 2017 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.

Specialist Endoscopists Are Associated with a Decreased Risk of Incomplete Polyp Resection During Endoscopic Mucosal Resection in the Colon.

Science.gov (United States)

Tavakkoli, Anna; Law, Ryan J; Bedi, Aarti O; Prabhu, Anoop; Hiatt, Tadd; Anderson, Michelle A; Wamsteker, Erik J; Elmunzer, B Joseph; Piraka, Cyrus R; Scheiman, James M; Elta, Grace H; Kwon, Richard S

2017-09-01

Endoscopic experience is known to correlate with outcomes of endoscopic mucosal resection (EMR), particularly complete resection of the polyp tissue. Whether specialist endoscopists can protect against incomplete polypectomy in the setting of known risk factors for incomplete resection (IR) is unknown. We aimed to characterize how specialist endoscopists may help to mitigate the risk of IR of large sessile polyps. This is a retrospective cohort study of patients who underwent EMR at the University of Michigan from January 1, 2006, to November 15, 2015. The primary outcome was endoscopist-reported polyp tissue remaining at the end of the initial EMR attempt. Specialist endoscopists were defined as endoscopists who receive tertiary referrals for difficult colonoscopy cases and completed at least 20 EMR colonic polyp resections over the study period. A total of 257 patients with 269 polyps were included in the study. IR occurred in 40 (16%) cases. IR was associated with polyp size ≥ 40 mm [adjusted odds ratio (aOR) 3.31, 95% confidence interval (CI) 1.38-7.93], flat/laterally spreading polyps (aOR 2.61, 95% CI 1.24-5.48), and difficulty lifting the polyp (aOR 11.0, 95% CI 2.66-45.3). A specialist endoscopist performing the initial EMR was protective against IR, even in the setting of risk factors for IR (aOR 0.13, 95% CI 0.04-0.41). IR is associated with polyp size ≥ 40 mm, flat and/or laterally spreading polyps, and difficulty lifting the polyp. A specialist endoscopist initiating the EMR was protective of IR.

Subgap absorption in conjugated polymers

Energy Technology Data Exchange (ETDEWEB)

Sinclair, M.; Seager, C.H. (Sandia National Labs., Albuquerque, NM (USA)); McBranch, D.; Heeger, A.J. (California Univ., Santa Barbara, CA (USA)); Baker, G.L. (Bell Communications Research, Inc., Red Bank, NJ (USA))

1991-01-01

Along with X{sup (3)}, the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter which will ultimately determine the utility of conjugated polymers in active integrated optical devices. With an absorptance sensitivity of < 10{sup {minus}5}, Photothermal Deflection Spectroscopy (PDS) is ideal for determining the absorption coefficients of thin films of transparent'' materials. We have used PDS to measure the optical absorption spectra of the conjugated polymers poly(1,4-phenylene-vinylene) (and derivitives) and polydiacetylene-4BCMU in the spectral region from 0.55 eV to 3 eV. Our spectra show that the shape of the absorption edge varies considerably from polymer to polymer, with polydiacetylene-4BCMU having the steepest absorption edge. The minimum absorption coefficients measured varied somewhat with sample age and quality, but were typically in the range 1 cm{sup {minus}1} to 10 cm{sup {minus}1}. In the region below 1 eV, overtones of C-H stretching modes were observed, indicating that further improvements in transparency in this spectral region might be achieved via deuteration of fluorination. 11 refs., 4 figs.

Colonoscopic Polypectomy of Colorectal Polyps in Children Under General Anesthesia

Directory of Open Access Journals (Sweden)

Chien-Heng Lin

2009-02-01

Full Text Available In many countries, general anesthesia is not routinely used for colonoscopic polypectomy in children because of either feasibility or cost-effectiveness issues. However, we have been using general anesthesia for colonoscopic polypectomy in pediatric patients in our hospital for the past 5 years. The aim of this study was to evaluate the safety of the procedure and the degree of satisfaction that the patients' parents and endoscopists had with the use of general anesthesia. We retrospectively analyzed the results of colonoscopic polypectomies under general anesthesia in 18 patients performed between January 2001 and December 2005. The removed polyps were examined histologically and the patients were observed to assess complications during the first 24-hour postoperative period. The patients' parents' and endoscopists' satisfaction with the use of general anesthesia was surveyed after the procedure. In our patient group, there were 10 boys and eight girls. The mean age was 5.5 ± 3.4 years (range, 2–15 years. Seventeen of the 18 patients had rectal bleeding (mean duration, 3.7 months as the main symptom. There were 12 patients with juvenile polyps, four with hyperplastic polyps, one with juvenile polyposis and one with Peutz-Jeghers syndrome. The majority (70.6% of the polyps were located in the rectosigmoid colon. No significant complications related to colonoscopic polypectomy or anesthesia were observed. Satisfaction among parents and endoscopists ranged from good to excellent. General anesthesia is recommended for pediatric patients undergoing colonoscopic polypectomy.

Urethral polyp in a 1-month-old child

Energy Technology Data Exchange (ETDEWEB)

Beluffi, Giampiero [Department of Radiodiagnosis, IRCCS Policlinico S. Matteo, Section of Paediatric Radiology, Piazzale Golgi, 2, I-27100, Pavia PV (Italy); Berton, Francesca; Gola, Giada [University of Pavia, IRCCS Policlinico S. Matteo, Institute of Radiology, Pavia (Italy); Chiari, Giorgio; Romano, Piero; Cassani, Ferdinando [IRCCS Policlinico S. Matteo, Division of Paediatric Surgery, Pavia (Italy)

2005-07-01

Urethral polyps are a rare finding in children, particularly in the very young. They are suspected by the presence of various clinical signs such as obstruction, voiding dysfunction and haematuria. There is an association with other urinary tract congenital anomalies. They are usually benign fibro-epithelial lesions with no tendency to recur and are treated by surgical ablation, fulguration or laser therapy. We report a 1-month-old boy with an antenatally diagnosed left ectopic pelvic kidney, postnatal urinary tract infection and no clinical signs of obstruction. Voiding cystourethrography to exclude vesico-ureteric reflux showed a trabeculated bladder and a mobile filling defect in the posterior urethra. Owing to its large size, cystotomy was necessary to remove the polyp successfully. (orig.)

Urethral polyp in a 1-month-old child

International Nuclear Information System (INIS)

Beluffi, Giampiero; Berton, Francesca; Gola, Giada; Chiari, Giorgio; Romano, Piero; Cassani, Ferdinando

2005-01-01

Urethral polyps are a rare finding in children, particularly in the very young. They are suspected by the presence of various clinical signs such as obstruction, voiding dysfunction and haematuria. There is an association with other urinary tract congenital anomalies. They are usually benign fibro-epithelial lesions with no tendency to recur and are treated by surgical ablation, fulguration or laser therapy. We report a 1-month-old boy with an antenatally diagnosed left ectopic pelvic kidney, postnatal urinary tract infection and no clinical signs of obstruction. Voiding cystourethrography to exclude vesico-ureteric reflux showed a trabeculated bladder and a mobile filling defect in the posterior urethra. Owing to its large size, cystotomy was necessary to remove the polyp successfully. (orig.)

Tunable magneto-conductance and magneto-electroluminescence in polymer light-emitting electrochemical planar devices

Energy Technology Data Exchange (ETDEWEB)

Geng, R.; Mayhew, N. T.; Nguyen, T. D., E-mail: ngtho@uga.edu [Department of Physics and Astronomy, University of Georgia, Athens, Georgia 30602 (United States)

2013-12-09

We report studies of magneto-conductance (MC) and magneto-electroluminescence (MEL) in polymer light-emitting electrochemical planar devices using “super-yellow” poly-(phenylene vinylene). We observed consistent negative MC while MEL becomes positive when electroluminescence quantum efficiency (ELQE) increases. At an optimal ELQE, the MC has a much narrower width than the MEL, indicating that the MC and MEL do not share a common origin. However, MC reverses and has the same width as MEL when exposed to a threshold laser power. We show that the e-h pair model can explain the positive MEL and MC while the negative MC can be explained by the bipolaron model.

Fullerene-doped conducting polymers: effects of enhanced photoconductivity and quenched photoluminescence

International Nuclear Information System (INIS)

Yoshino, K.; Yin, X.H.; Muro, K.; Kiyomatsu, S.; Morita, S.; Zakhidov, A.A.; Noguchi, T.; Ohnishi, T.

1993-01-01

It is found that fullerenes (C 60 , C 70 ), due to their strong electron accepting abilities can be hole generators in conducting polymers sensitizing photoinduced charge transfer. Here we report that photoconductivity of poly(2,5-dialkoxy-p-phenylene-vinylene) OO-PPV is found to be remarkably enhanced by several orders of magnitude upon introduction of several mol % of C 60 . Positive polarons (P + ) photogenerated with increased efficiency due to autoionization of excitons and/or photopumping from fullerene are considered to be responsible for enhanced photoconductivity. Photoluminescence of polymer is strongly quenched upon C 60 doping due to dissociation of excitons accompanied by electron transfer to fullerene. (orig.)

Controlling charge injection in organic electronic devices using self-assembled monolayers

Energy Technology Data Exchange (ETDEWEB)

Campbell, I.H.; Kress, J.D.; Martin, R.L.; Smith, D.L. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Barashkov, N.N.; Ferraris, J.P. [The University of Texas at Dallas, Richardson, Texas 75083 (United States)

1997-12-01

We demonstrate control and improvement of charge injection in organic electronic devices by utilizing self-assembled monolayers (SAMs) to manipulate the Schottky energy barrier between a metal electrode and the organic electronic material. Hole injection from Cu electrodes into the electroluminescent conjugated polymer poly[2-methoxy,5-(2{sup {prime}}-ethyl-hexyloxy)-1,4-phenylene vinylene] was varied by using two conjugated-thiol based SAMs. The chemically modified electrodes were incorporated in organic diode structures and changes in the metal/polymer Schottky energy barriers and current{endash}voltage characteristics were measured. Decreasing (increasing) the Schottky energy barrier improves (degrades) charge injection into the polymer. {copyright} {ital 1997 American Institute of Physics.}

Tunable magneto-conductance and magneto-electroluminescence in polymer light-emitting electrochemical planar devices

International Nuclear Information System (INIS)

Geng, R.; Mayhew, N. T.; Nguyen, T. D.

2013-01-01

We report studies of magneto-conductance (MC) and magneto-electroluminescence (MEL) in polymer light-emitting electrochemical planar devices using “super-yellow” poly-(phenylene vinylene). We observed consistent negative MC while MEL becomes positive when electroluminescence quantum efficiency (ELQE) increases. At an optimal ELQE, the MC has a much narrower width than the MEL, indicating that the MC and MEL do not share a common origin. However, MC reverses and has the same width as MEL when exposed to a threshold laser power. We show that the e-h pair model can explain the positive MEL and MC while the negative MC can be explained by the bipolaron model

Demographic And Histopathological Characteristics Of Colorectal Polyps: A Descriptive Study Based On Samples Obtained From Symptomatic Patients

Directory of Open Access Journals (Sweden)

Cekodhima Genta

2016-06-01

Full Text Available Colorectal polyps (CP are common among individuals older than 50 years. Some polyp types can precede colorectal cancer (CRC. This study aimed at describing histopathological characteristics of colorectal polyps in relation to age and gender among symptomatic patients referred for a colonoscopy examination during 2011-2014 in Tirana, Albania.

Management and diagnosis of gallbladder polyps: a systematic review.

Science.gov (United States)

Babu, Benoy I; Dennison, Ashley R; Garcea, Giuseppe

2015-05-01

Recommendation for management of gallbladder polyps (GBPs) >1 cm is cholecystectomy. No consensus exists on management of GBPs extraction was used to retrieve specified end points. Literature search yielded 43 manuscripts with a dataset of 11,685 patients with GBPs. M:F ratio was 1.3:1. Average age (range) was 49 years (32-83). Patients with malignant GBPs had an average (range) age of 58 (50-66) years with M:F ratio of 0.78:1. Cholesterol polyps constituted 60.5% of GBPs followed by adenomas (15.2%) and cancer (11.6%). Malignant GBPs ≥1 cm, 1 cm is appropriate. For GBPs 10 mm.

Emission Behavior of Crystalline 1,4-Bis(4-phenylthiophene-2-yl)benzene Film Under Optical Excitation with Ultra Short Pulses.

Science.gov (United States)

Mochizuki, Hiroyuki; Kawaguchi, Yoshizo; Sasaki, Fumio; Hotta, Shu

2016-04-01

We evaluated emission behaviors of crystallized films of 1,4-bis(5-phenylthiophene-2-yl)benzene (AC5) in detail which was a representative thiophene/phenylene co-oligomer. The crystallized AC5 films were prepared by vapor deposition onto a substrate and thermal treatment. The AC5 films consisted of a crystalline domain with the size of several tens of micrometers. We used femtosecond laser pulses for the excitation of the AC5 films. As a result, the femtosecond laser pulses did not induce re-absorption above excitation energy densities of their laser threshold. The obtained gain value for AC5 crystallized film was large, over 150 cm-1. Furthermore, the emission cross section of the crystallized AC5 film was nearly 10(-16) cm2.

Increased polyp detection using narrow band imaging compared with high resolution endoscopy in patients with hyperplastic polyposis syndrome

NARCIS (Netherlands)

Boparai, K. S.; van den Broek, F. J. C.; van Eeden, S.; Fockens, P.; Dekker, E.

2011-01-01

Hyperplastic polyposis syndrome (HPS) is associated with colorectal cancer and is characterized by multiple hyperplastic polyps, sessile serrated adenomas (SSAs) and adenomas. Narrow band imaging (NBI) may improve the detection of polyps in HPS. We aimed to compare polyp miss rates with NBI with

Prevalence of colorectal adenomatous polyps in patients with chronic obstructive pulmonary disease

Directory of Open Access Journals (Sweden)

Chun EM

2015-05-01

Full Text Available Eun Mi Chun, Seo Woo Kim, So Yeon Lim Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Ewha Womans University School of Medicine, Seoul, Republic of Korea Background: Colorectal adenomatous polyps are precancerous lesions of colorectal cancer. The aim of this study was to assess the prevalence of colorectal adenomatous polyps in chronic obstructive pulmonary disease (COPD patients and determine whether COPD is associated with colorectal malignant potential.Methods: Subjects who had undergone post-bronchodilator spirometry and colonoscopy and were 40 years or older were selected from the hospital database. COPD was defined as a spirometry in which the ratio of forced expiratory volume in 1 second (FEV1 and forced vital capacity (FVC is <0.7 in post-bronchodilator spirometry. The non-COPD group was matched for both age and sex, and were defined as having an FEV1, FVC, and FEV1/FVC ≥0.7 in spirometry. Finally, 333 patients were retrospectively reviewed; of this group, 82 patients had COPD.Results: Among the subjects, 201 patients (60% were nonsmokers, while 78 (23% were current smokers. The prevalence of colorectal adenomatous polyps was 39% (98/251 in the non-COPD group and 66% (54/82 in the COPD group. Among 54 patients with adenomatous polyps in the COPD group, 47 had tubular adenoma and seven had villous adenoma. Multiple logistic regression analyses revealed that only COPD patients whom matched to the criteria of COPD by pulmonary function test (odds ratio 2.1, 95% confidence interval: 1.1–3.8; P=0.019 were independently associated with colorectal malignant potential.Conclusion: The risk of colorectal malignant potential in the COPD group was higher than in the non-COPD group. We may suggest that COPD patients should consider regular colonoscopic evaluation to screen for premalignant colon polyps regardless of smoking. Keywords: COPD, colorectal adenomatous polyp, smoking, chronic obstructive pulmonary

Confocal Endomicroscopy of Colorectal Polyps

Directory of Open Access Journals (Sweden)

Vivian M. Ussui

2012-01-01

Full Text Available Confocal laser endomicroscopy (CLE is one of several novel methods that provide real-time, high-resolution imaging at a micron scale via endoscopes. CLE has the potential to be a disruptive technology in that it can change the current algorithms that depend on biopsy to perform surveillance of high-risk conditions. Furthermore, it allows on-table decision making that has the potential to guide therapy in real time and reduce the need for repeated procedures. CLE and related technologies are often termed “virtual biopsy” as they simulate the images seen in traditional histology. However, the imaging of living tissue allows more than just pragmatic convenience; it also allows imaging of living tissue such as active capillary circulation, cellular death, and vascular and endothelial translocation, thus extending beyond what is capable in traditional biopsy. Immediate potential applications of CLE are to guide biopsy sampling in Barrett's esophagus and inflammatory bowel disease surveillance, evaluation of colorectal polyps, and intraductal imaging of the pancreas and bile duct. Data on these applications is rapidly emerging, and more is needed to clearly demonstrate the optimal applications of CLE. In this paper, we will focus on the role of CLE as applied to colorectal polyps detected during colonoscopy.

Degradation of poly(2,6-dimethylphenylene oxide) and poly(phenylene sulfide) by gamma irradiation

International Nuclear Information System (INIS)

Hill, D.J.T.; Hunter, D.S.; Lewis, D.A.; O'Donnell, J.H.; Pomery, P.J.

1990-01-01

Electron spin resonance (ESR) spectroscopy and volatile product analysis have been used to examine the degradation of poly[oxy(2,6-dimethyl-1,4-phenylene)], PPO, and poly(thio-1,4-phenylene), PPS, by γ-radiation. Radiation chemical yields (G-values) for trapped radicals were 0.60 and 0.16 after irradiation at 77 K, and 0.33 and 0.04 after irradiation at 300 K, for PPO and PPS, respectively. The ESR spectra of PPO can be analyzed in terms of PhO·, PhCH 2 · and cyclohexadienyl radicals, whereas PPS contained predominantly photobleachable radical ions. G(H 2 ) = 0.08 and G(CH 4 ) = 0.015 for PPO irradiated at 300 K: G(H 2 ) = 0.03 for PPS. The radicals in PPO indicate main-chain scission of the Ph-O bond and loss of H from CH 3 in equal amounts. The radical ions in PPS decayed without the formation of neutral radicals indicating little bond scission and extremely high radiation resistance, which is confirmed by the low G(R) and G(H 2 ) values. (author)

The Fibroepithelial Polyp of the Urethra: A Rare Cause of Urinary Terention In Children

Directory of Open Access Journals (Sweden)

Nihat Uluocak

2012-10-01

Full Text Available Benign fibroepithelial polyp of the prostatic urethra is a rare congenital lesion. It is most commonly diagnosed in the pediatric population and causes various urinary symptoms. In this case report, we presented a thirteen months old boy with a posterior urethral polyp who admitted to our clinic with complaints of obstructive urinary symptoms. An obstructing mass extending from bladder neck to prostatic urethra was seen in endoscopy. The lesion was completely removed by transure-thral resection. Pathological evaluation of the specimen revealed fibroepithelial polyp of the urethra. At postoperative follow up periods no complications of mic-turition at control examinations.

Intravenous, contrast-enhanced MR colonography using air as endoluminal contrast agent: Impact on colorectal polyp detection.

LENUS (Irish Health Repository)

Keeling, Aoife N

2012-02-01

PURPOSE: To compare diagnostic accuracy and patient tolerance of MR colonography with intravenous contrast and luminal air (MRC) to conventional colonoscopy (CC). MATERIALS AND METHODS: IRB approval and written informed consent were obtained. Forty-six patients, both screening and symptomatic, underwent MRC followed by CC. The MRC technique employed 3D T1W spoiled gradient echo sequences performed after the administration of gadopenetate dimeglumine, with parallel imaging. The diagnostic accuracy and tolerance of patients for MRC was compared to CC. RESULTS: Twenty-four polyps were detected in eighteen patients with CC (5 polyps >\\/=10mm, 4 polyps 6-9mm, 15 polyps <\\/=5mm). MRC was 66.7% (12\\/18) sensitive and 96.4% (27\\/28) specific for polyp detection on a per-patient basis. When analyzed by polyp size, sensitivity and specificity of MRC was 100% (5\\/5) and 100% (19\\/19), respectively, for lesions greater than 10mm, 100% (4\\/4) and 100% (20\\/20) for lesions 6-9mm, and sensitivity of 20% (3\\/15) lesions less than 5mm. The sensitivity and specificity of MRC for detecting significant lesions (>6mm) was 100% (9\\/9) and 100% (15\\/15), respectively. Regarding tolerance of the exams, there were no significant differences between MRC and CC. Thirty-five percent (n=16) of patients preferred MRC as a future screening test compared to 33% (n=15) for CC. CONCLUSION: MRC using air as an intraluminal contrast agent is a feasible and well-tolerated technique for detecting colonic polyps >\\/=6mm in size. Further studies are warranted.

Intravenous, contrast-enhanced MR colonography using air as endoluminal contrast agent: Impact on colorectal polyp detection.

LENUS (Irish Health Repository)

Keeling, Aoife N

2010-12-03

PURPOSE: To compare diagnostic accuracy and patient tolerance of MR colonography with intravenous contrast and luminal air (MRC) to conventional colonoscopy (CC). MATERIALS AND METHODS: IRB approval and written informed consent were obtained. Forty-six patients, both screening and symptomatic, underwent MRC followed by CC. The MRC technique employed 3D T1W spoiled gradient echo sequences performed after the administration of gadopenetate dimeglumine, with parallel imaging. The diagnostic accuracy and tolerance of patients for MRC was compared to CC. RESULTS: Twenty-four polyps were detected in eighteen patients with CC (5 polyps ≥10mm, 4 polyps 6-9mm, 15 polyps ≤5mm). MRC was 66.7% (12\\/18) sensitive and 96.4% (27\\/28) specific for polyp detection on a per-patient basis. When analyzed by polyp size, sensitivity and specificity of MRC was 100% (5\\/5) and 100% (19\\/19), respectively, for lesions greater than 10mm, 100% (4\\/4) and 100% (20\\/20) for lesions 6-9mm, and sensitivity of 20% (3\\/15) lesions less than 5mm. The sensitivity and specificity of MRC for detecting significant lesions (>6mm) was 100% (9\\/9) and 100% (15\\/15), respectively. Regarding tolerance of the exams, there were no significant differences between MRC and CC. Thirty-five percent (n=16) of patients preferred MRC as a future screening test compared to 33% (n=15) for CC. CONCLUSION: MRC using air as an intraluminal contrast agent is a feasible and well-tolerated technique for detecting colonic polyps ≥6mm in size. Further studies are warranted.

Detection of flat colorectal polyps at screening CT colonography in comparison with conventional polypoid lesions

Energy Technology Data Exchange (ETDEWEB)

Sakamoto, Takashi; Urata, Joji [Diagnostic Imaging Center, Saiseikai Kumamoto Hospital, Kumamoto (Japan); Mitsuzaki, Katsuhiko; Matsuda, Katsuhiko; Kawakami, Megumi [Medical Examination Center, Saiseikai Kumamoto Hospital, Kumamoto (Japan); Utsunomiya, Daisuke; Yamamura, Sadahiro; Yamashita, Yasuyuki [Diagnostic Radiology, Faculty of Life Sciences, Kumamoto Univ., Kumamoto (Japan)], e-mail: utsunomi@kumamoto-u.ac.jp

2012-09-15

Background: Although the screening of small, flat polyps is clinically important, the role of CT colonography (CTC) screening in their detection has not been thoroughly investigated. Purpose: To evaluate the detection capability and usefulness of CTC in the screening of flat and polypoid lesions by comparing CTC with optic colonoscopy findings as the gold standard. Material and Methods: We evaluated the CTC detection capability for flat colorectal polyps with a flat surface and a height not exceeding 3 mm (n = 42) by comparing to conventional polypoid lesions (n = 418) according to the polyp diameter. Four types of reconstruction images including multiplanar reconstruction, volume rendering, virtual gross pathology, and virtual endoscopic images were used for visual analysis. We compared the abilities of the four reconstructions for polyp visualization. Results: Detection sensitivity for flat polyps was 31.3 %, 44.4 %, and 87.5 % for lesions measuring 2-3 mm, 4-5 mm, and {>=}6 mm, respectively; the corresponding sensitivity for polypoid lesions was 47.6 %, 79.0 %, and 91.7 %. The overall sensitivity for flat lesions (47.6%) was significantly lower than polypoid lesions (64.1%). Virtual endoscopic imaging showed best visualization among the four reconstructions. Colon cancers were detected in eight patients by optic colonoscopy, and CTC detected colon cancers in all eight patients. Conclusion: CTC using 64-row multidetector CT is useful for colon cancer screening to detect colorectal polyps while the detection of small, flat lesions is still challenging.

Foods and food groups associated with the incidence of colorectal polyps: the Adventist Health Study.

Science.gov (United States)

Tantamango, Yessenia M; Knutsen, Synnove F; Beeson, W Lawrence; Fraser, Gary; Sabate, Joan

2011-01-01

Colorectal cancer (CRC) is a leading cause of cancer death in the United States. The majority of CRC arise in adenomatous polyps and 25-35% of colon adenoma risk could be avoidable by modifying diet and lifestyle habits. We assessed the association between diet and the risk of self-reported physician-diagnosed colorectal polyps among 2,818 subjects who had undergone colonoscopy. Subjects participated in 2 cohort studies: the AHS-1 in 1976 and the AHS-2 from 2002-2005. Multivariate logistic regression analysis was used to estimate the period risk of incident cases of polyps; 441 cases of colorectal polyps were identified. Multivariate analysis adjusted by age, sex, body mass index, and education showed a protective association with higher frequency of consumption of cooked green vegetables (OR 1 time/d vs. Consumption of legumes at least 3 times/wk reduced the risk by 33% after adjusting for meat intake. Consumption of brown rice at least 1 time/wk reduced the risk by 40%. These associations showed a dose-response effect. High frequency of consumption of cooked green vegetables, dried fruit, legumes, and brown rice was associated with a decreased risk of colorectal polyps.

Polyp morphology: an interobserver evaluation for the Paris classification among international experts.

Science.gov (United States)

van Doorn, Sascha C; Hazewinkel, Y; East, James E; van Leerdam, Monique E; Rastogi, Amit; Pellisé, Maria; Sanduleanu-Dascalescu, Silvia; Bastiaansen, Barbara A J; Fockens, Paul; Dekker, Evelien

2015-01-01

The Paris classification is an international classification system for describing polyp morphology. Thus far, the validity and reproducibility of this classification have not been assessed. We aimed to determine the interobserver agreement for the Paris classification among seven Western expert endoscopists. A total of 85 short endoscopic video clips depicting polyps were created and assessed by seven expert endoscopists according to the Paris classification. After a digital training module, the same 85 polyps were assessed again. We calculated the interobserver agreement with a Fleiss kappa and as the proportion of pairwise agreement. The interobserver agreement of the Paris classification among seven experts was moderate with a Fleiss kappa of 0.42 and a mean pairwise agreement of 67%. The proportion of lesions assessed as "flat" by the experts ranged between 13 and 40% (Pagreement did not change (kappa 0.38, pairwise agreement 60%). Our study is the first to validate the Paris classification for polyp morphology. We demonstrated only a moderate interobserver agreement among international Western experts for this classification system. Our data suggest that, in its current version, the use of this classification system in daily practice is questionable and it is unsuitable for comparative endoscopic research. We therefore suggest introduction of a simplification of the classification system.

Polyp Detection, Characterization, and Management Using Narrow-Band Imaging with/without Magnification

Directory of Open Access Journals (Sweden)

Takahiro Utsumi

2015-11-01

Full Text Available Narrow-band imaging (NBI is a new imaging technology that was developed in 2006 and has since spread worldwide. Because of its convenience, NBI has been replacing the role of chromoendoscopy. Here we review the efficacy of NBI with/without magnification for detection, characterization, and management of colorectal polyps, and future perspectives for the technology, including education. Recent studies have shown that the next-generation NBI system can detect significantly more colonic polyps than white light imaging, suggesting that NBI may become the modality of choice from the beginning of screening. The capillary pattern revealed by NBI, and the NBI International Colorectal Endoscopic classification are helpful for prediction of histology and for estimating the depth of invasion of colorectal cancer. However, NBI with magnifying colonoscopy is not superior to magnifying chromoendoscopy for estimation of invasion depth. Currently, therefore, chromoendoscopy should also be performed additionally if deep submucosal invasive cancer is suspected. If endoscopists become able to accurately estimate colorectal polyp pathology using NBI, this will allow adenomatous polyps to be resected and discarded; thus, reducing both the risk of polypectomy and costs. In order to achieve this goal, a suitable system for education and training in in vivo diagnostics will be necessary.

Multi-detector row CT colonography: effect of collimation, pitch, and orientation on polyp detection in a human colectomy specimen.

Science.gov (United States)

Taylor, Stuart A; Halligan, Steve; Bartram, Clive I; Morgan, Paul R; Talbot, Ian C; Fry, Nicola; Saunders, Brian P; Khosraviani, Kirosh; Atkin, Wendy

2003-10-01

To investigate the effects of orientation, collimation, pitch, and tube current setting on polyp detection at multi-detector row computed tomographic (CT) colonography and to determine the optimal combination of scanning parameters for screening. A colectomy specimen containing 117 polyps of different sizes was insufflated and imaged with a multi-detector row CT scanner at various collimation (1.25 and 2.5 mm), pitch (3 and 6), and tube current (50, 100, and 150 mA) settings. Two-dimensional multiplanar reformatted images and three-dimensional endoluminal surface renderings from the 12 resultant data sets were examined by one observer for the presence and conspicuity of polyps. The results were analyzed with Poisson regression and logistic regression to determine the effects of scanning parameters and of specimen orientation on polyp detection. The percentage of polyps that were detected significantly increased when collimation (P =.008) and table feed (P =.03) were decreased. Increased tube current resulted in improved detection only of polyps with a diameter of less than 5 mm. Polyps of less than 5 mm were optimally depicted with a collimation of 1.25 mm, a pitch of 3, and a tube current setting of 150 mA; polyps with a diameter greater than 5 mm were adequately depicted with 1.25-mm collimation and with either pitch setting and any of the three tube current settings. Small polyps in the transverse segment (positioned at a 90 degrees angle to the z axis of scanning) were significantly less visible than those in parallel or oblique orientations (P detector row CT is highly dependent on collimation, pitch, and, to a lesser extent, tube current. Collimation of 1.25 mm, combined with pitch of 6 and tube current of 50 mA, provides for reliable detection of polyps 5 mm or larger while limiting the effective radiation dose. Polyps smaller than 5 mm, however, may be poorly depicted with use of these settings in the transverse colon. Copyright RSNA, 2003

Clinical evaluation of endoscopic trimodal imaging for the detection and differentiation of colonic polyps.

Science.gov (United States)

van den Broek, Frank J C; Fockens, Paul; Van Eeden, Susanne; Kara, Mohammed A; Hardwick, James C H; Reitsma, Johannes B; Dekker, Evelien

2009-03-01

Endoscopic trimodal imaging (ETMI) incorporates high-resolution endoscopy (HRE) and autofluorescence imaging (AFI) for adenoma detection, and narrow-band imaging (NBI) for differentiation of adenomas from nonneoplastic polyps. The aim of this study was to compare AFI with HRE for adenoma detection and to assess the diagnostic accuracy of NBI for differentiation of polyps. This was a randomized trial of tandem colonoscopies. The study was performed at the Academic Medical Center in Amsterdam. One hundred patients underwent colonoscopy with ETMI. Each colonic segment was examined twice for polyps, once with HRE and once with AFI, in random order per patient. All detected polyps were assessed with NBI for pit pattern and with AFI for color, and subsequently removed. Histopathology served as the gold standard for diagnosis. The main outcome measures of this study were adenoma miss-rates of AFI and HRE, and diagnostic accuracy of NBI and AFI for differentiating adenomas from nonneoplastic polyps. Among 50 patients examined with AFI first, 32 adenomas were detected initially. Subsequent inspection with HRE identified 8 additional adenomas. Among 50 patients examined with HRE first, 35 adenomas were detected initially. Successive AFI yielded 14 additional adenomas. The adenoma miss-rates of AFI and HRE therefore were 20% and 29%, respectively (P = .351). The sensitivity, specificity, and overall accuracy of NBI for differentiation were 90%, 70%, and 79%, respectively; corresponding figures for AFI were 99%, 35%, and 63%, respectively. The overall adenoma miss-rate was 25%; AFI did not significantly reduce the adenoma miss-rate compared with HRE. Both NBI and AFI had a disappointing diagnostic accuracy for polyp differentiation, although AFI had a high sensitivity.

Efficient p-phenylene based OLEDs with mixed interfacial exciplex emission

International Nuclear Information System (INIS)

Data, P.; Motyka, R.; Lapkowski, M.; Suwinski, J.; Jursenas, S.; Kreiza, G.; Miasojedovas, A.; Monkman, A.P.

