Sample records for 189-c 289-f 189-k

  1. Record of Decision Remedial Alternative Selection for the C, F, K, and P-Area Coal Pile Runoff Basins (189-C, 289-F, 189-K, and 189-P)

    SciTech Connect

    Morgan, Randall


    The C-, F-, K-, and P-Area Coal Pile Runoff Basins (189-C, 289-F, 189-K, and 189-P) (C-, F-, K-, and P-CPRBs) waste units are listed as Resource Conservation and Recovery Act (RCRA) 3004(u) Solid Waste Management Units/Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) units in Appendix C of the Federal Facility Agreement (FFA) for the Savannah River Site (SRS). The C-, F-, K-, and P-CPRBS comprise a single operable unit which was remediated under an early removal action during the summer of 1997. Slightly elevated levels of naturally occurring metals and radionuclides in the coal-laden sediments and shallow soils were confined to the 0-1 foot interval below the basin floor. These source materials were identified as low level threat wastes. Under the Removal Site Evaluation Report/Wastewater Closure Plan for the C-, F-, K-, and P-Area Coal Pile Runoff Basins (189-C, 289-F, 189-K, and 189-P) (U) (WSRC 1997b), the coal-laden sediments and shallow soils were removed from each of the four basins during the summer of 1997. At least four feet of clean backfill was placed in each basin to restore the area to the surrounding grade. This removal action completely freed the four CPRBS of the source material for the constituents of concern and the sulfide minerals, which were reducing the pH of the infiltrate. Because the source material has been removed from the CPRBs, releases of hazardous substances will not occur from this operable unit and there is no imminent or substantial endangerment to public health, welfare, or the environment.

  2. R-189 (C-620) air compressor control logic software documentation. Revision 1

    SciTech Connect

    Walter, K.E.


    This relates to FFTF plant air compressors. Purpose of this document is to provide an updated Computer Software Description for the software to be used on R-189 (C-620-C) air compressor programmable controllers. Logic software design changes were required to allow automatic starting of a compressor that had not been previously started.

  3. 1.89 kW all-fiberized and polarization-maintained amplifiers with narrow linewidth and near-diffraction-limited beam quality.


    Ma, Pengfei; Tao, Rumao; Su, Rongtao; Wang, Xiaolin; Zhou, Pu; Liu, Zejin


    In this manuscript, we demonstrate high power, all-fiberized and polarization-maintained amplifiers with narrow linewidth and near-diffraction-limited beam quality by simultaneously suppressing detrimental stimulated Brillouin scattering (SBS) and mode instability (MI) effects. Compared with strictly single frequency amplification, the SBS threshold is scaled up to 12 dB, 15.4 dB, and higher than 18 dB by subsequently using three-stage cascaded phase modulation systems. Output powers of 477 W, 1040 W, and 1890 W are achieved with full widths at half maximums (FWHMs) of within 6 GHz, ~18.5 GHz, and ~45 GHz, respectively. The MI threshold is increased from ~738 W to 1890 W by coiling the active fiber in the main amplifier. Both the polarization extinction ratio (PER) and beam quality (M2 factor) are maintained well during the power scaling process. To the best of our knowledge, this is the first demonstration of all-fiberized amplifiers with narrow linewidth, near linear polarization, and near-diffraction-limited beam quality at 2 kW power-level. PMID:26907067

  4. One step hydrothermal synthesis of a carbon nanotube/cerium oxide nanocomposite and its electrochemical properties

    NASA Astrophysics Data System (ADS)

    Kalubarme, Ramchandra S.; Kim, Yong-Han; Park, Chan-Jin


    A carbon nanotube (CNT)/cerium oxide composite was prepared by a one-pot hydrothermal reaction in the presence of KOH and capping agent polyvinylpyrrolidone. The nanocomposite displayed pronounced capacitive behaviour with very small diffusion resistance. The electrochemical performance of the composite electrode in a symmetric supercapacitor displayed a high energy density of 35.9 Wh kg-1 corresponding to a specific capacitance of 289 F g-1. These composite electrodes also demonstrated a long cycle life with better capacity retention.

  5. Mutations affecting two adjacent amino acid residues in the alpha subunit of RNA polymerase block transcriptional activation by the bacteriophage P2 Ogr protein.

    PubMed Central

    Ayers, D J; Sunshine, M G; Six, E W; Christie, G E


    The bacteriophage P2 ogr gene product is a positive regulator of transcription from P2 late promoters. The ogr gene was originally defined by compensatory mutations that overcame the block to P2 growth imposed by a host mutation, rpoA109, in the gene encoding the alpha subunit of RNA polymerase. DNA sequence analysis has confirmed that this mutation affects the C-terminal region of the alpha subunit, changing a leucine residue at position 290 to a histidine (rpoAL290H). We have employed a reporter plasmid system to screen other, previously described, rpoA mutants for effects on activation of a P2 late promoter and have identified a second allele, rpoA155, that blocks P2 late transcription. This mutation lies just upstream of rpoAL290H, changing the leucine residue at position 289 to a phenylalanine (rpoAL289F). The effect of the rpoAL289F mutation is not suppressed by the rpoAL290H-compensatory P2 ogr mutation. P2 ogr mutants that overcome the block imposed by rpoAL289F were isolated and characterized. Our results are consistent with a direct interaction between Ogr and the alpha subunit of RNA polymerase and support a model in which transcription factor contact sites within the C terminus of alpha are discrete and tightly clustered. PMID:8002564

  6. Thermal analysis of a high energy propulsion system /hydrazine and liquid fluorine/ for a rover class Mars Orbiter

    NASA Technical Reports Server (NTRS)

    Stultz, J. W.


    Maintaining cryogenic fluorine at a -189 C during the interplanetary cruise period to Mars is a major thermal problem. At this low temperature the heat rejection by radiation is severely limited and the allowable thermal load to the fluorine tank is less than approximately 8 watts. Previous studies generally constrain the spacecraft to an inline tank configuration which tends to maximize the fluorine tank's view and heat rejection to space. With the Inertial Upper Stage, sufficient stack height may not be available on the Shuttle for an inline tank configuration. Therefore, this study addresses the more thermally constraining side by side tank configuration.

  7. The structural basis for T-antigen hydrolysis by Streptococcus pneumoniae: a target for structure-based vaccine design.


    Caines, Matthew E C; Zhu, Haizhong; Vuckovic, Marija; Willis, Lisa M; Withers, Stephen G; Wakarchuk, Warren W; Strynadka, Natalie C J


    Streptococcus pneumoniae endo-alpha-N-acetylgalactosaminidase is a cell surface-anchored glycoside hydrolase from family GH101 involved in the breakdown of mucin type O-linked glycans. The 189-kDa mature enzyme specifically hydrolyzes the T-antigen disaccharide from extracellular host glycoproteins and is representative of a broadly important class of virulence factors that have remained structurally uncharacterized due to their large size and highly modular nature. Here we report a 2.9 angstroms resolution crystal structure that remarkably captures the multidomain architecture and characterizes a catalytic center unexpectedly resembling that of alpha-amylases. Our analysis presents a complete model of glycoprotein recognition and provides a basis for the structure-based design of novel Streptococcus vaccines and therapeutics. PMID:18784084

  8. Dosimeter for the measurement of UV exposures related to melanoma induction.


    Turnbull, David J; Parisi, Alfio V


    This paper reports on the development of a dosimeter for the measurement of biologically effective UV exposures related to melanoma induction. The melanoma (UVMel) dosimeter is based on the combination of polysulfone and nalidixic acid. This research found that the combination of these photosensitive chromophores reacts to UV wavelengths from 290 to 390 nm. It was found that a large change in optical absorbance occurred at 345 nm when the dosimeter was employed to quantify the solar UV waveband. Preliminary results indicate that this UVMel dosimeter can measure exposures of more than 189 kJ m(-2) of biologically effective weighted solar UV radiation with an inter-dosimeter variability of no more than +/-5%. PMID:20551501

  9. Structural, dielectric and vibrational studies of the new mixed solid solution of thallium potassium sulfate selenate tellurate

    NASA Astrophysics Data System (ADS)

    Elferjani, A.; Abdelhedi, M.; Dammak, M.; Kolsi, A. W.


    The new mixed compound Tl1.89K0.11(SO4)0.9(SeO4)0.1Te(OH)6 which is crystallized in the monoclinic system with space group P21/ c was analyzed at room temperature using X-ray diffractometer data. The unit cell parameters are a = 12.3308(7), b = 7.2011(4), c = 12.0298(8) Å, β = 110.755(4)°, V = 998.87(11) Å3 and Z = 4. The final refinement led to R = 0.035 and Rw = 0.038. The main feature of these atomic arrangements is the coexistence of three and different anions (SO4 2-, SeO4 2- and TeO6 6- groups) in the unit cell, connected by hydrogen bonds (O-H···O) which make the building of the crystal. The Tl+ and K+ cations, occupying the same positions, are located between these polyhedral. The crystals of Tl1.89K0.11(SO4)0.9(SeO4)0.1Te(OH)6 underwent three endothermic peaks at 377, 466 and 472 K. These transitions were detected by DSC and analyzed by dielectric measurements using the impedance and modulus spectroscopy techniques. The IR and Raman spectra recorded at room temperature in the frequency ranges (50-1200) and (400-4000) cm-1, respectively, have confirmed the presence of TeO6 6-, SO4 2- and SeO4 2- groups in the crystal.

  10. [Genetic variation and association of prostaglandin F2alpha receptor (PTGFR) gene with sow maternal behaviors in a White Duroc x Erhualian resource population].


    Yang, Zhu-Qing; Ren, Jun; Zhang, Zhi-Yan; Chen, Cong-Ying


    Maternal behaviors of sows around parturition are important for survival of newborn offspring. Failure to establish normal maternal bonds such as maternal infanticide and crushing often occurs in some individuals. It causes both significant economic losses to the pig industry and severe problems of piglet welfare. Prostaglandin F2-alpha not only can stimulate the nest-building behavior of sows before parturition but also plays an important role in reproductive process and maternal behavior through protein FP encoded by the prostaglandin F receptor gene (PTGFR) as its receptor. In this study, genetic variation and association study of PTGFR gene with nest-building behavior, maternal infanticide, and crushing behavior was carried out in a White Duroc x Erhualian resource population. As a result, five synonymous mutations were identified on exon 1 and exon 2. Exon 1 g .250 A>G, Exon 1 g.619 G>A and Exon 2 g.483 T>C were chosen for genotyping in individuals of F0, F1 and 289 F2 sows. Family-based transmission disequilibrium test (TDT) demonstrated that there were no significant associations of 3 SNPs and haplotypes of PTGFR gene with sow nest-building, maternal infanticide and crushing behavior (P > 0.05). Therefore, it can be concluded that PTGFR gene is not the causative candidate gene for sow maternal behaviors. PMID:21513166

  11. VizieR Online Data Catalog: SMaSH+: observations and companion detection (Sana+, 2014)

    NASA Astrophysics Data System (ADS)

    Sana, H.; Le Bouquin, J.-B.; Lacour, S.; Berger, J.-P.; Duvert, G.; Gauchet, L.; Norris, B.; Olofsson, J.; Pickel, D.; Zins, G.; Absil, O.; de Koter, A.; Kratter, K.; Schnurr, O.; Zinnecker, H.


