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Sample records for antimon och ett

  1. Characterization of the Antimonial Antileishmanial Agent Meglumine Antimonate (Glucantime)

    PubMed Central

    Roberts, William L.; McMurray, Walter J.; Rainey, Petrie M.

    1998-01-01

    Meglumine antimonate (Glucantime), a drug of choice for the treatment of leishmaniasis, is produced by the reaction of pentavalent antimony with N-methyl-d-glucamine, a carbohydrate derivative. We investigated the structure and composition of meglumine antimonate, which remain poorly understood, despite 50 years of use. Measurement of the antimony content of meglumine antimonate powder indicated a 1:1.37 molar ratio of antimony to N-methyl-d-glucamine. Osmolality measurements performed with meglumine antimonate solutions demonstrated an average of 1.43 antimony atoms per molecule of meglumine antimonate. The osmolality of a 1:10 dilution of stock meglumine antimonate increased by 45% over 8 days, suggesting hydrolysis to less complex species. A comparison of the proton nuclear magnetic resonance spectra of N-methyl-d-glucamine and meglumine antimonate revealed an increase in complexity in the latter but with all of the resonances of the former still being evident, consistent with the presence of coordination complexes between antimony and each of the N-methyl-d-glucamine hydroxyls. Fast atom bombardment and electrospray ionization mass spectrometry coupled with several derivatization procedures provided evidence that up to four N-methyl-d-glucamine hydroxyls are coordinated with each antimony. A series of oligomers were observed. The major moiety has a molecular mass of 507 atomic mass units and consists of NMG-Sb-NMG, where Sb represents antimony and NMG represents N-methyl-d-glucamine. Additional species containing up to four antimony atoms and five N-methyl-d-glucamine moieties and corresponding to the general form (NMG-Sb)n-NMG are also present. These results suggest that this agent is a complex mixture that exists in equilibrium in aqueous solution. PMID:9593130

  2. Electrochemical reaction of lithium with nanosized vanadium antimonate

    SciTech Connect

    Morales, Julian; Sanchez, Luis . E-mail: luis-sanchez@uco.es; Martin, Francisco; Berry, Frank

    2006-08-15

    Nanometric vanadium antimonate, VSbO{sub 4}, was prepared by mechanical milling from Sb{sub 2}O{sub 3} and V{sub 2}O{sub 5} and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Mossbaueer spectroscopy (MS) and X-ray photoelectron spectroscopy (XPS) techniques. Its reactivity towards lithium was examined by testing Li/VSbO{sub 4} cells under galvanostatic and potentiostatic regimes. The amount of Li inserted was found to be consistent with a two-step process involving the reactions (i) VSbO{sub 4}+8 Li{sup {yields}}Sb+V+4 Li{sub 2}O and (ii) Sb+3 Li{sup {yields}}Li{sub 3}Sb, the former being virtually irreversible and the latter reversible as suggested by the shape of the anodic and cathodic curves. Ex situ XPS measurements of the discharged and charged electrode provided direct evidence of the formation of alloyed Sb and confirmed the results of the potentiostatic curves regarding the irreversible or reversible character of the previous reactions. The Li/VSbO{sub 4} cell exhibited acceptable electrochemical performance, which surpassed that of other Sb-based compounds as the likely result of the formation of V and its associated enhanced electrode conductivity. - Graphical abstract: TEM image of nanosized VSbO{sub 4} sample.

  3. Meglumine antimonate treatment enhances phagocytosis and TNF-α production by monocytes in human cutaneous leishmaniasis.

    PubMed

    de Saldanha, Rosana Regina; Martins-Papa, Marianna Carminatti; Sampaio, Raimunda Nonata Ribeiro; Muniz-Junqueira, Maria Imaculada

    2012-10-01

    This work evaluated phagocytic function, hydrogen peroxide (H(2)O(2)), TNF-α and IL-10 production by monocytes and serum INF-γ levels in New World human cutaneous leishmaniasis and the influence of meglumine antimonate treatment on these immune functions. The phagocytic capacity of monocytes in untreated Leishmania-infected individuals was significantly (2.5 times) lower than that of healthy controls, and antimonial treatment increased the phagocytosis by monocytes by about five times at the end of therapy. The leishmaniasis patients showed 3.9 times higher H(2)O(2) production than controls and treatment with meglumine antimonate did not influence the production of H(2)O(2), which remained enhanced until the end of treatment. Individuals with leishmaniasis showed 6.3 times lower TNF-α production than healthy individuals and meglumine antimonate treatment caused a significant increment (11.9 times) in its production. INF-γ serum levels were higher in Leishmania-infected individuals than healthy controls, and the production of IL-10 by monocytes was not influenced by infection or antimonial treatment. Enhancement of monocyte functions by the antimonial treatment suggests that the immunomodulatory effects of the drug may also play a part in the way meglumine antimonate acts against the parasite in human leishmaniasis, by directly increasing phagocytosis and TNF-α production. Copyright © 2012 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

  4. Dissimilatory antimonate reduction and production of antimony trioxide microcrystals by a novel microorganism.

    PubMed

    Abin, Christopher A; Hollibaugh, James T

    2014-01-01

    Antimony (Sb) is a metalloid that has been exploited by humans since the beginning of modern civilization. The importance of Sb to such diverse industries as nanotechnology and health is underscored by the fact that it is currently the ninth-most mined metal worldwide. Although its toxicity mirrors that of its Group 15 neighbor arsenic, its environmental chemistry is very different, and, unlike arsenic, relatively little is known about the fate and transport of Sb, especially with regard to biologically mediated redox reactions. To further our understanding of the interactions between microorganisms and Sb, we have isolated a bacterium that is capable of using antimonate [Sb(V)] as a terminal electron acceptor for anaerobic respiration, resulting in the precipitation of antimonite [Sb(III)] as microcrystals of antimony trioxide. The bacterium, designated strain MLFW-2, is a sporulating member of a deeply branching lineage within the order Bacillales (phylum Firmicutes). This report provides the first unequivocal evidence that a bacterium is capable of conserving energy for growth and reproduction from the reduction of antimonate. Moreover, microbiological antimonate reduction may serve as a novel route for the production of antimony trioxide microcrystals of commercial significance to the nanotechnology industry.

  5. Synthesis of calcium antimonate nano-crystals by the 18th dynasty Egyptian glassmakers

    NASA Astrophysics Data System (ADS)

    Lahlil, S.; Biron, I.; Cotte, M.; Susini, J.; Menguy, N.

    2010-01-01

    During the 18th Egyptian dynasty (1570-1292 B.C.), opaque white, blue and turquoise glasses were opacified by calcium antimonate crystals dispersed in a vitreous matrix. The technological processes as well as the antimony sources used to manufacture these crystals remain unknown. Our results shed a new light on glassmaking history: contrary to what was thought, we demonstrate that Egyptian glassmakers did not use in situ crystallization but first synthesized calcium antimonate opacifiers, which do not exist in nature, and then added them to a glass. Furthermore, using transmission electron microscopy (TEM) for the first time in the study of Egyptian opaque glasses, we show that these opacifiers were nano-crystals. Prior to this research, such a process for glassmaking has not been suggested for any kind of ancient opaque glass production. Studying various preparation methods for calcium antimonate, we propose that Egyptian craftsmen could have produced Ca2Sb2O7 by using mixtures of Sb2O3 or Sb2O5 with calcium carbonates (atomic ratio Sb/Ca=1) heat treated between 1000 and 1100°C. We developed an original strategy focused on the investigation of the crystals and the vitreous matrices using an appropriate suite of high-sensitivity and high-resolution micro- and nano-analytical techniques (scanning electron microscopy (SEM), X-ray diffraction (XRD), TEM). Synchrotron-based micro X-ray absorption near edge spectroscopy (μ-XANES) proved to be very well suited to the selective measure of the antimony oxidation state in the vitreous matrix. This work is the starting point for a complete reassessment not only of ancient Egyptian glass studies but more generally of high-temperature technologies used throughout antiquity.

  6. Pentoxifylline prevents the meglumine antimonate-induced renal toxicity in rats, but not that induced by the inorganic antimony pentachloride.

    PubMed

    de Moura, Flávio José Dutra; Leal, Pushkin Pires; de Souza Furtado, Rogério; Muniz-Junqueira, Maria Imaculada; Veiga, Joel Paulo Russomano

    2008-01-14

    Tumor necrosis factor-alpha (TNF-alpha) is a mediator of inflammation and has an important role in human and experimental renal diseases. Pentoxifylline (PTX) has been shown to inhibit cytokine synthesis, including TNF-alpha. The aim of the present study was to examine the effect of PTX on meglumine antimonate (Sb(V)) and antimony pentachloride (SbCl(5))-induced renal toxicity in rats. Sixty Wistar rats were divided into six groups according to the treatment employed over the period of 7 days: group I-saline (NaCl 0.9%); group II-PTX plus saline; group III-meglumine antimonate (Sb(V)) plus saline; group IV-meglumine antimonate (Sb(V)) plus PTX; group V-SbCl(5) plus saline; group VI-SbCl(5) with PTX. The animals' urinary concentration ability was evaluated before and after the end of the treatment. Urine and blood osmolality, sodium and creatinine concentration, and urine volume per minute (V) were determined. Creatinine clearance (CrCl), fractional sodium excretion (FE(Na)), and urine to plasma osmolality ratio (U/P osm) were calculated. TNF-alpha concentration in blood was assessed. On the seventh day, the animals were sacrificed and their kidneys were submitted to histological analysis. The meglumine antimonate (Sb(V))-treated animals showed an impaired renal capacity to concentrate urine, with low values of the ratio U/P osm, reduction in CrCl, and an increment in TNF-alpha serum levels. PTX associated with meglumine antimonate (Sb(V)) reduced TNF-alpha serum levels and was effective in preventing renal functional alterations. Rats treated with SbCl(5) showed functional and histopathologic alterations compatible with acute tubular necrosis, and treatment with PTX did not prevent SbCl(5)-induced nephrotoxicity. PTX was effective in preventing renal functional alterations induced by meglumine antimonate (Sb(V)) in rats.

  7. Autotrophic antimonate bio-reduction using hydrogen as the electron donor.

    PubMed

    Lai, Chun-Yu; Wen, Li-Lian; Zhang, Yin; Luo, Shan-Shan; Wang, Qing-Ying; Luo, Yi-Hao; Chen, Ran; Yang, Xiaoe; Rittmann, Bruce E; Zhao, He-Ping

    2016-01-01

    Antimony (Sb), a toxic metalloid, is soluble as antimonate (Sb(V)). While bio-reduction of Sb(V) is an effective Sb-removal approach, its bio-reduction has been coupled to oxidation of only organic electron donors. In this study, we demonstrate, for the first time, the feasibility of autotrophic microbial Sb(V) reduction using hydrogen gas (H2) as the electron donor without extra organic carbon source. SEM and EDS analysis confirmed the production of the mineral precipitate Sb2O3. When H2 was utilized as the electron donor, the consortium was able to fully reduce 650 μM of Sb(V) to Sb(III) in 10 days, a rate comparable to the culture using lactate as the electron donor. The H2-fed culture directed a much larger fraction of it donor electrons to Sb(V) reduction than did the lactate-fed culture. While 98% of the electrons from H2 were used to reduce Sb(V) by the H2-fed culture, only 12% of the electrons from lactate was used to reduce Sb(V) by the lactate-fed culture. The rest of the electrons from lactate went to acetate and propionate through fermentation, to methane through methanogenesis, and to biomass synthesis. High-throughput sequencing confirmed that the microbial community for the lactate-fed culture was much more diverse than that for the H2-fed culture, which was dominated by a short rod-shaped phylotype of Rhizobium (α-Protobacteria) that may have been active in Sb(V) reduction.

  8. Pharmacokinetics of liposome-encapsulated meglumine antimonate after intramuscular and subcutaneous administration in dogs.

    PubMed

    Valladares, J E; Freixas, J; Alberola, J; Franquelo, C; Cristofol, C; Arboix, M

    1997-10-01

    Controlling canine leishmaniasis may reduce the incidence of human leishmaniasis, which affect immunocompromised persons, especially those with human immunodeficiency virus infection. Thus, the pharmacokinetics of liposome-encapsulated meglumine antimonate (LMA) in dogs was studied after intramuscular (I.M.) and subcutaneous (S.C.) administration. Serum concentration-time data for both forms of administration were best described by a triexponential open model. The absorption phase showed statistically significant differences between I.M. and S.C. administrations (K01(I.M.) = 0.046/min, K01(S.C.) = 0.025/min). The first phase of decrease of plasma concentrations showed a longer half-life for S.C. than for I.M. administration, with the delay being caused by the slow absorption process after S.C. injection. Mean terminal phase half-lives after administration of I.M. and S.C. were 904.1 min and 637.4 min, respectively. Peak plasma concentrations after administration of I.M. (Cmax = 43.8 microg/ml) and S.C. (Cmax = 24.9 microg/ml) were detected at 42.8 min and 79.8 min, respectively. Urinary excretion of antimony for both routes surpassed 80% during the first 6 hr, with the rest of the drug being excreted slowly over the following 18 hr. The results obtained with this formulation suggest that for treating canine leishmaniasis, it would be more advisable to inject LMA intramuscularly if we assume that the significantly higher Cmax observed after I.M. administration is more relevant to dog's clinical outcome than is maintenance of concentrations over longer periods.

  9. Meglumine antimonate directly increases phagocytosis, superoxide anion and TNF-alpha production, but only via TNF-alpha it indirectly increases nitric oxide production by phagocytes of healthy individuals, in vitro.

    PubMed

    Muniz-Junqueira, Maria Imaculada; de Paula-Coelho, Viviany Nicolau

    2008-12-10

    Leishmania has developed mechanisms to escape from immune defense of phagocytes by inhibiting microbicidal oxygen and nitrogen radicals. This work evaluated the influence of meglumine antimonate (Sb(V)) on the phagocyte functions involved in the defense against leishmania, through phagocytosis, reactive oxygen, nitrogen and TNF-alpha production in the absence or presence of the drug, in vitro. Meglumine antimonate increased the number of Saccharomyces cerevisiae ingested by monocyte and the percentage of these cells engaged in phagocytosis, which resulted in an increase of the monocyte phagocytic index by 158%. Meglumine antimonate also increased the number of S. cerevisiae ingested by neutrophil and the percentage of these cells engaged in phagocytosis, increasing the neutrophil phagocytic index by 219%. The median of percent reduction of NBT was significantly increased after treatment with this pentavalent antimony from 89.5% to 96.5%. Meglumine antimonate had no influence on nitric oxide production, but it significantly increased the mean+/-SEM production of tumor necrosis factor by 230%. However, monocytes incubated with TNF significantly increased NO production. This antimonial increased the phagocytic capacity of monocytes and neutrophils and enhanced superoxide anion production by phagocytes, which represent the first line of defense against the parasite. Furthermore, meglumine antimonate increased TNF, and via this cytokine, it may also indirectly increase NO production. Our data suggest that these immunomodulatory effects of meglumine antimonate may play a role in fighting leishmania and that meglumine antimonate provides the phagocytes with a mechanism that prevents leishmania from escaping immune defense.

  10. Prospective evaluation of serum pancreatic lipase immunoreactivity and troponin I concentrations in Leishmania infantum-infected dogs treated with meglumine antimonate.

    PubMed

    Xenoulis, Panagiotis G; Saridomichelakis, Manolis N; Chatzis, Manolis K; Kasabalis, Dimitris; Petanides, Theodoros; Suchodolski, Jan S; Steiner, Jörg M

    2014-07-14

    Canine leishmaniosis (CanL) caused by Leishmania infantum is an important zoonotic disease. One of the most commonly used drugs for the treatment of CanL is meglumine antimonate. Drugs of this class have been associated with pancreatitis and cardiotoxicity in humans infected with Leishmania spp. The aim of this study was to measure serum canine pancreatic lipase immunoreactivity (Spec cPL) and cardiac troponin I (cTnI) concentrations in dogs with leishmaniosis during treatment with meglumine antimonate, and to compare them with those of dogs with leishmaniosis not treated with this drug. A total of 30 non-uremic dogs with leishmaniosis, living in Greece, were prospectively enrolled into the study. Of the 30 dogs, 20 (Group A) were treated with a combination of meglumine antimonate (100mg/kg, SC, q24 h) and allopurinol (10mg/kg, PO, q12h) for 28 days, while 10 dogs (Group B) were treated with allopurinol alone (10mg/kg, PO, q12h) for 28 days. Blood samples were collected at timepoint 0 (before treatment) and at 14 and 28 days after the initiation of treatment. None of the dogs treated with meglumine antiomonate had a Spec cPL concentration suggestive of pancreatitis (≥ 400 μg/L) or clinical signs suggestive of pancreatitis at any of the timepoints. Similarly, none of the dogs treated with meglumine antiomonate had a serum cTnI concentration above the upper limit of the reference range (>0.5 ng/mL) or clinical evidence of cardiotoxicity at any of the 3 timepoints. In the present study, meglumine antimonate treatment in dogs with leishmaniosis did not result in clinical or laboratory evidence of either pancreatitis or cardiotoxicity. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Phil Ochs: No Place in This World

    ERIC Educational Resources Information Center

    Doughty, Howard A.

    2005-01-01

    Phil Ochs was a prominent topical songwriter and singer in the 1960s. He was conventionally considered second only to Bob Dylan in terms of popularity, creativity and influence in the specific genre of contemporary folk music commonly known as "protest music." Whereas Dylan successfully reinvented himself many times in terms of his musical style…

  12. Vibrational spectroscopic study of the antimonate mineral bindheimite Pb 2Sb 2O 6(O,OH)

    NASA Astrophysics Data System (ADS)

    Bahfenne, Silmarilly; Frost, Ray L.

    2009-09-01

    Raman spectroscopy complimented with infrared spectroscopy has been used to characterise the antimonate mineral bindheimite Pb 2Sb 2O 6(O,OH). The mineral is characterised by an intense Raman band at 656 cm -1 assigned to SbO stretching vibrations. Other lower intensity bands at 664, 749 and 814 cm -1 are also assigned to stretching vibrations. This observation suggests the non-equivalence of SbO units in the structure. Low intensity Raman bands at 293, 312 and 328 cm -1 are assigned to the OSbO bending vibrations. Infrared bands at 979, 1008, 1037 and 1058 cm -1 may be assigned to δOH deformation modes of SbOH units. Infrared bands at 1603 and 1640 cm -1 are assigned to water bending vibrations, suggesting that water is involved in the bindheimite structure. Broad infrared bands centred upon 3250 cm -1 supports this concept. Thus the true formula of bindheimite is questioned and probably should be written as Pb 2Sb 2O 6(O,OH,H 2O).

  13. Crystallization and preliminary crystallographic characterization of LmACR2, an arsenate/antimonate reductase from Leishmania major

    SciTech Connect

    Bisacchi, Davide; Zhou, Yao; Rosen, Barry P.; Mukhopadhyay, Rita; Bordo, Domenico

    2006-10-01

    LmACR2 from L. major is the first rhodanese-like enzyme directly involved in the reduction of arsenate and antimonate to be crystallized. Diffraction data have been collected to 1.99 Å resolution using synchrotron X-rays. Arsenic is present in the biosphere owing either to the presence of pesticides and herbicides used in agricultural and industrial activities or to leaching from geological formations. The health effects of prolonged exposure to arsenic can be devastating and may lead to various forms of cancer. Antimony(V), which is chemically very similar to arsenic, is used instead in the treatment of leishmaniasis, an infection caused by the protozoan parasite Leishmania sp.; the reduction of pentavalent antimony contained in the drug Pentostam to the active trivalent form arises from the presence in the Leishmania genome of a gene, LmACR2, coding for the protein LmACR2 (14.5 kDa, 127 amino acids) that displays weak but significant sequence similarity to the catalytic domain of Cdc25 phosphatase and to rhodanese enzymes. For structural characterization, LmACR2 was overexpressed, purified to homogeneity and crystallized in a trigonal space group (P321 or P3{sub 1}21/P3{sub 2}21). The protein crystallized in two distinct trigonal crystal forms, with unit-cell parameters a = b = 111.0, c = 86.1 Å and a = b = 111.0, c = 175.6 Å, respectively. At a synchrotron beamline, the diffraction pattern extended to a resolution limit of 1.99 Å.

  14. A new strontium antimonate{sup III} Sr{sub 5}Sb{sub 22}O{sub 38}: Synthesis, crystal structure and characterizations

    SciTech Connect

    Geng, Lei; Meng, Chang-Yu; Lin, Chen-Sheng; Cheng, Wen-Dan

    2013-07-15

    A new strontium antimonate{sup III}, Sr{sub 5}Sb{sub 22}O{sub 38}, has been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction. It crystallizes in the P2{sub 1}/n space group of the monoclinic system with a=11.739(9) Å, b=12.014(10) Å, c=16.412(13) Å, β=91.460(8)°, V=2314.0(3) Å{sup 3}. The crystal structure is built of seven trigonal–pyramidal SbO{sub 3} and four sphenoid SbO{sub 4} polyhedra which are connected through sharing corner-oxygen atoms to form the complex three-dimensional {sub ∞}{sup 3}[Sb{sub 22}O{sub 38}]{sup 10−} anionic network with two different intersectant tunnels along the [111-bar ] and [11-bar 1-bar ] directions accommodating the electric charge balanced Sr{sup 2+} cations. First-principles electronic structure calculations based on the density functional theory (DFT) and the UV–vis diffuse reflectance spectroscopy measurements both indicate that the compound belongs to a direct band insulator with an optical gap value of 3.3 eV. - Graphical abstract: The 2D Sb–O slabs are stacked through sharing oxygen atoms to form the 3D network structure of the new strontium antimonate{sup III} Sr{sub 5}Sb{sub 22}O{sub 38}. - Highlights: • A new strontium antimonate{sup III}, Sr{sub 5}Sb{sub 22}O{sub 38}, has been hydrothermally synthesized. • The single crystal structure was determined by X-ray diffraction. • The powder XRD and UV–vis absorption spectroscopy were studied. • Theoretical studies interpret the relationships between optical absorption and crystal structure.

  15. Atmospheric chemistry of CF3CF2OCH3

    NASA Astrophysics Data System (ADS)

    Østerstrøm, Freja F.; Nielsen, Ole John; Wallington, Timothy J.

    2016-06-01

    Smog chamber Fourier transform infrared techniques were used to investigate the kinetics of the reaction of CF3CF2OCH3 with Cl atoms and OH radicals: k(Cl + CF3CF2OCH3) = (1.09 ± 0.16) × 10-13 and k(OH + CF3CF2OCH3) = (1.28 ± 0.19) × 10-14 cm3 molecule-1 s-1 in 700 Torr total pressure of N2/O2 at 296 ± 2 K. The Cl-initiated oxidation of CF3CF2OCH3 gives CF3CF2OCHO in a yield indistinguishable from 100%. An estimate of k(Cl + CF3CF2OCHO) = (1.18 ± 0.34) × 10-14 cm3 molecule-1 s-1 is provided. Based on the OH reaction rate, the atmospheric lifetime of CF3CF2OCH3 is estimated to be 5.0 years. The 100-year time horizon global warming potential of CF3CF2OCH3 is estimated to be 585. The atmospheric impact of CF3CF2OCH3 is discussed.

  16. The ABC-F protein EttA gates ribosome entry into the translation elongation cycle

    PubMed Central

    Boël, Grégory; Smith, Paul C.; Ning, Wei; Englander, Michael T.; Chen, Bo; Hashem, Yaser; Testa, Anthony J.; Fischer, Jeffrey J.; Wieden, Hans-Joachim; Frank, Joachim; Gonzalez, Ruben L.; Hunt, John F.

    2014-01-01

    ABC-F proteins have evaded functional characterization even though they comprise one of the most widely distributed branches of the ATP-binding cassette (ABC) superfamily. Herein, we demonstrate that YjjK, the most prevalent eubacterial ABC-F protein, gates ribosome entry into the translation elongation cycle through a nucleotide-dependent interaction sensitive to ATP/ADP ratio. Accordingly, we rename this protein Energy-dependent Translational Throttle A (EttA). We determined the crystal structure of Escherichia coli EttA and used it to design mutants for biochemical studies, including enzymological assays of the initial steps of protein synthesis. These studies suggest that EttA may regulate protein synthesis in energy-depleted cells, which have a low ATP/ADP ratio. Consistent with this inference, ΔettA cells exhibit a severe fitness defect in long-term stationary phase. These studies demonstrate that an ABC-F protein regulates protein synthesis via a novel mechanism sensitive to cellular energy status. PMID:24389466

  17. The ABC-F protein EttA gates ribosome entry into the translation elongation cycle.

    PubMed

    Boël, Grégory; Smith, Paul C; Ning, Wei; Englander, Michael T; Chen, Bo; Hashem, Yaser; Testa, Anthony J; Fischer, Jeffrey J; Wieden, Hans-Joachim; Frank, Joachim; Gonzalez, Ruben L; Hunt, John F

    2014-02-01

    ABC-F proteins have evaded functional characterization even though they compose one of the most widely distributed branches of the ATP-binding cassette (ABC) superfamily. Herein, we demonstrate that YjjK, the most prevalent eubacterial ABC-F protein, gates ribosome entry into the translation elongation cycle through a nucleotide-dependent interaction sensitive to ATP/ADP ratio. Accordingly, we rename this protein energy-dependent translational throttle A (EttA). We determined the crystal structure of Escherichia coli EttA and used it to design mutants for biochemical studies including enzymological assays of the initial steps of protein synthesis. These studies suggest that EttA may regulate protein synthesis in energy-depleted cells, which have a low ATP/ADP ratio. Consistently with this inference, EttA-deleted cells exhibit a severe fitness defect in long-term stationary phase. These studies demonstrate that an ABC-F protein regulates protein synthesis via a new mechanism sensitive to cellular energy status.

  18. Thyroid function in 36 dogs with leishmaniosis due to Leishmania infantum before and during treatment with allopurinol with or without meglumine antimonate.

    PubMed

    Saridomichelakis, Manolis N; Xenoulis, Panagiotis G; Chatzis, Manolis K; Kasabalis, Dimitris; Steiner, Jörg M; Suchodolski, Jan S; Petanides, Theodoros

    2013-10-18

    Hypothyroidism may predispose to the development of canine leishmaniosis or it may appear during the course of the latter due to infiltration and destruction of the thyroid gland by infected macrophages. The main purpose of this study was to evaluate thyroid function through measurement of serum total thyroxin (tT₄), free thyroxin (fT₄), and canine thyroid stimulating hormone (cTSH) concentrations in 36 dogs with leishmaniosis, before and after 2 and 4 weeks of treatment with allopurinol with or without meglumine antimonate. Before treatment 27/36 (75%) dogs had serum tT₄ concentrations below the lower limit of the reference interval but only 2 of them had concurrently serum fT₄ concentrations below the lower limit of the reference interval and none had increased serum cTSH concentrations. During treatment there were no significant changes in serum tT₄ or fT₄ concentrations, whereas a significant increase in serum cTSH was observed. Two dogs had decreased serum tT₄ and fT₄ but normal cTSH concentrations before treatment and two other dogs had decreased serum tT₄ and increased cTSH, but normal fT₄ concentrations during the treatment period. Although hypothyroidism could not be definitively excluded in these dogs it is considered unlikely based on their overall hormonal profile, clinical presentation, and response to treatment. Therefore, hypothyroidism does not appear to be an important predisposing disease or a frequent complication of canine leishmaniosis. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Removal of Antimonite (Sb(III)) and Antimonate (Sb(V)) from Aqueous Solution Using Carbon Nanofibers That Are Decorated with Zirconium Oxide (ZrO2).

    PubMed

    Luo, Jinming; Luo, Xubiao; Crittenden, John; Qu, Jiuhui; Bai, Yaohui; Peng, Yue; Li, Junhua

    2015-09-15

    Zirconium oxide (ZrO2)-carbon nanofibers (ZCN) were fabricated and batch experiments were used to determine antimonite (Sb(III)) and antimonate (Sb(V)) adsorption isotherms and kinetics. ZCN have a maximum Sb(III) and Sb(V) adsorption capacity of 70.83 and 57.17 mg/g, respectively. The adsorption process between ZCN and Sb was identified to be an exothermic and follows an ion-exchange reaction. The application of ZCN was demonstrated using tap water spiked with Sb (200 μg/L). We found that the concentration of Sb was well below the maximum contaminant level for drinking water with ZCN dosages of 2 g/L. X-ray photoelectron spectroscopy (XPS) revealed that an ionic bond of Zr-O was formed with Sb(III) and Sb(V). Based on the density functional theory (DFT) calculations, Sb(III) formed Sb-O and O-Zr bonds on the surface of the tetragonal ZrO2 (t-ZrO2) (111) plane and monoclinic ZrO2 planes (m-ZrO2) (111) plane when it adsorbs. Only an O-Zr bond was formed on the surface of t-ZrO2 (111) plane and m-ZrO2 (111) plane for Sb(V) adsorption. The adsorption energy (Ead) of Sb(III) and Sb(V) onto t-ZrO2 (111) plane were 1.13 and 6.07 eV, which were higher than that of m-ZrO2 (0.76 and 3.35 eV, respectively).

  20. Computational exploration of regioselectivity and atmospheric lifetime in NO3-initiated reactions of CH3OCH3 and CH3OCH2CH3.

    PubMed

    Ye, Jin-Ting; Bai, Feng-Yang; Shi, Shao-Qing; Pan, Xiu-Mei

    2017-03-01

    The NO3-initiated reactions of CH3OCH3 and CH3OCH2CH3 have been investigated by the BHandHLYP method in conjunction with the 6-311G(d,p) basis set. Thermodynamic and kinetic data are further refined using the comparatively accurate CCSD(T) method. According to the values of reaction enthalpies (ΔHr,298(θ)) and reaction Gibbs free energies (ΔGr,298(θ)) from CH3OCH2CH3 with NO3 system, we find that H-abstraction pathway from the α-CH2 group is more exothermic. It is further confirmed by the calculated CH bond dissociation energy of CH3OCH2CH3 molecule. All the rate constants, computed through means of canonical variational transition state with small-curvature tunneling correction, are fitted to the three-parameter expressions k1=1.54×10(-23)T(3.34)exp(-1035.53/T) and k2=3.55×10(-26)T(4.31)exp(-281.24/T)cm(3)molecule(-1)s(-1) and branching ratios are computed over the temperature range 200-600K. The branching ratios are also discussed. The atmospheric lifetimes of CH3OCH3 and CH3OCH2CH3 determined by the NO3 radical are about 270 and 29days, respectively. Copyright © 2017. Published by Elsevier Inc.

  1. Comparison of the effect of LMA and ETT on ventilation and intragastric pressure in pediatric laparoscopic procedures.

    PubMed

    Ozdamar, D; Güvenç, B H; Toker, K; Solak, M; Ekingen, G

    2010-08-01

    The aim of our study was to compare classic laryngeal mask airway (LMA-C) with the endotracheal tube (ETT) in pediatric laparoscopic surgery to evaluate the intragastric pressures (IGP) using intragastric pressure monitoring. We also sought to investigate the related influence on respiratory parameters. The Ethics Committee of the Health Institution approved the study protocol. A total of 40 patients, ASA I-II, three and a half months to 12 years old were included in this randomized study. Two study groups were formed: the ETT group and the LMA-C group. A nasogastric tube was inserted following induction to evacuate any intragastric gas and fluid before application of either LMA-C or ETT. The change in IGP was measured with a transducer, which was attached to the nasogastric tube. IGP, peak airway pressures (PAP), SPO2 and ETCO2 were recorded. Repeated ANOVA measures were used to evaluate the change in IGP, PAP, SPO2 and ETCO2 times in both groups. The change in IGP was not significant among the groups except at 15 and 30 minutes (P<0.05). The changes in PAP, SPO2, and ETCO2 levels were not significant. The perioperative intragastric pressure evaluation failed to show any significant change in intragastric pressures and ventilation parameters due to the application of LMA-C in this study. We advocate LMA-C application as a feasible anesthetic device in pediatric laparoscopic surgery.

  2. EttA regulates translation by binding to the ribosomal E site and restricting ribosome-tRNA dynamics

    PubMed Central

    Chen, Bo; Boël, Grégory; Hashem, Yaser; Ning, Wei; Fei, Jingyi; Wang, Chi; Gonzalez, Ruben L.; Hunt, John F.; Frank, Joachim

    2014-01-01

    Cells express many ribosome-interacting factors whose functions and molecular mechanisms remain unknown. Here, we elucidate the mechanism of a newly characterized regulatory translation factor, Energy-dependent Translational Throttle A (EttA), which is an Escherichia coli representative of the ATP-binding cassette F (ABC-F) protein family. Using cryo-EM, we demonstrate that the ATP-bound form of EttA binds to the ribosomal tRNA exit (E) site, where it forms bridging interactions between the ribosomal L1 stalk and the tRNA bound in the peptidyl-tRNA binding (P) site. Using single-molecule fluorescence resonance energy transfer (smFRET), we show that the ATP-bound form of EttA restricts ribosome and tRNA dynamics required for protein synthesis. This work represents the first example, to our knowledge, where the detailed molecular mechanism of any ABC-F family protein has been determined and establishes a framework for elucidating the mechanisms of other regulatory translation factors. PMID:24389465

  3. Water-soluble derivatives of 25-OCH3-PPD and their anti-proliferative activities.

    PubMed

    Zhou, Wu-Xi; Sun, Yuan-Yuan; Yuan, Wei-Hui; Zhao, Yu-Qing

    2017-03-18

    (20R)-25-Methoxyl-dammarane-3β,12β,20-triol (25-OCH3-PPD, AD-1) is a dammarane-type sapogenin showing anti-tumor potential. In the search for new anti-tumor agents with higher potency than our previously identified compound 25-OCH3-PPD, 11 novel sulfamic acid and diacid derivatives that could improve water solubility and contribute to good drug potency and pharmacokinetic profiles were designed and synthesized. Their in vitro anti-tumor activities in MCF-7, A-549, HCT-116, and BGC-823 cell lines and one normal cell line were tested by standard MTT assay. Results showed that compared with compound 25-OCH3-PPD, compounds 1, 4, and 5 exhibited higher cytotoxic activity on almost all cell lines, together with lower toxicity in the normal cell. In particular, compound 1 exhibited the best anti-tumor activity in the in vitro assays. The water solubility of 25-OCH3-PPD and its derivatives was tested and the results showed that the solubility of 25-OCH3-PPD sulfamic acid and diacid derivatives were better than that of 25-OCH3-PPD in water, which may provide valuable data for the research and development of new anti-tumor agents.

  4. Shock tube investigation of CH3 + CH3OCH3.

    PubMed

    Tranter, Robert S; Lynch, Patrick T; Annesley, Christopher J

    2012-07-12

    The title reaction has been investigated in a diaphragmless shock tube by laser schlieren densitometry over the temperature range 1163-1629 K and pressures of 60, 120, and 240 Torr. Methyl radicals were produced by dissociation of 2,3-butanedione in the presence of an excess of dimethyl ether. Rate coefficients for CH(3) + CH(3)OCH(3) were obtained from simulations of the experimental data yielding the following expression which is valid over the range 1100-1700 K: k = (10.19 ± 3.0)T(3.78) exp((-4878/T)) cm(3) mol(-1)s(-1). The experimental results are in good agreement with estimates by Curran and co-workers [Fischer, S. L.; Dryer, F. L.; Curran, H. J. Int. J. Chem. Kinet.2000, 32 (12), 713-740. Curran, H. J.; Fischer, S. L.; Dryer, F. L. Int. J. Chem. Kinet.2000, 32 (12), 741-759] but about a factor of 2.6 lower than those of Zhao et al. [Zhao, Z.; Chaos, M.; Kazakov, A.; Dryer, F. L. Int. J. Chem. Kinet.2008, 40 (1), 1-18].

  5. Transition from two to one integument in Prunus species: expression pattern of INNER NO OUTER (INO), ABERRANT TESTA SHAPE (ATS) and ETTIN (ETT).

    PubMed

    Lora, Jorge; Hormaza, José I; Herrero, Maria

    2015-10-01

    While gymnosperm ovules have one integument, in most angiosperms two integuments surround the ovules. Unitegmic ovules have arisen independently several times during the evolution of angiosperms, but the ultimate genetic cause of the presence of a single integument remains elusive. We compared species of the genus Prunus that have different numbers of integuments: bitegmic species, such as Prunus armeniaca (apricot) and Prunus persica (peach), and unitegmic species, such as Prunus incisa, analyzing the expression pattern of genes that are involved in integument development in Arabidopsis thaliana: INNER NO OUTER (INO), ABERRANT TESTA SHAPE (ATS) and ETTIN (ETT). Bitegmic and unitegmic species showed similar INO expression patterns, indicative of the conservation of an outer integument. However, expression of ETT, which occurs in the boundary of the outer and inner integuments, was altered in unitegmic ovules, which showed lack of ETT expression. These results strongly suggest that the presence of a single integument could be attributable to the amalgamation of two integuments and support the role of ETT in the fusion of the outer and inner integuments in unitegmic ovules, a situation that could be widespread in other unitegmic species of angiosperms.

  6. Analysis of the Vibrational Spectra of P_3N_3(OCH_2CF_3)_6 and P_4N_4(OCH_2CF_3)_8

    NASA Astrophysics Data System (ADS)

    King, Adrian K.; Plant, David F.; Golding, Peter; Lawson, Michael A.; Davies, Paul B.

    2011-06-01

    The cyclic phosphazene trimer P_3N_3(OCH_2CF_3)_6 and the related cyclic tetramer P_4N_4(OCH_2CF_3)_8 have been proposed as the major low-to-medium temperature pyrolysis products of the parent polyphosphazene (PN(OCH_2CF_3)_2)_n. Recently, both molecules have been synthesized, isolated and their vapour-phase vibrational spectra recorded using a high-resolution FTIR instrument. The interpretation of these spectra is achieved primarily by comparison with the results of high-quality density functional calculations, which enable the principal absorption features to be assigned and conclusions to be drawn regarding the geometries and conformations adopted by both molecules. These in turn allow interesting comparisons to be made with analogous cyclic halo-phosphazenes such as P_3N_3Cl_6 and P_4N_4Cl_8. Work to record in situ the spectra of the vapour-phase pyrolysis products of (PN(OCH_2CF_3)_2)_n and to analyse these results in terms of the tetramer and trimer spectra will also be presented. S. V. Peddada and J. H. Magill Macromolecules 16 (1983) 1258-1264. H. R. Allcock, G. S. McDonnell, G. H. Riding, and I. Manners Chem. Mater. 2 (1990) 425-432. T. R. Manley and D. A. Williams Spectrochimica Acta 23A (1966) 149-165. V. Varma, J. R. Fernandez and C. N. R. Rao J. Mol. Struct. 198 (1989) 403-412.

  7. Direct amidation of unprotected amino acids using B(OCH2CF3)3.

    PubMed

    Lanigan, Rachel M; Karaluka, Valerija; Sabatini, Marco T; Starkov, Pavel; Badland, Matthew; Boulton, Lee; Sheppard, Tom D

    2016-07-07

    A commercially available borate ester, B(OCH2CF3)3, can be used to achieve protecting-group free direct amidation of α-amino acids with a range of amines in cyclopentyl methyl ether. The method can be applied to the synthesis of medicinally relevant compounds, and can be scaled up to obtain gram quantities of products.

  8. High-temperature X-ray diffraction measurements of fluorite-related rare earth antimonates Ln{sub 3}SbO{sub 7} (Ln=Nd, Tb) and their magnetic properties

    SciTech Connect

    Hinatsu, Yukio Doi, Yoshihiro

    2014-09-15

    Ternary rare-earth antimonates Ln{sub 3}SbO{sub 7} (Ln=rare earths) were prepared, and their structures were determined by X-ray diffraction measurements. They crystallize in an orthorhombic superstructure of cubic fluorite (space group Cmcm for Ln=La, Pr; Ccmm for Ln=Sm–Dy), in which Ln{sup 3+} ions occupy two different crystallographic sites (the 8-coordinated and 7-coordinated). For Ln=Nd, two phases with the Cmcm and Ccmm space groups coexist at room temperature. When the temperature was increased, the Nd{sub 3}SbO{sub 7} compound transformed into a single phase with the space group Cmcm. Through magnetic susceptibility measurements, an antiferromagnetic transition was observed at 3.0 K (Ln=Nd) and 7.8 K (Ln=Tb). Analysis of the magnetic specific heat for Tb{sub 3}SbO{sub 7} indicates that the 8-coordinated Tb ions magnetically orders at 7.8 K, and with furthermore decreasing temperature, the 7-coordinated Tb ions shows antiferromagnetic ordering at 3.0 K. - Graphical abstract: Temperature dependence of the specific heat divided by temperature (C{sub p}/T) and the magnetic entropy (S{sub mag}) for Tb{sub 3}SbO{sub 7}. Two-step magnetic transition has been observed. - Highlights: • The phase transition of Nd{sub 3}SbO{sub 7} is from the Ccmm space group to the Cmcm one. • Nd{sub 3}SbO{sub 7} shows an antiferromagnetic transition at 3.0 K. • For Tb{sub 3}SbO{sub 7}, two-step magnetic transition has been observed at 7.8 and 3.0 K.

  9. Atmospheric degradation mechanism of CF{sub 3}OCH{sub 3}

    SciTech Connect

    Christensen, L.K.; Wallington, T.J.; Guschin, A.; Hurley, M.D.

    1999-05-27

    Recognition of the adverse effect of chlorofluorocarbon (CFC) release into the atmosphere has led to an international effort to replace CFCs with environmentally acceptable alternatives. Hydrofluoroethers (HFEs) are a class of compounds which have been developed to replace CFCs in applications such as the cleaning of electronic equipment, heat transfer agents in refrigeration systems, and carrier fluids for lubricant deposition. HFEs are volatile compounds and are released into the atmosphere when used. CF{sub 3}OCH{sub 3} has not been used commercially but is one of the simplest fluoroethers and serves as a model compound for the group of fluorinated ethers. A smog chamber/FTIR technique was used to study the Cl atom initiated oxidation of CF{sub 3}OCH{sub 3} in 700 Torr of N{sub 2}/O{sub 2} at 296 K. Using relative rate techniques it was determined that {kappa}(Cl + CF{sub 3}OCH{sub 3}) = (1.4 {+-} 0.2) {times} 10{sup {minus}13} and {kappa}(Cl + CF{sub 3}OC(O)H) = (9.8 {+-} 1.2) {times} 10{sup {minus}15} cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}. At 700 Torr of N{sub 2}/O{sub 2} diluent at 296 K reaction with O{sub 2} is the only loss mechanism of the CF{sub 3}OCH{sub 2}O{sup {sm_bullet}} radical. The infrared spectra of the peroxy nitrates CF{sub 3}OCH{sub 2}O{sub 2}NO{sub 2} and CF{sub 3}OC(O)O{sub 2}NO{sub 2} were recorded and compared to the nonfluorinated analogues CH{sub 3}OCH{sub 2}O{sub 2}NO{sub 2} and CH{sub 3}OC(O)O{sub 2}NO{sub 2}. The thermal decomposition rate of CF{sub 3}OC(O)NO{sub 2} is (2.3 {+-} 0.1) {times} 10{sup {minus}4} s{sup {minus}1} in 700 Torr of N{sub 2} at 295.8 K. The reaction of CF{sub 3}OC(O)O{sub 2} radicals with HO{sub 2} radicals gives CF{sub 3}OC(O)H in a yield of (80 {+-} 11)%. The results are discussed with respect to the atmospheric degradation mechanism of CF{sub 3}OCH{sub 3} and other ethers.

  10. Study and orientation of the Mt. Oche `Dragon House' in Euboea, Greece

    NASA Astrophysics Data System (ADS)

    Theodossiou, E.; Manimanis, V. N.; Katsiotis, M.; Papanikolaou, D.

    2009-07-01

    In southern Euboea, Central Greece, there are several megalithic buildings known as ‘drakospita’ (or dragon houses) whose builders and purpose are unknown. On 22 March 2002 and 4 July 2004 we visited the bestpreserved of all drakospita on top of Mt. Oche, measured its dimensions and calculated its orientation based on the azimuth of sunset and moonrise. A Sirius-rise orientation corresponding to ca 1100 B.C., not inconsistent with previous archaeological dating based on artefacts found inside the structure, indicates a religious/astronomical purpose for the building. It could probably be argued that at least the famous drakospito at Mt. Oche was not only a place of worship but also an ancient astronomical observatory.

  11. Studenters fritids--och motionsvanor i Umea och Madison. Ett bidrag till forstaelsen av Pierre Bourdieus vetenskapliga metodologi. Akademiska avhanlingar, Pedagogiska institutionen Nr. 58 (Leisure and Exercise Habits among Students in Umea and Madison. A Contribution to the Understanding of Pierre Bourdieu's Scientific Methodology. Academic Dissertation, Faculty of Social Sciences No. 58).

    ERIC Educational Resources Information Center

    Lofgren, Kent

    This study, presented in Swedish with an English summary, analyzed differences between student groups at Umea University, Sweden, and the University of Wisconsin-Madison in terms of study situations, experiences of the university environment, exercise and sports activities, and the connections between study and leisure time activities. The study…

  12. The ether lipid ET-18-OCH3 increases cytosolic Ca2+ concentrations in Madin Darby canine kidney cells.

    PubMed

    Jan, C R; Wu, S N; Tseng, C J

    1999-07-01

    The effect of the ether lipid 1-O-octadecyl-2-O-methyl-sn-glycero-3-phosphorylcholine (ET-18-OCH3) on the intracellular free Ca2+ concentration ([Ca2+]i) in Madin Darby canine kidney (MDCK) cells was studied using fura-2 as the Ca2+ probe. In Ca2+ medium, ET-18-OCH3 induced a significant rise in [Ca2+]i at concentrations between 10-100 microM with a concentration-dependent delay of 45-175 s. The [Ca2+]i signal was composed of a gradual rise and a sustained plateau. In Ca2+-free medium, ET-18-OCH3 (10-100 microM) induced a Ca2+ release from internal Ca2+ stores with a concentration-dependent delay of 45-175 s. This discharge of internal Ca2+ triggered capacitative Ca2+ entry in a concentration-dependent manner. This capacitative Ca2+ entry was not inhibited by econazole (25 microM), 1-[beta-[3-(4-methoxyphenyl)propoxy]-4-methoxyphenethyl]-1H-imidazole hydrochloride (SKF96365; 50 microM), nifedipine (10 microM), verapamil (10 microM), diltiazem (10 microM) and cadmium (0.5 microM). Methyl 2-(phenylthio)ethyl-1,4-dihydro-2,4,6-trimethylpyridine-3,5-dicarboxylat e (PCA-4248), a platelet-activating factor (PAF) receptor antagonist, inhibited 25 microM ET-18-OCH3-induced [Ca2+]i rise in a concentration-dependent manner between 1-20 microM, with 20 microM exerting a complete block. The [Ca2+]i rise induced by ET-18-OCH3 (25 microM) was not altered when the production of inositol 1,4,5-trisphosphate (IP3) was suppressed by the phospholipase C inhibitor U73122 (2 microM), but was partly inhibited by the phospholipase D inhibitor propranolol (0.1 mM) or the phospholipase A2 inhibitor aristolochic acid (20-40 microM). In Ca2+-free medium, pretreatment with 25 microM ET-18-OCH3 completely depleted the endoplasmic reticulum Ca2+ pump inhibitor thapsigargin-sensitive Ca2+ store. In contrast, pretreatment with thapsigargin abolished 0.1 mM ATP-induced [Ca2+]i rise without altering the ET-18-OCH3-induced [Ca2+]i rise. This suggests that ET-18-OCH3 depleted thapsigargin

  13. Phage resistance of a marine bacterium, Roseobacter denitrificans OCh114, as revealed by comparative proteomics.

    PubMed

    Huang, Chunxiao; Zhang, Yongyu; Jiao, Nianzhi

    2010-08-01

    Roseobacter is a dominant lineage in the marine environment. This group of bacteria is diverse in terms of both their phylogenetic composition and their physiological potential. Roseobacter denitrificans OCh114 is one of the most studied bacteria of the Roseobacter lineage. Recently, a lytic phage (RDJLPhi1) that infects this bacterium was isolated and a mutant strain (M1) of OCh114 that is resistant to RDJLPhi1 was also obtained. Here, we investigate the mechanisms supporting phage resistance of M1. Our results excluded the possibilities of several phage resistance mechanisms, including abortive infection, lysogeny, and the clustered regularly interspaced short palindromic repeats (CRISPRs) related mechanism. Adsorption kinetics assays revealed that adsorption inhibition might be a potential cause for the phage resistance of M1. Comparative proteomic analysis of M1 and OCh114 revealed significant changes in the membrane protein compliment of these bacteria. Five membrane proteins with important biological functions were significantly down-regulated in the phage-resistant M1. Meanwhile, several outer membrane porins with different modifications and an OmpA family domain protein were markedly up-regulated. We hypothesize that the down-regulated membrane proteins in M1 may serve as the potential phage receptors, whose absence prevented the adsorption of phage RDJLPhi1 to host cells and subsequent infection.

  14. Distributed Denial of Service Attack Source Detection Using Efficient Traceback Technique (ETT) in Cloud-Assisted Healthcare Environment.

    PubMed

    Latif, Rabia; Abbas, Haider; Latif, Seemab; Masood, Ashraf

    2016-07-01

    Security and privacy are the first and foremost concerns that should be given special attention when dealing with Wireless Body Area Networks (WBANs). As WBAN sensors operate in an unattended environment and carry critical patient health information, Distributed Denial of Service (DDoS) attack is one of the major attacks in WBAN environment that not only exhausts the available resources but also influence the reliability of information being transmitted. This research work is an extension of our previous work in which a machine learning based attack detection algorithm is proposed to detect DDoS attack in WBAN environment. However, in order to avoid complexity, no consideration was given to the traceback mechanism. During traceback, the challenge lies in reconstructing the attack path leading to identify the attack source. Among existing traceback techniques, Probabilistic Packet Marking (PPM) approach is the most commonly used technique in conventional IP- based networks. However, since marking probability assignment has significant effect on both the convergence time and performance of a scheme, it is not directly applicable in WBAN environment due to high convergence time and overhead on intermediate nodes. Therefore, in this paper we have proposed a new scheme called Efficient Traceback Technique (ETT) based on Dynamic Probability Packet Marking (DPPM) approach and uses MAC header in place of IP header. Instead of using fixed marking probability, the proposed scheme uses variable marking probability based on the number of hops travelled by a packet to reach the target node. Finally, path reconstruction algorithms are proposed to traceback an attacker. Evaluation and simulation results indicate that the proposed solution outperforms fixed PPM in terms of convergence time and computational overhead on nodes.

  15. Natural product ginsenoside 25-OCH3-PPD inhibits breast cancer growth and metastasis through down-regulating MDM2.

    PubMed

    Wang, Wei; Zhang, Xu; Qin, Jiang-Jiang; Voruganti, Sukesh; Nag, Subhasree Ashok; Wang, Ming-Hai; Wang, Hui; Zhang, Ruiwen

    2012-01-01

    Although ginseng and related herbs have a long history of utility for various health benefits, their application in cancer therapy and underlying mechanisms of action are not fully understood. Our recent work has shown that 20(S)-25-methoxyl-dammarane-3β, 12β, 20-triol (25-OCH(3)-PPD), a newly identified ginsenoside from Panax notoginseng, exerts activities against a variety of cancer cells in vitro and in vivo. This study was designed to investigate its anti-breast cancer activity and the underlying mechanisms of action. We observed that 25-OCH(3)-PPD decreased the survival of breast cancer cells by induction of apoptosis and G1 phase arrest and inhibited the growth of breast cancer xenografts in vivo. We further demonstrated that, in a dose- and time-dependent manner, 25-OCH(3)-PPD inhibited MDM2 expression at both transcriptional and post-translational levels in human breast cancer cells with various p53 statuses (wild type and mutant). Moreover, 25-OCH(3)-PPD inhibited in vitro cell migration, reduced the expression of epithelial-to-mesenchymal transition (EMT) markers, and prevented in vivo metastasis of breast cancer. In summary, 25-OCH(3)-PPD is a potential therapeutic and anti-metastatic agent for human breast cancer through down-regulating MDM2. Further preclinical and clinical development of this agent is warranted.

  16. Diversity of Ochrobactrum species in food animals, antibiotic resistance phenotypes and polymorphisms in the blaOCH gene.

    PubMed

    Alonso, Carla Andrea; Kwabugge, Yakubu A; Anyanwu, Madubuike U; Torres, Carmen; Chah, Kennedy F

    2017-09-15

    Twenty-six lactose non-fermenting, oxidase, urease and citrate-positive Gram-negative rods, isolated from broiler chickens, pigs and cattle at slaughter, were subjected to the matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry and 16S rDNA sequencing for identification. Susceptibility to 14 antimicrobials was determined by the disc diffusion method. Ochrobactrum isolates resistant to third-generation cephalosporins were PCR-screened for the presence of the Ochrobactrum anthropi ampC gene (blaOCH). A 547-bp internal segment of blaOCH in the Ochrobactrum spp isolates was amplified with a newly designed primer set, and a phylogenetic reconstruction based on the complete amino acid sequence of blaOCH obtained from nine Ochrobactrum strains in our collection and 20 O. anthropi available in the GenBank was undertaken. All the Ochrobactrum isolates were resistant to the expanded-spectrum beta-lactams and streptomycin. None of the isolates was resistant to imipenem while 41.7% to 50.0% of them were resistant to fluoroquinolones. The blaOCH gene was detected in 16 (66.7%) and 20 (83.3%) of the 24 Ochrobactrum isolates (O. intermedium/O. tritici species), using primers designed for O. anthropi and the newly designed primer set, respectively. Six blaOCH variants grouped into two divergent clusters were identified. This is the first report of the complete nucleotide sequence of the blaOCH gene in non-antropi Ochrobactrum species. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. A General Method for Imine Formation Using B(OCH2CF3)3.

    PubMed

    Reeves, Jonathan T; Visco, Michael D; Marsini, Maurice A; Grinberg, Nelu; Busacca, Carl A; Mattson, Anita E; Senanayake, Chris H

    2015-05-15

    Tris(2,2,2-trifluoroethyl)borate [B(OCH2CF3)3] was found to be a mild and general reagent for the formation of a variety of imines by condensation of amides or amines with carbonyl compounds. N-Sulfinyl, N-toluenesulfonyl, N-(dimethylamino)sulfamoyl, N-diphenylphosphinoyl, N-(α-methylbenzyl), and N-(4-methoxyphenyl) aldimines are all accessible using this reagent at room temperature. The reactions are operationally simple, and the products are obtained without special workup or isolation procedures.

  18. Comparison Of Several Metrology Techniques For In-line Process Monitoring Of Porous SiOCH

    SciTech Connect

    Fossati, D.; Imbert, G.; Beitia, C.; Yu, L.; Plantier, L.; Volpi, F.

    2007-09-26

    As porous SiOCH is a widely used inter-metal dielectric for 65 nm nodes and below, the control of its elaboration process by in-line monitoring is necessary to guarantee successful integration of the material. In this paper, the sensitivities of several non-destructive metrology techniques towards the film elaboration process drifts are investigated. It appears that the two steps of the process should be monitored separately and that corona charge method is the most sensitive technique of the review for this application.

  19. Functional characterization of the gene FoOCH1 encoding a putative α-1,6-mannosyltransferase in Fusarium oxysporum f. sp. cubense.

    PubMed

    Li, Min-Hui; Xie, Xiao-Ling; Lin, Xian-Feng; Shi, Jin-Xiu; Ding, Zhao-Jian; Ling, Jin-Feng; Xi, Ping-Gen; Zhou, Jia-Nuan; Leng, Yueqiang; Zhong, Shaobin; Jiang, Zi-De

    2014-04-01

    Fusarium oxysporum f. sp. cubense (FOC) is the causal agent of banana Fusarium wilt and has become one of the most destructive pathogens threatening the banana production worldwide. However, few genes related to morphogenesis and pathogenicity of this fungal pathogen have been functionally characterized. In this study, we identified and characterized the disrupted gene in a T-DNA insertional mutant (L953) of FOC with significantly reduced virulence on banana plants. The gene disrupted by T-DNA insertion in L953 harbors an open reading frame, which encodes a protein with homology to α-1,6-mannosyltransferase (OCH1) in fungi. The deletion mutants (ΔFoOCH1) of the OCH1 orthologue (FoOCH1) in FOC were impaired in fungal growth, exhibited brighter staining with fluorescein isothiocyanate (FITC)-Concanavalin A, had less cell wall proteins and secreted more proteins into liquid media than the wild type. Furthermore, the mutation or deletion of FoOCH1 led to loss of ability to penetrate cellophane membrane and decline in hyphal attachment and colonization as well as virulence to the banana host. The mutant phenotypes were fully restored by complementation with the wild type FoOCH1 gene. Our data provide a first evidence for the critical role of FoOCH1 in maintenance of cell wall integrity and virulence of F. oxysporum f. sp. cubense. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Mechanism of plasma-induced damage to low-k SiOCH films during plasma ashing of organic resists

    SciTech Connect

    Takeda, Keigo; Miyawaki, Yudai; Takashima, Seigo; Fukasawa, Masanaga; Oshima, Keiji; Nagahata, Kazunori; Tatsumi, Tetsuya; Hori, Masaru

    2011-02-01

    Plasma-induced damage to porous SiOCH (p-SiOCH) films during organic resist film ashing using dual-frequency capacitively coupled O{sub 2} plasmas was investigated using the pallet for plasma evaluation method developed by our group. The damage was characterized by ellipsometry and Fourier-transform infrared spectroscopy. Individual and synergetic damage associated with vacuum ultraviolet (VUV) and UV radiation, radicals, and ions in the O{sub 2} plasma were clarified. It was found that the damage was caused not only by radicals but also by synergetic reactions of radicals with VUV and UV radiation emitted by the plasmas. It is noteworthy that the damage induced by plasma exposure without ion bombardment was larger than the damage with ion bombardment. These results differed from those obtained using an H{sub 2}/N{sub 2} plasma for resist ashing. Finally, the mechanism of damage to p-SiOCH caused by O{sub 2} and H{sub 2}/N{sub 2} plasma ashing of organic resist films is discussed. These results are very important in understanding the mechanism of plasma-induced damage to p-SiOCH films.

  1. Meta-analyses of microarrays of Arabidopsis asymmetric leaves1 (as1), as2 and their modifying mutants reveal a critical role for the ETT pathway in stabilization of adaxial-abaxial patterning and cell division during leaf development.

    PubMed

    Takahashi, Hiro; Iwakawa, Hidekazu; Ishibashi, Nanako; Kojima, Shoko; Matsumura, Yoko; Prananingrum, Pratiwi; Iwasaki, Mayumi; Takahashi, Anna; Ikezaki, Masaya; Luo, Lilan; Kobayashi, Takeshi; Machida, Yasunori; Machida, Chiyoko

    2013-03-01

    It is necessary to use algorithms to analyze gene expression data from DNA microarrays, such as in clustering and machine learning. Previously, we developed the knowledge-based fuzzy adaptive resonance theory (KB-FuzzyART), a clustering algorithm suitable for analyzing gene expression data, to find clues for identifying gene networks. Leaf primordia form around the shoot apical meristem (SAM), which consists of indeterminate stem cells. Upon initiation of leaf development, adaxial-abaxial patterning is crucial for lateral expansion, via cellular proliferation, and the formation of flat symmetric leaves. Many regulatory genes that specify such patterning have been identified. Analysis by the KB-FuzzyART and subsequent molecular and genetic analyses previously showed that ASYMMETRIC LEAVES1 (AS1) and AS2 repress the expression of some abaxial-determinant genes, such as AUXIN RESPONSE FACTOR3 (ARF3)/ETTIN (ETT) and ARF4, which are responsible for defects in leaf adaxial-abaxial polarity in as1 and as2. In the present study, genetic analysis revealed that ARF3/ETT and ARF4 were regulated by modifier genes, BOBBER1 (BOB1) and ELONGATA3 (ELO3), together with AS1-AS2. We analyzed expression arrays with as2 elo3 and as2 bob1, and extracted genes downstream of ARF3/ETT by using KB-FuzzyART and molecular analyses. The results showed that expression of Kip-related protein (KRP) (for inhibitors of cyclin-dependent protein kinases) and Isopentenyltransferase (IPT) (for biosynthesis of cytokinin) genes were controlled by AS1-AS2 through ARF3/ETT and ARF4 functions, which suggests that the AS1-AS2-ETT pathway plays a critical role in controlling the cell division cycle and the biosynthesis of cytokinin around SAM to stabilize leaf development in Arabidopsis thaliana.

  2. Disproportionation and thermochemical sulfate reduction reactions in S-H2O-CH4 and S-D2O-CH4 systems from 200 to 340 °C at elevated pressures

    NASA Astrophysics Data System (ADS)

    Yuan, Shunda; Chou, I.-Ming; Burruss, Robert C.

    2013-10-01

    Elemental sulfur, as a transient intermediate compound, by-product, or catalyst, plays significant roles in thermochemical sulfate reduction (TSR) reactions. However, the mechanisms of the reactions in S-H2O-hydrocarbons systems are not clear. To improve our understanding of reaction mechanisms, we conducted a series of experiments between 200 and 340 °C for S-H2O-CH4, S-D2O-CH4, and S-CH4-1m ZnBr2 systems in fused silica capillary capsules (FSCCs). After a heating period ranging from 24 to 2160 h (hrs), the quenched samples were analyzed by Raman spectroscopy. Combined with the in situ Raman spectra collected at high temperatures and pressures in the S-H2O and S-H2O-CH4 systems, our results showed that (1) the disproportionation of sulfur in the S-H2O-CH4 system occurred at temperatures above 200 °C and produced H2S, SO42-, and possibly trace amount of HSO4-; (2) sulfate (and bisulfate), in the presence of sulfur, can be reduced by methane between 250 and 340 °C to produce CO2 and H2S, and these TSR temperatures are much closer to those of the natural system (<200 °C) than those of any previous experiments; (3) the disproportionation and TSR reactions in the S-H2O-CH4 system may take place simultaneously, with TSR being favored at higher temperatures; and (4) in the system S-D2O-CH4, both TSR and the competitive disproportionation reactions occurred simultaneously at temperatures above 300 °C, but these reactions were very slow at lower temperatures. Our observation of methane reaction at 250 °C in a laboratory time scale suggests that, in a geologic time scale, methane may be destroyed by TSR reactions at temperatures >200 °C that can be reached by deep drilling for hydrocarbon resources.

  3. The mechanism of low-k SiOCH film modification by oxygen atoms

    SciTech Connect

    Braginsky, O. V.; Kovalev, A. S.; Lopaev, D. V.; Malykhin, E. M.; Mankelevich, Yu. A.; Rakhimova, T. V.; Rakhimov, A. T.; Vasilieva, A. N.; Zyryanov, S. M.; Baklanov, M. R.

    2010-10-15

    The interaction of oxygen atoms with three types of plasma enhanced chemical vapor deposition low-k SiOCH films is studied. The samples were treated by O atoms in the far plasma afterglow conditions in a special experimental system designed for this study. The experimental system allowed avoiding the effect of ions and vacuum ultraviolet (VUV) photons on surface reactions and controlling the oxygen atom concentration over the samples. Fourier-transform infrared spectroscopy, x-ray fluorescence, and atomic force microscopy techniques were used to analyze the changes occurring in low-k films. Monte Carlo model for O atom interaction with low-k material that includes penetration, recombination, and reactions with methyl groups was developed. It is shown that the surface recombination on the pore wall surface determines the profile and penetration depth of O atoms into the films. The reaction of O atoms with methyl groups has lower probability and therefore proceeds in the background mode.

  4. Theoretical study and rate constant calculation of the CH2O+CH3 reaction

    NASA Astrophysics Data System (ADS)

    Liu, Jing-yao; Li, Ze-sheng; Wu, Jia-yan; Wei, Zhi-gang; Zhang, Gang; Sun, Chia-chung

    2003-10-01

    The potential energy surface of the CH2O+CH3 reaction is explored at the MP2/6-311++G(d,p), MP4SDQ/6-311G(d,p), and QCISD(T)/6-311+G(3df,2p) (single point) levels of theory. Theoretical calculations suggest that the major product channel (R1) is the hydrogen abstraction leading to the product P1 CHO+CH4 (R1), while the addition process leading to P2H+CH3CHO (R2) appears to be negligibly small. The calculated enthalpies and dissociation activation energies for CH3CH2O and CH3OCH2 radicals involved in the reaction are in line with the experimental values. Dual-level dynamics calculation is carried out for the direct hydrogen abstraction channel. The energy profile of (R1) is refined with the interpolated single-point energies (ISPE) method at the QCISD(T)//MP2 level. The rate constants, which are evaluated by canonical variational transition-state theory (CVT) including small-curvature tunneling (SCT) correction, are in good agreement with the available experimental data. It is shown that tunneling effect plays a significant role in the rate constant calculation; and as a result, the CVT/SCT rate constants exhibit typical non-Arrhenius behavior over a wide temperature range 300-2000 K. The three parameter expression is k=6.35×10-26 T4.4 exp(-2450/T) cm3 molecule-1 s-1.

  5. Analysis of the Pressure and Temperature Dependence of the Complex-Forming Bimolecular Reaction CH3OCH3 + Fe(.).

    PubMed

    Ard, Shaun G; Johnson, Ryan S; Martinez, Oscar; Shuman, Nicholas S; Guo, Hua; Troe, Jürgen; Viggiano, Albert

    2016-07-14

    The kinetics of the reaction CH3OCH3 + Fe(+) has been studied between 250 and 600 K in the buffer gas He at pressures between 0.4 and 1.6 Torr. Total rate constants and branching ratios for the formation of Fe(+)O(CH3)2 adducts and of Fe(+)OCH2 + CH4 products were determined. Quantum-chemical calculations provided the parameters required for an analysis in terms of statistical unimolecular rate theory. The analysis employed a recently developed simplified representation of the rates of complex-forming bimolecular reactions, separating association and chemical activation contributions. Satisfactory agreement between experimental results and kinetic modeling was obtained that allows for an extrapolation of the data over wide ranges of conditions. Possible reaction pathways with or without spin-inversion are discussed in relation to the kinetic modeling results.

  6. Direct synthesis of amides from carboxylic acids and amines using B(OCH2CF3)3.

    PubMed

    Lanigan, Rachel M; Starkov, Pavel; Sheppard, Tom D

    2013-05-03

    B(OCH2CF3)3, prepared from readily available B2O3 and 2,2,2-trifluoroethanol, is as an effective reagent for the direct amidation of a variety of carboxylic acids with a broad range of amines. In most cases, the amide products can be purified by a simple filtration procedure using commercially available resins, with no need for aqueous workup or chromatography. The amidation of N-protected amino acids with both primary and secondary amines proceeds effectively, with very low levels of racemization. B(OCH2CF3)3 can also be used for the formylation of a range of amines in good to excellent yield, via transamidation of dimethylformamide.

  7. Direct Synthesis of Amides from Carboxylic Acids and Amines Using B(OCH2CF3)3

    PubMed Central

    2013-01-01

    B(OCH2CF3)3, prepared from readily available B2O3 and 2,2,2-trifluoroethanol, is as an effective reagent for the direct amidation of a variety of carboxylic acids with a broad range of amines. In most cases, the amide products can be purified by a simple filtration procedure using commercially available resins, with no need for aqueous workup or chromatography. The amidation of N-protected amino acids with both primary and secondary amines proceeds effectively, with very low levels of racemization. B(OCH2CF3)3 can also be used for the formylation of a range of amines in good to excellent yield, via transamidation of dimethylformamide. PMID:23586467

  8. Atmospheric chemistry of CF{sub 3}C(O)OCH{sub 2}CF{sub 3}: UV spectra and kinetic data for CF{sub 3}C(O)OCH({sm_bullet})CF{sub 3} and CF{sub 3}C(O)OCH(OO{sm_bullet})CF{sub 3} radicals, and atmospheric fate of CF{sub 3}C(O)OCH(O{sm_bullet})CF{sub 3} radicals

    SciTech Connect

    Stein, T.N.N.; Christensen, L.K.; Platz, J.; Sehested, J.; Nielsen, O.J.; Wallington, T.J.

    1999-07-22

    Recognition of the adverse effect of chlorofluorocarbon (CFC) release into the atmosphere has led to an international effort to replace CFCs with environmentally acceptable alternatives. Hydrofluoroethers (HFEs) are fluids designed to replace CFCs in applications such as the cleaning of electronic equipment, heat transfer agents in refrigeration systems, and carrier fluids for lubricant deposition. HFEs are volatile compounds and will be released into the atmosphere during its use. In the atmosphere, photochemical oxidation of HFEs will lead to the formation of fluorinated esters and fluorinated formates. The atmospheric fate of these products is unknown at the present. To improve their understanding of the atmospheric chemistry of esters the authors have studied the atmospheric chemistry of 2,2,2-trifluoroethyltrifluoroacetate CF{sub 3}C(O)OCH{sub 2}CF{sub 3} (bp = 55.0 C). This compound provides insight into the behavior of alkyl, alkyl peroxy, and alkoxy radicals formed {alpha} to the ester functionality. The atmospheric fate of CF{sub 3}C(O)OCH(O{sup {sm_bullet}})CF{sub 3} radicals was investigated in a FTIR smog chamber. Three loss processes for the CF{sub 3}C(O)OCH(O{sup {sm_bullet}})CF{sub 3} radicals were identified at 296 K and 700 Torr total pressure, reaction with O{sub 2} to form CF{sub 3}C(O)OC(O)CF{sub 3}, {alpha}-rearrangement to form CF{sub 3}C(O){sm_bullet} radicals and CF{sub 3}C(O)OH, and decomposition via a mechanism which is unclear. In 760 Torr of air at 296 K, 65% of the CF{sub 3}C(O)OCH(O{sm_bullet})CF{sub 3} radicals react with oxygen, 18% undergo {alpha}-rearrangement, while the fate of the remaining 17% is unclear.

  9. Hydrogen and methanol exchange processes for (TMP)Rh-OCH3(CH3OH) in binary solutions of methanol and benzene.

    PubMed

    Sarkar, Sounak; Li, Shan; Wayland, Bradford B

    2011-04-18

    Tetramesityl porphinato rhodium(III) methoxide ((TMP)Rh-OCH(3)) binds with methanol in benzene to form a 1:1 methanol complex ((TMP)Rh-OCH(3)(CH(3)OH)) (1). Dynamic processes are observed to occur for the rhodium(III) methoxide methanol complex (1) that involve both hydrogen and methanol exchange. Hydrogen exchange between coordinated methanol and methoxide through methanol in solution results in an interchange of the environments for the non-equivalent porphyrin faces that contain methoxide and methanol ligands. Interchange of the environments of the coordinated methanol and methoxide sites in 1 produces interchange of the inequivalent mesityl o-CH(3) groups, but methanol ligand exchange occurs on one face of the porphyrin and the mesityl o-CH(3) groups remain inequivalent. Rate constants for dynamic processes are evaluated by full line shape analysis for the (1)H NMR of the mesityl o-CH(3) and high field methyl resonances of coordinated methanol and methoxide groups in 1. The rate constant for interchange of the inequivalent porphyrin faces is associated with hydrogen exchange between 1 and methanol in solution and is observed to increase regularly with the increase in the mole fraction of methanol. The rate constant for methanol ligand exchange between 1 and the solution varies with the solution composition and fluctuates in a manner that parallels the change in the activation energy for methanol diffusion which is a consequence of solution non-ideality from hydrogen bonded clusters.

  10. Astronomical Orientations Of Dragon Houses (Laka Palli, Kapsala, Oche) And Armena Gate (Euboea, Greece)

    NASA Astrophysics Data System (ADS)

    Liritzis, I.; Artelaris, G.

    The preliminary investigation of the astronomical orientation of monuments at Styra, southern Euboea, includes the triple so called 'dragon house' complex at Laka Palli, one dragon house at Kapsala and one on the summit of Mount Oche, and a monumental gate in the megalithic fortification wall at Armena. Recent luminescence testing dates these remains to approximately the Classical period with apparent re-use in Roman and later times. Thus far no definite astronomical orientation has been determined in the layout of the structures and no celestial stone markers or similar features have been found associated with the dragon houses, however, the relationship of significant stars, constellations and solar stands was well known in antiquity, and the limited results presented here suggests the possibility for further investigation. This study, which considered possible orientations related to sun rise and sun set for the summer and winter solstice, as well as, alignments towards equinoxes and major bright stars and constellations, did observe a general preference for a southern orientation at most of the sites and a possible feature for time observations in the dragon house complex at Laka Palli.

  11. High pressure Raman spectroscopy of H2O-CH3OH mixtures.

    PubMed

    Hsieh, Wen-Pin; Chien, Yu-Hsiang

    2015-02-23

    Complex intra-molecular interactions and the hydrogen-bonding network in H2O-volatile mixtures play critical roles in many dynamics processes in physical chemistry, biology, and Earth and planetary sciences. We used high pressure Raman spectroscopy to study the pressure evolution of vibrational frequencies and bonding behavior in H2O-CH3OH mixtures. We found that the presence of low CH3OH content in H2O increases the transition pressure where water crystallizes to ice VI, but does not significantly change the pressure where ice VI transforms to ice VII. Furthermore, the stiffening rates of C-H stretching frequencies dω/dP in CH3OH significantly decrease upon the crystallization of water, and the softening rates of the O-H stretching frequencies of ice VII are suppressed over a narrow pressure range, after which the frequencies of these modes shift with pressure in ways similar to pure CH3OH and ice VII, respectively. Such complex pressure evolution of Raman frequencies along with pronounced variations in Raman intensities of CH3OH within the sample, and the hysteresis of the water-ice VI phase transition suggest pressure-induced segregation of low content CH3OH from ice VII. These findings indicate the significant influence of volatiles on the crystallization of sub-surface ocean and thermal evolution within large icy planets and satellites.

  12. Towards understanding intrinsic degradation and breakdown mechanisms in SiOCH low-k dielectrics

    SciTech Connect

    Wu, C. De Wolf, I.; Li, Y.; Ciofi, I.; Kauerauf, Th.; Bömmels, J.; Tőkei, Zs.; Croes, K.

    2015-02-14

    The degradation and breakdown mechanisms of a SiOCH low-k material with k = 2.3 (25% porosity) and thicknesses ranging from 90 nm to 20 nm were investigated. By combining the time dependent dielectric breakdown data at positive/negative bias stress with the thickness scaling results, dielectric failure is proven to be intrinsic and not influenced by copper drift or metal barrier deposition induced dielectric damage. It is shown that stress induced leakage current (SILC) can be used as a measure of dielectric degradation. Therefore, low field lifetimes can be safely estimated using SILC extrapolation. Based on our results, both the impact damage model and the power law model have a good accuracy for low field lifetime prediction. Recovery and anneal experiments are used to study the physical nature causing the observed negative flatband voltage shifts in our metal-insulator-semiconductor planar capacitor structures, where hydrogen induced unstable fast and slow donor type interface states are hypothesized to be the root cause of the observed shifts. We suggest that atomic hydrogen is released from the dielectric during electron injection and migrates to the interfacial region. Our model is further supported by an observed irreversible SILC change during the recovery and anneal studies. The degradation mechanism proposed in this work, supported by the low field lifetime data, provides a feasible explanation for intrinsic low-k dielectric failure.

  13. Disproportionation and Thermochemical Sulfate Reduction Reactions in S-H2O-CH4 and S-D2O-CH4 Systems from 200 to 340 °C at Elevated Pressures

    NASA Astrophysics Data System (ADS)

    Chou, I.; Yuan, S.; Burruss, R. C.

    2010-12-01

    Elemental sulfur plays significant roles in thermochemical sulfate reduction (TSR) reactions as a transient intermediate oxidation state compound, by-product, or catalyst. However, the mechanisms of the reactions in S-H2O-hydrocarbon systems are not clear. To improve our understanding of reaction mechanisms, we conducted a series of experiments between 200 and 340 °C for S-H2O-CH4, S-D2O-CH4, and S-CH4-1m ZnBr2 systems in fused silica capillary capsules. After a heating period ranging from one to 90 days, the quenched samples were analyzed by Raman spectroscopy. Our results showed that the disproportionation of sulfur in the S-H2O-CH4 system occurred at temperatures above 200 °C and produced H2S, SO42-, and HSO4-. We also observed that the amounts of SO42- and HSO4- decreased for the samples quenched from 250 and 340 °C, and at the same time the amounts of CO2 and H2S increased. To demonstrate that the observed consumption of SO42- and HSO4- in the S-H2O-CH4 system at 300 °C was due to TSR instead of the back reaction between SO42- (or HSO4-) and H2S to form S during and after quench, we introduced 1m ZnBr2 to remove H2S as a ZnS precipitate, as soon as it formed. In these experiments sulfate species decreased and CO2 and H2S increased consistent with TSR and no back reaction. When compared with previously published experiments, our temperatures between 250 and 340 °C are much closer to natural systems (<200 °C) with documented TSR. Also, to demonstrate the relationship between disproportionation and TSR reactions in the S-H2O-CH4 system, we conducted experiments in the S-D2O-CH4 system at 250 and 300 °C. Only small Raman signals for CO2 and no signals for H2S and D2S were detected in the sample quenched from 250 °C, indicating that both the disproportionation reaction and the TSR reaction were very slow at this temperature. After heating at 300 °C for 40 h, Raman signals of the quenched sample indicated significant amount of D2S was produced through the

  14. H2/N2 plasma damage on porous dielectric SiOCH film evaluated by in situ film characterization and plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Yamamoto, Hiroshi; Takeda, Keigo; Ishikawa, Kenji; Ito, Masafumi; Sekine, Makoto; Hori, Masaru; Kaminatsui, Takeshi; Hayashi, Hisataka; Sakai, Itsuko; Ohiwa, Tokuhisa

    2011-04-01

    This study investigates the mechanism of H2/N2 plasma ashing damage of porous SiOCH films. Porous SiOCH films were treated by a H2/N2 plasma using a 100-MHz capacitively coupled plasma etcher. The impact of ions, radicals, and vacuum ultraviolet radiation on the porous SiOCH films was investigated using in situ bulk analysis techniques such as spectroscopic ellipsometry and Fourier-transform infrared spectroscopy and ex situ film characterization techniques such as dynamic secondary ion mass spectrometry and x-ray photoelectron spectroscopy. In addition, plasma analysis including vacuum ultraviolet absorption spectroscopy was performed. The film characterization and plasma analysis show that the extraction of methyl by H radicals was enhanced by light while N radicals were responsible for inhibit the extraction of Si-CH3 bonds by forming nitride layer. The H2/N2 plasma damage mechanism is discussed based on characterization of the film and plasma diagnostics.

  15. Investigation of the O+allyl addition/elimination reaction pathways from the OCH(2)CHCH(2) radical intermediate.

    PubMed

    Fitzpatrick, Benjamin L; Lau, Kai-Chung; Butler, Laurie J; Lee, Shih-Huang; Lin, Jim Jr-Min

    2008-08-28

    These experiments study the preparation of and product channels resulting from OCH(2)CHCH(2), a key radical intermediate in the O+allyl bimolecular reaction. The data include velocity map imaging and molecular beam scattering results to probe the photolytic generation of the radical intermediate and the subsequent pathways by which the radicals access the energetically allowed product channels of the bimolecular reaction. The photodissociation of epichlorohydrin at 193.3 nm produces chlorine atoms and c-OCH(2)CHCH(2) radicals; these undergo a facile ring opening to the OCH(2)CHCH(2) radical intermediate. State-selective resonance-enhanced multiphoton ionization (REMPI) detection resolves the velocity distributions of ground and spin-orbit excited state chlorine independently, allowing for a more accurate determination of the internal energy distribution of the nascent radicals. We obtain good agreement detecting the velocity distributions of the Cl atoms with REMPI, vacuum ultraviolet (VUV) photoionization at 13.8 eV, and electron bombardment ionization; all show a bimodal distribution of recoil kinetic energies. The dominant high recoil kinetic energy feature peaks near 33 kcalmol. To elucidate the product channels resulting from the OCH(2)CHCH(2) radical intermediate, the crossed laser-molecular beam experiment uses VUV photoionization and detects the velocity distribution of the possible products. The data identify the three dominant product channels as C(3)H(4)O (acrolein)+H, C(2)H(4)+HCO (formyl radical), and H(2)CO (formaldehyde)+C(2)H(3). A small signal from C(2)H(2)O (ketene) product is also detected. The measured velocity distributions and relative signal intensities at me=27, 28, and 29 at two photoionization energies show that the most exothermic product channel, C(2)H(5)+CO, does not contribute significantly to the product branching. The higher internal energy onset of the acrolein+H product channel is consistent with the relative barriers en route to

  16. Investigation of the O+allyl addition/elimination reaction pathways from the OCH2CHCH2 radical intermediate

    NASA Astrophysics Data System (ADS)

    Fitzpatrick, Benjamin L.; Lau, Kai-Chung; Butler, Laurie J.; Lee, Shih-Huang; Lin, Jim-Min, Jr.

