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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. 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.

  4. 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.

  5. 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.

  6. 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).

  7. 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…

  8. 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.

  9. 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.

  10. 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.

  11. 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).

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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…

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  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. 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.

  14. 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.

  15. 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

  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. 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.

  19. 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.

  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. 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.

  2. 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.

  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. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. 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.

  11. 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+.

  12. 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).

  13. 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.

  14. 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…

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. Communication: Direct observation of a hydrophobic bond in loop closure of a capped (-OCH2CH2-)n oligomer in water

    NASA Astrophysics Data System (ADS)

    Chaudhari, Mangesh I.; Pratt, Lawrence R.; Paulaitis, Michael E.

    2010-12-01

    The small r variation of the probability density P(r) for end-to-end separations of a -CH _2CH _3 capped (-OCH _2CH _2-) _n oligomer in water is computed to be closely similar to the CH _4\\cdots CH _4 potential of mean force under the same circumstances. Since the aqueous solution CH _4\\cdots CH _4 potential of mean force is the natural physical definition of a primitive hydrophobic bond, the present result identifies an experimentally accessible circumstance for direct observation of a hydrophobic bond which has not been observed previously because of the low solubility of CH _4 in water. The physical picture is that the soluble chain molecules carry the capping groups into aqueous solution, and permits them to find one another with reasonable frequency. Comparison with the corresponding results without the solvent shows that hydration of the solute oxygen atoms swells the chain molecule globule. This supports the view that the chain molecule globule might have a secondary effect on the hydrophobic interaction that is of first interest here. The volume of the chain molecule globule is important for comparing the probabilities with and without solvent because it characterizes the local concentration of capping groups. Study of other capping groups to enable x-ray and neutron diffraction measurements of P(r) is discussed.

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 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...

  7. 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.

  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. 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.

  11. {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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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)

  18. 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.

  19. 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

  20. 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…

  1. 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.

  2. 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.…

  3. 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…

  4. 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…

  5. 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…

  6. 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…

  7. 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.

  8. Enlisted Personnel Individualized Career System (EPICS) Design, Development, and Implementation

    DTIC Science & Technology

    1984-01-01

    I 0 TV CI.MPICAIWSO 6P.S PM (Mme Due ae* SEPICS features use of 3PAs, deferred formal training, and an individualized career... advancement...3.0 Use of Simpson 260-5P multimeter ETT 4.0 Variational analysis of DC series circuits ErT 5.0 Parallel DC circuits ETT 6.0 Combination DC circuits ETT...7.0 Special DC circuits ETT 8.0 Introduction to AC test equipment4 ETT 9.0 Introduction to inductors ETT 10.0 Transformer identification and

  9. 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…

  10. 40 CFR 63.11459 - What definitions apply to this subpart?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... metal-based compounds, such as lead oxide, chromium oxide, and sodium antimonate; metal ores, such as chromite and pyrolusite; and other substances that are intentionally added to a glass manufacturing...

  11. 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

  12. 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…

  13. 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.…

  14. 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.

  15. 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.

  16. 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…

  17. 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…

  18. 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…

  19. 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…

  20. 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…

  1. 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.

  2. 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…

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. [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.

  8. 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…

  9. 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…

  10. 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…

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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…

  19. [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.

  20. 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.

  1. 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

  2. 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

  3. 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].

  4. Field Testing New Plot Designs and Methods for Determining Hydrophytic Vegetation during Wetland Delineations in the United States

    DTIC Science & Technology

    2014-03-01

    Engineers. Walter Ochs provided the ini- tial idea for evaluating the 80% approach based on differences in the standard deviation. Christy Everett and Jim...Godswire provided assistance in selecting sites to collect the CRREL data. Bruce Allen, Lindsey Lefevbre, Walter Ochs , Corinna Photos, Bill Sipple...vegetation determination (USACE 2010a). The 80.0% value was developed in 2005 (R. Lichvar and W. Ochs , unpublished data) by analyzing a national set of

  5. 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

  6. 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

  7. 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…

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 40 CFR 421.142 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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...

  4. 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...

  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...

  6. 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

  7. 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...

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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

  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. 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.

  16. 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

  17. 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

  18. 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.

  19. 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

  20. Comparison of prophylactic effects of polyurethane cylindrical or tapered cuff and polyvinyl chloride cuff endotracheal tubes on ventilator-associated pneumonia.

    PubMed

    Mahmoodpoor, Ata; Peyrovi-far, Ali; Hamishehkar, Hadi; Bakhtyiari, Zhaleh; Mirinezhad, Mir Mousa; Hamidi, Masoud; Golzari, Samad Eslam Jamal

    2013-08-07

    Because microaspiration of contaminated supraglottic secretions past the endotracheal tube cuff is considered to be central in the pathogenesis of pneumonia, improved design of tracheal tubes with new cuff material and shape have reduced the size and number of folds, which together with the addition of suction ports above the cuff to drain pooled subglottic secretions leads to reduced aspiration of oropharyngeal secretions. So we conducted a study to compare the prophylactic effects of polyurethane-cylindrical or tapered cuff and polyvinyl chloride cuff endotracheal tubes (ETT) on ventilator-associated pneumonia. This randomized clinical trial was carried out in a 12 bed surgical intensive care unit. 96 patients expected to require mechanical ventilation more than 96 hours were randomly allocated to one of three following groups: Polyvinyl chloride cuff (PCV) ETT, Polyurethane (PU) cylindrical Sealguard ETT and PU Taperguard ETT. Cuff pressure monitored every three hours 3 days in all patients. Mean cuff pressure didn't have significant difference between three groups during 72 hours. Pneumonia was seen in 11 patients (34%) in group PVC, 8 (25%) in Sealguard and 7 (21%) in Taperguard group. Changes in mean cuff pressure between Sealguard and PVC tubes and also between Taperguard and PVC tubes did not show any significant difference. There was no significant difference in overinflation between three groups. The use of ETT with PU material results in reducing ventilator-associated pneumonia compared to ETT with PVC cuff. In PU tubes Taperguard has less incidence of ventilator-associated pneumonia compared to Sealguard tubes.

  1. 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.

  2. 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

  3. 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...

  4. 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...

  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. 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.

  8. 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

  9. 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

  10. 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).

  11. 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.

  12. 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.

  13. 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).

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. Endotracheal Tube Cuff Management at Altitude

    DTIC Science & Technology

    2014-02-05

    adults Fixed wing/3,000 Cuff pressure 45 cm H2O at 3,000 ft Mann [11] ETTs LMA Air filled Diameter Bench top Rotor wing/10,000 Cuff diameter...increased by 4.5 mm at 10,000 ft Wilson [12] LMA Air filled Pressure Adult & infant mannequin Fixed wing/6,000 Rotor wing/2,200 Cuff pressure...120 cm H2O at 5,000 ft Miyashiro [13] ETTs LMA Air filled Pressure Tracheal model Ground ascent/ 7,874 Cuff pressure > 80 cm H2O at 8,000

  7. 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

  8. 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

  9. 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.

  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. 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.

  12. 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.

  13. 2011 North Plains research field 12-200 limited irrigation corn production study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  14. 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

  15. Algorithm Development for the Multi-Fluid Plasma Model

    DTIC Science & Technology

    2011-05-30

    to preserve the diver- gence constraint relations. Figure 2 shows the results for the GEM challenge ( Geospace Environmental Modeling Magnetic...Bhattacharjee, A. Otto, and P. L. Pritch- ett. Geospace Environmental Modeling (GEM) Magnetic Reconnection Challenge. Journal of Geophysical Research, 106

  16. 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.

  17. 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

  18. 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

  19. 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.

  20. 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

  1. 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…

  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. 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).

  4. Protective effect of an aphrodisiac herb Tribulus terrestris Linn on cadmium-induced testicular damage

    PubMed Central

    Rajendar, B.; Bharavi, K.; Rao, G. S.; Kishore, P.V.S; Kumar, P. Ravi; Kumar, C.S.V Satish; Patel, T. Pankaj

    2011-01-01

    Aim: The aim of the present study was to investigate whether Tribulus terrestris Linn (TT) could protect the cadmium (Cd)-induced testicular tissue peroxidation in rats and to explore the underlying mechanism of the same. Materials and Methods: In vitro and in vivo studies were conducted to know the protective effect of ethanolic extract of TT (eTT) in Cd toxicity. In in vitro studies, total antioxidant and ferrous metal ion chelating activity of TT was studied. In vivo studies were conducted in rats. A total of 40 Wistar strain adult male rats were divided into four groups. Group 1 served as control, while group 2 to 4 received CdCl2 (3 mg/kg b. wt. s/c once a week). In addition to Cd, group 3 and 4 rats also received eTT (5 mg/kg b.wt. daily as oral gavage) and α-tocopherol (75 mg/kg daily by oral gavage), respectively. At the end of 6th week, all the rats were sacrificed and the separated testes were weighted and processed for estimation of tissue peroxidation markers, antioxidant markers, functional markers, and Cd concentration. The testes were also subjected to histopathological screening. Results: In in vitro studies, the percentage of metal ion chelating activity of 50 μg/ml of eTT and α-tocopherol were 2.76 and 9.39, respectively, and the antioxidant capacity of eTT was equivalent to 0.063 μg of α-tocopherol/μg of eTT. In in vivo studies, administration of Cd significantly reduced the absolute and relative testicular weight, antioxidant markers such as superoxide dismutase and glutathione, and functional markers such as LDH and ALP, along with significant increase in peroxidation markers such as malondialdehyde and protein carbonyls in testicular tissue. Testes of Cd only-treated group showed histological insults like necrotic changes in seminiferous tubules and interstitium, shrunken tubules with desquamated basal lamina, vacuolization and destruction of sertoli cells, and degenerating Leydig cells. This group also had higher Cd levels in testicular

  5. 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

  6. 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.

  7. 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.

  8. 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.

  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. 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.

  11. 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.

  12. 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.

  13. [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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Synthesis, Characterization, and Modification of Poly(Organophosphazenes), that Bear Both 2,2,2-Trifluoroethoxy and Phenoxy Groups

    DTIC Science & Technology

    1993-05-18

    tissues to the surfaces of these various polymers . Results and Discussion Synthesis and Composition of Polymers . (a) Competitive Reactions of Sodium...attached MAY 2 6 1993U •i• ’ 2 6293-11554 14. SUBJECT TE’RMS’ 1. NUMBER OF PAGES Polymers , phosphazenes, synthesis , elastomers 45 16. PRICE CODE 17...of NP(OCH2CF 3)2 , NP(OCH 2CF3 )(OPh) and NP(OPh)2 units in the polymer are dependent on both the synthesis method and the amounts of CF3CH20- Na+ and

  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. 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.

  2. 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.

  3. 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.”

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. Smoking and Soldier Performance: A Literature Review

    DTIC Science & Technology

    1986-06-01

    components in cigarette smoke such as benzopyrene and polonium , have been implicated in develop- ient of lung cancer (Clee and Clark 1982), nicotine...the decreased ability of smokers to clear dust particles from their lungs as a 152 possible factor in increased cancer among asbestos and uranium...Behavioral pharmacology of cigar- ette smoking. Advances in Behavioral Pharmacology. 4:131- 210 . Henningfield, J. E., Chait, L. D., anO Griffiths, R. R

  15. 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

  16. 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

  17. 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.

  18. 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.).

  19. 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

  20. 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.

  1. 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

  2. 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

  3. I Will Never Forget: An Analysis of the POW/MIA (Prisoners of War/Missing in Action) Episode in the War in Southeast Asia.

    DTIC Science & Technology

    1982-05-01

    Purcell, Benjamin H., Col Ett: ueiler, Harry L., SSgL Rander, Donald J., SFC . Flora, Carroll E. Jr., SFC Ray, Johnnie L., Capt Frank, ::artin 3.. SS...Jr., Lt Col Elander, William J., Jr., Maj Brenneman, Richard C., Capt Ellis, Jeffrey T., Capt Bridger, Barry B., Capt Ellis, Leon F., Capt Brodak...j * Guy, Theodore W.., Col Logn, c.., t Hall, George R., It Col Lollar. . Hall, Keith I., 1.:aj Luna , jose I., Capz *: Hanson, Gregg 0., 2t

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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.

  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. 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.

  11. 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.

  12. 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…

  13. 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…

  14. 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.

  15. 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.

  16. 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,…

  17. 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…

  18. 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)

  19. 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…

  20. 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…

  1. 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…

  2. 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)

  3. 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…

  4. 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?

  5. 40 CFR Table 2 to Subpart Jj of... - List of Volatile Hazardous Air Pollutants

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (Aroclors) 1336363 Polycyclic Organic Matter b 1,3-Propane sultone 1120714 beta-Propiolactone 57578... glycol ethers with the structure: R-(OCH2CH2)n—OH. Polymers are excluded from the glycol category. b Includes organic compounds with more than one benzene ring, and which have a boiling point greater than...

  6. 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.

  7. 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

  8. 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,…

  9. 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.

  10. 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,…

  11. Deciphering the Molecular Mechanisms of Breast Cancer

    DTIC Science & Technology

    2005-03-01

    suppressor genes in mitotic and meiotic Epstein, J.A., Yen, T.J., and Shiekhattar, R. (2001). A human BRCA2 complex containing a structural DNA... meiotic cells. Cell 88, 265–275. 96, 11364–11369. Scully, R., Chen, J., Ochs, R.L., Keegan, K., Hoehstra, M., Feunteun, J., and Livingston, D.M. (1997c

  12. 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…

  13. 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.

  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. 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.

  16. 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.

  17. 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

  18. 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

  19. OCO and NCO chelated derivatives of heavier group 15 elements. Study on possibility of cyclization reaction via intramolecular ether bond cleavage.

    PubMed

    Dostál, Libor; Jambor, Roman; Růžička, Aleš; Jirásko, Robert; Holeček, Jaroslav; De Proft, Frank

    2011-09-21

    A set of four pincer ligands, either the OCO type ligands L(1-3) [2,6-(ROCH(2))(2)C(6)H(3)](-), where R = Me (L(1)), mesityl (L(2)), t-Bu (L(3)) or novel NCO ligand [2-(Me(2)NCH(2))-6-(t-BuOCH(2))C(6)H(3)](-) was studied. The reaction of L(4)Li with PCl(3) resulted in isolation of [2-(OCH(2))-6-(Me(2)NCH(2))C(6)H(3)]PCl (1) as a result of intramolecular ether bond cleavage and elimination of t-BuCl. The conversion between the organolithium compounds L(1,2,4)Li and AsCl(3) led to the desired chlorides, i.e. (L(1))(2)AsCl (2), L(2)AsCl(2) (3), L(4)AsCl(2) (5), but an analogous reaction using the L(3)Li compound gave [2-(OCH(2))-6-(t-BuOCH(2))C(6)H(3)]AsCl (4) as a result of intramolecular cyclization. The organoantimony chloride L(3)SbCl(2) was shown to undergo very slow cyclization in CDCl(3) again via elimination of t-BuCl giving [2-(OCH(2))-6-(t-BuOCH(2))C(6)H(3)]SbCl (6) and it was demonstrated that this reaction may be accelerated by preparation of L(3)Sb(Cl)(OTf) (7) with more Lewis acidic central atom. On the contrary, both antimony derivatives of the NCO ligand L(4), not only the chloride L(4)SbCl(2) (8) but also the ionic pair containing highly Lewis acidic cation [L(4)SbCl](+)[CB(11)H(12)](-) (9), are stable without any indication for etheral bond cleavage. The situation is rather similar in the case of organobismuth derivatives of L(4), which allowed isolation of compounds L(4)BiCl(2) (10), L(4)Bi(Cl)(OTf) (11) and [L(4)BiCl](+)[CB(11)H(12)](-) (12). All studied compounds were characterized by the help of (1)H and (13)C NMR spectroscopy, ESI mass spectrometry, elemental analysis and (except 1) by single-crystal X-ray diffraction.

  20. Experimental PDT: studies on new Si-phthalocyanines and Si-naphthalocyanines in Cremophor emulsions

    NASA Astrophysics Data System (ADS)

    Shopova, Maria; Mantareva, Vanya; Woehrle, Dieter; Mueller, Silke

    1996-12-01

    In the present work the following silicon (IV) - phthalocyanines and -naphthalocyanines bearing methoxyethylene glycol or methoxypolyethylene glycol covalently bound at the silicon are investigated: SiPc[OCH2CH2OCH3]2 (SiPc1), SiNc[OCH2CH2OCH3]2 (SiNc), SiPc[(OCH2CH2)nOCH3] with n approximately 115 (SiPc2). The phototherapeutic effect was shown at Lewis lung carcinoma implanted in mice. SiPc2 is monomeric soluble in water whereas the other two compounds aggregated in this solvent. Therefore these compounds were dissolved monomer in in aqueous Cremophor solution before in vivo administration. Laser irradiation was applied 7 days after implantation and 24 h after drug administration at the following wavelength (eta) ext: 672 nm for SiPc1 and SiPc2, 782 nm for SiNc. In all cases a fluence rate of 370 mW/cm2 at fluence of 360 J/cm2 was used. The assessment criteria for the tumor response were the changes in the mean tumor diameter with time, regrowth delay and average survival time (AST). According to the first parameter the most promising result was obtained after treatment with SiPc1. For example the mean tumor diameter increases as follows: SiPc1 less than SiPc2 less than SiNc very much less than control group without photosensitizer. The regrowth delay showed the same trend. however, for AST another dependence was observed. AST was the longest for SiPc2 (26 days) and shortest for SiNc (22 days). Compared to the control group (without sensitizer and irradiation) the AST was 9 days longer after SiPc2 treatment. Comparing SiPc1 and SiPc2 the chain length of the substituents does not influence the phototherapeutic properties. The detected therapeutic results probably are connected with the long wavelength absorption of the photosensitizers. The relatively lower affectivity of SiNc may be due to a lower degree of tumor accumulation as it was observed in our preliminary pharmacokinetic studies. It is also possible that the shorter AST after treatment with SiNc is

  1. Anion Transport in Liposomes Responds to Variations in the Anchor Chains and the Fourth Amino Acid of Heptapeptide Ion Channels

    PubMed Central

    Ferdani, Riccardo; Pajewski, Robert; Djedovič, Natasha; Pajewska, Jolanta; Schlesinger, Paul H.; Gokel, George W.

    2008-01-01

    Seven heptapeptide derivatives have been prepared. The peptide structure is (Gly)3Xxx(Gly)3 in which Xxx stands for a variable amino acid. The amino acid variations include azetidine carboxylic acid, pipecolic acid, meta-aminobenzoic acid, proline, and leucine. All seven compounds have a C-terminal benzyl group. In all cases, the heptapeptide's N-terminus was linked to diglycolic acid and a dialkylamine. In five cases, the N-terminal group was didecylamine and in two cases, N-ethyl-N-decyl. Chloride and carboxyfluorescein release from phospholipid vesicles was studied with the result that C10H21N(C2H5) COCH2OCH2CO-NH-(Gly)3Leu(Gly)3-OCH2Ph was the most active. Hill analysis showed that this compound involves pore formation by four monomer units rather than two, as previously found for other members of this family. PMID:19169373

  2. Increasing the activity and enantioselectivity of lipases by sol-gel immobilization: further advancements of practical interest.

    PubMed

    Tielmann, Patrick; Kierkels, Hans; Zonta, Albin; Ilie, Adriana; Reetz, Manfred T

    2014-06-21

    The entrapment of lipases in hydrophobic silicate matrices formed by sol-gel mediated hydrolysis of RSi(OCH3)3/Si(OCH3)4 as originally reported in 1996 has been improved over the years by a number of modifications. In the production of second-generation sol-gel lipase immobilizates, a variety of additives during the sol-gel process leads to increased activity and enhanced stereoselectivity in esterifying kinetic resolution. Recent advances in this type of lipase immobilization are reviewed here, in addition to new results regarding the sol-gel entrapment of the lipase from Burkholderia cepacia. It constitutes an excellent heterogeneous biocatalyst in the acylating kinetic resolution of two synthetically and industrially important chiral alcohols, rac-sulcatol and rac-trans-2-methoxycyclohexanol. The observation that the catalyst can be used 10 times in recycling experiments without losing its significant activity or enantioselectivity demonstrates the practical viability of the sol-gel approach.

  3. Saturation of the Large Aperture Scintillometer

    NASA Astrophysics Data System (ADS)

    Kohsiek, W.; Meijninger, W. M. L.; Debruin, H. A. R.; Beyrich, F.

    2006-10-01

    The saturation aspects of a large aperture (0.3 m) scintillometer operating over a 10-km path were investigated. Measurements were made over mainly forested, hilly terrain with typical maximum sensible heat fluxes of 300-400 W m -2, and over flat terrain with mainly grass, and typical maximum heat fluxes of 100-150 W m-2. Scintillometer-based fluxes were compared with eddy-correlation observations. Two different schemes for calculating the reduction of scintillation caused by saturation were applied: one based on the work of Hill and Clifford, the other based on Frehlich and Ochs. Without saturation correction, the scintillation fluxes were lower than the eddy-correlation fluxes; the saturation correction according to Frehlich and Ochs increased the scintillometer fluxes to an unrealistic level. Correcting the fluxes after the theory of the Hill and Clifford gave satisfying results

  4. Synthesis of ketones from biomass-derived feedstock

    NASA Astrophysics Data System (ADS)

    Meng, Qinglei; Hou, Minqiang; Liu, Huizhen; Song, Jinliang; Han, Buxing

    2017-01-01

    Cyclohexanone and its derivatives are very important chemicals, which are currently produced mainly by oxidation of cyclohexane or alkylcyclohexane, hydrogenation of phenols, and alkylation of cyclohexanone. Here we report that bromide salt-modified Pd/C in H2O/CH2Cl2 can efficiently catalyse the transformation of aromatic ethers, which can be derived from biomass, to cyclohexanone and its derivatives via hydrogenation and hydrolysis processes. The yield of cyclohexanone from anisole can reach 96%, and the yields of cyclohexanone derivatives produced from the aromatic ethers, which can be extracted from plants or derived from lignin, are also satisfactory. Detailed study shows that the Pd, bromide salt and H2O/CH2Cl2 work cooperatively to promote the desired reaction and inhibit the side reaction. Thus high yields of desired products can be obtained. This work opens the way for production of ketones from aromatic ethers that can be derived from biomass.

  5. New State Records of Mosquitoes for Colorado.

    PubMed

    Rose, Dominic A; Kondratieff, B C; Weissmann, M J

    2015-06-01

    The 1967 treatment of the Mosquitoes of Colorado by Harmston and Lawson and subsequent publications have recorded 46 culicid species from Colorado. As part of a study to create an updated synopsis of the mosquitoes of Colorado, adult trapping at numerous localities was conducted in Colorado during the summers of 2013 and 2014. This review also included an examination of mosquito specimens in various relevant museum collections. Aedes (Ochlerotatus) niphadopsis and Ae. (Och.) spencerii spencerii were collected during the 2013 and 2014 field seasons. Records for Ae. (Och.) canadensis canadensis, Ae. (Stegomyia) aegypti, and Uranotaenia (Pseudoficalbia) anhydor syntheta were obtained from examination of museum specimens. These species constitute new state records for Colorado, with 51 species now known from the state.

  6. Synthesis of ketones from biomass-derived feedstock

    PubMed Central

    Meng, Qinglei; Hou, Minqiang; Liu, Huizhen; Song, Jinliang; Han, Buxing

    2017-01-01

    Cyclohexanone and its derivatives are very important chemicals, which are currently produced mainly by oxidation of cyclohexane or alkylcyclohexane, hydrogenation of phenols, and alkylation of cyclohexanone. Here we report that bromide salt-modified Pd/C in H2O/CH2Cl2 can efficiently catalyse the transformation of aromatic ethers, which can be derived from biomass, to cyclohexanone and its derivatives via hydrogenation and hydrolysis processes. The yield of cyclohexanone from anisole can reach 96%, and the yields of cyclohexanone derivatives produced from the aromatic ethers, which can be extracted from plants or derived from lignin, are also satisfactory. Detailed study shows that the Pd, bromide salt and H2O/CH2Cl2 work cooperatively to promote the desired reaction and inhibit the side reaction. Thus high yields of desired products can be obtained. This work opens the way for production of ketones from aromatic ethers that can be derived from biomass. PMID:28139709

  7. Method for synthesizing thin film electrodes

    DOEpatents

    Boyle, Timothy J.

    2007-03-13

    A method for making a thin-film electrode, either an anode or a cathode, by preparing a precursor solution using an alkoxide reactant, depositing multiple thin film layers with each layer approximately 500 1000 .ANG. in thickness, and heating the layers to above 600.degree. C. to achieve a material with electrochemical properties suitable for use in a thin film battery. The preparation of the anode precursor solution uses Sn(OCH.sub.2C(CH.sub.3).sub.3).sub.2 dissolved in a solvent in the presence of HO.sub.2CCH.sub.3 and the cathode precursor solution is formed by dissolving a mixture of (Li(OCH.sub.2C(CH.sub.3).sub.3)).sub.8 and Co(O.sub.2CCH.sub.3).H.sub.2O in at least one polar solvent.

  8. Effect of organic substituents on the adsorption of carbon dioxide on a metal-organic framework

    NASA Astrophysics Data System (ADS)

    Thu Ha, Nguyen Thi; Lefedova, O. V.; Ha, Nguyen Ngoc

    2017-01-01

    The adsorption of carbon dioxide on the MOF-5 metal-organic framework and modifications of it obtained by replacing the hydrogen atoms in the organic ligands with electron donor (-CH3,-OCH3) or electron acceptor groups (-CN,-NO2) is investigated using the grand canonical Monte Carlo (GCMC) method and density functional theory (DFT). It is shown that the adsorption of carbon dioxide molecules on the structures of metal-organic frameworks is most likely on Zn4O clusters, and that the adsorption of carbon dioxide is of a physical nature. The presence of substituents-CH3,-OCH3,-CN in metal-organic frameworks increases their capacity to adsorb carbon dioxide, while that of nitro groups (-NO2) has the opposite effect.

  9. The Synthesis and Characterization of Aromatic Hybrid Anderson–Evans POMs and their Serum Albumin Interactions: The Shift from Polar to Hydrophobic Interactions

    PubMed Central

    Al-Sayed, Emir; Blazevic, Amir; Roller, Alexander; Rompel, Annette

    2015-01-01

    Four aromatic hybrid Anderson polyoxomolybdates with Fe3+ or Mn3+ as the central heteroatom have been synthesized by using a pre-functionalization protocol and characterized by using single-crystal X-ray diffraction, FTIR, ESI-MS, 1H NMR spectroscopy, and elemental analysis. Structural analysis revealed the formation of (TBA)3[FeMo6O18{(OCH2)3CNHCOC6H5}2]⋅3.5 ACN (TBA-FeMo6-bzn; TBA=tetrabutylammonium, ACN=acetonitrile, bzn=TRIS-benzoic acid alkanolamide, TRIS–R=(HOCH2)3C–R)), (TBA)3[FeMo6O18{(OCH2)3CNHCOC8H7}2]⋅2.5 ACN (TBA-FeMo6-cin; cin=TRIS-cinnamic acid alkanolamide), (TBA)3[MnMo6O18{(OCH2)3CNHCOC6H5}2]⋅3.5 ACN (TBA-MnMo6-bzn), and (TBA)3[MnMo6O18{(OCH2)3CNHCOC8H7}2]⋅2.5 ACN (TBA-MnMo6-cin). To make these four compounds applicable in biological systems, an ion exchange was performed that gave the water-soluble (up to 80 mm) sodium salts Na3[FeMo6O18{(OCH2)3CNHCOC6H5}2] (Na-FeMo6-bzn), Na3[FeMo6O18{(OCH2)3CNHCOC8H7}2] (Na-FeMo6-cin), Na3[MnMo6O18{(OCH2)3CNHCOC6H5}2] (Na-MnMo6-bzn), and Na3[MnMo6O18{(OCH2)3CNHCOC8H7}2] (Na-MnMo6-cin). The hydrolytic stability of the sodium salts was examined by applying ESI-MS in the pH range of 4 to 9. Sodium dodecylsulfate–polyacrylamide gel electrophoresis (SDS-PAGE) showed that human and bovine serum albumin (HSA and BSA) remain intact in solutions that contain up to 100 equivalents of the sodium salts over more than 4 d at 20 °C. Tryptophan (Trp) fluorescence quenching was applied to study the interactions between the sodium salts and HSA and BSA at pH 5.5 and 7.4. The quenching constants were extracted by using Stern–Volmer analysis, which suggested the formation of a 1:1 POM–protein complex in all samples. It is suggested that the aromatic hybrid POM approaches subdomain IIA of HSA and exhibits hydrophobic interactions with its hydrophobic tails, whereas the Anderson core is stabilized through electrostatic interactions with polar amino acid side chains from, for example

  10. The Synthesis and Characterization of Aromatic Hybrid Anderson-Evans POMs and their Serum Albumin Interactions: The Shift from Polar to Hydrophobic Interactions.

    PubMed

    Al-Sayed, Emir; Blazevic, Amir; Roller, Alexander; Rompel, Annette

    2015-12-01

    Four aromatic hybrid Anderson polyoxomolybdates with Fe(3+) or Mn(3+) as the central heteroatom have been synthesized by using a pre-functionalization protocol and characterized by using single-crystal X-ray diffraction, FTIR, ESI-MS, (1) H NMR spectroscopy, and elemental analysis. Structural analysis revealed the formation of (TBA)3 [FeMo6 O18 {(OCH2 )3 CNHCOC6 H5 }2 ]⋅3.5 ACN (TBA-FeMo6 -bzn; TBA=tetrabutylammonium, ACN=acetonitrile, bzn=TRIS-benzoic acid alkanolamide, TRISR=(HOCH2 )3 CR)), (TBA)3 [FeMo6 O18 {(OCH2 )3 CNHCOC8 H7 }2 ]⋅2.5 ACN (TBA-FeMo6 -cin; cin=TRIS-cinnamic acid alkanolamide), (TBA)3 [MnMo6 O18 {(OCH2 )3 CNHCOC6 H5 }2 ]⋅3.5 ACN (TBA-MnMo6 -bzn), and (TBA)3 [MnMo6 O18 {(OCH2 )3 CNHCOC8 H7 }2 ]⋅2.5 ACN (TBA-MnMo6 -cin). To make these four compounds applicable in biological systems, an ion exchange was performed that gave the water-soluble (up to 80 mM) sodium salts Na3 [FeMo6 O18 {(OCH2 )3 CNHCOC6 H5 }2 ] (Na-FeMo6 -bzn), Na3 [FeMo6 O18 {(OCH2 )3 CNHCOC8 H7 }2 ] (Na-FeMo6 -cin), Na3 [MnMo6 O18 {(OCH2 )3 CNHCOC6 H5 }2 ] (Na-MnMo6 -bzn), and Na3 [MnMo6 O18 {(OCH2 )3 CNHCOC8 H7 }2 ] (Na-MnMo6 -cin). The hydrolytic stability of the sodium salts was examined by applying ESI-MS in the pH range of 4 to 9. Sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that human and bovine serum albumin (HSA and BSA) remain intact in solutions that contain up to 100 equivalents of the sodium salts over more than 4 d at 20 °C. Tryptophan (Trp) fluorescence quenching was applied to study the interactions between the sodium salts and HSA and BSA at pH 5.5 and 7.4. The quenching constants were extracted by using Stern-Volmer analysis, which suggested the formation of a 1:1 POM-protein complex in all samples. It is suggested that the aromatic hybrid POM approaches subdomain IIA of HSA and exhibits hydrophobic interactions with its hydrophobic tails, whereas the Anderson core is stabilized through electrostatic

  11. Associated species in vaporized methanol-formaldehyde solutions

    SciTech Connect

    Silverman, D.C.; Freeman, J.J.

    1983-07-01

    Analysis of vaporized methanolic formaldehyde (50 mol % methanol) by gas chromatography revealed a sum of mole percents of formaldehyde, water, and methanol greater than 100%. This inconsistency was not found with vaporized solutions containing 1 or 10 mol % methanol. Direct evidence for an adduct of methanol and formaldehyde (CH/sub 3/OCH/sub 2/OH) in the vapor phase was found by use of infrared spectroscopy. The spectrum exhibited an absorption at 1140 cm/sup -1/ corresponding to a C-O-C stretch. Reasonable agreement was found between the C-O-C mole percent estimated from infrared spectroscopy, the increased amount of material detected by gas chromatography, and the estimated equilibrium mole percent of the adduct CH/sub 3/OCH/sub 2/OH. These results confirm that in completely vaporized methanolic formaldehyde at 373 to 423 K, one type of adduct predominates. It contains one molecule each of formaldehyde and methanol.

  12. Differentiation of neotropical fish species with statistical analysis of fourier transform infrared photoacoustic spectroscopy data.

    PubMed

    Almeida, Francylaine S; Lima, Sandro M; Andrade, Luis H C; Súarez, Yzel R

    2012-07-01

    Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS) was applied to nineteen fish species in Brazil's Upper Paraná River basin to identify differences in the structural composition of their scales. To differentiate the species, a canonical discriminant analysis was used to indicate the most important absorption peaks in the mid-infrared region. Significant differences were found in the chemical composition of scales among the studied fish species, with Wilk's lambda = 5.2 × 10(-6), F((13,18,394)) = 37.57, and P < 0.001, indicating that O-CH(2) wag at 1396 cm(-1) can be used as a biomarker of this species group. The species could be categorized into four groups according to phylogenetic similarity, suggesting that the O-CH(2) 1396 cm(-1) absorbance is related to the biological traits of each species. This procedure can also be used to complement evolutionary studies.

  13. Independent Review of Elemental Phosphorus Remediation at the Eastern Michaud Flats FMC Operable Unit near Pocatello, Idaho

    SciTech Connect

    Martino, L. E.; Jerden, J. J.; Kimmell, T. A.; Quinn, J.

    2016-01-01

    If, despite risks to workers and these potential impacts, stakeholders decide that P4 wastes need to be excavated and treated, the Review Team determined that a number of the ETTs examined warrant further consideration for the treatment of P4 waste that has been characterized (for example, P4 waste present in the historical ponds). Nevertheless, concerns about the health and safety of site investigation workers using then-available investigation approaches prevented the collection of subsurface samples containing P4 from large areas of the site (e.g., the railroad swale, the vadose zone beneath the Furnace Building, and the abandoned railcars), As a result, the contaminant CSM in those particular areas was not refined enough to allow the Review Team to draw conclusions about using some of the ETTs to treat P4 waste in those areas. The readiness of an ETT for implementation varies depending on many factors, including stakeholder input, permitting, and remedial action construction requirements. Technologies that could be ready for use in the near term (within 1 year) include the following: mechanical excavation, containment technologies, off-site incineration, and drying and mechanical mixing under a tent structure. Technologies that could be ready for use in the mid-term (1 to 2 years) include cutter suction dredging, thermal-hydraulic dredging, and underground pipeline cleaning technologies. Technologies requiring a longer lead time (2 to 5 years) include on-site incineration, a land disposal restriction waste treatment system, an Albright & Wilson batch mud still, post-treatment on-site disposal, and post-treatment off-site disposal.

  14. Lifshitz topological transitions, induced by doping and deformation in single-crystal bismuth wires

    NASA Astrophysics Data System (ADS)

    Nikolaeva, A. A.; Konopko, L. A.; Huber, T. E.; Kobylianskaya, A. K.; Para, Gh. I.

    2017-02-01

    The features associated with the manifestation of Lifshitz electron topological transitions (ETT) in glass-insulated bismuth wires upon qualitative changes to the topology of the Fermi surface are investigated. The variation of the energy spectrum parameters was implemented by doping Bi with an acceptor impurity Sn and using elastic strain of up to 2%, relative to the elongation in the weakly-doped p-type Bi wires. Pure and doped glass-insulated single-crystal bismuth with different diameters and (1011) orientations along the axis were prepared by the Ulitovsky liquid phase casting method. For the first time, ETT-induced anomalies are observed along the temperature dependences of the thermoemf α(T) as triple-changes of the α sign (given heavy doping of Bi wires with an acceptor impurity Sn). The concentration and energy position of the Σ-band given a high degree of bismuth doping with Sn was assessed using the Shubnikov-de Haas effect oscillations, which were detected both from L-electrons and from T-holes in magnetic fields of up to 14 T. It is shown that the Lifshitz electron-topological transitions with elastic deformation of weakly-doped p-type Bi wires are accompanied by anomalies along the deformation dependences of the thermoemf at low temperatures. The effect is interpreted in terms of the formation of a selective scattering channel of L-carriers into the T-band with a high density of states, which is in good agreement with existing theoretical ETT models.

  15. Neuro-otological findings in psychiatric patients with nystagmus.

    PubMed

    Kiyomizu, Kensuke; Matsuda, Keiji; Torihara, Koji; Nakayama, Meiho; Ishida, Yasushi; Yoshida, Kensei; Tono, Tetsuya

    2011-12-01

    To evaluate whether neuro-otological tests have clinical significance in psychiatric patients with nystagmus who have inner ear and/or brain dysfunction, we performed neuro-otological tests on 56 psychiatric patients with nystagmus (38 men, 18 women) (age range 40-97; mean age ± SD 61.6 ± 10.5 years). Patients were classified according to the underlying diseases: schizophrenia (25 cases), organic psychiatric disorders (14 cases), alcoholism (16 cases) and excited mental retardation (1 case). Caloric test results showed a normal response in 30 (75%) cases, right canal paresis (CP) in 4 (10%), left CP in 4 (10%) and bilateral CP in 2 (5%). Therefore, 10 (25%) cases had CP. The results of the eye tracking tests (ETT) were sorted into five categories: 4 (8.2%) cases smooth (normal), 8 (16.3%) slightly saccadic, 28 (57.1%) saccadic, 8 (16.3%) ataxic, and 1 (2%) no tracking ability. Therefore, 45 (91.8%) cases had abnormal ETT results. Pure tone audiometry showed normal hearing in 24 (47.1%) cases, right hearing loss (HL) in 3 (5.8%), left HL in 3 (5.8%) and bilateral HL in 21 (41.2%). Therefore, 27 (52.9%) cases had HL. The patients were classified as organic or functional groups. In ETT there was a significant difference between these two groups. These results indicate that neuro-otological tests with video-oculography are very important not only for neurological or neuro-otological patients with nystagmus, but also for psychiatric patients with nystagmus.

