I

Distribution by Scientific Domains

Kinds of I

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  • Terms modified by I

  • i activity
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  • i data
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  • i diabetes
  • i diabetes mellitu
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  • i draw
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  • i end
  • i enzyme
  • i error
  • i error control
  • i error rate
  • i evidence
  • i expression
  • i family
  • i feel
  • i fibre
  • i find
  • i find evidence
  • i finish
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  • i gel
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  • i know
  • i lay
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  • i look
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  • i mania
  • i mean
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  • i metabolite
  • i metabotropic glutamate receptor
  • i molecule
  • i mrna
  • i mutation
  • i note
  • i offer
  • i outline
  • i pathway
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  • i peptide
  • i point
  • i polyketide synthase
  • i polymorphism
  • i present
  • i pressure ulcer
  • i production
  • i protein
  • i ratio
  • i receptor
  • i region
  • i reply
  • i report
  • i response
  • i review
  • i see
  • i seek
  • i sequence
  • i show
  • i stay
  • i studies
  • i study
  • i subunit
  • i take
  • i take issue
  • i term
  • i test
  • i trace
  • i transmembrane protein
  • i trauma center
  • i trauma centre
  • i trial
  • i trials
  • i try
  • i tumor
  • i turn
  • i type
  • i use
  • i used
  • i used data
  • i v
  • i want
  • i wish

  • Selected Abstracts


    Oligonucleotide Analogues with Integrated Bases and Backbone.

    HELVETICA CHIMICA ACTA, Issue 5 2007
    Part 1
    Abstract The self-complementary (Z)-configured U*[ce]A(*) dinucleotide analogues 6, 8, 10, 12, 14, and 16, and the A*[ce]U(*) dimers 19, 21, 23, 25, 27, and 29 were prepared by partial hydrogenation of the corresponding ethynylene linked dimers. Photolysis of 14 led to the (E)-alkene 17. These dinucleotide analogues associate in CDCl3 solution, as evidenced by NMR and CD spectroscopy. The thermodynamic parameters of the duplexation were determined by van't Hoff analysis. The (Z)-configured U*[ce]A(*) dimers 14 and 16 form cyclic duplexes connected by Watson,Crick H-bonds, the (E)-configured U*[ce]A dimer 17 forms linear duplexes, and the U*[ce]A(*) allyl alcohols 6, 8, 10, and 12 form mixtures of linear and cyclic duplexes. The C(6/I)-unsubstituted A*[ce]U allyl alcohols 19 and 23 form linear duplexes, whereas the C(6/I)-substituted A*[ce]U* allyl alcohols 21 and 25, and the C(5,/I)-deoxy A*[ce]U(*) dimers 27 and 29 also form minor amounts of cyclic duplexes. The influence of intra- and intermolecular H-bonding of the allyl alcohols and the influence of the base sequence upon the formation of cyclic duplexes are discussed. [source]


    Oligonucleotide Analogues with Integrated Bases and Backbone.

    HELVETICA CHIMICA ACTA, Issue 12 2006

    Abstract The self-complementary UA and AU dinucleotide analogues 41,45, 47, 48, and 51,60 were prepared by Sonogashira coupling of 6-iodouridines with C(5,) -ethynylated adenosines and of 8-iodoadenosines with C(5,) -ethynylated uridines. The dinucleotide analogues associate in CDCl3 solution. The C(6/I) -unsubstituted AU dimers 51 and 54 prefer an anti -oriented uracilyl group and form stretched linear duplexes. The UA propargyl alcohols 41 and 43,45 possess a persistent intramolecular O(5,/I)H,,,N(3/I) H-bond and, thus, a syn -oriented adeninyl and a gt - or tg -oriented ethynyl moiety; they form corrugated linear duplexes. All other dimers form cyclic duplexes characterized by syn -oriented nucleobases. The preferred orientation of the ethynyl moiety (the C(4,),C(5,) torsion angle) defines a conformation between gg and one where the ethynyl group eclipses O(4,/I). The UA dimers 42, 47, and 48 form Watson,Crick H-bonds, the AU dimers 56 and 58,60 H-bonds of the Watson,Crick -type, the AU dimers 53 and 55 reverse- Hoogsteen, and 57Hoogsteen H-bonds. The pairing mode depends on the substituent of C(5,/I) (H, OSiiPr3; OH) and on the H-bonds of HOC(5,/I) in the AU dimers. Association constants were derived from the concentration-dependent chemical shift for HN(3) of the uracilyl moiety; they vary from 45,104,M,1 for linear duplexes to 197,2307,M,1 for cyclic duplexes. The thermodynamic parameters were determined by van't Hoff analysis of the temperature-dependence of the (concentration-dependent) chemical shift for HN(3) of the uracilyl moiety. Neglecting stacking energies, one finds an average energy of 3.5,4.0,kcal/mol per intermolecular H-bond. Base stacking is evidenced by the temperature-dependent CD spectra. The crystal structure of 54 shows two antiparallel chains of dimers connected by Watson-Crick H-bonds. The chains are bridged by a strong H-bond between the propargylic OH and OC(4) and by weak reverse A,,,A Hoogsteen H-bonds. [source]


    Influence of response factors on determining equilibrium association constants of non-covalent complexes by electrospray ionization mass spectrometry

    JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 5 2003
    Valérie Gabelica
    Abstract A method for determining the equilibrium association constant of a complexation reaction A + B , AB by electrospray ionization mass spectrometry is described. The method consists in measuring the relative intensities of the peaks corresponding to A and to AB in equimolar A,B solutions at different concentrations C0. The results are fitted by a non-linear least-squares procedure, with the two variable parameters being the equilibrium association constant Ka and a factor R, defined by I(AB)/I(A) = R × [AB]/[A]. The factor R is the ratio between the response factors of AB and A, and corrects for the relative electrospray responses of the complex and the free substrate A, mass discrimination of instrumental origin and/or moderate in-source dissociation. The method is illustrated with the following two systems: complexes between a double-stranded 12-base pair oligonucleotide and minor groove binders, and cyclodextrin complexes with ,,,-dicarboxylic acids. For the oligonucleotide complexes, it is found that the response of the complex is not dramatically different to the response of the free oligonucleotide duplex, as the double helix conformation is disturbed by the drug only to a minor extent. In the case of cyclodextrin complexes, these complexes were found to have a much higher response than free cyclodextrin. This may be due to the fact that cyclodextrin is neutral in solution, whereas the complex is charged, but it can also stem from the fact that a significant proportion of the complex is in a non-inclusion geometry. The present method requires the exact determination of the concentrations of the reactants and is applicable to 1 : 1 complexes. Copyright © 2003 John Wiley & Sons, Ltd. [source]