    The bulk of the Southern MAssive Stars at High angular resolution survey (SMaSH+) observations has been obtained in the course of a European Southern Observatory (ESO) large program (189.C-0644) which was granted 20 VLTI/PIONIER nights over the period 2012 April-2013 March and 3 NACO/SAM nights in 2013 June. The NACO observations are complemented by a 2011 pilot program and additional programs in 2012 and 2013 for a total of 13 VLT/UT4 nights. Thirteen stars have further been observed as backup targets of various PIONIER runs from 2013 December to 2014 August. The practical limiting magnitude of PIONIER in its small spectral dispersion mode is H=7.5. (5 data files).

  12. Ultrasonic characterization of slurries in an autoclave reactor at elevated temperature

    SciTech Connect

    Soong, Y.; Gamwo, I.K.; Blackwell, A.G.; Harke, F.W.; Schehl, R.R.; Zarochak, M.F.


    The application of the three-phase slurry reactor system for coal liquefaction processing and chemical industries has recently received considerable attention. To design and efficiently operate a three-phase slurry reactor, the degree of dispersion of the solid (catalyst) in the reactor must be understood and controlled. An ultrasonic technique was developed to measure the concentration of solids in an autoclave reactor. Preliminary measurements were conducted on slurries consisting of molten paraffin wax, glass beads, and nitrogen bubbles at 189 C. The data show that the velocity and attenuation of the sound are well-defined functions of the solid and gas concentrations in the molten wax. The results suggest possibilities for directly measuring solids concentration during operation of a three-phase slurry reactor.

  13. Solids concentration measurements in molten wax by an ultrasonic technique

    SciTech Connect

    Soong, Y.; Gamwo, I.K.; Blackwell, A.G.; Schehl, R.R.; Zarochak, M.F.


    The application of the three-phase slurry reactor system to coal liquefaction processing and chemical industries has recently received considerable attention. To design and efficiently operate a three-phase slurry reactor, the degree of dispersion of the solid (catalyst) in the reactor should be understood. The solids distribution within the reactor greatly affects its performance. An ultrasonic technique is under development for measuring solids concentration in a three-phase slurry reactor. Preliminary measurements have been made on slurries consisting of molten paraffin wax, glass beads, and nitrogen bubbles at 189 C. The data show that the velocity and attenuation of the sound are well-defined functions of the solid and gas concentrations in the molten wax.

  14. Strategies for genetic study of hearing loss in the Brazilian northeastern region

    PubMed Central

    Melo, Uirá S; Santos, Silvana; Cavalcanti, Hannalice G; Andrade, Wagner T; Dantas, Vitor G; Rosa, Marine RD; Mingroni-Netto, Regina C


    The overall aim of this study was to estimate the contribution of genetic factors to the etiology of hearing loss (HL) in two counties in the Brazilian northeastern region. A cross-sectional study, based on the key informant approach (KI) was conducted in Queimadas and Gado Bravo counties (Paraíba, Northeast Brazil). The sample consisted of 182 patients with HL. Genetic screening of the most frequent mutations associated with HL was performed for all samples. DFNB1 mutations were the most frequently found in both counties. The c.35delG mutation was detected in homozygosis in seven non-syndromic probands in Queimadas (7/76, 9.2%) and only a single homozygote with this mutation was found in Gado Bravo (1/44, 2.3%). We also detected the del(GJB6-D13S1854) mutation in non-syndromic probands from Gado Bravo (2/44, 4.5%). The c.189C>A (p.TyrY63*) mutation in the CLRN1 gene was detected in homozygosis in 21/23 Usher syndrome patients from Gado Bravo and it was not found in Queimadas. Cases with probable genetic etiology contributed approximately to half of HL probands in each county (54.6% in Gado Bravo and 45.7% in Queimadas). We confirm the importance of DFNB1 locus to non-syndromic HL but we show that the frequency of mutations in the northeastern region differs somewhat from those reported in southeastern Brazil and other populations. In addition, the extremely high frequency of individuals with Usher syndrome with c.189C>A variation in CLRN1 indicates the need for a specific screening of this mutation. PMID:24596593

  15. High prevalence of clinical and environmental triazole-resistant Aspergillus fumigatus in Iran: is it a challenging issue?


    Nabili, Mojtaba; Shokohi, Tahereh; Moazeni, Maryam; Khodavaisy, Sadegh; Aliyali, Masoud; Badiee, Parisa; Zarrinfar, Hossein; Hagen, Ferry; Badali, Hamid


    Triazole antifungal agents are the mainstay of aspergillosis treatment. As highlighted in numerous studies, the global increase in the prevalence of triazole resistance could hamper the management of aspergillosis. In the present three-year study, 513 samples (213 clinical and 300 environmental samples) from 10 provinces of Iran were processed and screened in terms of azole resistance (4 and 1 mg l-1 of itraconazole and voriconazole, respectively), using selective plates. Overall, 150 A. fumigatus isolates (71 clinical and 79 environmental isolates) were detected. The isolates were confirmed by partial sequencing of the β-tubulin gene. Afterwards, in vitro antifungal susceptibility tests against triazole agents were performed, based on the Clinical and Laboratory Standards Institute (CLSI) M38-A2 document. The CYP51A gene was sequenced in order to detect mutations. The MIC of itraconazole against 10 (6.6 %) strains, including clinical (n=3, 4.2 %) and environmental (n=7, 8.8 %) strains, was higher than the breakpoint and epidemiological cut-off value. Based on the findings, the prevalence of azole-resistant A. fumigatus in Iran has increased remarkablyfrom 3.3 % to 6.6 % in comparison with earlier epidemiological research. Among resistant isolates, TR34/L98H mutations in the CYP51A gene were the most prevalent (n=8, 80 %), whereas other point mutations (F46Y, G54W, Y121F, G138C, M172V, F219C, M220I, D255E, T289F, G432C and G448S mutations) were not detected. Although the number of patients affected by azole-resistant A. fumigatus isolates was limited, strict supervision of clinical azole-resistant A. fumigatus isolates and persistent environmental screening of azole resistance are vital to the development of approaches for the management of azole resistance in human pathogenic fungi. PMID:27008655

  16. A pre seismic radio anomaly revealed in the area where the Abruzzo earthquake (M=6.3) occurred on 6 April 2009

    NASA Astrophysics Data System (ADS)

    Biagi, P. F.; Castellana, L.; Maggipinto, T.; Loiacono, D.; Schiavulli, L.; Ligonzo, T.; Fiore, M.; Suciu, E.; Ermini, A.


    On 6 April 2009 a strong (Mw=6.3) earthquake occurred in the Abruzzo region (central Italy). Since 1996, the intensity of CLT (f=189 kHz, Sicily, Italy), MCO (f=216 kHz, France) and CZE (f=270 kHz, Czech Republic) broadcast signals has been collected with a ten minutes sampling rate by a receiver operating in a place located about 13 km far from the epicenter. During March 2009, the old receiver was substituted with a new one able to measure, with one minute sampling rate, the intensity of five VLF signals and five LF signals radiated by transmitters located in different zones of Europe. The MCO and CZE transmitters mentioned above are included among them. From 31 March to 1 April the intensity of the MCO radio signal dropped and this drop was observed only in this signal. The possibility that the drop was connected to problems in the transmitter or in the receiver was investigated and excluded. So, the drop indicates a defocusing of the radiated signal. Since no particular meteorological situation along the path transmitter-receiver happened, the defocusing must be related to other causes, and a possibility is presented that it is a precursor of the Abruzzo earthquake.

  17. Catalytic combustion of ethane over palladium foil in the 300--450 C range: Kinetics and surface composition studies

    SciTech Connect

    Descorme, C.; Jacobs, P.W.; Somorjai, G.A.


    Catalytic oxidation of ethane over palladium foils was studied and the kinetic parameters were determined for the reaction. The studies were carried out at 800 Torr total pressure over a wide range of reaction conditions in the temperature range of 300--425 C. The catalyst surface composition was characterized before and after reaction by Auger electron spectroscopy (AES). While the authors detected only metallic palladium before reaction, the postreaction analysis showed significant formation of PdO{sub x}, a surface oxide, at all temperatures and under all ethane/oxygen ratios. The catalyst that exhibits optimum combustion activity is the one covered with 0.3 to 0.5 monolayer of oxygen. Carbon monoxide temperature-programmed desorption (CO-TPD) was used to evaluate the surface area of the metallic and oxidized palladium in order to normalize the measured catalytic reaction rates. Apparent activation energies of 104, 116, and 189 kJ/mol under fuel lean, stoichiometric, and fuel-rick conditions, respectively, were observed. While CO{sub 2} is the main carbonaceous product, unoxidized and partially oxidized species, methane and ethylene, are produced in small amounts. The product distribution is typically 98.6 mol% CO{sub 2}, 0.9 mol% C{sub 2}H{sub 4}, and 0.5 mol% CH{sub 4} at 10% conversion during a reaction at 350 C under stoichiometric conditions.

  18. Relaxor nature in lead-free Sr{sub 5}LaTi{sub 3}Nb{sub 7}O{sub 30} tetragonal tungsten bronze ceramics

    SciTech Connect

    Li Zhu, Xiao; Li, Kun; Qiang Liu, Xiao; Ming Chen, Xiang; Asif Rafiq, Muhammad


    Lead-free tetragonal tungsten bronze Sr{sub 5}LaTi{sub 3}Nb{sub 7}O{sub 30} ceramics were prepared and the correlation of the relaxor nature and crystal structure was studied using dielectric spectroscopy and powder X-ray diffraction. Three dielectric relaxations were observed below the deviation temperature T{sub D}∼ 330 K. Relaxation I and II followed the Vogel-Fulcher law with the freezing temperatures of 189 K and ∼90 K. Low temperature relaxation III, which was first observed in filled tungsten bronze, followed well the Arrhenius law. Dielectric response becomes static below 50 K. Polarization-field (P-E) hysteresis loops were evaluated from 183 K to 298 K. P{sub r} value of 0.41μC/cm{sup 2} was observed at 183 K. Deviation of lattice parameter c from the linear contraction and increasing of tetragonality (c/a ratio) were observed below T{sub D}, reflecting the structure change during the formation of polar nanoregions and the following freezing process. Opposite tendency was observed below 100 K for all the lattice parameters, corresponding to relaxation III. Generally, the main dielectric relaxation I and II were attributed to flipping and breathing of polar nanoregions along c axis, while the concerted rotations of the oxygen octahedra in the ab plane were suggested as the origin of relaxation III.

  19. In vitro culture of Parascaris equorum larvae and initial investigation of parasite excretory-secretory products.


    Burk, Steffanie V; Dangoudoubiyam, Sriveny; Brewster-Barnes, Tammy; Bryant, Uneeda K; Howe, Daniel K; Carter, Craig N; Vanzant, Eric S; Harmon, Robert J; Kazacos, Kevin R; Rossano, Mary G


    Currently, diagnosis of Parascaris equorum infection in equids is limited to patent infections. The goals of this study were to culture P. equorum larvae in vitro and identify excretory-secretory (ES) products for prepatent diagnostic testing. Parascaris equorum L2/L3 larvae were hatched and cultured for up to 3 weeks for ES product collection. Fifth stage (L5) P. equorum were also cultured for ES product collection. Examination of ES fractions by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and silver stain revealed L2/L3 products ranging from 12-94 kDa and L5 products ranging from 12-189 kDa. Western blot analyses were conducted using polyclonal antibodies produced against P. equorum or Baylisascaris procyonis L2/L3 ES products, sera from rabbits inoculated with B. procyonis or Toxocara canis eggs, and sera from animals naturally infected with P. equorum or T. canis. Western blot results indicated parasite antigens migrating at 19 and 34 kDa may be useful for specifically detecting P. equorum infections. PMID:25209615

  20. Relaxor nature in lead-free Sr5LaTi3Nb7O30 tetragonal tungsten bronze ceramics

    NASA Astrophysics Data System (ADS)

    Li Zhu, Xiao; Li, Kun; Asif Rafiq, Muhammad; Qiang Liu, Xiao; Ming Chen, Xiang


    Lead-free tetragonal tungsten bronze Sr5LaTi3Nb7O30 ceramics were prepared and the correlation of the relaxor nature and crystal structure was studied using dielectric spectroscopy and powder X-ray diffraction. Three dielectric relaxations were observed below the deviation temperature TD ˜ 330 K. Relaxation I and II followed the Vogel-Fulcher law with the freezing temperatures of 189 K and ˜90 K. Low temperature relaxation III, which was first observed in filled tungsten bronze, followed well the Arrhenius law. Dielectric response becomes static below 50 K. Polarization-field (P-E) hysteresis loops were evaluated from 183 K to 298 K. Pr value of 0.41μC/cm2 was observed at 183 K. Deviation of lattice parameter c from the linear contraction and increasing of tetragonality (c/a ratio) were observed below TD, reflecting the structure change during the formation of polar nanoregions and the following freezing process. Opposite tendency was observed below 100 K for all the lattice parameters, corresponding to relaxation III. Generally, the main dielectric relaxation I and II were attributed to flipping and breathing of polar nanoregions along c axis, while the concerted rotations of the oxygen octahedra in the ab plane were suggested as the origin of relaxation III.