2015-01-01

Organic electronics, mainly due to the advancement of OLED (Organic Light Emitting Diode) technology, is a fast developing research area, and has already revolutionized the displays market. This direction presents the use of exciplex emitters and thermally activated delayed fluorescence (TADF) in OLEDs. This is shown through electrochemical characterisation of six p-phenylene derivatives for application in optoelectronic devices and presents the possibility the compounds’ use as OLED emitters. In these OLED devices, it is established that selenophene based compounds with a “heavy-atom effect” can be used as potential emitters when exciplex phenomena are involved.

Registration of central paths and colonic polyps between supine and prone scans in computed tomography colonography: Pilot study

International Nuclear Information System (INIS)

Li Ping; Napel, Sandy; Acar, Burak; Paik, David S.; Jeffrey, R. Brooke Jr.; Beaulieu, Christopher F.

2004-01-01

Computed tomography colonography (CTC) is a minimally invasive method that allows the evaluation of the colon wall from CT sections of the abdomen/pelvis. The primary goal of CTC is to detect colonic polyps, precursors to colorectal cancer. Because imperfect cleansing and distension can cause portions of the colon wall to be collapsed, covered with water, and/or covered with retained stool, patients are scanned in both prone and supine positions. We believe that both reading efficiency and computer aided detection (CAD) of CTC images can be improved by accurate registration of data from the supine and prone positions. We developed a two-stage approach that first registers the colonic central paths using a heuristic and automated algorithm and then matches polyps or polyp candidates (CAD hits) by a statistical approach. We evaluated the registration algorithm on 24 patient cases. After path registration, the mean misalignment distance between prone and supine identical anatomic landmarks was reduced from 47.08 to 12.66 mm, a 73% improvement. The polyp registration algorithm was specifically evaluated using eight patient cases for which radiologists identified polyps separately for both supine and prone data sets, and then manually registered corresponding pairs. The algorithm correctly matched 78% of these pairs without user input. The algorithm was also applied to the 30 highest-scoring CAD hits in the prone and supine scans and showed a success rate of 50% in automatically registering corresponding polyp pairs. Finally, we computed the average number of CAD hits that need to be manually compared in order to find the correct matches among the top 30 CAD hits. With polyp registration, the average number of comparisons was 1.78 per polyp, as opposed to 4.28 comparisons without polyp registration

Metastatic Carcinoma Occurring in a Gastric Hyperplastic Polyp Mimicking Primary Gastric Cancer: The First Reported Case

Directory of Open Access Journals (Sweden)

Gabriel M. Groisman

2014-01-01

Full Text Available Hyperplastic polyps of the stomach are regarded as benign. However, in rare cases they may contain incipient primary carcinomas. To our knowledge, breast carcinoma metastatic to a gastric hyperplastic polyp has not yet been reported. We describe the case of a 69-year-old woman to whom a gastric polyp was endoscopically excised. The patient had previously undergone a right mastectomy for mixed, invasive ductal and lobular carcinoma 5 years earlier. Histological sections from the gastric lesion showed typical features of hyperplastic polyp with foci of poorly differentiated adenocarcinoma including signet ring cells infiltrating the lamina propria. The histologic findings were consistent with a primary gastric cancer. However, the carcinoma cells were immunopositive for estrogen and progesterone receptors and GATA3 and negative for CDX2, Hep Par 1, and MUC5AC. E-cadherin showed membranous reactivity in some of the carcinoma cells while in others it was negative. Accordingly, metastatic mixed, lobular and ductal breast carcinoma was diagnosed. We conclude that metastatic adenocarcinoma mimicking primary gastric cancer can be rarely encountered in hyperplastic gastric polyps.

Computer-assisted detection of colonic polyps with CT colonography using neural networks and binary classification trees

International Nuclear Information System (INIS)

Jerebko, Anna K.; Summers, Ronald M.; Malley, James D.; Franaszek, Marek; Johnson, C. Daniel

2003-01-01

Detection of colonic polyps in CT colonography is problematic due to complexities of polyp shape and the surface of the normal colon. Published results indicate the feasibility of computer-aided detection of polyps but better classifiers are needed to improve specificity. In this paper we compare the classification results of two approaches: neural networks and recursive binary trees. As our starting point we collect surface geometry information from three-dimensional reconstruction of the colon, followed by a filter based on selected variables such as region density, Gaussian and average curvature and sphericity. The filter returns sites that are candidate polyps, based on earlier work using detection thresholds, to which the neural nets or the binary trees are applied. A data set of 39 polyps from 3 to 25 mm in size was used in our investigation. For both neural net and binary trees we use tenfold cross-validation to better estimate the true error rates. The backpropagation neural net with one hidden layer trained with Levenberg-Marquardt algorithm achieved the best results: sensitivity 90% and specificity 95% with 16 false positives per study

Effects of Surgery on the Phonation Threshold Pressure in Patients With Vocal Fold Polyps

Directory of Open Access Journals (Sweden)

Tyng-Guey Wang

2010-01-01

Conclusion: Laryngomicrosurgery can lower PTP in patients with vocal fold polyps and improve the ease of phonation. PTP is one of the objective measurements for assessing the effects of surgery in patients with vocal fold polyps. Use of an accelerometer to detect vocal fold vibration improved the measurement of PTP.

Nanomechanical testing of circular freestanding polymer films with sub-micron thickness

International Nuclear Information System (INIS)

Maner, Kyle C.; Begley, Matthew R.; Oliver, Warren C.

2004-01-01

This paper describes techniques to create freestanding films over perfectly circular spans (windows) and measure their mechanical properties using instrumented nanoindentation. Test samples were created by spin-casting polymer films over glass plates with embedded fibers, which were subsequently etched using a relatively weak acid to leave freestanding circular spans. The freestanding spans were tested using an instrumented nanoindenter over a wide range of applied loads and displacements. Material properties can be extracted from measured load-deflection responses using straightforward models for point-loads on circular plates or membranes. Results are presented for poly(methyl methacrylate) and poly(2,6,dimethyl,1,4,phenylene ether) films with thickness ranging from 350 to 750 nm. The properties derived from freestanding tests are compared with traditional nanoindentation of films on intact substrates. The freestanding approach has key advantages for characterizing micron-scale behavior of compliant materials, notably greater ease and applicability of sample preparation over other micro-fabrication techniques and straightforward analytical or numerical models

The CIMP Phenotype in BRAF Mutant Serrated Polyps from a Prospective Colonoscopy Patient Cohort

Directory of Open Access Journals (Sweden)

Winnie C. Fernando

2014-01-01

Full Text Available Colorectal cancers arising via the serrated pathway are often associated with BRAF V600E mutation, CpG island methylator phenotype (CIMP, and microsatellite instability. Previous studies have shown a strong association between BRAF V600E mutation and serrated polyps. This study aims to evaluate CIMP status of all the serrated polyp subtypes and its association with functionally important genes such as MLH1, p16, and IGFBP7. CIMP status and methylation were evaluated using the real-time based MethyLight assay in 154 serrated polyps and 63 conventional adenomas. Results showed that CIMP-high serrated polyps were strongly associated with BRAF mutation and proximal colon. CIMP-high was uncommon in conventional adenomas (1.59%, occurred in 8.25% of hyperplastic polyps (HPs, and became common in sessile serrated adenomas (SSAs (51.43%. MLH1 methylation was mainly observed in the proximal colon and was significantly associated with BRAF mutation and CIMP-high. The number of samples methylated for p16 and IGFBP7 was the highest in SSAs. The methylation panel we used to detect CIMP is highly specific for CIMP-high cancers. With this panel, we demonstrate that CIMP-high is much more common in SSAs than HPs. This suggests that CIMP-high correlates with increased risk of malignant transformation which was also observed in methylation of functionally important genes.

The CIMP Phenotype in BRAF Mutant Serrated Polyps from a Prospective Colonoscopy Patient Cohort.

Science.gov (United States)

Fernando, Winnie C; Miranda, Mariska S; Worthley, Daniel L; Togashi, Kazutomo; Watters, Dianne J; Leggett, Barbara A; Spring, Kevin J

2014-01-01

Colorectal cancers arising via the serrated pathway are often associated with BRAF V600E mutation, CpG island methylator phenotype (CIMP), and microsatellite instability. Previous studies have shown a strong association between BRAF V600E mutation and serrated polyps. This study aims to evaluate CIMP status of all the serrated polyp subtypes and its association with functionally important genes such as MLH1, p16, and IGFBP7. CIMP status and methylation were evaluated using the real-time based MethyLight assay in 154 serrated polyps and 63 conventional adenomas. Results showed that CIMP-high serrated polyps were strongly associated with BRAF mutation and proximal colon. CIMP-high was uncommon in conventional adenomas (1.59%), occurred in 8.25% of hyperplastic polyps (HPs), and became common in sessile serrated adenomas (SSAs) (51.43%). MLH1 methylation was mainly observed in the proximal colon and was significantly associated with BRAF mutation and CIMP-high. The number of samples methylated for p16 and IGFBP7 was the highest in SSAs. The methylation panel we used to detect CIMP is highly specific for CIMP-high cancers. With this panel, we demonstrate that CIMP-high is much more common in SSAs than HPs. This suggests that CIMP-high correlates with increased risk of malignant transformation which was also observed in methylation of functionally important genes.

Poly-P storage by natural biofilms in streams with varying biogeochemistry

Science.gov (United States)

Carrick, H. J.

2015-12-01

Anthropogenic inputs of nitrogen (N) and phosphorus (P) have increased in many watersheds throughout the world; these inputs have been linked to the eutrophication of inland and coastal waters worldwide. We selected and surveyed 20, third-order streams that supported a range of water column biogeochemical conditions (conductivity, nutrient concentrations) located in the mid-Atlantic region, USA. Biofilm biomass, algal taxonomic composition, and nutrient stoichiometry (C, N, P, and poly-P) were measured at all stream sites. Pulse-amplitude modulation fluorometry (PAM) was used to estimate photosynthetic parameters for stream biofilms (e.g., alpha, Pmax), while microbiology techniques were used to verify poly-P storage by pro- and eukaryotic components of the biofilm (e.g., epi-fluorescent staining). As anticipated, chlorophyll ranged over 2 orders of magnitude among the streams (range 10-1,000 mg/m2). Biofilm chlorophyll and algal biovolume levels increased with water column nutrient contents, while the C:P ratio within the biofilm decreased. Both pro and eukaryotic organisms were present in resident biofilms and actively stored intracellular poly-P. Finally, the rate of photosynthetic within the biofilms appeared to be driven the nutritional condition of the biofilms; pmax and alpha values increased with significantly with stream biofilm poly-P content (r2 = 0.35 and 0.44, respectively). These results indicated that where nutrients are plentiful, biofilms P storage is favored, and this is likely a key regulator of stream biofilm biomass and productivity.

Template-free electrosynthesis of aligned poly(p-phenylene) microtubules

Institute of Scientific and Technical Information of China (English)

无

2003-01-01

Poly(p-phenylene) (PPP) microtubules with diameters of 0.2-0.8μm and lengths of～10 (m have been synthesized by direct oxidation of benzene in the mixed electrolyte of boron trifluoride diethyl etherate (BFEE) and trifluoroacetic acid (TFA) (BFEE:TFA= 2:1, by volume), containing a certain amount of sodium dodecylbenzene- sulfonate (SDBS) as surfactant. The microtubules were grown vertically on the working electrode surface. The tubular morphology has been confirmed by scanning and transmission electron microscopies and the chain structure of the skin of the tubules has been characterized by Raman spectroscopy. The electrode property, monomer/surfactant molar ratio and the value of applied potential have strong effects on the morphology of the microtubules.

Heterogeneous ion-exchange polyethylene-based membranes with sulfonated poly(1,4-phenylene sulfide) particles

Czech Academy of Sciences Publication Activity Database

Schauer, Jan; Brožová, Libuše; Pientka, Zbyněk; Bouzek, K.

2006-01-01

Roč. 200, 1-3 (2006), s. 632-633 ISSN 0011-9164. [Conference Euromembrane. Giardini Naxos - Taormina, 24.09.2006-28.09.2006] R&D Projects: GA ČR GA203/05/0080 Institutional research plan: CEZ:AV0Z40500505 Keywords : ion-exchange membrane * poly(phenylene sulfide) * fuel cell Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.917, year: 2006

Energy Level Tuning of Poly(phenylene-alt-dithienobenzothiadiazole)s for Low Photon Energy Loss Solar Cells.

Science.gov (United States)

Heuvel, Ruurd; van Franeker, Jacobus J; Janssen, René A J

2017-03-01

Six poly(phenylene- alt -dithienobenzothiadiazole)-based polymers have been synthesized for application in polymer-fullerene solar cells. Hydrogen, fluorine, or nitrile substitution on benzo-thiadiazole and alkoxy or ester substitution on the phenylene moiety are investigated to reduce the energy loss per converted photon. Power conversion efficiencies (PCEs) up to 6.6% have been obtained. The best performance is found for the polymer-fullerene combination with distinct phase separation and crystalline domains. This improves the maximum external quantum efficiency for charge formation and collection to 66%. The resulting higher photocurrent compensates for the relatively large energy loss per photon ( E loss = 0.97 eV) in achieving a high PCE. By contrast, the poly-mer that provides a reduced energy loss ( E loss = 0.49 eV) gives a lower photocurrent and a reduced PCE of 1.8% because the external quantum efficiency of 17% is limited by a suboptimal morphology and a reduced driving force for charge transfer.

Gallbladder Polyps: An Ambiguous Cause of Biliary Colic

African Journals Online (AJOL)

However, ultrasonography revealed multiple hyperechoic mass lesions protruding in the gallbladder lumen suggestive of gallbladder polyps [Figure 1], largest one measured 8.2 mm [Figure 2]. Subsequently, the patient underwent conventional 4-port laparoscopic cholecystectomy. Histopathology revealed the benign ...

The prevalence of high dysplastic colonic adenomatous polyps in a 3 year endoscopic retrospective study from a single clinical center

Directory of Open Access Journals (Sweden)

Alexandru C. Septimiu

2017-04-01

Full Text Available Introduction: Many colon neoplastic tumors come from the malignancy of adenomatous polyps (70%-90% that were not timely diagnosed in order to be resected. Materials and Methods: We conducted a retrospective study regarding the incidence of adenomatous polyps during 1.000 consecutive colonoscopies performed in our Upper and Lower Digestive Endoscopy Laboratory during a three-year period. Results: During these colonoscopies, some targeted polyps were biopsied or completely removed and the samples had been sent to a complete anatomopathological examination. Taking into consideration the results, the polyps were classified after the histological type and the form of dysplasia, in order to determine the polyp forms that present a high risk of malignancy. Conclusion: Given the rather high frequency of malignant polyps discovered during our study, we highly recommend colonoscopy as a method of choice for routine monitoring of selected cases.

The Assessment of the Colo-rectal Polyps in Order to the New Diagnostic and Therapeutic Strategies

Directory of Open Access Journals (Sweden)

Raluca Diac Andreea

2015-09-01

Full Text Available Objective. Assessment of the histological and endoscopic features of the colo-rectal polyps is requered for the application of the new diagnostic and therapeutical strategies in the managment of the diminutive polyps.

Drug Combo Decreases Colorectal Polyps in People with FAP

Science.gov (United States)

In people with familial adenomatous polyposis, or FAP, a combination treatment of erlotinib (Tarceva) and sulindac (Aflodac) decreased the number of precancerous colorectal polyps, according to recently published clinical trial results.

Automated image-based colon cleansing for laxative-free CT colonography computer-aided polyp detection

International Nuclear Information System (INIS)

Linguraru, Marius George; Panjwani, Neil; Fletcher, Joel G.; Summer, Ronald M.

2011-01-01

Purpose: To evaluate the performance of a computer-aided detection (CAD) system for detecting colonic polyps at noncathartic computed tomography colonography (CTC) in conjunction with an automated image-based colon cleansing algorithm. Methods: An automated colon cleansing algorithm was designed to detect and subtract tagged-stool, accounting for heterogeneity and poor tagging, to be used in conjunction with a colon CAD system. The method is locally adaptive and combines intensity, shape, and texture analysis with probabilistic optimization. CTC data from cathartic-free bowel preparation were acquired for testing and training the parameters. Patients underwent various colonic preparations with barium or Gastroview in divided doses over 48 h before scanning. No laxatives were administered and no dietary modifications were required. Cases were selected from a polyp-enriched cohort and included scans in which at least 90% of the solid stool was visually estimated to be tagged and each colonic segment was distended in either the prone or supine view. The CAD system was run comparatively with and without the stool subtraction algorithm. Results: The dataset comprised 38 CTC scans from prone and/or supine scans of 19 patients containing 44 polyps larger than 10 mm (22 unique polyps, if matched between prone and supine scans). The results are robust on fine details around folds, thin-stool linings on the colonic wall, near polyps and in large fluid/stool pools. The sensitivity of the CAD system is 70.5% per polyp at a rate of 5.75 false positives/scan without using the stool subtraction module. This detection improved significantly (p = 0.009) after automated colon cleansing on cathartic-free data to 86.4% true positive rate at 5.75 false positives/scan. Conclusions: An automated image-based colon cleansing algorithm designed to overcome the challenges of the noncathartic colon significantly improves the sensitivity of colon CAD by approximately 15%.

Most bowel cancer symptoms do not indicate colorectal cancer and polyps: a systematic review

Directory of Open Access Journals (Sweden)

Chan Siew F

2011-05-01

Full Text Available Abstract Background Bowel symptoms are often considered an indication to perform colonoscopy to identify or rule out colorectal cancer or precancerous polyps. Investigation of bowel symptoms for this purpose is recommended by numerous clinical guidelines. However, the evidence for this practice is unclear. The objective of this study is to systematically review the evidence about the association between bowel symptoms and colorectal cancer or polyps. Methods We searched the literature extensively up to December 2008, using MEDLINE and EMBASE and following references. For inclusion in the review, papers from cross sectional, case control and cohort studies had to provide a 2×2 table of symptoms by diagnosis (colorectal cancer or polyps or sufficient data from which that table could be constructed. The search procedure, quality appraisal, and data extraction was done twice, with disagreements resolved with another reviewer. Summary ROC analysis was used to assess the diagnostic performance of symptoms to detect colorectal cancer and polyps. Results Colorectal cancer was associated with rectal bleeding (AUC 0.66; LR+ 1.9; LR- 0.7 and weight loss (AUC 0.67, LR+ 2.5, LR- 0.9. Neither of these symptoms was associated with the presence of polyps. There was no significant association of colorectal cancer or polyps with change in bowel habit, constipation, diarrhoea or abdominal pain. Neither the clinical setting (primary or specialist care nor study type was associated with accuracy. Most studies had methodological flaws. There was no consistency in the way symptoms were elicited or interpreted in the studies. Conclusions Current evidence suggests that the common practice of performing colonoscopies to identify cancers in people with bowel symptoms is warranted only for rectal bleeding and the general symptom of weight loss. Bodies preparing guidelines for clinicians and consumers to improve early detection of colorectal cancer need to take into

Invasive adenocarcinoma arising from a mixed hyperplastic/adenomatous polyp and synchronous transverse colon cancer.

Science.gov (United States)

Chen, Chuang-Wei; Hsiao, Koung-Hong; Yue, Chung-Tai; Wang, Chia-Chi

2013-08-28

An admixture of hyperplastic and adenomatous components within the same polyp is unusual. Adenocarcinoma arising from a mixed hyperplastic/adenomatous polyp (MHAP) occurs even more rarely. We report the first case of a 59-year-old male who presented with invasive adenocarcinoma originating from a MHAP at a sigmoid colon and synchronous transverse colon cancer.

Invasive adenocarcinoma arising from a mixed hyperplastic/adenomatous polyp and synchronous transverse colon cancer

OpenAIRE

Chen, Chuang-Wei; Hsiao, Koung-Hong; Yue, Chung-Tai; Wang, Chia-Chi

2013-01-01

An admixture of hyperplastic and adenomatous components within the same polyp is unusual. Adenocarcinoma arising from a mixed hyperplastic/adenomatous polyp (MHAP) occurs even more rarely. We report the first case of a 59-year-old male who presented with invasive adenocarcinoma originating from a MHAP at a sigmoid colon and synchronous transverse colon cancer.

Polyp prevalence at colonoscopy among Nigerians: A prospective ...

African Journals Online (AJOL)

Polyp prevalence at colonoscopy among Nigerians: A prospective observational study. ... Materials and Methods: This is a prospective study of all colonoscopy examinations performed at the endoscopy unit of our hospital from January, 2007 to December 2013. The patient demographics, indications for colonoscopy, ...

Association of meat intake and meat-derived mutagen exposure with the risk of colorectal polyps by histologic type

Science.gov (United States)

Fu, Zhenming; Shrubsole, Martha J.; Smalley, Walter E.; Wu, Huiyun; Chen, Zhi; Shyr, Yu; Ness, Reid M.; Zheng, Wei

2011-01-01

Background The association of meat intake and meat-derived mutagens with colorectal tumor risk remains unclear. We evaluated this hypothesis in a large colonoscopy-based case-control study. Methods Included in the study were 2,543 polyp patients [(1,881 with adenomas, and 622 with hyperplastic polyp (HPP)] and 3,764 polyp-free controls. Surveys obtained information about meat intake by cooking methods and doneness levels plus other suspected or known risk factors for colorectal tumors. Unconditional logistic regression was used to derive odds ratios (ORs) after adjusting for potential confounders. Results High intake of red meat and processed meat (P-trend meat cooked using high-temperature cooking methods (P-trend ≤ 0.01), was associated with an elevated risk for colorectal polyps. A significant positive association between exposures to meat-derived heterocyclic amines and risk of polyps was found for both adenomas and hyperplastic polyps. Furthermore, the positive association with red-meat intake and heterocyclic amine exposure was stronger for multiple adenomas than single adenoma and serrated than non-serrated adenomas. Conclusion This study supports a role for red meat and meat-derived mutagen exposure in the development of colorectal tumor. PMID:21803984

Diagnostic accuracy of transabdominal high-resolution US for staging gallbladder cancer and differential diagnosis of neoplastic polyps compared with EUS.

Science.gov (United States)

Lee, Jeong Sub; Kim, Jung Hoon; Kim, Yong Jae; Ryu, Ji Kon; Kim, Yong-Tae; Lee, Jae Young; Han, Joon Koo

2017-07-01

To compare the diagnostic accuracy of transabdominal high-resolution ultrasound (HRUS) for staging gallbladder cancer and differential diagnosis of neoplastic polyps compared with endoscopic ultrasound (EUS) and pathology. Among 125 patients who underwent both HRUS and EUS, we included 29 pathologically proven cancers (T1 = 7, T2 = 19, T3 = 3) including 15 polypoid cancers and 50 surgically proven polyps (neoplastic = 30, non-neoplastic = 20). We reviewed formal reports and assessed the accuracy of HRUS and EUS for diagnosing cancer as well as the differential diagnosis of neoplastic polyps. Statistical analyses were performed using chi-square tests. The sensitivity, specificity, PPV, and NPV for gallbladder cancer were 82.7 %, 44.4 %, 82.7 %, and 44 % using HRUS and 86.2 %, 22.2 %, 78.1 %, and 33.3 % using EUS. HRUS and EUS correctly diagnosed the stage in 13 and 12 patients. The sensitivity, specificity, PPV, and NPV for neoplastic polyps were 80 %, 80 %, 86 %, and 73 % using HRUS and 73 %, 85 %, 88 %, and 69 % using EUS. Single polyps (8/20 vs. 21/30), larger (1.0 ± 0.28 cm vs. 1.9 ± 0.85 cm) polyps, and older age (52.5 ± 13.2 vs. 66.1 ± 10.3 years) were common in neoplastic polyps (p diagnostic accuracy for GB cancer compared with EUS. • HRUS and EUS showed similar diagnostic accuracy for differentiating neoplastic polyps. • Single, larger polyps and older age were common in neoplastic polyps. • HRUS is less invasive compared with EUS.

A role for the epidermal growth factor receptor signaling in development of intestinal serrated polyps in mice and humans.

Science.gov (United States)

Bongers, Gerold; Muniz, Luciana R; Pacer, Michelle E; Iuga, Alina C; Thirunarayanan, Nanthakumar; Slinger, Erik; Smit, Martine J; Reddy, E Premkumar; Mayer, Lloyd; Furtado, Glaucia C; Harpaz, Noam; Lira, Sergio A

2012-09-01

Epithelial cancers can be initiated by activating mutations in components of the mitogen-activated protein kinase signaling pathway such as v-raf murine sarcoma viral oncogene homolog B1 (BRAF), v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS), or epidermal growth factor receptor (EGFR). Human intestinal serrated polyps are a heterogeneous group of benign lesions, but some progress to colorectal cancer. Tumors that arise from these polyps frequently contain activating mutations in BRAF or KRAS, but little is known about the role of EGFR activation in their development. Polyp samples were obtained from adults during screening colonoscopies at Mount Sinai Hospital in New York. We measured levels of EGFR protein and phosphorylation in human serrated polyps by immunohistochemical and immunoblot analyses. We generated transgenic mice that express the ligand for EGFR, Heparin-binding EGF-like growth factor (HB-EGF), in the intestine. EGFR and the extracellular-regulated kinases (ERK)1/2 were phosphorylated in serrated areas of human hyperplastic polyps (HPPs), sessile serrated adenomas, and traditional serrated adenomas. EGFR and ERK1/2 were phosphorylated in the absence of KRAS or BRAF activating mutations in a subset of HPP. Transgenic expression of the EGFR ligand HB-EGF in the intestines of mice promoted development of small cecal serrated polyps. Mice that expressed a combination of HB-EGF and US28 (a constitutively active, G-protein-coupled receptor that increases processing of HB-EGF from the membrane) rapidly developed large cecal serrated polyps. These polyps were similar to HPPs and had increased phosphorylation of EGFR and ERK1/2 within the serrated epithelium. Administration of pharmacologic inhibitors of EGFR or MAPK to these transgenic mice significantly reduced polyp development. Activation of EGFR signaling in the intestine of mice promotes development of serrated polyps. EGFR signaling also is activated in human HPPs, sessile serrated adenomas

Computer-aided detection of colorectal polyps: can it improve sensitivity of less-experienced readers? Preliminary findings.

Science.gov (United States)

Baker, Mark E; Bogoni, Luca; Obuchowski, Nancy A; Dass, Chandra; Kendzierski, Renee M; Remer, Erick M; Einstein, David M; Cathier, Pascal; Jerebko, Anna; Lakare, Sarang; Blum, Andrew; Caroline, Dina F; Macari, Michael

2007-10-01

To determine whether computer-aided detection (CAD) applied to computed tomographic (CT) colonography can help improve sensitivity of polyp detection by less-experienced radiologist readers, with colonoscopy or consensus used as the reference standard. The release of the CT colonographic studies was approved by the individual institutional review boards of each institution. Institutions from the United States were HIPAA compliant. Written informed consent was waived at all institutions. The CT colonographic studies in 30 patients from six institutions were collected; 24 images depicted at least one confirmed polyp 6 mm or larger (39 total polyps) and six depicted no polyps. By using an investigational software package, seven less-experienced readers from two institutions evaluated the CT colonographic images and marked or scored polyps by using a five-point scale before and after CAD. The time needed to interpret the CT colonographic findings without CAD and then to re-evaluate them with CAD was recorded. For each reader, the McNemar test, adjusted for clustered data, was used to compare sensitivities for readers without and with CAD; a Wilcoxon signed-rank test was used to analyze the number of false-positive results per patient. The average sensitivity of the seven readers for polyp detection was significantly improved with CAD-from 0.810 to 0.908 (P=.0152). The number of false-positive results per patient without and with CAD increased from 0.70 to 0.96 (95% confidence interval for the increase: -0.39, 0.91). The mean total time for the readings was 17 minutes 54 seconds; for interpretation of CT colonographic findings alone, the mean time was 14 minutes 16 seconds; and for review of CAD findings, the mean time was 3 minutes 38 seconds. Results of this feasibility study suggest that CAD for CT colonography significantly improves per-polyp detection for less-experienced readers. Copyright (c) RSNA, 2007.

Ectopic lymphoid tissues support local immunoglobulin production in patients with chronic rhinosinusitis with nasal polyps.

Science.gov (United States)

Song, Jia; Wang, Hai; Zhang, Ya-Na; Cao, Ping-Ping; Liao, Bo; Wang, Zhe-Zheng; Shi, Li-Li; Yao, Yin; Zhai, Guan-Ting; Wang, Zhi-Chao; Liu, Li-Meng; Zeng, Ming; Lu, Xiang; Wang, Heng; Yang, Xiang-Ping; Yu, Di; Bachert, Claus; Liu, Zheng

2018-03-01

The contribution of ectopic lymphoid tissues (eLTs) to local immunoglobulin hyperproduction in patients with chronic rhinosinusitis with nasal polyps (CRSwNP) is unclear. We sought to explore the cellular basis, formation mechanisms, and function of eLTs in patients with CRSwNP. We graded lymphoid aggregations in sinonasal mucosa and histologically studied their structures. The expression of lymphorganogenic factors and molecules required for immunoglobulin production was measured by using real-time PCR, and their localization was analyzed by means of immunohistochemistry and immunofluorescence. The phenotype of follicular helper T cells was analyzed by performing flow cytometry. Immunoglobulin levels were quantified by using the Bio-Plex assay or ImmunoCAP system. Nasal tissue explants were challenged ex vivo with Dermatophagoides pteronyssinus group 1 (Der p 1), and the expression of Iε-Cμ and Iε-Cγ circle transcripts was detected by using seminested PCR. Increased formation of eLTs with germinal center-like structures was discovered in patients with eosinophilic (20.69%) and noneosinophilic (17.31%) CRSwNP compared with that in patients with chronic rhinosinusitis without nasal polyps (5.66%) and control subjects (3.70%). The presence of eLTs was associated with increased expression of lymphorganogenic and inflammatory chemokines and cytokines, as well as their receptors. The expression of molecules required for immunoglobulin production, generation of follicular helper T cells, and production of IgE in eosinophilic polyps and IgG and IgA in both eosinophilic and noneosinophilic polyps were predominantly upregulated in patients with eLTs. After Der p 1 challenge ex vivo, Iε-Cμ transcript was detected only in eosinophilic polyps with eLTs but not in polyps without eLTs and noneosinophilic polyps. eLTs might support local immunoglobulin production and therefore significantly contribute to the development of CRSwNP. Copyright © 2017 American Academy of

Anionic catalyst binders based on trimethylamine-quaternized poly(2,6-dimethyl-1,4-phenylene oxide) for alkaline electrolyzers

Czech Academy of Sciences Publication Activity Database

Schauer, Jan; Hnát, J.; Brožová, Libuše; Žitka, Jan; Bouzek, K.

2015-01-01

Roč. 473, 1 January (2015), s. 267-273 ISSN 0376-7388 Institutional support: RVO:61389013 Keywords : poly(2,6-dimethyl-1,4-phenylene oxide) * bromination * trimethylamine Subject RIV: CD - Macromolecular Chemistry Impact factor: 5.557, year: 2015

The differentiation and prognostic implication of the solitary colonic polyp and the polyposis syndromes: A radiologic, histologic, and pathologic approach

International Nuclear Information System (INIS)

Olmsted, W.W.; Lichtenstein, J.E.

1987-01-01

The differential diagnosis of the solitary colonic polyp and the implications and prognostic significance of the solitary colonic polyp and the polyposis syndromes are frequently confusing because of imprecise and overlapping terminology. Such confusion may lead to misdiagnosis or overdiagnosis and improper patient treatment and surveillance. In the first part of this course, basic terms are defined to acquaint all participants with current common ground. The most frequently occurring solitary polyps (e.g., the colonic adenoma, hyperplastic polyp, Peutz-Jeghers hamartoma, juvenile hamartoma, and inflammatory polyp) are illustrated in detail with radiologic-histologic-pathologic correlation. The prognostic significance of each type of lesion and a scheme for proper colonic surveillance is discussed. In the second part of the session, there is a thorough discussion of multiple colonic polyps and the polyposis syndromes. Radiologic-pathologic correlation are used to illustrate these entities, and therapeutic and diagnostic implications are thoroughly covered. The differential diagnosis of the polyposis syndromes, including lymphoid abnormalities, pneumatosis intestinalis, and colitis cystica profunda, are mentioned. The participant should expect to gain a full understanding of the solitary and multiple colonic polyp states and algorithms for prognosis and treatment

Rh-I-UEA-1 Polymerized Liposomes Target and Image Adenomatous Polyps in the APCMin/+ Mouse Using Optical Colonography

Directory of Open Access Journals (Sweden)

Celeste A. Roney

2011-07-01

Full Text Available Mutated adenomatous polyposis coli (APC genes predispose transformations to neoplasia, progressing to colorectal carcinoma. Early detection facilitates clinical management and therapy. Novel lectin-mediated polymerized targeted liposomes (Rh-I-UEA-1, with polyp specificity and incorporated imaging agents were fabricated to locate and image adenomatous polyps in APCMin/+ mice. The biomarker α-l-fucose covalently joins the liposomal conjugated lectin Ulex europaeus agglutinin (UEA-1, via glycosidic linkage to the polyp mucin layer. Multispectral optical imaging (MSI corroborated a global perspective of specific binding (rhodamine B 532 nm emission, 590–620 nm excitation of targeted Rh-I-UEA-1 polymerized liposomes to polyps with 1.4-fold labeling efficiency. High-resolution coregistered optical coherence tomography (OCT and fluorescence molecular imaging (FMI reveal the spatial correlation of contrast distribution and tissue morphology. Freshly excised APCMin bowels were incubated with targeted liposomes (UEA-1 lectin, control liposomes (no lectin, or iohexol (Omnipaque and imaged by the three techniques. Computed tomographic quantitative analyses did not confirm that targeted liposomes more strongly bound polyps than nontargeted liposomes or iohexol (Omnipaque alone. OCT, with anatomic depth capabilities, along with the coregistered FMI, substantiated Rh-I-UEA-1 liposome binding along the mucinous polyp surface. UEA-1 lectin denotes α-l-fucose biomarker carbohydrate expression at the mucin glycoprotein layer; Rh-I-UEA-1 polymerized liposomes target and image adenomatous polyps in APCMin mice.