    Ultraviolet and visible Raman spectroscopic investigations of nanocrystalline carbon thin films grown by bias-assisted hot-filament chemical vapor deposition

    JOURNAL OF RAMAN SPECTROSCOPY, Issue 3 2003
    S. Gupta
    Abstract The structural bonding in a series of nanocrystalline carbon thin films grown under different substrate biasing conditions was analyzed using Raman spectroscopy in both the visible and ultraviolet (uv) regimes of the spectrum. The nanocrystalline carbon thin films studied were deposited by the hot-filament chemical vapor deposition (HFCVD) technique using a 2% concentration of methane in hydrogen. The films were deposited on molybdenum substrates under various substrate biasing conditions. A positive bias (forward) produced a continuous flow of electrons from the filament on to the substrate, whereas a negative bias (negative) caused the substrate to be bombarded with positive ions. Films were also grown under no bias, for comparison. Differences in the Raman spectra obtained with visible (,L = 514.5 nm) and uv (,L = 244.0 nm) excitation sources were investigated. Apart from the basic features consisting of D and G bands at around 1360 and 1580 cm,1 in the case of visible Raman spectra, an extra feature at around 1060 cm,1, denoted a T band, appeared in the uv Raman spectra only. Hence, uv Raman scattering measurements clearly revealed the presence of sp3 -bonded carbon atoms. The position and its intensity ratio with respect to the G peak [(I(T)/I(G)] were used to provide a reliable means to measure the sp3 C bonding fraction, which is both semi-quantitative and non-destructive. The sp3 content estimated within the microstructure of n-C thin films was found to be around 60,80%. Further, probing the samples with two different photons (visible and uv) allowed us to estimate qualitatively the amount and clustering of sp2 sites. This technique provided a fast and reliable microstructural characterization of disordered carbons. The dispersion in the Raman features is specific to each carbon system and, therefore, can be used as a fingerprint. These findings point at the similarities of bias-assisted HFCVD nanocrystalline carbon (n-C) materials and the tetrahedrally bonded amorphous carbon (ta -C) materials grown by ion-beam assisted deposition (IBAD). Copyright © 2003 John Wiley & Sons, Ltd. [source]


    Diverse transport modes by the solute carrier 26 family of anion transporters

    THE JOURNAL OF PHYSIOLOGY, Issue 10 2009
    Ehud Ohana
    The solute carrier 26 (SLC26) transporters are anion transporters with diverse substrate specificity. Several members are ubiquitous while others show limited tissue distribution. They are expressed in many epithelia and to the extent known, play a central role in anion secretion and absorption. Members of the family are primarily Cl, transporters, although some members transport mainly SO42,, Cl,, HCO3, or I,. A defining feature of the family is their functional diversity. Slc26a1 and Slc26a2 function as specific SO42, transporters while Slc26a4 functions as an electroneutral Cl,/I,/HCO3, exchanger. Slc26a3 and Slc26a6 function as coupled electrogenic Cl,/HCO3, exchangers or as bona fide anion channels. SLC26A7 and SLC26A9 function exclusively as Cl, channels. This short review discusses the functional diversity of the SLC26 transporters. [source]


    OPTIMAL AND ADAPTIVE SEMI-PARAMETRIC NARROWBAND AND BROADBAND AND MAXIMUM LIKELIHOOD ESTIMATION OF THE LONG-MEMORY PARAMETER FOR REAL EXCHANGE RATES,

    THE MANCHESTER SCHOOL, Issue 2 2005
    SAEED HERAVI
    The nature of the time series properties of real exchange rates remains a contentious issue primarily because of the implications for purchasing power parity. In particular are real exchange rates best characterized as stationary and non-persistent; nonstationary but non-persistent; or nonstationary and persistent? Most assessments of this issue use the I(0)/I(1) paradigm, which only allows the first and last of these options. In contrast, in the I(d) paradigm, d fractional, all three are possible, with the crucial parameter d determining the long-run properties of the process. This study includes estimation of d by three methods of semi-parametric estimation in the frequency domain, using both local and global (Fourier) frequency estimation, and maximum likelihood estimation of ARFIMA models in the time domain. We give a transparent assessment of the key selection parameters in each method, particularly estimation of the truncation parameters for the semi-parametric methods. Two other important developments are also included. We implement Tanaka's locally best invariant parametric tests based on maximum likelihood estimation of the long-memory parameter and include a recent extension of the Dickey,Fuller approach, referred to as fractional Dickey,Fuller (FD-F), to fractionally integrated series, which allows a much wider range of generating processes under the alternative hypothesis. With this more general approach, we find very little evidence of stationarity for 10 real exchange rates for developed countries and some very limited evidence of nonstationarity but non-persistence, and none of the FD-F tests leads to rejection of the null of a unit root. [source]


    MOCVD of Platinum Films from (CH3)3CH3CpPt and Pt(acac)2: Nanostructure, Conformality, and Electrical Resistivity,

    CHEMICAL VAPOR DEPOSITION, Issue 4 2003
    J. Goswami
    Abstract A potentially manufacturable liquid-source MOCVD process was applied to deposit platinum (Pt) films (12,140,nm) on thermally oxidized Si substrates. The deposition of Pt films was carried out at a substrate temperature of 350,°C by oxygen-assisted pyrolysis of complex precursors in a low-pressure, hot-wall reactor. The effects of two different metal,organic precursors, a) trimethyl methyl cyclopentadienyl platinum [(CH3)3CH3CpPt], and b) platinum acetylacetonate [Pt(acac)2], on the properties of Pt films were studied. Although the polycrystalline Pt films deposited from Pt(acac)2 exhibited a preferred (111) orientation with a X-ray intensity ratio of I(111)/I(200),=,40, the films deposited from (CH3)3CH3CpPt were highly (111) oriented with I(111)/I(200),=,270. The following properties were typical of Pt films from Pt(acac)2 as compared to Pt films from (CH3)3CH3CpPt: finer grain size (25,nm vs. 50,nm), smaller root mean square (rms) surface roughness (5,nm vs. 15,nm), and better step coverage (95,% vs. 35,%). These experimental findings indicated that growth of Pt films from Pt(acac)2 occurred under the kinetically-limited regime, whereas the deposition of Pt from (CH3)3CH3CpPt was limited by the mass transport rate. Additionally, the temperature (4.2,293,K) dependence of the electrical resistivities (,) of Pt films was measured and the electron mean free paths were estimated. It was observed that ,(T) deviated from Matthiessen's rule. [source]


