365 research outputs found

    Three-Dimensional Myocardial Perfusion Maps by Contrast Echocardiography

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    We evaluated the clinical applicability of a system for three-dimensional (3-D) display of a perfusion map following myocardial contrast echocardiography (MCE). The system was used in 12 patients (9 males and 3 females, mean age 52 ± 10 years) undergoing interventional treatment of chronic total coronary occlusion. In each patient three standard apical views were acquired at baseline with sonicated IopamidolR injections into the left coronary artery (LCA) and into the right coronary artery (RCA). Following successful recanalization of the occluded artery MCE was repeated. The patients tolerated the procedure well. Acquisition of three standard apical views provided sufficient information for the reconstruction of 3-D perfusion maps containing the 16 standard left ventricular (LV) segments. Side-by-side display of the perfusion maps obtained following LCA and RCA echocontrast injections allowed us to classify the myocardial segments (192) into three groups: (1) those supplied by one major artery (124); (2) those supplied by collaterals from contralateral or both major arteries (58); and (3) segments supplied by none of the major arteries (10). Decreased opacification was observed in 50 segme

    Josephson dynamics for coupled polariton modes under the atom-field interaction in the cavity

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    We consider a new approach to the problem of Bose-Einstein condensation (BEC) of polaritons for atom-field interaction under the strong coupling regime in the cavity. We investigate the dynamics of two macroscopically populated polariton modes corresponding to the upper and lower branch energy states coupled via Kerr-like nonlinearity of atomic medium. We found out the dispersion relations for new type of collective excitations in the system under consideration. Various temporal regimes like linear (nonlinear) Josephson transition and/or Rabi oscillations, macroscopic quantum self-trapping (MQST) dynamics for population imbalance of polariton modes are predicted. We also examine the switching properties for time-averaged population imbalance depending on initial conditions, effective nonlinear parameter of atomic medium and kinetic energy of low-branch polaritons.Comment: 10 pages, 6 postscript figures, uses svjour.cl

    Evaluation of osteoprotegerin level and selected inflammatory markers in patients with essential hypertension

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    Wstęp W ostatnich badaniach wykazano, że stężenie osteoprotegryny (OPG) w surowicy wzrasta w związku z postępem zmian miażdzycowych tętnic wieńcowych, chorobą wieńcową, zawałem serca i przyszłymi chorobami układu sercowo-naczyniowego. Celem pracy było oznaczenie stężenia OPG i poszukiwanie związku między OPG i wybranymi markerami zapalnymi u pacjentów z nadciśnieniem tętniczym. Materiał i metody Do badania włączono 30 pacjentów z samoistnym nadciśnieniem tętniczym. Grupę kontrolną stanowiło 10 zdrowych osób. Przeprowadzono pełne badanie kliniczne. U wszystkich uczestników badania oznaczono stężenie OPG w surowicy metodą immunoenzymatyczną, stężenie w surowicy wysokoczułego białka C-reaktywnego (hsCRP) - metodą turbidymetrii i czynnika martwicy nowotworów &#945; (TNF-&#945;) - metodą radioimunnometryczną. Wyniki U pacjentów z samoistnym nadciśnieniem tętniczym stężenia OPG, hsCRP oraz TNF-&#945; w surowicy krwi znamiennie statystycznie przewyższały wartości obserwowane u osób z grupy kontrolnej (p < 0,05). Stwierdzono również dodatnią korelację między stężeniami OPG i TNF-&#945; (p < 0,05). Wnioski Nadciśnienie tętnicze cechuje nasilony proces zapalny. Wzajemna relacja stężenia OPG i stężenia TNF-&#945; może stanowić wyjaśnienie współwystępowania kalcyfikacji tętnic wieńcowych i progresji miażdżycy ze stanem zapalnym w tej grupie pacjentów. Nadciśnienie Tętnicze 2010, tom 14, nr 5, strony 375-380.Background Recent studies suggest that serum osteoprotegerin (OPG) levels increase in association with coronary artery calcification, coronary artery disease, stroke and future cardiovascular events. The aim of this study was to determine serum OPG levels and to investigate the relationship between OPG and selected inflammatory markers in hypertensive patients. Material and methods Thirty patients with hypertension were studied. As a control 10 healthy volunteers were used. Physical examination was performed. Plasma OPG concentrations (OPG, enzyme-linked immunosorbent assay), high-sensitivity C-reactive protein (hs-CRP, turbidimetry method) and tumor necrosis factor &#945; (TNF-&#945;, radioimmunoassay) were determined. Results The levels of plasma OPG, hsCRP and TNF-&#945; significantly exceeded those observed in the control group (p < 0.05). Positive correlation between OPG and TNF-&#945; (p < 0.05) was found. Conclusions Hypertension is characterized by increased inflammatory process. The association of elevated OPG with TNF-&#945; may provide a mechanistic link between coronary artery calcification, atherosclerosis progression and inflammation in this group of patients. Arterial Hypertension 2010, vol. 14, no 5, pages 375-380