The comparison of CT virtual colonoscopy with video colonoscopy (the detection of simulated polyps in pig colon)

International Nuclear Information System (INIS)

Tang Wen; Gong Jianping; Gao Zhixin; Lu Zhian

2000-01-01

Objective: To assess the value of CT virtual colonoscopy for the detection of simulated polyps in pig colon. Methods: Injecting the smelted wax under the mucosa to simulate the polyps in pig colon, then detected by video colonoscopy and scanned by helical CT. The images were obtained with collimation 3 mm, 5 mm, 10 mm and with the table pitch 1 and 2. All images were reconstructed at 1 mm intervals. Results: The shapes were depicted as follows: those greater than 10 mm in diameter polyps were clearly depicted. 5-9 mm in diameter polyps were faintly depicted. Those smaller than 5 mm in diameter were depicted difficulty. The details depicted: polyps larger than 10 mm in diameter and 5-9 mm in diameter were clearly depicted and that smaller than 5 mm in diameter were depicted difficulty. The images quality lowered with the increasing collimation and pitch. Conclusion: CT virtual colonoscopy is a non-invasive diagnostic technique. It can show the inner wall of colon as same as video colonoscopy does, and is a good alternative in clinical application

Importance of X-ray diagnosis of colorectal polyps as compared to the endoscopic method

International Nuclear Information System (INIS)

Lass, B.

1980-01-01

The importance of X-ray diagnosis of colorectal polyps as compared with endoscopy is assessed on the basis of the literature and the authoress's own investigations. These make clean that the double contrast method attains a degree of accuracy approaching that of endoscopy. Some investigations by the authoress in 98 patients show that the procedure permits to recognize 72% of polyps under 1 cm of length and 81% above if the patients are well prepared. 4 out of 129 polyps were not detected by endoscopy. Coloscopy is not an infallible method. Both methods should not be viewed as rivalling but as complementary ones. Knowledge of the limitations and methods, and contant endeavour to combine all methods will entail the best diagnostic results. (orig.) [de

Crystal structure of a diaryl carbonate: 1,3-phenylene bis(phenyl carbonate

Directory of Open Access Journals (Sweden)

Marina A. Solomos

2017-12-01

Full Text Available The whole molecule of the title compound, C20H14O6, is generated by mirror symmetry, the mirror bisecting the central benzene ring. The carbonate groups adopt an s-cis-s-cis conformation, with torsion angles of 58.7 (2 and 116.32 (15°. The crystal structure of 1,3-phenylene bis(phenyl carbonate contains no strong hydrogen bonds, though weak C—H...O and offset π–π interactions are observed, forming layers parallel to the ac plane.

A case of bilateral vocal fold mucosal bridges, bilateral trans-vocal fold type III sulci vocales, and an intracordal polyp.

Science.gov (United States)

Tan, Melin; Pitman, Michael J

2011-07-01

We present a patient with a novel finding of bilateral mucosal bridges, bilateral type III trans-vocal fold sulci vocales, and a vocal fold polyp. Although sulci and mucosal bridges occur in the vocal folds, it is rare to find multiples of these lesions in a single patient, and it is even more uncommon when they occur in conjunction with a vocal fold polyp. To our knowledge, this is the first description of a vocal fold polyp in combination with multiple vocal fold bridges and multiple type III sulci vocales in a single patient. To describe and visually present the diagnosis and treatment of a patient with an intracordal polyp, bilateral mucosal bridges, as well as bilateral type III trans-vocal fold sulci vocales. Presentation of a set of high definition intraoperative photos displaying the extent of the vocal fold lesions and the resection of the intracordal polyp. This patient presented with only 6 months of significant dysphonia. It was felt that the recent change in voice was because of the polyp and not the bridges or sulci vocales. Considering the patient's presentation and the possible morbidity of resection of mucosal bridges and sulci, only the polyp was excised. Postoperatively, the patient's voice returned to his acceptable mild baseline dysphonia, and the benefit has persisted 6 months postoperatively. The combination of bilateral mucosal bridges, bilateral type III sulcus vocalis, and an intracordal polyp in one patient is rare if not novel. Treatment of the polyp alone returned the patient's voice to his lifelong baseline of mild dysphonia. Copyright © 2011 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Evidence-based investigation of the influence of computer-aided detection of polyps on screening of colon cancer with CT colonography

International Nuclear Information System (INIS)

Yoshida, Hiroyuki

2008-01-01

Computed tomographic colonography (CTC), also known as virtual colonoscopy, is a CT examination of the colon for colorectal neoplasms. Recent large-scale clinical trials have demonstrated that CTC yields sensitivity comparable to optical colonoscopy in the detection of clinically significant polyps in a screening population, making CTC a promising technique for screening of colon cancer. For CTC to be a clinically practical means of screening, it must reliably and consistently detect polyps with high accuracy. However, high-level expertise is required to interpret the resulting CT images to find polyps, resulting in variable diagnostic accuracy among radiologists in the detection of polyps. A key technology to overcome this problem and to bring CTC to prime time for screening of colorectal cancer is computer-aided detection (CAD) of polyps. CAD automatically detects the locations of suspicious polyps in CTC images and presents them to radiologists. CAD has the potential to increase diagnostic performance in the detection of polyps as well as to reduce variability of the diagnostic accuracy among radiologists. This paper presents an evidence-based investigation of the influence of CAD on screening of colon cancer with CTC by describing the benefits of using CAD in the diagnosis of CTC, the fundamental CAD scheme for the detection of polyps in CTC, its detection performance, the effect on the improvement of detection performance, as well as the current and future challenges in CAD. (author)

Interobserver agreement in the histologic diagnosis of colorectal polyps. the experience of the multicenter adenoma colorectal study (SMAC).

Science.gov (United States)

Costantini, Massimo; Sciallero, Stefania; Giannini, Augusto; Gatteschi, Beatrice; Rinaldi, Paolo; Lanzanova, Giuseppe; Bonelli, Luigina; Casetti, Tino; Bertinelli, Elisabetta; Giuliani, Orietta; Castiglione, Guido; Mantellini, Paola; Naldoni, Carlo; Bruzzi, Paolo

2003-03-01

Current clinical practice guidelines for patients with colorectal polyps are mainly based on the histologic characteristics of their lesions. However, interobserver variability in the assessment of specific polyp characteristics was evaluated in very few studies. The purpose of this study was to evaluate the interobserver agreement of four pathologists in the diagnosis of histologic type of colorectal polyps and in the degree of dysplasia and of infiltrating carcinoma in adenomas. A stratified random sample of 100 polyps was obtained from the 4,889 polyps resected within the Multicentre Adenoma Colorectal Study (SMAC), and the slides were blindly reviewed by the four pathologists. Agreement was analyzed using kappa statistics. A median kappa of 0.89 (range 0.79-1.0) was estimated for the interobserver agreement for the diagnosis of hyperplastic polyp vs. adenoma. The agreement in the diagnosis of tubular, tubulovillous, and villous type, was given by median kappa values of 0.50, 0.15, and 0.36, respectively. The median kappa for the diagnosis of infiltrating carcinoma was 0.78 (range 0.73-0.84). Agreement on diagnosis of adenoma histologic subtypes, degrees of dysplasia, or infiltrating carcinoma in adenoma was moderate. A simpler classifications might help to better identify patients at different risk of colorectal cancer.

Observation of the energy transfer sequence in an organic host–guest system of a luminescent polymer and a phosphorescent molecule

International Nuclear Information System (INIS)

Basel, Tek; Sun, Dali; Gautam, Bhoj; Valy Vardeny, Z.

2014-01-01

We used steady state optical spectroscopies such as photoluminescence and photoinduced absorption (PA), and magnetic-field PA (MPA) for studying the energy transfer dynamics in films and organic light emitting diodes (OLED) based on host–guest blends with different guest concentrations of the fluorescent polymer poly-[2-methoxy, 5-(2′-ethyl-hexyloxy)phenylene vinylene] (MEHPPV-host), and phosphorescent molecule PtII-tetraphenyltetrabenzoporphyrin [Pt(tpbp); guest]. We show that the energy transfer process between the excited states of the host polymer and guest molecule takes a ‘ping-pong’ type sequence, because the lowest guest triplet exciton energy, E T (guest), lies higher than that of the host, E T (host). Upon photon excitation the photogenerated singlet excitons in the host polymer chains first undergo a Förster resonant energy transfer process to the guest singlet manifold, which subsequently reaches E T (guest) by intersystem crossing. Because E T (guest)>E T (host) there is a subsequent Dexter type energy transfer from E T (guest) to E T (host). This energy transfer sequence has profound influence on the photoluminescence and electroluminescence emission spectra in both films and OLED devices based on the MEHPPV-Pt(tpbp) system. - Highlights: • We studied electroluminescence of OLEDs based on host–guest blends. • The emission efficiency decreases with the guest concentration. • We found a dominant Dexter energy transfer from the triplet(guest) to triplet(host). • Energy transfer occurs from the host to guest and back to the host again

Pre-exposure to simultaneous, but not individual, climate change stressors limits acclimation capacity of Irukandji jellyfish polyps to predicted climate scenarios

Science.gov (United States)

Klein, Shannon G.; Pitt, Kylie A.; Carroll, Anthony R.

2017-09-01

Researchers have investigated the immediate effects of end-of-century climate change scenarios on many marine species, yet it remains unclear whether we can reliably predict how marine species may respond to future conditions because biota may become either more or less resistant over time. Here, we examined the role of pre-exposure to elevated temperature and reduced pH in mitigating the potential negative effects of future ocean conditions on polyps of a dangerous Irukandji jellyfish Alatina alata. We pre-exposed polyps to elevated temperature (28 °C) and reduced pH (7.6), in a full factorial experiment that ran for 14 d. We secondarily exposed original polyps and their daughter polyps to either current (pH 8.0, 25 °C) or future conditions (pH 7.6, 28 °C) for a further 34 d to assess potential phenotypic plastic responses and whether asexual offspring could benefit from parental pre-exposure. Polyp fitness was characterised as asexual reproduction, respiration, feeding, and protein concentrations. Pre-exposure to elevated temperature alone partially mitigated the negative effects of future conditions on polyp fitness, while pre-exposure to reduced pH in isolation completely mitigated the negative effects of future conditions on polyp fitness. Pre-exposure to the dual stressors, however, reduced fitness under future conditions relative to those in the control treatment. Under future conditions, polyps had higher respiration rates regardless of the conditions they were pre-exposed to, suggesting that metabolic rates will be higher under future conditions. Parent and daughter polyps responded similarly to the various treatments tested, demonstrating that parental pre-exposure did not confer any benefit to asexual offspring under future conditions. Importantly, we demonstrate that while pre-exposure to the stressors individually may allow Irukandji polyps to acclimate over short timescales, the stressors are unlikely to occur in isolation in the long term, and

Pre-exposure to simultaneous, but not individual, climate change stressors limits acclimation capacity of Irukandji jellyfish polyps to predicted climate scenarios

KAUST Repository

Klein, Shannon G.; Pitt, Kylie A.; Carroll, Anthony R.

2017-01-01

Researchers have investigated the immediate effects of end-of-century climate change scenarios on many marine species, yet it remains unclear whether we can reliably predict how marine species may respond to future conditions because biota may become either more or less resistant over time. Here, we examined the role of pre-exposure to elevated temperature and reduced pH in mitigating the potential negative effects of future ocean conditions on polyps of a dangerous Irukandji jellyfish Alatina alata. We pre-exposed polyps to elevated temperature (28 °C) and reduced pH (7.6), in a full factorial experiment that ran for 14 d. We secondarily exposed original polyps and their daughter polyps to either current (pH 8.0, 25 °C) or future conditions (pH 7.6, 28 °C) for a further 34 d to assess potential phenotypic plastic responses and whether asexual offspring could benefit from parental pre-exposure. Polyp fitness was characterised as asexual reproduction, respiration, feeding, and protein concentrations. Pre-exposure to elevated temperature alone partially mitigated the negative effects of future conditions on polyp fitness, while pre-exposure to reduced pH in isolation completely mitigated the negative effects of future conditions on polyp fitness. Pre-exposure to the dual stressors, however, reduced fitness under future conditions relative to those in the control treatment. Under future conditions, polyps had higher respiration rates regardless of the conditions they were pre-exposed to, suggesting that metabolic rates will be higher under future conditions. Parent and daughter polyps responded similarly to the various treatments tested, demonstrating that parental pre-exposure did not confer any benefit to asexual offspring under future conditions. Importantly, we demonstrate that while pre-exposure to the stressors individually may allow Irukandji polyps to acclimate over short timescales, the stressors are unlikely to occur in isolation in the long term, and

Pre-exposure to simultaneous, but not individual, climate change stressors limits acclimation capacity of Irukandji jellyfish polyps to predicted climate scenarios

KAUST Repository

Klein, Shannon G.

2017-05-20

Researchers have investigated the immediate effects of end-of-century climate change scenarios on many marine species, yet it remains unclear whether we can reliably predict how marine species may respond to future conditions because biota may become either more or less resistant over time. Here, we examined the role of pre-exposure to elevated temperature and reduced pH in mitigating the potential negative effects of future ocean conditions on polyps of a dangerous Irukandji jellyfish Alatina alata. We pre-exposed polyps to elevated temperature (28 °C) and reduced pH (7.6), in a full factorial experiment that ran for 14 d. We secondarily exposed original polyps and their daughter polyps to either current (pH 8.0, 25 °C) or future conditions (pH 7.6, 28 °C) for a further 34 d to assess potential phenotypic plastic responses and whether asexual offspring could benefit from parental pre-exposure. Polyp fitness was characterised as asexual reproduction, respiration, feeding, and protein concentrations. Pre-exposure to elevated temperature alone partially mitigated the negative effects of future conditions on polyp fitness, while pre-exposure to reduced pH in isolation completely mitigated the negative effects of future conditions on polyp fitness. Pre-exposure to the dual stressors, however, reduced fitness under future conditions relative to those in the control treatment. Under future conditions, polyps had higher respiration rates regardless of the conditions they were pre-exposed to, suggesting that metabolic rates will be higher under future conditions. Parent and daughter polyps responded similarly to the various treatments tested, demonstrating that parental pre-exposure did not confer any benefit to asexual offspring under future conditions. Importantly, we demonstrate that while pre-exposure to the stressors individually may allow Irukandji polyps to acclimate over short timescales, the stressors are unlikely to occur in isolation in the long term, and

A randomised controlled trial of Outpatient versus inpatient Polyp Treatment (OPT) for abnormal uterine bleeding.

Science.gov (United States)

Clark, T Justin; Middleton, Lee J; Cooper, Natalie Am; Diwakar, Lavanya; Denny, Elaine; Smith, Paul; Gennard, Laura; Stobert, Lynda; Roberts, Tracy E; Cheed, Versha; Bingham, Tracey; Jowett, Sue; Brettell, Elizabeth; Connor, Mary; Jones, Sian E; Daniels, Jane P

2015-07-01

Uterine polyps cause abnormal bleeding in women and conventional practice is to remove them in hospital under general anaesthetic. Advances in technology make it possible to perform polypectomy in an outpatient setting, yet evidence of effectiveness is limited. To test the hypothesis that in women with abnormal uterine bleeding (AUB) associated with benign uterine polyp(s), outpatient polyp treatment achieved as good, or no more than 25% worse, alleviation of bleeding symptoms at 6 months compared with standard inpatient treatment. The hypothesis that response to uterine polyp treatment differed according to the pattern of AUB, menopausal status and longer-term follow-up was tested. The cost-effectiveness and acceptability of outpatient polypectomy was examined. A multicentre, non-inferiority, randomised controlled trial, incorporating a cost-effectiveness analysis and supplemented by a parallel patient preference study. Patient acceptability was evaluated by interview in a qualitative study. Outpatient hysteroscopy clinics and inpatient gynaecology departments within UK NHS hospitals. Women with AUB - defined as heavy menstrual bleeding (formerly known as menorrhagia) (HMB), intermenstrual bleeding or postmenopausal bleeding - and hysteroscopically diagnosed uterine polyps. We randomly assigned 507 women, using a minimisation algorithm, to outpatient polypectomy compared with conventional inpatient polypectomy as a day case in hospital under general anaesthesia. The primary outcome was successful treatment at 6 months, determined by the woman's assessment of her bleeding. Secondary outcomes included quality of life, procedure feasibility, acceptability and cost per quality-adjusted life-year (QALY) gained. At 6 months, 73% (166/228) of women who underwent outpatient polypectomy were successfully treated compared with 80% (168/211) following inpatient polypectomy [relative risk (RR) 0.91, 95% confidence interval (CI) 0.82 to 1.02]. The lower end of the CIs showed

Eviendep® reduces number and size of duodenal polyps in familial adenomatous polyposis patients with ileal pouch-anal anastomosis.

Science.gov (United States)

Calabrese, Carlo; Praticò, Chiara; Calafiore, Andrea; Coscia, Maurizio; Gentilini, Lorenzo; Poggioli, Gilberto; Gionchetti, Paolo; Campieri, Massimo; Rizzello, Fernando

2013-09-14

To evaluate if 3 mo oral supplementation with Eviendep® was able to reduce the number of duodenal polyps in familial adenomatous polyposis (FAP) patients with ileal pouch-anal anastomosis (IPAA). Eleven FAP patients with IPAA and duodenal polyps were enrolled. They underwent upper gastrointestinal (GI) endoscopy at the baseline and after 3 mo of treatment. Each patient received 5 mg Eviendep twice a day, at breakfast and dinner time, for 3 mo. Two endoscopists evaluated in a blinded manner the number and size of duodenal polyps. Upper GI endoscopies with biopsies were performed at the baseline (T0) with the assessment of the Spigelman score. Polyps > 10 mm were removed during endoscopy and at the end of the procedure a new Spigelman score was determined (T1). The procedure was repeated 3 mo after the baseline (T2). Four photograms were examined for each patient, at T1 and T2. The examined area was divided into 3 segments: duodenal bulb, second and third portion duodenum. Biopsy specimens were taken from all polyps > 10 mm and from all suspicious ones, defined by the presence of a central depression, irregular surface, or irregular vascular pattern. Histology was classified according to the updated Vienna criteria. At baseline the mean number of duodenal detected polyps was 27.7 and mean sizes were 15.8 mm; the mean Spigelman score was 7.1. After polypectomy the mean number of duodenal detected polyps was 25.7 and mean sizes were 7.6 mm; the mean Spigelman score was 6.4. After 3 mo of Eviendep bid, all patients showed a reduction of number and size of duodenal polyps. The mean number of duodenal polyps was 8 (P = 0.021) and mean size was 4.4 mm; the mean Spigelman score was 6.6. Interrater agreement was measured. Lesions > 1 cm found a very good degree of concordance (kappa 0.851) and a good concordance was as well encountered for smaller lesions (kappa 0.641). Our study demonstrated that short-term (90 d) supplementation with Eviendep® in FAP patients with IPAA

Individual polyp detection rate in routine daily endoscopy practice depends on case-mix.

Science.gov (United States)

Loffeld, R J L F; Liberov, B; Dekkers, P E P

2015-07-01

The adenoma detection rate (ADR), a marker of endoscopic quality, is confounded by selection bias. It is not known what the ADR is in normal daily practice. To study the polyp detection rate (PDR) in different endoscopists in the course of years. All consecutive endoscopies of the colon done in 11 years were included. Endoscopies in the regular surveillance programme after polyp removal and after surgery because of colorectal cancer or diverticular disease were scored separately. The number of yearly procedures per endoscopist and presence of polyps, anastomoses, surveillance and cancer were noted. In the period of 11 years, 14,908 consecutive endoscopies of colon and rectum were done by four endoscopists. Two endoscopists had a significantly lower PDR than the other two (p case-mix of patients presented for endoscopy. This result debates the use of the ADR as quality indicator for individual endoscopists.

Korean Guidelines for Colorectal Cancer Screening and Polyp Detection

International Nuclear Information System (INIS)

Lee, Bo In; Hong, Sung Pil; Kim, Seong Eun

2012-01-01

Colorectal cancer is currently the second most common cancer among Korean males and the fourth most common among females. Since the majority of colorectal cancer case present following the prolonged transformation of adenomas into carcinomas, early detection and removal of colorectal adenomas are vital methods in its prevention. Considering the increasing incidence of colorectal cancer and polyps in Korea, it is very important to establish national guidelines for colorectal cancer screening and polyp detection. The proposed guidelines have been developed by the Korean Multi-Society Task Force using evidence-based methods. Systematic reviews and meta-analyses have been used to form the statements contained in the guidelines. This paper discusses the epidemiology of colorectal cancers and adenomas in Korea as well as optimal methods for screening of colorectal cancer and detection of adenomas including fecal occult blood tests, radiologic tests, and endoscopic examinations.

A rare cause of glans penis masses in childhood: Fibroepithelial polyp

Science.gov (United States)

Şencan, Arzu; Şencan, Aydın; Günşar, Cüneyt; Çayırlı, Hasan; Neşe, Nalan

2015-01-01

Fibroepithelial polyps of glans penis are very rarely seen in childhood. A 6-month-old male admitted to our institution with a slowly enlarging glans penis mass on the ventral side of the glans penis. The mass was totally excised, and hystopathological diagnosis was a fibroepithelial polyp. All of the reported cases published previously, except one, are of adult age and all of them have been associated with the history of long-term condom catheter use. The presence of the case in childhood; however, suggests that the pathology might be congenital. This is the second pediatric case presented in the English literature. PMID:25552832

Comparison of hand-craft feature based SVM and CNN based deep learning framework for automatic polyp classification.

Science.gov (United States)

Younghak Shin; Balasingham, Ilangko

2017-07-01

Colonoscopy is a standard method for screening polyps by highly trained physicians. Miss-detected polyps in colonoscopy are potential risk factor for colorectal cancer. In this study, we investigate an automatic polyp classification framework. We aim to compare two different approaches named hand-craft feature method and convolutional neural network (CNN) based deep learning method. Combined shape and color features are used for hand craft feature extraction and support vector machine (SVM) method is adopted for classification. For CNN approach, three convolution and pooling based deep learning framework is used for classification purpose. The proposed framework is evaluated using three public polyp databases. From the experimental results, we have shown that the CNN based deep learning framework shows better classification performance than the hand-craft feature based methods. It achieves over 90% of classification accuracy, sensitivity, specificity and precision.

Gastric Polyp Growth during Endoscopic Surveillance for Esophageal Varices or Barrett's Esophagus.

Science.gov (United States)

Livovsky, Dan M; Pappo, Orit; Skarzhinsky, Galina; Peretz, Asaf; Turvall, Elliot; Ackerman, Zvi

2016-05-01

We recently observed patients with chronic liver disease (CLD) or chronic reflux symptoms (CRS) who developed gastric polyps (GPs) while undergoing surveillance gastroscopies for the detection of esophageal varices or Barrett's esophagus, respectively. To identify risk factors for GP growth and estimate its growth rate. GP growth rate was defined as the number of days since the first gastroscopy (without polyps) in the surveillance program, until the gastroscopy when a GP was discovered. Gastric polyp growth rates in CLD and CRS patients were similar. However, hyperplastic gastric polyps (HGPs) were detected more often (87.5% vs. 60.5%, P = 0.051) and at a higher number (2.57 ± 1.33 vs. 1.65 ± 0.93, P = 0.021) in the CLD patients. Subgroup analysis revealed the following findings only in CLD patients with HGPs: (i) a positive correlation between the GP growth rate and the patient's age; the older the patient, the higher the GP growth rate (r = 0.7, P = 0.004). (ii) A negative correlation between the patient's age and the Ki-67 proliferation index value; the older the patient, the lower the Ki-67 value (r = -0.64, P = 0.02). No correlation was detected between Ki-67 values of HGPs in CLD patients and the presence of portal hypertension, infection with Helicobacter pylori, or proton pump inhibitor use. In comparison with CRS patients, CLD patients developed HGPs more often and at a greater number. Young CLD patients may have a tendency to develop HGPs at a faster rate than elderly CLD patients.

Prevalence and characteristics of endometrial polyps in patients with abnormal uterine bleeding

Directory of Open Access Journals (Sweden)

Đorđević Biljana

2008-01-01

Full Text Available Background/Aim. The prevalence of endometrial polyps (EPs in the general female population is about 24%. Abnormal uterine bleeding is frequently the presenting symptom of EPs. The aim of this study was to determine the prevalence and characteristics of EPs in patients with abnormal uterine bleeding. Methods. The prevalence and characteristics of EPs were investigated in 961 patients with abnormal uterine bleeding who underwent dilatation and curettage between January and December 2006. Regarding histopathological features of EPs (presence of atypical hyperplasia or endometrial carcinoma, patients were divided into two groups: group A - patients who had EPs and EPs with hyperplasia without atypia (n = 204 and group B - patients who had EPs with atypical hyperplasia and EPs with carcinoma (n = 7. Results. In 211 (21.94% patients EPs were found with abnormal uterine bleeding. Histopathologically, there were 175 (82.94% EPs, 29 (13.74% EPs with hyperplasia without atypia, 5 (2.37% EPs with atypical hyperplasia, and 2 (0.95% EPs with endometrial carcinoma. Contrary to the patients with EPs and EPs with hyperplasia without atypia (group A, patients who had EPs with atypical hyperplasia and EPs with carcinoma (group B were older (p < 0.05, and more commonly postmenopausal (p < 0.05 and with hypertension (p < 0.05, all of statistical significance. Conclusion. The prevalence of endometrial polyps in patients with abnormal uterine bleeding according to our data was 21.95%. Atypical hyperplasia and endometrial carcinoma were rarely confined to a polyp. Older age, postmenopausal period and hypertension may increase the risk of premalignant and malignant changes in endometrial polyps.

Prolapsed submucous uterine fibroid polyp associated with urinary ...

African Journals Online (AJOL)

A rare case of prolapsed submucous uterine fibroid polyp associated with intemittent acute urinary retention in a 34 year old Para 4+4 woman is described. She presented with one year history of increased menstrual blood loss and secondary dysmenorrhea and six months history of a mass protruding down the vagina, ...

Feature-guided analysis for reduction of false positives in CAD of polyps for computed tomographic colonography

International Nuclear Information System (INIS)

Naeppi, Janne; Yoshida, Hiroyuki

2003-01-01

We evaluated the effect of our novel technique of feature-guided analysis of polyps on the reduction of false-positive (FP) findings generated by our computer-aided diagnosis (CAD) scheme for the detection of polyps from computed tomography colonographic data sets. The detection performance obtained by use of feature-guided analysis in the segmentation and feature analysis of polyp candidates was compared with that obtained by use of our previously employed fuzzy clustering technique. We also evaluated the effect of a feature called modified gradient concentration (MGC) on the detection performance. A total of 144 data sets, representing prone and supine views of 72 patients that included 14 patients with 21 colorectal polyps 5-25 mm in diameter, were used in the evaluation. At a 100% by-patient (95% by-polyp) detection sensitivity, the FP rate of our CAD scheme with feature-guided analysis based on round-robin evaluation was 1.3 (1.5) FP detections per patient. This corresponds to a 70-75 % reduction in the number of FPs obtained by use of fuzzy clustering at the same sensitivity levels. Application of the MGC feature instead of our previously used gradient concentration feature did not improve the detection result. The results indicate that feature-guided analysis is useful for achieving high sensitivity and a low FP rate in our CAD scheme

Didactic training vs. computer-based self-learning in the prediction of diminutive colon polyp histology by trainees: a randomized controlled study.

Science.gov (United States)

Khan, Taimur; Cinnor, Birtukan; Gupta, Neil; Hosford, Lindsay; Bansal, Ajay; Olyaee, Mojtaba S; Wani, Sachin; Rastogi, Amit

2017-12-01

Background and study aim  Experts can accurately predict diminutive polyp histology, but the ideal method to train nonexperts is not known. The aim of the study was to compare accuracy in diminutive polyp histology characterization using narrow-band imaging (NBI) between participants undergoing classroom didactic training vs. computer-based self-learning. Participants and methods  Trainees at two institutions were randomized to classroom didactic training or computer-based self-learning. In didactic training, experienced endoscopists reviewed a presentation on NBI patterns for adenomatous and hyperplastic polyps and 40 NBI videos, along with interactive discussion. The self-learning group reviewed the same presentation of 40 teaching videos independently, without interactive discussion. A total of 40 testing videos of diminutive polyps under NBI were then evaluated by both groups. Performance characteristics were calculated by comparing predicted and actual histology. Fisher's exact test was used and P  didactic training and 9 self-learning). A larger proportion of polyps were diagnosed with high confidence in the classroom group (66.5 % vs. 50.8 %; P  didactic training for predicting diminutive polyp histology. This approach can help in widespread training and clinical implementation of real-time polyp histology characterization. © Georg Thieme Verlag KG Stuttgart · New York.

The Association Between Molecular Markers in Colorectal Sessile Serrated Polyps and Colorectal Cancer Risk

Science.gov (United States)

2017-08-01

AWARD NUMBER: W81XWH-15-1-0273 TITLE: The Association between Molecular Markers in Colorectal Sessile Serrated Polyps and Colorectal Cancer ... Colorectal Cancer Risk 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-15-1-0273 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Andrea Burnett-Hartman 5d... cancer in patients with sessile serrated colorectal polyps (SSPs). The project’s specific aims are as follows: 1) Estimate the risk of colorectal

Gas transport properties of polybenzimidazole and poly(phenylene oxide) mixed matrix membranes incorporated with PDA-functionalised titanate nanotubes

Czech Academy of Sciences Publication Activity Database

Giel, Verena; Perchacz, Magdalena; Kredatusová, Jana; Pientka, Zbyněk

2017-01-01

Roč. 12, č. 1 (2017), s. 1-15, č. článku 3. ISSN 1931-7573 R&D Projects: GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : polybenzimidazole * poly(phenylene oxide) * titanate nanotubes Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science

The clinical significance and synchronous polyp burden of large (≥ 20 mm) sessile serrated polyps in patients without serrated polyposis syndrome.

Science.gov (United States)

Desomer, Lobke; Tate, David J; Jayanna, Mahesh; Pellise, Maria; Awadie, Halim; Burgess, Nicholas G; McLeod, Duncan; Mahajan, Hema; Lee, Eric Y T; Williams, Stephen J; Bourke, Michael J

2018-05-08

 Sessile serrated polyps (SSPs) are important precursors of colorectal carcinoma and interval cancer. Large SSPs (≥ 20 mm) outside the definition of serrated polyposis syndrome (SPS) have not been studied in comparison with SPS. We aimed to describe the characteristics of patients with large SSPs in this context.  Patients with at least one SSP (≥ 20 mm) were eligible. Data from three consecutive colonoscopies were used to compare clinical and endoscopic characteristics in three patient groups: SPS, a solitary large SSP, and patients with at least two SSPs without fulfilling the criteria for SPS (oligo-SSP). Data on the diagnostic colonoscopy were collected retrospectively, whereas the remaining data was collected prospectively.  67/146 patients (45.9 %) had SPS, 53/146 (36.3 %) had a solitary SSP, and 26/146 (17.8 %) were categorized as oligo-SSP. Personal (16.4 %, 9.4 %, and 11.5 %, respectively) and family (17.9 %, 17.0 %, and 23.1 %, respectively) history of colorectal carcinoma did not differ significantly between groups. Polyp burden was greater in SPS compared with solitary SSP but was not different from oligo-SSP (advanced adenomas: SPS 32.8 % vs. solitary SSP 9.4 % [ P  = 0.002] vs. oligo-SSP 34.6 % [ P  = 0.87]; ≥ 10 conventional adenomas: 11.9 % vs. 0 % [ P  = 0.01] vs. 3.8 % [ P  = 0.44], respectively). Dysplasia in large SSPs was frequent in all groups (41.1 % overall). SPS was recognized by referring endoscopists in only 9.0 % of cases.  Patients with oligo-SSPs have similar synchronous polyp burden and clinical characteristics as patients with SPS and may require similar surveillance. Modification of the criteria for the diagnosis of SPS to include this group seems warranted. Patients with a solitary SSP have a lower risk of synchronous polyps, including advanced adenomas. Larger studies are warranted to determine whether these patients may return to standard surveillance

Can we ease the financial burden of colonoscopy? Using real-time endoscopic assessment of polyp histology to predict surveillance intervals.