    UV/Vis to NIR Photoconduction in Cyclopalladated Complexes

    CHEMISTRY - AN ASIAN JOURNAL, Issue 7 2009
    Nicolas Godbert
    Abstract Funky discotics: Photoconductivity is measured in newly synthesized cyclopalladated metallomesogens exhibiting hexagonal columnar mesophases at room temperature. The tuning of the HOMO/LUMO energy levels by modification of the chain/core linkage (ester 1 vs ether 2) makes compound 2 photoconductive across the whole UV/Vis/NIR range. The incorporation of a rigid core, formed by a cyclopalladated azobenzene fragment bonded to an ancillary Schiff base ligand, into molecules with 12 or 11 peripheral alkyl chains has been successfully achieved. These new complexes, 1 and 2, respectively, are columnar liquid crystals between room temperature and about 50,°C. Both cyclometallated and ancillary ligands have been polyalkylated through either aryl ester (electron-withdrawing group) or aryl ether (electron-releasing group) linkages, in order to tune the HOMO/LUMO energy levels. The photoconductive properties of 1 and 2 have been studied as a function of their absorption properties before and after annealing, from the UV/Vis to NIR region. Compared with the reference compounds, tris-alkynyl benzene discotics, these new materials gave similar performances (,/I,8×10,13,S,cm,W,1 with E=10,V,,m,1 at ,=370,nm). Moreover, complex 2 shows a normalized photoconductivity ,/I=8.5×10,13,S,cm,W,1 at ,=760,nm. Organic photoconductors in such a high wavelength spectral range are not common and are usually assembled by mixing dyes with organic semiconductors. [source]


    Photovoltaic activity of Ti/MCM-41

    CHEMPHYSCHEM, Issue 1 2009
    Pedro Atienzar Dr.
    Abstract Ti/MCM-41 is a well-known heterogeneous catalyst for alkene epoxidation with organic peroxides. This titanosilicate contains isolated titanium atoms forming part of a framework of mesoporous silica whose structure is formed by parallel hexagonal channels 3.2 nm in diameter. The surface area and porosity of Ti/MCM-41 are about 880 m2,g,1 and 0.70 cm3,g,1, respectively. These values are among the highest for any material. Herein, we show that Ti/MCM-41 exhibits photovoltaic activity. Dye-sensitized solar cells using mesoporous Ti/MCM-41 (2.8,5.7,% Ti content) as active layer, black dye N3 as photosensitizer and I3,/I, in methoxyacetonitrile as electrolyte exhibit a VOC, JSC and FF of 0.44 V, 0.045 mA,cm,2 and 0.33, respectively. These values compare well against 0.75 V, 4.1 mA,cm,2 and 0.64, respectively, measured for analogous solar cells using conventional P-25 TiO2. However, the specific current density (JSC/Ti atom) for the Ti/MCM-41 is very similar to that of P25 TiO2. [source]


    A study of the massive star-forming region M8 using images from the Spitzer Infrared Array Camera

    MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2010
    Dewangan Lokesh Kumar
    ABSTRACT We present photometry and images (3.6, 4.5, 5.8 and 8.0 ,m) from the Spitzer Infrared Array Camera (IRAC) of the star-forming region Messier 8 (M8). The IRAC photometry reveals ongoing star formation in the M8 complex, with 64 class 0/I and 168 class II sources identified in several locations in the vicinity of submm gas cores/clumps. Nearly 60 per cent of these young stellar objects (YSOs) occur in about seven small clusters. The spatial surface density of the clustered YSOs is determined to be about 10,20 YSOs pc,2. Fresh star formation by the process of ,collect and collapse' might have been triggered by the expanding H ii regions and winds from massive stars. IRAC ratio images are generated and studied in order to identify possible diagnostic emission regions in M8. The image of 4.5/8.0 ,m reveals a Br, counterpart of the optical Hourglass H ii region, while the ratio 8.0/4.5 ,m indicates PAH emission in a cavity-like structure to the east of the Hourglass. The ratio maps of 3.6/4.5, 5.8/4.5 and 8.0/4.5 ,m seem to identify PAH emission regions in the sharp ridges and filamentary structures seen east to west and north-east to south-west in the M8 complex. [source]


    Disparities in medical care among commercially insured patients with newly diagnosed breast cancer

    CANCER, Issue 1 2010
    Opportunities for intervention
    Abstract BACKGROUND: African-American women have increased breast cancer mortality compared with white women. Diagnostic and treatment gaps may contribute to this disparity. METHODS: In this retrospective, longitudinal cohort study, Southern US health plan claims data and linked medical charts were used to identify racial disparities in the diagnoses, treatment, and mortality of commercially insured women with newly diagnosed breast cancer. White women (n = 476) and African-American women (n = 99) with newly diagnosed breast cancer were identified by breast cancer claims codes (International Classification of Diseases, Ninth Revision, Clinical Modification codes 174, 233.0, 238.3, and 239.3) between January 2000 and December 2004. Race, diagnoses (breast cancer stage, estrogen/progesterone receptor [ER/PR]-positive status), treatment (breast-conserving surgery, antiestrogen therapy, and chemotherapy interruption or reduction), and all-cause mortality were assessed from medical charts. Multivariate regression analyses were adjusted for age, geography, and socioeconomic status to test the association of race with diagnoses/treatment. RESULTS: White women were older (P < .001) and had higher rates of diagnosis at stage 0/I (55.2% vs 38.4%; P < .05) than African-American women. More white women had positive ER/PR status (75% vs 56% African-American; P = .001) and received antiestrogen therapy if they were positive (37.2% vs 27.3% African-American; P < .001). White women received slightly more breast-conserving surgery and chemotherapy dose modification than African-American women (P value nonsignificant). African-American women had a higher mortality rate (8.1%) than white women (3.6%; P = .06). In adjusted analyses, African-American women were diagnosed at later stages (odds ratio, 1.71; P = .02), and white women received more antiestrogen therapy (odds ratio, 2.1; P = .03). CONCLUSIONS: Disparities in medical care among patients with newly diagnosed breast cancer were evident between African-American women and white women despite health plan insurance coverage. Interventions that address the gaps identified are needed. Cancer 2010. © 2010 American Cancer Society. [source]