  1. Peeling single-stranded DNA from graphite surface to determine oligonucleotide binding energy by force spectroscopy.


    Manohar, Suresh; Mantz, Amber R; Bancroft, Kevin E; Hui, Chung-Yuen; Jagota, Anand; Vezenov, Dmitri V


    We measured the force required to peel single-stranded DNA molecules from single-crystal graphite using chemical force microscopy. Force traces during retraction of a tip chemically modified with oligonucleotides displayed characteristic plateaus with abrupt force jumps, which we interpreted as a steady state peeling process punctuated by complete detachment of one or more molecules. We were able to differentiate between bases in pyrimidine homopolymers; peeling forces were 85.3 - 4.7 pN for polythymine and 60.8 +/- 5.5 pN for polycytosine, substantially independent of salt concentration and the rate of detachment. We developed a model for peeling a freely jointed chain from the graphite surface and estimated the average binding energy per monomer to be 11.5 +/- 0.6 k(B)T and 8.3 +/- 0.7 k(B)T in the cases of thymine and cytosine nucleotides, respectively. The equilibrium free-energy profile simulated using molecular dynamics had a potential well of 18.9 k(B)T for thymidine, showing that nonelectrostatic interactions dominate the binding. The discrepancy between the experiment and theory indicates that not all bases are adsorbed on the surface or that there is a population of conformations in which they adsorb. Force spectroscopy using oligonucleotides covalently linked to AFM tips provides a flexible and unambiguous means to quantify the strength of interactions between DNA and a number of substrates, potentially including nanomaterials such as carbon nanotubes. PMID:19368004

  2. A new antigenic variant of human influenza A (H3N2) virus isolated from airport and community surveillance in Taiwan in early 2009.


    Yang, Ji-Rong; Lin, Chao-Hua; Chen, Chun-Jung; Liu, Jian-Liang; Huang, Yuan-Pin; Kuo, Chuan-Yi; Yao, Ching-Yuan; Hsu, Li-Ching; Lo, Je; Ho, Yu-Lin; Wu, Ho-Sheng; Liu, Ming-Tsan


    A new variant of influenza A H3N2 virus emerged in January 2009 and became the dominant strain in Taiwan in April 2009. The variant was also detected in imported cases from various regions, including East and Southeast Asia and North America, indicating that it has circulated globally. Compared to the 2009-2010 vaccine strain, A/Brisbane/10/2007, the hemagglutinin gene of this variant exhibited five substitutions, E62K, N144K, K158N, K173Q and N189K, which are located in the antigenic sites E, A, B, D and B respectively, and it was antigenically distinct from A/Brisbane/10/2007 with more than eight-fold titer reduction in the hemagglutination inhibition reaction. The A/Perth/16/2009 (H3N2)-like virus recommended by World Health Organization for use in the 2010 southern hemisphere and 2010-2011 northern influenza seasons exhibited the same substitutions like this new variant. In addition to regional or community influenza surveillance, the imported cases or airport fever screening surveillance may be a good resource to monitor the evolution of the virus and benefit the real-time information of global influenza circulation. PMID:20347893

  3. BRAT1 mutations present with a spectrum of clinical severity.


    Srivastava, Siddharth; Olson, Heather E; Cohen, Julie S; Gubbels, Cynthia S; Lincoln, Sharyn; Davis, Brigette Tippin; Shahmirzadi, Layla; Gupta, Siddharth; Picker, Jonathan; Yu, Timothy W; Miller, David T; Soul, Janet S; Poretti, Andrea; Naidu, SakkuBai


    Mutations in BRAT1, encoding BRCA1-associated ATM activator 1, are associated with a severe phenotype known as rigidity and multifocal seizure syndrome, lethal neonatal (RMFSL; OMIM # 614498), characterized by intractable seizures, hypertonia, autonomic instability, and early death. We expand the phenotypic spectrum of BRAT1 related disorders by reporting on four individuals with various BRAT1 mutations resulting in clinical severity that is either mild or moderate compared to the severe phenotype seen in RMFSL. Representing mild severity are three individuals (Patients 1-3), who are girls (including two sisters, Patients 1-2) between 4 and 10 years old, with subtle dysmorphisms, intellectual disability, ataxia or dyspraxia, and cerebellar atrophy on brain MRI; additionally, Patient 3 has well-controlled epilepsy and microcephaly. Representing moderate severity is a 15-month-old boy (Patient 4) with severe global developmental delay, refractory epilepsy, microcephaly, spasticity, hyperkinetic movements, dysautonomia, and chronic lung disease. In contrast to RMFSL, his seizure onset occurred later at 4 months of age, and he is still alive. All four of the individuals have compound heterozygous BRAT1 mutations discovered via whole exome sequencing: c.638dupA (p.Val214Glyfs*189); c.803+1G>C (splice site mutation) in Patients 1-2; c.638dupA (p.Val214Glyfs*189); c.419T>C (p.Leu140Pro) in Patient 3; and c.171delG (p.Glu57Aspfs*7); c.419T>C (p.Leu140Pro) in Patient 4. Only the c.638dupA (p.Val214Glyfs*189) mutation has been previously reported in association with RMFSL. These patients illustrate that, compared with RMFSL, BRAT1 mutations can result in both moderately severe presentations evident by later-onset epilepsy and survival past infancy, as well as milder presentations that include intellectual disability, ataxia/dyspraxia, and cerebellar atrophy. © 2016 Wiley Periodicals, Inc. PMID:27282546

  4. Mixed-phased particles in polar stratospheric ice clouds

    NASA Astrophysics Data System (ADS)

    Bogdan, Anatoli; Molina, Mario J.; Loerting, Thomas


    Keywords: polar stratospheric clouds (PSCs), ozone depletion, differential scanning calorimeter. The rate of chlorine activation reactions, which lead to ozone depletion in the winter/spring polar stratosphere (Molina, 1994), depends on the phase state of the surface of polar stratospheric cloud (PSC) ice crystals (McNeil et al., 2006). PSCs are thought to consist of solid ice and NAT (nitric acid trihydrate, HNO3× 3H2O) particles and supercooled HNO3/H2SO4/H2O droplets. The corresponding PSCs are called Type II, Ia, and Ib PSCs, respectively (Zondlo et al., 1998). Type II PSCs are formed in the Antarctic region below the ice frost point of 189 K by homogeneous freezing of HNO3/H2SO4/H2O droplets (Chang et al., 1999) with the excess of HNO3. The PSC ice crystals are thought to be solid. However, the fate of H+, NO3-, SO42- ions during freezing was not investigated. Our differential scanning calorimetry (DSC) studies of freezing emulsified HNO3/H2SO4/H2O droplets of sizes and compositions representative of the polar stratosphere demonstrate that during the freezing of the droplets, H+, NO3-, SO42- are expelled from the ice lattice. The expelled ions form a residual solution around the formed ice crystals. The residual solution does not freeze but transforms to glassy state at ~150 K (Bogdan et al., 2010). By contrast to glass-formation in these nitric-acid rich ternary mixtures the residual solution freezes in the case of sulphuric-acid rich ternary mixtures (Bogdan and Molina, 2009). For example, we can consider the phase separation into ice and a residual solution during the freezing of 23/3 wt% HNO3/H2SO4/H2O droplets. On cooling, ice is formed at ~189 K. This is inferred from the fact that the corresponding melting peak at ~248 K exactly matches the melting point of ice in the phase diagram of HNO3/H2SO4/H2O containing 3 wt % H2SO4. After the ice has formed, the glass transition occurs at Tg ≈ 150 K. The appearance of the glass transition indicates that the

  5. Assessment, design and control strategy development of a fuel cell hybrid electric vehicle for CSU's EcoCAR

    NASA Astrophysics Data System (ADS)

    Fox, Matthew D.

    Advanced automotive technology assessment and powertrain design are increasingly performed through modeling, simulation, and optimization. But technology assessments usually target many competing criteria making any individual optimization challenging and arbitrary. Further, independent design simulations and optimizations take considerable time to execute, and design constraints and objectives change throughout the design process. Changes in design considerations usually require re-processing of simulations and more time. In this thesis, these challenges are confronted through CSU's participation in the EcoCAR2 hybrid vehicle design competition. The complexity of the competition's design objectives leveraged development of a decision support system tool to aid in multi-criteria decision making across technologies and to perform powertrain optimization. To make the decision support system interactive, and bypass the problem of long simulation times, a new approach was taken. The result of this research is CSU's architecture selection and component sizing, which optimizes a composite objective function representing the competition score. The selected architecture is an electric vehicle with an onboard range extending hydrogen fuel cell system. The vehicle has a 145kW traction motor, 18.9kWh of lithium ion battery, a 15kW fuel cell system, and 5kg of hydrogen storage capacity. Finally, a control strategy was developed that improves the vehicles performance throughout the driving range under variable driving conditions. In conclusion, the design process used in this research is reviewed and evaluated against other common design methodologies. I conclude, through the highlighted case studies, that the approach is more comprehensive than other popular design methodologies and is likely to lead to a higher quality product. The upfront modeling work and decision support system formulation will pay off in superior and timely knowledge transfer and more informed design decisions. The hypothesis is supported by the three case studies examined in this thesis.


    NASA Astrophysics Data System (ADS)

    Biagi, P. F.; Castellana, L.; Maggipinto, T.; Ermini, A.


    Since 1996, the intensity of CLT (f=189 kHz, Sicily, Italy), MCO (f=216 kHz, France) and CZE (f=270 kHz, Czech Republic) broadcast signals has been collected with a ten minutes sampling rate by a receiver operating in a place located about 13 km far from the epicenter of the Abruzzo earthquake (M=6.3, April 6, 2009). During March 2009, the old receiver was substituted with a new one for measuring, with one minute sampling rate, the intensity of five VLF signals and five LF signals radiated by transmitters located in different zone of Europe. Two of the previous transmitters are included among them. In the period March 31-April 1 the intensity of the MCO radio signal dropped and this drop was observed only in this signal. The possibility that the drop was connected to problems in the transmitter or in the receiver was investigated and excluded. So, the drop indicates a defocusing of the radiated signal. Since none particular meteorological situation along the path transmitter-receiver happened, the defocusing must be related to other causes. The possibility that it is a precursor of the Abruzzo earthquake is presented. Beside, the flow rate of a natural spring located in the same place of the receiver is being sampled from 1992. During September-October 2008 the flow rate was abnormal with respect to all the previous periods. Also this anomaly takes the shape of a precursor of the Abruzzo earthquake. Probably, it is mainly related to the seismic sequence that started in the zone in the middle of January 2009 and that lasted up to the earthquake.