    2008-08-01

    These experiments study the preparation of and product channels resulting from OCH2CHCH2, a key radical intermediate in the O+allyl bimolecular reaction. The data include velocity map imaging and molecular beam scattering results to probe the photolytic generation of the radical intermediate and the subsequent pathways by which the radicals access the energetically allowed product channels of the bimolecular reaction. The photodissociation of epichlorohydrin at 193.3 nm produces chlorine atoms and c-OCH2CHCH2 radicals; these undergo a facile ring opening to the OCH2CHCH2 radical intermediate. State-selective resonance-enhanced multiphoton ionization (REMPI) detection resolves the velocity distributions of ground and spin-orbit excited state chlorine independently, allowing for a more accurate determination of the internal energy distribution of the nascent radicals. We obtain good agreement detecting the velocity distributions of the Cl atoms with REMPI, vacuum ultraviolet (VUV) photoionization at 13.8 eV, and electron bombardment ionization; all show a bimodal distribution of recoil kinetic energies. The dominant high recoil kinetic energy feature peaks near 33 kcal/mol. To elucidate the product channels resulting from the OCH2CHCH2 radical intermediate, the crossed laser-molecular beam experiment uses VUV photoionization and detects the velocity distribution of the possible products. The data identify the three dominant product channels as C3H4O (acrolein)+H, C2H4+HCO (formyl radical), and H2CO (formaldehyde)+C2H3. A small signal from C2H2O (ketene) product is also detected. The measured velocity distributions and relative signal intensities at m/e=27, 28, and 29 at two photoionization energies show that the most exothermic product channel, C2H5+CO, does not contribute significantly to the product branching. The higher internal energy onset of the acrolein+H product channel is consistent with the relative barriers en route to each of these product channels

  17. Hydrogen isotope systematics of H2-H2O-CH4 during hydrogenotrophic methanogenesis

    NASA Astrophysics Data System (ADS)

    Kobayashi, M.; Kawagucci, S.; Hattori, S.; Yamada, K.; Ueno, Y.; Takai, K.; Yoshida, N.

    2011-12-01

    Hydrogen and carbon isotopes of CH4 have been utilized to trace microbial processes. The isotope fractionations during hydrogenotrophic methanogenesis, one of the major processes of environmental CH4, have been studied by several laboratory incubations. For the carbon isotope, H2 concentration is thought to be the major parameter controlling the carbon isotope fractionation by hydrogenotrophic methanogenesis. For the hydrogen, on the other hand, factors controlling isotope fractionation remain poorly understood, although H2 concentration is suggested to be important. This uncertainty prevents us to utilize δD-CH4 value as the tracer. The most important and principal question is whether all hydrogen atoms in microbially-generated CH4 come from environmental H2O or not. To answer the question, we investigated the D/H systematics of H2-H2O-CH4 during hydrogenotrophic methanogenesis by pure culture incubation with softly deuterium-enriched H2 and/or H2O. Our results demonstrate that δD-CH4 value produced by hydrogenotrophic methanogens depends not only on δD-H2O value but also on δD-H2 value. We observed constant correlation between δD-H2 and δD-CH4 values as well as between δD-H2O and δD-CH4 values, which suggests that hydrogen (/deuterium) atom of substrate H2 is also transferred to the product CH4. This implies that the range of δD-CH4 value produced by hydrogenotrophic methanogenesis should be re-evaluated considering the distribution of δD-H2 and δD-H2O values in natural environments.

  18. Crystal and molecular structures of the first trans-macro-ansa monocyclophosphazene macrocycle, trans-N 3P 3Cl 4 [HN-(CH 2) 3-O-(CH 2) 6-O-(CH 2) 3-NH

    NASA Astrophysics Data System (ADS)

    Zanin, Bruno; Sournies, François; Labarre, Jean-François; Enjalbert, Renée; Galy, Jean

    1990-11-01

    The reaction of N 3P 3Cl 6 with 4,11-dioxatetradecane-1,14-diamine (designated 3O6O3) in a heterogeneous medium (interface process) of toluene and saturated aqueous Na 2CO 3 leads stereoselectively to a trans monocyclophosphazene 19-crown-ether species ( trans MACRO-ANSA 3O6O3) which crystallizes in the monoclinic system, P2 1/ na=8.539(2), b=8.997(3), c=30.123(4) Å, β=91.65(2)°, V=2313(2) Å 3, Z=4, Dx=1.456 Mg m -3, R=0.054 for 2826 unique reflections and 236 variable parameters. The structure exhibits a spatial arrangement with one [HN-(CH 2) 3-O-(CH 2) 6-O-(CH 2) 3-NH] as an arch, grafted in a trans configuration onto two different phosphorus atoms ( trans non-gem disubstitution) of one N 3P 3Cl 4 moiety. This fortuitously discovered trans-19-crown-ether-shaped macrocyclic structure defies the well-established description of the electronic structure of six-membered cyclophosphazene rings.

  19. Long persistent near infrared luminescence nanoprobes LiGa5O8:Cr3+-PEG-OCH3 for in vivo imaging

    NASA Astrophysics Data System (ADS)

    Fu, Xiaoyan; Liu, Chunlin; Shi, Junpeng; Man, Huizi; Xu, Jia; Zhang, Hongwu

    2014-09-01

    The Cr3+-doped LiGa5O8 nanoparticles (LGNPs) with long-persistent near-infrared phosphorescence were obtained through a sol-gel approach followed by heat treatment at 800 °C in air. The obtained results reveal that the nanoparticles with an average diameter of 100 nm are well defined and have pure structure of LiGa5O8. After illumination for 3 min using a 254 nm UV lamp, the LGNPs exhibit strong near-infrared peak at ca. 720 nm belonging to tissue transparency window which can last for more than 1 h. Via surface modified with PEG-5000-OCH3, the LGNPs-PEG-OCH3 exhibit excellent biocompatibility and low toxicity. Under in vitro pre-excitation using a 254 nm UV lamp for 3 min, the in vivo distribution of the LGNPs-PEG-OCH3 in the abdomen can be detected in real time for more than 1 h. All the results indicate that the LGNPs-PEG-OCH3 can be used as potential nanoprobes to realize in vivo, real time and long time imaging with high sensitivity.

  20. Induction of apoptosis in human mitogen-activated peripheral blood T-lymphocytes by the ether phospholipid ET-18-OCH3: Involvement of the Fas receptor/ligand system

    PubMed Central

    Cabaner, Christelle; Gajate, Consuelo; Macho, Antonio; Muñoz, Eduardo; Modolell, Manuel; Mollinedo, Faustino

    1999-01-01

    Activated T-cells constitute a target for treatment of autoimmune diseases. We have found that the antitumour ether phospholipid 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine (ET-18-OCH3; edelfosine) induced dose- and time-dependent apoptosis in human mitogen-activated peripheral blood T-lymphocytes, but not in resting T-cells. T-lymphocytes were stimulated with phytohemagglutinin and interleukin-2 or with concanavalin A. Apoptosis was assessed by DNA fragmentation through cell cycle and TUNEL analyses, as well as through visualization of internucleosomal DNA fragmentation in agarose gels.The ET-18-OCH3-mediated apoptotic response in activated T-lymphocytes was less intense than in human leukaemic T cell lines, such as Jurkat cells and Peer cells; namely about 25% apoptosis in activated T-cells versus about 46–61% apoptosis in T leukaemic cells after 24 h treatment with 10 μM ET-18-OCH3.The ET-18-OCH3 thioether analogue BM 41.440 (ilmofosine) showed a similar apoptotic capacity to that found with ET-18-OCH3 in activated T-cells, whereas the phospholipid analogue hexadecylphosphocholine (miltefosine) failed to promote this response.The uptake of [3H]-ET-18-OCH3 was much larger in activated T-cells than in resting lymphocytes.Using a cytofluorimetric approach we have found that ET-18-OCH3 induced disruption of the mitochondrial transmembrane potential and production of reactive oxygen species in activated T-cells, but not in resting lymphocytes.ET-18-OCH3 induced an increase in Fas (APO-1/CD95) ligand mRNA expression in activated T-cells, and incubation with a blocking anti-Fas (APO-1/CD95) antibody partially inhibited the ET-18-OCH3-induced apoptosis of activated T-lymphocytes.These results demonstrate that mitogen-activated T-cells, unlike resting lymphocytes, are able to take up significant amounts of ET-18-OCH3, and are susceptible to undergo apoptosis by the ether lipid via, in part, the Fas (APO-1/CD95) receptor/ligand system. This ET-18-OCH3

  1. Characterization of Cu(II) and Cd(II) resistance mechanisms in Sphingobium sp. PHE-SPH and Ochrobactrum sp. PHE-OCH and their potential application in the bioremediation of heavy metal-phenanthrene co-contaminated sites.

    PubMed

    Chen, Chen; Lei, Wenrui; Lu, Min; Zhang, Jianan; Zhang, Zhou; Luo, Chunling; Chen, Yahua; Hong, Qing; Shen, Zhenguo

    2016-04-01

    Soil that is co-contaminated with heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) is difficult to bioremediate due to the ability of toxic metals to inhibit PAH degradation by bacteria. We demonstrated the resistance mechanisms to Cu(II) and Cd(II) of two newly isolated strains of Sphingobium sp. PHE-SPH and Ochrobactrum sp. PHE-OCH and further tested their potential application in the bioremediation of HM-phenanthrene (PhA) co-contaminated sites. The PHE-SPH and PHE-OCH strains tolerated 4.63 and 4.34 mM Cu(II) and also showed tolerance to 0.48 and 1.52 mM Cd(II), respectively. Diverse resistance patterns were detected between the two strains. In PHE-OCH cells, the maximum accumulation of Cu(II) occurred in the cell wall, while the maximum accumulation was in the cytoplasm of PHE-SPH cells. This resulted in a sudden suppression of growth in PHE-OCH and a gradual inhibition in PHE-SPH as the concentration of Cu(II) increased. Organic acid production was markedly higher in PHE-OCH than in PHE-SPH, which may also have a role in the resistance mechanisms, and contributes to the higher Cd(II) tolerance of PHE-OCH. The factors involved in the absorption of Cu(II) or Cd(II) in PHE-SPH and PHE-OCH were identified as proteins and carbohydrates by Fourier transform infrared (FT-IR) spectroscopy. Furthermore, both strains showed the ability to efficiently degrade PhA and maintained this high degradation efficiency under HM stress. The high tolerance to HMs and the PhA degradation capacity make Sphingobium sp. PHE-SPH and Ochrobactrum sp. PHE-OCH excellent candidate organisms for the bioremediation of HM-PhA co-contaminated sites.

  2. A single-molecule magnet featuring a parallelogram [Dy4(OCH2-)4] core and two magnetic relaxation processes.

    PubMed

    Liu, Cai-Ming; Zhang, De-Qing; Zhu, Dao-Ben

    2013-10-01

    An alkoxido-bridged tetranuclear Dy(iii) complex, [Dy4(H3L)2(OAc)6]·2EtOH {, H6L = 1,3-bis[tris(hydroxymethyl)methylamino]propane}, has been solvothermally synthesized and characterized. An X-ray crystallographic study revealed that complex possesses a novel "parallelogram" [Dy4(OCH2-)4] core, and a new binding mode η(3):η(3):η(1):η(1):η(1):η(2):μ(4) of the Bis-tris propane ligand was observed. Magnetic investigations indicated that it is a single-molecule magnet (SMM), showing two distinct magnetic relaxation processes with the energy barriers of 44 K and 107 K, respectively. Such a two-step magnetic relaxation process could be well described by the sum of two modified Debye functions.

  3. Disruption of the OCH1 and MNN1 genes decrease N-glycosylation on glycoprotein expressed in Kluyveromyces lactis.

    PubMed

    Liu, Bo; Gong, Xin; Chang, Shaohong; Yang, Yili; Song, Miao; Duan, Demin; Wang, Lina; Ma, Qingjun; Wu, Jun

    2009-08-20

    Glycoproteins secreted by the yeast Kluyveromyces lactis are usually modified by the addition at asparagines-linked glycosylation sites of heterogeneous mannan residues. The secreted glycoproteins in K. lactis that become hypermannosylated will bear a non-human glycosylation pattern and can adversely affect the half-life, tissue distribution and immunogenicity of a therapeutic protein. Here, we describe engineering a K. lactis strain to produce non-hypermannosylated glycoprotein, decreasing the outer-chain mannose residues of N-linked oligosaccharides. We investigated and developed the method of two-step homologous recombination to knockout the OCH1 gene, encoding alpha1,6-mannosyltransferase and MNN1 gene, which is homologue of Saccharomyces cerevisiae MNN1, encoding a putative alpha1,3-mannosyltransferase. We found the Kloch1 mutant strain has a defect in hyperglycosylation, inability in adding mannose to the core oligosaccharide. The N-linked oligosaccharides assembled on a secretory glycoprotein, HSA/GM-CSF in Kloch1 mutant, contained oligosaccharide Man(13-14)GlcNAc(2), and in Kloch1 mnn1 mutant, contained oligosaccharide Man(9-11)GlcNAc(2), whereas those in the wild-type strain, consisted of oligosaccharides with heterogeneous sizes, Man(>30)GlcNAc(2). Taken together, these results indicated that KlOch1p plays a key role in the outer-chain mannosylation of N-linked oligosaccharides in K. lactis. The KlMnn1p, was proved to be certain contribution to the outer hypermannosylation, most possibly encodes alpha1,3-mannosyltransferase. Therefore, the Kloch1 and Kloch1 mnn1 mutants can be used as a foundational host to produce glycoproteins lacking the outer-chain hypermannoses and further maybe applicable to be a promising system for yeast therapeutic protein production.

  4. Damage by radicals and photons during plasma cleaning of porous low-k SiOCH. II. Water uptake and change in dielectric constant

    SciTech Connect

    Shoeb, Juline; Kushner, Mark J.

    2012-07-15

    Porous dielectric materials provide lower capacitances that reduce RC time delays in integrated circuits. Typical low-k materials include porous SiOCH-silicon dioxide with carbon groups, principally CH{sub 3}, lining the pores. With a high porosity, internally connected pores provide pathways for reactive species to enter into the material. Fluorocarbon plasmas are often used to etch SiOCH, a process that leaves a fluorocarbon polymer on the surface that must later be removed. During cleaning using Ar/O{sub 2} or He/H{sub 2} plasmas, reactions of radicals that diffuse into the SiOCH and photons that penetrate into the SiOCH can remove -CH{sub 3} groups. Due to its higher reactivity, cleaning with Ar/O{sub 2} plasmas removes more -CH{sub 3} groups than He/H{sub 2} plasmas, and so produce more free radical sites, such as -SiO{sub 2} Bullet (a -SiO{sub 2}-CH{sub 3} site with the -CH{sub 3} group removed).Upon exposure to humid air, these free radical sites can chemisorb H{sub 2}O to form hydrophilic Si-OH which can further physisorb H{sub 2}O through hydrogen bonding to form Si-OH(H{sub 2}O). With the high dielectric constant of water, even a small percentage of water uptake can significantly increase the effective dielectric constant of SiOCH. In this paper, we report on results from a computational investigation of the cleaning of SiOCH using Ar/O{sub 2} or He/H{sub 2} plasmas and subsequent exposure to humid air. The authors found that plasma cleaning with He/H{sub 2} mixtures produce less demethylation than cleaning with Ar/O{sub 2} plasmas, as so results in less water uptake, and a smaller increase in dielectric constant. The water that produces the increase in dielectric constant is roughly half chemisorbed and half physisorbed, the latter of which can be removed with mild heating. Sealing the pores with NH{sub 3} plasma treatment reduces water uptake and helps prevent the increase in dielectric constant.

  5. Cyanido Antimonate(III) and Bismuthate(III) Anions.

    PubMed

    Arlt, Sören; Harloff, Jörg; Schulz, Axel; Stoffers, Alrik; Villinger, Alexander

    2016-12-05

    The reaction of in situ generated E(CN)3 (E = Sb, Bi) with different amounts of [Ph4P]CN and [PPN]CN ([PPN](+) = [Ph3P-N-PPh3](+)) was studied, affording salts bearing the novel ions [E(CN)5](2-), [Bi2(CN)11](5-), and [Bi(CN)6](3-). The valence lone pair of electrons on the central atom of antimony and bismuth(III) compounds can be either sterically active in an unsymmetric fashion (three shorter bonds + x longer bonds) or symmetric (with rather long averaged bonds). In the presence of weakly coordinating cations (e.g., [Ph4P](+) and [PPN](+)), the solid-state structures of salts with [E(CN)5](2-) anions contain well-separated cations and monomeric anions, which display a sterically active lone pair and a monomeric square-based pyramidal (pseudo-octahedral) structure. The [Bi(CN)5·MeCN](2-) acetonitrile adduct ion exhibits a strongly distorted octahedral structure, which is better understood as a [5 + 1] coordination. The intriguing [Ph4P]6[Bi2(CN)11]CN salt consists of separated cations and anions as well as well-separated [Bi2(CN)11](5-) and CN(-) ions. The structure of the molecular [Bi2(CN)11](5-) ion can be described as two square-based-pyramidal [Bi(CN)5](2-) fragments connected by a disordered bridging CN(-) ion, thereby leading to a distorted-octahedral environment around the two Bi centers. Here the steric effect of the lone pair is much less pronounced but still present.

  6. Design of peptides with alpha,beta-dehydro residues: pseudo-tripeptide N-benzyloxycarbonyl-DeltaLeu-L-Ala-L-Leu-OCH3.

    PubMed

    Makker, Jyoti; Dey, Sharmistha; Kumar, Pravindra; Singh, Tej P

    2002-04-01

    The title peptide N-benzyloxycarbonyl-DeltaLeu-L-Ala-L-Leu-OCH(3) [methyl N-(benzyloxycarbonyl)-alpha,beta-dehydroleucyl-L-alanyl-L-leucinate], C(24)H(35)N(3)O(6), was synthesized in the solution phase. The peptide adopts a type II' beta-turn conformation which is stabilized by an intramolecular 4 --> 1 N-H* * *O hydrogen bond. The crystal packing is stabilized by two intermolecular N-H* * *O hydrogen bonds.

  7. A Study of Structural Changes in Pressed Semiproducts from Aluminum Alloy V95ochT2 in the Range of Dark Spots

    NASA Astrophysics Data System (ADS)

    Shigapov, A. I.; Il'inkova, T. A.; Kuryntsev, S. V.; Petrova, E. P.

    2017-01-01

    Seven heats of alloy V95ochT2 are studied after a heat treatment imitating the conditions of the appearance of dark spots in the production process and anodic oxidizing (anodizing). The mechanical properties, the hardness, the structure, and the electrical conductivity of the alloy are determined. The causes and conditions of the appearance of dark spots are analyzed. The transparence of the film is shown to worsen upon formation of particles of second phase in the alloy.

  8. H{sub 2}/N{sub 2} plasma damage on porous dielectric SiOCH film evaluated by in situ film characterization and plasma diagnostics

    SciTech Connect

    Yamamoto, Hiroshi; Takeda, Keigo; Ishikawa, Kenji; Hori, Masaru; Ito, Masafumi; Sekine, Makoto; Kaminatsui, Takeshi; Hayashi, Hisataka; Sakai, Itsuko; Ohiwa, Tokuhisa

    2011-04-15

    This study investigates the mechanism of H{sub 2}/N{sub 2} plasma ashing damage of porous SiOCH films. Porous SiOCH films were treated by a H{sub 2}/N{sub 2} plasma using a 100-MHz capacitively coupled plasma etcher. The impact of ions, radicals, and vacuum ultraviolet radiation on the porous SiOCH films was investigated using in situ bulk analysis techniques such as spectroscopic ellipsometry and Fourier-transform infrared spectroscopy and ex situ film characterization techniques such as dynamic secondary ion mass spectrometry and x-ray photoelectron spectroscopy. In addition, plasma analysis including vacuum ultraviolet absorption spectroscopy was performed. The film characterization and plasma analysis show that the extraction of methyl by H radicals was enhanced by light while N radicals were responsible for inhibit the extraction of Si-CH{sub 3} bonds by forming nitride layer. The H{sub 2}/N{sub 2} plasma damage mechanism is discussed based on characterization of the film and plasma diagnostics.

  9. Structural analysis of HS(CD(2))(12)(O-CH(2)-CH(2))(6)OCH(3) monolayers on gold by means of polarization modulation infrared reflection absorption spectroscopy. progress of the reaction with bromine.

    PubMed

    Brand, Izabella; Nullmeier, Martina; Klüner, Thorsten; Jogireddy, Rajamalleswaramma; Christoffers, Jens; Wittstock, Gunther

    2010-01-05

    A self-assembled monolayer (SAM) on gold was formed with specifically perdeuterated hexaethylene glycol-terminated alkanethiol HS(CD(2))(12)(O-CH(2)-CH(2))(6)OCH(3) (D-OEG). The structure of the d-alkane and the oligoethylene glycol (OEG) parts of the molecule in a SAM was studied by means of polarization modulation infrared reflection absorption spectroscopy. The D-OEG monolayers are highly ordered and exist in a crystalline phase. The d-alkane chain adopts an all-trans conformation. Both, the d-alkane chain and long axis of the OEG part make an angle of 26.0 degrees +/- 1.5 degrees with respect to the surface normal, a value characteristic for the tilt of solid n-alkane thiols in the SAMs on Au. The positions of nu(as)(COC) and CH(2) wagging and rocking modes indicate a helical arrangement of the OEG chains. The D-OEG SAMs were exposed to 25 muM Br(2) in two ways: (i) by immersion into the Br(2) solution and (ii) in the galvanic cell Au|D-OEG SAM|25 muM Br(2) + 0.1 M Na(2)SO(4)|| 50 muM KBr + 0.1 M Na(2)SO(4)|Au. In the galvanic cell, the oxidant (Br(2)) is scavenged by a heterogeneous electron transfer reaction, slowing the reaction of D-OEG with Br(2). The slow progress of the reaction with Br(2) allowed us to draw conclusions about molecular rearrangements taking place during this reaction. The reaction with Br(2) starts on boundaries and/or defects present in the SAM. First, at the defect place, the alpha-C atom of the OEG chain reacts with Br(2) and the OEG part of the molecule is removed from the monolayer. In consequence an increase in disorder in the OEG part of the SAM is observed. The same mechanism of the reaction with Br(2) is applied for the d-dodecane alkanethiol part of the molecule. This reaction is slow, thus the order and the tilt of the hydrocarbon chain changes only a little during the reaction time.

  10. Conformational and spectroscopic study of xanthogen ethyl formates, ROC(S)SC(O)OCH2CH3. Isolation of CH3CH2OC(O)SH

    NASA Astrophysics Data System (ADS)

    Juncal, Luciana C.; Cozzarín, Melina V.; Romano, Rosana M.

    2015-03-01

    ROC(S)SC(O)OCH2CH3, with R = CH3sbnd , (CH3)2CHsbnd and CH3(CH2)2sbnd , were obtained through the reaction between potassium xanthate salts, ROC(S)SK, and ethyl chloroformate, ClC(O)OCH2CH3. The liquid compounds were identified and characterized by 1H and 13C NMR and mass spectrometry. The conformations adopted by the molecules were studied by DFT methods. 6 conformers were theoretically predicted for R = CH3sbnd and (CH3)2CHsbnd , while the conformational flexibility of the n-propyl substituent increases the total number of feasible rotamers to 21. For the three molecules, the conformers can be associated in 3 groups, being the most stable the AS forms - the Cdbnd S double bond anti (A) with respect to the Csbnd S single bond and the Ssbnd C single bond syn (S) with respect to the Cdbnd O double bond - followed by AA and SS conformers. The vibrational spectra were interpreted in terms of the predicted conformational equilibrium, presenting the ν(Cdbnd O) spectral region signals corresponding to the three groups of conformers. A moderated pre-resonance Raman enhancement of the ν(Cdbnd S) vibrational mode of CH3(CH2)2OC(S)SC(O)OCH2CH3 was detected, when the excitation radiation approaches the energy of a n → π∗ electronic transition associated with the Cdbnd S chromophore. UV-visible spectra in different solvents were measured and interpreted in terms of TD-DFT calculations. The unknown molecule CH3CH2OC(O)SH was isolated by the UV-visible photolysis of CH3OC(S)SC(O)OCH2CH3 isolated in Ar matrix, and also obtained as a side-product of the reaction between potassium xanthate salts, ROC(S)SK, and ethyl chloroformate, ClC(O)OCH2CH3.

  11. The effect of VUV radiation from Ar/O2 plasmas on low-k SiOCH films

    NASA Astrophysics Data System (ADS)

    Lee, J.; Graves, D. B.

    2011-08-01

    The degradation of porous low-k materials, like SiOCH, under plasma processing continues to be a problem in the next generation of integrated-circuit fabrication. Due to the exposure of the film to many species during plasma treatment, such as photons, ions, radicals, etc, it is difficult to identify the mechanisms responsible for plasma-induced damage. Using a vacuum beam apparatus with a calibrated Xe vacuum ultraviolet (VUV) lamp, we show that 147 nm VUV photons and molecular O2 alone can damage these low-k materials. Using Fourier-transform infrared (FTIR) spectroscopy, we show that VUV/O2 exposure causes a loss of methylated species, resulting in a hydrophilic, SiOx-like layer that is susceptible to H2O absorption, leading to an increased dielectric constant. The effect of VUV radiation on chemical modification of porous SiOCH films in the vacuum beam apparatus and in Ar and O2 plasma exposure was found to be a significant contributor to dielectric damage. Measurements of dielectric constant change using a mercury probe are consistent with chemical modification inferred from FTIR analysis. Furthermore, the extent of chemical modification appears to be limited by the penetration depth of the VUV photons, which is dependent on wavelength of radiation. The creation of a SiOx-like layer near the surface of the material, which grows deeper as more methyl is extracted, introduces a dynamic change of VUV absorption throughout the material over time. As a result, the rate of methyl loss is continuously changing during the exposure. We present a model that attempts to capture this dynamic behaviour and compare the model predictions to experimental data through a fitting parameter that represents the effective photo-induced methyl removal. While this model accurately simulates the methyl loss through VUV exposure by the Xe lamp and Ar plasma, the methyl loss from VUV photons in O2 plasma are only accurately depicted at longer exposure times. We conclude that other

  12. Analysis of the kinetics and yields of OH radical production from the CH3OCH2 + O2 reaction in the temperature range 195-650 K: an experimental and computational study.

    PubMed

    Eskola, A J; Carr, S A; Shannon, R J; Wang, B; Blitz, M A; Pilling, M J; Seakins, P W; Robertson, S H

    2014-08-28

    The methoxymethyl radical, CH3OCH2, is an important intermediate in the low temperature combustion of dimethyl ether. The kinetics and yields of OH from the reaction of the methoxymethyl radical with O2 have been measured over the temperature and pressure ranges of 195-650 K and 5-500 Torr by detecting the hydroxyl radical using laser-induced fluorescence following the excimer laser photolysis (248 nm) of CH3OCH2Br. The reaction proceeds via the formation of an energized CH3OCH2O2 adduct, which either dissociates to OH + 2 H2CO or is collisionally stabilized by the buffer gas. At temperatures above 550 K, a secondary source of OH was observed consistent with thermal decomposition of stabilized CH3OCH2O2 radicals. In order to quantify OH production from the CH3OCH2 + O2 reaction, extensive relative and absolute OH yield measurements were performed over the same (T, P) conditions as the kinetic experiments. The reaction was studied at sufficiently low radical concentrations (∼10(11) cm(-3)) that secondary (radical + radical) reactions were unimportant and the rate coefficients could be extracted from simple bi- or triexponential analysis. Ab initio (CBS-GB3)/master equation calculations (using the program MESMER) of the CH3OCH2 + O2 system were also performed to better understand this combustion-related reaction as well as be able to extrapolate experimental results to higher temperatures and pressures. To obtain agreement with experimental results (both kinetics and yield data), energies of the key transition states were substantially reduced (by 20-40 kJ mol(-1)) from their ab initio values and the effect of hindered rotations in the CH3OCH2 and CH3OCH2OO intermediates were taken into account. The optimized master equation model was used to generate a set of pressure and temperature dependent rate coefficients for the component nine phenomenological reactions that describe the CH3OCH2 + O2 system, including four well-skipping reactions. The rate coefficients were

  13. Disproportionation and thermochemical sulfate reduction reactions in S-H20-Ch4 and S-D2O-CH4 systems from 200 to 340 °C at elevated pressures

    USGS Publications Warehouse

    Yuan, Shunda; Chou, I-Ming; Burruss, Robert A.

    2013-01-01

    Elemental sulfur, as a transient intermediate compound, by-product, or catalyst, plays significant roles in thermochemical sulfate reduction (TSR) reactions. However, the mechanisms of the reactions in S-H2O-hydrocarbons systems are not clear. To improve our understanding of reaction mechanisms, we conducted a series of experiments between 200 and 340 °C for S-H2O-CH4, S-D2O-CH4, and S-CH4-1m ZnBr2 systems in fused silica capillary capsules (FSCC). After a heating period ranging from 24 to 2160 hours (hrs), the quenched samples were analyzed by Raman spectroscopy. Combined with the in situ Raman spectra collected at high temperatures and pressures in the S-H2O and S-H2O-CH4 systems, our results showed that (1) the disproportionation of sulfur in the S-H2O-CH4 system occurred at temperatures above 200 °C and produced H2S, SO42-, and possibly trace amount of HSO4-; (2) sulfate (and bisulfate), in the presence of sulfur, can be reduced by methane between 250 and 340 °C to produce CO2 and H2S, and these TSR temperatures are much closer to those of the natural system (2O-CH4 system may take place simultaneously, with TSR being favored at higher temperatures; and (4) in the system S-D2O-CH4, both TSR and the competitive disproportionation reactions occurred simultaneously at temperatures above 300 °C, but these reactions were very slow at lower temperatures. Our observation of methane reaction at 250 °C in a laboratory time scale suggests that, in a geologic time scale, methane may be destroyed by TSR reactions at temperatures > 200 °C that can be reached by deep drilling for hydrocarbon resources.

  14. An organo-functionalized metal-oxide cluster, [VO6{(OCH2CH2)2N(CH2CH2OH)}6], with Anderson-like structure.

    PubMed

    Li, H; Swenson, L; Doedens, R J; Khan, M I

    2016-10-18

    A new polyoxovanadium cluster compound, [VO6{(OCH2CH2)2N(CH2CH2OH)}6]·0.5CH3CN, was synthesized and characterized by single-crystal X-ray diffraction analysis, FTIR and UV-vis spectroscopy, and TGA. The cluster is composed of a fully reduced cyclic {V6N6O18} framework, which adopts an Anderson-like structure and is comprised of a ring of six edge-sharing {VO5N} octahedra incorporating six {(OCH2CH2)2N(CH2CH2OH)} ligands. Two (OCH2CH2-) arms of each of the six triethanolamine ligands are directly incorporated into the oxometalate core and the third {-CH2CH2OH} arm remains pendant. In the condensed phase, the clusters form discrete hcp layers through inter-cluster hydrogen bonding. These layers stack through soft chemical interactions to form a 3D network structure. The neutral cluster, [VO6{(OCH2CH2)2N(CH2CH2OH)}6], is the isopolyoxovanadium analogue to the cationic clusters contained in a series of heteropolyoxovanadium compounds previously introduced by our laboratory, e.g., [LiVO6{(OCH2CH2)2N(CH2CH2OH)}6](+); its existence shows that a heteroatom is not required to form or stabilize the common organofunctionalized vanadium oxide framework: [VO6{(OCH2CH2)2N(CH2CH2OH)}6]. To the best of our knowledge, the isopolyoxovanadium and heteropolyoxovanadium clusters represent the first reported isopoly-heteropoly analogues in the polyoxometalate field. We compare the TGA profile, FTIR and UV-vis spectra of the new compound with two of its cationic heteropoly analogues.

  15. The Cl-initiated oxidation of CH(3)C(O)OCH=CH (2), CH (3)C(O)OCH (2)CH=CH (2), and CH (2)=CHC(O)O(CH (2)) (3)CH (3) in the troposphere.

    PubMed

    Blanco, María B; Bejan, Iustinian; Barnes, Ian; Wiesen, Peter; Teruel, Mariano A

    2009-09-01

    Unsaturated esters are emitted to the atmosphere from biogenic and anthropogenic sources, including those from the polymer industry. Little information exists concerning the atmospheric degradation of unsaturated esters, which are mainly initiated by OH radicals. Limited information is available on the degradation of alkenes by Cl atoms and almost no data exists for the reactions of unsaturated esters with Cl atoms. This data is necessary to assess the impact of such reactions in maritime environments where, under circumstances, OH radical- and Cl atom-initiated oxidation of the compounds can be important. Rate coefficients for the reactions of chlorine atoms with vinyl acetate, allyl acetate, and n-butyl acrylate have been determined at 298 +/- 3 K and atmospheric pressure. The kinetic data have been used in combination with that for structurally similar compounds to infer the kinetic contributions from the possible reaction channels to the overall reaction rate. The decay of the organics was followed using in situ Fourier transform infrared spectroscopy and the rate coefficients were determined using a relative kinetic method and different hydrocarbon reference compounds. The following room temperature rate coefficients (in cm(3) molecule(-1) s(-1)) were obtained: k (1) (Cl + CH(3)C(O)OCH=CH(2)) = (2.68 +/- 0.91) x 10(-10), k (2) (Cl + CH(3)C(O)OCH(2)CH=CH(2)) = (1.30 +/- 0.45) x 10(-10), and k (3) (Cl + CH(2)=CHC(O)O(CH(2))(3)CH(3)) = (2.50 +/- 0.78) x 10(-10), where the uncertainties are a combination of the 2sigma statistical errors from linear regression analyses and a contribution to cover uncertainties in the rate coefficients of the reference hydrocarbons. This is the first kinetic study of the title reactions under atmospheric conditions. The kinetic data were analyzed in terms of reactivity trends and used to estimate the atmospheric lifetimes of the esters and assess their potential importance in the marine atmosphere. Although reaction with OH radicals

  16. A computational study of the addition of ReO3L (L = Cl(-), CH3, OCH3 and Cp) to ethenone.

    PubMed

    Aniagyei, Albert; Tia, Richard; Adei, Evans

    2016-01-01

    The periselectivity and chemoselectivity of the addition of transition metal oxides of the type ReO3L (L = Cl, CH3, OCH3 and Cp) to ethenone have been explored at the MO6 and B3LYP/LACVP* levels of theory. The activation barriers and reaction energies for the stepwise and concerted addition pathways involving multiple spin states have been computed. In the reaction of ReO3L (L = Cl(-), OCH3, CH3 and Cp) with ethenone, the concerted [2 + 2] addition of the metal oxide across the C=C and C=O double bond to form either metalla-2-oxetane-3-one or metalla-2,4-dioxolane is the most kinetically favored over the formation of metalla-2,5-dioxolane-3-one from the direct [3 + 2] addition pathway. The trends in activation and reaction energies for the formation of metalla-2-oxetane-3-one and metalla-2,4-dioxolane are Cp < Cl(-) < OCH3 < CH3 and Cp < OCH3 < CH3 < Cl(-) and for the reaction energies are Cp < OCH3 < Cl(-) < CH3 and Cp < CH3 < OCH3 < Cl CH3. The concerted [3 + 2] addition of the metal oxide across the C=C double of the ethenone to form species metalla-2,5-dioxolane-3-one is thermodynamically the most favored for the ligand L = Cp. The direct [2 + 2] addition pathways leading to the formations of metalla-2-oxetane-3-one and metalla-2,4-dioxolane is thermodynamically the most favored for the ligands L = OCH3 and Cl(-). The difference between the calculated [2 + 2] activation barriers for the addition of the metal oxide LReO3 across the C=C and C=O functionalities of ethenone are small except for the case of L = Cl(-) and OCH3. The rearrangement of the metalla-2-oxetane-3-one-metalla-2,5-dioxolane-3-one even though feasible, are unfavorable due to high activation energies of their rate-determining steps. For the rearrangement of the metalla-2-oxetane-3-one to metalla-2,5-dioxolane-3-one, the trends in activation barriers is found to follow the order OCH3 < Cl(-) < CH3 < Cp. The trends in the activation energies for

  17. Investigation of the O+allyl addition/elimination reaction pathways from the OCH{sub 2}CHCH{sub 2} radical intermediate

    SciTech Connect

    FitzPatrick, Benjamin L.; Lau, K.-C.; Butler, Laurie J.; Lee, S.-H.; Lin, Jim Jr-Min

    2008-08-28

    These experiments study the preparation of and product channels resulting from OCH{sub 2}CHCH{sub 2}, a key radical intermediate in the O+allyl bimolecular reaction. The data include velocity map imaging and molecular beam scattering results to probe the photolytic generation of the radical intermediate and the subsequent pathways by which the radicals access the energetically allowed product channels of the bimolecular reaction. The photodissociation of epichlorohydrin at 193.3 nm produces chlorine atoms and c-OCH{sub 2}CHCH{sub 2} radicals; these undergo a facile ring opening to the OCH{sub 2}CHCH{sub 2} radical intermediate. State-selective resonance-enhanced multiphoton ionization (REMPI) detection resolves the velocity distributions of ground and spin-orbit excited state chlorine independently, allowing for a more accurate determination of the internal energy distribution of the nascent radicals. We obtain good agreement detecting the velocity distributions of the Cl atoms with REMPI, vacuum ultraviolet (VUV) photoionization at 13.8 eV, and electron bombardment ionization; all show a bimodal distribution of recoil kinetic energies. The dominant high recoil kinetic energy feature peaks near 33 kcal/mol. To elucidate the product channels resulting from the OCH{sub 2}CHCH{sub 2} radical intermediate, the crossed laser-molecular beam experiment uses VUV photoionization and detects the velocity distribution of the possible products. The data identify the three dominant product channels as C{sub 3}H{sub 4}O (acrolein)+H, C{sub 2}H{sub 4}+HCO (formyl radical), and H{sub 2}CO (formaldehyde)+C{sub 2}H{sub 3}. A small signal from C{sub 2}H{sub 2}O (ketene) product is also detected. The measured velocity distributions and relative signal intensities at m/e=27, 28, and 29 at two photoionization energies show that the most exothermic product channel, C{sub 2}H{sub 5}+CO, does not contribute significantly to the product branching. The higher internal energy onset of the

  18. Distribution of eukaryotic serine racemases in the bacterial domain and characterization of a representative protein in Roseobacter litoralis Och 149.

    PubMed

    Kubota, Takaaki; Shimamura, Shigeru; Kobayashi, Tohru; Nunoura, Takuro; Deguchi, Shigeru

    2016-01-01

    Two distinct bacterial and eukaryotic serine racemases (SRs) have been identified based on phylogenetic and biochemical characteristics. Although some reports have suggested that marine heterotrophic bacteria have the potential to produce d-serine, the gene encoding bacterial SRs is not found in those bacterial genomes. In this study, using in-depth genomic analysis, we found that eukaryotic SR homologues were distributed widely in various bacterial genomes. Additionally, we selected a eukaryotic SR homologue from a marine heterotrophic bacterium, Roseobacter litoralis Och 149 (RiSR), and constructed an RiSR gene expression system in Escherichia coli for studying the properties of the enzyme. Among the tested amino acids, the recombinant RiSR exhibited both racemization and dehydration activities only towards serine, similar to many eukaryotic SRs. Mg2+ and MgATP enhanced both activities of RiSR, whereas EDTA abolished these enzymatic activities. The enzymatic properties and domain structure of RiSR were similar to those of eukaryotic SRs, particularly mammalian SRs. However, RiSR showed lower catalytic efficiency for L-serine dehydration (kcat/Km=0.094 min(-1) mM(-1)) than those of eukaryotic SRs reported to date (kcat/Km=0.6-21 min(-1) mM(-1)). In contrast, the catalytic efficiency for L-serine racemization of RiSR (kcat/Km=3.14 min(-1) mM(-1)) was 34-fold higher than that of l-serine dehydration. These data suggested that RiSR primarily catalysed serine racemization rather than dehydration.

  19. The H2O-CH3F Complex: a Combined Microwave and Infrared Spectroscopic Study Supported by Structure Calculations

    NASA Astrophysics Data System (ADS)

    Gnanasekar, Sharon Priya; Goubet, Manuel; Arunan, Elangannan; Georges, Robert; Soulard, Pascale; Asselin, Pierre; Huet, T. R.; Pirali, Olivier

    2015-06-01

    The H2O-CH3F complex could have two geometries, one with a hydrogen bond and one with the newly proposed carbon bond. While in general carbon bonds are weaker than hydrogen bonds, this complex appears to have comparable energies for the two structures. Infrared (IR) and microwave (MW) spectroscopic measurements using, respectively, the Jet-AILES apparatus and the FTMW spectrometer at the PhLAM laboratory, have been carried out to determine the structure of this complex. The IR spectrum shows the formation of the CH3F- H2O hydrogen bonded complex and small red-shifts in OH frequency most probably due to (CH3F)m-(H2O)n clusters. Noticeably, addition of CH_3F in the mixture promotes the formation of small water clusters. Preliminary MW spectroscopic measurements indicate the formation of the hydrogen bonded complex. So far, we have no experimental evidence for the carbon bonded structure. However, calculations of the Ar-CH3F complex show three energetically equivalent structures: a T-shape, a "fluorine" bond and a carbon bond. The MW spectrum of the (Ar)n-CH3F complexes is currently under analysis. Mani, D; Arunan, E. Phys. Chem. Chem. Phys. 2013, 15, 14377. Cirtog, M; Asselin, P; Soulard, P; Tremblay, B; Madebene, B; Alikhani, M. E; Georges, R; Moudens, A; Goubet, M; Huet, T.R; Pirali, O; Roy, P. J. Phys. Chem. A. 2011, 115, 2523 Kassi, S; Petitprez, D; Wlodarczak, G. J. Mol. Struct. 2000, 517-518, 375

  20. The remarkable dissociation chemistry of 2-aminoxyethanol ions NH2OCH2CH2OH+studied by experiment and theory

    NASA Astrophysics Data System (ADS)

    Jobst, Karl J.; Ruttink, Paul J. A.; Terlouw, Johan K.

    2008-02-01

    Low-energy 2-aminoxyethanol molecular ions NH2OCH2CH2OH+ exhibit a surprisingly rich gas-phase ion chemistry. They spontaneously undergo five major dissociations in the microsecond timeframe, yielding ions of m/z 61, 60, 46, 32 and 18. Our tandem mass spectrometry experiments indicate that these reactions correspond to the generation of HOCH2CH(OH)+ (protonated glycolaldehyde), HOCH2C(O)H+ (ionized glycolaldehyde), HC(OH)NH2+ (protonated formamide), CH2OH2+ (the methylene oxonium ion) and NH4+. A mechanistic analysis of these processes using the CBS-QB3 model chemistry shows that the molecular ions undergo a 1,4-H shift followed by a facile isomerization into the ion-molecule complex [HOCH2C(O)H+]...[NH3] which acts as the reacting configuration for the five exothermic dissociation processes. Analysis of the D-labelled isotopomer ND2OCH2CH2OD+, in conjunction with our computational results, shows that proton-transport catalysis may be responsible for the partial conversion of the m/z 60 glycolaldehyde ions into the more stable 1,2-dihydroxyethene isomer HOC(H)C(H)OH+.

  1. A DFT study on the functionalization of a BN nanosheet with PCsbnd X, (PC = phenyl carbamate, X = OCH3, CH3, NH2, NO2 and CN)

    NASA Astrophysics Data System (ADS)

    Beheshtian, Javad; Soleymanabadi, Hamed; Peyghan, Ali Ahmadi; Bagheri, Zargham

    2013-03-01

    By using density functional theory calculations, we investigated the chemical functionalization of a BN nanosheet with different organo-azo derivatives including PCsbnd X, (PC = phenyl carbamate, X = OCH3, CH3, NH2, NO2 and CN) in terms of geometric, energetic, and electronic properties. Reaction energies have been calculated to be in the range of 0.19 to 0.35 eV which is augmented by increasing the electron withdrawing characteristic of the functional groups so that the relative magnitude order is sbnd NO2 > sbnd CN > sbnd OCH3 > sbnd CH3 > sbnd NH2. The chemical functionalization leads to a decrease in HOMO/LUMO energy gap of BN sheet especially after adsorption of PCsbnd NO2 by about 1.88 eV. Conduction level and Fermi level of the BN sheet are shifted to lower energies upon the functionalization of the sheet with PCsbnd NO2 and PCsbnd CN, thus, it leads to an increment in work function of the sheet, impeding the field electron emission.

  2. Isoelectronic caesium compounds: the triphosphenide Cs[tBu3SiPPPSitBu3] and the enolate Cs[OCH=CH2].

    PubMed

    Lerner, Hans-Wolfram; Sänger, Inge; Schödel, Frauke; Lorbach, Andreas; Bolte, Michael; Wagner, Matthias

    2008-02-14

    The caesium triphosphenide Cs[tBu3SiPPPSitBu3] was accessible from the reaction of CsF with the sodium triphosphenide Na[tBu3SiPPPSitBu3] in tetrahydrofuran at room temperature. In contrast to the preparation of tetrahydrofuran-solvated silanides M[SitBu3] (M = Li, Na, K), our efforts to synthesize the caesium silanide Cs[SitBu3] as a tetrahydrofuran complex failed. When tBu3SiBr was treated with an excess of caesium metal in tetrahydrofuran at room temperature, the caesium enolate Cs[OCH=CH2] and the supersilane tBu3SiH formed rather than the silanide Cs[SitBu3]. X-Ray quality crystals of the enolate Cs[OCH=CH2] (orthorhombic, Pnma) were obtained from tetrahydrofuran at ambient temperature. In contrast to the structures of its homologues M[tBu3SiPPPSitBu3] (M = Na, K), the caesium triphosphenide Cs[tBu3SiPPPSitBu3] features a polymer in the solid state (orthorhombic, Cmcm).

  3. Impact of Hydrocarbon Control in Ultraviolet-Assisted Restoration Process for Extremely Porous Plasma Enhanced Chemical Vapor Deposition SiOCH Films with k = 2.0

    NASA Astrophysics Data System (ADS)

    Kimura, Yosuke; Ishikawa, Dai; Nakano, Akinori; Kobayashi, Akiko; Matsushita, Kiyohiro; de Roest, David; Kobayashi, Nobuyoshi

    2012-05-01

    We investigated the effects of UV-assisted restoration on porous plasma-enhanced chemical vapor deposition (PECVD) SiOCH films with k = 2.0 and 2.3 having high porosities. By applying the UV-assisted restoration to O2-plasma-damaged films with k = 2.0 and 2.3, the recovery of the k-value was observed on the k = 2.3 film in proportion to -OH group reduction. However, the k = 2.0 film did not show recovery in spite of -OH group reduction. We found that hydrocarbon content in the k = 2.0 film was significantly increased by the UV-assisted restoration compared with the k = 2.3 film. According to these findings, we optimized the UV-assisted restoration to achieve improved controllability of the hydrocarbon uptake in the k = 2.0 film and confirmed the recovery of the k-value for O2-plasma-damaged film. Thus, adjusting the hydrocarbon uptake was crucial for restoring extremely porous SiOCH film.

  4. Theoretical investigation on the atmospheric fate of CF3C(O)OCH 2O radical: alpha-ester rearrangement vs oxidation at 298 K.

    PubMed

    Mishra, Bhupesh Kumar

    2014-09-01

    A theoretical study on the mechanism of the thermal decomposition of CF(3)C(O)OCH(2)O radical is presented for the first time. Geometry optimization and frequency calculations were performed at the MPWB1K/6-31 + G(d, p) level of theory and energetic information further refined by calculating the energy of the species using G2(MP2) theory. Three plausible decomposition pathways including α-ester rearrangement, reaction with O(2) and thermal decomposition (C-O bond scission) were considered in detail. Our results reveal that reaction with O(2) is the dominant path for the decomposition of CF(3)C(O)OCH(2)O radical in the atmosphere, involving the lowest energy barrier, which is in accord with experimental findings. Our theoretical results also suggest that α-ester rearrangement leading to the formation of trifluoroacetic acid TFA makes a negligible contribution to decomposition of the title alkoxy radical. The thermal rate constants for the above decomposition pathways were evaluated using canonical transition state theory (CTST) at 298 K.

  5. An extended π-system and enhanced electronic delocalization on symmetric [Ru3O(CH3COO)6(L)3](n) complexes combined with azanaphthalene ligands.

    PubMed

    Possato, Bruna; Deflon, Victor M; Naal, Zeki; Formiga, André L B; Nikolaou, Sofia

    2017-06-28

    We report on the investigation of a new series of symmetric trinuclear ruthenium complexes combined with azanaphthalene ligands: [Ru3O(CH3COO)6(L)3]PF6 where L = (1) quinazoline (qui), (2) 5-nitroisoquinoline (5-nitroiq), (3) 5-bromoisoquinoline (5-briq), (4) isoquinoline (iq), (5) 5-aminoisoquinoline (5-amiq), and (6) 5,6,7,8-tetrahydroisoquinoline (thiq). The crystal structure of complex 1, [Ru3O(CH3COO)6(qui)3]PF6, was determined by X-ray diffraction analysis, showing a high degree of co-planarity between the [Ru3O] plane and the azanaphthalene ligands. Spectroscopic (UV-visible, NMR and infra-red) and electrochemical (cyclic voltammetry and spectroelectrochemistry) data showed correlation with the pKa values of the azanaphthalene ligands and this dependence was rationalized in terms of the molecular orbital of the [Ru3O] unit and the structure of the ligands. By analysing the spectroscopic and electrochemical correlations, the ability of the azanaphthalene ligands to extend the electronic π-system of the [Ru3O] unit to the periphery of the compounds was demonstrated. This electronic effect accounts for the planarity of the structure of complex 1. It was also shown through molecular modeling results that, to explain the spectroscopic and electrochemical behaviour of these species, it is not possible to neglect the electronic mixing between the metallic and the acetate orbitals. Finally, this work revealed that electronic coupling is more pronounced in the azanaphthalene series of complexes than in pyridinic analogues and it is this coupling that determines the spectroscopic and electrochemical behaviour of the new species.

  6. Chiral and nonchiral [OsX2(diphosphane)(diamine)] (X: Cl, OCH2CF3) complexes for fast hydrogenation of carbonyl compounds.

    PubMed

    Baratta, Walter; Barbato, Cinzia; Magnolia, Santo; Siega, Katia; Rigo, Pierluigi

    2010-03-08

    The osmium complexes trans-[OsCl(2)(dppf)(diamine)] (dppf: 1,1'-bis(diphenylphosphino)ferrocene; diamine: ethylenediamine in 3, propylenediamine in 4) were prepared by the reaction of [OsCl(2)(PPh(3))(3)] (1) with the ferrocenyl diphosphane, dppf and the corresponding diamine in dichloromethane. The reaction of derivative 3 with NaOCH(2)CF(3) in toluene afforded the alkoxide cis-[Os(OCH(2)CF(3))(2)(dppf)(ethylenediamine)] (5). The novel precursor [Os(2)Cl(4)(P(m-tolyl)(3))(5)] (2) allows the synthesis of the chiral complexes trans-[OsCl(2)(diphosphane)(1,2-diamine)] (6-9; diphosphane: (R)-[6,6'-dimethoxy(1,1'-biphenyl)-2,2'-diyl]bis[1,1-bis(3,5-dimethylphenyl)phosphane] (xylMeObiphep) or (R)-(1,1'-binaphthalene)-2,2'-diylbis[1,1-bis(3,5-dimethylphenyl)phosphane] (xylbinap); diamine=(R,R)-1,2-diphenylethylenediamine (dpen) or (R,R)-1,2-diaminocyclohexane (dach)), obtained by the treatment of 2 with the diphosphane and the 1,2-diamine in toluene at reflux temperature. Compounds 3-5 in ethanol and in the presence of NaOEt catalyze the reduction of methyl aryl, dialkyl, and diaryl ketones and aldehydes with H(2) at low pressure (5 atm), with substrate/catalyst (S/C) ratios of 10,000-200,000 and achieving turnover frequencies (TOFs) of up to 3.0 x 10(5) h(-1) at 70 degrees C. By employment of the chiral compounds 6-9, different ketones, including alkyl aryl, bulky tert-butyl, and cyclic ketones, have successfully been hydrogenated with enantioselectivities up to 99% and with S/C ratios of 5000-100,000 and TOFs of up to 4.1 x 10(4) h(-1) at 60 degrees C.

  7. Rotational Spectrum, Conformational Composition, and Quantum Chemical Calculations of Cyanomethyl Formate (HC(O)OCH2C≡N), a Compound of Potential Astrochemical Interest.

    PubMed

    Samdal, Svein; Møllendal, Harald; Carles, Sophie

    2015-08-27

    The rotational spectrum of cyanomethyl formate (HC(O)OCH2C≡N) has been recorded in the 12–123 GHz spectral range. The spectra of two conformers were assigned. The rotamer denoted I has a symmetry plane and two out-of plane hydrogen atoms belonging to the cyanomethyl (CH2CN) moiety. In the conformer called II, the cyanomethyl group is rotated 80.3° out of this plane. Conformer I has an energy that is 1.4(6) kJ/mol lower than the energy of II according to relative intensity measurements. A large number of rotational transitions have been assigned for the ground and vibrationally excited states of the two conformers and accurate spectroscopic constants have been obtained. These constants should predict frequencies of transitions outside the investigated spectral range with a very high degree of precision. It is suggested that cyanomethyl formate is a potential interstellar compound. This suggestion is based on the fact that its congener methyl formate (HC(O)OCH3) exists across a large variety of interstellar environments and the fact that cyanides are very prevalent in the Universe. The experimental work has been augmented by high-level quantum chemical calculations. The CCSD/cc-pVQZ calculations are found to predict structures of the two forms that are very close to the Born–Oppenheimer equilibrium structures. MP2/cc-pVTZ predictions of several vibration–rotation interaction constants were generally found to be rather inaccurate. A gas-phase reaction between methyl formate and the cyanomethyl radical CH2CN to produce a hydrogen atom and cyanomethyl formate was mimicked using MP2/cc-pVTZ calculations. It was found that this reaction is not favored thermodynamically. It is also conjectured that the possible formation of cyanomethyl formate might be catalyzed and take place on interstellar particles.

  8. Forskolebarn och TV.

    ERIC Educational Resources Information Center

    Sonesson, Inga

    This analysis of the relationship between mothers' attitudes toward TV and children's viewing habits, and the relationships between this behavior and the personal and/or social problems of the child, is based on data gathered in interviews with 250 preschool children, their mothers, and their teachers. Findings indicate a positive correlation…

  9. Atmospheric chemistry of C4F9OC2H5 (HFE-7200), C4F9OCH3 (HFE-7100), C3F7OCH3 (HFE-7000) and C3F7CH2OH: temperature dependence of the kinetics of their reactions with OH radicals, atmospheric lifetimes and global warming potentials.

    PubMed

    Bravo, Iván; Díaz-de-Mera, Yolanda; Aranda, Alfonso; Smith, Kevin; Shine, Keith P; Marston, George

    2010-05-21

    The atmospheric chemistry of several gases used in industrial applications, C(4)F(9)OC(2)H(5) (HFE-7200), C(4)F(9)OCH(3) (HFE-7100), C(3)F(7)OCH(3) (HFE-7000) and C(3)F(7)CH(2)OH, has been studied. The discharge flow technique coupled with mass-spectrometric detection has been used to study the kinetics of their reactions with OH radicals as a function of temperature. The infrared spectra of the compounds have also been measured. The following Arrhenius expressions for the reactions were determined (in units of cm(3) molecule(-1) s(-1)): k(OH + HFE-7200) = (6.9(-1.7)(+2.3)) x 10(-11) exp(-(2030 +/- 190)/T); k(OH + HFE-7100) = (2.8(-1.5)(+3.2)) x 10(-11) exp(-(2200 +/- 490)/T); k(OH + HFE-7000) = (2.0(-0.7)(+1.2)) x 10(-11) exp(-(2130 +/- 290)/T); and k(OH + C(3)F(7)CH(2)OH) = (1.4(-0.2)(+0.3)) x 10(-11) exp(-(1460 +/- 120)/T). From the infrared spectra, radiative forcing efficiencies were determined and compared with earlier estimates in the literature. These were combined with the kinetic data to estimate 100-year time horizon global warming potentials relative to CO(2) of 69, 337, 499 and 36 for HFE-7200, HFE-7100, HFE-7000 and CF(3)CF(2)CF(2)CH(2)OH, respectively.

  10. Dinuclear [(V(V)O(putrebactin))2(μ-OCH3)2] formed in solution as established from LC-MS measurements using 50V-enriched V2O5.

    PubMed

    Soe, Cho Zin; Pakchung, Amalie A H; Codd, Rachel

    2014-06-02

    Analysis of 1:1 solutions of V(V) and the macrocyclic dihydroxamic acid siderophore putrebactin (pbH2) in 1:1 H2O/CH3OH using triple quadrupole liquid chromatography-mass spectrometry (LC-MS-QQQ) (pH ≈ 4) showed two well-resolved peaks (tR(1) 10.85 min; tR(2) 14.27 min) using simultaneous detection modes (absorbance, 450 nm; selective ion monitoring, m/z 437) characteristic of the previously identified oxidoV(V) complex [V(V)O(pb)](+) ([M](+), m/zcalc 437.1). Peak 1 gave mass spectrometry (MS) signals consistent with [V(V)O(pb)](+), together with [V(V)O(pb)(OH)] and the dinuclear complexes [(V(V)O(pb))2(μ-OH)](+) and [(V(V)O(pb))2(μ-OH)2]. Peak 2 gave MS signals consistent with [V(V)O(pb)](+), together with [V(V)O(pb)(OCH3)] and the dinuclear complexes [(V(V)O(pb))2(μ-OCH3)](+) and [(V(V)O(pb))2(μ-OCH3)2]. This analysis showed that two groups of V(V)/pbH2 complexes with water- or methanol-derived ancillary ligands were resolved by liquid chromatography (LC). The detection of [V(V)O(pb)](+) in both peaks could be accounted for by its production from dissociation (peak 1: [(V(V)O(pb))2(μ-OH)](+) → [V(V)O(pb)](+) + [V(V)O(pb)(OH)]; peak 2: [(V(V)O(pb))2(μ-OCH3)](+) → [V(V)O(pb)](+) + [V(V)O(pb)(OCH3)]). The assignment of the signal at m/zobs 959.2 (100%) as the dinuclear complex [(V(V)O(pb))2(μ-OCH3)2] ([M + Na(+)](+), m/zcalc 959.3) and not an ion cluster of mononuclear [V(V)O(pb)(OCH3)] ({2[M] + Na(+)}(+), m/zcalc 959.3) was made unequivocal by the use of (50)V-enriched V2O5, which gave a signal with an isotope pattern comprising the sum of the patterns of the three constituent (51)V-(51)V, (51)V-(50)V, and (50)V-(50)V species. Coordination of methoxide was confirmed upon the replacement of CH3OH with CD3OD, which generated [(V(V)O(pb))2(μ-OCD3)2] ([M + Na(+)](+), m/zcalc 965.3, m/zobs 965.3). Analysis of 1:1 solutions of Mo(VI) and pbH2 showed a single peak in the LC (tR 16.04 min), which gave MS signals that were characterized as mononuclear [Mo

  11. Evaluation of a Novel Approach for Peptide Sequencing: Laser-induced Acoustic Desorption Combined with P(OCH3)2+ Chemical Ionization and Collision-activated Dissociation in a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer

    PubMed Central

    Somuramasami, Jayalakshmi; Kenttämaa, Hilkka I.

    2007-01-01

    A novel mass spectrometric method has been developed for obtaining sequence information on small peptides. The peptides are desorbed as intact neutral molecules into a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR) by means of laser-induced acoustic desorption (LIAD). Reactions of the neutral peptides with the dimethoxyphosphenium ion, P(OCH3)2+, occur predominantly by addition of the peptide to P(OCH3)2+ followed by the loss of two methanol molecules, thus yielding product ions with the composition (peptide + P − 2H)+. Upon sustained off-resonance irradiation for collision-activated dissociation (SORI-CAD), the (peptide + P − 2H)+ ions undergo successive losses of CO and NH = CHR or H2O, CO, and NH = CHR to yield sequence-related fragment ions in addition to the regular an- and bn-type ions. Under the same conditions, SORI-CAD of the analogous protonated peptides predominantly yields the regular an- and bn-type ions. The mechanisms of the reactions of peptides with P(OCH3)2+ and the dissociation of the (peptide + P − 2H)+ ions were examined by using model peptides and molecular orbital calculations. PMID:17157527

  12. Evaluation of a novel approach for peptide sequencing: laser-induced acoustic desorption combined with P(OCH(3))(2)(+) chemical ionization and collision-activated dissociation in a Fourier transform ion cyclotron resonance mass spectrometer.

    PubMed

    Somuramasami, Jayalakshmi; Kenttämaa, Hilkka I

    2007-03-01

    A novel mass spectrometric method has been developed for obtaining sequence information on small peptides. The peptides are desorbed as intact neutral molecules into a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR) by means of laser-induced acoustic desorption (LIAD). Reactions of the neutral peptides with the dimethoxyphosphenium ion, P(OCH(3))(2)(+), occur predominantly by addition of the peptide to P(OCH(3))(2)(+) followed by the loss of two methanol molecules, thus yielding product ions with the composition (peptide + P - 2H)(+). Upon sustained off-resonance irradiation for collision-activated dissociation (SORI-CAD), the (peptide + P - 2H)(+) ions undergo successive losses of CO and NHCHR or H(2)O, CO, and NHCHR to yield sequence-related fragment ions in addition to the regular a(n)- and b(n)-type ions. Under the same conditions, SORI-CAD of the analogous protonated peptides predominantly yields the regular a(n)- and b(n)-type ions. The mechanisms of the reactions of peptides with P(OCH(3))(2)(+) and the dissociation of the (peptide + P - 2H)(+) ions were examined by using model peptides and molecular orbital calculations.

  13. Global Uncertainty Propagation and Sensitivity Analysis in the CH3OCH2 + O2 System: Combining Experiment and Theory To Constrain Key Rate Coefficients in DME Combustion.

    PubMed

    Shannon, R J; Tomlin, A S; Robertson, S H; Blitz, M A; Pilling, M J; Seakins, P W

    2015-07-16

    Statistical rate theory calculations, in particular formulations of the chemical master equation, are widely used to calculate rate coefficients of interest in combustion environments as a function of temperature and pressure. However, despite the increasing accuracy of electronic structure calculations, small uncertainties in the input parameters for these master equation models can lead to relatively large uncertainties in the calculated rate coefficients. Master equation input parameters may be constrained further by using experimental data and the relationship between experiment and theory warrants further investigation. In this work, the CH3OCH2 + O2 system, of relevance to the combustion of dimethyl ether (DME), is used as an example and the input parameters for master equation calculations on this system are refined through fitting to experimental data. Complementing these fitting calculations, global sensitivity analysis is used to explore which input parameters are constrained by which experimental conditions, and which parameters need to be further constrained to accurately predict key elementary rate coefficients. Finally, uncertainties in the calculated rate coefficients are obtained using both correlated and uncorrelated distributions of input parameters.

  14. Investigating the H2-He-H2O-CH4 equation of state in the deep troposphere of Jupiter

    NASA Astrophysics Data System (ADS)

    Karpowicz, Bryan M.; Steffes, Paul G.

    2013-03-01

    In this work, a new equation of state for a H2-He-H2O-CH4 mixture is presented. The equation is optimized for the deep jovian atmosphere (∼100 bars) where the NASA Juno Microwave Radiometer (MWR) will probe. The methodology used is based upon that of Lemmon and Jacobsen (Lemmon, E.W., Jacobsen, R.T. [2004]. J. Phys. Chem. Ref. Data 33, 593-+) and Kunz et al. (Kunz, O., Klimeck, R., Wagner, W., Jaeschke, M. [2006]. Technical Monograph, VDI-Verlag). This methodology is used in combination with available published thermodynamic measurements and with new pressure-Volume-Temperature (pVT) measurements of H2-H2O mixtures conducted with the jovian simulator described in Karpowicz and Steffes (Karpowicz, B.M., Steffes, P.G. [2011]. Icarus 212, 210-223). In addition to being necessary to interpret laboratory measurements, the new equation of state is important in developing temperature pressure profiles of the deep jovian atmosphere. This is demonstrated by incorporating the new equation of state into an updated version of the DeBoer (DeBoer, D.R. [1995]. Ph.D. Thesis, Georgia Institute of Technology) Thermo-Chemical Model (TCM), and viewing its effect on the resulting simulated jovian atmospheric profiles.

  15. H2O-CH4 and H2S-CH4 complexes: a direct comparison through molecular beam experiments and ab initio calculations.

    PubMed

    Cappelletti, David; Bartocci, Alessio; Frati, Federica; Roncaratti, Luiz F; Belpassi, Leonardo; Tarantelli, Francesco; Lakshmi, Prabha Aiswarya; Arunan, Elangannan; Pirani, Fernando

    2015-11-11

    New molecular beam scattering experiments have been performed to measure the total (elastic plus inelastic) cross sections as a function of the velocity in collisions between water and hydrogen sulfide projectile molecules and the methane target. Measured data have been exploited to characterize the range and strength of the intermolecular interaction in such systems, which are of relevance as they drive the gas phase molecular dynamics and the clathrate formation. Complementary information has been obtained by rotational spectra, recorded for the hydrogen sulfide-methane complex, with a pulsed nozzle Fourier transform microwave spectrometer. Extensive ab initio calculations have been performed to rationalize all the experimental findings. The combination of experimental and theoretical information has established the ground for the understanding of the nature of the interaction and allows for its basic components to be modelled, including charge transfer, in these weakly bound systems. The intermolecular potential for H2S-CH4 is significantly less anisotropic than for H2O-CH4, although both of them have potential minima that can be characterized as 'hydrogen bonded'.

  16. On the Formation of the C2H6O Isomers Ethanol (C2H5OH) and Dimethyl Ether (CH3OCH3) in Star-forming Regions

    NASA Astrophysics Data System (ADS)

    Bergantini, Alexandre; Maksyutenko, Pavlo; Kaiser, Ralf I.

    2017-06-01

    The structural isomers ethanol (CH3CH2OH) and dimethyl ether (CH3OCH3) were detected in several low-, intermediate-, and high-mass star-forming regions, including Sgr B2, Orion, and W33A, with the relative abundance ratios of ethanol/dimethyl ether varying from about 0.03 to 3.4. Until now, no experimental data regarding the formation mechanisms and branching ratios of these two species in laboratory simulation experiments could be provided. Here, we exploit tunable photoionization reflectron time-of-flight mass spectrometry (PI-ReTOF-MS) to detect and analyze the production of complex organic molecules (COMs) resulting from the exposure of water/methane (H2O/CH4) ices to energetic electrons. The main goal is to understand the formation mechanisms in star-forming regions of two C2H6O isomers: ethanol (CH3CH2OH) and dimethyl ether (CH3OCH3). The results show that the experimental branching ratios favor the synthesis of ethanol versus dimethyl ether (31 ± 11:1). This finding diverges from the abundances observed toward most star-forming regions, suggesting that production routes on interstellar grains to form dimethyl ether might be missing; alternatively, ethanol can be overproduced in the present simulation experiments, such as via radical-radical recombination pathways involving ethyl and hydroxyl radicals. Finally, the PI-ReTOF-MS data suggest the formation of methylacetylene (C3H4), ketene (CH2CO), propene (C3H6), vinyl alcohol (CH2CHOH), acetaldehyde (CH3CHO), and methyl hydroperoxide (CH3OOH), in addition to ethane (C2H6), methanol (CH3OH), and CO2 detected from infrared spectroscopy. The yield of all the confirmed species is also determined.

  17. Oxovanadium alkoxides: Structure, reactivity, and sup 51 V NMR characteristics. Crystal and molecular structures of VO(OCH sub 2 CH sub 2 Cl) sub 3 and VOCl sub 2 (THF) sub 2 H sub 2 O

    SciTech Connect

    Priebsch, W.; Rehder, D. )

    1990-08-08

    The vanadyl esters VO(OR){sub 3} (R = Me, Et, Pr, iPr, sBu, tBu, CH{sub 2}CH{sub 2}F, CH{sub 2}CH{sub 2}Cl, CH{sub 2}CCl{sub 3}) have been prepared and their association properties in pentane investigated by {sup 51}V NMR. Limiting (low concentration) {delta}({sup 51}V) values depend on the bulk of R (highest {sup 51}V shielding for tBu). Shielding decreases with increasing concentration (more pronounced for small R groups), owing to the formation of oligomers, probably connected by {mu}-OR groups. The X-ray diffraction study of VO(OCH{sub 2}CH{sub 2}Cl){sub 3} reveals dimer association of molecules belonging to adjacent unit cells via long V-OR bonds (226.1 (2) pm), and a trigonal-bipyramidal geometry for each monomeric unit. From the reaction between VOCl{sub 3} and diols (glycol, 1,3-propanediol, 1,2-, 2,3-, 1,3-, and 1,4-butanediol), complexes are obtained that contain the {l brace}VOCl(OR){sub 2}{r brace} and {l brace}VOCl{sub 2}OR{r brace} moieties and the alcohol coordinated in the monofunctional or bifunctional (chelating and bridging) mode. The {sup 51}V NMR spectrum of VOCl{sub 2}OCH(Me)CH(Me)OH exhibits resolved {sup 51}V-{sup 35,37}Cl coupling: J({sup 51}V-{sup 35}Cl) = 100 Hz; J({sup 51}V-{sup 37}Cl) = 83 Hz. V{sup V}OCl{sub 2}(OCH{sub 2}CH{sub 2}CH{sub 2}OH) reacts with 1,4-butanediol to form V{sup IV}OCl{sub 2}(THF){sub 2}(OH{sub 2}). In the presence of COCL{sub 3}, THF undergoes ether splitting, chlorination, and coordination to vanadium to yield VOCl{sub 2}(OCH{sub 2}CH{sub 2}CH{sub 2}CH{sub 2}Cl). 35 refs., 7 figs., 7 tabs.

  18. Enthalpy of hydrophobic hydration separately estimated for each -CH2-, -CF2-, and -OCH2CH2- unit component of amphiphiles and of related compounds.

    PubMed

    Seimiya, Tsutomu

    2003-10-15

    The enthalpy of hydrophobic hydration, DeltaH(HH), was separately estimated for each apolar segment of amphiphiles and of related compounds. The specimens analyzed in this study were the homologs and analogs of sodium alkyl sulfate, alkyltrimethylammonium bromide, ammonium perfluoroalkylcarboxylate, and polyethylene glycols. The DeltaH(HH) was calculated from the adiabatic compressibility beta of aqueous solution systematically measured for each homologs at varying concentrations and temperatures. Those data reported in the previous paper were utilized. The DeltaH(HH) estimated for each -CH(2)-, -CF(2)-, and -OCH(2)CH(2)- segments in both hydrophobic and hydrophilic parts of the amphiphiles was found to change depending on its locations in the molecule. The DeltaH(HH) for the first -CH(2)- unit which is adjacent to the head sulfate group of H(CH(2))(n)SO(4)Na was found to be negligibly small; however, it increases gradually as the position of the unit moves apart from the anionic head group and attains as large as -26.5 kcal/mol for the eighth -CH(2)-. The change of DeltaH(HH) of -CF(2)- unit in F(CF(2))(n)COONH(4) shows the similar tendency to H(CH(2))(n)SO(4)Na. The value of DeltaH(HH) is as small as -8 kcal/mol for the first -CF(2)-, however, it increases to -16 kcal/mol for the fifth -CF(2)-, which is 1.5 times larger than that of the fifth -CH(2)- of alkyl sulfate. Contrary to this, all the DeltaH(HH) of the methylenes of cationic surfactant ranging from the second to the eighth -CH(2)- units of H(CH(2))(n)N(CH(3))(3)Br take a similar value around -8 kcal/mol of -CH(2)- irrespective of their positions. The first -CH(2)- unit which is equivalent to that of quaternary ammonium [HCH(2)](4)NBr shows slightly higher value of -9.0 kcal/mol of the first -CH(2)- than those for the second to eighth -CH(2)-. This seems to suggest that the cationic core nitrogen has an enhancing effect on hydrophobic hydration. The hydration enthalpy DeltaH(OEH) of each oxyethylene (OE

  19. Correlation between stress-induced leakage current and dielectric degradation in ultra-porous SiOCH low-k materials

    SciTech Connect

    Wu, C. De Wolf, I.; Li, Y.; Leśniewska, A.; Varela Pedreira, O.; Marneffe, J.-F. de; Ciofi, I.; Verdonck, P.; Baklanov, M. R.; Bömmels, J.; Tőkei, Zs.; Croes, K.

    2015-10-28

    Stress-Induced Leakage Current (SILC) behavior during the dielectric degradation of ultra-porous SiOCH low-k materials was investigated. Under high voltage stress, SILC increases to a critical value before final hard breakdown. This SILC increase rate is mainly driven by the injected charges and is negligibly influenced by temperature and voltage. SILC is found to be transient and shows a t{sup −1} relaxation behavior, where t is the storage time at low voltages. This t{sup −1} transient behavior, described by the tunneling front model, is caused by both electron charging of neutral defects in the dielectric close to the cathode interface and discharging of donor defects close to the anode interface. These defects have a uniform density distribution within the probed depth range, which is confirmed by the observed flat band voltage shift results collected during the low voltage storage. By applying an additional discharging step after the low voltage storage, the trap energies and spatial distributions are derived. In a highly degraded low-k dielectric, the majority of defects have a trap depth between 3.4 eV and 3.6 eV and a density level of 1 × 10{sup 18 }eV{sup −1 }cm{sup −3}. The relation between the defect density N and the total amount of the injected charges Q is measured to be sub-linear, N ∼ Q{sup 0.45±0.07}. The physical nature of these stress-induced defects is suggested to be caused by the degradation of the Si-O based skeleton in the low-k dielectric.

  20. The Golgi α-1,6 mannosyltransferase KlOch1p of Kluyveromyces lactis is required for Ca2+/calmodulin-based signaling and for proper mitochondrial functionality

    PubMed Central

    2009-01-01

    Background Protein N-glycosylation is a relevant metabolic pathway in eukaryotes and plays key roles in cell processes. In yeasts, outer chain branching is initiated in the Golgi apparatus by the alpha-1,6-mannosyltransferase Och1p. Results Here we report that, in Kluyveromyces lactis, this glycosyltransferase is also required to maintain functional mitochondria and calcium homeostasis. Cells carrying a mutation in KlOCH1 gene showed altered mitochondrial morphology, increased accumulation of ROS and reduced expression of calcium signalling genes such as calmodulin and calcineurin. Intracellular calcium concentration was also reduced in the mutant cells with respect to the wild type counterparts. Phenotypes that occur in cells lacking the alpha-1,6-mannosyltransferase, including oxidative stress and impaired mitochondria functionality, were suppressed by increased dosage of KlCmd1p. This, in turn, acts through the action of calcineurin. Conclusions Proper functioning of the alpha-1,6-mannosyltransferase in the N-glycosylation pathway of K. lactis is required for maintaining normal calcium homeostasis; this is necessary for physiological mitochondria dynamics and functionality. PMID:20003441

  1. Fluid evolution in the H 2O-CH 4-CO 2-NaCl system during emerald mineralization at Gravelotte, Murchison Greenstone Belt, Northeast Transvaal, South Africa

    NASA Astrophysics Data System (ADS)

    Nwe, Yin Yin; Morteani, Giulio

    1993-01-01

    Fluid evolution during emerald mineralization at the Gravelotte emerald mine has been studied by microthermometry and laser Raman microprobe spectrometry. The emeralds and associated phenakites occur on the flanks of a highly metasomatised albitite pegmatoid body and in the biotite schists at and near its contact. The fluids lie in the H 2O-CH 4-CO 2-NaCl system and four types of inclusions are characterised based on time of trapping and fluid contents. The earliest type 1 inclusions, found in phenakites and the emeralds which formed from them, are low salinity (<6 wt% NaCl) with up to 18 mol% CH 4. The carbonic phase contains over 93 mol% CH 4 and variable small amounts of CO 2, C 2H 6, N 2, and H 2S. The solvus crest for this system lies at ≈400°C, closer to the H 2O end of the join. With time the fluids become less CH 4 rich and more saline. The type 2 fluids are highly variable in both CH 4-CO 2 contents and salinity, reflecting mixing of type 1 fluids with higher salinity brines. The late type 3 and 4 inclusions are CH 4-CO 2-free high salinity inclusions with up to 38 wt% NaCl. Trapping conditions for the type 1 fluids were around 450-500°C and 4 kb based on model isochores and geologic evidence. During the trapping of type 2 inclusions, fluid pressures probably fluctuated due to opening and resealing of fractures. Approximate P- T ranges of trapping for these and other later inclusions have been defined, minimum trapping temperatures for types 2, 3, and 4 being, respectively, 250, 150, and 240°C, and pressures in the range of 1-4 kb. Calculations of ƒ O 2 show an initial low ƒ O 2 between QFM and the synthetic graphite-CH 4 buffer for the type 1 fluids. This rises to above QFM in the later stages. Such low initial values are uncharacteristic of granitic pegmatite systems, and it is suggested that the phenakites formed in the post-magmatic stage of alkali metasomatism when the albitization took place. In the later stages, phenakite was converted to

  2. Synthesis, structure and reactivity of rare-earth metallacarborane alkyls [η(1):η(5)-O(CH2)2C2B9H9]Ln(σ:η(1)-CH2C6H4-o-NMe2)(THF)2.

    PubMed

    Yang, Jingying; Xie, Zuowei

    2015-04-14

    Rare-earth metallacarborane alkyls can be stabilized by the incorporation of a functional sidearm into both π and σ ligands. Reaction of [Me3NH][7,8-O(CH2)2-7,8-C2B9H10] with one equiv. of Ln(CH2C6H4-o-NMe2)3 gave metallacarborane alkyls [η(1):η(5)-O(CH2)2C2B9H9]Ln(σ:η(1)-CH2C6H4-o-NMe2)(THF)2 (Ln = Y (), Gd (), Er ()) via alkane elimination. They represent the first examples of rare-earth metallacarborane alkyls. Treatment of with RN[double bond, length as m-dash]C[double bond, length as m-dash]NR (R = Cy, (i)Pr) or 2-benzoylpyridine afforded the corresponding mono-insertion products [η(1):η(5)-O(CH2)2C2B9H9]Y[η(2)-(RN)2C(CH2C6H4-o-NMe2)](DME) (R = Cy (), (i)Pr ()) or [η(1):η(5)-O(CH2)2C2B9H9]Y[C5H4NC(Ph)(CH2C6H4-o-NMe2)O](THF)2 (), respectively. Complex also reacted with ArNCO or ArNC (Ar = 2,6-diisopropylphenyl, 2,6-dimethylphenyl) to give di-insertion products [η(1):η(5)-O(CH2)2C2B9H9]Y[OC([double bond, length as m-dash]NC6H3Me2)N(C6H3Me2)C(CH2C6H4-o-NMe2)O](THF)2 () or [η(1):η(5)-O(CH2)2C2B9H9]Y[C([double bond, length as m-dash]NC6H3(i)Pr2)C([double bond, length as m-dash]NC6H3(i)Pr2)(CH2C6H4-o-NMe2)](DME) (). These results showed that the reactivity pattern of the Ln-C σ bond in rare-earth metallacarborane alkyls was dependent on the nature of the unsaturated organic molecules. New complexes were characterized by various spectroscopic techniques and elemental analysis. Some were further confirmed by single-crystal X-ray analysis.

  3. Transfer of Amide and 2-Methoxyethoxy Groups and Sodium Encapsulation in the Reaction of TaCl3[N(TMS)2]2 with Sodium Bis(2-methoxyethoxy)aluminum Hydride: X-ray Structure of [NaAl{N(TMS)2}(OCH2CH2OMe)3]2

    SciTech Connect

    Huang, Shih-Huang Huang; Wang, Xiaoping; Richmond, Michael G.

    2009-01-01

    The reaction between the tantalum compound TaCl3[N(TMS)2]2 and the hydridic reducing agent sodium bis(2-methoxyethoxy)aluminum hydride (Vitride) has been investigated in toluene solution at room temperature and found to afford the dimeric aluminate complex [NaAl{N(TMS)2}(OCH2CH2OMe)3]2 as the sole isolable product. The molecular structure of the product establishes the existence of a four-coordinate aluminum atom and the formal transfer of the 2-methoxyethoxy and bis(trimethylsilyl)amide groups to the aluminate product. The aggregation of two NaAl{N(TMS)2}(OCH2CH2OMe)3 units serves to bind the two sodium cations in a crown-ether fashion through six ancillary oxygen atoms.

  4. VAPOR PRESSURES, LIQUID MOLAR VOLUMES, VAPOR NON- IDEALITIES, AND CRITICAL PROPERTIES OF SOME FLUORINATED ETHERS: CF3OCF2OCF3, CF3OCF2 CF2H, c-CF2CF2CF2O, CF3OCF2H, AND CF3OCH3; AND OF CCl3F AND CF2ClH

    EPA Science Inventory

    Vapor pressures, compressibilities, expansivities, and molar volumes of the liquid phase have been measured between room temperature and the critical temperature for a series of fluorinated ethers: CF3OCF2OCF3, CF3OCF2CF2H, c-CF2CF2CF2O, CF3OCF2H, and CF3OCH3. Vapor-phase non-ide...

  5. VAPOR PRESSURES, LIQUID MOLAR VOLUMES, VAPOR NON- IDEALITIES, AND CRITICAL PROPERTIES OF SOME FLUORINATED ETHERS: CF3OCF2OCF3, CF3OCF2 CF2H, c-CF2CF2CF2O, CF3OCF2H, AND CF3OCH3; AND OF CCl3F AND CF2ClH

    EPA Science Inventory

    Vapor pressures, compressibilities, expansivities, and molar volumes of the liquid phase have been measured between room temperature and the critical temperature for a series of fluorinated ethers: CF3OCF2OCF3, CF3OCF2CF2H, c-CF2CF2CF2O, CF3OCF2H, and CF3OCH3. Vapor-phase non-ide...