    Distribution of ,-tocopherol in fillets of turbot (Scophthalmus maximus) and Atlantic halibut (Hippoglossus hippoglossus), following dietary ,-tocopheryl acetate supplementation

    AQUACULTURE NUTRITION, Issue 2 2004
    N. Ruff
    Abstract The present study investigated the distribution of , -tocopherol (vitamin E) in fillets of turbot (Scophthalmus maximus) and Atlantic halibut (Hippoglossus hippoglossus). Turbot and Atlantic halibut were fed commercial diets, supplemented with different levels of , -tocopheryl acetate at the dietary target levels of 100, 500 and 1000 mg , -tocopheryl acetate kg,1 diet. The actual levels were 72, 547 and 969 for turbot, while halibut received 189, 613 and 875 mg , -tocopheryl acetate kg,1 diet. Turbot were fed the diets for 24 weeks, while Atlantic halibut were fed for 20 weeks prior to slaughter. At the end of the feeding periods fish had reached a final weight of around 1 kg. Fish were slaughtered and filleted. From the four fillets obtained per fish, 22 samples were taken from designated areas and analysed for their , -tocopherol content. The average concentrations of , -tocopherol incorporated in turbot and Atlantic halibut increased with increasing levels of , -tocopheryl acetate in the diet. Atlantic halibut had significantly (P < 0.05) more , -tocopherol in positions 2/II and 1/I than in position 9/IX. Turbot had significantly (P < 0.05) more , -tocopherol in position 2/II than in positions 1/I, 4/IV and 11/XI. By mapping , -tocopherol concentrations in fish fillets, a high degree of quality prediction may be established. Moreover, this study may help scientists in their choice of sampling position, when investigating if , -tocopheryl acetate supplementation resulted in successful , -tocopherol incorporation. [source]


    Peptoid residues and ,-turn formation

    JOURNAL OF PEPTIDE SCIENCE, Issue 6 2002
    Mario Rainaldi
    Abstract A set of terminally protected tripeptoids containing a residue of either N -methylglycine or N - isobutylglycine in position i + 1/i + 2 were synthesized and tested for intramolecularly H-bonded ,-turn formation. By exploiting FT-IR absorption and 1H NMR techniques, their folding tendencies were compared with those of a variety of reference peptides. The amount of ,-turn induction and the relative extent of the various types of intramolecularly H-bonded ,-turn conformers were determined in chloroform solution. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd. [source]


    Oligonucleotide Analogues with Integrated Bases and Backbone.

    HELVETICA CHIMICA ACTA, Issue 12 2006

    Abstract The self-complementary UA and AU dinucleotide analogues 41,45, 47, 48, and 51,60 were prepared by Sonogashira coupling of 6-iodouridines with C(5,) -ethynylated adenosines and of 8-iodoadenosines with C(5,) -ethynylated uridines. The dinucleotide analogues associate in CDCl3 solution. The C(6/I) -unsubstituted AU dimers 51 and 54 prefer an anti -oriented uracilyl group and form stretched linear duplexes. The UA propargyl alcohols 41 and 43,45 possess a persistent intramolecular O(5,/I)H,,,N(3/I) H-bond and, thus, a syn -oriented adeninyl and a gt - or tg -oriented ethynyl moiety; they form corrugated linear duplexes. All other dimers form cyclic duplexes characterized by syn -oriented nucleobases. The preferred orientation of the ethynyl moiety (the C(4,),C(5,) torsion angle) defines a conformation between gg and one where the ethynyl group eclipses O(4,/I). The UA dimers 42, 47, and 48 form Watson,Crick H-bonds, the AU dimers 56 and 58,60 H-bonds of the Watson,Crick -type, the AU dimers 53 and 55 reverse- Hoogsteen, and 57Hoogsteen H-bonds. The pairing mode depends on the substituent of C(5,/I) (H, OSiiPr3; OH) and on the H-bonds of HOC(5,/I) in the AU dimers. Association constants were derived from the concentration-dependent chemical shift for HN(3) of the uracilyl moiety; they vary from 45,104,M,1 for linear duplexes to 197,2307,M,1 for cyclic duplexes. The thermodynamic parameters were determined by van't Hoff analysis of the temperature-dependence of the (concentration-dependent) chemical shift for HN(3) of the uracilyl moiety. Neglecting stacking energies, one finds an average energy of 3.5,4.0,kcal/mol per intermolecular H-bond. Base stacking is evidenced by the temperature-dependent CD spectra. The crystal structure of 54 shows two antiparallel chains of dimers connected by Watson-Crick H-bonds. The chains are bridged by a strong H-bond between the propargylic OH and OC(4) and by weak reverse A,,,A Hoogsteen H-bonds. [source]


    Oligonucleotide Analogues with Integrated Bases and Backbone.

    HELVETICA CHIMICA ACTA, Issue 5 2007
    Part 1
    Abstract The self-complementary (Z)-configured U*[ce]A(*) dinucleotide analogues 6, 8, 10, 12, 14, and 16, and the A*[ce]U(*) dimers 19, 21, 23, 25, 27, and 29 were prepared by partial hydrogenation of the corresponding ethynylene linked dimers. Photolysis of 14 led to the (E)-alkene 17. These dinucleotide analogues associate in CDCl3 solution, as evidenced by NMR and CD spectroscopy. The thermodynamic parameters of the duplexation were determined by van't Hoff analysis. The (Z)-configured U*[ce]A(*) dimers 14 and 16 form cyclic duplexes connected by Watson,Crick H-bonds, the (E)-configured U*[ce]A dimer 17 forms linear duplexes, and the U*[ce]A(*) allyl alcohols 6, 8, 10, and 12 form mixtures of linear and cyclic duplexes. The C(6/I)-unsubstituted A*[ce]U allyl alcohols 19 and 23 form linear duplexes, whereas the C(6/I)-substituted A*[ce]U* allyl alcohols 21 and 25, and the C(5,/I)-deoxy A*[ce]U(*) dimers 27 and 29 also form minor amounts of cyclic duplexes. The influence of intra- and intermolecular H-bonding of the allyl alcohols and the influence of the base sequence upon the formation of cyclic duplexes are discussed. [source]


    Oligonucleotide Analogues with Integrated Bases and Backbone.