  16. Retrospective analysis of vocal cord-to-suprasternal notch distance

    PubMed Central

    Kim, Hyerim; Chang, Jee-Eun; Ryu, Jung-Hee; Jung, Haesun; Min, Seong-Won; Lee, Jung-Man; Hwang, Jin-Young

    2017-01-01

    Abstract Endotracheal tube (ETT) positioning using the cuff ballottement test, which confirms that the inflated cuff is positioned at the suprasternal notch with squeezing or inflating a pilot balloon, has been reported to be a simple and reliable method of preventing endobronchial intubation. However, in patients with a short vocal cord-to-suprasternal notch, ETT placement using the cuff ballottement test can cause vocal cord injury. In the present study, we assessed the distance from a point 15 mm below the vocal cord to the suprasternal notch (VSD-15), the safe position for ETT cuff placement above the suprasternal notch, and investigated variables for predicting VSD-15. We retrospectively examined neck computed tomography in 427 adult patients and measured VSD-15 and the distance from the thyroid notch to the suprasternal notch (TSD). Patient height, weight, sex, and age were also recorded. In total, 47 patients (11.0%) showed a VSD-15 shorter than 45 mm. VSD-15 significantly correlated with TSD (r = 0.778, P < 0.001) and height (r = 0.312, P < 0.001), and inversely correlated with age (r = −0.321, P < 0.001). In multiple linear regression models, a formula was obtained for VSD-15 (VSD-15 [mm] = −6.220 + 0.744 × TSD [mm] + 0.092 × height [cm] − 0.065 × age [years], R2 = 0.621). The cuff ballottement test should be used cautiously in patients with a predicted short VSD-15. VSD-15 can be predicted from TSD, height, and age. PMID:28207550

  17. Rescue Ventilation Through a Small-Bore Transtracheal Cannula in Severe Hypoxic Pigs Using Expiratory Ventilation Assistance

    PubMed Central

    Hamaekers, Ankie E.; van der Beek, Tim; Theunissen, Maurice

    2015-01-01

    BACKGROUND: Suction-generated expiratory ventilation assistance (EVA) has been proposed as a way to facilitate bidirectional ventilation through a small-bore transtracheal cannula (TC). In this study, we investigated the efficiency of ventilation with EVA for restoring oxygenation and ventilation in a pig model of acute hypoxia. METHODS: Six pigs (61–76 kg) were anesthetized and ventilated (intermittent positive pressure ventilation) via a cuffed endotracheal tube (ETT). Monitoring lines were placed, and a 75-mm long, 2-mm inner diameter TC was inserted. After the baseline recordings, the ventilator was disconnected. After 2 minutes of apnea, reoxygenation with EVA was initiated through the TC and continued for 15 minutes with the ETT occluded. In the second part of the study, the experiment was repeated with the ETT either partially obstructed or left open. Airway pressures and hemodynamic data were recorded, and arterial blood gases were measured. Descriptive statistical analysis was performed. RESULTS: With a completely or partially obstructed upper airway, ventilation with EVA restored oxygenation to baseline levels in all animals within 20 seconds. In a completely obstructed airway, Paco2 remained stable for 15 minutes. At lesser degrees of airway obstruction, the time to reoxygenation was delayed. Efficacy probably was limited when the airway was completely unobstructed, with 2 of 6 animals having a Pao2 <85 mm Hg even after 15 minutes of ventilation with EVA and a mean Paco2 increased up to 90 mm Hg. CONCLUSIONS: In severe hypoxic pigs, ventilation with EVA restored oxygenation quickly in case of a completely or partially obstructed upper airway. Reoxygenation and ventilation were less efficient when the upper airway was completely unobstructed. PMID:25565319

  18. Frequency and distribution of early tooth loss and endodontic treatment needs of permanent first molars in a Turkish pediatric population

    PubMed Central

    Demirbuga, Sezer; Tuncay, Oznur; Cantekin, Kenan; Cayabatmaz, Muhammed; Dincer, Asiye Nur; Kilinc, Halil İbrahim; Sekerci, Ahmet Ercan

    2013-01-01

    Objectives: The objective of this study is to evaluate the frequency and distribution of early tooth loss and endodontic treatment needs of permanent first molars in a Turkish pediatric population. Materials and Methods: A total of 7,895 panoramic radiographs taken for routine dental examination at the Department of Oral Maxillofacial Radiology between 2008 and 2012 years were investigated. Two independent specialists evaluated early tooth loss and endodontic treatment needs of permanent first molars using panoramic radiography and patient anamnesis forms. The teeth were classified according to the following data: (a) Missing teeth, (b) teeth requiring extraction, (c) endodontically treated teeth (ETT), (d) teeth requiring endodontic therapy. The data also classified according to four factors: Age group (6-12 and 13-16), gender (boy and girl), jaw (mandible and maxilla) and side (right and left). A Chi-square test was used for statistical analyses. Results: A total of 19,488 and 12,092 teeth were evaluated in the child group and adolescent group respectively. All data were higher in adolescents than children (P < 0.001). For gender factor, only ETT was higher in girls than it was in boys (P < 0.001). For the jaw factor, all data were higher (P < 0.001) in mandible than in the maxilla. For the side factor, no statistical difference existed between right and left. Conclusions: Early tooth loss and endodontic treatment needs of permanent first molars showed variability according to age groups and jaws. When the results were compared according to the side and gender factors, no statistical difference was found (P > 0.05) except with the data of ETT in gender groups. PMID:24966738

  19. Autoinducer-2 of Streptococcus mitis as a Target Molecule to Inhibit Pathogenic Multi-Species Biofilm Formation In Vitro and in an Endotracheal Intubation Rat Model

    PubMed Central

    Wang, Zhengli; Xiang, Qingqing; Yang, Ting; Li, Luquan; Yang, Jingli; Li, Hongong; He, Yu; Zhang, Yunhui; Lu, Qi; Yu, Jialin

    2016-01-01

    Streptococcus mitis (S. mitis) and Pseudomonas aeruginosa (P. aeruginosa) are typically found in the upper respiratory tract of infants. We previously found that P. aeruginosa and S. mitis were two of the most common bacteria in biofilms on newborns’ endotracheal tubes (ETTs) and in their sputa and that S. mitis was able to produce autoinducer-2 (AI-2), whereas P. aeruginosa was not. Recently, we also found that exogenous AI-2 and S. mitis could influence the behaviors of P. aeruginosa. We hypothesized that S. mitis contributes to this interspecies interaction and that inhibition of AI-2 could result in inhibition of these effects. To test this hypothesis, we selected PAO1 as a representative model strain of P. aeruginosa and evaluated the effect of S. mitis as well as an AI-2 analog (D-ribose) on mono- and co-culture biofilms in both in vitro and in vivo models. In this context, S. mitis promoted PAO1 biofilm formation and pathogenicity. Dual-species (PAO1 and S. mitis) biofilms exhibited higher expression of quorum sensing genes than single-species (PAO1) biofilms did. Additionally, ETTs covered in dual-species biofilms increased the mortality rate and aggravated lung infection compared with ETTs covered in mono-species biofilms in an endotracheal intubation rat model, all of which was inhibited by D-ribose. Our results demonstrated that S. mitis AI-2 plays an important role in interspecies interactions with PAO1 and may be a target for inhibition of biofilm formation and infection in ventilator-associated pneumonia. PMID:26903968

  20. Do physical examination and CT-scan measures of femoral neck anteversion and tibial torsion relate to each other?

    PubMed

    Sangeux, Morgan; Mahy, Jessica; Graham, H Kerr

    2014-01-01

    Informed clinical decision making for femoral and/or tibial de-rotation osteotomies requires accurate measurement of patient function through gait analysis and anatomy through physical examination of bony torsions. Validity of gait analysis has been extensively studied; however, controversy remains regarding the accuracy of physical examination measurements of femoral and tibial torsion. Comparison between CT-scans and physical examination measurements of femoral neck anteversion (FNA) and external tibial torsion (ETT) were retrospectively obtained for 98 (FNA) and 64 (ETT) patients who attended a tertiary hospital for instrumented gait analysis between 2007 and 2010. The physical examination methods studied for femoral neck anteversion were the trochanteric prominence angle test (TPAT) and the maximum hip rotation arc midpoint (Arc midpoint) and for external tibial torsion the transmalleolar axis (TMA). Results showed that all physical examination measurements statistically differed to the CT-scans (bias(standard deviation): -2(14) for TPAT, -10(12) for Arc midpoint and -16(9) for TMA). Bland and Altman plots showed that method disagreements increased with increasing bony torsions in all cases but notably for TPAT. Regression analysis showed that only TMA and CT-scan measurement of external tibial torsion demonstrated good (R(2)=57%) correlation. Correlations for both TPAT (R(2)=14%) and Arc midpoint (R(2)=39%) with CT-scan measurements of FNA were limited. We conclude that physical examination should be considered as screening techniques rather than definitive measurement methods for FNA and ETT. Further research is required to develop more accurate measurement methods to accompany instrumented gait analysis.

  1. Organotitanium(IV) compounds as catalysts for the polymerization of isocyanates: The polymerization of isocyanates with functionalized side chains

    SciTech Connect

    Patten, T.E.; Novak, B.M. Lawrence Berkeley Lab., CA )

    1993-02-01

    Catalysts of the form CpTiCl[sub 2]X, where X = [minus]OCH[sub 2]CF[sub 3], [minus]N(CH[sub 3])[sub 2], or [minus]CH[sub 3] (2a, 2b, 2c; Cp = [eta][sup 5]-cyclopentadienyl), CP*TiCl[sub 2]OCH[sub 2]CF[sub 3](3; Cp* = [eta][sup 5]-pentamethylcyclopentadienyl), and Cp[sub 2]TiClOCH[sub 2]-CF[sub 3](4) were used to polymerize a variety of isocyanates. Titanium-alkoxide, -amide, and -alkyl bonds were all found to be active in initiating the insertion of isocyanate monomer. An advantageous consequence of the lesser Lewis acidity of 2a-c relative to TiCl[sub 3]OCH[sub 2]CF[sub 3](1) is that the polymerization of highly functionalized monomers is possible using 2a-c and not 1. 2-Isocyanotoethyl methacrylate (2IEM) was polymerized, using 2b, through the isocyanato group to a linear polymer; the resulting properties of this material were found to be quite different from what was reported by Graham et al. 2IEM trimer was synthesized and subsequently cross-linked using a free-radical initiator, and it was found that the properties of this material matched those of the earlier report. The Diels-Alder adduct of 2IEM with cyclopentadiene, 2-((2-isocyanatoethoxy)carbonyl)-2-methylbicyclo[2.2.1]hept-5-ene (2IECMBH) was prepared and also polymerized using 2b. The use of cyclopentadienyltitanium trichloride derivatives also provides a general route through which a wide variety of end groups may be incorporated onto the end of the polyisocyanate chain.

  2. Chiral Pharmaceutical Intermediaries Obtained by Reduction of 2-Halo-1-(4-substituted phenyl)-ethanones Mediated by Geotrichum candidum CCT 1205 and Rhodotorula glutinis CCT 2182

    PubMed Central

    Fardelone, Lucídio C.; Rodrigues, J. Augusto R.; Moran, Paulo J. S.

    2011-01-01

    Enantioselective reductions of p-R1-C6H4C(O)CH2R2 (R1 = Cl, Br, CH3, OCH3, NO2 and R2 = Br, Cl) mediated by Geotrichum candidum CCT 1205 and Rhodotorula glutinis CCT 2182 afforded the corresponding halohydrins with complementary R and S configurations, respectively, in excellent yield and enantiomeric excesses. The obtained (R)- or (S)-halohydrins are important building blocks in chemical and pharmaceutical industries. PMID:21687613

  3. Utilization of useless pesticides in a plasma reactor

    NASA Astrophysics Data System (ADS)

    Lozhechnik, A. V.; Mossé, A. L.; Savchin, V. V.; Skomorokhov, D. S.; Khvedchin, I. V.

    2011-09-01

    Investigations on destruction of isophene C14H18O7N2 and the butyl ether of 2,4-dichlorophenoxyacetic acid (Cl2C6H3OCH2COOCH2CH(CH3)2) are performed. The plasma treatment of toxic waste is implemented in a plasma reactor with a three-jet mixing chamber. Air is used as the plasma-forming gas.

  4. Cholesteric Liquid Crystal Glass Platinum Acetylides

    DTIC Science & Technology

    2014-06-01

    cholesteric glasses at room temperature, a series of platinum acetylide complexes modified with cholesterol has been synthesized. The materials synthesized...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...glasses at room temperature, a series of platinum acetylide complexes modified with cholesterol has been synthesized. The materials synthesized

  5. Multilingual Affordances in a Swedish Preschool: An Action Research Project

    ERIC Educational Resources Information Center

    Ljunggren, Åsa

    2016-01-01

    This article summarizes the work and the main findings of an action research project that was conducted in an early childhood education and care setting in the city of Malmö, Sweden in the autumn of 2013 and spring 2014. Rönnerman's model (Aktionsforskning i praktiken: förskola och skola på vetenskaplig grund [Action research in practice:…

  6. Bridge Busters: The 397th Bombardment Group (Medium) and the B-26 Marauder in World War II

    DTIC Science & Technology

    2015-06-01

    BRIDGE BUSTERS: THE 397TH BOMBARDMENT GROUP (MEDIUM) AND THE B-26 MARAUDER IN WORLD WAR II BY LIEUTENANT COLONEL DAVID OCH A THESIS...v ABSTRACT This study examines the concept of medium bombardment and the role of the Martin B-26 Marauder in World War II (WWII) through...1944: The Climactic Battle of World War II (New York: Simon & Schuster, 1994), 239. 2 History, 397th Bombardment Group, June 1944. 2 and capable

  7. Theoretical spectroscopic characterization at low temperatures of S-methyl thioformate and O-methyl thioformate

    SciTech Connect

    Senent, M. L.; Puzzarini, C.; Hochlaf, M.; Domínguez-Gómez, R.; Carvajal, M.

    2014-09-14

    Highly correlated ab initio methods are employed to determine spectroscopic properties at low temperatures of two S-analogs of methyl formate: S-methyl thioformate CH{sub 3}-S-CHO (MSCHO) and O-methyl thioformate CH{sub 3}-O-CHS (MOCHS). Both species are detectable and they are expected to play an important role in Astrochemistry. Molecular properties are compared with those of the O-analog, methyl formate. Both isomers present two conformers cis and trans. cis-CH{sub 3}-S-CHO represents the most stable structure lying 4372.2 cm{sup −1} below cis-CH{sub 3}-O-CHS. The energy difference between the cis and trans forms is drastically lower for MSCHO (1134 cm{sup −1}) than for MOCHS (1963.6 cm{sup −1}). Harmonic and anharmonic fundamentals and the corresponding intensities, as well as the rotational constants for the ground vibrational and first excited torsional states and the centrifugal distortions constants, are provided. Low torsional energy levels have been obtained by solving variationally a two dimensional Hamiltonian expressed in terms of the two torsional degrees of freedom. The corresponding 2D potential energy surfaces have been computed at the CCSD(T)/aug-cc-pVTZ level of theory. The methyl torsional barriers V{sub 3}(cis) are determined to be 139.7 cm{sup −1} (CH{sub 3}-S-CHO) and 670.4 cm{sup −1} (CH{sub 3}-O-CHS). The A/E splitting of ground torsional state has been estimated to be 0.438 cm{sup −1} for CH{sub 3}-S-CHO and negligible for CH{sub 3}-O-CHS.

  8. Energetics and Dynamics of the Reactions of O(3P) with Dimethyl Methylphosphonate and Saria

    DTIC Science & Technology

    2009-09-15

    a SN2 -like transition geometry, Figure 3c, the axial O-C-H bond angle is slightly bent more for reaction 4, Figure 3d. The products of reaction 4 are...Energetics and Dynamics of the Reactions of O(3P) with Dimethyl Methylphosphonate and Sarin Patrick F. Conforti and Matthew Braunstein* Spectral...calculations were performed on the reaction systems O(3P) + sarin and O(3P) + dimethyl methylphosphonate (DMMP), a sarin simulant. Transition state

  9. A theoretical investigation on kinetics, mechanism, and thermochemistry of the gas-phase reactions of methyl fluoroacetate with OH radicals and fate of alkoxy radical.

    PubMed

    Mishra, Bhupesh Kumar; Deka, Ramesh Chandra

    2014-09-25

    We theoretically investigated OH-initiated hydrogen abstraction reactions of methyl fluoroacetate (MFA) CH2FC(O)OCH3 at the MPWB1K level of theory in conjunction with the 6-31+G(d,p) basis set. Thermodynamic and kinetic data are computed using the comparatively accurate G2(MP2) method. Two most stable conformers of MFA are identified, and the energy difference between them is found to be only 0.32 kcal mol(-1). Both of them are considered for rate coefficient calculations, and the contribution from each of the conformers is found to be quite significant. We propose an indirect mechanism due to validation of pre- and post-reactive complexes. The rate parameters are determined using canonical transition state theory and energetics at the G2(MP2) level. The temperature dependence of the rate constant can be described by the Arrhenius expressions: k = 8.79 × 10(-13) exp[(-377.27 ± 64)/T] cm(3) molecule(-1) s(-1) over a temperature range of 250-450 K. The ΔfH°298 for CH2FC(O)OCH3, CH2FC(O)OC(•)H2, and C(•)HFC(O)OCH3 are also computed using an isodesmic procedure. The OH-driven atmospheric lifetime of MFA was estimated to be 24 days. A mechanistic study to shed light on the atmospheric degradation and the sole fate for the consumption of CH2FC(O)OCH2O(•) radical has also been reported.

  10. Minimum structure requirement of immunomodulatory glycolipids for predominant Th2 cytokine induction and the discovery of non-linear phytosphingosine analogs.

    PubMed

    Toba, Tetsuya; Murata, Kenji; Nakanishi, Kyoko; Takahashi, Bitoku; Takemoto, Naohiro; Akabane, Minako; Nakatsuka, Takashi; Imajo, Seiichi; Yamamura, Takashi; Miyake, Sachiko; Annoura, Hirokazu

    2007-05-15

    Analogs of immunomodulatory glycolipid OCH (2) were prepared and minimum structure requirement to exhibit equivalent profiles was disclosed. Analogs bearing non-linear hydrocarbon chain in the phytosphingosine moiety (18, 19) were shown for the first time to possess comparable cytokine inducing profile to 2. Molecular modeling of 2/hCD1d complex based on the crystal structure of alpha-GalCer (1)/hCD1d complex is also described.

  11. Synthesis of Potential Prophylactic Agents against Cyanide Intoxication

    DTIC Science & Technology

    1993-04-12

    compiles th« synthetic procedures described in reports submitted for quarters 9-12 of this contract. We have also colligated structures of all...tingle example of ihn compound class was submitted for biological evaluation this report period, and the physical properties of this agent (1) are...condensation of propiophenone »ith diethyl oxalate (Eq. II) The physical properties of these compounds are summarized in Table 2. a cr, 3 F 4 OCH3 5 CH3

  12. Activation of C-O and C-C bonds and formation of novel HAlOH-ether complexes: an EPR study of the reaction of ground-state Al atoms with methylethyl ether and diethyl ether.

    PubMed

    Brunet, François D; Feola, Julie C; Joly, Helen A

    2012-03-15

    Reaction mixtures, containing Al atoms and methylethyl ether (MEE) or diethyl ether (DEE) in an adamantane matrix, were prepared with the aid of a metal-atom reactor known as a rotating cryostat. The EPR spectra of the resulting products were recorded from 77-260 K, at 10 K intervals. Al atoms were found to insert into methyl-O, ethyl-O, and C-C bonds to form CH(3)AlOCH(2)CH(3), CH(3)OAlCH(2)CH(3), and CH(3)OCH(2)AlCH(3), respectively, in the case of MEE while DEE produced CH(3)CH(2)AlOCH(2)CH(3) and CH(3)AlCH(2)OCH(2)CH(3), respectively. From the intensity of the transition lines attributed to the Al atom C-O insertion products of MEE, insertion into the methyl-O bond is preferred. The Al hyperfine interaction (hfi) extracted from the EPR spectra of the C-O insertion products was greater than that of the C-C insertion products, that is, 5.4% greater for the DEE system and 7% greater for the MEE system. The increase in Al hfi is thought to arise from the increased electron-withdrawing ability of the substituents bonded to Al. Besides HAlOH, resulting from the reaction of Al atoms with adventitious water, novel mixed HAlOH:MEE and HAlOH:DEE complexes were identified with the aid of isotopic studies involving H(2)(17)O and D(2)O. The Al and H hfi of HAlOH were found to decrease upon complex formation. These findings are consistent with the nuclear hfi calculated using a density functional theory (DFT) method with close agreement between theory and experiment occurring at the B3LYP level using a 6-311+G(2df,p) basis set.

  13. Effects of age and sex on copper absorption, turnover, and status

    SciTech Connect

    Johnson, P.E.; Milne, D.B. )

    1991-03-15

    Healthy, free-living men and women aged 20 to 59 years were studied to determine the effects of age and sex on Cu absorption, biological half-life (BH) and status. Additional women who were taking oral contraceptives (OCH) or estrogens were compared to women the same ages who did not take hormones. After an overnight fast, subjects provided a blood sample and ate breakfast labeled with 2.5 {mu}Ci Cu-67. Total Cu-67 ingested was determined after the meal by counting subjects in a whole-body gamma counter. Whole body retention of Cu-67 was monitored by 10 additional counts during the next 21 days. Cu absorption (%A) was calculated by extrapolation of the linear portion of a semi-log plot of % retention vs time. BH was {minus}1n2/slope. %A was significantly greater in women than men aged 20-50, but was not affected by age. BH was not significantly affected by either age or sex. Plasma Cu, enzymatic ceruloplasmin (Cp), and RID Cp were significantly higher in women than men, but SOD and in vitro Cu-67 uptake by RBCs did not differ. None of the biochemical indices were significantly affected by age, except RID Cp, which increased with age. Plasma Cu, enzymatic Cp, and SOD activity were higher in women aged 20-39 taking OCH than in those not taking OCH, but %A and BH did not differ between the groups. Trends in women 50-59 taking estrogen or not were similar to findings for women with/without OCH. These data suggest that dietary Cu requirements may differ between men and women.

  14. Identification of Small Ligands Targeting Breast Cancer by In Vivo Screening of Peptide Libraries in Breast Cancer Patients

    DTIC Science & Technology

    2000-09-01

    Lindgren CG, Ochs HD: Impaired in vivo and in vitro antibody responses to bacteriophage (j)X 174 in juvenile rheumatoid arthritis . J Rheumatol 14(5):957...4 (Adverse Event) (Mild) (Moderate) (Severe) (or Life Threatening;) DERMATOLOGI C Skin none or no change scatter macular or scatter macular or...generalized exfoliative papular eruption papular eruption symptomatic dermatitis or or erythema that is or erythema with macular , papular, ulcerating

  15. Chemistry Within Molecular Clusters

    DTIC Science & Technology

    1990-01-01

    DME )nCH3OCH 2 +). We speculate that this is due to the fragments being consumed by an ion-molecule reaction within the cluster. One likely candidate is...the ion-molecule reaction of the fragment cations with a neutral DME , within the bulk cluster to form a trimethyloxonlum cation intermediate. This...the observed products. We therefore speculate that the DME cluster reactions leading to the same products, should involve the same mechanism found to

  16. Chemistry Within Molecular Clusters

    DTIC Science & Technology

    1992-06-01

    and ( DME ).CH 3OCH2+). We speculate that this is due to the fragments being consumed by an ion-molecule reaction within the cluster. A likely candidate...is the ion-molecule reaction of the fragment cations with a neutral DME within the bulk cluster, to form a trimethyloxonium cation intermediate...a trimethyloxonium intermediate as the common intermediate for the observed products. We therefore speculate that the DME cluster reactions leading to

  17. Theoretical spectroscopic characterization at low temperatures of S-methyl thioformate and O-methyl thioformate.

    PubMed

    Senent, M L; Puzzarini, C; Hochlaf, M; Domínguez-Gómez, R; Carvajal, M

    2014-09-14

    Highly correlated ab initio methods are employed to determine spectroscopic properties at low temperatures of two S-analogs of methyl formate: S-methyl thioformate CH3-S-CHO (MSCHO) and O-methyl thioformate CH3-O-CHS (MOCHS). Both species are detectable and they are expected to play an important role in Astrochemistry. Molecular properties are compared with those of the O-analog, methyl formate. Both isomers present two conformers cis and trans. cis-CH3-S-CHO represents the most stable structure lying 4372.2 cm(-1) below cis-CH3-O-CHS. The energy difference between the cis and trans forms is drastically lower for MSCHO (1134 cm(-1)) than for MOCHS (1963.6 cm(-1)). Harmonic and anharmonic fundamentals and the corresponding intensities, as well as the rotational constants for the ground vibrational and first excited torsional states and the centrifugal distortions constants, are provided. Low torsional energy levels have been obtained by solving variationally a two dimensional Hamiltonian expressed in terms of the two torsional degrees of freedom. The corresponding 2D potential energy surfaces have been computed at the CCSD(T)/aug-cc-pVTZ level of theory. The methyl torsional barriers V3(cis) are determined to be 139.7 cm(-1) (CH3-S-CHO) and 670.4 cm(-1) (CH3-O-CHS). The A/E splitting of ground torsional state has been estimated to be 0.438 cm(-1) for CH3-S-CHO and negligible for CH3-O-CHS.

  18. Synthesis, characterization, and OFET properties of amphiphilic heteroleptic tris(phthalocyaninato) europium(III) complexes with hydrophilic poly(oxyethylene) substituents.

    PubMed

    Li, Renjie; Ma, Pan; Dong, Shuai; Zhang, Xianyao; Chen, Yanli; Li, Xiyou; Jiang, Jianzhuang

    2007-12-24

    A series of amphiphilic heteroleptic tris(phthalocyaninato) europium complexes with hydrophilic poly(oxyethylene) heads and hydrophobic alkoxy tails {Pc[(OC2H4)2OCH3]8}Eu{Pc[(OC2H4)2OCH3]8}Eu[Pc(OCnH2n + 1)8] (n = 6, 8, 10,12) (1-4) were designed and prepared from the reaction between homoleptic bis(phthalocyaninato) europium compound {Pc[(OC2H4)2OCH3]8}Eu{Pc[(OC2H4)2OCH3]8} and metal-free 2,3,9,10,16,17,23,24-octakis(alkoxy)phthalocyanine H2Pc(OCnH2n + 1)8 (n = 6, 8, 10,12) in the presence of Eu(acac)3.H2O (Hacac = acetylacetone) in boiling 1,2,4-trichlorobenzene (TCB). These novel sandwich triple-decker complexes have been characterized by a wide range of spectroscopic methods and have been electrochemically studied. With the help of the Langmuir-Blodgett (LB) technique, these typical amphiphilic triple-decker complexes have been fabricated into organic field effect transistors (OFET) with an unusual bottom contact configuration. The devices display good OFET performance with the carrier mobility for holes in the direction parallel to the aromatic phthalocyanine rings, which shows dependence on the length of the hydrophobic alkoxy side chains, decreasing from 0.46 for 1 to 0.014 cm2 V(-1) s(-1) for 4 along with the increase in the carbon number in the hydrophobic alkoxy side chains.

  19. Synthesis and Characterization of New Phosphazene Polymers.

    DTIC Science & Technology

    1988-01-21

    reaction of a poly( alkyl /arylphosphazene). In this study, one-half of the methyl groups in [Ph(Me)PN]n (chosen for its solubility in THF as opposed to...polymerization reaction ; and (5) the derivative chemistry of the preformed poly( alkyl /arylphosphazenes)., Synthesis of Poly( alkyl /arylphosphazenes) SC A... vessels , these phosphoranimines quantitatively eliminate the silyl ether byproduct, Me3SiOCH2CF 3 , to form the poly( alkyl /arylphosphazenes). The synthesis

  20. Gas-phase oxidation of methyl crotonate and ethyl crotonate. kinetic study of their reactions toward OH radicals and Cl atoms.

    PubMed

    Teruel, Mariano A; Benitez-Villalba, Julio; Caballero, Norma; Blanco, María B

    2012-06-21

    Rate coefficients for the reactions of hydroxyl radicals and chlorine atoms with methyl crotonate and ethyl crotonate have been determined at 298 K and atmospheric pressure. The decay of the organics was monitored using gas chromatography with flame ionization detection (GC-FID), and the rate constants were determined using the relative rate method with different reference compounds. Room temperature rate coeficcients were found to be (in cm(3) molecule(-1) s(-1)): k(1)(OH + CH(3)CH═CHC(O)OCH(3)) = (4.65 ± 0.65) × 10(-11), k(2)(Cl + CH(3)CH═CHC(O)OCH(3)) = (2.20 ± 0.55) × 10(-10), k(3)(OH + CH(3)CH═CHC(O)OCH(2)CH(3)) = (4.96 ± 0.61) × 10(-11), and k(4)(Cl + CH(3)CH═CHC(O)OCH(2)CH(3)) = (2.52 ± 0.62) × 10(-10) with uncertainties representing ±2σ. This is the first determination of k(1), k(3), and k(4) under atmospheric pressure. The rate coefficients are compared with previous determinations for other unsaturated and oxygenated VOCs and reactivity trends are presented. In addition, a comparison between the experimentally determined k(OH) with k(OH) predicted from k vs E(HOMO) relationships is presented. On the other hand, product identification under atmospheric conditions has been performed for the first time for these unsaturated esters by the GC-MS technique in NO(x)-free conditions. 2-Hydroxypropanal, acetaldehyde, formaldehyde, and formic acid were positively observed as degradation products in agreement with the addition of OH to C2 and C3 of the double bond, followed by decomposition of the 2,3- or 3,2-hydroxyalkoxy radicals formed. Atmospheric lifetimes, based on of the homogeneous sinks of the unsaturated esters studied, are estimated from the kinetic data obtained in the present work.

  1. Unimolecular thermal decomposition of dimethoxybenzenes

    SciTech Connect

    Robichaud, David J. Mukarakate, Calvin; Nimlos, Mark R.; Scheer, Adam M.; Ormond, Thomas K.; Buckingham, Grant T.; Ellison, G. Barney

    2014-06-21

    The unimolecular thermal decomposition mechanisms of o-, m-, and p-dimethoxybenzene (CH{sub 3}O-C{sub 6}H{sub 4}-OCH{sub 3}) 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-CH{sub 3}O-C{sub 6}H{sub 4}-OCH{sub 3}, intramolecular H-transfer dominates leading to the formation of o-hydroxybenzaldehyde (o-HO-C{sub 6}H{sub 4}-CHO) and phenol (C{sub 6}H{sub 5}OH). Para-CH{sub 3}O-C{sub 6}H{sub 4}-OCH{sub 3} immediately breaks the second methoxy bond to form p-benzoquinone, which decomposes further to cyclopentadienone (C{sub 5}H{sub 4}=O). Finally, the m-CH{sub 3}O-C{sub 6}H{sub 4}-OCH{sub 3} isomer will predominantly follow a ring-reduction/CO-elimination mechanism to form C{sub 5}H{sub 4}=O. Electronic structure calculations and transition state theory are used to confirm mechanisms and comment on kinetics. Implications for lignin pyrolysis are discussed.

  2. Calcium-based Lewis acid catalysts.

    PubMed

    Begouin, Jeanne-Marie; Niggemann, Meike

    2013-06-17

    Recently, Lewis acidic calcium salts bearing weakly coordinating anions such as Ca(NTf₂)₂, Ca(OTf)₂, CaF₂ and Ca[OCH(CF₃)₂]₂ have been discovered as catalysts for the transformation of alcohols, olefins and carbonyl compounds. High stability towards air and moisture, selectivity and high reactivity under mild reaction conditions render these catalysts a sustainable and mild alternative to transition metals, rare-earth metals or strong Brønsted acids.

  3. New Record and Updated Checklists of the Mosquitoes of Afghanistan and Iraq

    DTIC Science & Technology

    2008-08-12

    claviger (Meigen). Although Buck et al. (1972), Ward (1972), Danilov (1985a, 1985b) reported Cx. univittatus Theobald from Afghanistan, it actually...refers to Cx. perexiguus Theobald according to Harbach (1988). Danilov (1978) stated that Ae. versicolor (Barraud) “may be expected in the mountain...K Ae.(Och. pulcritarsis (Rondani) D - Ae. (Stegomyia) aegypti (Linnaeus) - Anopheles (Anopheles) algeriensis Theobald A3, D, G, W, X A2, G, P An

  4. The Art and Science of Psychological Operations: Case Studies of Military Application. Volume Two

    DTIC Science & Technology

    1976-04-01

    dividends to be drawn from such investments. It would be surprising if Britain rv ere not concerned in this form of peaceful competition for: If it is...Stalin’s lifetime some essential enements of the strategy w!,ich has paid considerable political dividends to Khrushchev were worked out at least in...the Afro-Asian Jiunst-- Conference, Conakry. October 15-22, 1962 "L’Emigration et le travail forc6," "La Situation politique ," "Paruis politiques ett

  5. Nuclear Techniques for Plasma Diagnostics.

    DTIC Science & Technology

    1979-04-23

    ers ar e ’ usually u’~ett t o s ep ar a t e ’ t h e n eu t cons and x rays . In e x p e r i r n ’n t s w her e I ic x — r a \\ pu iso is Sn I S ic...DAViS EGSG , INC. ALBU QUER QUE D IV IS ION P.O. BOX 10218 ALBUQUERQUE, NM 87114 1 CV ATTN: TECHNICAL LIBRARY FORD AEROSPACE & COMMUNICATIONS CORP

  6. Sugar Creek Basin North Carolina and South Carolina, Feasibility Report and Environmental Impact Statement for Water Resources Development.

    DTIC Science & Technology

    1982-10-01

    are featured in the larger parks. Three swimming pools, 15 corimunity centern , a iolf couirse, Park Center arena, and *f Mern i St !i uv’ ar, -fl 1...ietion of Strate ies. Efforts during Stage I centered on the idintificat ion of problems and needs in the stu dy art-a, ssabisent of broad- planninq...cultura9 3:i ccc: 1 ooortuni ties, and other factors. LNVIRQN-’’ErJAL- . rETT,1JC-: AND ’IATURAL PESOURCES The SJugar I Ee asin lies within the Central

  7. Developing Tactical Commanders at CGSOC for the Future AirLand Battlefield

    DTIC Science & Technology

    1991-01-04

    and history. Airland BaLtLe Futr (ALB-F), sentor Army leaders and cu|rrent an thors ettIIaI sizL’ w LI tIpo rta|ce of these same c’ommniland cotlpoilets...high and the margin for error will grow smaller .... At a time when technology and electronic devices appear to offer an easy path to overcome the...learn by doing himself. In this case, he normally learns by trial and error (on the job training). The painter can also learn from someone else he

  8. Complete Obstruction of Endotracheal Tube in an Infant with a Retropharyngeal and Anterior Mediastinal Abscess

    PubMed Central

    Greene, Nathaniel H.

    2017-01-01

    Intraoperative ventilatory failure is not an uncommon complication; however, acute endotracheal obstruction by a foreign body or blood clot can be difficult to quickly discriminate from other causes. Once the diagnosis is made, quick action is needed to restore ventilation. The ultimate solution is to exchange the endotracheal tube; however, there can be other ways of resolving this in situations where reintubation would be difficult or unsafe. This case report discusses such an event in an infant with multiple airway challenges including a retropharyngeal and anterior mediastinal abscess. We have also formulated a pathway based on various case reports involving complete ETT obstruction. PMID:28299222

  9. Factor analysis of laboratory and clinical measurements of dyspnea in patients with chronic obstructive pulmonary disease.

    PubMed

    Nguyen, Huong Q; Altinger, Julie; Carrieri-Kohlman, Virginia; Gormley, Jenny M; Stulbarg, Michael S

    2003-02-01

    The primary purpose of this study was to determine if there are three distinct factors representing ratings of dyspnea during laboratory exercise, clinical ratings of dyspnea, and pulmonary function in patients with moderate to severe chronic obstructive pulmonary disease (COPD) (n = 92) using factor analysis. Subjects (mean age 66 +/- 7 yrs; FEV1% predicted 44.7 +/- 14.0) were randomly assigned to one of three treatment groups to test the effects of three education and exercise training programs. Outcomes were evaluated at baseline and at 2 months after the intervention. Dyspnea ratings with laboratory exercise (SOB) were measured during incremental (ITT) and endurance (ETT) treadmill tests, and a six-minute walk (6MW) using the modified Borg scale. Clinical measures of dyspnea were measured with the Baseline and Transitional Dyspnea Index (BDI/TDI), UCSD Shortness of Breath Questionnaire (SOBQ), Medical Research Council Dyspnea Scale (MRC), Dyspnea subscale of the Chronic Respiratory Questionnaire (CRQ-D), and a global dyspnea question. Pulmonary function parameters included FEV1% predicted, FEV1/FVC, and RV/TLC. The factor analysis yielded three factors that accounted for 58.7% of the total variance in the data: Factor 1, "Dyspnea with Laboratory Exercise" comprised ETT SOB end, ETT SOB isotime, ITTSOB end, ITT SOB isotime, ITT SOB/Time and ETT SOB/Time. Factor 2, "Clinical Dyspnea," comprised 6MW SOB, 6MW SOB/Feet, BDI, SOBQ, MRC, Global SOB, CRQ-D. Measures of airway resistance (FEV1% predicted, FEV1/FVC) and hyperinflation (RV/TLC) loaded on a third factor, "Pulmonary Function." An additional post hoc factor analysis with post-intervention data provided similar results. The Global SOB question and ITT SOB isostage variables were relatively more sensitive to change compared to the other outcome variables. We conclude that pulmonary function, clinical ratings of dyspnea, and laboratory ratings of dyspnea are three separate and independent factors and should be

  10. Micro-patterned surfaces reduce bacterial colonization and biofilm formation in vitro: Potential for enhancing endotracheal tube designs

    PubMed Central

    2014-01-01

    Background Ventilator-associated pneumonia (VAP) is a leading hospital acquired infection in intensive care units despite improved patient care practices and advancements in endotracheal tube (ETT) designs. The ETT provides a conduit for bacterial access to the lower respiratory tract and a substratum for biofilm formation, both of which lead to VAP. A novel microscopic ordered surface topography, the Sharklet micro-pattern, has been shown to decrease surface attachment of numerous microorganisms, and may provide an alternative strategy for VAP prevention if included on the surface of an ETT. To evaluate the feasibility of this micro-pattern for this application, the microbial range of performance was investigated in addition to biofilm studies with and without a mucin-rich medium to simulate the tracheal environment in vitro. Methods The top five pathogens associated with ETT-related pneumonia, Methicillin-Resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Klebsiella pneumonia, Acinetobacter baumannii, and Escherichia coli, were evaluated for attachment to micro-patterned and un-patterned silicone surfaces in a short-term colonization assay. Two key pathogens, MRSA and Pseudomonas aeruginosa, were evaluated for biofilm formation in a nutrient rich broth for four days and minimal media for 24 hours, respectively, on each surface type. P. aeruginosa was further evaluated for biofilm formation on each surface type in a mucin-modified medium mimicking tracheal mucosal secretions. Results are reported as percent reductions and significance is based on t-tests and ANOVA models of log reductions. All experiments were replicated at least three times. Results Micro-patterned surfaces demonstrated reductions in microbial colonization for a broad range of species, with up to 99.9% (p < 0.05) reduction compared to un-patterned controls. Biofilm formation was also reduced, with 67% (p = 0.12) and 52% (p = 0.05) reductions in MRSA and P. aeruginosa

  11. Vehicle Mobility Assessment for Project Wheels Study Group

    DTIC Science & Technology

    1972-07-01

    for obtaining the reliable on-time information needed. 2 I 2. AMC-71 GROUND MOBILITY HODEL 2.1 Purpose The AMC-71 Ground Mobility Model is designed ...printed, refiled, ett., by an output routine designed to meet the needs of the particular study. 5 The basic output of AMC-71 is vehicle speed in each of a...road inflation pressures. The M52OE1 8-ton, 4xJ cargo truck is equipped with earthmover tires designed to operato at approximately 25 percent

  12. Wanat: Combat Action in Afghanistan, 2008

    DTIC Science & Technology

    2010-01-01

    events of that day through the eyes of the leaders and Soldiers of Task Force Rock . It is meant to provide context to the chaos and complexity of...Battalion, 503d Infantry (“The Rock ”), as well as members of the 62d Engineer Battalion, USMC ETT 5-3, and the staffs of the 173d Airborne Brigade...Operation ROCK MOVE ........... 53 Chapter 2. The Establishment of COP Kahler, 8-12 July 2008 ........ 69 ROCK MOVE—The Plan

  13. Robust Optimization and Sensitivity Analysis with Multi-Objective Genetic Algorithms: Single- and Multi-Disciplinary Applications

    DTIC Science & Technology

    2007-01-01

    WCCSR Ru radius of uncertainty from the approximation model t target variables tij corresponding target variables for coupling variables yij...of the variance 2σ̂ for Eq. (2.5) is given by o T n/)ˆ()ˆ(ˆ 12 ββσ vuvu −−= −R (2.9) The Mean Squared Error (MSE) s2...ttg ttg .ttg -ttg L-g tttt t w ttEttEtE b ttcttctcwL L f µ µ (3.13) In Eq. (3.13), the notations (ρ1, ρ2, ρ3

  14. Comments on the ring-opening polymerization of morpholine-2,5-dione derivatives by various metal catalysts and characterization of the products formed in the reactions involving R2SnX2, where X = OPr(i) and NMe2 and R = Bu(n), Ph and p-Me2NC6H4.