  6. Synthesis and characterization of a new monophosphate (5-Cl-2,4-(OCH{sub 3}){sub 2}C{sub 6}H{sub 2}NH{sub 3})H{sub 2}PO{sub 4}

    SciTech Connect

    Kefi, R.; Abid, S.; Nasr, C. Ben . E-mail: cherif.bennasr@fsb.rnu.tn; Rzaigui, M.

    2007-03-22

    Chemical preparation, crystal structure and NMR spectroscopy of a new organic cation 5-chloro(2,4-dimethoxy)anilinium monophosphate H{sub 2}PO{sub 4} are given. This new compound crystallizes in the monoclinic system, with the space group P2{sub 1}/c and the following parameters: a=5.524(2)A, b=9.303(2)A, c=23.388(2)A, {beta}=90.66(4), V=1201.8(2)A{sup 3}, Z=4 and D{sub x}=1.573gcm{sup -3}. Crystal structure has been determined and refined to R=0.031 and R{sub w}=0.080 using 1702 independent reflections. Structure can be described as an infinite (H{sub 2}PO{sub 4}){sub n}{sup n-} corrugated chains in the a-direction. The organic groups (5-Cl-2,4-(OCH{sub 3}){sub 2}C{sub 6}H{sub 2}NH{sub 3}){sup +} are anchored between adjacent polyanions through multiple hydrogen bonds. This compound is also investigated by IR, thermal, and solid-state, {sup 13}C, {sup 31}P MAS NMR spectroscopies.

  7. Photochemical properties of hydrofluoroethers CH3OCHF2, CH3OCF3, and CHF2OCH2CF3: reactivity toward OH, IR absorption cross sections, atmospheric lifetimes, and global warming potentials.

    PubMed

    Orkin, Vladimir L; Khamaganov, Victor G; Guschin, Andrey G

    2014-11-13

    Rate constants for the gas phase reactions of OH radicals with three partially fluorinated ethers, CH3OCF3 (kHFE-143a), CH3OCHF2 (kHFE-152a), and CHF2OCH2CF3 (kHFE-245fa2), were measured using a discharge flow-electron paramagnetic resonance technique over the temperature range 298-460 K. The temperature dependences of the rate constants can be represented by the following expressions: kHFE-143a(T) = (1.10 ± 0.20) × 10(-12) × exp{-(1324 ± 61)/T} cm(3) molecule(-1) s(-1); kHFE-152a(T) = (11.6 ± 4.2) × 10(-12) × exp{-(1728 ± 133)/T} cm(3) molecule(-1) s(-1); and kHFE-245fa2(T) = (3.04 ± 0.57) × 10(-12) × exp{-(1665 ± 66)/T} cm(3) molecule(-1) s(-1). The atmospheric lifetimes due to reactions with tropospheric OH were estimated to be 5.2, 1.9, and 5.6 years, respectively. The IR absorption cross sections of these fluorinated ethers were measured between 400 and 2000 cm(-1), and their global warming potentials were estimated.

  8. [Ni(OH)3W6O18(OCH2)3CCH2OH]4–: the first tris-functionalized Anderson-type heteropolytungstate† †Electronic supplementary information (ESI) available: Experimental procedures, synthesis details, characterization data, including IR, ESI-MS, TGA, elemental analysis and X-ray crystallography with CIF file. CCDC 1477611. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c6cc04326g Click here for additional data file. Click here for additional data file.

    PubMed Central

    Gumerova, Nadiia I.; Roller, Alexander

    2016-01-01

    Na2[TMA]2[Ni(OH)3W6O18(OCH2)3CCH2OH]·9H2O represents the first covalent tris-functionalized Anderson-type heteropolytungstate and was characterized by single-crystal X-ray diffraction, electrospray ionization mass spectrometry, TGA and IR spectroscopy. Zeta potential measurements in solutions containing human serum albumin were performed to investigate electrostatic interactions with [Ni(OH)3W6O18(OCH2)3CCH2OH]4–. PMID:27355393

  9. Structure of the puf operon of the obligately aerobic, bacteriochlorophyll alpha-containing bacterium Roseobacter denitrificans OCh114 and its expression in a Rhodobacter capsulatus puf puc deletion mutant.

    PubMed Central

    Kortlüke, C; Breese, K; Gad'on, N; Labahn, A; Drews, G

    1997-01-01

    Roseobacter denitrificans (Erythrobacter species strain OCh114) synthesizes bacteriochlorophyll a (BChl) and the photosynthetic apparatus only in the presence of oxygen and is unable to carry out primary photosynthetic reactions and to grow photosynthetically under anoxic conditions. The puf operon of R. denitrificans has the same five genes in the same order as in many photosynthetic bacteria, i.e., pufBALMC. PufC, the tetraheme subunit of the reaction center (RC), consists of 352 amino acids (Mr, 39,043); 20 and 34% of the total amino acids are identical to those of PufC of Chloroflexus aurantiacus and Rubrivivax gelatinosus, respectively. The N-terminal hydrophobic domain is probably responsible for anchoring the subunit in the membrane. Four heme-binding domains are homologous to those of PufC in several purple bacteria. Sequences similar to pufQ and pufX of Rhodobacter capsulatus were not detected on the chromosome of R. denitrificans. The puf operon of R. denitrificans was expressed in trans in Escherichia coli, and all gene products were synthesized. The Roseobacter puf operon was also expressed in R. capsulatus CK11, a puf puc double-deletion mutant. For the first time, an RC/light-harvesting complex I core complex was heterologously synthesized. The strongest expression of the R. denitrificans puf operon was observed under the control of the R. capsulatus puf promoter, in the presence of pufQ and pufX and in the absence of pufC. Charge recombination between the primary donor P+ and the primary ubiquinone Q(A)- was observed in the transconjugant, showing that the M and L subunits of the RC were correctly assembled. The transconjugants did not grow photosynthetically under anoxic conditions. PMID:9286973

  10. Ab Initio Variational Transition State Theory and Master Equation Study of the Reaction of (OH){sub 3}SiOCH{sub 2} + CH{sub 3} {<- ->} (OH){sub 3}SiOC{sub 2}H{sub 5}

    SciTech Connect

    Nurkowski, Daniel; Klippenstein, Stephen J.; Georgievskii, Yuri; Verdicchio, Marco; Jasper, Ahren W.; Akroyd, Jethro; Mosbach, Sebastian; Kraft, Markus

    2015-05-01

    In this paper we use variable reaction coordinate variational transition state theory (VRC-TST) to calculate the reaction rate constants for the two reactions, R1: (OH)(3)SiOCH2 + CH3 reversible arrow (OH)(3)SiOC2H5, and R2: CH2OH + CH3 reversible arrow C2H5OH. The first reaction is an important channel during the thermal decomposition of tetraethoxysilane (TEOS), and its rate coefficient is the main focus of this work. The second reaction is analogous to the first and is used as a basis for comparison. The interaction energies are obtained on-the-fly at the CASPT2(2e,2o)/cc-pVDZ level of theory. A one-dimensional correction to the sampled energies was introduced to account for the energetic effects of geometry relaxation along the reaction path. The computed, high-pressure rate coefficients were calculated to be, R1: k(1) = 2.406x10(-10)T(-0.301) exp(-271.4/T) cm(3) molecule(-1) s(-1) and R2: k(2) = 1.316x10(-10)T(-0.189) exp(-256.5/T) cm(3) molecule(-1) s(-1). These rates differ fromeach other by only 10%-30% over the temperature range 300-2000 K. A comparison of the computed rates with experimental data shows good agreement and an improvement over previous results. The pressure dependency of the reaction R1 is explored by solving a master equation using helium as a bath gas. The results obtained show that the reaction is only weakly pressure dependent over the temperature range 300-1700 K, with the predicted rate constant being within 50% of its high-pressure limit at atmospheric pressure.

  11. Magnetic and Thermal Properties of Low-Dimensional Single-Crystalline Transition-Metal Antimonates and Tantalates

    NASA Astrophysics Data System (ADS)

    Christian, Aaron Brandon

    This work contributes to the study of magnetic interactions in the low-dimensional antiferromagnets M(Sb,Ta)2O6, where M is a transition metal. By virtue of the trirutile structure, M-O-O-M chains propagate along [110] at z = 0 and [110] at z = 1/2 of the unit cell. These chains are separated along [001] by sheets of weakly-interacting diamagnetic ions. The spin-exchange coupling perpendicular to the chains is weak, permitting the low-dimensional classification. Single crystals have been grown using chemical vapor deposition and the floating zone method. Magnetization, in-field heat capacity, and high-resolution thermal expansion measurements have been performed along various axes, revealing significant anisotropy due to the peculiar magnetic structures and low dimensionality. The Neel temperature, TN, at which long-range order occurs is found to be unstable against the application of magnetic field above 2 T. Large fields tend to lower TN of the set of moments with projections along the applied field. Moments which are aligned perpendicular to the field are significantly less affected. This can lead to the formation of a secondary peak in heat capacity when magnetic field is along either [110] or [110]. The change in heat capacity at the location of the newly formed peak means there is a change in entropy, which depends upon the direction of applied field with respect to the magnetic moments. Consequently, an anisotropic magnetocaloric effect arises due to the unique magnetic structure. The anisotropic nature of this effect has potential applications in magnetic refrigeration.

  12. Structural consequences of the one-electron reduction of d4 [Mo(CO)2(eta-PhC[triple bond]CPh)Tp']+ and the electronic structure of the d5 radicals [M(CO)L(eta-MeC[triple bond]CMe)Tp'] {L = CO and P(OCH2)3CEt}.

    PubMed

    Adams, Christopher J; Bartlett, Ian M; Boonyuen, Supakorn; Connelly, Neil G; Harding, David J; Hayward, Owen D; McInnes, Eric J L; Orpen, A Guy; Quayle, Michael J; Rieger, Philip H

    2006-07-28

    Reduction of [M(CO)2(eta-RC[triple bond]CR')Tp']X {Tp' = hydrotris(3,5-dimethylpyrazolyl)borate, M = Mo, X = [PF6]-, R = R' = Ph, C6H4OMe-4 or Me; R = Ph, R' = H; M = W, X = [BF4]-, R = R' = Ph or Me; R = Ph, R' = H} with [Co(eta-C5H5)2] gave paramagnetic [M(CO)2(eta-RC[triple bond]CR')Tp'], characterised by IR and ESR spectroscopy. X-Ray structural studies on the redox pair [Mo(CO)2(eta-PhC[triple bond]CPh)Tp'] and [Mo(CO)2(eta-PhC[triple bond]CPh)Tp'][PF6] showed that oxidation is accompanied by a lengthening of the C[triple bond]C bond and shortening of the Mo-C(alkyne) bonds, consistent with removal of an electron from an orbital antibonding with respect to the Mo-alkyne bond, and with conversion of the alkyne from a three- to a four-electron donor. Reduction of [Mo(CO)(NCMe)(eta-MeC[triple bond]CMe)Tp'][PF6] with [Co(eta-C5H5)2] in CH2Cl2 gives [MoCl(CO)(eta-MeC[triple bond]CMe)Tp'], via nitrile substitution in [Mo(CO)(NCMe)(eta-MeC[triple bond]CMe)Tp'], whereas a similar reaction with [M(CO){P(OCH2)3CEt}(eta-MeC[triple bond]CMe)Tp']+ (M = Mo or W) gives the phosphite-containing radicals [M(CO){P(OCH2)3CEt}(eta-MeC[triple bond]CMe)Tp']. ESR spectroscopic studies and DFT calculations on [M(CO)L(eta-MeC[triple bond]CMe)Tp'] {M = Mo or W, L = CO or P(OCH2)3CEt} show the SOMO of the neutral d5 species (the LUMO of the d4 cations) to be largely d(yz) in character although much more delocalised in the W complexes. Non-coincidence effects between the g and metal hyperfine matrices in the Mo spectra indicate hybridisation of the metal d-orbitals in the SOMO, consistent with a rotation of the coordinated alkyne about the M-C2 axis.

  13. Swedish use and validation of Valpar work samples for patients with musculoskeletal neck and shoulder pain.

    PubMed

    Schult, M L; Söderback, I; Jacobs, K

    1995-01-01

    I studien beskrivs vad e bedömning av arbetskapacitet (BAK) innehåller Vid en bedömning av arbetskapacitet jämförs kraven för att utföra ett specifikt arbete, definierat i "The dictionary of Occupational Titles" (DOT), och patientens förmåga att utföra ett arbote vilket definieras med hjälp av sju variabler. Allmän utbildnings nivä. Speciella yrkesförberedelser. Anlag, Intresseområden, Personlig läggning. Fysiska drav och Miljöpåverkan. En bedömning av arbetskapaciteten kan ske antingen genom att observera patienten under arbete påarbetsplatsen eller under simulerat arbete tex genom att använda Valpar systemets arbetsprover.Vid Rehabiliteringsmedicinska kliniken, Karolinska Sjukhuset har tvä av de standardiserade arbetsprovema använts. VCWS 8 "Simulerad moontering" och VCWS 9 "Simulerade rorelser for hela kroppen" for att förbättra bedömningen av patientens arbetskapacitet. VCWS 8 mäter "en persons förmaga att utföra ett monteringsarbete som kräver repetetiva fysiska manipulationer" och VCWS 9 mäter "en persons formåga att röra på bålen, nacken, armarna, händerna och fingrama när de relaterar till funktionellt utförande av ett arbete". Valideringen av arbetsprovema för Svensk anvandning gjordes på en grupp patienter (n = 97) med muskuloskelettal nack- och skulder smärta som deltog i ett rehabiliteringsprogram. VCWS 9 utfördes av åttiofem patienter och VCWS 9 av sextionic patienter.Medelvärdet for patienterna som slutförde VCWS 8 var 83.1% av industriell standard nivå (mätt enligt MTM-Method-Time-Measurement) där den lä gsta gränsen är 87.5% för ett godkännt utförende. Detta innebär att de "inte moter" kraven för detta specifika arbete. I motsats till detta sä nädde patientema som utförde VCWS 9 ett medelvärde pä 108.6% vilket overstiger kravet (87.5%) för industriell standard. Det oväntade resultatet kan kanske förklaras av att patienternas intresseområden vad gäller arbetsfalt endast sammanfoll med

  14. {sup 203,205}Tl NMR Studies of Crystallographically Characterized Thallium Alkoxides. X-Ray Structures of [Tl(OCH{sub 2}CH{sub 3})]4 and [Tl(OAr)]{sub infinity} where OAr = OC{sub 6}H{sub 3}(Me){sub 2}-2,6 and OC{sub 6}H{sub 3}(Pr{sup i}){sub 2}-2,6

    SciTech Connect

    ZECHMANN,CECILIA A.; BOYLE,TIMOTHY J.; PEDROTTY,DAWN M.; ALAM,TODD M.; LANG,DAVID P.; SCOTT,BRIAN L.

    2000-07-25

    [Tl(OCH{sub 2}CH{sub 3})]{sub 4}, (1) was reacted with excess HOR to prepare a series of [Tl(OR)]{sub n} where OR= OCHMe{sub 2} (2, n = 4), OCMe{sub 3} (3, n = 4), OCH{sub 2}CMe{sub 3} (4, n = 4), OC{sub 6}H{sub 3}(Me){sub 2}-2,6 (5, n = {infinity}), and OC{sub 6}H{sub 3}(Pr{sup i}){sub 2}-2,6 (6, n = {infinity}). Single crystal X-ray diffraction was used to determine the structure of compounds ligated by more sterically demanding ligands. Compound 4 was found to adopt a cubane structure, while 5 and 6 formed linear polymeric structures. These compounds were additionally characterized by {sup 203,205}Tl solution and {sup 205}Tl solid state NMR. Compounds 1--4 were found to remain intact in solution while the polymeric species, 5 and 6, appeared to be fluxional. While variations in the solution and solid state structures for the tetrameric [Tl(OR)]{sub 4} and polymeric [Tl(OAr)]{sub {infinity}} may be influenced by the steric hindrance of their respective ligands, the covalency of the species is believed to be more an effect of the parent alcohol acidity.

  15. Vanadium complexes of the N(CH2CH2S)3(3-) and O(CH2CH2S)2(2-) ligands with coligands relevant to nitrogen fixation processes.

    PubMed

    Davies, S C; Hughes, D L; Janas, Z; Jerzykiewicz, L B; Richards, R L; Sanders, J R; Silverston, J E; Sobota, P

    hydrolysis and to [V(NS3)(NCPh3)] (11) by reaction with ClCPh3. Compound 10 is converted into 1 by [NMe4]OH and to [V(NS3)NLi(THF)2] (12) by LiNPri in THF. A further range of imido complexes [V(NS3)(NR4)] (R4 = C6H4Y-4 where Y = H (13a), OMe (13b), Me (13c), Cl (13d), Br (13e), NO2 (13f); R4 = C6H4Y-3, where Y = OMe (13g); Cl (13h); R4 = C6H3Y2-3,4, where Y = Me (13i); Cl (13j); R4 = C6H11 (13k)) has been prepared by reaction of 1 with R4NCO. The precursor complex [V(OS2)O(dipp)] (14) [OS2(2-) = O(CH2CH2S)2(2-)] has been prepared from [VO(OPri)3], Hdipp, and OS2H2. It reacts with NH2NMe2 to give [V(OS2)(NNMe2)(dipp)] (15) and with N3SiMe3 to give [V(OS2)(NSiMe3)(dipp)] (16). A second oxide precursor, formulated as [V(OS2)1.5O] (17), has also been obtained, and it reacts with SiMe3NHNMe2 to give [V(OS2)(NNMe2)(OSiMe3)] (18). The X-ray crystal structures of the complexes 2b, 2c, 4, 6, 7a, 8a, 9, 10, 13d, 14, 15, 16, and 18 have been determined, and the 51V NMR and other spectroscopic parameters of the complexes are discussed in terms of electronic effects.

  16. Theoretical insight into OH- and Cl-initiated oxidation of CF3OCH(CF3)2 and CF3OCF2CF2H & fate of CF3OC(X•)(CF3)2 and CF3OCF2CF2X• radicals (X=O, O2)

    NASA Astrophysics Data System (ADS)

    Bai, Feng-Yang; Ma, Yuan; Lv, Shuang; Pan, Xiu-Mei; Jia, Xiu-Juan

    2017-01-01

    In this study, the mechanistic and kinetic analysis for reactions of CF3OCH(CF3)2 and CF3OCF2CF2H with OH radicals and Cl atoms have been performed at the CCSD(T)//B3LYP/6-311++G(d,p) level. Kinetic isotope effects for reactions CF3OCH(CF3)2/CF3OCD(CF3)2 and CF3OCF2CF2H/CF3OCF2CF2D with OH and Cl were estimated so as to provide the theoretical estimation for future laboratory investigation. All rate constants, computed by canonical variational transition state theory (CVT) with the small-curvature tunneling correction (SCT), are in reasonable agreement with the limited experimental data. Standard enthalpies of formation for the species were also calculated. Atmospheric lifetime and global warming potentials (GWPs) of the reaction species were estimated, the large lifetimes and GWPs show that the environmental impact of them cannot be ignored. The organic nitrates can be produced by the further oxidation of CF3OC(•)(CF3)2 and CF3OCF2CF2• in the presence of O2 and NO. The subsequent decomposition pathways of CF3OC(O•)(CF3)2 and CF3OCF2CF2O• radicals were studied in detail. The derived Arrhenius expressions for the rate coefficients over 230–350 K are: k T(1) = 5.00 × 10‑24T3.57 exp(‑849.73/T), k T(2) = 1.79 × 10‑24T4.84 exp(‑4262.65/T), kT(3) = 1.94 × 10‑24 T4.18 exp(‑884.26/T), and k T(4) = 9.44 × 10‑28T5.25 exp(‑913.45/T) cm3 molecule‑1 s‑1.

  17. Theoretical insight into OH- and Cl-initiated oxidation of CF3OCH(CF3)2 and CF3OCF2CF2H & fate of CF3OC(X•)(CF3)2 and CF3OCF2CF2X• radicals (X=O, O2)

    PubMed Central

    Bai, Feng-Yang; Ma, Yuan; Lv, Shuang; Pan, Xiu-Mei; Jia, Xiu-Juan

    2017-01-01

    In this study, the mechanistic and kinetic analysis for reactions of CF3OCH(CF3)2 and CF3OCF2CF2H with OH radicals and Cl atoms have been performed at the CCSD(T)//B3LYP/6-311++G(d,p) level. Kinetic isotope effects for reactions CF3OCH(CF3)2/CF3OCD(CF3)2 and CF3OCF2CF2H/CF3OCF2CF2D with OH and Cl were estimated so as to provide the theoretical estimation for future laboratory investigation. All rate constants, computed by canonical variational transition state theory (CVT) with the small-curvature tunneling correction (SCT), are in reasonable agreement with the limited experimental data. Standard enthalpies of formation for the species were also calculated. Atmospheric lifetime and global warming potentials (GWPs) of the reaction species were estimated, the large lifetimes and GWPs show that the environmental impact of them cannot be ignored. The organic nitrates can be produced by the further oxidation of CF3OC(•)(CF3)2 and CF3OCF2CF2• in the presence of O2 and NO. The subsequent decomposition pathways of CF3OC(O•)(CF3)2 and CF3OCF2CF2O• radicals were studied in detail. The derived Arrhenius expressions for the rate coefficients over 230–350 K are: k T(1) = 5.00 × 10−24T3.57 exp(−849.73/T), k T(2) = 1.79 × 10−24T4.84 exp(−4262.65/T), kT(3) = 1.94 × 10−24 T4.18 exp(−884.26/T), and k T(4) = 9.44 × 10−28T5.25 exp(−913.45/T) cm3 molecule−1 s−1. PMID:28067283

  18. An ab initio study on tunability of σ-hole interactions in XHS:PH2Y and XH2P:SHY complexes (X = F, Cl, Br; Y = H, OH, OCH3, CH3, C2H5, and NH2).

    PubMed

    Esrafili, Mehdi D; Mohammadirad, Nafiseh

    2015-07-01

    Quantum chemical calculations are performed to investigate the tunability of σ-hole interactions in chalcogen-bonded XHS:PH2Y and pnicogen-bonded XH2P:SHY complexes, where X  =  F, Cl, Br and Y  =  H, OH, OCH3, CH3, C2H5, NH2. The formation of these binary complexes can be understood in terms of molecular electrostatic potentials (MEPs), considering the P and S atoms as an electron acceptor or an electron donor in the chalcogen and pnicogen bonds. The strength of the XHS:PH2Y and XH2P:SHY complexes for a given Y increases as follows: X = Br < Cl < F. In addition, an acceptable linear relationship is found between the interaction energies and the magnitudes of the product of most positive and negative MEPs. This finding along with the electron density difference maps provides a clear picture of the electrostatic nature of the interactions in the XHS:PH2Y and XH2P:SHY complexes. The calculated spin-spin coupling constants across the chalcogen bond interactions in the XHS:PH2Y complexes display a quadratic dependence with the P···S binding distance.

  19. Atmospheric chemistry of HFE-7000 (CF(3)CF (2)CF (2)OCH (3)) and 2,2,3,3,4,4,4-heptafluoro-1-butanol (CF (3)CF (2)CF (2)CH (2)OH): kinetic rate coefficients and temperature dependence of reactions with chlorine atoms.

    PubMed

    Díaz-de-Mera, Yolanda; Aranda, Alfonso; Bravo, Iván; Rodríguez, Diana; Rodríguez, Ana; Moreno, Elena

    2008-10-01

    The adverse environmental impacts of chlorinated hydrocarbons on the Earth's ozone layer have focused attention on the effort to replace these compounds by nonchlorinated substitutes with environmental acceptability. Hydrofluoroethers (HFEs) and fluorinated alcohols are currently being introduced in many applications for this purpose. Nevertheless, the presence of a great number of C-F bonds drives to atmospheric long-lived compounds with infrared absorption features. Thus, it is necessary to improve our knowledge about lifetimes and global warming potentials (GWP) for these compounds in order to get a complete evaluation of their environmental impact. Tropospheric degradation is expected to be initiated mainly by OH reactions in the gas phase. Nevertheless, Cl atoms reaction may also be important since rate constants are generally larger than those of OH. In the present work, we report the results obtained in the study of the reactions of Cl radicals with HFE-7000 (CF(3)CF(2)CF(2)OCH(3)) (1) and its isomer CF(3)CF(2)CF(2)CH(2)OH (2). Kinetic rate coefficients with Cl atoms have been measured using the discharge flow tube-mass spectrometric technique at 1 Torr of total pressure. The reactions of these chlorofluorocarbons (CFCs) substitutes have been studied under pseudo-first-order kinetic conditions in excess of the fluorinated compounds over Cl atoms. The temperature ranges were 266-333 and 298-353 K for reactions of HFE-7000 and CF(3)CF(2)CF(2)CH(2)OH, respectively. The measured room temperature rate constants were k(Cl+CF(3)CF(2)CF(2)OCH(3)) = (1.24 +/- 0.28) x 10(-13) cm(3) molecule(-1) s(-1)and k(Cl+CF(3)CF(2)CF(2)CH(2)OH) = (8.35 +/- 1.63) x 10(-13) cm(3) molecule(-1) s(-1) (errors are 2sigma + 10% to cover systematic errors). The Arrhenius expression for reaction 1 was k (1)(266-333 K) = (6.1 +/- 3.8) x 10(-13)exp[-(445 +/- 186)/T] cm(3) molecule(-1) s(-1) and k (2)(298-353 K) = (1.9 +/- 0.7) x 10(-12)exp[-(244 +/- 125)/T] cm(3) molecule(-1) s(-1) (errors

  20. Extending the functionality of the slurry ferrihydrite-DGT method: Performance evaluation for the measurement of vanadate, arsenate, antimonate and molybdate in water.

    PubMed

    Zhang, Shu; Williams, Paul N; Zhou, Chun-Yang; Ma, Lena Q; Luo, Jun

    2017-10-01

    The monitoring of oxyanions in waters, presents significant challenges due to their relatively low concentrations, and a characteristically changeable/unstable/reactive geochemistry with high spatial and temporal turnover. This results in a very heterogeneous pattern of mobility and bioavailability, which is difficult to capture reliably and in a cost effective manner. The diffusive gradients in thin-films (DGT) technique is a popular analytical tool for testing water quality, primarily because it provides a time-integrated measurement. However, to date, the most widely used DGT configuration for oxyanion sampling, the slurry ferrihydrite binding layer (SF-DGT) has only been fully characterized for phosphate. Confirmatory testing of the functional range of ionic strengths, pH, deployment times and ionic competition effects, that the SF-DGT's operates within has not been carried out, but is addressed in this study for V(V), As(V), Sb(V), and Mo(VI). In this study SF-DGT Sb(V) measurements functioned over the largest range of conditions (ionic strength, 0.1-500 mM; pH 3.86-9.90), while ionic strengths above 100 and 500 mM were found to be problematic for As(V) and Mo(VI), respectively. Low pH (below 4) caused inferences with V(V), conversely As(V) and Mo(VI) determination faltered/deviated from predicted responses in pH conditions of ∼9. SF-DGT measurements adequately predicted up to weeklong averaged in situ metal oxyanion concentrations in a freshwater river. This study concludes that the SF-DGT configuration is highly suitable for pollution monitoring applications in freshwater systems for key oxyanion species. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Reactivity of [{l{underscore}brace}Mn{sup 4}(salpn){r{underscore}brace}{sub 2}({micro}-O,{micro}-OCH{sub 3})]{sup +} and [{l{underscore}brace}Mn{sup IV}(salpn){r{underscore}brace}{sub 2}({micro}-O,{micro}-OH)]{sup +}: Effects of proton liability and hydrogen bonding

    SciTech Connect

    Baldwin, M.J.; Law, N.A.; Stemmler, T.L.; Kampf, J.W.; Penner-Hahn, J.E.; Pecoraro, V.L.

    1999-10-18

    It was previously shown that the addition of 1 equiv of a strong acid to [Mn{sup IV}(salpn)({micro}-O)]{sub 2}, 1, generates the oxo/hydroxo complex [{l{underscore}brace}Mn{sup IV}(salpn){r{underscore}brace}{sub 2}({micro}-O,{micro}-OH)](CF{sub 3}SO{sub 3}), 2, which emphasized the basicity of the {micro}{sub 2}-O{sup 2{minus}} units in the [Mn{sup IV}({micro}-O)]{sub 2} dimers. The authors now demonstrate the inherent nucleophilicity of those {micro}{sub 2}-O{sup 2{minus}} units by showing that the addition of methyl triflate to 1 results in formation of the oxo/methoxo-bridged Mn{sup IV} dimer [{l{underscore}brace}Mn{sup IV}(salph){r{underscore}brace}{sub 2}({micro}-O,{micro}-OCH{sub 3})](CF{sub 3}SO{sub 3}), 3. EXAFS analysis of 3 demonstrates that alkylation of an oxo bridge results in the same structural modification of the [Mn{sup IV}({micro}-O)]{sub 2} core as an oxo bridge protonation. Electrochemical and spectroscopic comparisons of 3 to 2 indicate that 3 is a good electronic structure analogue for 2 without the complication of proton lability and hydrogen bonding. Indeed, 2 and 3 react nearly identically with hydrogen peroxide and with strong acids. In contrast, the products of their reactions with amines, acetate, and triphenylphosphine are dramatically different. The proton lability of 2 results in simple proton transfer, circumventing the slower redox reactions of these substrates with 3. Isotopic labeling, kinetic, and EPR-monitored radical trap studies lead to a proposed reduction-oxidation mechanistic scheme for the reactions of 3 with amines and triphenylphosphine. The Mn{sup III} product of this reaction, [Mn{sup III}(salpn)(Ph{sub 3}PO)](CF{sub 3}SO{sub 3}), was isolated and crystallographically characterized as a dimerized complex. The redox nature of the reactions is confirmed by trapping of a reduced Mn intermediate which is identified by EPR spectroscopy. Comparison of the reactions of 2 and 3 demonstrates the dramatic effect of proton

  2. Greenhouse Gas-ette Fall 1988, Spring, Fall 1989, Winter, Spring, Fall 1990.

    ERIC Educational Resources Information Center

    Greenhouse Gas-ette, 1990

    1990-01-01

    This newsletter is for educators interested in developing lessons related to global climate change. The newsletter contains sample lessons, news items involving global climate change on an international scale, and background information on issues related to global climate change. (CW)

  3. Greenhouse Gas-ette Fall 1988, Spring, Fall 1989, Winter, Spring, Fall 1990.

    ERIC Educational Resources Information Center

    Greenhouse Gas-ette, 1990

    1990-01-01

    This newsletter is for educators interested in developing lessons related to global climate change. The newsletter contains sample lessons, news items involving global climate change on an international scale, and background information on issues related to global climate change. (CW)

  4. Propulsion Velocity and ETT on Biomagnetic Assessment of the Human Esophagus

    NASA Astrophysics Data System (ADS)

    Cordova-Fraga, T.; Cano, E.; Bravo-Miranda, C.; Huerta, R.; De la Roca-Chiapas, J. M.; Bernal, J. J.; Sosa, M.

    2008-08-01

    Esophagus transit time measurement is a common clinical practical. Biomagnetic techniques and modern instrumentation can perform non invasive and functional assessments of the gastrointestinal tract. This study presents the evaluation of the esophagus transit time and propulsion velocity of a magnetic marker from the mouth to stomach using water vs. a swallow easy substance recently patented. A group of ten healthy subjects from 45 to 55 years, were evaluated in identical conditions for two times, they ingested randomly a magnetic marker in an anatomical body position of 45°, one times with water and the other one with a patented substance developed in order to help the subjects to swallow pills. The esophagus transit time was shorter when the subjects ingested the magnetic marker with the swallow easy substance than they ingested the magnetic marker with same quantity of water

  5. Description and modelling of the solar-hydrogen-biogas-fuel cell system in GlashusEtt

    NASA Astrophysics Data System (ADS)

    Hedström, L.; Wallmark, C.; Alvfors, P.; Rissanen, M.; Stridh, B.; Ekman, J.

    The need to reduce pollutant emissions and utilise the world's available energy resources more efficiently has led to increased attention towards e.g. fuel cells, but also to other alternative energy solutions. In order to further understand and evaluate the prerequisites for sustainable and energy-saving systems, ABB and Fortum have equipped an environmental information centre, located in Hammarby Sjöstad, Stockholm, Sweden, with an alternative energy system. The system is being used to demonstrate and evaluate how a system based on fuel cells and solar cells can function as a complement to existing electricity and heat production. The stationary energy system is situated on the top level of a three-floor glass building and is open to the public. The alternative energy system consists of a fuel cell system, a photovoltaic (PV) cell array, an electrolyser, hydrogen storage tanks, a biogas burner, dc/ac inverters, heat exchangers and an accumulator tank. The fuel cell system includes a reformer and a polymer electrolyte fuel cell (PEFC) with a maximum rated electrical output of 4 kW el and a maximum thermal output of 6.5 kW th. The fuel cell stack can be operated with reformed biogas, or directly using hydrogen produced by the electrolyser. The cell stack in the electrolyser consists of proton exchange membrane (PEM) cells. To evaluate different automatic control strategies for the system, a simplified dynamic model has been developed in MATLAB Simulink. The model based on measurement data taken from the actual system. The evaluation is based on demand curves, investment costs, electricity prices and irradiation. Evaluation criteria included in the model are electrical and total efficiencies as well as economic parameters.

  6. Propulsion Velocity and ETT on Biomagnetic Assessment of the Human Esophagus

    SciTech Connect

    Cordova-Fraga, T.; Cano, E.; Bravo-Miranda, C.; De la Roca-Chiapas, J. M.; Bernal, J. J.; Sosa, M.; Huerta, R.

    2008-08-11

    Esophagus transit time measurement is a common clinical practical. Biomagnetic techniques and modern instrumentation can perform non invasive and functional assessments of the gastrointestinal tract. This study presents the evaluation of the esophagus transit time and propulsion velocity of a magnetic marker from the mouth to stomach using water vs. a swallow easy substance recently patented. A group of ten healthy subjects from 45 to 55 years, were evaluated in identical conditions for two times, they ingested randomly a magnetic marker in an anatomical body position of 45 deg., one times with water and the other one with a patented substance developed in order to help the subjects to swallow pills. The esophagus transit time was shorter when the subjects ingested the magnetic marker with the swallow easy substance than they ingested the magnetic marker with same quantity of water.

  7. Energetics of the O-H bond and of intramolecular hydrogen bonding in HOC6H4C(O)Y (Y = H, CH3, CH2CH=CH2, C[triple bond]CH, CH2F, NH2, NHCH3, NO2, OH, OCH3, OCN, CN, F, Cl, SH, and SCH3) compounds.

    PubMed

    Bernardes, Carlos E S; Minas da Piedade, Manuel E

    2008-10-09

    The energetics of the phenolic O-H bond in a series of 2- and 4-HOC 6H 4C(O)Y (Y = H, CH3, CH 2CH=CH2, C[triple bond]CH, CH2F, NH2, NHCH 3, NO2, OH, OCH3, OCN, CN, F, Cl, SH, and SCH3) compounds and of the intramolecular O...H hydrogen bond in 2-HOC 6H 4C(O)Y, was investigated by using a combination of experimental and theoretical methods. The standard molar enthalpies of formation of 2-hydroxybenzaldehyde (2HBA), 4-hydroxybenzaldehyde (4HBA), 2'-hydroxyacetophenone (2HAP), 2-hydroxybenzamide (2HBM), and 4-hydroxybenzamide (4HBM), at 298.15 K, were determined by micro- or macrocombustion calorimetry. The corresponding enthalpies of vaporization or sublimation were also measured by Calvet drop-calorimetry and Knudsen effusion measurements. The combination of the obtained experimental data led to Delta f H m (o)(2HBA, g) = -238.3 +/- 2.5 kJ.mol (-1), DeltafHm(o)(4HBA, g) = -220.3 +/- 2.0 kJ.mol(-1), Delta f H m (o)(2HAP, g) = -291.8 +/- 2.1 kJ.mol(-1), DeltafHm(o)(2HBM, g) = -304.8 +/- 1.5 kJ.mol (-1), and DeltafHm(o) (4HBM, g) = -278.4 +/- 2.4 kJ.mol (-1). These values, were used to assess the predictions of the B3LYP/6-31G(d,p), B3LYP/6-311+G(d,p), B3LYP/aug-cc-pVDZ, B3P86/6-31G(d,p), B3P86/6-311+G(d,p), B3P86/aug-cc-pVDZ, and CBS-QB3 methods, for the enthalpies of a series of isodesmic gas phase reactions. In general, the CBS-QB3 method was able to reproduce the experimental enthalpies of reaction within their uncertainties. The B3LYP/6-311+G(d,p) method, with a slightly poorer accuracy than the CBS-QB3 approach, achieved the best performance of the tested DFT models. It was further used to analyze the trends of the intramolecular O...H hydrogen bond in 2-HOC 6H 4C(O)Y evaluated by the ortho-para method and to compare the energetics of the phenolic O-H bond in 2- and 4-HOC 6H 4C(O)Y compounds. It was concluded that the O-H bond "strength" is systematically larger for 2-hydroxybenzoyl than for the corresponding 4-hydroxybenzoyl isomers mainly due to the presence of

  8. Smabarnens Kultur-Och Mediebarometer. (Barometer of Children's Cultural Activity).

    ERIC Educational Resources Information Center

    Filipson, Leni; Schyller, Ingela

    This is the first of a planned series of investigations of the media habits and other cultural activities of 3- to 8-year-old Swedish children. Diagrams show the percent of children who use the various media on an average day and the frequency of their participation in such activities as visits to the theater, museum, or library. The amount of…

  9. Synthesis, characterization, structural and biological aspects of copper(II) dithiocarbamate complexes - Part II, [Cu{S2CN(Me)(R1)}2], [Cu{S2CN(Me)(R2)}2] and [Cu{S2CN(R3)(R4)}2] {R1 = CH2CH(OMe)2, R2 = 2-methyl-1,3-dioxolane, R3 = CH2(CH2)2NCHPhOCH2Ph and R4 = CH2CH2OH}

    NASA Astrophysics Data System (ADS)

    Ferreira, Isabella P.; de Lima, Geraldo M.; Paniago, Eucler B.; Takahashi, Jacqueline A.; Krambrock, Klaus; Pinheiro, Carlos B.; Wardell, James L.; Visentin, Lorenzo C.

    2013-09-01

    Three new copper(II) dithiocarbamates (DTC), [Cu{S2CN(Me)(R1)}2] (1), [Cu{S2CN(Me)(R2)}2] (2) and [Cu{S2CN(R3)(R4)}2] (3) with R1 = CH2CH(OMe)2, R2 = 2-methyl-1,3-dioxolane, R3 = CH2(CH2)2NCHPhOCH2Ph and R4 = CH2CH2OH, have been synthesized and characterized by different spectroscopic techniques. Complexes (1) and (2) display typical EPR spectra for separated Cu(II) centers, and the spectrum of (3) is characteristic of two magnetically coupled Cu(II) ions with S = 1. The X-ray crystallographic determination has shown that complexes (1) and (2) crystallise in the triclinic and monoclinic systems. In addition both complexes are monomers in which the geometry at each Cu(II) is square planar. The in vitro antimicrobial activity of the sodium salts of ligands, and of the Cu(II)-DTC complexes have been screened against Aspergillus flavus, Aspergillus niger, Aspergillus parasiticus, Penicillium citrinum and Curvularia senegalensis, as well as Gram positive and Gram negative bacteria. Finally, the toxic effects of complexes (1)-(3) were performed using Chlorella vulgaris.

  10. Avoid falling for a jerk(ette): Effectiveness of the Premarital Interpersonal Choices and Knowledge Program among Emerging Adults.

    PubMed

    Bradford, Kay; Stewart, J Wade; Pfister, Roxane; Higginbotham, Brian J

    2016-10-01

    Premarital education may help emerging adults form healthy relationships, but evaluation research is needed, particularly with community samples. We studied emerging adults in the Premarital Interpersonal Choices and Knowledge (PICK) program, using a pre- to post- and a posttest-then-retrospective-pretest design to examine change in perceived relationship skills, partner selection, relational patterns, and relationship behaviors and attitudes. Mixed models analyses showed that scores for the treatment group (n = 682) increased from pre to post on all four outcomes. Changes in scores for the nonequivalent comparison group (n = 462) were nonsignificant. In addition, significant differences between pre- and retrospective prescores demonstrated evidence for response shift bias. The results suggest that the PICK program helps participants increase their knowledge regarding the components of healthy relationship formation. © 2016 American Association for Marriage and Family Therapy.

  11. Synthesis and characterization of rare-earth barium antimonates, a new group of complex perovskites suitable as substrates for YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} films

    SciTech Connect

    Kurian, J.; Koshy, J.; Wariar, P.R.S.; Yadava, Y.P.; Damodaran, A.D.

    1995-04-01

    A new group of complex perovskites, REBa{sub 2}SbO{sub 6} (where RE = Pr, Sm, and Gd), have been synthesized and sintered as single phase materials by the solid state reaction method. These materials are found to be isostructural and to have a complex cubic perovskite structure. X-ray diffraction and resistivity measurements have shown that there is no detectable chemical reaction between YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} and REBa{sub 2}SbO{sub 6} even under severe heat treatment at 950{degrees}C and that the addition of REBa{sub 2}SbO{sub 6} up to 20 vol% in YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} shows no detrimental effect on the superconducting properties of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}. The dielectric constant and loss factor values of the sintered REBa{sub 2}SbO{sub 6} materials are in a range suitable for their use as substrates for microwave applications. Thick films of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} fabricated on polycrystalline REBa{sub 2}SbO{sub 6} substrates give superconducting zero resistivity transition temperature T{sub c(0)} = 92 K, indicating the suitability of these materials as substrates for YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} films.

  12. Kop- och saljsystem inom barnomsorgen: Konsekvenser for Personal, Foraldrar och barn (A New Charging System in Child Care: Consequences for Personnel, Parents, and Children).

    ERIC Educational Resources Information Center

    Ekholm, Bodil; Ellstrom, Eva

    The aim of this study was to examined the impact of a new charging system in child care in two different Swedish municipalities, on personnel, parents, and children. Four day care centers situated in different socioeconomic areas were studied. A qualitative approach was used, and data were collected by means of interviews and a questionnaire.…

  13. Placebo-Controlled Clinical Trial of Sodium Stibogluconate (Pentostam) vs. Ketoconazole for Treating Cutaneous Leishmaniasis in Guatemala

    DTIC Science & Technology

    1991-04-23

    trial of meglumine antimonate for cutaneous leishmaniasis caused by L. major and found that the antimonial, which cured only 48% of the patients, was...develop a clinical response by the 13-wcck examination. Patients who wcre removed from the study were treated with meglumine antimonate at a dose of 20...resolved 3 days after kctoconiazolC trc, tment ccased. The patient was successfully treated with meglumine antimonate. The second patient devclqpcd

  14. Dagliga Separationer och Tidig Daghemsstart (Daily Separations and Early Entry into Day Care).

    ERIC Educational Resources Information Center

    Harsman, Ingrid

    The purpose of this thesis [Swedish language with English abstract and summary] was to study the reactions of infants when they started attending day care centers and to elucidate the process of adjustment. The theoretical perspective employed is the J. Bowlby/M. Ainsworth attachment theory. U. Bronfenbrenner's ecological theory of human…

  15. Aetervinning av faerg och ridaevatten med ultrafiltrering (recycling of paint and water curtains with ultrafiltration)

    SciTech Connect

    Fortkamp, U.; Allard, A.S.; Ekengren, O.

    1997-12-01

    Painting in spray booths causes overspray that is collected by a water curtain. The mixture of water and paint is commonly treated by means of precipitation. By means of this method, water can be used again but a paint sludge is created. Within this project, it was investigated how the paint as well as the water can be recycled. Separation by membrane filtration was tested for different paints in laboratory scale (0.2 liter volume). It was possible to separate all tested paints from the water and to concentrate it. At large scale (15 to 75 liters volume), an emulsion paint and a dispersion paint were tested. Under the tested conditions, it was slightly easier to concentrate the emulsion paint than the dispersion paint. It was possible to concentrate the paints to the original dry substance percentage. An important aspect of membrane filtration is cleaning of the membrane when the performance decreases. It was possible to clean all the tested membranes, but in many cases it was difficult. A ceramic membrane and a membrane of polyaramide showed the best results with regard to flux and cleaning of the membrane under the tested conditions. During the performance of the project two new applications of membrane filtration of paint were found. The method can be used for waste minimization by only separating the paint in an easy way at low costs. A third application is treating cleaning water from paint manufacturing.

  16. Daghemsvistelse I Retrospektivt Perspektiv: En teori- och metodprovande studie (Daycare in Retrospect).

    ERIC Educational Resources Information Center

    Torstenson-Ed, Tullie

    This Swedish language report describes a preliminary study to test a retrospective life-history-inspired approach to studying children's experiences in a day care center, and whether children's experiences vary in different educational contexts and in relation to the teachers' experiences. The theoretical part of the study dealt with theories of…

  17. An Analysis of Textual Cohesion in a Passage from Maria Gripe's "Hugo och Josefin."

    ERIC Educational Resources Information Center

    Andersson, Erik

    Sentence-by-sentence analysis of factual or propositional cohesion in the first 29 lines of a Swedish children's story finds several sources of coherence that contribute to its cohesion. First, the text receives much coherence from its description of a single event, a situation where happenings are normal and expected. Second, a rather primitive…

  18. Dagliga Separationer och Tidig Daghemsstart (Daily Separations and Early Entry into Day Care).

    ERIC Educational Resources Information Center

    Harsman, Ingrid

    The purpose of this thesis [Swedish language with English abstract and summary] was to study the reactions of infants when they started attending day care centers and to elucidate the process of adjustment. The theoretical perspective employed is the J. Bowlby/M. Ainsworth attachment theory. U. Bronfenbrenner's ecological theory of human…

  19. Library Work and Automation; A Summary of the Swedish Report "Biblioteksarbete och Automatisk Databehandling."

    ERIC Educational Resources Information Center

    Royal Library, Stockholm (Sweden).

    The work of the Committee on the use of automation in Swedish research libraries has differed from that of a normal study group by virtue of its heavy concentration on the practical aspects of library catalog work, the present status of which is the main theme of this report. The model presented implies total and simultaneous integration of all…

  20. Experimental and DFT study of nitrogen atoms interactions with SiOCH low- κ films

    NASA Astrophysics Data System (ADS)

    Voronina, Ekaterina N.; Mankelevich, Yuri A.; Rakhimova, Tatyana V.; Palov, Alexander P.; Lopaev, Dmitry V.; Zyryanov, Sergey M.; Zotovich, Alexey I.; Baklanov, Mikhail R.

    2017-05-01

    Damage of porous organosilicate glass (OSG) films with low dielectric constants (low-κ films) in plasma processing is a critical problem for modern microelectronics. For this problem, understanding and revealing of basic reaction steps for radicals etching and damage are of importance. Previously we have studied experimentally and theoretically the etching and damage of low-κ dielectric films under oxygen and fluorine atoms. Here the effects of N atoms on OSG films are studied experimentally by Fourier Transform InfraRed (FTIR) spectroscopy method and theoretically by density functional theory (DFT) method. Experimental FTIR spectra are compared with calculated vibrational spectra to reveal the relevant surface SiCHxNy groups which could be produced in multi-step reactive collisions of N atoms in ground and lower metastable states with OSG low-κ dielectric films. Contribution to the Topical Issue "Many Particle Spectroscopy of Atoms, Molecules, Clusters and Surfaces", edited by A.N. Grum-Grzhimailo, E.V. Gryzlova, Yu V. Popov, and A.V. Solov'yov.

  1. Stereodynamics study of the exchange reaction O (3P) + CH4 → H + OCH3

    NASA Astrophysics Data System (ADS)

    Cheng, Da-Hai; Yuan, Jiu-Chuang; Yang, Tian-Gang; Chen, Mao-Du

    2013-06-01

    A new London—Eyring—Polanyi—Sato potential energy surface is employed in this work to study the stereo properties of the O(3P) + CH4 → H + CH3O reaction in its rovibrationally ground state using the quasiclassical trajectory method (QCT). Our calculations are performed at a range of collision energies, Ec = 1.5 eV~ 3.5 eV, and the excitation function obtained by the QCT method accords well with the experimental data. The product rotational polarization is calculated, and the product shows a strong rotational polarization in the centre-of-mass coordinate system. The orientation of the product rotational angular momenta is sensitive to the increase in collision energy, and the alignment of the product rotational angular momenta shows some of the properties of the heavy heavy—light mass combination reactions. In the isotopic substituted reaction study, when the H atoms in methane are replaced by D atoms, the rotational polarization is obviously reduced. The polarization-dependent differential cross section is also studied by this QCT calculation to provide detailed information about the rotational alignment and orientation of the product.

  2. Experimental Test Results of Energy Efficient Transport (ETT) High-Lift Airfoil in Langley Low-Turbulence Pressure Tunnel-Supplement

    NASA Technical Reports Server (NTRS)

    Morgan, Harry L., Jr.

    2002-01-01

    This report describes the results of an experimental study conducted in the Langley Low-Turbulence Pressure Tunnel to determine the effects of Reynolds number and Mach number on the two-dimensional aerodynamic performance of the Langley Energy Efficient Transport (EET) High-Lift Airfoil. The high-lift airfoil was a supercritical-type airfoil with a thickness-to-chord ratio of 0.12 and was equipped with a leading-edge slat and a double-slotted trailing-edge flap. The leading-edge slat could be deflected 30deg, 40deg, 50deg, and 60deg, and the trailing-edge flaps could be deflected to 15deg, 30deg, 45deg, and 60deg. The gaps and overlaps for the slat and flaps were fixed at each deflection resulting in 16 different configurations. All 16 configurations were tested through a Reynolds number range of 2.5 to 18 million at a Mach number of 0.20. Selected configurations were also tested through a Mach number range of 0.10 to 0.35. The plotted and tabulated force, moment, and pressure data are available on the CD-ROM supplement L-18221.

  3. Subsolidus phase relations in Na{sub 2}O-CuO-Sb{sub 2}O{sub n} system and crystal structure of new sodium copper antimonate Na{sub 3}Cu{sub 2}SbO{sub 6}

    SciTech Connect

    Smirnova, O.A.; Nalbandyan, V.B. . E-mail: vbn@rsu.ru; Petrenko, A.A.; Avdeev, M.

    2005-04-15

    Subsolidus phase relation studies in the NaSb{sub 3}O{sub 7}-Na{sub 3}SbO{sub 4}-CuO-CuSb{sub 2}O{sub 6} quadrangle of Na{sub 2}O-CuO-Sb{sub 2}O{sub n} system at 1123-1173K revealed the formation of one new compound Na{sub 3}Cu{sub 2}SbO{sub 6}. It is a superstructure derived from {alpha}-NaFeO{sub 2} type, space group C2/m, lattice constants: a=5.6759(1)A, b=8.8659(1)A, c=5.8379(1)A, {beta}=113.289(1){sup o}. All ions are in octahedral environment, but CuO{sub 6} polyhedron exhibits strong elongation due to Jahn-Teller effect (Cu-O: 2.000(2)Ax2, 2.021(2)Ax2, 2.494(3)Ax2), whereas SbO{sub 6} octahedron is almost regular. The relationship to other similar superlattices is discussed.

  4. a Comparison of the Molecular Structures of C_4H_9OCH_3, C_4H_9SCH_3, C_5H_{11}OCH_3, and C_5H_{11}SCH_3 Using Microwave Spectroscopy

    NASA Astrophysics Data System (ADS)

    Long, Brittany E.; Betancur, Juan; Choi, Yoon Jeong; Cooke, S. A.; Grubbs, G. S., II; Ogulnick, Jonathan; Holmes, Tara

    2017-06-01

    Pure rotational spectra of the title molecules have been recorded using chirped pulse Fourier transform microwave spectroscopy. Under our experimental conditions only one conformer has been observed for each of the four compounds. These conformers have torsional angles of CXCC = 180^o, XCCC = 60^o, CCCC = 180^o, and, for the C_5H_{11}-X-CH_3 species, CCCC_{Methyl} = 180^o. These angles correspond to anti-gauche-anti conformations for the butyl methyl ether/thioether species, and anti-gauche-anti-anti conformations for the pentyl methyl ether/thioether species. Splittings due to the internal rotation of the X-CH_3 group are observed in both butyl species but are not observed in the pentyl species. The barrier to the X-CH_3 internal rotation has been investigated through spectral analyses and quantum chemical calculations. The differences in the internal rotation barrier between the ethers and thioethers will be discussed and will further be compared to the barriers obtained for similar molecules.

  5. Characterization by NMR of reactants and products of hydrofluoroether isomers, CF3(CF2)3OCH3 and (CF3)2C(F)CF2OCH3, reacting with isopropyl alcohol.

    PubMed

    Knachel, Howard C; Benin, Vladimir; Moddeman, William E; Birkbeck, Janine C; Kestner, Thomas A; Young, Tanya L

    2013-07-01

    The 3M Company product Novec™ 71IPA DL, a mixture of methoxyperfluorobutane, methoxyperfluoroisobutane and 4.5 wt.% isopropyl alcohol, has been found to be very stable at ambient temperature, producing fluoride at the rate of ~1 ppm/year. Our earlier kinetic and theoretical studies have identified the reaction mechanism. This paper identifies the (1)H and (19)F NMR chemical shifts, multiplicities, and coupling constants of reactants and the major products that result from aging the mixture in sealed Pyrex NMR tubes for periods up to 1.8 years at temperatures from 26 °C to 102 °C. Chemical shifts and coupling constants of fluorine and hydrogen atoms on the hydrofluoroethers and isopropyl alcohol are traced through the reactions to their values in the products--esters, isopropylmethyl ether, and HF. These spectral positions, multiplicities, and coupling constants are presented in table format and as figures to clarify the transformations observed as the samples age. Copyright © 2013 John Wiley & Sons, Ltd.

  6. Sma Barn Pa Daghem: En studie av personalens samspel med barn och foraldrar vid lamning, hamtning och fri lek (Infants at Day Care: A Study of Staff Interaction with Children and Their Parents during Leaving, Collecting and Free Play).

    ERIC Educational Resources Information Center

    Lothigius, Anita Holmstedt

    This thesis presents a picture of how staff interact with infants (age group 1-3 years old) and parents at three day care centers. The study focused on the situations of leaving and collecting the children and the children's time of free play both in and outdoors. The theoretical content has an attachment/psycho-dynamical perspective with emphasis…

  7. Daghemsklimat: Bakgrund, syfte och matinstrument. (The Climate of Day-Care Centers: Theoretical Backgrounds and Methods of Measurement).

    ERIC Educational Resources Information Center

    Ekholm, Bodil; And Others

    Using a new approach to studying day care centers, this study focused on the total climate of the day care center and the climate's effects on children's social and emotional behavior. A theoretical model for analyzing day care climate is presented. The model includes variables such as job satisfaction, work atmosphere, interactions between…

  8. Speciallararens Kunskaper Och Kompetens: Intervjuer med tio speciallarare (The Special Teacher's Knowledge and Competence: Interviews with Ten Special Teachers).

    ERIC Educational Resources Information Center

    Vernersson, Inga-Lill

    This thesis reports on a study in which 10 Swedish special education teachers were interviewed concerning the following six topics: (1) personal background and choice of a career; (2) professional knowledge; (3) the role of a special education teacher; (4) educational goals and methods; (5) cooperation; and (6) thoughts about the future.…

  9. Micropatterned Endotracheal Tubes Reduce Secretion-Related Lumen Occlusion.

    PubMed

    Mann, Ethan E; Magin, Chelsea M; Mettetal, M Ryan; May, Rhea M; Henry, MiKayla M; DeLoid, Heather; Prater, Justin; Sullivan, Lauren; Thomas, John G; Twite, Mark D; Parker, Albert E; Brennan, Anthony B; Reddy, Shravanthi T

    2016-12-01

    Tracheal intubation disrupts physiological homeostasis of secretion production and clearance, resulting in secretion accumulation within endotracheal tubes (ETTs). Novel in vitro and in vivo models were developed to specifically recapitulate the clinical manifestations of ETT occlusion. The novel Sharklet™ micropatterned ETT was evaluated, using these models, for the ability to reduce the accumulation of both bacterial biofilm and airway mucus compared to a standard care ETT. Novel ETTs with micropattern on the inner and outer surfaces were placed adjacent to standard care ETTs in in vitro biofilm and airway patency (AP) models. The primary outcome for the biofilm model was to compare commercially-available ETTs (standard care and silver-coated) to micropatterned for quantity of biofilm accumulation. The AP model's primary outcome was to evaluate accumulation of artificial airway mucus. A 24-h ovine mechanical ventilation model evaluated the primary outcome of relative quantity of airway secretion accumulation in the ETTs tested. The secondary outcome was measuring the effect of secretion accumulation in the ETTs on airway resistance. Micropatterned ETTs significantly reduced biofilm by 71% (p = 0.016) compared to smooth ETTs. Moreover, micropatterned ETTs reduced lumen occlusion, in the AP model, as measured by cross-sectional area, in distal (85%, p = 0.005), middle (84%, p = 0.001) and proximal (81%, p = 0.002) sections compared to standard care ETTs. Micropatterned ETTs reduced the volume of secretion accumulation in a sheep model of occlusion by 61% (p < 0.001) after 24 h of mechanical ventilation. Importantly, micropatterned ETTs reduced the rise in ventilation peak inspiratory pressures over time by as much as 49% (p = 0.005) compared to standard care ETTs. Micropatterned ETTs, demonstrated here to reduce bacterial contamination and mucus occlusion, will have the capacity to limit complications occurring during mechanical ventilation and

  10. Epinephrine delivery during neonatal resuscitation: comparison of direct endotracheal tube vs catheter inserted into endotracheal tube administration.

    PubMed

    Rehan, Virender K; Garcia, Maricela; Kao, Justin; Tucker, Christina M; Patel, Satish M

    2004-11-01

    The optimal method for epinephrine administration during neonatal resuscitation is not known. We hypothesized that epinephrine will be delivered more efficiently when administered via a feeding catheter inserted into the endotracheal tube (C-ETT) vs when administered directly into the ETT (D-ETT). Our objectives were to (1) compare the delivery of epinephrine to the distal end of the ETT when administered via D-ETT vs C-ETT; (2) measure the retention of epinephrine within the ETT vs the feeding catheter used for the drug delivery; and (3) compare the delivery of the drug with and without an air flush after administration via C-ETT. All experiments were performed in vitro, simulating epinephrine administration during neonatal resuscitation, according to the standard guidelines. Radiolabeled epinephrine, diluted to 1 microCi/ml, was used and experiments were repeated at least 4 times. Epinephrine administration via D-ETT was followed by one manual breath via a self-inflating bag attached to the ETT. Epinephrine delivery via C-ETT was followed by 1 ml saline flush, and in some experiments, this was also followed by a 1 cm(3) air flush. Epinephrine delivery and retention were assessed by measuring the radioactive content of the effluent fluid and that of the ETT or of the feeding catheter used for drug delivery. Significantly higher dosage of the drug was delivered when administered via D-ETT vs C-ETT, if air flush following C-ETT method was not used. However, with an air flush following the saline flush after the drug instillation, there was no difference in the amount of epinephrine delivered between the two methods. Retention in the ETT wall or the catheter was <7.5% of the administered dose with either method. Without an air flush following C-ETT method of epinephrine delivery, higher dosage of the drug is delivered via D-ETT vs C-ETT method. An air flush following the saline flush during C-ETT method improves drug delivery. Given that the C-ETT method is more

  11. The supine-to-prone position change induces modification of endotracheal tube cuff pressure accompanied by tube displacement.

    PubMed

    Minonishi, Toshiyuki; Kinoshita, Hiroyuki; Hirayama, Michiko; Kawahito, Shinji; Azma, Toshiharu; Hatakeyama, Noboru; Fujiwara, Yoshihiro

    2013-02-01

    To determine whether the supine-to-prone position change displaced the endotracheal tube (ETT) and, if so, whether the displacement related to this change modified ETT cuff pressure. Prospective study. Operating room of a university hospital. 132 intubated, adult, ASA physical status 1, 2, and 3 patients undergoing lumbar spine surgery. After induction of anesthesia, each patient's trachea was intubated. The insertion depth of each ETT was 23 cm for men and 21 cm for women at the upper incisors. In the supine position and after the supine-to-prone position change with the head rotated to the right, the length from the carina to ETT tip and ETT cuff pressure were measured. After the supine-to-prone position change, 91.7% patients had ETT tube displacement. Of these, 48% of patients' ETT moved ≥ 10 mm, whereas 86.3% of patients had changes in tube cuff pressure. There was a slight but significant correlation between ETT movement and change in cuff pressure. Depending on the position change, ETT cuff pressure decreased and the ETT tended to withdraw. After the supine-to-prone position change, patients had ETT tube displacement. Such ETT movement may be accompanied by a decrease in cuff pressure. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Prevention of airway fires: testing the safety of endotracheal tubes and surgical devices in a mechanical model.

    PubMed

    Roy, Soham; Smith, Lee P

    2015-01-01

    This study was designed to assess the ability of carbon dioxide (CO2) lasers and radiofrequency ablation devices (Coblator) (ArthoCare Corporation, Sunnyvale, CA) to ignite either a non-reinforced (polyvinylchloride) endotracheal tube (ETT) or an aluminum and fluoroplastic wrapped silicon ("laser safe") ETT at varying titrations of oxygen in a mechanical model of airway surgery. Non-reinforced and laser safe ETTs were suspended in a mechanical model imitating endoscopic airway surgery. A CO2 laser set at 5-30 watts was fired at the ETT at oxygen concentrations ranging from 21% to 88%. The process was repeated using a radiofrequency ablation (RFA) device. All trials were repeated to ensure accuracy. The CO2 laser ignited a fire when contacting a non-reinforced ETT in under 2 seconds at oxygen concentrations as low as 44%. The CO2 laser could not ignite a laser safe ETT under any conditions, unless it struck the non-reinforced distal tip of the ETT. With the RFA, a fire could not be ignited with either reinforced or non-reinforced ETTs. RFA presents no risk of ignition in simulated airway surgery. CO2 lasers should be utilized with a reinforced ETT or no ETT, as fires can easily ignite when lasers strike a non-reinforced ETT. Decreasing the fraction of inspired oxygen reduces the risk of fire. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Insights on the role of antimicrobial cuffed endotracheal tubes in preventing transtracheal transmission of VAP pathogens from an in vitro model of microaspiration and microbial proliferation.

    PubMed

    Rosenblatt, Joel; Reitzel, Ruth; Jiang, Ying; Hachem, Ray; Raad, Issam

    2014-01-01

    We developed an in vitro model to evaluate the effect of different cuffed endotracheal tubes (ETTs) on transtracheal transmission of ventilator-associated pneumonia (VAP) pathogens along external surfaces of ETTs. The model independently assessed the relative contributions of microbial proliferation to the distal tip and microaspiration of contaminated secretions past the cuff by testing in three modes: microaspiration only, microbial proliferation only, and simultaneous microaspiration and microbial proliferation. We evaluated transmission of methicillin resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa (PA) in the presence of a standard ETT; a soft, tapered cuff ETT with subglottic suctioning; and a novel antimicrobial gendine (combination of gentian violet and chlorhexidine) ETT in the model. In the microaspiration only mode, when leakage past the cuff occurred quickly, no ETT prevented transmission. When microaspiration was delayed, the gendine ETT was able to completely disinfect the fluid above the cuff and thereby prevent transmission of pathogens. In microbial proliferation only mode, the gendine ETT was the sole ETT that prevented transmission. With both mechanisms simultaneously available, transmission was dependent on how long microaspiration was delayed. Potent antimicrobial ETTs, such as a gendine ETT, can make unique contributions to prevent VAP when microaspiration is gradual.

  14. Structural phase transitions and crystal chemistry of the series Ba{sub 2} LnB'O{sub 6} (Ln=lanthanide and B'=Nb{sup 5+} or Sb{sup 5+})

    SciTech Connect

    Saines, Paul J.; Kennedy, Brendan J. Elcombe, Margaret M.

    2007-02-15

    The structures of 28 compounds in the two series Ba{sub 2} LnSbO{sub 6} and Ba{sub 2} LnNbO{sub 6} have been examined using synchrotron X-ray and in selected cases neutron powder diffraction at, below and above ambient temperature. The antimonate series is found to undergo a sequence of phase transitions from monoclinic to rhombohedral to cubic symmetry with both decreasing ionic radii of the lanthanides and increasing temperature. Compounds in the series Ba{sub 2} LnNbO{sub 6}, on the other hand, feature an intermediate tetragonal structure instead of the rhombohedral structure exhibited by the antimonates. This difference in symmetry is thought to be caused by {pi}-bonding in the niobates that is absent in the antimonates. The bonding environments of the cations in these compounds have also been examined with overbonding of the lanthanide and niobium cations being caused by the unusually large B-site cations. - Graphical abstract: Lattice parameters versus temperature for Ba{sub 2}NdNbO{sub 6}. The formation of the I4/m tetragonal phase contrasts with the antimonate series where a rhombohedral structure occurs instead. This difference is believed to be caused by the presence of {pi}-bonding present in the niobates but absent in the antimonates.

  15. Incremental change in cross sectional area in small endotracheal tubes: A call for more size options.

    PubMed

    Mortelliti, Caroline L; Mortelliti, Anthony J

    2016-08-01

    To elucidate the relatively large incremental percent change (IPC) in cross sectional area (CSA) in currently available small endotracheal tubes (ETTs), and to make recommendation for lesser incremental change in CSA in these smaller ETTs, in order to minimize iatrogenic airway injury. The CSAs of a commercially available line of ETTs were calculated, and the IPC of the CSA between consecutive size ETTs was calculated and graphed. The average IPC in CSA with large ETTs was applied to calculate identical IPC in the CSA for a theoretical, smaller ETT series, and the dimensions of a new theoretical series of proposed small ETTs were defined. The IPC of CSA in the larger (5.0-8.0 mm inner diameter (ID)) ETTs was 17.07%, and the IPC of CSA in the smaller ETTs (2.0-4.0 mm ID) is remarkably larger (38.08%). Applying the relatively smaller IPC of CSA from larger ETTs to a theoretical sequence of small ETTs, starting with the 2.5 mm ID ETT, suggests that intermediate sizes of small ETTs (ID 2.745 mm, 3.254 mm, and 3.859 mm) should exist. We recommend manufacturers produce additional small ETT size options at the intuitive intermediate sizes of 2.75 mm, 3.25 mm, and 3.75 mm ID in order to improve airway management for infants and small children. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  16. An ab initio determination of the bending-torsion-torsion spectrum of dimethyl ether, CH3OCH3 and CD3OCD3

    NASA Astrophysics Data System (ADS)

    Senent, M. L.; Moule, D. C.; Smeyers, Y. G.

    1995-04-01

    We have calculated the potential energy hypersurface of dimethyl ether with respect to the COC bending coordinate α and the torsional angles of the two methyl groups, θ1 and θ2. Two sets of ab initio calculations were carried out. The first was made at the level MP2/6-31G(d,p) in which the structural coordinates were fully relaxed except for the grid points on the hypersurface. More extensive calculation were carried out with MP4 corrections for electron correlation with the same molecular structure. The torsional bending Hamiltonian matrix was symmetrized by the operations of the G36 nonrigid group and was solved variationally. The effect of explicitly considering the bending mode in the three-dimensional treatment was determined by a comparison to the two-dimensional model in which the flexibility of the frame was absorbed into the calculation by the fully relaxed method. It was found that the three-dimensional calculation gave a much better account of the sin(3θ1)sin(θ2) intermode coupling than the two-dimensional treatment.

  17. Att Tolka Barns Signaler: Gravt utvecklingsstorda flerhandikappade barns lek och kommunikation (To Interpret Childrens' Signals: Play and Communication in Profoundly Mentally Retarded and Multiply Handicapped Children).

    ERIC Educational Resources Information Center

    Brodin, Jane

    Written in Swedish with an English-language summary, this report describes a study which examined the interaction between mothers or caregivers and their children with profound mental retardation and multiple disabilities, particularly looking at the function of play in communicative interaction. The six children all had five or six handicaps in…

  18. Proposal of New Precursors for Plasma-Enhanced Chemical Vapor Deposition of SiOCH Low-k Films with Plasma Damage Resistance

    NASA Astrophysics Data System (ADS)

    Yoshi Ohashi,; Nobuo Tajima,; Yonghua Xu,; Takeshi Kada,; Shuji Nagano,; Hideharu Shimizu,; Satoshi Hasaka,

    2010-05-01

    We propose new precursors for bulk low-k films with plasma damage resistance. Our newly designed precursors contain long-chain hydrocarbon groups such as i-butyl and n-propyl groups. Using these precursors, we successfully produced films containing Si-CH2-Si groups by plasma-enhanced chemical vapor deposition (PECVD). The plasma damage resistance of these films under NH3 plasma treatment was studied. It was found that the increase in the k-value (Δ k) is smaller in films with more Si-CH2-Si groups.

  19. Proposal of New Precursors for Plasma-Enhanced Chemical Vapor Deposition of SiOCH Low-k Films with Plasma Damage Resistance

    NASA Astrophysics Data System (ADS)

    Ohashi, Yoshi; Tajima, Nobuo; Xu, Yonghua; Kada, Takeshi; Nagano, Shuji; Shimizu, Hideharu; Hasaka, Satoshi

    2010-05-01

    We propose new precursors for bulk low-k films with plasma damage resistance. Our newly designed precursors contain long-chain hydrocarbon groups such as i-butyl and n-propyl groups. Using these precursors, we successfully produced films containing Si-CH2-Si groups by plasma-enhanced chemical vapor deposition (PECVD). The plasma damage resistance of these films under NH3 plasma treatment was studied. It was found that the increase in the k-value (Δk) is smaller in films with more Si-CH2-Si groups.

  20. Knowledge and Life-Experiences: Finland Seen through Its Libraries and Information Services = Kunskap och Upplevelser: Finland som BDI-land.

    ERIC Educational Resources Information Center

    Laaksovirta, Tuula H.; Haavisto, Tuula

    This illustrated publication, printed in both English and Finnish, describes Finland's libraries and information services. Topics covered include: (1) library users; (2) the conceptual role of the library; (3) the growth and development of the library system through Finland's agrarian, industrial, and budding infotech social phases; (4) the…

  1. Still Picture Telephones for Persons with Profound Mental Retardation. Telematik och Handikapp, Rapport 92:9 (Telematics and Disability, Report 92:9).

    ERIC Educational Resources Information Center

    Brodin, Jane; Bjorck-Akesson, Eva

    This project studied the use of still picture telephones by four Swedish adults (ages 25-45) with profound mental retardation and additional severe disabilities. After 5 to 6 months of subjects employing still picture telephones on a regular basis in their daily lives, relatives, staff from group homes, and other caregivers completed…

  2. 12 Daghem: Beskrivning av uppfostringsklimat och sociala relationer (Twelve Day Care Centers: A Multisite Comparison of Day-Care Climate and Social Relations).

    ERIC Educational Resources Information Center

    Ekholm, Bodil; Hedin, Anna

    Twelve day care centers in a Swedish commune were systematically observed. Centers were selected on the basis of responses to a questionnaire on attitudes about upbringing which was answered by all the personnel at the 104 day care centers in the commune. Four of the selected centers represented a so-called "present-focused" upbringing…

  3. Daghemsklimat: Uppfostringsattityder, engagemang och kanslor infor arbetet hos daghemspersonal. (Attitudes of Child-Rearing, Engagements and Feelings towards Work by Personnel at Day-Care Centers).

    ERIC Educational Resources Information Center

    Jonsson, Arne

    Approximately 900 employees in the day care centers in one Swedish commune answered a questionnaire measuring child rearing attitudes and personnel's engagement and feelings concerning their work with the children. The child rearing attitudes were described as either "present-focused" or "future-focused." Of particular interest…

  4. Principles of Biochemistry, Second Edition by H. Robert Horton, Laurence A. Moran, Raymond S. Ochs, J. David Rawn, K. Gray Scrimgeour

    NASA Astrophysics Data System (ADS)

    Voige, William H.

    1997-02-01

    Prentice Hall: Upper Saddle River, NJ, 1996. xxix + 801 pp. Figs. and tables. 22.4 x 28.4 cm. This book follows the format that has become standard for biochemistry texts. Sections begin with short declarative statements of principles that are explained concisely in the following paragraphs. The best chapters proceed in a straightforward and logical manner. The lipids chapter is exemplary. A discussion of molecular structure, beginning with fatty acids, is followed by membrane structure, transport, and signal transduction.

  5. Fortursbarn och "vanliga" barn pa tolv daghem: Jamforande observationer. (Mainstreamed Children and "Ordinary" Children in Twelve Day-Care Centers: An Observational Study).

    ERIC Educational Resources Information Center

    Ekholm, Bodil; Hedin, Anna

    Observations of one mainstreamed child and one "ordinary child" at each of 12 day care centers were compared. Five of the 12 mainstreamed children were mentally retarded, and seven had a slight developmental retardation mainly due to deprivation. Observations of 10-minute duration, totaling 4 hours and dispersed across 7 days, focused on…

  6. Daghemsklimat: Uppfostringsattityder, engagemang och kanslor infor arbetet hos daghemspersonal. (Attitudes of Child-Rearing, Engagements and Feelings towards Work by Personnel at Day-Care Centers).

    ERIC Educational Resources Information Center

    Jonsson, Arne

    Approximately 900 employees in the day care centers in one Swedish commune answered a questionnaire measuring child rearing attitudes and personnel's engagement and feelings concerning their work with the children. The child rearing attitudes were described as either "present-focused" or "future-focused." Of particular interest…

  7. Li[B(OCH2CF3)4]: synthesis, characterization and electrochemical application as a conducting salt for LiSB batteries.

    PubMed

    Rohde, Michael; Eiden, Philipp; Leppert, Verena; Schmidt, Michael; Garsuch, Arnd; Semrau, Guenter; Krossing, Ingo

    2015-02-23

    A new Li salt with views to success in electrolytes is synthesized in excellent yields from lithium borohydride with excess 2,2,2-trifluorethanol (HOTfe) in toluene and at least two equivalents of 1,2-dimethoxyethane (DME). The salt Li[B(OTfe)4 ] is obtained in multigram scale without impurities, as long as DME is present during the reaction. It is characterized by heteronuclear magnetic resonance and vibrational spectroscopy (IR and Raman), has high thermal stability (Tdecomposition >271 °C, DSC) and shows long-term stability in water. The concentration-dependent electrical conductivity of Li[B(OTfe)4 ] is measured in water, acetone, EC/DMC, EC/DMC/DME, ethyl acetate and THF at RT In DME (0.8 mol L(-1) ) it is 3.9 mS cm(-1) , which is satisfactory for the use in lithium-sulfur batteries (LiSB). Cyclic voltammetry confirms the electrochemical stability of Li[B(OTfe)4 ] in a potential range of 0 to 4.8 V vs. Li/Li(+) . The performance of Li[B(OTfe)4 ] as conducting salt in a 0.2 mol L(-1) solution in 1:1 wt % DME/DOL is investigated in LiSB test cells. After the 40th cycle, 86 % of the capacity remains, with a coulombic efficiency of around 97 % for each cycle. This indicates a considerable performance improvement for LiSB, if compared to the standard Li[NTf2 ]/DOL/DME electrolyte system.

  8. [A Pichia pastoris with alpha-1, 6-mannosyltransferases deletion and its use in expression of HSA/GM-CSF chimera].

    PubMed

    Wang, Yue; Gong, Xin; Chang, Shao-Hong; Liu, Bo; Song, Miao; Huang, Hai-Hua; Wu, Jun

    2007-09-01

    Yeast is a widely used host for recombinant protein expression. However, glycoproteins derived from yeast contain N-glycan of high mannose type and are usually hyperglycosylated. alpha-1,6-mannosyltransferases gene (och1) encodes the enzyme that initiates the first step of out-chain elongation of high mannose type N-glycan in yeast, which is different from that in human. So, a high efficient method to knockout target gene by two-step recombination was established and was used to delete och1. In the first recombinant, a plasmid with och1::ADE1 and ura3 gene was linearized in the downstream of och1 and inserted to the och1 site of P. pastoris genome, where the upstream and downstream of och1 were duplicated. In the second recombinant, the duplicated fragments of och1 were exchanged and the och1 deletion strains were selected on the plates containing 5-FOA, but no adenine. Then the och1 deletion strain was applied to express an human serum albumin (HSA) granulocyte-macrophage colony-stimulating factor (GM-CSF) chimera. Different with the hyperglycosylated HSA/GM-CSF chimera expressed in wild type P. pastoris, the chimera expressed in the och1 deletion strain, contained smaller N-glycan. The results suggested that the och1 mutant yeast may be more suitable for production of recombinant glycoproteins. And the och 1 deletion strain could be used for further re-engineering to produce complex human glycoproteins.

  9. Ultrasonography for endotracheal tube position in infants and children.

    PubMed

    Jaeel, Pooja; Sheth, Mansi; Nguyen, Jimmy

    2017-03-01

    Ultrasonography (US) has been shown to be effective for verifying endotracheal tube (ETT) position in adults but has been less studied in infants and children. We review the literature regarding US for ETT positioning in the pediatric population. A literature search was conducted using the Ovid and MEDLINE databases with search terms regarding US relating to ETT intubation and positioning in infants and children. Most studies in neonates and infants used the midsagittal suprasternal view. Studies reported >80% visualization of the ETT tip by US, and US interpretation of the ETT position correlated with the XR position in 73-100% of cases. Studies of older children used the suprasternal views, substernal views, and mid-axillary intercostal views. US appears comparable to XR and capnography in determining ETT position in this population.

  10. Komvux-Proven i Engelska VT 1989: Jamforelser mellan Komvux och Gymnasieskolan i Fraga om Provresultat och Betyg. Rapport nr 1990:06. (National Standardized Tests in English in Adult Education 1989: Comparison between Adult and Upper Secondary Students Test Results and School Leaving Grades. Report No. 1990:06).

    ERIC Educational Resources Information Center

    Oscarson, Mats

    This report describes the results of adult education students and upper secondary school students on two recently introduced standardized English tests in Sweden. Comparisons of the results are made between these two categories of students because they are entitled to compete, on an equal basis, for admission into restricted intake programs of…

  11. Perspektiv pa Las och Skrivinlarning: En Litteraturstudie som Belyser Las och Skrivinlarning utifran Fyra Teoretiska Perspektiv Samt en Instrument-Provande Barnstudie (Perspectives on Learning To Read and Write: Literature Review on Reading and Writing Acquisition through Examination of Four Theroretical Perspectives and Attitude Measures of Preschool Children).

    ERIC Educational Resources Information Center

    Fahlen, Rose-Marie

    This report focuses on the processes of learning to read and write in the initial phases. Two studies are presented. The first is a review of four theoretical approaches, including Jerome Bruner's representation theory, and theories of concept learning, metacognition, and metalinguistic awareness. The purpose of the literature study was to examine…

  12. Spectroscopy of new Sm(III) orange emitting phosphors of the type Na[Sm(SP)4], Na[Sm(WO)4] (where SP = C6H5S(O)2NP(O)(OCH3)2-; WO = CCl3C(O)NP(O)(OCH3)2-) and the polymeric materials obtained on their base

    NASA Astrophysics Data System (ADS)

    Cybińska, Joanna; Guzik, Małgorzata; Gerasymchuk, Yuriy; Trush, Victor A.; Lisiecki, Radosław; Legendziewicz, Janina

    2017-01-01

    Among a wide variety of solid state materials lanthanide beta-diketonates, their derivatives and polymeric materials based on them have become essential for advance technologies. Thus they are the subject of extensive spectroscopic studies. Using appropriate lanthanide chelates for the emission layer one can achieve electroluminescence covering the spectrum from blue to infrared. Moreover, compounds with proper chromophores can be the best way to excite and enhance the emission although the f-f transitions have forbidden character. Two types of new Sm(III) chelates; phosphoro and sulfono-derivatives of beta-diketones and polymeric materials on their base were obtained and characterized by the high resolution photoluminescence spectroscopy at 293, 77 and 4 K, as well as by luminescence decay times. Those new type of phosphors shows strong orange emission after excitation at 404 nm Sm(III) states and 280 nm ligand bands. Radiative transition probabilities were calculated from absorption spectra and Judd- Ofelt parameters evaluated. Effects of the temperature, rigidity of polymeric lattice and the energy of excitation on intensities of the Sm(III) fluorescence were studied. The paths of energy transfer are analysed and mechanism of this process is proposed.

  13. Hogskoleprovet: "En Andra Chans" Eller "Ytterligare en Oppen Dorr." Fem gymnasielarare om egna och gymnasieelevers synpunkter pa betyg och hogskoleprovet (Effects in Upper Secondary School of a More Extensive Use of the Higher Education Selection Test in the Admission to Higher Education).