    HELVETICA CHIMICA ACTA, Issue 12 2006

    Abstract The self-complementary UA and AU dinucleotide analogues 41,45, 47, 48, and 51,60 were prepared by Sonogashira coupling of 6-iodouridines with C(5,) -ethynylated adenosines and of 8-iodoadenosines with C(5,) -ethynylated uridines. The dinucleotide analogues associate in CDCl3 solution. The C(6/I) -unsubstituted AU dimers 51 and 54 prefer an anti -oriented uracilyl group and form stretched linear duplexes. The UA propargyl alcohols 41 and 43,45 possess a persistent intramolecular O(5,/I)H,,,N(3/I) H-bond and, thus, a syn -oriented adeninyl and a gt - or tg -oriented ethynyl moiety; they form corrugated linear duplexes. All other dimers form cyclic duplexes characterized by syn -oriented nucleobases. The preferred orientation of the ethynyl moiety (the C(4,),C(5,) torsion angle) defines a conformation between gg and one where the ethynyl group eclipses O(4,/I). The UA dimers 42, 47, and 48 form Watson,Crick H-bonds, the AU dimers 56 and 58,60 H-bonds of the Watson,Crick -type, the AU dimers 53 and 55 reverse- Hoogsteen, and 57Hoogsteen H-bonds. The pairing mode depends on the substituent of C(5,/I) (H, OSiiPr3; OH) and on the H-bonds of HOC(5,/I) in the AU dimers. Association constants were derived from the concentration-dependent chemical shift for HN(3) of the uracilyl moiety; they vary from 45,104,M,1 for linear duplexes to 197,2307,M,1 for cyclic duplexes. The thermodynamic parameters were determined by van't Hoff analysis of the temperature-dependence of the (concentration-dependent) chemical shift for HN(3) of the uracilyl moiety. Neglecting stacking energies, one finds an average energy of 3.5,4.0,kcal/mol per intermolecular H-bond. Base stacking is evidenced by the temperature-dependent CD spectra. The crystal structure of 54 shows two antiparallel chains of dimers connected by Watson-Crick H-bonds. The chains are bridged by a strong H-bond between the propargylic OH and OC(4) and by weak reverse A,,,A Hoogsteen H-bonds. [source]


    Aggregative adherence of uropathogenic Proteus mirabilis to cultured epithelial cells

    FEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 2 2007
    Sérgio P.D. Rocha
    Abstract Proteus mirabilis is an important cause of urinary tract infection (UTI) in patients with complicated urinary tracts. Thirty-five strains of P. mirabilis isolated from UTI were examined for the adherence capacity to epithelial cells. All isolates displayed the aggregative adherence (AA) to HEp-2 cells, a phenotype similarly presented in LLC-MK2 cells. Biofilm formation on polystyrene was also observed in all strains. The mannose-resistant Proteus -like fimbriae (MR/P), Type I fimbriae and AAF/I, II and III fimbriae of enteroaggregative Escherichia coli were searched by the presence of their respective adhesin-encoding genes. Only the MR/P fimbrial subunits encoding genes mrpA and mrpH were detected in all isolates, as well as MR/P expression. A mutation in mrpA demonstrated that MR/P is involved in aggregative adherence to HEp-2 cells, as well as in biofilm formation. However, these phenotypes are multifactorial, because the mrpA mutation reduced but did not abolish both phenotypes. The present results reinforce the importance of MR/P as a virulence factor in P. mirabilis due to its association with AA and biofilm formation, which is an important step for the establishment of UTI in catheterized patients. [source]


    Characterization of adhesin variants in Indian isolates of enteroaggregative Escherichia coli

    FEMS MICROBIOLOGY LETTERS, Issue 2 2006
    Renu Bhardwaj
    Abstract Enteroaggregative Escherichia coli (EAEC) are causative agents of diarrhea, being characterized by aggregative adherence to cultured epithelial cells. In this study, phenotypic properties of EAEC were analyzed with respect to AA, hemagglutination, clump and biofilm formation, all of which are mediated by aggregative adherence fimbriae (AAF). The strains were also screened for AAF types, AAF adhesin variants and Dr adhesin by PCR. Of the three known AAF types, AAF/I and AAF/II adhesin variants were identified. An association between the AAF/adhesin genotypes and the subtypes/scores of phenotypic properties was sought and it was observed that strains harboring same adhesins displayed different subtypes/scores and vice versa. [source]


    Inhibitory functioning across ADHD subtypes: Recent findings, clinical implications, and future directions

    DEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 4 2008
    Zachary W. Adams
    Abstract Although growing consensus supports the role of deficient behavioral inhibition as a central feature of the combined subtype of ADHD (ADHD/C; Barkley 1997 Psychol Bull 121:65,94; Nigg 2001 Psychol Bull 127:571,598), little research has focused on how this finding generalizes to the primarily inattentive subtype (ADHD/I). This question holds particular relevance in light of recent work suggesting that ADHD/I might be better characterized as a disorder separate from ADHD/C (Diamond 2005 Dev Psychopathol 17:807,825; Milich et al. 2001 Clin Psychol Sci Pract 8:463,488). This article describes major findings in the area of inhibitory performance in ADHD and highlights recent research suggesting important areas of divergence between the subtypes. In particular, preliminary findings point to potential differences between the subtypes with respect to how children process important contextual information from the environment, such as preparatory cues that precede responses and rewarding or punishing feedback following behavior. These suggestive findings are discussed in the context of treatment implications, which could involve differential intervention approaches for each subtype targeted to the specific deficit profiles that characterize each group of children. Future research avenues aimed toward building a sound theoretical model of ADHD/I and a better understanding of its relation to ADHD/C are also presented. Specifically, investigators are encouraged to continue studying the complex interplay between inhibitory and attentional processes, as this area seems particularly promising in its ability to improve our understanding of the potentially distinct pathologies underlying the ADHD subtypes. © 2008 Wiley-Liss, Inc. Dev Disabil Res Rev 2008;14:268,275. [source]


    Effects of sequential exposure to lipopolysaccharide and heat stress on dental pulp cells

    JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 3 2006
    Chiaki Kitamura
    Abstract In the present study, we examined the effects of sequential exposure to bacterial lipopolysaccharide (LPS) and heat stress on dental pulp cells. LPS induced the proliferation of pulp cells through the activation of p38 MAPK. HSP27 was expressed in cells with or without LPS during the entire period of heat stress, while transiently phosphorylated by short-term heat stress. In LPS-treated cells, short-term heat stress also induced the phosphorylation of HSF1. The immediate phosphorylation of HSF1 and HSP27 in LPS-treated cells by short-term heat stress occurred dependent on the activation of p38 MAPK. However, with long-term heat stress, the activation of HSF1 and induction of HSP27 occurred independent of p38 MAPK. Further, full activation of Akt in LPS-treated cells was immediately induced by short-term heat stress and lasted during the entire period of heat stress. I,B, was induced and phosphorylated throughout sequential exposure to LPS and heat stress. These results suggest that LPS has the unique effects on the cytoprotection and the cell death of pulp cells during heat stress through the modification and the activation of heat stress responsive molecules, HSF1 and HSP27, and cell survival molecules, Akt and NF-,B/I,B,. J. Cell. Biochem. 99: 797,806, 2006. © 2006 Wiley-Liss, Inc. [source]


    Effects of Clinacanthus siamensis leaf extract on influenza virus infection

    MICROBIOLOGY AND IMMUNOLOGY, Issue 2 2009
    Mali Wirotesangthong
    ABSTRACT Ethanolic extracts of 20 medicinal plants were screened for influenza virus NA inhibition and in vitro antiviral activities using MDCK cells in an MTT assay. The vaccine proteins of influenza virus A/New Caledonia/20/99 (H1N1), mouse-adapted influenza virus A/Guizhou/54/89 (A/G)(H3N2) and mouse-adapted influenza virus B/Ibaraki/2/85 (B/I) were used in the NA inhibition assay, and mouse-adapted influenza viruses A/PR/8/34 (H1N1), A/G and B/I were used in the in vitro antiviral assay. The results of the in vitro antiviral assay indicated that the A/G virus was the most susceptible and an extract of the leaf of CS possessed the highest in vitro anti-A/G virus activity (41.98%). Therefore, the A/G virus and the CS extract were selected for studying in vivo anti-influenza virus activity. BALB/c mice were treated with CS extract (100 mg/kg per day, 5 times) orally from 4 hr before to 4 days after infection. CS extract elicited significant production of anti-influenza virus IgG1 antibody in BAW and increased mouse weight compared to oseltamivir (0.1 mg/kg per day) on day 19 or water on days 17,19 of infection. Moreover, CS extract produced a higher anti-influenza virus IgA antibody level in BAW compared to oseltamivir, and a tendency towards an increase in anti-influenza virus IgA compared to water was shown. The results suggest that CS extract has a protective effect against influenza virus infection. [source]


    Callosal contribution to ocular dominance in rat primary visual cortex

    EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2010
    Chiara Cerri
    Abstract Ocular dominance (OD) plasticity triggered by monocular eyelid suture is a classic paradigm for studying experience-dependent changes in neural connectivity. Recently, rodents have become the most popular model for studies of OD plasticity. It is therefore important to determine how OD is determined in the rodent primary visual cortex. In particular, cortical cells receive considerable inputs from the contralateral hemisphere via callosal axons, but the role of these connections in controlling eye preference remains controversial. Here we have examined the role of callosal connections in binocularity of the visual cortex in naïve young rats. We recorded cortical responses evoked by stimulation of each eye before and after acute silencing, via stereotaxic tetrodotoxin (TTX) injection, of the lateral geniculate nucleus ipsilateral to the recording site. This protocol allowed us to isolate visual responses transmitted via the corpus callosum. Cortical binocularity was assessed by visual evoked potential (VEP) and single-unit recordings. We found that acute silencing of afferent geniculocortical input produced a very significant reduction in the contralateral-to-ipsilateral (C/I) VEP ratio, and a marked shift towards the ipsilateral eye in the OD distribution of cortical cells. Analysis of absolute strength of each eye indicated a dramatic decrease in contralateral eye responses following TTX, while those of the ipsilateral eye were reduced but maintained a more evident input. We conclude that callosal connections contribute to normal OD mainly by carrying visual input from the ipsilateral eye. These data have important implications for the interpretation of OD plasticity following alterations of visual experience. [source]


    Iterative interference cancellation and channel estimation in multibeam satellite systems

    INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 3 2007
    J. P. Millerioux
    Abstract This paper deals with the use of non-linear multiuser detection techniques to mitigate co-channel interference on the reverse link of multibeam satellite systems. These techniques allow more capacity efficient frequency reuse strategies than classical ones, as they make possible to cope with lower C/I. The considered system takes as a starting point the DVB-RCS standard, with the use of convolutional coding, and the use of the Ka-band. We propose different iterative interference cancellation schemes, which operate at the beamformer outputs, and which use information from decoders. The proposed receivers assume an initial single-user synchronization step: frame synchronization and timing recovery, and then perform channel estimation: beamformer coefficients; signal carrier phases and signal amplitudes. In a first step, these receivers are evaluated by simulation in terms of bit error rate and of channel estimation error on two interference configurations. For one of these receivers, sensitivity to imperfect timing recovery and to low-frequency offsets from user terminals is evaluated. In a second step, since the receiver performances highly depend on the interference configuration, we propose an approach to evaluate performances on a multibeam coverage (by taking into account the variability of interference configurations on the coverage). This method is used to compare different receivers on an example based on a coverage designed on a digital focal array feed reflector antenna. Copyright © 2007 John Wiley & Sons, Ltd. [source]


    Resource management model and performance evaluation for satellite communications

    INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 2 2001
    Axel Jahn
    Abstract Efficient resource management is mandatory to achieve maximum system capacity for next generation communications systems. Resource management deals with the available spectral band, time, power, and space for a transmission signal. It includes (i) the frequency planning, (ii) the selection of transmit power, and (iii) the assignment of the channels and access nodes to the users. The paper presents a generalized notation as well as graph algorithms for resource management problems. Impairment graphs can be used for frequency planning, whereas flow graphs are suitable for channel access problems. To evaluate the performance of the resource management, service criteria (such as blocking or the carrier to interference ratio C/I) or efficiency criteria (bandwidth requirements) can be derived from the graphs. The resource management techniques are applied to satellite networks with non-geostationary orbits yielding time-variant network topologies. As a simple example, the channel assignment and capacity optimization of the EuroSky Way system are shown. Furthermore, a comparison of fixed, dynamic and hybrid channel allocation schemes (FCA, DCA, HCA) for a typical MEO satellite scenario is given. Satellite diversity and its impact on bandwidth requirement and transmission quality is also examined. Finally, it is shown how spread spectrum systems can be investigated with the presented tools. Copyright © 2001 John Wiley & Sons, Ltd. [source]