    PubMed

    Chisholm, M H; Galucci, J; Krempner, C; Wiggenhorn, C

    2006-02-14

    (3S,6S)-3-Isopropyl-6-methyl-morpholine-2,5-dione (1), and (3S,6S)-3,6-dimethyl-morpholine-2,5-dione (2), do not enter into ring-opening polymerization reactions with metal catalyst precursors commonly employed for lactides, and with Sn(II) octanoate, only low molecular weight oligomers are obtained. Reactions with R2SnX2 compounds, where R = Ph, Bu(n) and p-Me2NC6H4 and X = OPr(i) or NMe2, reveal that ring-opening of the morpholine-2,5-diones does occur, but that polymerization is terminated by the formation of kinetically-inert products such as {Ph2Sn[mu,eta(3)-OCH(Me)CONCH(Pr(i))COOPr(i)]}2 (3), and {[Bu(n))2Sn[mu,eta(3)-OCH(Me)CONCH(Me)CONMe2]}2 (4), with elimination of HX. Ph3SnOPr(i) is seen to react reversibly with morpholine-2,5-diones in toluene-d8 by 1H NMR spectroscopy while (Bu(n))3SnNMe2 reacts by ring opening to give (Bu(n))3SnOCH(Me)C(O)NHCHMeC(O)NMe2. The new organotin compounds have been characterized by 1H, 13C{1H} and 118Sn NMR spectroscopy and compounds 1, 2, 3 and 4 by single crystal X-ray crystallography.

  15. Crystal structures of triazine-3-thione derivatives by reaction with copper and cobalt salts.

    PubMed

    López-Torres, Elena; Mendiola, Maria Antonia; Pastor, César J

    2006-04-03

    The reaction of 5-methoxy-5,6-diphenyl-4,5-dihydro-2H-[1,2,4]triazine-3-thione L1H2OCH3 with copper(II) chloride leads to the formation of an organic molecule L2 containing two triazine rings linked by a new S-S bond. A binuclear copper(II) complex, 1, containing L1 is also isolated. The reaction of L1H2OCH3 with copper(I) chloride yields a hexanuclear cluster of copper(I), 2, in which the copper atoms form a distorted octahedron with the ligand L1 acting as an NS chelate and sulfur bridge, giving to the copper ion a trigonal geometry by one N and two S atoms. In any reaction of the disulfide L2 with metal salts, complexes containing this molecule are isolated. Reactions with copper(I) and copper(II) chloride and nickel(II) and cadmium(II) nitrate produce the S-S bond cleavage, giving complexes containing the triazine L1 behaving as the NS anion, which show spectroscopic characteristics identical with those formed by reaction with L1H2OCH3. However, the reaction with cobalt(II) nitrate gives a low-spin octahedral cobalt(III) complex, in which an asymmetric rupture of the disulfide L2 has been produced, giving an unexpected complex with a new ligand and keeping the S-S bond.

  16. Mechanisms for glycolipid antigen-driven cytokine polarization by Valpha14i NKT cells.

    PubMed

    Sullivan, Barbara A; Nagarajan, Niranjana A; Wingender, Gerhard; Wang, Jing; Scott, Iain; Tsuji, Moriya; Franck, Richard W; Porcelli, Steven A; Zajonc, Dirk M; Kronenberg, Mitchell

    2010-01-01

    Certain glycolipid Ags for Valpha14i NKT cells can direct the overall cytokine balance of the immune response. Th2-biasing OCH has a lower TCR avidity than the most potent agonist known, alpha-galactosylceramide. Although the CD1d-exposed portions of OCH and alpha-galactosylceramide are identical, structural analysis indicates that there are subtle CD1d conformational differences due to differences in the buried lipid portion of these two Ags, likely accounting for the difference in antigenic potency. Th1-biasing C-glycoside/CD1d has even weaker TCR interactions than OCH/CD1d. Despite this, C-glycoside caused a greater downstream activation of NK cells to produce IFN-gamma, accounting for its promotion of Th1 responses. We found that this difference correlated with the finding that C-glycoside/CD1d complexes survive much longer in vivo. Therefore, we suggest that the pharmacokinetic properties of glycolipids are a major determinant of cytokine skewing, suggesting a pathway for designing therapeutic glycolipids for modulating invariant NKT cell responses.

  17. Fluorine in drug design: a case study with fluoroanisoles.

    PubMed

    Xing, Li; Blakemore, David C; Narayanan, Arjun; Unwalla, Ray; Lovering, Frank; Denny, R Aldrin; Zhou, Huanyu; Bunnage, Mark E

    2015-04-01

    Anisole and fluoroanisoles display distinct conformational preferences, as evident from a survey of their crystal structures. In addition to altering the free ligand conformation, various degrees of fluorination have a strong impact on physicochemical and pharmacokinetic properties. Analysis of anisole and fluoroanisole matched molecular pairs in the Pfizer corporate database reveals interesting trends: 1) PhOCF3 increases log D by ~1 log unit over PhOCH3 compounds; 2) PhOCF3 shows lower passive permeability despite its higher lipophilicity; and 3) PhOCF3 does not appreciably improve metabolic stability over PhOCH3 . Emerging from the investigation, difluoroanisole (PhOCF2 H) strikes a better balance of properties with noticeable advantages of log D and transcellular permeability over PhOCF3 . Synthetic assessment illustrates that the routes to access difluoroanisoles are often more straightforward than those for trifluoroanisoles. Whereas replacing PhOCH3 with PhOCF3 is a common tactic to optimize ADME properties, our analysis suggests PhOCF2 H may be a more attractive alternative, and greater exploitation of this motif is recommended.

  18. Origin of Substituent Effect on Tautomeric Behavior of 1,2,4-Triazole Derivatives: Combined Spectroscopic and Theoretical Study.

    PubMed

    Sergeieva, Tetiana; Bilichenko, Maria; Holodnyak, Sergiy; Monaykina, Yulia V; Okovytyy, Sergiy I; Kovalenko, Sergiy I; Voronkov, Eugene; Leszczynski, Jerzy

    2016-12-29

    The reaction of 2-aryl-[1,2,4]triazolo[1,5-c]quinazolines with nucleophilic reagents (hydrazine hydrate, sodium hydroxide, sodium methoxide, hydrochloric acid) under acidic conditions leads to formation of compounds that tend to tautomerize. The products of the transformation are distinguished by the position (ortho-, meta-, para-) of the OCH3 group in the aryl moiety. To assign their structures we used the combined approach: experiment and theoretical modeling. The procedure included calculation of the relative stability for possible tautomers, simulation of UV/vis spectra for the most stable forms, and comparison of the resulting curves with the experimental spectral data taking into account the Boltzmann weighting. Through computations, we showed that the orientation of OCH3 substituent remarkably impacts on the tautomeric behavior of triazoles. In the case of ortho-OCH3 it is controlled by formation of the intramolecular hydrogen bond while for meta- and para- derivatives the degree of conjugation plays the decisive role. In order to balance the accuracy and cost of calculations we evaluated the performance of selected DFT methods and 6-31G*, 6-311++G**, and STO(##)-3Gel basis sets. The last one is a physically justified basis set previously constructed in our group, and its combination with PBE1PBE approach is shown to be the best choice for UV/vis simulations in the frame of the current research.

  19. Structural characterization of a beta-diketone hydrolase from the cyanobacterium Anabaena sp. PCC 7120 in native and product-bound forms, a coenzyme A-independent member of the crotonase suprafamily.

    PubMed

    Bennett, Joseph P; Whittingham, Jean L; Brzozowski, A Marek; Leonard, Philip M; Grogan, Gideon

    2007-01-09

    The gene alr4455 from the well-studied cyanobacterium Anabaena sp. PCC 7120 encodes a crotonase orthologue that displays beta-diketone hydrolase activity. Anabaena beta-diketone hydrolase (ABDH), in common with 6-oxocamphor hydrolase (OCH) from Rhodococcus sp. NCIMB 9784, catalyzes the desymmetrization of bicyclo[2.2.2]octane-2,6-dione to yield [(S)-3-oxocyclohexyl]acetic acid, a reaction unusual among the crotonase superfamily as the substrate is not an acyl-CoA thioester. The structure of ABDH has been determined to a resolution of 1.5 A in both native and ligand-bound forms. ABDH forms a hexamer similar to OCH and features one active site per enzyme monomer. The arrangement of side chains in the active site indicates that while the catalytic chemistry may be conserved in OCH orthologues, the structural determinants of substrate specificity are different. In the active site of ligand-bound forms that had been cocrystallized with the bicyclic diketone substrate bicyclo[2.2.2]octane-2,6-dione was found the product of the asymmetric enzymatic retro-Claisen reaction [(S)-3-oxocyclohexyl]acetic acid. The structures of ABDH in both native and ligand-bound forms reveal further details about structural variation and modes of coenzyme A-independent activity within the crotonases and provide further evidence of a wider suprafamily of enzymes that have recruited the crotonase fold for the catalysis of reactions other than those regularly attributed to canonical superfamily members.

  20. Substituent effects on hydrogen bonding of aromatic amide-carboxylate

    NASA Astrophysics Data System (ADS)

    Sen, Ibrahim; Kara, Hulya; Azizoglu, Akın

    2016-10-01

    N-(p-benzoyl)-anthranilic acid (BAA) derivatives have been synthesized with different substituents (X: Br, Cl, OCH3, CH3), and their crystal structures have been analyzed in order to understand the variations in their molecular geometries with respect to the substituents by using 1H NMR, 13C NMR, IR and X-ray single-crystal diffraction. The carboxylic acid group forms classic Osbnd H ⋯ O hydrogen bonded dimers in a centrosymmetric R22(8) ring motifs for BAA-Br and BAA-Cl. However, no carboxylic acid group forms classic Osbnd H ⋯ O hydrogen bonded dimers in BAA-OCH3 and BAA-CH3. The asymmetric unit consists of two crystallographically independent molecules in BAA-OCH3. DFT computations show that the interaction energies between monomer and dimer are in the range of 0.5-3.8 kcal/mol with the B3LYP/6-31 + G*, B3LYP/6-31 ++G*, B3LYP/6-31 ++G**, and B3LYP/AUG-cc-pVDZ levels of theory. The presence of different hydrogen bond patterns is also governed by the substrate. For monomeric compounds studied herein, theoretical calculations lead to two low-energy conformers; trans (a) and cis (b). Former one is more stable than latter by about 4 kcal/mol.

  1. Substituent effects on hydrogen bonding of aromatic amide-carboxylate.

    PubMed

    Sen, Ibrahim; Kara, Hulya; Azizoglu, Akın

    2016-10-05

    N-(p-benzoyl)-anthranilic acid (BAA) derivatives have been synthesized with different substituents (X: Br, Cl, OCH3, CH3), and their crystal structures have been analyzed in order to understand the variations in their molecular geometries with respect to the substituents by using (1)H NMR, (13)C NMR, IR and X-ray single-crystal diffraction. The carboxylic acid group forms classic OH⋯O hydrogen bonded dimers in a centrosymmetric R2(2)(8) ring motifs for BAA-Br and BAA-Cl. However, no carboxylic acid group forms classic OH⋯O hydrogen bonded dimers in BAA-OCH3 and BAA-CH3. The asymmetric unit consists of two crystallographically independent molecules in BAA-OCH3. DFT computations show that the interaction energies between monomer and dimer are in the range of 0.5-3.8kcal/mol with the B3LYP/6-31+G*, B3LYP/6-31++G*, B3LYP/6-31++G**, and B3LYP/AUG-cc-pVDZ levels of theory. The presence of different hydrogen bond patterns is also governed by the substrate. For monomeric compounds studied herein, theoretical calculations lead to two low-energy conformers; trans (a) and cis (b). Former one is more stable than latter by about 4kcal/mol.

  2. Photoelectron velocity-map imaging spectroscopic and theoretical study on the reactivity of the gold atom toward CH3SH, CH3OH, and H2O.

    PubMed

    Qin, Zhengbo; Cong, Ran; Wu, Xia; Liu, Zhiling; Xie, Hua; Tang, Zichao; Jiang, Ling; Fan, Hongjun

    2013-07-21

    Photoelectron velocity-map imaging spectroscopy has been used to study the reaction of the anionic gold atom with the HR (R = SCH3, OCH3, OH) molecules. The solvated [Au···HR](-) and inserted [HAuR](-) products have been experimentally observed for R = SCH3, whereas only solvated [Au⋯HR](-) products were found for R = OCH3 and OH. This significant difference in the photoelectron spectra suggests the different reactivity of the Au(-) toward the CH3SH, CH3OH, and H2O molecules. Second order Møller-Plesset perturbation theory and coupled-cluster single double triple excitation calculations have been performed to aid the structural assignment of the spectra and to explore the reaction mechanism. Activation energies for the isomerizations of the solvated structures to the inserted ones in the Au(-)∕Au + HR reactions (R = OCH3 and OH) are predicted to be much higher than those for the Au(-)∕Au + CH3SH reactions, supporting the experimental observation. Theoretical calculations provide the evidence that the intriguing [HAuSCH3](-) product may be formed by the attachment of the electron onto the neutral HAuSCH3 species or the isomerization from the anionic [Au···HSCH3](-) one. These findings should be helpful for understanding the feature that the thiols are able to form the staple motifs, whereas CH3OH and H2O are not.

  3. Hydrogen production for fuel cells through methane reforming at low temperatures

    NASA Astrophysics Data System (ADS)

    Liu, Zhong-Wen; Jun, Ki-Won; Roh, Hyun-Seog; Park, Sang-Eon

    Hydrogen production for fuel cells through methane (CH 4) reforming at low temperatures has been investigated both thermodynamically and experimentally. From the thermodynamic equilibrium analysis, it is concluded that steam reforming of CH 4 (SRM) at low pressure and a high steam-to-CH 4 ratio can be achieved without significant loss of hydrogen yield at a low temperature such as 550 °C. A scheme for the production of hydrogen for fuel cells at low temperatures by burning the unconverted CH 4 to supply the heat for SRM is proposed and the calculated value of the heat-balanced temperature is 548 °C. SRM with and/or without the presence of oxygen at low temperatures is experimentally investigated over a Ni/Ce-ZrO 2/θ-Al 2O 3 catalyst. The catalyst shows high activity and stability towards SRM at temperatures from 400 to 650 °C. The effects of O 2:CH 4 and H 2O:CH 4 ratios on the conversion of CH 4, the hydrogen yield, the selectivity for carbon monoxide, and the H 2:CO ratio are investigated at 650 °C with a constant CH 4 space velocity. Results indicate that CH 4 conversion increases significantly with increasing O 2:CH 4 or H 2O:CH 4 ratio, and the hydrogen content in dry tail gas increases with the H 2O:CH 4 ratio.

  4. Vibrational Spectra and Adsorption of Trisiloxane Superspreading Surfactant at Air/Water Interface Studied with Sum Frequency Generation Vibrational Spectroscopy

    NASA Astrophysics Data System (ADS)

    Feng, Jun; Wu, Dan; Wen, Jia; Liu, Shi-lin; Wang, Hong-fei

    2008-08-01

    The C-H stretch vibrational spectra of the trisiloxane superspreading surfactant Silwet L-77 ((CH3)3Si-O-Si(CH3)(C3H6)(OCH2CH2)7-8OCH3)-O-Si(CH3)3) at the air/water interface are measured with the surface Sum Frequency Generation Vibrational Spectroscopy (SFG-VS). The spectra are dominated with the features from the -Si-CH3 groups around 2905 cm-1 (symmetric stretch or SS mode) and 2957 cm-1 (mostly the asymmetric stretch or AS mode), and with the weak but apparent contribution from the -O-CH2- groups around 2880 cm-1 (symmetric stretch or SS mode). Comparison of the polarization dependent SFG spectra below and above the critical aggregate or micelle concentration (CAC) indicates that the molecular orientation of the C-H related molecular groups remained unchanged at different surface densities of the Silwet L-77 surfactant. The SFG-VS adsorption isotherm suggested that there was no sign of Silwet L-77 bilayer structure formation at the air/water interface. The Gibbs adsorption free energy of the Silwet surfactant to the air/water interface is -42.2±0.8kcal/mol, indicating the unusually strong adsorption ability of the Silwet L-77 superspreading surfactant.

  5. Study of RF-excited Diethylene Glycol Dimethyl Ether Plasmas by Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Algatti, M. A.; Mota, R. P.; Moreira Júnior, P. W. P.; Honda, R. Y.; Kayama, M. E.; Kostov, K. G.

    2012-12-01

    This paper deals with the study of the fragmentation process of diethylene glycol dimethyl ether (CH3O(CH2CH2O)2CH3) (diglyme here in) molecule in low pressure RF excited plasma discharges. The study was carried out using mass spectrometry. The results showed that for a fixed pressure, the increase of the RF power coupled to the plasma chamber from 1 to 35 W produced a plasma environment much more reactive which increases the population of the ionized species like CH2+ (15 amu), C2H4+ (28 amu), CH3O+ (31 amu), C2H4O+ (44 amu), CH3OCH2CH2+ (59 amu) and CH3OCH2CH2O+ (75 amu). This fact may be attributed to the increase of the electronic temperature that makes predominant the occurrence of inelastic processes that promotes molecular fragmentation. For a fixed value of RF power the increase of pressure from 50 mTorr to 100 mTorr produces the decreasing of the above mentioned chemical species due the lower electronic mean free path. These results suggest that if one wants to keep the monomer's functionality within the plasma deposited films resulting from such kind of discharges one must operate in low power conditions.

  6. Dual-level direct dynamics studies for the reactions of dimethyl ether with hydrogen atom and methyl radical.

    PubMed

    Wu, Jia-Yan; Liu, Jing-Yao; Li, Ze-Sheng; Huang, Xu-Ri; Sun, Chia-Chung

    2003-04-15

    The dual-level direct dynamics approach is employed to study the dynamics of the CH(3)OCH(3) + H (R1) and CH(3)OCH(3) + CH(3) (R2) reactions. Low-level calculations of the potential energy surface are carried out at the MP2/6-311+G(d,p) level of theory. High-level energetic information is obtained at the QCISD(T) level of theory with the 6-311+G(3df,3pd) basis set. The dynamics calculations are performed using variational transition state theory (VTST) with the interpolated single-point energies (ISPE) method, and small-curvature tunneling (SCT) is included. It is shown that the reaction of CH(3)OCH(3) with H (R1) may proceed much easier and with a lower barrier height than the reaction with CH(3) radical (R2). The calculated rate constants and activation energies are in good agreement with the experimental values. The calculated rate constants are fitted to k(R1) = 1.16 x 10(-19) T(3) exp(-1922/T) and k(R2) = 1.66 x 10(-28) T(5) exp(-3086/T) cm(3) mol(-1) s(-1) over a temperature range 207-2100 K. Furthermore, a small variational effect and large tunneling effect in the lower temperature range are found for the two reactions.

  7. Saccharomyces Cerevisiae Hoc1, a Suppressor of Pkc1, Encodes a Putative Glycosyltransferase

    PubMed Central

    Neiman, A. M.; Mhaiskar, V.; Manus, V.; Galibert, F.; Dean, N.

    1997-01-01

    The Saccharomyces cerevisiae gene PKC1 encodes a protein kinase C isozyme that regulates cell wall synthesis. Here we describe the characterization of HOC1, a gene identified by its ability to suppress the cell lysis phenotype of pkc1-371 cells. The HOC1 gene (Homologous to OCH1) is predicted to encode a type II integral membrane protein that strongly resembles Och1p, an α-1,6-mannosyltransferase. Immunofluorescence studies localized Hoc1p to the Golgi apparatus. While overexpression of HOC1 rescued the pkc1-371 temperature-sensitive cell lysis phenotype, disruption of HOC1 lowered the restrictive temperature of the pkc1-371 allele. Disruption of HOC1 also resulted in hypersensitivity to Calcofluor White and hygromycin B, phenotypes characteristic of defects in cell wall integrity and protein glycosylation, respectively. The function of HOC1 appears to be distinct from that of OCH1. Taken together, these results suggest that HOC1 encodes a Golgi-localized putative mannosyltransferase required for the proper construction of the cell wall. PMID:9055074

  8. Methyl-perfluoroheptene-ethers (CH3OC7F13): measured OH radical reaction rate coefficients for several isomers and enantiomers and their atmospheric lifetimes and global warming potentials.

    PubMed

    Jubb, Aaron M; Gierczak, Tomasz; Baasandorj, Munkhbayar; Waterland, Robert L; Burkholder, James B

    2014-05-06

    Mixtures of methyl-perfluoroheptene-ethers (CH3OC7F13, MPHEs) are currently in use as replacements for perfluorinated alkanes (PFCs) and poly-ether heat transfer fluids, which are persistent greenhouse gases with lifetimes >1000 years. At present, the atmospheric processing and environmental impact from the use of MPHEs is unknown. In this work, rate coefficients at 296 K for the gas-phase reaction of the OH radical with six key isomers (including stereoisomers and enantiomers) of MPHEs used commercially were measured using a relative rate method. Rate coefficients for the six MPHE isomers ranged from ∼ 0.1 to 2.9 × 10(-12) cm(3) molecule(-1) s(-1) with a strong stereoisomer and -OCH3 group position dependence; the (E)-stereoisomers with the -OCH3 group in an α- position relative to the double bond had the greatest reactivity. Rate coefficients measured for the d3-MPHE isomer analogues showed decreased reactivity consistent with a minor contribution of H atom abstraction from the -OCH3 group to the overall reactivity. Estimated atmospheric lifetimes for the MPHE isomers range from days to months. Atmospheric lifetimes, radiative efficiencies, and global warming potentials for these short-lived MPHE isomers were estimated based on the measured OH rate coefficients along with measured and theoretically calculated MPHE infrared absorption spectra. Our results highlight the importance of quantifying the atmospheric impact of individual components in an isomeric mixture.

  9. Self-Assembled Amphiphilic Water Oxidation Catalysts: Control of O-O Bond Formation Pathways by Different Aggregation Patterns.

    PubMed

    Yang, Bing; Jiang, Xin; Guo, Qing; Lei, Tao; Zhang, Li-Ping; Chen, Bin; Tung, Chen-Ho; Wu, Li-Zhu

    2016-05-17

    The oxidation of water to molecular oxygen is the key step to realize water splitting from both biological and chemical perspective. In an effort to understand how water oxidation occurs on a molecular level, a large number of molecular catalysts have been synthesized to find an easy access to higher oxidation states as well as their capacity to make O-O bond. However, most of them function in a mixture of organic solvent and water and the O-O bond formation pathway is still a subject of intense debate. Herein, we design the first amphiphilic Ru-bda (H2 bda=2,2'-bipyridine-6,6'-dicarboxylic acid) water oxidation catalysts (WOCs) of formula [Ru(II) (bda)(4-OTEG-pyridine)2 ] (1, OTEG=OCH2 CH2 OCH2 CH2 OCH3 ) and [Ru(II) (bda)(PySO3 Na)2 ] (2, PySO3 (-) =pyridine-3-sulfonate), which possess good solubility in water. Dynamic light scattering (DLS), scanning electron microscope (SEM), critical aggregation concentration (CAC) experiments and product analysis demonstrate that they enable to self-assemble in water and form the O-O bond through different routes even though they have the same bda(2-) backbone. This work illustrates for the first time that the O-O bond formation pathway can be regulated by the interaction of ancillary ligands at supramolecular level.

  10. Photoelectron velocity-map imaging spectroscopic and theoretical study on the reactivity of the gold atom toward CH3SH, CH3OH, and H2O

    NASA Astrophysics Data System (ADS)

    Qin, Zhengbo; Cong, Ran; Wu, Xia; Liu, Zhiling; Xie, Hua; Tang, Zichao; Jiang, Ling; Fan, Hongjun

    2013-07-01

    Photoelectron velocity-map imaging spectroscopy has been used to study the reaction of the anionic gold atom with the HR (R = SCH3, OCH3, OH) molecules. The solvated [Au⋯HR]- and inserted [HAuR]- products have been experimentally observed for R = SCH3, whereas only solvated [Au⋯HR]- products were found for R = OCH3 and OH. This significant difference in the photoelectron spectra suggests the different reactivity of the Au- toward the CH3SH, CH3OH, and H2O molecules. Second order Møller-Plesset perturbation theory and coupled-cluster single double triple excitation calculations have been performed to aid the structural assignment of the spectra and to explore the reaction mechanism. Activation energies for the isomerizations of the solvated structures to the inserted ones in the Au-/Au + HR reactions (R = OCH3 and OH) are predicted to be much higher than those for the Au-/Au + CH3SH reactions, supporting the experimental observation. Theoretical calculations provide the evidence that the intriguing [HAuSCH3]- product may be formed by the attachment of the electron onto the neutral HAuSCH3 species or the isomerization from the anionic [Au⋯HSCH3]- one. These findings should be helpful for understanding the feature that the thiols are able to form the staple motifs, whereas CH3OH and H2O are not.

  11. In vivo antileishmanial activity and chemical profile of polar extract from Selaginella sellowii.

    PubMed

    Queiroz, Dayane Priscilla de Souza; Carollo, Carlos Alexandre; Kadri, Mônica Cristina Toffoli; Rizk, Yasmin Silva; Araujo, Vanessa Carneiro Pereira de; Monteiro, Paulo Eduardo de Oliveira; Rodrigues, Patrik Oening; Oshiro, Elisa Teruya; Matos, Maria de Fátima Cepa; Arruda, Carla Cardozo Pinto de

    2016-03-01

    The polar hydroethanolic extract from Selaginella sellowii(SSPHE) has been previously proven active on intracellular amastigotes (in vitro test) and now was tested on hamsters infected with Leishmania (Leishmania) amazonensis (in vivo test). SSPHE suppressed a 100% of the parasite load in the infection site and draining lymph nodes at an intralesional dose of 50 mg/kg/day × 5, which was similar to the results observed in hamsters treated with N-methylglucamine antimonate (Sb) (28 mg/Kg/day × 5). When orally administered, SSPHE (50 mg/kg/day × 20) suppressed 99.2% of the parasite load in infected footpads, while Sb suppressed 98.5%. SSPHE also enhanced the release of nitric oxide through the intralesional route in comparison to Sb. The chemical fingerprint of SSPHE by high-performance liquid chromatography with diode-array detection and tandem mass spectrometry showed the presence of biflavonoids and high molecular weight phenylpropanoid glycosides. These compounds may have a synergistic action in vivo. Histopathological study revealed that the intralesional treatment with SSPHE induced an intense inflammatory infiltrate, composed mainly of mononuclear cells. The present findings reinforce the potential of this natural product as a source of future drug candidates for American cutaneous leishmaniasis.

  12. High antiferromagnetic transition temperature of a honeycomb compound SrRu2O6

    DOE PAGES

    Tian, Wei; Svoboda, Chris; Ochi, M.; ...

    2015-09-14

    We study the high-temperature magnetic order in a quasi-two-dimensional honeycomb compound SrRu2O6 by measuring magnetization and neutron powder diffraction with both polarized and unpolarized neutrons. SrRu2O6 crystallizes into the hexagonal lead antimonate (PbSb2O6, space group P31m) structure with layers of edge-sharing RuO6 octahedra separated by Sr2+ ions. SrRu2O6 is found to order at TN = 565 K with Ru moments coupled antiferromagnetically both in plane and out of plane. The magnetic moment is 1.30(2) μB/Ru at room temperature and is along the crystallographic c axis in the G-type magnetic structure. We perform density functional calculations with constrained random-phase approximation (RPA)more » to obtain the electronic structure and effective intra- and interorbital interaction parameters. The projected density of states shows strong hybridization between Ru 4d and O 2p. By downfolding to the target t2g bands we extract the effective magnetic Hamiltonian and perform Monte Carlo simulations to determine the transition temperature as a function of interand intraplane couplings. We find a weak interplane coupling, 3% of the strong intraplane coupling, permits three-dimensional magnetic order at the observed TN .« less

  13. Composition and microstructure of maiolica from the museum of ceramics in Ascoli Piceno (Italy): evidences by electron microscopy and microanalysis

    NASA Astrophysics Data System (ADS)

    Gulmini, M.; Scognamiglio, F.; Roselli, G.; Vaggelli, G.

    2015-09-01

    The present work focuses on majolica objects from the collection of the museum of ceramic in Ascoli Piceno (Italy). The scientific investigation was performed on fragments detached from seven maiolicas attributed to the Castelli production (Abruzzi region) and one majolica from the Ascoli Piceno production (Marche region). The Castelli artifacts (late sixteenth-early eighteenth century) belong to the decorated style known as " compendiario." The piece from Ascoli Piceno recalls the decoration style of the other considered objects and is attributable to the "Paci" manufacture (first half of the nineteenth century). The selected objects were investigated by fiber optics reflectance spectroscopy, micro-X-ray fluorescence spectroscopy and scanning electron microscopy coupled with electron-dispersive X-ray spectrometry. The ceramic bodies of all objects are calcareous, whereas the glazes are lead-alkali type opacified by tin dioxide. Blue and purplish-red decorations were obtained by cobalt and manganese compounds dissolved in the glaze, respectively. Yellow and orange decorations were obtained by particles of lead antimonate and hematite. Finally, black decorations were obtained using compounds rich in manganese and iron. The study contributes to knowledge on the production of Castelli ceramics and presents first archaeometric data on the maiolica production from Ascoli Piceno. The scientific examination highlights continuity with the Renaissance production, and the joint contribution of the three analytical techniques suggests distinctive features among different productions, thus integrating and refining the information obtained by the art-historical study.

  14. Dating ancient mosaic glasses by luminescence: The case study of San Pietro in Vaticano

    NASA Astrophysics Data System (ADS)

    Galli, A.; Martini, M.; Sibilia, E.; Vandini, M.; Villa, I.

    2011-12-01

    The preliminary results of a study on the dosimetric properties of a set of glass tesserae from the mosaics of the vaults of St. Peter's Basilica in Rome (late XVI century) are reported. The main goal of the research was to assess the possibility of dating them by means of luminescence techniques. The samples had already been extensively studied and investigated from a historical, artistic and compositional point of view. The period of the making of the mosaic was rather well known, and could be the basis to test the experimental procedures we used for dosimetry. The experiments also aimed at demonstrating the validity of the hypothesis we put forward, i.e. the positive link between the presence of micro-crystals and the luminescence sensitivity in mosaic glass: to this aim, the samples richer in crystalline inclusions were selected. The role of calcium antimonate and cassiterite was definitely demonstrated. For what concerns their thermoluminescence (TL) characteristics, a preliminary investigation suggested that the available configuration of the detection systems did not properly fit the wavelength of the emitted TL. Much more promising results have been achieved by the use of Optically Stimulated Luminescence (OSL), even if the measured absorbed doses were rather scattered. For one sample with high OSL sensitivity, it was possible to establish its recent age, relative to one of the documented restorations that took place during the last century.

  15. Calcium transport mechanism in molting crayfish revealed by microanalysis

    SciTech Connect

    Mizuhira, V.; Ueno, M.

    1983-01-01

    Crayfish provide a good model in which to study the transport mechanism of Ca ions. During the molting stage, decalcified Ca ions are transferred into the blood and accumulate in the gastrolith epithelium, after which a gastrolith is formed on the surface of the epithelium. The gastrolith is dissolved in the stomach after molting, and the Ca is reabsorbed and redistributed throughout the newly formed exoskeleton. We studied the mechanism of Ca transport by cytochemical precipitation of Ca ions and by electron microanalysis, including X-ray microanalysis (EDX) and electron energy-loss spectroscopy (EELS), with a computer. In EDX analysis, the fine precipitates of K-antimonate in the gastrolith mitochondria clearly defined Ca with antimony; we also observed a large amount of Ca-oxalate in the mitochondria, and Ca-K X-ray pulses were clearly defined. Ca-K X-rays were also detected from fresh freeze-substituted mitochondria. Finally, we succeeded in taking a Ca-L EELS image from the mitochondria of fresh freeze-substituted thin sections. Only a very small amount of Ca was detected from the cell membrane and other organelles. Ca-adenosine triphosphatase (ATPase) and Mg-ATPase activity was also very clearly demonstrated in the mitochondria. These enzymes may play an important role in Ca metabolism.

  16. In vivo antileishmanial activity and chemical profile of polar extract from Selaginella sellowii

    PubMed Central

    Queiroz, Dayane Priscilla de Souza; Carollo, Carlos Alexandre; Kadri, Mônica Cristina Toffoli; Rizk, Yasmin Silva; de Araujo, Vanessa Carneiro Pereira; Monteiro, Paulo Eduardo de Oliveira; Rodrigues, Patrik Oening; Oshiro, Elisa Teruya; Matos, Maria de Fátima Cepa; de Arruda, Carla Cardozo Pinto

    2016-01-01

    The polar hydroethanolic extract from Selaginella sellowii(SSPHE) has been previously proven active on intracellular amastigotes (in vitro test) and now was tested on hamsters infected with Leishmania (Leishmania) amazonensis (in vivo test). SSPHE suppressed a 100% of the parasite load in the infection site and draining lymph nodes at an intralesional dose of 50 mg/kg/day × 5, which was similar to the results observed in hamsters treated with N-methylglucamine antimonate (Sb) (28 mg/Kg/day × 5). When orally administered, SSPHE (50 mg/kg/day × 20) suppressed 99.2% of the parasite load in infected footpads, while Sb suppressed 98.5%. SSPHE also enhanced the release of nitric oxide through the intralesional route in comparison to Sb. The chemical fingerprint of SSPHE by high-performance liquid chromatography with diode-array detection and tandem mass spectrometry showed the presence of biflavonoids and high molecular weight phenylpropanoid glycosides. These compounds may have a synergistic action in vivo. Histopathological study revealed that the intralesional treatment with SSPHE induced an intense inflammatory infiltrate, composed mainly of mononuclear cells. The present findings reinforce the potential of this natural product as a source of future drug candidates for American cutaneous leishmaniasis. PMID:26910353

  17. Calcium and Calmodulin Localization in Gravitropically-responding Plant Organs

    NASA Technical Reports Server (NTRS)

    Roux, S. J.

    1985-01-01

    Antimonate staining procedures were used to detect calcium redistribution changes in corn roots. Results show that an asymmetric redistribution of Ca is induced by a gravitropic stimulus in roots as it is in shoots. Since this response occurs within 10 min, at least 5 min before any visible bending, it could play a role in the regulation of root gravitropism. Two different general approaches were used to localize calmodulin in plant tissue: radioimmunoassay of its content in tissue and in purified subcellular organelles, and immunocytochemical detection of it in roots and coleoptiles. Radioimmunoassay results indicate that calmodulin is present in large quantities in pllant cells and that it is specifically associated with mitochondria, etioplasts and nuclei. An assayed of an extract of soluble wall proteins revealed that over 1% of these proteins was calmodulin. Controls indicate that this calmodulin is not cytoplasmic in origin. A reaction product from anti-calmodulin was found mainly in the root cap cells, moderately in metazylem elements, in some cells in the stele surrounding metaxylem elements and in cortical cells.

  18. An update on the diagnosis and treatment of canine leishmaniosis caused by Leishmania infantum (syn. L. chagasi).

    PubMed

    Noli, Chiara; Saridomichelakis, Manolis N

    2014-12-01

    Canine leishmaniosis caused by Leishmania infantum is still a common disease in endemic areas, such as the Mediterranean countries, and has progressively expanded into non-endemic areas like Central and Northern Europe. The aim of this article is to critically review current knowledge on the diagnosis and treatment of this disease. In dogs with typical clinical signs and clinicopathological abnormalities, diagnosis is relatively easy based on the exclusion of major differentials, the demonstration of the parasite (e.g., with lymph node and/or skin cytology) and the presence of Leishmania-specific immunoglobulin G antibodies (quantitative serology). In less typical cases, these criteria together with the exclusion of possible differentials and the demonstration of compatible histological lesions in affected organs and tissues form the basis for a sound diagnosis. In clinically healthy dogs, molecular techniques are the most sensitive means for detecting L. infantum infection. Treatment of canine leishmaniosis should follow clinical staging and is usually based on meglumine antimonate or miltefosine administration for a few weeks in combination with allopurinol for several months. However, allopurinol monotherapy may be used in very mild cases as well as in dogs with end stage kidney disease. Aminosidine administered once daily at a revised dosage shows some promise but additional controlled studies are needed. Close attention to published guidelines regarding treatment and follow-up is necessary to achieve the best possible therapeutic outcome.