    Advances in small lasers

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    M.T.H was supported by an Australian Research council Future Fellowship research grant for this work. M.C.G. is grateful to the Scottish Funding Council (via SUPA) for financial support.Small lasers have dimensions or modes sizes close to or smaller than the wavelength of emitted light. In recent years there has been significant progress towards reducing the size and improving the characteristics of these devices. This work has been led primarily by the innovative use of new materials and cavity designs. This Review summarizes some of the latest developments, particularly in metallic and plasmonic lasers, improvements in small dielectric lasers, and the emerging area of small bio-compatible or bio-derived lasers. We examine the different approaches employed to reduce size and how they result in significant differences in the final device, particularly between metal- and dielectric-cavity lasers. We also present potential applications for the various forms of small lasers, and indicate where further developments are required.PostprintPeer reviewe

    The endogenous anti-angiogenic VEGF isoform, VEGF165b inhibits human tumour growth in mice

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    Vascular endothelial growth factor-A is widely regarded as the principal stimulator of angiogenesis required for tumour growth. VEGF is generated as multiple isoforms of two families, the pro-angiogenic family generated by proximal splice site selection in the terminal exon, termed VEGFxxx, and the anti-angiogenic family formed by distal splice site selection in the terminal exon, termed VEGFxxxb, where xxx is the amino acid number. The most studied isoforms, VEGF165 and VEGF165b have been shown to be present in tumour and normal tissues respectively. VEGF165b has been shown to inhibit VEGF- and hypoxia-induced angiogenesis, and VEGF-induced cell migration and proliferation in vitro. Here we show that overexpression of VEGF165b by tumour cells inhibits the growth of prostate carcinoma, Ewing's sarcoma and renal cell carcinoma in xenografted mouse tumour models. Moreover, VEGF165b overexpression inhibited tumour cell-mediated migration and proliferation of endothelial cells. These data show that overexpression of VEGF165b can inhibit growth of multiple tumour types in vivo indicating that VEGF165b has potential as an anti-angiogenic, anti-tumour strategy in a number of different tumour types, either by control of VEGF165b expression by regulation of splicing, overexpression of VEGF165b, or therapeutic delivery of VEGF165b to tumours

    D* Production in Deep Inelastic Scattering at HERA

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    This paper presents measurements of D^{*\pm} production in deep inelastic scattering from collisions between 27.5 GeV positrons and 820 GeV protons. The data have been taken with the ZEUS detector at HERA. The decay channel D+(D0Kπ+)π+D^{*+}\to (D^0 \to K^- \pi^+) \pi^+ (+ c.c.) has been used in the study. The e+pe^+p cross section for inclusive D^{*\pm} production with 5<Q2<100GeV25<Q^2<100 GeV^2 and y<0.7y<0.7 is 5.3 \pms 1.0 \pms 0.8 nb in the kinematic region {1.3<pT(D±)<9.01.3<p_T(D^{*\pm})<9.0 GeV and η(D±)<1.5| \eta(D^{*\pm}) |<1.5}. Differential cross sections as functions of p_T(D^{*\pm}), η(D±),W\eta(D^{*\pm}), W and Q2Q^2 are compared with next-to-leading order QCD calculations based on the photon-gluon fusion production mechanism. After an extrapolation of the cross section to the full kinematic region in p_T(D^{*\pm}) and η\eta(D^{*\pm}), the charm contribution F2ccˉ(x,Q2)F_2^{c\bar{c}}(x,Q^2) to the proton structure function is determined for Bjorken xx between 2 \cdot 104^{-4} and 5 \cdot 103^{-3}.Comment: 17 pages including 4 figure

    Plastisol Foaming Process. Decomposition of the Foaming Agent, Polymer Behavior in the Corresponding Temperature Range and Resulting Foam Properties

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    The decomposition of azodicarbonamide, used as foaming agent in PVC - plasticizer (1/1) plastisols was studied by DSC. Nineteen different plasticizers, all belonging to the ester family, two being polymeric (polyadipates), were compared. The temperature of maximum decomposition rate (in anisothermal regime at 5 K min-1 scanning rate), ranges between 434 and 452 K. The heat of decomposition ranges between 8.7 and 12.5 J g -1. Some trends of variation of these parameters appear significant and are discussed in terms of solvent (matrix) and viscosity effects on the decomposition reactions. The shear modulus at 1 Hz frequency was determined at the temperature of maximum rate of foaming agent decomposition, and differs significantly from a sample to another. The foam density was determined at ambient temperature and the volume fraction of bubbles was used as criterion to judge the efficiency of the foaming process. The results reveal the existence of an optimal shear modulus of the order of 2 kPa that corresponds roughly to plasticizer molar masses of the order of 450 ± 50 g mol-1. Heavier plasticizers, especially polymeric ones are too difficult to deform. Lighter plasticizers such as diethyl phthalate (DEP) deform too easily and presumably facilitate bubble collapse

    Observation of Scaling Violations in Scaled Momentum Distributions at HERA

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    Charged particle production has been measured in deep inelastic scattering (DIS) events over a large range of xx and Q2Q^2 using the ZEUS detector. The evolution of the scaled momentum, xpx_p, with Q2,Q^2, in the range 10 to 1280 GeV2GeV^2, has been investigated in the current fragmentation region of the Breit frame. The results show clear evidence, in a single experiment, for scaling violations in scaled momenta as a function of Q2Q^2.Comment: 21 pages including 4 figures, to be published in Physics Letters B. Two references adde
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