    ERIC Educational Resources Information Center

    Gustavsson, Maria

    This study was designed to examine the attitudes of teachers and students in Swedish upper secondary schools in regard to the use of higher education scholastic aptitude test (SAT) scores in lieu of secondary school grades to gain entrance into higher education programs. Since 1991 applicants to higher education have been allowed to take the…

  14. Randomised trial of estimating oral endotracheal tube insertion depth in newborns using weight or vocal cord guide.

    PubMed

    Gill, Irwin; Stafford, Aisling; Murphy, Madeleine C; Geoghegan, Aisling R; Crealey, Miranda; Laffan, Eoghan; O'Donnell, Colm Patrick Finbarr

    2017-09-07

    When intubating newborns, clinicians aim to position the endotracheal tube (ETT) tip in the midtrachea. The depth to which ETTs should be inserted is often estimated using the infant's weight. ETTs are frequently incorrectly positioned in newborns, most often inserted too far. Using the vocal cord guide (a mark at the distal end of the ETT) to guide insertion depth has been recommended. To determine whether estimating ETT insertion depth using the vocal cord guide rather than weight results in more correctly positioned ETT tips. Single-centre randomised controlled trial. Level III neonatal intensive care unit (NICU) at a university maternity hospital (National Maternity Hospital, Dublin, Ireland). Newborn infants without congenital anomalies intubated in the NICU. Participants were randomised to have ETT insertion depth estimated using weight [insertion depth (cm) = weight (kg) +6] or vocal cord guide. Correct ETT position, that is, tip between the upper border of the first thoracic vertebra (T1) and the lower border of the second thoracic vertebra (T2) on a chest X-ray as determined by one paediatric radiologist masked to group assignment. 136 participants were randomised. The proportion of correctly positioned ETTs was similar in both groups (weight 30/69 (44%) vs vocal cord guide 27/67 (40%), p=0.731). Most incorrectly positioned ETT (69/79, 87%) were too low. Estimating ETT insertion depth using the vocal cord guide did not result in more correctly positioned ETT tips. ISRCTN39654846. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  15. Effect of 90° counterclockwise rotation of the endotracheal tube on its advancement through the larynx during nasal fiberoptic intubation in children: a randomized and blinded study.

    PubMed

    Choudhry, Dinesh K; Brenn, B Randall; Lutwin-Kawalec, Malgorzata; Sacks, Karen; Nesargi, Susmita; He, Zhaoping

    2016-04-01

    Resistance to the passage of the endotracheal tube (ETT) is frequently encountered in children as it is advanced over the fiberoptic scope for placement into the trachea because it gets hung up at the laryngeal inlet. Literature in adults indicates that a 90° counterclockwise rotation (CCR) of the ETT before advancing results in smooth passage. We found no literature in children. Our aim was to study if a 90° counterclockwise rotation (CCR) of the ETT before advancement leads to smooth passage of the ETT into the larynx in children. Following IRB approval, we performed this study in two parts: Part 1: An unblinded, observational, pilot study on 20 children scheduled for oral rehabilitation where we concurrently used a fiberoptic scope nasally and GlideScope orally. We visualized the ETT path and observed that 90° CCR allowed smooth passage without hang up. Part 2: A blinded and randomized study on 40 children to confirm if 90° CCR from the outset would improve passage of the ETT during nasal intubation with a fiberoptic scope in children. All children were divided into two groups: group S, ETT bevel facing left; group R, ETT bevel facing down. In Part 1, we observed that the ETT got hung up in 57% of children with standard bevel direction (facing left) and in 0% of children when prerotated. In Part 2, efficacy of prerotation was confirmed; the ETT got hung up in 50% of children in group S but in only 10.5% of children in group R. A change in ETT tip orientation from bevel facing left to facing down by 90° CCR, leads to a significantly higher first-attempt success rate by nasal approach in children. We believe the ETT should be rotated before insertion into the nostril to ensure that full 90° CCR of the tip has been accomplished. © 2016 John Wiley & Sons Ltd.

  16. Laryngeal resistance before and after minor surgery: endotracheal tube versus Laryngeal Mask Airway.

    PubMed

    Tanaka, Atsuko; Isono, Shiroh; Ishikawa, Teruhiko; Sato, Jiro; Nishino, Takashi

    2003-08-01

    The placement of an endotracheal tube (ETT) may promote laryngeal swelling, which is an important cause of upper airway obstruction after extubation. The authors hypothesized that laryngeal swelling after ETT placement increases laryngeal resistance and tested that hypothesis by comparing postoperative laryngeal patency between patients with ETT placement and those with a Laryngeal Mask Airway trade mark (LMA). Fourteen adult patients who underwent elective minor surgeries were randomly allocated to two groups whose airway would be managed through ETTs (the ETT group) or LMAs (the LMA group) during the surgery. While maintaining at sevoflurane 1 minimum alveolar concentration, the authors measured laryngeal resistance before and after surgery, during both spontaneous breathing and mechanical ventilation under complete paralysis. In addition, they endoscopically measured the vocal cord angle under complete paralysis. In association with marked swelling of the vocal cords, the vocal cord angle significantly decreased after surgery in the ETT group, whereas the angle did not change in the LMA group. Laryngeal resistance during mechanical ventilation significantly increased only in the ETT group. Laryngeal resistance during spontaneous breathing significantly increased after surgeries in both groups. Postoperative laryngeal resistance increases at least in part because of laryngeal swelling in patients with ETT placement, whereas alteration of laryngeal neural control mechanisms has been also indicated. The use of the LMA trade mark has an advantage over ETT placement in order to avoid postoperative laryngeal swelling.

  17. 40 CFR 63.11459 - What definitions apply to this subpart?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (sodium carbonate), salt cake (sodium sulfate), and potash (potassium carbonate); metal oxides and other metal-based compounds, such as lead oxide, chromium oxide, and sodium antimonate; metal ores, such as... to the atmosphere. Glass manufacturing metal HAP means an oxide or other compound of any of the...

  18. 40 CFR 63.11459 - What definitions apply to this subpart?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (sodium carbonate), salt cake (sodium sulfate), and potash (potassium carbonate); metal oxides and other metal-based compounds, such as lead oxide, chromium oxide, and sodium antimonate; metal ores, such as... to the atmosphere. Glass manufacturing metal HAP means an oxide or other compound of any of the...

  19. Rediscovering ancient glass technologies through the examination of opacifier crystals

    NASA Astrophysics Data System (ADS)

    Lahlil, S.; Biron, I.; Galoisy, L.; Morin, G.

    2008-07-01

    The aim of the study is to understand how antimonate opacifying crystals were obtained throughout history. Two archaeological glass productions opacified with calcium and lead antimonates are studied in this paper, in order to rediscover ancient opaque glass technologies: Roman mosaic tesserae (1st cent. B.C. 4th cent. A.D.) and Nevers lampworking glass (18th cent. A.D.). The fine examination of crystalline phases and of the vitreous matrix is undertaken using various and complementary techniques. Results are compared with a modern reference production, for which the technological process is well known. We demonstrate that Ca-antimonate opacifiers in Roman mosaic tesserae, as well as in Nevers lampworking glass, were obtained by in situ crystallization. Nevertheless, Roman and Nevers glass would have undergone different firing processes. We propose that the addition of previously synthesized crystals or the use of “anime” could be the process used to obtain Pb-antimonate opacified glass, for both productions studied. We demonstrate that CaO, PbO and Sb2O3 concentrations in the bulk compositions and in the matrices, and their evolution with the crystallinity ratio, offer robust criteria for the distinction of the opacification process used. Also, the different crystalline structures help to provide information on the experimental conditions.

  20. INORGANIC CATIONS IN RAT KIDNEY

    PubMed Central

    Tandler, C. J.; Kierszenbaum, A. L.

    1971-01-01

    For localization of pyroantimonate-precipitable cations, rat kidney was fixed by perfusion with a saturated aqueous solution of potassium pyroantimonate (pH about 9.2, without addition of any conventional fixative). A remarkably good preservation of the tissue and cell morphology was obtained as well as a consistent and reproducible localization of the insoluble antimonate salts of magnesium, calcium, and sodium. All proximal and distal tubules and glomeruli were delimited by massive electron-opaque precipitates localized in the basement membrane and, to a lesser extent, in adjacent connective tissue. In the intraglomerular capillaries the antimonate precipitate was encountered in the basement membranes and also between the foot processes. In addition to a more or less uniform distribution in the cytoplasm and between the microvilli of the brush border, antimonate precipitates were found in all cell nuclei, mainly between the masses of condensed chromatin. The mitochondria usually contained a few large antimonate deposits which probably correspond to the so-called "dense granules" observed after conventional fixations. PMID:4106544

  1. A multi-spectroscopic approach to the characterization of early glaze opacifiers: Studies on an Achaemenid glazed brick found at Susa, south-western Iran (mid-first millennium BC)

    NASA Astrophysics Data System (ADS)

    Holakooei, Parviz

    2013-12-01

    This paper presents the results of micro-Raman spectroscopy, energy dispersive X-ray fluorescence (XRF), and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) studies performed on an Achaemenid glazed brick found at Susa (mid-first millennium BC). The results showed that calcium antimonate (CaSb2O6) and lead antimonate (Pb2Sb2O7) were used as white and yellow opacifiers in the white and orange glazes respectively. Moreover, the mixture of calcium antimonate and lead antimonate were used as opacifier in the green glaze. In addition, green, turquoise, blue, and orange colors were achieved by the dissolution of copper, cobalt, and iron-bearing materials in an alkali glaze. A black glazed line, whose color was obtained by copper and iron oxides, was used to separate the colored glazes. The present paper strongly suggests invasive micro-Raman spectroscopy for the identification of the opacifiers used in the early vitreous materials.

  2. Endotracheal tube resistance and inertance in a model of mechanical ventilation of newborns and small infants-the impact of ventilator settings on tracheal pressure swings.

    PubMed

    Hentschel, Roland; Buntzel, Julia; Guttmann, Josef; Schumann, Stefan

    2011-09-01

    Resistive properties of endotracheal tubes (ETTs) are particularly relevant in newborns and small infants who are generally ventilated through ETTs with a small inner diameter. The ventilation rate is also high and the inspiratory time (ti) is short. These conditions effectuate high airway flows with excessive flow acceleration, so airway resistance and inertance play an important role. We carried out a model study to investigate the impact of varying ETT size, lung compliance and ventilator settings, such as peak inspiratory pressure (PIP), positive end expiratory pressure (PEEP) and inspiratory time (ti) on the pressure-flow characteristics with respect to the resistive and inertive properties of the ETT. Pressure at the Y piece was compared to direct measurement of intratracheal pressure (P(trach)) at the tip of the ETT, and pressure drop (ΔP(ETT)) was calculated. Applying published tube coefficients (Rohrer's constants and inertance), P(trach) was calculated from ventilator readings and compared to measured P(trach) using the root-mean-square error. The most relevant for ΔP(ETT) was the ETT size, followed by (in descending order) PIP, compliance, ti and PEEP, with gas flow velocity being the principle in common for all these parameters. Depending on the ventilator settings ΔP(ETT) exceeded 8 mbar in the smallest 2.0 mm ETT. Consideration of inertance as an additional effect in this setting yielded a better agreement of calculated versus measured P(trach) than Rohrer's constants alone. We speculate that exact tracheal pressure tracings calculated from ventilator readings by applying Rohrer's equation and the inertance determination to small size ETTs would be helpful. As an integral part of ventilator software this would (1) allow an estimate of work of breathing and implementation of an automatic tube compensation, and (2) be important for gentle ventilation in respiratory care, especially of small infants, since it enables the physician to estimate

  3. INORGANIC CATIONS IN THE CELL NUCLEUS

    PubMed Central

    Tres, Laura L.; Kierszenbaum, A. L.; Tandler, C. J.

    1972-01-01

    Earlier reports indicated the presence of significant amounts of inorganic salts in the nucleus. In the present study the possibility that this might be related to the transcription process was tested on seminiferous epithelium of the adult mouse, using potassium pyroantimonate as a fixative. The results indicated that a correlation exists between the inorganic cations comprising the pyroantimonate-precipitable fraction and the RNA synthetic activity. During meiotic prophase an accumulation of cation-antimonate precipitates occurs dispersed through the middle pachytene nuclei, the stage in which RNA synthesis reaches a maximum. At other stages (zygotene to diplotene), where RNA synthesis falls to a low level, that pattern is not seen; cation-antimonate deposits are restricted to a few masses in areas apparently free of chromatin. The condensed sex chromosomes, the heterochromatin of the "basal knobs," the axial elements, and the synaptonemal complexes are devoid of antimonate deposits during the meiotic prophase. The Sertoli cells, active in RNA synthesis in both nucleoplasm and nucleolus, show cation-antimonate deposits at these sites. In the nucleoplasm some "patches" of precipitates appear coincident with clusters of interchromatin granules; in the nucleolus the inorganic cations are mainly located in the fibrillar and/or amorphous areas, whereas relatively few are shown by the granular component. The condensed chromatin bodies associated with the nucleolus were always free of antimonate precipitates. It is suggested that the observed sites of inorganic cation accumulation within the nucleus may at least partially indicate the presence of RNA polymerases, the activity of which is dependent on divalent cations. PMID:4112542

  4. Decreased Staphylococcus aureus biofilm formation on nanomodified endotracheal tubes: a dynamic airway model

    PubMed Central

    Machado, Mary C; Tarquinio, Keiko M; Webster, Thomas J

    2012-01-01

    Ventilator-associated pneumonia (VAP) is a serious and costly clinical problem. Specifically, receiving mechanical ventilation for over 24 hours increases the risk of VAP and is associated with high morbidity, mortality, and medical costs. Cost-effective endotracheal tubes (ETTs) that are resistant to bacterial infections could help prevent this problem. The objective of this study was to determine differences in the growth of Staphylococcus aureus on nanomodified and unmodified polyvinyl chloride (PVC) ETTs under dynamic airway conditions simulating a ventilated patient. PVC ETTs were modified to have nanometer surface features by soaking them in Rhizopus arrhisus, a fungal lipase. Twenty-four-hour experiments (supported by computational models) showed that airflow conditions within the ETT influenced both the location and the concentration of bacterial growth on the ETTs, especially within areas of tube curvature. More importantly, experiments revealed a 1.5 log reduction in the total number of S. aureus on the novel nanomodified ETTs compared with the conventional ETTs after 24 hours of airflow. This dynamic study showed that lipase etching can create nanorough surface features on PVC ETTs that suppress S. aureus growth, and thus may provide clinicians with an effective and inexpensive tool to combat VAP. PMID:22904622

  5. Decreased Staphylococcus aureus biofilm formation on nanomodified endotracheal tubes: a dynamic airway model.

    PubMed

    Machado, Mary C; Tarquinio, Keiko M; Webster, Thomas J

    2012-01-01

    Ventilator-associated pneumonia (VAP) is a serious and costly clinical problem. Specifically, receiving mechanical ventilation for over 24 hours increases the risk of VAP and is associated with high morbidity, mortality, and medical costs. Cost-effective endotracheal tubes (ETTs) that are resistant to bacterial infections could help prevent this problem. The objective of this study was to determine differences in the growth of Staphylococcus aureus on nanomodified and unmodified polyvinyl chloride (PVC) ETTs under dynamic airway conditions simulating a ventilated patient. PVC ETTs were modified to have nanometer surface features by soaking them in Rhizopus arrhisus, a fungal lipase. Twenty-four-hour experiments (supported by computational models) showed that airflow conditions within the ETT influenced both the location and the concentration of bacterial growth on the ETTs, especially within areas of tube curvature. More importantly, experiments revealed a 1.5 log reduction in the total number of S. aureus on the novel nanomodified ETTs compared with the conventional ETTs after 24 hours of airflow. This dynamic study showed that lipase etching can create nanorough surface features on PVC ETTs that suppress S. aureus growth, and thus may provide clinicians with an effective and inexpensive tool to combat VAP.

  6. Computer-aided detection of malpositioned endotracheal tubes in portable chest radiographs

    NASA Astrophysics Data System (ADS)

    Huo, Zhimin; Mao, Hongda; Zhang, Jane; Sykes, Anne-Marie; Munn, Samson; Wandtke, John

    2014-03-01

    Portable chest radiographic images play a critical role in examining and monitoring the condition and progress of critically ill patients in intensive care units (ICUs). For example, portable chest images are acquired to ensure that tubes inserted into the patients are properly positioned for effective treatment. In this paper, we present a system that automatically detects the position of an endotracheal tube (ETT), which is inserted into the trachea to assist patients who have difficulty breathing. The computer detection includes the detections of the lung field, spine line, and aortic arch. These detections lead to the identification of regions of interest (ROIs) used for the subsequent detection of the ETT and carina. The detection of the ETT and carina is performed within the ROIs. Our ETT and carina detection methods were trained and tested on a large number of images. The locations of the ETT and carina were confirmed by an experienced radiologist for the purpose of performance evaluation. Our ETT detection achieved an average sensitivity of 85% at less than 0.1 false-positive detections per image. The carina approach correctly identified the carina location within a 10 mm distance from the truth location for 81% of the 217 testing images. We expect our system will assist ICU clinicians to detect malpositioned ETTs and reposition malpositioned ETTs more effectively and efficiently.

  7. Ventilator associated pneumonia and endotracheal tube repositioning: an underrated risk factor.

    PubMed

    McGovern Murphy, F; Raymond, M; Menard, P-A; Bejar-Ardiles, K-R; Carignan, A; Lesur, O

    2014-12-01

    Aspiration of secretions toward lower airways potentially occurs during endotracheal tube (ETT) repositioning in mechanically ventilated patients in the intensive care unit and may be a risk factor for developing ventilator-associated pneumonia (VAP). This case-control study confirms that repositioning of the ETT is an independent risk factor for VAP.

  8. Preventing cuff rupture during tracheostomy: importance of endotracheal tube positioning.

    PubMed

    Sood, Amit; Taheri, M Reza; Joshi, Arjun S

    2014-09-01

    The objective of our study is to describe the technique of distal endotracheal tube (ETT) positioning for avoiding cuff rupture and validate the technique in a virtual tracheostomy model. A prospective nonrandomized case series of 129 patients who had undergone tracheostomy using the senior author's technique were evaluated. Primary outcome was ETT cuff rupture. One hundred normal patient computed tomography (CT) scans were used to generate a virtual tracheostomy model, and the probability of cuff rupture, among other values, was obtained. One hundred twenty-three of 129 patients underwent tracheostomy without cuff rupture when the distal tip of the ETT was placed just proximal to the carina. After analysis of 100 3-dimensional CT scans, the average distance from the tracheotomy to the superior aspect of the cuff was 54.6 mm in men and 39.87 mm in women when a 6.5-size ETT was used, and 44.8 mm in men and 30.07 mm in women when a 7.5-size ETT was used. Virtual tracheotomy between the second and third tracheal rings resulted in no probability of inadvertent ETT cuff rupture. Distal ETT positioning during tracheostomy should be considered for avoiding inadvertent ETT cuff rupture. © The Author(s) 2014.

  9. Effective Teaching Training. Program Evaluation.

    ERIC Educational Resources Information Center

    Vanderburg, Arne S.; Shainline, Michael

    Workshops for teachers given under the Effective Teaching Training (ETT) program of the Albuquerque (New Mexico) Public Schools were evaluated. Based on the Upland Model of Effective Teaching, ETT will be extended to all teachers and administrators in the district by the end of the 1988-89 school year. Interviews, workshop ratings, and…

  10. [Final report for DOE contract FG03-88ER13882

    SciTech Connect

    1999-04-30

    The female reproductive organ, the gynoecium, is the most complex structure that plants produce. The molecular mechanisms that coordinate its development are unknown, but can be dissected by molecular genetics. The ettin (ett) mutation provides a remarkable window for viewing gynoecium development. ett induced alterations result from misinterpretation of positional information along longitudinal and transverse gynoecial axes. Molecular cloning revealed the ETT encoded amino acid sequence is homologous to transcriptional factors involved in signaling by the plant hormone auxin. Early ETT gene expression marks the site of the future outgrowth of the gynoecium. The primary gene sequence and pattern of expression of ETT fits with a role in hormone mediated signaling for regional development in the female organ.

  11. Comparison of rest and exercise radionuclide angiocardiography and exercise treadmill testing for diagnosis of anatomically extensive coronary artery disease

    SciTech Connect

    Campos, C.T.; Chu, H.W.; D'Agostino, H.J. Jr.; Jones, R.H.

    1983-06-01

    The accuracy of rest and exercise radionuclide angiocardiography (RNA) and exercise treadmill testing (ETT) for diagnosis of three-vessel or left main coronary artery disease (extensive CAD) was determined in 544 patients. ETT and RNA sensitivities were similar (88% vs 92%, NS), but ETT was more specific than RNA (46% vs 34%, p less than 0.01). The prevalence of extensive CAD in patients with a positive treadmill (41%) increased only 3% when the RNA was also positive. However, in the 292 patients with a negative or indeterminate ETT, a positive RNA increased this prevalence from 16% to 23%, while a negative RNA decreased this prevalence to 5%. These results support the initial use of ETT followed by RNA if the treadmill is negative or indeterminate for diagnosis in a population with a high prevalence of extensive CAD. This approach separates patients into subgroups with a high or low probability of extensive CAD.

  12. Securing endotracheal tubes: does NeoBar availability improve tube position?

    PubMed

    Brinsmead, Tammy Lee; Davies, Mark William

    2010-05-01

    To assess if neonatal endotracheal tube (ETT) position improved with introduction of the NeoBar. This retrospective study compared two cohorts of intubated neonates and their x-rays. During the first 2-month study period, ETTs were secured with tape only--the 'Tape-only' period; during the second study period, they were secured with a NeoBar (or tape if the NeoBar was unsuitable)--the 'NeoBar' period. ETT tip position was assessed subjectively as very high, high, OK, low, or very low; and objectively by vertebral body position and the ETT-tip-to-T1 distance. During the Tape-only period, 59 babies had 275 x-rays with an ETT visible. During the NeoBar period, 67 babies had 331 x-rays with an ETT visible. There were 160 (58.2%) and 193 (58.3%) assessed as OK during the Tape-only and NeoBar periods, respectively (Fisher's Exact Test, P= 1.0). There were more very high tubes during the NeoBar period, and more low and very low tubes during the Tape-only period (Chi-squared test, P= 0.011). A similar trend was observed with the distribution of the ETT-tip-to-T1 distance (difference not statistically significant, Mann-Whitney test, P= 0.079). During both time periods, less than two-thirds of ETTs were located in an acceptable position. For ETTs in unacceptable positions, there were more tubes in the higher positions during the NeoBar period, and more tubes in the lower positions during the Tape-only period. Further investigation is necessary to clarify if the differences in ETT position on x-ray correlate with relevant clinical outcomes.

  13. Comparison of intubation performance by junior emergency department doctors using gum elastic bougie versus stylet reinforced endotracheal tube insertion techniques.

    PubMed

    Brazil, Victoria; Grobler, Catharina; Greenslade, Jaimi; Burke, John

    2012-04-01

    Endotracheal intubation is a challenging procedure in emergency medicine. Junior doctors lack experience and confidence in this task. The use of a gum elastic bougie (GEB) to facilitate intubation may improve success rates, especially in difficult situations. Junior doctors working in the ED were studied. Endotracheal intubation was simulated using part-task trainers in "easy" positioning and "difficult" positioning modes. Intubation was attempted in both positions using either an endotracheal tube, with re-enforcing stylet (ETT-S), or insertion of a gum elastic bougie (GEB), with subsequent passage of the endotracheal tube over the bougie. Success rates and time to complete intubation were measured with GEB, and with ETT-S. Participants were asked to record the perceived ease of intubation. One hundred and four intubations were performed by 26 study subjects. Overall, mean time to intubation with ETT-S technique was 16.14 s (14.49-17.98 95% CI), and was faster than with GEB 24.18 (21.45-27.25 95% CI) in both airway difficulty grades (P < 0.01). The success rate for intubation using the GEB was 100%, compared with 92.9% with ETT-S. This difference was not statistically significant. Perceived ease of intubation was similar for GEB and ETT-S (VAS 6.808 vs 6.904). The use of a GEB marginally increases the time taken to perform endotracheal intubation. Success rates for junior doctors attempting endotracheal intubation were not significantly different between the two techniques. Success rates for novice practitioners using a GEB were high after even limited instruction and practice. © 2011 The Authors. EMA © 2011 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

  14. Resistance of pediatric and neonatal endotracheal tubes: influence of flow rate, size, and shape.

    PubMed

    Manczur, T; Greenough, A; Nicholson, G P; Rafferty, G F

    2000-05-01

    The aim of this study was to determine the resistances of endotracheal tubes (ETTs) commonly used in neonatal and pediatric intensive care units and the relationship of resistance to flow rate, size, and shape of ETT. Laboratory-based measurements. We examined straight tubes with inner diameters between 2.5 and 6 mm and shouldered (Cole) tubes with inner diameter/outer diameter between 2.5/4 and 3.5/5 mm. We assessed ETT resistance at standard and "appropriate for patient use" lengths at flow rates from 0 L/min to 30 L/min. We used calibrated rotameters to control the flow of gas and proximal static pressure measured by using either an industrial draft gauge or a differential pressure transducer. The ETT resistance was calculated by dividing the proximal ETT pressure by the measured flow and expressed as the mean of three measurements at each flow rate. Resistance increased as ETT diameter decreased; at flows of 5 L/min and 10 L/min, the resistances of the 6 mm inner diameter ETT were 3.1 H2O/L/sec and 4.6 cm H20/L/ sec, respectively, and the resistances of the 2.5 mm inner diameter ETT were 81.2 H2O/L/sec and 139.4 cm H20/L/sec, respectively. Shortening an ETT to a length appropriate for patient use (e.g., a 4.0 mm inner diameter, from 20.7 to 11.3 cm) reduced its resistance on average by 22%. The resistance of a Cole tube was approximately 50% lower than that of a straight tube with an inner diameter corresponding to the narrow part of the shouldered tube. Our results suggest that the use of a small-diameter, straight ETT will significantly increase the work of breathing.

  15. Prompt correction of endotracheal tube positioning after intubation prevents further inappropriate positions.

    PubMed

    Rigini, Nugzar; Boaz, Mona; Ezri, Tiberiu; Evron, Shmuel; Trigub, Dimitry; Jackobashvilli, Simon; Izakson, Alexander

    2011-08-01

    To determine whether the timely correction of endotracheal tube (ETT) positioning prevents further inappropriate positions. Prospective crossover study. University-affiliated hospital. 44 adult, ASA physical status 1, 2, and 3 patients undergoing open or laparoscopic abdominal procedures. ETT positioning was verified by both auscultation and fiberoptic bronchoscopy (FOB), after intubation, and before extubation. In laparoscopic procedures, two additional measurements were performed: after maximal abdominal gas insufflation and with head-down position. An ETT in the bronchus or at the carina was considered an inappropriate placement. An ETT ≤ one cm from the carina was considered a critical placement. The frequency of inappropriate and critical ETT positioning with both auscultation and FOB and the number of ETTs that remained in an incorrect position despite repositioning. FOB detected 5 inappropriately positioned ETTs, 4 of which were also detected by chest auscultation (P = 0.99). Critical positioning was detected by FOB in 6 patients, three of which were also detected by auscultation (P = 0.24). There were 15 other "out-of-desired range" positions (out of the 3-5 cm range) - one placed too high and 14 placed too low, while 18 were placed within the range of positions. All patients with inappropriate ETT positioning were women (P = 0.005). Age, body mass index, Mallampati grade > 3, thyromental distance < 6 cm, or laryngoscopy grade ≥ 2 were not associated with either inappropriate or critical placement. No episodes of inappropriate or critical positioning were detected by FOB or auscultation at the end of surgery. Early detection and prompt correction of inappropriate ETT positioning after intubation prevented further ETT migration into undesired positions. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. Factors Associated with Misplaced Endotracheal Tubes During Intubation in Pediatric Patients.

    PubMed

    Miller, Kelsey A; Kimia, Amir; Monuteaux, Michael C; Nagler, Joshua

    2016-07-01

    Correct positioning of the endotracheal tube (ETT) during emergent pediatric intubations can be challenging, and incorrect placement may be associated with higher rates of complications. The aims of this study are to: 1) assess the prevalence of clinically undetected misplaced ETTs after intubation in the pediatric emergency department; 2) identify predictors of ETT misplacement; and 3) evaluate for any association between intubation-related complications and ETT position. In this retrospective cross-sectional study, the primary outcome was rate of unrecognized low or high ETTs detected on confirmatory chest radiographs. The secondary outcome was frequency of complications (i.e., hypoxemia, difficult ventilation, atelectasis, pneumothorax, pneumomediastinum, and aspiration) associated with misplaced ETTs. Multivariable analyses were used to evaluate the associations between patient and procedural characteristics and misplaced ETTs and between ETT position and complications. Seventy-seven of 201 (38.3%) intubations performed in the emergency department resulted in clinically unrecognized misplaced ETTs. Of the misplaced tubes, 45 of 77 (58%) were identified as low and 32 (42%) were high. In multivariable analyses, female sex and decreasing age were associated with increased risk of low tube placement (odds ratio for female sex, 2.4 [95% confidence interval, 1.1-5.1]; odds ratio of decreasing age, 1.16 [95% confidence interval, 1.0-1.3]). Low tube misplacement was associated with an increased risk of intubation-related complications compared to both correct and high tube placement (p < 0.05, Chi-square). Clinically unrecognized ETT misplacement occurs frequently in the pediatric emergency department, with low placement being most common, particularly in girls and younger children. Measures to improve clinical or radiographic recognition of incorrect tube position should be considered. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. CCSD(T) study of the infrared spectrum of ethyl-methyl-ether isotopic varieties

    NASA Astrophysics Data System (ADS)

    Senent, M. L.; Ruiz, R.; Villa, M.; Domínguez-Gómez, R.

    2010-02-01

    Band positions for the infrared bands of various ethyl-methyl-ether isotopomers (CH 3CH 2OCH 2D, CH 2DCH 2OCH 3, CH 3CH 2OCD 3, CD 3CH 2OCH 3, CH 3CD 2OCH 3, CH 3CH 2O 13CH 3, 13CH 3CH 2OCH 3, and CH 313CH 2OCH 3) are determined using second order perturbation theory. For species showing G18 symmetry, band position are calculated variationally from a CCSD(T)/cc-pVTZ three-dimensional potential energy surface corrected vibrationally. Potential energy barriers, fundamental frequencies, and rotational constants for excited vibrational levels, are also provided. Calculated frequencies for CH 3CH 2OCD 3 confirm experimental assignments and our predictions for the most abundant isotopomer [4].

  18. Molecular Basis for the Toxicity of Schweinfurthins to Breast Cancer cells

    DTIC Science & Technology

    2005-05-01

    OCH 3 DIPEA, OCH3 nBuLi,o OCH3 HO.MOMI MOMO geranyl bromide Br 95% Br 19 OH 20 OMOM 21 OMOM 63%j AD-mix-a, MeSO 2 NH 2 OCH3 OCH3 MOMO 1) MsCI, TEA...OH MOMO 0,, I 2) K2CO 3 , MeOH OMOM HO = OMOM 36%• F,0° [a]D = -649O 2250%)/IEDC, DMAP, OCH3 R-O-methylphenylacetic acid Ŕ OCHO Ph MOMO HO’ OH3...Gaumond, B. R.; closed in due course. Marsh, H. C. J. Med Chem. 2003, 46, 2697-2705. OMOM OMOM O=P(OEt)2 MOMO @ • MOMO . OMOM NaH, 15C5 OMOM N O1

  19. [BLOODSUCKING MOSQUITOES (DIPTERA: CULICIDAE) IN, THE TULA REGION ARE POTENTIAL VECTORS OF DIROFILARIAS].

    PubMed

    Bogacheva, A S; Ganushkina, L A; Lopatina, Yu V

    2015-01-01

    Bloodsucking mosquitoes were collected in Tula and its Region in May to August 2013-2014. The fauna included 17 species from 5 genera in the subfamily Culicinae and Anopheles maculipennis complex in the subsystem Anophelinae. Ochlerotatus cantans was a dominant species in the collections. The dominant species also included Aedes einereus, Ae. vexans, Ae. geniculatus, Och. diantaeus, Och. intrudens, Och. Cataphylla, and Culex pipiens. The possible value of different mosquito species Dirofilaria repens and D. immitis as vectors of dirofilarasis was discussed.

  20. Improving Domain-specific Machine Translation by Constraining the Language Model

    DTIC Science & Technology

    2012-07-01

    of greater amounts of training data in the two models, especially in the target language model (Brants et al., 2007). Och (2005) reports findings...train with the largest language models (NIST, 2006). The highest scoring Arabic-English system used a 1-trillion-word language model ( Och , 2006...References Brants, T.; Popat, A. C.; Xu, P.; Och , F. J.; Dean, J. Large Language Models in Machine Translation. Joint Meeting of the Conference on Empirical

  1. Fluid inclusions in the system H sub 2 O-CH sub 4 -NaCl-CO sub 2 from metasomatic tourmaline within the border unit of the Tanco zoned granitic pegmatite, S. E. Manitoba

    SciTech Connect

    Thomas, A.V.; Spooner, E.T. )

    1988-05-01

    Fluid inclusions from the tourmaline phase of alteration of the footwall amphibolite from the Tanco zoned granitic pegmatite lie in the system H{sub 2}O-CH{sub 4}-NaCl-CO{sub 2}. These inclusions contain a liquid and vapor phase at room temperature and develop a second liquid phase on cooling in the range {minus}77 to {minus}95{degree}C: the second liquid and the vapor are methane. Isochores for inclusions showing vapor phase (CH{sub 4}) homogenization were constructed from the equations of Jacobs and Kerrick (1981). The intersections of these isochores with the univariant melting curves for methane clathrate hydrates give estimates of salinity for the inclusions of between 7 and 10 equivalent wt.% NaCl, which are lower than those derived from measurement of the depression of the melting point of ice; a result consistent with salt exclusion by clathrate. The bulk composition of the fluid is estimated to be 91 mol.% H{sub 2}O, 6 mol.% CH{sub 4}, 2 equiv. mol.% NaCl and <1 mol.% CO{sub 2}. Total homogenization temperatures have a mean value of 371{degree}C {plus minus} 36{degree}C. Calculation of f{sub O2} from the bulk inclusion composition gives values near WI at these conditions which is unreasonably low for fluids derived from the pegmatite, which were probably between QFM and HM. The metasomatic fluids may have resulted from fluid mixing in the wall rock immediately adjacent to the pegmatite. The fluid derived from the pegmatite, a H{sub 2}O-CO{sub 2} fluid, introduced the B necessary to form tourmaline in the amphibolite. Supporting evidence is provided by pegmatite wall zone fluids with higher CH{sub 4} than the bulk of the pegmatite H{sub 2}O-CO{sub 2} fluids, suggesting marginal fluid contamination.

  2. Characterisation of temperature-dependent phase transitions in 2,2-trimethylenedioxy-4,4,6,6-tetrachlorocyclotriphosphazene, N3P3Cl4[O(CH2)3O].

    PubMed

    Coles, Simon J; Davies, David B; Hursthouse, Michael B; Huth, Susanne L; Kiliç, Adem; Light, Mark E; Odlyha, Marianne; Rutherford, John S; Shaw, Robert A; Uslu, Aylin

    2007-07-18

    The crystal structure of 2,2-trimethylenedioxy-4,4,6,6-tetrachlorocyclo triphosphazene has been determined at 120, 274 and 293 K. The result at 293 K confirms the room temperature Cmc2(1) structure, but at the lower temperatures the space group is Pna2(1). Nevertheless the basic structure remains the same, with only small displacements of the atoms, amounting to an average of 25 pm between 120 and 293 K. X-ray diffraction and DSC results indicate that the phase transition takes place in two steps between 274 - 293 K and provides an understanding of previous NQR results. In the intermediate temperature range the molecules are displaced from their room temperature positions in such a way as to give an average structure with Cmc2(1) symmetry. The overall phase transition is consistent with the occurrence of a soft lattice mode at room temperature in which a large displacement of the molecule in the x-direction is coupled with a flexing motion about an axis defined by the nitrogen atoms in the N1 and N3 positions.

  3. Larande I Produktionssytem. En studie av operatorsarbete i hogautomatiserad process--och verkstadsindustri = Learning in Production Systems. A Study of Operator Work in Highly Automated Process and Manufacturing Industry. Linkoping Studies in Education and Psychology, No. 63.

    ERIC Educational Resources Information Center

    Davidson, Bo; Svedin, Per-Olof

    This study of the conditions of developmental on-the-job training and learning for operators in highly automated industries is written in Swedish but contains an English abstract and 18-page summary. The summary begins with the study objectives, which were to determine the following: (1) conditions of developmental on-the-job learning in highly…

  4. Theoretical study of the mechanisms and kinetics of the reactions of hydroperoxy (HO2) radicals with hydroxymethylperoxy (HOCH2O2) and methoxymethylperoxy (CH3OCH2O2) radicals.

    PubMed

    Shao, Youxiang; Hou, Hua; Wang, Baoshan

    2014-11-07

    The reactions of hydroperoxy radicals with hydroxymethylperoxy and methoxymethylperoxy radicals were studied using the hybrid density functional theory and the coupled-cluster theory with complete basis set extrapolation. In contrast with the unsubstituted alkylperoxy reactions, it was found that OH-substitution has a significant effect on the reaction mechanism. Several hydrogen bonding reaction precursors exist at the start of the reaction. The reaction pathways show a strongly anisotropic character. The preferred transition states are four-, five-, six-, or seven-membered cyclic structures. The predicted rate coefficients are expressed as k(T) = 8.48 × 10(-24)T(3.55)e(2164/T) + 2.37 × 10(-29)T(4.70)e(3954/T) cm(3) molecule(-1) s(-1). Based on the available experimental data in the temperature range 275-333 K, the theoretical and experimental results are in agreement with a relative average deviation of only 8%. The nascent products at low and high temperatures are hydroperoxide molecules and hydroxyl radicals, respectively. A potential source has been found for the production of formic acid and new insights into the experimental observations are presented.

  5. Highly Selective Sensing of Li(+) in H2O/CH3CN via Fluorescence 'Turn-on' Response of a Coumarin-Indole Linked Dyad: an Experimental and Theoretical Study.

    PubMed

    Kumari, Santosh; Joshi, Sunita; Sarmah, Amrit; Pant, Debi; Sakhuja, Rajeev

    2016-11-01

    A coumarin-indole dyad, N-((7-hydroxy-2-oxo-2H-chromen-4-yl)methyl)-1H-indole-2-carboxamide has been synthesized and characterized by (1)H-NMR and (13)C-NMR. Effect of various metal ions on fluorescent behavior was also studied. The synthesized compound showed remarkable specificity towards Li(+) in organo-aqueous medium over other metal ions. Coordination of the compound with Li(+) induces a turn-on fluorescence response. The sensor exhibited good binding constant and low detection limit towards Li(+). Experimental results have been verified with Density Functional Theory and Time Dependent Density Functional Theory calculations.

  6. Oxo Complexes of Tungstenocene via Oxidation of (W(Eta(5)-C5H5)2(OCH3) (CH3)) and Related Reactions: Synthesis, Structural Characterization, and Photodisproportionation of the Spin Paired d(1)-d(1) Oxo Bridged Dimer ((W(Eta(5)-C5H5)2(CH3))2(Mu-O))2(+) and Synthesis and Charaterization of the d(0) Terminal Oxo Complex (W(Eta(5)-C5H5)2(O)(CH3))(+)

    DTIC Science & Technology

    1993-02-15

    work was supported in part by the Office of Na\\ al Research We thank Dr . Steven Geib and Professor Bruce Foxman for helpful discusions of the X-ra...techniques or a Vacuum Atmospheres dr % box under an atmosphere of prepunfied nitrogen unless otherise noted Glass%%are wvas flame dncd under vacuum or...of Naval Research (2)" Dr . Richard W. Drisko (1) Chemistry Division, Code 1113 Naval Civil Engineering 800 North Quincy Street Laboratory Arlington

  7. Prevalence, diagnosis and management of ectopic thyroid glands.

    PubMed

    Santangelo, Giuseppe; Pellino, Gianluca; De Falco, Nadia; Colella, Giuseppe; D'Amato, Salvatore; Maglione, M Grazia; De Luca, Roberto; Canonico, Silvestro; De Falco, Massimo

    2016-04-01

    Ectopic thyroid tissue (ETT) is an uncommon entity that may be found anywhere along the line of the obliterated thyroglossal duct, usually from the tongue to the diaphragm. We performed a retrospective analysis of patients undergoing surgical treatment for thyroid disease between January 2000 and December 2013, seeking for ETT All patients with prior neck surgery or trauma were excluded. The clinic-pathologic features, prevalence and diagnosis of the lesions were collected and analyzed. Out of 3092 included patients, 28 ETT were identified (0.9%). The anatomical site of ETT was as follows: lateral cervical in 6 (21.4%), along the thyroglossal duct in 6 (21.4%), mediastinal in 5 (17.9%), lingual in 5 (17.9%), sublingual in 3 (10.7%), and submandibular in 3 (10.7%). Histopathology revealed 27 benign lesions and 1 (3.6%) papillary carcinoma. ETT is found in less than 1% of patients receiving thyroid surgery. Diagnosis of ETT requires clinical imaging. Surgery is a prudent choice due to the potential of malignant evolution of ETT.

  8. Effects of anatomical position on esophageal transit time: A biomagnetic diagnostic technique

    PubMed Central

    Cordova-Fraga, Teodoro; Sosa, Modesto; Wiechers, Carlos; la Roca-Chiapas, Jose Maria De; Moreles, Alejandro Maldonado; Bernal-Alvarado, Jesus; Huerta-Franco, Raquel

    2008-01-01

    AIM: To study the esophageal transit time (ETT) and compare its mean value among three anatomical inclinations of the body; and to analyze the correlation of ETT to body mass index (BMI). METHODS: A biomagnetic technique was implemented to perform this study: (1) The transit time of a magnetic marker (MM) through the esophagus was measured using two fluxgate sensors placed over the chest of 14 healthy subjects; (2) the ETT was assessed in three anatomical positions (at upright, fowler, and supine positions; 90º, 45º and 0º, respectively). RESULTS: ANOVA and Tuckey post-hoc tests demonstrated significant differences between ETT mean of the different positions. The ETT means were 5.2 ± 1.1 s, 6.1 ± 1.5 s, and 23.6 ± 9.2 s for 90º, 45º and 0º, respectively. Pearson correlation results were r = -0.716 and P < 0.001 by subjects’ anatomical position, and r = -0.024 and P > 0.05 according the subject’s BMI. CONCLUSION: We demonstrated that using this biomagnetic technique, it is possible to measure the ETT and the effects of the anatomical position on the ETT. PMID:18837088

  9. ETTIN (ARF3) physically interacts with KANADI proteins to form a functional complex essential for integument development and polarity determination in Arabidopsis.

    PubMed

    Kelley, Dior R; Arreola, Alexandra; Gallagher, Thomas L; Gasser, Charles S

    2012-03-01

    KANADI (KAN) transcription factors promote abaxial cell fate throughout plant development and are required for organ formation during embryo, leaf, carpel and ovule development. ABERRANT TESTA SHAPE (ATS, or KAN4) is necessary during ovule development to maintain the boundary between the two ovule integuments and to promote inner integument growth. Yeast two-hybrid assays identified ETTIN (ETT, or AUXIN RESPONSE FACTOR 3) as a transcription factor that could physically interact with ATS. ATS and ETT were shown to physically interact in vivo in transiently transformed tobacco epidermal cells using bimolecular fluorescence complementation. ATS and ETT were found to share an overlapping expression pattern during Arabidopsis ovule development and loss of either gene resulted in congenital fusion of the integuments and altered seed morphology. We hypothesize that in wild-type ovules a physical interaction between ATS and ETT allows these proteins to act in concert to define the boundary between integument primordia. We further show protein-protein interaction in yeast between ETT and KAN1, a paralog of ATS. Thus, a direct physical association between ETT and KAN proteins underpins their previously described common role in polarity establishment and organogenesis. We propose that ETT-KAN protein complex(es) constitute part of an auxin-dependent regulatory module that plays a conserved role in a variety of developmental contexts.

  10. Comparative effectiveness of exercise electrocardiography with or without myocardial perfusion single photon emission computed tomography in women with suspected coronary artery disease: results from the What Is the Optimal Method for Ischemia Evaluation in Women (WOMEN) trial.

    PubMed

    Shaw, Leslee J; Mieres, Jennifer H; Hendel, Robert H; Boden, William E; Gulati, Martha; Veledar, Emir; Hachamovitch, Rory; Arrighi, James A; Merz, C Noel Bairey; Gibbons, Raymond J; Wenger, Nanette K; Heller, Gary V

    2011-09-13

    There is a paucity of randomized trials regarding diagnostic testing in women with suspected coronary artery disease (CAD). It remains unclear whether the addition of myocardial perfusion imaging (MPI) to the standard ECG exercise treadmill test (ETT) provides incremental information to improve clinical decision making in women with suspected CAD. We randomized symptomatic women with suspected CAD, an interpretable ECG, and ≥5 metabolic equivalents on the Duke Activity Status Index to 1 of 2 diagnostic strategies: ETT or exercise MPI. The primary end point was 2-year incidence of major adverse cardiac events, defined as CAD death or hospitalization for an acute coronary syndrome or heart failure. A total of 824 women were randomized to ETT or exercise MPI. For women randomized to ETT, ECG results were normal in 64%, indeterminate in 16%, and abnormal in 20%. By comparison, the exercise MPI results were normal in 91%, mildly abnormal in 3%, and moderate to severely abnormal in 6%. At 2 years, there was no difference in major adverse cardiac events (98.0% for ETT and 97.7% for MPI; P=0.59). Compared with ETT, index testing costs were higher for exercise MPI (P<0.001), whereas downstream procedural costs were slightly lower (P=0.0008). Overall, the cumulative diagnostic cost savings was 48% for ETT compared with exercise MPI (P<0.001). In low-risk, exercising women, a diagnostic strategy that uses ETT versus exercise MPI yields similar 2-year posttest outcomes while providing significant diagnostic cost savings. The ETT with selective follow-up testing should be considered as the initial diagnostic strategy in symptomatic women with suspected CAD. http://www.clinicaltrials.gov. Unique identifier: NCT00282711.

  11. The use of a novel cleaning closed suction system reduces the volume of secretions within the endotracheal tube as assessed by micro-computed tomography: a randomized clinical trial.

    PubMed

    Coppadoro, Andrea; Bellani, Giacomo; Bronco, Alfio; Lucchini, Alberto; Bramati, Simone; Zambelli, Vanessa; Marcolin, Roberto; Pesenti, Antonio

    2015-12-01

    Early after intubation, a layer of biofilm covers the inner lumen of the endotracheal tube (ETT). Cleaning the ETT might prevent airways colonization by pathogens, reduce resistance to airflow, and decrease sudden ETT obstruction. We investigated the effectiveness of a cleaning closed suction system in maintaining the endotracheal tube free from secretions. We conducted a single center, randomized controlled trial, in the general intensive care unit of a tertiary-level university hospital. We enrolled 40 adult critically ill patients expected to remain intubated for more than 48 h, within 24 h from intubation. Patients were randomized to receive three ETT cleaning maneuvers/day using a novel device (Airway Medix Closed Suction System™, cleaning group) or to standard care (no ETT cleaning, standard closed suction, control group). After extubation, the amount of secretions in the ETTs was measured by micro-computed tomography. The volume of secretions in the ETTs from the cleaning group was lower than controls (0.081 [0.021-0.306] vs. 0.568 [0.162-0.756] mL, p = 0.001), corresponding to a cross-sectional area reduction six times lower (1[0-3] vs. 6 [2-10] %, p = 0.001). In a subset of 16 patients, the resistance to airflow tended to be lower after 1 day of treatment (p = 0.063) and was lower after 2 days (0.024), while no difference was present at enrollment (p = 0.922). ETT colonization did not differ between the two groups. The use of a novel cleaning closed suction system proved to be effective in reducing secretions present in the ETT after extubation, possibly reducing resistance to airflow during intubation. clinicaltrials.gov NCT01912105.

  12. In search of the false-negative exercise treadmill testing evidence-based use of exercise echocardiography.

    PubMed

    Southard, Jeffrey; Baker, Larry; Schaefer, Saul

    2008-01-01

    Controversy exists regarding the role of exercise treadmill testing (ETT) versus exercise stress echocardiography (ESE) as the appropriate initial noninvasive test to risk-stratify patients with chest pain. The majority of studies to date that evaluated these methodologies included patients with poor functional status and baseline electrocardiogram (ECG) abnormalities, potentially limiting the sensitivity of ETT. We examined the hypothesis that given stringent standards of exercise duration and ECG interpretability, the ETT would have a high diagnostic sensitivity for the presence of significant coronary artery disease (CAD). Results of concurrent ETT and ESE in 3,098 patients were examined, and the subset of patients with a negative ETT and positive ESE (-ETT/ + ESE) were reviewed for the presence of CAD as a function of exercise duration (< or > or = 6 min) and baseline ECG normality. In those patients with a - ETT/ + ESE who exercised > or = 6 min, 54 had a normal baseline ECG, 22 underwent angiography and 6 had CAD (all of whom had either small, grafted or collateralized vessels). Patients with a - ETT/ + ESE who were incapable of exercising 6 min were more frequently older and female. Mortality was significantly greater in the < 6 min exercise duration group (31.4 versus 3.1%). These findings support the use of the ETT without imaging as the initial test in patients with chest pain who have a normal baseline ECG and are able to exercise 6 min. Using these criteria, false negative findings are generally seen in patients without critical large vessel epicardial disease. The ESE should be reserved as the initial test for patients with an abnormal baseline ECG or reduced functional capacity. 2007 Wiley Periodicals, Inc

  13. Differentiation of stem cells into insulin-producing cells under the influence of nanostructural polyoxometalates.

    PubMed

    Bâlici, Ştefana; Şuşman, Sergiu; Rusu, Dan; Nicula, Gheorghe Zsolt; Soriţău, Olga; Rusu, Mariana; Biris, Alexandru S; Matei, Horea

    2016-03-01

    Two polyoxometalates (POMs) with W were synthesized by a two-step, self-assembling method. They were used for stimulation of mesenchymal stem cell differentiation into insulin-producing cells. The nanocompounds (tris(vanadyl)-substituted tungsto-antimonate(III) anions [POM1] and tris-butyltin-21-tungsto-9-antimonate(III) anions [POM2]) were characterized by analytical techniques, including ultraviolet-visible, Fourier transform infrared, nuclear magnetic resonance spectroscopy, and transmission electron microscopy. We found that these polyoxotungstates, with 2-4 nm diameters, did not present toxic effects at the tested concentrations. In vitro, POM1 stimulated differentiation of a greater number of dithizone-positive cells (also organized in clusters) than the second nanocompound (POM2). Based on our in vitro studies, we have concluded that both the POMs tested had significant biological activity acting as active stimuli for differentiation of stem cells into insulin-producing cells.

  14. Microwave fixation and localization of calcium in synaptic terminals using x-ray microanalysis and electron energy loss spectroscopy imaging.

    PubMed

    Mizuhira, V; Hasegawa, H

    1997-01-01

    The distribution of calcium ions is demonstrated in synaptic terminals by means of a two-step chemical precipitation of calcium ions in the rat brain. K-oxalate/K-antimonate chemical replacement with simultaneous computerized microwave irradiation was used. This precipitate in nerve cell structures was investigated by computerized electron probe x-ray microanalysis (EDX) and electron energy loss spectroscopic (EELS) imaging. The values obtained by EDX agreed with those of the standard sample and theoretical values of Ca-antimonate. Typical EELS spectra of Ca:L, O:K, and Sb:M were obtained from nerve terminals in the same tissue block as that used for EDX analysis. Excellent net Ca:L and Sb:M EELS digital images were obtained after their background images were subtracted. Calcium ions were distributed in the nerve terminals, synaptic vesicles, mitochondria, and synaptic membranes.

  15. Evaluation of a new circuit configuration for the VDR-4 high-frequency percussive ventilator.

    PubMed

    Jones, Samuel W; Short, Kathy A; Hanson, William J; Hendrix, Laura; Charles, Anthony G; Cairns, Bruce A

    2010-01-01

    High-frequency percussive ventilation (HFPV) by the VDR-4(R) has been a successful mode of ventilation in the management of inhalation injuries for nearly 20 years. A limitation of the standard VDR-4 ventilator circuit is that the sliding venturi manifold is heavy in weight and is normally connected directly to the patient's endotracheal tube (ETT), resulting in potentially hazardous torque on the ETT. In this study, we evaluate the mechanics of a new circuit for the VDR-4 that relocates the sliding venturi manifold portion of the circuit away from the ETT into the ventilator proper. This new VDR-4 circuit configuration may have an important impact on patient safety.

  16. Comparison of the cuff pressure of a TaperGuard endotracheal tube and a cylindrical endotracheal tube after lateral rotation of head during middle ear surgery: A single-blind, randomized clinical consort study.

    PubMed

    Choi, Eunkyung; Park, Yongmin; Jeon, Younghoon

    2017-03-01

    Positional change affects the cuff pressure of an endotracheal tube (ETT) in treacheally intubated patients. We compared the cuff pressure of a TaperGuard ETT and a cylindrical ETT after lateral rotation of head during middle ear surgery. Fifty-two patients aged 18-70 years underwent a tympanomastoidectomy under general anesthesia were randomly allocated to receive endotracheal intubation with cylindrical (group C, n = 26) or TaperGuard ETTs (group T, n = 26). After endotracheal intubation, the ETT cuff pressure was set at 22 cmH2O in the neutral position of head. After lateral rotation of head, the cuff pressure was measured again and readjusted to 22 cmH2O. In addition, the change of distance from the carina to the tip of the ETT was measured before and after the positional change. The incidence of cough, sore throat, and hoarseness was assessed at 30 minutes, 6 hours, and 24 hours after surgery. There was no difference in demographic data between groups. After lateral rotation of head, the cuff pressure significantly increased in group T (11.9 ± 2.3 cmH2O) compared with group C (6.0 ± 1.9 cmH2O) (P < 0.001). The incidence of a cuff pressure >30 cmH2O was higher in group T (96.2%) than in group C (30.8%) (P < 0.001). In addition, the degree of displacement of an ETT was greater in group T (11.0 ± 1.7 mm) than in group C (7.2 ± 2.6 mm) (P < 0.001). The overall incidences of postoperative sore throat, hoarseness, and cough at 30 minutes, 6 hours, and 24 hours after surgery were comparable between two groups. The cuff pressure was higher in the TaperGuard ETT than in the cylindrical ETT after positional change of head from neutral to lateral rotation. In addition, after a positional change, the extent of displacement of ETT was greater in the TaperGuard ETT than in the cylindrical ETT.

  17. Comparison of the cuff pressure of a TaperGuard endotracheal tube and a cylindrical endotracheal tube after lateral rotation of head during middle ear surgery

    PubMed Central

    Choi, Eunkyung; Park, Yongmin; Jeon, Younghoon

    2017-01-01

    Abstract Background: Positional change affects the cuff pressure of an endotracheal tube (ETT) in treacheally intubated patients. We compared the cuff pressure of a TaperGuard ETT and a cylindrical ETT after lateral rotation of head during middle ear surgery. Methods: Fifty-two patients aged 18–70 years underwent a tympanomastoidectomy under general anesthesia were randomly allocated to receive endotracheal intubation with cylindrical (group C, n = 26) or TaperGuard ETTs (group T, n = 26). After endotracheal intubation, the ETT cuff pressure was set at 22 cmH2O in the neutral position of head. After lateral rotation of head, the cuff pressure was measured again and readjusted to 22 cmH2O. In addition, the change of distance from the carina to the tip of the ETT was measured before and after the positional change. The incidence of cough, sore throat, and hoarseness was assessed at 30 minutes, 6 hours, and 24 hours after surgery. Results: There was no difference in demographic data between groups. After lateral rotation of head, the cuff pressure significantly increased in group T (11.9 ± 2.3 cmH2O) compared with group C (6.0 ± 1.9 cmH2O) (P < 0.001). The incidence of a cuff pressure >30 cmH2O was higher in group T (96.2%) than in group C (30.8%) (P < 0.001). In addition, the degree of displacement of an ETT was greater in group T (11.0 ± 1.7 mm) than in group C (7.2 ± 2.6 mm) (P < 0.001). The overall incidences of postoperative sore throat, hoarseness, and cough at 30 minutes, 6 hours, and 24 hours after surgery were comparable between two groups. Conclusion: The cuff pressure was higher in the TaperGuard ETT than in the cylindrical ETT after positional change of head from neutral to lateral rotation. In addition, after a positional change, the extent of displacement of ETT was greater in the TaperGuard ETT than in the cylindrical ETT. PMID:28272230

  18. Discordance of exercise thallium testing with coronary arteriography in patients with atypical presentations

    SciTech Connect

    Bungo, M.W.; Leland, O.S. Jr.

    1983-01-01

    Eighty-one patients with diagnostically difficult clinical presentations suggesting coronary disease underwent symptom-limited maximal-exercise treadmill testing (ETT) and exercise radionuclide scanning with /sup 201/Tl. Results of these tests were in agreement in only 47 percent of the cases. Either exercise thallium or ETT was positive in 94 percent of patients with disease. Among a population with a disease prevalence of 67 percent, agreement between exercise thallium an ETT predicted disease in 92 percent of instances or excluded disease in 82 percent of instances. Frequent discordance between these two tests in 53 percent of the cases unfortunately limits this usefulness.

  19. Test procedure for cation exchange chromatography

    SciTech Connect

    Cooper, T.D.

    1994-08-24

    The purpose of this test plan is to demonstrate the synthesis of inorganic antimonate ion exchangers and compare their performance against the standard organic cation exchangers. Of particular interest is the degradation rate of both inorganic and organic cation exchangers. This degradation rate will be tracked by determining the ion exchange capacity and thermal stability as a function of time, radiation dose, and chemical reaction.

  20. 40 CFR 421.146 - Pretreatment standards for new sources.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... pounds) of antimony contained in sodium antimonate product Antimony 30.150 13.440 Arsenic 21.720 9.687... metal produced by electrowinning Antimony 30.150 13.440 Arsenic 21.720 9.687 Mercury 2.344 0.937 (c... produced by electrowinning Antimony 60.310 26.870 Arsenic 43.430 19.370 Mercury 4.687 1.875 ...

  1. 40 CFR 421.142 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... contained in sodium antimonate product Antimony 44.840 20.000 Arsenic 32.650 14.530 Mercury 3.906 1.562... produced by electrowinning Antimony 44.840 20.000 Arsenic 32.650 14.530 Mercury 3.906 1.562 Total suspended... produced by electrowinning Antimony 89.680 40.000 Arsenic 65.310 29.060 Mercury 7.812 3.125 Total suspended...

  2. 40 CFR 421.142 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... contained in sodium antimonate product Antimony 44.840 20.000 Arsenic 32.650 14.530 Mercury 3.906 1.562... produced by electrowinning Antimony 44.840 20.000 Arsenic 32.650 14.530 Mercury 3.906 1.562 Total suspended... produced by electrowinning Antimony 89.680 40.000 Arsenic 65.310 29.060 Mercury 7.812 3.125 Total suspended...

  3. 40 CFR 421.146 - Pretreatment standards for new sources.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... pounds) of antimony contained in sodium antimonate product Antimony 30.150 13.440 Arsenic 21.720 9.687... metal produced by electrowinning Antimony 30.150 13.440 Arsenic 21.720 9.687 Mercury 2.344 0.937 (c... produced by electrowinning Antimony 60.310 26.870 Arsenic 43.430 19.370 Mercury 4.687 1.875 ...

  4. 40 CFR 421.143 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... sodium antimonate product Antimony 30.150 13.440 Arsenic 21.720 9.687 Mercury 2.344 0.937 (b) Fouled... electrowinning Antimony 30.150 13.440 Arsenic 21.720 9.687 Mercury 2.344 0.937 (c) Cathode Antimony Wash Water... electrowinning Antimony 60.310 26.870 Arsenic 43.430 19.370 Mercury 4.687 1.875 ...

  5. 40 CFR 421.142 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... contained in sodium antimonate product Antimony 44.840 20.000 Arsenic 32.650 14.530 Mercury 3.906 1.562... produced by electrowinning Antimony 44.840 20.000 Arsenic 32.650 14.530 Mercury 3.906 1.562 Total suspended... produced by electrowinning Antimony 89.680 40.000 Arsenic 65.310 29.060 Mercury 7.812 3.125 Total suspended...

  6. 40 CFR 421.143 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... sodium antimonate product Antimony 30.150 13.440 Arsenic 21.720 9.687 Mercury 2.344 0.937 (b) Fouled... electrowinning Antimony 30.150 13.440 Arsenic 21.720 9.687 Mercury 2.344 0.937 (c) Cathode Antimony Wash Water... electrowinning Antimony 60.310 26.870 Arsenic 43.430 19.370 Mercury 4.687 1.875 ...

  7. 40 CFR 421.146 - Pretreatment standards for new sources.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... pounds) of antimony contained in sodium antimonate product Antimony 30.150 13.440 Arsenic 21.720 9.687... metal produced by electrowinning Antimony 30.150 13.440 Arsenic 21.720 9.687 Mercury 2.344 0.937 (c... produced by electrowinning Antimony 60.310 26.870 Arsenic 43.430 19.370 Mercury 4.687 1.875 ...

  8. 40 CFR 421.146 - Pretreatment standards for new sources.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... pounds) of antimony contained in sodium antimonate product Antimony 30.150 13.440 Arsenic 21.720 9.687... metal produced by electrowinning Antimony 30.150 13.440 Arsenic 21.720 9.687 Mercury 2.344 0.937 (c... produced by electrowinning Antimony 60.310 26.870 Arsenic 43.430 19.370 Mercury 4.687 1.875 ...

  9. 40 CFR 421.142 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... contained in sodium antimonate product Antimony 44.840 20.000 Arsenic 32.650 14.530 Mercury 3.906 1.562... produced by electrowinning Antimony 44.840 20.000 Arsenic 32.650 14.530 Mercury 3.906 1.562 Total suspended... produced by electrowinning Antimony 89.680 40.000 Arsenic 65.310 29.060 Mercury 7.812 3.125 Total suspended...

  10. 40 CFR 421.143 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... sodium antimonate product Antimony 30.150 13.440 Arsenic 21.720 9.687 Mercury 2.344 0.937 (b) Fouled... electrowinning Antimony 30.150 13.440 Arsenic 21.720 9.687 Mercury 2.344 0.937 (c) Cathode Antimony Wash Water... electrowinning Antimony 60.310 26.870 Arsenic 43.430 19.370 Mercury 4.687 1.875 ...

  11. 40 CFR 421.143 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... sodium antimonate product Antimony 30.150 13.440 Arsenic 21.720 9.687 Mercury 2.344 0.937 (b) Fouled... electrowinning Antimony 30.150 13.440 Arsenic 21.720 9.687 Mercury 2.344 0.937 (c) Cathode Antimony Wash Water... electrowinning Antimony 60.310 26.870 Arsenic 43.430 19.370 Mercury 4.687 1.875 ...

  12. 40 CFR 421.146 - Pretreatment standards for new sources.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... pounds) of antimony contained in sodium antimonate product Antimony 30.150 13.440 Arsenic 21.720 9.687... metal produced by electrowinning Antimony 30.150 13.440 Arsenic 21.720 9.687 Mercury 2.344 0.937 (c... produced by electrowinning Antimony 60.310 26.870 Arsenic 43.430 19.370 Mercury 4.687 1.875 ...

  13. 40 CFR 421.143 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... sodium antimonate product Antimony 30.150 13.440 Arsenic 21.720 9.687 Mercury 2.344 0.937 (b) Fouled... electrowinning Antimony 30.150 13.440 Arsenic 21.720 9.687 Mercury 2.344 0.937 (c) Cathode Antimony Wash Water... electrowinning Antimony 60.310 26.870 Arsenic 43.430 19.370 Mercury 4.687 1.875 ...

  14. Multipurpose Corrosion Inhibitors for Aerospace Materials in Naval Environments

    DTIC Science & Technology

    1987-06-04

    environment becomes acidic, as is the case at the crack-tip. Molybdates. tungstates , vanadates, bismuthates, antimonates, peroxycarbonates are the compounds...inhibitors, the results of Parrish et al (17) have been used. A one percent solution of sodium chloride at pH 2, suggested as an extreme possible condition...used to study the effect of inhibitors. Among the inhibitors investigated, sodium dichromate and sodium molybdate were found to significantly inhibit

  15. Alkali oxide-tantalum, niobium and antimony oxide ionic conductors

    NASA Technical Reports Server (NTRS)

    Roth, R. S.; Brower, W. S.; Parker, H. S.; Minor, D. B.; Waring, J. L.

    1975-01-01

    The phase equilibrium relations of four systems were investigated in detail. These consisted of sodium and potassium antimonates with antimony oxide and tantalum and niobium oxide with rubidium oxide as far as the ratio 4Rb2O:llB2O5 (B=Nb, Ta). The ternary system NaSbO3-Sb2O4-NaF was investigated extensively to determine the actual composition of the body centered cubic sodium antimonate. Various other binary and ternary oxide systems involving alkali oxides were examined in lesser detail. The phases synthesized were screened by ion exchange methods to determine mobility of the mobility of the alkali ion within the niobium, tantalum or antimony oxide (fluoride) structural framework. Five structure types warranted further investigation; these structure types are (1) hexagonal tungsten bronze (HTB), (2) pyrochlore, (3) the hybrid HTB-pyrochlore hexagonal ordered phases, (4) body centered cubic antimonates and (5) 2K2O:3Nb2O5. Although all of these phases exhibit good ion exchange properties only the pyrochlore was prepared with Na(+) ions as an equilibrium phase and as a low porosity ceramic. Sb(+3) in the channel interferes with ionic conductivity in this case, although relatively good ionic conductivity was found for the metastable Na(+) ion exchanged analogs of RbTa2O5F and KTaWO6 pyrochlore phases.

  16. THE DISTRIBUTION OF INORGANIC CATIONS IN MOUSE TESTIS

    PubMed Central

    Kierszenbaum, Abraham L.; Libanati, Cesar M.; Tandler, Carlos J.

    1971-01-01

    For localization of pyroantimonate-precipitable cations, mouse testes were fixed with a saturated aqueous solution of potassium pyroantimonate (pH about 9.2, without addition of any conventional fixative), hardened with formaldehyde, and postosmicated. A good preservation of the cell membranes and over-all cell morphology is obtained as well as a consistent and reproducible localization of the insoluble antimonate salts of magnesium, calcium, and sodium. Four sites of prominent antimonate deposits are revealed, besides a more or less uniform distribution of the precipitates. These sites are: (a) In the walls of the seminiferous tubules, localized in two concentric layers corresponding to the inner and outer layers of the tubular wall; (b) Around the blood vessels and adjacent connective tissue; (c) At the area of contact between the Sertoli cell and spermatids, where a double line of precipitate surrounds the head of the mature spermatids; and (d) In the cell nuclei, disposed between regions of the condensed chromatin. The nucleus of mature spermatids did not show any sign of antimonate precipitation. The implications of this inorganic cation distribution are discussed with relation to their anionic counterparts, their localization in other animal and plant tissues, and the possibility that those sites may represent barriers to the free passage of ions. PMID:4101521

  17. Treatment of air pollution control residues with iron rich waste sulfuric acid: does it work for antimony (Sb)?

    PubMed

    Okkenhaug, Gudny; Breedveld, Gijs D; Kirkeng, Terje; Lægreid, Marit; Mæhlum, Trond; Mulder, Jan

    2013-03-15

    Antimony (Sb) in air pollution control (APC) residues from municipal solid waste incineration has gained increased focus due to strict Sb leaching limits set by the EU landfill directive. Here we study the chemical speciation and solubility of Sb at the APC treatment facility NOAH Langøya (Norway), where iron (Fe)-rich sulfuric acid (∼3.6M, 2.3% Fe(II)), a waste product from the industrial extraction of ilmenite, is used for neutralization. Antimony in water extracts of untreated APC residues occurred exclusively as pentavalent antimonate, even at low pH and Eh values. The Sb solubility increased substantially at pH<10, possibly due to the dissolution of ettringite (at alkaline pH) or calcium (Ca)-antimonate. Treated APC residues, stored anoxically in the laboratory, simulating the conditions at the NOAH Langøya landfill, gave rise to decreasing concentrations of Sb in porewater, occurring exclusively as Sb(V). Concentrations of Sb decreased from 87-918μgL(-1) (day 3) to 18-69μgL(-1) (day 600). We hypothesize that an initial sorption of Sb to Fe(II)-Fe(III) hydroxides (green rust) and eventually precipitation of Ca- and Fe-antimonates (tripuhyite; FeSbO4) occurred. We conclude that Fe-rich, sulfuric acid waste is efficient to immobilize Sb in APC residues from waste incineration. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Cytochemical localization of calcium in soybean root cap cells in microgravity

    NASA Astrophysics Data System (ADS)

    Klymchuk, D. O.; Brown, C. S.; Chapman, D. K.; Vorobyova, T. V.; Martyn, G. M.

    The antimonate precipitation technique was used to evaluate the effects of microgravity and ethylene on the cellular and subcellular distribution of free calcium ions in soybean root apices. Soybean (Glycine max L. [Merr.]) dry seeds were launched, activated by hydration, and germinated in the presence of KMnO4 (to remove ethylene) and in its absence onboard the space shuttle Columbia during the STS-87 mission. Primary root apices of 6-day old seedlings were fixed for electron microscopy after landing. Ultrastructural studies indicated that antimonate precipitation appeared as individual electron-dense particles which were more or less round in shape and varied in diameter from 10 nm (minimum size beginning from which the particles were well identified) to 90 nm. It was revealed that analyzed root cap cells varied in both the precipitate particle sizes and the amount particles per unit of the cellular area. In both flight and ground control treatments, antimonate precipitation level increases from apical meristem cells to peripheral (secretory) cells of root apices. In root cap statocytes, subcellular localization of precipitate particles was revealed in the cytoplasm, nucleus and small vacuoles. The quantitative analysis showed a reduction of precipitate density in the cytoplasm and the nucleus, and an increase in precipitate density in the vacuoles from statocytes of both spaceflight treatments in comparison with ground controls.

  19. ORGANONICKEL CHEMISTRY IN THE CATALYTIC HYDRODECHLORINATION OF POLYCHLOROBIPHENYLS (PCBS): LIGAND STERIC EFFECTS AND MOLECULAR STRUCTURE OF REACTION INTERMEDIATES. (R823526)

    EPA Science Inventory

    Abstract

    Soluble homogeneous organophosphorus¯¯nickel complexes have been used to detoxify polychlorinated biphenyls (PCBs) by catalyzed hydrodechlorination using NaBH2(OCH2CH2OCH3)2 as the hyd...

  20. High Power Large Aperture Radar Methods for Meteor Observations

    DTIC Science & Technology

    2002-10-18

    the annual Swedish radio science conference RVK-02 (Radio Vetenskap och Kommunikation ) in Stockholm and at XXVIIth URSI General Assembly, Maastricht...Distribution Measurements with the EISCAT and Arecibo HPLA Radars, RVK-02 (RadioVetenskap och Kommunikation ) proceedings, 97-100, 2002. (5) Janches, D

  1. ORGANONICKEL CHEMISTRY IN THE CATALYTIC HYDRODECHLORINATION OF POLYCHLOROBIPHENYLS (PCBS): LIGAND STERIC EFFECTS AND MOLECULAR STRUCTURE OF REACTION INTERMEDIATES. (R823526)

    EPA Science Inventory

    Abstract

    Soluble homogeneous organophosphorus¯¯nickel complexes have been used to detoxify polychlorinated biphenyls (PCBs) by catalyzed hydrodechlorination using NaBH2(OCH2CH2OCH3)2 as the hyd...

  2. COMPONENTS OF SURFACE AND SUBSURFACE CONNECTIVITY IN A LARGE OREGON (USA) RIVER--WHAT CAN BE RESTORED?

    EPA Science Inventory

    We conducted research on the Willamette River in western Oregon (USA) to determine the ecological functions of off-channel habitats (OCH). OCHs have declined in our 70 km study reach of the active floodplain since European settlement. Surface and subsurface connectivity between...

  3. Fluoxetine Hydrochloride Enhances In Vitro Susceptibility to Chloroquine in Resistant Plasmodium falciparum

    DTIC Science & Technology

    1992-12-01

    chloroquine- (12), ketotifen (1), tetrandrine (20, 21), and cyproheptadine susceptible clone D6 (50% inhibitory concentration [IC 5o], (16). !s3 ng/ml). IC... CYPROHEPTADINE KETOTIFEN N OCN3 HICO N ’IN ~~OCH3 NN H 0 OCH.3 TETRANDRINE FIG. 1. Structures of fluoxetine and other drugs that have been reported to

  4. Ecological Functions of Off-Channel Habitats of the Willamette River, Oregon, Database and Documentation (1997-2001)

    EPA Science Inventory

    The database from the Ecological Functions of Off-Channel Habitats of the Willamette River, Oregon project (OCH Project) contains data collected from 1997 through 2001 from multiple research areas of the project, and project documents such as the OCH Research Plan, Quality Assura...

  5. Discourse Markers in Chinese Conversational Narrative

    ERIC Educational Resources Information Center

    Xiao, Yang

    2010-01-01

    This study examines the indexicality of discourse markers (DMs) in Chinese conversational narrative. Drawing upon theoretical and methodological principles related to narrative dimensions (Ochs & Capps, 2001), narrative desires (Ochs, 1997, 2004), and narrative positioning (Bamberg, 1997), this work proposes an integrated analytical framework for…

  6. Ecological Functions of Off-Channel Habitats of the Willamette River, Oregon, Database and Documentation (1997-2001)

    EPA Science Inventory

    The database from the Ecological Functions of Off-Channel Habitats of the Willamette River, Oregon project (OCH Project) contains data collected from 1997 through 2001 from multiple research areas of the project, and project documents such as the OCH Research Plan, Quality Assura...

  7. Audit of Endotracheal Tube Suction in a Pediatric Intensive Care Unit.

    PubMed

    Davies, Kylie; Bulsara, Max K; Ramelet, Anne-Sylvie; Monterosso, Leanne

    2017-02-01

    We report outcomes of a clinical audit examining criteria used in clinical practice to rationalize endotracheal tube (ETT) suction, and the extent these matched criteria in the Endotracheal Suction Assessment Tool(ESAT)©. A retrospective audit of patient notes ( N = 292) and analyses of criteria documented by pediatric intensive care nurses to rationalize ETT suction were undertaken. The median number of documented respiratory and ventilation status criteria per ETT suction event that matched the ESAT© criteria was 2 [Interquartile Range (IQR) 1-6]. All criteria listed within the ESAT© were documented within the reviewed notes. A direct link was established between criteria used for current clinical practice of ETT suction and the ESAT©. The ESAT©, therefore, reflects documented clinical decision making and could be used as both a clinical and educational guide for inexperienced pediatric critical care nurses. Modification to the ESAT © requires "preparation for extubation" to be added.

  8. Intratracheal ectopic thyroid tissue: a case report and literature review.

    PubMed

    Byrd, Michael C; Thompson, Lester D R; Wieneke, Jacqueline A

    2003-07-01

    We discuss a case of intratracheal ectopic thyroid tissue (ETT) that was retrieved from the files of the Otorhinolaryngic--Head and Neck Pathology Registry at the Armed Forces Institute of Pathology. The patient was a 54-year-old man who had a history of papillary thyroid carcinoma, which had been treated with a subtotal thyroidectomy. During routine follow-up 4 years later, the patient's primary care physician detected an elevated thyroglobulin level. Further referrals and evaluations revealed that the patient had intratracheal ETT. The patient refused to undergo surgical excision and remains without evidence of recurrent carcinoma. In a MEDLINE literature review, we found only 13 other well-documented cases of intratracheal ETT since 1966; in all but two cases, patients had benign disease. Once the possibility of thyroid carcinoma has been eliminated by histologic examination, intratracheal ETT can be managed by complete surgical excision with the prospect of an excellent long-term clinical outcome.

  9. A new species of Aedes Meigen subgenus Ochlerotatus Lynch Arribálzaga (Diptera: Culicidae) from the coastal wetlands of the desert in northern Chile: morphological and molecular identification.

    PubMed

    González, Christian R; Reyes, Carolina; Rada-Chaparro, Viviana; Saldarriaga-Córdoba, Mónica

    2017-06-01

    Aedes (Ochlerotatus) sallumae González & Reyes n. sp. is described and validated using morphological characters of the adult male and female, male genitalia and immature stages, and its cytochrome oxidase unit 1 mitochondrial gene sequence (COI). Aedes (Och.) sallumae is morphologically close to Ae. (Och.) albifasciatus (Macquart). However, these species can be distinguished based on characters of the males and females, male genitalia and fourth-instar larvae. Aedes (Och.) sallumae was collected in the geographically isolated desert zone of northern Chile, the Atacama Desert. This isolation suggests allopatric speciation, with Ae. (Och.) sallumae divergent from its sister species Ae. (Och.) albifasciatus. Molecular characterization showed a difference of more than 8% between these species, supporting their recognition as different species.

  10. Respiratory mechanics during high-frequency oscillatory ventilation: a physical model and preterm infant study.

    PubMed

    Singh, Rachana; Courtney, Sherry E; Weisner, Michael D; Habib, Robert H

    2012-04-01

    Accurate mechanics measurements during high-frequency oscillatory ventilation (HFOV) facilitate optimizing ventilator support settings. Yet, these are influenced substantially by endotracheal tube (ETT) contributions, which may dominate when leaks around uncuffed ETT are present. We hypothesized that 1) the effective removal of ETT leaks may be confirmed via direct comparison of measured vs. model-predicted mean intratracheal pressure [mPtr (meas) vs. mPtr (pred)], and 2) reproducible respiratory system resistance (Rrs) and compliance (Crs) may be derived from no-leak oscillatory Ptr and proximal flow. With the use of ETT test-lung models, proximal airway opening (Pao) and distal (Ptr) pressures and flows were measured during slow-cuff inflations until leaks are removed. These were repeated for combinations of HFOV settings [frequency, mean airway pressure (Paw), oscillation amplitudes (ΔP), and inspiratory time (%t(I))] and varying test-lung Crs. Results showed that leaks around the ETT will 1) systematically reduce the effective distending pressures and lung-delivered oscillatory volumes, and 2) derived mechanical properties are increasingly nonphysiologic as leaks worsen. Mean pressures were systematically reduced along the ventilator circuit and ETT (Paw > Pao > Ptr), even for no-leak conditions. ETT size-specific regression models were then derived for predicting mPtr based on mean Pao (mPao), ΔP, %t(I), and frequency. Next, in 10 of 11 studied preterm infants (0.77 ± 0.24 kg), no-to-minimal leak was confirmed based on excellent agreement between mPtr (meas) and mPtr (pred), and consequently, their oscillatory respiratory mechanics were evaluated. Infant resistance at the proximal ETT (R(ETT); resistance airway opening = R(ETT) + Rrs; P < 0.001) and ETT inertance (P = 0.014) increased significantly with increasing ΔP (50%, 100%, and 150% baseline), whereas Rrs showed a modest, nonsignificant increase (P = 0.14), and Crs was essentially unchanged (P = 0

  11. Application of a flexible lightwand in percutaneous dilatational tracheotomy.

    PubMed

    Zhao, Zhuang; Pan, Shu; Wang, Dunwei; Wang, Chengyu; Li, Zhiwen

    2017-06-23

    By comparing flexible lightwand-assisted and conventional endotracheal tube (ETT) withdrawal in percutaneous dilatational tracheotomy (PDT), this paper aims to provide guidance for precise ETT withdrawal by anesthesiologists and accurate determination of the incision site by surgeons. Sixty patients who underwent PDT in our hospital were randomly divided into the lightwand group (Group L, n=30) and the withdrawal group (Group W, n=30) using the envelope method. For Group L patients, a flexible lightwand was inserted into an ETT (based on the patient's size), the light source was positioned at the root of the cuff, and the depth from the root of the cuff to the end of the ETT was marked. The flexible lightwand was inserted into the patient's ETT to the marked depth. The ETT along with the flexible lightwand was withdrawn until the highlighted spot was located at the level of the thyroid cartilage. The incision site was approximately 3 finger widths (approximately 4.8cm) below the highlighted spot. For Group W patients, the ETT was withdrawn to a tube depth of 17cm at the upper incisors in males and 15cm in females, and surgeons determined incision sites without assistance. The following metrics were recorded for the two groups: occurrences of inadvertent extubation, ETT puncture and cuff rupture; success rate of first puncture; hypoxia rate; SpO2 at the time of tracheostomy cannula intubation (T1); and postoperative hemorrhage rate. Inadvertent extubation, ETT puncture and cuff rupture occurred significantly less frequently in Group L than in Group W, and the success rate of first puncture and SpO2 at T1 were markedly higher in Group L than in Group W. Moreover, significant between-group differences in hypoxia rate and postoperative hemorrhage rate were observed. The use of a flexible lightwand in PDT is a safe and effective approach. This approach can effectively and directly guide precise ETT repositioning and provide incision site confirmation with few intra- and

  12. Heart Rate Variability, Catecholamine and Hemodynamic Responses During Rest and Stress in Coronary Artery Disease Patients: The PIMI Study

    DTIC Science & Technology

    2007-01-31

    Chierchia, S. L. (1997). Angina pectoris and the personality factor: the relevance of psychosocial factors in myocardial ischaemia. Eur Heart J, 18(6), 892...25 ischemic events were asymptomatic (no angina ) and the decreases in HRV (HF and LF) were correlated with high levels of...angioplasty (PTCA) within 6 months of qualifying ETT, cardiac surgery requiring thoracotomy, unstable angina within 4 weeks of qualifying ETT

  13. Influence of Low Peak Respiratory Exchange Ratio on Cardiac Rehabilitation in Patients With Coronary Artery Disease

    PubMed Central

    2016-01-01

    Objective To compare and analyze the effects of cardiac rehabilitation (CR) in two groups based on the peak respiratory exchange ratio (RERpeak) 1.1 values using the exercise tolerance test (ETT) results, and to investigate the reasons for early termination of ETT. Methods Patients with acute coronary syndrome who participated in CR exercise training were selected and all subjects underwent 6 weeks of CR exercise training. ETT was performed on a treadmill using a Modified Bruce Protocol before and after CR exercise training. According to the result of the first ETT, the subjects were divided into two groups: those with an RERpeak≥1.1 (n=33) and those with an RERpeak<1.1 (n=22). We investigated the reasons for ETT termination and compared the effect of CR between the groups. Results The reasons for the early termination of the first ETT in the RERpeak<1.1 group were subjective dyspnea, abnormal cardiovascular responses, leg fatigue and other problems. After a 6-week CR, the peak oxygen consumption (VO2peak) and ETT time increased, and the rate of perceived exertion (RPE) and RPP (rate pressure product) at stage 3 decreased in both the RERpeak<1.1 and RERpeak≥1.1 groups. Conclusion CR exercise training improved exercise capacity, not only in the RERpeak≥1.1 group, but also in the RERpeak<1.1 group. This means that patients with a lower exercise tolerance could also benefit from the effects of CR. Thoughtful consideration to identify the direct and indirect causes for the early termination of ETT would be necessary to improve the efficiency of CR. PMID:28119843

  14. ProSeal Laryngeal Mask Airway as an Alternative to Standard Endotracheal Tube in Securing Upper Airway in the Patients Undergoing Beating-heart Coronary Artery Bypass Grafting

    PubMed Central

    Shah, Kalpana

    2017-01-01

    Background: ProSeal laryngeal mask airways (PLMAs) are routinely used after failed tracheal intubation as airway rescue, facilitating tracheal intubation by acting as a conduit and to secure airway during emergencies. In long duration surgeries, use of endotracheal tube (ETT) is associated with various hemodynamic complications, which are minimally affected during PLMA use. However, except for few studies, there are no significant data available that promote the use of laryngeal mask during cardiac surgery. This prospective study was conducted with the objective of demonstrating the advantages of PLMA over ETT in the patients undergoing beating-heart coronary artery bypass graft (CABG). Methodology: This prospective, interventional study was carried out in 200 patients who underwent beating-heart CABG. Patients were randomized in equal numbers to either ETT group or PLMA group, and various hemodynamic and respiratory parameters were observed at different time points. Results: Patients in PLMA group had mean systolic blood pressure 126.10 ± 5.31 mmHg compared to the patients of ETT group 143.75 ± 6.02 mmHg. Pulse rate in the PLMA group was less (74.52 ± 10.79 per min) (P < 0.05) compared to ETT group (81.72 ± 9.8). Thus, hemodynamic changes were significantly lower (P < 0.05) in PLMA than in ETT group. Respiratory parameters such as oxygen saturation, pressure CO2 (pCO2), peak airway pressure, and lung compliance were similar to ETT group at all evaluation times. The incidence of adverse events was also lower in PLMA group. Conclusion: In experience hand, PLMA offers advantages over the ETT in airway management in the patients undergoing beating-heart CABG. PMID:28074798

  15. Incidence of endotracheal tube colonization with the use of PneuX endotracheal tubes in patients following cardiac surgery.