  19. PXRF, μ-XRF, vacuum μ-XRF, and EPMA analysis of Email Champlevé objects present in Belgian museums.

    PubMed

    Van der Linden, Veerle; Meesdom, Eva; Devos, Annemie; Van Dooren, Rita; Nieuwdorp, Hans; Janssen, Elsje; Balace, Sophie; Vekemans, Bart; Vincze, Laszlo; Janssens, Koen

    2011-10-01

    The enamel of 20 Email Champlevé objects dating between the 12th and 19th centuries was investigated by means of microscopic and portable X-ray fluorescence analysis (μ-XRF and PXRF). Seven of these objects were microsampled and the fragments were analyzed with electron probe microanalysis (EPMA) and vacuum μ-XRF to obtain quantitative data about the composition of the glass used to produce these enameled objects. As a result of the evolution of the raw materials employed to produce the base glass, three different compositional groups could be discriminated. The first group consisted of soda-lime-silica glass with a sodium source of mineral origin (with low K content) that was opacified by addition of calcium antimonate crystals. This type of glass was only used in objects made in the 12th century. Email Champlevé objects from the beginning of the 13th century onward were enameled with soda-lime-silica glass with a sodium source of vegetal origin. This type of glass, which has a higher potassium content, was opacified with SnO2 crystals. The glass used for 19th century Email Champlevé artifacts was produced with synthetic and purified components resulting in a different chemical composition compared to the other groups. Although the four analytical techniques employed in this study have their own specific characteristics, they were all found to be suitable for classifying the objects into the different chronological categories.

  20. The Fluid Processing Apparatus: from Flight Hardware to Electron Micrographs

    NASA Technical Reports Server (NTRS)

    Hilaire, Emmanuel; Brown, Christopher S.; Guikema, James A.

    1995-01-01

    Since the early years of space biology, a major drawback in spaceflight plant experiments has been the inability to fix specimens in microgravity, relying instead on fixation after return to Earth. As there, it is of a growing interest to look at the effect of microgravity on the structure and the developmental polarity of root graviperceptive cells, or columella cells, and so, it is important to use flight hardware which allows specimen fixation in space therefore avoiding the confounding effects of rapid readaptation to gravity after landing. As part of the Bioserve Space Technologies, a Center for the Commercial Development of Space (CCDS), we now have experiment flight opportunities through the Commercial Generic Bioprocessing Apparatus (CGBA) payload. In this study the Fluid Processing Apparatus (FPA) was used to grow seedlings for a limited period of time prior to fixation of the tissue in a microgravity environment. Upon return to Earth, the samples were processed for electron microscopy. This report describes the microscopic data obtained from the two space flights (STS-54 and STS-60). In both cases, the electron micrographs of the columella cells revealed well preserved cell structure, well defined microtubules, and the presence of calcium precipitates formed by a antimonate precipitation method.

  1. Chronic exposure to arsenic in drinking water can lead to resistance to antimonial drugs in a mouse model of visceral leishmaniasis.

    PubMed

    Perry, Meghan R; Wyllie, Susan; Raab, Andrea; Feldmann, Joerg; Fairlamb, Alan H

    2013-12-03

    The Indian subcontinent is the only region where arsenic contamination of drinking water coexists with widespread resistance to antimonial drugs that are used to treat the parasitic disease visceral leishmaniasis. We have previously proposed that selection for parasite resistance within visceral leishmaniasis patients who have been exposed to trivalent arsenic results in cross-resistance to the related metalloid antimony, present in the pentavalent state as a complex in drugs such as sodium stibogluconate (Pentostam) and meglumine antimonate (Glucantime). To test this hypothesis, Leishmania donovani was serially passaged in mice exposed to arsenic in drinking water at environmentally relevant levels (10 or 100 ppm). Arsenic accumulation in organs and other tissues was proportional to the level of exposure and similar to that previously reported in human liver biopsies. After five monthly passages in mice exposed to arsenic, isolated parasites were found to be completely refractory to 500 μg · mL(-1) Pentostam compared with the control passage group (38.5 μg · mL(-1)) cultured in vitro in mouse peritoneal macrophages. Reassessment of resistant parasites following further passage for 4 mo in mice without arsenic exposure showed that resistance was stable. Treatment of infected mice with Pentostam confirmed that resistance observed in vitro also occurred in vivo. We conclude that arsenic contamination may have played a significant role in the development of Leishmania antimonial resistance in Bihar because inadequate treatment with antimonial drugs is not exclusive to India, whereas widespread antimonial resistance is.

  2. Distribution of calcium in the stigma and style of tobacco during pollen germination and tube elongation.

    PubMed

    Ge, Li Li; Xie, Chao Tian; Tian, Hui Qiao; Russell, Scott D

    2009-06-01

    Potassium antimonate was used to locate loosely bound calcium in the stigma and style of tobacco. The tobacco stigma is wet and covered by a thick layer of glycoprotein exudate at anthesis. The exudate contains abundant vesicles, which are densely labeled with calcium precipitates. When pollen grains arrive at the stigma, become hydrated, and as the pollen swells, Ca(2+) precipitates accumulate at the aperture. Calcium precipitates that accumulate in pollen cytoplasm are initially concentrated within small vacuoles, but as germination proceeds these appear to fuse, forming prominent, densely labeled vesicles that preferentially accumulate near the proximal region of the growing tube. Although the stigma has abundant particles, few calcium precipitates are observed in the transmitting tissue from anthesis to 11 h after pollination. However, at 22 h after pollination, accumulation of calcium increases distally from the stigmatic interface with the transmitting tissue through the length of the style to the ovary. An examination of flowering plants with differing floral biology will be needed to understand the role of loosely bound calcium accumulation and its relationship to tissue-level changes in calcium uptake, maintenance of other calcium pools, including [Ca(2+)](cyt), and in pollen and style maturation during the progamic phase.

  3. Cytochemical localization of calcium in cap cells of primary roots of Zea mays L

    NASA Technical Reports Server (NTRS)

    Moore, R.

    1986-01-01

    The distribution of calcium (Ca) in caps of vertically- and horizontally-oriented roots of Zea mays was monitored to determine its possible role in root graviresponsiveness. A modification of the antimonate precipitation procedure was used to localize Ca in situ. In vertically-oriented roots, the presumed graviperceptive (i.e., columella) cells were characterized by minimal and symmetric staining of the plasmalemma and mitochondria. No precipitate was present in plasmodesmata or cell walls. Within 5 min after horizontal reorientation, staining was associated with the portion of the cell wall adjacent to the distal end of the cell. This asymmetric staining persisted throughout the onset of gravicurvature. No staining of lateral cell walls of columella cells was observed at any stage of gravicurvature, suggesting that a lateral flow of Ca through the columella tissue of horizontally-oriented roots does not occur. The outermost peripheral cells of roots oriented horizontally and vertically secrete Ca through plasmodesmata-like structures in their cell walls. These results are discussed relative to proposed roles of root-cap Ca in root gravicurvature.

  4. Polychrome glass from Etruscan sites: first non-destructive characterization with synchrotron μ-XRF, μ-XANES and XRPD

    NASA Astrophysics Data System (ADS)

    Arletti, R.; Vezzalini, G.; Quartieri, S.; Ferrari, D.; Merlini, M.; Cotte, M.

    2008-07-01

    This work is devoted to the characterization of a suite of very rare, highly decorated and coloured glass vessels and beads from the VII to the IV century BC. The most serious difficulty in developing this study was that any sampling even micro-sampling was absolutely forbidden. As a consequence, the mineralogical and chemical nature of chromophores and opacifiers present in these Iron Age finds were identified by means of the following synchrotron-based, strictly non-destructive, techniques: micro X-ray fluorescence (μ-XRF), Fe K-edge micro X-ray absorption near edge spectroscopy (μ-XANES) and X-ray powder diffraction (XRPD). The μ-XRF mapping evidenced high levels of Pb and Sb in the yellow decorations and the presence of only Sb in the white and light-blue ones. Purple and black glass show high amounts of Mn and Fe, respectively. The XRPD analyses confirmed the presence of lead and calcium antimonates in yellow, turquoise and white decorations. Fe K-edge μ-XANES spectra were collected in different coloured parts of the finds, thus enabling the mapping of the oxidation state of these elements across the samples. In most of the samples iron is present in the reduced form Fe2+ in the bulk glass of the vessels, and in the oxidized form Fe3+ in the decorations, indicating that these glass artefacts were produced in at least two distinct processing steps under different furnace conditions.

  5. A fruitful demonstration in sensors based on upconversion luminescence of Yb3+/Er3+codoped Sb2O3-WO3-Li2O (SWL) glass-ceramic

    NASA Astrophysics Data System (ADS)

    Prasad Sukul, Prasenjit; Kumar, Kaushal

    2016-07-01

    In this article, erbium and ytterbium doped lithium tungsten antimonate (Yb3+/Er3+:Sb2O3-WO3-Li2O) glass-ceramics (GC) is synthesized and its novel applications in temperature sensing and detection of latent fingerprints is studied. It is also estimated that this material could be useful as a solar cell concentrator. The upconversion emission studies on Yb3+/Er3+:SWL glass-ceramics have shown intense green emission at 525 nm (2H11/2 → 4I15/2) & 545 nm (4s3/2 → 4I15/2). The variation of UC intensities with external temperature have shown a well-fashioned pattern, which suggests that the 2H11/2 and 4S3/2 levels of Er3+ ion are thermally coupled and can act as a temperature sensor in the 300-500 K temperature range. Dry powder of Yb3+/Er3+:SWL glass-ceramic is used to develop latent fingerprint with high contrast in green color on glass slide.

  6. Properties of the arsenate reductase of plasmid R773.

    PubMed

    Gladysheva, T B; Oden, K L; Rosen, B P

    1994-06-14

    Resistance to toxic oxyanions in Escherichia coli is conferred by the ars operon carried on plasmid R773. The gene products of this operon catalyze extrusion of antimonials and arsenicals from cells of E. coli, thus providing resistance to those toxic oxyanions. In addition, resistance to arsenate is conferred by the product of the arsC gene. In this report, purified ArsC protein was shown to catalyze reduction of arsenate to arsenite. The enzymatic activity of the ArsC protein required glutaredoxin as a source of reducing equivalents. Other reductants, including glutathione and thioredoxin, were not effective electron donors. A spectrophotometric assay was devised in which arsenate reduction was coupled to NADPH oxidation. The results obtained with the coupled assay corresponded to those found by direct reduction of radioactive arsenate to arsenite. The only substrate of the reaction was arsenate (Km = 8 mM); other oxyanions including phosphate, sulfate, and antimonate were not reduced. Phosphate and sulfate were weak inhibitors, while the product, arsenite, was a stronger inhibitor (Ki = 0.1 mM). Arsenate reductase activity exhibited a pH optimum of 6.3-6.8. These results indicate that the ArsC protein is a novel reductase, and elucidation of its enzymatic mechanism should be of interest.

  7. Reactions of Monomeric [1,2,4-(Me3C)3C5H2]2CeH and CO with orwithout H2:An Experimental and Computational Study

    SciTech Connect

    Werkema, Evan L.; Maron, Laurent; Eisenstein, Odile; Andersen,Richard A.

    2006-09-07

    Addition of CO to [1,2,4-(Me3C)3C5H2]2CeH, Cp'2CeH, intoluene yields the cis (Cp'2Ce)2(mu-OCHCHO), in which the cis enediolategroup bridges the two metallocene fragments. The cis enediolatequantitatively isomerizes intramolecularly to the trans-enediolate inC6D6 at 100oC over seven months. When the solvent is pentane,Cp'2Ce(OCH2)CeCp'2 forms, in which the oxomethylene group or theformaldehyde dianion bridges the two metallocene fragments. The cisenediolate is suggested to form by insertion of CO into the Ce-C bond ofCp'2Ce(OCH2)CeCp'2 generating Cp'2CeOCH2COCeCp'2. The stereochemistry ofthe cis-enediolate is determined by a 1,2-hydrogen shift in the OCH2COfragment that has the OC(H2) bond anti periplanar relative to the carbenelone pair. The bridging oxomethylene complex reacts with H2, but not withCH4, to give Cp'2CeOMe, which is also the product of the reaction betweenCp'2CeH and a mixture of CO and H2. The oxomethylene complex reacts withCO to give the cis enediolate complex. DFT calculations on C5H5 modelmetallocenes show that the reaction of Cp2CeH with CO and H2 to giveCp2CeOMe is exoergic by 50 kcal mol-1. The net reaction proceeds by aseries of elementary reactions that occur after the formyl complex,Cp2Ce(eta-2 CHO), is formed by further reaction with H2. The key pointthat emerges from the calculated potential energy surface is thebifunctional nature of the metal formyl in which the carbon atom behavesas a donor and acceptor. Replacing H2 by CH4 increases the activationenergy barrier by 17 kcal mol-1.

  8. Molecular cycloencapsulation augments solubility and improves therapeutic index of brominated noscapine in prostate cancer cells.

    PubMed

    Madan, Jitender; Baruah, Bharat; Nagaraju, Mulpuri; Abdalla, Mohamed O; Yates, Clayton; Turner, Timothy; Rangari, Vijay; Hamelberg, Donald; Aneja, Ritu

    2012-05-07

    We have previously shown that a novel microtubule-modulating noscapinoid, EM011 (9-Br-Nos), displays potent anticancer activity by inhibition of cellular proliferation and induction of apoptosis in prostate cancer cells and preclinical mice models. However, physicochemical and cellular barriers encumber the development of viable formulations for future clinical translation. To circumvent these limitations, we have synthesized EM011-cyclodextrin inclusion complexes to improve solubility and enhance therapeutic index of EM011. Phase solubility analysis indicated that EM011 formed a 1:1 stoichiometric complex with β-CD and methyl-β-CD, with a stability constant (K(c)) of 2.42 × 10(-3) M and 4.85 × 10(-3) M, respectively. Fourier transform infrared spectroscopy suggested the penetrance of either a O-CH(2) or OCH(3)-C(6)H(4)-OCH(3) moiety of EM011 in the β-CD or methyl-β-CD cavity. In addition, multifarious techniques, namely, differential scanning calorimetry, powder X-ray diffraction, scanning electron microscopy, NMR spectroscopy, and computational studies validated the cage complex of EM011 with β-CD and methyl-β-CD. Moreover, rotating frame overhauser enhancement spectroscopy showed that the H(a) proton of the OCH(3)-C(6)H(4)-OCH(3) moiety was in close proximity with H3 proton of the β-CD or methyl-β-CD cavity. Furthermore, we found that the solubility of EM011 in phosphate buffer saline (pH 7.4) was enhanced by ~11 fold and ~21 fold upon complexation with β-CD and methyl-β-CD, respectively. The enhanced dissolution of the drug CD-complexes in aqueous phase remarkably decreased their IC(50) to 28.5 μM (9-Br-Nos-β-CD) and 12.5 μM (9-Br-Nos-methyl-β-CD) in PC-3 cells compared to free EM011 (~200 μM). This is the first report to demonstrate the novel construction of cylcodextrin-based nanosupramolecular vehicles for enhanced delivery of EM011 that warrants in vivo evaluation for the superior management of prostate cancer.

  9. Molecular cycloencapsulation augments solubility and improves therapeutic index of brominated noscapine in prostate cancer cells

    PubMed Central

    Madan, Jitender; Baruah, Bharat; Nagaraju, Mulpuri; Abdalla, Mohamed O.; Yates, Clayton; Turner, Timothy; Rangari, Vijay; Hamelberg, Donald; Aneja, Ritu

    2012-01-01

    We have previously shown that a novel microtubule-modulating noscapinoid, EM011 (9-Br-Nos), displays potent anticancer activity by inhibition of cellular proliferation and induction of apoptosis in prostate cancer cells and preclinical mice models. However, physicochemical and cellular barriers encumber the development of viable formulations for future clinical translation. To circumvent these limitations, we have synthesized EM011-cyclodextrin inclusion complexes to improve solubility and enhance therapeutic index of EM011. Phase solubility analysis indicated that EM011 formed a 1:1 stoichiometric complex with β-CD and methyl-β-CD, with a stability constant (Kc) of 2.42 × 10−3 M and 4.85 × 10−3 M, respectively. Fourier transform infrared spectroscopy suggested the penetrance of either O-CH2 or OCH3-C6H4-OCH3 moiety of EM011 in the β-CD or methyl-β-CD cavity. In addition, multifarious techniques viz., differential scanning calorimetry, powder X-ray diffraction, scanning electron microscopy, NMR spectroscopy, and computational studies validated the cage complex of EM011 with β-CD and methyl-β-CD. Moreover, rotating frame overhauser enhancement spectroscopy showed that the Ha proton of OCH3-C6H4-OCH3 moiety was in close proximity with H3 proton of β-CD or methyl-β-CD cavity. Furthermore, we found that the solubility of EM011 in phosphate buffer saline (pH 7.4) was enhanced by ∼11 fold and ∼21 fold upon complexation with β-CD and methyl-β-CD, respectively. The enhanced dissolution of the drug CD-complexes in aqueous phase remarkably decreased their IC50 to 28.5 μM (9-Br-Nos-β-CD) and 12.5 μM (9-Br-Nos-methyl-β-CD) in PC-3 cells compared to free EM011 (∼200 μM). This is the first report to demonstrate the novel construction of cylcodextrin-based nanosupramolecular vehicles for enhanced delivery of EM011 that warrants in vivo evaluation for the superior management of prostate cancer. PMID:22540277

  10. Effect of nebulized eucalyptus on contamination of microbial plaque of endotracheal tube in ventilated patients

    PubMed Central

    Amini, Nazanin; Rezaei, Korosh; Yazdannik, Ahmadreza

    2016-01-01

    Background: Formation of biofilm and bacterial colonization within the endotracheal tube (ETT) are significant sources of airway contamination and play a role in the development of ventilator-associated pneumonia (VAP). This study was conducted to examine the effect of nebulized eucalyptus (NE) on bacterial colonization of ETT biofilm. Materials and Methods: We performed a randomized clinical trial in three intensive care units (ICUs) of an educational hospital. Seventy intubated patients were selected and randomly divided into intervention (n = 35) and control (n = 35) groups. The intervention group received 4 ml (5%) of eucalyptus in 6 ml normal saline every 8 h. The placebo group received only 10 ml of normal saline in the same way. On extubation, the interior of the tube was immediately sampled using a sterile swab for standard microbiological analysis. Chi-square and Fisher's exact tests were used for statistical analysis in SPSS. P values less than 0.05 were considered statistically significant. Results: In both samples, Klebsiella pneumoniae and Acinetobacter baumannii were the most frequently isolated bacteria. In the control group, heavy colonization was greater than in the intervention group (P = 0.002). The frequency of isolation of K. pneumoniae in the intervention group was lower than in the control group (P < 0.001). However, there was no difference between the two groups in other isolated bacteria. Conclusions: NE can reduce microbial contamination of the endotracheal tube biofilm in ventilated patients. Moreover, K. pneumoniae was the most sensitive to NE. PMID:27095990

  11. Classifying movement behaviour in relation to environmental conditions using hidden Markov models.

    PubMed

    Patterson, Toby A; Basson, Marinelle; Bravington, Mark V; Gunn, John S

    2009-11-01

    1. Linking the movement and behaviour of animals to their environment is a central problem in ecology. Through the use of electronic tagging and tracking (ETT), collection of in situ data from free-roaming animals is now commonplace, yet statistical approaches enabling direct relation of movement observations to environmental conditions are still in development. 2. In this study, we examine the hidden Markov model (HMM) for behavioural analysis of tracking data. HMMs allow for prediction of latent behavioural states while directly accounting for the serial dependence prevalent in ETT data. Updating the probability of behavioural switches with tag or remote-sensing data provides a statistical method that links environmental data to behaviour in a direct and integrated manner. 3. It is important to assess the reliability of state categorization over the range of time-series lengths typically collected from field instruments and when movement behaviours are similar between movement states. Simulation with varying lengths of times series data and contrast between average movements within each state was used to test the HMMs ability to estimate movement parameters. 4. To demonstrate the methods in a realistic setting, the HMMs were used to categorize resident and migratory phases and the relationship between movement behaviour and ocean temperature using electronic tagging data from southern bluefin tuna (Thunnus maccoyii). Diagnostic tools to evaluate the suitability of different models and inferential methods for investigating differences in behaviour between individuals are also demonstrated.

  12. Exaggerated blood pressure response during the exercise treadmill test as a risk factor for hypertension

    PubMed Central

    Lima, S.G.; Albuquerque, M.F.P.M.; Oliveira, J.R.M.; Ayres, C.F.J.; Cunha, J.E.G.; Oliveira, D.F.; Lemos, R.R.; Souza, M.B.R.; Silva, O. Barbosa e

    2013-01-01

    Exaggerated blood pressure response (EBPR) during the exercise treadmill test (ETT) has been considered to be a risk factor for hypertension. The relationship of polymorphisms of the renin-angiotensin system gene with hypertension has not been established. Our objective was to evaluate whether EBPR during exercise is a clinical marker for hypertension. The study concerned a historical cohort of normotensive individuals. The exposed individuals were those who presented EBPR. At the end of the observation period (41.7 months = 3.5 years), the development of hypertension was analyzed within the two groups. Genetic polymorphisms and blood pressure behavior were assessed as independent variables, together with the classical risk factors for hypertension. The I/D gene polymorphism of the angiotensin-converting enzyme and M235T of angiotensinogen were ruled out as risk factors for hypertension. EBPR during ETT is not an independent influence on the chances of developing hypertension. No differences were observed between the hypertensive and normotensive individuals regarding gender (P = 0.655), skin color (P = 0.636), family history of hypertension (P = 0.225), diabetes mellitus (P = 0.285), or hypertriglyceridemia (P = 0.734). The risk of developing hypertension increased with increasing body mass index (BMI) and advancing age. The risk factors, which independently influenced the development of hypertension, were age and BMI. EBPR did not constitute an independent risk factor for hypertension and is probably a preclinical phase in the spectrum of normotension and hypertension. PMID:23598646

  13. A genetic link between epigenetic repressor AS1-AS2 and a putative small subunit processome in leaf polarity establishment of Arabidopsis

    PubMed Central

    Matsumura, Yoko; Ohbayashi, Iwai; Takahashi, Hiro; Kojima, Shoko; Ishibashi, Nanako; Keta, Sumie; Nakagawa, Ayami; Hayashi, Rika; Saéz-Vásquez, Julio; Echeverria, Manuel; Sugiyama, Munetaka; Nakamura, Kenzo; Machida, Chiyoko

    2016-01-01

    ABSTRACT Although the DEAD-box RNA helicase family is ubiquitous in eukaryotes, its developmental role remains unelucidated. Here, we report that cooperative action between the Arabidopsis nucleolar protein RH10, an ortholog of human DEAD-box RNA helicase DDX47, and the epigenetic repressor complex of ASYMMETRIC-LEAVES1 (AS1) and AS2 (AS1-AS2) is critical to repress abaxial (ventral) genes ETT/ARF3 and ARF4, which leads to adaxial (dorsal) development in leaf primordia at shoot apices. Double mutations of rh10-1 and as2 (or as1) synergistically up-regulated the abaxial genes, which generated abaxialized filamentous leaves with loss of the adaxial domain. DDX47 is part of the small subunit processome (SSUP) that mediates rRNA biogenesis. In rh10-1 we found various defects in SSUP-related events, such as: accumulation of 35S/33S rRNA precursors; reduction in the 18S/25S ratio; and nucleolar hypertrophy. Double mutants of as2 with mutations of genes that encode other candidate SSUP-related components such as nucleolin and putative rRNA methyltransferase exhibited similar synergistic defects caused by up-regulation of ETT/ARF3 and ARF4. These results suggest a tight link between putative SSUP and AS1-AS2 in repression of the abaxial-determining genes for cell fate decisions for adaxial development. PMID:27334696

  14. Who gets admitted to the Chest Pain Unit (CPU) and how do we manage them? Improving the use of the CPU in Waikato DHB, New Zealand.

    PubMed

    Jade, Judith; Huggan, Paul; Stephenson, Douglas

    2015-01-01

    Chest pain is a commonly encountered presentation in the emergency department (ED). The chest pain unit at Waikato DHB is designed for patients with likely stable angina, who are at low risk of acute coronary syndrome (ACS), with a normal ECG and Troponin T, who have a history which is highly suggestive of coronary artery disease (CAD). Two issues were identified with patient care on the unit (1) the number of inappropriate admissions and (2) the number of inappropriate exercise tolerance tests. A baseline study showed that 73% of admissions did not fulfil the criteria and the majority of patients (72%) had an exercise tolerance test (ETT) irrespective of clinical picture. We delivered educational presentations to key stakeholders and the implementation of a new fast track chest pain pathway for discharging patients directly from the ED. There was an improvement in the number of patients inappropriately admitted, which fell to 61%. However, the number of inappropriate ETTs did not decrease, and were still performed on 76.9% of patients.

  15. Prediction of the mid-tracheal level using surface anatomical landmarks in adults

    PubMed Central

    Jang, Young-Eun; Kim, Eun-Hee; Song, In-Kyung; Lee, Ji-Hyun; Ryu, Ho-Geoul; Kim, Hee-Soo; Kim, Jin-Tae

    2017-01-01

    Abstract Endotracheal tube (ETT) should be placed at the optimal level to avoid single lung ventilation or accidental extubation. This study was performed to estimate the mid-tracheal level by using surface anatomical landmarks in adult patients. Neck computed tomography images of 329 adult patients between the ages of 16 and 79 years were reviewed. In the midline sagittal plane, the levels corresponding to the vocal cords, cricoid cartilage, suprasternal notch, manubriosternal junction, and carina were identified. The surface distances from the cricoid cartilage to the suprasternal notch (extCC-SSN) and that from the suprasternal notch to the manubriosternal junction (extSSN-MSJ) were measured. The relationship between mid-tracheal level and the surface distances was analyzed using Bland–Altman plot. The difference between the extCC-SSN and the mid-tracheal level was −6.6 (12.5) mm, and the difference between the extSSN-MSJ and the mid-tracheal level was −19.2 (6.1) mm. The difference between the extCC-SSN and the mid-tracheal level was smaller in females compared with males [−1.7 (11.7) mm vs −12.8 (10.7) mm; P < 0.001]. The mid-tracheal level, which is helpful in planning the insertion depth of an ETT, can be predicted by the surface distance between the cricoid cartilage and suprasternal notch in adults, especially in females. PMID:28328810

  16. Fiberoptic intubation through laryngeal mask airway for management of difficult airway in a child with Klippel-Feil syndrome.

    PubMed

    Bhat, Ravi; Mane, Rajesh S; Patil, Manjunath C; Suresh, S N

    2014-07-01

    The ideal airway management modality in pediatric patients with syndromes like Klippel-Feil syndrome is a great challenge and is technically difficult for an anesthesiologist. Half of the patients present with the classic triad of short neck, low hairline, and fusion of cervical vertebra. Numerous associated anomalies like scoliosis or kyphosis, cleft palate, respiratory problems, deafness, genitourinary abnormalities, Sprengel's deformity (wherein the scapulae ride high on the back), synkinesia, cervical ribs, and congenital heart diseases may further add to the difficulty. Fiberoptic bronchoscopy alone can be technically difficult and patient cooperation also becomes very important, which is difficult in pediatric patients. Fiberoptic bronchoscopy with the aid of supraglottic airway devices is a viable alternative in the management of difficult airway in children. We report a case of Klippel-Feil syndrome in an 18-month-old girl posted for cleft palate surgery. Imaging of spine revealed complete fusion of the cervical vertebrae with hypoplastic C3 and C6 vertebrae and thoracic kyphosis. We successfully managed airway in this patient by fiberoptic intubation through classic laryngeal mask airway (LMA). After intubation, we used second smaller endotracheal tube (ETT) to stabilize and elongate the first ETT while removing the LMA.

  17. Endoscopic Appearance of Oropharyngeal and Upper GI Kaposi's Sarcoma in an Immunocompromised Patient.

    PubMed

    Darr, Umar; Renno, Anas; Khan, Zubair; Alkully, Turki; Moslim, Maitham A; Kamal, Sehrish; Nawras, Ali

    2017-01-01

    Introduction. Kaposi's sarcoma (KS) usually manifests as a cutaneous disease but GI manifestation is often rare. It is associated with human herpes virus-8 (HHV-8) and seen in immunocompromised patients. In the USA, use of highly active antiretroviral therapy (HAART) has drastically reduced incidence of KS in HIV patients. Case Presentation. A 65-year-old male with human immunodeficiency virus (HIV) was admitted to the intensive care unit (ICU) with cardiopulmonary arrest secondary to hyperkalemia of 7.5 meq/L. Following placement of orogastric and endotracheal tube (ETT), a significant amount of blood was noticed in the ETT. Hemoglobin trended down from 9.6 mg/dL to 6.7 mg/dL over five days. Stool guaiac was positive. Esophagogastroduodenoscopy (EGD) was performed and revealed multiple large hypervascularized violaceous submucosal nodular lesions with stigmata of bleeding seen on the soft palate and pharynx and within the cricopharyngeal area close to the vocal cords. Biopsy of the soft palate lesions showed proliferation of neoplastic spindle shaped cells arranged in bundles with slit-like capillary spaces containing erythrocytes consistent with Kaposi's sarcoma. Biopsy was positive for HHV-8. Colonoscopy was unremarkable. There were no cutaneous manifestations of the disease. Conclusion. GI involvement of Kaposi's sarcoma must be considered in immunocompromised patients and can be confirmed by endoscopic methods.

  18. Numerical investigation of pulmonary drug delivery under mechanical ventilation conditions

    NASA Astrophysics Data System (ADS)

    Banerjee, Arindam; van Rhein, Timothy

    2012-11-01

    The effects of mechanical ventilation waveform on fluid flow and particle deposition were studied in a computer model of the human airways. The frequency with which aerosolized drugs are delivered to mechanically ventilated patients demonstrates the importance of understanding the effects of ventilation parameters. This study focuses specifically on the effects of mechanical ventilation waveforms using a computer model of the airways of patient undergoing mechanical ventilation treatment from the endotracheal tube to generation G7. Waveforms were modeled as those commonly used by commercial mechanical ventilators. Turbulence was modeled with LES. User defined particle force models were used to model the drag force with the Cunningham correction factor, the Saffman lift force, and Brownian motion force. The endotracheal tube (ETT) was found to be an important geometric feature, causing a fluid jet towards the right main bronchus, increased turbulence, and a recirculation zone in the right main bronchus. In addition to the enhanced deposition seen at the carinas of the airway bifurcations, enhanced deposition was also seen in the right main bronchus due to impaction and turbulent dispersion resulting from the fluid structures created by the ETT. Authors acknowledge financial support through University of Missouri Research Board Award.

  19. CO2 Absorption Using Fluorine Functionalized Ionic Liquids: Interplay of Hydrogen and σ-Hole Interactions.

    PubMed

    Rao, Soniya S; Gejji, Shridhar P

    2016-03-03

    Use of ionic liquids (ILs) for CO2 capture offers certain advantages over currently used methodologies and is of growing interest. With this perspective, ILs composed of S-ethyl-N,N,N',N'-tetramethylthiouronium ([ETT]) and 1-hexyl-3-methylimidazolium ([Hmim]) cations and tris(pentafluoroethyl)trifluorophosphate ([FEP]) anion have been investigated. The present work unravels the noncovalent interactions accompanying CO2 capture by these ILs. Electronic structure of ion pairs and their CO2 absorbed [ETT][FEP]·n(CO2) and [Hmim][FEP]·n(CO2) (n up to 30) complexes are derived. The anisotropy in molecular electrostatic potential dictates the binding of CO2 through the interplay of (i) halogen bonding (O···F) between electron deficient σ-holes on fluorines, (ii) electrostatic C···F interactions between electron deficient carbons of CO2 and the electron-rich fluorine atoms, and the (iii) hydrogen bonding (O···H) interactions from the cation. The manifestations of these interactions on binding energies, polarizabilities, and vibrational spectra of CO2 absorbed complexes are presented. Consequent "frequency shift" accompanying hydrogen and halogen bonding exhibit complementary characteristics in the infrared spectra of CO2 absorbed complexes. Correlation of binding energies to absorbed CO2 molecules further demonstrate that [Hmim] based ILs are more efficient for CO2 capture applications.

  20. Endoscopic Appearance of Oropharyngeal and Upper GI Kaposi's Sarcoma in an Immunocompromised Patient

    PubMed Central

    Renno, Anas; Khan, Zubair; Alkully, Turki; Kamal, Sehrish; Nawras, Ali

    2017-01-01

    Introduction. Kaposi's sarcoma (KS) usually manifests as a cutaneous disease but GI manifestation is often rare. It is associated with human herpes virus-8 (HHV-8) and seen in immunocompromised patients. In the USA, use of highly active antiretroviral therapy (HAART) has drastically reduced incidence of KS in HIV patients. Case Presentation. A 65-year-old male with human immunodeficiency virus (HIV) was admitted to the intensive care unit (ICU) with cardiopulmonary arrest secondary to hyperkalemia of 7.5 meq/L. Following placement of orogastric and endotracheal tube (ETT), a significant amount of blood was noticed in the ETT. Hemoglobin trended down from 9.6 mg/dL to 6.7 mg/dL over five days. Stool guaiac was positive. Esophagogastroduodenoscopy (EGD) was performed and revealed multiple large hypervascularized violaceous submucosal nodular lesions with stigmata of bleeding seen on the soft palate and pharynx and within the cricopharyngeal area close to the vocal cords. Biopsy of the soft palate lesions showed proliferation of neoplastic spindle shaped cells arranged in bundles with slit-like capillary spaces containing erythrocytes consistent with Kaposi's sarcoma. Biopsy was positive for HHV-8. Colonoscopy was unremarkable. There were no cutaneous manifestations of the disease. Conclusion. GI involvement of Kaposi's sarcoma must be considered in immunocompromised patients and can be confirmed by endoscopic methods. PMID:28261507

  1. Implementing a perpetual anesthesia setup standardized for the trauma room in a level I trauma center.

    PubMed

    Faircloth, Amanda C; Ford, Mary B

    2013-02-01

    The trauma room in a level I trauma center is a dynamic environment that provides little room for error. Significant variability can exist if anesthesia providers set up the room differently. Standardization provides a system that is consistent, reliable, and cost-effective. This study examines the process of creating and implementing a standardized anesthesia setup in the trauma room of a level I trauma center. As a result of this study, the medication cart and airway setups have been standardized. Providers are encouraged to only draw up medications that will be immediately used and to ensure that prefilled syringes have been incorporated into the pharmacy formulary. Using the EZ Endo prestyleted endotracheal tube (ETT) vs a regular ETT with stylet has yielded an annual cost savings of $2,673. Ensuring that items such as an esophageal temperature probe, humidifier, and nasogastric tube are available but unopened has provided a savings of $1,989.25 per year. The reservoir bag has been changed to a latex-free bag, and 3 central line kits including an arterial line kit are routinely stocked. An ultrasound machine dedicated for central line access, GlideScope, rapid fluid infuser, and Airtraq laryngoscope have all been incorporated into the permanent setup in the trauma room.

  2. Formation of ethylene glycol and other complex organic molecules in star-forming regions

    NASA Astrophysics Data System (ADS)

    Rivilla, V. M.; Beltrán, M. T.; Cesaroni, R.; Fontani, F.; Codella, C.; Zhang, Q.

    2017-02-01

    Context. The detection of complex organic molecules related with prebiotic chemistry in star-forming regions allows us to investigate how the basic building blocks of life are formed. Aims: Ethylene glycol (CH2OH)2 is the simplest sugar alcohol and the reduced alcohol of the simplest sugar glycoladehyde (CH2OHCHO). We study the molecular abundance and spatial distribution of (CH2OH)2, CH2OHCHO and other chemically related complex organic species (CH3OCHO, CH3OCH3, and C2H5OH) towards the chemically rich massive star-forming region G31.41+0.31. Methods: We analyzed multiple single-dish (Green Bank Telescope and IRAM 30 m) and interferometric (Submillimeter Array) spectra towards G31.41+0.31, covering a range of frequencies from 45 to 258 GHz. We fitted the observed spectra with a local thermodynamic equilibrium (LTE) synthetic spectra, and obtained excitation temperatures and column densities. We compared our findings in G31.41+0.31 with the results found in other environments, including low- and high-mass star-forming regions, quiescent clouds and comets. Results: We report for the first time the presence of the aGg' conformer of (CH2OH)2 towards G31.41+0.31, detecting more than 30 unblended lines. We also detected multiple transitions of other complex organic molecules such as CH2OHCHO, CH3OCHO, CH3OCH3, and C2H5OH. The high angular resolution images show that the (CH2OH)2 emission is very compact, peaking towards the maximum of the 1.3 mm continuum. These observations suggest that low abundance complex organic molecules, like (CH2OH)2 or CH2OHCHO, are good probes of the gas located closer to the forming stars. Our analysis confirms that (CH2OH)2 is more abundant than CH2OHCHO in G31.41+0.31, as previously observed in other interstellar regions. Comparing different star-forming regions we find evidence of an increase of the (CH2OH)2/CH2OHCHO abundance ratio with the luminosity of the source. The CH3OCH3/CH3OCHO and (CH2OH)2/C2H5OH ratios are nearly constant with

  3. On the structural and electronic considerations concerning the reactivity of metal-metal multiple bonds

    NASA Astrophysics Data System (ADS)

    Glasgow, Katherine Campbell

    2000-10-01

    The previously known compound W2(OCH2tBu) 6(py)2 is crystallographically characterized. Its solid state structure is described and compared with other M2(OR)6L 2 complexes. Upon treatment with isoprene, the complex W2(OCH 2tBu)6(py)(mu-isoprene) forms. The solid state structure is disordered with respect to the orientation of the diene; two different configurations are seen in the crystal structure. These two isomers are in equilibrium in solution and are visible by 1H NMR spectroscopy. Multidimensional NMR experiments are used to assign the structures of the two isomers in solution. Through the use of spin magnetization transfer, it has been determined that the two isomers interconvert through the loss of isoprene. The DeltaH° and DeltaS° values for the equilibrium are determined. The starting material W2(OCH2tBu) 6(py)2 had been previously determined to be an olefin hydrogenation catalyst. It has been determined that cyclic olefins are hydrogenated in a cis manner, and a kinetic isotope effect of 1.7 has been measured. It has been determined that olefins which form isolable adducts with W 2(OCH2tBu)6(py)2, such as isoprene, undergo hydrogenation at approximately the same rate as olefins which do not show evidence of adduct formation. The complex W2(OCH2tBu)6(py) 2had been found to couple aldehydes and ketones stoichiometrically to give olefins. The reaction was found to proceed in a stepwise manner through the alkylidene intermediate W2(OCH2tBu) 6(py)(O)(mu-CHR), allowing the selective cross coupling of aldehydes and ketones. More studies have been undertaken to help determine the scope of the reaction. Competition experiments have been performed to determine reaction preferences. Unsaturated and functionalized aldehydes have been studied to determine the tolerance of the reaction to certain chemical groups. The role of pyridine in this reaction has been studied, especially concerning its reactivity with the alkylidene intermediate. The dimetal tetracarboxylate

  4. Hydrogen-bonding Interactions between Apigenin and Ethanol/Water: A Theoretical Study

    NASA Astrophysics Data System (ADS)

    Zheng, Yan-Zhen; Zhou, Yu; Liang, Qin; Chen, Da-Fu; Guo, Rui; Lai, Rong-Cai

    2016-10-01

    In this work, hydrogen-bonding interactions between apigenin and water/ethanol were investigated from a theoretical perspective using quantum chemical calculations. Two conformations of apigenin molecule were considered in this work. The following results were found. (1) For apigenin monomer, the molecular structure is non-planar, and all of the hydrogen and oxygen atoms can be hydrogen-bonding sites. (2) Eight and seven optimized geometries are obtained for apigenin (I)–H2O/CH3CH2OH and apigenin (II)–H2O/CH3CH2OH complexes, respectively. In apigenin, excluding the aromatic hydrogen atoms in the phenyl substituent, all other hydrogen atoms and the oxygen atoms form hydrogen-bonds with H2O and CH3CH2OH. (3) In apigenin–H2O/CH3CH2OH complexes, the electron density and the E(2) in the related localized anti-bonding orbital are increased upon hydrogen-bond formation. These are the cause of the elongation and red-shift of the X‑H bond. The sum of the charge change transfers from the hydrogen-bond acceptor to donor. The stronger interaction makes the charge change more intense than in the less stable structures. (4) Most of the hydrogen-bonds in the complexes are electrostatic in nature. However, the C4‑O5···H, C9‑O4···H and C13‑O2···H hydrogen-bonds have some degree of covalent character. Furthermore, the hydroxyl groups of the apigenin molecule are the preferred hydrogen-bonding sites.

