7 research outputs found

    13^{13}C NMR observation of a nonmagnetic charge-ordered state in the organic conductor κ\kappa-(ET)2_{2}Hg(SCN)2_{2}Cl

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    We investigated the local magnetism of the organic conductor, κ\kappa-(ET)2_{2}Hg(SCN)2_{2}Cl, with a quasi-triangular lattice of weakly dimerized molecules through 13^{13}C NMR spectroscopy. The NMR spectra and nuclear relaxation show that charge disproportionation occurs, associated with the metal-insulator transition at 31 K. The relaxation rate indicates that the paramagnetic spins in the insulating phase undergo a transition into a spin-singlet ground state with the emergence of orphan spins, a possible valence-bond-glass state. The present results are in high contrast to the spin-cluster paramagnetism of the electric dipole-liquid candidate, κ\kappa--(ET)2_{2}Hg(SCN)2_{2}Br, having nearly identical material parameters. This fact indicates that these two systems are on the verge between distinct phases in both charge and spin degrees of freedom; a spin-singlet charge-ordered state versus a spin-active Mott insulating state, competing with each other on a triangular lattice of dimerized sites

    THE EFFECT OF STATIN ADDED TO ANTIHYPERTENSIVE THERAPY ON ARTERIAL STIFFNESS IN HYPERTENSIVE PATIENTS AT HIGH CARDIOVASCULAR RISK

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    Background. Little is known about the effect of statins addition to standard antihypertensive therapy on blood pressure level and vascular stiffness in high-risk hypertensive patients.The aim of the study was to assess the dynamics of vascular stiffness in hypertensive patients of high or very high cardiovascular risk under the influence of rosuvastatin addition to combined two-component amlodipine and lisinopril antihypertensive therapy.Materials and methods. We investigated 60 hypertensive patients who were randomized into two groups: the 1st group received a fixed amlodipine/lisinopril combination, the 2nd one followed the same regimen of therapy with addition of 20 mg rosuvastatin. Mean office and ambulatory blood pressure as well as central aortic blood pressure and pulse wave velocity were evaluated in both groups before and after 24-week follow-up period.Results. At end of follow-up period the office and average daily blood pressure significantly decreased in both groups, with more prominent office diastolic blood pressure decline in the 2nd one. The central aortic blood pressure equally decreased in both groups. The augmentation index significantly reduced in both groups, mostly in the 2nd one. The carotid-femoral pulse wave velocity declined in both groups to the same extent. The carotid-radial pulse wave velocity decreased statistically only in the second group.Conclusions. Addition of rosuvastatin to a fixed amlodipine/lisinopril combination in high/very high cardiovascular risk hypertensive patients was accompanied by more pronounced decline of diastolic blood pressure and augmentation index, as well as significantly reduction of pulse wave velocity

    Drug Correction of Vascular Remodeling in Patients with Hypertension: Results of 52-Week Prospective Study ARTERIA-AG

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    Aim. To study the long-term dynamics of vascular remodeling in patients with hypertension and high and very high cardiovascular risk when statin is added to antihypertensive therapy with a fixed combination of calcium antagonist and angiotensin converting enzyme (ACE) inhibitor.Material and methods. Hypertensive patients (n=75) with high and very high cardiovascular risk (age 51.5 [44;58] years) were included in the study. Patients were randomized into two groups. The first group (n=36) received a fixed combination of amlodipine and lisinopril in starting dose of 5/10 mg/day. The second group (n=39) received the same antihypertensive therapy and additionally rosuvastatin (20 mg/day). The follow-up period was 52 weeks. The effect of therapy on the following parameters was evaluated: level of office and average daily blood pressure (BP), central BP in the aorta, augmentation index (AIx), pulse wave velocity (PWV), endothelium-dependent brachial artery vasodilation, carotid intima-media complex thickness, carotid arteries plaque height, and blood lipid profile indicators.Results. A significant decrease in office and average daily BP was found in both groups: from 171.5 (152;194)/104.5 (97;112) to 140.0 (129;154)/87.0 (83;95) mm Hg and from 142.1 (135;153)/86.7 (83;97) to 124.6 (119;133)/76.5 (73;80) mm Hg, respectively, in the 1st group; from 169.5 (160;190)/103.5 (95;109) to 135.0 (125;141)/83.0 (77;88) mm Hg and from 139.9 (136;152)/86.2 (80;92) to 125.1 (118;134)/74.0 (70;81) mm Hg, respectively, in the 2nd group (p<0.001 for all changes). The frequency of reaching the target office BP level was higher in the 2nd group (p=0.031). Significant decrease in total cholesterol by 33.1% and low-density lipoprotein cholesterol by 50.0% was observed in the group 2. Central BP in the aorta decreased in both groups; the degree of central BP reduction did not differ significantly. AIx decreased from 36.5 (24;41)% to 25.0 (15;36)% (p=0.04) in the 1st group and from 36.0 (30;41)% to 24.0 (20;32)% in the 2nd group (p<0.0001) with a more pronounced decrease in AIx after 24 weeks of therapy (-4.8% and -9.4%, respectively, p=0.036). This trend continued at the end of the observation (-6.4% and -10.8%, respectively, p=0.08). Carotid-femoral and carotid-radial PWV decreased only in the 2nd group from 9.5 (8.2;10.7) to 8.3 (7.6;8.9) m/s (p=0.003) and from 9,6 (8.5;10.6) to 8.4 (7.9;9.3) m/s (p=0.01), respectively. A significant decrease in the thickness of the intima-media from 1.08 (1.0;1.2) to 1.02 (0.9;1.1) cm (p<0.0001) and the height of the plaque from 2.2 (2,2;1.7) to 2.1 (2.1;1.7) mm (p=0.001) was found in the 2nd group.Conclusion. Addition of rosuvastatin to the fixed combination of amlodipine and lisinopril in treatment of hypertensive patients with high and very high cardiovascular risk was accompanied by a more frequent (compared with amlodipine and lisinopril only) achievement of the target office BP level and more pronounced reduction in the following indicators: augmentation index, carotid-femoral and carotid-radial PWV, intima-media thickness, plaque height, total cholesterol and low density lipoprotein cholesterol blood levels