    PubMed

    Senanayake, E L; Giri, R; Gopal, S; Nevill, A; Luckraz, H

    2017-01-01

    Ventilator-associated pneumonia (VAP) develops in up to 25% of patients following cardiac surgery. Colonization of the endotracheal tube (ETT) contributes to VAP. The PneuX ETT has been shown to halve VAP in high-risk patients undergoing cardiac surgery. This article reports on the secondary analysis of bacterial colonization in relation to VAP between the PneuX and standard ETTs. In this randomized controlled trial, patients were randomized on a 1:1 basis to Group A (PneuX ET, N=120) or Group B (standard ETT, N=120). Patients aged >70 years with or without impaired left ventricular function (<50%) undergoing elective and urgent cardiac surgery were included in this study. Incidence of postoperative VAP and analysis of bacterial colonization within the ETT (N=234) were measured for patients requiring <24 h, 24-48 h and >48 h of intubation. Baseline patient demographics were comparable. VAP was lower in Group A compared with Group B (10.8% vs 21%; P=0.03). The incidence of VAP was lower at each time point for Group A. There was a lower incidence of ETT colonization in Group A for patients needing >48 h of intubation. There was no difference in the type of bacterial colonization (P=0.5) or the mean number of colony-forming units [4.35x10(7) (1.18x10(8)) and 2.16x10(8) (1.24x10(9)) in Groups A and B, respectively (P=0.8)]. Colonization of the ETT does not seem to play an important role in early-onset VAP. There is a tendency for reduced colonization in the PneuX ETT with longer intubation times. This may have an impact on reducing the incidence of late-onset VAP. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  16. Predicting endotracheal tube size by length in newborns.

    PubMed

    Luten, Robert; Kahn, Nagma; Wears, Robert; Kissoon, Niranjan

    2007-05-01

    The objective of this study was to determine the relationship of length to endotracheal tube (ETT) size in newborns and to use this relationship to develop a tool for predicting ETT size. The study, a prospective derivation, and validation of a predictive model, took place in the neonatal intensive care units (NICUs) in two urban teaching hospitals. Subjects included: ETT derivation set - 39 intubated neonates admitted to the NICU; Validation set - 69 intubated newborns from the same NICU. Leak percentages were measured in intubated neonates where the actual ETT size did not correlate with the tape-determined ETT size. Interventions were length, weight, and leak measurements. A prototype tape was developed using the derivation set and published anthropometric studies. The accuracy of the tape was validated on a separate set of newborns. The average relative difference between tape-predicted weight and actual weight was 9.5% (confidence interval [CI] = 8.3-10.6%) and was evenly distributed throughout all the weight groups. The tape predicted actual ETT size in 96% of cases (CI 86.3-99.5%) and was correct within 1 tube size (1/2 mm) in 100% (CI 94.8-100%). The only error in prediction of ETT size was in underestimation. Length-based weight estimations were tested on 100 subjects and predicted actual weight within 20% in 94% of cases. We concluded that length is an accurate predictor of ETT size and weight in term and preterm newborns and may be useful in situations in which weights are unobtainable, such as emergency resuscitation.

  17. Decreased Pseudomonas aeruginosa biofilm formation on nanomodified endotracheal tubes: a dynamic lung model

    PubMed Central

    Machado, Mary C; Webster, Thomas J

    2016-01-01

    Ventilator-associated pneumonia (VAP) is a serious complication of mechanical ventilation that has been shown to be associated with increased mortality rates and medical costs in the pediatric intensive care unit. Currently, there is no cost-effective solution to the problems posed by VAP. Endotracheal tubes (ETTs) that are resistant to bacterial colonization and that inhibit biofilm formation could provide a novel solution to the problems posed by VAP. The objective of this in vitro study was to evaluate differences in the growth of Pseudomonas aeruginosa on unmodified polyvinyl chloride (PVC) ETTs and on ETTs etched with a fungal lipase, Rhizopus arrhizus, to create nanoscale surface features. These differences were evaluated using an in vitro model of the pediatric airway to simulate a ventilated patient in the pediatric intensive care unit. Each experiment was run for 24 hours and was supported by computational models of the ETT. Dynamic conditions within the ETT had an impact on the location of bacterial growth within the tube. These conditions also quantitatively affected bacterial growth especially within the areas of tube curvature. Most importantly, experiments in the in vitro model revealed a 2.7 log reduction in the number (colony forming units/mL) of P. aeruginosa on the nanoroughened ETTs compared to the untreated PVC ETTs after 24 hours. This reduction in total colony forming units/mL along the x-axis of the tube was similar to previous studies completed for Staphylococcus aureus. Thus, this dynamic study showed that lipase etching can create surface features of nanoscale roughness on PVC ETTs that decrease bacterial attachment of P. aeruginosa without the use of antibiotics and may provide clinicians with an effective and inexpensive tool to combat VAP. PMID:27563242

  18. Decreased Pseudomonas aeruginosa biofilm formation on nanomodified endotracheal tubes: a dynamic lung model.

    PubMed

    Machado, Mary C; Webster, Thomas J

    2016-01-01

    Ventilator-associated pneumonia (VAP) is a serious complication of mechanical ventilation that has been shown to be associated with increased mortality rates and medical costs in the pediatric intensive care unit. Currently, there is no cost-effective solution to the problems posed by VAP. Endotracheal tubes (ETTs) that are resistant to bacterial colonization and that inhibit biofilm formation could provide a novel solution to the problems posed by VAP. The objective of this in vitro study was to evaluate differences in the growth of Pseudomonas aeruginosa on unmodified polyvinyl chloride (PVC) ETTs and on ETTs etched with a fungal lipase, Rhizopus arrhizus, to create nanoscale surface features. These differences were evaluated using an in vitro model of the pediatric airway to simulate a ventilated patient in the pediatric intensive care unit. Each experiment was run for 24 hours and was supported by computational models of the ETT. Dynamic conditions within the ETT had an impact on the location of bacterial growth within the tube. These conditions also quantitatively affected bacterial growth especially within the areas of tube curvature. Most importantly, experiments in the in vitro model revealed a 2.7 log reduction in the number (colony forming units/mL) of P. aeruginosa on the nanoroughened ETTs compared to the untreated PVC ETTs after 24 hours. This reduction in total colony forming units/mL along the x-axis of the tube was similar to previous studies completed for Staphylococcus aureus. Thus, this dynamic study showed that lipase etching can create surface features of nanoscale roughness on PVC ETTs that decrease bacterial attachment of P. aeruginosa without the use of antibiotics and may provide clinicians with an effective and inexpensive tool to combat VAP.

  19. Epistaxis during nasotracheal intubation: a randomized trial of the Parker Flex-Tip™ nasal endotracheal tube with a posterior facing bevel versus a standard nasal RAE endotracheal tube.

    PubMed

    Earle, Rosie; Shanahan, Enda; Vaghadia, Himat; Sawka, Andrew; Tang, Raymond

    2017-04-01

    Nasotracheal intubation is a widely performed technique to facilitate anesthesia induction during oral, dental, and maxillofacial surgeries. The technique poses several risks not encountered with oropharyngeal intubation, most commonly epistaxis due to nasal mucosal abrasion. The purpose of this study was to test whether the use of the Parker Flex-Tip™ (PFT) nasal endotracheal tube (ETT) with a posterior facing bevel reduces epistaxis when compared with the standard nasal RAE ETT with a leftward facing bevel. Sixty American Society of Anesthesiologists physical status I and II patients undergoing oral or maxillofacial surgery with nasotracheal intubation were recruited. Patients were randomized to either a standard nasal RAE ETT or a PFT nasal ETT. The ETT was thermosoftened and lubricated for both study groups prior to insertion, and the size of the tube was chosen at the discretion of the attending anesthesiologist. The primary outcome was the incidence of epistaxis, with a secondary outcome of epistaxis severity (scored as none, mild, moderate, or severe). An investigator measured both outcomes five minutes after intubation was completed. Mild or moderate epistaxis was experienced by 22 of 30 (73%) patients in the PFT group compared with 21 of 30 (70%) patients in the standard nasal RAE ETT group (absolute risk reduction, 3%; 95% confidence interval, -19 to 25; P = 0.78). There were no occurrences of severe epistaxis in either group. There was no difference in the incidence or severity of epistaxis following nasal intubation using the Parker Flex-Tip nasal ETT when compared with a standard nasal RAE ETT. This trial was registered at ClinicalTrials.gov, identifier: NCT02315677.

  20. Predictors of postoperative sore throat in intubated children.

    PubMed

    Calder, Alyson; Hegarty, Mary; Erb, Thomas O; von Ungern-Sternberg, Britta S

    2012-03-01

    The incidence of postoperative sore throat (POST) following intubation is not well defined in the pediatric population. The etiology is multifactorial and includes impairment of subglottic mucosal perfusion and edema as a result of the pressures exerted by cuffed or uncuffed tubes. To determine the incidence of, and risk factors for, POST in intubated children undergoing elective day-case surgery. Five hundred patients aged 3-16 years were studied prospectively. Endotracheal tube (ETT) choice (cuffed or uncuffed) was left to the anesthetist. The cuff was inflated either until loss of audible leak or to a determined pressure using a cuff manometer. The research team then measured the cuff pressure (CP). POST incidence and intensity was determined by interviewing patients prior to discharge from the same day procedure unit. Chi-square testing and stepwise logistic regression were used to determine the predictors of POST. Of the 111 (22%) children developed a sore throat, 19 (3.8%) a sore neck, and 5 (1%) a sore jaw. 19% of patients with cuffed ETTs complained of sore throat compared with 37% of those intubated with an uncuffed ETT. The incidence of POST increased with CP; 0-10% at 0 cmH(2)O, 4% at 11-20 cmH(2)O, 20% at 21-30 cmH(2)O, 68% at CP 31-40 cmH(2)O, and 96% at CP >40 cmH(2)O. The ETT CP and use of uncuffed ETTs were univariate predictors of POST. Children intubated with uncuffed ETTs are more likely to have POST. ETT CP is positively correlated with the incidence of POST. When using cuffed ETTs, CP should be routinely measured intraoperatively. © 2011 Blackwell Publishing Ltd.

  1. Atmospheric photooxidation of fluoroacetates as a source of fluorocarboxylic acids.

    PubMed

    Blanco, M B; Bejan, I; Barnes, I; Wiesen, P; Teruel, Mariano A

    2010-04-01

    A 1080 L environmental chamber with in situ FTIR spectroscopy detection was used to study the product distribution and the mechanism of the Cl-initiated photooxidation of a series of fluoroacetates. The gas-phase reactions of Cl atoms with ethyl trifluoroacetate (CF(3)C(O)OCH(2)CH(3)), methyl trifluoroacetate (CF(3)C(O)OCH(3)), and methyl difluoroacetate (CF(2)HC(O)OCH(3)) were investigated at 296 +/- 2 K and atmospheric pressure (approximately 760 Torr) of synthetic air. The fate of the fluoroalkoxy radicals formed in the reaction with Cl atoms mainly occurs through (i) an H-atom abstraction by reaction with O(2,) to produce the corresponding fluoroanhydride and (ii) an alpha-ester rearrangement via a five-membered ring intermediate to give the corresponding fluoroacetic acid. The yields of fluoroacids (CF(2)XC(O)OH, with X = H, F) obtained were as follows: 78 +/- 5, 23 +/- 2, and 30 +/- 5% for CF(3)C(O)OCH(2)CH(3), CF(3)C(O)OCH(3), and CF(2)HC(O)OCH(3,), respectively. Yields of OCH(2)CH(3), CF(3)C(O)OCH(3), and CF(2)HC(O)OCH(3), respectively. Formation of CF(2)O, with yield of 13 +/- 2% has been observed for the reaction of Cl with CF(2)HC(O)OCH(3). The measured yields are rationalized in terms of mechanisms consisting of competitive reaction channels for the radicals formed in the oxidation, that is, reaction with O(2), alpha-ester rearrangement and a decomposition pathway. The stability of the five-membered transition state of the alpha-ester rearrangement is correlated with the acid yields observed for the different fluoroacetates. Atmospheric implications, especially with regard to the fluorocarboxylic acid formation, are discussed.

  2. Parallel structural evolution of auxin response factors in the angiosperms.

    PubMed

    Finet, Cédric; Fourquin, Chloé; Vinauger, Marion; Berne-Dedieu, Annick; Chambrier, Pierre; Paindavoine, Sandrine; Scutt, Charles P

    2010-09-01

    Here we analyze the structural evolution of the paralogous transcription factors ETTIN (ETT/ARF3) and AUXIN RESPONSE FACTOR 4 (ARF4), which control the development of floral organs and leaves in the model angiosperm Arabidopsis. ETT is truncated at its C terminus, and consequently lacks two regulatory domains present in most other ARFs, including ARF4. Our analysis indicates ETT and ARF4 to have been generated by the duplication of a non-truncated ARF gene prior to the radiation of the extant angiosperms. We furthermore show that either ETT or ARF4 orthologs have become modified to encode truncated ARF proteins, lacking C-terminal regulatory domains, in representatives of three groups that separated early in angiosperm evolution: Amborellales, Nymphaeales and the remaining angiosperm clade. Interestingly, the production of truncated ARF4 transcripts in Amborellales occurs through an alternative splicing mechanism, rather than through a permanent truncation, as in the other groups studied. To gain insight into the potential functional significance of truncations to ETT and ARF4, we tested the capacity of native, truncated and chimeric coding sequences of these genes to restore a wild-type phenotype to Arabidopsis ett mutants. We discuss the results of this analysis in the context of the structural evolution of ARF genes in the angiosperms.

  3. Digital palpation of endotracheal tube tip as a method of confirming endotracheal tube position in neonates: an open-label, three-armed randomized controlled trial.

    PubMed

    Saboo, Ashwin R; Dutta, Sourabh; Sodhi, Kushaljit Singh

    2013-10-01

    To compare the malposition rates of endotracheal tubes (ETTs) when the insertional length (IL) is determined by a weight-based nomogram versus when IL is determined by palpation of the ETT tip. Open-label, randomized controlled trial (RCT). Level III neonatal intensive care unit (NICU). All newborn babies admitted in NICU requiring intubation. Subjects were randomly allocated to one of three groups, wherein IL was determined by (i) weight-based nomogram alone, (ii) weight-based nomogram combined with suprasternal palpation of ETT tip performed by specially trained neonatology fellows, or (iii) combination of weight-based and suprasternal methods by personnel not specially trained. Rate of malposition of ETT as judged on chest X-ray (CXR). Fifty seven babies were randomized into group 1(n = 15), group 2 (n = 20), and group 3 (n = 22). The proportion of correct ETT placement was highest in group 2, being 66.7%, 83.3%, and 66.7% in groups 1 through 3, respectively (P value = 0.58). No complication was attributable to palpation technique. Suprasternal palpation shows promise as a simple, safe, and teachable method of confirming ETT position in neonates. © 2013 John Wiley & Sons Ltd.

  4. The Arabidopsis STV1 Protein, Responsible for Translation Reinitiation, Is Required for Auxin-Mediated Gynoecium PatterningW⃞

    PubMed Central

    Nishimura, Taisuke; Wada, Takuji; Yamamoto, Kotaro T.; Okada, Kiyotaka

    2005-01-01

    Ribosomal protein L24 (RPL24) is implicated in translation reinitiation of polycistronic genes. A newly isolated Arabidopsis thaliana short valve1 (stv1) mutant, in which one of the RPL24-encoding genes, RPL24B, is deleted, shows specific defects in the apical-basal patterning of the gynoecium, in addition to phenotypes induced by ribosome deficiency. A similar gynoecium phenotype is caused by mutations in the auxin response factor (ARF) genes ETTIN (ETT) and MONOPTEROS (MP), which have upstream open reading frames (uORFs) in their 5′-transcript leader sequences. Gynoecia of a double mutant of stv1 and a weak ett mutant allele are similar to those of a strong ett allele, and transformation with a uORF-eliminated ETT construct partially suppressed the stv1 gynoecium phenotype, implying that STV1 could influence ETT translation through its uORFs. Analyses of 5′-leader-reporter gene fusions showed that the uORFs of ETT and MP negatively regulate the translation of the downstream major ORFs, indicating that translation reinitiation is an important step for the expression of these proteins. Taken together, we propose that perturbation of translation reinitiation of the ARF transcripts causes the defects in gynoecium patterning observed in the stv1 mutant. PMID:16227452

  5. Endotracheal tube size selection guidelines for Chinese children: prospective study of 533 cases.

    PubMed

    Wang, T K; Wu, R S; Chen, C; Chang, T C; Hseih, F S; Tan, P P

    1997-05-01

    Appropriate selection of the size of an endotracheal tube (ETT) for use in children is important both in general anesthesia and critical care practice. Past published data on guidelines for selecting ETT size in children are based on Caucasian measurements. As body build is generally different in Chinese children compared with Caucasians of the same age group, guidelines for Chinese children are needed. The aim of this study was to determine guidelines for ETT size selection by recording and comparing age, body weight, length, head girth and circumference of the right fifth finger of the child. Correlations between internal diameter (ID) of the chosen ETT and the child's data were calculated and compared. In this study, 533 Chinese children. American Society of Anesthesiolgists class I or II, aged from 3 months to 6 years, undergoing oral intubation for general anesthesia for minor pediatric surgery were enrolled. Our results showed that body length (height) had the best correlation to the size of an uncuffed oral ETT. Through stepwise regression, a formula. ETT ID = 2 + (body length (cm)/30), was obtained.

  6. Extrauterine epithelioid trophoblastic tumor in hysterectomized woman.

    PubMed

    Kim, Ji-Hye; Lee, Sun Kyung; Hwang, Soo Hyun; Kim, Jung-Sun; Yoon, Gun; Lee, Yoo-Young; Kim, Tae-Joong; Choi, Chel Hun; Kim, Byoung-Gie; Bae, Duk-Soo; Lee, Jeong-Won

    2017-01-01

    Epithelioid trophoblastic tumor (ETT) is a very rare variant of gestational trophoblastic disease (GTD) which arises in reproductive age women with prior gestational history. Although abnormal vaginal bleeding is the most common symptom of ETT, there are no reported pathognomonic symptoms of ETT because of its rarity. ETT is similar to placental site trophoblastic tumor in terms of its slow growing characteristic and microscopic findings. Therefore, it could be misdiagnosed as placental site trophoblastic tumor or other types of GTD. Unlike other types of GTD, primary treatment of ETT is surgical resection because of its chemo-resistant nature. Accordingly, immunohistochemical staining is essential for accurate diagnosis and appropriate treatment. Here, we report a case of a 42-year-old hysterectomized woman with pelvic masses who suffered from abdominal pain. Through laparotomy, tumors were resected completely and they were diagnosed as ETT through immunohistochemical stain. This report provides more evidence about its clinical features, diagnosis, and treatment including a brief review of the literature.

  7. ST elevation in the lead aVR during exercise treadmill testing may indicate left main coronary artery disease.

    PubMed

    Ozmen, Namik; Yiginer, Omer; Uz, Omer; Kardesoglu, Ejder; Aparci, Mustafa; Isilak, Zafer; Cingozbay, Bekir Yilmaz; Cebeci, Bekir Sitki; Kocum, Halil Tolga

    2010-10-01

    exercise treadmill testing (ETT) is the most widely used method for evaluating patients with coronary artery disease. Predicting the left main coronary artery (LMCA) disease before invasive procedures is very important in risk assessment because of its severe clinical outcome. To examine whether ST elevation in lead aVR during ETT may suggest LMCA disease since the lead aVR is the reciprocal lead of LMCA. in this study, 61 patients with positive ETT were included. The study group consisted of 21 patients with ST elevation in lead aVR. Forty patients, also having positive ETT, but without ST elevation in lead aVR comprised the control group. All patients underwent coronary angiography. coronary angiography in the study group revealed significant LMCA stenosis in 16 (76%) patients, whereas LMCA disease was present in only 3 (8%) patients from the control group. There was no significant coronary artery stenosis in 5 patients in the study group and 12 patients in the control group. Of the 16 patients who had LMCA stenosis, 9 had isolated LMCA disease and 7 had additional stenotic lesions in LAD or circumflex coronary arteries. The sensitivity and specificity of ST segment elevation in lead aVR during ETT was 84% and 88%, respectively. The values of positive and negative predictive value of this finding in diagnosing the presence of LMCA were 76% and 93%, respectively. ST segment elevation in lead aVR during ETT may point to a high probability of the presence of LMCA disease.

  8. Extrauterine epithelioid trophoblastic tumor in hysterectomized woman

    PubMed Central

    Kim, Ji-Hye; Lee, Sun Kyung; Hwang, Soo Hyun; Kim, Jung-Sun; Yoon, Gun; Lee, Yoo-Young; Kim, Tae-Joong; Choi, Chel Hun; Kim, Byoung-Gie; Bae, Duk-Soo

    2017-01-01

    Epithelioid trophoblastic tumor (ETT) is a very rare variant of gestational trophoblastic disease (GTD) which arises in reproductive age women with prior gestational history. Although abnormal vaginal bleeding is the most common symptom of ETT, there are no reported pathognomonic symptoms of ETT because of its rarity. ETT is similar to placental site trophoblastic tumor in terms of its slow growing characteristic and microscopic findings. Therefore, it could be misdiagnosed as placental site trophoblastic tumor or other types of GTD. Unlike other types of GTD, primary treatment of ETT is surgical resection because of its chemo-resistant nature. Accordingly, immunohistochemical staining is essential for accurate diagnosis and appropriate treatment. Here, we report a case of a 42-year-old hysterectomized woman with pelvic masses who suffered from abdominal pain. Through laparotomy, tumors were resected completely and they were diagnosed as ETT through immunohistochemical stain. This report provides more evidence about its clinical features, diagnosis, and treatment including a brief review of the literature. PMID:28217684

  9. The insecure airway: a comparison of knots and commercial devices for securing endotracheal tubes.

    PubMed

    Lovett, Paris B; Flaxman, Alexander; Stürmann, Kai M; Bijur, Polly

    2006-05-24

    Endotracheal Tubes (ETTs) are commonly secured using adhesive tape, cloth tape, or commercial devices. The objectives of the study were (1) To compare degrees of movement of ETTs secured with 6 different commercial devices and (2) To compare movement of ETTs secured with cloth tape tied with 3 different knots (hitches). A 17 cm diameter PVC tube with 14 mm "mouth" hole in the side served as a mannequin. ETTs were subjected to repeated jerks, using a cable and pulley system. (1) Total movement of ETTs relative to "mouth" (measure used for devices) (2) Slippage of ETT through securing knot (measure used for knots). Among commercial devices, the Dale showed less movement than other devices, although some differences between devices did not reach significance. Among knots, Magnus and Clove Hitches produced less slippage than the Cow Hitch, but these differences did not reach statistical significance. Among devices tested, the Dale was most secure. Within the scope offered by the small sample sizes, there were no statistically significant differences between the knots in this study.

  10. Fructose-enhanced reduction of bacterial growth on nanorough surfaces.

    PubMed

    Durmus, Naside Gozde; Taylor, Erik N; Inci, Fatih; Kummer, Kim M; Tarquinio, Keiko M; Webster, Thomas J

    2012-01-01

    Patients on mechanical ventilators for extended periods of time often face the risk of developing ventilator-associated pneumonia. During the ventilation process, patients incapable of breathing are intubated with polyvinyl chloride (PVC) endotracheal tubes (ETTs). PVC ETTs provide surfaces where bacteria can attach and proliferate from the contaminated oropharyngeal space to the sterile bronchoalveolar area. To overcome this problem, ETTs can be coated with antimicrobial agents. However, such coatings may easily delaminate during use. Recently, it has been shown that changes in material topography at the nanometer level can provide antibacterial properties. In addition, some metabolites, such as fructose, have been found to increase the efficiency of antibiotics used to treat Staphylococcus aureus (S. aureus) infections. In this study, we combined the antibacterial effect of nanorough ETT topographies with sugar metabolites to decrease bacterial growth and biofilm formation on ETTs. We present for the first time that the presence of fructose on the nanorough surfaces decreases the number of planktonic S. aureus bacteria in the solution and biofilm formation on the surface after 24 hours. We thus envision that this method has the potential to impact the future of surface engineering of biomaterials leading to more successful clinical outcomes in terms of longer ETT lifetimes, minimized infections, and decreased antibiotic usage; all of which can decrease the presence of antibiotic resistant bacteria in the clinical setting.

  11. Comparison of 2 techniques of laryngeal tube exchange in a randomized controlled simulation study.

    PubMed

    Budde, Arne O; Schwarz, Adam; Dalal, Priti G; Sinz, Elizabeth H; Vaida, Sonia J

    2015-02-01

    Laryngeal tubes (LT) are often used as rescue airway devices. Among prehospital medical personnel, the success rates are high and significantly faster compared to an endotracheal tube (ETT). Therefore, LTs are increasingly used in the prehospital setting. The exchange of an LT for an ETT may often be desirable. Two fiberoptic bronchoscope-facilitated techniques have been described to exchange an LT for an ETT: an intraluminal technique using an Aintree intubating catheter and an extraluminal technique using a nasal route alongside the LT. In this randomized cross-over mannequin study, we compared the intraluminal with the extraluminal exchange technique. The primary outcome was time to achieve an effective airway through an ETT. We hypothesized that the intraluminal technique would be significantly faster. Thirty anesthesia providers were recruited to the study. Each participant attempted both techniques in an intubation simulation model. The tube exchange time was recorded from picking up the fiberoptic bronchoscope until confirmation of ventilation with the ETT. Four participants in each group had a failed attempt at intubation. Time to establish an endotracheal intubation was significantly shorter with the intraluminal technique vs the extraluminal technique (77.5 vs 140 seconds; P=.03). Based on the results of our study, we suggest that the intraluminal technique may be a suitable alternative for a fiberoptic-guided rapid exchange of an LT for an ETT to establish an effective airway in a challenging situation. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Comparison of endoscopic transcanal myringoplasty and endoscopic type I tympanoplasty in repairing medium-sized tympanic perforations.

    PubMed

    Tseng, Chih-Chieh; Lai, Ming-Tang; Wu, Chia-Che; Yuan, Sheng-Po; Ding, Yi-Fang

    2017-12-01

    The tympanomeatal flap elevation technique has been used in tympanoplasty for decades; however, this procedure has disadvantages. In recent years, endoscopic transcanal myringoplasty (ETM) has been increasingly practiced and has yielded positive results.This study compares the efficacy of ETM and endoscopic type I tympanoplasty (ETT) in repairing medium-sized perforations of the tympanic membrane. This retrospective medical record review included patients undergoing surgery for medium-sized perforations of the tympanic membrane from January 1, 2013 to August 1, 2015. We divided our patients into 2 groups: the ETM group and ETT group. The main outcome measure was comparison of the graft take rates and hearing results between ETM and ETT. A total of 113 patients were enrolled in this study; of these patients, 64 underwent ETM and 49 received ETT. The overall graft take rates and improvement of air-bone gaps were comparable between the groups. However, the patients in the ETM group had shorter operative times and fewer follow-up visits over 3 months than those in the ETT group did. We recommend that ETM (instead of ETT) be used for repairing medium-sized perforations of the tympanic membrane. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Analysis of HO2 and OH formation mechanisms using FM and UV spectroscopy in dimethyl ether oxidation.

    PubMed

    Suzaki, Kotaro; Tsuchiya, Kentaro; Koshi, Mitsuo; Tezaki, Atsumu

    2007-05-17

    Product formation pathways in the photolytically initiated oxidation of CH3OCH3 have been investigated as a function of temperature (298-600 K) and pressure (20-90 Torr) through the detection of HO2 and OH using Near-infrared frequency modulation spectroscopy, as well as the detection of CH3OCH2O2 using UV absorption spectroscopy. The reaction was initiated by pulsed photolysis with a mixture of Cl2, O2, and CH3OCH3. The HO2 and OH yield is obtained by comparison with an established reference mixture, including CH3OH. The CH3OCH2O2 yield is also obtained through the procedure of estimating the CH3OCH2O2/HO2 ratio from their UV absorption. A notable finding is that the OH yield is 1 order of magnitude larger than those known in C2 and C3 alkanes, increasing from 10% to 40% with increasing temperature. The HO2 yield increases gradually until 500 K and sharply up to 40% over 500 K. The CH3OCH2O2 profile has a prompt rise, followed by a gradual decay whose time constant is consistent with slow HO2 formation. To predict species profiles and yields, simple chlorine-initiated oxidation model of DME under low-pressure condition was constructed based on the existing model and the new reaction pathways, which were derived from this study. To model rapid OH formation, OH direct formation from CH3OCH2 + O2 was required. We have also proposed that a new HCO formation pathway via QOOH isomerization to HOQO species and OH + CH3OCH2O2 --> HO2 + CH3OCH2O are to be considered, to account for the fast and slow HO2 formations, as well as the total yield. The constructed model including these new pathways has successfully predicted experimental results throughout the entire temperature and pressure ranges investigated. It was revealed that the HO2 formation mechanism changes at 500 K, i.e., HCO + O2 via HCHO + OH and the above proposed direct HCO formation dominates over 500 K, while a series of reactions following CH3OCH2O2 self-reaction and OH + CH3OCH2O2 reaction mainly contribute

  14. Agreement between lower esophageal and nasopharyngeal temperatures in children ventilated with an endotracheal tube with leak.

    PubMed

    Snoek, Aarjan P; Saffer, Emily

    2016-02-01

    A temperature probe placed in the lower third of the esophagus accurately reflects core temperature in anesthetized children. Temperature probes are commonly placed in the nasopharynx in children, but when utilizing an uncuffed endotracheal tube (ETT) with a softly audible leak, ventilated gases from the trachea can escape upwards toward the nasopharynx, thereby potentially causing a cooling effect in the nasopharynx. We sought to establish if nasopharyngeal and lower esophageal temperatures are in agreement in children undergoing general anesthesia, both in scenarios of ventilation with a cuffed ETT that has minimal or no leak (cuff up), as well as an ETT with leak (cuff down). A prospective, crossover agreement study was performed on anesthetized children. Children were intubated with a MicroCuff(®) ETT and had temperature probes inserted into both the nasopharynx and lower esophagus. Under standardized ventilator and gas flow settings, temperatures were recorded with the ETT cuff inflated, and with the cuff deflated. Bland-Altman plots were utilized to assess agreement of temperatures. Fifty patients successfully completed this study. The mean difference between esophageal and nasopharyngeal temperature was found to be -0.03°C in the presence of minimal or no leak around the ETT (cuff up), with 95% limits of agreement (LOA) of -0.22 to 0.15°C. The mean difference between esophageal and nasopharyngeal temperature was found to be 0.1°C when a larger leak existed around the ETT (cuff down), with LOA of -0.31 to 0.51°C. Nasopharyngeal temperature accurately reflects lower esophageal temperature when there is minimal or no ETT leak. When a larger ETT leak is present, nasopharyngeal temperature is on average 0.1°C cooler than lower esophageal temperature. As the nasopharyngeal temperature probe site confers the advantage of simplicity of accurate placement compared to its esophageal counterpart, our findings support the use of nasopharyngeal temperature probes

  15. Effect of cuffed and uncuffed endotracheal tubes on the oropharyngeal oxygen and volatile anesthetic agent concentration in children.

    PubMed

    Raman, Vidya; Tobias, Joseph D; Bryant, Jason; Rice, Julie; Jatana, Kris; Merz, Meredith; Elmaraghy, Charles; Kang, D Richard

    2012-06-01

    Over the past 5 years, there has been a change in the clinical practice of pediatric anesthesiology with a transition to the use of cuffed instead of uncuffed endotracheal tubes (ETTs) in infants and children. As the trachea is sealed, one advantage is to eliminate the contamination of the oropharynx with oxygen which should be advantageous during adenotonsillectomy where there is a risk of airway fire. The current study prospectively assesses the oropharyngeal oxygen and volatile anesthetic agent concentration during adenotonsillectomy in infants and children. Following the induction of general anesthesia in patients scheduled for adenoidectomy, tonsillectomy or adenotonsillectomy, the trachea was intubated. The use of a cuffed or uncuffed ETT and the use of spontaneous (SV) or positive pressure ventilation (PPV) were at the discretion of the anesthesia team. The oxygen concentration was kept at 100% oxygen until the study was completed. Following placement of the mouth gag, the otolaryngolist placed into the oropharynx a small bore catheter, which was attached to a standard anesthesia gas monitoring device which sampled the gas at 150mL/min. The concentration of the oxygen and the concentration of the anesthetic agent in the oropharynx were measured for 5 breaths. The cohort for the study included 200 patients ranging in age from 1 to 18 years. With the use of a cuffed ETT and either SV or PPV, the oxygen concentration in the oropharynx was 20-21% and the volatile agent concentration was 0% in all 118 patients. With the use of an uncuffed ETT and the administration of 100% oxygen, there was significant contamination of the oropharynx noted during both PPV and SV. The mean oxygen concentration was 71% during PPV with an uncuffed ETT and 65% during SV with an uncuffed ETT. In these patients, the oropharyngeal oxygenation concentration exceeded 30% in 73 of the 82 patients (89%). The oropharyngeal oxygen and agent concentration was greater when the leak around the

  16. The pressure drop across the endotracheal tube in mechanically ventilated pediatric patients.

    PubMed

    Spaeth, Johannes; Steinmann, Daniel; Kaltofen, Heike; Guttmann, Josef; Schumann, Stefan

    2015-04-01

    During mechanical ventilation, the airway pressure (Paw) is usually monitored. However, Paw comprises the endotracheal tube (ETT)-related pressure drop (∆PETT ) and thus does not reflect the pressure in the patients' lungs. Therefore, monitoring of mechanical ventilation should be based on the tracheal pressure (Ptrach ). We systematically investigated potential factors influencing ∆PETT in pediatric ETTs. In this study, the flow-dependent pressure drop across pediatric ETTs from four manufacturers [2.0-4.5 mm inner diameter (ID)] was estimated in a physical model of the upper airways. Additionally, ∆PETT was examined with the ETTs shortened to 75% of their original length and at different curvatures. In nine healthy mechanically ventilated children (aged between 9 days and 29 months), Ptrach was compared to Paw . ∆PETT was nonlinearly flow dependent. Low IDs corresponded to high ∆PETT . Differences between ETTs from different manufacturers were identified. Shortening of the ETTs' length by 25% reduced ∆PETT on average by 14% of the value at original length. Ventilation frequency and tube curvature did not influence ∆PETT to a relevant extent. In the pediatric patients, the root mean square deviation between Paw and Ptrach was 2.3 cm H2O. Paw and Ptrach differ considerably (by ∆PETT ) during mechanical ventilation of pediatric patients. The ETTs' ID, tube length, and manufacturer type are significant factors for ∆PETT and should be taken into account when Paw is valuated. For this purpose, Ptrach can be continuously calculated with good precision by means of the Rohrer approximation. © 2014 John Wiley & Sons Ltd.

  17. Ultrasonographic Measurement of Subglottic Diameter for Paediatric Cuffed Endotracheal Tube Size Selection: Feasibility Report

    PubMed Central

    Altun, Demet; Sungur, Mukadder Orhan; Ali, Achmet; Bingül, Emre Sertaç; Seyhan, Tülay Özkan; Çamcı, Emre

    2016-01-01

    Objective The aim of this feasibility study was to investigate the first attempt success of ultrasonography (USG) in paediatric patients in predicting an appropriate cuffed endotracheal tube (ETT) size. Methods Fifty children who were 1–10 years of age and who received general anaesthesia with endotracheal intubation for adenoidectomy or adenotonsillectomy were enrolled in the study. In all participants, the transverse diameter of the subglottic airway was measured with USG at the cricoid level without ventilation. The outer diameter (OD) of the maximum allowable ETT was chosen according to the measured subglottic airway diameter. In the presence of resistance to passage of the tube into the trachea or in the absence of an audible leak at airway pressure of >25 cm H2O, the ETT was replaced with a tube whose internal diameter (ID) was 0.5 mm smaller. If a leak was audible at airway pressures of <10 cm H2O, if a seal could not be achieved with a cuff pressure of >25 cm H2O or if a peak airway pressure of >25 cm H2O was observed during ventilation, the tube was changed to a tube one size larger. The OD of the best-fit ETT was converted to the ID. The best-fit ID, the requirement for ETT replacement, the duration of airway diameter measurement by USG and the peak airway pressure were recorded. Results The success rate of the first attempt with USG was 86%; the ETT was replaced in five patients with a tube one size larger and in two patients with a tube one size smaller. Conclusion Our findings show the subglottic diameter measured by USG to be a reliable predictor in estimating the appropriate paediatric ETT size. PMID:28058141

  18. Radiological evaluation of tube depth and complications of prehospital endotracheal intubation in pediatric trauma: a descriptive study.

    PubMed

    Simons, T; Söderlund, T; Handolin, L

    2017-01-27

    Pediatric prehospital endotracheal intubation (PHETI) is a difficult and rarely performed procedure that remains the gold standard for prehospital airway management when ventilation and/or anesthesia is required, but high complications rates, including malposition continue to concern. We reviewed the experience in our institution of pediatric intubations with particular emphasis on the position of the endotracheal tube (ETT) tip within the trachea and related complications. Intubated pediatric patients presenting directly from the scene to our level 1 trauma center, between 2006 and 2014, were included in our study. Patient records and radiographs were retrospectively reviewed to identify the ETT tip-to-carina distance and possible intubation-related complications. ETT tips identified beyond the carina on radiographs or by clinical diagnosis were defined as misplaced. Because head movement causes a significant ETT movement within the trachea, which is age related, we also defined ETT tip placement (1) less than 2 cm above the carina in children younger than 8 and (2) less than 3 cm above the carina in children 8 years or older as "near miss" intubations. From a total of 34 cases, ETT misplacement was identified in seven cases. Diagnosis was made radiologically in five cases and clinically in two cases. Four of these patients had left lung atelectasis due to tube misplacement. Tube thoracotomy was performed in two of these patients without concurrent evidence of chest injury. "Near miss" intubations accounted for 7/9 and 9/25 in children <8 years and ≥8 years old, respectively, totaling 16/34, with two of these leading to late displacements. Pediatric endotracheal tube intubation carries a high rate of tube malposition and left lung atelectasis in our experience of pediatric trauma patients, with less than a third of ETTs placed in a safe position.

  19. Airway management with endotracheal tube versus Combitube during parabolic flights.

    PubMed

    Rabitsch, Werner; Moser, Doris; Inzunza, Michelle R; Niedermayr, Monika; Köstler, Wolfgang J; Staudinger, Thomas; Locker, Gottfried J; Schellongowski, Peter; Wulkersdorfer, Beatrix; Rich, James M; Meyer, Brigitte; Benumof, Jonathan L; Frass, Michael

    2006-10-01

    Training of National Aeronautics and Space Administration space shuttle astronauts revealed difficult airway management with endotracheal tubes (ETTs) under microgravity conditions. The authors performed a randomized comparative study of ETT and Combitube (ETC; Tyco Healthcare, Pleasanton, CA). The aim of the study was to evaluate ease, time of insertion, and success rates during normogravity and parabolic flights using mannequins. After normogravity experiments, four flyers performed intubation on a mannequin during the flights. Sixty-two intubation attempts were performed using the ETC (normogravity, 29; microgravity, 33), and 58 intubation attempts were performed using the ETT (each 29 attempts, both conditions). Time to completion of the intubation procedure, success rate, and ease of insertion were recorded. The ETC performed equally well between normogravity (median, 18 s; range, 17-25 s) and microgravity (median, 18.5 s; range, 17-28 s), whereas the ETT performed significantly slower under microgravity (median, 20 s; range, 17-27 s) as compared with normogravity (median, 18 s; range, 16-22 s; P = 0.019). One hundred nine of 120 (90%) were successful. The ETT and ETC were comparable with respect to successful intubations, under normogravity or microgravity, respectively. Both the ETC and ETT perform comparably well. Slight differences could be found with respect to time of insertion in favor of the ETC. Because this is the first experiment using the ETC on the KC-135, it is shown that there is enough time to perform the insertion procedure. Because the ETC airway requires less training and is easier to insert than an ETT, it is recommended for further study as an alternative airway to what is currently on the shuttle.

  20. I-gel as an alternative to endotracheal tube in adult laparoscopic surgeries: A comparative study

    PubMed Central

    Badheka, Jigisha Prahladrai; Jadliwala, Rashida Mohammedi; Chhaya, Vrajeshchandra Amrishbhi; Parmar, Vandana Surendrabhai; Vasani, Amit; Rajyaguru, Ajay Maganlal

    2015-01-01

    BACKGROUND: The tracheal tube is always considered to be the gold standard for laparoscopic surgeries. As conventional laryngoscopy guided endotracheal intubation evokes significant hypertension and tachycardia, we have used I-gel, second generation extraglottic airway device, in an attempt to overcome these drawbacks. We conducted this study to compare haemodynamic changes during insertion, efficacy of ventilation, and complications with the use of I-gel when compared with endotracheal tube (ETT) in laparoscopic surgeries. MATERIALS AND METHODS: A total of 60 American Society of Anaesthesiologists physical status I and II adult patients undergoing elective laparoscopic surgeries were randomly allocated to one of the two groups of 30 patients each: Group-A (I-gel) in which patients airway was secured with appropriate sized I-gel, and Group-B (ETT) in which patients airway was secured with laryngoscopy - guided endotracheal intubation. Ease, attempts and time for insertion of airway device, haemodynamic and ventilatory parameters at different time intervals, and attempts for gastric tube insertion, and perioperative complications were recorded. RESULTS: There was significant rise in pulse rate and mean blood pressure during insertion with use of ETT when compared to I-gel. Furthermore, time required for I-gel insertion was significantly less when compared with ETT. However ease and attempts for airway device insertion, attempts for gastric tube insertion and efficacy of ventilation were comparable between two groups. CONCLUSION: We concluded that I-gel requires less time for insertion with minimal haemodynamic changes when compared to ETT. I-gel also provides adequate positive-pressure ventilation, comparable with ETT. Hence I-gel can be a safe and suitable alternative to ETT for laparoscopic surgeries. PMID:26622115

  1. Significance of a clean-tip catheter closed suctioning system in a high-setting ventilated, super morbidly obese patient with profuse respiratory secretions.

    PubMed

    Mazlan, Mohd Zulfakar; Mohd Zaini, Rhendra Hardy; Hassan, Shamsul Kamalrujan; Ali, Saedah; Che Omar, Sanihah; Wan Hassan, Wan Mohd Nazaruddin

    2017-01-01

    Closed suctioning is commonly used in the context of high-setting mechanical ventilation (MV), given its ability to prevent lung volume loss that otherwise accompanies open suctioning. However, closed suctioning systems (CSS) are not equivalent regarding components and capabilities, and thus this technique may be differentially effective to adequately clear patient secretions from an endotracheal tube (ETT), which is of paramount importance when the tube size makes the ETT particularly vulnerable to block by patient secretions. A 25-year-old super morbidly obese female (body mass index = 55 kg/meter(2)) presented with worsening shortness of breath. For MV, pairing of a 6 mm (mm) diameter ETT to accommodate the patient's vocal cord edema, with a CSS not designed to maintain a clean catheter tip, precipitated ETT blockage and respiratory acidosis. Replacement of these devices with a 6.5 mm ETT and a CSS designed to keep the catheter tip clean resolved the complications. After use of the different ETT and CSS for approximately one week, the patient was discharged to home. The clean-tip catheter CSS enabled a more patent airway than its counterpart device that did not have this feature. Use of a clean-tip catheter CSS was an important care development for this patient, because this individual's super morbidly obese condition minimized tolerance for MV complications that would exacerbate her pre-existing tenuous respiratory health status. Special attention should be given to the choices of ETT size and CSS to manage super morbidly obese patients who have a history of difficult airway access.

  2. Tactile sensitivity of vital and endodontically treated teeth.

    PubMed

    Schneider, Birte-Juliane; Freitag-Wolf, Sandra; Kern, Matthias

    2014-11-01

    Endodontically treated teeth (ETT) used as abutments for removable partial dental prostheses (RPDPs) have an increased fracture risk as compared to vital abutments. One suggested explanation is that ETT exhibit a lower threshold level for tactile sensitivity than vital teeth. Therefore, this study compared the threshold for tactile sensitivity of vital teeth and ETT in the same individuals. Forty participants with double crown-retained RPDPs fixed to vital teeth and ETT were included in the study. Each subject had at least one vital and one corresponding contralateral endodontically treated abutment tooth in the same jaw. After removal of the RPDP, an increasing centric force (0cN to max. 2000cN) was separately applied axially to both free-standing abutment teeth using a force gauge while the patient was asked to give three acoustic signals: (1) when noticing the first contact, (2) when noticing pressure and (3) when the pressure became displeasing. Afterwards, the same trial was performed with an eccentric force applied parallel to the tooth axis. Statistical analysis revealed no significant differences in the threshold of tactile sensitivity of vital teeth and ETT to either centric or eccentric loading (p>0.05). Eccentric loading showed lower mean threshold values compared to centric loading. A large variability of tactile sensitivity between individuals was noted. However, there were no gender-related significant differences in tactile sensitivity (p>0.05). The tactile sensitivity of vital and non-vital teeth seems comparable. The assumption that a lower threshold level for tactile sensitivity in ETT than in vital teeth is responsible for their increased fracture risk could not be confirmed. Therefore, other reasons, e.g. loss of hard tissue due to root canal treatment, have to be considered responsible for the increased fracture risk of ETT. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. Comparison of clinical efficacy and cost of a cardiac imaging strategy versus a traditional exercise test strategy for the investigation of patients with suspected stable coronary artery disease.

    PubMed

    Demir, Ozan M; Bashir, Abdullah; Marshall, Kathy; Douglas, Martina; Wasan, Balvinder; Plein, Sven; Alfakih, Khaled

    2015-06-15

    We evaluated the clinical efficacy and cost of a cardiac imaging strategy versus a traditional exercise tolerance test (ETT) strategy for the investigation of suspected stable coronary artery disease (CAD). We retrospectively collected data of consecutive patients seen in rapid access chest pain clinics at 2 UK hospitals for a period of 12 months. Hospital A investigated patients by performing ETT. Hospital B investigated patients using cardiac imaging test; 483 patients from hospital A and 295 from hospital B were included. In hospital A, 209 patients (43.3%) had contraindication to ETT. Of those who had ETT, 151 (55.1%) had negative ETT, 68 (24.8%) had equivocal ETT, and 55 (20.1%) had positive ETT, of which 53 (96.4%) had invasive coronary angiography (ICA), and of these 23 (43.4%) had obstructive CAD. In hospital B, 26 patients (8.8%) with low pretest probability had calcium score and 3 (11.5%) were positive leading to computed tomography coronary angiography; 98 patients (33.2%) with intermediate pretest probability had computed tomography coronary angiography and 5 (5.1%) were positive; 77 patients (26.1%) had stress echocardiogram and 6 (7.8%) were positive; and 57 patients (19.3%) had myocardial perfusion scintigraphy and 11 (19.3%) were positive. Hospital A performed 127 ICA (26.3% of population) and 52 (40.9%) had obstructive CAD. Hospital B performed 63 ICA (21.4% of population) and 32 (50.8%) had obstructive CAD. The average cost per patient in hospital A was £566.6 ± 490.0 ($875 ± 758) and in hospital B was £487.9 ± 469.6 ($750 ± 725) (p <0.001). In conclusion, our results suggest that a cardiac imaging pathway leads to fewer ICA and a higher yield of obstructive CAD at lower cost per patient. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. How much force is required to dislodge an alternate airway?

    PubMed

    Carlson, Jestin N; Mayrose, James; Wang, Henry E

    2010-01-01

    Endotracheal tube (ETT) dislodgment is a potentially catastrophic adverse event. Newer alternate airway devices-esophageal-tracheal Combitube (ETC), King laryngeal tube disposable airway (King LT), and laryngeal mask airway (LMA)-are easier to insert, but their relative extubating forces remain unknown. To examine the applied forces required to dislodge an ETC, King LT, LMA, and ETT. We used five recently deceased adult unembalmed cadavers. In random order, we sequentially inserted an ETC, King LT, LMA, and standard ETT. Because commercial tube holders are not designed for all alternate airways, we secured the devices with a standard adhesive tape method. Using a precision digital force measuring device, we measured the minimum manually applied axial force (lb) that dislodged each airway device at least 4 cm. We compared required dislodgment forces between airway devices using a mixed-effects regression model, adjusting for cadaver height, weight, neck circumference, and thyromental distance. Characteristics of the cadavers were as follows (median, interquartile range [IQR]): height 172 cm (167-177), weight 98 kg (84-120), neck circumference 46.5 cm (41-52), and thyromental distance 7.5 cm (7.5-8). Required axial dislodgment forces for each airway device were as follows (median, IQR): ETC 28.3 lb (19.0-28.6), King LT 12.5 lb (11.7-13.3), LMA 18.3 lb (14.0-21.9), and ETT 14.4 lb (13.5-22.1). The ETC required twice as much dislodgment force as the ETT (adjusted difference 16.7 lb, 95% confidence interval [CI]: 8.3 to 25.1). The King LT and LMA dislodgment forces were similar to that of the ETT (King LT vs. ETT adjusted difference 5.9 lb, 95% CI: -2.4 to 14.2; LMA vs. ETT 8.1 lb, 95% CI: -0.2 to 16.5). In a cadaver model of unintended airway dislodgment, the ETC required the most force for dislodgment. The King LT and LMA performed similarly to a standard ETT.

  5. Antimony leaching from MSWI bottom ash: modelling of the effect of pH and carbonation.

    PubMed

    Cornelis, Geert; Van Gerven, Tom; Vandecasteele, Carlo

    2012-02-01

    Development of treatment methods to reduce Sb leaching from municipal solid waste incinerator (MSWI) bottom ash, such as accelerated carbonation, is being complicated by insufficient understanding of Sb geochemistry. The leaching of antimonate (Sb(V)) and antimonite (Sb(III)) in MSWI bottom was studied as a function of pH and degree of carbonation. While total (Sb(V)+Sb(III)) leaching was lowest (1.2 mg kg(-1)) at the natural pH (i.e. 10.6) of uncarbonated bottom ash, HPLC-ICP-MS analysis showed that acidification and carbonation increased Sb(V) leaching, but decreased Sb(III) leaching, probably because Sb(III)(OH)(4)(-) became less stable. PHREEQC geochemical modelling suggested that Sb(V) concentrations approached equilibrium with the romeites, i.e. calcium antimonates, Ca(1.13)Sb(2)(OH)(0.26)·0.74H(2)O at pH=10.6 and Ca[Sb(OH)(6)](2) at pH=8. It is hypothesised that not interaction with ettringite but dissolution of romeite controls antimonate leaching in the pH range 8-11 in MSWI bottom ash, because while Ca is preferentially leached from romeite, the mineral structures containing more Ca at higher pH are less soluble. A model was proposed where acidification and carbonation both lead to lower Ca(2+) and/or hydroxyl concentration, which removes Ca(2+) and hydroxyls from the romeite structure and leads to comparably higher Sb(V) concentration in equilibrium with romeite. Sb solubility depends on pH and Ca(2+) availability in this model, which has implications for bottom ash valorisation and risk assessment.

  6. Adult intensive care patients' perception of endotracheal tube-related discomforts: a prospective evaluation.

    PubMed

    Samuelson, Karin A M

    2011-01-01

    This study was designed to investigate adult patients' perceptions of endotracheal tube (ETT)-related discomfort at 5 days and 2 months after discharge from the intensive care unit (ICU). This prospective cohort study in 2 general ICUs included 250 intubated, mechanically ventilated adults admitted for more than 24 hours. Patients were interviewed 5 days and 2 months after discharge from the ICU about their ETT-related discomfort, using a modified Swedish ETT version of the ICU Stressful Experience Questionnaire that comprises 14 items. Of 116 patients describing their ETT experience during their ICU stay, 88% rated their discomfort as moderately to extremely stressful. At 2 months after discharge from the ICU, 23% (51/226) reported bothersome discomfort, vs. 46% (104/226) 5 days after discharge from the ICU, and 10 patients suffered from severe, persistent hoarseness. The incidence of bothersome subjective complaints after tracheal intubation in the intensive-care setting is high, and severe ETT-related problems may persist several months after extubation. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. A multifaceted quality improvement program improves endotracheal tube confirmation documentation in the emergency department.

    PubMed

    Phelan, Michael P; Hustey, Fredric M; Glauser, Jonathan M; Bena, James

    2015-01-01

    Confirmation of endotracheal tube (ETT) position is an essential part of emergency department (ED) airway care. The study team evaluated the effect of a multifaceted quality improvement initiative on improving confirmation documentation rates. Rates of documentation of appropriate methods of ETT position confirmation were better for patients undergoing ETT placement in the study site ED than for those arriving already intubated (103/127 [81.1%] vs 19/71 [26.8%]; relative risk [RR] = 3.03; 95% confidence interval [CI] = 2.04 to 4.49). Overall rates of documentation of appropriate methods of ETT position confirmation were higher after the intervention (557/758 [73.5%] vs 122/198 [61.6%]; RR = 1.19; 95% CI = 1.06 to 1.34), with a greater increase among the group presenting to the ED with an ETT already placed (116/259 [44.8%] vs 19/71 [26.8%]; RR = 1.67; 95% CI = 1.11 to 2.51) compared with those intubated in the study site ED (103/127 [81.1%] vs 441/499 [88.4%]; RR = 0.92; 95% CI = 0.8389 to 1.0039).

  8. Community analysis of dental plaque and endotracheal tube biofilms from mechanically ventilated patients.

    PubMed

    Marino, Poala J; Wise, Matt P; Smith, Ann; Marchesi, Julian R; Riggio, Marcello P; Lewis, Michael A O; Williams, David W

    2017-06-01

    Mechanically ventilated patients are at risk for developing ventilator-associated pneumonia, and it has been reported that dental plaque provides a reservoir of respiratory pathogens that may aspirate to the lungs and endotracheal tube (ETT) biofilms. For the first time, metataxonomics was used to simultaneously characterize the microbiome of dental plaque, ETTs, and non-directed bronchial lavages (NBLs) in mechanically ventilated patients to determine similarities in respective microbial communities and therefore likely associations. Bacterial 16S rRNA gene sequences from 34 samples of dental plaque, NBLs, and ETTs from 12 adult mechanically ventilated patients were analyzed. No significant differences in the microbial communities of these samples were evident. Detected bacteria were primarily oral species (e.g., Fusobacterium nucleatum, Streptococcus salivarius, Prevotella melaninogenica) with respiratory pathogens (Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcuspneumoniae, and Haemophilus influenzae) also in high abundance. The high similarity between the microbiomes of dental plaque, NBLs, and ETTs suggests that the oral cavity is indeed an important site involved in microbial aspiration to the lower airway and ETT. As such, maintenance of good oral hygiene is likely to be highly important in limiting aspiration of bacteria in this vulnerable patient group. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. False-positive colorimetric capnometry after ingestion of carbonated beverages.

    PubMed

    Keller, William Ryan; Biehler, Jefrey; Linares, Marc Yves-Rene; Garcia-Pena, Barbara M

    2009-02-01

    To investigate the potential for false-positive colorimetric capnometric readings during esophageal intubation after ingestion of carbonated beverages. The study was conducted in the human patient simulation laboratory of a tertiary care pediatric hospital. The sole outcome measurement was the capnometric indicator membrane color after expiration for 10 breaths. Readings were recorded for scenarios simulating 8 different models. For all carbonated beverage trials with a cuffed endotracheal tube (ETT) and those with 2 and 6 oz of beverage in the gastric sac with an uncuffed ETT, a false-positive result was observed on the capnometer's indicator for breaths 1 through 10. The sensitivity of the capnometer for the detection of CO2 after full exhalation of breath 6 for these trials was 100%. For trials containing 12 oz in the gastric sac and an uncuffed ETT, yellow was observed on the capnometer indicator for breaths 1 through 3, tan for breaths 4 through 6, and purple for breath 7. The sensitivity of the capnometer for the detection of adequate CO2 after full exhalation of breath 6 for these trials was 0%. The overall sensitivity of the capnometer for the carbonated beverage models with a cuffed ETT was 100%, whereas the combined sensitivity for the trials with an uncuffed ETT was 67%. Under proper circumstances, a significant potential exists for false-positive colorimetric capnometric results in the presence of even small amounts of carbonated beverages.

  10. Placental site trophoblastic tumors and epithelioid trophoblastic tumors: Biology, natural history, and treatment modalities.

    PubMed

    Horowitz, Neil S; Goldstein, Donald P; Berkowitz, Ross S

    2017-01-01

    Placental site (PSTT) and epithelioid trophoblastic tumor (ETT) are rare types of gestational trophoblastic neoplasia (GTN) that arise from intermediate trophoblast. Given that this cell of origin is different from other forms of GTN, it is not surprising that the clinical presentation, tumor marker profile, and treatment paradigm for PSTT and ETT are quite different as well. The mainstay for therapy for stage I PSTT and ETT is hysterectomy with adjuvant chemotherapy reserved for those presenting greater than four years from the antecedent pregnancy. Surgery is also important for metastatic disease. There is no standardized chemotherapy regimen for advanced stage disease but often consists of a platinum-containing combination therapy, usually EMA-EP or TE/TP. Despite its rarity, PSTT and ETT account for a disproportionate percentage of mortality from GTN likely resulting from their relative chemotherapy resistance. Novel therapeutic modalities therefore are needed to improve the outcomes of women with advanced stage or resistant PSTT and ETT. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Lung recruitment and endotracheal suction in ventilated preterm infants measured with electrical impedance tomography.

    PubMed

    Hough, Judith L; Shearman, Andrew D; Liley, Helen; Grant, Caroline A; Schibler, Andreas

    2014-11-01

    Although suctioning is a standard airway maintenance procedure, there are significant associated risks, such as loss of lung volume due to high negative suction pressures. This study aims to assess the extent and duration of change in end-expiratory level (EEL) resulting from endotracheal tube (ETT) suction and to examine the relationship between EEL and regional lung ventilation in ventilated preterm infants with respiratory distress syndrome. A prospective observational clinical study of the effect of ETT suction on 20 non-muscle-relaxed preterm infants with respiratory distress syndrome (RDS) on conventional mechanical ventilation was conducted in a neonatal intensive care unit. Ventilation distribution was measured with regional impedance amplitudes and EEL using electrical impedance tomography. ETT suction resulted in a significant increase in EEL post-suction (P < 0.01). Regionally, anterior EEL decreased and posterior EEL increased post-suction, suggesting heterogeneity. Tidal volume was significantly lower in volume-guarantee ventilation compared with pressure-controlled ventilation (P = 0.04). ETT suction in non-muscle-relaxed and ventilated preterm infants with RDS results in significant lung volume increase that is maintained for at least 90 min. Regional differences in distribution of ventilation with ETT suction suggest that the behaviour of the lung is heterogeneous in nature. © 2014 The Authors. Journal of Paediatrics and Child Health © 2014 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

  12. Clinical indicators for the initiation of endotracheal suction in children: An integrative review.

    PubMed

    Davies, K; Monterosso, L; Bulsara, M; Ramelet, A S

    2015-02-01

    Critical decisions and interpretation of observations by the nurse caring for the paediatric intensive care (PIC) patient can have dramatic and potential adverse impact on the clinical stability of the patient. A common PIC procedure is endotracheal tube (ETT) suction, however there is inconsistent evidence regarding the clinical indicators to guide and support nursing action. Justification for performing this procedure is not clearly defined within the literature. Further, a review of the literature has failed to establish clear standards for determining if the procedure is warranted, especially for paediatric patients. The objective of the review is to identify current clinical indicators used in practice to determine why ETT suction should be performed. An integrative review using a systematic approach to summarise the empirical and theoretical evidence within the literature as it relates to clinical practice was used. Consensus of opinion indicates that ETT suctioning should only be performed when clinically indicated. There is no general consensus regarding which clinical indicators should be measured and used to guide the decision to perform ETT suctioning. Research is required to identify the clinical indicators that could be used to design a valid and clinically appropriate tool to use to assist in the decision making process to perform ETT suction. Copyright © 2014. Published by Elsevier Ltd.

  13. Ventilator-associated pneumonia or endotracheal tube-associated pneumonia? An approach to the pathogenesis and preventive strategies emphasizing the importance of endotracheal tube.

    PubMed

    Pneumatikos, Ioannis A; Dragoumanis, Christos K; Bouros, Demosthenes E

    2009-03-01

    Ventilator-associated pneumonia is the most common nosocomial infection in the intensive care unit, and it is associated with prolonged hospitalization, increased health care costs, and high attributable mortality. During the past several decades, numerous studies focused on the crucial role of the endotracheal tube (ETT) in the pathogenesis of ventilator-associated pneumonia. Tracheal intubation thwarts the cough reflex, compromises mucocilliary clearance, injures the tracheal epithelial surface, provides a direct conduit for rapid access of bacteria from upper into the lower respiratory tract, and allows the formation of biofilm on the ETT surface. The combination of these factors puts the mechanically ventilated patient at great jeopardy of developing ventilator-associated pneumonia. Many preventive strategies have arisen from this understanding: control of intracuff pressure, aspiration of subglottic secretions, decontamination of subglottic area, use of antiseptic impregnated ETTs, and elimination or prevention of the ETT biofilm formation. The authors review the role of ETT management for the prevention of the ventilator-associated pneumonia.

  14. Bactericidal effects of silver plus titanium dioxide-coated endotracheal tubes on Pseudomonas aeruginosa and Staphylococcus aureus.

    PubMed

    Tarquinio, Keiko M; Kothurkar, Nikhil K; Goswami, Dharendra Y; Sanders, Ronald C; Zaritsky, Arno L; LeVine, Ann Marie

    2010-04-07

    Ventilator-associated pneumonia (VAP) is a nosocomial infection resulting in significant morbidity and mortality. Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) are pathogens associated with VAP. Silver (Ag) coating of endotracheal tubes (ETTs) reduces bacterial colonization, however titanium dioxide (TiO(2)) coating has not been studied. Five types of ETT coatings were applied over silica layer: Ag, solgel TiO(2), solgel TiO(2) with Ag, Degussa P25 TiO(2) (Degussa TiO(2)), and Degussa TiO(2) with Ag. After ETTs were incubated with P. aeruginosa or S. aureus; colonization was determined quantitatively. Pseudomonas aeruginosa and S. aureus grew for 5 days on standard ETTs. Compared to standard ETTs, P. aeruginosa growth was significantly inhibited by solgel TiO(2) with Ag at 24 hours, and by Degussa TiO(2) with Ag at 24 and 48 hours after inoculation. No significant difference in S. aureus growth was observed between the control and any of the five coatings for 5 days. In vitro, solgel TiO(2) with Ag and Degussa TiO(2) with Ag both attenuated P. aeruginosa growth, but demonstrated no effect on S. aureus colonization. Further studies using alternative coating and incorporating UV light exposure are needed to identify their potential utility in reducing VAP.

  15. Intraoperative atelectasis due to endotracheal tube cuff herniation: a case report.

    PubMed

    Moazeni Bitgani, Mohammad; Madineh, Hossein

    2012-01-01

    Endotracheal tube (ETT) cuff herniation is a rare, and often difficult to diagnose, cause of bronchial obstruction. We present a case of outside cuff herniation of an endotracheal tube that caused pulmonary right lung atelectasis. A 29-year-old man ,a case of car accident with multiple fractures, was admitted to the emergency ward and transferred to the operating room(OR) for open reduction and internal fixation (ORIF) of all fractures .The procedures were done under general anesthesia (G/A). The past medical history of the patient did not indicate any problem. Anesthesia was induced with thiopental, atracurium and then maintained by propofol and remifentanyl infusions and 100% O2 via orally inserted ETT. The patient was positioned in left lateral decubitus position for operation. Two hours after induction of anesthesia, the oxygen saturation level dropped to 85 % and the breath sounds in the right side of the chest were weakened. The chest x-ray images showed right lung atelectasis especially in the upper lobe. The problem was disappeared after removal of the ETT. In this case, we observed that an ETT cuff herniation can be a cause of airway obstruction. If there is a decreased unilateral breath sounds, we recommend replacement or repositioning of ETT.

  16. Tin(II) alkoxide hydrolysis products for use as base catalysts

    DOEpatents

    Boyle, Timothy J.

    2002-01-01

    Tin alkoxide compounds are provided with accessible electrons. The compounds are a polymeric tin alkoxide, [Sn(OCH.sub.2 C(CH.sub.3).sub.3).sub.2 ].sub.n, and the hydrolysis products Sn.sub.6 O.sub.4 (OCH.sub.2 C(CH.sub.3).sub.3).sub.4 and Sn.sub.5 O.sub.2 (OCH.sub.2 C(CH.sub.3).sub.3).sub.6. The hydrolysis products are formed by hydrolyzing the [Sn(OCH.sub.2 C(CH.sub.3).sub.3).sub.2 ].sub.n in a solvent with controlled amounts of water, between 0.1 and 2 moles of water per mole of the polymeric tin alkoxide.

  17. GSFC_20170308_2017-8679_041

    NASA Image and Video Library

    2017-03-08

    Lt. Governor Rutherford and staff visited Goddard on March 8, 2017. They toured James Webb Space Telescope with Bill Ochs and Robotics Operations Center with Ben Reed. They also met John Mather, Nobel Prize winner.

  18. GSFC_20170308_2017-8679_036

    NASA Image and Video Library

    2017-03-08

    Lt. Governor Rutherford and staff visited Goddard on March 8, 2017. They toured James Webb Space Telescope with Bill Ochs and Robotic Operations Center with Ben Reed. They also met John Mather, Nobel Prize winner.

  19. GSFC_20170308_2017-8679_015

    NASA Image and Video Library

    2017-03-08

    Lt. Governor Rutherford and staff visited Goddard on March 8, 2017. They toured James Webb Space Telescope with Bill Ochs and Robotic Operations Center with Ben Reed. They also met John Mather, Nobel Prize winner.

  20. James Webb Space Telescope (JWST) Town Hall - Panel question and

    NASA Image and Video Library

    2016-11-02

    James Webb Space Telescope (JWST) Town Hall - Panel question and answer - Bill Ochs; Dr. John Mather; Dr. Eric Smith; Thomas Zurbuchen; Center Director Chris Scolese; NASA Administrator Charlie Bolden.

  1. Saponins of the ivy plant, Hedera helix, and their leishmanicidic activity.

    PubMed

    Majester-Savornin, B; Elias, R; Diaz-Lanza, A M; Balansard, G; Gasquet, M; Delmas, F

    1991-06-01

    Antileishmanial activity is reported for the first time for saponins of ivy, Hedera helix L., in vitro on promastigote and amastigote forms of Leishmania infantum and Leishmania tropica. The compounds tested were an extract containing 60% of saponic complex (CS 60), the bidesmosides hederasaponin B, C, and D (saponin K10), their corresponding monodesmosides alpha-, beta-, and delta-hederin, and hederagenin. CS 60 and bidesmosides have shown no effect. Monodesmosides were found to be as effective on promastigote forms as the reference compound (pentamidine). Against amastigote forms only hederagenin exhibited a significant activity which was equivalent to that of the reference compound (N-methylglucamine antimonate).

  2. Rearrangement of a Krebs-type polyoxometalate upon coordination of N,O-bis(bidentate) ligands.

    PubMed

    Artetxe, Beñat; Reinoso, Santiago; San Felices, Leire; Lezama, Luis; Pache, Aroa; Vicent, Cristian; Gutiérrez-Zorrilla, Juan M

    2015-01-20

    Selective coordination of 2,3-pyzdc to the Krebs-type [{Ni(H2O)3}2(WO2)2(SbW9O33)2](10-) anion promotes a skeletal rearrangement that results in the [(2,3-pyzdc)2{NaNi2(H2O)4Sb2W20O70}2](22-) (Ni4) hybrid dimer showing a novel dinickel containing a 20-tungsto-2-antimonate(III) framework stabilized by N,O-bis(bidentate) bridging ligands. The solution stability and magnetism of Ni4 is discussed.

  3. Antimony tin oxide (ATO) nanoparticle formation from H2O2 solutions: a new generic film coating from basic solutions.

    PubMed

    Sladkevich, Sergey; Mikhaylov, Alexey A; Prikhodchenko, Petr V; Tripol'skaya, Tatiana A; Lev, Ovadia

    2010-10-18

    A generic method for conductive film coating of minerals and acid-sensitive materials by antimony-doped tin oxide (ATO) is introduced. The coating was performed from a hydrogen peroxide stabilized stannate and antimonate precursor solution. This is the first demonstration of ATO coating from an organic ligand-free solution. Uniform coating of different clays and other irregular configurations by monosized 5 nm ATO particles was demonstrated. The deposition mechanism and the observed preference for mineral surface coating over homogeneous agglomeration of the tin oxide particles are explained by a hydrogen peroxide capping mechanism and hydrogen bonding of the hydroperoxo nanoparticles to the H(2)O(2)-activated mineral surfaces.

  4. Theoretical Investigation of Mechanisms for the Gas-Phase Unimolecular Decomposition of DMMP

    NASA Astrophysics Data System (ADS)

    Yang, Li; Shroll, Robert M.; Zhang, Jiaxu; Lourderaj, U.; Hase, William L.

    2009-11-01

    All species involved in the multichannel decomposition of gas-phase dimethyl methylphosphonate (DMMP) were investigated by electronic structure calculations. Geometries for stationary structures along the reaction paths, were fully optimized with the MP2 method and the B3LYP and MPW1K DFT functionals, and the 6-31G*, 6-31++G**, and aug-cc-pVDZ basis sets. The geometries determined by the B3LYP and MPW1K functionals are in very good agreement with the MP2 values. Increasing the basis set size from 6-31G* to aug-cc-pVDZ does not significantly alter this result. Single point energy calculations were carried out with highly accurate but computationally more expensive CBS-QB3 theory. DMMP has three conformers, which lead to the four primary product channels, (O)P(CH2)(OCH3) + CH3OH, (O)P(CH3) (OCH3)(OH) + CH2, c-(O)P(CH3)OCH2 + CH3OH, and (O)P(CH3)(OCH3)(OCH) + H2. The first channel has the lowest energy barrier and is expected to be the most important pathway. It occurs via C-H and P-O bond cleavages accompanied by O-H bond formation. The other three channels have higher and similar energy barriers, and are expected to have smaller and similar rates. The product (O)P(CH3)(OCH3)(OCH) undergoes a secondary decomposition to form (OH)P(CH3)(OCH3) + CO.

  5. α-1,6-Mannosylation of N-Linked Oligosaccharide Present on Cell Wall Proteins Is Required for Their Incorporation into the Cell Wall in the Filamentous Fungus Neurospora crassa▿†

    PubMed Central

    Maddi, Abhiram; Free, Stephen J.

    2010-01-01

    The enzyme α-1,6-mannosyltransferase (OCH-1) is required for the synthesis of galactomannans attached to the N-linked oligosaccharides of Neurospora crassa cell wall proteins. The Neurospora crassa och-1 mutant has a tight colonial phenotype and a defective cell wall. A carbohydrate analysis of the och-1 mutant cell wall revealed a 10-fold reduction in the levels of mannose and galactose and a total lack of 1,6-linked mannose residues. Analysis of the integral cell wall protein from wild-type and och-1 mutant cells showed that the mutant cell wall had reduced protein content. The och-1 mutant was found to secrete 18-fold more protein than wild-type cells. Proteomic analysis of the proteins released by the mutant into the growth medium identified seven of the major cell wall proteins. Western blot analysis of ACW-1 and GEL-1 (two glycosylphosphatidylinositol [GPI]-anchored proteins that are covalently integrated into the wild-type cell wall) showed that high levels of these proteins were being released into the medium by the och-1 mutant. High levels of ACW-1 and GEL-1 were also released from the och-1 mutant cell wall by subjecting the wall to boiling in a 1% SDS solution, indicating that these proteins are not being covalently integrated into the mutant cell wall. From these results, we conclude that N-linked mannosylation of cell wall proteins by OCH-1 is required for their efficient covalent incorporation into the cell wall. PMID:20870880

  6. Cholesteric Liquid Crystal Glass Platinum Acetylides

    DTIC Science & Technology

    2014-06-01

    have the formula trans-Pt(PR3)(cholesterol (3 or 4)- ethynyl benzoate)(1-ethynyl-4-X- benzene ), where R = Et, Bu or Oct and X = H, F, OCH3 and CN. A...have the formula trans-Pt(PR3)(cholesterol (3 or 4)-ethynyl benzoate)(1-ethynyl-4- X- benzene ), where R = Et, Bu or Oct and X = H, F, OCH3 and CN. A

  7. Perspectives on Pentaerythritol Tetranitrate (PETN) Decomposition

    SciTech Connect

    Chambers, D; Brackett, C; Sparkman, D O

    2002-07-01

    This report evaluates the large body of work involving the decomposition of PETN and identifies the major decomposition routes and byproducts. From these studies it becomes apparent that the PETN decomposition mechanisms and the resulting byproducts are primarily determined by the chemical environment. In the absence of water, PETN can decompose through the scission of the O-NO{sup 2} bond resulting in the formation of an alkoxy radical and NO{sub 2}. Because of the relatively high reactivity of both these initial byproducts, they are believed to drive a number of autocatalytic reactions eventually forming (NO{sub 2}OCH{sub 2}){sub 3}CCHO, (NO{sub 2}OCH{sub 2}){sub 2}C=CHONO{sub 2}, NO{sub 2}OCH=C=CHONO{sub 2}, (NO{sub 2}OCH{sub 2}){sub 3}C-NO{sub 2}, (NO{sub 2}OCH{sub 2}){sub 2}C(NO{sub 2}){sub 2}, NO{sub 2}OCH{sub 2}C(NO{sub 2}){sub 3}, and C(NO{sub 2}){sub 4} as well as polymer-like species such as di-PEHN and tri-PEON. Surprisingly, the products of many of these proposed autocatalytic reactions have never been analytically validated. Conversely, in the presence of water, PETN has been shown to decompose primarily to mono, di, and tri nitrates of pentaerythritol.

  8. Enhancement of the Gene Targeting Efficiency of Non-Conventional Yeasts by Increasing Genetic Redundancy

    PubMed Central

    Chen, Zao; Sun, Hongbing; Li, Pengfei; He, Ning; Zhu, Taicheng; Li, Yin

    2013-01-01

    In contrast to model yeasts, gene targeting efficiencies of non-conventional yeasts are usually low, which greatly limits the research and applications of these organisms. In this study, we aimed to enhance the gene targeting efficiency of non-conventional yeasts by improving the fitness of mutant strains, particularly by increasing the genetic redundancy of host cells. To demonstrate this process, OCH1 gene deletion in Pichia pastoris was performed. Extra copies of the OCH1 gene on a helper plasmid were provided for the P. pastoris GS115 strain before the native OCH1 gene in the genomic DNA was knocked out. The redundancy in OCH1 gene significantly eliminated the growth defects of the och1 mutant and increased the deletion efficiency of the OCH1 gene by two orders of magnitude with the same length of homologous flanks. The same strategy was used to delete the KU70 and SGS1 genes. The targeting efficiencies of KU70 and SGS1 were increased by 1- and 23-fold, respectively. Therefore, this study provided an efficient strategy for the deletion of “stubborn” genes in non-conventional yeasts. This study further showed that cellular fitness is potentially an important factor that can limit the efficiency of gene targeting. PMID:23505447

  9. Improved oral bioavailability of 20(R)-25-methoxyl-dammarane-3β, 12β, 20-triol using nanoemulsion based on phospholipid complex: design, characterization, and in vivo pharmacokinetics in rats

    PubMed Central

    Zhang, Xiangrong; Zhang, Yi; Guo, Shuang; Bai, Feifei; Wu, Tong; Zhao, Yuqing

    2016-01-01

    The aim of the study was to improve the oral absorption of the compound 25-OCH3-PPD with poor hydrophilicity and lipophilicity. 25-OCH3-PPD-phospholipid complex was prepared by solvent evaporation, then characterized by differential scanning calorimetry, scanning electron microscopy, and infrared absorption spectroscopy. The aqueous solubility and oil–water partition coefficient were compared with the free compound. A nanoemulsion loaded with 25-OCH3-PPD-phospholipid complex was developed by dissolving the complex in water in the presence of hydrophilic surfactant under sonication. After oral administration of the nanoemulsion and the suspension of 25-OCH3-PPD in rats, the concentrations of 25-OCH3-PPD in plasma were determined by high-performance liquid chromatography–tandem mass spectrometry method. The results showed that the solubility of the complex in water and n-octanol was enhanced. The oil–water partition coefficient improved 1.7 times. Peak plasma concentration and area under the curve(0–24 h) of the nanoemulsion of 25-OCH3-PPD-phospholipid complex were higher than that of free compound by 3.9- and 3.5-folds. PMID:27877020

  10. Synthesis, physicochemical analysis of two new hemilabile ether-phosphine ligands and their first stable bis-ether-phosphine/cobalt(II) tetrahedral complexes

    NASA Astrophysics Data System (ADS)

    Warad, Ismail; Barakat, Assem

    2017-04-01

    New tridentate ether-phosphine {P, 2O} and ether-phosphine oxide {OP, 2O} ligands with P and O donor-atoms have been synthesized starting from ClCH2CH(OCH3)2. The oxidation process of Ph2PCH2CH(OCH3)2 to its oxide derivative Ph2P(dbnd O)CH2CH(OCH3)2 was monitored by 31P NMR for the first time. The desired ligands and their Co(II) complexes structures were deduced from IR, EA, MS, NMR, UV-Vis., TG/DTG and XRD physical measurements. The tridentate chelating coordination behavior of the ether-phosphine wasn't detected leading only to the mono-dentate coordination mode through the phosphorous atoms to set up a X2Co[η1-Ph2PCH2CH(OCH3)2]2 as final isomer formula (X = Cl or Br). The Cl2Co[η1-Ph2PCH2CH(OCH3)2]2 isomer belongs to complex 1 was supported by single crystal measurement. Polar/non-polar intermolecular short contacts were detected by XRD and Hirshfeld surface theoretical analysis.