    Visualization of Surface-specific Antigens in Various Strains of Enterotoxigenic E. coli

    ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2005
    S. Lüdi
    Proteinaceous surface antigens of enterotoxigenic E. coli (ETEC) appear as pili, and are important virulence factors as they allow bacteria to attach to the small intestinal mucosa. Surface antigens are classified as colonization factor antigens (CFA) and coli surface antigens (CS). Known groups include CFA/I, CFA/II (consisting of CS1, CS2 and CS3), CA/III and CFA/IV (consisting of CS4, CS5 and CS6). The goal of the present study was to examine the morphology of pili by transmission electron microscopy (TEM) and to localize specific surface antigens by immunolabelling. Using different strains of E. coli grown under various culture conditions, pili were visualized by negative staining and corresponding surface antigens were demonstrated by immunogold-labelling using both polyclonal and monoclonal antibodies. Expression of pili was dependent on culture conditions and sample handling. In contrast to CFA/I and CS3, CS6 pili were not detectable after negative staining. Selected antibodies, however, allowed surface antigens to be demonstrated unequivocally. These results will be of value in investigating the expression of colonizing factors in genetically modified bacterial strains. [source]


    Crystallization and preliminary X-ray diffraction analyses of several forms of the CfaB major subunit of enterotoxigenic Escherichia coli CFA/I fimbriae

    ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 3 2009
    Yong-Fu Li
    Enterotoxigenic Escherichia coli (ETEC), a major global cause of diarrhea, initiates the pathogenic process via fimbriae-mediated attachment to the small intestinal epithelium. A common prototypic ETEC fimbria, colonization factor antigen I (CFA/I), consists of a tip-localized minor adhesive subunit CfaE and the stalk-forming major subunit CfaB, both of which are necessary for fimbrial assembly. To elucidate the structure of CFA/I at atomic resolution, three recombinant proteins were generated consisting of fusions of the minor and major subunits (CfaEB) and of two (CfaBB) and three (CfaBBB) repeats of the major subunit. Crystals of CfaEB diffracted X-rays to 2.1,Å resolution and displayed the symmetry of space group P21. CfaBB exhibited a crystal diffraction limit of 2.3,Å resolution and had the symmetry of space group P21212. CfaBBB crystallized in the monoclinic space group C2 and diffracted X-rays to 2.3,Å resolution. These structures were determined using the molecular-replacement method. [source]


    Interaction of Implantable Defibrillator Therapy with Angiotensin-Converting Enzyme Deletion/Insertion Polymorphism

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 10 2004
    MANINDER S. BEDI M.D.
    Introduction: The angiotensin-converting enzyme deletion allele (ACE D) decreases survival in patients with advanced heart failure. Whether the adverse impact on survival reflects an increased risk of pump failure or arrhythmic sudden death remains uncertain. If the ACE D genotype increases the risk of sudden death, implantable cardioverter defibrillator (ICD) therapy should diminish its negative impact. We sought to evaluate the effect of ICD therapy on ACE D genetic risk. Methods and Results: The Genetic Risk Assessment of Cardiac Events (GRACE) study enrolled 479 patients at the University of Pittsburgh between 1996 and 2001. Blood was genotyped for the ACE D/I (deletion/insertion) polymorphism. Of the 479 patients, 82 (77% male, 84% Caucasian, age 56 ± 11 years, 60% ischemic, left ventricular ejection fraction 0.23 ± 0.08) received an ICD and were selected for outcomes analysis (mean follow-up 871 ± 538 days). Transplant-free survival and survival alone were compared in ACE DD patients (n = 24, 29%) versus ACE DI/II patients (n = 58, 71%). Survival was significantly improved in ACE DI/II patients compared to those without an ICD (1 year: 93% vs 87%; 2 year: 89% vs 77%; P = 0.02) but not in ACE DD patients. Transplant-free survival among patients with an ICD was significantly worse in ACE DD versus ACE DI/II (1 year: 67% vs 88%, 2 year: 55% vs 80%, P = 0.03). Analysis of survival as a single endpoint revealed a similar result (1 year = 78% vs 94%; 2 year: 72% vs 88%; P = 0.05). ICD telemetry data showed a nonsignificant trend toward fewer individuals with arrhythmias in the ACE-DD group (46% vs 65%, P = 0.22) Conclusion: ICDs do not diminish the adverse influence of the ACE DD genotype on survival. This finding suggests that mortality in this high-risk genetic subset of patients is due to progression of heart failure rather than arrhythmic sudden death. [source]


    Classification of hydrological regimes of northern floodplain basins (Peace,Athabasca Delta, Canada) from analysis of stable isotopes (,18O, ,2H) and water chemistry

    HYDROLOGICAL PROCESSES, Issue 2 2007
    Brent B. Wolfe
    Abstract We used stable isotopes (,18O and ,2H) and water chemistry to characterize the water balance and hydrolimnological relationships of 57 shallow aquatic basins in the Peace-Athabasca Delta (PAD), northern Alberta, Canada, based on sampling at the end of the 2000 thaw season. Evaporation-to-inflow ratios (E/I) were estimated using an isotope mass-balance model tailored to accommodate basin-specific input water compositions, which provided an effective, first-order, quantitative framework for identifying water balances and associated limnological characteristics spanning three main, previously identified drainage types. Open-drainage basins (E/I < 0·4; n = 5), characterized by low alkalinity, low concentrations of nitrogen, dissolved organic carbon (DOC) and ions, and high minerogenic turbidity, include large, shallow basins that dominate the interior of the PAD and experience frequent or continuous river channel connection. Closed-drainage basins (E/I , 1·0; n = 16), in contrast, possess high alkalinity and high concentrations of nitrogen, DOC, and ions, and low minerogenic turbidity, and are located primarily in the relict and infrequently flooded landscape of the northern Peace sector of the delta. Several basins fall into the restricted-drainage category (0·4 # E/I < 1·0; n = 26) with intermediate water chemistries and are predominant in the southern Athabasca sector, which is subject to active fluviodeltaic processes, including intermittent flooding from riverbank overflow. Integration of isotopic and limnological data also revealed evidence for a new fourth drainage type, mainly located near the large open-drainage lakes that occupy the central portion of the delta but within the Athabasca sector (n = 10). These basins were very shallow (<50 cm deep) at the time of sampling and isotopically depleted, corresponding to E/I characteristic of restricted- and open-drainage conditions. However, they are limnologically similar to closed-drainage basins except for higher conductivity and higher concentrations of Ca2+ and Na+, and lower concentrations of SiO2 and chlorophyll c. These distinct features are due to the overriding influence of recent summer rainfall on the basin water balance and chemistry. The close relationships evident between water balances and limnological conditions suggest that past and future changes in hydrology are likely to be coupled with marked alterations in water chemistry and, hence, the ecology of aquatic environments in the PAD. Copyright © 2006 John Wiley & Sons, Ltd. [source]