  5. Hydrogen-bonding Interactions between Apigenin and Ethanol/Water: A Theoretical Study

    PubMed Central

    Zheng, Yan-Zhen; Zhou, Yu; Liang, Qin; Chen, Da-Fu; Guo, Rui; Lai, Rong-Cai

    2016-01-01

    In this work, hydrogen-bonding interactions between apigenin and water/ethanol were investigated from a theoretical perspective using quantum chemical calculations. Two conformations of apigenin molecule were considered in this work. The following results were found. (1) For apigenin monomer, the molecular structure is non-planar, and all of the hydrogen and oxygen atoms can be hydrogen-bonding sites. (2) Eight and seven optimized geometries are obtained for apigenin (I)–H2O/CH3CH2OH and apigenin (II)–H2O/CH3CH2OH complexes, respectively. In apigenin, excluding the aromatic hydrogen atoms in the phenyl substituent, all other hydrogen atoms and the oxygen atoms form hydrogen-bonds with H2O and CH3CH2OH. (3) In apigenin–H2O/CH3CH2OH complexes, the electron density and the E(2) in the related localized anti-bonding orbital are increased upon hydrogen-bond formation. These are the cause of the elongation and red-shift of the X−H bond. The sum of the charge change transfers from the hydrogen-bond acceptor to donor. The stronger interaction makes the charge change more intense than in the less stable structures. (4) Most of the hydrogen-bonds in the complexes are electrostatic in nature. However, the C4−O5···H, C9−O4···H and C13−O2···H hydrogen-bonds have some degree of covalent character. Furthermore, the hydroxyl groups of the apigenin molecule are the preferred hydrogen-bonding sites. PMID:27698481

  6. Synthesis, characteristic and theoretical investigation of the structure, electronic properties and second-order nonlinearity of salicylaldehyde Schiff base and their derivatives

    NASA Astrophysics Data System (ADS)

    Tang, Guo-Dong; Zhao, Jian-Ying; Li, Rong-Qing; Yuan-Cao; Zhang, Zai-Chao

    2011-01-01

    A series of asymmetric donor-acceptor substituted salen-type Schiff-bases have been synthesized and their structures, electronic properties and second order nonlinearities were investigated by DFT methods. In order to verify the stable of these Schiff-base derivates, the IR spectrum of these Schiff-base derivates were calculated, the result showed that these compounds are stable. The results of TD-DFT calculation indicate that the derivatives with the electron-donating group (CH 3, OCH 3 or N(C 2H 5) 2) have a red shift absorption compared to derivatives with the electron-withdrawing group (NO 2). The analysis of MOS indicates that the CN group has contribution to the LUMO orbital while the groups of OCH 3, N(C 2H 5) 2 and NO 2 have contribution to the HOMO orbital. OCH 3, N(C 2H 5) 2 as electron rich groups, made the derivates have a larger first static hyperpolarizability. However, the compound (II) with a NO 2 substituent, also has a large first static hyperpolarizability. This is probably because of the special transition model, namely the values of two oscillator strength f ( fHOMO-1-LUMO = 0.405, fHOMO-LUMO = 0.321) are almost equal. In order to understand the influence of the energy gap (Δ E) between the HOMO and the LUMO orbitals on the first static hyperpolarizability, we calculated the energy gap (Δ E) of all Schiff-base compounds. The results show that the smaller the HOMO-LUMO energy gap is, the larger the first static hyperpolarizability is.

  7. Synthesis of a TREN in which the aryl substituents are part of a 45 atom macrocycle.

    PubMed

    Cain, Matthew F; Forrest, William P; Peryshkov, Dmitry V; Schrock, Richard R; Müller, Peter

    2013-10-16

    A substituted TREN has been prepared in which the aryl groups in (ArylNHCH2CH2)3N are substituted at the 3- and 5-positions with a total of six OCH2(CH2)nCH═CH2 groups (n = 1, 2, 3). Molybdenum nitride complexes, [(ArylNCH2CH2)3N]Mo(N), have been isolated as adducts that contain B(C6F5)3 bound to the nitride. Two of these [(ArylNCH2CH2)3N]Mo(NB(C6F5)3) complexes (n = 1 and 3) were crystallographically characterized. After removal of the borane from [(ArylNCH2CH2)3N]Mo(NB(C6F5)3) with PMe3, ring-closing olefin metathesis (RCM) was employed to join the aryl rings with OCH2(CH2)nCH═CH(CH2)nCH2O links (n = 1-3) between them. RCM worked best with a W(O)(CHCMe3)(Me2Pyr)(OHMT)(PMe2Ph) catalyst (OHMT = hexamethylterphenoxide, Me2Pyr = 2,5-dimethylpyrrolide) and n = 3. The macrocyclic ligand was removed from the metal through hydrolysis and isolated in 70-75% yields relative to the borane adducts. Crystallographic characterization showed that the macrocyclic TREN ligand in which n = 3 contains three cis double bonds. Hydrogenation produced a TREN in which the three links are saturated, i.e., O(CH2)10O.

  8. An OEGylated thiol monolayer for the tethering of liposomes and the study of liposome interactions.

    PubMed

    Briand, Elisabeth; Humblot, Vincent; Pradier, Claire-Marie; Kasemo, Bengt; Svedhem, Sofia

    2010-06-15

    The aim of the present work is to develop a protocol for the specific immobilization of liposomes, via tethers, onto functionalized gold surfaces, and in addition to give one example for such a surface architecture. All surface functionalization steps are charcerized and controlled. First, mixed thiolate self-assembled monolayers (SAMs) prepared from COOH- and OCH(3)-terminated oligo(ethylene glycol) (OEG) alkane thiols were characterized by polarization modulation reflection absorption infrared spectroscopy (PM-RAIRS) and by X-ray photoemission spectroscopy (XPS). The composition of the mixed SAMs was found to be close to that of the thiol solution. Next, grafting of biotin conjugated with an NH(2)-terminated OEG spacer (biotin-OEG-NH(2)) to the COOH groups via conventional amine coupling was optimized with respect to the COOH/OCH(3) ratio of the SAM. The grafting of biotin-OEG-NH(2) was assessed by monitoring the binding of neutravidin and albumin to the biotinylated surfaces using quartz crystal microbalance with dissipation monitoring (QCM-D), as well as by PM-RAIRS. It was shown that a COOH/OCH(3) ratio of around 0.3 was sufficient to saturate the SAMs with neutravidin. Finally, tethering of liposomes onto the neutravidin-terminated SAMs, was achieved. As an application example, of a close packed layer of tethered liposomes was exposed to the membrane-penetrating peptide melittin. As monitored by QCM-D, the liposomes fused when interacting with the peptide and ruptured into an extended, supported lipid bilayer over the whole surface. In summary, the described surface modification has potential for the development of assays requiring tethered intact liposomes, or tethered planar bilayers. Such surface architectures are especially important for the study of transmembrane proteins and peptides.

  9. Slip Rate Determination of Thrusts Along the Edge of NE Tibet From in situ-Produced Cosmogenic Nuclides

    NASA Astrophysics Data System (ADS)

    Hetzel, R.; Niedermann, S.; Tao, M.; Ivy-Ochs, S.; Stokes, S.; Strecker, M. R.; Kubik, P. W.

    2005-12-01

    The Qilian Shan forms a seismically active fold-and-thrust-belt along the NE margin of the Tibetan Plateau that evolved during the Neogene-Quaternary and continues to advance north-northeastward (Meyer et al., 1998; Tapponnier et al., 2001). Active thrust faults transecting Late Pleistocene alluvial fan deposits form spectacular fault scarps that are locally incised by rivers which form flights of terraces. By combining structural investigations, satellite imagery, topographic profiling, surface exposure, and luminescence dating we have determined slip rates for several thrust faults (Hetzel et al. 2002, 2004a,b). Our results are consistent with geologic and GPS constraints, which suggest that NNE-directed shortening across the northeastern Tibetan Plateau is distributed on several active faults with a total shortening rate of about 4 to 10 mm/yr. References Hetzel, R., S. Niedermann, M. Tao, P.W. Kubik, S. Ivy-Ochs, B. Gao, M.R. Strecker (2002a), Nature, 417, 428-432. Hetzel, R., M. Tao, S. Niedermann, M.R. Strecker, S. Ivy-Ochs, P.W. Kubik, B. Gao (2004a), Terra Nova 16, 157-162. Hetzel R., M. Tao, S. Stokes, S. Niedermann, S. Ivy-Ochs, G. Bo, M.R. Strecker, P.W. Kubik (2004b), Tectonics 23, TC6006, doi:10.1029/2004TC001653. Meyer, B., P. Tapponnier, L. Bourjot, F. Metivier, Y. Gaudemer, G. Peltzer, G. Shunmin, C. Zhitai (1998), Geophys. J. Int., 135, 1-47. Tapponnier, P., Z. Xu, F. Roger, B. Meyer, N. Arnaud, G. Wittlinger, J. Yang (2001), Science, 294, 1671-1677.

  10. Multiheteromacrocycles that Complex Metal Ions. Second Progress Report, 1 May 1975 -- 30 April 1976

    DOE R&D Accomplishments Database

    Cram, D. J.

    1976-01-15

    Objective is to develop cyclic and polycyclic host organic compounds to complex and lipophilize metal ions. Macrorings were synthesized: (OCH{sub 2} CH{sub 2} O CH{sub 2}COCH{sub 2} COCH{sub 2}){sub 2} and (OCH{sub 2} CH{sub 2} O CH{sub 2} COCH{sub 2} COCH{sub 2}){sub 3}. The smaller ring complexes divalent metals 10{sup 1+9} times better than the open-chain model CH{sub 3} O CH{sub 2} CO CH{sub 2} COCH{sub 2} O CH{sub 3}, and the order in which metal ions are complexed is Cu{sup 2+}, UO{sub 2}{sup 2+} greater than Ni{sup 2+} greater than Fe{sup 2+}, Co{sup 2+}, Zn{sup 2+}, Cd{sup 2+} greater than Mn{sup 2+}. The UO{sub 2}{sup 2+} and Cu{sup 2+} complexes were isolated and characterized. The larger ring complexes trivalent metals 10{sup 0.9-1.7} times better than the open- chain model compound, and the order is La{sup 3+}, Ce{sup 3+} greater than Cr{sup 3+}. Five other macrocycles were also synthesized, and their binding constants with Na, K, NH{sub 4}, and Cs picrates were measured. Six compounds containing one macroring and two inward-pointing ArOH or ArOCH{sub 3} groups were also prepared and tested for binding of Li, Na, K, Rb, and NH{sub 4} picrates. Racemic compounds containing two binaphthyls and its sulfur analog were prepared. Cage-shaped multiheteromacrocycles containing ten O ligand sites or four S and six O ligand sites were prepared and the binding capability of the first compound for picrates studied. Two ring systems with phosphonate ester groups were also prepared. (DLC)

  11. CNN pincer ruthenium catalysts for hydrogenation and transfer hydrogenation of ketones: experimental and computational studies.

    PubMed

    Baratta, Walter; Baldino, Salvatore; Calhorda, Maria José; Costa, Paulo J; Esposito, Gennaro; Herdtweck, Eberhardt; Magnolia, Santo; Mealli, Carlo; Messaoudi, Abdelatif; Mason, Sax A; Veiros, Luis F

    2014-10-13

    Reaction of [RuCl(CNN)(dppb)] (1-Cl) (HCNN=2-aminomethyl-6-(4-methylphenyl)pyridine; dppb=Ph2 P(CH2 )4 PPh2 ) with NaOCH2 CF3 leads to the amine-alkoxide [Ru(CNN)(OCH2 CF3 )(dppb)] (1-OCH2 CF3 ), whose neutron diffraction study reveals a short RuO⋅⋅⋅HN bond length. Treatment of 1-Cl with NaOEt and EtOH affords the alkoxide [Ru(CNN)(OEt)(dppb)]⋅(EtOH)n (1-OEt⋅n EtOH), which equilibrates with the hydride [RuH(CNN)(dppb)] (1-H) and acetaldehyde. Compound 1-OEt⋅n EtOH reacts reversibly with H2 leading to 1-H and EtOH through dihydrogen splitting. NMR spectroscopic studies on 1-OEt⋅n EtOH and 1-H reveal hydrogen bond interactions and exchange processes. The chloride 1-Cl catalyzes the hydrogenation (5 atm of H2 ) of ketones to alcohols (turnover frequency (TOF) up to 6.5×10(4) h(-1) , 40 °C). DFT calculations were performed on the reaction of [RuH(CNN')(dmpb)] (2-H) (HCNN'=2-aminomethyl-6-(phenyl)pyridine; dmpb=Me2 P(CH2 )4 PMe2 ) with acetone and with one molecule of 2-propanol, in alcohol, with the alkoxide complex being the most stable species. In the first step, the Ru-hydride transfers one hydrogen atom to the carbon of the ketone, whereas the second hydrogen transfer from NH2 is mediated by the alcohol and leads to the key "amide" intermediate. Regeneration of the hydride complex may occur by reaction with 2-propanol or with H2 ; both pathways have low barriers and are alcohol assisted.

  12. Synthesis, characteristic and theoretical investigation of the structure, electronic properties and second-order nonlinearity of salicylaldehyde Schiff base and their derivatives.

    PubMed

    Tang, Guo-Dong; Zhao, Jian-Ying; Li, Rong-Qing; Yuan-Cao; Zhang, Zai-Chao

    2011-01-01

    A series of asymmetric donor-acceptor substituted salen-type Schiff-bases have been synthesized and their structures, electronic properties and second order nonlinearities were investigated by DFT methods. In order to verify the stable of these Schiff-base derivates, the IR spectrum of these Schiff-base derivates were calculated, the result showed that these compounds are stable. The results of TD-DFT calculation indicate that the derivatives with the electron-donating group (CH3, OCH3 or N(C2H5)2) have a red shift absorption compared to derivatives with the electron-withdrawing group (NO2). The analysis of MOS indicates that the CN group has contribution to the LUMO orbital while the groups of OCH3, N(C2H5)2 and NO2 have contribution to the HOMO orbital. OCH3, N(C2H5)2 as electron rich groups, made the derivates have a larger first static hyperpolarizability. However, the compound (II) with a NO2 substituent, also has a large first static hyperpolarizability. This is probably because of the special transition model, namely the values of two oscillator strength f (fHOMO-1-LUMO=0.405, fHOMO-LUMO=0.321) are almost equal. In order to understand the influence of the energy gap (ΔE) between the HOMO and the LUMO orbitals on the first static hyperpolarizability, we calculated the energy gap (ΔE) of all Schiff-base compounds. The results show that the smaller the HOMO-LUMO energy gap is, the larger the first static hyperpolarizability is.

  13. Searching for trans ethyl methyl ether in Orion KL★,★★

    PubMed Central

    Tercero, B.; Cernicharo, J.; López, A.; Brouillet, N.; Kolesniková, L.; Motiyenko, R. A.; Margulès, L.; Alonso, J. L.; Guillemin, J.-C.

    2015-01-01

    We report on the tentative detection of trans ethyl methyl ether (tEME), t-CH3CH2OCH3, through the identification of a large number of rotational lines from each one of the spin states of the molecule towards Orion KL. We also search for gauche-trans-n-propanol, Gt-n-CH3CH2CH2OH, an isomer of tEME in the same source. We have identified lines of both species in the IRAM 30 m line survey and in the ALMA Science Verification data. We have obtained ALMA maps to establish the spatial distribution of these species. Whereas tEME mainly arises from the compact ridge component of Orion, Gt-n-propanol appears at the emission peak of ethanol (south hot core). The derived column densities of these species at the location of their emission peaks are ≤(4.0 ± 0.8) × 1015 cm−2 and ≤(1.0 ± 0.2)× 1015 cm−2 for tEME and Gt-n-propanol, respectively. The rotational temperature is ~100 K for both molecules. We also provide maps of CH3OCOH, CH3CH2OCOH, CH3OCH3, CH3OH, and CH3CH2OH to compare the distribution of these organic saturated O-bearing species containing methyl and ethyl groups in this region. Abundance ratios of related species and upper limits to the abundances of non-detected ethers are provided. We derive an abundance ratio N(CH3OCH3)/N(tEME) ≥ 150 in the compact ridge of Orion. PMID:26869726

  14. Thorium-mediated ring-opening of tetrahydrofuran and the development of a new thorium starting material: preparation and chemistry of ThI4(DME)2.

    PubMed

    Travia, Nicholas E; Monreal, Marisa J; Scott, Brian L; Kiplinger, Jaqueline L

    2012-12-28

    The thorium(IV) tetraiodide complex ThI(4)(DME)(2) (3) (DME = 1,2-dimethoxyethane) has been prepared in high yield by reacting the corresponding chloride complex ThCl(4)(DME)(2) with an excess of trimethylsilyl iodide (Me(3)SiI) in toluene. This new route avoids the use of thorium metal as a reagent. ThI(4)(DME)(2) (3) exhibits excellent thermal stability compared to ThI(4)(THF)(4) (1), which undergoes rapid ring-opening of THF at ambient temperature to yield the iodobutoxide complex ThI(3)[O(CH(2))(4)I](THF)(3) (2). Subsequent ligand-exchange between 2 and DME affords ThI(3)[O(CH(2))(4)I](DME)(2) (11), which can be converted to 3 with Me(3)SiI. Salt metathesis between 2 and K(L(Me)) (L(Me) = (2,6-(i)Pr(2)C(6)H(3))NC(Me)CHC(Me)N(2,6-(i)Pr(2)C(6)H(3))) cleanly gives (L(Me))ThI(2)[O(CH(2))(4)I](THF) (10), which is a rare example of a thorium β-diketiminate complex. Complexes 2, 10, and 11 represent the first reported examples of THF ring-opening mediated by thorium. The synthetic utility of ThI(4)(DME)(2) (3) is demonstrated by preparation of thorium(IV) alkoxide, amide, and organometallic compounds.

  15. Rate constants for the reaction of OH radicals with n-propyl, n-butyl, iso-butyl and tert-butyl vinyl ethers

    NASA Astrophysics Data System (ADS)

    Thiault, G.; Mellouki, A.

    Rate constants for the reaction of OH radicals with n-propyl vinyl ether (PVE, CH 3CH 2CH 2OCH dbnd CH 2), n-butyl vinyl ether (BVE, CH 3CH 2CH 2CH 2OCH dbnd CH 2), iso-butyl vinyl ether (IBVE, (CH 3) 2CHCH 2OCH dbnd CH 2) and tert-butyl vinyl ether (TBVE, (CH 3) 3COCH dbnd CH 2), have been measured in the temperature and pressure ranges 232-373 K and 30-300 Torr using the pulsed laser photolysis-laser-induced fluorescence method, and at 298 K and 760 Torr using the relative method. The obtained results are k1=(9.3±0.6)×10 -12 exp[(708±20)/ T], k2=(1.5±0.2)×10 -11 exp[(572±42)/ T], k3=(1.6±0.1)×10 -11 exp[(567±20)/ T], k4=(1.7±0.2)×10 -11 exp[(549±25)/ T] cm 3 molecule -1 s -1. The values at 298 K are k1=(1.0±0.1)×10 -10, k2=(1.0±0.1)×10 -10, k3=(1.1±0.1)×10 -10, k4=(1.1±0.1)×10 -10 cm 3 molecule -1 s -1. The deduced tropospheric lifetimes of these ethers for reaction with OH are of the order of 1 h and they are comparable to those for reaction with ozone.

  16. Searching for trans ethyl methyl ether in Orion KL(.)

    PubMed

    Tercero, B; Cernicharo, J; López, A; Brouillet, N; Kolesniková, L; Motiyenko, R A; Margulès, L; Alonso, J L; Guillemin, J-C

    2015-10-01

    We report on the tentative detection of trans ethyl methyl ether (tEME), t-CH3CH2OCH3, through the identification of a large number of rotational lines from each one of the spin states of the molecule towards Orion KL. We also search for gauche-trans-n-propanol, Gt-n-CH3CH2CH2OH, an isomer of tEME in the same source. We have identified lines of both species in the IRAM 30 m line survey and in the ALMA Science Verification data. We have obtained ALMA maps to establish the spatial distribution of these species. Whereas tEME mainly arises from the compact ridge component of Orion, Gt-n-propanol appears at the emission peak of ethanol (south hot core). The derived column densities of these species at the location of their emission peaks are ≤(4.0 ± 0.8) × 10(15) cm(-2) and ≤(1.0 ± 0.2)× 10(15) cm(-2) for tEME and Gt-n-propanol, respectively. The rotational temperature is ~100 K for both molecules. We also provide maps of CH3OCOH, CH3CH2OCOH, CH3OCH3, CH3OH, and CH3CH2OH to compare the distribution of these organic saturated O-bearing species containing methyl and ethyl groups in this region. Abundance ratios of related species and upper limits to the abundances of non-detected ethers are provided. We derive an abundance ratio N(CH3OCH3)/N(tEME) ≥ 150 in the compact ridge of Orion.

  17. Kinetics of the degradation of sulfur mustard on ambient and moist concrete.

    PubMed

    Brevett, Carol A S; Sumpter, Kenneth B; Nickol, Robert G

    2009-02-15

    The rate of degradation of the chemical warfare agent sulfur mustard, bis(2-chloroethyl) sulfide, was measured on ambient and moist concrete using (13)C Solid State Magic Angle Spinning Nuclear Magnetic Resonance (SSMAS NMR). Three samples of concrete made by the same formulation, but differing in age and alkalinity were used. The sulfur mustard eventually degraded to thiodiglycol and 1,4-oxathiane via the intermediate sulfonium ions CH-TG, H-TG, H-2TG and O(CH(2)CH(2))(2)S(+)CH(2)CH(2)OH on all of the concrete samples, and in addition formed 8-31% vinyl moieties on the newer, more alkaline concrete samples. This is the first observation of the formation of O(CH(2)CH(2))(2)S(+)CH(2)CH(2)OH on a solid substrate. The addition of 2-chloroethanol to concrete on which mustard had fully degraded to thiodiglycol and 1,4-oxathiane resulted in the formation of O(CH(2)CH(2))(2)S(+)CH(2)CH(2)OH, thus demonstrating the reversibility of sulfur mustard degradation pathways. The sulfur mustard degradation half-lives on ambient concrete at 22 degrees C ranged from 3.5 to 54 weeks. When the substrates were moistened, the degradation half-lives at 22 degrees C ranged from 75 to 350h. The degradation of sulfur mustard occurred more quickly at elevated temperatures and with added water. The non-volatile toxic sulfonium ions persisted for months to years on concrete at 22 degrees C and weeks to months on concrete at 35 degrees C, before decomposing to the relatively non-toxic compounds thiodiglycol and 1,4-oxathiane.

  18. Probe electrospray ionization (PESI) mass spectrometry with discontinuous atmospheric pressure interface (DAPI).

    PubMed

    Hiraoka, Kenzo; Usmanov, Dilshadbek T; Chen, Lee Chuin; Ninomiya, Satoshi; Mandal, Mridul K; Saha, Subhrakanti

    2015-01-01

    Probe electrospray ionization (PESI) using a 0.2 mm outside diameter titanium wire was performed and the generated ions were introduced into the mass spectrometer via a discontinuous atmospheric pressure interface using a pinch valve. Time-lapse PESI mass spectra were acquired by gradually increasing delay time for the pinch valve opening with respect to the start of each electrospray event when a high voltage was applied. The opening time of the pinch valve was 20 ms. Time-resolved PESI mass spectra showed marked differences for 10 mM NaCl, 10(-5) M gramicidin S and insulin in H(2)O/CH(3)OH/CH(3)COOH/CH(3)COONH(4) (65/35/1) with and without the addition of 10 mM CH(3)COONH(4). This was ascribed to the pH change of the liquid attached to the needle caused by electrochemical reactions taking place at the interface between the metal probe and the solution. NaCl cluster ions appeared only after the depletion of analytes. For the mixed solution of 10(-5) M cytochrome c, insulin, and gramicidin S in H(2)O/CH(3)OH/CH(3)COOH (65/35/1), a sequential appearance of analyte ions in the order of cytochrome c→insulin→gramicidin S was observed. The present technique was applied to three narcotic samples; methamphetamine, morphine and codeine. Limits of detection for these compounds were 10 ppb in H(2)O/CH(3)OH (1/1) for the single sampling with a pinch valve opening time of 200 ms.

  19. Formation of polyhydroxyalkanoate in aerobic anoxygenic phototrophic bacteria and its relationship to carbon source and light availability.

    PubMed

    Xiao, Na; Jiao, Nianzhi

    2011-11-01

    Aerobic anoxygenic phototrophic bacteria (AAPB) are unique players in carbon cycling in the ocean. Cellular carbon storage is an important mechanism regulating the nutrition status of AAPB but is not yet well understood. In this paper, six AAPB species (Dinoroseobacter sp. JL1447, Roseobacter denitrificans OCh 114, Roseobacter litoralis OCh 149, Dinoroseobacter shibae DFL 12(T), Labrenzia alexandrii DFL 11(T), and Erythrobacter longus DSMZ 6997) were examined, and all of them demonstrated the ability to form the carbon polymer polyhydroxyalkanoate (PHA) in the cell. The PHA in Dinoroseobacter sp. JL1447 was identified as poly-beta-hydroxybutyrate (PHB) according to evidence from Fourier transform infrared spectroscopy, differential scanning calorimetry, and (1)H nuclear magnetic resonance spectroscopy examinations. Carbon sources turned out to be critical for PHA production in AAPB. Among the eight media tested with Dinoroseobacter sp. JL1447, sodium acetate, giving a PHA production rate of 72%, was the most productive carbon source, followed by glucose, with a 68% PHA production rate. Such PHA production rates are among the highest recorded for all bacteria. The C/N ratio of substrates was verified by the experiments as another key factor in PHA production. In the case of R. denitrificans OCh 114, PHA was not detected when the organism was cultured at C/N ratios of <2 but became apparent at C/N ratios of >3. Light is also important for the formation of PHA in AAPB. In the case of Dinoroseobacter sp. JL1447, up to a one-quarter increase in PHB production was observed when the culture underwent growth in a light-dark cycle compared to growth completely in the dark.

  20. Surface characterization of biocidal polyurethane modifiers having poly(3,3-substituted)oxetane soft blocks with alkylammonium side chains.

    PubMed

    Kurt, Pinar; Gamble, Lara J; Wynne, Kenneth J

    2008-06-03

    This paper focuses on surface characterization of P[ AB] copolyoxetane soft block polyurethanes having either fluorous (3FOx, -CH2OCH 2CF3) or PEG-like (ME2Ox, -CH2(OCH2CH2) 2OCH3), A side chains and alkylammonium, B side chains. Physical surface characterization data were analyzed in light of the previously observed order of antimicrobial effectiveness for a set of four surface modifiers. Ample physical evidence for surface concentration of fluorous 2 wt % P[ AB]-polyurethane modifiers was obtained from XPS, contact angles, ATR-IR spectroscopy, and TM-AFM. In TM-AFM phase imaging, the most effective biocidal surface modifier, 2 wt % HMDI-BD(30)/P[(3FOx)(C12)-0.89:0.11]-PU, showed a nanoscale phase-separated structure consisting of 200 nm domains with background features about 10 times smaller. Despite similar surface characterization data, the 2 wt % fluorous C6 analog ranked third in contact biocidal effectiveness. Physical evidence for surface concentration of 2 wt % P[(ME2Ox)(C12)-0.86:0.14]-PU was modest, considering that antimicrobial effectiveness was second only to 2 wt % HMDI-BD(30)/P[(3FOx)(C12)-0.89:0.11]-PU. In this set of surface modifiers, nanoscale morphology is largely driven by the fluorous component, whereas antimicrobial effectiveness is more strongly influenced by alkylammonium chain length. The effect of alkylammonium side chain length on surface concentration and antimicrobial behavior is more pronounced for ME2Ox polyurethanes compared to the 3FOx analogs.

  1. Polyelectrolyte complex/PVA membranes for diffusion dialysis.

    PubMed

    Wang, Cong; Wu, Cuiming; Wu, Yonghui; Gu, Jingjing; Xu, Tongwen

    2013-10-15

    Polyelectrolyte complexes (PECs)/polyvinyl alcohol (PVA) membranes are prepared from PVA, anion exchange and cation exchange multisilicon copolymers, which contain plenty of functional groups of OH, N(+)(CH3)3/Si(OCH3)3, and SO3Na/Si(OCH3)3, respectively. The OH and Si(OCH3)3 groups can undertake sol-gel reaction to form crosslinking structure, while the N(+)(CH3)3 and SO3Na groups can be combined through electrostatic interaction. The PECs/PVA membranes exhibit improved thermal stability, swelling resistance and flexibility as compared with single anion or cation exchange hybrid membranes. The PECs/PVA membranes have the water uptakes (WR) of 25.3-70.4%, initial decomposition temperatures (IDTs) of 246-285°C, tensile strength of 23.1-33.8 MPa, and elongation at break of 3.5-13.1%. The membranes can be potentially applied for both acid and alkali recovery through diffusion dialysis (DD) process. The separation factor (S) for HCl/FeCl2 mixture can reach up to 89.9, which is about five times higher than that of commercial DF-120 membrane (18.5 at 25°C). The dialysis coefficients of NaOH (UOH) are in the range of 0.014-0.019 m/h, around 7-9 times higher than the value of commercial SPPO membrane (0.002 m/h at 25°C). The membranes also show potential usefulness for industrial acidic and alkali wastes treatment.

  2. Detection and Identification of the Keto-Hydroperoxide (HOOCH2OCHO) and Other Intermediates during Low-Temperature Oxidation of Dimethyl Ether.

    PubMed

    Moshammer, Kai; Jasper, Ahren W; Popolan-Vaida, Denisia M; Lucassen, Arnas; Diévart, Pascal; Selim, Hatem; Eskola, Arkke J; Taatjes, Craig A; Leone, Stephen R; Sarathy, S Mani; Ju, Yiguang; Dagaut, Philippe; Kohse-Höinghaus, Katharina; Hansen, Nils

    2015-07-16

    In this paper we report the detection and identification of the keto-hydroperoxide (hydroperoxymethyl formate, HPMF, HOOCH2OCHO) and other partially oxidized intermediate species arising from the low-temperature (540 K) oxidation of dimethyl ether (DME). These observations were made possible by coupling a jet-stirred reactor with molecular-beam sampling capabilities, operated near atmospheric pressure, to a reflectron time-of-flight mass spectrometer that employs single-photon ionization via tunable synchrotron-generated vacuum-ultraviolet radiation. On the basis of experimentally observed ionization thresholds and fragmentation appearance energies, interpreted with the aid of ab initio calculations, we have identified HPMF and its conceivable decomposition products HC(O)O(O)CH (formic acid anhydride), HC(O)OOH (performic acid), and HOC(O)OH (carbonic acid). Other intermediates that were detected and identified include HC(O)OCH3 (methyl formate), cycl-CH2-O-CH2-O- (1,3-dioxetane), CH3OOH (methyl hydroperoxide), HC(O)OH (formic acid), and H2O2 (hydrogen peroxide). We show that the theoretical characterization of multiple conformeric structures of some intermediates is required when interpreting the experimentally observed ionization thresholds, and a simple method is presented for estimating the importance of multiple conformers at the estimated temperature (∼100 K) of the present molecular beam. We also discuss possible formation pathways of the detected species: for example, supported by potential energy surface calculations, we show that performic acid may be a minor channel of the O2 + ĊH2OCH2OOH reaction, resulting from the decomposition of the HOOCH2OĊHOOH intermediate, which predominantly leads to the HPMF.

  3. The effect of solution chemistry on the preparation of MgAl{sub 2}O{sub 4} by hydrothermal-assisted sol-gel processing

    SciTech Connect

    Amini, M.M. . E-mail: m-pouramini@cc.sbu.ac.ir; Mirzaee, M.; Sepanj, N.

    2007-03-22

    Preparation of magnesium aluminate spinel powder by hydrothermal-assisted sol-gel processing from MgAl{sub 2}(OCH{sub 2}CH{sub 2}OR){sub 8}, R=CH{sub 3} (1), CH{sub 2}CH{sub 2}OCH{sub 3} (2), MgAl{sub 2}[OCH(CH{sub 3}){sub 2}]{sub 8} (3) and MgAl{sub 2}(O- {sup s}Bu){sub 8} (4) in toluene and parent alcohol has been investigated. Coordination status of aluminum atom in precursors was determined by {sup 27}Al NMR and correlation between coordination number of aluminum and development of spinel phase in hydrothermal-assisted sol-gel processing has been studied. The gels obtained from hydrothermal-assisted hydrolysis of magnesium-aluminum alkoxides that contain six-coordinated aluminum atoms in solution (1 and 2) after calcination at 700 deg. C resulted in the formation of pure spinel phase, whereas in similar hydrolysis and calcination processes of precursors that contain four-coordinated aluminum (3 and 4) spinel phase forms along with some Al{sub 2}O{sub 3} and MgO. Selected powders obtained from hydrothermal-assisted sol-gel processing were characterized by thermal analysis (TGA/DSC), X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). Results indicate that the coordination status of aluminum in the precursor is very crucial for the formation of pure phase spinel. The morphology of prepared spinels was studied by SEM and the results showed that the solvent in hydrothermal-assisted sol-gel processing has a marked effect on the morphology of the resulting MgAl{sub 2}O{sub 4}. In hydrothermal-assisted sol-gel processing of aluminum-magnesium alkoxides in hydrophobic solvent, spherical particles are formed, while in the parent alcohol, non-spherical powders are formed.

  4. Effects of Glutamine and Omega-3 Fatty Acids on Erythrocyte Deformability and Oxidative Damage in Rat Model of Enterocolitis

    PubMed Central

    Cehreli, Ruksan; Akpinar, Hale; Artmann, Aysegul Temiz; Sagol, Ozgul

    2015-01-01

    Background The aim of the study was to investigate preventive effects of glutamine (Gln), omega-3 fatty acids (FA) on erythrocyte deformability (EDEF) in rat model of indomethacin-induced enterocolitis. Methods Nineteen Wistar albino male rats were divided into three groups: control group, colitis induced by indomethacin and were fed with a standard laboratory diet (group 1), and colitis induced by indomethacin and were also fed with Gln, omega-3 FA (group 2). An investigation was performed in a rat model of experimental colitis induced by subcutaneous injections of 2 mL intdomethacine solution applied at 24 and 48 hours intervals to male Wistar rats for 14 days. Gln and omega-3 FA were added to the daily standard diets of the animals during 14 days of injections. During the study, changes in body weight were evaluated. The intestines were examined, and colitis was macroscopic and histologically scored. The circulating tumor necrosis factor alpha (TNF-α) and interleukine-1β (IL-1β), erythrocyte transit time (ETT) and thiobarbituric acid reactive substances (TBARS) levels were determined in addition to calculation of EDEF indices in all groups. Results No significant differences in body weight changes could be determined between the standard diet and special diet groups at the end of the experiment. After macroscopic and microscopic scoring, in all of the groups that colitis was found induced, the lowest microscopic score was observed in the group 2. But Gln and omega-3 FA supplemented diet did not change the mean macroscopic and histological scores in all rats. The proliferating cell nuclear antigen (PCNA) levels were significantly higher in group 1 and group 2 compared to the control group. Effects of the diet on circulating TNF-α and IL-1β levels were found correlated with inflammation but statistically significant differences were not found in the group 1 and group 2 (P < 0.05). The ETT and TBARS levels in standard and special diet groups were significantly

  5. Structure-spectroscopic property relationships in a series of platinum acetylides

    NASA Astrophysics Data System (ADS)

    Cooper, Thomas M.; Haley, Joy E.; Krein, Douglas M.; Burke, Aaron R.; Slagle, Jonathan E.

    2016-09-01

    In order to understand electronic and conformational effects on structure-spectroscopic property relationships in platinum acetylides, we synthesized a model series of chromophores trans-Pt(PBu3)2(C-CPhenyl-X)2, where X = NH2, OCH3, diphenylamino, t-Bu, methyl, H, F, benzothiazole, trifluoromethyl, CN and nitro. We collected linear spectra, including ground state absorption, phosphorescence and phosphorescence excitation spectra. We also performed DFT and TDDFT calculations on the ground and excited state properties of these compounds. The calculations and experimental data show the excited state properties are a function of the electronic properties of the substituents and the molecular conformation.

  6. New leads in speculative behavior

    NASA Astrophysics Data System (ADS)

    Kindler, A.; Bourgeois-Gironde, S.; Lefebvre, G.; Solomon, S.

