141 research outputs found
Exercise tolerance and quality of life in patients with known or suspected coronary artery disease
Background: Coronary artery disease (CAD) is known to impact on patients’ physical and mental health. The relationship between performance on treadmill exercise tolerance test (ETT) and health-related quality of life (HRQL)has never been specifically investigated in the setting of CAD. Methods: Consecutive patients undergoing an ETT with the Bruce protocol during a diagnostic workup for CAD (n = 1,631, age 55 ± 12 years) were evaluated. Exercise-related indices were recorded. Detailed information on cardiovascular risk factors and past medical history were obtained. HRQLwas assessed with the use of the validated 36-Item Short Form Survey (SF-36) questionnaire. Results: Increasing age and the presence of cardiovascular risk factors and comorbidities correlated with lower scores on the physical and mental health component of SF-36(all P < 0.05). Subjects with arrhythmias during exercise and slow recovery of systolic blood pressure had lower scores on the physical health indices or the Social Role Functioning component (P < 0.05). Achieved target heart rate and good exercise tolerance were independently associated with better scores of the physical and mental health domains of SF-36 and overall HRQLscores (β = 0.05 for target HR and PCS-36, β = 1.86 and β = 1.66 per increasing stage of exercise tolerance and PCS-36 and MCS-36, respectively, P < 0.001 for all associations). Ischemic ECG changes were associated with worse scores on Physical Functioning (β = − 3.2, P = 0.02) and Bodily Pain (β = − 4.55, P = 0.026). Conclusion: ETT parameters are associated with HRQL indices in patients evaluated for possible CAD. Physical conditioning may increase patient well-being and could serve as a complementary target in conjunction with cardiovascular drug therapy
On the 4f25d → 4f3 interconfigurational transitions of Nd3+ ions in K2YF5 and LiYF4 crystal hosts
The Laser Induced Fluorescence (LIF) spectrum of K2YF5:Nd3+ (PFYK:Nd) and LiYF4:Nd3+ (YLF:Nd) single crystals, pumped by the fluorine F2 pulsed discharge molecular laser at 157.6 nm, was obtained in the Vacuum Ultraviolet (VUV) region of the spectrum. The fluorescence peaks were assigned to the 4f25d → 4f3 dipole allowed transitions of the Nd3+ ion. The 180 nm band of the LIF spectrum from the crystals indicates that the 4f25d → 4f3 dipole transitions originate from the low Stark components of the 4K11/2 level of the 4f25d configuration. The absorption spectrum of the crystal samples in the VUV was obtained as well and spectroscopic assignment of the levels of the 4f25d configuration was made. The electric crystal field splits all the levels of single and mixed configuration. The energy of the Stark components of the 4f25d configuration in YLF:Nd was shifted by few hundred cm-1 relative to that of PFYK:Nd. We observed eleven and nine dipole transitions, between the 4I9/2 ground level of the 4f3 configuration and the Stark components of the levels of the 4f25d configuration of the Nd3+ ion, in YLF and PFYK crystal hosts, respectively. © 1998 Elsevier Science B.V
On the VUV and UV 4f7(8S)5d > 4f8 interconfigurational transitions of Tb3+ ions in LiLuF4 single crystal hosts
The laser induced fluorescence spectrum of Tb3+ ions in LiLuF4 single crystals, pumped by a fluorine pulsed discharge molecular laser at 157.6 nm, was obtained in the vacuum ultraviolet (VUV) and ultraviolet (UV) regions of the spectrum. The 4f75d > 4f8 dipole allowed transitions originate from the Stark components and the edge of the levels of the 4f7(8S)5d electronic configuration. The LIF spectra were interpreted on the basis of phonon trapping and phonon reabsorption within the levels of the 4f75d electronic configuration. The absorption spectrum of the crystal samples in the VUV was obtained as well. We observed eight transitions between the ground level 4f8(7F6) and the Stark components of the levels of the 4f7(8S)5d electronic configuration and five transitions between the ground level 4f8(7F6) and the Stark components of the levels of the 4f7(6P)5d electronic configuration. The edge of the levels of the 4f75d electronic configuration was found to be at 45.2 × 103 ± 0.2 × 103 cm-1 and the band gap of the crystal host was 77.6 × 103 ± 0.3 × 103 cm-1 wide. © 1998 Elsevier Science B.V. All rights reserved