  7. Sorptive removal of trinitroglycerin (TNG) from water using nanostructured silica-based materials.


    Saad, Rabih; Thibutot, Sonia; Ampleman, Guy; Hawari, Jalal


    Trinitroglycerin (TNG), a nitrate ester, is widely used in the pharmaceutical industry for the treatment of angina pectoris (chest pain) and by the military for the manufacturing of dynamite and propellants. Currently, TNG is considered as a key environmental contaminant due to the discharge of wastewater tainted with the chemical from various military and pharmaceutical industries. The present study describes the use of a nanostructured silica material (Mobil Composite Material no. 48 [MCM-48]) prepared by mixing tetraethylorthosilicate (TEOS) and cetyltrimethylammonium bromide (CTAB) to remove TNG from water. The sorption of TNG onto MCM-48 rapidly reached equilibrium within 1 h. Sorption kinetics were best described using a pseudo-second order model, whereas sorption isotherms were best interpreted using the Langmuir model. The latter gave a maximum sorption capacity of 55.2 mg g(-1) at 40 degrees C. The enthalpy and entropy of TNG sorption onto MCM-48 were 1.89 kJ mol(-1) and 79.0 J mol(-1).K(-1), indicating the endothermic nature of the TNG sorption onto MCM-48. When MCM-48 was heated at 540 degrees C for 5 h, the resulting calcined material (absence of the surfactant) did not sorb TNG, suggesting that the surfactant component of the nanomaterial was responsible for TNG sorption. Finally, we found that MCM-48 lost approximately 30% of its original sorption capacity after five sorption-desorption cycles. In conclusion, the nanostructured silica based sorbent, with high sorption capacity and remarkable reusability, should constitute the basis for the development of an effective technology for the removal of TNG from contaminated water. PMID:20176831

  8. Crack growth rates and metallographic examinations of Alloy 600 and Alloy 82/182 from field components and laboratory materials tested in PWR environments.

    SciTech Connect

    Alexandreanu, B.; Chopra, O. K.; Shack, W. J.


    In light water reactors, components made of nickel-base alloys are susceptible to environmentally assisted cracking. This report summarizes the crack growth rate results and related metallography for field and laboratory-procured Alloy 600 and its weld alloys tested in pressurized water reactor (PWR) environments. The report also presents crack growth rate (CGR) results for a shielded-metal-arc weld of Alloy 182 in a simulated PWR environment as a function of temperature between 290 C and 350 C. These data were used to determine the activation energy for crack growth in Alloy 182 welds. The tests were performed by measuring the changes in the stress corrosion CGR as the temperatures were varied during the test. The difference in electrochemical potential between the specimen and the Ni/NiO line was maintained constant at each temperature by adjusting the hydrogen overpressure on the water supply tank. The CGR data as a function of temperature yielded activation energies of 252 kJ/mol for a double-J weld and 189 kJ/mol for a deep-groove weld. These values are in good agreement with the data reported in the literature. The data reported here and those in the literature suggest that the average activation energy for Alloy 182 welds is on the order of 220-230 kJ/mol, higher than the 130 kJ/mol commonly used for Alloy 600. The consequences of using a larger value of activation energy for SCC CGR data analysis are discussed.

  9. On-sky performance of a high resolution silicon immersion grating spectrometer

    NASA Astrophysics Data System (ADS)

    Ge, Jian; Powell, Scott; Zhao, Bo; Schofield, Sidney; Varosi, Frank; Warner, Craig; Liu, Jian; Sithajan, Sirinrat; Avner, Louis; Jakeman, Hali; Gittelmacher, Jakob A.; Yoder, William A.; Muterspaugh, Matthew; Williamson, Michael; Maxwell, J. E.


    High resolution infrared spectroscopy has been a major challenging task to accomplish in astronomy due to the enormous size and cost of IR spectrographs built with traditional gratings. A silicon immersion grating, due to its over three times high dispersion over a traditional reflective grating, offers a compact and low cost design of new generation IR high resolution spectrographs. Here we report the on-sky performance of the first silicon immersion grating spectrometer, called Florida IR Silicon immersion grating spectromeTer (FIRST), commissioned at the 2-meter Automatic Spectroscopic Telescope (AST) of Fairborn Observatory in Arizona in October 2013. The measured spectral resolution is R=50,000 with a 50 mm diameter spectrograph pupil and a blaze angle of 54.7 degree. The 1.4-1.8 μm wavelength region (the Red channel) is completely covered in a single exposure with a 2kx2k H2RG IR array while the 0.8-1.35 μm region is nearly completely covered by the cross-dispersed echelle mode (the Blue channel) at R=50,000 in a single exposure. The instrument is operated in a high vacuum (about 1 micro torr) and cryogenic temperatures (the bench at 189K and the detector at 87K) and with a precise temperature control. It is primarily used for high precision Doppler measurements (~3 m/s) of low mass M dwarf stars for the identification and characterization of extrasolar planets. A plan for a high cadence and high precision survey of habitable super-Earths around ~150 nearby M dwarfs and a major upgrade with integral field unit low resolution spectroscopy are also introduced.

  10. Simultaneous measurement of plantar pressure and shear forces in diabetic individuals.


    Perry, Julie E; Hall, James O; Davis, Brian L


    Plantar foot ulceration is a diabetic complication whose underlying causative factors are still not fully understood. The goal of the current work was to simultaneously record plantar pressure and shear and examine the interrelationship of these forces; specifically, if peak shear and pressure occurred at the same site/time and whether adjacent shear forces had a greater tendency to be directed towards or away from each other. A custom built 16 transducer array was used to record forefoot shear and pressure during gait initiation in a cohort of 12 neuropathic diabetic individuals. The individuals were barefoot and the transducers were covered with a 5 mm thick layer of Minorplast. The greatest pressure occurred in the medial metatarsal heads (189 kPa) and the greatest shear in the lateral metatarsal heads (33 kPa). The interaction of the shear forces revealed that the plantar tissue was stretched to a greater magnitude than it was bunched (24 kPa vs 12 kPa, averaged over all regions). Normal distributions were determined for stretching and bunching in both the medial-lateral and anterior-posterior directions. When shear and pressure were considered in combination, half of the neuropathic individuals had peak shear and pressure occurring at the same site. These peak stresses did not occur at the same time (average difference of 0.186 s). The results of this study help to further characterize tissue stresses experienced on the plantar surface of the foot during gait initiation in neuropathic diabetic individuals. PMID:11809586

  11. Heterogeneous reaction HOCl + HBr {r_arrow} BrCl + H{sub 2}O on ice films

    SciTech Connect

    Chu, L.; Chu, L.T.


    Heterogeneous reactions on the surface of polar stratospheric clouds (PSCs) are critical to an understanding of the annual appearance of the Antarctic ozone hole. The heterogeneous reaction HOCl + HBr(s) {r_arrow} BrCl + H{sub 2}O(s) on the ice surface at 189 and 220 K has been investigated in a flow reactor interfaced with a differentially pumped quadrupole mass spectrometer. Pseudo first-order decay of HOCl over the HBr-treated ice surfaces has been determined under the condition of P{sub HOCl} < P{sub HBr}. For the HBr partial pressure in the range of 1.1 {times} 10{sup {minus}7} to 6.6 {times} 10{sup {minus}5} Torr, the reaction probability ({gamma}{sub g}) was determined in the range of 0.06 to 0.38 at 189 K. The reaction probability is in the range of 0.01 to 0.07 at 220 K for HBr partial pressure from 7.2 {times} 10{sup {minus}7} to 1.3 {times} 10{sup {minus}5} Torr. The reaction probability was found to be strongly dependent on the ice surface temperature. The reaction probability is higher at the lower temperature than that at the warmer temperature and a mechanistic explanation is provided. The true reaction probabilities ({gamma}{sub t}) of the reaction were calculated using a pore diffusion model. The kinetic analysis indicates that the heterogeneous reaction of HOCl + HBr may follow the Eley-Rideal type of mechanism. Also, the heat of uptake of HOCl on ice was determined to be about {minus}8.5 {+-} 2 kcal/mol.

  12. Matrilysin-1 (MMP7) cleaves galectin-3 and inhibits wound healing in intestinal epithelial cells

    PubMed Central

    Puthenedam, Manjula; Wu, Feng; Shetye, Alysha; Michaels, Alex; Rhee, Ki-Jong; Kwon, John H


    Background Galectin-3 is an animal lectin that has been implicated in wound healing and is decreased in inflammatory bowel disease (IBD). Matrix metalloproteinase-7 (MMP7) also known as matrilysin-1, a protease shown to cleave extracellular matrix proteins, is highly expressed in IBD tissues, especially at the leading edge of gastrointestinal ulcers. The ability of MMP7 to cleave galectin-3 and influence wound healing has not been reported previously. Aim To determine whether MMP7 cleaves galectin-3 and modulates wound healing in intestinal epithelial cells. Methods The cleaved fragments of galectin-3 were identified by N-terminal sequencing and mass spectrometry. Western blotting was used to detect the cleaved galectin-3 products in a colonic epithelial cell line (T84 cells). Cell migration was studied by in vitro scratch method. Results We demonstrate for the first time that MMP7 cleaves galectin-3 in vitro, resulting in three cleaved fragments (20.2 kDa, 18.9 kDa and 15.5 kDa). Exogenous treatment of T84 cells with recombinant MMP7 resulted in the appearance of secreted galectin-3 cleavage fragments in the supernatant. MMP7 inhibited cell migration and resulted in wound retraction and the addition of MMP7 to galectin-3 abrogated the wound healing and cell migration induced by galectin-3. Conclusions We have demonstrated that galectin-3 is a substrate for MMP7. Cleavage of galectin-3 may be one mechanism by which MMP7 inhibits wound healing. This study has significance in understanding delayed wound healing in chronic intestinal diseases like intestinal ulcers and IBD where MMP7 protein expression is elevated with a decreased galectin-3 protein expression. PMID:20812334

  13. Isolation, structure, and surfactant properties of polysaccharides from Ulva lactuca L. from South China Sea.


    Tian, Hua; Yin, Xueqiong; Zeng, Qinghuan; Zhu, Li; Chen, Junhua


    Two polysaccharides (ULP1 and ULP2) were isolated through ultrasonic-assisted extraction from green seaweed Ulva lactuca L. which was collected from the South China Sea. The highest yield of 17.57% was obtained under the conditions of 2% NaOH, 90 °C, material/water mass ratio 1:80, liquid extraction 5h and subsequent ultrasound-assisted extraction 1h. The structure of ULPs were characterized with periodate oxidation followed by Smith degradation, (1)H NMR, (13)C NMR spectroscopy, FTIR, and GPC. The molecular weights of ULP1 and ULP2 were 189 kDa and 230 kDa, respectively. The structural characteristics of ULP1 and ULP2 were quite similar. They were composed of rhamnose, xylose, glucose, and glucuronic acid. The content of rhamnose, xylose, glucose, glucuronic acid, sulfate was 51.2%, 12.3%, 20.1%, 16.4%, 12.0% for ULP1, respectively, and 60.8%, 14.2%, 8.2%, 16.8%, 26.8%, respectively, for ULP2. Both ULP1 and ULP2 showed good surface activity. 5 mg/mL ULP1 (2.62×10(-2) mmol/L) decreased the water surface tension to 51.63 mN/m. The critical micellar concentration of ULP1 and ULP2 was 1.01 mg/mL (5.3×10(-3) mmol/L) and 1.14 mg/mL (5.0×10(-3) mmol/L), respectively. PMID:26026981

  14. Tensile failure behavior of plain carbon steels at elevated temperatures

    NASA Astrophysics Data System (ADS)

    Wray, P. J.