    2017-02-01

    The Kiyotaki and Wright (1989) (henceforth KW) model of money emergence as a medium of exchange has been studied from various perspectives in recent papers. In the present work we propose a minimalistic model for the behavior of agents in the KW framework, which may either reproduce the theoretical predictions of Kiyotaki and Wright (1989) on the emerging Nash equilibria, or (less closely) the empirical results of Brown (1996), Duffy and Ochs (1999) and our own, introduced in a first part of the present paper. The main import is the systematic computer scanning of speculative monetary equilibria under drastic bounded rationality of agents, based on behavior previously observed in the lab.

  7. Theoretical study of the pyrolysis of vanillin as a model of secondary lignin pyrolysis

    NASA Astrophysics Data System (ADS)

    Wang, Meng; Liu, Chao; Xu, Xiaoxiao; Li, Qibin

    2016-06-01

    The unimolecular and bimolecular decomposition reactions in processes of vanillin pyrolysis were theoretically investigated by employing density functional theory (DFT) method at M06-2X/6-31 G+(d,p) level. The result shows that the homolytic cleavage of O-CH3 bond could be the dominant initial step in the pyrolysis of vanillin. The hydrogen abstractions from functional groups of vanillin by the formed radicals play important roles in the formation of main products. Both formyl, hydroxyl and methoxyl group contribute to the formation of CO. Benzene is formed from the hydrogen addition reaction between hydrogen radical and phenol at high temperature.

  8. Adsorption of Trimethyl Phosphite on H-KA, H-NaA, H-CaA and H-NaX Zeolites: an IR Study

    NASA Astrophysics Data System (ADS)

    Çiçek, E.; Bardakçı, B.; Ucun, F.; Bahçeli, S.

    2003-06-01

    Infrared spectroscopy has been used in adsorption studies of trimethyl phosphite (TMP) on the hydrogen (H) form of the A-type and 13X zeolites. Infrared spectra of H-zeolites, except H-KA, show that TMP reacts rapidly with silanol hydroxyls on their surfaces and gives rise to form product molecules such as SiOCH3 and liquid dimethyl phosphite. The unaccomplished adsorption on the H-KA zeolite has been attributed to the occurence of stable KOH hydroxyls with not-exchanged K cations instead of SiOH hydroxyls on this zeolite.

  9. Determination of the Minimum Energy Conformations of Benzyl Alcohol and 2-Phenethyl Alcohol

    DTIC Science & Technology

    1989-12-14

    ethylbenzyl alcohol (4-EtBA), 2 - methylbenzyl alcohol (2 -MeBA), 3- methylbenzyl alcohol (3-MeBA), 2 -PEA, 2-(o-methyl phenyl)-ethanol (2-(o-CH3)-PEA...conformers in the ground state. 3. 3- Methylbenzyl alcohol and 3-Fluorobenzyl alcohol The TOFMS of jet-cooled 3-MeBA is presented in Fig. 3. As found...these peaks are thus exactly the same as those for BA. This molecule has a single stable conformer, just as BA. 4. 2- Methylbenzyl alcohol The mass

  10. Propenyl ether monomers for photopolymerization

    DOEpatents

    Crivello, J.V.

    1996-10-22

    Propenyl ether monomers of formula A(OCH{double_bond}CHCH{sub 3}){sub n} wherein n is an integer from one to six and A is selected from cyclic ethers, polyether and alkanes are disclosed. The monomers are readily polymerized in the presence of cationic photoinitiators, when exposed to actinic radiation, to form poly(propenyl ethers) that are useful for coatings, sealants, varnishes and adhesives. Compositions for preparing polymeric coatings comprising the compounds of the above formula together with particular cationic photoinitiators are also disclosed, as are processes for making the monomers from allyl halides and readily available alcohols. The process involves rearranging the resulting allyl ethers to propenyl ethers.

  11. Process for making propenyl ethers and photopolymerizable compositions containing them

    DOEpatents

    Crivello, J.V.

    1996-01-23

    Propenyl ether monomers of formula A(OCH{double_bond}CHCH{sub 3}){sub n} (V) wherein n is an integer from one to six and A is selected from cyclic ethers, polyether, and alkanes are disclosed. The monomers are readily polymerized in the presence of cationic photoinitiators, when exposed to actinic radiation, to form poly(propenyl ethers) that are useful for coatings, sealants, varnishes and adhesives. Compositions for preparing polymeric coatings comprising the compounds of formula V together with particular cationic photoinitiators are also disclosed, as are processes for making the monomers from allyl halides and readily available alcohols. The process involves rearranging the resulting allyl ethers to propenyl ethers.

  12. Mass analyzed threshold ionization spectroscopy of p-methylanisole cation and the substitution effect

    NASA Astrophysics Data System (ADS)

    Huang, Jiangou; Li, Changyong; Tzeng, Wen Bih

    2005-10-01

    The adiabatic ionization energy of p-methylanisole is measured to be 63 972 ± 5 cm -1, which is red-shifted with respect to those of anisole and toluene. This indicates that the interaction of either CH 3 or OCH 3 group with the ring is stronger in the cationic D 0 state than that in the neutral S 0 state. Most of the observed MATI bands result from in-plane ring vibrations. The frequencies of vibrations 9b, 6a, and 1 of the p-methylanisole cation are found to be 407, 515, and 811 cm -1, respectively.

  13. Energy In Action: The Construction Of Physics Ideas In Multiple Modes

    NASA Astrophysics Data System (ADS)

    Close, Eleanor W.; Close, Hunter G.; McKagan, Sarah B.; Scherr, Rachel E.

    2010-10-01

    In a course organized around the development of diverse representations, no single mode of expression offers a complete picture of participants' understanding of the nature of energy. Instead, we argue, their understanding is actively constructed through the simultaneous use of a range of quite different kinds of representational resources (Goodwin, 2000; Hutchins, 1995; Ochs, Gonzales, & Jacoby, 1996), including not only words and prosody but also gestures, symbolic objects, participants moving their bodies in concert, and whatever other communicative modes the course invites them to use. Examples are provided from a teacher professional development course on energy.

  14. Multidimensional intermittency in hadronic collisions

    NASA Astrophysics Data System (ADS)

    Pan, Jicai; Hwa, Rudolph C.

    1992-12-01

    The study of intermittency in high-energy hadronic collisions by the Monte Carlo code ecco is extended to three-dimensional phase space. Strong intermittency is found in agreement with the data. Fluctuation in the impact parameter is responsible for the intermittency in lnpT, and the transverse-momentum conservation leads to negative intermittency slopes in the azimuthal angle φ. The Ochs-Wosiek plots are linear in all dimensions having universal slopes. An exponent ν=1.448 emerges to characterize multiparticle production in pp collisions. The properties of G moments are also examined, and the fractal dimensions determined.

  15. Multidimensional intermittency in hadronic collisions

    NASA Astrophysics Data System (ADS)

    Pan, J.; Hwa, R. C.

    1992-06-01

    The study of intermittency in high-energy hadronic collisions by the Monte Carlo code ECCO is extended to 3-dimensional phase space. Strong intermittency is found in agreement with the data. Fluctuation in the impact parameter is responsible for the intermittency in 1np(sub T), and the transverse-momentum conservation leads to negative intermittency slopes in the azimuthal angle (phi). The Ochs-Wosiek plots are linear in all dimensions having universal slopes. An exponent nu = 1.448 emerges to characterize multiparticle production in pp collisions. The properties of G moments are also examined, and the fractal dimensions determined.

  16. Outer scale of atmospheric turbulence

    NASA Astrophysics Data System (ADS)

    Lukin, Vladimir P.

    2005-10-01

    In the early 70's, the scientists in Italy (A.Consortini, M.Bertolotti, L.Ronchi), USA (R.Buser, Ochs, S.Clifford) and USSR (V.Pokasov, V.Lukin) almost simultaneously discovered the phenomenon of deviation from the power law and the effect of saturation for the structure phase function. During a period of 35 years we have performed successively the investigations of the effect of low-frequency spectral range of atmospheric turbulence on the optical characteristics. The influence of the turbulence models as well as a outer scale of turbulence on the characteristics of telescopes and systems of laser beam formations has been determined too.

  17. Vinyloxychloro-cyclotriphosphazenes.

    DTIC Science & Technology

    1982-12-06

    SECURITY CLASSIFICATION OF THIS PAGE (When De( Ente*d- 82 12 2() 001 OFFICE OF NAVAL RESEARCH Contract NOQ477C-0605 Project NIf 356-663 Technical Report No...Jpc : 7.32; 6-N(Me2 )=36.3 (d); 3JpC = 3.7; 016 6 831 6 = ( C - H ) ( ~ -2 2-P(OCHfCH2 )2 group: C - 141.8 (s), C8 - 100.4 (W). P NMR: -P(OCH-CH2

  18. Aerodynamics of Power Plant Installation

    DTIC Science & Technology

    1981-09-01

    dtant dquipd de 5 prisos de preasion d’arret ; Is valeur stationnAire eat relevde en extrdmitA du tube d’amortissement grflce A un capteur consnutd...doen is bande 0,2 Hz - 630 Hz, l’dchantilionnage eat raialisd do des nivesux de contrainte. rencontrds. Un capteur d’accdldration dtait dgaiement...informetionafournies par len capteurs ntationflaires pour un nombte de Mach moyen dens Iy ma och. vo~isn do 0,43. Cotte carte eat I comparer 4 cellia

  19. On the family- and genus-series nomina in Gyrinidae Latreille, 1810 (Coleoptera, Adephaga).

    PubMed

    Gustafson, Grey T; Miller, Kelly B

    2013-10-29

    All available genus- and family- group nomina for the Gyrinidae (Coleoptera: Adephaga) are listed along with original citation, original and current status, type nominal taxon with method of designation, and known synonymies and incorrect subsequent spellings. The nomina included follow the most current classification. Discussion is provided clarifying numerous nomenclatural problems with original spellings, correct authorship and type designation. Dineutini Ochs, 1926 syn. nov. is found to be a junior homonym of Dineutini Desmarest, 1851, and Enhydrini Régimbart, 1882 syn. nov. and its justified emendation Enhydrusini (Anonymous 2012) are here synonymized with Dineutini Desmarest, 1851.

  20. Syntheses of 4,6'-epoxymorphinan derivatives and their pharmacologies.

    PubMed

    Nemoto, Toru; Fujii, Hideaki; Narita, Minoru; Miyoshi, Kan; Nakamura, Atsushi; Suzuki, Tsutomu; Nagase, Hiroshi

    2008-04-15

    A modification of the message site in the skeleton of naltrexone was carried out to improve the potency and selectivity of the compound for an opioid receptor subtype. In the course of conversion, we synthesized 7-membered ring ether derivatives, which had an inserted OCH(2) group between 4- and 6-positions of morphinan skeleton. One of the 7-membered ring ether derivatives possessed more potent antagonistic activity than naltrexone for the mu opioid receptor. Another compound possessing 17-methyl group derived from noroxycodone may be a mu opioid receptor partial agonist and showed analgesic activity. We are currently examining the subtype selectivity of these compounds.

  1. Synthesis of homoleptic barium alkoxides and aryloxides and their reactions with Al(CH(3))(3): a convenient route to heterometallic species.

    PubMed

    Utko, Józef; Szafert, Sławomir; Jerzykiewicz, Lucjan B; Sobota, Piotr

    2005-07-25

    Reactions of metallic Ba with benzofuranol (dbbfoH) or diethylene glycol give homoleptic and homonuclear complexes Ba(dbbfo)(2)(dbbfoH)(2).3dbbfoH and Ba{O(CH(2)CH(2)O)(2)}{O(CH(2)CH(2)OH)(2)}(2) (60-89%). Both compounds and formerly described Ba{O(CH(2)CH(2)O)(2)Me}(2) react with Al(CH(3))(3) to yield trinuclear heterobimetallic low-coordinated barium compounds with structure and geometry depending on the reaction stoichiometry and crystallization procedure.

  2. Triaryl (Z)-olefins suitable for radiolabeling with iodine-124 or fluorine-18 radionuclides for positron emission tomography imaging of estrogen positive breast tumors.

    PubMed

    Abdellatif, Khaled R A; Velázquez, Carlos A; Huang, Zhangjian; Chowdhury, Morshed A; Knaus, Edward E

    2011-02-15

    A group of (Z)-1,2-diphenyl-1-[4-[2-(4-methylpiperazin-1-yl)ethoxy]phenyl]but-1-enes were synthesized using methodologies that will allow incorporation of a [(124)I]iodine substituent at the para-position of either the C-1 phenyl ring or the C-2 phenyl ring, or a [(18)F]OCH(2)CH(2)F substituent at the para-position of the C-2 phenyl ring. These [(124)I] and [(18)F] radiotracers are designed as potential radiopharmaceuticals to image estrogen positive breast tumors using positron emission tomography (PET).

  3. Research on Organofluorine Chemistry for 700 Degrees F Thermooxidative Stability

    DTIC Science & Technology

    1994-06-29

    8217) 4 NC-OC (CF’), CH, + NC- OCH2CF3 The products can be readily converted to amides , i.e., R-O CN H O,/KOH >C2H3OH 0()~ Conversion of these amides ...isopropyl)phenyl, pentamethylcyclopentadiene (Cp’), (b) highly substituted methyl systems, e.g., bis (trimethylsilyl)methyl and tris(trimethylsilyl)methyl... fluorosulfonyl derivatives, find application in the production of strong sulfonic acids, ion-exchange resins, surface active agents and perfluorinated

  4. Characterization of supramolecular (H2O)18 water morphology and water-methanol (H2O)15(CH3OH)3 clusters in a novel phosphorus functionalized trimeric amino acid host.

    PubMed

    Raghuraman, Kannan; Katti, Kavita K; Barbour, Leonard J; Pillarsetty, Nagavarakishore; Barnes, Charles L; Katti, Kattesh V

    2003-06-11

    Phosphorus functionalized trimeric alanine compounds (l)- and (d)-P(CH(2)NHCH(CH(3))COOH)(3) 2 are prepared in 90% yields by the Mannich reaction of Tris(hydroxymethyl)phosphine 1 with (l)- or (d)- Alanine in aqueous media. The hydration properties of (l)-2 and (d)-2 in water and water-methanol mixtures are described. The crystal structure analysis of (l)-2.4H(2)O, reveals that the alanine molecules pack to form two-dimensional bilayers running parallel to (001). The layered structural motif depicts two closely packed monolayers of 2 each oriented with its phosphorus atoms projected at the center of the bilayer and adjacent monolayers are held together by hydrogen bonds between amine and carboxylate groups. The water bilayers are juxtaposed with the H-bonded alanine trimers leading to 18-membered (H(2)O)(18) water rings. Exposure of aqueous solution of (l)-2 and (d)-2 to methanol vapors resulted in closely packed (l)-2 and (d)-2 solvated with mixed water-methanol (H(2)O)(15)(CH(3)OH)(3) clusters. The O-O distances in the mixed methanol-water clusters of (l)-2.3H(2)O.CH(3)OH and (d)-2.3H(2)O.CH(3)OH (O-O(average) = 2.857 A) are nearly identical to the O-O distance observed in the supramolecular (H(2)O)(18) water structure (O-O(average) = 2.859 A) implying the retention of the hydrogen bonded structure in water despite the accommodation of hydrophobic methanol groups within the supramolecular (H(2)O)(15)(CH(3)OH)(3) framework. The O-O distances in (l)-2.3H(2)O.CH(3)OH and (d)-2.3H(2)O.CH(3)OH and in (H(2)O)(18) are very close to the O-O distance reported for liquid water (2.85 A).

  5. Contact sensitivity to nonoxynols as a cause of intolerance to antiseptic preparations.

    PubMed

    Dooms-Goossens, A; Deveylder, H; de Alam, A G; Lachapelle, J M; Tennstedt, D; Degreef, H

    1989-10-01

    Twelve cases of allergic contact dermatitis caused by antiseptic preparations are presented. The reactions resulted not from the active principles but rather from nonoxynols used in the offending substances as nonionic surface-active agents. Nonoxynols are ethoxylated alkyl phenols or nonylphenylethers that conform in general to the formula C9H19C6H4(OCH2CH2)nOH. They have emulsifying, wetting, foaming, and solubilizing properties and are used in a large number of industrial, household, agricultural, cosmetic, and pharmaceutical products. They also are used as spermicides. There are very few reports in the literature of skin problems caused by nonoxynols.

  6. The Formation of N- and O-Heterocycles from the Irradiation of Benzene and Naphthalene in H2O/NH3- Containing Ices

    NASA Technical Reports Server (NTRS)

    Sandford, S. A.; Materese, C. K.; Nuevo, M.

    2015-01-01

    Aromatic hydrocarbons are an important class of molecules for both astrochemistry and astrobiology (Fig. 1). Within this class of molecules, polycyclic aromatic hydrocarbons (PAHs) are known to be ubiquitous in many astrophysical environments, and are likely present in interstellar clouds and protostellar disks. In dense clouds, PAHs are expected to condense onto grains as part of mixed molecular ice mantles dominated by small molecules like H2O,CH3OH, NH3, CO, and CO2. These ices are exposed to ionizing radiation in the form of cosmic rays and ambient high-energy X-ray and UV photons.

  7. Phosphazenes with Olefinic Side Groups: Proton Abstraction Reactions of Fluoroalkoxy Derivatives.

    DTIC Science & Technology

    1982-06-24

    OPh) (OC(Li)=CF2) 13 and [NP(OC(Li)CF2)2]3 1 respectively. These species are stable in solution at -78*C, but react with electrophiles such as 2...an -OCH2CF3 side group to generate an -OC(M)-CF2 unit. Subsequent treatment with an electrophile was designed to yield an -OC(R)-CF2 side group...resonances for the fluorine atoms in 2 and 5 appeared as multiplets due to the slight differences in chemical shift between the cis and trans

  8. 1-(2-Thienyl)-2-phenylethylamines as potential non-stimulant anorectics.

    PubMed

    Mrongovius, R I; Ghosh, P; Bolt, A G; Ternai, B

    1981-01-01

    A series of 1-(2-thienyl)-2-phenylethylamines was synthesized and tested for anorectic and motor activity effects in rats. Phenyl ring substituents included Cl, Br, F, CF3, CH3, OCH3, and NO2; amino group substituents included alkyl, benzyl and acetyl groups. About half of the compounds produced significant anorexia; only one of these active anorectics increased motor activity. The three most potent non-stimulant anorectics were: 1-(2-thienyl)-2-(4-chlorophenyl)ethylamine, its N-isopropyl analogue, and N-isopropyl-1-(2-thienyl)-2-(4-fluorophenyl)ethylamine.

  9. Increasing the activity and enantioselectivity of lipases by sol-gel immobilization: further advancements of practical interest

    NASA Astrophysics Data System (ADS)

    Tielmann, Patrick; Kierkels, Hans; Zonta, Albin; Ilie, Adriana; Reetz, Manfred T.

    2014-05-01

    The entrapment of lipases in hydrophobic silicate matrices formed by sol-gel mediated hydrolysis of RSi(OCH3)3/Si(OCH3)4 as originally reported in 1996 has been improved over the years by a number of modifications. In the production of second-generation sol-gel lipase immobilizates, a variety of additives during the sol-gel process leads to increased activity and enhanced stereoselectivity in esterifying kinetic resolution. Recent advances in this type of lipase immobilization are reviewed here, in addition to new results regarding the sol-gel entrapment of the lipase from Burkholderia cepacia. It constitutes an excellent heterogeneous biocatalyst in the acylating kinetic resolution of two synthetically and industrially important chiral alcohols, rac-sulcatol and rac-trans-2-methoxycyclohexanol. The observation that the catalyst can be used 10 times in recycling experiments without losing its significant activity or enantioselectivity demonstrates the practical viability of the sol-gel approach.The entrapment of lipases in hydrophobic silicate matrices formed by sol-gel mediated hydrolysis of RSi(OCH3)3/Si(OCH3)4 as originally reported in 1996 has been improved over the years by a number of modifications. In the production of second-generation sol-gel lipase immobilizates, a variety of additives during the sol-gel process leads to increased activity and enhanced stereoselectivity in esterifying kinetic resolution. Recent advances in this type of lipase immobilization are reviewed here, in addition to new results regarding the sol-gel entrapment of the lipase from Burkholderia cepacia. It constitutes an excellent heterogeneous biocatalyst in the acylating kinetic resolution of two synthetically and industrially important chiral alcohols, rac-sulcatol and rac-trans-2-methoxycyclohexanol. The observation that the catalyst can be used 10 times in recycling experiments without losing its significant activity or enantioselectivity demonstrates the practical viability of

  10. [Oligonucleotide analogues bearing an acyclonucleoside linked by an internucleotide amide bond].

    PubMed

    Kochetkova, S V; Fillipova, E A; Kolganova, N A; Timofeev, E N; Florent'ev, V L

    2008-01-01

    Oligonucleotide analogues bearing an acyclocytidine linked to thymidine by an amide (3'-O-CH2-CO-N-5') bond were synthesized. Melting curves of duplexes formed by modified oligonucleotides and complementary natural oligomers were obtained and thermodynamic parameters of their formation were measured. Replacement of dCpT by a modified dinucleotide only moderately decreased the melting temperature of these modified duplexes in comparison with unmodified duplexes containing complementary natural bases. CD spectra of modified duplexes were studied, and the duplex spatial structures are discussed. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2008, vol. 34, no. 2; see also http://www.maik.ru.

  11. Non-Lethal Defense III, Johns Hopkins Applied Physics Laboratory, Laurel, Maryland, February 25 & 26, 1998, Revised Agenda.

    DTIC Science & Technology

    1998-02-26

    CH-CH3 R, -CH2 -O-CH2 -CH-OH 0 CH 3 Scheme 3 In Scheme 2, each primary hydroxyl group in the polyol is reacted with lactic acid to produce a terminal...as they arrived. As with all conferences of this nature , a number of people have worked for several months to pull it all together. We are indebted...or LTL weapons were developed in this period-the taser (which fires two wire-tethered barbs) and the less lethal kinetic munitions (such as rubber

  12. An effective route to fluorine containing asymmetric alpha-aminophosphonates using chiral Bronsted acid catalyst.

    PubMed

    Bhadury, Pinaki S; Zhang, Yuping; Zhang, Sha; Song, Baoan; Yang, Song; Hu, Deyu; Chen, Zhuo; Xue, Wei; Jin, Linhong

    2009-05-01

    Asymmetric addition of dialkyl phosphites (--CH2CH3, --CH2CH2CH3, --CH(CH3)2, --CH2(CH2)3CH3, --CH2CH2OCH3 and --CH2CH2OC2H5) induced by chiral organocatalyst e.g. (R)- and (S)-3,3'-[3,5-bis(trifluoromethyl)phenyl]2-1,1'-binaphthyl phosphate on fluorinated aldimines derived from cinnamaldehyde has been found effective to give new bioactive alpha-aminophosphonates in good yields (58-73%) and high enantiomeric excess (64.6%-90.6%) under mild conditions.

  13. Viscosity of Metals in Explosion Welding

    DTIC Science & Technology

    1974-11-19

    bglish sin fin can coo tg tan ct cot oh sinh oh cooh th tanh cth ooth Bh ech cch coch arc sin ow 1 arc coo OO8ŕ arc tg tan-1 arc ctg oot ŕ are ec...30c1l arc cooe 080 ŕ arc oh minhŕ arc ch cooh - 1 are tim tan- arc oth coth-1 arc sch ch-1 arc och coch -1 rot curl Ig log FTD-HT-23-1992-74 ii GREEK

  14. FTIR gas-phase kinetic study on the reactions of some acrylate esters with OH radicals and Cl atoms.

    PubMed

    Moreno, A; Gallego-Iniesta, M P; Taccone, R; Martín, M P; Cabañas, B; Salgado, M S

    2014-10-01

    Acrylate esters are α,β-unsaturated esters that contain vinyl groups directly attached to the carbonyl carbon. These compounds are widely used in the production of plastics and resins. Atmospheric degradation processes of these compounds are currently not well understood. The kinetics of the gas phase reactions of OH radicals with methyl 3-methylacrylate and methyl 3,3-dimethylacrylate were determined using the relative rate technique in a 50 L Pyrex photoreactor using in situ FTIR spectroscopy at room temperature (298 ± 2 K) and atmospheric pressure (708 ± 8 Torr) with air as the bath gas. Rate coefficients obtained were (in units cm(3) molecule(-1) s(-1)): (3.27 ± 0.33) × 10(-11) and (4.43 ± 0.42) × 10(-11), for CH3CH═CHC(O)OCH3 and (CH3)2CH═CHC(O)OCH3, respectively. The same technique was used to study the gas phase reactions of hexyl acrylate and ethyl hexyl acrylate with OH radicals and Cl atoms. In the experiments with Cl, N2 and air were used as the bath gases. The following rate coefficients were obtained (in cm(3) molecule(-1) s(-1)): k3 (CH2═CHC(O)O(CH2)5CH3 + Cl) = (3.31 ± 0.31) × 10(-10), k4(CH2═CHC(O)OCH2CH(CH2CH3)(CH2)3CH3 + Cl) = (3.46 ± 0.31) × 10(-10), k5(CH2═CHC(O)O(CH2)5CH3 + OH) = (2.28 ± 0.23) × 10(-11), and k6(CH2═CHC(O)OCH2CH(CH2CH3)(CH2)3CH3 + OH) = (2.74 ± 0.26) × 10(-11). The reactivity increased with the number of methyl substituents on the double bond and with the chain length of the alkyl group in -C(O)OR. Estimations of the atmospheric lifetimes clearly indicate that the dominant atmospheric loss process for these compounds is their daytime reaction with the hydroxyl radical. In coastal areas and in some polluted environments, Cl atom-initiated degradation of these compounds can be significant, if not dominant. Maximum Incremental Reactivity (MIR) index and global warming potential (GWP) were also calculated, and it was concluded that these compounds have significant MIR values, but they do

  15. A zwitterionic carbanion frustrated by boranes--dihydrogen cleavage with weak Lewis acids via an "inverse" frustrated Lewis pair approach.

    PubMed

    Li, Hui; Aquino, Adelia J A; Cordes, David B; Hung-Low, Fernando; Hase, William L; Krempner, Clemens

    2013-10-30

    The synthesis, structural characterization, and acid-base chemistry of [C(SiMe2OCH2CH2OMe)3]Na (2), a sterically encumbered zwitterionic organosodium compound, is reported. 2 is a strong Brønsted base that forms frustrated Lewis pairs (FLPs) with a number of boron-containing Lewis acids ranging from weakly Lewis acidic aryl and alkyl boranes to various alkyl borates. These intermolecular FLPs readily cleave H2, which confirms that even poor Lewis acids can engage in FLP-mediated H2 cleavage provided that the present bulky base is of sufficiently high Brønsted basicity.

  16. Performance Evaluation of Potential Fuel System Icing Inhibitors in Aviation Jet Fuel Using the US Navy Aircraft Fuel System Icing Simulator

    DTIC Science & Technology

    1997-05-29

    candidate. Empirical formula: CgH14°4. o HC II 21’O~CH3 HC-CH3 HL....Oy CH32 I o 5 NAVAIRWARCENACDIVTRENTON-LR-PPE-97-3 (20) 2-Methyl-l,3- Propanediol ...friendly FSII candidate. Empirical formula: C4H1002. H2C-OH --/ HC- CH3 / H2C-OH (21) A mixture ofthree components (8% 2-Methy1-1,3- Propanediol ; 48% 3...Navy/U.S. Air ForceFSn development project; an environmentally friendly FSII candidate. 2-Methyl-l,3- Propanediol 3-Hydroxy-2-MethylPropyl Acetate + o

  17. Synthesis of Peptides Containing C-Terminal Methyl Esters Using Trityl Side-Chain Anchoring: Application to the Synthesis of a-Factor and a-Factor Analogs

    PubMed Central

    Diaz-Rodriguez, Veronica; Mullen, Daniel G.; Ganusova, Elena; Becker, Jeffrey M.; Distefano, Mark D.

    2012-01-01

    A new cysteine anchoring method was developed for the synthesis of peptides containing C-terminal cysteine methyl esters. This method consists of attachment of Fmoc-Cys-OCH3 to either 2-ClTrt-Cl or Trt-Cl resins (via the side-chain thiol) followed by preparation of the desired peptide using Fmoc-based SPPS. We applied this method to the synthesis of the mating pheromone a-factor and a 5-FAM labeled a-factor analog. The peptides were obtained with high yield and purity and were shown to be bioactive in a growth arrest assay. PMID:23121562

  18. Propenyl ether monomers for photopolymerization

    DOEpatents

    Crivello, James V.

    1996-01-01

    Propenyl ether monomers of formula V A(OCH.dbd.CHCH.sub.3).sub.n wherein n is an integer from one to six and A is selected from cyclic ethers, polyether and alkanes are disclosed. The monomers are readily polymerized in the presence of cationic photoinitiators, when exposed to actinic radiation, to form poly(propenyl ethers) that are useful for coatings, sealants, varnishes and adhesives. Compositions for preparing polymeric coatings comprising the compounds of formula V together with particular cationic photoinitiators are also disclosed, as are processes for making the monomers from allyl halides and readily available alcohols. The process involves rearranging the resulting allyl ethers to propenyl ethers.

  19. Process for making propenyl ethers and photopolymerizable compositions containing them

    DOEpatents

    Crivello, James V.

    1996-01-01

    Propenyl ether monomers of formula V A(OCH.dbd.CHCH.sub.3).sub.n wherein n is an integer from one to six and A is selected from cyclic ethers, polyether and alkanes are disclosed. The monomers are readily polymerized in the presence of cationic photoinitiators, when exposed to actinic radiation, to form poly(propenyl ethers) that are useful for coatings, sealants, varnishes and adhesives. Compositions for preparing polymeric coatings comprising the compounds of formula V together with particular cationic photoinitiators are also disclosed, as are processes for making the monomers from allyl halides and readily available alcohols. The process involves rearranging the resulting allyl ethers to propenyl ethers.

  20. Synthesis Laboratory for the U.S. Army Medical Research Institute of Infectious Diseases Selection Panel

    DTIC Science & Technology

    1988-01-19

    ANNUAL PROGRESS REPORT John A. Secrist III Cecil D. Kwong / Charles A. Krauth ’ Angela G. Ford Yajnanarayana H. R. Jois Deborah A. Carter...C. A. Krauth A. G. Ford H. R. Y. Jois D. A. Carter Analytical Services Dr. W. C. Coburn Dr. J. M. Riordan M. C. Kirk C. Richards R. T...7022 00361S 2.0 q /^ K ^^C=NNHCNHj *"S/ CH, 7023 003677 2.0 g S II C=NNHCNH, I 2 CH3 702> 003678 2.0 g NH "«1-®- OCH, HCIO„ 7037 003679

  1. Synthesis of peptides containing C-terminal methyl esters using trityl side-chain anchoring: application to the synthesis of a-factor and a-factor analogs.

    PubMed

    Diaz-Rodriguez, Veronica; Mullen, Daniel G; Ganusova, Elena; Becker, Jeffrey M; Distefano, Mark D

    2012-11-16

    A new cysteine anchoring method was developed for the synthesis of peptides containing C-terminal cysteine methyl esters. This method consists of attachment of Fmoc-Cys-OCH(3) to either 2-ClTrt-Cl or Trt-Cl resins (via the side-chain thiol) followed by preparation of the desired peptide using Fmoc-based SPPS. We applied this method to the synthesis of the mating pheromone a-factor and a 5-FAM labeled a-factor analog. The peptides were obtained with high yield and purity and were shown to be bioactive in a growth arrest assay.

  2. Alkylation of urinary guanine in mice by the organophosphorus insecticide tetrachlorvinphos.

    PubMed

    Zayed, S M; Mostafa, I Y; Hegazi, B

    1984-06-01

    The methylating capability of tetrachlorvinphos on urinary guanine in mice has been investigated using an insecticide labeled at both O-CH3 groups. Following intraperitoneal administration of the 14C-labeled insecticide to mice, about 0.57% of the radioactivity in the O- to 24-hr samples was associated with the purine fraction. The amount of [7-14C]methylguanine in 0- to 48-hr urine samples, estimated as fraction of applied dose, was 26-31 X 10(-5). The results obtained indicate possible chemical alkylation of urinary guanine. On the other hand, a considerable portion of radioactivity is probably incorporated via the C-1 pool.

  3. New sandwich-type lanthanide complexes based on closed-macrocyclic Schiff base and phthalocyanine molecules.

    PubMed

    Gao, Feng; Feng, Xiaowan; Yang, Liu; Chen, Xiaoyu

    2016-04-25

    Two new sandwich-type lanthanide complexes with the general formula [(Pc)2Ln3(L)(OAc)(OCH3)2] (Ln(3+) = Dy(3+) () and Er(3+) ()) were successfully synthesized and structurally characterized based on closed-macrocyclic Schiff base and phthalocyanine molecules. The magnetic properties and structure-property relationship in this multi-decker system were investigated. Interestingly, the corresponding dysprosium complex shows typical single-molecule magnetic behavior with ferromagnetic dipole-dipole interactions and the slow relaxation of magnetization.

  4. Electrospray ionization tandem mass spectrometric study of protonated and alkali- cationized α/ε-hybrid peptides: differentiation of a pair of dipeptide positional isomers.

    PubMed

    Ramesh Babu, A; Raju, G; Purna Chander, C; Shoban Babu, B; Srinivas, R; Sharma, G V M

    2016-01-01

    A new class of Boc-N-protected hybrid peptides derived from L- Ala and ε(6)-Caa (L-Ala = L-Alanine, Caa = C-linked carboamino acid derived from D-xylose) have been studied by positive ion electrospray ionization (ESI) ion-trap tandem mass spectrometry (MS/MS). MS(n) spectra of protonated and alkali-cationized hybrid peptides produce characteristic fragmentation involving the peptide backbone, the tert-butyloxycarbonyl (Boc) group, and the side chain. The dipeptide positional isomers are differentiated by the collision-induced dissociation (CID) of the protonated and alkali-cationized peptides. The CID of [M + H](+) ion of Boc-NH-L-Ala-ε-Caa- OCH3 (1) shows a prominent [M + H - C4H8](+) ion, which is totally absent for its positional isomer Boc-NH-ε-Caa-L-Ala-OCH3 (6), which instead shows significant loss of t-butanol. The formation of the [M + Cat - C4H8](+) ion is totally absent and [M + Cat - Boc + H](+) is prominent in the CID of the [M + Cat](+) ion of Boc-NH-L-Ala-ε-Caa- OCH3 (1), whereas the former is highly abundant and the latter is of low abundance for its positional isomer Boc-NH-ε-Caa-L-Ala-OCH3 (6). It is observed that 'b' ions are abundant when oxazolone structures are formed through a five-membered cyclic transition state in tetra-, penta-, and hexapeptides and the cyclization process for larger 'b' ions led to an insignificant abundance. However, the significant 'b' ion is formed in ε,α-dipeptide, which may have a seven-membered substituted 2-oxoazepanium ion structure. The MS(n) spectra of [M + Cat - Boc + H](+) ions of these peptides are found to be significantly different to those of [M + H - Boc + H](+) ions. The CID spectra of [M + Cat - Boc + H](+) ions of peptide acids containing L-Ala at the C-terminus show an abundant N-terminal rearrangement ion, [b(n) + 17 + Cat](+), which is absent for the peptide acids containing ε-Caa at the C-terminus. Thus, the results of these hybrid peptides

  5. Chapter 25 First-Principles Investigation of Dimethyl Ether Steam Reforming

    NASA Astrophysics Data System (ADS)

    Fukushima, Kimichika

    This paper reports the investigation of dimethyl ether (DME) steam reforming and related processes. The study uses the X[alpha] molecular orbital theory, which has been successfully applied to analyze material properties. It was found that, when H2O approaches Al on a surface of Si oxides (and pure Al2O3), charge transfer between H2O and the surface destabilizes the H2O. Approach of the destabilized H to a CH3OCH3 molecule then produces CH3OH. Finally, injection of CO2, by-produced in the reforming, to coal seam was shown to increase the CH4 production by substitution.

  6. Cyclodextrin Complexes of Reduced Bromonoscapine in Guar Gum Microspheres Enhance Colonic Drug Delivery

    PubMed Central

    2015-01-01

    Here, we report improved solubility and enhanced colonic delivery of reduced bromonoscapine (Red-Br-Nos), a cyclic ether brominated analogue of noscapine, upon encapsulation of its cyclodextrin (CD) complexes in bioresponsive guar gum microspheres (GGM). Phase–solubility analysis suggested that Red-Br-Nos complexed with β-CD and methyl-β-CD in a 1:1 stoichiometry, with a stability constant (Kc) of 2.29 × 103 M–1 and 4.27 × 103 M–1. Fourier transforms infrared spectroscopy indicated entrance of an O–CH2 or OCH3–C6H4–OCH3 moiety of Red-Br-Nos in the β-CD or methyl-β-CD cavity. Furthermore, the cage complex of Red-Br-Nos with β-CD and methyl-β-CD was validated by several spectral techniques. Rotating frame Overhauser enhancement spectroscopy revealed that the Ha proton of the OCH3–C6H4–OCH3 moiety was closer to the H5 proton of β-CD and the H3 proton of the methyl-β-CD cavity. The solubility of Red-Br-Nos in phosphate buffer saline (PBS, pH ∼ 7.4) was improved by ∼10.7-fold and ∼21.2-fold when mixed with β-CD and methyl-β-CD, respectively. This increase in solubility led to a favorable decline in the IC50 by ∼2-fold and ∼3-fold for Red-Br-Nos−β-CD-GGM and Red-Br-Nos–methyl-β-CD-GGM formulations respectively, compared to free Red-Br-Nos−β-CD and Red-Br-Nos–methyl-β-CD in human colon HT-29 cells. GGM-bearing drug complex formulations were found to be highly cytotoxic to the HT-29 cell line and further effective with simultaneous continuous release of Red-Br-Nos from microspheres. This is the first study to showing the preparation of drug-complex loaded GGMS for colon delivery of Red-Br-Nos that warrants preclinical assessment for the effective management of colon cancer. PMID:25350222

  7. Changes in vacuolation in the root apex cells of soybean seedlings in microgravity

    NASA Astrophysics Data System (ADS)

    Klymchuk, D.; Kordyum, E.; Chapman, D.; Brown, C.; Vorobyova, T.