Tiny Rare-Earth Fluoride Nanoparticles Activate Tumour Cell Growth via Electrical Polar Interactions
© 2018, The Author(s). Localised extracellular interactions between nanoparticles and transmembrane signal receptors may well activate cancer cell growth. Herein, tiny LaF3 and PrF3 nanoparticles in DMEM+FBS suspensions stimulated tumour cell growth in three different human cell lines (A549, SW837 and MCF7). Size distribution of nanoparticles, activation of AKT and ERK signalling pathways and viability tests pointed to mechanical stimulation of ligand adhesion binding sites of integrins and EGFR via a synergistic action of an ensemble of tiny size nanoparticles (< 10 nm). While tiny size nanoparticles may be well associated with the activation of EGFR, integrin interplay with nanoparticles remains a multifaceted issue. A theoretical motif shows that, within the requisite pN force scale, each ligand adhesion binding site can be activated by a tiny size dielectric nanoparticle via electrical dipole interaction. The size of the active nanoparticle stayed specified by the amount of the surface charges on the ligand adhesion binding site and the nanoparticle, and also by the separating distance between them. The polar component of the electrical dipole force remained inversely proportional to the second power of nanoparticle’s size, evincing that only tiny size dielectric nanoparticles might stimulate cancer cell growth via electrical dipole interactions. The work contributes towards recognising different cytoskeletal stressing modes of cancer cells
Vacuum-ultraviolet interconfigurational 4f3 → 4f 25d absorption and emission studies of the Nd3+ ion in KYF, YF, and YLF crystal hosts
The laser-induced vacuum-ultraviolet fluorescence spectra of KY 3F10:Nd3+ (KYF:Nd) and YF3:Nd 3+ (YF:Nd) single crystals pumped by a pulsed-discharge molecular F2 laser at 157 nm were obtained. A number of new fluorescence peaks were observed and were assigned to the 4f 25d → 4f3 dipole-allowed transitions of the Nd3+ ion. The absorption spectra of LiYF4:Nd3+ (YLF:Nd), KYF:Nd, and YF:Nd crystal samples in the vacuumultraviolet spectral regions were also obtained. Finally, the splitting of the states of the 4f25d configuration of the Nd 3+ ion, which is due to the crystal field, was observed in all the crystal samples. © 1995 Optical Society of America
Surface profile gradient in amorphous Ta<inf>2</inf>O<inf>5</inf> semi conductive layers regulates nanoscale electric current stability
© 2016 The Author(s)A link between the morphological characteristics and the electric properties of amorphous layers is established by means of atomic, conductive, electrostatic force and thermal scanning microscopy. Using amorphous Ta2O5 (a-Ta2O5) semiconductive layer, it is found that surface profile gradients (morphological gradient), are highly correlated to both the electron energy gradient of trapped electrons in interactive Coulombic sites and the thermal gradient along conductive paths and thus thermal and electric properties are correlated with surface morphology at the nanoscale. Furthermore, morphological and electron energy gradients along opposite conductive paths of electrons intrinsically impose a current stability anisotropy. For either long conductive paths (L > 1 μm) or along symmetric nanodomains, current stability for both positive and negative currents i is demonstrated. On the contrary, for short conductive paths along non-symmetric nanodomains, the set of independent variables (L, i) is spanned by two current stability/intability loci. One locus specifies a stable state for negative currents, while the other locus also describes a stable state for positive currents
Surface profile gradient in amorphous Ta<inf>2</inf>O<inf>5</inf> semi conductive layers regulates nanoscale electric current stability