Science.gov (United States)

Chandran, S; Parker, F; Lontos, S; Vaughan, R; Efthymiou, M

2015-12-01

Polyps identified at colonoscopy are predominantly diminutive (1%) of high-grade dysplasia or carcinoma; however, the cost of histological assessment is substantial. The aim of this study was to determine whether prediction of colonoscopy surveillance intervals based on real-time endoscopic assessment of polyp histology is accurate and cost effective. A prospective cohort study was conducted across a tertiary care and private community hospital. Ninety-four patients underwent colonoscopy and polypectomy of diminutive (≤5 mm) polyps from October 2012 to July 2013, yielding a total of 159 polyps. Polyps were examined and classified according to the Sano-Emura classification system. The endoscopic assessment (optical diagnosis) of polyp histology was used to predict appropriate colonoscopy surveillance intervals. The main outcome measure was the accuracy of optical diagnosis of diminutive colonic polyps against the gold standard of histological assessment. Optical diagnosis was correct in 105/108 (97.2%) adenomas. This yielded a sensitivity, specificity and positive and negative predictive values (with 95%CI) of 97.2% (92.1-99.4%), 78.4% (64.7-88.7%), 90.5% (83.7-95.2%) and 93% (80.9-98.5%) respectively. Ninety-two (98%) patients were correctly triaged to their repeat surveillance colonoscopy. Based on these findings, a cut and discard approach would have resulted in a saving of $319.77 per patient. Endoscopists within a tertiary care setting can accurately predict diminutive polyp histology and confer an appropriate surveillance interval with an associated financial benefit to the healthcare system. However, limitations to its application in the community setting exist, which may improve with further training and high-definition colonoscopes. © 2015 Royal Australasian College of Physicians.

Hyperspectral imaging of colonic polyps in vivo (Conference Presentation)

Science.gov (United States)

Clancy, Neil T.; Elson, Daniel S.; Teare, Julian

2017-02-01

Standard endoscopic tools restrict clinicians to making subjective visual assessments of lesions detected in the bowel, with classification results depending strongly on experience level and training. Histological examination of resected tissue remains the diagnostic gold standard, meaning that all detected lesions are routinely removed. This subjects the patient to risk of polypectomy-related injury, and places significant workload and economic burdens on the hospital. An objective endoscopic classification method would allow hyperplastic polyps, with no malignant potential, to be left in situ, or low grade adenomas to be resected and discarded without histology. A miniature multimodal flexible endoscope is proposed to obtain hyperspectral reflectance and dual excitation autofluorescence information from polyps in vivo. This is placed inside the working channel of a conventional colonoscope, with the external scanning and detection optics on a bedside trolley. A blue and violet laser diode pair excite endogenous fluorophores in the respiration chain, while the colonoscope's xenon light source provides broadband white light for diffuse reflectance measurements. A push-broom HSI scanner collects the hypercube. System characterisation experiments are presented, defining resolution limits as well as acquisition settings for optimal spectral, spatial and temporal performance. The first in vivo results in human subjects are presented, demonstrating the clinical utility of the device. The optical properties (reflectance and autofluorescence) of imaged polyps are quantified and compared to the histologically-confirmed tissue type as well as the clinician's visual assessment. Further clinical studies will allow construction of a full robust training dataset for development of classification schemes.

Alcohol hyper-responsiveness in chronic rhinosinusitis with nasal polyps.

Science.gov (United States)

De Schryver, Els; Derycke, Lara; Campo, Paloma; Gabriels, Eline; Joos, Guy F; Van Zele, Thibaut; Bachert, Claus; Hellings, Peter W; Gevaert, Philippe

2017-02-01

An important percentage of subjects diagnosed with chronic upper airway disease report alcohol-induced worsening of their symptoms. The prevalence and characteristics of respiratory reactions provoked by alcohol-containing drinks have not been fully investigated yet. The aim of this study was to estimate the prevalence and characteristics of alcohol hyper-responsiveness in patients with chronic airway disease and healthy controls. Furthermore, nasal inflammation was evaluated in nasal polyp patients with and without hyper-responsiveness. We evaluated the prevalence and characteristics of alcohol-induced respiratory complaints in 1281 subjects. Chronic rhinosinusitis with nasal polyps (CRSwNP) patients with and without NSAID exacerbated respiratory disease (NERD), chronic rhinosinusitis patients without nasal polyps (CRSsNP), allergic rhinitis (AR) patients and healthy controls were approached by means of a questionnaire. Inflammatory markers (eosinophilic cationic protein (ECP), IL-5, IgE, SAE-specific IgE, IL-17, TNFα and IFNγ) in tissue were then compared between alcohol hyper-responsive and non-hyper-responsive CRSwNP patients. The highest prevalence of nasal and bronchial alcohol hyper-responsiveness was observed in patients with NERD, followed by CRSwNP, and less frequent in CRSsNP, AR and healthy controls. Alcohol hyper-responsiveness is significantly more prevalent in CRSwNP patients suffering from recurrent disease and in patients with severe symptomatology. In nasal tissue of the hyper-responsive CRSwNP group, we observed significantly higher nasal levels of the eosinophilic biomarker ECP. Nasal hyper-responsiveness to alcohol is significantly more prevalent in severe eosinophilic upper airway disease. © 2016 John Wiley & Sons Ltd.

Environmental control of asexual reproduction and somatic growth of Aurelia spp. (Cnidaria, Scyphozoa) polyps from the Adriatic Sea

OpenAIRE

Hubot, Nathan; Lucas, Cathy H.; Piraino, Stefano

2017-01-01

Polyps of two moon jellyfish species, Aurelia coerulea and A.relicta, from two Adriatic Sea coastal habitats were incubated under multiple combinations of temperature (14, 21 °C), salinity (24, 37 ppt) and food regime (9.3, 18.6, 27.9 μg C ind‾¹ week‾¹) to comparatively assess how these factors may influence major asexual reproduction processes in the two species. Both species exhibited a shared pattern of budding mode (Directly Budded Polyps: DBP; Stolonal Budded Polyps: SBP), with DBP favo...

Hamartomatous Polyp of the Tonsil: A Case Report

African Journals Online (AJOL)

dysphagia. These are nonspecific symptoms due to mass effect. We present a case of hamartomatous polyp to stress on the benign nature of this rare lesion, clinically diagnosed as neoplasm. We want to emphasize the hamartomatous nature of this lesion with review of literature. CASE REPORT. A 17‑year‑old male patient ...

European Position Paper on Rhinosinusitis and Nasal Polyps 2012

NARCIS (Netherlands)

Fokkens, Wytske J.; Lund, Valerie J.; Mullol, Joachim; Bachert, Claus; Alobid, Isam; Baroody, Fuad; Cohen, Noam; Cervin, Anders; Douglas, Richard; Gevaert, Philippe; Georgalas, Christos; Goossens, Herman; Harvey, Richard; Hellings, Peter; Hopkins, Claire; Jones, Nick; Joos, Guy; Kalogjera, Livije; Kern, Bob; Kowalski, Marek; Price, David; Riechelmann, Herbert; Schlosser, Rodney; Senior, Brent; Thomas, Mike; Toskala, Elina; Voegels, Richard; Wang, De Yun; Wormald, Peter John

2012-01-01

The European Position Paper on Rhinosinusitis and Nasal Polyps 2012 is the update of similar evidence based position papers published in 2005 and 2007.The document contains chapters on definitions and classification, we now also proposed definitions for difficult to treat rhinosinusitis, control of

A CLINICAL STUDY OF ENDOMETRIAL HISTOPATHOLOGY IN AUB AND INCIDENCE OF ENDOMETRIAL POLYP IN AUB

Directory of Open Access Journals (Sweden)

Renuka Devi Balakrishnan

2016-11-01

Full Text Available BACKGROUND Abnormal Uterine Bleeding (AUB is one of the most common menstrual complaints and a frequent indication for hysterectomy. It can be a manifestation of any number of pathological entities. Causes of AUB ranges from organic pathologies like leiomyoma, polyps, adenomyosis and malignancy to conditions like coagulopathy and drug-induced AUB and aetiologies vary in different age groups. Histopathological evaluation of endometrium is very vital to identify the cause of AUB. The objectives of this study are to, 1. To evaluate the endometrial histopathology in AUB, and 2. To estimate the incidence of endometrial polyp in AUB. MATERIALS AND METHODS This is a prospective study carried out on 120 women who presented with AUB. Endometrial samples collected were analysed for their histopathological pattern. RESULTS Out of 120 endometrial samples analysed among women of 30-39 years, proliferative endometrium was seen in 43.3% and secretory endometrium in 33.3% and endometrial polyp in 13.3%. In women of 40-49 years, proliferative endometrium in 36.8%, secretory endometrium in 30.9% and disordered proliferative endometrium was seen in 19% of women. The incidence of endometrial polyp was found to be 8.3% in our study. CONCLUSION There is an age-specific relation of abnormal endometrial histopathology. Among abnormal endometrial pathology, disordered proliferative endometrium was more common in perimenopausal age group and endometrial polyps in reproductive age group. The results of this study indicate that benign endometrial histopathology is common in AUB suggesting a role for more conservative therapeutic strategies.

The association between recreational physical activity, sedentary time, and colorectal polyps in a population screened for colorectal cancer.

Science.gov (United States)

Brenner, Darren R; Shaw, Eileen; Yannitsos, Demetra H; Warkentin, Matthew T; Brockton, Nigel T; McGregor, S Elizabeth; Town, Susanna; Hilsden, Robert J

2018-04-01

Regular recreational moderate to vigorous physical activity (rMVPA) has been previously associated with a reduced risk of colorectal cancer (CRC), however, few studies have examined the association of rMVPA with colorectal polyps, the pre-malignant precursor lesions. The objective of this study was to examine the associations between physical activity and sitting time and polyps at the time of screening. We conducted a cross-sectional study of 2496 individuals undergoing screening-related colonoscopy in Calgary, Alberta, Canada. Physical activity and sitting time were characterized using hours of rMVPA, meeting physical activity recommendations and hours of sitting time using self-reported data obtained from the International Physical Activity Questionnaire. Logistic regression models were used to estimate the crude and adjusted odds ratios (OR) for presence of polyps associated with rMVPA and sitting time. Meeting physical activity guidelines of ≥150 min/week was non-significantly associated with a modest decrease in odds of having ≥1 polyp at screening (OR adj  = 0.95, 95% CI: 0.80-1.14). In males, threshold effects for sitting time were observed for up to 20 h/week (OR adj per hour sitting = 1.07, 95% CI: 1.01-1.13). In stratified analysis, larger inverse associations were observed between physical activity and the presence of polyps in females, obese individuals, and ever smokers, compared to pooled findings. In this large CRC screening population, there was a suggestive association between increased rMVPA and reduced prevalence of polyps at screening, particularly among females. Even low amounts of regular sitting time (0-20 h/day) were associated with the presence of polyps, particularly among males. Further research on rMVPA and sitting time is necessary to better inform strategies to reduce the frequency of pre-malignant colorectal lesions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Electronic states of thiophene/phenylene co-oligomers: Extreme-ultra violet excited photoelectron spectroscopy observations and density functional theory calculations

International Nuclear Information System (INIS)

Kawaguchi, Yoshizo; Sasaki, Fumio; Mochizuki, Hiroyuki; Ishitsuka, Tomoaki; Tomie, Toshihisa; Ootsuka, Teruhisa; Watanabe, Shuji; Shimoi, Yukihiro; Yamao, Takeshi; Hotta, Shu

2013-01-01

We have investigated electronic states in the valence electron bands for the thin films of three thiophene/phenylene co-oligomer (TPCO) compounds, 2,5-bis(4-biphenylyl)thiophene (BP1T), 1,4-bis(5-phenylthiophen-2-yl)benzene (AC5), and 1,4-bis{5-[4-(trifluoromethyl)phenyl]thiophen-2-yl}benzene (AC5-CF 3 ), by using extreme-UV excited photoelectron spectroscopy (EUPS). By comparing both EUPS spectra and secondary electron spectra between AC5 and AC5-CF 3 , we confirm that CF 3 substitution to AC5 deepens valence states by 2 eV, and increases the ionization energy by 3 eV. From the cut-off positions of secondary electron spectra, the work functions of AC5, AC5-CF 3 , and BP1T are evaluated to be 3.8 eV, 4.8 eV, and 4.0 eV, respectively. We calculate molecular orbital (MO) energy levels by the density functional theory and compare results of calculations with those of experiments. Densities of states obtained by broadening MO levels well explain the overall features of experimental EUPS spectra of three TPCOs.

Giant esophageal fibrovascular polyp with clinical behaviour of inflammatory pseudotumor: A case report and the literature review

Directory of Open Access Journals (Sweden)

Ćuk Vladimir

2014-01-01

Full Text Available Introduction. Esophageal fibrovascular polyps are rare, benign, intraluminal, submucosal tumor-like lesions, characterized by pedunculated masses which can demonstrate enormous growth. The most frequent symptoms are dysphagia, vomiting and weight loss. Fibrovascular polyps with long stalks can regurgitate into the airways and cause asphyxia. Esophageal inflammatory pseudotumor is extremely rare lesion accompanied with various systemic manifestations as fever, anemia and thrombocytosis. Case report. We presented a 29-year-old man complaining of a long-lasting fever and dysphagia. He was found to have huge pedunculated submucosal tumor of esophagus, surgically completely resected. Histopathological examination showed that this giant tumor, 24 x 9 x 6 cm, was a fibrovascular polyp. The postoperative course was uneventful. The preoperative fever, anemia and thrombocytosis disappeared and did not recur in the postoperative course. Conclusion. We reported a patient with giant esophageal pedunculated tumor with clinical manifestations of inflammatory pseudotumor and histopathological picture of fibrovascular polyp, that we have not found described in the literature before.

Physical activity reduces risk for colon polyps in a multiethnic colorectal cancer screening population

Directory of Open Access Journals (Sweden)

Sanchez Nelson F

2012-06-01

Full Text Available Abstract Background Identifying modifiable factors that influence the epidemiology of colorectal cancer incidence among multiethnic groups might be informative for the development of public health strategies targeting the disease. Minimal data exists describing the impact of physical activity on colorectal polyp risk in United States minority populations. The aim of this study is to evaluate the relationship of exercise on the prevalence of polyps in a multiethnic colorectal cancer screening population. Results We enrolled 982 patients: 558 Hispanic, 202 Asian,149 Black, and 69 White. Patients who reported exercising one or more hours weekly had a lower prevalence of any polyps (25.3% vs 33.2%, P = 0.008 as well as adenomas (13.8 vs. 18.9%, P = 0.03 compared to those who did not exercise. Black and Hispanic patients and those who were overweight or obese also had lower prevalence of polyps if they led an active lifestyle. Multivariate analysis revealed that age >55, male sex, and Black race/ethnicity were positively associated with the presence of adenomas, while a history of exercising one hour or more weekly was an independent negative predictor for the presence of adenomas anywhere in the colon (OR 0.67; 95% CI 0.4 - 0.9, P = 0.03. Conclusions Exercising one hour per week was associated with a lower prevalence of polyps and adenomas when compared to those who exercised less or not at all. An active lifestyle provides benefits to groups who are at risk for colorectal cancer, such as Blacks. It also provides significant protection to overweight and obese individuals. Public health initiatives should promote physical activity as a cancer prevention tool in multiethnic populations. Trial registration none

Non-classical light emission from single conjugated polymers

Science.gov (United States)

Hollars, Christopher; Lane, Stephen; Huser, Thomas

2002-03-01

Photon-antibunching from single, isolated molecules of collapsed-chain poly[2-methoxy,5-(2’-ethyl-hexyloxy)-p-phenylene-vinylene] (MEH-PPV) has been observed using confocal microscopy techniques. Efficient inter-segment energy transfer in collapsed-chain conjugated polymers leads to emission from an average of only 2-3 active sites on a polymer chain that is composed of hundreds of quasi-chromophores. These few centers consist of the segments with the lowest excitation energy and are supplied by the efficient light-harvesting and energy transfer of the surrounding higher-energy segments. This effect depends on the conformation of the polymer molecules, which is controlled by solvent polarity. These results provide new insight into the controversial photophysics of conjugated polymers and their application in optoelectronic devices.

Observation of the subgap optical absorption in polymer-fullerene blend solar cells

International Nuclear Information System (INIS)

Goris, L.; Poruba, A.; Hod'akova, L.; Vanecek, M.; Haenen, K.; Nesladek, M.; Wagner, P.; Vanderzande, D.; Schepper, L. de; Manca, J. V.

2006-01-01

This letter reports on highly sensitive optical absorption measurements on organic donor-acceptor solar cells, using Fourier-transform photocurrent spectroscopy (FTPS). The spectra cover an unprecedented dynamic range of eight to nine orders of magnitude making it possible to detect defect and disorder related sub-band gap transitions. Direct measurements on fully encapsulated solar cells with an active layer of poly[2-methoxy-5-(3 ' ,7 ' -dimethyl-octyloxy)]-p-phenylene-vinylene: (6,6)-phenyl-C61-butyric-acid (1:4 weight ratio) enabled a study of the intrinsic defect generation due to UV illumination. Solar cell temperature annealing effects in poly(3-hexylthiophene):PCBM (1:2 weight ratio) cells and the induced morphological changes are related to the changes in the absorption spectrum, as determined with FTPS

The addition of disilanes to cumulenes

Energy Technology Data Exchange (ETDEWEB)

Chen, Yiyuan [Iowa State Univ., Ames, IA (United States)

1997-10-08

The syntheses of silicon-containing compounds and the studies of their rearrangements have been active research areas in the Barton research group. Previously, the addition of disilanes to acetylenes was studied in the group and an intramolecular 2S + 2A mechanism has been proposed. In this thesis, the work is focused on the addition of disilanes to cumulenes. The syntheses of the precursors are discussed and the possible mechanisms for their thermal, photochemical and catalytic rearrangements are proposed. Conjugated organic polymers have been studied in the group since 1985 because of their potential for exhibiting high electroconductivity, photoconductivity, strong non-linear optical response and intense fluorescence. In the second section of this dissertation, the synthesis and property studies of poly(phenylene vinylene) analogues are discussed.

Analysis of risk factors and morphological ultrasound image for gallbladder polyp in adults living in Busan and Gyeongnam provinces

Energy Technology Data Exchange (ETDEWEB)

An, Hyeon [Dept. of Radiology, Inje University Busan Paik Hospital, Busan (Korea, Republic of); Hwang, Chul Hwan [Dept. of Radiation Oncology, Pusan National University Hospital, Busan (Korea, Republic of); Kim, Chang Soo; Ko, Sung Jin [Dept. of Radiological Science, College of Health Sciences, Catholic University of Pusan, Busan (Korea, Republic of)

2016-09-15

This study were to evaluate risk factors of GB polpy in Busan and Gyeongnam area. This study was performed with patients by abdominal ultrasonography among the patients who came to the P hospital from January to May 2016. Among them, risk factors were analyzed on 399 people at the same time when abdominal ultrasonography and hematological test. The statistical analysis of risk factors related to the GB ployp was performed by independent t-test and chi-square test. In consider of difference verification result for calculations odds ratio about independent variables, multiple logistic regression analysis to conduct verify adequacy by calculating forecasting model from variable. As a result, GB polyp risk factors have relevance to male, HBsAg positive, triglyceride. GB polyp risk factors confirmed to male, HBsAg positive, triglyceride were calculated forecasting model and forecasting probability value. Forecasting probability sensitivity 61.0%, specificity 76.8%, ROC area under curve 0.735 showed, it confirmed validity of forecasting model. When analyzing the GB polyps morphologically, among the GB polyp types observed from abdominal ultrasonography, the hyperechoic and homogeneous pattern with neck was the largest as shown from 27.5% and two GB polyps were shown most from 38%, sizes were shown most by maximum diameter, 5 to 10mm from 53%. As a disease accompany with GB polyp showed mild fatty liver(23%), diffuse hepatopathy(21%)

Helicobacter Pylori Associated Gastritis Increases Risk of Colorectal Polyps: a Hospital Based-Cross-Sectional Study in Nakhon Ratchasima Province, Northeastern Thailand.

Science.gov (United States)

Tongtawee, Taweesak; Kaewpitoon, Soraya; Kaewpitoon, Natthawut; Dechsukhum, Chavaboon; Leeanansaksiri, Wilairat; Loyd, Ryan A; Matrakool, Likit; Panpimanmas, Sukij

2016-01-01

Colorectal polyps are common in Thailand, particularly in the northeastern region. The present study aimed to determine any correlation between Helicobacter pylori-associated gastritis and colorectal polyps in the Thai population. A total of 303 patients undergoing esophagogastroduodenoscopy with colonoscopy for investigation of chronic abdominal pain participated in this study from November 2014 to October 2015. A diagnosis of Helicobacter pylori associated gastritis was made if the bacteria were seen on histopathological examination and a rapid urease test was positive. Colorectal polyps were confirmed by histological examination of colorectal biopsies. Patient demographic data were analyzed for correlations. The prevalence of colorectal polyps was 77 (25.4%), lesions being found more frequently in Helicobacter pylori infected patients than non-infected subjects [38.4% vs. 12.5%; Odds Ratio (OR) (95% CI): 2.26 (1.32 - 3.86), p gastritis were at high risk of having adenomas featuring dysplasia [OR (95% CI): 1.15 (1.16 - 7.99); P = 0.02]. There was no varaition in location of polyps, age group, sex and gastric lesions with respect to Helicobacter pylori status. This study showed that Helicobacter pylori associated gastritis is associated with an increased risk of colorectal polyps, especially adenomas with dysplasia in the Thai population. Patients with Helicobacter pylori-associated gastritis may benefit from concurrent colonoscopy for diagnosis of colorectal polyps as a preventive and early treatment for colorectal cancer.

Mixed T helper cell signatures in chronic rhinosinusitis with and without polyps.

Directory of Open Access Journals (Sweden)

Lara Derycke

Full Text Available In chronic rhinosinusitis (CRS different phenotypes have been reported based on cytokine profile and inflammatory cell patterns. The aim of this study was to characterize the intracytoplasmatic cytokines of T cells infiltrating the inflamed sinonasal mucosa.Infiltrated T cells and tissue homogenates from sinonasal mucosal samples of 7 healthy subjects, 9 patients with CRS without nasal polyp (CRSsNP, 15 with CRS with nasal polyps (CRSwNP and 5 cystic fibrosis patients (CF-NP were analyzed for cytokine expression using flow cytometry and multiplex analysis respectively. Intracytoplasmic cytokinesin T cells were analyzed after stimulation of nasal polyps with Staphylococcus aureus enterotoxin B for 24 hours.The number of T cells per total living cells was significantly higher in patients with CRSwNP vs. CRSsNP and controls. 85% of the CD4(+ T cells showed to be memory T cells. The effector T cells present in all tissues have a predominant Th1 phenotype. Only in CRSwNP, a significant fraction of T cells produced the Th2 cytokines IL-4 and IL-5, while nasal polyps from CF patients were characterized by a higher CD4/CD8 T cell ratio and an increased number of Th17 cells. 24 h stimulation with SEB resulted in a significant induction of CD4(+ T cells producing IL-10 (Tr1 cells.T cell cytokine patterns in healthy and inflamed sinonasal mucosa revealed that Th2 cells (IL-4 and IL-5 producing cells are significantly increased in CRSwNP mucosal inflammation. Exposure to SEB stimulates Tr1 cells that may contribute to the Th2 bias in CRSwNP.

Thin Film Polyamide Membranes with Photoresponsive Antibacterial Activity

KAUST Repository

Duong, Phuoc H. H.

2017-08-09

Membranes containing a photosensitizer molecule as part of the selective layer are proposed with demonstrated anti-biofouling activity. For the membrane preparation, mixtures of an amine-functionalized photosensitizer molecule, (5,10,15,20-(tetra-4-aminophenyl)porphyrin) and m-phenylene diamine (MPD) reacted with trimesoyl chloride (TMC) by interfacial polymerization to form thin polyamide films on top of an asymmetric porous support. A highly permeable membrane (35.4 Lm−2h−1bar−1) with 99 % rejection of Brilliant Blue R (826 g/mol) was obtained using 0.25 wt% porphyrin and 0.75 wt% MPD as amine monomers. Under visible light exposure, singlet oxygen (1O2) is generated in the porphyrin containing-polyamide film, reaching the bacteria in the feed by diffusion and enhancing the biofouling resistance and anti-microbial activity. Anti-biofouling and anti-microbial photoactivity in solution are demonstrated on Staphylococcus aureus at different porphyrin concentrations and light exposure time.

Thin Film Polyamide Membranes with Photoresponsive Antibacterial Activity

KAUST Repository

Duong, Phuoc H. H.; Hong, Pei-Ying; Musteata, Valentina-Elena; Peinemann, Klaus-Viktor; Nunes, Suzana Pereira

2017-01-01

Membranes containing a photosensitizer molecule as part of the selective layer are proposed with demonstrated anti-biofouling activity. For the membrane preparation, mixtures of an amine-functionalized photosensitizer molecule, (5,10,15,20-(tetra-4-aminophenyl)porphyrin) and m-phenylene diamine (MPD) reacted with trimesoyl chloride (TMC) by interfacial polymerization to form thin polyamide films on top of an asymmetric porous support. A highly permeable membrane (35.4 Lm−2h−1bar−1) with 99 % rejection of Brilliant Blue R (826 g/mol) was obtained using 0.25 wt% porphyrin and 0.75 wt% MPD as amine monomers. Under visible light exposure, singlet oxygen (1O2) is generated in the porphyrin containing-polyamide film, reaching the bacteria in the feed by diffusion and enhancing the biofouling resistance and anti-microbial activity. Anti-biofouling and anti-microbial photoactivity in solution are demonstrated on Staphylococcus aureus at different porphyrin concentrations and light exposure time.

BRAF, KRAS and PIK3CA mutations in colorectal serrated polyps and cancer: Primary or secondary genetic events in colorectal carcinogenesis?

Directory of Open Access Journals (Sweden)

Schmitt Fernando

2008-09-01

Full Text Available Abstract Background BRAF, KRAS and PIK3CA mutations are frequently found in sporadic colorectal cancer (CRC. In contrast to KRAS and PIK3CA mutations, BRAF mutations are associated with tumours harbouring CpG Island methylation phenotype (CIMP, MLH1 methylation and microsatellite instability (MSI. We aimed at determine the frequency of KRAS, BRAF and PIK3CA mutations in the process of colorectal tumourigenesis using a series of colorectal polyps and carcinomas. In the series of polyps CIMP, MLH1 methylation and MSI were also studied. Methods Mutation analyses were performed by PCR/sequencing. Bisulfite treated DNA was used to study CIMP and MLH1 methylation. MSI was detected by pentaplex PCR and Genescan analysis of quasimonomorphic mononucleotide repeats. Chi Square test and Fisher's Exact test were used to perform association studies. Results KRAS, PIK3CA or BRAF occur in 71% of polyps and were mutually exclusive. KRAS mutations occur in 35% of polyps. PIK3CA was found in one of the polyps. V600E BRAF mutations occur in 29% of cases, all of them classified as serrated adenoma. CIMP phenotype occurred in 25% of the polyps and all were mutated for BRAF. MLH1 methylation was not detected and all the polyps were microsatellite stable. The comparison between the frequency of oncogenic mutations in polyps and CRC (MSI and MSS lead us to demonstrate that KRAS and PIK3CA are likely to precede both types of CRC. BRAF mutations are likely to precede MSI carcinomas since the frequency found in serrated polyps is similar to what is found in MSI CRC (P = 0.9112, but statistically different from what is found in microsatellite stable (MSS tumours (P = 0.0191. Conclusion Our results show that BRAF, KRAS and PIK3CA mutations occur prior to malignant transformation demonstrating that these oncogenic alterations are primary genetic events in colorectal carcinogenesis. Further, we show that BRAF mutations occur in association with CIMP phenotype in colorectal

BRAF, KRAS and PIK3CA mutations in colorectal serrated polyps and cancer: Primary or secondary genetic events in colorectal carcinogenesis?

International Nuclear Information System (INIS)

Velho, Sérgia; Moutinho, Cátia; Cirnes, Luís; Albuquerque, Cristina; Hamelin, Richard; Schmitt, Fernando; Carneiro, Fátima; Oliveira, Carla; Seruca, Raquel

2008-01-01

BRAF, KRAS and PIK3CA mutations are frequently found in sporadic colorectal cancer (CRC). In contrast to KRAS and PIK3CA mutations, BRAF mutations are associated with tumours harbouring CpG Island methylation phenotype (CIMP), MLH1 methylation and microsatellite instability (MSI). We aimed at determine the frequency of KRAS, BRAF and PIK3CA mutations in the process of colorectal tumourigenesis using a series of colorectal polyps and carcinomas. In the series of polyps CIMP, MLH1 methylation and MSI were also studied. Mutation analyses were performed by PCR/sequencing. Bisulfite treated DNA was used to study CIMP and MLH1 methylation. MSI was detected by pentaplex PCR and Genescan analysis of quasimonomorphic mononucleotide repeats. Chi Square test and Fisher's Exact test were used to perform association studies. KRAS, PIK3CA or BRAF occur in 71% of polyps and were mutually exclusive. KRAS mutations occur in 35% of polyps. PIK3CA was found in one of the polyps. V600E BRAF mutations occur in 29% of cases, all of them classified as serrated adenoma. CIMP phenotype occurred in 25% of the polyps and all were mutated for BRAF. MLH1 methylation was not detected and all the polyps were microsatellite stable. The comparison between the frequency of oncogenic mutations in polyps and CRC (MSI and MSS) lead us to demonstrate that KRAS and PIK3CA are likely to precede both types of CRC. BRAF mutations are likely to precede MSI carcinomas since the frequency found in serrated polyps is similar to what is found in MSI CRC (P = 0.9112), but statistically different from what is found in microsatellite stable (MSS) tumours (P = 0.0191). Our results show that BRAF, KRAS and PIK3CA mutations occur prior to malignant transformation demonstrating that these oncogenic alterations are primary genetic events in colorectal carcinogenesis. Further, we show that BRAF mutations occur in association with CIMP phenotype in colorectal serrated polyps and verified that colorectal serrated

Clinical Significance of Contralateral Reactive Lesion in Vocal Fold Polyp and Cyst.

Science.gov (United States)

Cho, Jung-Hae; Choi, Yong-Sug; Joo, Young-Hoon; Park, Young-Hak; Sun, Dong-Il

2018-01-01

We investigated the clinical significance of contralateral reactive lesions in patients undergoing laryngeal microsurgery for benign vocal fold lesions such as vocal polyps and cysts. This was a retrospective, single institution cohort study. Patient medical records were reviewed for demographic characteristics; acoustic, aerodynamic, and perceptual analyses; and Voice Handicap Index score before and after laryngeal microsurgery. Definitive diagnoses were made via intraoperative microlaryngoscopic evaluations. Clinical parameters were assessed to identify risk factors for contralateral reactive lesions. We evaluated surgical outcome using voice analysis. We enrolled 268 patients (109 men and 159 women) with benign vocal fold lesions. A total of 195 (72.8%) had a contralateral reactive vocal fold lesion. A multivariable analysis revealed that being a never smoker and having a hoarseness duration ≥6 months, vocal polyps, and small primary lesions were independent risk factors for contralateral reactive lesions (P vocal fold lesions are frequently detected in patients with vocal polyp and cyst. The reactive lesions had an adverse effect on voice quality. Simultaneous excision of primary and contralateral reactive lesions may be an alternative treatment for better voice outcome. Copyright © 2018 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Risk factors for colorectal cancer in patients with multiple serrated polyps: a cross-sectional case series from genetics clinics.