    In this study, changes in the vacuolation in root apex cells of soybean (Glycine max L. [Merr.]) seedlings grown in microgravity were investigated. Dry seeds were mounted within BRIC (Biological Research in Canister) before launching, activated and germinated on board the space shuttle Columbia (STS 87). Spaceflight and- ground control seedlings were grown in the presence of KMnO4 (to remove ethylene) and in the absence of KMnO4 for 6 days. After landing, seedling root apices were fixed in a solutions (2.5% (w/v) glutaraldehyde in 0.1 M cacodilate buffer and 2% (w/v) glutaraldehyde, 2.5% (w/v) formaldehyde, 2% (w/v) potassium antimonate K[Sb(OH)6] in 0.1 M K2HPO4 buffer) with osmolarity (accounted theoretically) 0.45 and 1.26 osmol for study of cell ultrastructure and subcellular free calcium ion distribution correspondingly. The concentration of ethylene in all spaceflight canisters were significantly higher than in the ground controls. Seedling growth and lateral root formation decreased in microgravity and the progressive vacuolation in root apex cells, particularly in collumela cells, was observed unlike the ground controls. In addition, plasmolysis in collumela cells of spaceflight roots treated by solution with relatively high osmolarity occurred. The appearance of plasmolysis permitted the evaluation of the water status of cells. The water potential of the spaceflight cells is higher than the surrounding fxative solution (1.26 osmol). Ai decrease in osmotic potential and/or an increase in turgor potential may bring about increases in cell water potential. However, the plasmolysed (i.e. nonturgid) cells imply that increases in water potential accompanied with a decrease in osmotic potential. In such cells, changes in vacuolation, which may be involved to maintain turgor pressure or may be a result of intensification of other vacuole functions as digestion, storage are discussed.

  8. Changes in vacuolation in the root apex cells of soybean seedlings in microgravity

    NASA Astrophysics Data System (ADS)

    Klymchuk, D. O.; Kordyum, E. L.; Vorobyova, T. V.; Chapman, D. K.; Brown, C. S.

    2003-05-01

    Changes in the vacuolation in root apex cells of soybean ( Glycine max L. [Merr.]) seedlings grown in microgravity were investigated. Spaceflight and ground control seedlings were grown in the absence or presence of KMnO 4 (to remove ethylene) for 6 days. After landing, in order to study of cell ultrastructure and subcellular free calcium ion distribution, seedling root apices were fixed in 2.5% (w/v) glutaraldehyde in 0.1 M cacodylate buffer and 2% (w/v) glutaraldehyde, 2.5% (w/v) formaldehyde, 2% (w/v) potassium antimonate K[Sb(OH) 6] in 0.1 M K 2HPO 4 buffer with an osmolarity (calculated theoretically) of 0.45 and 1.26 osmol. The concentrations of ethylene in all spaceflight canisters were significantly higher than in the ground control canisters. Seedling growth was reduced in the spaceflight-exposed plants. Additionally, the spaceflight-exposed plants exhibited progressive vacuolation in the root apex cells, particularly in the columella cells, to a greater degree than the ground controls. Plasmolysis was observed in columella cells of spaceflight roots fixed in solutions with relatively high osmolarity (1.26 osmol). The appearance of plasmolysis permitted the evaluation of the water status of cells. The water potential of the spaceflight cells was higher than the surrounding fixative solution. A decrease in osmotic potential and/or an increase in turgor potential may have induced increases in cell water potential. However, the plasmolysed (i.e. nonturgid) cells implied that increases in water potential were accompanied with a decrease in osmotic potential. In such cells changes in vacuolation may have been involved to maintain turgor pressure or may have been a result of intensification of other vacuolar functions like digestion and storage

  9. Simultaneous removal of Cd(II) and Sb(V) by Fe-Mn binary oxide: Positive effects of Cd(II) on Sb(V) adsorption.

    PubMed

    Liu, Ruiping; Liu, Feng; Hu, Chengzhi; He, Zan; Liu, Huijuan; Qu, Jiuhui

    2015-12-30

    The coexistence of cadmium ion (Cd(II)) and antimonate (Sb(V)) creates the need for their simultaneous removal. This study aims to investigate the effects of positively-charged Cd(II) on the removal of negative Sb(V) ions by Fe-Mn binary oxide (FMBO) and associated mechanisms. The maximum Sb(V) adsorption density (Qmax,Sb(V)) increased from 1.02 to 1.32 and 2.01 mmol/g in the presence of Cd(II) at 0.25 and 0.50 mmol/L. Cd(2+) exhibited a more significant positive effect than both calcium ion (Ca(2+)) and manganese ion (Mn(2+)). Cd(2+) showed higher affinity towards FMBO and increased its ζ-potential more significantly compared to Ca(2+) and Mn(2+). The simultaneous adsorption of Sb(V) and Cd(II) onto FMBO can be achieved over a wide initial pH (pHi) range from 2 to 9, and QSb(V) decreases whereas QCd(II) increases with elevated pHi. Their combined values, as expressed by QSb(V)+Cd(II), amount to about 2 mmol/g and vary slightly in the pHi range 4-9. FTIR and XPS spectra indicate the significant synergistic effect of Cd(II) on Sb(V) adsorption onto FMBO, and that little chemical valence transformation occurs. These results may be valuable for the treatment of wastewater with coexisting heavy metals such as Cd(II) and Sb(V).

  10. Three-Dimensional Reduced Graphene Oxide Coupled with Mn3O4 for Highly Efficient Removal of Sb(III) and Sb(V) from Water.

    PubMed

    Zou, Jian-Ping; Liu, Hui-Long; Luo, Jinming; Xing, Qiu-Ju; Du, Hong-Mei; Jiang, Xun-Heng; Luo, Xu-Biao; Luo, Sheng-Lian; Suib, Steven L

    2016-07-20

    Highly porous, three-dimensional (3D) nanostructured composite adsorbents of reduced graphene oxides/Mn3O4 (RGO/Mn3O4) were fabricated by a facile method of a combination of reflux condensation and solvothermal reactions and systemically characterized. The as-prepared RGO/Mn3O4 possesses a mesoporous 3D structure, in which Mn3O4 nanoparticles are uniformly deposited on the surface of the reduced graphene oxide. The adsorption properties of RGO/Mn3O4 to antimonite (Sb(III)) and antimonate (Sb(V)) were investigated using batch experiments of adsorption isotherms and kinetics. Experimental results show that the RGO/Mn3O4 composite has fast liquid transport and superior adsorption capacity toward antimony (Sb) species in comparison to six recent adsorbents reported in the literature and summarized in a table in this paper. Theoretical maximum adsorption capacities of RGO/Mn3O4 toward Sb(III) and Sb(V) are 151.84 and 105.50 mg/g, respectively, modeled by Langmuir isotherms. The application of RGO/Mn3O4 was demonstrated by using drinking water spiked with Sb (320 μg/L). Fixed-bed column adsorption experiments indicate that the effective breakthrough volumes were 859 and 633 mL bed volumes (BVs) for the Sb(III) and Sb(V), respectively, until the maximum contaminant level of 5 ppb was reached, which is below the maximum limits allowed in drinking water according to the most stringent regulations. The advantages of being nontoxic, highly stable, and resistant to acid and alkali and having high adsorption capacity toward Sb(III) and Sb(V) confirm the great potential application of RGO/Mn3O4 in Sb-spiked water treatment.

  11. Abiotic and biotic factors responsible for antimonite oxidation in Agrobacterium tumefaciens GW4

    PubMed Central

    Li, Jingxin; Yang, Birong; Shi, Manman; Yuan, Kai; Guo, Wei; Wang, Qian; Wang, Gejiao

    2017-01-01

    Antimonite [Sb(III)]-oxidizing bacteria can transform the toxic Sb(III) into the less toxic antimonate [Sb(V)]. Recently, the cytoplasmic Sb(III)-oxidase AnoA and the periplasmic arsenite [As(III)] oxidase AioAB were shown to responsible for bacterial Sb(III) oxidation, however, disruption of each gene only partially decreased Sb(III) oxidation efficiency. This study showed that in Agrobacterium tumefaciens GW4, Sb(III) induced cellular H2O2 content and H2O2 degradation gene katA. Gene knock-out/complementation of katA, anoA, aioA and anoA/aioA and Sb(III) oxidation and growth experiments showed that katA, anoA and aioA were essential for Sb(III) oxidation and resistance and katA was also essential for H2O2 resistance. Furthermore, linear correlations were observed between cellular H2O2 and Sb(V) content in vivo and chemical H2O2 and Sb(V) content in vitro (R2 = 0.93 and 0.94, respectively). These results indicate that besides the biotic factors, the cellular H2O2 induced by Sb(III) also catalyzes bacterial Sb(III) oxidation as an abiotic oxidant. The data reveal a novel mechanism that bacterial Sb(III) oxidation is associated with abiotic (cellular H2O2) and biotic (AnoA and AioAB) factors and Sb(III) oxidation process consumes cellular H2O2 which contributes to microbial detoxification of both Sb(III) and cellular H2O2. PMID:28252030

  12. Phosphate reclaim from simulated and real eutrophic water by magnetic biochar derived from water hyacinth.

    PubMed

    Cai, Ru; Wang, Xin; Ji, Xionghui; Peng, Bo; Tan, Changyin; Huang, Xi

    2017-02-01

    In this study, the efficiency and mechanism of aqueous phosphate removal by magnetic biochar derived from water hyacinth (MW) were investigated. The MW pyrolyzed at 450 °C (MW450) exhibited the most prominent phosphate sorption capacity, which was estimated to be 5.07 mg g(-1) based on Langmuir-Freundlich model. At an initial phosphorus (P) concentration of 1 mg l(-1), >90% P removal was achieved over pH 3-9, but the efficiency decreased sharply at pH > 10. The presence of arsenate and carbonate could remarkably decrease P sorption, while the inhibition effects of antimonate, nitrate and sulfate were less significant. In further application of MW450 to reclaim P from eutrophic lake waters (0.71-0.94 mg l(-1) total P), ∼96% P removals were attained in the batch studies and the effluent P concentrations in the column tests were reduced to <0.05 mg l(-1) within 509-1019 empty bed volumes. As indicated by XRD, MW450 surface was dominated by Fe3O4 and Fe2O3, resulting in a good ferromagnetic property of this composite (saturation magnetization 45.8 emu g(-1)). Based on XPS, P sorption onto MW450 occurred mainly by surface complexation with the hydroxyl via ligand exchange. These results highlighted that MW derived from highly damaging water hyacinth could provide a promising alternative for P removal from most eutrophic waters.

  13. Antimony and arsenic leaching from secondary lead smelter air-pollution-control residues.

    PubMed

    Ettler, Vojtech; Mihaljevic, Martin; Sebek, Ondrej

    2010-07-01

    Environments in the vicinity of the lead (Pb) smelters are contaminated by emissions containing high concentrations of antimony (Sb) and arsenic (As). Air-pollution-control (APC) residues from bag-type filters from a secondary Pb smelter were subjected to leaching experiments to elucidate the controlling mechanisms of Sb and As release. Kinetic batch leaching tests at a liquid-to-solid (L/S) ratio of 10 L kg(- 1) within the time frame of 720 hours and batch leaching at various L/S ratios (ranging from 1 to 1000 L kg(-1)) were performed. In contrast to other inorganic contaminants (Pb, Cd, Zn), less than 1% of the total Sb and As content was leached from the residues. At a L/S ratio of 10, the As and Sb concentrations in the leachates exceeded the EU limit values for non-hazardous waste (0.2 and 0.07 mg L(-1) ). According to PHREEQC-2 calculations, the concentrations of As and Sb are controlled by the precipitation of complex arsenates and antimonates mainly at low L/S ratios. The washing and related chemical/mineralogical transformation of APC residues was suggested as a technological pre-treatment process before their re-smelting in a blast furnace. The Ferrox-like processing of the resulting contaminated process water/leachate was simulated using the PHREEQC-2 code. Significant reduction was obtained in the concentration of some key contaminants (As, Cu, Pb, Zn) related to sorption on newly formed hydrous ferric oxides, whereas Sb and Cd exhibited only limited attenuation.

  14. Global Regulator IscR Positively Contributes to Antimonite Resistance and Oxidation in Comamonas testosteroni S44

    PubMed Central

    Liu, Hongliang; Zhuang, Weiping; Zhang, Shengzhe; Rensing, Christopher; Huang, Jun; Li, Jie; Wang, Gejiao

    2015-01-01

    Antimonial compounds can be found as a toxic contaminant in the environment. Knowledge on mechanisms of microbial Sb oxidation and its role in microbial tolerance are limited. Previously, we found that Comamonas testosteroni S44 was resistant to multiple heavy metals and was able to oxidize the toxic antimonite [Sb(III)] to the much less toxic antimonate [Sb(V)]. In this study, transposon mutagenesis was performed in C. testosteroni S44 to isolate genes responsible for Sb(III) resistance and oxidation. An insertion mutation into iscR, which regulates genes involved in the biosynthesis of Fe-S clusters, generated a strain called iscR-280. This mutant strain was complemented with a plasmid carrying iscR to generate strain iscR-280C. Compared to the wild type S44 and iscR-280C, strain iscR-280 showed lower resistance to Sb(III) and a lower Sb(III) oxidation rate. Strain iscR-280 also showed lower resistance to As(III), Cd(II), Cu(II), and H2O2. In addition, intracellular γ-glutamylcysteine ligase (γ-GCL) activity and glutathione (GSH) content were decreased in the mutated strain iscR-280. Real-time RT-PCR and lacZ fusion expression assay indicated that transcription of iscR and iscS was induced by Sb(III). Results of electrophoretic mobility shift assay (EMSA) and bacterial one-hybrid (B1H) system demonstrated a positive interaction between IscR and its promoter region. The diverse defective phenotypes and various expression patterns suggest a role for IscR in contributing to multi-metal(loid)s resistance and Sb(III) oxidation via Fe-S cluster biogenesis and oxidative stress protection. Bacterial Sb(III) oxidation is a detoxification reaction. PMID:26734615

  15. Changes in vacuolation in the root apex cells of soybean seedlings in microgravity

    NASA Technical Reports Server (NTRS)

    Klymchuk, D. O.; Kordyum, E. L.; Vorobyova, T. V.; Chapman, D. K.; Brown, C. S.

    2003-01-01

    Changes in the vacuolation in root apex cells of soybean (Glycine max L. [Merr.]) seedlings grown in microgravity were investigated. Spaceflight and ground control seedlings were grown in the absence or presence of KMnO4 (to remove ethylene) for 6 days. After landing, in order to study of cell ultrastructure and subcellular free calcium ion distribution, seedling root apices were fixed in 2.5% (w/v) glutaraldehyde in 0.1 M cacodylate buffer and 2% (w/v) glutaraldehyde, 2.5% (w/v) formaldehyde, 2% (w/v) potassium antimonate K[Sb(OH)6] in 0.1 M K2HPO4 buffer with an osmolarity (calculated theoretically) of 0.45 and 1.26 osmol. The concentrations of ethylene in all spaceflight canisters were significantly higher than in the ground control canisters. Seedling growth was reduced in the spaceflight-exposed plants. Additionally, the spaceflight-exposed plants exhibited progressive vacuolation in the root apex cells, particularly in the columella cells, to a greater degree than the ground controls. Plasmolysis was observed in columella cells of spaceflight roots fixed in solutions with relatively high osmolarity (1.26 osmol). The appearance of plasmolysis permitted the evaluation of the water status of cells. The water potential of the spaceflight cells was higher than the surrounding fixative solution. A decrease in osmotic potential and/or an increase in turgor potential may have induced increases in cell water potential. However, the plasmolysed (i.e. non-turgid) cells implied that increases in water potential were accompanied with a decrease in osmotic potential. In such cells changes in vacuolation may have been involved to maintain turgor pressure or may have been a result of intensification of other vacuolar functions like digestion and storage. c2003 COSPAR. Published by Elsevier Ltd. All rights reserved.

  16. Oxalic acid has an additional, detoxifying function in Sclerotinia sclerotiorum pathogenesis.

    PubMed

    Heller, Annerose; Witt-Geiges, Tanja

    2013-01-01

    The mechanism of the diseases caused by the necrotroph plant pathogen Sclerotinia sclerotiorum is not well understood. To investigate the role of oxalic acid during infection high resolution, light-, scanning-, transmission electron microscopy and various histochemical staining methods were used. Our inoculation method allowed us to follow degradation of host plant tissue around single hyphae and to observe the reaction of host cells in direct contact with single invading hyphae. After penetration the outer epidermal cell wall matrix appeared degraded around subcuticular hyphae (12-24 hpi). Calcium oxalate crystals were detected in advanced (36-48 hpi) and late (72 hpi) infection stages, but not in early stages. In early infection stages, surprisingly, no toxic effect of oxalic acid eventually secreted by S. sclerotiorum was observed. As oxalic acid is a common metabolite in plants, we propose that attacked host cells are able to metabolize oxalic acid in the early infection stage and translocate it to their vacuoles where it is stored as calcium oxalate. The effects, observed on healthy tissue upon external application of oxalic acid to non-infected, living tissue and cell wall degradation of dead host cells starting at the inner side of the walls support this idea. The results indicate that oxalic acid concentrations in the early stage of infection stay below the toxic level. In plant and fungi oxalic acid/calcium oxalate plays an important role in calcium regulation. Oxalic acid likely could quench calcium ions released during cell wall breakdown to protect growing hyphae from toxic calcium concentrations in the infection area. As calcium antimonate-precipitates were found in vesicles of young hyphae, we propose that calcium is translocated to the older parts of hyphae and detoxified by building non-toxic, stable oxalate crystals. We propose an infection model where oxalic acid plays a detoxifying role in late infection stages.

  17. High antiferromagnetic transition temperature of a honeycomb compound SrRu2O6

    SciTech Connect

    Tian, Wei; Svoboda, Chris; Ochi, M.; Matsuda, M.; Cao, Huibo; Cheng, J. -G.; Sales, B. C.; Mandrus, D.; Arita, R.; Trivedi, Nandini; Yan, Jiaqiang

    2015-09-14

    We study the high-temperature magnetic order in a quasi-two-dimensional honeycomb compound SrRu2O6 by measuring magnetization and neutron powder diffraction with both polarized and unpolarized neutrons. SrRu2O6 crystallizes into the hexagonal lead antimonate (PbSb2O6, space group P31m) structure with layers of edge-sharing RuO6 octahedra separated by Sr2+ ions. SrRu2O6 is found to order at TN = 565 K with Ru moments coupled antiferromagnetically both in plane and out of plane. The magnetic moment is 1.30(2) μB/Ru at room temperature and is along the crystallographic c axis in the G-type magnetic structure. We perform density functional calculations with constrained random-phase approximation (RPA) to obtain the electronic structure and effective intra- and interorbital interaction parameters. The projected density of states shows strong hybridization between Ru 4d and O 2p. By downfolding to the target t2g bands we extract the effective magnetic Hamiltonian and perform Monte Carlo simulations to determine the transition temperature as a function of interand intraplane couplings. We find a weak interplane coupling, 3% of the strong intraplane coupling, permits three-dimensional magnetic order at the observed TN .

  18. Residence of silver in mineral deposits of the Thunder Mountain caldera complex, Central Idaho, U.S.A.

    USGS Publications Warehouse

    Leonard, B.F.; Christian, R.P.

    1987-01-01

    Silver is an accessory element in gold, antimony, and tungsten deposits of the caldera complex. Most of the deposits are economically of low grade and genetically of xenothermal or epithermal character. Their gold- and silver-bearing minerals are usually disseminated, fine grained, and difficult to study. Sparsely disseminated pyrite and arsenoprite are common associates. Identified silver minerals are: native silver and electrum; the sulfides acanthite, argentite (the latter always inverted to acanthite), and members of the Silberkies group; the sulfosalts matildite, miargyrite, pyrargyrite, argentian tetrahedrite, and unnamed Ag-Sb-S and Ag-Fe-Sb-S minerals; the telluride hessite and the selenide naumannite; halides of the cerargyrite group; and the antimonate stetefeldtite. Suspected silver minerals include the sulfide uytenbogaardtite and the sulfosalts andorite, diaphorite, and polybasite. Electrum, acanthite, and argentian tetrahedrite are common, though nowhere abundant. The other silver minerals are rare. Silver is present as a minor element in the structure of some varieties of other minerals. These include arsenopyrite, chalcopyrite, chalcostibite, covelline, digenite, galena, sphalerite, and stibnite. The search for adventitious Ag in most of these minerals has been cursory. The results merely indicate that elemental silver is not confined to discrete silver minerals and is, therefore, an additional complication for the recovery of silver-bearing material from some deposits. Silver occurs cryptically in some plants of the region. At Red Mountain, for example, the ashed sapwood of Douglas-fir (Pseudotsuga menziesii) contains 2 to 300 ppm Ag. Silver in the ashed wood is roughly 100 times as abundant as it is in soil. The phenomenon, useful in biogeochemical exploration, deserves the attention of mineralogists. ?? 1987 Springer-Verlag.

  19. In vivo/In vitro immune responses to L. major isolates from patients with no clinical response to Glucantime

    PubMed Central

    Saberi, Sedigheh; Arjmand, Reza; Soleimanifard, Simindokht; Khamesipour, Ali; Hosseini, Seyed Mohsen; Salehi, Mansoor; Varshosaz, Jaleh; Palizban, Abbas Ali; Hejazi, Seyed Hossein

    2016-01-01

    Background: Leishmaniasis is a major health problem in some endemic areas of tropical and subtropical areas of the world. Interleukin-12 (IL-12) and interferon gamma (IFN-γ) are essential cytokines associated with initiation of Th1 response. The main objective of this study was to evaluate of the type of immune response to L. major isolates from patients with no clinical response to antimonite (Glucantime). Materials and Methods: This experimental study was carried out during 2013–2014. In the current study Leishmania major were isolated from 10 CL patients with a history of at least one course of treatment with Meglumine antimonate (Sb5). The isolates were used to evaluate in vitro and in vivo response to Sb5. J774 murine macrophage cell line was used for in vitro tests and Balb/c mice was used for in vivo studies. IL-12 gene expression was evaluated using Real-time PCR and IFN-γ serum level was quantified using ELISA technique. SPSS (version: 20), analysis of Covariance (ANCOVA) was used for statistical analysis. Results: PCR results confirmed that all 10 isolates were L. major. The mean of IL-12 gene expression in vitro, in vivo and IFN-γ serum levels (pg/ml) after 2 and 3 weeks treatment in vivo, increased significantly following the treatment with Glucantime in the two groups of Balb/c mice infected either with patients' isolates or standard L. major. No significant difference was seen between the patients' isolates and standard species. Conclusions: Although the L. major were isolated from patients with active lesion and no clinical response to Glucantime after at least one courses of Glucantime treatment but in vivo and in vitro immune response of L. major isolates showed no difference between the patients' isolates and standard L. major. PMID:27563636

  20. Abiotic and biotic factors responsible for antimonite oxidation in Agrobacterium tumefaciens GW4

    NASA Astrophysics Data System (ADS)

    Li, Jingxin; Yang, Birong; Shi, Manman; Yuan, Kai; Guo, Wei; Wang, Qian; Wang, Gejiao

    2017-03-01

    Antimonite [Sb(III)]-oxidizing bacteria can transform the toxic Sb(III) into the less toxic antimonate [Sb(V)]. Recently, the cytoplasmic Sb(III)-oxidase AnoA and the periplasmic arsenite [As(III)] oxidase AioAB were shown to responsible for bacterial Sb(III) oxidation, however, disruption of each gene only partially decreased Sb(III) oxidation efficiency. This study showed that in Agrobacterium tumefaciens GW4, Sb(III) induced cellular H2O2 content and H2O2 degradation gene katA. Gene knock-out/complementation of katA, anoA, aioA and anoA/aioA and Sb(III) oxidation and growth experiments showed that katA, anoA and aioA were essential for Sb(III) oxidation and resistance and katA was also essential for H2O2 resistance. Furthermore, linear correlations were observed between cellular H2O2 and Sb(V) content in vivo and chemical H2O2 and Sb(V) content in vitro (R2 = 0.93 and 0.94, respectively). These results indicate that besides the biotic factors, the cellular H2O2 induced by Sb(III) also catalyzes bacterial Sb(III) oxidation as an abiotic oxidant. The data reveal a novel mechanism that bacterial Sb(III) oxidation is associated with abiotic (cellular H2O2) and biotic (AnoA and AioAB) factors and Sb(III) oxidation process consumes cellular H2O2 which contributes to microbial detoxification of both Sb(III) and cellular H2O2.

  1. First Report on Determination of Possible Movement of Corps and Division Artillery Utilizing C-47, B-17, and B-24 Air Planes, and First Report on Ordnance Program No. 6077

    DTIC Science & Technology

    1944-02-12

    parallol with the longitudinal axis of tho Plano ~. Additional boxes were placed in the center Tith the 1long axis transverse to the longitudinal axis of...crv-:-,ette ro~ur-cls T;:. fo lrai_ 2! - 1 .ý Pie for. nl oad inZ - *7 -harý V.ok. adltitional .1"M .,lm ca =i’,c c-mrried - 2. -4 a8a to~* z I, 2...61 under wneels. b. ~ pie es f p ari in ~ 2" 6" x 6 ’ for block i . C. Threa pleces off llu-btzr I" x 6" 36 urder doll., d.IYo blocks 6,1 x 6- x.Ld

  2. Technology Insertion (TI)/Industrial Process Improvement (IPI) Task Order Number 1. Data Base Documentation Book for SA-ALC/MATPSS (Assembly and Test GTE’s)

    DTIC Science & Technology

    1989-08-14

    8217 -- - AD-A237 070 JMENTATION PAGE _ N tt t *. 0 ’t o0t o f im lt0 e o mn’t0 tfverage Itott I ( flh t Ett 9 ain q ’ tc "I"? O" 3t W turce* i i...technology Insertion (TI)/Industrial Process Improvement (IPI).D(taas%V’ocumentatioh ,ook Folume-; f or SA-ALC/MATPSS (Assembl’V & Test GTE’s X . this...ffo6A Fir W~ r-uFL sTAgTFR &FEs) 13e r14 JET FUE STRT~ER (jFS) c! ?6O7A ,F15 (&/FI-RAL 6-iARt9,-; X k/6rR )27I2A F/ ACcfKS~tQR VR,]F (,FARBcX (At&-) Od

  3. Humidification on Ventilated Patients: Heated Humidifications or Heat and Moisture Exchangers?

    PubMed

    Cerpa, F; Cáceres, D; Romero-Dapueto, C; Giugliano-Jaramillo, C; Pérez, R; Budini, H; Hidalgo, V; Gutiérrez, T; Molina, J; Keymer, J

    2015-01-01

    The normal physiology of conditioning of inspired gases is altered when the patient requires an artificial airway access and an invasive mechanical ventilation (IMV). The endotracheal tube (ETT) removes the natural mechanisms of filtration, humidification and warming of inspired air. Despite the noninvasive ventilation (NIMV) in the upper airways, humidification of inspired gas may not be optimal mainly due to the high flow that is being created by the leakage compensation, among other aspects. Any moisture and heating deficit is compensated by the large airways of the tracheobronchial tree, these are poorly suited for this task, which alters mucociliary function, quality of secretions, and homeostasis gas exchange system. To avoid the occurrence of these events, external devices that provide humidification, heating and filtration have been developed, with different degrees of evidence that support their use.

  4. Humidification on Ventilated Patients: Heated Humidifications or Heat and Moisture Exchangers?

    PubMed Central

    Cerpa, F; Cáceres, D; Romero-Dapueto, C; Giugliano-Jaramillo, C; Pérez, R; Budini, H; Hidalgo, V; Gutiérrez, T; Molina, J; Keymer, J

    2015-01-01

    The normal physiology of conditioning of inspired gases is altered when the patient requires an artificial airway access and an invasive mechanical ventilation (IMV). The endotracheal tube (ETT) removes the natural mechanisms of filtration, humidification and warming of inspired air. Despite the noninvasive ventilation (NIMV) in the upper airways, humidification of inspired gas may not be optimal mainly due to the high flow that is being created by the leakage compensation, among other aspects. Any moisture and heating deficit is compensated by the large airways of the tracheobronchial tree, these are poorly suited for this task, which alters mucociliary function, quality of secretions, and homeostasis gas exchange system. To avoid the occurrence of these events, external devices that provide humidification, heating and filtration have been developed, with different degrees of evidence that support their use. PMID:26312102

  5. Catalogue of UBVRI photometry of T Tauri stars and analysis of the causes of their variability

    NASA Technical Reports Server (NTRS)

    Herbst, William; Herbst, Debra K.; Grossman, Elan J.; Weinstein, Daryl

    1994-01-01

    A computer-based catalogue of UBVRI photoelectric photometry of T Tauri stars and their earlier type analogs has been compiled. It presently includes over 10 000 entries on 80 stars and will be updated on a regular basis; it is available on Internet. The catalogue is used to analyze the sometimes bizarre light variations of pre-main-sequence stars on time scales of days to months in an attempt to illuminate the nature and causes of the phenomenon. It is useful in discussing their light variations to divide the stars into three groups according to their spectra. These are: weak T Tauri stars (WTTS; spectral class later than K0 and W(sub H-alpha less than 10 A), classical T Tauri stars (CTTS; spectral class later than K0 and W(sub H-alpha) greater than 10 A), and early type T Tauri stars (ETTS; spectral class of K0 or earlier). Three distinct types of variability are displayed by stars in the catalogue. Type I variations are periodic in VRI and undoubtedly caused by rotational modulation of a star with an asymmetric distribution of cool spots on its surface. Irregular flare activity is sometimes seen on such stars in U and B. Type I variations are easiest to see on WTTS but are clearly present on CTTS and ETTS as well. Type II variations are caused by hot 'spots' or zones and, it is argued, result from changes in the excess or 'veiling' continuum commonly attributed to an accretion boundary layer or impact zone of a magnetically channeled accretion flow. This type of variation is seen predominantly or solely in CTTS. A subcategory, designated Type IIp, consists of stars which display periodic variations caused by hot spots. Whereas cool spots may last for hundreds or thousands of rotations, hot spots appear to come and go on a much shorter time scale. This suggests that both unsteady accretion and rotation of the star contribute to Type II variations. It is shown that a third type of variation exists among ETTS, including stars as early as A type. UX Ori is a typical

  6. Numerical Methods for Singularly Perturbed Differential Equations with Applications

    DTIC Science & Technology

    1993-03-31

    e e on . :nOrmaton Send comments r t e@aradg tt •rden estimate :ir an, nher t p ( of At,$ -tr :C "Id~tn t-to" He&aQa .Jtters Ser vces. Directorate ror...no,) at ton Do~ers I.ors snap gr-c),rs 󈧝 .ette’i.D -e a _2 2 4 r to 4 S e )f management -no 8..aqet. Paer .s0r RC~edu ci P ’,ect 0C,04-0’S .󈨜...refinement and coarsening (h-refinement, order variation ( p -refinement), and occasionally, mesh motion (r-refinement), we addressed problems in

  7. DMSP Special Sensor Microwave/Imager Calibration/Validation

    DTIC Science & Technology

    1991-05-20

    DMAX. When D > 1, the ice concentration will be more than 90% -And old ice is arcsent in the fleid of view. 1 1A. I LTL)I 9-f(seoson) 1, TA37 -1(u"os4)I...N I>NID 1yF-cs NI ___ T___ 37:tr7J=3)j -I- Mc OGE r1LTER RIOR AThm(spt4fRE.- - -- 1 tIS/T37>NI2 N "-OX2 O>CMIN2 ~-y Ofi>N14)c A * N T937-I V37. TA37 §T...n N rTA37-$(T837) TO ~ TUS,-rC- TA37 ) - I C7ET-T7U Fi&r 1OA. -cniu 40 lOA-9 The data points for which D < DmAx and D > Dm are given a second test. This

  8. An Interactive Computer Session to Initiate Physical Activity in Sedentary Cardiac Patients: Randomized Controlled Trial

    PubMed Central

    Smith-Ray, Renae L; Dzewaltowski, David A; Glasgow, Russell E; Lee, Rebecca E; Thomas, Deborah SK; Xu, Stanley; Estabrooks, Paul A

    2015-01-01

    Background Physical activity (PA) improves many facets of health. Despite this, the majority of American adults are insufficiently active. Adults who visit a physician complaining of chest pain and related cardiovascular symptoms are often referred for further testing. However, when this testing does not reveal an underlying disease or pathology, patients typically receive no additional standard care services. A PA intervention delivered within the clinic setting may be an effective strategy for improving the health of this population at a time when they may be motivated to take preventive action. Objective Our aim was to determine the effectiveness of a tailored, computer-based, interactive personal action planning session to initiate PA among a group of sedentary cardiac patients following exercise treadmill testing (ETT). Methods This study was part of a larger 2x2 randomized controlled trial to determine the impact of environmental and social-cognitive intervention approaches on the initiation and maintenance of weekly PA for patients post ETT. Participants who were referred to an ETT center but had a negative-test (ie, stress tests results indicated no apparent cardiac issues) were randomized to one of four treatment arms: (1) increased environmental accessibility to PA resources via the provision of a free voucher to a fitness facility in close proximity to their home or workplace (ENV), (2) a tailored social cognitive intervention (SC) using a “5 As”-based (ask, advise, assess, assist, and arrange) personal action planning tool, (3) combined intervention of both ENV and SC approaches (COMBO), or (4) a matched contact nutrition control (CON). Each intervention was delivered using a computer-based interactive session. A general linear model for repeated measures was conducted with change in PA behavior from baseline to 1-month post interactive computer session as the primary outcome. Results Sedentary participants (n=452; 34.7% participation rate) without

  9. Summary of the Northeast Artificial Intelligence Consortium (NAIC)

    DTIC Science & Technology

    1991-09-01

    rwwmg ranjac , s ,ct vm V w- ta so’l-e- gattwrig anl r %w-,"g Tor d"n reec " ,T rr wid rmwmV tlcdeax, of rformrou Serd cTrrts r wdeg u- s b’u-d e,te cr m...y Orw aspec c: ’ded=of iormr ru.dig & ux for redc"- & ,ase to WastVcn Hoec e*tts S wuvc DcIaraoe for forz Operg us a iRepl . 12s 5 .-e-i-c D Nis HkwW... S l* 1204. Arkxpcr VA 202432, n to &is Office of Mwvgrr rt and BLcxg Ppwwork Reducr1 Prj ;t (0704-010 ). WsagwigtoR OC 205C3 . AGENCY USE ONLY

  10. Bias/Variance Analysis for Relational Domains

    DTIC Science & Technology

    2007-08-15

    EDtr ,Dte,t[L(t, y)] = EDtr ,Dte,t[(t − y)2] = Et[(t − E[t])2] + EDtr ,Dte...y − E[t])2] = NT (x) + EDtr ,Dte[(y − EDtr ,Dte[y] + EDtr ,Dte[y]− E[t])2] = NT (x) + EDtr ,Dte[(y − EDtr ,Dte[y])2 + ( EDtr ,Dte[y]− E[t])2 + 2(y − EDtr ,Dte...y]) · ( EDtr ,Dte[y]− E[t])] = NT (x) + EDtr ,Dte[(y − EDtr ,Dte[y])2] + ( EDtr ,Dte[y]− E[t])2 = NT (x) + VT (x) + BT (x) In this decomposition the

  11. Endotracheal Suctioning in Preterm Infants Using Four-Handed versus Routine Care

    PubMed Central

    Cone, Sharon; Pickler, Rita H.; Grap, Mary Jo; McGrath, Jacqueline; Wiley, Paul M.

    2013-01-01

    Objective To evaluate the effect of four-handed care on preterm infants’ physiologic and behavioral responses to and recovery from endotracheal suctioning versus routine endotracheal (ETT) suctioning. Design Randomized crossover design with infants as their own controls. Setting Single-family-room newborn intensive care unit in an academic health center. Participants Ten intubated infants on conventional ventilation with inline suctioning who were fewer than 37 weeks gestation at birth, and less than one week of age. Methods Each infant was observed twice on a single day. One observation involved routine ETT suctioning and one involved four-handed care. Physiologic and behavioral response data were collected. Results No differences were noted when comparing baseline heart rate (HR) or oxygen saturation (SpO2) data to those obtained during and after suctioning while in the routine care condition. In the four-handed care condition, mean SpO2 increased from preobservation 95.49 to during observation saturation 97.75 (p = .001). Salivary cortisol levels did not differ between groups at baseline or postsuctioning. No significant difference in behavior state was observed between the two conditions. More stress and defense behaviors occurred postsuctioning when infants received routine care as opposed to four-handed care (p = .001) and more self-regulatory behaviors were exhibited by infants during (p = .019) and after suctioning (p = .016) when receiving four-handed care. No statistical difference was found in the number of monitor call-backs postsuctioning. Conclusions Four-handed care during suctioning was associated with a decrease in stress and defense behaviors and an increase in self-regulatory behaviors. PMID:23316894

  12. The effect of mouth prop on endotracheal tube intracuff pressure in children during dental rehabilitation under general anaesthesia.

    PubMed

    Canpolat, Dilek Günay; Cantekin, Kenan; Bayram, Adnan; Yıldırım, Mustafa Denizhan

    2017-01-20

    Although the endotracheal tube (ETT) cuff may be associated with tracheal morbidity, cuffed tubes may reduce the aspiration risk in oral procedures. Dentists must use a mouth prop to facilitate oral visualization and to protect the oral soft tissues during dental rehabilitation under general anaesthesia (DRGA). The aim of this study was to evaluate the effect of mouth prop on endotracheal tube intracuff pressure in children during DRGA. Two-hundred and three ASA I-II patients, <18 years of age (mean: 5.3 ± 2.4 years) were included in the prospective observational study whose comprehensive dental treatment was performed under general anaesthesia. Following the induction of general anaesthesia, placement of a cuffed endotracheal tube which was an appropriate size for children was fixed. The intracuff pressure was measured intermittently after the intubation (baseline) (T0), immediately after the mouth prop (T1), 30 min after the mouth prop (T2), after taking out the mouth prop (T3) and just before extubation (T4). The mean intracuff pressure was 28.3 ± 2.01 cm H2O at T0. The mean intracuff pressure significantly increased at T1 (30.8 ± 2.7) and T2 (29.6 ± 3.7) compared to T0 (P < 0.001). No significant differences were observed between the duration of the procedure and intracuff pressure or postoperative complications (P > 0.05). Cough, sore throat and nausea were observed in 4, 1 and 5 patients, respectively. Because a mouth prop may increase the intracuff pressure of ETT, strict measurement and readjustment of cuff pressures should be employed when used in children during DRGA.