    Enantioselective [4+2]-Cycloaddition Reaction of a Photochemically Generated o -Quinodimethane: Mechanistic Details, Association Studies, and Pressure Effects

    CHEMISTRY - A EUROPEAN JOURNAL, Issue 9 2004
    Benjamin Grosch Dipl.
    Abstract 1,2,3,4-Tetrahydro-2-oxoquinoline-5-aldehyde (2) was prepared from m -aminobenzoic acid and 3-ethoxyacryloyl chloride (4) in 19,% overall yield. Compound 2 underwent a photochemically induced [4+2]-cycloaddition reaction with various dienophiles upon irradiation in toluene solution. The exo product 10,a was obtained with acrylonitrile (9,a) as the dienophile, whereas methyl acrylate (9,b) and dimethyl fumarate (9,c) furnished the endo products 11,b and 11,c (69,77,% yield). The reactions proceeded at ,60,°C in the presence of the chiral complexing agent 1 (1.2 equiv) with excellent enantioselectivity (91,94,% ee). The enantiomeric excess increases in the course of the photocycloaddition as a result of the lower product association to 1. The intermediate (E)-dienol 8 was spectroscopically detected at ,196,°C in an EPA (diethyl ether/isopentane/ethanol) glass matrix. The association of the substrate 2 to the complexing agent 1 was studied by circular dichroism (CD) titration. The measured association constant (KA) was 589,M,1 at room temperature (25,°C) and normal pressure (0.1 MPa). An increase in pressure led to an increased association. At 400 MPa the measured value of KA was 703,M,1. Despite the stronger association the enantioselectivity of the reaction decreased with increasing pressure. At 25,°C the enantiomeric excess for the enantioselective reaction 2 + 9,a,10,a decreased from 68,% ee at 0.1 MPa to 58,% ee at 350 MPa. This surprising behavior is explained by different activation volumes for the diastereomeric transition states leading to 10,a and ent - 10,a. 1,2,3,4-Tetrahydro-2-oxochinolin-5-aldehyd (2) wurde ausgehend von m -Aminobenzoesäure und 3-Ethoxyacryloylchlorid (4) in fünf Schritten und einer Gesamtausbeute von 19,% hergestellt. Die Verbindung ließ sich in Toluol als Lösungsmittel mit verschiedenen Dienophilen in einer photochemisch induzierten [4+2]-Cycloaddition umsetzen (69,77,% Ausbeute), wobei als Hauptprodukt mit Acrylnitril (9,a) das exo -Produkt 10,a entstand. Methylacrylat (9,b) und Dimethylfumarat (9,c) lieferten die endo -Produkte 11,b and 11,c. In Gegenwart des chiralen Komplexierungsreagenz, 1 (1.2 Äquiv.) verliefen die Reaktionen mit exzellenter Enantioselektivität (91,94,% ee). Der Enantiomerenüberschuß nahm im Verlauf der photochemischen Umsetzung zu, was man auf die relativ zum Substrat 2 niedrigere Assoziation des Produkts zurückführen kann. Das intermediär gebildete (E)-Dienol 8 wurde spektroskopisch in einer EPA (Ether/i -Pentan/Ethanol) Glasmatrix bei ,196,°C nachgewiesen. Die Assoziation des Substrats 2 an das Komplexierungsreagenz 1 wurde durch CD-Titration genauer untersucht. Die Assoziationskonstante (KA) wurde bei Zimmertemperatur (25,°C) und Normaldruck (0.1 MPa) zu 589,M,1bestimmt. Bei höherem Druck beobachtete man eine verstärkte Assoziation und bei 400 MPa wurde eine Assoziationskonstante von KA=703,M,1bestimmt. Trotz der stärkeren Assoziaion nahm die Enantioselektivität mit wachsendem Druck ab. Bei 25,°C sank der Enantiomerenüberschuß der enantioselektiven Reation 2 + 9,a,10,a von 68,% ee bei 0.1 MPa auf 58,% ee bei 350 MPa. Dieses überraschende Verhalten läßt sich möglicherweise durch die unterschiedlichen Aktivierungsvolumina für die Übergangszustände erklären, die zu 10,a und ent - 10,a führen. [source]


    DNA vaccines against chronic lung infections by Pseudomonas aeruginosa

    FEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 2-3 2003
    J Staczek
    Abstract Vaccines containing outer membrane protein F (OprF) of Pseudomonas aeruginosa are effective in reducing lesion severity in a mouse pulmonary chronic infection model. One OprF-based vaccine, called F/I, contains carboxy oprF sequences fused to oprI in an expression vector. When delivered three times biolistically by gene gun, the F/I vaccine induces protection that is antibody-mediated in outbred mice. To demonstrate the role of F/I -induced antibody-mediated immunity, B-cell-deficient [B(,)] and B-cell-intact [B(+)] mice were immunized with F/I, challenged with Pseudomonas, and examined for lesion severity. As expected, F/I -immunized B(+) mice had fewer and less severe lesions than vector-immunized B(+) mice. However, surprisingly, F/I - and vector-immunized B(,) mice were equally protected to levels similar to F/I -immunized B(+) mice. Examination of immune cell populations and cytokine levels indicated a relative increase in the quantity of CD3+ T-lymphocytes in vector- or F/I -immunized and challenged B(,) mice compared to B(+) mice. These data indicate the protective role played by cell-mediated immunity in B(,) mice, which supports our hypothesis that cell-mediated immunity can play an important role in protection against P. aeruginosa. [source]