Directory of Open Access Journals (Sweden)

Daniel D Buchanan

2010-07-01

Full Text Available Patients with multiple serrated polyps are at an increased risk for developing colorectal cancer (CRC. Recent reports have linked cigarette smoking with the subset of CRC that develops from serrated polyps. The aim of this work therefore was to investigate the association between smoking and the risk of CRC in high-risk genetics clinic patients presenting with multiple serrated polyps.We identified 151 Caucasian individuals with multiple serrated polyps including at least 5 outside the rectum, and classified patients into non-smokers, current or former smokers at the time of initial diagnosis of polyposis. Cases were individuals with multiple serrated polyps who presented with CRC. Controls were individuals with multiple serrated polyps and no CRC. Multivariate logistic regression was performed to estimate associations between smoking and CRC with adjustment for age at first presentation, sex and co-existing traditional adenomas, a feature that has been consistently linked with CRC risk in patients with multiple serrated polyps. CRC was present in 56 (37% individuals at presentation. Patients with at least one adenoma were 4 times more likely to present with CRC compared with patients without adenomas (OR = 4.09; 95%CI 1.27 to 13.14; P = 0.02. For females, the odds of CRC decreased by 90% in current smokers as compared to never smokers (OR = 0.10; 95%CI 0.02 to 0.47; P = 0.004 after adjusting for age and adenomas. For males, there was no relationship between current smoking and CRC. There was no statistical evidence of an association between former smoking and CRC for both sexes.A decreased odds for CRC was identified in females with multiple serrated polyps who currently smoke, independent of age and the presence of a traditional adenoma. Investigations into the biological basis for these observations could lead to non-smoking-related therapies being developed to decrease the risk of CRC and colectomy in these patients.

Synthesis and characterization of Th(IV) complex of bis-schiff base from o-vanillin and o-phenylene diamine

International Nuclear Information System (INIS)

Fan Yuhua; Bi Caifeng; Bao Meng

1997-01-01

The new solid complex of thorium nitrate with bis-schiff base (L) derived from o-vanillie and o-phenylene diamine has been synthesized and characterized by elemental analysis, DTA-TG, IR, UV and molar conductance analysis. The composition of the complex is confirmed to be ThL(NO 3 ) 4

Sessile serrated polyps of the colorectum are rare in patients with Lynch syndrome and in familial colorectal cancer families

DEFF Research Database (Denmark)

Andersen, S H; Lykke, E; Folker, M B

2008-01-01

Whereas the generally accepted carcinogenesis pathway of the microsatellite instabile high (MSI-H) colorectal carcinoma (CRC) involves the traditional adenoma in patients with Lynch syndrome, a serrate pathway involving serrate adenomas (SA) and sessile serrate polyps (SSP) characterize...... the sporadic MSI-H counterpart. Recent studies have, however, challenged such simple one-pathway models, inviting the consideration of alternative, unexpected pathways. Here, the issue as to the possible role of SSP, primarily in the context of Lynch syndrome, but also in subjects from familial CRC families...... (FCF) is addressed. Polyps coded as hyperplastic polyps (HP) from subjects with Lynch syndrome and FCF enrolled in the HNPCC-register at the Hvidovre University Hospital as well as adenomas from this population were retrieved and reviewed for features of SSP. Ninety-eight polyps coded as HP and 41...

Massive-training artificial neural network (MTANN) for reduction of false positives in computer-aided detection of polyps: Suppression of rectal tubes

International Nuclear Information System (INIS)

Suzuki, Kenji; Yoshida, Hiroyuki; Naeppi, Janne; Dachman, Abraham H.

2006-01-01

One of the limitations of the current computer-aided detection (CAD) of polyps in CT colonography (CTC) is a relatively large number of false-positive (FP) detections. Rectal tubes (RTs) are one of the typical sources of FPs because a portion of a RT, especially a portion of a bulbous tip, often exhibits a cap-like shape that closely mimics the appearance of a small polyp. Radiologists can easily recognize and dismiss RT-induced FPs; thus, they may lose their confidence in CAD as an effective tool if the CAD scheme generates such ''obvious'' FPs due to RTs consistently. In addition, RT-induced FPs may distract radiologists from less common true positives in the rectum. Therefore, removal RT-induced FPs as well as other types of FPs is desirable while maintaining a high sensitivity in the detection of polyps. We developed a three-dimensional (3D) massive-training artificial neural network (MTANN) for distinction between polyps and RTs in 3D CTC volumetric data. The 3D MTANN is a supervised volume-processing technique which is trained with input CTC volumes and the corresponding ''teaching'' volumes. The teaching volume for a polyp contains a 3D Gaussian distribution, and that for a RT contains zeros for enhancement of polyps and suppression of RTs, respectively. For distinction between polyps and nonpolyps including RTs, a 3D scoring method based on a 3D Gaussian weighting function is applied to the output of the trained 3D MTANN. Our database consisted of CTC examinations of 73 patients, scanned in both supine and prone positions (146 CTC data sets in total), with optical colonoscopy as a reference standard for the presence of polyps. Fifteen patients had 28 polyps, 15 of which were 5-9 mm and 13 were 10-25 mm in size. These CTC cases were subjected to our previously reported CAD scheme that included centerline-based segmentation of the colon, shape-based detection of polyps, and reduction of FPs by use of a Bayesian neural network based on geometric and texture

Hyperplastic Polyps Are Innocuous Lesions in Hereditary Nonpolyposis Colorectal Cancers

Directory of Open Access Journals (Sweden)

D. Speake

2011-01-01

Full Text Available Aims. To compare methylation profiles, protein expression, and microsatellite instability (MSI of sporadic, HNPCC, and familial hyperplastic polyps (HPs. Methods. Methylation-specific PCR (MSP and pyrosequencing assessed p16, MGMT, hMLH-1, MINT 1, and MINT 31 methylation. IHC (Immunohistochemistry assessed Ki67, CK20, hMLH-1, hMSH-2, and hMSH-6 protein expression. MSI analysis was performed on those polyps with adequate DNA remaining. Results. 124 HPs were identified 78 sporadic, 21 HNPCC, 25 familial, and the HNPCC group demonstrated no significant differences in overall methylation (P=.186 Chi2. The familial group demonstrated significantly less over all methylation levels (P=.004 Chi2. Conclusions. HPs that occur in HNPCC have no more worrying features at a molecular level than those patients with HPs in a sporadic setting.

The Heidelberg POLYP - a flexible and fault-tolerant poly-processor

International Nuclear Information System (INIS)

Maenner, R.; Deluigi, B.

1981-01-01

The Heidelberg poly-processor system POLYP is described. It is intended to be used in nuclear physics for reprocessing of experimental data, in high energy physics as second-stage trigger processor, and generally in other applications requiring high-computing power. The POLYP system consists of any number of I/O-processors, processor modules (eventually of different types), global memory segments, and a host processor. All modules (up to several hundred) are connected by a multiple common-data-bus system; all processors, additionally, by a multiple sync bus system for processor/task-scheduling. All hard- and software is designed to be decentralized and free of bottle-necks. Most hardware-faults like single-bit errors in memory or multi-bit errors during transfers are automatically corrected. Defective modules, buses, etc., can be removed with only a graceful degradation of the system-throughput. (orig.)

Calcification process dynamics in coral primary polyps as observed using a calcein incubation method

Directory of Open Access Journals (Sweden)

Yoshikazu Ohno

2017-03-01

Full Text Available Calcification processes are largely unknown in scleractinian corals. In this study, live confocal imaging was used to elucidate the spatiotemporal dynamics of the calcification process in aposymbiotic primary polyps of the coral species Acropora digitifera. The fluorophore calcein was used as a calcium deposition marker and a visible indicator of extracellular fluid distribution at the tissue-skeleton interface (subcalicoblastic medium, SCM in primary polyp tissues. Under continuous incubation in calcein-containing seawater, initial crystallization and skeletal growth were visualized among the calicoblastic cells in live primary polyp tissues. Additionally, the distribution of calcein-stained SCM and contraction movements of the pockets of SCM were captured at intervals of a few minutes. Our experimental system provided several new insights into coral calcification, particularly as a first step in monitoring the relationship between cellular dynamics and calcification in vivo. Our study suggests that coral calcification initiates at intercellular spaces, a finding that may contribute to the general understanding of coral calcification processes.

Gastroduodenal Intussusception Caused by a Peutz- Jeghers Polyp in a Young Child: A Case Report

Energy Technology Data Exchange (ETDEWEB)

Roh, Jae Eun; Cho, Bum Sang; Lee, Seung Young; Jeon, Min Hee; Lee, Ji Hyuk; Lee, Ho Chang; Koo, Ji Hae [Chungbuk National University College of Medicine, Cheongju (Korea, Republic of)

2010-09-15

Gastroduodenal intussusception is a rare condition caused by the prolapse of a gastric tumor with subsequent invagination of a portion of the gastric wall into the duodenum. Various gastric lesions including adenoma, lipoma, leiomyoma, hamartoma, adenocarcinoma, gastrointestinal stromal tumor (GIST), and as in our case a Peutz- Jeghers polyp, can serve as a lead point of intussusception. Only three cases of gastroduodenal intussusception secondary to a Peutz-Jeghers polyp have been reported. We experienced a case of gastroduodenal intussusception in a 36-month-old boy who presented with intermittent nonbilious vomiting, abdominal pain, and anemia. An abdominal ultrasound and contrast enhanced CT scan showed gastrointestinal intussusception and a mass-like lesion in the second portion of duodenum. A laparotomy revealed a 7x8 cm sized mass at the gastric body, which was pathologically confirmed as a Peutz-Jeghers polyp

Evaluation of promoter methylation status of MLH1 gene in Iranian patients with colorectal tumors and adenoma polyps.

Science.gov (United States)

Zarandi, Ashkan; Irani, Shiva; Savabkar, Sanaz; Chaleshi, Vahid; Ghavideldarestani, Maryam; Mirfakhraie, Reza; Khodadoostan, Mahsa; Nazemalhosseini-Mojarad, Ehsan; Asadzadeh Aghdaei, Hamid

2017-01-01

The aim of this study was to evaluate the methylation status of the promoter region of MLH1 gene in colorectal cancer (CRC) and its precursor lesions as well as elucidate its association with various clinicopathological characteristics among Iranian population. Epigenetic silencing of mismatch repair genes, such as MLH1 , by methylation of CpG islands of their promoter region has been proved to be an important mechanism in colorectal carcinogenesis. Fifty colorectal cancer and polyp tissue samples including 13 Primary colorectal tumor and 37 Adenoma polyp samples were enrolled in this study. Methylation-specific polymerase chain reaction (MSP) was performed to find the frequency of MLH1 Promoter Methylation. Promoter methylation of MLH1 gene was detected in 5 out of 13 tumor tissues and 4 out of 37 adenoma polyp. The frequency of MLH1 methylation in tumor samples was significantly higher compared to that in polyp tissues (P= 0.026). No significant association was observed between MLH1 promoter methylation and clinicopathological characteristics of the patients. The frequency of  MLH1  promoter methylation in CRC and colon polyp was 18%. Our findings indicated that methylation of MLH1 promoter region alone cannot be considered as a biomarker for early detection of CRC.

Histogram-based adaptive gray level scaling for texture feature classification of colorectal polyps

Science.gov (United States)

Pomeroy, Marc; Lu, Hongbing; Pickhardt, Perry J.; Liang, Zhengrong

2018-02-01

Texture features have played an ever increasing role in computer aided detection (CADe) and diagnosis (CADx) methods since their inception. Texture features are often used as a method of false positive reduction for CADe packages, especially for detecting colorectal polyps and distinguishing them from falsely tagged residual stool and healthy colon wall folds. While texture features have shown great success there, the performance of texture features for CADx have lagged behind primarily because of the more similar features among different polyps types. In this paper, we present an adaptive gray level scaling and compare it to the conventional equal-spacing of gray level bins. We use a dataset taken from computed tomography colonography patients, with 392 polyp regions of interest (ROIs) identified and have a confirmed diagnosis through pathology. Using the histogram information from the entire ROI dataset, we generate the gray level bins such that each bin contains roughly the same number of voxels Each image ROI is the scaled down to two different numbers of gray levels, using both an equal spacing of Hounsfield units for each bin, and our adaptive method. We compute a set of texture features from the scaled images including 30 gray level co-occurrence matrix (GLCM) features and 11 gray level run length matrix (GLRLM) features. Using a random forest classifier to distinguish between hyperplastic polyps and all others (adenomas and adenocarcinomas), we find that the adaptive gray level scaling can improve performance based on the area under the receiver operating characteristic curve by up to 4.6%.

Processing of intractable polymers using reactive solvents: 1. Poly(2,6-dimethyl-1,4-phenylene ether)/epoxy resin

NARCIS (Netherlands)

Venderbosch, R.W.; Meijer, H.E.H.; Lemstra, P.J.

1994-01-01

A new processing route for poly(2,6-dimethyl-1,4-phenylene ether) (PPE), an intractable polymer on account of its thermal and oxidative sensitivity, was explored. PPE can be dissolved at elevated temperatures in epoxy resin and these solutions can then be processed at temperatures as low as 175°C.

Surveillance of FAP: a prospective blinded comparison of capsule endoscopy and other GI imaging to detect small bowel polyps

Directory of Open Access Journals (Sweden)

Tescher Paul

2010-04-01

Full Text Available Abstract Background Familial adenomatous polyposis (FAP is a hereditary disorder characterized by polyposis along the gastrointestinal tract. Information on adenoma status below the duodenum has previously been restricted due to its inaccessibility in vivo. Capsule Endoscopy (CE may provide a useful adjunct in screening for polyposis in the small bowel in FAP patients. This study aims to evaluate the effectiveness of CE in the assessment of patients with FAP, compared to other imaging modalities for the detection of small bowel polyps. Method 20 consecutive patients with previously diagnosed FAP and duodenal polyps, presenting for routine surveillance of polyps at The Royal Melbourne Hospital were recruited. Each fasted patient initially underwent a magnetic resonance image (MRI of the abdomen, and a barium small bowel follow-through study. Capsule Endoscopy was performed four weeks later on the fasted patient. An upper gastrointestinal side-viewing endoscopy was done one (1 to two (2 weeks after this. Endoscopists and investigators were blinded to results of other investigations and patient history. Results Within the stomach, upper gastrointestinal endoscopy found more polyps than other forms of imaging. SBFT and MRI generally performed poorly, identifying fewer polyps than both upper gastrointestinal and capsule endoscopy. CE was the only form of imaging that identified polyps in all segments of the small bowel as well as the only form of imaging able to provide multiple findings outside the stomach/duodenum. Conclusion CE provides important information on possible polyp development distal to the duodenum, which may lead to surgical intervention. The place of CE as an adjunct in surveillance of FAP for a specific subset needs consideration and confirmation in replication studies. Trial Registration Australian New Zealand Clinical Trials Registry ACTRN12608000616370

Three-Dimensional Flow Separation Induced by a Model Vocal Fold Polyp

Science.gov (United States)

Stewart, Kelley C.; Erath, Byron D.; Plesniak, Michael W.

2012-11-01

The fluid-structure energy exchange process for normal speech has been studied extensively, but it is not well understood for pathological conditions. Polyps and nodules, which are geometric abnormalities that form on the medial surface of the vocal folds, can disrupt vocal fold dynamics and thus can have devastating consequences on a patient's ability to communicate. A recent in-vitro investigation of a model polyp in a driven vocal fold apparatus demonstrated that such a geometric abnormality considerably disrupts the glottal jet behavior and that this flow field adjustment was a likely reason for the severe degradation of the vocal quality in patients. Understanding of the formation and propagation of vortical structures from a geometric protuberance, and their subsequent impact on the aerodynamic loadings that drive vocal fold dynamic, is a critical component in advancing the treatment of this pathological condition. The present investigation concerns the three-dimensional flow separation induced by a wall-mounted prolate hemispheroid with a 2:1 aspect ratio in cross flow, i.e. a model vocal fold polyp. Unsteady three-dimensional flow separation and its impact of the wall pressure loading are examined using skin friction line visualization and wall pressure measurements. Supported by the National Science Foundation, Grant No. CBET-1236351 and GW Center for Biomimetics and Bioinspired Engineering (COBRE).

Synthesis and luminescent properties of star-burst D-π-A compounds based on 1,3,5-triazine core and carbazole end-capped phenylene ethynylene arms

Energy Technology Data Exchange (ETDEWEB)

Zhang, Zheng [Department of Applied Chemistry, Nanjing Tech University, Nanjing 210009 (China); Liu, Rui, E-mail: rui.liu@njtech.edu.cn [Department of Applied Chemistry, Nanjing Tech University, Nanjing 210009 (China); Zhu, Xiaolin [Department of Applied Chemistry, Nanjing Tech University, Nanjing 210009 (China); Li, Yuhao [Department of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433 (China); Chang, Jin [Queensland University of Technology, 2 George St., Brisbane 4000 (Australia); Zhu, Hongjun, E-mail: zhuhjnjut@hotmail.com [Department of Applied Chemistry, Nanjing Tech University, Nanjing 210009 (China); Ma, Liangwei; Lv, Wangjie; Guo, Jun [Department of Applied Chemistry, Nanjing Tech University, Nanjing 210009 (China)

2014-12-15

Two new star-burst compounds based on 1,3,5-triazine core and carbazole end-capped phenylene ethynylene arms (1a and 1b) were synthesized and characterized. Their photophysical properties were investigated systematically via spectroscopic and theoretical methods. Both compounds exhibit strong {sup 1}π–π{sup ⁎} transitions in the UV region and intense {sup 1}π–π{sup ⁎}/intramolecular charge transfer ({sup 1}ICT) absorption bands in the UV–vis region. Introducing the carbazole end-capped phenylene ethynylene arm on the 1,3,5-triazine core causes a slight bathochromic shift and enhanced molar extinction coefficient of the {sup 1}π–π{sup ⁎}/{sup 1}ICT transition band. Both compounds are emissive in solution at room temperature and 77 K, which exhibit pronounced positive solvatochromic effect. The emitting state could be ascribed to {sup 1}ICT state in more polar solvent, and {sup 1}π–π{sup ⁎} state in low-polarity solvent. The high emission quantum yields (Φ{sub em}=0.90∼1.0) of 1a and 1b (in hexane and toluene) make them potential candidates as efficient light-emitting materials. The spectroscopic studies and theoretical calculations indicate that the photophysical properties of these compounds can be tuned by the carbazole end-capped phenylene ethynylene arm, which would also be useful for rational design of photofunctional materials. - Highlights: • Star-burst compounds based on 1,3,5-triazine core and carbazole end-capped phenylene ethynylene arms. • Photophysical properties of target compounds were investigated systematically via spectroscopic and theoretical methods. • The relatively high fluorescence quantum yields make them potential candidates as light-emitting materials.

Prostatic-type polyp in the bladder. A case report

DEFF Research Database (Denmark)

Hansen, B J; Christensen, S W; Eldrup, J

1989-01-01

A case of prostatic-type polyp in the wall of the urinary bladder in a 73-year-old male is presented. The literature concerning ectopic prostatic tissue in the urinary tract is reviewed and it is concluded that the lesion is benign. However, recurrence has been reported in two cases. The etiology...

Resonant stimulation of Raman scattering from single-crystal thiophene/phenylene co-oligomers

International Nuclear Information System (INIS)

Yanagi, Hisao; Marutani, Yusuke; Matsuoka, Naoki; Hiramatsu, Toru; Ishizumi, Atsushi; Sasaki, Fumio; Hotta, Shu

2013-01-01

Amplified Raman scattering was observed from single crystals of thiophene/phenylene co-oligomers (TPCOs). Under ns-pulsed excitation, the TPCO crystals exhibited amplified spontaneous emission (ASE) at resonant absorption wavelengths. With increasing excitation wavelength to the 0-0 absorption edge, the stimulated resonant Raman peaks appeared both in the 0-1 and 0-2 ASE band regions. When the excitation wavelength coincided with the 0-1 ASE band energy, the Raman peaks selectively appeared in the 0-2 ASE band. Such unusual enhancement of the 0-2 Raman scattering was ascribed to resonant stimulation via vibronic coupling with electronic transitions in the uniaxially oriented TPCO molecules

Distribution kinetics of 3H-labelled p-phenylene diamine - - a hair dye

International Nuclear Information System (INIS)

Rehani, M.M.; Jain, I.S.; Sharma, S.K.

1981-01-01

The distribution kinetics of the 3 H-labelled p-phenylene diamine (a hair dye compound), was studied when administered iv and when applied percutaneously. The tracer experiments in rabbits after iv administration showed a biphasic blood clearance with half life values of 24 min and 43.5 h and quick-percutaneous absorption. The tissue distribution pattern investigated after iv and percutaneous administration in 16 different tissues and also in blood did not demonstrate any target organ for selective localisation of the dye. Not more than 0.06 percent of the iv administered radioactivity was measured per 10 mg of any tissue at 12th day. (author)

Poly(p-Phenylene Sulfonic Acids). PEMs with frozen-in free volume

Energy Technology Data Exchange (ETDEWEB)

Litt, Morton [Case Western Reserve Univ., Cleveland, OH (United States)

2016-01-21

Early work with rigid rod aromatic polyelectrolytes implied that steric hindrance in packing of the rigid rods left unoccupied volumes that could absorb and hold water molecules strongly. We called this “frozen in free volume). It is illustrated and contrasted with the packing of flexible backbone polyelectrolytes (Reference 5 of this report). This was quantified for poly(biphenylene disulfonic acid) (PBDSA) and poly(phenylene disulfonic acid) (PPDSA). We found that PPDSA held three water molecules per acid group down to 11% relative humidity (RH) and had very high conductivity even at these low RHs. (Reference 1 of report.) The frozen-in free volume was calculated to be equivalent to a λ of 3.5. The work reported below concentrated on studying these polymers and their copolymers with biphenylene disulfonic acid. As expected, the polyelectrolytes are water soluble. Several approaches towards making water stable films were studied. Grafting alkyl benzene substituents on sulfonic acid groups had worked for PBPDSA (1) so it was tried with PPDSA and a 20%/80% copolymer of BPDSA and PDSA (B20P80). T-butyl, n-octyl and n-dodecyl benzene were grafted. Good films could be made. Water absorption and conductivity were studied as a function of RH and temperature (Reference 2). When less than 20% of the sulfonic acid groups were grafted, conductivity was much higher than that of Nafion NR212 at all RHs. At low graft levels, conductivity was ten times higher. Mechanical properties and swelling were acceptable below 90% RH. However, all the films were unstable in water and slowly disintegrated. The proposed explanation was that the molecules formed nano-aggregates in solution held together by hydrophobic bonding. Their cast films disintegrated when placed in water since hydrophobic bonding between the nano-aggregates was poor. We then shifted to crosslinking as a method to produce water stable films (References 3 and 4). Biphenyl could easily be reacted with the polymer

Pulp polyp - A periapical lesion: Radiographic observational study

Directory of Open Access Journals (Sweden)

Kandagal V Suresh

2015-01-01

Full Text Available Introduction: Pulp polyp (PP is a chronic hyperplastic condition resulting in formation of granulation tissue and proliferative mass. The radiographic appearance of PP has innumerable presentations. Diagnosing and treatment planning of periapical lesions, heavily relies on the radiographic changes surrounding the root structures. Objective: To evaluate different radiographic periapical changes in clinically detected PP patients. Materials and Methods: Patients reporting to Department of Oral Medicine and Radiology and who were clinically diagnosed with PP by an oral diagnostician were subjected to radiographic examination. Digital intraoral periapical radiographs of 50 patients with PP were taken. Various periapical changes in the digital radiographs were recorded by a skilled oral radiologist. The data obtained was subjected to statistical analysis using SPSS ver 17.0 and P-value was set at <0.05 as significant. Result: Periapical changes like periodontal space widening (PDLW, loss of lamina dura, periapical abscess, periapical granuloma, hypercementosis, condensing osteitis and root resorption were noted. Periodontal space widening was seen in all patients (100%, loss of lamina dura was noted in 72%, periapical rarefying osteitis in 56%, condensing osteitis in 8%, hypercementosis, periapical granuloma, and root resorption were seen in 4% of PP patients. Majority of PP were asymptomatic (66%. Pulp polyp was commonly seen in mandibular first molar followed by mandibular second molar and maxillary first molar. Statistically significant difference was noticed between periapical changes in PP patients (P value <0.0001. All PP patients showed definite periapical changes suggesting it to be a periapical lesion. Conclusion: Pulp polyp is confined to the pulpal portion of the tooth which, may or may not cause changes in periapical region. The results of the present study showed that majority of the PP patients were associated with definite periapical

Dark Antimicrobial Mechanisms of Cationic Phenylene Ethynylene Polymers and Oligomers against Escherichia coli

Directory of Open Access Journals (Sweden)

Taylor D. Canady

2011-07-01

Full Text Available The interactions of poly(phenylene ethynylene (PPE-based cationic conjugated polyelectrolytes (CPEs and oligo-phenylene ethynylenes (OPEs with E. coli cells are investigated to gain insights into the differences in the dark killing mechanisms between CPEs and OPEs. A laboratory strain of E. coli with antibiotic resistance is included in this work to study the influence of antibiotic resistance on the antimicrobial activity of the CPEs and OPEs. In agreement with our previous findings, these compounds can efficiently perturb the bacterial cell wall and cytoplasmic membrane, resulting in bacterial cell death. Electron microscopy imaging and cytoplasmic membrane permeability assays reveal that the oligomeric OPEs penetrate the bacterial outer membrane and interact efficiently with the bacterial cytoplasmic membrane. In contrast, the polymeric CPEs cause serious damage to the cell surface. In addition, the minimum inhibitory concentration (MIC and hemolytic concentration (HC of the CPEs and OPEs are also measured to compare their antimicrobial activities against two different strains of E. coli with the compounds’ toxicity levels against human red blood cells (RBC. MIC and HC measurements are in good agreement with our previous model membrane perturbation study, which reveals that the different membrane perturbation abilities of the CPEs and OPEs are in part responsible for their selectivity towards bacteria compared to mammalian cells. Our study gives insight to several structural features of the PPE-based CPEs and OPEs that modulate their antimicrobial properties and that these features can serve as a basis for further tuning their structures to optimize antimicrobial properties.

Modelling coral polyp calcification in relation to ocean acidification

Directory of Open Access Journals (Sweden)

S. Hohn

2012-11-01

Full Text Available Rising atmospheric CO₂ concentrations due to anthropogenic emissions induce changes in the carbonate chemistry of the oceans and, ultimately, a drop in ocean pH. This acidification process can harm calcifying organisms like coccolithophores, molluscs, echinoderms, and corals. It is expected that ocean acidification in combination with other anthropogenic stressors will cause a severe decline in coral abundance by the end of this century, with associated disastrous effects on reef ecosystems. Despite the growing importance of the topic, little progress has been made with respect to modelling the impact of acidification on coral calcification. Here we present a model for a coral polyp that simulates the carbonate system in four different compartments: the seawater, the polyp tissue, the coelenteron, and the calcifying fluid. Precipitation of calcium carbonate takes place in the metabolically controlled calcifying fluid beneath the polyp tissue. The model is adjusted to a state of activity as observed by direct microsensor measurements in the calcifying fluid. We find that a transport mechanism for bicarbonate is required to supplement carbon into the calcifying fluid because CO₂ diffusion alone is not sufficient to sustain the observed calcification rates. Simulated CO₂ perturbation experiments reveal decreasing calcification rates under elevated pCO₂ despite the strong metabolic control of the calcifying fluid. Diffusion of CO₂ through the tissue into the calcifying fluid increases with increasing seawater pCO₂, leading to decreased aragonite saturation in the calcifying fluid. Our modelling study provides important insights into the complexity of the calcification process at the organism level and helps to quantify the effect of ocean acidification on corals.

Enhanced chemical sensing organic thin-film transistors

Science.gov (United States)

Tanese, M. C.; Torsi, L.; Farinola, G. M.; Valli, L.; Hassan Omar, O.; Giancane, G.; Ieva, E.; Babudri, F.; Palmisano, F.; Naso, F.; Zambonin, P. G.

2007-09-01

Organic thin film transistor (OTFT) sensors are capable of fast, sensitive and reliable detection of a variety of analytes. They have been successfully tested towards many chemical and biological "odor" molecules showing high selectivity, and displaying the additional advantage of being compatible with plastic technologies. Their versatility is based on the possibility to control the device properties, from molecular design up to device architecture. Here phenylene-thiophene based organic semiconductors functionalized with ad hoc chosen side groups are used as active layers in sensing OTFTs. These materials, indeed, combine the detection capability of organic molecules (particularly in the case of bio-substituted systems) with the electronic properties of the conjugated backbone. A new OTFT structure including Langmuir-Schäfer layer by layer organic thin films is here proposed to perform chemical detection of organic vapors, including vapor phase chiral molecules such as citronellol vapors, with a detection limit in the ppm range. Thermally evaporated α6T based OTFT sensors are used as well to be employed as standard system in order to compare sensors performances.

Dendrimeric Thin-Film Composite Membranes: Free Volume, Roughness, and Fouling Resistance

KAUST Repository

Phuoc, Duong

2017-11-10

Copolyamide films with a thickness from 50 to 780 nm were fabricated by interfacial polymerization between mixtures of m-phenylene diamine and primary amine-terminated polyamidoamine dendrimers (PAMAM) in the aqueous phase and trimesoyl chloride (TMC) in the organic phase. Different PAMAM generations (G0, d = 15 Å, Z = 4; G3, d = 36 Å, Z = 32; and G5, d = 54, Z = 128, where d is the measured diameter and Z is the number of terminal groups) and concentrations were used to obtain copolyamide films with different crosslinked structures. The influences of the concentration and degree of branching (PAMAM generation) on free volume were analysed via positon annihilation spectroscopy (PAS) and correlated with the separation properties of copolyamide films. Besides, surface and intrinsic properties of copolyamide films under different conditions were compared. The high hydrophilicity of PAMAM in the copolyamide network leads to the formation of a hydration layer on the copolyamide surface, which minimizes fouling. The separation performance of copolyamide membranes with various PAMAM networks was investigated in forward osmosis (FO) experiments. Understanding the correlation between the PAMAM structure/concentration, free volume, thickness, and surface intrinsic properties leads to the design of suitable fouling resistant thin-film composite membranes in a single interfacial polymerization process.

Observation of the energy transfer sequence in an organic host–guest system of a luminescent polymer and a phosphorescent molecule

Energy Technology Data Exchange (ETDEWEB)

Basel, Tek; Sun, Dali; Gautam, Bhoj; Valy Vardeny, Z., E-mail: val@physics.utah.edu

2014-11-15

We used steady state optical spectroscopies such as photoluminescence and photoinduced absorption (PA), and magnetic-field PA (MPA) for studying the energy transfer dynamics in films and organic light emitting diodes (OLED) based on host–guest blends with different guest concentrations of the fluorescent polymer poly-[2-methoxy, 5-(2′-ethyl-hexyloxy)phenylene vinylene] (MEHPPV-host), and phosphorescent molecule PtII-tetraphenyltetrabenzoporphyrin [Pt(tpbp); guest]. We show that the energy transfer process between the excited states of the host polymer and guest molecule takes a ‘ping-pong’ type sequence, because the lowest guest triplet exciton energy, E{sub T}(guest), lies higher than that of the host, E{sub T}(host). Upon photon excitation the photogenerated singlet excitons in the host polymer chains first undergo a Förster resonant energy transfer process to the guest singlet manifold, which subsequently reaches E{sub T}(guest) by intersystem crossing. Because E{sub T}(guest)>E{sub T}(host) there is a subsequent Dexter type energy transfer from E{sub T}(guest) to E{sub T}(host). This energy transfer sequence has profound influence on the photoluminescence and electroluminescence emission spectra in both films and OLED devices based on the MEHPPV-Pt(tpbp) system. - Highlights: • We studied electroluminescence of OLEDs based on host–guest blends. • The emission efficiency decreases with the guest concentration. • We found a dominant Dexter energy transfer from the triplet(guest) to triplet(host). • Energy transfer occurs from the host to guest and back to the host again.