  11. A simple synthetic route to polyoxovanadate-based organic-inorganic hybrids using EEDQ as an ester coupling agent.

    PubMed

    Bayaguud, Aruuhan; Li, JianDa; She, Shan; Wei, Yongge

    2017-04-05

    A reaction strategy for the post-functionalization of hexavanadate derivatives is presented herein. In this study, five polyoxovanadate-based organic-inorganic hybrids TBA2[V6O13{(OCH2)3CCOO(CH2)15CH3}2] (2), TBA2[V6O13{(OCH2)3CCOO(CH2)8CH[double bond, length as m-dash]CH2}2] (3), TBA2[V6O13{(OCH2)3CCOOCH2CF3}2] (4), TBA2[V6O13{(OCH2)3CCOO(CH2CH2O)3CH3}2] (5), and TBA2[V6O13{(OCH2)3CCOO(CH2)12OH}2]·2CH3CH2OH (6) were successfully synthesized via esterification of carboxylic acid groups-containing TBA2[V6O13{(OCH2)3CCOOH}2] (1) with five alcohols possessing different functional groups. These hybrids were characterized by single crystal X-ray diffraction, IR, ESI-MS, (1)H and (13)C-NMR spectroscopies, and elemental analysis. Moreover, the formation of large vesicles was observed in a mixed solution of compound 2 due to its surfactant-like structure.

  12. Intonation and expressivity: a single case study of classical western singing.

    PubMed

    Sundberg, Johan; Lã, Filipa M B; Himonides, Evangelos

    2013-05-01

    Previous studies have shown that singers tend to sharpen phrase-peak tones as compared with equally tempered tuning (ETT). Here we test the hypothesis that this can serve the purpose of musical expressivity. Data were drawn from earlier recordings, where a professional baritone sang excerpts as void of musical expression as he could (Neutral) and as expressive as in a concert (Concert). Fundamental frequency averaged over tones was examined and compared with ETT. Phrase-peak tones were sharper in excited examples, particularly in the Concert versions. These tones were flattened to ETT using the Melodyne software. The manipulated and original versions were presented pairwise to a musician panel that was asked to choose the more expressive version. By and large, the original versions were perceived as more expressive, thus supporting the common claim that intonation is a means for adding expressivity to a performance.

  13. Endocrowns: review

    PubMed Central

    Sevimli, Gaye; Cengiz, Seda; Oruc, M. Selcuk

    2015-01-01

    The ideal restoration of endodontically treated teeth (ETT) has been widely and controversially discussed in the literature. Prevention of healthy dental structure is essential to help mechanical stabilization of tooth-restoration integrity, increase the amount of suitable surfaces for adhesion and thus positively affect the long-term success. ETT are affected by a higher risk of biomechanical failure than vital teeth. With the development of adhesive systems, the need for post-core restorations is also reduced. Especially for restoration of excessively damaged ETT, endocrowns have been used as an alternative to the conventional post-core and fixed partial dentures. Compared to conventional methods, good aesthetics, better mechanical performance, and less cost and clinic time are the advantages of endocrowns. PMID:28955538

  14. Discordance of exercise thallium testing with coronary arteriography in patients with atypical presentations

    NASA Technical Reports Server (NTRS)

    Bungo, M. W.; Leland, O. S., Jr.

    1983-01-01

    Eighty-one patients with diagnostically difficult clinical presentations suggesting coronary artery disease underwent symptom-limited maximal-exercise treadmill testing (ETT) and exercise radionuclide scanning with thallium-201 followed by coronary angiography. Results showed that in nearly half of the patients (47%) these tests were in agreement, while either exercise thallium or ETT was positive in 94% of patients with coronary artery disease. It was found that agreement between exercise thallium and ETT tests predicted disease in 92% of the instances or excluded disease in 82% of the instances. It is concluded that despite frequent discord between these two tests in 53% of the cases, a significant gain in exclusive diagnostic capability is realized when applied to a patient population anticipated to have a disease prevalence equal to the 67% encountered in this study.

  15. Nitrous oxide pollution in the operating room. A comparison of two modes of ventilation.

    PubMed

    Noorddin, Y; Raha, A R; Jaafar, M Z; Rozaidi, S H W; Muraly, S; Marlizan, M Y

    2007-06-01

    The use of laryngeal mask airway (LMA) as an alternative to the endotracheal tube (ETT) is becoming more popular in the practice of anesthesia. It is undeniable that this device has numerous advantages over endotracheal tube, however it does not provide an airtight seal between the airway and atmospheric gases. This may lead to pollution of the operating room environment with nitrous oxide. One hundreds adult patients undergoing general anaesthesia were divided into two groups. The airway in Group I was maintained with LMA with spontaneous ventilation and ETT with intermittent positive pressure ventilation (IPPV) was used for Group II. The result demonstrated that the ETT group recorded concentrations of nitrous oxide that were well above the NIOSH recommended eight hour time weighted average of 25ppm throughout the duration of surgery when compared to patients using LMA.

  16. Discordance of exercise thallium testing with coronary arteriography in patients with atypical presentations

    NASA Technical Reports Server (NTRS)

    Bungo, M. W.; Leland, O. S., Jr.

    1983-01-01

    Eighty-one patients with diagnostically difficult clinical presentations suggesting coronary artery disease underwent symptom-limited maximal-exercise treadmill testing (ETT) and exercise radionuclide scanning with thallium-201 followed by coronary angiography. Results showed that in nearly half of the patients (47%) these tests were in agreement, while either exercise thallium or ETT was positive in 94% of patients with coronary artery disease. It was found that agreement between exercise thallium and ETT tests predicted disease in 92% of the instances or excluded disease in 82% of the instances. It is concluded that despite frequent discord between these two tests in 53% of the cases, a significant gain in exclusive diagnostic capability is realized when applied to a patient population anticipated to have a disease prevalence equal to the 67% encountered in this study.

  17. The unusual amino acid l-ergothioneine is a physiologic cytoprotectant

    PubMed Central

    Paul, BD; Snyder, SH

    2010-01-01

    Ergothioneine (ET) is an unusual sulfur-containing derivative of the amino acid, histidine, which is derived exclusively through the diet. Although ET was isolated a century ago, its physiologic function has not been clearly established. Recently, a highly specific transporter for ET (ETT) was identified in mammalian tissues, which explains abundant tissue levels of ET and implies a physiologic role. Using RNA interference, we depleted cells of its transporter. Cells lacking ETT are more susceptible to oxidative stress, resulting in increased mitochondrial DNA damage, protein oxidation and lipid peroxidation. ETT is concentrated in mitochondria, suggesting a specific role in protecting mitochondrial components such as DNA from oxidative damage associated with mitochondrial generation of superoxide. In combating cytotoxic effects of pyrogallol, a known superoxide generator, ET is as potent as glutathione. Because of its dietary origin and the toxicity associated with its depletion, ET may represent a new vitamin whose physiologic roles include antioxidant cytoprotection. PMID:19911007

  18. Are specialized endotracheal tubes and heat-and-moisture exchangers cost-effective in preventing ventilator associated pneumonia?

    PubMed

    Gentile, Michael A; Siobal, Mark S

    2010-02-01

    Ventilator-associated pneumonia (VAP) is a common and serious complication of mechanical ventilation via an artificial airway. As with all nosocomial infections, VAP increases costs, morbidity, and mortality in the intensive care unit (ICU). VAP prevention is a multifaceted priority of the intensive care team, and can include the use of specialized artificial airways and heat-and-moisture exchangers (HME). Substantial evidence supports the use of endotracheal tubes (ETTs) that allow subglottic suctioning; silver-coated and antiseptic-impregnated ETTs; ETTs with thin-walled polyurethane cuffs; and HMEs, but these devices also can have adverse effects. Controversy still exists regarding the evidence, cost-effectiveness, and disadvantages and risks of these devices.

  19. Subglottic stenosis: another challenge for intubation and potential mechanism of airway obstruction in Pierre Robin Sequence.

    PubMed

    Knapp, Kolin; Powitzky, Rosser; Digoy, Paul

    2011-09-01

    To determine the endotracheal tube (ETT) size and presence of subglottic narrowing in children less than 1 year old with Pierre Robin Sequence (PRS). We performed a retrospective review from 2005 to 2009 of infants with PRS who underwent diagnostic laryngoscopy (DL) and intubation. Fifteen children with a median age of 25 days were reviewed. All patients, except one, were born full term. Subglottic narrowing was visualized in 5 patients (33%). 73% of all patients required an ETT size smaller than what is recommended by intubation guidelines in the literature in regards to normative data based on age and weight. Infants with PRS may have a higher incidence of subglottic stenosis and require a smaller ETT compared to the normal population. This pilot study warrants a larger prospective investigation to validate these findings. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  20. A semi-Dirac point and an electromagnetic topological transition in a dielectric photonic crystal.

    PubMed

    Wu, Ying

    2014-01-27

    Accidental degeneracy in a photonic crystal consisting of a square array of elliptical dielectric cylinders leads to both a semi-Dirac point at the center of the Brillouin zone and an electromagnetic topological transition (ETT). A perturbation method is deduced to affirm the peculiar linear-parabolic dispersion near the semi-Dirac point. An effective medium theory is developed to explain the simultaneous semi-Dirac point and ETT and to show that the photonic crystal is either a zero-refractive-index material or an epsilon-near-zero material at the semi-Dirac point. Drastic changes in the wave manipulation properties at the semi-Dirac point, resulting from ETT, are described.

  1. Perioperative and anesthetic management of complete tracheal rupture in one dog and one cat.

    PubMed

    Morath, Ute; Gendron, Karine; Revés, Nuria Vizcaíno; Adami, Chiara

    2015-01-01

    The authors describe two animals (one dog and one cat) that were presented with severe respiratory distress after trauma. Computerized tomographic imaging under general anesthesia revealed, in both cases, complete tracheal transection. Hypoxic episodes during anesthesia were relieved by keeping the endotracheal tube (ETT) positioned in the cranial part of the transected trachea and by allowing spontaneous breathing. Surgical preparation was performed quickly, and patients were kept in a sternal position to improve ventilation and oxygenation, and were only turned into dorsal recumbency shortly before surgical incision. A sterile ETT was guided into the distal part of the transected trachea by the surgeon, at which point mechanical ventilation was started. Both animals were successfully discharged from hospital a few days after surgery. Rapid and well-coordinated teamwork seemed to contribute to the good outcome. Precise planning and communication between anesthetists, surgeons, and technicians, as well as a quick course of action prior to correct ETT positioning helped to overcome critical phases.

  2. Neonatal outcomes based on mode and intensity of delivery room resuscitation.

    PubMed

    Bashir, A; Bird, B; Wu, L; Welles, S; Taylor, H; Anday, E; Bhandari, V

    2017-10-01

    To examine outcomes of neonates based on the mode and intensity of resuscitation received in the delivery room (DR). A retrospective study of 439 infants with birth weight ⩽1500 g receiving DR resuscitation at two hospital centers in Philadelphia, Pennsylvania. Of 439 infants, 22 (5%) received routine care, 188 (43%) received noninvasive positive pressure ventilation (PPV) and 229 (52%) received endotracheal tube (ETT) intubation in the DR. Adjusted odds for respiratory distress syndrome was associated with lower rates in infants requiring lower intensity of DR resuscitation (P<0.001). Noninvasive PPV vs ETT was associated with decreased odds of developing intraventricular hemorrhage and retinopathy of prematurity (P<0.05). Routine vs noninvasive PPV or ETT had decreased odds of developing bronchopulmonary dysplasia (P<0.05). Decreased intensity of DR resuscitation was associated with a decreased risk of specific morbidities.

  3. Fluid inclusion volatile analysis by gas chromatography with photoionization/micro-thermal conductivity detectors: Applications to magmatic MoS sub 2 and other H sub 2 O-CO sub 2 and H sub 2 O-CH sub 4 fluids

    SciTech Connect

    Bray, C.J.; Spooner, E.T.C. )

    1992-01-01

    Eighteen fluid inclusion volatile peaks have been detected and identified from 1-2 g samples (quartz) by gas chromatography using heated on-line crushing, helium carrier gas, a single porous polymer column, two temperature programmed conditions for separate sample aliquots, micro-thermal conductivity (TCD) and photoionization detectors (PID), and off-line digital peak processing. In order of retention time these volatile peaks are: N{sub 2}, Ar, CO, CH{sub 4}, CO{sub 2}, C{sub 2}H{sub 4}, C{sub 2}H{sub 6}, C{sub 2}H{sub 2}, COS, C{sub 3}H{sub 6}, C{sub 3}H{sub 8}, C{sub 3}H{sub 4} (propyne), H{sub 2}O, SO{sub 2} {plus minus} iso-C{sub 4}H{sub 10} {plus minus} C{sub 4}H{sub 8} (1-butene) {plus minus} CH{sub 3}SH, C{sub 4}H{sub 8} (iso-butylene), ( ) C{sub 4}H{sub 6} (1,3 butadiene), and {plus minus} n-C{sub 4}H{sub 10} {plus minus}C{sub 4}H{sub 8} (trans-2-butene). H{sub 2}O is analyzed directly. O{sub 2} can be analyzed cryogenically between N{sub 2} and Ar, but has not been detected in natural samples to date in this study. Initial inclusion volatile analyses of fluids of interpreted magmatic origin from the Cretaceous Boss Mtn. monzogranite stock-related MoS{sub 2} deposit, central British Columbia of 97 mol% H{sub 2}O, 3% CO{sub 2}, 140-150 ppm N{sub 2}, and 16-39 ppm CH{sub 4} are reasonable in comparison with high temperature volcanic gas analyses from four, active calc-alkaline volcanoes, e.g., the H{sub 2}O contents of volcanic gases from the White Island (New Zealand), Mount St. Helens (Washington, USA), Merapi (Bali, Indonesia), and Momotombo (Nicaragua) volcanoes are 88-95%, > 90%, 88-95% and 93%, respectively; CO{sub 2} contents are 3-10%, 1-10%, 3-8%, and 3.5%. It appears that low, but significant concentrations of alkanes, alkenes, and alkynes have been detected in magmatically derived fluids.

  4. Aerosolized KL4 surfactant improves short-term survival and gas exchange in spontaneously breathing newborn pigs with hydrochloric acid-induced acute lung injury.

    PubMed

    Lampland, Andrea L; Wolfson, Marla R; Mazela, Jan; Henderson, Christopher; Gregory, Timothy J; Meyers, Patricia; Plumm, Brenda; Worwa, Cathy; Mammel, Mark C

    2014-05-01

    Surfactant therapy may be beneficial in acute lung injury (ALI). In spontaneously breathing newborn pigs with ALI supported with continuous positive airway pressure (CPAP), we evaluated the hypothesis that aerosolized KL4 surfactant (AERO KL4 S) would provide a similar therapeutic effect as intratracheal KL4 surfactant (ETT KL4 S) when compared to controls. We randomized pigs with HCl-induced ALI to: (1) 175 mg/kg KL4 surfactant via endotracheal tube (ETT); (2) AERO KL4 S (22.5 mg/min phospholipid) for 60 min via continuous positive airway pressure (CPAP); or (3) sham procedure on CPAP. We obtained physiologic data and arterial blood gases throughout the 3-hr study. At study end, lungs were excised for analysis of interleukin-8 (IL-8), myeloperoxidase (MPO) levels and histomorphometric data. Pigs treated with ETT KL4 S and AERO KL4 S had improved survival and sustained pO2 compared to controls. The AERO KL4 S group had higher pH compared to controls. Lung IL-8 levels were lower in the AERO KL4 S group compared to controls. Histomorphometric analysis showed less hemorrhage in the ETT and AERO KL4 S groups compared to controls. The AERO KL4 S group had more open lung units per fixed-field than the ETT KL4 S or controls. AERO KL4 S produced similar improvements in survival, physiology, inflammatory markers, and morphology as ETT KL4 S in an ALI model. © 2013 Wiley Periodicals, Inc.

  5. Flow resistance, work of breathing of humidifiers, and endotracheal tubes in the hyperbaric chamber.

    PubMed

    Arieli, Ran; Daskalovic, Yohanan; Ertracht, Ofir; Arieli, Yehuda; Adir, Yohai; Abramovich, Amir; Halpern, Pinchas

    2011-09-01

    Humidification of inspired gas is critical in ventilated patients, usually achieved by heat and moisture exchange devices (HMEs). HME and the endotracheal tube (ETT) add airflow resistance. Ventilated patients are sometimes treated in hyperbaric chambers. Increased gas density may increase total airway resistance, peak pressures (PPs), and mechanical work of breathing (WOB). We tested the added WOB imposed by HMEs and various sizes of ETT under hyperbaric conditions. We mechanically ventilated 4 types of HMEs and 3 ETTs at 6 minute ventilation volumes (7-19.5 L/min) in a hyperbaric chamber at pressures of 1 to 6 atmospheres absolute (ATA). Peak pressure increased with increasing chamber pressure with an HME alone, from 2 cm H₂O at 1 ATA to 6 cm H(2)O at 6 ATA. Work of breathing was low at 1 ATA (0.2 J/L) and increased to 1.2 J/L at 6 ATA at minute ventilation = 19.5 L/min. Connecting the HME to an ETT increased PP as a function of peak flow and chamber pressure. Reduction of the ETT diameter (9 > 8 > 7.5 mm) and increase in chamber pressure increased the PP up to 27.7 cm H₂O, resistance to 33.2 cmH₂O*s/L, and WOB to 3.76 J/L at 6 ATA with a 7.5-mm EET. These are much greater than the usually accepted critical peak pressures of 25 cm H₂O and WOB of 1.5 to 2.0 J/L. Endotracheal tubes less than 8 mm produce significant added WOB and airway pressure swings under hyperbaric conditions. The hyperbaric critical care clinician is advised to use the largest possible ETT. The tested HMEs add negligible resistance and WOB in the chamber. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Tracheal rapid ultrasound saline test (T.R.U.S.T.) for confirming correct endotracheal tube depth in children.

    PubMed

    Tessaro, Mark O; Salant, Evan P; Arroyo, Alexander C; Haines, Lawrence E; Dickman, Eitan

    2015-04-01

    We evaluated the accuracy of tracheal ultrasonography of a saline-inflated endotracheal tube (ETT) cuff for confirming correct ETT insertion depth. We performed a prospective feasibility study of children undergoing endotracheal intubation for surgery. Tracheal ultrasonography at the suprasternal notch was performed during transient endobronchial intubation and inflation of the cuff with saline, and with the ETT at a correct endotracheal position. Ultrasound videos were recorded at both positions, which were confirmed by fiberoptic bronchoscopy. These videos were shown to two independent blinded reviewers, who determined the presence or absence of a saline-inflated cuff. The primary outcome was accuracy of tracheal ultrasonography for appropriate ETT insertion depth. Forty-two patients were enrolled. For correct endotracheal versus endobronchial positioning, pooled results from the reviewers revealed a sensitivity of 98.8% (95% CI=90-100%), a specificity of 96.4% (95% CI=87-100%), a PPV of 96.5% (95% CI=87-100%), a NPV of 98.8% (95% CI=89-100%), a positive likelihood ratio of 32 (95% CI=6-185), and a negative likelihood ratio of 0.015 (95% CI=0.004-0.2). Agreement between reviewers was high (kappa co-efficient=0.93; 95% CI=0.86 to 1). The mean duration of the ultrasound exam was 4.0s (range 1.0-15.0s). Sonographic visualization of a saline-inflated ETT cuff at the suprasternal notch is an accurate and rapid method for confirming correct ETT insertion depth in children. Copyright © 2015. Published by Elsevier Ireland Ltd.

  7. Gender differences in sore throat and hoarseness following endotracheal tube or laryngeal mask airway: a prospective study

    PubMed Central

    2014-01-01

    Background Postoperative sore throat and hoarseness are common minor complications following airway manipulation. This study was primarily done to determine gender differences in the incidence of these symptoms and the location of POST after laryngeal mask airway (LMA) and endotracheal tube (ETT). Methods A total of 112 men and 185 women were included during a four month period. All patients were evaluated postoperatively and after 24 hours about the occurrence of sore throat, its location and hoarseness. If the patients had any symptom, they were followed-up at 48, 72 and 96 hours until the symptoms resolved. Results There was no significant gender difference in postoperative sore throat (POST) and postoperative hoarseness (PH) when analyzing both airway devices together. The incidence of sore throat and hoarseness were higher postoperatively after an ETT than an LMA (32% vs. 19%, p = 0.012) and 57% vs. 33% (p < 0.001) respectively. Significantly more women than men had POST after an LMA (26% vs. 6%, p = 0.004). No significant gender difference was found in either POST or PH after an ETT or in the incidence of PH after an LMA. More patients located their pain below the larynx after an ETT vs. an LMA (24% vs. 4%). Pain above the larynx was more common after an LMA than an ETT (52% vs. 37%). Conclusions In a clinical setting where women are intubated with a smaller size ETT than men, there were no significant differences in POST or PH between genders. Additionally, more women than men have POST when an LMA is used. Awareness of POST and PH may help streamline patients in whom the best airway device could be used during anesthesia and surgery. PMID:25061426

  8. Examining the relationship between exercise tolerance and isoproterenol-based cardiac reserve in murine models of heart failure.

    PubMed

    Richards, Daniel A; Bao, Weike; Rambo, Mary V; Burgert, Mark; Jucker, Beat M; Lenhard, Stephen C

    2013-05-01

    The loss of cardiac reserve is, in part, responsible for exercise intolerance in late-stage heart failure (HF). Exercise tolerance testing (ETT) has been performed in mouse models of HF; however, treadmill performance and at-rest cardiac indexes determined by magnetic resonance imaging (MRI) rarely correlate. The present study adopted a stress-MRI technique for comparison with ETT in HF models, using isoproterenol (ISO) to evoke cardiac reserve responses. Male C57BL/6J mice were randomly subjected to myocardial infarction (MI), transverse aortic constriction (TAC), or sham surgery under general anesthesia. Mice underwent serial ETT on a graded treadmill with follow-up ISO stress-MRI. TAC mice showed consistent exercise intolerance, with a 16.2% reduction in peak oxygen consumption vs. sham at 15-wk postsurgery (WPS). MI and sham mice had similar peak oxygen consumption from 7 WPS onward. Time to a respiratory exchange ratio of 1.0 correlated with ETT distance (r = 0.64; P < 0.001). The change in ejection fraction under ISO stress was reduced in HF mice at 4 WPS [10.1 ± 3.9% change (Δ) and 8.9 ± 3.5%Δ in MI and TAC, respectively, compared with 32.0 ± 3.5%Δ in sham; P < 0.001]. However, cardiac reserve differences between surgery groups were not observed at 16 WPS in terms of ejection fraction or cardiac output. In addition, ETT did not correlate with cardiac indexes under ISO stress. In conclusion, ISO stress was unable to reflect consistent differences in ETT between HF and healthy mice, suggesting cardiac-specific indexes are not the sole factors in defining exercise intolerance in mouse HF models.

  9. The Prevalence of Oral Flora in the Biofilm Microbiota of the Endotracheal Tube.

    PubMed

    Bardes, James M; Waters, Christopher; Motlagh, Hamed; Wilson, Alison

    2016-05-01

    The endotracheal tube (ETT) is recognized as an independent factor for infection in intubated patients. The presence of biofilm contributes to the development of pneumonia. Standard culturing techniques are inadequate to detect many of the bacteria present in a biofilm. Delineation of the microbiota in the ETT is needed to further understand infections in ventilated patients. A prospective, observational study was performed at a university, Level I trauma center. Twenty ETT were collected at extubation. Bioluminal accretions were removed and quantified. DNA was extracted and 16S ribosomal RNA gene analysis performed using the Human Oral Microbe Identification Microarray. Twenty ETT were evaluated. Mean age was 47.5 years (19-82). Five were smokers. Mean ventilator days was 3.6 ± 3.1. Mean intensive care unit days was 7.8 ± 6.3. In those ETT, 87 different bacterial species were identified. Mean number of bacterial species identified was 16 ± 9 (3-35). There was no relationship between duration of intubation and number of species (P = 0.5). Nonsmokers had a greater variety of bacteria than smokers (P = 0.03). Patients with pneumonia did not have a greater variety of bacteria (P = 0.14). Parvimonas micra presence was associated with reintubation (P = 0.01). The most common species in smokers were different from nonsmokers. There is a wide variety of bacteria present in an ETT, many of which cannot be cultured by standard means. Variation is not correlated to duration of intubation or accretion volume. Studies to evaluate these bacteria and their interaction with the biofilm may further delineate factors in development of infections.

  10. Is I-gel airway a better option to endotracheal tube airway for sevoflurane-fentanyl anesthesia during cardiac surgery?

    PubMed Central

    Elgebaly, Ahmed Said; Eldabaa, Ahmed Ali

    2014-01-01

    Background: Anesthetists used lower doses of fentanyl, successfully with hemodynamic control by titrating volatile anesthetic agents or vasodilators for fast-tracking in cardiac surgery. Hypothesis: Lower total doses of anesthetics and fentanyl could be required with hemodynamic control by use of supraglottic devices than endotracheal tube (ETT) and helps in fast-tracking. Design: A prospective randomized observational clinical trial study. Aims: The authors compared the utility of I-gel airway with a conventional ETT during the induction and maintenance of anesthesia with sevoflurane and fentanyl in adults undergoing cardiac surgery. Patients and Methods: A total of 49 adult patients underwent cardiac surgery were randomized into two groups according to the airway management: I-gel group (n = 23) and ETT group (n = 26). Doses of fentanyl and hemodynamic parameters (heart rate [HR], mean arterial pressure [MAP] central venous pressure [CVP], pulmonary artery pressure [PAP], and pulmonary capillary wedge pressure [PCWP]) were recorded preoperative, 5 min following tracheal intubation or I-gel airway insertion, after skin incision, after stenotomy, and after weaning off bypass. Results: None of the patients in the I-gel group required additional doses of fentanyl during the I-gel insertion, compared with 74% of the patients during laryngoscopy and endotracheal insertion in the ETT group, for an average total dose of 22.6 ± 0.6 μg/kg. The MAP and HR did not significantly differ from the baseline values at any point of measurement in either group. Furthermore, CVP, PAP, and PCWP measured during the procedure were significantly lower in I-gel group than ETT group. Extubation required more amount of time in ETT than I- gel group. Conclusion: The I-gel airway is well-tolerated by adult patients undergoing cardiac surgery, and requires lower total doses of anesthetics than endotracheal intubation with hemodynamic control and helps in fast-tracking. PMID:25886229

  11. Manual ventilation and open suction procedures contribute to negative pressures in a mechanical lung model

    PubMed Central

    Nakstad, Espen Rostrup; Opdahl, Helge; Heyerdahl, Fridtjof; Borchsenius, Fredrik; Skjønsberg, Ole Henning

    2017-01-01

    Introduction Removal of pulmonary secretions in mechanically ventilated patients usually requires suction with closed catheter systems or flexible bronchoscopes. Manual ventilation is occasionally performed during such procedures if clinicians suspect inadequate ventilation. Suctioning can also be performed with the ventilator entirely disconnected from the endotracheal tube (ETT). The aim of this study was to investigate if these two procedures generate negative airway pressures, which may contribute to atelectasis. Methods The effects of device insertion and suctioning in ETTs were examined in a mechanical lung model with a pressure transducer inserted distal to ETTs of 9 mm, 8 mm and 7 mm internal diameter (ID). A 16 Fr bronchoscope and 12, 14 and 16 Fr suction catheters were used at two different vacuum levels during manual ventilation and with the ETTs disconnected. Results During manual ventilation with ETTs of 9 mm, 8 mm and 7 mm ID, and bronchoscopic suctioning at moderate suction level, peak pressure (PPEAK) dropped from 23, 22 and 24.5 cm H2O to 16, 16 and 15 cm H2O, respectively. Maximum suction reduced PPEAK to 20, 17 and 11 cm H2O, respectively, and the end-expiratory pressure fell from 5, 5.5 and 4.5 cm H2O to –2, –6 and –17 cm H2O. Suctioning through disconnected ETTs (open suction procedure) gave negative model airway pressures throughout the duration of the procedures. Conclusions Manual ventilation and open suction procedures induce negative end-expiratory pressure during endotracheal suctioning, which may have clinical implications in patients who need high PEEP (positive end-expiratory pressure). PMID:28725445

  12. Manual ventilation and open suction procedures contribute to negative pressures in a mechanical lung model.

    PubMed

    Nakstad, Espen Rostrup; Opdahl, Helge; Heyerdahl, Fridtjof; Borchsenius, Fredrik; Skjønsberg, Ole Henning

    2017-01-01

    Removal of pulmonary secretions in mechanically ventilated patients usually requires suction with closed catheter systems or flexible bronchoscopes. Manual ventilation is occasionally performed during such procedures if clinicians suspect inadequate ventilation. Suctioning can also be performed with the ventilator entirely disconnected from the endotracheal tube (ETT). The aim of this study was to investigate if these two procedures generate negative airway pressures, which may contribute to atelectasis. The effects of device insertion and suctioning in ETTs were examined in a mechanical lung model with a pressure transducer inserted distal to ETTs of 9 mm, 8 mm and 7 mm internal diameter (ID). A 16 Fr bronchoscope and 12, 14 and 16 Fr suction catheters were used at two different vacuum levels during manual ventilation and with the ETTs disconnected. During manual ventilation with ETTs of 9 mm, 8 mm and 7 mm ID, and bronchoscopic suctioning at moderate suction level, peak pressure (PPEAK) dropped from 23, 22 and 24.5 cm H2O to 16, 16 and 15 cm H2O, respectively. Maximum suction reduced PPEAK to 20, 17 and 11 cm H2O, respectively, and the end-expiratory pressure fell from 5, 5.5 and 4.5 cm H2O to -2, -6 and -17 cm H2O. Suctioning through disconnected ETTs (open suction procedure) gave negative model airway pressures throughout the duration of the procedures. Manual ventilation and open suction procedures induce negative end-expiratory pressure during endotracheal suctioning, which may have clinical implications in patients who need high PEEP (positive end-expiratory pressure).

  13. The minimal leak test technique for endotracheal cuff maintenance.

    PubMed

    Harvie, D A; Darvall, J N; Dodd, M; De La Cruz, A; Tacey, M; D'Costa, R L; Ward, D

    2016-09-01

    Endotracheal tube (ETT) cuff pressure management is an essential part of airway management in intubated and mechanically ventilated patients. Both under- and over-inflation of the ETT cuff can lead to patient complications, with an ideal pressure range of 20-30 cmH2O defined. A range of techniques are employed to ensure adequate ETT cuff inflation, with little comparative data. We performed an observational cross-sectional study in a tertiary metropolitan ICU, assessing the relationship between the minimal leak test and cuff manometry. Forty-five mechanically ventilated patients, over a three-month period, had ETT cuff manometry performed at the same time as their routine cuff maintenance (minimal leak test). Bedside nurse measurements were compared with investigator measurements. At the endpoint of cuff inflation, 20 of 45 patients (44%) had cuff pressures between 20 and 30 cmH2O; 11 of 45 patients (24%) had cuff pressures <20 cmH2O; 14 of 45 patients (31%) had cuff pressures ≥30 cmH2O. Univariate analysis demonstrated an association between both patient obesity and female gender requiring less ETT cuff volume (P=0.008 and P <0.001 respectively), though this association was lost on multivariate analysis. No association was demonstrated between any measured variables and cuff pressures. Inter-operator reliability in performing the minimal leak test showed no evidence of bias between nurse and investigators (Pearson coefficient = 0.897). We conclude the minimal leak test for maintenance of ETT cuffs leads to both over- and under-inflation, and alternative techniques, such as cuff manometry, should be employed.

  14. Survey on restoration of endodontically treated anterior teeth: a questionnaire based study.

    PubMed

    Ratnakar, P; Bhosgi, Rashmi; Metta, Kiran Kumar; Aggarwal, Kanika; Vinuta, S; Singh, Navneet

    2014-01-01

    The aim of endodontic and restorative dentistry is the conservation of natural tooth structure. Endodontically treated tooth (ETT) undergoes loss of tooth structure and changes in physical characteristics. Therefore, proper selection of restoration for ETT is mandatory. The clinical approach of restoring ETT needs taking into considerations several issues. However, the best way to restore teeth after root canal treatment has long been and still a controversial subject to debate. Therefore, this study was carried out to detect the frequency of preferred methods of restoring ETT under different conditions. A questionnaire was framed and distributed among prosthodontists, endodontist and general practitioners of north India region to find out the frequency of best suitable material and method regarding restoration of ETT. 220 questionnaires were sent by electronic mail out of which 110 were received back. The questionnaire contained different methods of restoration of endodontically treated anterior teeth at different conditions (percentages) of remaining sound tooth structure. Respondents were asked to indicate their preferred method of restoration of those teeth. Results showed that majority of respondents (51.82%) preferred to restore the tooth only with a tooth-color restorative material in condition A. In condition B, majority of respondents preferred to use tooth colored crown (44.55%) and prefabricated post and tooth colored restoration (24.5%). Whereas in condition C, most of the respondents preferred to use a cast post and core/crown (80.91%). From the findings of the present study, it can be concluded that the unrestored ETT is susceptible to fracture, which could lead to loss of tooth and that the maximum preservation of healthy tooth structure and use of restorative materials with mechanical properties similar to dental structure favor greater longevity of tooth restoration complex.

  15. Measurement of endotracheal tube cuff pressure: Instrumental versus conventional method

    PubMed Central

    Khan, Mueen Ullah; Khokar, Rashid; Qureshi, Sadia; Al Zahrani, Tariq; Aqil, Mansoor; Shiraz, Motasim

    2016-01-01

    Objective: To evaluate the conventional practice of endotracheal tube (ETT) cuff inflation and pressure measurement as compared to the instrumental method. Study Design: Prospective observational study. Place and Duration of Study: Department of Anaesthesia, King Saud University Hospital, Riyadh, Saudi Arabia (June 2014–July 2014). Methods: A total of 100 adult patients were observed according to the syringe size used Group-1 (10 ml) and Group-2 (20 ml) for ETT cuff inflation in general anesthesia. Patients with anticipated difficult intubation, risk for aspiration, known anatomical laryngotracheal abnormalities, and emergency cases were excluded. Trachea was intubated with size 8 or 8.5 mm and 7.0 or 7.5 mm ETT in male and female patients respectively. The ETT cuff was inflated with air by one of the anesthesia technician. Cuff pressures were measured using aneroid manometer. ETT cuff pressure of 20–30 cm of water was considered as standard. Results: In 69% of the patients, the cuff pressure measurements were above the standard. Age (P = 0.806), weight (P = 0.527), height (P = 0.850), and gender (P = 1.00) were comparable in both groups. The mean cuff pressure in Group-1 and Group-2 was 32.52 ± 6.39 and 38.90 ± 6.60 cm of water (P = 0.001). The cuff inflation with 20 ml syringe resulted in higher cuff pressure as compared to 10cc syringe 37.73 ± 4.23 versus 40.74 ± 5.01 (86% vs. 52%, P = 0.013). Conclusion: The conventional method for ETT cuff inflation and pressure measuring is unreliable. As a routine instrumental cuff pressure, monitoring is suggested. PMID:27833487

  16. Detection of endobronchial intubation by monitoring the CO2 level above the endotracheal cuff.

    PubMed

    Efrati, Shai; Deutsch, Israel; Weksler, Nathan; Gurman, Gabriel M

    2015-02-01

    Early detection of accidental endobronchial intubation (EBI) is still an unsolved problem in anesthesia and critical care daily practice. The aim of this study was to evaluate the ability of monitoring above cuff CO2 to detect EBI (the working hypothesis was that the origin of CO2 is from the unventilated, but still perfused, lung). Six goats were intubated under general anesthesia and the ETT positioning was verified by a flexible bronchoscope. The AnapnoGuard system, already successfully used to detect air leak around the ETT cuff, was used for continuous monitoring of above-the-cuff CO2 level. When the ETT distal tip was located in the trachea, with an average cuff pressure of 15 mmHg, absence of CO2 above the cuff was observed. The ETT was then deliberately advanced into one of the main bronchi under flexible bronchoscopic vision. In all six cases the immediate presence of CO2 above the cuff was identified. Further automatic inflation of the cuff, up to a level of 27 mmHg, did not affect the above-the-cuff measured CO2 level. Withdrawal of the ETT and repositioning of its distal tip in mid-trachea caused the disappearance of CO2 above the cuff in a maximum of 3 min, confirming the absence of air leak and the correct positioning of the ETT. Our results suggest that measurement of the above-the-cuff CO2 level could offer a reliable, on-line solution for early identification of accidental EBI. Further studies are planned to validate the efficacy of the method in a clinical setup.

  17. Endotracheal Tube Cuff Pressures in Patients Intubated Prior to Helicopter EMS Transport

    PubMed Central

    Tennyson, Joseph; Ford-Webb, Tucker; Weisberg, Stacy; LeBlanc, Donald

    2016-01-01

    Introduction Endotracheal intubation is a common intervention in critical care patients undergoing helicopter emergency medical services (HEMS) transportation. Measurement of endotracheal tube (ETT) cuff pressures is not common practice in patients referred to our service. Animal studies have demonstrated an association between the pressure of the ETT cuff on the tracheal mucosa and decreased blood flow leading to mucosal ischemia and scarring. Cuff pressures greater than 30 cmH2O impede mucosal capillary blood flow. Multiple prior studies have recommended 30 cmH2O as the maximum safe cuff inflation pressure. This study sought to evaluate the inflation pressures in ETT cuffs of patients presenting to HEMS. Methods We enrolled a convenience sample of patients presenting to UMass Memorial LifeFlight who were intubated by the sending facility or emergency medical services (EMS) agency. Flight crews measured the ETT cuff pressures using a commercially available device. Those patients intubated by the flight crew were excluded from this analysis as the cuff was inflated with the manometer to a standardized pressure. Crews logged the results on a research form, and we analyzed the data using Microsoft Excel and an online statistical analysis tool. Results We analyzed data for 55 patients. There was a mean age of 57 years (range 18–90). The mean ETT cuff pressure was 70 (95% CI= [61–80]) cmH2O. The mean lies 40 cmH2O above the maximum accepted value of 30 cmH2O (p<0.0001). Eighty-four percent (84%) of patients encountered had pressures above the recommended maximum. The most frequently recorded pressure was >120 cmH2O, the maximum pressure on the analog gauge. Conclusion Patients presenting to HEMS after intubation by the referral agency (EMS or hospital) have ETT cuffs inflated to pressures that are, on average, more than double the recommended maximum. These patients are at risk for tracheal mucosal injury and scarring from decreased mucosal capillary blood flow

  18. Endotracheal Tube Cuff Pressures in Patients Intubated Prior to Helicopter EMS Transport.

    PubMed

    Tennyson, Joseph; Ford-Webb, Tucker; Weisberg, Stacy; LeBlanc, Donald

    2016-11-01

    Endotracheal intubation is a common intervention in critical care patients undergoing helicopter emergency medical services (HEMS) transportation. Measurement of endotracheal tube (ETT) cuff pressures is not common practice in patients referred to our service. Animal studies have demonstrated an association between the pressure of the ETT cuff on the tracheal mucosa and decreased blood flow leading to mucosal ischemia and scarring. Cuff pressures greater than 30 cmH2O impede mucosal capillary blood flow. Multiple prior studies have recommended 30 cmH2O as the maximum safe cuff inflation pressure. This study sought to evaluate the inflation pressures in ETT cuffs of patients presenting to HEMS. We enrolled a convenience sample of patients presenting to UMass Memorial LifeFlight who were intubated by the sending facility or emergency medical services (EMS) agency. Flight crews measured the ETT cuff pressures using a commercially available device. Those patients intubated by the flight crew were excluded from this analysis as the cuff was inflated with the manometer to a standardized pressure. Crews logged the results on a research form, and we analyzed the data using Microsoft Excel and an online statistical analysis tool. We analyzed data for 55 patients. There was a mean age of 57 years (range 18-90). The mean ETT cuff pressure was 70 (95% CI= [61-80]) cmH2O. The mean lies 40 cmH2O above the maximum accepted value of 30 cmH2O (p<0.0001). Eighty-four percent (84%) of patients encountered had pressures above the recommended maximum. The most frequently recorded pressure was >120 cmH2O, the maximum pressure on the analog gauge. Patients presenting to HEMS after intubation by the referral agency (EMS or hospital) have ETT cuffs inflated to pressures that are, on average, more than double the recommended maximum. These patients are at risk for tracheal mucosal injury and scarring from decreased mucosal capillary blood flow. Hospital and EMS providers should use ETT cuff

  19. Ultrastructural Analysis of In Vivo Hypoglycemiant Effect of Two Polyoxometalates in Rats with Streptozotocin-Induced Diabetes.

    PubMed

    Bâlici, Ştefana; Wankeu-Nya, Modeste; Rusu, Dan; Nicula, Gheorghe Z; Rusu, Mariana; Florea, Adrian; Matei, Horea

    2015-10-01

    Two polyoxometalates (POMs), synthesized through a self-assembling method, were used in the treatment of streptozotocin (STZ)-induced diabetic rats. One of these nanocompounds [tris(vanadyl)-substituted tungsto-antimonate(III)-anions—POM1] was previously described in the literature, whereas the second [tris-butyltin-21-tungsto-9-antimonate(III)-anions—POM2], was prepared by us based on our original formula. In rats with STZ-induced diabetes treated with POMs (up to a cumulative dose of 4 mg/kg bodyweight at the end of the treatments), statistically significant reduced levels of blood glucose were measured after 3 weeks, as compared with the diabetic control groups (DCGs). Ultrastructural analysis of pancreatic β-cells (including the mean diameter of secretory vesicles and of their insulin granules) in the treated diabetic rats proved the POMs contribute to limitation of cellular degeneration triggered by STZ, as well as to the presence of increased amounts of insulin-containing vesicles as compared with the DCG. The two POMs also showed hepatoprotective properties when ultrastructural aspects of hepatocytes in the experimental groups of rats were studied. Based on our in vivo studies, we concluded that the two POMs tested achieved hypoglycemiant effects by preventing STZ-triggered apoptosis of pancreatic β-cells and stimulation of insulin synthesis.

  20. Microgravity and clinorotation cause redistribution of free calcium in sweet clover columella cells

    NASA Technical Reports Server (NTRS)

    Hilaire, E.; Paulsen, A. Q.; Brown, C. S.; Guikema, J. A.; Spooner, B. S. (Principal Investigator)

    1995-01-01

    In higher plants, calcium redistribution is believed to be crucial for the root to respond to a change in the direction of the gravity vector. To test the effects of clinorotation and microgravity on calcium localization in higher plant roots, sweet clover (Melilotus alba L.) seedlings were germinated and grown for two days on a slow rotating clinostat or in microgravity on the US Space Shuttle flight STS-60. Subsequently, the tissue was treated with a fixative containing antimonate (a calcium precipitating agent) during clinorotation or in microgravity and processed for electron microscopy. In root columella cells of clinorotated plants, antimonate precipitates were localized adjacent to the cell wall in a unilateral manner. Columella cells exposed to microgravity were characterized by precipitates mostly located adjacent to the proximal and lateral cell wall. In all treatments some punctate precipitates were associated with vacuoles, amyloplasts, mitochondria, and euchromatin of the nucleus. A quantitative study revealed a decreased number of precipitates associated with the nucleus and the amyloplasts in columella cells exposed to microgravity as compared to ground controls. These data suggest that roots perceive a change in the gravitational field, as produced by clinorotation or space flights, and respond respectively differently by a redistribution of free calcium.

  1. Microgravity and clinorotation cause redistribution of free calcium in sweet clover columella cells

    NASA Technical Reports Server (NTRS)

    Hilaire, E.; Paulsen, A. Q.; Brown, C. S.; Guikema, J. A.; Spooner, B. S. (Principal Investigator)

    1995-01-01

    In higher plants, calcium redistribution is believed to be crucial for the root to respond to a change in the direction of the gravity vector. To test the effects of clinorotation and microgravity on calcium localization in higher plant roots, sweet clover (Melilotus alba L.) seedlings were germinated and grown for two days on a slow rotating clinostat or in microgravity on the US Space Shuttle flight STS-60. Subsequently, the tissue was treated with a fixative containing antimonate (a calcium precipitating agent) during clinorotation or in microgravity and processed for electron microscopy. In root columella cells of clinorotated plants, antimonate precipitates were localized adjacent to the cell wall in a unilateral manner. Columella cells exposed to microgravity were characterized by precipitates mostly located adjacent to the proximal and lateral cell wall. In all treatments some punctate precipitates were associated with vacuoles, amyloplasts, mitochondria, and euchromatin of the nucleus. A quantitative study revealed a decreased number of precipitates associated with the nucleus and the amyloplasts in columella cells exposed to microgravity as compared to ground controls. These data suggest that roots perceive a change in the gravitational field, as produced by clinorotation or space flights, and respond respectively differently by a redistribution of free calcium.

  2. Enthalpy of formation of anisole: implications for the controversy on the O-H bond dissociation enthalpy in phenol.

    PubMed

    Simões, Ricardo G; Agapito, Filipe; Diogo, Hermínio P; da Piedade, Manuel E Minas

    2014-11-20

    Significant discrepancies in the literature data for the enthalpy of formation of gaseous anisole, ΔfHmo(PhOCH3, g), have fueled an ongoing controversy regarding the most reliable enthalpy of formation of the phenoxy radical and of the gas phase O-H bond dissociation enthalpy, DHo(PhO-H), in phenol. In the present work ΔfHmo(PhOCH3, g) was reassessed using a combination of calorimetric determinations and high-level (W2-F12) ab initio calculations. Static-bomb combustion calorimetry led to the standard molar enthalpy of formation of liquid anisole at 298.15 K, ΔfHmo(PhOCH3, l) = −(117.1 ± 1.4) kJ·mol(-1). The corresponding enthalpy of vaporization was obtained as, ΔvapHmo(PhOCH3) = 46.41 ± 0.26 kJ·mol(-1), by Calvet-drop microcalorimetry. These results give ΔfHmo(PhOCH3, g) = −(70.7 ± 1.4) kJ·mol(-1), in excellent agreement with ΔfHmo(PhOCH3, g) = −(70.8 ± 3.2) kJ·mol(-1), obtained from the W2-F12 calculations. The ΔfHmo(PhOCH3, g) here recommended leads to ΔfHmo(PhO•, g) = 55.5 ± 2.4 kJ·mol(-)1 and DH°(PhO-H) = 368.1 ± 2.6 kJ·mol(-1).

  3. Electrochemical storage cell containing a substituted anisole or di-anisole redox shuttle additive for overcharge protection and suitable for use in liquid organic and solid polymer electrolytes

    SciTech Connect

    Kerr, John B.; Tian, Minmin

    1998-12-01

    A electrochemical cell is described comprising an anode, a cathode, a solid polymer electrolyte; and a redox shuttle additive to protect the cell against overcharging and a redox shuttle additive to protect the cell against overcharging selected from the group consisting of: (a) a substituted anisole having the general formula shown in a figure (in an uncharged state): where R{sub 1} is selected from the group consisting of H, 0CH{sub 3}, OCH{sub 2}CH{sub 3}, and OCH{sub 2}phenyl, and R{sub 2} is selected from the group consisting of OCH{sub 3}, OCH{sub 2}CH{sub 3}, OCH{sub 2} phenyl, and O{sup {minus}}Li{sup +}; and (b) a di-anisole compound having the general formula shown in a second figure (in an uncharged state): where R is selected from the group consisting of -OCH{sup 3} and -CH{sub 3}, m is either 1 or 0, n is either 1 or 0, and X is selected from the group consisting of -OCH{sub 3} (methoxy) or its lithium salt -O{sup {minus}}Li{sup +}. The lithium salt of the di-anisole is the preferred form of the redox shuttle additive because the shuttle anion will then initially have a single negative charge, it loses two electrons when it is oxidized at the cathode, and then moves toward the anode as a single positively charged species where it is then reduced to a single negatively charged species by gaining back two electrons.

  4. Risk of aspiration during anesthesia in patients with congenital insensitivity to pain with anhidrosis: case reports and review of the literature.

    PubMed

    Zlotnik, Alexander; Gruenbaum, Shaun E; Rozet, Irene; Zhumadilov, Agzam; Shapira, Yoram

    2010-10-01

    Congenital insensitivity to pain with anhidrosis (CIPA) is a rare autosomal recessive disease, characterized by episodes of unexplained fever, anhidrosis, pain insensitivity despite intact tactile perception, self-mutilating behavior, mental retardation, and autonomic nervous system (ANS) abnormalities. We present a case series of three patients with CIPA who underwent semielective orthopedic surgery under general anesthesia complicated by intraoperative regurgitation, and subsequent aspiration in two of the three cases. All three patients were nil per os (NPO) for at least 8 h prior to surgery. Two patients had their airways maintained with a laryngeal mask airway (LMA), and one patient had an endotracheal tube (ETT). The patients with an LMA suffered aspiration of gastric contents and subsequently developed hypoxic cardiac arrest. Although the patient with an ETT in situ regurgitated intraoperatively, the presence of the ETT prevented aspiration and any further potential complications. We review the perioperative complications typically observed in patients with CIPA and discuss the risks of using an LMA in these patients. We recommend that patients with CIPA always should be considered as having a "full stomach", regardless of the duration of their NPO status, due to their coexisting ANS abnormalities. Therefore, rapid-sequence induction with an ETT should be utilized for the anesthetic management in every patient with CIPA.

  5. Strategic Requirements for the Army to the Year 2000. Volume II. The World Environment to the Year 2000.

    DTIC Science & Technology

    1982-11-01

    masses to sur- vive Khomeini’s death. Nevertheless, the problems facing the post-Khomeini leadership will be monumental. A significant and vocal ...the next two decades. Saud Ar1big A n tbh ett " oesf lba now e Gu.l Saudi Arabia is increasingly assuming a leadership role in the area. After the Iran

  6. Physiological Responses During the Lower Body Positive Pressure Supported Treadmill Test

    PubMed Central

    2016-01-01

    Objective To quantify changes in cardiopulmonary function using a lower body positive pressure supported (LBPPS) treadmill during the exercise tolerance test (ETT) in healthy subjects before applying the LBPPS treadmill in patients with gait problems. Methods We evaluated 30 healthy subjects who were able to walk independently. The ETT was performed using the Modified Bruce Protocol (stages 1–5) at four levels (0%, 40%, 60%, and 80%) of LBPPS. The time interval at each level of the LBPPS treadmill test was 20 minutes to recover to baseline status. We measured systolic blood pressure, diastolic blood pressure, peak heart rate (PHR), rating of perceived exertion (RPE), metabolic equivalents (METs), and oxygen consumption rate (VO2) during each LBPPS condition. Results Systolic blood pressure increased as the LBPPS level was increased (40% to 80%). PHR, RPE, METs, and VO2 were negatively associated with the LBPPS condition, although they were not always significant different among the LBPPS levels. The equation from a random effect linear regression model was as follows: VO2 (mL/kg/min)=(2.75×stage)+(–0.14×LBPPS level)+11.9 (r2=0.69). Conclusion Detection of the changes in physiological parameters during a submaximal ETT using the LBPPS system may be helpful for applying the LBPPS treadmill in patients who cannot perform the ETT due to gait problems, even at submaximal intensity. PMID:27847722

  7. Coexisting epithelioid trophoblastic tumor and placental site trophoblastic tumor of the uterus following a term pregnancy: report of a case and review of literature.

    PubMed

    Zhang, Xiaofei; Zhou, Caiyun; Yu, Minghua; Chen, Xiaoduan

    2015-01-01

    Gestational trophoblastic neoplasms are a group of fetal trophoblastic tumors including choriocarcinomas, epithelioid trophoblastic tumors (ETTs), and placental site trophoblastic tumors (PSTTs). Mixed gestational trophoblastic neoplasms are extremely rare. The existence of mixed gestational trophoblastic neoplasms that were composed of choriocarcinoma and/or PSTT and/or ETT was also reported. Herein, we present a case of uterine mixed gestational trophoblastic neoplasm which is ETT admixed with PSTT, and reviewed 9 cases of mixed gestational trophoblastic neoplasms reported in English literature available. The most common combination was a choriocarcinoma admixed with an ETT and/or PSTT. Mixed gestational trophoblastic neoplasms present in women of reproductive age and rare in postmenopausal, Abnormal vaginal bleeding is the most common presenting symptom, serum β-HCG levels are elevated, mostly below 2500 mIU/ml, the tumor was limited to uterus in 7 cases, the rest of 3 with pulmonary metastases at the time of diagnosis. Mixed gestational trophoblastic neoplasms have more similar clinical features with intermediate trophoblastic tumors (ITTs). Total hysterectomy with lymph node dissection is recommended treatment for mixed gestational trophoblastic neoplasms, and chemotherapy should be used in patients with metastatic disease and with nonmetastatic disease who have adverse prognostic factors.

  8. Coexisting epithelioid trophoblastic tumor and placental site trophoblastic tumor of the uterus following a term pregnancy: report of a case and review of literature

    PubMed Central

    Zhang, Xiaofei; zhou, Caiyun; Yu, Minghua; Chen, Xiaoduan

    2015-01-01

    Gestational trophoblastic neoplasms are a group of fetal trophoblastic tumors including choriocarcinomas, epithelioid trophoblastic tumors (ETTs), and placental site trophoblastic tumors (PSTTs). Mixed gestational trophoblastic neoplasms are extremely rare. The existence of mixed gestational trophoblastic neoplasms that were composed of choriocarcinoma and/or PSTT and/or ETT was also reported. Herein, we present a case of uterine mixed gestational trophoblastic neoplasm which is ETT admixed with PSTT, and reviewed 9 cases of mixed gestational trophoblastic neoplasms reported in English literature available. The most common combination was a choriocarcinoma admixed with an ETT and/or PSTT. Mixed gestational trophoblastic neoplasms present in women of reproductive age and rare in postmenopausal, Abnormal vaginal bleeding is the most common presenting symptom, serum β-HCG levels are elevated, mostly below 2500 mIU/ml, the tumor was limited to uterus in 7 cases, the rest of 3 with pulmonary metastases at the time of diagnosis. Mixed gestational trophoblastic neoplasms have more similar clinical features with intermediate trophoblastic tumors (ITTs). Total hysterectomy with lymph node dissection is recommended treatment for mixed gestational trophoblastic neoplasms, and chemotherapy should be used in patients with metastatic disease and with nonmetastatic disease who have adverse prognostic factors. PMID:26261623

  9. Endotracheal Tube Cuff Pressure Following Intubation

    DTIC Science & Technology

    2005-09-08

    inflated ETT cuff. This method may lead to erroneous cuff pressures. Fernandez, Blanch, Mancebo, Bonsoms, and Artigas studied the accuracy of...Laryngologica, 345, suppl: 1-71. 10. Fernandez, R., Blanch, L., Mancebo, J., Bonsoms, N., Artigas , A. (1990). Endotracheal tube cuff pressure assessment

  10. Ease of intubation with the Parker Flex-Tip or a standard Mallinckrodt endotracheal tube using a video laryngoscope (GlideScope).

    PubMed

    Radesic, Brian P; Winkelman, Chris; Einsporn, Richard; Kless, Jack

    2012-10-01

    Two endotracheal tubes (ETTs) are available for use in operative suites for intubation: the Parker Flex-Tip (PFT, Parker Medical) and the standard Mallinckrodt (Covidien). To the authors' knowledge, no study has compared these 2 ETTs with each other when the anesthesia provider uses the GlideScope video laryngoscope (Verathon) for intubation. The purpose of the study was to determine if there are differences related to ease of intubation reported by anesthesia providers who use the PFT tube compared with the standard tube while using the GlideScope. The study was a randomized block intervention design. The sample consisted of 58 observed intubations in an operating room setting. Data analysis was completed with a 2-factor analysis of covariance using 2 covariates. The PFT tube in suboptimal conditions demonstrated a significantly greater ease of intubation, as measured by decreased time for ETT insertion and greater ease of ETT insertion score. The number of redirections at the glottis to intubate the trachea once the glottis was visualized was not statistically different. Based on the findings from this study, anesthesia providers may want to consider the use of the PFT tube when using the GlideScope to promote ease of intubation.

  11. The effect of lidocaine jelly on a taper-shaped cuff of an endotracheal tube on the postoperative sore throat: a prospective randomized study: A CONSORT compliant article.

    PubMed

    Lee, Jiwon; Lee, Yong-Cheol; Son, Je-Do; Lee, Jae-Yoon; Kim, Hyun-Chang

    2017-09-01

    Postoperative sore throat (POST) following general anesthesia with endotracheal intubation is a common complication. We hypothesized that lidocaine jelly applied to the tapered cuff of the endotracheal tube (ETT) might decrease the incidence of POST most commonly arising from endotracheal intubation. A total of 208 patients under general anesthesia were randomly assigned into 1 of 2 groups. In the lidocaine group (n = 104), the distal part of ETTs with tapered-shaped cuff was lubricated with lidocaine jelly. In the control group (n = 104), the distal part of ETTs with tapered-shaped cuff was lubricated with normal saline. The incidence of POST, hoarseness, and cough in the postanesthesia patients was compared. The overall incidence of POST was higher in the lidocaine group than in the normal saline group [60 (58%) vs 40 (39%), P = .006]. The incidence of POST at 1 hour postoperatively was higher in the lidocaine group than in the normal saline group [53 (51%) vs 32 (31%), P = .003]. The overall incidence of hoarseness for 24 hours postoperatively was comparable (P = .487). The overall incidence of cough for 24 hours postoperatively is higher in the lidocaine group (P = .045). The lidocaine jelly applied at the distal part of ETT with tapered-shaped cuff increased the overall incidence of POST in patients undergoing general anesthesia.

  12. 2011 North Plains research field 12-200 limited irrigation corn production study

    USDA-ARS?s Scientific Manuscript database

    The North Plains Water Conservation District started a water conservation project in 2010 on corn irrigation aimed at using just 12 inches of irrigation and producing 200 bu/ac of corn. This report is for 2011, the second year of the study, conducted at the North Plains Research Field (NPRF) in Ett...

  13. European Training Thesaurus: A Multilingual Synopsis

    ERIC Educational Resources Information Center

    Cedefop - European Centre for the Development of Vocational Training, 2012

    2012-01-01

    Education and training issues are similar across Europe, but how can we ensure we mean the same things with the same terms? The new format of the European training thesaurus (ETT) is a multilingual synopsis. It is an online tool enabling those working in education, training and employment to have a common understanding of terms. It helps…

  14. Interprocessor Communication Issues in Fat-Tree Architectures,

    DTIC Science & Technology

    1985-10-01

    34 CAMBRIDGE MASSA CHUS ETTS 0 2 1 3 9 VLSI Memo No. 85-268 October 1985 Interprocessor Communication Issues in Fat-Tree Architectures* Alexander Toichl...8217 + - .. ’ .’ .’+ .’ ’. . . . -. - ., ’. . . . .’’ .- . . - .’ . .. -, . .’% .. ’ .. +. ’ - " . , . ’. - .- . .°, ’ - . " ’ . ’ . .. . ,’ . -.... . .. ... ° ..ool Interprocessor Communication Issues in Fat-Tree

  15. Feasibility of a Novel Optoacoustic Device to Precisely Localize Endotracheal Tube Positioning in a Cadaver Model

    DTIC Science & Technology

    2016-11-02

    extubations are especially disastrous during casualty transport when clinical expertise and resources are limited. In the intensive care unit, at least 20% of...of inadvertent tube dislodgement. Physical examination has relatively low sensitivity for determining ETT position (primarily trachea vs. esophagus...of optical tomography (high optical contrast) and ultrasound imaging (minimal scattering of acoustic waves) to yield high contrast, sensitivity, and

  16. The effect of lidocaine jelly on a taper-shaped cuff of an endotracheal tube on the postoperative sore throat: a prospective randomized study

    PubMed Central

    Lee, Jiwon; Lee, Yong-Cheol; Son, Je-Do; Lee, Jae-Yoon; Kim, Hyun-Chang

    2017-01-01

    Abstract Background: Postoperative sore throat (POST) following general anesthesia with endotracheal intubation is a common complication. We hypothesized that lidocaine jelly applied to the tapered cuff of the endotracheal tube (ETT) might decrease the incidence of POST most commonly arising from endotracheal intubation. Methods: A total of 208 patients under general anesthesia were randomly assigned into 1 of 2 groups. In the lidocaine group (n = 104), the distal part of ETTs with tapered-shaped cuff was lubricated with lidocaine jelly. In the control group (n = 104), the distal part of ETTs with tapered-shaped cuff was lubricated with normal saline. The incidence of POST, hoarseness, and cough in the postanesthesia patients was compared. Results: The overall incidence of POST was higher in the lidocaine group than in the normal saline group [60 (58%) vs 40 (39%), P = .006]. The incidence of POST at 1 hour postoperatively was higher in the lidocaine group than in the normal saline group [53 (51%) vs 32 (31%), P = .003]. The overall incidence of hoarseness for 24 hours postoperatively was comparable (P = .487). The overall incidence of cough for 24 hours postoperatively is higher in the lidocaine group (P = .045). Conclusion: The lidocaine jelly applied at the distal part of ETT with tapered-shaped cuff increased the overall incidence of POST in patients undergoing general anesthesia. PMID:28906414

  17. Efficacy of benzydamine hydrochloride dripping at endotracheal tube cuff for prevention of postoperative sore throat.

    PubMed

    Nimmaanrat, Sasikaan; Chokkijchai, Kedsirin; Chanchayanon, Thavat

    2013-10-01

    Postoperative sore throat (POST) is a frequent consequence following ETT intubation, which may negatively affect the postoperative course and patient satisfaction. Benzydamine hydrochloride is a topically-applied non-steroidal anti-inflammatory drug (NSAID). The authors evaluated the analgesic effect of benzydamine hydrochloride dripping on the ETT cuff on POST. Eighty-six patients participated in this randomized controlled trial. They were assigned into either the benzydamine hydrochloride or the control group. The whole ETT cuff was dripped either with 3 ml (4.5 mg) of benzydamine hydrochloride or nothing five minutes prior to anesthesia induction. The incidence and severity of POST at 0, 2, 4, 6, 12 and 24 hours postoperatively were assessed. The potential adverse effects of benzydamine hydrochloride (throat numbness throat burning sensation, dry mouth, and thirst) were also evaluated. Twenty-five patients (58.14%) in each group had POST (p-value = 1). The severity of POST (calculated from affected patients) in both groups at different time points was not significantly different. Patients in the benzydamine hydrochloride group did not have a higher incidence of adverse effects. We found that dripping benzydamine hydrochloride on the ETT cuff neither reduced the incidence of POST nor increased the incidence of adverse effects in comparison with no intervention.

  18. Technologic advances in endotracheal tubes for prevention of ventilator-associated pneumonia.

    PubMed

    Fernandez, Juan F; Levine, Stephanie M; Restrepo, Marcos I

    2012-07-01

    Ventilator-associated pneumonia (VAP) is associated with high morbidity, mortality, and costs. Interventions to prevent VAP are a high priority in the care of critically ill patients requiring mechanical ventilation (MV). Multiple interventions are recommended by evidence-based practice guidelines to prevent VAP, but there is a growing interest in those related to the endotracheal tube (ETT) as the main target linked to VAP. Microaspiration and biofilm formation are the two most important mechanisms implicated in the colonization of the tracheal bronchial tree and the development of VAP. Microaspiration occurs when there is distal migration of microorganisms present in the secretions accumulated above the ETT cuff. Biofilm formation has been described as the development of a network of secretions and attached microorganisms that migrate along the ETT cuff polymer and inside the lumen, facilitating the transfer to the sterile bronchial tree. Therefore, our objective was to review the literature related to recent advances in ETT technologies regarding their impact on the control of microaspiration and biofilm formation in patients on MV, and the subsequent impact on VAP.

  19. The endotracheal tube microbiome associated with Pseudomonas aeruginosa or Staphylococcus epidermidis

    PubMed Central

    Hotterbeekx, An; Xavier, Basil B.; Bielen, Kenny; Lammens, Christine; Moons, Pieter; Schepens, Tom; Ieven, Margareta; Jorens, Philippe G; Goossens, Herman; Kumar-Singh, Samir; Malhotra-Kumar, Surbhi

    2016-01-01

    Ventilator-associated pneumonia (VAP) is one of the commonest hospital-acquired infections associated with high mortality. VAP pathogenesis is closely linked to organisms colonizing the endotracheal tube (ETT) such as Staphylococcus epidermidis and Pseudomonas aeruginosa, the former a common commensal with pathogenic potential and the latter a known VAP pathogen. However, recent gut microbiome studies show that pathogens rarely function alone. Hence, we determined the ETT microbial consortium co-colonizing with S. epidermidis or P. aeruginosa to understand its importance in the development of VAP and for patient prognosis. Using bacterial 16S rRNA and fungal ITS-II sequencing on ETT biomass showing presence of P. aeruginosa and/or S. epidermidis on culture, we found that presence of P. aeruginosa correlated inversely with patient survival and with bacterial species diversity. A decision tree, using 16S rRNA and patient parameters, to predict patient survival was generated. Patients with a relative abundance of Pseudomonadaceae <4.6% and of Staphylococcaceae <70.8% had the highest chance of survival. When Pseudomonadaceae were >4.6%, age of patient <66.5 years was the most important predictor of patient survival. These data indicate that the composition of the ETT microbiome correlates with patient prognosis, and presence of P. aeruginosa is an important predictor of patient outcome. PMID:27812037

  20. Predictors of Posterior Glottic Stenosis: A Multi-Institutional Case-Control Study.

    PubMed

    Hillel, Alexander T; Karatayli-Ozgursoy, Selmin; Samad, Idris; Best, Simon R A; Pandian, Vinciya; Giraldez, Laureano; Gross, Jennifer; Wootten, Christopher; Gelbard, Alexander; Akst, Lee M; Johns, Michael M

    2016-03-01

    To assess intrinsic and extrinsic risk factors in the development of posterior glottic stenosis (PGS) in intubated patients. Patients diagnosed with PGS between September 2012 and May 2014 at 3 tertiary care university hospitals were included. Patient demographics, comorbidities, duration of intubation, endotracheal tube (ETT) size, and indication for intubation were recorded. Patients with PGS were compared to control patients represented by patients intubated in intensive care units (ICU). Thirty-six PGS patients were identified. After exclusion, 28 PGS patients (14 male, 14 female) and 112 (65 male, 47 female) controls were studied. Multivariate analysis demonstrated ischemia (P < .05), diabetes (P < .01), and length of intubation (P < .01) were significant risk factors for the development of PGS. Fourteen of 14 (100%) males were intubated with a size 8 or larger ETT compared to 47 of 65 (72.3%) male controls (P < .05). Posterior glottic stenosis (P < .01), length of intubation (P < .001), and obstructive sleep apnea (P < .05) were significant risk factors for tracheostomy. Duration of intubation, ischemia, diabetes mellitus, and large ETT size (8 or greater) in males were significant risk factors for the development of PGS. Reducing the use of size 8 ETTs and earlier planned tracheostomy in high-risk patients may reduce the incidence of PGS and improve ICU safety. © The Author(s) 2015.

  1. Electronic topological transition in zinc metal? A 67Zn-Mössbauer investigation

    NASA Astrophysics Data System (ADS)

    Potzel, Walter

    2000-11-01

    The question concerning the existence of an electronic topological transition (ETT) in Zn metal under quasi-hydrostatic pressure at ˜6.6 GPa caused a considerable controversy in the literature. We briefly review low-temperature 67Zn-Mössbauer data and scalar-relativistic augmented plane wave calculations and give a consistent interpretation in terms of an ETT. To highlight some important aspects of the controversy two theoretical and two experimental publications will be discussed in more detail. At present the existence of an ETT in Zn metal is disputed both from an experimental and from a theoretical point of view. The suggestion of a transition to a commensurate spin-density wave at ˜6.6 GPa instead of an ETT may reconcile the seemingly contradictory results of 67Zn-Mössbauer experiments at 4.2 K and of room temperature inelastic neutron scattering measurements. However, it does not explain the anomalies found in theoretical calculations performed for Zn metal in this pressure range. Considerable experimental and theoretical efforts are required to confirm - or rule out - a spin-density-wave transition.

  2. Measurements of endotracheal tube cuff contact pressure using fibre Bragg gratings

    NASA Astrophysics Data System (ADS)

    Hernandez, F. U.; Correia, R.; Korposh, S.; Morgan, S. P.; Hayes-Gill, B. R.; James, S. W.; Evans, D.; Norris, A.

    2015-09-01

    An optical fibre Bragg grating (FBG) was used to measure local strain (due to contact pressure) at the interface of a cuffed endotracheal tube (ETT) tested in a tracheal model. The tracheal model consisted of a corrugated tube. Two FBG sensors written in a single optical fibre were attached to the outside wall of the cuff of the ETT. Intracuff endotracheal pressure was measured using a digital manometer, while the contact pressure between the model trachea and the ETT was measured using Flexiforce sensors. Changes in the Bragg wavelengths in response to the inflation of the cuff of the ETT, and concomitant pressure increase, were observed to be dependent on the location of the FBGs at the corrugations, i.e., the annular peaks and troughs of the corrugated tube. The performance of both contact pressure sensors FBG and Flexiforce suggests that FBG technology is better suited to this application as it allows the measurement of contact pressures on non-uniform surfaces such as in the tracheal model.

  3. Hydroxyl end groups influence in vibrational and transport properties in polymer/monomer solutions: the PEO/EG case

    NASA Astrophysics Data System (ADS)

    Crupi, V.; Faraone, A.; Majolino, D.; Migliardo, P.; Venuti, V.; Villari, V.

    A study has been made of vibrational properties in ethylene glycol (EG; H(OCH2CH2)OH) and EG monomethyl ether (EGmE; CH3(OCH2CH2)OH) in solution together with poly(ethylene oxide) (PEO; H(OCH2CH2)nOH) at different concentrations, performed by Fourier transform infrared absorbance (FT-IR) spectroscopy. The results ae compared with previous viscometry and photon correlation spectroscopy (PCS) studies, using EG dimethyl ether (EGdE; CH3(OCH2CH2)OCH3) as solvent as well. These homologous systems differ from each other in the number of OH end groups, in particular two for EG, one for EgmE and zero for EGdE. Combining analysis of the vibrational and transport properties of EG, EGmE and EGdE in solution with PEO over a wide range of concentration made it possible to check the quality (good theta or poor) of these three different solvents and the role played by the hydrogen bond in the various solute-solvent interaction mechanisms, resulting in the well known de Gennes scaling law.

  4. Structural basis for piRNA 2'-O-methylated 3'-end recognition by Piwi PAZ (Piwi/Argonaute/Zwille) domains.

    PubMed

    Tian, Yuan; Simanshu, Dhirendra K; Ma, Jin-Biao; Patel, Dinshaw J

    2011-01-18

    Argonaute and Piwi proteins are key players in the RNA silencing pathway, with the former interacting with micro-RNAs (miRNAs) and siRNAs, whereas the latter targets piwi-interacting RNAs (piRNAs) that are 2'-O-methylated (2(')-OCH(3)) at their 3' ends. Germline-specific piRNAs and Piwi proteins play a critical role in genome defense against transposable elements, thereby protecting the genome against transposon-induced defects in gametogenesis and fertility. Humans contain four Piwi family proteins designated Hiwi1, Hiwi2, Hiwi3, and Hili. We report on the structures of Hili-PAZ (Piwi/Argonaute/Zwille) domain in the free state and Hiwi1 PAZ domain bound to self-complementary 14-mer RNAs (12-bp + 2-nt overhang) containing 2(')-OCH(3) and 2'-OH at their 3' ends. These structures explain the molecular basis underlying accommodation of the 2(')-OCH(3) group within a preformed Hiwi1 PAZ domain binding pocket, whose hydrophobic characteristics account for the preferential binding of 2(')-OCH(3) over 2'-OH 3' ends. These results contrast with the more restricted binding pocket for the human Ago1 PAZ domain, which exhibits a reverse order, with preferential binding of 2'-OH over 2(')-OCH(3) 3' ends.

  5. Mechanical properties and interface characteristics of nanoporous low-k materials.

    PubMed

    Si, Lina; Guo, Dan; Xie, Guoxin; Luo, Jianbin

    2014-08-27

    Low dielectric constant (low-k) insulator films with outstanding mechanical strength and fracture resistance are needed urgently for the new generation of ultra-large-scale integrated circuits (ULSI). In this paper, the mechanical properties of low-k materials and the adhesion strengths between these materials with silica have been analyzed by using molecular dynamics (MD) simulations. Atomistic models of two kinds of representative low-k materials [nanoporous amorphous silica (n-a-SiO2) and SiOCH] and their contact models with silica have been constructed. The mechanical strength of the n-a-SiO2 film decreased with the increase of porosity, and the relationship between the normalized elastic modulus and porosity was modeled. The modulus of the SiOCH film with -CH2- groups was enhanced compared with that without -CH2- groups, and the mechanism was discussed. Through investigations of the adhesion strengths between n-a-SiO2, SiOCH, and silica, it was shown that the adhesion strengths of the n-a-SiO2/silica interfaces decreased with porosity. The adhesion strengths of the SiOCH films with both -CH2- groups and -CH3 groups were higher than that of the SiOCH film merely with -CH3 groups.

  6. Site-selective electroless metallization on porous organosilica films by multisurface modification of alkyl monolayer and vacuum plasma.

    PubMed

    Chen, Giin-Shan; Chen, Sung-Te; Chen, Yenying W; Hsu, Yen-Che

    2013-01-15

    Taking plasma-enhanced chemical vapor deposited porous SiOCH (p-SiOCH) and octadecyltrichlorosilane (OTS) as model cases, this study elucidates the chemical reaction pathways for alkyl-based self-assembled monolayers (SAMs) on porous carbon-doped organosilica films under N(2)-H(2) vacuum plasma illumination. In contrast to previous findings that carboxylic groups are found in alkyl-based SAMs only by exposure to oxygen-based plasma, this study discovers that, upon exposure to reductive nitrogen-based vacuum plasma, surface carboxylic functional groups can be instantly formed on OTS-coated p-SiOCH films. Particular attention is given to developing a multisurface modification process, starting with the modification of p-SiOCH films by N(2)-H(2) plasma and continuing with SAM deposition and plasma patterning; this ultimately leads to site-selective seeding for the spatially controlled fabrication of Cu-wire metallization by electroless deposition. Plasma diagnosis and X-ray near-edge absorption and Fourier transform infrared spectroscopies show that, by adequately controlling the plasma parameters, the bulk of the p-SiOCH films are free from plasma damage (in terms of degradation in bonding structures and electrical properties); the formation of the seed-trapping carboxylic functional groups on the surface, the key factor for the validity of this new seeding process, is due to a water-mediated chemical oxygenation route.

  7. Structural basis for piRNA 2'-O-methylated 3'-end recognition by Piwi PAZ (Piwi/Argonaute/Zwille) domains

    PubMed Central

    Tian, Yuan; Simanshu, Dhirendra K.; Ma, Jin-Biao; Patel, Dinshaw J.

    2011-01-01

    Argonaute and Piwi proteins are key players in the RNA silencing pathway, with the former interacting with micro-RNAs (miRNAs) and siRNAs, whereas the latter targets piwi-interacting RNAs (piRNAs) that are 2′-O-methylated (2′-OCH3) at their 3′ ends. Germline-specific piRNAs and Piwi proteins play a critical role in genome defense against transposable elements, thereby protecting the genome against transposon-induced defects in gametogenesis and fertility. Humans contain four Piwi family proteins designated Hiwi1, Hiwi2, Hiwi3, and Hili. We report on the structures of Hili-PAZ (Piwi/Argonaute/Zwille) domain in the free state and Hiwi1 PAZ domain bound to self-complementary 14-mer RNAs (12-bp + 2-nt overhang) containing 2′-OCH3 and 2′-OH at their 3′ ends. These structures explain the molecular basis underlying accommodation of the 2′-OCH3 group within a preformed Hiwi1 PAZ domain binding pocket, whose hydrophobic characteristics account for the preferential binding of 2′-OCH3 over 2′-OH 3′ ends. These results contrast with the more restricted binding pocket for the human Ago1 PAZ domain, which exhibits a reverse order, with preferential binding of 2′-OH over 2′-OCH3 3′ ends. PMID:21193640

  8. Unimolecular thermal decomposition of dimethoxybenzenes

    NASA Astrophysics Data System (ADS)

    Robichaud, David J.; Scheer, Adam M.; Mukarakate, Calvin; Ormond, Thomas K.; Buckingham, Grant T.; Ellison, G. Barney; Nimlos, Mark R.

    2014-06-01

    The unimolecular thermal decomposition mechanisms of o-, m-, and p-dimethoxybenzene (CH3O-C6H4-OCH3) have been studied using a high temperature, microtubular (μtubular) SiC reactor with a residence time of 100 μs. Product detection was carried out using single photon ionization (SPI, 10.487 eV) and resonance enhanced multiphoton ionization (REMPI) time-of-flight mass spectrometry and matrix infrared absorption spectroscopy from 400 K to 1600 K. The initial pyrolytic step for each isomer is methoxy bond homolysis to eliminate methyl radical. Subsequent thermolysis is unique for each isomer. In the case of o-CH3O-C6H4-OCH3, intramolecular H-transfer dominates leading to the formation of o-hydroxybenzaldehyde (o-HO-C6H4-CHO) and phenol (C6H5OH). Para-CH3O-C6H4-OCH3 immediately breaks the second methoxy bond to form p-benzoquinone, which decomposes further to cyclopentadienone (C5H4=O). Finally, the m-CH3O-C6H4-OCH3 isomer will predominantly follow a ring-reduction/CO-elimination mechanism to form C5H4=O. Electronic structure calculations and transition state theory are used to confirm mechanisms and comment on kinetics. Implications for lignin pyrolysis are discussed.

  9. Oxidative demethylation in monooxygenase model systems. Competing pathways for binuclear and helical multinuclear copper(I) complexes

    SciTech Connect

    Gelling, O.J.; Feringa, B.L. )

    1990-10-10

    The ligand 2,6-bis(N-(2-pyridylethyl)formimidoyl)-1-methoxybenzene (2,6-BPB-1-OCH{sub 3}) (4) reacts with Cu-(CH{sub 3}CN){sub 4}BF{sub 4} to form novel binuclear copper(I) complexes (Cu{sub 2}(2,6-BPB-1-OCH{sub 3})(BF{sub 4}){sub 2}(CH{sub 3}CN){sub 4}) (11) and (Cu{sub 2}(2,6-BPB-1-OCH{sub 3})(BF{sub 4}){sub 2}(CH{sub 2}Cl{sub 2}){sub 0.5}) (14), or the helical polynuclear copper(I) complex (Cu(2,6-BPB-1-OCH{sub 3})(BF{sub 4})){sub n} (16). The complexes mimic certain monooxygenases as they rapidly take up O{sub 2} followed by demethylation of the anisole moiety (up to 95% yield). {sup 18}O experiments are provided that show competing aryl-oxygen ({ge}60%) and alkyl-oxygen (20%) bond cleavage pathways. Introduction of a p-methoxy substituent in the arene moiety of complex 11 decreases the oxygenation rate and led to an unprecedented O{sub 2} induced arene-OCH{sub 3}-OCD{sub 3} exchange at 20{degree}C in CD{sub 3}OD. A mechanistic rational is given.

  10. Review of multiple endocrine neoplasia type 2A in children: therapeutic results of early thyroidectomy and prognostic value of codon analysis.

    PubMed

    Szinnai, Gabor; Meier, Christian; Komminoth, Paul; Zumsteg, Urs W

    2003-02-01

    The aim of this study was first to investigate whether early total thyroidectomy (ETT; 1-5 years of age) can prevent medullary thyroid carcinoma with persistent or recurrent disease (PRD) in pediatric patients with multiple endocrine neoplasia type 2A (MEN-2A) and second, to evaluate the strength of codon analysis in children with MEN-2A as prognostic parameter. Case reports and review of the literature for pediatric patients with MEN-2A were conducted. Inclusion criteria were age (0-20 years) and histologic degree of C-cell disease (normal = N, C-cell hyperplasia = CCH, medullary thyroid carcinoma = MTC, metastatic MTC = MMTC). To evaluate therapeutic results of ETT (1-5 years) versus late total thyroidectomy (LTT; 6-20 years), age-dependent histologic stages of C-cell disease and postoperative occurrence of PRD were compared. Prognostic value of specific codons, age-dependent histologic distribution, and long-term outcome were analyzed. In a total of 260 cases, 42 (16%) underwent ETT, and 218 (84%) underwent LTT. Histologic analysis showed significant difference between ETT versus LTT (57% vs 76%) regarding malignant stage of C-cell disease (of combined rate of MTC and MMTC). Long-term outcome was documented in 74 patients (28%). During a median follow-up period of 2 years (range: 0-15 years), 21 of 65 of the LTT group versus 0 of 9 of the ETT group suffered PRD. Information about codon analysis was available in 150 patients (58%). Mutated codons were c634 (63%), c618 (19%), c620 (9%), and c804 (6%). Codon-related histologic analysis resulted in prognostic differences: 81% of patients with c634-mutation had MCT or MMTC in contrast to c804 (44%), c618 (34%), and c620 (7%). Fifteen of 17 MMTC and 7 of 9 PRD occurred in patients with c634-mutation. 1) ETT until 5 years of age in MEN-2A gene carriers results in significant reduction of MTC and MMTC in favor of CCH and improved disease-free long-term outcome. 2) Codon analysis is an important prognostic factor. Timing

  11. Effect of Endotracheal Tube Size on Vocal Outcomes After Thyroidectomy: A Randomized Clinical Trial.

    PubMed

    Mehanna, Rania; Hennessy, Anthony; Mannion, Stephen; O'Leary, Gerard; Sheahan, Patrick

    2015-08-01

    The optimum size of endotracheal tube (ETT) for general anesthesia remains unresolved. Choice of ETT size may be of particular relevance to thyroid surgery because of the increased risk of laryngeal trauma and concerns regarding postoperative vocal outcomes. To test our hypothesis that intubation with a smaller ETT would lead to reduced postoperative vocal impairment and associated reduced laryngoscopic evidence of laryngeal trauma compared with intubation with a standard-size ETT. This double-blind randomized clinical trial studied patients 18 years and older undergoing elective thyroidectomy at an academic teaching hospital from October 15, 2012, through June 13, 2013. Patients were randomized to group 1 (standard-size ETT, 8.0 mm for men and 7.5 mm for women; n = 24) or group 2 (small ETT, 7.0 mm for men and 6.5 mm for women; n = 25). Patients were assessed preoperatively and at 24 hours and 3 weeks postoperatively. Fiberoptic videolaryngoscopy with modified scoring system, voice assessment using the GRBAS (grade, roughness, breathiness, asthenia, strain) rating scale, vocal self-assessment using the 30-item Voice Handicap Index, and subjective pain score. At 24 hours, no significant differences were found between patients in groups 1 and 2 in change in GRBAS scores, change in laryngoscopic score (1.71 vs 1.76, P = .90), or postoperative pain score (3.3 vs 3.2, P = .91). At 3 weeks, no significant differences were found in changes in the 30-item Voice Handicap Index score (-2.2 vs -1.3, P = .74), GRBAS scores, or laryngoscopic score (0.25 vs 0.16, P = .67). We did not find evidence that smaller ETT size for thyroidectomy has any significant effect on postoperative vocal outcomes, incidence of laryngeal trauma as assessed by laryngoscopy, or pain scores. However, because of the small sample size, our study may have been underpowered to detect small differences. clinicaltrials.gov Identifier: NCT02136459.