    The onset of tensile instability and the occurrence of fracture in plain carbon steels containing up to 1.89C has been examined in the temperature range 500 to 1300 °C and the strain-rate range 6 X lO-6 to 2 × 10-2 s-1. In the ferrite-plus-pearlite mixtures at temperatures below the eutectoid temperature, the work-hardening exponent decreases with increasing amount of pearlite, and there is a corresponding decrease in the Considére strain. However, the onset of necking is delayed to well beyond the Considére strain, and these mixtures are inherently ductile even at the eutectoid composition. In the austenite region, the general intrusion of dynamic recrystallization compctes with intergranular embrittlement at temperatures below about 1050 °C. The embrittlement is related to precipitation which takes place either during cooling (MnS) or at the deformation temperature [AIN, Nb (CN), etc.]. In hypereutectoid steels, the ductility of austenite-plus-cementite and pearlite-plus-cementite mixtures diminishes drastically with decreasing temperature and increasing amount of cementite. The areas of possible fracture modes are mapped in temperature-strain rate and temperature-carbon content space.

  15. Effect of molybdenum, vanadium, boron on mechanical properties of high chromium white cast iron in as-cast condition

    NASA Astrophysics Data System (ADS)

    Nurjaman, F.; Sumardi, S.; Shofi, A.; Aryati, M.; Suharno, B.


    In this experiment, the effect of the addition carbide forming elements on high chromium white cast iron, such as molybdenum, vanadium and boron on its mechanical properties and microstructure was investigated. The high chromium white cast iron was produced by casting process and formed in 50 mm size of grinding balls with several compositions. Characterization of these grinding balls was conducted by using some testing methods, such as: chemical and microstructure analysis, hardness, and impact test. From the results, the addition of molybdenum, vanadium, and boron on high chromium white cast iron provided a significant improvement on its hardness, but reduced its toughness. Molybdenum induced fully austenitic matrix and Mo2C formation among eutectic M7C3 carbide. Vanadium was dissolved in the matrix and carbide. While boron was played a role to form fine eutectic carbide. Grinding balls with 1.89 C-13.1 Cr-1.32 Mo-1.36 V-0.00051 B in as-cast condition had the highest hardness, which was caused by finer structure of eutectic carbide, needle like structure (upper bainite) matrix, and martensite on its carbide boundary.

  16. Appearance and possible homing of two species of sculpins in Maine tidepools

    USGS Publications Warehouse

    Muring, J.R.


    Two species of sculpins (Cottidae), the grubby, Myoxocephalus aenaeus, and the shorthorn sculpin, M. scorpius, were studied in rocky tidepools along the coast of Maine. Fishes were captured and measured during 116 sampling trips between 1979 and 1996. Both of these species of sculpins are from the northwestern Atlantic Ocean and are present in tidepools nearly every month of the year and are the only fish species found in Maine tidepools during winter. Both sculpin species are important components of tidepool ecosystems and dominate the rocky tidepool fish communities from late autumn to early spring, a time when other fish species decline in abundance or are absent. There was no apparent relationship between sculpin abundance and salinity, but the two species of Myoxocephalus were encountered in water temperatures of 1.5 to 18.9??C, with 55.0% of the shorthorn sculpins and 57.3% of the grubbies encountered in tidepools where water temperatures ranged from 12 to 15??C. Between 1988 and 1996, 102 individuals from both species were marked. Of these, 21.3% were recaptured, some repeatedly in the same tidepools and even at specific locations within tidepools over successive tidal cycles - an indication of homing behavior.

  17. Electrophysiological Characteristics of Six Mutations in hClC-1 of Korean Patients with Myotonia Congenita

    PubMed Central

    Ha, Kotdaji; Kim, Sung-Young; Hong, Chansik; Myeong, Jongyun; Shin, Jin-Hong; Kim, Dae-Seong; Jeon, Ju-Hong; So, Insuk


    ClC-1 is a member of a large family of voltage-gated chloride channels, abundantly expressed in human skeletal muscle. Mutations in ClC-1 are associated with myotonia congenita (MC) and result in loss of regulation of membrane excitability in skeletal muscle. We studied the electrophysiological characteristics of six mutants found among Korean MC patients, using patch clamp methods in HEK293 cells. Here, we found that the autosomal dominant mutants S189C and P480S displayed reduced chloride conductances compared to WT. Autosomal recessive mutant M128I did not show a typical rapid deactivation of Cl− currents. While sporadic mutant G523D displayed sustained activation of Cl− currents in the whole cell traces, the other sporadic mutants, M373L and M609K, demonstrated rapid deactivations. V1/2 of these mutants was shifted to more depolarizing potentials. In order to identify potential effects on gating processes, slow and fast gating was analyzed for each mutant. We show that slow gating of the mutants tends to be shifted toward more positive potentials in comparison to WT. Collectively, these six mutants found among Korean patients demonstrated modifications of channel gating behaviors and reduced chloride conductances that likely contribute to the physiologic changes of MC. PMID:24625573

  18. Linkage of an ABCC transporter to a single QTL that controls Ostrinia nubilalis larval resistance to the Bacillus thuringiensis Cry1Fa toxin.


    Coates, Brad S; Siegfried, Blair D


    Field evolved resistance of insect populations to Bacillus thuringiensis (Bt) crystalline (Cry) toxins expressed by crop plants has resulted in reduced control of insect feeding damage to field crops, and threatens the sustainability of Bt transgenic technologies. A single quantitative trait locus (QTL) that determines resistance in Ostrinia nubilalis larvae capable of surviving on reproductive stage transgenic corn that express the Bt Cry1Fa toxin was previously mapped to linkage group 12 (LG12) in a backcross pedigree. Fine mapping with high-throughput single nucleotide polymorphism (SNP) anchor markers, a candidate ABC transporter (abcc2) marker, and de novo mutations predicted from a genotyping-by-sequencing (GBS) data redefined a 268.8 cM LG12. The single QTL on LG12 spanned an approximate 46.1 cM region, in which marker 02302.286 and abcc2 were ≤ 2.81 cM, and the GBS marker 697 was an estimated 1.89 cM distant from the causal genetic factor. This positional mapping data showed that an O. nubilalis genome region encoding an abcc2 transporter is in proximity to a single QTL involved in the inheritance of Cry1F resistance, and will assist in the future identification the mutation(s) involved with this phenotype. PMID:26093031

  19. Estimation of computed tomography dose index in cone beam computed tomography: MOSFET measurements and Monte Carlo simulations.


    Kim, Sangroh; Yoshizumi, Terry; Toncheva, Greta; Yoo, Sua; Yin, Fang-Fang; Frush, Donald


    To address the lack of accurate dose estimation method in cone beam computed tomography (CBCT), we performed point dose metal oxide semiconductor field-effect transistor (MOSFET) measurements and Monte Carlo (MC) simulations. A Varian On-Board Imager (OBI) was employed to measure point doses in the polymethyl methacrylate (PMMA) CT phantoms with MOSFETs for standard and low dose modes. A MC model of the OBI x-ray tube was developed using BEAMnrc/EGSnrc MC system and validated by the half value layer, x-ray spectrum and lateral and depth dose profiles. We compared the weighted computed tomography dose index (CTDIw) between MOSFET measurements and MC simulations. The CTDIw was found to be 8.39 cGy for the head scan and 4.58 cGy for the body scan from the MOSFET measurements in standard dose mode, and 1.89 cGy for the head and 1.11 cGy for the body in low dose mode, respectively. The CTDIw from MC compared well to the MOSFET measurements within 5% differences. In conclusion, a MC model for Varian CBCT has been established and this approach may be easily extended from the CBCT geometry to multi-detector CT geometry. PMID:20386198

  20. BCR-ABL kinase domain mutations, including 2 novel mutations in imatinib resistant Malaysian chronic myeloid leukemia patients-Frequency and clinical outcome.


    Elias, Marjanu Hikmah; Baba, Abdul Aziz; Azlan, Husin; Rosline, Hassan; Sim, Goh Ai; Padmini, Menon; Fadilah, S Abdul Wahid; Ankathil, Ravindran


    Discovery of imatinib mesylate (IM) as the targeted BCR-ABL protein tyrosine kinase inhibitor (TKI) has resulted in its use as the frontline therapy for chronic myeloid leukemia (CML) across the world. Although high response rates are observed in CML patients who receive IM treatment, a significant number of patients develop resistance to IM. Resistance to IM in patients has been associated with a heterogeneous array of mechanisms of which point mutations within the ABL tyrosine kinase domain (TKD) are the frequently documented. The types and frequencies of mutations reported in different population studies have shown wide variability. We screened 125 Malaysian CML patients on IM therapy who showed either TKI refractory or resistance to IM to investigate the frequency and pattern of BCR-ABL kinase domain mutations among Malaysian CML patients undergoing IM therapy and to determine the clinical significance. Mutational screening using denaturing high performance liquid chromatography (dHPLC) followed by DNA sequencing was performed on 125 IM resistant Malaysian CML patients. Mutations were detected in 28 patients (22.4%). Fifteen different types of mutations (T315I, E255K, G250E, M351T, F359C, G251E, Y253H, V289F, E355G, N368S, L387M, H369R, A397P, E355A, D276G), including 2 novel mutations were identified, with T315I as the predominant type of mutation. The data generated from clinical and molecular parameters studied were correlated with the survival of CML patients. Patients with Y253H, M351T and E355G TKD mutations showed poorer prognosis compared to those without mutation. Interestingly, when the prognostic impact of the observed mutations was compared inter-individually, E355G and Y253H mutations were associated with more adverse prognosis and shorter survival (P=0.025 and 0.005 respectively) than T315I mutation. Results suggest that apart from those mutations occurring in the three crucial regions (catalytic domain, P-loop and activation-loop), other rare

  1. Selected cysteine point mutations confer mercurial sensitivity to the mercurial-insensitive water channel MIWC/AQP-4.


    Shi, L B; Verkman, A S


    The mercurial-insensitive water channel (MIWC or AQP-4) is a 30-32 kDA integral membrane protein expressed widely in fluid-transporting epithelia [Hasegawa et al. (1994) J. Biol. Chem. 269, 5497-5500]. To investigate the mercurial insensitivity and key residues involved in MIWC-mediated water transport, amino acids just proximal to the conserved NPA motifs (residues 69-74 and 187-190) were mutated individually to cysteine. Complementary RNAs were expressed in Xenopus oocytes for assay of osmotic water permeability (Pf) and HgCl2 inhibition dose-response. Oocytes expressing the cysteine mutants were highly water permeable, with Pf values (24-33 x 10(-3) cm/s) not different from that of wild-type (WT) MIWC. Pf was reversibly inhibited by HgCl2 in mutants S70C, G71C, G72C, H73C, and S189C but insensitive to HgCl2 in the other mutants. K1/2 values for 50% inhibition of Pf by HgCl2 were as follows (in millimolar): 0.40 (S70C), 0.36 (G71C), 0.14 (G72C), 0.45 (H73C), 0.24 (S189C), and > 1 for WT MIWC and the other mutants. To test the hypothesis that these residues are near the MIWC aqueous pore, residues 72 and 188 were mutated individually to the larger amino acid tryptophan. Pf in oocytes expressing mutants G72W or A188W (1.3-1.4 x 10(-3) cm/s) was not greater than that in water-injected oocytes even though these proteins were expressed at the oocyte plasma membrane as shown by quantitative immunofluorescence. Coinjection of cRNAs encoding WT MIWC and G72W or A188W indicated a dominant negative effect; Pf (x 10(-3) cm/s) was 22 (0.25 ng of WT), 10 (0.25 ng of WT + 0.25 ng of G72W), and 12 (0.25 ng of WT + 0.25 ng of A188W). Taken together, these results suggest the MIWC is mercurial-insensitive because of absence of a cysteine residue near the NPA motifs and that residues 70-73 and 189 are located at or near the MIWC aqueous pore. In contrast to previous data for the channel-forming integral protein of 28kDa (CHIP28), the finding of a dominant negative phenotype for