Synchronous cecal adenocarcinoma and multiple colonic in situ carcinomas in hamartomatous polyps in a case of isolated Peutz–Jeghers syndrome

Directory of Open Access Journals (Sweden)

Yahia Z Gad

2011-03-01

Full Text Available Yahia Z Gad1, Doaa H Bakr1, Mohammad G El-Ebeidy21Department of Internal Medicine, 2Department of Surgery, Mansoura Specialized Medical Hospital, Mansoura University, Mansoura, EgyptBackground: Peutz–Jeghers syndrome (PJS is a rare autosomal dominant disease characterized by mucocutaneous pigmentation and hamartomatous polyps of the entire gastrointestinal tract. A Peutz–Jeghers polyp (PJP in a patient without pigmentation or a family history of the disease is called an isolated or solitary PJP. Individuals with PJS carry a very high risk of developing gastrointestinal (GI as well as extra-GI malignancies. This case report documents lesion multiplicity and their malignant potential in a young patient with PJS presenting in a serious condition for the first time.Case report: An 18-year-old female Egyptian patient was admitted with hematochezia and remarkable anemia. After appropriate resuscitation and consent, colonoscopic evaluation revealed seven pedunculated colonic polyps at the ascending and the transverse colon, and numerous variable-sized sessile polyps were scattered all over the colon. To establish hemostasis, endoscopic polypectomy for pedunculated polyps and argon plasma photocoagulation for the bleeding sessile polyps were performed. Histopathological examination revealed cecal adenocarcinoma in one specimen and two simultaneous in situ carcinoma at the transverse and the sigmoid colon in the mucosae of the excised histologically proven hamartomatous polyps. Additionally, one focal in situ carcinoma in the resected colon was detected.Conclusions: When considering the family history, serious GI neoplastic lesions may be unmasked in young patients with PJS who present with hematochezia, even in the absence of its characteristic mucocutaneous pigmented lesions. GI endoscopic surveillance programs should be adopted for diagnosed cases of PJS and their families. Genetic prenatal screening for early detection is the best option for

Self organized growth of organic thiophene-phenylene nanowires on silicate surfaces

DEFF Research Database (Denmark)

Balzer, F.; Schiek, Manuela; Lützen, Arne

2009-01-01

changes in the choice of the substrate lead to distinctly different growth behavior. On muscovite, a commensurate wetting layer of lying molecules is initially formed with subsequent formation of clusters, which assemble into mutually parallel nanowires. The wires grow along a 110 muscovite direction......Results of a systematic study of the growth of blue-green light-emitting 2,5-di-4-biphenyl-thiophene (PPTPP) molecules on the (001) faces of the sheet silicates muscovite and phlogopite mica are reported. This includes morphology, crystallography, and optical properties. It is shown that small....... In comparison to similar organic molecules, it is found that overall PPTPP has a growth behavior more similar to that of the p-phenylenes as compared to that of the α-thiophenes....

Severe dyspnea due to a giant antrochoanal polyp

OpenAIRE

Coloma-Milano M; Gil-Carcedo-Sañudo E; Gil-Carcedo-García LM.; Martín-Batista S; Madrigal-Revuelta M; Vallejo-Valdezate LA

2012-01-01

SummaryIntroduction: The antrochoanal polyp is a prevalent pathology in teenagers and young adults. It usually presents with nasal obstruction.Patient and method: Case report: An 80-year-old male with alcoholic encephalopathy, chronic bronchial disease of unknown etiology and polypoid chronic rhinosinusitis came to the emergency service with severe dyspnea without laryngeal features.Anterior rhinoscopy showed a polypoid mass in left nostril that prevented the visualization with nasal endoscop...

Causative Role of Ureaplasma Urealyticum and other Sexually Transmitted Infections in the Urethral Meatus Polyp Development in Women

Directory of Open Access Journals (Sweden)

Tatyana S. Taranina

2013-09-01

Full Text Available The objective of this study was the investigation of the influence of ureaplasmal infection on the development of urethral meatus polyps in women. The article presents the results of the examination of women with chronic cystitis and urethritis over a 0.5- to 5-year duration, complicated by the presence of urethral meatus polyps and associated with concomitant Ureaplasma urealyticum and other sexually transmitted infections (STI. This was based on the culture analysis of the cervical and urethral content, and PCR-diagnostics of STI, as well as a complex pathomorphologic study of the resected polyps, including electron microscopy. In this study, 98 women between 45 and 60 years (52.5±4.9 years were examined, who had undergone radiowave resection of the polyps: 52 women were infected by STI, including Ureaplasma urealyticum, Mycoplasma genitalium, Mycoplasma hominis, Chlamydia trachomatis and Trichomonas vaginalis, while the remaining 46 women had been diagnosed as not having STI. According to the culture results in the women with STI, U. urealyticum was identified as a monoinfection in 69% of cases, while in the remaining 31% of cases it was evident in the form of mixed infections, mainly in association with Mycoplasma hominis (17.5% and Trichomonas vaginalis (13.5%. Pathomorphological examination of the urethral meatus polyps of the women with U. urealyticum and other STI demonstrated the proliferative character of the remodeling of the surface epithelium with hyperplasia, acanthosis, and keratinization of the stratified squamous epithelium and synchronous changes in the underlying connective tissue - impaired microcirculation and the diffuse inflammatory cell infiltrates with transepithelial leukopedesis. Using electron microscopy in the fibroblasts and plasma cells of the resected polyps the markers of U. urealyticum were detected in patients with negative results of the bacteriological diagnostic methods.

Pyrene-Containing ortho-Oligo(phenylene)ethynylene Foldamer as a Ratiometric Probe Based on Circularly Polarized Luminescence.

Science.gov (United States)

Reiné, Pablo; Justicia, Jose; Morcillo, Sara P; Abbate, Sergio; Vaz, Belen; Ribagorda, María; Orte, Ángel; Álvarez de Cienfuegos, Luis; Longhi, Giovanna; Campaña, Araceli G; Miguel, Delia; Cuerva, Juan M

2018-04-20

In this manuscript, we report the first synthesis of an organic monomolecular emitter, which behaves as a circularly polarized luminescence (CPL)-based ratiometric probe. The enantiopure helical ortho-oligo(phenylene)ethynylene ( o-OPE) core has been prepared by a new and efficient macrocyclization reaction. The combination of such o-OPE helical skeleton and a pyrene couple leads to two different CPL emission features in a single structure whose ratio linearly responds to silver(I) concentration.

The rare presentations of a large polyp and an esophageal carcinoma in heterotropic gastric mucosa: a case series

Directory of Open Access Journals (Sweden)

Alagozlu Hakan

2007-11-01

Full Text Available Abstract Background Heterotopic gastric mucosa (HGM is commonly seen in the upper esophagus during endoscopyand is generally considered a benign disease. A hyperplastic polyp and an adenocarcinoma arising in heterotopic gastric mucosa are quite rare occurences. Case presentations We present two cases: The first is a patient who suffered from dysphagia because of a large hyperplastic polyp that arose from HGM; the polyp was excised endoscopically. Secondly, we report a rare case of adenocarcinoma arising in HGM of the cervical esophagus. Conclusion Morphologic changes or malignant transformation can develop in the inlet patch. Therefore, gastroenterologists should be aware of the possibility of HGM just distal to the upper esophageal sphincter.

Endometrial Polyps and Abnormal Uterine Bleeding (AUB-P): What is the relationship, how are they diagnosed and how are they treated?

Science.gov (United States)

Clark, T Justin; Stevenson, Helen

2017-04-01

The diagnosis and treatment of endometrial polyps will be familiar to most gynaecologists. However, the aetiology and natural history of these focal intrauterine lesions are yet to be elucidated. This lack of clarity is also true with regard to their clinical significance; whilst endometrial polyps are highly prevalent in all types of abnormal uterine bleeding (AUB), they are also commonly found in women without AUB. These controversies will be discussed along with current thoughts on the diagnosis and treatment of endometrial polyps. Criteria for diagnosis of uterine polyps vary according to the test used, but optimal testing is not yet solidified. Recent data from randomised trials evaluating new and established surgical technologies as well as comparing treatment protocols and settings will be examined. Copyright © 2016. Published by Elsevier Ltd.

Optical Spectroscopy

DEFF Research Database (Denmark)

Thyrhaug, Erling

The work presented in this thesis is broadly concerned with how complexation reactions and molecular motion can be characterized with the standard techniques in optical spectroscopy. The thesis aims to show a relatively broad range of methods for probing physico-chemical properties in fluorophore...... information about chemical equilibria, kinetics and molecular motion by monitoring changes in optical properties of the system. The five presented research projects are largely unrelated to each other both in aim and in what property is probed, however they are all connected in that they are fluorophore...... reactions by optical spectroscopy. In project 1 simple steady-state absorption and fluorescence spectroscopy is used to determine the stoichiometries and equilibrium constants in the inclusion complex formation between cyclodextrins and derivatives of the water-insoluble oligo(phenylene vinylene) in aqueous...

Charge transport and recombination in bulk heterojunction solar cells studied by the photoinduced charge extraction in linearly increasing voltage technique

Science.gov (United States)

Mozer, A. J.; Sariciftci, N. S.; Lutsen, L.; Vanderzande, D.; Österbacka, R.; Westerling, M.; Juška, G.

2005-03-01

Charge carrier mobility and recombination in a bulk heterojunction solar cell based on the mixture of poly[2-methoxy-5-(3,7-dimethyloctyloxy)-phenylene vinylene] (MDMO-PPV) and 1-(3-methoxycarbonyl)propyl-1-phenyl-(6,6)-C61 (PCBM) has been studied using the novel technique of photoinduced charge carrier extraction in a linearly increasing voltage (Photo-CELIV). In this technique, charge carriers are photogenerated by a short laser flash, and extracted under a reverse bias voltage ramp after an adjustable delay time (tdel). The Photo-CELIV mobility at room temperature is found to be μ =2×10-4cm2V-1s-1, which is almost independent on charge carrier density, but slightly dependent on tdel. Furthermore, determination of charge carrier lifetime and demonstration of an electric field dependent mobility is presented.

Computer-Aided Detection of Polyps in CT Colonography Using Logistic Regression

NARCIS (Netherlands)

Van Ravesteijn, V.F.; Van Wijk, C.; Vos, F.M.; Truyen, R.; Peters, J.F.; Stoker, J.; Van Vliet, L.J.

2010-01-01

We present a computer-aided detection (CAD) system for computed tomography colonography that orders the polyps according to clinical relevance. TheCADsystem consists of two steps: candidate detection and supervised classification. The characteristics of the detection step lead to specific choices

The serrated neoplasia pathway of colorectal tumors: Identification of MUC5AC hypomethylation as an early marker of polyps with malignant potential.

Science.gov (United States)

Renaud, Florence; Mariette, Christophe; Vincent, Audrey; Wacrenier, Agnès; Maunoury, Vincent; Leclerc, Julie; Coppin, Lucie; Crépin, Michel; Van Seuningen, Isabelle; Leteurtre, Emmanuelle; Buisine, Marie-Pierre

2016-03-15

The serrated neoplasia pathway accounts for 20-30% of colorectal cancers (CRC), which are characterized by extensive methylation (CpG island methylation phenotype, CIMP), frequent BRAF mutation and high microsatellite instability (MSI). We recently identified MUC5AC mucin gene hypomethylation as a specific marker of MSI CRC. The early identification of preneoplastic lesions among serrated polyps is currently challenging. Here, we performed a detailed pathological and molecular analysis of a large series of colorectal serrated polyps and evaluated the usefulness of mucin genes MUC2 and MUC5AC to differentiate serrated polyps and to identify lesions with malignant potential. A series of 330 colorectal polyps including 218 serrated polyps [42 goblet cell-rich hyperplastic polyps (GCHP), 68 microvesicular hyperplastic polyps (MVHP), 100 sessile serrated adenoma (SSA) and eight traditional serrated adenoma (TSA)] and 112 conventional adenomas was analyzed for BRAF/KRAS mutations, MSI, CIMP, MLH1 and MGMT methylation, and MUC2 and MUC5AC expression and methylation. We show that MUC5AC hypomethylation is an early event in the serrated neoplasia pathway, and specifically detects MVHP and SSA, arguing for a filiation between MVHP, SSA and CIMP-H/MSI CRC, whereas GCHP and TSA arise from a distinct pathway. Moreover, MUC5AC hypomethylation specifically identified serrated lesions with BRAF mutation, CIMP-H or MSI, suggesting that it may be useful to identify serrated neoplasia pathway-related precursor lesions. Our data suggest that MVHP should be recognized among HP and require particular attention. © 2015 UICC.

Synthesis and properties of sulfonated poly(phenylene sulfone)s without ether linkage by Diels–Alder reaction for PEMFC application

International Nuclear Information System (INIS)

Lim, Youngdon; Lee, Hyunchul; Lee, Soonho; Jang, Hohyoun; Hossain, Md. Awlad; Cho, Younggil; Kim, Taeho; Hong, Youngtaik; Kim, Whangi

2014-01-01

A new sulfonated poly(phenylene sulfone) polymer (SPPS) was synthesized by Diels-Alder polymerization from 1,4-bis(2,4,5-triphenylcyclopentadienone)benzene (BTPCPB) and 4,4′-diethynylphenylsulfone, and followed by sulfonation reaction with chlorosulfuric acid. A series of sulfonated poly(phenylene sulfone)s (SPPS) with different degrees of sulfonation was prepared in a controllable manner with chlorosulfuric acid. These polymers showed good solubility in aprotic polar solvents, dimethyl acetamide (DMAC) and dimethyl sulfoxide (DMSO). Three different polymer membranes were studied by 1 H NMR spectroscopy, and thermogravimetric analysis (TGA). The ion exchange capacity (IEC) and proton conductivity of SPPS were evaluated according to the degrees of sulfonation. The water uptake (WU) of the synthesized SPPS membranes ranged from 38%∼75%, compared with 32% for Nafion 211 ® at 80 °C. The SPPS membranes exhibited proton conductivities (at 80 °C under 90% RH) of 110.2 mS/cm compared with 102.7 mS/cm for Nafion 211 ® . Power density was performed by single cell and showed similar to Nafion value

Phase-separation phenomena in solutions of poly(2,6-dimethyl-1,4-phenylene oxide). I. Thermodynamic parameters of solutions in toluene

NARCIS (Netherlands)

Koenhen, D.M.; Smolders, C.A.

1977-01-01

New experimental data have been collected on thermodynamic properties of solutions of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) in toluene. The Flory-Huggins interaction parameters g have been determined from light scattering measurements. These values are in agreement with values obtained by

Rhinoplasty via the midface degloving approach for nasal deformity due to nasal polyps: A case report of Woakes’ syndrome

Directory of Open Access Journals (Sweden)

Misato Ueda, MD

2017-09-01

Full Text Available Nasal polyps are inflammatory proliferative tumors arising from the mucosa of the nasal cavity and paranasal sinuses. Although many cases concerning nasal polyps have been reported, those involving external nasal deformities are rare. We report a case of nasal polyposis filling the nasal cavity and paranasal sinuses, leading to external nasal and facial deformities. The condition above is known as Woakes’ syndrome, which is characterized by severe recurrent nasal polyps with deformity of the nasal pyramid, leading to broadening of the nose. We performed nasal osteotomy and facial bone-shaving via the midface degloving approach, which improved the patient’s facial appearance.

Max-AUC feature selection in computer-aided detection of polyps in CT colonography.

Science.gov (United States)

Xu, Jian-Wu; Suzuki, Kenji

2014-03-01

We propose a feature selection method based on a sequential forward floating selection (SFFS) procedure to improve the performance of a classifier in computerized detection of polyps in CT colonography (CTC). The feature selection method is coupled with a nonlinear support vector machine (SVM) classifier. Unlike the conventional linear method based on Wilks' lambda, the proposed method selected the most relevant features that would maximize the area under the receiver operating characteristic curve (AUC), which directly maximizes classification performance, evaluated based on AUC value, in the computer-aided detection (CADe) scheme. We presented two variants of the proposed method with different stopping criteria used in the SFFS procedure. The first variant searched all feature combinations allowed in the SFFS procedure and selected the subsets that maximize the AUC values. The second variant performed a statistical test at each step during the SFFS procedure, and it was terminated if the increase in the AUC value was not statistically significant. The advantage of the second variant is its lower computational cost. To test the performance of the proposed method, we compared it against the popular stepwise feature selection method based on Wilks' lambda for a colonic-polyp database (25 polyps and 2624 nonpolyps). We extracted 75 morphologic, gray-level-based, and texture features from the segmented lesion candidate regions. The two variants of the proposed feature selection method chose 29 and 7 features, respectively. Two SVM classifiers trained with these selected features yielded a 96% by-polyp sensitivity at false-positive (FP) rates of 4.1 and 6.5 per patient, respectively. Experiments showed a significant improvement in the performance of the classifier with the proposed feature selection method over that with the popular stepwise feature selection based on Wilks' lambda that yielded 18.0 FPs per patient at the same sensitivity level.

Effect of tea saponin on ephyrae and polyps of the moon jellyfish Aurelia sp.1.

Directory of Open Access Journals (Sweden)

Zhijun Dong

Full Text Available The moon jellyfish (Aurelia sp.1 is thought to be a nuisance for the sea cucumber aquaculture, which commonly occur in the sea cucumber (Apostichopus japonicus culture ponds of the Yellow Sea, China. To develop an appropriate method to control Aurelia sp.1 blooms, the toxic effects of tea saponin on Aurelia sp.1 ephyrae and polyps were tested in laboratory experiments. Our results revealed that tea saponin caused significant morphological changes, behavioral abnormality and mortality in Aurelia sp.1 ephyrae and polyps in 24 h and 48 h exposure experiments. The 24 h and 48 h median lethal concentrations (LC50 values of tea saponin for Aurelia sp.1 ephyrae were 1.9 and 1.1 mg L-1 respectively, while the LC50 value for Aurelia sp.1 polyps was 0.4 mg L-1 after 24h and 48 h of exposure to tea saponin. Comparison with literature results of tea saponin on A. japonicus indicates that the resistance of A. japonicus to tea saponin is 12-18 times greater than that of Aurelia sp.1 ephyrae. Therefore, the appropriate tea saponin dosage for the control of Aurelia sp.1 should be paid enough attention in order to minimize possible damage for sea cucumber. We suggest that the recommended level of tea saponin to eradicate Aurelia sp.1 ephyrae and polyps in sea cucumber culture ponds be lower than 1.35 mg L-1.

Effect of tea saponin on ephyrae and polyps of the moon jellyfish Aurelia sp.1.

Science.gov (United States)

Dong, Zhijun; Sun, Tingting; Liang, Likun; Wang, Lei

2017-01-01

The moon jellyfish (Aurelia sp.1) is thought to be a nuisance for the sea cucumber aquaculture, which commonly occur in the sea cucumber (Apostichopus japonicus) culture ponds of the Yellow Sea, China. To develop an appropriate method to control Aurelia sp.1 blooms, the toxic effects of tea saponin on Aurelia sp.1 ephyrae and polyps were tested in laboratory experiments. Our results revealed that tea saponin caused significant morphological changes, behavioral abnormality and mortality in Aurelia sp.1 ephyrae and polyps in 24 h and 48 h exposure experiments. The 24 h and 48 h median lethal concentrations (LC50) values of tea saponin for Aurelia sp.1 ephyrae were 1.9 and 1.1 mg L-1 respectively, while the LC50 value for Aurelia sp.1 polyps was 0.4 mg L-1 after 24h and 48 h of exposure to tea saponin. Comparison with literature results of tea saponin on A. japonicus indicates that the resistance of A. japonicus to tea saponin is 12-18 times greater than that of Aurelia sp.1 ephyrae. Therefore, the appropriate tea saponin dosage for the control of Aurelia sp.1 should be paid enough attention in order to minimize possible damage for sea cucumber. We suggest that the recommended level of tea saponin to eradicate Aurelia sp.1 ephyrae and polyps in sea cucumber culture ponds be lower than 1.35 mg L-1.

Original Article Nasal polyps - clinical profile and management in ...

African Journals Online (AJOL)

ETN

may be presenting complaint of cystic fibrosis 7. In this study, most of the subjects (91%) with nasal polyps were between second and sixth decades of life with an average age of 34 years. Fifty –one percent were found to be between third and fourth decades of life A male predominance in this study is in consonance with ...

Adherence to colorectal polyp surveillance guidelines: is there a 'scope' to increase the opportunities for screening?

LENUS (Irish Health Repository)

O'Connor, Anthony

2012-02-01

Colorectal polyps are usually asymptomatic and are found opportunistically. Individuals with adenomata are at increased risk for cancer and therefore guidelines exist for surveillance of these lesions including those of the British Society of Gastroenterology (BSG). Deviation from these guidelines is common and increases the workload of endoscopy. We examined those individuals waiting for endoscopy for polyp surveillance to see whether strict adherence to BSG guidelines could facilitate opportunities for screening. A total of 413 patients with earlier colonic polyps were examined, of whom 50 patients were excluded based on having alternative indications for surveillance, 179 (49.3%) were appropriately scheduled for surveillance and 184 patients (55.9%) were scheduled incorrectly. Seventy-nine patients (30%) could have been discharged; of these, 59 had hyperplastic polyps. Of the remaining 105 inappropriate triages under surveillance at the wrong interval, seven patients were scheduled for too infrequent surveillance and 98 were too frequent. A total of 284 patients with adenomatous polyps were under surveillance of whom 11 patients (3.8%) were in the high-risk category and all were appropriately scheduled, and 75 patients (26.4%) were in the intermediate-risk category, of whom 48 were appropriately scheduled, 20 were incorrectly triaged as high risk and seven were triaged as low risk. A total of 198 (69.7%) patients were in the low-risk category, 117 of these were correctly triaged, 15 were incorrectly triaged as high risk and 66 were classified as intermediate risk. Over a five-year period, 318 unnecessary colonoscopies are being performed. On the basis of the data obtained from a population-based colorectal screening programme using immunohistochemical-faecal occult blood testing in our department another 1516 patients could be screened annually without requiring any additional endoscopy resources, if strict adherence to guidelines was assured.

Interaction between poly(vinyl pyridine) and poly(2,6-dimethyl-1,4-phenylene oxide) : A copolymer blend miscibility study

NARCIS (Netherlands)

de Wit, Joost; van Ekenstein, Gert Alberda; ten Brinke, Gerrit

2007-01-01

The phase behavior of blends of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) with random copolymers of styrene and 2-vinyl pyridine, Poly(S-co-2VP), as well as with random copolymers of styrene and 4-vinyl pyridine, Poly(S-co-4VP), has been investigated in order to estimate the values of the

High-performance ferroelectric memory based on phase-separated films of polymer blends

KAUST Repository

Khan, Yasser; Bhansali, Unnat Sampatraj; Almadhoun, Mahmoud N.; Odeh, Ihab N.; Cha, Dong Kyu; Alshareef, Husam N.

2013-01-01

High-performance polymer memory is fabricated using blends of ferroelectric poly(vinylidene-fluoride-trifluoroethylene) (P(VDF-TrFE)) and highly insulating poly(p-phenylene oxide) (PPO). The blend films spontaneously phase separate into amorphous PPO nanospheres embedded in a semicrystalline P(VDF-TrFE) matrix. Using low molecular weight PPO with high miscibility in a common solvent, i.e., methyl ethyl ketone, blend films are spin cast with extremely low roughness (Rrms ≈ 4.92 nm) and achieve nanoscale phase seperation (PPO domain size < 200 nm). These blend devices display highly improved ferroelectric and dielectric performance with low dielectric losses (<0.2 up to 1 MHz), enhanced thermal stability (up to ≈353 K), excellent fatigue endurance (80% retention after 106 cycles at 1 KHz) and high dielectric breakdown fields (≈360 MV/m). © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High-performance ferroelectric memory based on phase-separated films of polymer blends

KAUST Repository

Khan, Yasser

2013-10-29

High-performance polymer memory is fabricated using blends of ferroelectric poly(vinylidene-fluoride-trifluoroethylene) (P(VDF-TrFE)) and highly insulating poly(p-phenylene oxide) (PPO). The blend films spontaneously phase separate into amorphous PPO nanospheres embedded in a semicrystalline P(VDF-TrFE) matrix. Using low molecular weight PPO with high miscibility in a common solvent, i.e., methyl ethyl ketone, blend films are spin cast with extremely low roughness (Rrms ≈ 4.92 nm) and achieve nanoscale phase seperation (PPO domain size < 200 nm). These blend devices display highly improved ferroelectric and dielectric performance with low dielectric losses (<0.2 up to 1 MHz), enhanced thermal stability (up to ≈353 K), excellent fatigue endurance (80% retention after 106 cycles at 1 KHz) and high dielectric breakdown fields (≈360 MV/m). © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preoperative care of Polypoid exposed mucosal template in bladder exstrophy: the role of high-barrier plastic wraps in reducing inflammation and polyp size.

Science.gov (United States)

Sabetkish, Nastaran; Sabetkish, Shabnam; Kajbafzadeh, Abdol-Mohammad

2018-01-26

To assess the role of high-barrier plastic wrap in reducing the number and size of polyps, as well as decreasing the inflammation and allergic reactions in exstrophy cases, and to compare the results with the application of low-barrier wrap. Eight patients with bladder exstrophy-epispadias complex (BEEC) that had used a low density polyethylene (LDPE) wrap for coverage of the exposed polypoid bladder in preoperative care management were referred. The main complaint of their parents was increase in size and number of polyps. After a period of 2 months using the same wrap and observing the increasing pattern in size of polyps, these patients were recommended to use a high-barrier wrap which is made of polyvinylidene chloride (PVdC), until closure. Patients were monitored for the number and size of polyps before and after the change of barriers. The incidence of para-exstrophy skin infection/inflammation and skin allergy were assessed. Biopsies were taken from the polyps to identify histopathological characteristics of the exposed polyps. The high barrier wrap was applied for a mean ± SD duration of 12±2.1 months. Polyps' size and number decreased after 12 months. No allergic reaction was detected in patients after the usage of PVdC; three patients suffered from low-grade skin allergy when LDPE was applied. Also, pre-malignant changes were observed in none of the patients in histopathological examination after the application of PVdC. Polyps' size and number and skin allergy may significantly decrease with the use of a high-barrier wrap. Certain PVdC wraps with more integrity and less evaporative permeability may be more "exstrophy-friendly". Copyright® by the International Brazilian Journal of Urology.

Giant ileal inflammatory fibroid polyp: a rare cause of intestinal intussusception

Directory of Open Access Journals (Sweden)

Daniel Cury Ogata

2012-09-01

Full Text Available Ileal inflammatory fibroid polyp is a rare non-neoplastic lesion of the gastrointestinal tract. Intussusception caused by an inflammatory fibroid polyps is uncommon. The authors report a case of a 75 year-old female patient presenting with ileal obstruction due to intussusception of a polypoid lesion. The patient underwent surgical treatment and histopathology confirmed the diagnosis.Os pólipos fibroides inflamatórios são raras lesões não neoplásicas do trato gastrointestinal e a intussuscepção devido a essa entidade é incomum. Os autores relatam um caso de paciente do sexo feminino, 75 anos, que apresentou obstrução ileal devido a uma intussuscepção por lesão polipoide. A paciente foi submetida a tratamento cirúrgico, sendo diagnosticado pólipo fibroide inflamatório do íleo.

M-Polynomials and topological indices of V-Phenylenic Nanotubes and Nanotori.

Science.gov (United States)

Kwun, Young Chel; Munir, Mobeen; Nazeer, Waqas; Rafique, Shazia; Min Kang, Shin

2017-08-18

V-Phenylenic nanotubes and nanotori are most comprehensively studied nanostructures due to widespread applications in the production of catalytic, gas-sensing and corrosion-resistant materials. Representing chemical compounds with M-polynomial is a recent idea and it produces nice formulas of degree-based topological indices which correlate chemical properties of the material under investigation. These indices are used in the development of quantitative structure-activity relationships (QSARs) in which the biological activity and other properties of molecules like boiling point, stability, strain energy etc. are correlated with their structures. In this paper, we determine general closed formulae for M-polynomials of V-Phylenic nanotubes and nanotori. We recover important topological degree-based indices. We also give different graphs of topological indices and their relations with the parameters of structures.

Is prevalence of colorectal polyps higher in patients with family history of colorectal cancer?

Directory of Open Access Journals (Sweden)

Sthela Maria Murad-Regadas

2015-07-01

Full Text Available Objectives: To assess the prevalence of polyps in patients with a family history of colorectal cancer, in comparison to asymptomatic individuals with indication for screening. Methods: A prospective study in a group of patients who underwent colonoscopy between 2012 and 2014. Patients were divided into two groups: Group I: no family history of colorectal cancer, and Group II: with a family history in first-degree relatives. Demographic characteristics, findings on colonoscopy, presence, location and histological type of polyps were evaluated, comparing the two groups. Results: 214 patients were evaluated: 162 in Group I and 52 in Group II. The distribution of patients with polyps was similar in relation to gender: polyps were evidenced in Group I in 33 (20% female patients vs. 10 (6% male patients (p = 1.00; in Group II, the presence of polyps was evidenced in 9 (17% female patients vs. 2 (4% male patients (p = 1.00. Polypoid lesions were found in 54 patients (25%, with 43 (26% in Group I and 11 (21% in Group II. The prevalence of adenomas was similar in both groups (Group I = 18/37% vs. Group II = 10/50% (p = 0.83. Conclusion: In this preliminary study, no correlation was found between prevalence of polyps and a family history of colorectal cancer. Resumo: Objetivos: Avaliar a prevalência de pólipos em pacientes com história familiar de câncer colorretal comparando com indivíduos assintomáticos com indicação para rastreamento. Métodos: Estudo prospectivo realizado em um grupo de indivíduos submetidos à colonoscopia entre 2012 e 2014. Os pacientes foram distribuídos em dois grupos: Grupo I: sem história familiar de câncer colorretal e Grupo II: com história familiar em parentes de primeiro grau. Avaliaram-se características demográficas, achados na colonoscopia, presença, localização e tipo histológico dos pólipos, comparando os dois grupos. Resultados: Foram avaliados 214 pacientes, 162 incluídas no grupo I e 52

Phase-separation phenomena in solutions of poly(2,6-dimethyl-1,4 phenylene oxide). II. Differential scanning calorimetry of solutions in toluene

NARCIS (Netherlands)

Koenhen, D.M.; Smolders, C.A.

1977-01-01

The phase-separation phenomena observed in solutions of poly(2,6 dimethyl-1,4 phenylene oxide) in toluene have been investigated by differential scanning calorimetry. These measurements supplement the experimental evidence in favor of the concept that the phase transitions observed are

Inorganic polyphosphate (polyP) as an activator and structural component of the mitochondrial permeability transition pore.

Science.gov (United States)

Solesio, Maria E; Elustondo, Pia A; Zakharian, Eleonora; Pavlov, Evgeny V

2016-02-01

Mitochondrial permeability transition pore (mPTP) is a large channel located in the mitochondrial inner membrane. The opening of mPTP during pathological calcium overload leads to the membrane depolarization and disruption of ATP production. mPTP activation has been implicated as a central event during the process of stress-induced cell death. mPTP is a supramolecular complex composed of many proteins. Recent studies suggest that mitochondrial ATPase plays the central role in the formation of mPTP. However, the structure of the central conducting pore part of mPTP (mPTPore) remains elusive. Here we review current models proposed for the mPTPore and involvement of polyP in its formation and regulation. We discuss the underestimated role of polyP as an effector and a putative structural component of the mPTPore. We propose the hypothesis that inclusion of polyP can explain such properties of mPTP activity as calcium activation, selectivity and voltage-dependence. © 2016 Authors; published by Portland Press Limited.

Hybrid thin-film solar cells comprising mesoporous titanium dioxide and conjugated polymers; Hybride Duennschicht-Solarzellen aus mesoporoesem Titandioxid und konjugierten Polymeren

Energy Technology Data Exchange (ETDEWEB)

Schattauer, Sylvia

2010-12-01

The main objective of this thesis is to study the active components and their interactions in so called organic hybrid solar cells. These consist of a thin inorganic titanium dioxide layer, combined with a polymer layer. In general, the efficiency of these hybrid solar cells is determined by the light absorption in the donor polymer, the dissociation of excitons at the heterojunction between TiO{sub 2} and polymer, as well as the generation and extraction of free charge carriers. To optimize the solar cells, the physical interactions between the materials are modified and the influences of various preparation parameters are systematically investigated. Among others, important findings regarding the optimal use of materials and preparation conditions as well as detailed investigations of fundamental factors such as film morphology and polymer infiltration are presented in more detail. First, a variety of titanium dioxide layer were produced, from which a selection for use in hybrid solar cells was made. The obtained films show differences in surface structure, film morphology and crystallinity, depending on the way how the TiO{sub 2} layer has been prepared. All these properties of the TiO{sub 2} films may strongly affect the performance of the hybrid solar cells, by influencing e.g. the exciton diffusion length, the efficiency of exciton dissociation at the hybrid interface, and the carrier transport properties. Detailed investigations were made for mesoporous TiO{sub 2} layer following a new nanoparticle synthesis route, which allows to produce crystalline particles during the synthesis. As donor component, conjugated polymers, either derivatives of cyclohexylamino-poly(p-phenylene vinylene) (PPV) or a thiophene are used. The preparation routine also includes a thermal treatment of the TiO{sub 2} layers, revealing a temperature-dependent change in morphology, but not of the crystal structure. The effects on the solar cell properties have been documented and

Biodegradable Oxamide-Phenylene-Based Mesoporous Organosilica Nanoparticles with Unprecedented Drug Payloads for Delivery in Cells

KAUST Repository

Croissant, Jonas

2016-06-03

We describe biodegradable mesoporous hybrid NPs in the presence of proteins, and its application for drug delivery. We synthesized oxamide-phenylene-based mesoporous organosilica nanoparticles (MON) in the absence of silica source which had a remarkably high organic content with a high surface area. Oxamide functions provided biodegradability in the presence of trypsin model proteins. MON displayed exceptionally high payloads of hydrophilic and hydrophobic drugs (up to 84 wt%), and a unique zero premature leakage without the pore capping, unlike mesoporous silica. MON were biocompatible and internalized into cancer cells for drug delivery.