  12. Conventional Versus Video Laryngoscopy for Tracheal Tube Exchange: Glottic Visualization, Success Rates, Complications, and Rescue Alternatives in the High-Risk Difficult Airway Patient.

    PubMed

    Mort, Thomas C; Braffett, Barbara H

    2015-08-01

    Tracheal tube exchange is a simple concept but not a simple procedure because hypoxemia, esophageal intubation, and loss of airway may occur with life-threatening ramifications. Combining laryngoscopy with an airway exchange catheter (AEC) may lessen the exchange risk. Laryngoscopy is useful for a pre-exchange examination and to open a pathway for endotracheal tube (ETT) passage. Direct laryngoscopy (DL) is hampered by a restricted "line of sight"; thus, airway assessment and exchange may proceed blindly and contribute to difficulty and complications. We hypothesized that video laryngoscopy (VL), when compared with DL, will improve glottic viewing for airway assessment, and the VL-AEC method of ETT exchange will result in a reduction in airway and hemodynamic complications in high-risk patients when compared with a historical group of patients who underwent DL + AEC-assisted exchange. Critically ill patients requiring an ETT exchange underwent DL-assisted pre-exchange airway assessment. If the DL-assisted pre-exchange assessment rendered a "poor view," these patients underwent a VL-based airway assessment followed by a VL-assisted ETT exchange procedure. The DL and VL pre-exchange assessments were compared. The attempts, complications, and rescue devices required for ETT exchange were analyzed. These exchange results were then compared with a historical control group of patients who (1) were classified as a poor view on DL-assisted pre-exchange airway assessment; and (2) underwent a DL + AEC-assisted exchange. The airway assessment and ETT exchange were performed by a board-certified anesthesiologist from the Department of Anesthesiology alone or with anesthesia resident assistance. Three hundred twenty-eight patients with a poor view on initial DL examination underwent a subsequent VL with comparison of views with the 337 patients in the historical control group (DL + AEC). A majority (88%) had a "full or near-full view" on VL examination. The first-pass success

  13. Evaluating Risk Factors for Pediatric Post-extubation Upper Airway Obstruction Using a Physiology-based Tool

    PubMed Central

    Hotz, Justin; Morzov, Rica; Flink, Rutger; Kamerkar, Asavari; Ross, Patrick A.; Newth, Christopher J. L.

    2016-01-01

    Rationale: Subglottic edema is the most common cause of pediatric extubation failure, but few studies have confirmed risk factors or prevention strategies. This may be due to subjective assessment of stridor or inability to differentiate supraglottic from subglottic disease. Objectives: Objective 1 was to assess the utility of calibrated respiratory inductance plethysmography (RIP) and esophageal manometry to identify clinically significant post-extubation upper airway obstruction (UAO) and differentiate subglottic from supraglottic UAO. Objective 2 was to identify risk factors for subglottic UAO, stratified by cuffed versus uncuffed endotracheal tubes (ETTs). Methods: We conducted a single-center prospective study of children receiving mechanical ventilation. UAO was defined by inspiratory flow limitation (measured by RIP and esophageal manometry) and classified as subglottic or supraglottic based on airway maneuver response. Clinicians performed simultaneous blinded clinical UAO assessment at the bedside. Measurements and Main Results: A total of 409 children were included, 98 of whom had post-extubation UAO and 49 (12%) of whom were subglottic. The reintubation rate was 34 (8.3%) of 409, with 14 (41%) of these 34 attributable to subglottic UAO. Five minutes after extubation, RIP and esophageal manometry better identified patients who subsequently received UAO treatment than clinical UAO assessment (P < 0.006). Risk factors independently associated with subglottic UAO included low cuff leak volume or high preextubation leak pressure, poor sedation, and preexisting UAO (P < 0.04) for cuffed ETTs; and age (range, 1 mo to 5 yr) for uncuffed ETTs (P < 0.04). For uncuffed ETTs, the presence or absence of preextubation leak was not associated with subglottic UAO. Conclusions: RIP and esophageal manometry can objectively identify subglottic UAO after extubation. Using this technique, preextubation leak pressures or cuff leak volumes predict subglottic UAO in

  14. Improving aerosol drug delivery during invasive mechanical ventilation with redesigned components.

    PubMed

    Longest, P Worth; Azimi, Mandana; Golshahi, Laleh; Hindle, Michael

    2014-05-01

    Patients receiving invasive mechanical ventilation with an endotracheal tube (ETT) can often benefit from pharmaceutical aerosols; however, drug delivery through the ventilator circuit is known to be very inefficient. The objective of this study was to improve the delivery of aerosol through an invasive mechanical ventilation system by redesigning circuit components using a streamlining approach. Redesigned components were the T-connector interface between the nebulizer and ventilator line and the Y-connector leading to the ETT. The streamlining approach seeks to minimize aerosol deposition and loss by eliminating sharp changes in flow direction and tubing diameter that lead to flow disruption. Both in vitro experiments and computational fluid dynamic (CFD) simulations were applied to analyze deposition and emitted dose of drug for multiple droplet size distributions, flows, and ETT sizes used in adults. The experimental results demonstrated that the streamlined components improved delivery through the circuit by factors ranging from 1.3 to 1.5 compared with a commercial system for adult ETT sizes of 8 and 9 mm. The overall delivery efficiency was based on the bimodal aspect of the aerosol distributions and could not be predicted by median diameter alone. CFD results indicated a 20-fold decrease in turbulence in the junction region for the streamlined Y resulting in a maximum 9-fold decrease in droplet deposition. The relative effectiveness of the streamlined designs was found to increase with increasing particle size and increasing flow, with a maximum improvement in emitted dose of 1.9-fold. Streamlined components can significantly improve the delivery of pharmaceutical aerosols during mechanical ventilation based on an analysis of multiple aerosol generation devices, ETT sizes, and flows.

  15. End-tidal capnography and upper airway ultrasonography in the rapid confirmation of endotracheal tube placement in patients requiring intubation for general anaesthesia.

    PubMed

    Abhishek, Chintamani; Munta, Kartik; Rao, S Manimala; Chandrasekhar, C N

    2017-06-01

    Confirmation of correct endotracheal tube placement is essential immediately after intubation for general anaesthesia. In this study, we have compared upper airway ultrasonography (USG) with reference to capnography for rapid confirmation of endotracheal tube placement after general anaesthesia. A prospective, single centre, observational study was conducted on 100 patients requiring tracheal intubation for general anaesthesia. Both capnography and upper airway USG were performed immediately after intubation to confirm the endotracheal tube (ETT) placement. Sensitivity, specificity, and positive and negative predictive values of upper airway USG were determined against capnography as the reference method. Agreement between the methods and time required to determine ETT placement by the two methods were assessed with kappa statistics and Student's t-test. Upper airway USG detected all five cases of oesophageal intubation, but could not detect five patients with correct tracheal intubation. Upper airway USG had a sensitivity of 96.84% (95% confidence interval [CI]: 94.25%-96.84%), specificity of 100% (95% CI: 50.6%-100%), positive predictive value of 100% (95% CI: 97.3%-100%) and negative predictive value of 62.5% (95% CI: 31.6%-62.5%). Kappa value was found to be 0.76, indicating a good agreement between upper airway USG and capnography for confirmation of ETT placement. Time taken for confirmation of ETT by capnography was 8.989 ± 1.043 s vs. 12.0 ± 1.318 s for upper airway USG (P < 0.001). Both capnography and upper airway USG may be used as primary procedures for the confirmation of ETT placement.

  16. Tracheal tube cuff inflation guided by pressure volume loop closure associated with lower postoperative cuff-related complications: Prospective, randomized clinical trial

    PubMed Central

    Almarakbi, Waleed A.; Kaki, Abdullah M.

    2014-01-01

    Background: The main function of an endotracheal tube (ETT) cuff is to prevent aspiration. High cuff pressure is usually associated with postoperative complications. We tried to compare cuff inflation guided by pressure volume loop closure (PV-L) with those by just to seal technique (JS) and assess the postoperative incidence of sore throat, cough and hoarseness. Materials and Methods: In a prospective, randomized clinical trial, 100 patients’ tracheas were intubated. In the first group (n = 50), ETT cuff inflation was guided by PV-L, while in the second group (n. = 50) the ETT cuff was inflated using the JS technique. Intracuff pressures and volumes were measured. The incidence of postoperative cuff-related complications was reported. Results: Demographic data and durations of intubation were comparable between the groups. The use of PV-L was associated with a lesser amount of intracuff air [4.05 (3.7-4.5) vs 5 (4.8-5.5), P < 0.001] and lower cuff pressure than those in the JS group [18.25 (18-19) vs 33 (32-35), P ≤ 0.001]. The incidence of postextubation cuff-related complications was significantly less frequent among the PV-L group patients as compared with the JS group patients (P ≤ 0.009), except for hoarseness of voice, which was less frequent among the PV-L group, but not statistically significant (P ≤ 0.065). Multiple regression models for prediction of intra-cuff pressure after intubation and before extubation revealed a statistically significant association with the technique used for cuff inflation (P < 0.0001). Conclusions: The study confirms that PV-L-guided ETT cuff inflation is an effective way to seal the airway and associates with a lower ETT cuff pressure and lower incidence of cuff-related complications. PMID:25191181

  17. The effect of intracuff alkalinized 2% lidocaine on emergence coughing, sore throat, and hoarseness in smokers.

    PubMed

    Navarro, Laís Helena Camacho; Lima, Rodrigo Moreira e; Aguiar, Andressa Simões; Braz, José Reinaldo Cerqueira; Carness, Jeffrey M; Módolo, Norma Sueli Pinheiro

    2012-01-01

    We evaluated whether endotracheal tube (ETT) intracuff alkalinized lidocaine was superior to saline in blunting emergence coughing, postoperative sore throat, and hoarseness in smokers. In our prospective, double-blind trial, we enrolled 50 smoking patients undergoing surgery under general anesthesia including nitrous oxide (N2O). Patients were randomly allocated to receive either ETT intracuff 2% lidocaine plus 8.4% sodium bicarbonate (L group), or ETT intracuff 0.9% saline (S group). The ETT cuff was inflated to achieve a cuff pressure that prevented air leak during positive pressure ventilation. Incidence of emergence coughing, sore throat, and hoarseness were analyzed. The volume of inflation solution, the intracuff pressure, the duration of anesthesia, the time elapsed to extubation after discontinuation of anesthesia, and the volume of the inflation solution and the air withdrawn from the ETT cuff were also recorded. Intracuff alkalinized 2% lidocaine was superior to saline in blunting emergence coughing (p < 0.001). The incidence of sore throat was significantly lower in the L group at the post-anesthesia care unit (PACU) (p = 0.02). However, at 24 hours after extubation, sore throat incidence was similar in both groups (p = 0.07). Incidence of hoarseness was similar in both groups. Intracuff pressure in the saline group increased with time while the intracuff pressure in the lidocaine group remained constant. The present study demonstrated that the intracuff alkalinized 2% lidocaine was superior to saline in decreasing the incidence of emergence coughing and sore throat during the postoperative period in smokers.

  18. Does sealing endotracheal tube cuff pressure diminish the frequency of postoperative laryngotracheal complaints after nitrous oxide anesthesia?

    PubMed

    Braz, José Reinaldo Cerqueira; Volney, Alexandre; Navarro, Laís Helena Camacho; Braz, Leandro Gobbo; Nakamura, Giane

    2004-08-01

    To study endotracheal tube (ETT) cuff pressures during nitrous oxide (N2O) anesthesia when the cuffs are inflated with air to achieve sealing pressure, and to evaluate the frequency of postoperative laryngotracheal complaints. Prospective, randomized, blind study. Metropolitan teaching hospital. 50 ASA physical status I and II patients scheduled for elective abdominal surgery. Patients received standard general anesthesia with 66% N2O in oxygen. In 25 patients, the ETT cuff was inflated with air to achieve a sealing pressure (Pseal group). In 25 patients, the ETT cuff was inflated with air to achieve a pressure of 25 cm H2O (P25 group). ETT intracuff pressures were recorded before (control) and at 30, 60, 90, 120, and 150 minutes during N2O administration. We investigated the frequency and intensity of sore throat, hoarseness, and dysphagia in patients in the Post-Anesthesia Care Unit (PACU) and 24 hours following tracheal extubation. The cuff pressures in the Pseal group were significantly lower than in the P25 group at all time points studied (p < 0.001), with a significant increase with time in both groups (p < 0.001). The cuff pressures exceeded the critical pressure of 30 cm H2O only after 90 minutes in the Pseal group and already by 30 minutes in the P25 group. The frequency and intensity of sore throat, hoarseness, and dysphagia were similar in both groups in the PACU and 24 hours after tracheal extubation (p > 0.05). Minimum ETT sealing cuff pressure during N2O anesthesia did not prevent, but instead attenuated, the increase in cuff pressure and did not decrease postoperative laryngotracheal complaints. Copyright 2004 Elsevier Inc.

  19. Clinical evaluation of C-MAC videolaryngoscope with or without use of stylet for endotracheal intubation in patients with cervical spine immobilization.

    PubMed

    Gupta, Nidhi; Rath, Girija Prasad; Prabhakar, Hemanshu

    2013-10-01

    This study was carried out to evaluate the relative efficacy of the C-MAC videolaryngoscope as compared to the conventional Macintosh laryngoscope using both styletted and non-styletted endotracheal tube (ETT) in patients undergoing elective cervical spine surgery with head and neck stabilized by manual in-line stabilization. We randomized 120 consenting adults into four groups (30 each) to undergo tracheal intubation using either the Macintosh laryngoscope or C-MAC videolaryngoscope with styletted and non-styletted ETT. There was no significant difference between the C-MAC videolaryngoscope and Macintosh laryngoscope in Intubation Difficulty Scale (IDS) score using either styletted [median (IQR) 2 (1, 3) vs. 3 (2, 4); p = 0.58] or non-styletted ETT [median (IQR) 4 (2, 6) vs. 3 (2, 8); p = 1.00]. Similarly, when using a similar ETT-stylet assembly, the duration of successful intubation attempt, first attempt success rate, complications, use of airway optimization maneuvers, and adjuncts to facilitate intubation were comparable. The Cormack-Lehane view of the glottis was better with the C-MAC videolaryngoscope (p < 0.001). The use of stylet significantly reduced the IDS score [median (IQR) 2 (1, 3) vs. 4 (2, 6); p = 0.02], intubation time [median (IQR) 27 s (23, 31) vs. 52 s (28, 76); p < 0.001], and use of gum elastic bougie (3.3% vs. 43.3%, p < 0.001) with the C-MAC videolaryngoscope whereas no such effect was observed with the Macintosh laryngoscope. Use of the C-MAC videolaryngoscope and Macintosh laryngoscope resulted in similar levels of intubation difficulty during cervical immobilization when used with a similar ETT-stylet assembly. The inclusion of the stylet significantly reduced the intubation difficulty experienced with the C-MAC videolaryngoscope.

  20. Development and evaluation of a treadmill-based exercise tolerance test in cardiac rehabilitation

    PubMed Central

    Adams, Jenny; Cheng, Dunlei; Barton, Stephanie; Bigej-Cerqua, Janet; Mims, Lisa; Molden, Jennifer; Anderson, Valerie

    2013-01-01

    Cardiac rehabilitation exercise prescriptions should be based on exercise stress tests; however, limitations in performing stress tests in this setting typically force reliance on subjective measures like the Duke Activity Status Index (DASI). We developed and evaluated a treadmill-based exercise tolerance test (ETT) to provide objective physiologic measures without requiring additional equipment or insurance charges. The ETT is stopped when the patient's Borg scale rating of perceived exertion (RPE) reaches 15 or when any sign/symptom indicates risk of an adverse event. Outcomes of the study included reasons for stopping; maximum heart rate, systolic blood pressure, and rate pressure product; and adverse events. We tested equivalence to the DASI as requiring the 95% confidence interval for the mean difference between DASI and ETT metabolic equivalents (METs) to fall within the range (–1, 1). Among 502 consecutive cardiac rehabilitation patients, one suffered a panic attack; no other adverse events occurred. Most (80%) stopped because they reached an RPE of 15; the remaining 20% were stopped on indications that continuing risked an adverse event. Mean maximum systolic blood pressure, heart rate, and rate pressure product were significantly (P < 0.001) below thresholds of the American Association of Cardiovascular and Pulmonary Rehabilitation. Two patients’ heart rates exceeded 150 beats per minute, but their rate pressure products remained below 36,000. The mean difference between DASI and ETT METs was −0.8 (−0.98, −0.65), indicating equivalence at our threshold. In conclusion, the ETT can be performed within cardiac rehabilitation, providing a functional capacity assessment equivalent to the DASI and objective physiologic measures for developing exercise prescriptions and measuring progress. PMID:23814381

  1. [Kinking of the endotracheal tube in a prone patient associated with the inadequate withdrawal maneuver of the Pentax-AWS Airway Scope].

    PubMed

    Ohata, Hiroto; Iida, Yuko; Kito, Kazuhiro; Kawamura, Michika; Yamashita, Mika; Ohta, Shuichiro; Ueda, Norio; Iida, Hiroki

    2013-06-01

    We report a case of intraoperative kinking of an endotracheal tube (ETT) in a prone patient during spine surgery. We postulate that one of the risk factors involved with kinking was the inadequate withdrawal maneuver of Pentax-AWS Airway Scope (AWS). Patient was a 69-year-old woman with hypertension, diabetes mellitus, and rheumatoid arthritis, undergoing C4-6 laminoplasty under general anesthesia in the prone position. A 7.0-mm polyvinyl endotracheal tube (Paker Flex-Tip Tube) was placed to 21 cm at the right angle of the mouse without difficulty using the AWS. Both peak inspiratory pressure (PIP) and partial pressure of end-tidal carbon dioxide began to rise gradually from 24 to 28 cmH2O and 38 to 44 mmHg, respectively. Although over 30 cmH2O in PIP repeatedly appeared after that, we did not find any remarkable change of ventilation except for weak breath sound. Thereafter, when we checked the tube with a flexible fiberoptic bronchoscope, it could not pass through the tube. At first, we asked the surgeon to release neck flexion as much as possible. This procedure could not correct the kink completely but allowed the passage of bronchoscope in the ETT. Then, we tried to reposition the ETT by inserting the bronchoscope beyond the point of kinking for maintaining luminal patency and adequate ventilation. The subsequent anesthetic course was uneventful. Kinking of the ETT in the oral cavity is an uncommon problem but we must keep in mind as one of the differential diagnoses. When using the AWS for endotracheal intubation, we recommend the confirmation of the position of the ETT to be normal in the oral cavity by direct laryngoscopy.

  2. Discovery of the ergothioneine transporter

    PubMed Central

    Gründemann, Dirk; Harlfinger, Stephanie; Golz, Stefan; Geerts, Andreas; Lazar, Andreas; Berkels, Reinhard; Jung, Norma; Rubbert, Andrea; Schömig, Edgar

    2005-01-01

    Variants of the SLC22A4 gene are associated with susceptibility to rheumatoid arthritis and Crohn's disease. SLC22A4 codes for an integral membrane protein, OCTN1, that has been presumed to carry organic cations like tetraethylammonium across the plasma membrane. Here, we show that the key substrate of this transporter is in fact ergothioneine (ET). Human OCTN1 was expressed in 293 cells. A substrate lead, stachydrine (alias proline betaine), was identified by liquid chromatography MS difference shading, a new substrate search strategy. Analysis of transport efficiency of stachydrine-related solutes, affinity, and Na+ dependence indicates that the physiological substrate is ET. Efficiency of transport of ET was as high as 195 μl per min per mg of protein. By contrast, the carnitine transporter OCTN2 from rat did not transport ET at all. Because ET is transported >100 times more efficiently than tetraethylammonium and carnitine, we propose the functional name ETT (ET transporter) instead of OCTN1. ET, all of which is absorbed from food, is an intracellular antioxidant with metal ion affinity. Its particular purpose is unresolved. Cells with expression of ETT accumulate ET to high levels and avidly retain it. By contrast, cells lacking ETT do not accumulate ET, because their plasma membrane is virtually impermeable for this compound. The real-time PCR expression profile of human ETT, with strong expression in CD71+ cells, is consistent with a pivotal function of ET in erythrocytes. Moreover, prominent expression of ETT in monocytes and SLC22A4 polymorphism associations suggest a protective role of ET in chronic inflammatory disorders. PMID:15795384

  3. Pressure attenuation during high-frequency airway clearance therapy across different size endotracheal tubes: An in vitro study.

    PubMed

    Smallwood, Craig D; Bullock, Kevin J; Gouldstone, Andrew

    2016-08-01

    High-frequency airway clearance therapy is a positive pressure secretion clearance modality used in pediatric and adult applications. However, pressure attenuation across different size endotracheal tubes (ETT) has not been adequately described. This study quantifies attenuation in an in vitro model. The MetaNeb® System was used to deliver high-frequency pressure pulses to 3.0, 4.0, 6.0 and 8.0mm ID ETTs connected to a test lung during mechanical ventilation. The experimental setup included a 3D-printed trachea model and imbedded pressure sensors. The pressure attenuation (Patt%) was calculated: Patt%=[(Pproximal-Pdistal)/Pproximal]x100. The effect of pulse frequency on Pdistal and Pproximal was quantified. Patt% was inversely and linearly related to ETT ID and (y=-7.924x+74.36; R(2)=0.9917, P=.0042 for 4.0Hz pulse frequency and y=-7.382+9.445, R(2)=0.9964, P=.0018 for 3.0Hz pulse frequency). Patt% across the 3.0, 4.0, 6.0 and 8.0mm I.D. ETTs was 48.88±10.25%, 40.87±5.22%, 27.97±5.29%, and 9.90±1.9% respectively. Selecting the 4.0Hz frequency mode demonstrated higher Pproximal and Pdistal compared to the 3.0Hz frequency mode (P=.0049 and P=.0065). Observed Pdistal was <30cmH2O for all experiments. In an in vitro model, pressure attenuation was linearly related to the inner diameter of the endotracheal tube; with decreasing attenuation as the ETT size increased. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Comparative efficiency of exercise stress testing with and without stress-only myocardial perfusion imaging in patients with low-risk chest pain.

    PubMed

    Amirian, Jossef; Javdan, Omid; Misher, Jason; Diamond, Joseph; Raio, Christopher; Rudolph, Gary; Druz, Regina S

    2017-01-12

    To compare major adverse cardiac event (MACE), downstream resource utilization, and direct cost of care for low-risk chest pain patients observed in the clinical decision unit (CDU) with exercise treadmill testing (ETT) and with stress-only myocardial perfusion imaging (sMPI). CDUs are poised to increase efficiency and resource utilization. However, the optimal testing strategy that would assure favorable outcomes while decreasing cost is not defined. 1016 subjects from 2 locations were propensity score-matched (PSM) by age, gender, pre-test likelihood, Duke treadmill score, and test results. Outcomes were length of stay >24 hours, MACE (acute coronary syndrome, revascularization, cardiac death), downstream resource use (admission for chest pain, repeat testing, angiography), and mean direct cost per patient. PSM yielded 680 patients (340 matches). 98% of all tests were normal. 96.6% of patients were discharged from the CDU within 24 hours but twice as many exceeded 24 hours in the sMPI group. There were no cardiac deaths. MACE rate was 1.47% at 72 hours and 1% at 1 year. Downstream resource use was 4.82% at 72 hours, and 7.69% at 1 year. The sMPI group was event-free longer than the ETT group reflecting less repeat testing. The mean direct cost was 30% higher for sMPI ($3168.70) vs. ETT ($2226.96). Low-risk chest pain patients in the observation unit had low MACE rate, not different for ETT vs. sMPI. The majority of ETT and sMPI tests were normal. The sMPI reduced additional testing, but resulted in greater expense and longer stay.

  5. Lipase degradation of plasticized polyvinyl chloride endotracheal tube surfaces to create nanoscale features.

    PubMed

    Machado, Mary C; Webster, Thomas J

    2017-01-01

    Polyvinyl chloride (PVC) endotracheal tubes (ETTs) nanoetched with a fungal lipase have been shown to reduce bacterial growth and biofilm formation and could be an inexpensive solution to the complex problem of ventilator-associated pneumonia (VAP). Although bacterial growth and colonization on these nanoetched materials have been well characterized, little is known about the mechanism by which the fungal lipase degrades the PVC and, thus, alters its properties to minimize bacteria functions. This study used X-ray photoelectron spectroscopy (XPS) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) to better describe the surface chemistry of both unetched and lipase nanoetched PVC ETT. ATR-FTIR analysis of the unetched and treated surfaces showed a similar presence of a plasticizer. This was confirmed by XPS analysis, which showed an increase of carbon and the presence of oxygen on both unetched and nanoetched surfaces. A quantitative comparison of the FTIR spectra revealed significant correlations (Pearson's correlation, R=0.997 [R(2)=0.994, P<0.001]) between the unetched and nanomodified PVC ETT spectra, demonstrating similar surface chemistry. This analysis showed no shifting or widening of the bands in the spectra and no significant changes in the intensity of the infrared peaks due to the degradation of the plasticizer by the fungal lipase. In contrast, results from this study did demonstrate significantly increased nanoscale surface features on the lipase etched compared to non-etched PVC ETTs. This led to a change in surface energetics, which altered ion adsorption to the ETTs. Thus, these results showed that PVC surfaces nanoetched with a 0.1% lipase solution for 48 hours have no significant change on surface chemistry but do significantly increase nanoscale surface roughness and alters ion adsorption, which suggests that the unique properties of these materials, including their previously reported ability to decrease

  6. Impact of endotracheal tube size on preextubation respiratory variables.

    PubMed

    Mehta, Sangeeta; Heffer, Matthew J; Maham, Nava; Nelson, David L; Klinger, James R; Levy, Mitchell M

    2010-09-01

    Many parameters have been evaluated to predict successful extubation. These are all affected by extrapulmonary variables. The purpose of this study was to evaluate the effect of endotracheal tube (ETT) size on preextubation predictors of successful extubation. Twenty-two intubated and mechanically ventilated subjects were recruited when ready for extubation. Subjects were ventilated with T-piece, continuous positive airway pressure (CPAP) of 5 cm H(2)O, and pressure support ventilation (PSV) of 5 cm H(2)O in randomized order for 15 minutes each. Pulmonary mechanics-including respiratory frequency (f), tidal volume (V(T)), f/V(T) ratio, negative change in esophageal pressure, pressure time product (PTP), work of breathing, and the airway occlusion pressure 100 milliseconds after the onset of inspiratory flow-were measured using a microprocessor-based monitor at the end of each interval. After extubation, measurement of pulmonary mechanics was repeated at 15 and 60 minutes. In patients with 7.0- or 7.5-mm ETT compared with patients with 8.0-mm ETT, (1) f was significantly higher during all ventilatory modes and 15 minutes after extubation; (2) V(T) during PSV and CPAP was significantly lower; (3) mean f/V(T) was significantly higher (122 ± 57 vs 69 ± 35, P = .026); and (4) PTP was significantly higher during CPAP, PSV, and 15 minutes after extubation. There was a nonsignificant trend toward increased negative change in esophageal pressure, work of breathing, and airway occlusion pressure 100 milliseconds after the onset of inspiratory flow in the smaller-ETT group. The ETT size has a significant impact on f, V(T), f/V(T) ratio, and PTP. Copyright © 2010 Elsevier Inc. All rights reserved.

  7. Exercise-induced ischemia initiates the second window of protection in humans independent of collateral recruitment.

    PubMed

    Lambiase, Pier D; Edwards, Richard J; Cusack, Michael R; Bucknall, Clifford A; Redwood, Simon R; Marber, Michael S

    2003-04-02

    This study was designed to examine if exercise-induced ischemia initiated late preconditioning in humans that becomes manifest during subsequent exercise and serial balloon occlusion of the left anterior descending coronary artery (LAD). The existence of late preconditioning in humans is controversial. We therefore compared myocardial responses to exercise-induced and intracoronary balloon inflation-induced ischemia in two groups of patients subjected to different temporal patterns of ischemia. Thirty patients with stable angina secondary to single-vessel LAD disease underwent percutaneous coronary intervention (PCI) after two separate exercise tolerance test (ETT) protocols designed to investigate isolated early preconditioning (IEP) alone or the second window of protection (SWOP). The IEP subjects underwent three sequential ETTs at least two weeks before PCI. The SWOP subjects underwent five sequential ETTs commencing 24 h before PCI. During PCI there was no significant difference in intracoronary pressure-derived collateral flow index (CFI) between groups (IEP = 0.15 +/- 0.13, SWOP = 0.19 +/- 0.15). In SWOP patients, compared with the initial ETT, the ETT performed 24 h later had a 40% (p < 0.001) increase in time to 0.1-mV ST depression and a 60% (p < 0.05) decrease in ventricular ectopic frequency. During the first balloon inflation, peak ST elevation was reduced by 49% (p < 0.05) in the SWOP versus the IEP group, and the dependence on CFI observed in the IEP group was abolished (analysis of covariance, p < 0.05). The significant attenuation of ST elevation (47%, p < 0.005) seen at the time of the second inflation in the IEP patients was not seen in the SWOP patients. Exercise-induced ischemia triggers late preconditioning in humans, which becomes manifest during exercise and PCI. This is the first evidence that ischemia induced by coronary occlusion is attenuated in humans by a late preconditioning effect induced by exercise.

  8. Exercise testing in asymptomatic gene carriers exposes a latent electrical substrate of arrhythmogenic right ventricular cardiomyopathy.

    PubMed

    Perrin, Mark J; Angaran, Paul; Laksman, Zachary; Zhang, Hanfei; Porepa, Liane F; Rutberg, Julie; James, Cynthia; Krahn, Andrew D; Judge, Daniel P; Calkins, Hugh; Gollob, Michael H

    2013-11-05

    The aim of this study was to determine if exercise testing could expose a latent electrical substrate of arrhythmogenic right ventricular cardiomyopathy (ARVC) in asymptomatic gene carriers. Management of asymptomatic ARVC gene carriers is challenging because of variable penetrance of disease and the recognition that sudden cardiac death may be the first clinical manifestation. Exercise-induced abnormalities during exercise treadmill testing (ETT) were initially compared in 60 subjects: 30 asymptomatic ARVC gene carriers and 30 healthy controls. In phase 2 of the study, ETT results of 25 patients with ARVC with histories of sustained ventricular arrhythmia or cardiac arrest were evaluated to determine if ETT abnormalities in asymptomatic gene carriers were common to patients with a malignant electrical form of the disease. Depolarization abnormalities during ETT were found to develop more frequently in asymptomatic gene carriers compared with healthy controls: epsilon waves appeared in 4 of 28 (14%) compared with 0 of 30 (0%) (p = 0.048), premature ventricular contractions in 17 of 30 (57%) compared with 3 of 30 (10%) (p = 0.0003), and new QRS terminal activation duration ≥ 55 ms in 7 of 22 (32%) compared with 2 of 29 (7%) (p = 0.03). Superior axis premature ventricular contractions occurred only in gene carriers. In the second phase of the study, the frequency of these abnormalities was found to be high in patients with symptomatic ARVC: new epsilon waves appeared in 3 of 18 (17%), superior axis premature ventricular contractions in 21 of 25 (84%), and new terminal activation duration ≥ 55 ms in 8 of 12 (67%). Exercise testing exposes a latent electrical substrate in asymptomatic ARVC gene carriers that is shared by patients with ARVC with histories of ventricular arrhythmia. ETT may be useful in guiding treatment decisions, exercise prescription, and prioritizing medical surveillance in asymptomatic ARVC gene carriers. Copyright © 2013 American College of

  9. Study of the OH and Cl-initiated oxidation, IR absorption cross-section, radiative forcing, and global warming potential of four C4-hydrofluoroethers.

    PubMed

    Oyaro, Nathan; Sellevåg, Stig R; Nielsen, Claus J

    2004-11-01

    Infrared absorption cross-sections and OH and Cl reaction rate coefficients for four C4-hydrofluoroethers (CF3)2CHOCH3, CF3CH2OCH2CF3, CF3CF2CH2OCH3, and CHF2CF2CH2OCH3 are reported. Relative rate measurements at 298 K and 1013 hPa of OH and Cl reaction rate coefficients give k(OH+(CF3)2CHOCH3) = (1.27+/-0.13) x 10(-13), k(OH+CF3CH2OCH2CF3) = (1.51+/-0.24) x 10(-13), k(OH+CF3CF2CH2OCH3) = (6.42+/-0.33) x 10(-13), k(OH+CHF2CF2CH2OCH3) = (8.7 +/-0.5) x 10(-13), k(Cl+(CF3)2CHOCH3) = (8.4+/-1.3) x 10(-12), k(Cl+CF3CH2OCH2CF3) = (6.5+/-1.7) x 10(-13), k(Cl+CF3CF2CH2OCH3) = (4.0+/-0.8) x 10(-11), and k(Cl+CHF2CF2CH2OCH3) = (2.65+/-0.17) x 10(-11) cm3 molecule(-1) s(-1). The primary products of the OH and Cl reactions with the fluorinated ethers have been identified as esters, and OH and Cl reaction rate coefficients for one of these, CF3CH2OCHO, are reported: k(OH+CF3CH2OCHO) = (7.7+/-0.9) x 10(-14) and kCl+CF3CH2OCHO) = (6.3+/-1.9) x 10(-14) cm3 molecule(-1) s(-1) The rate coefficient for the Cl-atom reaction with CHF2CH2F is derived as k(Cl+CHF2CH2F) = (3.0+/-0.9) x 10(-14) cm3 molecule(-1) s(-1) at 298 K. The error limits include 3sigma from the statistical data analyses as well as the errors in the rate coefficients of the reference compounds employed. The tropospheric lifetimes of the hydrofluoroethers are estimated to be short tauOH((CF3)2CHOCH3) approximately 100 days, tauOH(CF3CH2OCH2CF3) approximately 80 days, tauOH(CF3CF2CH2OCH3) approximately 20 days, and tauOH(CHF2CF2CH2OCH3) approximately 14 days, and their global warming potentials are small compared to CFC-11.

  10. Tetra­hydro­berberine, a pharmacologically active naturally occurring alkaloid

    PubMed Central

    Pingali, Subramanya; Donahue, James P.; Payton-Stewart, Florastina

    2015-01-01

    Tetra­hydro­berberine (systematic name: 9,10-dimeth­oxy-5,8,13,13a-tetra­hydro-6H-benzo[g][1,3]benzodioxolo[5,6-a]quinolizine), C20H21NO4, a widely distributed naturally occurring alkaloid, has been crystallized as a racemic mixture about an inversion center. A bent conformation of the mol­ecule is observed, with an angle of 24.72 (5)° between the arene rings at the two ends of the reduced quinolizinium core. The inter­molecular hydrogen bonds that play an apparent role in crystal packing are 1,3-benzodioxole –CH2⋯OCH3 and –OCH3⋯OCH3 inter­actions between neighboring mol­ecules. PMID:25836282

  11. Theoretical studies on atmospheric chemistry of HFE-245mc and perfluoro-ethyl formate: Reaction with OH radicals, atmospheric fate of alkoxy radical and global warming potential

    NASA Astrophysics Data System (ADS)

    Lily, Makroni; Baidya, Bidisha; Chandra, Asit K.

    2017-02-01

    Theoretical studies have been performed on the kinetics, mechanism and thermochemistry of the hydrogen abstraction reactions of CF3CF2OCH3 (HFE-245mc) and CF3CF2OCHO with OH radical using DFT based M06-2X method. IRC calculation shows that both hydrogen abstraction reactions proceed via weakly bound hydrogen-bonded complex preceding to the formation of transition state. The rate coefficients calculated by canonical transition state theory along with Eckart's tunnelling correction at 298 K: k1(CF3CF2OCH3 + OH) = 1.09 × 10-14 and k2(CF3CF2OCHO + OH) = 1.03 × 10-14 cm3 molecule-1 s-1 are in very good agreement with the experimental values. The atmospheric implications of CF3CF2OCH3 and CF3CF2OCHO are also discussed.

  12. Transparent Optical Protection Ring Architectures and Applications

    NASA Astrophysics Data System (ADS)

    Li, Ming-Jun; Soulliere, Mark J.; Tebben, Daniel J.; Nederlof, Leo; Vaughn, Mark D.; Wagner, Richard E.

    2005-10-01

    This paper reviews recent progress in optical protection rings with the focus on transparent optical protection rings. Different optical protection ring architectures, such as dedicated and shared protection rings, in both the optical-channel (OCh) layer and the optical multiplex section (OMS) layer, are described. In particular, OCh shared protection rings (OChSPRINGs) are discussed in detail including node-architecture designs, ring protocols, triggers, and messaging channels. Feasibility studies and experimental results from Corning Inc. and other companies are reviewed. The paper also discusses how protection-switching times scale with number of nodes and number of wavelengths, and shows examples of applications using the scaling rules for practical optical networks such as metro, regional, and long-haul ring networks. The cost benefits of transparent optical protection rings are analyzed using a typical metro network. Finally, the paper discusses remaining issues and future developments in the optical protection ring area.

  13. Tetrahydroberberine, a pharmacologically active naturally occurring alkaloid.

    PubMed

    Pingali, Subramanya; Donahue, James P; Payton-Stewart, Florastina

    2015-04-01

    Tetrahydroberberine (systematic name: 9,10-dimethoxy-5,8,13,13a-tetrahydro-6H-benzo[g][1,3]benzodioxolo[5,6-a]quinolizine), C20H21NO4, a widely distributed naturally occurring alkaloid, has been crystallized as a racemic mixture about an inversion center. A bent conformation of the molecule is observed, with an angle of 24.72 (5)° between the arene rings at the two ends of the reduced quinolizinium core. The intermolecular hydrogen bonds that play an apparent role in crystal packing are 1,3-benzodioxole -CH2···OCH3 and -OCH3···OCH3 interactions between neighboring molecules.

  14. End of Year Report for 1 October 1984 through 30 September 1985 for Contract Number N00014-84-K-0289,

    DTIC Science & Technology

    1985-09-30

    of LiBF4 and methoxyethyldimethyl ethyl ammonium fluoroborate - which may conduct by the same mechanism as Li 2 SO4 since it exhibits a strong disord...supplied by a The appropriate route to such a material evi- "sacrificial" portion of LiBF4 (previously dried with dently will involve a reduction in...Ttr/°C(A Htr)c Tm(4 Hm)C I MeOCH 2 CH 2 N EtMe 2 BF 4 -08 13(21.7) 2 MeOCH 2 CH 2 N 4 +EtMe 2 BF 4 - LiBF4 -79 -70(3.9)02(1.7) 98(5.6) 3 MeOCH2 CH2 N

  15. Tolerance of β-diketone hydrolases as representatives of the crotonase superfamily towards organic solvents.

    PubMed

    Siirola, Elina; Grischek, Barbara; Clay, Dorina; Frank, Annika; Grogan, Gideon; Kroutil, Wolfgang

    2011-12-01

    Crotonase superfamily enzymes catalyze a wide variety of reactions, including hydrolytic C-C bond cleavage in symmetrical β-diketones by 6-oxo camphor hydrolase (OCH) from Rhodococcus sp. The organic solvent tolerance and temperature stability of OCH and its structurally related ortholog Anabaena β-diketone hydrolase have been investigated. Both enzymes showed excellent tolerance toward organic solvents; for instance, even in the presence of 80% (v/v) THF or dioxane, OCH was still active. In most solvent mixtures, except methanol, the stereospecificity was conserved (>99% e.e. of product), hence neither the type of solvent nor its concentration appeared to have an effect on the stereoselectivity of the enzyme. Attempts to correlate the observed activities with log P, functional solvent group or denaturing capacity (DC) of the solvent were only successful in the case of DC for water miscible solvents. This study represents the first investigation of organic solvent stability for members of the crotonase superfamily.

  16. Temporal assessment of traumatic axonal injury in the rat corpus callosum and optic chiasm.

    PubMed

    Zakaria, Nisrine; Kallakuri, Srinivasu; Bandaru, Sharath; Cavanaugh, John M

    2012-07-27

    Impaired axoplasmic transport (IAT) and neurofilament compaction (NFC), two common axonal pathology processes involved in traumatic axonal injury (TAI), have been well characterized. TAI is found clinically and in animal models in brainstem white matter (WM) tracts and in the corpus callosum (CC), optic chiasm (Och), and internal capsule. Previous published quantitative studies of the time course of TAI expression induced by the Marmarou impact acceleration model have been limited to the brainstem. Accordingly, this study assessed the extent of IAT and NFC in the CC and Och at 8h, 28 h, 3 days and 7 days after traumatic brain injury (TBI) induction by the Marmarou impact acceleration model. IAT peak density was observed at 8h in the CC and 28 h in the Och post-TBI. NFC peak density was observed at 28 h in both structures. The density of IAT and NFC decreased with increasing survival time in both structures. The NFC density time profile followed a similar trend in both the Och and CC, whereas the IAT density time profile was variable between the Och and CC. Furthermore, a strong linear relationship was observed between IAT and NFC in the CC but not in the Och. These findings highlight the heterogeneity of TAI as evidenced by variable IAT and NFC injury time profiles in each anatomical structure. This variability indicates the requirement of multiple markers for a comprehensive TAI evaluation and multiple targeted treatments for TAI polypathology within its therapeutic window time frame. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. C---lH...O and O...H...O bonded intermediates in the dissociation of low energy methyl glycolate radical cations

    NASA Astrophysics Data System (ADS)

    Suh, Dennis; Kingsmill, Carol A.; Ruttink, Paul J. A.; Burgers, Peter C.; Terlouw, Johan K.

    1995-08-01

    Low energy methyl glycolate radical cations HOCH2C(=O)OCH3+, 1, abundantly lose HCO, yielding protonated methyl formate H---C(OH)OCH3+. Tandem mass spectrometry based experiments on 2H, 13C and 18O labelled isotopologues show that this loss is largely (about 75%) atom specific. Analysis of the atom connectivity in the product ions indicates that the reaction proceeds analogously to the loss of HCO and CH3CO from ionized acetol HOCH2C(=O)CH3+ and acetoin HOCH(CH3)C(=O)CH3+, respectively. The mechanism, it is proposed, involves isomerization of 1 to the key intermediate CH2=O... H---C(=O)OCH3+, an H-bridged ion-dipole complex of neutral formaldehyde and ionized methyl formate. Next, charge transfer takes place to produce CH3OC(H)=O...HC(H)=O+, an H-bridged ion-dipole complex of ionized formaldehyde and neutral methyl formate, followed by proton transfer to generate the products. Preliminary ab initio calculations executed at the UMP3/6-31G*//6-31G*+ZPVE level of theory are presented in support of this proposal. The non-specific loss of HCO from 1 (about 25%) is rationalized to occur via the same mechanism, but after communication with isomeric dimethyl carbonate ions CH3OC(=O)OCH3+, 2, via the O...H...O bonded intermediate [CH2=O...H...O=C---OCH3]+. The latter pathway is even more important in the formation of CH2OH+ ions from 1 which, it is shown, is not a simple bond cleavage reaction, but may involve consecutive or concerted losses of CH3 and CO2 from the above O...H...O bonded species. Ionized methyl lactate HOCH(CH3)C(=O)OCH3+, the higher homologue of 1, shows a unimolecular chemistry which is akin to that of 1.

  18. Influence of boron concentration on growth characteristic and electro-catalytic performance of boron-doped diamond electrodes prepared by direct current plasma chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Feng, Yujie; Lv, Jiangwei; Liu, Junfeng; Gao, Na; Peng, Hongyan; Chen, Yuqiang

    2011-02-01

    A series of boron-doped diamond (BDD) electrodes were prepared by direct current plasma chemical vapor deposition (DC-PCVD) with different compositions of CH4/H2/B(OCH3)3 gas mixture. A maximum growth rate of 0.65 mg cm-2 h-1 was obtained with CH4/H2/B(OCH3)3 radio of 4/190/10 and this growth condition was also a turning point for discharge plasma stability which arose from the addition of B(OCH3)3 that changed electron energy distribution and influenced the plasma reaction. The surface coating structure and electro-catalytic performance of the BDD electrodes were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, Hall test, and electrochemical measurement and electro-catalytic oxidation in phenol solution. It is suggested that the boron doping level and the thermal stress in the films are the main factors affecting the electro-catalytic characteristics of the electrodes. Low boron doping level with CH4/H2/B(OCH3)3 ratio of 4/199/1 decreased the films electrical conductivity and its electro-catalytic activity. When the carrier concentration in the films reached around 1020 cm-3 with CH4/H2/B(OCH3)3 ratio over a range of 4/195/5-4/185/15, the thermal stress in the films was the key reason that influenced the electro-catalytic activity of the electrodes for its effect on diamond lattice expansion. Therefore, the BDD electrode with modest CH4/H2/B(OCH3)3 ratio of 4/190/10 possessed the best phenol removal efficiency.

  19. Organic pollutant burden of the giant mussels Choromytilus chorus from the south-central Chilean coast.

    PubMed

    Toro, Beatriz; Palma-Fleming, Hernán; Navarro, Jorge M

    2004-04-01

    A comparative quantitative analysis was made on the contents of organochlorines (OCh) and polycyclic aromatic hydrocarbons (PAH) in tissues of the giant mussel Choromytilus chorus from three bays in south-central Chile exposed to various degrees of pollutant input. Mussels from the three bays contained levels of OCh near the detection limits of method, with a tendency to be slightly higher in the polluted bay (San Vicente) than in the other bays (Corral and Yaldad). PAH levels and types in Corral and Yaldad were well below of carcinogenicity permitted in mussels for human consumption.

  20. Nitroaliphatic difluoroformals

    DOEpatents

    Peters, Howard M.; Simon, Jr., Robert L.

    1978-01-01

    Nitroaliphatic difluoroformals of the formula RCH.sub.2 OCF.sub.2 OCH.sub.2 R' wherein R = FC(NO.sub.2).sub.2 -- and R' = F.sub.2 C(NO.sub.2)-- or CF.sub.3 --; or R = R' = CF.sub.3 OCH.sub.2 C(NO.sub.2).sub.2 --. The compounds are prepared in accordance with the following reaction: ##STR1## carried out at temperatures of from about 95.degree. C to about 150.degree. C. The compounds are especially useful as energetic plasticizers in explosive compositions.

  1. A rare tetranuclear thorium(IV) μ4 -oxo cluster and dinuclear thorium(IV) complex assembled by carbon-oxygen bond activation of 1,2-dimethoxyethane (DME).

    PubMed

    Travia, Nicholas E; Scott, Brian L; Kiplinger, Jaqueline L

    2014-12-15

    The synthesis and X-ray crystal structure of two new multinuclear thorium complexes are reported. The tetranuclear μ4 -oxo cluster complex Th4 (μ4 -O)(μ-Cl)2 I6 [κ(2) (O,O')-μ-O(CH2 )2 OCH3 ]6 and the dinuclear complex Th2 I5 [κ(2) (O,O')-μ-O(CH2 )2 OCH3 ]3 (DME) (DME=dimethoxyethane) are formed by CO bond activation of 1,2-dimethoxyethane (DME) mediated by thorium iodide complexes.

  2. Spectroscopic characterization of the complex between water and the simplest Criegee intermediate CH2OO.

    PubMed

    Nakajima, Masakazu; Endo, Yasuki

    2014-04-07

    The hydrogen-bonded complex between water and the simplest Criegee intermediate CH2OO was detected by Fourier-transform microwave spectroscopy under a jet-cooled condition. Both a-type and b-type rotational transitions were observed for H2O-CH2OO and D2O-CH2OO. The determined rotational constants enable us to conclude that the complex has an almost planar ring structure with the terminal oxygen atom of CH2OO being a strong proton acceptor.

  3. Spectroscopic characterization of the complex between water and the simplest Criegee intermediate CH2OO

    NASA Astrophysics Data System (ADS)

    Nakajima, Masakazu; Endo, Yasuki

    2014-04-01

    The hydrogen-bonded complex between water and the simplest Criegee intermediate CH2OO was detected by Fourier-transform microwave spectroscopy under a jet-cooled condition. Both a-type and b-type rotational transitions were observed for H2O-CH2OO and D2O-CH2OO. The determined rotational constants enable us to conclude that the complex has an almost planar ring structure with the terminal oxygen atom of CH2OO being a strong proton acceptor.

  4. Stabile Radikalanionen von Aromaten: Strahlenchemische Erzeugung in Gegenwart von Natrium-dihydridobis( 2-methoxyethoxy) aluminat

    NASA Astrophysics Data System (ADS)

    Getoff, Nikola; Haenel, Matthias W.; Hildenbrand, Knut; Richter, Udo-Burckhard; Solar, Sonja

    1990-02-01

    Arenes are reduced at room temperature to their very long-lived radical anions by exposing the solution of the arene and NaAlH2(OCH2CH2OCH3 )2 (1) in dimethoxyethane (DME) to an ionizing radiation (electrons, gamma- or X-rays) for few minutes: Thereby 1 is acting as a scavenger for the solvent counter ions which are produced concomitantly to solvated electrons by the radiolysis. The method is very convenient for the ESR and UV-VIS spectroscopy of aromatic radical anions.

  5. Analysis of torsional spectra of molecules with two internal C3v rotors. II - Far infrared and low frequency Raman spectra of dimethylether isotopes

    NASA Technical Reports Server (NTRS)

    Groner, P.; Durig, J. R.

    1977-01-01

    The torsional far infrared and Raman spectra of gaseous CH3OCH3, CD3OCH3, and CD3OCD3 are presented. They are analyzed using a computer program which is based on the results of an extensive investigation of the isometric groups and of the symmetry groups of the rotation-internal rotation Hamiltonians of a series of semirigid two-top models. Four or more Fourier coefficients of the potential functions in two variables could be determined for each isotope. Strong evidence was found for Fermi-resonance-type interactions with the COC bending mode.

  6. Microbial Antimony Biogeochemistry: Enzymes, Regulation, and Related Metabolic Pathways

    PubMed Central

    Li, Jingxin; Wang, Qian; Oremland, Ronald S.; Kulp, Thomas R.; Rensing, Christopher

    2016-01-01

    Antimony (Sb) is a toxic metalloid that occurs widely at trace concentrations in soil, aquatic systems, and the atmosphere. Nowadays, with the development of its new industrial applications and the corresponding expansion of antimony mining activities, the phenomenon of antimony pollution has become an increasingly serious concern. In recent years, research interest in Sb has been growing and reflects a fundamental scientific concern regarding Sb in the environment. In this review, we summarize the recent research on bacterial antimony transformations, especially those regarding antimony uptake, efflux, antimonite oxidation, and antimonate reduction. We conclude that our current understanding of antimony biochemistry and biogeochemistry is roughly equivalent to where that of arsenic was some 20 years ago. This portends the possibility of future discoveries with regard to the ability of microorganisms to conserve energy for their growth from antimony redox reactions and the isolation of new species of “antimonotrophs.” PMID:27342551

  7. Antimony uptake by Zea mays (L.) and Helianthus annuus (L.) from nutrient solution.

    PubMed

    Tschan, Martin; Robinson, Brett; Schulin, Rainer

    2008-04-01

    We investigated the extent of Sb uptake by maize (Zea mays) and sunflower (Helianthus annuus) from nutrient solutions containing concentrations from 3 to 24 mg/L of potassium antimonate, with the aim of determining the potential of Sb to enter the food chain. The maximum shoot Sb concentrations in Z. mays and H. annuus were 41 mg/kg and 77 mg/kg dry weight, respectively. There was no significant difference in Sb uptake between species. The average bioaccumulation coefficients (the plant/solution concentration quotients) were 1.02 and 1.93 for Z. mays and H. annuus, respectively. Phosphate addition did not affect plant growth or Sb uptake. Antimony uptake by both Z. mays and H. annuus is unlikely to pose a health risk to animals and humans.

  8. Microbial antimony biogeochemistry: Enzymes, regulation, and related metabolic pathways

    USGS Publications Warehouse

    Li, Jingxin; Qian Wang,; Oremland, Ronald S.; Kulp, Thomas R.; Rensing, Christopher; Wang, Gejiao

    2016-01-01

    Antimony (Sb) is a toxic metalloid that occurs widely at trace concentrations in soil, aquatic systems, and the atmosphere. Nowadays, with the development of its new industrial applications and the corresponding expansion of antimony mining activities, the phenomenon of antimony pollution has become an increasingly serious concern. In recent years, research interest in Sb has been growing and reflects a fundamental scientific concern regarding Sb in the environment. In this review, we summarize the recent research on bacterial antimony transformations, especially those regarding antimony uptake, efflux, antimonite oxidation, and antimonate reduction. We conclude that our current understanding of antimony biochemistry and biogeochemistry is roughly equivalent to where that of arsenic was some 20 years ago. This portends the possibility of future discoveries with regard to the ability of microorganisms to conserve energy for their growth from antimony redox reactions and the isolation of new species of “antimonotrophs.”

  9. Effect of heat shock on ultrastructure and calcium distribution in Lavandula pinnata L. glandular trichomes.

    PubMed

    Huang, S S; Kirchoff, B K; Liao, J P

    2013-02-01

    The effects of heat shock (HS) on the ultrastructure and calcium distribution of Lavandula pinnata secretory trichomes are examined using transmission electron microscopy and potassium antimonate precipitation. After 48-h HS at 40°C, plastids become distorted and lack stroma and osmiophilic deposits, the cristae of the mitochondria become indistinct, the endoplasmic reticulum acquires a chain-like appearance with ribosomes prominently attached to the lamellae, and the plasma and organelle membranes become distorted. Heat shock is associated with a decrease in calcium precipitates in the trichomes, while the number of precipitates increases in the mesophyll cells. Prolonged exposure to elevated calcium levels may be toxic to the mesophyll cells, while the lack of calcium in the glands cell may deprive them of the normal protective advantages of elevated calcium levels. The inequality in calcium distribution may result not only from uptake from the transpiration stream, but also from redistribution of calcium from the trichomes to the mesophyll cells.

  10. Efficacy of the treatment of dogs with leishmaniosis with a combination of metronidazole and spiramycin.

    PubMed

    Pennisi, M G; De Majo, M; Masucci, M; Britti, D; Vitale, F; Del Maso, R

    2005-03-12

    Twenty-seven dogs infected naturally with Leishmania infantum were used in a randomised controlled trial to compare the clinical and parasitological efficacy of an oral treatment with a combination of metronidazole and spiramycin (13 dogs) with the efficacy of conventional treatment with meglumine antimonate and allopurinol (14 dogs) as controls. In the test group one dog had to be withdrawn from the treatment because it developed pemphigus foliaceus; 10 of the dogs were clinically responsive but none was cured parasitologically. In the control group four dogs were withdrawn from the treatment because of side effects; eight of the dogs were clinically responsive but none was cured parasitologically. The control group showed signs of improvement after an average of 30 days, whereas the test group did not show signs of improvement until after an average of 45 days.

  11. THE INTRACELLULAR LOCALIZATION OF INORGANIC CATIONS WITH POTASSIUM PYROANTIMONATE

    PubMed Central

    Tandler, Carlos J.; Libanati, César M.; Sanchis, Carlos A.

    1970-01-01

    Potassium pyroantimonate, when used as fixative (saturated or half-saturated, without addition of any conventional fixative) has been demonstrated to produce intracellular precipitates of the insoluble salts of calcium, magnesium, and sodium and to preserve the general cell morphology. In both animal and plant tissues, the electron-opaque antimonate precipitates were found deposited in the nucleus—as well as within the nucleolus—and in the cytoplasm, largely at the site of the ribonucleoprotein particles; the condensed chromatin appeared relatively free of precipitates. The inorganic cations are probably in a loosely bound state since they are not retained by conventional fixatives. The implications of this inorganic cation distribution in the intact cell are discussed in connection with their anionic counterparts, i.e., complexing of cations by fixed anionic charges and the coexistence of a large pool of inorganic orthophosphate anions in the nucleus and nucleolus. PMID:4935442

  12. Study of haemostatic disorders in experimentally induced leishmaniasis in Beagle dogs.

    PubMed

    Valladares, J E; Ruiz De Gopegui, R; Riera, C; Alberola, J; Gállego, M; Espada, Y; Portús, M; Arboix, M

    1998-01-01

    Haemostatic alterations in dogs experimentally infected with Leishmania infantum were studied before and after therapy with meglumine antimonate. Haemostatic function tests including platelet count, collagen-induced platelet aggregation, prothrombin time, activated partial thromboplastin time, thrombin time, plasma fibrinogen determination, and serum fibrinogen/fibrin degradation products concentration were performed. In the course of infection and before treatment, moderate thrombocytopenia (P<0.00001), decreased collagen induced platelet aggregation (P=0.0003), prolonged thrombin time (P=0.0117) and increased fibrinogen/fibrin degradation products were observed. Statistically significant differences of plasma fibrinogen concentration, prothrombin time, and activated partial thromboplastin time were not encountered. Haemostatic parameters returned to normal values after therapy. The results indicate that Leishmania infection may impair haemostasis suggesting induction of disseminated intravascular coagulation (DIC), and that treating dogs in an early stage of infection may potentially avoid the possibility of developing an uncompensated DIC.

  13. Light-addressable electrode with hydrogenated amorphous silicon and low-conductive passivation layer for stimulation of cultured neurons

    NASA Astrophysics Data System (ADS)

    Suzurikawa, Jun; Takahashi, Hirokazu; Kanzaki, Ryohei; Nakao, Masayuki; Takayama, Yuzo; Jimbo, Yasuhiko

    2007-02-01

    The authors propose a light-addressable planar electrode with a simple three-layer laminated structure that can induce pinpoint neuronal activation on the culture substrate. The structure consists of a tin oxide (SnO2), hydrogenated amorphous silicon (a-Si:H), and passivation layer. The passivation layer was a spin-coated low-conductive zinc antimonate (ZnOSb2O5)-dispersed epoxy, which was proved to be effective for preventing penetration of culture medium and thus avoiding deterioration of a-Si :H layer. Illumination to the electrode locally elevated the conductivity with 60-fold stimulus charge density. The fluo-4 calcium imaging of neurons cultured on the developed electrode showed that the neuronal activation was confined around the illuminated location, thus demonstrating the light-addressing capability of the proposed electrode.

  14. Correlation between structure of polyoxotungstates and their inhibitory activity on polymerases.

    PubMed

    Herve, M; Sinoussi-Barre, F; Chermann, J C; Herve, G; Jasmin, C

    1983-10-14

    The 21-tungsto-9-antimonate (TA, HPA 23), a polyoxotungstate, has shown a significant antiviral activity in vivo and in vitro. It inhibits viral and bacterial DNA polymerases. In this paper, several compounds of two polyoxotungstic families, tungstoantimonates and tungstoarsenates, have been used to specify the mechanism of polymerase inhibition. It has been demonstrated that the inhibitory activity of polyoxotungstates is not related to the occupation of their coordinates sites by cations, nor to the nature of these bound cations. Kinetic studies and binding assays have shown that polyoxotungstates bind to the polymerases in competition with the nucleic acid template. This result seems to be related to their polyanionic nature. Furthermore, the size and charge of these compounds may play a prominent part in their affinity for the polymerases.

  15. Is Neuromuscular Blocker Necessary in Pediatric Patients Undergoing Laparoscopic Inguinal Hernia Repair with Percutaneous Internal Ring Suturing?

    PubMed

    Ahiskalioglu, Ali; İnce, İlker; Ahiskalioglu, Elif Oral; Oral, Akgun; Aksoy, Mehmet; Yiğiter, Murat; Celikkaya, Mehmet Emin; Salman, Ahmet Bedii

    2017-06-01

    Purpose The aim of this study is to evaluate operating conditions during general anesthesia with or without neuromuscular blocker (NMB) in patients undergoing percutaneous internal ring suturing (PIRS). Materials and Methods In this study, 40 patients, with American Society of Anesthesiologists I and II between the ages of 1 and 12 years, were randomly assigned to two groups to receive muscle relaxant with endotracheal tube (ETT) (ETT group) or without muscle relaxant with supreme laryngeal mask airway (sLMA) (LMA group). Anesthesia was maintained with sevoflurane in oxygen (Fio 2 0.3-0.5), thiopental sodium, fentanyl, and rocuronium in ETT group. In LMA group, same protocol was used without rocuronium. Heart rate, blood pressure, peak airway pressure, end-tidal carbon dioxide (EtCO2), and Spo 2 were recorded before and during pneumoperitoneum maintained at a pressure of 8 to 10 mm Hg. Duration of surgery, recovery time, anesthetic time, and grade of quality view were also recorded. Airway problems (cough, hoarseness, laryngospasm, and aspiration) were recorded. Results In LMA group, there was a statistically significant reduction in recovery time versus ETT group (11.6 ± 4.08 vs. 17.15 ± 5.32 minutes; p = 0,001). There were no statistically significant differences grade of quality view between the two groups (p = 0.548). There were no statistically significant differences in oxygen saturation (Spo 2), peak airway pressure, and EtCO2 between the two groups before or during insufflation (p > 0.05). Postoperative airway complications were significantly more prevalent in the ETT group. There was no case of inadequate ventilation, regurgitation, or aspiration recorded. Conclusion sLMA is safe and suitable alternative to ETT and NMB is not necessary in general anesthesia with sLMA, pediatric patients undergoing laparoscopic hernia repair with PIRS. Georg Thieme Verlag KG Stuttgart · New York.

  16. Effects of intrapulmonary percussive ventilation on airway mucus clearance: A bench model

    PubMed Central

    Fernandez-Restrepo, Lorena; Shaffer, Lauren; Amalakuhan, Bravein; Restrepo, Marcos I; Peters, Jay; Restrepo, Ruben

    2017-01-01

    AIM To determine the ability of intrapulmonary percussive ventilation (IPV) to promote airway clearance in spontaneously breathing patients and those on mechanical ventilation. METHODS An artificial lung was used to simulate a spontaneously breathing patient (Group 1), and was then connected to a mechanical ventilator to simulate a patient on mechanical ventilation (Group 2). An 8.5 mm endotracheal tube (ETT) connected to the test lung, simulated the patient airway. Artificial mucus was instilled into the mid-portion of the ETT. A filter was attached at both ends of the ETT to collect the mucus displaced proximally (mouth-piece filter) and distally (lung filter). The IPV machine was attached to the proximal end of the ETT and was applied for 10-min each to Group 1 and 2. After each experiment, the weight of the various circuit components were determined and compared to their dry weights to calculate the weight of the displaced mucus. RESULTS In Group 1 (spontaneously breathing model), 26.8% ± 3.1% of the simulated mucus was displaced proximally, compared to 0% in Group 2 (the mechanically ventilated model) with a P-value of < 0.01. In fact, 17% ± 1.5% of the mucus in Group 2 remained in the mid-portion of the ETT where it was initially instilled and 80% ± 4.2% was displaced distally back towards the lung (P < 0.01). There was an overall statistically significant amount of mucus movement proximally towards the mouth-piece in the spontaneously breathing (SB) patient. There was also an overall statistically significant amount of mucus movement distally back towards the lung in the mechanically ventilated (MV) model. In the mechanically ventilated model, no mucus was observed to move towards the proximal/mouth piece section of the ETT. CONCLUSION This bench model suggests that IPV is associated with displacement of mucus towards the proximal mouthpiece in the SB patient, and distally in the MV model. PMID:28828301

  17. [A new bite block also serving as an endotracheal tube holder for infants].

    PubMed

    Kitamura, S; Fukumitsu, K; Taniguchi, A; Kinouchi, K; Tamai, H

    1999-08-01

    We developed a new type of bite block with a combined function as an endotracheal tube (ETT) holder for infants and small children to prevent airway troubles caused by tube kinking, dislodging, extubation and oral membrane trauma. One mm thick plastic plate sized 3.5 x 2 cm was curved to make an open roll. The outer surface of the roll was covered and glued with soft plastic tube (5.0 mm ID endotracheal tube), cut in 3.5 cm length to give an elastic outer surface for the patient's comfort. The rolled ends were diagonally cut to make an oblique slit of 3 mm width. A t-shaped flange made of soft vinyl plate was fixed at a third of the length of the roll to maintain the block's position relative to the lips and to make the fixation of the tube easier. In practical use, after endotracheal intubation is performed as usual, this bite block is put into the mouth and positioned at the oral angle with the flange on the patient's skin. The ETT is fit into the slit of the roll. The skin-facing surface of the flange is pasted to the skin with the double stick material usually used for colostomy stoma. The ETT and the bite block are fixed en bloc with fixing tapes around the mouth. Our bite block has following advantages over other types of bite blocks and tube holders especially for children; 1) the volume of foreign bodies (ETT and bite block) occupying the oral cavity can be reduced and this attenuates the patient's discomfort, 2) good holding of the ETT can prevent its dislodging and decrease the incidence of accidental extubation and 3) suctioning is easier because of wide oral space. The four sizes of the bite block suitable for 4.0, 4.5, 5.0, 5.5 and 6.0 mm ID ETTs are manufactured. We applied this device to several ICU patients and found its use practical and safe.

  18. Clinical value and severity of myocardial perfusion defects in asymptomatic diabetic patients with negative or weakly positive exercise treadmill test

    PubMed Central

    Zakavi, Seyed Rasoul; Taherpour, Mehdi; Moossavi, Zohreh; Sadeghi, Ramin; Kakhki, Vahidreza Dabbagh; Rokni, Haleh

    2013-01-01

    Objective: Although coronary artery disease (CAD) is the leading cause of death in type 2 diabetic patients, it is frequently asymptomatic. Myocardial perfusion imaging (MPI) is reported to show ischemia in a significant number of asymptomatic diabetic patients. We studied the prevalence and severity of myocardial perfusion defects in asymptomatic diabetic patients and its clinical impact. Methods and patients: One hundred thirty consecutive asymptomatic patients, aged 35-65 years with type 2 diabetes mellitus and with no history of CAD and no cardiac symptoms were recruited in the study. Echocardiography, electrocardiography (ECG), routine laboratory tests and exercise treadmill test (ETT) were performed and patients with weakly positive or negative ETT underwent Dipyridamole MPI. Patients with positive ETT were referred to coronary angiography. Patients were followed for at least 17 months (mean 21.7 months) and any cardiac event was recorded. Results: We studied 81 female and 49 male patients with mean age of 51.8 years. Negative, weakly positive and positive ETT result was noted in 74.3%, 15% and 10.7% respectively. 75% of patients with positive ETT had coronary artery disease in angiography. Gated myocardial perfusion SPECT was done in 106 patients. MPI showed reversible defect in 26.9% of the patients with a mean summed stress score of 3.3±1.8. Follow up completed in 112 patients and only one patient with abnormal MPI underwent coronary angiography followed by PTCA. No cardiac death, MI, UA or hospital admission occurred among our patients during follow up (17-26 months). Mean stress end diastolic volume (EDV) was significantly higher in patients with reversible defect compared to patients without reversible defect based on MPI findings (62.0±31.6 Vs 48.5±18.4 ml, P=0.04). Blood glucose and HbA1c were significantly higher in patients with ischemia compared to patients without ischemia (P<0.05). Meanwhile the ratio of TG to HDL was 6.06±3.2 in ischemic

  19. In vivo efficacy of oral and intralesional administration of 2-substituted quinolines in experimental treatment of new world cutaneous leishmaniasis caused by Leishmania amazonensis.

    PubMed Central

    Fournet, A; Ferreira, M E; Rojas De Arias, A; Torres De Ortiz, S; Fuentes, S; Nakayama, H; Schinini, A; Hocquemiller, R

    1996-01-01

    The antileishmanial efficacies of 2-n-propylquinoline, chimanines B and D, 2-n-pentylquinoline, 2-phenylquinoline, 2-(3,4-methylenedioxyphenylethyl) quinoline, and two total alkaloidal extracts of Galipea longiflora were evaluated in BALB/c mice infected with Leishmania amazonensis or Leishmania venezuelensis. Animals were treated for 4 to 6 weeks postinfection with a quinoline by the oral route at 50 mg/kg of body weight twice daily for 15 days or by five intralesional injections at intervals of 4 days with a quinoline at 50 mg/kg of body weight. The reference drug, N-methylglucamine antimonate (Glucantime), was administered by subcutaneous or intralesional injection (regimens of 14, 28, or 56 mg of pentavalent antimony [Sbv] per kg of body weight daily). Twice-daily oral treatment with chimanine B at 50 mg/kg resulted in a decrease in lesion weight by 70% (P < 0.001) and a decrease in the parasite loads by 95% (P < 0.001). Five injections of chimanine B at intervals of 4 days reduced the lesion weight by 74% and the parasite loads in the lesion by 90% compared with the values for the group of untreated mice. Subcutaneous administration of N-methylglucamine antimonate at 28 mg of Sbv kg per day for 15 days reduced the parasite burden by 95% (P < 0.001), and five intralesional injections at the same concentration reduced the parasite burden by 96% (P < 0.001). Other 2-substituted quinolines, 2-n-propylquinoline administered by the oral and intralesional routes, 2-phenylquinoline administered by the oral route, 2-n-pentylquinoline administered by intralesional injection, and two total alkaloidal extracts of G. longiflora administered by the oral route, had intermediate effects. These findings suggest that chimanine B may be chosen as a lead molecule in the development of oral therapy against leishmaniasis. PMID:8913444

  20. Oral capillary hemangioma: a clinical protocol of diagnosis and treatment in adults.

    PubMed

    da Silva, Walessa Brasil; Ribeiro, André Luis Ribeiro; de Menezes, Sílvio Augusto Fernandes; de Jesus Viana Pinheiro, João; de Melo Alves-Junior, Sérgio

    2014-12-01

    Hemangiomas are benign vascular anomalies characterized by benign proliferation of blood vessels. There are no well-defined criteria for the diagnosis and treatment of oral capillary hemangioma (OCH). The objective of this study is to report a safe, effective, and low-cost protocol for diagnosis and treatment of OCH. Eight patients were diagnosed with OCH, through two physical examination maneuvers-the diascopy and head lowering maneuver with abdominal compression (HLMAC). The treatment performed was sclerotherapy with ethanolamine oleate, weekly, until the disappearance of the lesion. No local anesthetics were administered prior to the sclerosing agent injection. All cases showed a complete remission of the lesions after sclerotherapy. There were no visible scars or compromise esthetics or normal function, and there was no evidence of recurrence. Only one patient had superficial ulceration, which remained asymptomatic and healed without specific treatment. This protocol was effective in the diagnosis of OCH through two physical examination maneuvers with low-cost and easy implementation, the diascopy and the HLMAC. The low concentration associated with a reduced amount of the sclerosing agent was responsible for the excellent results in the cases treated.

  1. Adolescent Tobacco and Cannabis Use: Young Adult Outcomes from the Ontario Child Health Study

    ERIC Educational Resources Information Center

    Georgiades, Katholiki; Boyle, Michael H.

    2007-01-01

    Background: This study examines the longitudinal associations between adolescent tobacco and cannabis use and young adult functioning. Methods: Data for analysis come from the Ontario Child Health Study (OCHS), a prospective study of child health, psychiatric disorder and adolescent substance use in a general population sample that began in 1983,…

  2. Peer Socialization into Gendered L2 Mandarin Practices in a Study Abroad Context: Talk in the Dorm

    ERIC Educational Resources Information Center

    Diao, Wenhao

    2016-01-01

    This article reports on the peer socialization of gendered Mandarin practices between three American students and their Chinese roommates in a college dorm in China. Gender is often perceived to be a salient identity category among adult L2 learners overseas. Drawing on the language socialization framework (Ochs and Schieffelin 1984), this study…

  3. Co-Construction in Korean Interaction

    ERIC Educational Resources Information Center

    Ju, Hee

    2011-01-01

    This dissertation explores co-construction of a situated activity in a current unit by mainly focusing on hearers' actions. The "co-construction" involves a process of interaction in which speakers and hearers jointly construct the form and the meaning of ongoing utterances even when they disagree with each other (Jacoby & Ochs,…

  4. A Voyage through the Radio Universe

    ERIC Educational Resources Information Center

    Spuck, Timothy

    2004-01-01

    Each year, professionals and amateurs alike make significant contributions to the field of astronomy. High school students can also conduct astronomy research. Since 1992, the Radio Astronomy Research Team from Oil City Area Senior High School (OCHS) in Oil City, Pennsylvania, has traveled each year to the National Radio Astronomy Observatory…

  5. Parental Expectations of the Swedish Municipal School of Arts

    ERIC Educational Resources Information Center

    Lilliedahl, Jonathan; Georgii-Hemming, Eva

    2009-01-01

    This article draws on a study designed to analyse parental expectations of the Swedish municipal school of arts (hereafter MSA) (in Swedish: kommunal musik- och kulturskola). The study is based on in-depth interviews conducted and informed by grounded theory. Although parental expectations are scarcely uniform, the study reveals a hope that the…

  6. Social Networking in an Intensive English Program Classroom: A Language Socialization Perspective

    ERIC Educational Resources Information Center

    Reinhardt, Jonathon; Zander, Victoria

    2011-01-01

    This ongoing project seeks to investigate the impact, inside and outside of class, of instruction focused on developing learner awareness of social-networking site (SNS) use in an American Intensive English Program (IEP). With language socialization as an interpretative framework (Duff, in press; Ochs, 1988; Watson-Gegeo, 2004), the project uses a…

  7. Debate on the Draft--Helping Students Decide Where They Stand.

    ERIC Educational Resources Information Center

    Victory, James

    1981-01-01

    Presents four exercises to help secondary school social studies students understand the complex issues of the draft. Students participate in a mock draft lottery, analyze Phil Och's Draft Dodger Rag, examine how individual experiences affect attitudes, and compare writings by Bill Mauldin and Ron Kovic. (KC)

  8. Socialising ESL Students into the Discourse of School Science through Academic Writing

    ERIC Educational Resources Information Center

    Huang, Jingzi

    2004-01-01

    This paper takes the view of "language socialization" (Schieffelin & Ochs, 1986) to examine, through a case study of a secondary ESL science class, the instructional process that aims at facilitating the integration of specific science content learning and the construction of a particular kind of written discourse typically found in school…

  9. The Spoken Self: An Ethnographic Exploration of Accent and Identity

    ERIC Educational Resources Information Center

    Rehn, Stefanie

    2010-01-01

    This study examines the relationship between accent and identity in three Chinese graduate students attending a large research-one university in the northeastern United States. The study is based on Och's (1993) concept if identity as jointly constructed by the individual herself and the persons and conventions of her culture. It also examines the…

  10. Social Networking in an Intensive English Program Classroom: A Language Socialization Perspective

    ERIC Educational Resources Information Center

    Reinhardt, Jonathon; Zander, Victoria

    2011-01-01

    This ongoing project seeks to investigate the impact, inside and outside of class, of instruction focused on developing learner awareness of social-networking site (SNS) use in an American Intensive English Program (IEP). With language socialization as an interpretative framework (Duff, in press; Ochs, 1988; Watson-Gegeo, 2004), the project uses a…

  11. Schools Reaching Out: An Introduction.

    ERIC Educational Resources Information Center

    Heleen, Owen

    1990-01-01

    Introduces an issue devoted to the Schools Reaching Out projects at David A. Ellis School in Roxbury (MA) and Adolph S. Ochs School in New York City. Projects attempt to link the schools with parents and their communities to promote the students' academic and social success. (DM)

  12. Legitimate Peripheral Participation and Language Learning: Two Quichua Learners in a Transnational Community

    ERIC Educational Resources Information Center

    Back, Michele

    2011-01-01

    Using data from a multisited ethnography of Ecuadorian transnational musicians, I applied Lave and Wenger's (1991) concept of legitimate peripheral participation and Jacoby and Ochs's (1995) notion of co-construction to examine two musicians' attempts to learn Quichua, an Ecuadorian indigenous language. Through an analysis aided by constructivist…

  13. Is the σ(600) a glueball? Two photon reactions can tell us

    NASA Astrophysics Data System (ADS)

    Pennington, M. R.

    2001-08-01

    Minkowski and Ochs have recently argued that the small two photon coupling of a conjectured σ(600) is so small that it is likely to be a glueball. We ask whether this can be so or whether it is simply gauge invariance that produces the observed low mass suppression?

  14. Synthesis, antityrosinase activity of curcumin analogues, and crystal structure of (1 E,4 E)-1,5-bis(4-ethoxyphenyl)penta-1,4-dien-3-one

    NASA Astrophysics Data System (ADS)

    Chantrapromma, S.; Ruanwas, P.; Boonnak, N.; Chantrapromma, K.; Fun, H.-K.

    2016-12-01

    Five derivatives of curcumin analogue ( R = OCH2CH3 ( 1), R = N(CH3)2 ( 2), R = 2,4,5-OCH3 ( 3), R = 2,4,6-OCH3 ( 4), and R = 3,4,5-OCH3 ( 5)) were synthesized and characterized by 1H NMR, FT-IR and UV-Vis spectroscopy. The synthesized derivatives were screened for antityrosinase activity, and found that 4 and 5 possess such activity. The crystal structure of 1 was determined by single crystal X-ray diffraction: monoclinic, sp. gr. P21/ c, a = 17.5728(15) Å, b = 5.9121(5) Å, c = 19.8269(13) Å, β = 121.155(5)°, Z = 4. The molecule 1 is twisted with the dihedral angle between two phenyl rings being 15.68(10)°. In the crystal packing, the molecules 1 are linked into chains by C-H···π interactions and further stacked by π···π interactions with the centroid-centroid distance of 3.9311(13) Å.

  15. Electron impact cross sections for surrogates of DNA sugar phosphate backbone

    NASA Astrophysics Data System (ADS)

    Bhowmik, Pooja; Joshipura, K. N.; Pandya, Siddharth

    2012-11-01

    Ionization and elastic cross sections by electron impact on H3PO4 and OP(OCH3)3 which are substitutes for the components of DNA phosphate group. We have employed the Complex Scattering Potential-ionization contribution (CSP-ic) formalism to calculate the cross sections in the energy range from ionization threshold to 2000 eV.

  16. Effects of Rho1, a small GTPase on the production of recombinant glycoproteins in Saccharomyces cerevisiae.

    PubMed

    Xu, Sha; Zhang, Ge-Yuan; Zhang, Huijie; Kitajima, Toshihiko; Nakanishi, Hideki; Gao, Xiao-Dong

    2016-10-21

    To humanize yeast N-glycosylation pathways, genes involved in yeast specific hyper-mannosylation must be disrupted followed by the introduction of genes catalyzing the synthesis, transport, and addition of human sugars. However, deletion of these genes, for instance, OCH1, which initiates hyper-mannosylation, could cause severe defects in cell growth, morphogenesis and response to environmental challenges. In this study, overexpression of RHO1, which encodes the Rho1p small GTPase, is confirmed to partially recover the growth defect of Saccharomyces cerevisiae Δalg3Δoch1 double mutant strain. In addition, transmission electron micrographs indicated that the cell wall structure of RHO1-expressed cells have an enhanced glucan layer and also a recovered mannoprotein layer, revealing the effect of Rho1p GTPase on cell wall biosynthesis. Similar complementation phenotypes have been confirmed by overexpression of the gene that encodes Fks2 protein, a catalytic subunit of a 1,3-β-glucan synthase. Besides the recovery of cell wall structure, the RHO1-overexpressed Δalg3Δoch1 strain also showed improved abilities in temperature tolerance, osmotic potential and drug sensitivity, which were not observed in the Δalg3Δoch1-FKS2 cells. Moreover, RHO1 overexpression could also increase N-glycan site occupancy and the amount of secreted glycoproteins. Overexpression of RHO1 in 'humanized' glycoprotein producing yeasts could significantly facilitate its future industrial applications for the production of therapeutic glycoproteins.

  17. The Brief Child and Family Phone Interview (BCFPI): 1. Rationale, Development, and Description of a Computerized Children's Mental Health Intake and Outcome Assessment Tool

    ERIC Educational Resources Information Center

    Cunningham, Charles E.; Boyle, Michael H.; Hong, Sunjin; Pettingill, Peter; Bohaychuk, Donna

    2009-01-01

    Background: This study describes the development of the Brief Child and Family Phone Interview (BCFPI)--a computer-assisted telephone interview which adapts the revised Ontario Child Health Study's (OCHS-R) parent, teacher, and youth self-report scales for administration as intake screening and treatment outcome measures in children's mental…

  18. Polymerizable 2(2-hydroxynaphthyl)2H-benzotriazole compounds

    DOEpatents

    Gomez, Peter M.; Neidlinger, Hermann H.