  2. Hybrid assembly of CPMV viruses and surface characteristics of different mutants.


    Portney, N G; Destito, G; Manchester, M; Ozkan, M


    There is a trend toward viral-based hybrid systems to furnish viral nanoparticles with enhanced features, for function beyond a delivery vehicle. Such hybrids have included Nanogold for microwave release, quantum dots and fluorescent moieties, to provide simultaneous imaging capabilities, and iron oxide particles for image enhancement in MRI. Other systems are the subject of ongoing and vigorous research. Nanogold surface decoration of cow pea mosaic virus (CPMV) to form NG-CPMV hybrids were explored to release fluorescent carriers using microwave energy as a model system in this presentation. Thus, emergent viral-based systems will have increasingly sophisticated architectures to provide versatile functions. Zeta potential (ZP) is a powerful tool to probe the electrostatic surface potential of biological materials and remains an untapped method for studying the interaction of nanoparticles with cells. An enormous effort is being made to study nanoparticle-cell interaction, but current throughput solutions (e.g., flow cytometry) cannot differentiate between surface-attached or endocytosed particles, while standard fluorescence microscopy is tedious and costly. CPMV-WT and other mutants (CPMV-T184C, CPMV-L189C) were studied using ZP methods and rationalized based on variations in their surface exposed residue character. Understanding such subtle changes can discretely alter the cell surface interactions due to charge affinity. Applying sensitive ZP measurements on viral nanoparticles is useful to elucidating the characteristics of the surface charge and the potential interaction modes with cell surfaces they may encounter. Thus, ZP can be a unique and efficient tool for studying cell-virus interactions and aid in development of future therapeutic strategies. PMID:19198570

  3. Conservation of antigen components from two recombinant hybrid proteins protective against malaria.

    PubMed Central

    Knapp, B; Nau, U; Hundt, E


    Recently, we have shown that two hybrid proteins carrying partial sequences of the blood-stage antigens SERP, HRPII, and MSAI from Plasmodium falciparum confer protective immunity on Aotus monkeys against an experimental parasite infection (B. Knapp, E. Hundt, B. Enders, and H. A. Küpper, Infect. Immun. 60:2397-2401, 1992). The malarial components of the hybrid proteins consist of amino acid residues 630 to 892 of SERP, amino acid residues 146 to 260 of MSAI, and the 189 C-terminal residues of HRPII. We have studied the diversity of these protein regions in field isolates of P. falciparum. Genomic DNA was extracted from the blood of six donors from two different areas where malaria is endemic. The gene regions of SERP and MSAI coding for the corresponding sequences of the protective hybrid proteins and the exon II region of the HRPII gene were amplified by polymerase chain reaction and sequenced. All three regions were found to be highly conserved. In the 262-amino-acid fragment of SERP, one single conservative amino acid substitution was found. The exon II region of HRPII showed only a slight variability in number and arrangement of the repeat units. The 115-amino-acid fragment of MSAI which is located within an N-terminal region known to be conserved among different parasite strains was shown to be the most variable among the vaccine components: amino acid substitutions were found in 14 different positions of this MSAI region when both laboratory strains and field isolates were compared. PMID:8432609

  4. Stereotactic Aspiration-Thrombolysis of Intracerebral Hemorrhage and its Impact on Perihematoma Brain Edema

    PubMed Central

    Barrett, Ryan J.; Keyl, Penelope M.; Hanley, Daniel F.; Johnson, Robert R.


    Background Recent reports suggest that when thrombolytic agents are administered within the clot, lysis rate accelerates at the expense of increased risk of worsening edema. To test this hypothesis, we report on the volumetric analysis of (1) the intraparenchymal hematoma and, (2) perihematomal edema in a cohort of ICH patients treated with intraclot rtPA. Methods A convenience sample of highly selected ICH patients underwent frameless stereotactic aspiration and thrombolysis (FAST) of the clot. Two milligrams of rtPA were administered every 12 h until ICH volume ≤10 cc, or catheter fenestrations were no longer in continuity with the clot. ICH and perihematomal edema volumes were calculated from CT scans. Using random effects linear regression we estimated the rate of hematoma and edema volume resolution as well as their relationship during the first 8 days of lytic therapy. Results Fifteen patients were treated, mean age: 60.7 years, median time from ictus to FAST: 1 (range 0–3) day. Using a random effects model that considered volume resolution over the first 8 days following lytic therapy we found that the both percentage hematoma and percentage perihematoma edema resolution per day were quadratic with respect to time. Percentage residual hematoma volume on day K = 97.7% − [24.36%*K] + [1.89%*K2]; P < 0.001 for both terms. Percentage residual edema on day K = 97.4% − [13.94%*K] + [1.30%*K2]; P < 0.001 for K and P = 0.01 for K2. Examination of each patient’s volume data suggests that there exists a strong direct relationship between perihematoma edema volume and same day hematoma volume. Conclusions In this cohort of ICH patients treated using FAST, volumetric analysis of ICH and perihematomal edema seems to suggest that local use of rtPA does not exacerbate brain edema formation. Furthermore, there seems to be a strong association between reduction in ICH volume and reduction in edema volume, as would be expected following the concept of “hemotoxicity” postulated by some investigators. PMID:18327659

  5. Migration of antimony from PET bottles into beverages: determination of the activation energy of diffusion and migration modelling compared with literature data.


    Welle, F; Franz, R


    Plastics bottles made from polyethylene terephthalate (PET) are increasingly used for soft drinks, mineral water, juices and beer. In this study a literature review is presented concerning antimony levels found both in PET materials as well as in foods and food simulants. On the other hand, 67 PET samples from the European bottle market were investigated for their residual antimony concentrations. A mean value of 224 ± 32 mg kg(-1) was found, the median was 220 mg kg(-1). Diffusion coefficients for antimony in PET bottle materials were experimentally determined at different temperature between 105 and 150°C. From these data, the activation energy of diffusion for antimony species from the PET bottle wall into beverages and food simulants was calculated. The obtained value of 189 kJ mol(-1) was found to be in good agreement with published data on PET microwave trays (184 kJ mol(-1)). Based on these results, the migration of antimony into beverages was predicted by mathematical migration modelling for different surface/volume ratios and antimony bottle wall concentrations. The results were compared with literature data as well as international legal limits and guidelines values for drinking water and the migration limit set from food packaging legislation. It was concluded that antimony levels in beverages due to migration from PET bottles manufactured according to the state of the art can never reach or exceed the European-specific migration limit of 40 microg kg(-1). Maximum migration levels caused by room-temperature storage even after 3 years will never be essentially higher than 2.5 microg kg(-1) and in any case will be below the European limit of 5 microg kg(-1) for drinking water. The results of this study confirm that the exposure of the consumer by antimony migration from PET bottles into beverages and even into edible oils reaches approximately 1% of the current tolerable daily intake (TDI) established by World Health Organisation (WHO). Having

  6. Magnetic interactions in equi-atomic rare-earth intermetallic alloys RScGe (R = Ce, Pr, Nd and Gd) studied by time differential perturbed angular correlation spectroscopy and ab initio calculations

    NASA Astrophysics Data System (ADS)

    Mishra, S N


    Applying the time differential perturbed angular correlation (TDPAC) technique we have measured electric and magnetic hyperfine fields of the 111Cd impurity in equi-atomic rare-earth intermetallic alloys RScGe (R = Ce, Pr and Gd) showing antiferro- and ferromagnetism with unusually high ordering temperatures. The Cd nuclei occupying the Sc site show high magnetic hyperfine fields with saturation values Bhf(0) = 21 kG, 45 kG and 189 kG in CeScGe, PrScGe and GdScGe, respectively. By comparing the results with the hyperfine field data of Cd in rare-earth metals and estimations from the RKKY model, we find evidence for the presence of additional spin density at the probe nucleus, possibly due to spin polarization of Sc d band electrons. The principal electric field gradient component Vzz in CeScGe, PrScGe and GdScGe has been determined to be 5.3 × 1021 V m-2, 5.5 × 1021 V m-2 and 5.6 × 1021 V m-2, respectively. Supplementing the experimental measurements, we have carried out ab initio calculations for pure and Cd-doped RScGe compounds with R = Ce, Pr, Nd and Gd using the full potential linearized augmented plane wave (FLAPW) method based on density functional theory (DFT). From the total energies calculated with and without spin polarization we find ferrimagnetic ground states for CeScGe and PrScGe while NdScGe and GdScGe are ferromagnetic. In addition, we find a sizable magnetic moment at the Sc site, increasing from ≈0.10 μB in CeScGe to ≈0.3 μB in GdScGe, confirming the spin polarization of Sc d band electrons. The calculated electric field gradient and magnetic hyperfine fields of the Cd impurity closely agree with the experimental values. We believe spin polarization of Sc 3d band electrons, strongly hybridized with spin polarized 5d band electrons of the rare-earth, enables a long range Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between RE 4f moments which in turn leads to high magnetic ordering temperatures in RScGe compounds.

  7. Possible earthquake precursors revealed by LF radio signals

    NASA Astrophysics Data System (ADS)

    Biagi, P. F.; Piccolo, R.; Ermini, A.; Martellucci, S.; Bellecci, C.; Hayakawa, M.; Capozzi, V.; Kingsley, S. P.

    Among radio signals, low frequency (LF) radio signals lie in the band between 30-300 kHz. Monitoring equipment with the ability to measure the electric strength of such signals at field sites, were designed and assembled in Italy. From 1993 onwards, the electric field strength of the MCO (216 kHz, France) broadcasting station has been collecting measurements at two sites in central Italy that were chosen according to very low noise levels. At the end of 1996, radio signals from the CLT (189 kHz, Italy) and CZE (270 kHz, Czech Republic) broadcasting stations were included in the measurements. Meteorological data from central Italy were also collected over the same time period in order to study the influence of weather conditions on the experimental measurements. During the monitoring period, we observed some evident attenuation of the electric field strength in some of the radio signals at some of the receivers. The duration of the attenuation observed was several days, so it could possibly be related to particular meteorological conditions. On the other hand, this phenomenon might represent precursors of moderate (3.0 < M < 3.5) earthquakes that occurred near the receivers (within 50 km) along the transmitter-receiver path. In this case, it is possible that the pre-seismic processes could have produced irregularities in the troposphere, such as ducts, reflecting layers and scattering zones, so that some local troposphere defocusing of the radio signals might have occurred. These observations were related only to moderate earthquakes and in these cases, suitable meteorological conditions were probably needed to observe the effect. Between February - March 1998, we observed at one measuring site, a significant increase in the CZE electric field strength. Unfortunately, we could not use the data of the other receiver in this case, due to frequent interruptions in the data set. The increase might have been a precursor of the strong seismic sequence (M = 5.0-6.0) that

  8. Variations in a LF radio-signal on the occasion of the recent seismic and volcanic activity in southern Italy

    NASA Astrophysics Data System (ADS)

    Biagi, P. F.; Piccolo, R.; Ermini, A.; Martellucci, S.; Bellecci, C.; Perna, G.; Capozzi, V.; Molchanov, O. A.; Hayakawa, M.