Antrochoanal Polyps: Clinical Presentation and the Role of Powered Endoscopic Polypectomy

Directory of Open Access Journals (Sweden)

Balwant Singh Gendeh

2004-01-01

Full Text Available Antrochoanal polyps are a rare clinical entity. In this review of patients treated between January 1996 and September 2002, there were 18 cases of antrochoanal polyps. The mean age of patients was 20 years. Nasal obstruction was the most common symptom (17 cases, 94%, followed by rhinorrhoea (44%, epistaxis (33%, postnasal drip (28%, and snoring (22%. Chronic sinusitis was the most common associated rhinological finding (50%. Various surgical approaches were used: endoscopic polypectomy and middle meatal antrostomy in seven patients (38.9%, powered endoscopic polypectomy and middle meatal antrostomy in seven patients (38.9%, endoscopic polypectomy and inferior meatal antrostomy in three patients (16.7% and Caldwell-Luc surgery in one patient (5.6%. No complications were noted in patients treated with powered instrumentation, including the three patients in whom combined transcanine approaches were used. We concluded that powered endoscopic polypectomy was safe and effective. It allowed a more complete dissection and may diminish the chance of recurrence.

Feasibility and diagnostic utility of video capsule endoscopy for the detection of small bowel polyps in patients with hereditary polyposis syndromes.

Science.gov (United States)

Schulmann, Karsten; Hollerbach, Stephan; Kraus, Katja; Willert, Jörg; Vogel, Tilman; Möslein, Gabriela; Pox, Christian; Reiser, Markus; Reinacher-Schick, Anke; Schmiegel, Wolff

2005-01-01

At present, surveillance of premalignant small bowel polyps in hereditary polyposis syndromes has a number of limitations. Capsule endoscopy (CE) is a promising new method to endoscopically assess the entire length of the small bowel. We prospectively examined 40 patients with hereditary polyposis syndromes (29 familial adenomatous polyposis (FAP), 11 Peutz-Jeghers syndrome (PJS)). Results were compared with push-enteroscopy (PE) results in FAP and with esophagogastroduodenoscopy, PE, (MR)-enteroclysis, and surgical specimen in PJS patients. A total of 76% of the patients with FAP with duodenal adenomas (n = 21) had additional adenomas in the proximal jejunum that could be detected by CE and PE. Moreover, 24% of these FAP patients had further polyps in the distal jejunum or ileum that could only be detected by CE. In contrast, in FAP patients without duodenal polyps (n = 8), jejunal or ileal polyps occurred rarely (12%). CE detected polyps in 10 of 11 patients with PJS, a rate superior to all other reference procedures employed. Importantly, the findings of CE had immediate impact on further clinical management in all PJS patients. Our results suggest that CE may be of clinical value in selected patients with FAP, whereas in PJS, CE could be used as first line surveillance procedure.

Genetic diversity, phylogroup distribution and virulence gene profile of pks positive Escherichia coli colonizing human intestinal polyps.

Science.gov (United States)

Sarshar, Meysam; Scribano, Daniela; Marazzato, Massimiliano; Ambrosi, Cecilia; Aprea, Maria Rita; Aleandri, Marta; Pronio, Annamaria; Longhi, Catia; Nicoletti, Mauro; Zagaglia, Carlo; Palamara, Anna Teresa; Conte, Maria Pia

2017-11-01

Some Escherichia coli strains of phylogroup B2 harbor a (pks) pathogenicity island that encodes a polyketide-peptide genotoxin called colibactin. It causes DNA double-strand breaks and megalocytosis in eukaryotic cells and it may contribute to cancer development. Study of bacterial community that colonizes the adenomatous polyp lesion, defined as precancerous lesions, could be helpful to assess if such pathogenic bacteria possess a role in the polyp progression to cancer. In this cross-sectional study, a total of 1500 E. coli isolates were obtained from biopsies of patients presenting adenomatous colon polyps, the normal tissues adjacent to the polyp lesion and patients presenting normal mucosa. pks island frequency, phylogenetic grouping, fingerprint genotyping, and virulence gene features of pks positive (pks + ) E. coli isolates were performed. We found pks + E. coli strongly colonize two patients presenting polypoid lesions and none were identified in patients presenting normal mucosa. Predominant phylogroups among pks + E. coli isolates were B2, followed by D. Clustering based on fragment profiles of composite analysis, typed the pks + isolates into 5 major clusters (I-V) and 17 sub-clusters, demonstrating a high level of genetic diversity among them. The most prevalent virulence genes were fimH and fyuA (100%), followed by vat (92%), hra and papA (69%), ibeA (28%), and hlyA (25%). Our results revealed that pks + E. coli can colonize the precancerous lesions, with a high distribution in both the polyp lesions and in normal tissues adjacent to the lesion. The high differences in fingerprinting patterns obtained indicate that pks + E. coli strains were genetically diverse, possibly allowing them to more easily adapt to environmental variations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Polyp Morphology: An Interobserver Evaluation for the Paris Classification Among International Experts

NARCIS (Netherlands)

van Doorn, Sascha C.; Hazewinkel, Y.; East, James E.; van Leerdam, Monique E.; Rastogi, Amit; Pellisé, Maria; Sanduleanu-Dascalescu, Silvia; Bastiaansen, Barbara A. J.; Fockens, Paul; Dekker, Evelien

2015-01-01

OBJECTIVES: The Paris classification is an international classification system for describing polyp morphology. Thus far, the validity and reproducibility of this classification have not been assessed. We aimed to determine the interobserver agreement for the Paris classification among seven Western

Improvement of surface wettability and interfacial adhesion of poly-(p-phenylene terephthalamide) by incorporation of the polyamide benzimidazole segment

International Nuclear Information System (INIS)

Cai Renqin; Peng Tao; Wang Fengde; Ye Guangdou; Xu Jianjun

2011-01-01

In order to investigate the effect of the polyamide benzimidazole group on the surface wettability and interfacial adhesion of fiber/matrix composites, surface features of two kinds of aramid fibers, poly (p-phenylene terephthalamide) fiber (Kevlar-49) and poly-(polyamide benzimidazole-co-p-phenylene terephthalamide) (DAFIII), have been analyzed by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and contact angle analysis (CAA) system, respectively. The results show that with the incorporation of the polyamide benzimidazole segment, more polar functional groups exist on DAFIII surface. The contact angles of water and diiodomethane on DAFIII surface get smaller. The surface free energy of DAFIII increases to 36.5 mJ/m 2 , which is 2.3% higher than that of Kevlar-49. In addition, DAFIII has a larger rough surface compared with that of Kevlar-49 due to different spinning processes. The interfacial shear strength (IFSS) of DAFIII/matrix composite is 25.7% higher than that of Kevlar-49/matrix composite, in agreement with the observed results from surface feature tests. SEM micrographs of failed micro-droplet specimens reveal a strong correlation between the fracture features and the observed test data.

A comparative study of standard vs. high definition colonoscopy for adenoma and hyperplastic polyp detection with optimized withdrawal technique.

Science.gov (United States)

East, J E; Stavrindis, M; Thomas-Gibson, S; Guenther, T; Tekkis, P P; Saunders, B P

2008-09-15

Colonoscopy has a known miss rate for polyps and adenomas. High definition (HD) colonoscopes may allow detection of subtle mucosal change, potentially aiding detection of adenomas and hyperplastic polyps. To compare detection rates between HD and standard definition (SD) colonoscopy. Prospective, cohort study with optimized withdrawal technique (withdrawal time >6 min, antispasmodic, position changes, re-examining flexures and folds). One hundred and thirty patients attending for routine colonoscopy were examined with either SD (n = 72) or HD (n = 58) colonoscopes. Groups were well matched. Sixty per cent of patients had at least one adenoma detected with SD vs. 71% with HD, P = 0.20, relative risk (benefit) 1.32 (95% CI 0.85-2.04). Eighty-eight adenomas (mean +/- standard deviation 1.2 +/- 1.4) were detected using SD vs. 93 (1.6 +/- 1.5) with HD, P = 0.12; however more nonflat, diminutive (9 mm) hyperplastic polyps was 7% (0.09 +/- 0.36). High definition did not lead to a significant increase in adenoma or hyperplastic polyp detection, but may help where comprehensive lesion detection is paramount. High detection rates appear possible with either SD or HD, when using an optimized withdrawal technique.

Evaluation of Usefulness of hs-CRP and Ferritin Assays in Patients with Nasal Polyps

Directory of Open Access Journals (Sweden)

Robert Partyka

2014-01-01

Full Text Available Background. Chronic nature of the nasal polyps, tendency to recurrence, and lack of satisfying treatment need the diagnostic’s parameters which show early inflammatory state as ferritin and hs-CRP. The Aim of Study. Assessment of hs-CRP and ferritin blood levels in nasal polyps patients in evaluation of treatment efficacy. Methods. All 38 patients were divided into 2 groups. Group I included 19 patients with anti-inflammatory therapy 2 weeks after surgery. Group II included 19 patients without anti-inflammatory therapy 2 weeks after surgery. The levels of hs-CRP and ferritin have been assessed before and 2 and 6 weeks after surgical treatment. Results. Research showed statistically significant difference of ferritin’s concentration between examined groups 6 weeks after surgery (P<0.05 and statistically significant difference of hs-CRP concentration 2 and 6 weeks after surgery (P<0.05. Conclusion. (1 The analysis of serum ferritin and hs-CRP concentrations can be useful in early postoperative detection of inflammatory state in patients with nasal polyps and for the effectiveness of therapy. (2 Lack of correlation between mean ferritin and hs-CRP serum levels, at each diagnostic and monitoring stage, shows that they are independent and cannot be determined interchangeably.

Gastric Polyp: A rare cause of Chronic Volvulus in an Adult ...

African Journals Online (AJOL)

Gastric Polyp: A rare cause of Chronic Volvulus in an Adult. ME Mohammed, I Elawad. Abstract. Gastric volvulus is a rare but potentially life-threatening cause of upper gastrointestinal obstruction. It presents clinically with epigastric pain radiating to the back and or left thoracic area or left abdominal quadrant and retching.

Electrochemically assisted mechanically controllable break junction studies on the stacking configurations of oligo(phenylene ethynylene)s molecular junctions

International Nuclear Information System (INIS)

Zheng, Jue-Ting; Yan, Run-Wen; Tian, Jing-Hua; Liu, Jun-Yang; Pei, Lin-Qi; Wu, De-Yin; Dai, Ke; Yang, Yang; Jin, Shan

2016-01-01

Highlights: • I-V characteristics of a series of oligo(phenylene ethynylene)s molecular junctions were measured. • Conductance values were found to be dependent on molecular length and substituent group. • The measured low conductance values were explained by theoretical calculations. • EC-MCBJ is feasible to fabricate and characterize molecular junctions. - Abstract: We demonstrate an electrochemically assisted mechanically controllable break junction (EC-MCBJ) approach for current-voltage characteristic (I-V curve) measurements of metal/molecule/metal junctions. A series of oligo(phenylene ethynylene)s compounds (OPEs), including those involving electron withdrawing substituent group and different backbone lengths, had been successfully designed, synthesized, and placed onto the fabricated nanogap to form molecular junctions. The observed evolution in the measured conductances of OPEs indicates that there is a dependence of conductance on molecular length and substituent group. Compared with those extracted from conductance histogram construction, the conductances of OPEs measured from I-V curves are considerably lower. Based on the transmission spectra of OPEs that calculated by density functional theory (DFT) combined with non-equilibrium Green’s function (NEGF) method, this difference was attributed to our distinct experimental operation, which may give rise to a stacking configuration of two OPE molecules.

A Rare Presentation of Odontogenic Keratocyst Mimicking an Antral Polyp

OpenAIRE

Sudhakar, S; Geethika, V; Ramaswamy, P; Kumar, PK; Sreenivasulu, P

2014-01-01

Maxillary sinus harbours many pathological lesions. Many of those presents as a sinonasal mass and are rarely symptomatic. These masses are usually an antral polyp, mucoceles or mucous retention cysts. Odontogenic keratocyst, a benign odontogenic lesion presenting within the maxillary sinus is a rare entity. We present a case of odontogenic keratocyst of the maxillary sinus in a 35 years old female.

Live imaging of cysteine-cathepsin activity reveals dynamics of focal inflammation, angiogenesis, and polyp growth.

Directory of Open Access Journals (Sweden)

Elias Gounaris

2008-08-01

Full Text Available It has been estimated that up to 30% of detectable polyps in patients regress spontaneously. One major challenge in the evaluation of effective therapy of cancer is the readout for tumor regression and favorable biological response to therapy. Inducible near infra-red (NIR fluorescent probes were utilized to visualize intestinal polyps of mice hemizygous for a novel truncation of the Adenomatous Polyposis coli (APC gene. Laser Scanning Confocal Microscopy in live mice allowed visualization of cathepsin activity in richly vascularized benign dysplastic lesions. Using biotinylated suicide inhibitors we quantified increased activities of the Cathepsin B & Z in the polyps. More than (3/4 of the probe signal was localized in CD11b(+Gr1(+ myeloid derived suppressor cells (MDSC and CD11b(+F4/80(+ macrophages infiltrating the lesions. Polyposis was attenuated through genetic ablation of cathepsin B, and suppressed by neutralization of TNFalpha in mice. In both cases, diminished probe signal was accounted for by loss of MDSC. Thus, in vivo NIR imaging of focal cathepsin activity reveals inflammatory reactions etiologically linked with cancer progression and is a suitable approach for monitoring response to therapy.

Complex rectal polyps: other treatment modalities required when offering a transanal endoscopic microsurgery service.

LENUS (Irish Health Repository)

Joyce, Myles R

2011-09-01

Complex rectal polyps may present a clinical challenge. The study aim was to assess different treatment modalities required in the management of patients referred for transanal endoscopic microsurgery.

Quantum modelling of photo-excited processes

International Nuclear Information System (INIS)

Ramos, Marta M.D.; Correia, Helena M.G.

2005-01-01

In the framework of quantum field theory and the dipole approximation, a self-consistent quantum molecular dynamics method is used to investigate the effect of chain length on the probability of formation or decay of both singlet and triplet excitons due to photon absorption or emission in isolated poly(p-phenylene vinylene) (PPV) chains. We found that the probability of the photo-induced intra-molecular singlet exciton formation and decay increases linearly with chain length and the probability for triplet exciton formation and decay does not depend on the chain length. Polymers with long chains have thus an advantage over small molecules in solar cell and light-emitting diode (LED) applications because their efficiency depends on the number of intra-molecular singlet excitons formed or emitted in the device, which is expected to increase with the conjugation length

Combating oxidative stress as a hallmark of cancer and aging: Computational modeling and synthesis of phenylene diamine analogs as potential antioxidant.

Science.gov (United States)

Abou-Zeid, Laila; Baraka, Hany N

2014-07-01

The cross talk between the over expression of oxygen-free radicals is known as reactive oxygen species (ROS) that is associated with the excessive telomerase activity (TA). Telomerase activity is an invariable finding where human telomerase (hTERT) has been implicated in tumor oxidative stress and redox-mediated malignancy. The hTERT over expression is a novel tumor marker and is promising as a novel class of therapeutic weapons to fight against cancer. A new series of phenylene diamines were designed, synthesized, and evaluated for their in vitro antioxidant as an indicator of inhibiting the oxidative stress tumor. Compounds 3b and 7b proved to be the most active antioxidants with high percentage ABTS inhibition ranged from 89.40% to 88.59% respectively. Molecular modeling studies indicated that the crest configuration of phenylene diamine nucleus with substitutions of trimethoxy benzamido functional proved to be crucial for enhancing the free radical scavenging activity. Molecular modeling exploration indicated the proper binding selectivity of the 3b and 7b to the 3KYL pocket with promising hTERT inhibitors as a hallmark of cancer.

Fecal blood loss in patients with colonic polyps: a comparison of measurements with 51chromium-labeled erythrocytes and with the Haemoccult test

International Nuclear Information System (INIS)

Herzog, P.; Holtermueller, K.H.; Preiss, J.; Fischer, J.; Ewe, K.; Schreiber, H.J.; Berres, M.

1982-01-01

The quantitative determinations of fecal daily blood loss after intravenous administration of 51 Cr-labeled erythrocytes in 44 patients with colonic polyps and in 11 controls were compared with the results of the daily performed Haemoccult test without dietary restrictions. A total of 642 stool specimens was analyzed for 51 Cr loss and the Haemoccult test. The mean fecal daily blood loss in the 34 patients with adenomatous polyps of the descending colon and rectosigmoid was 1.36 +/- 0.14 ml/day (mean +/- SEM), in the 10 patients with polyps of the ascending and transverse colon it was 1.28 +/- 0.31 ml/day, and in the 11 controls 0.62 +/- 0.07 ml/day. There was no positive Haemoccult test in the controls. In fecal specimens from patients with polyps in the descending colon and rectosigmoid containing 2.0-3.99 ml blood/day, the Haemoccult-test was positive in 86%. Fecal specimens from patients with polyps in the ascending colon and transverse colon containing equal blood loss yielded a positive Haemoccult test result in 26%. Thus, the positivity of the Haemoccult test is determined by the fecal daily blood loss and the anatomic location of colonic bleeding sites

Gastric polyps diagnosed by double-contrast upper gastrointestinal barium X-ray radiography mostly arise from the Helicobacter pylori-negative stomach with low risk of gastric cancer in Japan.

Science.gov (United States)

Takeuchi, Chihiro; Yamamichi, Nobutake; Shimamoto, Takeshi; Takahashi, Yu; Mitsushima, Toru; Koike, Kazuhiko

2017-03-01

Double-contrast upper gastrointestinal barium X-ray radiography (UGI-XR) is a method broadly used for gastric cancer screening in Japan. Gastric polyp is one of the most frequent findings detected by UGI-XR, but how to handle it remains controversial. Gastric polyps of the 17,264 generally healthy subjects in Japan who underwent UGI-XR or upper gastrointestinal endoscopy (UGI-ES) in 2010 were analyzed. Of the 6,433 UGI-XR examinees (3,405 men and 3,028 women, 47.4 ± 9.0 years old), gastric polyps were detected in 464 men (13.6 %) and 733 women (24.2 %) and were predominantly developed on the non-atrophic gastric mucosa (p gastric polyps has significant association with lower value of serum anti-Helicobacter pylori IgG titer, female gender, lighter smoking habit, older age, and normal range of body mass index (≥18.5 and gastric cancer occurred in 7 subjects (0.11 %), but none of them had gastric polyps at the beginning of the follow-up period. Of the 2,722 subjects with gastric polyps among the 10,831 UGI-ES examinees in the same period, 2,446 (89.9 %) had fundic, 267 (9.8 %) had hyperplastic, and 9 (0.3 %) had adenomatous/cancerous polyps. Gastric polyps diagnosed by UGI-XR predominantly arise on the Helicobacter pylori-negative gastric mucosa with a low risk of gastric cancer in Japan. In the prospective observation, none of the UGI-XR examinees with gastric polyps developed gastric cancer for at least 3 years subsequently.

Thin copolymer-cased light-emitting display made with fluorine-foped tin oxide substrates

Directory of Open Access Journals (Sweden)

Lessmann Rudolf

2004-01-01

Full Text Available Seven-segment displays are used to show numerical quantities in electronic equipment, being present in most of the low-end electronics. In this work we describe a novel organic light emitting display made with poly(1,10 decanedioxy 2 methoxy - 1,2 phenylene - 1,2 ethenylene - 3,6 dimethoxy - 1,4 phenylene - 1,2 ethenylene 3 methoxy - 1,4 - phenylene (OPPVDBC, tris(8-hydroxyquinolinealuminum salt (Alq3 and a hole injection layer (PEDOT:PSS: poly(3,4 - ethylenedioxythiophene : poly(styrenesulfonate. The general device structure is FTO/PEDOT:PSS/OPPVDBC/Ca/Al or FTO/PEDOT:PSS/OPPVDBC/Alq3/Ca/Al. The FTO (fluorine-doped tin oxide thin films are transparent (transmittance > 80 % in the visible region of the spectrum, conductive (< 15 omega/º for 200 nm thick films, and present high chemical stability.

Phase-separation phenomena in solutions of poly(2,6-dimethyl-1,4-phenylene oxide). III. Pulse-induced critical scattering of solutions in toluene

NARCIS (Netherlands)

Koenhen, D.M.; Smolders, C.A.; Gordon, M.

1977-01-01

For the polymer-solvent system poly(phenylene oxide) in toluene the mechanism and kinetics of crystallization have been studied with the Pulse Induced Critical Scattering technique. It was found that after a delay-time the growth mechanism was diffusion controlled. The delay-time is thought to be

A shift from distal to proximal neoplasia in the colon: a decade of polyps and CRC in Italy

Directory of Open Access Journals (Sweden)

Panzone Sergio

2010-11-01

Full Text Available Abstract Background In the last years a trend towards proximalization of colorectal carcinomas (CRC has been reported. This study aims to evaluate the distribution of CRC and adenomatous polyps (ADP to establish the presence of proximalization and to assess the potential predictors. Methods We retrieved histology reports of colonic specimens excised during colonoscopy, considering the exams performed between 1997 and 2006 at Cuneo Hospital, Italy. We compared the proportion of proximal lesions in the period 1997-2001 and in the period 2002-2006. Results Neoplastic lesions were detected in 3087 people. Proximal CRC moved from 25.9% (1997-2001 to 30.0% (2002-2006. Adjusting for sex and age, the difference was not significant (OR 1.23; 95% CI: 0,95-1,58. The proximal ADP proportion increased from 19.2% (1997-2001 to 26.0% (2002-2006 (OR: 1.43; 95% CI: 1.17-1.89. The corresponding figures for advanced proximal ADP were 6.6% and 9.5% (OR: 1.48; 95% CI: 1.02-2.17. Adjusting for gender, age, diagnostic period, symptoms and number of polyps the prevalence of proximal advanced ADP was increased among people ≥ 70 years compared to those aged 55-69 years (OR 1.49; 95% CI: 1.032.16. The main predictor of proximal advanced neoplasia was the number of polyps detected per exam (> 1 polyp versus 1 polyp: considering all ADP: OR 2.16; 95% CI: 1.59-2.93; considering advanced ADP OR 1.63; 95% CI: 1.08-2.46. Adjusting for these factors, the difference between the two periods was no longer significant. Conclusions CRC do not proximalize while a trend towards a proximal shift in adenomas was observed among people ≥ 70 years.

Endoscopic resection of large colorectal polyps Resección endoscópica de pólipos difíciles de colon

Directory of Open Access Journals (Sweden)

F. Pérez Roldán

2004-01-01

Full Text Available Backgrounds: endoscopic polypectomy is a common technique, but there are discrepancies over which treatment -surgical or endoscopic- to follow in case of polyps of 2 cm or larger. Objectives: to analyse the efficacy and complications of colonoscopic polypectomy of large colorectal polyps. Patients and methods: 147 polypectomies were performed on 142 patients over an eight-year period. The technique used was that of submucosal adrenaline 1:10000 or saline injection at the base of the polyp, followed by resection of the polyp using a diathermic snare in the smallest number of fragments. Remnant adenomatous tissue was fulgurated with an argon plasma coagulator. Lately, prophylactic hemoclips have been used for thick-pedicle polyps. Complete removal was defined as when a polyp was completely resected in one or more polypectomy sessions. Polypectomy failure was defined as when a polyp could not be completely resected or contained an invasive carcinoma. Results: the mean patient age was 67.9 years (range, 4-90 years, with 68 men and 79 women. There were 74 sessile polyps, and the most common location was the sigmoid colon. The most frequent histology was tubulovillous. Most of the polyps (96.6%, were resected and cured. This was not achieved in four cases of invasive carcinoma, and a villous polyp of the cecum. All pedunculated polyps were resected in one session, whereas the average number of colonoscopies for sessile polyps was 1.35 ± 0.6 (range, 1-4. The polypectomy was curative in all of the in situ carcinomata except one. As for complications, 2 colonic perforations (requiring surgery and 8 hemorrhages appeared, which were controlled via endoscopy. There was no associated mortality. Conclusions: endoscopic polypectomy of large polyps (≥ 2 cm is a safe, effective treatment, though it is not free from complications. Complete resection is achieved in a high percentage, and there are few relapses. It should be considered a technique of choice for

Análise dos pólipos colorretais em 3.491 videocolonoscopias Analysis of colorrectal polyps in 3.491 videocolonoscopies

Directory of Open Access Journals (Sweden)

José Mauro dos Santos

2008-09-01

Full Text Available INTRODUÇÃO: A ressecção dos pólipos do intestino grosso é uma medida importante na diminuição da incidência do câncer colorretal. O objetivo do presente estudo é verificar a incidência dos pólipos colorretais, seu tipo histológico, o índice de malignização e de ocorrência de novas lesões nos pacientes submetidos a exame colonoscópico por indicações diversas no Serviço de Coloproctologia do Hospital de Caridade de Florianópolis - SC. MÉTODO: Realizado estudo retrospectivo de 3491 pacientes submetidos à videocolonoscopia no período de janeiro de 1992 a outubro de 2006. Foi avaliada a incidência dos pólipos colorretais de acordo com sexo e idade, tipo histológico e a presença de adenocarcinoma. Foram excluídos deste estudo as síndromes polipóides genéticas e os pólipos não ressecados ou com exames anatomopatológicos incompletos ou extraviados. RESULTADOS: Dos 3491 exames realizados, foram encontrados pólipos em 1046 (29,96%, totalizando 1899 lesões em 865 pacientes. Destes 53,94% eram do sexo masculino, 46,06% feminino e 58,46% tinham mais de 60 anos. Foram avaliados 1579 pólipos colorretais, cujo estudo histopatológico mostrou 31,54% adenomas tubulares, 14,19% adenomas túbulo-vilosos, 1,65% adenomas vilosos, 36,03% pólipos hiperplásicos, 7,85% pólipos inflamatórios e 7,85 % de outros tipos histológicos. Foram observados 24 (1,52% adenocarcinomas polipóides e 18 (1,14% adenomas com focos de adenocarcinoma. CONCLUSÃO: A incidência de pólipos nos pacientes estudados foi bastante alta, sendo os adenomas o tipo histológico mais freqüente, com risco de malignização de 1,14% e os adenocarcinomas polipóides 1,52%. Os pacientes portadores de adenomas colorretais devem ser submetidos a exames de controle, devido ao alto índice de ocorrência de novas lesões.INTRODUCTION: The resection of colorectal polyps is an important role in decreasing the incidence of colorectal cancer. The objective of this

High strength films from oriented, hydrogen-bonded "graphamid" 2D polymer molecular ensembles.

Science.gov (United States)

Sandoz-Rosado, Emil; Beaudet, Todd D; Andzelm, Jan W; Wetzel, Eric D

2018-02-27

The linear polymer poly(p-phenylene terephthalamide), better known by its tradename Kevlar, is an icon of modern materials science due to its remarkable strength, stiffness, and environmental resistance. Here, we propose a new two-dimensional (2D) polymer, "graphamid", that closely resembles Kevlar in chemical structure, but is mechanically advantaged by virtue of its 2D structure. Using atomistic calculations, we show that graphamid comprises covalently-bonded sheets bridged by a high population of strong intermolecular hydrogen bonds. Molecular and micromechanical calculations predict that these strong intermolecular interactions allow stiff, high strength (6-8 GPa), and tough films from ensembles of finite graphamid molecules. In contrast, traditional 2D materials like graphene have weak intermolecular interactions, leading to ensembles of low strength (0.1-0.5 GPa) and brittle fracture behavior. These results suggest that hydrogen-bonded 2D polymers like graphamid would be transformative in enabling scalable, lightweight, high performance polymer films of unprecedented mechanical performance.

Hyoscine butylbromide for colorectal polyp detection: prospective, randomized, placebo-controlled trial

Directory of Open Access Journals (Sweden)

Carlos Eduardo Oliveira dos Santos

Full Text Available OBJECTIVES: The removal of pre-malignant colorectal lesions prevents cancer. Hyoscine has been proposed as a means of improving diagnosis by reducing colonic movements. The aim of this study was to analyze whether this anti-spasmodic enhances the detection of pre-malignant colorectal lesions. METHODS: In a randomized, double-blinded fashion patients received hyoscine or a saline solution in all consecutive colonoscopies in which the cecum was reached. Lesions were analysed with respect to number, size, location, histology and capillary pattern. RESULTS: A total of 440 colonoscopies were randomized. The overall polyp detection rate (PDR and the adenoma detection rate (ADR were 65.2% and 49.3%, respectively. In the hyoscine group, non-polypoid lesions were detected significantly more often (p=0.01. In the placebo group 281 lesions were diagnosed (202 adenomas and in the hyoscine group 282 lesions were detected (189 adenomas (p=0.23. The PDR and ADR were similar between the placebo and hyoscine groups (64% vs 66% and 50% vs 47%, respectively. No differences were observed between the two groups in the advanced-ADR or advanced neoplasia detection rate, as well the mean numbers of polyps, adenomas, advanced adenomas and advanced neoplasias detected per patient. The administration of hyoscine also did not improve the diagnostic accuracy of digital chromoendoscopy. The presence of adenomatous polyps in the right colon was detected significantly more frequently in the hyoscine group (OR 5.41 95% CI 2.7 - 11; p<0.01 vs OR 2.3 95% CI 1.1 - 4.6; p=0.02. CONCLUSION: The use of hyoscine before beginning the withdrawal of the colonoscope does not seem to enhance the PDR and the ADR.

A Rare Presentation of Odontogenic Keratocyst Mimicking an Antral Polyp

Directory of Open Access Journals (Sweden)

S Sudhakar

2014-02-01

Full Text Available Maxillary sinus harbours many pathological lesions. Many of those presents as a sinonasal mass and are rarely symptomatic. These masses are usually an antral polyp, mucoceles or mucous retention cysts. Odontogenic keratocyst, a benign odontogenic lesion presenting within the maxillary sinus is a rare entity. We present a case of odontogenic keratocyst of the maxillary sinus in a 35 years old female.

Usual Tumor at an Unusual Site - A Leiomyoma Masquerading as a Urethral Polyp.

Directory of Open Access Journals (Sweden)

Shilpa MN

2013-01-01

Full Text Available Polyps and papillomas encompass the most common benign tumors of the urethra.Leiomyoma of urethra is a rare clinical entity which can be diagnosed only with histopathological examination and only around 35 such cases have been reported worldwide.

Fibroepithelial polyps of the urethra in infants: A report of three cases

African Journals Online (AJOL)

A. Ksia

Fibroepithelial polyps of the urethra (FEPU) are rare benign epithe- lial tumors, more frequently encountered in males and in the posterior urethra. In this paper, we report our experience with three patients having FEPU (between January 2006 and December 2012) and discuss the etiology, clinical presentations, diagnosis, ...

Retroperitoneal laparoscopy management for ureteral fibroepithelial polyps causing hydronephrosis in children: a report of five cases.

Science.gov (United States)

Dai, L N; Chen, C D; Lin, X K; Wang, Y B; Xia, L G; Liu, P; Chen, X M; Li, Z R

2015-10-01

Hydronephrosis is a common disease in children and may be caused by ureteral fibroepithelial polyps (UFP). Ureteral fibroepithelial polyps are rare in children and are difficult to precisely diagnose before surgery. Surgical treatment for symptomatic UFP is recommended. At the present institution, retroperitoneal laparoscopy has been used to treat five boys with UFP since 2006. To highlight the significance of UFP as an etiological factor of hydronephrosis in children and evaluate the applicative value of retroperitoneal laparoscopy in the treatment of children with UFP. Between 2006 and 2013 five boys underwent retroperitoneal laparoscopy at the present institution. They were identified with UFP by review of the clinical database. Detailed data were collected, including: radiographic studies, gross anatomical pathology, and pathology and radiology reports. All boys had been followed up at least every 6 months. All of the boys were aged between 7 and 16 years (mean 9.8 years). The main symptoms were flank pain (all five) and hematuria (three). Radiographic examination showed that all of the boys presented with incomplete ureteral obstruction and hydronephrosis. The ureteral fibroepithelial polyps were located near the left UPJ or the left proximal ureter. All of the boys had the UFP removed: three underwent retroperitoneal laparoscopic dismembered Anderson-Hynes pyeloplasty and polypectomy, and two had retroperitoneal laparoscopic ureteral anastomosis. These polyps were all on the left side and between 15 and 35 mm in length (mean 22 mm) (Figure). All of the boys recovered well and were discharged from hospital. The postoperative histological report confirmed that the specimens were UFP. Hydronephrosis was periodically assessed by ultrasonography (using the same method as pre-surgical ultrasonography) after surgery. Mean follow-up was 33 months (range 6-58 months) and no complications were found afterwards. Ureteral fibroepithelial polyps are rare but rather

Processing of intractable polymers using reactive solvents. 2. Poly(2,6-Dimethyl-1,4-Phenylene Ether) as a Matrix Material for High-Performance Composites

NARCIS (Netherlands)

Venderbosch, R.W.; Meijer, H.E.H.; Lemstra, P.J.