  13. Electronic Topological Transition in Ag2Te at High-pressure

    PubMed Central

    Zhang, Yuhang; Li, Yan; Ma, Yanmei; Li, Yuwei; Li, Guanghui; Shao, Xuecheng; Wang, Hui; Cui, Tian; Wang, Xin; Zhu, Pinwen

    2015-01-01

    Recently, Ag2Te was experimentally confirmed to be a 3D topological insulator (TI) at ambient pressure. However, the high-pressure behaviors and properties of Ag2Te were rarely reported. Here, a pressure-induced electronic topological transition (ETT) is firstly found in Ag2Te at 1.8 GPa. Before ETT, the positive pressure coefficient of bulk band-gap, which is firstly found in TIs family, is found by both first-principle calculations and in situ high-pressure resistivity measurements. The electrical resistivity obtained at room temperature shows a maximum at 1.8 GPa, which is nearly 3.3 times to that at ambient pressure. This result indicates that the best bulk insulating character and topological nature in Ag2Te can be obtained at this pressure. Furthermore, the high-pressure structural behavior of Ag2Te has been investigated by in situ high-pressure synchrotron powder X-ray diffraction technique up to 33.0 GPa. The accurate pressure-induced phase transition sequence is firstly determined as P21/c → Cmca → Pnma. It is worth noting that the reported isostructural P21/c phase is not existed, and the reported structure of Cmca phase is corrected by CALYPSO methodology. The second high-pressure structure, a long puzzle to previous reports, is determined as Pnma phase. A pressure-induced metallization in Ag2Te is confirmed by the results of temperature-dependent resistivity measurements. PMID:26419707

  14. Abolishment of N-glycan mannosylphosphorylation in glyco-engineered Saccharomyces cerevisiae by double disruption of MNN4 and MNN14 genes.

    PubMed

    Kim, Yeong Hun; Kang, Ji-Yeon; Gil, Jin Young; Kim, Sang-Yoon; Shin, Keun Koo; Kang, Hyun Ah; Kim, Jeong-Yoon; Kwon, Ohsuk; Oh, Doo-Byoung

    2017-04-01

    Mannosylphosphorylated glycans are found only in fungi, including yeast, and the elimination of mannosylphosphates from glycans is a prerequisite for yeast glyco-engineering to produce human-compatible glycoproteins. In Saccharomyces cerevisiae, MNN4 and MNN6 genes are known to play roles in mannosylphosphorylation, but disruption of these genes does not completely remove the mannosylphosphates in N-glycans. This study was performed to find unknown key gene(s) involved in N-glycan mannosylphosphorylation in S. cerevisiae. For this purpose, each of one MNN4 and five MNN6 homologous genes were deleted from the och1Δmnn1Δmnn4Δmnn6Δ strain, which lacks yeast-specific hyper-mannosylation and the immunogenic α(1,3)-mannose structure. N-glycan profile analysis of cell wall mannoproteins and a secretory recombinant protein produced in mutants showed that the MNN14 gene, an MNN4 paralog with unknown function, is essential for N-glycan mannosylphosphorylation. Double disruption of MNN4 and MNN14 genes was enough to eliminate N-glycan mannosylphosphorylation. Our results suggest that the S. cerevisiae och1Δmnn1Δmnn4Δmnn14Δ strain, in which all yeast-specific N-glycan structures including mannosylphosphorylation are abolished, may have promise as a useful platform for glyco-engineering to produce therapeutic glycoproteins with human-compatible N-glycans.

  15. 2-Methoxyphenyl isocyanate and 2-Methoxyphenyl isothiocyanate: conformers, vibration structure and multiplet Fermi resonance.

    PubMed

    Yenagi, Jayashree; Nandurkar, Anita R; Tonannavar, J

    2012-06-01

    IR and Raman spectral measurements in the region 3500-400/50 cm(-1) have been made for the liquid samples of 2-Methoxyphenyl isocyanate and 2-Methoxyphenyl isothiocyanate. A complete assignment of the measured bands has been proposed as aided by conformational and vibration analyses at B3LYP/6-311++G** level of calculations. Three conformers for 2-Methoxyphenyl isocyanate and two for 2-Methoxyphenyl isothiocyanate have been determined. The tilt of the isocyanate (NCO) and isothiocyanate (NCS) moieties with respect to phenyl ring are in broad agreement with their parents. Stretching mode frequencies of methyl group (-OCH(3)) in 2-Methoxyphenyl isocyanate have been lowered in the 2900-2800 cm(-1); deformation asymmetric modes are IR strong and symmetric one Raman strong. In 2-Methoxyphenyl isothiocyanate, a similar pattern is true for stretching modes but deformation asymmetric modes are IR strong and symmetric mode has not been observed. Multiplet absorption band system near 2200 cm(-1) in 2-Methoxyphenyl isocyanate has been interpreted to be caused by Fermi resonance. A similar pattern in absorption near 2100 cm(-1) in 2-Methoxyphenyl isothiocyanate but more complex Raman band pattern has also been explained through Fermi resonance from heuristic stand-point. Many Raman modes in 1300-1100 cm(-1) are intensified apparently owing to isothiocyanate than isocyanate moiety. Phenyl ring breathing mode is shifted to 1040 cm(-1) as strong Raman; the symmetric stretching mode of O-CH(3) near 1023 cm(-1) as strong absorption.

  16. Nucleophilic substitution at silicon (SN2@Si) via a central reaction barrier.

    PubMed

    Bento, A Patrícia; Bickelhaupt, F Matthias

    2007-03-16

    It is textbook knowledge that nucleophilic substitution at carbon (SN2@C) proceeds via a central reaction barrier which disappears in the corresponding nucleophilic substitution reaction at silicon (SN2@Si). Here, we address the question why the central barrier disappears from SN2@C to SN2@Si despite the fact that these processes are isostructural and isoelectronic. To this end, we have explored and analyzed the potential energy surfaces (PES) of various Cl-+CR3Cl (R=H, CH3) and Cl-+SiR3Cl model reactions (R=H, CH3, C2H5, and OCH3). Our results show that the nature of the SN2 reaction barrier is in essence steric, but that it can be modulated by electronic factors. Thus, simply by increasing the steric demand of the substituents R around the silicon atom, the SN2@Si mechanism changes from its regular single-well PES (with a stable intermediate transition complex, TC), via a triple-well PES (with a pre- and a post-TS before and after the central TC), to a double-well PES (with a TS; R=OCH3), which is normally encountered for SN2@C reactions.

  17. Direct ab initio molecular dynamics study on a microsolvated SN2 reaction of OH-(H2O) with CH3Cl.

    PubMed

    Tachikawa, Hiroto

    2006-10-07

    Reaction dynamics for a microsolvated SN2 reaction OH-(H2O)+CH3Cl have been investigated by means of the direct ab initio molecular dynamics method. The relative center-of-mass collision energies were chosen as 10, 15, and 25 kcal/mol. Three reaction channels were found as products. These are (1) a channel leading to complete dissociation (the products are CH3OH+Cl- +H2O: denoted by channel I), (2) a solvation channel (the products are Cl-(H2O)+CH3OH: channel II), and (3) a complex formation channel (the products are CH3OH...H2O+Cl-: channel III). The branching ratios for the three channels were drastically changed as a function of center-of-mass collision energy. The ratio of complete dissociation channel (channel I) increased with increasing collision energy, whereas that of channel III decreased. The solvation channel (channel II) was minor at all collision energies. The selectivity of the reaction channels and the mechanism are discussed on the basis of the theoretical results.

  18. Direct ab initio molecular dynamics study on a microsolvated SN2 reaction of OH-(H2O) with CH3Cl

    NASA Astrophysics Data System (ADS)

    Tachikawa, Hiroto

    2006-10-01

    Reaction dynamics for a microsolvated SN2 reaction OH-(H2O)+CH3Cl have been investigated by means of the direct ab initio molecular dynamics method. The relative center-of-mass collision energies were chosen as 10, 15, and 25kcal/mol. Three reaction channels were found as products. These are (1) a channel leading to complete dissociation (the products are CH3OH+Cl-+H2O: denoted by channel I), (2) a solvation channel (the products are Cl-(H2O)+CH3OH: channel II), and (3) a complex formation channel (the products are CH3OH ⋯H2O+Cl-: channel III). The branching ratios for the three channels were drastically changed as a function of center-of-mass collision energy. The ratio of complete dissociation channel (channel I) increased with increasing collision energy, whereas that of channel III decreased. The solvation channel (channel II) was minor at all collision energies. The selectivity of the reaction channels and the mechanism are discussed on the basis of the theoretical results.

  19. One-pot Solvothermal Synthesis of Well-ordered Layered Sodium Aluminoalcoholate Complex: A Useful Precursor for the Preparation of Porous Al2O3 Particles.

    PubMed

    Li, Xiansen; Michaelis, Vladimir K; Ong, Ta-Chung; Smith, Stacey J; McKay, Ian; Müller, Peter; Griffin, Robert G; Wang, Evelyn N

    2014-04-14

    One-pot solvothermal synthesis of a robust tetranuclear sodium hexakis(glycolato)tris(methanolato)aluminate complex Na3[Al4(OCH3)3(OCH2CH2O)6] via a modified yet rigorous base-catalyzed transesterification mechanism is presented here. Single crystal X-ray diffraction (SCXRD) studies indicate that this unique Al complex contains three penta-coordinate Al(3+) ions, each bound to two bidentate ethylene glycolate chelators and one monodentate methanolate ligand. The remaining fourth Al(3+) ion is octahedrally coordinated to one oxygen atom from each of the six surrounding glycolate chelators, effectively stitching the three penta-coordinate Al moieties together into a novel tetranuclear Al complex. This aluminate complex is periodically self-assembled into well-ordered layers normal to the [110] axis with the intra-/inter-layer bindings involving extensive ionic bonds from the three charge-counterbalancing Na(+) cations rather than the more typical hydrogen bonding interactions as a result of the fewer free hydroxyl groups present in its structure. It can also serve as a valuable precursor toward the facile synthesis of high-surface-area alumina powders using a very efficient rapid pyrolysis technique.

  20. Synthesis and biological evaluation of pyrazolylthiazole carboxylic acids as potent anti-inflammatory-antimicrobial agents.

    PubMed

    Khloya, Poonam; Kumar, Satish; Kaushik, Pawan; Surain, Parveen; Kaushik, Dhirender; Sharma, Pawan K

    2015-03-15

    Current Letter presents design, synthesis and biological evaluation of a novel series of pyrazolylthiazole carboxylates 1a-1p and corresponding acid derivatives 2a-2p. All 32 novel compounds were tested for their in vivo anti-inflammatory activity by carrageenan-induced rat paw edema method as well as for in vitro antimicrobial activity. All the tested compounds exhibited excellent AI activity profile. Three compounds 1p (R=Cl, R(1)=Cl), 2c (R=H, R(1)=F) and 2n (R=Cl, R(1)=OCH3) were identified as potent anti-inflammatory agents exhibiting edema inhibition of 93.06-89.59% which is comparable to the reference drug indomethacin (91.32%) after 3h of carrageenan injection while most of the other compounds displayed inhibition ⩾80%. In addition, pyrazolylthiazole carboxylic acids (2a-2p) also showed good antimicrobial profile. Compound 2h (R=OCH3, R(1)=Cl) showed excellent antimicrobial activity (MIC 6.25μg/mL) against both Gram positive bacteria comparable with the reference drug ciprofloxacin (MIC 6.25μg/mL).

  1. Magneto-Structural Analysis of Iron(III) Keggin Polyoxometalates.

    PubMed

    Bandeira, Nuno A G; Sadeghi, Omid; Woods, Toby J; Zhang, Yuan-Zhu; Schnack, Jürgen; Dunbar, Kim; Nyman, May; Bo, Carles

    2017-02-16

    A computational study and magnetic susceptibility measurements of three homonuclear Fe(III) Keggin structures are herein presented: the [FeO4@Fe12F24(μ-OCH3)12](5-) anion (1), the [Bi6{FeO4@Fe12O12(OH)12}(μ-O2CCCl3)12](+) cation (2) and its polymorph [Bi6{FeO4@Fe12O12(OH)10(H2O)2}(μ-O2CCF3)10](3+) (3). These results are contrasted with the exchange interactions present in the previously characterized [Fe6(OH)3Ge2W18O68(OH)6](11-) and [H12As4Fe8W30O120(H2O)2](4-) anions. The computational analysis shows that the most significant antiferromagnetic spin coupling takes place at the junction between each of the {Fe3O6(OH)3}/{Fe3F6(OCH3)3} framework motifs, a possibility that had been previously discarded in the literature on the basis of the Fe-Fe distances. For all the examined iron(III) Keggin structures, it is found that the magnitude of the magnetic couplings within each structural subunit follows the same trend.

  2. Synthesis and characterizations of anion exchange organic-inorganic hybrid materials based on poly(2,6-dimethyl-1,4-phenylene oxide) (PPO)

    SciTech Connect

    Zhang Shaoling; Wu Cuiming; Xu Tongwen . E-mail: twxu@ustc.edu.cn; Gong Ming; Xu Xiaolong

    2005-07-15

    A series of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO)-based organic-inorganic hybrid materials for anion exchange were prepared through sol-gel process of polymer precursors PPO-Si(OCH{sub 3}){sub 3}. PPO-Si(OCH{sub 3}){sub 3} were obtained from the reaction of bromomethylated PPO with 3-aminopropyl-trimethoxysilane (A1110). These polymer precursors then underwent hydrolysis and condensation with additional A1110 to generate hybrid materials. The reaction to produce polymer precursors was identified by FTIR; while FTIR, TGA, XRD, SEM, as well as conventional ion exchange capacity (IEC) measurements were conducted for the structures and properties of the prepared hybrids. TGA results show that this series of hybrid materials possess high thermal stability; XRD and SEM indicate that the prepared hybrid materials are amorphous and the inorganic and organic contents show good compatibility if the ratio between them is proper. The IEC values of the hybrid materials due to the amine groups range from 1.13 mmol/gBPPO (material i) to 4.80 mmol/gBPPO (material iv)

  3. Visible-Light-Induced Olefin Activation Using 3D Aromatic Boron-Rich Cluster Photooxidants.

    PubMed

    Messina, Marco S; Axtell, Jonathan C; Wang, Yiqun; Chong, Paul; Wixtrom, Alex I; Kirlikovali, Kent O; Upton, Brianna M; Hunter, Bryan M; Shafaat, Oliver S; Khan, Saeed I; Winkler, Jay R; Gray, Harry B; Alexandrova, Anastassia N; Maynard, Heather D; Spokoyny, Alexander M

    2016-06-08

    We report a discovery that perfunctionalized icosahedral dodecaborate clusters of the type B12(OCH2Ar)12 (Ar = Ph or C6F5) can undergo photo-excitation with visible light, leading to a new class of metal-free photooxidants. Excitation in these species occurs as a result of the charge transfer between low-lying orbitals located on the benzyl substituents and an unoccupied orbital delocalized throughout the boron cluster core. Here we show how these species, photo-excited with a benchtop blue LED source, can exhibit excited-state reduction potentials as high as 3 V and can participate in electron-transfer processes with a broad range of styrene monomers, initiating their polymerization. Initiation is observed in cases of both electron-rich and electron-deficient styrene monomers at cluster loadings as low as 0.005 mol%. Furthermore, photo-excitation of B12(OCH2C6F5)12 in the presence of a less activated olefin such as isobutylene results in the production of highly branched poly(isobutylene). This work introduces a new class of air-stable, metal-free photo-redox reagents capable of mediating chemical transformations.

  4. A Theoretical Study of Methanol Oxidation Catalyzed by Isolated Vanadia Clusters Supported on the (101) Surface of Anatase

    SciTech Connect

    Shapovalov, Vladimir; Fievez, Tim; Bell, Alexis T.

    2012-08-13

    A theoretical model has been developed for describing isolated vanadate species dispersed on the (101) surface of anatase that takes into account the equilibration of the supported species with gas-phase oxygen. The lowest energy of the combined solid and gas phases identifies the VOx species with the optimal structure and composition. This model of VOx species supported on the surface of anatase is then used to analyze the reaction path for methanol oxidation to formaldehyde. The chemisorption of methanol is found to proceed preferentially by addition across a V-O-Ti bond to form V-OCH3 and Ti-OH species. The rate-limiting step for the formation of formaldehyde takes place via the transfer of a hydrogen atom from V-OCH3 bound to an oxygen atom bridging two Ti atoms, i.e., a Ti-O-Ti group located adjacent to the supported vanadate species. This step is found to have the lowest apparent activation energy of all pathways explored for the formation of formaldehyde.

  5. On the competition between hydrogen abstraction versus C-O bond fission in initiating dimethyl ether combustion

    SciTech Connect

    Francisco, J.

    1999-07-01

    There has been a growing interest in the potential use of dimethyl ether (DME) as a diesel fuel in compression ignition engines. There are two initiation steps involved in the combustion of DME, one involving C-O bond fission and the other involving hydrogen abstraction by molecular oxygen. The kinetics and thermodynamics of C-O bond fission were explored computationally in a previous paper. The present paper addresses the competing process--hydrogen abstraction by molecular oxygen. Ab initio molecular orbital calculations are used to study the structures and energetics of the reactants, products, and the transition state for the CH{sub 3}OCH{sub 3} + O{sub 2} reaction. The calculations predict a barrier for hydrogen abstraction from CH{sub 3}OCH{sub 3} by O{sub 2} of 47.4 kcal/mol. This is lower than the barrier height for C-O bond fission previously calculated to be 81.1 kcal/mol. The results support values used in current models for the combustion of DME. Moreover, an examination of rates for C-O bond fission versus hydrogen abstraction by O{sub 2} suggests that the bimolecular process is the dominant pathway.

  6. Atmospheric and combustion chemistry of dimethyl ether

    SciTech Connect

    Nielsen, O.J.; Egsgaard, H.; Larsen, E.; Sehested, J.; Wallington, T.J.

    1997-12-31

    It has been demonstrated that dimethyl ether (DME) is an ideal diesel fuel alternative. DME, CH{sub 3}OCH{sub 3}, combines good fuel properties with low exhaust emissions and low combustion noise. Large scale production of this fuel can take place using a single step catalytic process converting CH{sub 4} to DME. The fate of DME in the atmosphere has previously been studied. The atmospheric degradation is initiated by the reaction with hydroxyl radicals, which is also a common feature of combustion processes. Spectrokinetic investigations and product analysis were used to demonstrate that the intermediate oxy radical, CH{sub 3}OCH{sub 2}O, exhibits a novel reaction pathway of hydrogen atom ejection. The application of tandem mass spectrometry to chemi-ions based on supersonic molecular beam sampling has recently been demonstrated. The highly reactive ionic intermediates are sampled directly from the flame and identified by collision activation mass spectrometry and ion-molecule reactions. The mass spectrum reflects the distribution of the intermediates in the flame. The atmospheric degradation of DME as well as the unique fuel properties of a oxygen containing compound will be discussed.

  7. Competing Noncovalent Host-guest Interactions and H/D Exchange: Reactions of Benzyloxycarbonyl-Proline Glycine Dipeptide Variants with ND3

    NASA Astrophysics Data System (ADS)

    Miladi, Mahsan; Olaitan, Abayomi D.; Zekavat, Behrooz; Solouki, Touradj

    2015-11-01

    A combination of density functional theory calculations, hydrogen/deuterium exchange (HDX) reactions, ion mobility-mass spectrometry, and isotope labeling tandem mass spectrometry was used to study gas-phase "host-guest" type interactions of a benzyloxycarbonyl (Z)-capped proline (P) glycine (G) model dipeptide (i.e., Z-PG) and its various structural analogues with ND3. It is shown that in a solvent-free environment, structural differences between protonated and alkali metal ion (Na+, K+, or Cs+)-complexed species of Z-PG affect ND3 adduct formation. Specifically, [Z-PG + H]+ and [Z-PG-OCH3 + H]+ formed gas-phase ND3 adducts ([Z-PG (or Z-PG-OCH3) + H + ND3]+) but no ND3 adducts were observed for [Z-PG + alkali metal]+ or [Z-PG + H - CO2]+. Experimentally measured and theoretically calculated collision cross sections (CCSs) of protonated and alkali metal ion-complexed Z-PG species showed similar trends that agreed with the observed structural differences from molecular modeling results. Moreover, results from theoretical ND3 affinity calculations were consistent with experimental HDX observations, indicating a more stable ND3 adduct for [Z-PG + H]+ compared to [Z-PG + alkali metal]+ species. Molecular modeling and experimental MS results for [Z-PG + H]+ and [Z-PG + alkali metal]+ suggest that optimized cation-π and hydrogen bonding interactions of carbonyl groups in final products are important for ND3 adduct formation.

  8. Design of peptides with α,β-dehydro-residues: syntheses, crystal structures and molecular conformations of two ΔPhe-Trp containing peptides

    NASA Astrophysics Data System (ADS)

    Vijayaraghavan, R.; Makker, J.; Kumar, P.; Dey, S.; Singh, T. P.

    2003-06-01

    The ΔPhe-Trp is a newly designed moiety that was found inducing a unique conformation in peptides. The peptides Boc-L-Val-ΔPhe-L-Trp-OCH 3 (I) and Boc-L-Leu-ΔPhe-L-Trp-OCH 3 (II) were synthesized by azlactone method in solution phase. The peptide (I) was crystallized from its solution in ethanol-water mixture in orthorhombic space group P2 12 12 1 with a=10.663(3) Å, b=11.204(3) Å, c=26.516(10) Å and peptide (II) was crystallized from its solution in acetone in a monoclinic space group P2 1 with a=9.354(1)Å, b=11.218(4)Å, c=15.633(1)Å and β=101.83(1)°. The structures were determined by direct methods. Peptide (I) was refined to an R value of 0.059 for 1554 observed reflections [ I≥2 σ (I)] and peptide (II) was refined to an R value of 0.043 for 2920 observed reflections [ I≥2 σ (I)]. The structures of peptides (I) and (II) were found to be identical. They formed an unusual type VIa β-turn conformation which is observed for the first time with a ΔPhe residue at ( i+2) position indicating a unique influence of ΔPhe-Trp moiety in inducing a reproducible new structure in peptides.

  9. OH Production from Reactions of Organic Peroxy Radicals with HO2 : Recent Studies on Ether-Derived Peroxy Radicals

    NASA Astrophysics Data System (ADS)

    Orlando, J. J.; Tyndall, G. S.; Kegley Owen, C. S.; Reynoldson, N.

    2013-12-01

    There is now ample evidence supporting significant formation of OH radicals in the reaction of HO2 with certain organic peroxy radicals (RO2). These reaction channels serve to promote radical propagation, and thus have the potential to alter HOx budgets and partitioning and hence tropospheric oxidative capacity. While much focus has been placed on OH production from reactions involving carbonyl-containing RO2 species, it is also the case that other oxygen- substituted peroxy species (e.g., CH3OCH2OO, HOCH2OO) likely generate OH in their reactions with HO2 (see ref. 1 and refs therein). In this work, the Cl-atom-initiated oxidation of two ethers, diethyl and diisopropyl ether, is investigated over ranges of conditions in an environmental chamber, using both FTIR and GC-FID methods for product quantification. Preliminary analysis suggests that significant OH production is occurring in the reaction of HO2 with CH3CH2OCH(OO)CH3, and also provides evidence for a rapid unimolecular reaction of diisopropyl ether-derived peroxy radicals. Details of these and other results will be described. 1. Orlando, J. J., and G. S. Tyndall, 2012: Laboratory studies of organic peroxy radical chemistry: an overview with emphasis on recent issues of atmospheric significance, Chemical Society Reviews, 41, 6294-6317, doi: 10.1039/C2CS35166H.

  10. Intramolecular Oxidative O-Demethylation of an Oxoferryl Porphyrin Complexed with a Per-O-methylated β-Cyclodextrin Dimer.

    PubMed

    Kitagishi, Hiroaki; Kurosawa, Shun; Kano, Koji

    2016-11-22

    The intramolecular oxidation of ROCH3 to ROCH2 OH, where the latter compound spontaneously decomposed to ROH and HCHO, was observed during the reaction of the supramolecular complex (met-hemoCD3) with cumene hydroperoxide in aqueous solution. Met-hemoCD3 is composed of meso-tetrakis(4-sulfonatophenyl)porphinatoiron(III) (Fe(III) TPPS) and a per-O-methylated β-cyclodextrin dimer having an -OCH2 PyCH2 O- linker (Py=pyridine-3,5-diyl). The O=Fe(IV) TPPS complex was formed by the reaction of met-hemoCD3 with cumene hydroperoxide, and isolated by gel-filtration chromatography. Although the isolated O=Fe(IV) TPPS complex in the cyclodextrin cage was stable in aqueous solution at 25 °C, it was gradually converted to Fe(II) TPPS (t1/2 =7.6 h). This conversion was accompanied by oxidative O-demethylation of an OCH3 group in the cyclodextrin dimer. The results indicated that hydrogen abstraction by O=Fe(IV) TPPS from ROCH3 yields HO-Fe(III) TPPS and ROCH2(.) . This was followed by radical coupling to afford Fe(II) TPPS and ROCH2 OH. The hemiacetal (ROCH2 OH) immediately decomposed to ROH and HCHO. This study revealed the ability of oxoferryl porphyrin to induce two-electron oxidation.

  11. Hydrogen production by coupled catalytic partial oxidation and steam methane reforming at elevated pressure and temperature

    NASA Astrophysics Data System (ADS)

    Chen, Luwei; Hong, Qi; Lin, Jianyi; Dautzenberg, F. M.

    Hydrogen production by coupled catalytic partial oxidation (CPO) and steam methane reforming of methane (OSMR) at industrial conditions (high temperatures and pressures) have been studied over supported 1 wt.% NiB catalysts. Mixture of air/CH 4/H 2O was applied as the feed. The effects of O 2:CH 4 ratio, H 2O:CH 4 ratio and the gas hourly space velocity (GHSV) on oxy-steam reforming (OSRM) were also studied. Results indicate that CH 4 conversion increases significantly with increasing O 2:CH 4 or H 2O:CH 4 ratio. However, the hydrogen mole fraction goes through a maximum, depending on reaction conditions, e.g., pressure, temperature and the feed gases ratios. Carbon deposition on the catalysts has been greatly decreased after steam addition. The supported 1 wt.% NiB catalysts exhibit high stability with 85% methane conversion at 15 bar and 800 °C during 70 h time-on-stream reaction (CH 4:O 2:H 2O:N 2 = 1:0.5:1:1.887). The thermal efficiency was increased from 35.8% by CPO (without steam) to 55.6%. The presented data would be useful references for further design of enlarged scale hydrogen production system.

  12. Theoretical and experimental study of methane steam reforming reactions over nickel catalyst

    NASA Astrophysics Data System (ADS)

    Pistonesi, C.; Juan, A.; Irigoyen, B.; Amadeo, N.

    2007-02-01

    In this work we perform DFT theoretical calculations of methane and steam interactions on Ni(1 1 1) surface. The calculations allow us to improve our understanding of the competition between these reactants by catalytic sites in methane steam reforming (MSR) process. For this purpose we compare theoretical results with kinetic measurements of MSR on a Ni(II)-Al(III) catalyst prepared from lamellar double hydroxides as precursor. This comparison shows that, for low H 2O/CH 4 ratios methane and water intermediate species adsorb on different catalytic sites. While CHO species adsorbs on top of Ni atom, OH one occupies preferentially a tri-coordinate surface site. On the other hand, for high H 2O/CH 4 ratios a competency between these species by Ni sites would establish, diminishing methane conversion. In addition competition between methane and steam for Ni sites would lead to a decrease in CO production. Nevertheless, intermediate species adsorbed on different active sites would produce CO 2, whatever the steam/methane ratio. Thus, it would be optimum steam concentration in hydrocarbon feed and active sites distribution on catalyst surface, which could maximize H 2 production and minimize CO selectivity. The theoretical findings agree with kinetic measurements, which show that maximum methane conversion depends on steam partial pressure in the feed; whereas always, selectivity to CO 2 increases and to CO diminishes.

  13. One-pot solvothermal synthesis of a well-ordered layered sodium aluminoalcoholate complex: a useful precursor for the preparation of porous Al2O3 particles

    SciTech Connect

    Li, XS; Michaelis, VK; Ong, TC; Smith, SJ; McKay, I; Muller, P; Griffin, RG; Wang, EN

    2014-01-01

    One-pot solvothermal synthesis of a robust tetranuclear sodium hexakis(glycolato)tris(methanolato)aluminate complex Na-3[Al-4(OCH3)(3)(OCH2CH2O)(6)] via a modified yet rigorous base-catalyzed transesterification mechanism is presented here. Single crystal X-ray diffraction (SCXRD) studies indicate that this unique Al complex contains three pentacoordinate Al3+ ions, each bound to two bidentate ethylene glycolate chelators and one monodentate methanolate ligand. The remaining fourth Al3+ ion is octahedrally coordinated to one oxygen atom from each of the six surrounding glycolate chelators, effectively stitching the three pentacoordinate Al moieties together into a novel tetranuclear Al complex. This aluminate complex is periodically self-assembled into well-ordered layers normal to the [110] axis with the intra-/inter-layer bonding involving extensive ionic bonds from the three charge-counterbalancing Na+ cations rather than the more typical hydrogen bonding interactions as a result of fewer free hydroxyl groups present in its structure. It can also serve as a valuable precursor toward the facile synthesis of high-surface-area alumina powders using a very efficient rapid pyrolysis technique.

  14. Three-component one-pot synthesis of novel pyrido[2,3-d]pyrimidine indole substituted derivatives and DFT analysis

    NASA Astrophysics Data System (ADS)

    Rangel, Jovanni; Díaz-Uribe, Carlos; Rodriguez-Serrano, Angela; Zarate, Ximena; Serge, York; Vallejo, William; Nogueras, Manuel; Trilleras, Jorge; Quiroga, Jairo; Tatchen, Jörg; Cobo, Justo

    2017-06-01

    Pyridopyrimidines are heterocyclic aromatic compounds known by their antibacterial and medicinal properties. In this work, a series of pyrido[2,3-d]pyrimidine indole derivatives were synthesized by three-component one pot cyclocondensation Michael reaction between 2,6-diaminopirimidin-4(3H)-one, 3-(2-cyanoacetyl)indole and aromatic aldehydes in boiling acetic acid as solvent. The compounds differ with respect to the substituents of the aromatic aldehyde which are comprised by -C6H5, -4-ClC6H4, -4-NO2C6H4, -3,4-OCH2OC6H3, -3-OCH3,4-OH,5-NO2C6H2, and -3,4,5-tri-H3COC6H2, respectively. The compounds were synthesized with reasonable yields. They were characterized by and IR, mass, and NMR spectrometry. The protocol employed offers the convenient advantages of a one-step synthesis, considerable savings of solvents, and easy isolation of reaction products. In addition, DFT and TD-DFT quantum chemical calculations were used to characterize the geometry and electronic structure of the compounds.

  15. The New World whirligig beetles of the genus Dineutus Macleay, 1825 (Coleoptera, Gyrinidae, Gyrininae, Dineutini).

    PubMed

    Gustafson, Grey T; Miller, Kelly B

    2015-01-01

    All New World members of the whirligig beetle genus Dineutus Macleay, 1825 are treated. The New World Dineutus are found to be composed of 18 species and 6 subspecies: one species, Dineutusmexicanus Ochs, 1925, stat. n. is elevated from subspecies to species rank, and the subspecies Dineutuscarolinusmutchleri Ochs, 1925, syn. n. is synonymized here with the typical form. Lectotypes are designated for Dineutusdiscolor Aubé, 1838, Dineutesmetallicus Aubé, 1838, Dineutussolitarius Aubé, 1838, Dineutesanalis Régimbart, 1883, and Gyrinuslongimanus Olivier, 1795. Each taxonomic unit is provided with a taxonomic history, type locality, diagnosis, distribution, habitat information, and a discussion section. The aedeagus and male mesotarsal claws are illustrated, and dorsal and ventral habitus images of both sexes, for each species and subspecies are provided. General distribution maps are provided for all taxonimc units. A key to the genera of New World Gyrinidae, as well as all the New World Dineutus species is provided. General Dineutus anatomy as well as a clarification of homology and anatomical terms is included.

  16. Reactive Capture of Gold Nanoparticles by Strongly Physisorbed Monolayers on Graphite

    SciTech Connect

    Wei, Xiaoliang; Tong, Wenjun; Fidler, Vlastimil; Zimmt, Matthew B.

    2012-12-01

    Anthracene Diels Alder adducts (DAa) bearing two long side chains (H-(CH2)22O(CH2)6OCH2-) at the 1- and 5-positions form self-assembled monolayers (SAMs) at the phenyloctane - highly oriented pyrolytic graphite (HOPG) interface. The long DAa side chains promote strong physisorption of the monolayer to HOPG and maintain the monolayer morphology upon rinsing or incubation in ethanol and air-drying of the substrate. Incorporating a carboxylic acid group on the DAa core enables capture of 1 - 4 nm diameter gold nanoparticles (AuNP) provided (i) the monolayer containing DAa-carboxylic acids is treated with Cu2+ ions and (ii) the organic coating on the AuNP contains carboxylic acids (11-mercaptoundecanoic acid, MUA-AuNP). AuNP capture by the monolayer proceeds with formation of Cu2+ - carboxylate coordination complexes. The captured AuNP appear as mono- and multi-layered clusters at high coverage on HOPG. The surface density of the captured AuNPs can be adjusted from AuNP multi-layers to isolated AuNPs by varying incubation times, MUA-AuNP concentration, the number density of carboxylic acids in the monolayer, the number of MUA per AuNP, and the post-incubation treatments.

  17. Ab Initio Investigation of Polyethylene Glycol Coating of TiO2 Surfaces

    PubMed Central

    2016-01-01

    In biomedical applications, TiO2 nanoparticles are generally coated with polymers to prevent agglomeration, improve biocompatibility, and reduce cytotoxicity. Although the synthesis processes of such composite compounds are well established, there is still a substantial lack of information on the nature of the interaction between the titania surface and the organic macromolecules. In this work, the adsorption of polyethylene glycol (PEG) on the TiO2 (101) anatase surface is modeled by means of dispersion-corrected density functional theory (DFT-D2) calculations. The two extreme limits of an infinite PEG polymer [−(OCH2CH2)n], on one side, and of a short PEG dimer molecule [H(OCH2CH2)2OH], on the other, are analyzed. Many different molecular configurations and modes of adsorption are compared at increasing surface coverage densities. At low and medium coverage, PEG prefers to lay down on the surface, while at full coverage, the adsorption is maximized when PEG molecules bind perpendicularly to the surface and interact with each other through lateral dispersions, following a mushroom to brush transition. Finally, we also consider the adsorption of competing water molecules at different coverage densities, assessing whether PEG would remain bonded to the surface or desorb in the presence of the aqueous solvent. PMID:28058086

  18. Electrochemically assisted fabrication of size-exclusion films of organically modified silica and application to the voltammetry of phospholipids

    PubMed Central

    Mehdi, B. Layla; Rutkowska, Iwona A.; Kulesza, Pawel J.

    2013-01-01

    Modification of electrodes with nm-scale organically modified silica films with pores diameters controlled at 10- and 50-nm is described. An oxidation catalyst, mixed-valence ruthenium oxide with cyano crosslinks or gold nanoparticles protected by dirhodium-substituted phosophomolybdate (AuNP-Rh2PMo11), was immobilized in the pores. These systems comprise size-exclusion films at which the biological compounds, phosphatidylcholine and cardiolipin, were electrocatalytically oxidized without interference from surface-active concomitants such as bovine serum albumin. 10-nm pores were obtained by adding generation-4 poly(amidoamine) dendrimer, G4-PAMAM, to a (CH3)3SiOCH3 sol. 50-nm pores were obtained by modifying a glassy carbon electrode (GC) with a sub-monolayer film of aminopropyltriethoxylsilane, attaching 50-nm diameter poly(styrene sulfonate), PSS, spheres to the protonated amine, transferring this electrode to a (CH3)3SiOCH3 sol, and electrochemically generating hydronium at uncoated GC sites, which catalyzed ormosil growth around the PSS. Voltammetry of Fe(CN)63− and Ru(NH3)63+ demonstrated the absence of residual charge after removal of the templating agents. With the 50-nm system, the pore structure was sufficiently defined to use layer-by-layer electrostatic assembly of AuNP-Rh2PMo11 therein. Flow injection amperometry of phosphatidylcholine and cardiolipin demonstrated analytical utility of these electrodes. PMID:23935394

  19. The New World whirligig beetles of the genus Dineutus Macleay, 1825 (Coleoptera, Gyrinidae, Gyrininae, Dineutini)

    PubMed Central

    Gustafson, Grey T.; Miller, Kelly B.

    2015-01-01

    Abstract All New World members of the whirligig beetle genus Dineutus Macleay, 1825 are treated. The New World Dineutus are found to be composed of 18 species and 6 subspecies: one species, Dineutus mexicanus Ochs, 1925, stat. n. is elevated from subspecies to species rank, and the subspecies Dineutus carolinus mutchleri Ochs, 1925, syn. n. is synonymized here with the typical form. Lectotypes are designated for Dineutus discolor Aubé, 1838, Dineutes metallicus Aubé, 1838, Dineutus solitarius Aubé, 1838, Dineutes analis Régimbart, 1883, and Gyrinus longimanus Olivier, 1795. Each taxonomic unit is provided with a taxonomic history, type locality, diagnosis, distribution, habitat information, and a discussion section. The aedeagus and male mesotarsal claws are illustrated, and dorsal and ventral habitus images of both sexes, for each species and subspecies are provided. General distribution maps are provided for all taxonimc units. A key to the genera of New World Gyrinidae, as well as all the New World Dineutus species is provided. General Dineutus anatomy as well as a clarification of homology and anatomical terms is included. PMID:25685002

  20. T helper type 2-polarized invariant natural killer T cells reduce disease severity in acute intra-abdominal sepsis.

    PubMed

    Anantha, R V; Mazzuca, D M; Xu, S X; Porcelli, S A; Fraser, D D; Martin, C M; Welch, I; Mele, T; Haeryfar, S M M; McCormick, J K

    2014-11-01

    Sepsis is characterized by a severe systemic inflammatory response to infection that is associated with high morbidity and mortality despite optimal care. Invariant natural killer T (iNK T) cells are potent regulatory lymphocytes that can produce pro- and/or anti-inflammatory cytokines, thus shaping the course and nature of immune responses; however, little is known about their role in sepsis. We demonstrate here that patients with sepsis/severe sepsis have significantly elevated proportions of iNK T cells in their peripheral blood (as a percentage of their circulating T cells) compared to non-septic patients. We therefore investigated the role of iNK T cells in a mouse model of intra-abdominal sepsis (IAS). Our data show that iNK T cells are pathogenic in IAS, and that T helper type 2 (Th2) polarization of iNK T cells using the synthetic glycolipid OCH significantly reduces mortality from IAS. This reduction in mortality is associated with the systemic elevation of the anti-inflammatory cytokine interleukin (IL)-13 and reduction of several proinflammatory cytokines within the spleen, notably interleukin (IL)-17. Finally, we show that treatment of sepsis with OCH in mice is accompanied by significantly reduced apoptosis of splenic T and B lymphocytes and macrophages, but not natural killer cells. We propose that modulation of iNK T cell responses towards a Th2 phenotype may be an effective therapeutic strategy in early sepsis.