    Low Frequency (LF) radio signals lie in the band 30-300 kHz. The electric field strength of three LF broadcasting stations - CLT (f=189 kHz, Sicily, Italy), MCO (f=216 kHz, France) and CZE (f=270 kHz, Czech Republic) - has been monitored since 1997 with a sampling frequency of ten minutes at a site named AS and located in central Italy. During September-November 2002, we observed significant decreases in the electric field strength of the CLT broadcasting station. A similar effect does not seem to be present on the MCO and CZE radio signals. On September 6 an earthquake (M=5.6) occurred offshore, about 40km far from Palermo city (Sicily), starting a seismic crisis for more than one month; the strongest (M=4.6) aftershock occurred on September 27. On October 27, the Etna volcano (Sicily) started an eruption that in December was still active. Nearby several earthquakes occurred, the main ones with M=4.1-4.3. On October 31, an earthquake with M=5.4 occurred at the border between Molise and Puglia regions (Southern Italy) and under a collapsed school several children died. The CLT radio-signal decreases we observed appear clearly related to the previous seismic and volcanic activity with some possible premonitory behaviour. The LF signals are characterised by the ground-wave and the skywave propagation modes. The daytime electric field strength is lower than at night because the skywave is greatly attenuated by the lower ionosphere and the ground-wave alone is providing the signal which is faint. At night-time the low attenuation of the lower ionosphere permits an increase of 10-15 dB in the skywave signal such that the received signal is practically all due to the skywave propagation. The decreases in CLT radio-signal we mentioned previously seem to be related mainly to a reduction of the electric field strength of the ground wave. So changes in the ground conductivity seem to be the main candidates to justify the phenomenology we observed.

  9. Ozone loss rates in the Arctic winter stratosphere during 1994-2000 derived from POAM II/III and ILAS observations: Implications for relationships among ozone loss, PSC occurrence, and temperature

    NASA Astrophysics Data System (ADS)

    Terao, Yukio; Sugita, Takafumi; Sasano, Yasuhiro


    Quantitative chemical ozone loss rates at the 475 K isentropic surface inside the Arctic polar vortex are evaluated for six winters (January through March) using a satellite-based Match technique. Satellite observational data are taken from the Polar Ozone and Aerosol Measurement (POAM) II for 1994-1996, the Improved Limb Atmospheric Spectrometer (ILAS) for 1997, and the POAM III for 1999-2000. The largest ozone loss rates were observed in the end of January 1995 (˜50 ± 20 ppbv d-1), February 1996 (˜40-50 ± 15 ppbv d-1), February 1997 (˜40 ± 8 ppbv d-1), January 2000 (˜60 ± 30 ppbv d-1), and early March 2000 (˜40 ± 10 ppbv d-1). The probability of polar stratospheric cloud (PSC) existence is estimated using aerosol extinction coefficient data from POAM II/III and ILAS. Ozone loss and the PSC probability are strongly correlated and an absolute increase of 10% in the PSC probability is found to amplify the chemical ozone loss rate during Arctic winter by approximately 25 ± 6 ppbv per day or 3.2 ± 0.7 ppbv per sunlit hour. Relationships between average Arctic winter ozone loss rates and various PSC- and temperature-related indices are investigated, including the area of polar vortex that is colder than the threshold temperature for PSC existence (APSC), the PSC formation potential (PFP), and the potential for activation of chlorine (PACl). Of these three, PACl provides the best proxy representation of interannual variability in Arctic ozone loss at the 475 K level. Large ozone loss occurred primarily for air masses that experienced low temperatures between 187 K and 195 K within the previous 10 days and the ozone loss rates clearly increase with decreasing the minimum temperature. The particularly large ozone losses of ˜9 ± 3 ppbv per sunlit hour in February 1996 and January 2000 were associated with low minimum temperatures of 187-189 K, simultaneously with high PSC probabilities.

  10. Laboratory Studies of Model Stratospheric Aerosol Films Using Fourier Transform Infrared Spectroscopy.

    NASA Astrophysics Data System (ADS)

    Middlebrook, Ann Marie

    Heterogeneous chemistry plays an important role in the balance of stratospheric ozone. Although the chemical composition and phase of stratospheric aerosols affect their heterogeneous reactivity, these quantities have not been firmly established. Stratospheric sulfate aerosols (SSAs), found globally, are composed of mixtures of sulfuric acid and water. Type I polar stratospheric clouds (PSCs) composed of nitric acid and water can form when temperatures drop to {~}193 K, whereas Type II PSCs composed of pure ice form at or below the ice frost point ({~}189 K). This thesis focuses on using Fourier transform infrared (FTIR) spectroscopy to determine the likely composition and phase of stratospheric particles by examining thin nitric-acid/ice and sulfuric-acid/water films representative of polar and global stratospheric aerosols, respectively. First, we measured the composition of FTIR-characterized nitric-acid/ice films using mass spectrometry. Results confirmed the infrared assignments of nitric acid monohydrate (NAM), dihydrate (NAD), and amorphous HNO_3 /H_2O films. We also observed two infrared spectra for nitric acid trihydrate ( alpha- and beta-NAT). Using optical interference measurements at lambda = 632 nm, we obtained the real refractive indices for amorphous H_2O/HNO_3 (from 1.31 for dilute HNO_3 to 1.49 for pure HNO_3), NAM (1.53), alpha-NAT (1.51), beta -NAT (>=1.46), and ice (1.30) films. We then performed cooling experiments to determine which nitric-acid/ice might form in the stratosphere. Under stratospheric water and nitric acid partial pressures, either amorphous 3:1 H_2O:HNO _3 or beta-NAT films formed at temperatures above the ice frost point. Other experiments indicated that beta-NAT is the most stable nitric acid hydrate under stratospheric conditions. Thus we believe that Type I PSCs are composed of beta-NAT crystals. To mimic phase changes of SSAs, we subjected liquid sulfuric acid films to temperature cycles in the presence of water. While

  11. Competing hydrogen-bonding patterns and phase transitions of 1,2-diaminoethane at varied temperature and pressure.


    Budzianowski, Armand; Olejniczak, Anna; Katrusiak, Andrzej


    1,2-diaminoethane has been in-situ pressure- and temperature-frozen; apart from two known low-temperature phases, Ialpha and II, three new phases, Ibeta, Igamma and III, have been observed and their structures determined by X-ray diffraction. The measurements at 0.1 MPa were carried out at 274, 243 and 224 K, and 296 K measurements were made at 0.15 GPa (phase Ialpha), at 0.3 and 1.1 GPa (phase Ibeta), at 1.5 GPa (phase Igamma), and at 0.2, 0.3 and 0.5 GPa (phase III). All these phases are monoclinic, space group P2(1)/c, but the unit-cell dimension of phases Ialpha and III are very different at 296 K: aIalpha=5.078 (5), bIalpha=7.204 (8), cIalpha=5.528 (20) A, betaIalpha=115.2 (2) degrees at 0.15 GPa, and aIII=5.10 (3), bIII=5.212 (2), cIII=7.262 (12) A, betaIII=111.6 (4) degrees at 0.2 GPa, respectively; in both phases Z=2. An ambient-pressure low-temperature phase II has been observed below 189 K. Discontinuities in the unit-cell dimensions and in the N...N distance mark the isostructural transition between phases Ialpha and Ibeta at 0.2 GPa, which can be attributed to a damping process of the NH2 group rotations. In phase Igamma the unit-cell parameter a doubles and Z increases to 4. The molecule has inversion symmetry in all the structures determined. 1,2-Diaminoethane can be considered as a simple structural ice analogue, but with NH...N hydrogen bonds and with the H-atom donors (four in one molecule) in excess over H-atom acceptors (two per molecule). Thus, the transformations of 1,2-diaminoethane phases involving the conformational dynamics affect the hydrogen-bonding geometry and molecular association in the crystal. The 1,2-diaminoethane:1,2-dihydroxyethane mixture has been separated by pressure-freezing, and a solid 1,2-diaminoethane crystal in liquid 1,2-dihyroxyethane has been obtained. PMID:17108663

  12. Sequence and phylogenetic analysis of highly pathogenic avian influenza H5N1 viruses isolated during 2006–2008 outbreaks in Pakistan reveals genetic diversity

    PubMed Central


    Background Since the first outbreak recorded in northern areas of Pakistan in early 2006, highly pathogenic avian influenza H5N1 viruses were isolated from commercial poultry and wild/domestic birds from different areas of Pakistan up to July 2008. Different isolates of H5N1 were sequenced to explore the genetic diversity of these viruses. Results Phylogenetic analysis revealed close clustering and highest sequence identity in all 8 genes to HPAI H5N1 isolates belonging to unified H5 clade 2.2, sub-lineage EMA-3 recovered from Afghanistan during the same time period. Two subgroups within Pakistani H5N1 viruses, from domestic and wild birds, were observed on the basis of their sequence homology and mutations. HPAI motif, preferred receptor specificity for α-(2, 3) linkages, potential N-linked glycosylation sites and an additional glycosylation site at the globular head of HA protein of four Pakistani H5N1 isolates. While, the amino acids associated with sensitivities to various antiviral drugs (Oseltamivir, Zanamivir, Amantadine) were found conserved for the Pakistani H5N1 isolates. Conspicuously, some important mutations observed at critical positions of antigenic sites (S141P, D155S, R162I & P181S) and at receptor binding pocket (A185T, R189K & S217P) of HA-1. A high sequence similarity between Pakistani HP H5N1 and LP H9N2 viruses was also observed. Avian like host specific markers with the exception of E627K in PB2, K356R in PA, V33I in NP, I28V in M2 and L107F in NS2 proteins were also observed. Conclusions Various point mutations in different genes of H5 viruses from Pakistan were observed during its circulation in the field. The outbreaks started in Khyber Pakhtoon Khawa (North West) province in 2006 and spread to the Southern regions over a period of time. Though migratory birds may have a role for this continued endemicity of clade 2.2 H5N1 viruses during 2006–2008 in Pakistan, the possibility of their transmission through legal or illegal poultry trade

  13. A novel copper(II) coordination at His186 in full-length murine prion protein

    SciTech Connect

    Watanabe, Yasuko; Hiraoka, Wakako; Igarashi, Manabu; Ito, Kimihito; Shimoyama, Yuhei; Horiuchi, Motohiro; Yamamori, Tohru; Yasui, Hironobu; Kuwabara, Mikinori; Inagaki, Fuyuhiko; Inanami, Osamu


    To explore Cu(II) ion coordination by His{sup 186} in the C-terminal domain of full-length prion protein (moPrP), we utilized the magnetic dipolar interaction between a paramagnetic metal, Cu(II) ion, and a spin probe introduced in the neighborhood of the postulated binding site by the spin labeling technique (SDSL technique). Six moPrP mutants, moPrP(D143C), moPrP(Y148C), moPrP(E151C), moPrP(Y156C), moPrP(T189C), and moPrP(Y156C,H186A), were reacted with a methane thiosulfonate spin probe and a nitroxide residue (R1) was created in the binding site of each one. Line broadening of the ESR spectra was induced in the presence of Cu(II) ions in moPrP(Y148R1), moPrP(Y151R1), moPrP(Y156R1), and moPrP(T189R1) but not moPrP(D143R1). This line broadening indicated the presence of electron-electron dipolar interaction between Cu(II) and the nitroxide spin probe, suggesting that each interspin distance was within 20 A. The interspin distance ranges between Cu(II) and the spin probes of moPrP(Y148R1), moPrP(Y151R1), moPrP(Y156R1), and moPrP(T189R1) were estimated to be 12.1 A, 18.1 A, 10.7 A, and 8.4 A, respectively. In moPrP(Y156R1,H186A), line broadening between Cu(II) and the spin probe was not observed. These results suggest that a novel Cu(II) binding site is involved in His186 in the Helix2 region of the C-terminal domain of moPrP{sup C}.