© 2016 The Author(s)A link between the morphological characteristics and the electric properties of amorphous layers is established by means of atomic, conductive, electrostatic force and thermal scanning microscopy. Using amorphous Ta2O5 (a-Ta2O5) semiconductive layer, it is found that surface profile gradients (morphological gradient), are highly correlated to both the electron energy gradient of trapped electrons in interactive Coulombic sites and the thermal gradient along conductive paths and thus thermal and electric properties are correlated with surface morphology at the nanoscale. Furthermore, morphological and electron energy gradients along opposite conductive paths of electrons intrinsically impose a current stability anisotropy. For either long conductive paths (L > 1 μm) or along symmetric nanodomains, current stability for both positive and negative currents i is demonstrated. On the contrary, for short conductive paths along non-symmetric nanodomains, the set of independent variables (L, i) is spanned by two current stability/intability loci. One locus specifies a stable state for negative currents, while the other locus also describes a stable state for positive currents
VUV and UV fluorescence and absorption studies of tb3+ and tm3+ trivalent ions in liyf4 single crystal hosts
The laser induced fluorescence spectra of LiYF4: Tb3+ (YLF: Tb) and LiYF4:Tm3+ (YLF: Tm) single crystals, pumped by an F2 pulsed discharge molecular laser at 157 nm, were obtained in the vacuum ultraviolet (VUV) and ultraviolet (UV) regions of the spectrum, at room temperature. A number of new fluorescence peaks were observed for the first time. They were assigned to the dipole allowed transitions 4f75d→4f8 and 4f115d→4f12 of Tb3+ and Tm3+ ions respectively. The absorption spectra of the same crystal samples in the VUV and UV regions were taken as well. The edge (onset) and the energy of the states with 4fN-1 5d configuration were determined. © 1994 Taylor and Francis Ltd
Surface profile gradient in amorphous Ta<inf>2</inf>O<inf>5</inf> semi conductive layers regulates nanoscale electric current stability
© 2016 The Author(s).A link between the morphological characteristics and the electric properties of amorphous layers is established by means of atomic, conductive, electrostatic force and thermal scanning microscopy. Using amorphous Ta2O5 (a-Ta2O5) semiconductive layer, it is found that surface profile gradients (morphological gradient), are highly correlated to both the electron energy gradient of trapped electrons in interactive Coulombic sites and the thermal gradient along conductive paths and thus thermal and electric properties are correlated with surface morphology at the nanoscale.Furthermore, morphological and electron energy gradients along opposite conductive paths of electrons intrinsically impose a current stability anisotropy. For either long conductive paths (L .>. 1. μm) or along symmetric nanodomains, current stability for both positive and negative currents . i is demonstrated. On the contrary, for short conductive paths along non-symmetric nanodomains, the set of independent variables (L, i) is spanned by two current stability/intability loci. One locus specifies a stable state for negative currents, while the other locus also describes a stable state for positive currents
The Hellenic type of nondeletional hereditary persistence of fetal hemoglobin results from a novel mutation (g.-109G>T) in the HBG2 gene promoter
Nondeletional hereditary persistence of fetal hemoglobin (nd-HPFH), a rare hereditary condition resulting in elevated levels of fetal hemoglobin (Hb F) in adults, is associated with promoter mutations in the human fetal globin (HBG1 and HBG2) genes. In this paper, we report a novel type of nd-HPFH due to a HBG2 gene promoter mutation (HBG2:g.-109G>T). This mutation, located at the 3′ end of the HBG2 distal CCAAT box, was initially identified in an adult female subject of Central Greek origin and results in elevated Hb F levels (4.1%) and significantly increased Gγ-globin chain production (79.2%). Family studies and DNA analysis revealed that the HBG2:g.-109G>T mutation is also found in the family members in compound heterozygosity with the HBG2:g.-158C>T single nucleotide polymorphism or the silent HBB:g.-101C>T β-thalassemia mutation, resulting in the latter case in significantly elevated Hb F levels (14.3%). Electrophoretic mobility shift analysis revealed that the HBG2:g.-109G>T mutation abolishes a transcription factor binding site, consistent with previous observations using DNA footprinting analysis, suggesting that guanine at position HBG2/1:g.-109 is critical for NF-E3 binding. These data suggest that the HBG2:g-109G>T mutation has a functional role in increasing HBG2 transcription and is responsible for the HPFH phenotype observed in our index cases
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