1995-01-01

The application of poly(2,6-dimethyl-1,4-phenylene ether) (PPE) as a matrix material for continuous carbon fibre reinforced composites has been studied. Owing to the intractable nature of PPE, melt impregnation is not feasible and therefore a solution impregnation route was explored using epoxy

Zileuton, 5-lipoxygenase inhibitor, acts as a chemopreventive agent in intestinal polyposis, by modulating polyp and systemic inflammation.

Directory of Open Access Journals (Sweden)

Elias Gounaris

Full Text Available Leukotrienes and prostaglandins, products of arachidonic acid metabolism, sustain both systemic and lesion-localized inflammation. Tumor-associated Inflammation can also contribute to the pathogenesis of colon cancer. Patients with inflammatory bowel disease (IBD have increased risk of developing colon cancer. The levels of 5-lipoxygenase (5-LO, the key enzyme for leukotrienes production, are increased in colon cancer specimens and colonic dysplastic lesions. Here we report that Zileuton, a specific 5-LO inhibitor, can prevent polyp formation by efficiently reducing the tumor-associated and systemic inflammation in APCΔ468 mice.In the current study, we inhibited 5-LO by dietary administration of Zileuton in the APCΔ468 mouse model of polyposis and analyzed the effect of in vivo 5-LO inhibition on tumor-associated and systemic inflammation.Zileuton-fed mice developed fewer polyps and displayed marked reduction in systemic and polyp-associated inflammation. Pro-inflammatory cytokines and pro-inflammatory innate and adaptive immunity cells were reduced both in the lesions and systemically. As part of tumor-associated inflammation Leukotriene B4 (LTB4, product of 5-LO activity, is increased focally in human dysplastic lesions. The 5-LO enzymatic activity was reduced in the serum of Zileuton treated polyposis mice.This study demonstrates that dietary administration of 5-LO specific inhibitor in the polyposis mouse model decreases polyp burden, and suggests that Zileuton may be a potential chemo-preventive agent in patients that are high-risk of developing colon cancer.

Steady State and Time-Resolved Fluorescence Dynamics of Triphenylamine Based Oligomers with Phenylene/Thiophene/Furan in Solvents

International Nuclear Information System (INIS)

Qi, Zeng; Ying-Liang, Liu; Kang, Meng; Xiang-Jie, Zhao; Shu-Feng, Wang; Qi-Huang, Gong

2009-01-01

We investigate the photo-physical properties of a series of triphenylamine-based oligomers by steady-state and picosecond transient fluorescence measurements in solvents. The oligomers are composed alternatively with triphenylamine and phenylene/thiophene/furan group, bridged by vinyl group (PNB/PNT/PNF). Their fluorescence spectra show bathochromic phenomenon with solvent polarity and viscosity increasing. The fluorescence decays are bi-exponential for PNB and PNT, and tri-exponential for PNF in THF and aniline. The strong viscosity dependence suggests conformational relaxation along the PNF chain after photo excitation. (condensed matter: electronicstructure, electrical, magnetic, and opticalproperties)

Optical Response of Poly (1,4-Phenylene-1,2-Di (P-Phenoxyphenyl Vinylene Towards Oxygen Gas

Directory of Open Access Journals (Sweden)

F.S Mehamod

2017-10-01

with terephthaloydichloride and biphenylether as starting materials and anhydrous AlCl3 as the catalyst, while the dpop-PDV was synthesized via the McMurry coupling reaction. The polymerization was carried out in THF with TiCl4 and Zn as the catalyst and reducing agent respectively. Characterization on monomer and polymer had been carried out by using FTIR, GCMS, DSC, TGA, GPC and melting point measurement. Response of the polymer towards oxygen gas was described in terms of fluorescence spectra, repeatability, reproducibility and the response curve. Results obtained showed that the fluorescence intensity decreased upon exposure to O2 gas, indicating that the polymer was responsive to the presence of the O2 gas and the sample was found regenerable by flushing the polymer solution with N2 gas.

CT colonography: effect of computer-aided detection of colonic polyps as a second and concurrent reader for general radiologists with moderate experience in CT colonography

International Nuclear Information System (INIS)

Mang, Thomas; Ringel, Helmut; Weber, Michael; Bogoni, Luca; Anand, Vikram X.; Hermosillo, Gerardo; Raykar, Vikas; Salganicoff, Marcos; Wolf, Matthias; Chandra, Dass; Curtin, Andrew J.; Lev-Toaff, Anna S.; Noah, Ralph; Shaw, Robert; Summerton, Susan; Tappouni, Rafel F.R.; Obuchowski, Nancy A.

2014-01-01

To assess the effectiveness of computer-aided detection (CAD) as a second reader or concurrent reader in helping radiologists who are moderately experienced in computed tomographic colonography (CTC) to detect colorectal polyps. Seventy CTC datasets (34 patients: 66 polyps ≥6 mm; 36 patients: no abnormalities) were retrospectively reviewed by seven radiologists with moderate CTC experience. After primary unassisted evaluation, a CAD second read and, after a time interval of ≥4 weeks, a CAD concurrent read were performed. Areas under the receiver operating characteristic (ROC) curve (AUC), along with per-segment, per-polyp and per-patient sensitivities, and also reading times, were calculated for each reader with and without CAD. Of seven readers, 86 % and 71 % achieved a higher accuracy (segment-level AUC) when using CAD as second and concurrent reader respectively. Average segment-level AUCs with second and concurrent CAD (0.853 and 0.864) were significantly greater (p < 0.0001) than average AUC in the unaided evaluation (0.781). Per-segment, per-polyp, and per-patient sensitivities for polyps ≥6 mm were significantly higher in both CAD reading paradigms compared with unaided evaluation. Second-read CAD reduced readers' average segment and patient specificity by 0.007 and 0.036 (p = 0.005 and 0.011), respectively. CAD significantly improves the sensitivities of radiologists moderately experienced in CTC for polyp detection, both as second reader and concurrent reader. (orig.)

Factors associated with delayed bleeding after resection of large nonpedunculated colorectal polyps.

Science.gov (United States)

Elliott, Timothy R; Tsiamoulos, Zacharias P; Thomas-Gibson, Siwan; Suzuki, Noriko; Bourikas, Leonidas A; Hart, Ailsa; Bassett, Paul; Saunders, Brian P

2018-04-06

 Delayed bleeding is the most common significant complication after piecemeal endoscopic mucosal resection (p-EMR) of large nonpedunculated colorectal polyps (NPCPs). Risk factors for delayed bleeding are incompletely defined. We aimed to determine risk factors for delayed bleeding following p-EMR.  Data were analyzed from a prospective tertiary center audit of patients with NPCPs ≥ 20 mm who underwent p-EMR between 2010 and 2012. Patient, polyp, and procedure-related data were collected. Four post p-EMR defect factors were evaluated for interobserver agreement and included in analysis. Delayed bleeding severity was reported in accordance with guidelines. Predictors of bleeding were identified.  Delayed bleeding requiring hospitalization occurred after 22 of 330 procedures (6.7 %). A total of 11 patients required blood transfusion; of these, 4 underwent urgent colonoscopy, 1 underwent radiological embolization, and 1 required surgery. Interobserver agreement for identification of the four post p-EMR defect factors was moderate (kappa range 0.52 - 0.57). Factors associated with delayed bleeding were visible muscle fibers ( P  = 0.03) and the presence of a "cherry red spot" ( P  = 0.05) in the post p-EMR defect. Factors not associated with delayed bleeding were American Association of Anesthesiologists class, aspirin use, polyp size, site, and use of argon plasma coagulation.  Visible muscle fibers and the presence of a "cherry red spot" in the resection defect were associated with delayed bleeding after p-EMR. These findings suggest evaluation and photodocumentation of the post p-EMR defect is important and, when considered alongside other patient and procedural factors, may help to reduce the incidence and severity of delayed bleeding. © Georg Thieme Verlag KG Stuttgart · New York.

[Rectocolonic polyps in Senegal. Results of 1500 lower endoscopies carried out at the Dakar General Hospital].

Science.gov (United States)

Peghini, M; Barabe, P; Seurat, P; Philippon, G; Morcillo, R; Diallo, A; Gueye, P M

1987-01-01

57 polyps were discovered during 1,500 low endoscopies, and 24 of them were adenoma. In the same period of time, 26 proctocolitic adenocarcinomas were found. Adenomatous polyps appear to be 5 times less frequent in Senegal than in industrialized countries and frequency of colitic cancer should be of the same frequency, that is far less negligible. Even if proctocolitic cancer does not set up any Public Health problems one could envisage systematic screening of polyadenoma in every patient aged more than 40. Proctosigmoid being the seat of most adenoma, fibrosigmoidoscopy appears well adapted to this kind of screening because it does not require any preparation, it is easy to perform and well accepted.

NASAL MUCOUS MEMBRANE MICROFLORA IN PATIENTS WITH POLYPOUS RHINOSINUSITIS

Directory of Open Access Journals (Sweden)

O. A. Kolenchukova

2016-01-01

Full Text Available Nasal mucous membrane microbiocenosis Research amongst patients with polypous rhinosinusitis is conducted. Patients with polypous rhinosinusitis (PRS, n = 58 aged from 18 till 64 years and group of control (n = 156. For an microflora assessment of nasal mucous membrane during an exacerbation of a disease carried out crops of microorga nisms on nutrient differential and diagnostic agars. When studying the microflora received from nasal mucous membrane 407 cultures of microorganisms at PRS were revealed. In control group of 174 microorganisms cultures are revealed. Among isolates were established 6 genera of 9 species of bacteria at PRS against 6 genera and 8 species in group of control. Microflora quantitative structure research of nasal mucous membrane at PRS of rather control group considerable prevalence of the microorganisms belonging to the sorts Staphylococcus and Streptococcus, and also to Enterobacteriaceae was revealed. It is also revealed increase S. pneumoniae. When determining specific accessory of the microorganisms relating to the Staphylococcus genera in PRS group concerning control the increase in total number of the strains of S. aureus relating to coagulase-positive and S. haemolyticus, S. epidermidis relating to coagulase-negative staphylococcus was established. A big variety the coagulase-negative of Staphylococcus is also revealed: S. epidermidis, S. haemolyticus, S. hominis, S. cohnii, S. capitis, S. hyicius and S. xylosus. In control group of such types as S. capitis and S. hyicius it isn’t revealed. Thus at a polypous rhinosinusitis nasal mucous membrane the expressed dysbacteriosis takes place. The analysis of frequency of occurrence of the microorganisms belonging to different childbirth showed that in PRS group bacteria of the sort Streptococcus and this Nesseria, and also S. pneumoniae, S. pyogenes were most often allocated concerning control. The frequency prevalence analysis of the gene ra Staphylococcus related

Efficient sodium chlorate/calcium/aluminum cathode for polymer light-emitting diodes

International Nuclear Information System (INIS)

Hu Yufeng; Shi Shengwei; Zhang Yanguang; Zhou Quanguo; Wang Lixiang; Ma Dongge; Li Xinglin

2005-01-01

A cathode system comprising an ultra thin sodium chlorate (NaCl) layer and an overlaid calcium (Ca) metal in polymer light-emitting diodes (PLEDs) based on poly[2-methoxy,5-(2-ethylhexoxy)-1,4-phenylene vinylene] is presented. It is demonstrated that introducing a thin NaCl layer further improves the brightness and electroluminescent efficiency of PLEDs. The maximum brightness and efficiency, respectively, reached 22 000 cd/m 2 and 3.5 lm/W for PLEDs with a 1 nm NaCl layer, which are much higher than 18 500 cd/m 2 and 2.0 lm/W for PLEDs with Ca cathode. The investigation of the electron injection in electron-only devices with and without a NaCl layer indicates that the introduction of the NaCl layer substantially enhances the electron injection current, which in case of PLEDs leads to the improvement of the brightness and efficiency

40 CFR 721.4575 - L-aspartic acid, N,N′- [(1E) - 1,2 - ethenediylbis[(3-sulfo-4, 1-phenylene)imino [6-(phenylamino...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false L-aspartic acid, N,Nâ²- [(1E) - 1,2... Substances § 721.4575 L-aspartic acid, N,N′- [(1E) - 1,2 - ethenediylbis[(3-sulfo-4, 1-phenylene)imino [6... uses subject to reporting. (1) The chemical substance identified as l-aspartic acid, N,N′- [(1E) - 1,2...

Ursodeoxycholic acid counteracts celecoxib in reduction of duodenal polyps in patients with familial adenomatous polyposis: a multicentre, randomized controlled trial

Science.gov (United States)

2013-01-01

Background Due to prophylactic colectomy, mortality in patients with familial adenomatous polyposis (FAP) has changed, with duodenal cancer currently being the main cause of death. Although celecoxib reduces duodenal polyp density in patients with FAP, its long-term use may increase the risk of cardiovascular events and alternatives need to be explored. Preclinical studies suggest that the combination of celecoxib with ursodeoxycholic acid (UDCA) is a potentially effective strategy. We performed a randomized, double-blind, placebo-controlled trial to investigate the effect of celecoxib and UDCA co-treatment on duodenal adenomatosis in patients with FAP. Methods Patients with FAP received celecoxib (400 mg twice daily) and UDCA (1000-2000 mg daily, ~20-30 mg/kg/day, n=19) or celecoxib and placebo (n=18) orally for 6 months. Primary outcome was drug efficacy, assessed by comparing duodenal polyp density at pre- and post-intervention by blinded review of endoscopic recordings. As secondary outcomes, cell proliferation, apoptosis, and COX-2 levels in normal duodenal mucosa were assessed by immunohistochemistry or real-time quantitative polymerase chain reaction. Results In intention-to-treat analysis, deceased polyp density was observed after celecoxib/placebo treatment (p=0.029), whereas increased polyp density was observed after celecoxib/UDCA treatment (p=0.014). The difference in change in duodenal polyp density was statistically significant between the groups (p=0.011). No changes in secondary outcomes were observed. Thirty patients (81%) reported one or more adverse events, 16 patients (84%, Common Toxicity Criteria for Adverse Events version 3.0 (CTCAE) grade 1–3) treated with celecoxib/UDCA and 14 patients (78%, CTCAE grade 1–2) treated with celecoxib/placebo. Nine patients (24%) discontinued intervention prematurely, 5 patients (26%) treated with celecoxib/UDCA and 4 patients (22%) treated with celecoxib/placebo. Conclusions Celecoxib reduces duodenal

New-Style Laparoscope and Endoscope Cooperative Gallbladder-Preserving Surgery for Polyps

International Nuclear Information System (INIS)

Li, M.; Wu, H.; Wei, S.

2016-01-01

Objective: To evaluate the feasibility and safety of a new style of Laparoscope and Endoscope Cooperative gallbladderpreserving Surgery (LECS), an improved method of minimally invasive gallbladder-preserving polypectomy. Study Design: An experimental study. Place and Duration of Study: Department of General Surgery, The Second Affiliated Hospital of Soochow University, China, from January 2009 to July 2013. Methodology: Clinical data of patients subjected to LECS and Laparoscopic Cholecystectomy (LC) was analysed. The inclusion criteria were normal size clear gallbladder bile with total volume (FV) of the gallbladder = 15 - 25 ml, the Residual Volume (RV) = 5 ml, and the Emptying Figure (EF) > 75 percentage, with polyps diagnosed definitively by B-type ultrasonic imaging or CT desirous of preserving gallbladder. Exclusion criteria were a history of midsection surgery, serious diseases of any organ, hepatic injury, or coagulation disturbance. Mean hospital stay and complications were also noted. Independent sample t-test, the frequency comparison used chi-square test (N > 5), and Fisher's exact test (N < 5) were used for statistical test. Results: The mean hospital stay after LECS was 3.50 ± 0.31 days, and 3.50 ± 0.31 days for the LC group. The mean age in LC and LECS group was 50 ± 25.4 and 44 ± 12.1 years, respectively. Complications after operation in the LECS were indigestion and diarrhea; LC group had indigestion (9.33 percentage), diarrhea (10.67 percentage), and gastroesophageal reflux (6.6.7 percentage). In the 3 months follow-up after discharging from the hospital, no patient had recurrence of any gallbladder disease; at 1 year follow-up, 1 patient (1.28 percentage) developed cholesterol crystals; at 3-year follow-up, 3 cases (3.84 percentage) were found to have recurring polyps (2-4 pieces), and 2 (2.56 percentage) patients developed cholesterol crystals. Conclusion: Minimally invasive gallbladder-preserving polypectomy which used a CHIAO

Computer-Aided Diagnosis Based on Convolutional Neural Network System for Colorectal Polyp Classification: Preliminary Experience.

Science.gov (United States)

Komeda, Yoriaki; Handa, Hisashi; Watanabe, Tomohiro; Nomura, Takanobu; Kitahashi, Misaki; Sakurai, Toshiharu; Okamoto, Ayana; Minami, Tomohiro; Kono, Masashi; Arizumi, Tadaaki; Takenaka, Mamoru; Hagiwara, Satoru; Matsui, Shigenaga; Nishida, Naoshi; Kashida, Hiroshi; Kudo, Masatoshi

2017-01-01

Computer-aided diagnosis (CAD) is becoming a next-generation tool for the diagnosis of human disease. CAD for colon polyps has been suggested as a particularly useful tool for trainee colonoscopists, as the use of a CAD system avoids the complications associated with endoscopic resections. In addition to conventional CAD, a convolutional neural network (CNN) system utilizing artificial intelligence (AI) has been developing rapidly over the past 5 years. We attempted to generate a unique CNN-CAD system with an AI function that studied endoscopic images extracted from movies obtained with colonoscopes used in routine examinations. Here, we report our preliminary results of this novel CNN-CAD system for the diagnosis of colon polyps. A total of 1,200 images from cases of colonoscopy performed between January 2010 and December 2016 at Kindai University Hospital were used. These images were extracted from the video of actual endoscopic examinations. Additional video images from 10 cases of unlearned processes were retrospectively assessed in a pilot study. They were simply diagnosed as either an adenomatous or nonadenomatous polyp. The number of images used by AI to learn to distinguish adenomatous from nonadenomatous was 1,200:600. These images were extracted from the videos of actual endoscopic examinations. The size of each image was adjusted to 256 × 256 pixels. A 10-hold cross-validation was carried out. The accuracy of the 10-hold cross-validation is 0.751, where the accuracy is the ratio of the number of correct answers over the number of all the answers produced by the CNN. The decisions by the CNN were correct in 7 of 10 cases. A CNN-CAD system using routine colonoscopy might be useful for the rapid diagnosis of colorectal polyp classification. Further prospective studies in an in vivo setting are required to confirm the effectiveness of a CNN-CAD system in routine colonoscopy. © 2017 S. Karger AG, Basel.

Conducting Polymers

Indian Academy of Sciences (India)

would exhibit electronic conductivity, their conductivities (of compressed pellets) were indeed measured by others, and were found to be .... Polyaniline. Polyphenylene. Polypheny lene- vinylene. Table 1. G!NeRAl I ARTICl! structure. Maximum conductivity Stem Stability. Processability. ~. 1.5 x 105. Reacts with Film not n air.

Associations between inflammatory cells infiltrating the ethmoid sinus mucosa, and nasal polyp size and grade of ethmoid sinus opacification on CT images in chronic sinusitis

International Nuclear Information System (INIS)

Imajima, Naotoshi; Watanabe, So; Furuta, Atsuko; Shimizu, Toshiyuki; Yamada, Naohiro; Mochizuki, Yuichiro; Suzaki, Harumi

2009-01-01

We investigated the types and numbers of inflammatory cells that infiltrated the ethmoid sinus mucosa in cases of chronic sinusitis in order to identify any associations with nasal polyp size and the grade of ethmoid sinus opacification on computer tomography images. The subjects were patients with chronic sinusitis who underwent endoscopic sinus surgery. Seventeen subjects also had bronchial asthma as a complication (six with aspirin-induced asthma, 11 with another form of asthma) and 24 did not have bronchial asthma as a complication (16 with allergic rhinitis, 8 with chronic sinusitis alone). The nasal polyps in the patients with bronchial asthma were significantly larger than those in the patients without bronchial asthma. Investigation of the numbers of infiltrating inflammatory cells according to polyp size revealed significantly more eosinophils as polyp size increased. In addition, infiltration of significantly more mast cells was observed when the polyps were large. Assessment of the grade of opacification of the ethmoid sinuses on computer tomography images showed a significantly higher grade of opacification in the patients with bronchial asthma than in the patients without bronchial asthma. Comparisons between the grade of opacification of the ethmoid sinuses and the number of infiltrating inflammatory cells revealed significantly more infiltrating eosinophils and mast cells in the patients with intense ethmoid sinus opacification. The above findings suggest that eosinophils and mast cells play a major role in forming the persistent inflammation of the sinus mucosa and nasal polyp tissue of patients with chronic sinusitis complicated by bronchial asthma. (author)

An economic evaluation of outpatient versus inpatient polyp treatment for abnormal uterine bleeding.

Science.gov (United States)

Diwakar, L; Roberts, T E; Cooper, N A M; Middleton, L; Jowett, S; Daniels, J; Smith, P; Clark, T J

2016-03-01

To undertake a cost-effectiveness analysis of outpatient uterine polypectomy compared with standard inpatient treatment under general anaesthesia. Economic evaluation carried out alongside the multi-centre, pragmatic, non-inferiority, randomised controlled Outpatient Polyp Treatment (OPT) trial. The UK National Health Service (NHS) perspective was used in the estimation of costs and the interpretation of results. Thirty-one secondary care UK NHS hospitals between April 2008 and July 2011. Five hundred and seven women with abnormal uterine bleeding and hysteroscopically diagnosed endometrial polyps. Outpatient uterine polypectomy versus standard inpatient treatment. Clinicians were free to choose the technique for polypectomy within the allocated setting. Patient-reported effectiveness of the procedure determined by the women's self-assessment of bleeding at 6 months, and QALY gains at 6 and 12 months. Inpatient treatment was slightly more effective but more expensive than outpatient treatment, resulting in relatively high incremental cost-effectiveness ratios. Intention-to-treat analysis of the base case at 6 months revealed that it cost an additional £9421 per successfully treated patient in the inpatient group and £ 1,099,167 per additional QALY gained, when compared with outpatient treatment. At 12 months, these costs were £22,293 per additional effectively treated patient and £445,867 per additional QALY gained, respectively. Outpatient treatment of uterine polyps associated with abnormal uterine bleeding appears to be more cost-effective than inpatient treatment at willingness-to-pay thresholds acceptable to the NHS. HTA-funded OPT trial concluded that outpatient uterine polypectomy is cost-effective compared with inpatient polypectomy. © 2015 Royal College of Obstetricians and Gynaecologists.

The role of Phosphatidylinositol 3 kinase (PI3K and Cycloxygenase-2 (COX2 in carcinogenesis of colorectal polyps

Directory of Open Access Journals (Sweden)

Raul Alberto Anselmi Júnior

2018-01-01

Full Text Available Objectives: Determine immunohistochemical expression of Phosphatase and tensin homolog (PTEN, Phosphatidylinositol 3 kinase (PI3K, Cycloxygenase-2 (COX2 and one proliferation marker (Ki67 in colorectal polyps and correlate with clinical and pathological data in search of carcinogenic pathways. Methods: The reports of 297 polyps diagnosed through endoscopy were reviewed for parameters including age, gender, prior colorectal cancer, the presence of multiple polyps, and polyps’ location, appearance and size. Was conducted a microscopic morphometric computerized analysis of immunohistochemical expression using, the selected antibodies and correlated with clinical and pathological variables. Results: The tissue immunohistochemical expression was higher in right colon polyps for the proliferation marker and Phosphatidylinositol 3 kinase (p ≤ 0.0001 and 0.057 respectively. Cycloxygenase-2 and Phosphatase and tensin homolog demonstrated higher tissue immunoexpression in pedunculated polyps (p = 0.009 and 0.002 respectively. Cycloxygenase-2 exhibited higher immunoexpression in larger polyps (p = 0.005. Phosphatidylinositol 3 kinase, Cycloxygenase-2, Phosphatase and tensin homolog and the proliferation marker exhibited higher immunoexpression in high-grade dysplastic polyps (p = 0.031, 0.013, 0.044 and <0.001 respectively. Phosphatase and tensin homolog labeling was higher in polyps with high-grade dysplasia and lower in some of serrated lesions (p = 0.044. Conclusions: The greater expression of the proliferation marker and Phosphatidylinositol 3 kinase in the right colon may be related to right-sided colorectal carcinogenesis. The proliferation marker, Cycloxygenase-2 and Phosphatidylinositol 3 kinase results can be associated with progression of polyps to colorectal cancer. The higher Phosphatase and tensin homolog expression suggests its attempt to control the cell cycle. Resumo: Objetivos: Determinar a expressão imuno-histoquímica de

Clinical Evaluation of Endoscopic Trimodal Imaging for the Detection and Differentiation of Colonic Polyps

NARCIS (Netherlands)

van den Broek, Frank J. C.; Fockens, Paul; van Eeden, Susanne; Kara, Mohammed A.; Hardwick, James C. H.; Reitsma, Johannes B.; Dekker, Evelien

2009-01-01

Background & Aims: Endoscopic trimodal imaging (ETMI) incorporates high-resolution endoscopy (HRE) and autofluorescence imaging (AFI) for adenoma detection, and narrow-band imaging (NBI) for differentiation of adenomas from nonneoplastic polyps. The aim of this study was to compare AFI with HRE for

Metformin efficacy and safety for colorectal polyps: a double-blind randomized controlled trial

International Nuclear Information System (INIS)

Higurashi, Takuma; Fujisawa, Nobutaka; Uchiyama, Shiori; Ezuka, Akiko; Nagase, Hajime; Kessoku, Takaomi; Matsuhashi, Nobuyuki; Yamanaka, Shoji; Inayama, Yoshiaki; Morita, Satoshi; Nakajima, Atsushi; Takahashi, Hirokazu; Endo, Hiroki; Hosono, Kunihiro; Yamada, Eiji; Ohkubo, Hidenori; Sakai, Eiji; Uchiyama, Takashi; Hata, Yasuo

2012-01-01

Colorectal cancer is one of the major neoplasms and a leading cause of cancer death worldwide, and new preventive strategies are needed to lower the burden of this disease. Metformin, a biguanide, which is widely used for treating diabetes mellitus, has recently been suggestive to have a suppressive effect on tumorigenesis and cancer cell growth. In a previous study conducted in non-diabetic subjects, we showed that oral short-term low-dose metformin suppressed the development of colorectal aberrant crypt foci (ACF). ACF have been considered as a useful surrogate biomarker of CRC, although the biological significance of these lesions remains controversial. We devised a prospective randomized controlled trial to evaluate the chemopreventive effect of metformin against metachronous colorectal polyps and the safety of this drug in non-diabetic post-polypectomy patients. This study is a multi-center, double-blind, placebo-controlled, randomized controlled trial to be conducted in non-diabetic patients with a recent history of undergoing colorectal polypectomy. All adult patients visiting the Yokohama City University hospital or affiliated hospitals for polypectomy shall be recruited for the study. Eligible patients will then be allocated randomly into either one of two groups: the metformin group and the placebo group. Patients in the metformin group shall receive oral metformin at 250 mg per day, and those in the placebo group shall receive an oral placebo tablet. At the end of 1 year of administration of metformin/placebo, colonoscopy will be performed to evaluate the polyp formation. This is the first study proposed to explore the effect of metformin against colorectal polyp formation. Metformin activates AMPK, which inhibits the mammalian target of rapamycin (mTOR) pathway. The mTOR pathway plays an important role in the cellular protein translational machinery and cell proliferation. Patients with type 2 diabetes taking under treatment with metformin have been

Metformin efficacy and safety for colorectal polyps: a double-blind randomized controlled trial

Directory of Open Access Journals (Sweden)

Higurashi Takuma

2012-03-01

Full Text Available Abstract Background Colorectal cancer is one of the major neoplasms and a leading cause of cancer death worldwide, and new preventive strategies are needed to lower the burden of this disease. Metformin, a biguanide, which is widely used for treating diabetes mellitus, has recently been suggestive to have a suppressive effect on tumorigenesis and cancer cell growth. In a previous study conducted in non-diabetic subjects, we showed that oral short-term low-dose metformin suppressed the development of colorectal aberrant crypt foci (ACF. ACF have been considered as a useful surrogate biomarker of CRC, although the biological significance of these lesions remains controversial. We devised a prospective randomized controlled trial to evaluate the chemopreventive effect of metformin against metachronous colorectal polyps and the safety of this drug in non-diabetic post-polypectomy patients. Methods/Design This study is a multi-center, double-blind, placebo-controlled, randomized controlled trial to be conducted in non-diabetic patients with a recent history of undergoing colorectal polypectomy. All adult patients visiting the Yokohama City University hospital or affiliated hospitals for polypectomy shall be recruited for the study. Eligible patients will then be allocated randomly into either one of two groups: the metformin group and the placebo group. Patients in the metformin group shall receive oral metformin at 250 mg per day, and those in the placebo group shall receive an oral placebo tablet. At the end of 1 year of administration of metformin/placebo, colonoscopy will be performed to evaluate the polyp formation. Discussion This is the first study proposed to explore the effect of metformin against colorectal polyp formation. Metformin activates AMPK, which inhibits the mammalian target of rapamycin (mTOR pathway. The mTOR pathway plays an important role in the cellular protein translational machinery and cell proliferation. Patients with

New combinations for two coronate polyp species (Atorellidae and Nausithoidae, Coronatae, Scyphozoa, Cnidaria)

NARCIS (Netherlands)

Morandini, A.C.; Jarms, G.

2005-01-01

Within the order Coronatae, six valid species remain known only by their polyp stage. The inability to relate them to any medusae genera of the group is a problem that remains to be solved in the order. With the examination of type specimens, we reassign the species Stephanoscyphistoma sibogae and

Rapid promotion and progression of fibrovascular polyps by inflammation and/or hyperplasia in hamster check pouch: implications for carcinogenesis assay.

Science.gov (United States)

McGaughey, C; Jensen, J L

1983-03-01

Tumor initiation by topical application of 7,12-dimethylbenz[a]anthracene (DMBA) in dimethyl sulfoxide (DMSO) followed by topical application of retinyl acetate (RA), ethylphenylpropiolate, or acetic acid in DMSO at inflammatory and hyperplasiogenic dose regimens caused the rapid promotion of fibrovascular polyps with dysplastic epithelium in hamster cheek pouch. Such lesions did not occur in control animals initiated with DMBA followed by application of DMSO only, where inflammation was also minimal. At the dose regimen employed, RA caused obvious cytotoxicity and tissue destruction. With EPP and AA, there was no histological evidence of tissue destruction. At dose regimens resulting in minimal inflammation and no apparent cytotoxicity, RA promoted almost no polyps, but a higher yield of other tumor types. Thus, inflammation and/or hyperplasia apparently exerted a strong polyp-promoting and progressive influence. This and other differences between the tumorigenic responses of hamster-pouch mucosa and mouse skin suggest that the former supplement the latter in carcinogenic risk assessment.

Conformation of ionizable poly Para phenylene ethynylene in dilute solutions

International Nuclear Information System (INIS)

Wijesinghe, Sidath; Maskey, Sabina; Perahia, Dvora; Grest, Gary S.

2015-01-01

The conformation of dinonyl poly para phenylene ethynylenes (PPEs) with carboxylate side chains, equilibrated in solvents of different quality is studied using molecular dynamics simulations. PPEs are of interest because of their tunable electro-optical properties, chemical diversity, and functionality which are essential in wide range of applications. The polymer conformation determines the conjugation length and their assembly mode and affects electro-optical properties which are critical in their current and potential uses. The current study investigates the effect of carboxylate fraction on PPEs side chains on the conformation of chains in the dilute limit, in solvents of different quality. The dinonyl PPE chains are modeled atomistically, where the solvents are modeled both implicitly and explicitly. Dinonyl PPEs maintained a stretched out conformation up to a carboxylate fraction f of 0.7 in all solvents studied. The nonyl side chains are extended and oriented away from the PPE backbone in toluene and in implicit good solvent whereas in water and implicit poor solvent, the nonyl side chains are collapsed towards the PPE backbone. Thus, rotation around the aromatic ring is fast and no long range correlations are seen within the backbone

Lack of association between the 677 C to T polymorphism and colorectal hyperplastic polyps

NARCIS (Netherlands)