  14. Self-Propagating Frontal Polymerization in Water at Ambient Pressure

    NASA Technical Reports Server (NTRS)

    Olten, Nesrin; Kraigsley, Alison; Ronney, Paul D.


    Advances in polymer chemistry have led to the development of monomers and initiation agents that enable propagating free-radical polymerization fronts to exist. These fronts are driven by the exothermicity of the polymerization reaction and the transport of heat from the polymerized product to the reactant monomer/solvent/initiator solution. The thermal energy transported to the reactant solution causes the initiator to decompose, yielding free radicals, which start the free radical polymerization process as discussed in recent reviews. The use of polymerization processes based on propagating fronts has numerous applications. Perhaps the most important of these is that it enables rapid curing of polymers without external heating since the polymerization process itself provides the high temperatures necessary to initiate and sustain polymerization. This process also enables more uniform curing of arbitrarily thick samples since it does not rely on heat transfer from an external source, which will necessarily cause the temperature history of the sample to vary with distance from the surface according to a diffusion-like process. Frontal polymerization also enables filling and sealing of structures having cavities of arbitrary shape without having to externally heat the structure. Water at atmospheric pressure is most convenient solvent to employ and the most important for practical applications (because of the cost and environmental issues associated with DMSO and other solvents). Nevertheless, to our knowledge, steady, self-propagating polymerization fronts have not been reported in water at atmospheric pressure. Currently, polymerization fronts require a high boiling point solvent (either water at high pressures or an alternative solvent such as dimethyl sulfoxide (DMSO) (boiling point 189 C at atmospheric pressure.) Early work on frontal polymerization, employed pressures up to 5000 atm in order to avoid boiling of the monomer/solvent/initiator solution. High

  15. Swashplateless Helicopter Experimental Investigation: Primary Control with Trailing Edge Flaps Actuated with Piezobenders

    NASA Astrophysics Data System (ADS)

    Copp, Peter

    Helicopter rotor primary control is conventionally carried out using a swashplate with pitch links. Eliminating the swashplate promises to reduce the helicopter's parasitic power in high speed forward flight, as well as may lead to a hydraulic-less vehicle. A Mach-scale swashplateless rotor is designed with integrated piezobender-actuated trailing edge flaps and systematically tested on the benchtop, in the vacuum chamber and on the hoverstand. The blade is nominally based on the UH-60 rotor with a hover tip Mach number of 0.64. The blade diameter is 66 inches requiring 2400 RPM for Mach scale simulation. The rotor hub is modified to reduce the blade fundamental torsional frequency to less than 2.0/rev by replacing the rigid pitch links with linear springs, which results in an increase of the blade pitching response to the trailing edge flaps. Piezoelectric multilayer benders provide the necessary bandwidth, stroke and stiffness to drive the flaps for primary control while fitting inside the blade profile and withstanding the high centrifugal forces. This work focuses on several key issues. A piezobender designed from a soft piezoelectric material, PZT-5K4, is constructed. The new material is used to construct multi-layer benders with increased stroke for the same stiffness relative to hard materials such as PZT-5H2. Each layer has a thickness of 10 mils. The soft material with gold electrodes requires a different bonding method than hard material with nickel electrodes. With this new bonding method, the measured stiffness matches precisely the predicted stiffness for a 12 layer bender with 1.26 inch length and 1.0 inch width with a stiffness of 1.04 lb/mil. The final in-blade bender has a length of 1.38 inches and 1.0 inch width with a stiffness of 0.325 lb/mil and stroke of 20.2 mils for an energy output of 66.3 lb-mil. The behavior of piezobenders under very high electric fields is investigated. High field means +18.9 kV/cm (limited by arcing in air) and -3.54kV/cm (limited by depoling). An undocumented phenomenon is found called bender relaxation where the benders lose over half of their initial DC stroke over time. While the bender stiffness is shown not to change with electric field, the DC stroke is significantly less than AC stroke. A two-bladed Mach-scale rotor is constructed with each blade containing 2 flaps each actuated by a single piezobender. Each flap is 26.5% chord and 14% span for a total of 28% span centered at 75% of the blade radius. Flap motion of greater than 10 degrees half peak-peak is obtained for all 4 flaps at 900 RPM on the hoverstand. So, the flaps show promise for the Mach-scale rotor speed of 2400 RPM. A PID loop is implemented for closed loop control of flap amplitude and mean position. On the hoverstand at 900 RPM, the swashplateless concept is demonstrated. The linear springs used to lower the torsional frequency are shown to have minimum friction during rotation. 1/rev blade pitching of +/-1 degree is achieved at a torsional frequency of 1.5/rev for each blade. At resonance, the blade pitching for each blade is greater than +/-4 degrees. Primary control is demonstrated by measuring hub forces and moments. At resonance state, the flaps in conjunction with the blade pitching provide +/-15 lbs of normal force at a mean lift of 15 lbs yielding +/-100% lift authority. Significant hub forces and moments are produced as well. For a production swashplateless helicopter, it may be prudent to eliminate the pitch links by reducing the blade structural stiffness. A novel wire sensor system network is proposed in order to measure blade elastic flap bending, lead-lag bending and torsion. The theory for measuring blade twist is rigorously derived. A blade is constructed with the wire sensor network and validated on the benchtop for blade elastic bending and twist. This work is a step forward in achieving a swashplateless rotor system. Not only would this reduce drag in high speed forward flight, but it would lead to a hydraulic-less rotorcraft. This would be a major step in vertical flight aviation.

  16. The Blob, the Very Rare Massive Star and the Two Populations

    NASA Astrophysics Data System (ADS)


    The nebula N214 [1] is a large region of gas and dust located in a remote part of our neighbouring galaxy, the Large Magellanic Cloud. N214 is a quite remarkable site where massive stars are forming. In particular, its main component, N214C (also named NGC 2103 or DEM 293), is of special interest since it hosts a very rare massive star, known as Sk-71 51 [2] and belonging to a peculiar class with only a dozen known members in the whole sky. N214C thus provides an excellent opportunity for studying the formation site of such stars. Using ESO's 3.5-m New Technology telescope (NTT) located at La Silla (Chile) and the SuSI2 and EMMI instruments, astronomers from France and the USA [3] studied in great depth this unusual region by taking the highest resolution images so far as well as a series of spectra of the most prominent objects present. N214C is a complex of ionised hot gas, a so-called H II region [4], spreading over 170 by 125 light-years (see ESO PR Photo 12b/05). At the centre of the nebula lies Sk-71 51, the region's brightest and hottest star. At a distance of ~12 light-years north of Sk-71 51 runs a long arc of highly compressed gas created by the strong stellar wind of the star. There are a dozen less bright stars scattered across the nebula and mainly around Sk-71 51. Moreover, several fine, filamentary structures and fine pillars are visible. The green colour in the composite image, which covers the bulk of the N214C region, comes from doubly ionised oxygen atoms [5] and indicates that the nebula must be extremely hot over a very large extent. The Star Sk-71 51 decomposed ESO PR Photo 12c/05 ESO PR Photo 12c/05 The Cluster Around Sk-71 51 [Preview - JPEG: 400 x 620 pix - 189k] [Normal - JPEG: 800 x 1239 pix - 528k] Caption: ESO PR Photo 12c/05 shows a small field around the hot star Sk-71 51 as seen through the V filter. The left image shows a single frame after subtraction of the nebular background. The image quality - or seeing - is roughly 8.5 pixels

  17. And Then There Were Three...!

    NASA Astrophysics Data System (ADS)


    Observatory, recorded with a fixed TV-camera on January 27 at 03:00 UT, soon after the moment of "First Light" with the third 8.2-m VLT Unit Telescope ( MELIPAL ). The video sequences were transmitted via ESO's dedicated satellite communication link to the Headquarters in Garching for production of the Clip. It begins with a statement by the Manager of the VLT Project, Dr. Massimo Tarenghi , as exposures of the Crab Nebula are obtained with the telescope and the raw frames are successively displayed on the monitor screen. In a following sequence, ESO's Director General, Dr. Catherine Cesarsky , briefly relates the moment of "First Light" for MELIPAL , as she experienced it at the telescope controls. ESO Press Photo 04c/00 ESO Press Photo 04c/00 [Preview; JPEG: 400 x 300; 44k] [Full size; JPEG: 1600 x 1200; 241k] The computer screen with the image of a bright star, as recorded by the Guide Probe in the early evening of January 26; see also PR Photo 04a/00. This image was used for the initial adjustments by means of the active optics system. (Digital Photo). ESO Press Photo 04d/00 ESO Press Photo 04d/00 [Preview; JPEG: 400 x 314; 49k] [Full size; JPEG: 1528 x 1200; 189k] ESO staff at the moment of "First Light" for MELIPAL in the evening of January 26. The photo was made in the wooden hut on the telescope observing floor from where the telescope was controlled during the first hours. (Digital Photo). ESO PR Photos may be reproduced, if credit is given to the European Southern Observatory. The ESO PR Video Clips service to visitors to the ESO website provides "animated" illustrations of the ongoing work and events at the European Southern Observatory. The most recent clip was: ESO PR Video Clip 01/00 with aerial sequences from Paranal (12 January 2000). Information is also available on the web about other ESO videos.

  18. The Blob, the Very Rare Massive Star and the Two Populations

    NASA Astrophysics Data System (ADS)


    The nebula N214 [1] is a large region of gas and dust located in a remote part of our neighbouring galaxy, the Large Magellanic Cloud. N214 is a quite remarkable site where massive stars are forming. In particular, its main component, N214C (also named NGC 2103 or DEM 293), is of special interest since it hosts a very rare massive star, known as Sk-71 51 [2] and belonging to a peculiar class with only a dozen known members in the whole sky. N214C thus provides an excellent opportunity for studying the formation site of such stars. Using ESO's 3.5-m New Technology telescope (NTT) located at La Silla (Chile) and the SuSI2 and EMMI instruments, astronomers from France and the USA [3] studied in great depth this unusual region by taking the highest resolution images so far as well as a series of spectra of the most prominent objects present. N214C is a complex of ionised hot gas, a so-called H II region [4], spreading over 170 by 125 light-years (see ESO PR Photo 12b/05). At the centre of the nebula lies Sk-71 51, the region's brightest and hottest star. At a distance of ~12 light-years north of Sk-71 51 runs a long arc of highly compressed gas created by the strong stellar wind of the star. There are a dozen less bright stars scattered across the nebula and mainly around Sk-71 51. Moreover, several fine, filamentary structures and fine pillars are visible. The green colour in the composite image, which covers the bulk of the N214C region, comes from doubly ionised oxygen atoms [5] and indicates that the nebula must be extremely hot over a very large extent. The Star Sk-71 51 decomposed ESO PR Photo 12c/05 ESO PR Photo 12c/05 The Cluster Around Sk-71 51 [Preview - JPEG: 400 x 620 pix - 189k] [Normal - JPEG: 800 x 1239 pix - 528k] Caption: ESO PR Photo 12c/05 shows a small field around the hot star Sk-71 51 as seen through the V filter. The left image shows a single frame after subtraction of the nebular background. The image quality - or seeing - is roughly 8.5 pixels