    Layered Organic Conductors Based on BEDT-TTF and Ho, Dy, Tb Chlorides

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    Molecular semiconductors with lanthanide ions have been synthesized based on BEDT-TTF and lanthanide chlorides: (BEDT-TTF)2[HoCl2(H2O)6]Cl2(H2O)2 (1, which contains a 4f holmium cation), and (BEDT-TTF)2LnCl4(H2O)n (Ln = Dy, Tb, Ho (2–4), which contain 4f anions of lanthanides). Conductivity and EPR measurements have been carried out along with the SQUID magnetometry, and the crystal structure has been established for 1. The structure of 1 is characterized by an alternation of organic radical cation layers composed of BEDT-TTF chains and inorganic layers consisting of chains of the [HoCl2(H2O)6]+ cations interlinked by chlorine anions and crystallization water molecules. The magnetic susceptibility of 1–3 determined mainly by lanthanide ions follows the Curie–Weiss law with the Weiss temperatures of −3, −3, −2 K for 1–3, respectively, indicating weak antiferromagnetic coupling between paramagnetic lanthanide ions. The signals attributed to the BEDT-TTF+· radical cations only are observed in the EPR spectra of 1–3, which makes it possible to study their magnetic behavior. There are two types of chains in the organic layers of 1: the chains composed of neutral molecules and those formed by BEDT-TTF+· radical cations. As a result, uniform 1D antiferromagnetic coupling of spins is observed in the BEDT-TTF+· chains with estimated exchange interaction J = −10 K. The study of dynamic magnetic properties of 1–3 shows that these compounds are not SMMs

    Layered Organic Conductors Based on BEDT-TTF and Ho, Dy, Tb Chlorides

    No full text
    Molecular semiconductors with lanthanide ions have been synthesized based on BEDT-TTF and lanthanide chlorides: (BEDT-TTF)2[HoCl2(H2O)6]Cl2(H2O)2 (1, which contains a 4f holmium cation), and (BEDT-TTF)2LnCl4(H2O)n (Ln = Dy, Tb, Ho (2–4), which contain 4f anions of lanthanides). Conductivity and EPR measurements have been carried out along with the SQUID magnetometry, and the crystal structure has been established for 1. The structure of 1 is characterized by an alternation of organic radical cation layers composed of BEDT-TTF chains and inorganic layers consisting of chains of the [HoCl2(H2O)6]+ cations interlinked by chlorine anions and crystallization water molecules. The magnetic susceptibility of 1–3 determined mainly by lanthanide ions follows the Curie–Weiss law with the Weiss temperatures of −3, −3, −2 K for 1–3, respectively, indicating weak antiferromagnetic coupling between paramagnetic lanthanide ions. The signals attributed to the BEDT-TTF+· radical cations only are observed in the EPR spectra of 1–3, which makes it possible to study their magnetic behavior. There are two types of chains in the organic layers of 1: the chains composed of neutral molecules and those formed by BEDT-TTF+· radical cations. As a result, uniform 1D antiferromagnetic coupling of spins is observed in the BEDT-TTF+· chains with estimated exchange interaction J = −10 K. The study of dynamic magnetic properties of 1–3 shows that these compounds are not SMMs
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