    1991-01-01

    Benzotriazole compounds having the formula: ##STR1## wherein R.sub.1 is H, Cl, or OCH.sub.3 ; R.sub.2 is a hydroxynaphthyl group; and R.sub.3 is a vinyl unsaturated polymerizable group. Homopolymers or copolymers thereof are effective as UV light stabilizers and absorbers.

  19. Polymerizable 2(2-hydroxynaphthyl)2H-benzotriazole compounds

    DOEpatents

    Gomez, P.M.; Neidlinger, H.H.

    1991-07-16

    Benzotriazole compounds having the formula: ##STR1## wherein R.sub.1 is H, Cl, or OCH.sub.3 ; R.sub.2 is a hydroxynaphthyl group; and R.sub.3 is a vinyl unsaturated polymerizable group. Homopolymers or copolymers thereof are effective as UV light stabilizers and absorbers.

  20. Thermodynamic Properties of Carbosilane Dendrimers of the Sixth Generation with Ethylene Oxide Terminal Groups.

    PubMed

    Sologubov, Semen S; Markin, Alexey V; Smirnova, Natalia N; Novozhilova, Natalia A; Tatarinova, Elena A; Muzafarov, Aziz M

    2015-11-12

    The temperature dependences of heat capacities of carbosilane dendrimers of the sixth generation with ethyleneoxide terminal groups, denoted as G6[(OCH2CH2)1OCH3]256 and G6[(OCH2CH2)3OCH3]256, were measured in the temperature range from T = (6 to 520) K by precision adiabatic calorimetry and differential scanning calorimetry (DSC). In the above temperature range the physical transformations, such as glass transition and high-temperature relaxation transition, were detected. The standard thermodynamic characteristics of the revealed transformations were determined and analyzed. The standard thermodynamic functions, namely, heat capacity Cp°(T), enthalpy H°(T) - H°(0), entropy S°(T) - S°(0), and Gibbs energy G°(T) - H°(0) for the range from T → 0 to 520 K, and the standard entropies of formation ΔfS° of the investigated dendrimers in the devitrified state at T = 298.15 K, were calculated per corresponding moles of the notional structural units. The standard thermodynamic properties of dendrimers under study were discussed and compared with literature data for carbosilane dendrimers with different functional terminal groups.

  1. A Voyage through the Radio Universe

    ERIC Educational Resources Information Center

    Spuck, Timothy

    2004-01-01

    Each year, professionals and amateurs alike make significant contributions to the field of astronomy. High school students can also conduct astronomy research. Since 1992, the Radio Astronomy Research Team from Oil City Area Senior High School (OCHS) in Oil City, Pennsylvania, has traveled each year to the National Radio Astronomy Observatory…

  2. 1,2-Diphenylethylamines as potential non-stimulant anorectics.

    PubMed

    Ghosh, P; Bolt, A G; Mrongovius, R I

    1978-01-01

    A series of 1,2-diphenylethylamines has been synthesized in which the phenyl rings were substituted with Cl, OCH3 or CF3 at various positions and in various combinations. Four N-ethylpiperazino and N-ethylmorpholino compounds were also prepared. When tested in rats, some of the compounds were found to be potent anorectics and none of them stimulated motor activity.

  3. Escalation of Agitative Rhetoric: A Case Study of Mattachine Midwest, 1967-1970.

    ERIC Educational Resources Information Center

    Darsey, James

    This paper examines the adequacy of Bowers and Ochs' theory of social movements as applied to the escalating agitative strategies of a dissident group, the homosexual-rights organization Mattachine Midwest. The group's activities are described chronologically, in terms of the strategies employed: petition, promulgation, polarization,…

  4. Peer Socialization into Gendered L2 Mandarin Practices in a Study Abroad Context: Talk in the Dorm

    ERIC Educational Resources Information Center

    Diao, Wenhao

    2016-01-01

    This article reports on the peer socialization of gendered Mandarin practices between three American students and their Chinese roommates in a college dorm in China. Gender is often perceived to be a salient identity category among adult L2 learners overseas. Drawing on the language socialization framework (Ochs and Schieffelin 1984), this study…

  5. Parental Expectations of the Swedish Municipal School of Arts

    ERIC Educational Resources Information Center

    Lilliedahl, Jonathan; Georgii-Hemming, Eva

    2009-01-01

    This article draws on a study designed to analyse parental expectations of the Swedish municipal school of arts (hereafter MSA) (in Swedish: kommunal musik- och kulturskola). The study is based on in-depth interviews conducted and informed by grounded theory. Although parental expectations are scarcely uniform, the study reveals a hope that the…

  6. The Brief Child and Family Phone Interview (BCFPI): 1. Rationale, Development, and Description of a Computerized Children's Mental Health Intake and Outcome Assessment Tool

    ERIC Educational Resources Information Center

    Cunningham, Charles E.; Boyle, Michael H.; Hong, Sunjin; Pettingill, Peter; Bohaychuk, Donna

    2009-01-01

    Background: This study describes the development of the Brief Child and Family Phone Interview (BCFPI)--a computer-assisted telephone interview which adapts the revised Ontario Child Health Study's (OCHS-R) parent, teacher, and youth self-report scales for administration as intake screening and treatment outcome measures in children's mental…

  7. The Oscillating Jet Flap

    DTIC Science & Technology

    1976-03-05

    Borsting Superintendent Provost Reproduction of all or part of this report is authorized This report was prepared by: TTNH A^Tn-F.n SECURITY...Aerospace Laboratory, NLR, Amsterdam. 4. Carleman, T. (1922) "Sur la resolution de certaines equations integrales " Arkiv For Matematik, Astronomi Och Fysik

  8. Adolescent Tobacco and Cannabis Use: Young Adult Outcomes from the Ontario Child Health Study

    ERIC Educational Resources Information Center

    Georgiades, Katholiki; Boyle, Michael H.

    2007-01-01

    Background: This study examines the longitudinal associations between adolescent tobacco and cannabis use and young adult functioning. Methods: Data for analysis come from the Ontario Child Health Study (OCHS), a prospective study of child health, psychiatric disorder and adolescent substance use in a general population sample that began in 1983,…

  9. A Scientist or Salesman? Identity Construction through Referent Honorifics on a Japanese Shopping Channel Program

    ERIC Educational Resources Information Center

    Cook, Haruko Minegishi

    2013-01-01

    This paper explores how referent honorifics contribute to identity construction on a Japanese TV shopping channel program. Drawing on Ochs' twostep model of indexicality (1993, 1996) and Agah's proposal (1993) that honorifics are not directly linked to social status but index a "relative position within events of discursive interaction"…

  10. Co-Construction in Korean Interaction

    ERIC Educational Resources Information Center

    Ju, Hee

    2011-01-01

    This dissertation explores co-construction of a situated activity in a current unit by mainly focusing on hearers' actions. The "co-construction" involves a process of interaction in which speakers and hearers jointly construct the form and the meaning of ongoing utterances even when they disagree with each other (Jacoby & Ochs,…

  11. A Scientist or Salesman? Identity Construction through Referent Honorifics on a Japanese Shopping Channel Program

    ERIC Educational Resources Information Center

    Cook, Haruko Minegishi

    2013-01-01

    This paper explores how referent honorifics contribute to identity construction on a Japanese TV shopping channel program. Drawing on Ochs' twostep model of indexicality (1993, 1996) and Agah's proposal (1993) that honorifics are not directly linked to social status but index a "relative position within events of discursive interaction"…

  12. Role of Protein Glycosylation in Candida parapsilosis Cell Wall Integrity and Host Interaction

    PubMed Central

    Pérez-García, Luis A.; Csonka, Katalin; Flores-Carreón, Arturo; Estrada-Mata, Eine; Mellado-Mojica, Erika; Németh, Tibor; López-Ramírez, Luz A.; Toth, Renata; López, Mercedes G.; Vizler, Csaba; Marton, Annamaria; Tóth, Adél; Nosanchuk, Joshua D.; Gácser, Attila; Mora-Montes, Héctor M.

    2016-01-01

    Candida parapsilosis is an important, emerging opportunistic fungal pathogen. Highly mannosylated fungal cell wall proteins are initial contact points with host immune systems. In Candida albicans, Och1 is a Golgi α1,6-mannosyltransferase that plays a key role in the elaboration of the N-linked mannan outer chain. Here, we disrupted C. parapsilosis OCH1 to gain insights into the contribution of N-linked mannosylation to cell fitness and to interactions with immune cells. Loss of Och1 in C. parapsilosis resulted in cellular aggregation, failure of morphogenesis, enhanced susceptibility to cell wall perturbing agents and defects in wall composition. We removed the cell wall O-linked mannans by β-elimination, and assessed the relevance of mannans during interaction with human monocytes. Results indicated that O-linked mannans are important for IL-1β stimulation in a dectin-1 and TLR4-dependent pathway; whereas both, N- and O-linked mannans are equally important ligands for TNFα and IL-6 stimulation, but neither is involved in IL-10 production. Furthermore, mice infected with C. parapsilosis och1Δ null mutant cells had significantly lower fungal burdens compared to wild-type (WT)-challenged counterparts. Therefore, our data are the first to demonstrate that C. parapsilosis N- and O-linked mannans have different roles in host interactions than those reported for C. albicans. PMID:27014229

  13. Cyclo- and carbophosphazene-supported ligands for the assembly of heterometallic (Cu2+/Ca2+, Cu2+/Dy3+, Cu2+/Tb3+) complexes: synthesis, structure, and magnetism.

    PubMed

    Chandrasekhar, Vadapalli; Senapati, Tapas; Dey, Atanu; Das, Sourav; Kalisz, Marguerite; Clérac, Rodolphe

    2012-02-20

    The carbophosphazene and cyclophosphazene hydrazides, [{NC(N(CH(3))(2))}(2){NP{N(CH(3))NH(2)}(2)}] (1) and [N(3)P(3)(O(2)C(12)H(8))(2){N(CH(3))NH(2)}(2)] were condensed with o-vanillin to afford the multisite coordination ligands [{NC(N(CH(3))(2))}(2){NP{N(CH(3))N═CH-C(6)H(3)-(o-OH)(m-OCH(3))}(2)}] (2) and [{N(2)P(2)(O(2)C(12)H(8))(2)}{NP{N(CH(3))N═CH-C (6)H(3)-(o-OH)(m-OCH(3))}(2)}] (3), respectively. These ligands were used for the preparation of heterometallic complexes [{NC(N(CH(3))(2))}(2){NP{N(CH(3))N═CH-C(6)H(3)-(o-O)(m-OCH(3))}(2)}{CuCa(NO(3))(2)}] (4), [{NC(N(CH(3))(2))}(2){NP{N(CH(3))N═CH-C(6)H(3)-(o-O)(m-OCH(3))}(2)}{Cu(2)Ca(2)(NO(3))(4)}]·4H(2)O (5), [{NC(N(CH(3))(2))}(2){NP{N(CH(3))N═CH-C(6)H(3)-(o-O)(m-OCH(3))}(2)}{CuDy(NO(3))(4)}]·CH(3)COCH(3) (6), [{NP(O(2)C(12)H(8))}(2){NP{N(CH(3))N═CH-C(6)H(3)-(o-O)(m-OCH(3))}(2)}{CuDy(NO(3))(3)}] (7), and [{NP(O(2)C(12)H(8))}(2){NP{N(CH(3))N═CH-C(6)H(3)-(o-O)(m-OCH(3))}(2)}{CuTb(NO(3))(3)}] (8). The molecular structures of these compounds reveals that the ligands 2 and 3 possess dual coordination pockets which are used to specifically bind the transition metal ion and the alkaline earth/lanthanide metal ion; the Cu(2+)/Ca(2+), Cu(2+)/Tb(3+), and Cu(2+)/Dy(3+) pairs in these compounds are brought together by phenoxide and methoxy oxygen atoms. While 4, 6, 7, and 8 are dinuclear complexes, 5 is a tetranuclear complex. Detailed magnetic properties on 6-8 reveal that these compounds show weak couplings between the magnetic centers and magnetic anisotropy. However, the ac susceptibility experiments did not reveal any out of phase signal suggesting that in these compounds slow relaxation of magnetization is absent above 1.8 K.

  14. Involvement of T-cell immunoregulation by ochnaflavone in therapeutic effect on fungal arthritis due to Candida albicans.

    PubMed

    Lee, Jue-Hee

    2011-07-01

    Arthritis due to pathogenic fungi is a serious disease causing rapid destruction of the joint. In the pathogenesis of arthritis, T lymphocytes are considered to be one of the major immune cells. In present study, we examined the T cell immunoregulatory effect by ochnaflavone (Och), a biflavonoid, on arthritis caused by Candida albicans that is the most commonly associated with fungal arthritis. To examine the effects of ochnaflavonon Candida albicans-caused septic arthritis, an emulsified mixture of C. albicans cell wall and complete Freund's adjuvant (CACW/CFA) was injected into BALB/c mice via hind footpad route on days -3, -2, and -1. On Day 0, Och at 1 or 2 mg/dose/time was intratraperitoneally given to mice with the swollen footpad every other day for 3 times. The footpad-edema was measured for 20 days. Results revealed that Och reduced the edema at all dose levels and furthermore, there was app. 45% reduction of the edema in animals given 2 mg-dose at the peak of septic arthritis (p < 0.05). This anti-arthritic effect was accompanied by the diminishing of the DTH (delayed type hypersensitivity) activity against the CACW and by the provoking of the dominant T helper 2 (Th2) type cytokines production (IL-4 and Il-10), which appeared to result in a suppression of T helper 1 cytokines (IFN-γ and IL-2). Besides the T cell immunoregulatory activity, Och inhibited T cells activation as evidenced by the IL-2 reduction from PMA/ionomycin-stimulated Jurkat cell line and in addition, the compound killed macrophages in a dose-dependent manner (p < 0.05). However, Och caused no hemolysis (p < 0.05). These data implicate that Och, which has anti-arthritic activity based on the Th2 dominance as well as macrophage removal, can be safely administered into the blood circulation for treatment of the arthritis caused by C. albicans. Thus, it can be concluded that Och would be an ideal immunologically evaluated agent for treating of Candida arthritis.

  15. New aromatase inhibitors. Synthesis and biological activity of pyridyl-substituted tetralone derivatives.

    PubMed

    Bayer, H; Batzl, C; Hartmann, R W; Mannschreck, A

    1991-09-01

    The (E)-2-(4-pyridylmethylene)-1-tetralones 1-7 (1, H; 2, 5-OCH3; 3, 6-OCH3; 4, 7-OCH3; 5, 5-OH; 6, 6-OH; 7, 7-OH) were obtained by aldol condensation of the corresponding 1-tetralones with 4-pyridinecarboxaldehyde, and in the case of the OH compounds 5 and 7 subsequent ether cleavage of the OCH3-substituted 2-(4-pyridylmethylene)-1-tetralones. Catalytic hydrogenation of 1-4 gave the 2-(4-pyridylmethyl)-1-tetralones 8-11 (8, H; 9, 5-OCH3; 10, 6-OCH3; 11, 7-OCH3). Subsequent ether cleavage of 9-11 led to the corresponding OH compounds 12-14 (12, 5-OH; 13, 6-OH; 14, 7-OH). The enantiomers of 11 and 12 were separated semipreparatively by HPLC on triacetylcellulose. All compounds (1-14) showed an inhibition of human placental aromatase exhibiting relative potencies from 2.2 to 213 [compounds 6 and (+)-12, respectively; aromatase inhibitory potency of aminoglutethimide (AG) = 1]. The compounds exhibited no or only a weak inhibition of desmolase [cholesterol side chain cleavage enzyme; maximum activity shown by 12, 23% inhibition (25 microM); AG, 53% inhibition (25 microM)]. In vivo, however, the compounds were not superior to AG as far as the reduction of the plasma estradiol concentration and the mammary carcinoma (MC) inhibiting properties are concerned (PMSG-primed SD rats as well as DMBA-induced MC of the SD rat, pre- and postmenopausal experiments, and the transplantable MXT-MC of the BD2F1 mouse). This is due to a fast decrease of the plasma E2 concentration inhibiting effect as could be shown by a kinetic experiment. In addition, select compounds inhibited rat ovarian aromatase much less than human placental aromatase (12, factor of 10). Estrogenic effects as a cause for the poor in vivo activity of the test compounds could be excluded, since they did not show affinity for the estrogen receptor.

  16. Survival time of endodontically treated teeth: a 7-year retrospective clinical study

    NASA Astrophysics Data System (ADS)

    Baldea, Bogdan; Canjau, Silvana; Popescu, Dragos; Tudor, Anca; Todea, Carmen

    2014-01-01

    The aim of this retrospective clinical study was to examine the survival time of endodontically treated teeth (ETT) and the factors that may influence the failure risk, over a period of up to 7 years. The files of 67 patients that received metal free post and core restorations using a standardized technique were analyzed. The survival probability was assessed using Kaplan-Meyer analysis and Log Rank (Matel-Cox). Cox regression was used to assess the risk of failure and to identify possible covariates. The average survival time of the ETT was 6.6 Years. The cumulative failure rate was 5.82% for all type of the restored endodontically treated teeth. The main failure type was encountered in the cervical area of the teeth, and due to the extensive hard tissue loss, the teeth were extracted.

  17. Airway Complications during and after General Anesthesia: A Comparison, Systematic Review and Meta-Analysis of Using Flexible Laryngeal Mask Airways and Endotracheal Tubes

    PubMed Central

    Xu, Rui; Lian, Ying; Li, Wen Xian

    2016-01-01

    Objective Flexible laryngeal mask airways (FLMAs) have been widely used in thyroidectomy as well as cleft palate, nasal, upper chest, head and neck oncoplastic surgeries. This systematic review aims to compare the incidence of airway complications that occur during and after general anesthesia when using the FLMA and endotracheal intubation (ETT). We performed a quantitative meta-analysis of the results of randomized trials. Methods A comprehensive search of the PubMed, Embase and Cochrane Library databases was conducted using the key words "flexible laryngeal mask airway" and "endotracheal intubation". Only prospective randomized controlled trials (RCTs) that compared the FLMA and ETT were included. The relative risks (RRs) and the corresponding 95% confidence intervals (95% CIs) were calculated using a quality effects model in MetaXL 1.3 software to analyze the outcome data. Results Ten RCTs were included in this meta-analysis. There were no significant differences between the FLMA and ETT groups in the incidence of difficulty in positioning the airway [RR = 1.75, 95% CI = (0.70–4.40)]; the occurrence of sore throat at one hour and 24 hours postoperative [RR = 0.90, 95% CI = (0.13–6.18) and RR = 0.95, 95% CI = (0.81–1.13), respectively]; laryngospasms [RR = 0.58, 95% CI = (0.27–1.23)]; airway displacement [RR = 2.88, 95% CI = (0.58–14.33)]; aspiration [RR = 0.76, 95% CI = (0.06–8.88)]; or laryngotracheal soiling [RR = 0.34, 95% CI = (0.10–1.06)]. Patients treated with the FLMA had a lower incidence of hoarseness [RR = 0.31, 95% CI = (0.15–0.62)]; coughing [RR = 0.28, 95% CI = (0.15–0.51)] during recovery in the postanesthesia care unit (PACU); and oxygen desaturation [RR = 0.43, 95% CI = (0.26–0.72)] than did patients treated with ETT. However, the incidence of partial upper airway obstruction in FLMA patients was significantly greater than it was for ETT patients [RR = 4.01, 95% CI = (1.44–11.18)]. Conclusion This systematic review showed

  18. Laryngeal mask airways in ear, nose, and throat procedures.

    PubMed

    Mandel, Jeff E

    2010-09-01

    The use of laryngeal mask airway (LMA) and its variants in ear, nose, and throat procedures have been extensively described in case reports, retrospective reviews, and randomized clinical trials. The LMA has developed a considerable following because of its lack of tracheal stimulation, which can be a considerable advantage in ear, nose, and throat (ENT) procedures. The incidence of coughing on emergence has been shown to be lower with the LMA than with the endotracheal tube (ETT). Although other approaches to smooth emergence have been described, few would argue that it is as easy to achieve a smooth emergence with an ETT as with an LMA. Although patients certainly exist for whom the LMA is contraindicated, many will experience better results with the LMA because of the features delineated in this article.

  19. Ultrasonography of Extravaginal Testicular Torsion in Neonates

    PubMed Central

    Bombiński, Przemysław; Warchoł, Stanisław; Brzewski, Michał; Majkowska, Zofia; Dudek-Warchoł, Teresa; Żerańska, Maria; Panek, Małgorzata; Drop, Magdalena

    2016-01-01

    Summary Background Extravaginal testicular torsion (ETT), also called prenatal or perinatal, occurs prenatally and is present at birth or appears within the first month of life. It has different etiology than intravaginal torsion, which appears later in life. Testicular torsion must be taken into consideration in differential diagnosis of acute scrotum and should be confirmed or ruled out at first diagnostic step. Ultrasonography is a basic imaging modality, however diagnostic pitfalls are still possible. There is still wide discussion concerning management of ETT, which varies from immediate orchiectomy to conservative treatment resulting in testicle atrophy. Material/Methods In this article we present ultrasonographic spectrum of ETT in neonates, which were diagnosed and treated in our hospital during the last 8 years (2008–2015), in correlation with clinical and intraoperative findings. Results Thirteen neonates with ETT were enrolled in the study – 11 patients with a single testicle affected and 2 patients with bilateral testicular torsion. Most common signs on clinical examination were: hardened and enlarged testicle and discoloration of the scrotum. Most common ultrasonographic signs were: abnormal size or echostructure of the affected testicle and absence of the blood flow in Doppler ultrasonography. In 3 patients ultrasound elastography was performed, which appeared very useful in testicle structure assessment. Conclusions Testicular torsion may concern boys even in the perinatal period. Ultrasonographic picture of acute scrotum in young boys may be confused. Coexistence of the abnormal size or echostructure of the torsed testicle with absence of the blood flow in Doppler ultrasonography appear as very specific but late ultrasonographic sings. Ultrasound elastography may be a very useful tool for visualisation of a very common clinical sign – hardening of the necrotic testicle. PMID:27757176

  20. A randomized controlled trial of the laryngeal mask airway for surfactant administration in neonates.

    PubMed

    Barbosa, Rosilu F; Simões E Silva, Ana C; Silva, Yerkes P

    To compare the short-term efficacy of surfactant administration by laryngeal mask airway versus endotracheal tube. Preterm infants (28-35 weeks of gestational age), weighing 1kg or more, with respiratory distress syndrome, requiring nasal continuous positive airway pressure, with increased respiratory effort and/or fraction of inspired oxygen (FiO2)≥0.40 to maintain oxygen saturation 91-95%, were randomized to receive surfactant by LMA following nCPAP or by ETT following mechanical ventilation (MV). The primary outcome was a clinical response defined as FiO2≤0.30 three hours after surfactant. Secondary outcomes for LMA group were: need of surfactant retreatment during the first 24h, MV requirement, and presence of surfactant in gastric content. Forty-eight patients were randomized; 26 in the LMA group and 22 in the ETT group. Six of 26 patients (23%) in the LMA group and five of 22 patients (22.7%) in the ETT group did not meet the primary outcome (p=0.977). Fourteen (53.8%) of the LMA patients were not intubated nor ventilated; 12 (46.1%) were ventilated: for surfactant failure (23%), for nCPAP failure (11.5%), and for late complications (11.5%). Groups were similar regarding prenatal status, birth conditions, and adverse events. No significant gastric content was found in 61.5% of the LMA patients. Oxygen and second dose surfactant requirements, arterial/alveolar ratio, and morbidities were similar among groups. Surfactant administration by LMA showed short-term efficacy, with similar supplementary oxygen need compared to surfactant by ETT, and lower MV requirement. Further studies with larger sample size are necessary to confirm these results. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  1. Developments in Science and Technology

    DTIC Science & Technology

    1984-01-01

    rities to form the formyl (HCO) radical . Because fused silica is amorphous, the resulting electron spin resonance (ESR) spectrum of the HCO radical is...34Magnetophotoselective Pho- radical is not rigidly fixed in the silica host but executes tolysis of the Formyl Radical in Fused Silica," Chem. Phys. Lett...Photolysis of the Formyl Radical in Fused Silica," Cheat. pp. 74-78 (1984). Phs. 1.ett. 104, 413-417 (1984). W. G. Bath, F . W. )avid, and .. T. Miller

  2. Sequential Quadratic Programming Algorithms for Optimization

    DTIC Science & Technology

    1989-08-01

    series expansion for the activo constraints, -(X) = 0 = c(x*) + A*dkl1k - x*ll + O(ll.rk - X*I1I), 3.5. The penalty parameter 37 which implies that...sequence of Q P statiot ary miitts (no to that the sequence is bouinded). From the assumption that the correct activo ett ha been identified, it must hold

  3. C4 Software Technology Reference Guide - A Prototype.

    DTIC Science & Technology

    1997-01-10

    Baudoin, Claude & Hollowell , Glenn. Realizing the Object-Oriented Life- cycle. Englewood Cliffs, NJ: Prentice Hall, 1996. Embley, David W.; Jackson... Hollowell , Glenn. Realizing the Object-Oriented Life- cycle. Upper Saddle River, NJ: Prentice Hall, 1996. Ett, William. A Guide to Integration of...96] [Kamath 93] [Malan 95] ^ [Tokar 96] Author Baudoin, Claude & Hollowell , Glenn. Realizing the Object-Oriented Life- cycle. Upper Saddle River

  4. Visual Search in the Detection of Retinal Injury: A Feasibility Study

    DTIC Science & Technology

    2013-04-01

    D, Heyes A. et al. Mobility of people with retinitis pigmentosa as a function of vision and psychological variables. Optometry and Vision Science...AFRL-RH-FS-TR-2013-0019 Visual Search in the Detection of Retinal Injury: A Feasibility Study Thomas Kuyk TASC, Inc. Lei Liu The...Detection of Retinal Injury: A Feasibility Study" 2013 0019 LEON N. McLIN, JR., DR-III, DAF Work Unit Manager 711 HPW/ RHDO POLHAMUS.GARR ETT.D

  5. The air-leak test is not a good predictor of postextubation adverse events in children undergoing cardiac surgery.

    PubMed

    Suominen, Pertti K; Tuominen, Netta A; Salminen, Jukka T; Korpela, Reijo E; Klockars, Jaakko G M; Taivainen, Tomi R; Meretoja, Olli A

    2007-04-01

    The air-leak test is recommended as a method of assessing the appropriate size of an uncuffed endotracheal tube (ETT) in children. The authors' primary objective was to determine whether the air-leak test would predict adverse events and reintubations after the removal of the ETT in children who have undergone cardiac surgery. Prospective, observational, clinical study. University tertiary care hospital. Ninety-four children <10 years of age undergoing elective cardiac surgery requiring cardiopulmonary bypass surgery. The attending anesthesiologist assessed air-leak pressure after intubation in the operating room (OR). In addition, the air-leak test was performed in 42 patients before extubation in the pediatric intensive care unit (PICU). The incidence of adverse events and the number of failed extubations were recorded after removal of the ETT. Eleven of the 94 patients were excluded from the study. Four (4.3%) of the patients died in the PICU before extubation, and 7 patients were excluded for other reasons. The median age of the 83 children was 0.9 years (range 0.01-9.6 years). The total incidences of postextubation adverse events and failed extubations were 30.1% and 8.4%, respectively. An audible air leak < or =25 cmH(2)O airway pressure during the OR phase or before removal of the ETT during the PICU recovery phase had no significant predictive value for the incidence of adverse events (p = 0.63) or reintubations (p = 1.0). The patients undergoing simple and complete operations compared with more complex and incomplete operations had significantly fewer postextubation adverse events (p = 0.03). Neonates did not have a higher risk for postextubation adverse events (p = 0.64) or reintubations (p = 0.26) than older children. The air-leak test did not predict an increased risk for postextubation adverse events and reintubations in children undergoing elective congenital heart surgery.

  6. Friendly Extensible Transfer Tool Beta Version

    SciTech Connect

    Collins, William P.; Gutierrez, Kenneth M.; McRee, Susan R.; Sands, Daniel N.; Yaklin, Allan C.

    2016-04-15

    Often data transfer software is designed to meet specific requirements or apply to specific environments. Frequently, this requires source code integration for added functionality. An extensible data transfer framework is needed to more easily incorporate new capabilities, in modular fashion. Using FrETT framework, functionality may be incorporated (in many cases without need of source code) to handle new platform capabilities: I/O methods (e.g., platform specific data access), network transport methods, data processing (e.g., data compression.).

  7. Molecular genotyping of placental site and epithelioid trophoblastic tumours; female predominance.

    PubMed

    Zhao, Sihao; Sebire, Neil J; Kaur, Baljeet; Seckl, Michael J; Fisher, Rosemary A

    2016-09-01

    To investigate a large series of placental site trophoblastic tumours (PSTT) and epithelioid trophoblastic tumours (ETT) and determine the relationship between their development and the type and sex of both the immediately antecedent and causative pregnancies. The antecedent pregnancy was determined from patient records in 92 cases with a confirmed diagnosis of PSTT, ETT or mixed PSTT/ETT. In a subset of 57 cases, type and sex of the causative pregnancy was established by molecular genotyping of tumour tissue microdissected from formalin-fixed, paraffin-embedded blocks. The antecedent pregnancy was a normal live birth in 59 (64%) cases, a hydatidiform mole in 19 (21%) and other pregnancy loss in 14 (15%). Where the sex was recorded, 36 (78%) of 46 antecedent normal pregnancies were female, a significantly greater proportion than expected (p<0.0001). Genotyping of 57 cases found 15 (26%) to derive from hydatidiform moles while 42 (74%) arose in non-molar pregnancies. Where the causative pregnancy was non-molar, 38 (91%) tumours arose in female conceptions, significantly greater than expected (p<0.0001). Analysis of short tandem repeats on the X chromosome in three tumours with an XY chromosomal constitution confirmed that the X chromosome was maternal in origin. PSTT and ETT predominantly arise in female pregnancies but can develop in male pregnancies. A male derived X chromosome is not required for the development of these tumours. While these tumours are predominantly female it is not because most originate in complete hydatidiform moles. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. The Air Land Sea Bulletin. Issue No. 2008-3, September 2008

    DTIC Science & Technology

    2008-09-01

    artillery to improve, artillery mentors must know and teach consistently from year-to-year the same skills and crew drills across the entire ANA...English, and transliterated phonetically so mentors can use the proper words themselves and cut reliance on interpreters. TTP #3—Establish an...expect our ETTs to arrive in Afghanistan and begin coaching, teaching , and mentoring without first under- standing both the most fundamental issues

  9. Choices and Challenges: A Guide for the Battalion Commander’s Wife

    DTIC Science & Technology

    1991-05-28

    tradition you establish. 10 Take dance lessons; brush up nn your speaking skills; collect recipes for yroup gatherings; get ready for your first round of...8217 functions? Ideas? d. Annual dinner dance ? What rank? e. Hail and farewell ideas? f. Holiday parties: Christmas, Easter? g. As a group interested in...ettes! We wanted to tell you how excited we arc about our upcomi.; 19-91st Battalion Spring Dance on 10 June 1991 at the Embers and also to give you

  10. A prospective randomised comparison of the LMA ProSeal™ versus endotracheal tube on the severity of postoperative pain following gynaecological laparoscopy.

    PubMed

    Griffiths, J D; Nguyen, M; Lau, H; Grant, S; Williams, D I

    2013-01-01

    Pain and postoperative nausea and vomiting (PONV) are common problems after gynaecologic laparoscopy. Two recent studies have shown that morphine requirements and PONV are lower when an LMA ProSeal™ is used, rather than an endotracheal tube (ETT), for female patients undergoing breast and gynaecological surgery. We conducted a patient and observer-blinded randomised controlled trial, recruiting non-obese women without gastro-oesophageal reflux undergoing laparoscopic gynaecological surgery. Patients received a standardised relaxant general anaesthetic and then were randomised to receive either an LMA ProSeal or an endotracheal tube. Patients were assessed at two and 24 hours post-anaesthesia. The primary outcome was postoperative pain score and secondary endpoints included morphine consumption, postoperative emesis and adverse upper airway symptoms. We recruited 116 patients to the study, 57 patients in the ETT group and 59 patients in the LMA ProSeal group. The patients were similar in demographic and surgical characteristics. At two hours, the ETT group was similar to the LMA ProSeal group in regards to pain scores (Visual Analogue Scale 3.0 vs 3.5, P=0.86), morphine consumption (7.2 vs 7.4 mg, P=0.56) and PONV (47.4 vs 47.5%, P=0.99). After 24 hours, pain scores and PONV rates were also similar. No significant difference in rates of sore throat or dysphagia was observed between the ETT and LMA ProSeal groups. No significant complications were attributable to either airway device. The LMA ProSeal did not decrease pain or PONV in patients undergoing gynaecological laparoscopy when compared to endotracheal intubation.

  11. Approaches to Inflight Ear Oximetry.

    DTIC Science & Technology

    1980-10-01

    of arterial oxygen saturation. For centri- fuge experiments the floe,! ett-Packard ear oximeter, Model 47201A, has been successfully used both at...These difficulties are perhaps even more significant with respect to inflight experimental use. The difficulties are: 1. The bloodless ear is not truly...available (9), and a number of papers on both the clini- cal use (10-17) and the experimental use (1, 2, 18) of this equipment have been published since its

  12. Some Perspectives on Solution-Phase Electron-Transfer Processes

    DTIC Science & Technology

    1994-04-18

    bound media. 3 7 𔃾 1 A second, fundamentally different, approach to molecular solvent reorganization makes use of molecular-dynamics (ND) simulations ...see also the article in this issue by G. Voth). This group has successfully simulated the redox activation behavior of the well-known hexaaquo iron(IH...interactions abound in this highly charged/hydrogen-bonded system. On the other hand, model MD simulations for both dipole creation/annihilation 4 3 and ETT

  13. Alternative approaches to ventilator-associated pneumonia prevention.

    PubMed

    Berra, L; Sampson, J; Fumagalli, J; Panigada, M; Kolobow, T

    2011-03-01

    Ventilator-associated pneumonia (VAP), which develops in patients receiving mechanical ventilation, is the most common nosocomial infection in patients with acute respiratory failure. The major mechanism of lower respiratory tract colonization is aspiration of bacteria-colonized secretions from the oropharynx into the lower airways. The hydrostatic pressure of the secretions that collect in the subglottic space, which is the area above the endotracheal tube (ETT) cuff, or aerosolization of bacteria from the secretions collected within the respiratory tubing may facilitate the leakage into the lower airways. Ideally, the elimination of the mechanisms responsible for aspiration would decrease the incidence of VAP. Several preventive measures have been tested in clinical trials with little success.Here we present the results of our efforts to develop novel approaches for the prevention of VAP. Specifically, we found that keeping ventilated patients in a lateral position, which eliminates gravitational forces, is feasible and possibly advantageous. Additionally, several novel medical devices have been recently developed to prevent bacterial biofilm formation from the ETT and breathing tubing. These devices include coated ETTs, mucus shavers and mucus slurpers. Prevention of ETT bacterial colonization showed decreased bacterial colonization of the respiratory circuit and of the lower respiratory tract in laboratory studies and clinical trials. Future large studies should be designed to test the hypothesis that VAP can be prevented with these novel strategies. While there is a current focus on the use of respiratory devices to prevent biofilm formation and microaspiration, it is important to remember that lower respiratory tract colonization is multifactorial. Prevention of VAP cannot be achieved solely by eliminating bacterial biofilm on respiratory devices, and more comprehensive care of the intubated patient needs to be implemented.

  14. Tracheal size variability is associated with sex: implications for endotracheal tube selection.

    PubMed

    Karmakar, Arunabha; Pate, Mariah B; Solowski, Nancy L; Postma, Gregory N; Weinberger, Paul M

    2015-02-01

    Whereas selection of endotracheal tube (ETT) size in pediatric patients benefits from predictive nomograms, adult ETT sizing is relatively arbitrary. We sought to determine associations between cervical tracheal cross-sectional area (CTCSA) and clinical variables. One hundred thirty-two consecutive patients undergoing noncontrasted chest computed tomography (CT) at a single tertiary care institution from January 2010 to June 2011 were reviewed. Patients with improper CT technique, endotracheal intubation, and pulmonary/tracheal pathology were excluded. Tracheal luminal diameters in anteroposterior (D1) and transverse (D2) were measured 2 cm inferior to the cricoid and used to determine CTCSA = π*D1*D2*¼. The demographic variables of age, height, weight, and body mass index (BMI) were tested for association with CTCSA by Spearman correlation. Wilcoxon rank-sum test was used to compare CTCSA by race and sex. Multivariate linear regression was performed including all clinical variables. There were 91 patients who met inclusion criteria. There was no correlation between age, weight, or BMI and CTCSA. There was a significant positive correlation between patient height and CTCSA (P = .001, R = 0.35); however, this was confounded by sex. Female patients had significantly smaller CTCSA (mean = 241 mm(2)) compared to male patients (mean = 349 mm(2), P < .001). Multivariate linear regression stratified by sex revealed that height is correlated with CTCSA only in males (P = .028). Males also had more variability in CTCSA (SD 118.6) compared to females (SD 65.5). Our data suggest that selection of ETT size in male patients should include height as a predictive factor. For female patients, it may be appropriate to select a uniformly smaller diameter ETT size. © The Author(s) 2014.

  15. Atraumatic intubation: experience using a 5.0 endotracheal tube without a stylet for laryngeal surgery.

    PubMed

    Moore, Jaime E; Hu, Amanda; Rutt, Amy; Green, Parmis; Hawkshaw, Mary; Sataloff, Robert T

    2015-02-01

    Vocal fold injury is a well-know complication of intubation, with rates reported as high as 69%. Laryngology textbooks recommend the use of a small endotracheal tube (ETT) to help avoid these complications and optimize visualization. Case reports have suggested that the rigid stylet can lead to laryngeal injury. Given the additional risks, intubation without the stylet is our preferred practice. There is limited documentation in the literature regarding this viewpoint. Our study investigated the feasibility of and potential barriers to intubation using 5.0 ETT without a stylet. Prospective study. Consecutive adult patients undergoing laryngeal surgery were recruited for intubation with a 5.0 ETT without a stylet. Demographic data, specialty and training level of the intubator, and factors that would predict a difficult intubation were recorded. Descriptive statistical analysis was performed. Findings of the participants (n = 67) included average American Society of Anesthesiologists (ASA) physical status classification (2.2), average Mallampati score (1.7), average Cormack-Lehane grade (1.5), and average body mass index (28.0). Five patients (7.4%) required intubation using a stylet, and one of these five participants was intubated initially with a stylet. Of these five participants, 80% required use of a GlideScope (P < .001), and they had significantly higher ASA classification (P = .047) and number of intubation attempts (P = .042). One patient sustained an oropharyngeal injury during intubation with a stylet. No participants had laryngeal injury. Most patients can be intubated successfully using a 5.0 ETT without a stylet. There were no cases of laryngeal trauma with this technique. 2b. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

  16. Endotracheal tubes for critically ill patients: an in vivo analysis of associated tracheal injury, mucociliary clearance, and sealing efficacy.

    PubMed

    Li Bassi, Gianluigi; Luque, Nestor; Martí, Joan Daniel; Aguilera Xiol, Eli; Di Pasquale, Marta; Giunta, Valeria; Comaru, Talitha; Rigol, Montserrat; Terraneo, Silvia; De Rosa, Francesca; Rinaudo, Mariano; Crisafulli, Ernesto; Peralta Lepe, Rogelio Cesar; Agusti, Carles; Lucena, Carmen; Ferrer, Miguel; Fernández, Laia; Torres, Antoni

    2015-05-01

    Improvements in the design of the endotracheal tube (ETT) have been achieved in recent years. We evaluated tracheal injury associated with ETTs with novel high-volume low-pressure (HVLP) cuffs and subglottic secretions aspiration (SSA) and the effects on mucociliary clearance (MCC). Twenty-nine pigs were intubated with ETTs comprising cylindrical or tapered cuffs and made of polyvinylchloride (PVC) or polyurethane. In specific ETTs, SSA was performed every 2 h. Following 76 h of mechanical ventilation, pigs were weaned and extubated. Images of the tracheal wall were recorded before intubation, at extubation, and 24 and 96 h thereafter through a fluorescence bronchoscope. We calculated the red-to-green intensity ratio (R/G), an index of tracheal injury, and the green-plus-blue (G+B) intensity, an index of normalcy, of the most injured tracheal regions. MCC was assessed through fluoroscopic tracking of radiopaque markers. After 96 h from extubation, pigs were killed, and a pathologist scored injury. Cylindrical cuffs presented a smaller increase in R/G vs tapered cuffs (P = .011). Additionally, cuffs made of polyurethane produced a minor increase in R/G (P = .012) and less G+B intensity decline (P = .022) vs PVC cuffs. Particularly, a cuff made of polyurethane and with a smaller outer diameter outperformed all cuffs. SSA-related histologic injury ranged from cilia loss to subepithelial inflammation. MCC was 0.9 ± 1.8 and 0.4 ± 0.9 mm/min for polyurethane and PVC cuffs, respectively (P < .001). HVLP cuffs and SSA produce tracheal injury, and the recovery is incomplete up to 96 h following extubation. Small, cylindrical-shaped cuffs made of polyurethane cause less injury. MCC decline is reduced with polyurethane cuffs.

  17. Prevalence and predictors of out-of-range cuff pressure of endotracheal and tracheostomy tubes: a prospective cohort study in mechanically ventilated patients.

    PubMed

    Alzahrani, Amer R; Al Abbasi, Shatha; Abahoussin, Othman Khalid; Al Shehri, Tariq Othman; Al-Dorzi, Hasan M; Tamim, Hani M; Sadat, Musharaf; Arabi, Yaseen M

    2015-10-15

    Maintaining the cuff pressure of endotracheal tubes (ETTs) within 20-30 cmH2O is a standard practice. The aim of the study was to evaluate the effectiveness of standard practice in maintaining cuff pressure within the target range. This was a prospective observational study conducted in a tertiary-care intensive care unit, in which respiratory therapists (RTs) measured the cuff pressure 6 hourly by a handheld manometer. In this study, a research RT checked cuff pressure 2-4 h after the clinical RT measurement. Percentages of patients with cuff pressure levels above and below the target range were calculated. We identified predictors of low-cuff pressure. We analyzed 2120 cuff-pressure measurements. The mean cuff pressure was 27 ± 2 cmH2O by the clinical RT and 21 ± 5 cmH2O by the research RT (p < 0.0001). The clinical RT documented that 98.0 % of cuff pressures were within the normal range. The research RT found the cuff pressures to be within the normal range in only 41.5 %, below the range in 53 % and above the range in 5.5 %. Low cuff pressure was found more common with lower ETT size (OR, 0.34 per 0.5 unit increase in ETT size; 95 % CI, 0.15-0.79) and with lower peak airway pressure (OR per one cm H2O increment, 0.93; 95 % CI, 0.87-0.99) on multivariate analysis. Cuff pressure is frequently not maintained within the target range with low-cuff pressure being very common approximately 3 h after routine measurements. Low cuff pressure was associated with lower ETT size and lower peak airway pressure. There is a need to redesign the process for maintaining cuff pressure within the target range.

  18. Predictors and outcome of early-onset pneumonia after out-of-hospital cardiac arrest.

    PubMed

    Pabst, Dirk; Römer, Sonja; Samol, Alexander; Kümpers, Philipp; Waltenberger, Johannes; Lebiedz, Pia

    2013-09-01

    Early-onset pneumonia (EOP) after out-of-hospital cardiac arrest is frequently observed. Causative factors are loss of airway protection during cardiac arrest, pulmonary contusion, and emergency airway management. We assessed the incidence, risk factors, and clinical course of EOP, and evaluated the impact of an early exchange of the prehospitally inserted endotracheal tube (ETT). In our retrospective analysis we included 104 consecutive subjects admitted to our ICU after out-of-hospital cardiac arrest between 2007 and 2012. All subjects underwent therapeutic hypothermia. We analyzed clinical course, inflammation indicators, Clinical Pulmonary Infection Score, occurrence of EOP, duration of ventilatory support, microbiological findings, and short-term outcome. Of the 104 subjects, 46.2% received an exchange of ETT directly after hospital admission. Neither ETT exchange nor observed aspiration were associated with elevated CPIS or EOP, nor with proof of microorganisms in respiratory secretions. We found no differences in duration of ventilatory support, P(aO2)/F(IO2), ICU days, or outcome. C-reactive protein was significantly higher in subjects with aspiration (P = .046). Sex, age, smoking status, aspiration, cause of cardiac arrest, first detected heart rhythm, and use of supraglottic airways devices were not associated with EOP. Subjects with EOP had a longer need for ventilatory support (P = .005), higher tracheotomy rate (P = .03), longer ICU stay (P = .005), higher C-reactive protein (P < .001), higher body temperature (P = .003), higher Clinical Pulmonary Infection Score (P < .001), and lower P(aO2)/F(IO2) (P = .008). The rate of EOP was not significantly influenced by the exchange of the preclinically inserted ETT, but was associated with longer need for mechanical ventilation and ICU stay.

  19. Impaired heart rate recovery is associated with new-onset atrial fibrillation: a prospective cohort study.

    PubMed

    Maddox, Thomas M; Ross, Colleen; Ho, P Michael; Magid, David; Rumsfeld, John S

    2009-03-12

    Autonomic dysfunction appears to play a significant role in the development of atrial fibrillation (AF), and impaired heart rate recovery (HRR) during exercise treadmill testing (ETT) is a known marker for autonomic dysfunction. However, whether impaired HRR is associated with incident AF is unknown. We studied the association of impaired HRR with the development of incident AF, after controlling for demographic and clinical confounders. We studied 8236 patients referred for ETT between 2001 and 2004, and without a prior history of AF. Patients were categorized by normal or impaired HRR on ETT. The primary outcome was the development of AF. Cox proportional hazards modeling was used to control for demographic and clinical characteristics. Secondary analyses exploring a continuous relationship between impaired HRR and AF, and exploring interactions between cardiac medication use, HRR, and AF were also conducted. After adjustment, patients with impaired HRR were more likely to develop AF than patients with normal HRR (HR 1.43, 95% confidence interval (CI) 1.06, 1.93). In addition, there was a linear trend between impaired HRR and AF (HR 1.05 for each decreasing BPM in HRR, 95% CI 0.99, 1.11). No interactions between cardiac medications, HRR, and AF were noted. Patients with impaired HRR on ETT were more likely to develop new-onset AF, as compared to patients with normal HRR. These findings support the hypothesis that autonomic dysfunction mediates the development of AF, and suggest that interventions known to improve HRR, such as exercise training, may delay or prevent AF.

  20. Prototype Concept Design for U.S. Army Type IIIA Air Traffic Control Tower (ATCT).

    DTIC Science & Technology

    1984-10-01

    Insulated cores will be provided in all exterior doors and in all interior doors at the tower support module level that lead into the kitchen- ette area... assembled in box modules, they would create shear walls that would provide lateral load resistance. The module’s major disadvantage is its weight, which...be eliminated by the "H" option illustrated in Figure 12. The module now becomes one floor/ceiling assembly with columns positioned to end at half

  1. Knowledge, Attitudes and Practice of Restoring Endodontically Treated Teeth by Dentists in North of Saudi Arabia

    PubMed Central

    Akbar, Iftikhar

    2015-01-01

    Objectives The aim of this study was to determine the knowledge, current approaches, techniques and practices for the restoration of endodontically treated teeth (ETT) among general dental practitioners and specialists in north of Saudi Arabia. Methodology A standard questionnaire based survey containing 16 multiple choice questions about techniques and treatment methods, frequency of post, type of post, choice of luting cement, core material, reason of failure of endodontic treatment was distributed by hand and through email among 255 general dentists and specialists. The data were processed by using SPSS statistical software. Results The majority of clinicians (54%) believed that post reinforces the remaining tooth structure and reduces fracture probability. The ferrule effect was considered an important factor in increasing fracture resistance of the ETT (72%). The preferred technique for restoring ETT was core material along with 1–2 mm of ferule (41%) followed by prefabricated post and core build up (25%). On the basis of post material, the most common was metal (43%) followed by fiber post (41%). 2/3rd length of the root canal for the post length (67%), 4–5mm apical seal of gutta percha after post placement (47%) and for the post diameter, 1/3rd of root diameter (51%) was agreed by most of the participants. Composite resin (61%) was the most popular material for core foundation followed by amalgam (23%). Conclusion The surveyed practitioners had a sound knowledge of the techniques and materials for restoring ETT with the exception that post reinforces the remaining tooth structure and reduces fracture probability. PMID:25901132

  2. Comparative photodynamic therapy study using two phthalocyanine derivatives

    PubMed Central

    YSLAS, EDITH INÉS; MILLA, LAURA NATALIA; ROMANINI, SILVIA; DURANTINI, EDGARDO NÉSTOR; BERTUZZI, MABEL; RIVAROLA, VIVIANA ALICIA

    2010-01-01

    In the present study, a comparative photodynamic therapy (PDT) study was performed using the phthalocyanine derivatives, ZnPc(OCH3)4 and ZnPc(CF3)4, in a mouse tumor model, under identical experimental procedures. We studied the ablation of tumors induced by PDT. The end-point was to compare the photodynamic efficacy of ZnPc(OCH3)4 and ZnPc(CF3)4. ZnPc(OCH3)4 and ZnPc(CF3)4 were administered intraperitoneally at a dose of 0.2 mg/kg body weight. The injections of drugs were carried out in Balb/c mice bearing subcutaneously inoculated LM2 mouse mammary adenocarcinoma. Histological examination and serum biochemical parameters were used to evaluate hepatic and renal toxicity and function. Phototherapeutic studies were achieved employing a light intensity of 210 J/cm2. After PDT, tumoral regression analyses were carried out, and the degree of tumor cell death was measured utilizing the vital stain Evan’s blue. In this pilot study, we revealed that the cytotoxic effect of ZnPc(OCH3)4 after PDT led to a higher success rate compared to ZnPc(CF3)4-PDT when both were intraperitoneally injectioned. Both phthalocynanine derivatives were able to induce ablation in the tumors. In summary, these results demonstrate the feasibility of ZnPc(OCH3)4- or ZnPc(CF3)4-PDT and its potential as a treatment for small tumors. PMID:22993594

  3. Sex Steroids, Sex Hormone-Binding Globulin and Cardiovascular Health in Men and Postmenopausal Women: The Rotterdam Study.

    PubMed

    Jaspers, Loes; Dhana, Klodian; Muka, Taulant; Meun, Cindy; Kiefte-de Jong, Jessica C; Hofman, Albert; Laven, Joop S E; Franco, Oscar H; Kavousi, Maryam

    2016-07-01

    The concept of cardiovascular health was recently introduced. Sex steroids and sex hormone-binding globulin (SHBG) influence different health domains, but no studies assessed their role in cardiovascular health. To assess the association between estradiol (E2), testosterone (T), SHBG, and free androgen index (FAI) with cardiovascular health. Analyses included 1647 men (68.6 y) and 1564 naturally postmenopausal women (69.6 y) with available data on sex steroids and cardiovascular health from the population-based Rotterdam Study. E2, T, SHBG, and FAI. To define cardiovascular health, 7 metrics including 3 health factors (total cholesterol, fasting glucose, and blood pressure) and 4 health behaviors (physical activity, smoking, body mass index, and diet) were adopted. Three category levels of each metric were added up to a total score ranged 0-14. Logistic regression was performed to explore the association between E2, T, SHBG, and FAI and optimal cardiovascular health (OCH) (score of 11-14). OCH was reached by 153 men (9.3%) and 162 women (10.4%). The prevalence of OCH was higher in the lowest tertile of E2 (38.9%), and of T (43.8%), and the highest tertile of SHBG (48.1%) in women, and the highest tertile of T (43.1%) and SHBG (47.1%) in men. After adjustment for confounders, OCH was associated with lower T (odds ratio and 95% confidence interval, 0.69 [0.48-1.00]) and lower FAI (0.43 [0.32-0.57]) and higher levels of SHBG (4.55 [2.99-6.94]) among women and with higher levels of SHBG (2.56 [1.45-4.49]) in men. OCH was associated with sex steroids and with SHBG in both men and women. The complexity and temporality of the interrelation between sex steroids, SHBG, and cardiovascular health requires further investigation.

  4. The anatomical location and laterality of orbital cavernous haemangiomas.

    PubMed

    McNab, Alan A; Selva, Dinesh; Hardy, Thomas G; O'Donnell, Brett

    2014-10-01

    To determine the anatomical location and laterality of orbital cavernous haemangiomas (OCH). Retrospective case series. The records of 104 patients with OCH were analyzed. The anatomical location of each OCH defined by the location of a point at the centre of the lesion, and its laterality. There were 104 patients included in the study. No patient had more than one lesion. Sixteen (15.4%) were located in the anterior third of the orbit, 74 (71.2%) were in the middle third, and 14 (13.5%) in the posterior third. In the middle third, 10 of 74 (13.5%) were extraconal and 64 intraconal (86.5%), with 30 of 64 (46.9%) middle third intraconal lesions lying lateral to the optic nerve. Of 104 lesions, 56 (53.8%) were left sided, showing a trend towards a predilection for the left side (p = 0.065). If data from other published series which included data on laterality is added to our own data and analysed, 270 of 468 (57.7%) OCH occurred in the left orbit (p < 0.005). OCH may occur at almost any location within the orbit. The commonest location is the middle third of the orbit, in the intraconal space lateral to the optic nerve. This may reflect an origin of these lesions from the arterial side of the circulation, as there are more small arteries in the intraconal space lateral to the optic nerve than in other locations. A predilection for the left orbit remains unexplained.

  5. Environmental risk assessment of hydrofluoroethers (HFEs).

    PubMed

    Tsai, Wen-Tien

    2005-03-17

    Hydrofluoroethers (HFEs) are being used as third generation replacements to chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and perfluorocarbons (PFCs) because of their nearly zero stratospheric ozone depletion and relatively low global warming potential. HFEs have been developed under commercial uses as cleaning solvents (incl., HFE-7500, C7F15OC2H5; HFE-7200, C4F9OC2H5; HFE-7100, C4F9CH3; HFE-7000, n-C3F7OCH3), blowing agents (incl., HFE-245mc, CF3CF2OCH3; HFC-356mec, CF3CHFCF2OCH3), refrigerants (incl., HFE-143a, CF3OCH3; HFE-134, CHF2OCHF2; HFE-245mc, CF3CF2OCH3), and dry etching agents in semiconductor manufacturing, (incl., HFE-227me, CF3OCHFCF3). From the environmental, ecological, and health points of view, it is important to understand their environmental risks for these HFEs from a diversity of commercial applications and industrial processes. This paper aims to introduce these HFEs with respect to physiochemical properties, commercial uses, and environmental hazards (i.e. global warming, photochemical potential, fire and explosion hazard, and environmental partition). Further, it addresses the updated data on the human toxicity, occupational exposure and potential health risk of commercial HFEs. It is concluded that there are few HFEs that still possess some environmental hazards, including global warming, flammability hazard and adverse effect of exposure. The partition coefficient for these HFEs has been estimated using the group contribution method; the values of logKow for commercial HFEs have been estimated to be below 3.5.

  6. Heart Rate Variability Correlates to Functional Aerobic Impairment in Hemodialysis Patients

    PubMed Central

    Carreira, Maria Angela Magalhães de Queiroz; Nogueira, André Barros; Pena, Felipe Montes; Kiuchi, Marcio Galindo; Rodrigues, Ronaldo Campos; Rodrigues, Rodrigo da Rocha; de Matos, Jorge Paulo Strogoff; Lugon, Jocemir Ronaldo

    2015-01-01

    Background Autonomic dysfunction (AD) is highly prevalent in hemodialysis (HD) patients and has been implicated in their increased risk of cardiovascular mortality. Objective To correlate heart rate variability (HRV) during exercise treadmill test (ETT) with the values obtained when measuring functional aerobic impairment (FAI) in HD patients and controls. Methods Cross-sectional study involving HD patients and a control group. Clinical examination, blood sampling, transthoracic echocardiogram, 24-hour Holter, and ETT were performed. A symptom-limited ramp treadmill protocol with active recovery was employed. Heart rate variability was evaluated in time domain at exercise and recovery periods. Results Forty-one HD patients and 41 controls concluded the study. HD patients had higher FAI and lower HRV than controls (p<0.001 for both). A correlation was found between exercise HRV (SDNN) and FAI in both groups. This association was independent of age, sex, smoking, body mass index, diabetes, and clonidine or beta-blocker use, but not of hemoglobin levels. Conclusion No association was found between FAI and HRV on 24-hour Holter or at the recovery period of ETT. Of note, exercise HRV was inversely correlated with FAI in HD patients and controls. PMID:26131705

  7. Randomized clinical study comparing metallic and glass fiber post in restoration of endodontically treated teeth.

    PubMed

    Gbadebo, Olaide S; Ajayi, Deborah M; Oyekunle, Oyekunle O Dosumu; Shaba, Peter O

    2014-01-01

    Post-retained crowns are indicated for endodontically treated teeth (ETT) with severely damaged coronal tissue. Metallic custom and prefabricated posts have been used over the years, however, due to unacceptable color, extreme rigidity and corrosion, fiber posts, which are flexible, aesthetically pleasing and have modulus of elasticity comparable with dentin were introduced. To compare clinical performance of metallic and glass fiber posts in restoration of ETT. 40 ETT requiring post retained restorations were included. These teeth were randomly allocated into 2 groups. Twenty teeth were restored using a glass fiber-reinforced post (FRP) and 20 others received stainless steel parapost (PP), each in combination with composite core buildups. Patients were observed at 1 and 6 months after post placement and cementation of porcelain fused to metal (PFM) crown. Marginal gap consideration, post retention, post fracture, root fracture, crown fracture, crown decementation and loss of restoration were part of the data recorded. All teeth were assessed clinically and radiographically. Fisher's exact test was used for categorical values while log-rank test was used for descriptive statistical analysis. One tooth in the PP group failed, secondary to decementation of the PFM crown giving a 2.5% overall failure while none in the FRP group failed. The survival rate of FRP was thus 100% while it was 97.5% in the PP group. This however was not statistically significant (log-rank test, P = 0.32). Glass FRPs performed better than the metallic post based on short-term clinical performance.

  8. Exercise-triggered transient R-wave enhancement and ST-segment elevation in II, III, and aVF ECG leads: a testament to the "plasticity" of the QRS complex during ischemia.

    PubMed

    Madias, John E; Attari, Mehran

    2004-04-01

    We describe a patient with coronary artery disease who showed transiently augmented R-waves in his electrocardiogram (ECG) during the course of an exercise treadmill test (ETT), an ECG pattern occasionally associated with the hyperacute phase of myocardial infarction and variant angina. This change in the R-waves was noted in II, III, and aVF ECG leads and was associated with ST-segment elevation; both changed gradually and were normalized during the recovery period. Cardiac enzymes after ETT were negative, and arteriography revealed 3-vessel coronary artery disease, with a completely occluded right coronary artery. The ventriculogram showed very mild hypokinesis of the inferior left ventricular wall, while the global ejection fraction was 75%. These ECG changes, noted previously during ETT in precordial ECG leads, are herein reported to occur also in II, III, and aVF ECG leads. The generation of these ECG changes, which hinges upon a late unopposed depolarization occurring in the course and at the site of severe ischemic injury, constitutes a transient focal ventricular conduction abnormality.

  9. Endotracheal tube displacement during head and neck movements. Observational clinical trial.

    PubMed

    Tailleur, Robert; Bathory, Istvan; Dolci, Mirko; Frascarolo, Philippe; Kern, Christian; Schoettker, Patrick

    2016-08-01

    Measure the displacements of endotracheal tube (ETT) tip displacement during head and neck movements. Observational study. Ear-nose-throat (ENT) and neurosurgery operating room. We performed a maximal head-neck movement trial on 50 adult patients, American Society of Anaesthesiologists 1 or 2. Patients with body mass index >35 kg · m(-2), height <150 cm, airway malformations, pulmonary diseases, difficulties in neck flexion or extension, previous ENT surgery or radiotherapy, gastroesophageal reflux, or dental instability were excluded from the study. ENT and neurosurgery. We measured the change in distance between the ETT tip and the carina, using a fiberscope through the ETT. After intubation, a wide disparity of tube tip distance to the carina in the neutral position was noted with a median of 5.0 (3.5-7.0) cm. Cephalad tube movement was documented following maximal head and neck extension in 34 (68%) patients and right head rotation in 25 patients (50%). Caudal tube displacement was due to maximal head and neck flexion in 38 patients (76%) and left head rotation in 25 patients (50%). Selective right main bronchus intubation was noted in 2 (4%) patients after maximal head extension. Maximal head and neck movements led to unpredictable tube displacements. Proper reassessment of tube positioning after head and neck movement of intubated patients is therefore mandatory. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Effects of aerobic conditioning in lupus fatigue: a pilot study.

    PubMed

    Robb-Nicholson, L C; Daltroy, L; Eaton, H; Gall, V; Wright, E; Hartley, L H; Schur, P H; Liang, M H

    1989-12-01

    Fatigue, a complex symptom, significantly affects the quality of life in many patients with systemic lupus erythematosus (SLE). To understand this phenomenon, 23 patients with SLE and fatigue were studied. Standardized tests of depression (NIMH), fatigue, exercise tolerance (ETT) on a bicycle ergometer, and SLE activity were obtained. At baseline, SLE patients had significantly lower maximum oxygen consumption (VO2 max) than normals (p less than 0.005). Adjusted for age and sex, SLE patients perform at 54% of their expected maximum VO2, which is similar to published data from patients with rheumatoid arthritis. Depression by NIMH was not correlated with VO2 max or length of time on ETT. Fatigue measured by Profile of Mood States (POMS) was correlated with ETT time (r = 0.476, p less than 0.025) and with VO2 max (r = -0.402, p less than 0.07). After an 8-week aerobic conditioning programme the experimental group increased their aerobic capacity by 19% in contrast to 8% in controls. This change correlated with decreased fatigue as measured by visual analogue scales. Exercise did not exacerbate disease, and only two of 16 experimental subjects experienced transient joint symptoms during exercise.

  11. Comparison of quantification methods illustrates reduced Pseudomonas aeruginosa activity on nanorough polyvinyl chloride.

    PubMed

    Seil, Justin T; Rubien, Nathan M; Webster, Thomas J; Tarquinio, Keiko M

    2011-07-01

    Patients on mechanical ventilators for extended periods of time are faced with a high probability of developing ventilator associated pneumonia. Although this has been mostly addressed through the re-engineering of endotracheal tubes (ETTs) with antimicrobial materials, such material coatings may easily delaminate during use. However, the potential exists to apply nanotechnology to the ETT to avoid delamination but implement antibacterial properties. Selecting a protocol to evaluate in vitro material for anti-infection is difficult, partially due to the existence of conflicting reported methods of analysis. In this study, the susceptibility of conventional and nanorough polymeric materials to bacterial biofilm growth were evaluated. After creating nanorough polyvinyl chloride (PVC) ETTs, Pseudomonas aeruginosa biofilms were then grown on sample surfaces during a 24-h culture. Biofilms were then removed and assayed from sample surfaces using a variety of techniques. Comparisons between the different techniques used for biofilm removal indicated that vortexing provided adequate removal of the biofilm from sample surfaces. Most importantly, a protocol following the vortexing method of biofilm and bacteria removal provided an ∼40% lower yield of colony forming units from nanorough PVC compared to conventional PVC. This suggests that Pseudomonas aeruginosa are less adherent on nanorough PVC than conventional PVC.

  12. Strain induced Z{sub 2} topological insulating state of β-As{sub 2}Te{sub 3}

    SciTech Connect

    Pal, Koushik; Waghmare, Umesh V.

    2014-08-11

    Topological insulators are non-trivial quantum states of matter which exhibit a gap in the electronic structure of their bulk form, but a gapless metallic electronic spectrum at the surface. Here, we predict a uniaxial strain induced electronic topological transition (ETT) from a band to topological insulating state in the rhombohedral phase (space group: R3{sup ¯}m) of As{sub 2}Te{sub 3} (β-As{sub 2}Te{sub 3}) through first-principles calculations including spin-orbit coupling within density functional theory. The ETT in β-As{sub 2}Te{sub 3} is shown to occur at the uniaxial strain ϵ{sub zz} = −0.05 (σ{sub zz} = 1.77 GPa), passing through a Weyl metallic state with a single Dirac cone in its electronic structure at the Γ point. We demonstrate the ETT through band inversion and reversal of parity of the top of the valence and bottom of the conduction bands leading to change in the ℤ{sub 2} topological invariant ν{sub 0} from 0 to 1 across the transition. Based on its electronic structure and phonon dispersion, we propose ultra-thin films of As{sub 2}Te{sub 3} to be promising for use in ultra-thin stress sensors, charge pumps, and thermoelectrics.

  13. Comparison of EtView™ tracheoscopic ventilation tube and video-assisted fiberoptic bronchoscopy during percutaneous dilatational tracheostomy.

    PubMed

    Umutoglu, Tarik; Bakan, Mefkur; Topuz, Ufuk; Yilmaz, Sinan; Idin, Kadir; Alver, Selcuk; Ozturk, Erdogan; Salihoglu, Ziya

    2017-06-01

    Fiberoptic bronchoscopy (FOB) via endotracheal tube (ETT) is the most frequent utilized technique for monitoring of percutaneous dilatational tracheostomy (PDT) procedure while maintaining mechanical ventilation. Endoscopic guidance has increased the safety of this procedure; nevertheless, the use of a bronchoscope via ETT potentially may deteriorate ventilation and lead to hypercarbia and/or hypoxia. EtView tracheoscopic ventilation tube (EtView TVT) is a standard endotracheal tube with a camera and light source embedded at the tip. The objectives of this study are to introduce EtView TVT as a monitoring tool during PDT and to compare it with video assisted FOB via ETT. We hypothesized that using EtView TVT during PDT may obtain similar visualization; also may have advantages regarding better mechanical ventilation conditions when compared with video-assisted FOB via ETT. Patients, 18-75 years of age requiring mechanical ventilation scheduled for PDT were randomly allocated into two groups for airway monitorization to guide PDT procedure either with FOB via ETT (Group FOB, n = 12) or EtView TVT (Group EtView, n = 12). After standard anesthesia protocol, alveolar recruitment maneuver was applied and all patients were mechanically ventilated at pressure-controlled ventilation mode with same pressure levels. The primary outcome variable was the reduction in arterial oxygen partial pressure (PaO2) values during the procedure. Other respiratory variables and the effectiveness (the visualization and identification of relevant airway structures) of two techniques were the secondary outcome variables. Patients in both groups were comparable with respect to demographic characteristics and initial respiratory variables. Visualization and identification of relevant airway structures in any steps of the PDT procedure were also comparable. The decrease in minute ventilation in Group FOB was higher when compared with Group EtView (51 ± 4 % vs. 12 ± 7.3 %, p < 0

  14. A comparison of a traditional endotracheal tube versus ETView SL in endotracheal intubation during different emergency conditions: A randomized, crossover cadaver trial.

    PubMed

    Truszewski, Zenon; Krajewski, Paweł; Fudalej, Marcin; Smereka, Jacek; Frass, Michael; Robak, Oliver; Nguyen, Bianka; Ruetzler, Kurt; Szarpak, Lukasz

    2016-11-01

    Airway management is a crucial skill essential to paramedics and personnel working in Emergency Medical Services and Emergency Departments: Lack of practice, a difficult airway, or a trauma situation may limit the ability of paramedics to perform direct laryngoscopy during cardiopulmonary resuscitation. Videoscope devices are alternatives for airway management in these situations. The ETView VivaSight SL (ETView; ETView Ltd., Misgav, Israel) is a new, single-lumen airway tube with an integrated high-resolution imaging camera. To assess if the ETView VivaSight SL can be a superior alternative to a standard endotracheal tube for intubation in an adult cadaver model, both during and without simulated CPR. ETView VivaSight SL tube was investigated via an interventional, randomized, crossover, cadaver study. A total of 52 paramedics participated in the intubation of human cadavers in three different scenarios: a normal airway at rest without concomitant chest compression (CC) (scenario A), a normal airway with uninterrupted CC (scenario B) and manual in-line stabilization (scenario C). Time and rate of success for intubation, the glottic view scale, and ease-of-use of ETView vs. sETT intubation were assessed for each emergency scenario. The median time to intubation using ETView vs. sETT was compared for each of the aforementioned scenarios. For scenario A, time to first ventilation was achieved fastest for ETView, 19.5 [IQR, 16.5-22] sec, when compared to that of sETT at 21.5 [IQR, 20-25] sec (p = .013). In scenario B, the time for intubation using ETView was 21 [IQR, 18.5-24.5] sec (p < .001) and sETT was 27 [IQR, 24.5-31.5] sec. Time to first ventilation for scenario C was 23.5 [IQR, 19-25.5] sec for the ETView and 42.5 [IQR, 35-49.5] sec for sETT. In normal airways and situations with continuous chest compressions, the success rate for intubation of cadavers and the time to ventilation were improved with the ETView. The time to glottis view, tube insertion

  15. Lipase degradation of plasticized polyvinyl chloride endotracheal tube surfaces to create nanoscale features

    PubMed Central

    Machado, Mary C; Webster, Thomas J

    2017-01-01

    Polyvinyl chloride (PVC) endotracheal tubes (ETTs) nanoetched with a fungal lipase have been shown to reduce bacterial growth and biofilm formation and could be an inexpensive solution to the complex problem of ventilator-associated pneumonia (VAP). Although bacterial growth and colonization on these nanoetched materials have been well characterized, little is known about the mechanism by which the fungal lipase degrades the PVC and, thus, alters its properties to minimize bacteria functions. This study used X-ray photoelectron spectroscopy (XPS) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) to better describe the surface chemistry of both unetched and lipase nanoetched PVC ETT. ATR-FTIR analysis of the unetched and treated surfaces showed a similar presence of a plasticizer. This was confirmed by XPS analysis, which showed an increase of carbon and the presence of oxygen on both unetched and nanoetched surfaces. A quantitative comparison of the FTIR spectra revealed significant correlations (Pearson’s correlation, R=0.997 [R2=0.994, P<0.001]) between the unetched and nanomodified PVC ETT spectra, demonstrating similar surface chemistry. This analysis showed no shifting or widening of the bands in the spectra and no significant changes in the intensity of the infrared peaks due to the degradation of the plasticizer by the fungal lipase. In contrast, results from this study did demonstrate significantly increased nanoscale surface features on the lipase etched compared to non-etched PVC ETTs. This led to a change in surface energetics, which altered ion adsorption to the ETTs. Thus, these results showed that PVC surfaces nanoetched with a 0.1% lipase solution for 48 hours have no significant change on surface chemistry but do significantly increase nanoscale surface roughness and alters ion adsorption, which suggests that the unique properties of these materials, including their previously reported ability to decrease

  16. Deep versus shallow suction of endotracheal tubes in ventilated neonates and young infants.

    PubMed

    Gillies, Donna; Spence, Kaye

    2011-07-06

    Mechanical ventilation is commonly used in Neonatal Intensive Care Units to assist breathing in a variety of conditions. Mechanical ventilation is achieved through the placement of an endotracheal tube (ETT) which is left in-situ. The ETT is suctioned to prevent a build-up of secretions and blockage of the airway. Methods of suctioning the endotracheal tube vary according to institutional practice and the individual clinician performing the task. The depth of suctioning is one of these variables. The catheter may be passed to the tip of the ETT or beyond the tip into the trachea or bronchi to facilitate removal of secretions. However, trauma to the lower airways may result from the suction catheter being passed into the airway beyond the tip of the endotracheal tube. To compare the effectiveness and complications of deep (catheter passed beyond the tip of the ETT) versus shallow (catheter passed to length of ETT only) suctioning of the endotracheal tube in ventilated infants. In this first update the searches were expanded to the Cochrane Central Register of Controlled Trials (The Cochrane Library, March 30), MEDLINE (from January 1966 to May 30 2011), CINAHL (from 1982 to May 30 2011) and EMBASE (1980 to May 2011) using text words and subject headings relevant to endotracheal suctioning. There were no language restrictions. Controlled trials using random or quasi-random allocation of neonates receiving ventilatory support via an endotracheal tube to either deep or shallow endotracheal suctioning. The updated search resulted in 149 potentially relevant references. Two of the studies from this search were identified as potentially relevant. We included one of the potentially relevant studies and the other was excluded because it did not fit the inclusion criteria. One small crossover trial (n = 27) of shallow versus deep suctioning met the criteria for inclusion in this review. The reported outcomes were oxygen saturation and heart rate, during and after suctioning

  17. Effect of fiber posts on the fracture resistance of endodontically treated anterior teeth with cervical cavities: An in vitro study.

    PubMed

    Abduljawad, Mohammed; Samran, Abdulaziz; Kadour, Jadalkareem; Al-Afandi, Mahmoud; Ghazal, Mohamad; Kern, Matthias

    2016-07-01

    How the placement of fiber posts affects the fracture resistance of endodontically treated maxillary central incisors with cervical cavities is not well documented. The purpose of this in vitro study was to evaluate the effect of fiber posts on the fracture resistance of endodontically treated maxillary central incisors with cervical cavities. Fifty extracted human maxillary central incisors were selected and divided into 5 test groups (n=10) according to the restoration strategy: GHT, control group; endodontically treated teeth (ETT) without endodontic posts; GCV, ETT with cervical cavities simulating coronal destruction; GCF, ETT with cervical cavities and carbon fiber posts; GGF, ETT with cervical cavities and glass fiber posts; and GCP, ETT with cervical cavities and composite resin posts. After the fiber posts had been cemented with a resin cement and the foundations had been placed, all specimens were quasi statically loaded at 45 degrees in a universal testing machine until fracture. All specimens were evaluated for fracture modes. The data were then analyzed by 1-way ANOVA, followed by multiple comparisons with the Tukey HSD test (α=.05). The mode of failure was determined by visual inspection. The mean ±SD failure loads for the groups ranged from 718.2 ±89.8 N to 943.8 ±93.1 N. In a 1-way ANOVA followed by post hoc testing, GGFs had a higher fracture strength than all other groups (P≤.05). However, GCPs had a lower fracture strength than all other groups. Statistically significant differences were observed among groups (P≤.05), except between the GHT group and the GCF and GGF groups (P=.075, P=.226). All groups except GHT showed complete favorable fracture mode within the cervical third of the roots. Within the limitations of this in vitro study, placement of glass fiber posts significantly improved the fracture resistance of endodontically treated maxillary central incisors with cervical cavities. Copyright © 2016 Editorial Council for the

  18. Achieving a Safe Endotracheal Tube Cuff Pressure in the Prehospital Setting: Is It Time to Revise the Standard Cuff Inflation Practice?

    PubMed

    Carhart, Elliot; Stuck, Logan H; Salzman, Joshua G

    2016-01-01

    Numerous studies have reported unsafe endotracheal tube (ETT) cuff pressures (CP) in the prehospital environment. The purpose of this study was to identify an optimal cuff inflation volume (CIV) to achieve a safe CP (20-30 cmH2O). This observational study utilized 30 recently harvested ovine tracheae, which were warmed from refrigeration in a water bath at 85°F prior to testing. Each trachea was intubated with five different ETT sizes (6.0-8.0 mm), and each size tube was tested with six cuff inflation volumes (5-10 cc). The order of ETT size for each trachea and CIV for each size ETT was randomly pre-assigned. Data were descriptively summarized and categorized before mixed-effects logistic regression was used to determine optimal CIV. Only 113 CP measurements (12.6%, N = 900) were within the optimal range (M = 54.75 cmH2O, SD = 38.52), all of which resulted from a CIV 6 or 7 cc (61% and 39%, respectively). CIVs of 5 cc (n = 150) resulted in underinflation (<20 cmH2O) in all instances, while CIVs of 8, 9, or 10 cc (n = 150 each) resulted in overinflation (>30 cmH2O) in all instances, regardless of ETT size. The odds of achieving a safe CP were greater with CIV of 6 cc for tube sizes 6.0 (OR = 15.9, 95% CI = 3.85-65.58, p < 0.01) and 6.5 mm (OR = 3.16, 95% CI = 1.06-9.39, p = 0.039); however, there was no significant difference in the odds of achieving a safe CP between CIV of 6 and 7 cc for tube sizes 7.0, 7.5, or 8.0 mm. Neither trachea circumference (M = 7.11 cm, SD = 0.40), nor tissue temperature (M = 81.32°F, SD = 0.93) were found to be significant predictors of CP (p = 0.20 and 0.81, respectively). Our study showed a high frequency of CP measurements outside of the desired norms. The CIV range of 6-7 cc resulted in the highest likelihood of achieving the desired cuff pressure range, while cuffs inflated with 8-10 cc resulted in dangerously high CPs in all instances. In the absence of a more ideal solution, the results of this study suggest that narrowing the

  19. Unusual room temperature activation of 1,2-dialkoxyalkanes by niobium and tantalum pentachlorides.

    PubMed

    Marchetti, Fabio; Pampaloni, Guido; Zacchini, Stefano

    2008-12-28

    The outcome of the reactions of MCl(5) (M = Nb, 1a; M = Ta, 1b) with 1,2-dialkoxyalkanes [i.e. MeO(CH(2))(2)OMe (dme), EtO(CH(2))(2)OEt, MeOCH(2)CH(Me)OMe, MeO(CH(2))(2)OCH(2)Cl, MeO(CH(2))(2)O(CH(2))(2)OMe (diglyme)] depends strictly on the stoichiometry. In the 1 : 1 molar ratio reactions, single C-O bond cleavage occurs, resulting in formation of alkyl chloride and of the complexes [upper bond 1 start]MCl(4)[O(R)CH(R')CH(2)O][upper bond 1 end] [M = Nb, R = Me, R' = H, 3a; M = Ta, R = Me, R' = H, 3b; M = Nb, R = Et, R' = H, 5; M = Nb, R = R' = Me, 6; M = Nb, R = CH(2)Cl, R' = H, 7; M = Nb, R = (CH(2))(2)O(Me)NbCl(5), R' = H, 8], which have been characterized spectroscopically. Moreover, minor amounts of the oxo-bridged adducts MOCl(3)(dme)MCl(5) (M = Nb, 4a; M = Ta, 4b) have been isolated in the reactions involving dme. On the other hand, compounds react with two (or more) equivalents of dme mainly via a multiple C-O bond cleavage process, affording MOCl(3)(dme) (M = Nb, 2a; M = Ta, 2b), 1,4-dioxane and methyl chloride. The oxychloride compounds MOCl(3) (M = Nb, 11a; M = Ta, 11b) have been efficiently obtained by addition of TiCl(4) to 2. Compound 2a is reduced in high yield to the Nb(III) species NbCl(3)(dme), 12, upon treatment with SnBu(3)H. The oxychloride NbOCl(3)(diglyme), 9, 1,4-dioxane, CH(3)Cl and the hexachloroniobate salt [MeOCH(2)CH(2)OCH(2)CH(2)O(H)Me][NbCl(6)], 10, have been identified as products of the reaction of 1a with two equivalents of diglyme. The 1 : 2 molar ratio reaction of 1a with MeOCH(2)CH(Me)OMe gives 2,5-dimethyl-1,4-dioxane. Compound 1a reacts with two equivalents of EtO(CH(2))(2)OEt or MeO(CH(2))(2)OCH(2)Cl yielding Cl(CH(2))(2)OCH(2)CH(3) or O(CH(2)Cl)(2) and diglyme, respectively, but not dioxane, suggesting that fragmentation pathways different from that found for dme are operating. The X-ray molecular structures of 4a, 4b and 10 have been determined.

  20. Reduction of Endotracheal Tube Connector Dead Space Improves Ventilation: A Bench Test on a Model Lung Simulating an Extremely Low Birth Weight Neonate.

    PubMed

    Ivanov, Vadim A

    2016-02-01

    The reduction of instrumental dead space is a recognized approach to preventing ventilation-induced lung injury in premature infants. However, there are no published data regarding the effectiveness of instrumental dead-space reduction in endotracheal tube (ETT) connectors. We tested the impact of the Y-piece/ETT connector pairs with reduced instrumental dead space on CO2 elimination in a model of the premature neonate lung. The standard ETT connector was compared with a low-dead-space ETT connector and with a standard connector equipped with an insert. We compared the setups by measuring the CO2 elimination rate in an artificial lung ventilated via the connectors. The lung was connected to a ventilator via a standard circuit, a 2.5-mm ETT, and one of the connectors under investigation. The ventilator was run in volume-controlled continuous mandatory ventilation mode. The low-dead-space ETT connector/Y-piece and insert-equipped standard connector/Y-piece pairs had instrumental dead space reduced by 36 and 67%, respectively. With set tidal volumes (VT) of 2.5, 5, and 10 mL, in comparison with the standard ETT connector, the low-dead-space connector reduced CO2 elimination time by 4.5% (P < .05), 4.4% (P < .01), and 7.1% (not significant), respectively. The insert-equipped standard connector reduced CO2 elimination time by 13.5, 25.1, and 16.1% (all P < .01). The low-dead-space connector increased inspiratory resistance by 17.8% (P < .01), 9.6% (P < .05), and 5.0% (not significant); the insert-equipped standard connector increased inspiratory resistance by 9.1, 8.4, and 5.9% (all not significant). The low-dead-space connector decreased expiratory resistance by 6.8% (P < .01) and 1.8% (not significant) and increased it by 1.4% (not significant); the insert-equipped standard connector decreased expiratory resistance by 1.5 and 1% and increased it by 1% (all not significant). The low-dead-space connector increased work of breathing by 4.7% (P < .01), 3.8% (P < .01), and