First-Principles Calculation of the Cu-Li Phase Diagram

We present first-principles calculations of the solid-state portion of the Cu-Li phase diagram based on the cluster expansion formalism coupled with the use of (i) bond length-dependent transferable force constants and lattice dynamics calculations to model of vibrational disorder and (ii) lattice gas Monte Carlo simulations to model configurational disorder. These calculations help settle the existence of additional phases in the Cu-Li phase diagram that have been postulated, but not yet clearly established. Our calculations predict the presence of at least one additional phase and the associated predicted phase transitions are consistent with our electrochemical measurements, which exhibit clear plateaus in the electromotive force-composition curve

Coronary plaque redistribution after stent implantation is determined by lipid composition: A NIRS-IVUS analysis

Background: The composition of plaque impacts the results of stenting. The following study evaluated plaque redistribution related to stent implantation using combined near-infrared spectroscopy and intravascular ultrasound (NIRS-IVUS) imaging. Methods: The present study included 49 patients (mean age 66 ± 11 years, 75% males) presenting with non-ST elevation myocardial infarction (8%), unstable angina (49%) and stable coronary artery disease (43%). The following parameters were analyzed: mean plaque volume (MPV, mm3), plaque burden (PB, %), remodeling index (RI), and maximal lipid core burden index in a 4 mm segment (maxLCBI4mm). High-lipid burden lesions (HLB) were defined as by maxLCBI4mm > 265 with positive RI. Otherwise plaques were defined as low-lipid burden lesions (LLB). Measurements were done in the target lesion and in 4 mm edges of the stent before and after stent implantation. Results: MPV and maxLCBI4mm decreased in both HLB (MPV 144.70 [80.47, 274.25] vs. 97.60 [56.82, 223.45]; maxLCBI4mm: 564.11 ± 166.82 vs. 258.11 ± 234.24, p = 0.004) and LLB (MPV: 124.50 [68.00, 186.20] vs. 101.10 [67.87, 165.95]; maxLCBI4mm: 339.07 ± 268.22 vs. 124.60 ± 160.96, p < 0.001), but MPV decrease was greater in HLB (28.00 [22.60, 57.10] vs. 13.50 [1.50, 28.84], p = 0.019). Only at the proximal stent edge of LLB, maxLCBI4mm decreased (34 [0, 207] vs. 0 [0, 45], p = 0.049) and plaque burden increased (45.48 [40.34, 51.55] vs. 51.75 [47.48, 55.76], p = 0.030). Conclusions: NIRS-IVUS defined HLB characterized more significant decreases in plaque volume by stenting. Plaque redistribution to the proximal edge of the implanted stent occurred only in LLB

SERUM IGF-I AND HORMONAL RESPONSES TO INCREMENTAL EXERCISE IN ATHLETES WITH AND WITHOUT LEFT VENTRICULAR HYPERTROPHY

We investigated the response of insulin-like growth factor (IGF- I), insulin-like growth factor binding protein-3 (IGFBP-3) and some hormones, i.e., testosterone (T), growth hormone (GH), cortisol (C), and insulin (I), to maximal exercise in road cyclists with and without diagnosed left ventricular hypertrophy. M-mode and two-dimensional Doppler echocardiography was performed in 30 professional male endurance athletes and a group of 14 healthy untrained subjects using a Hewlett-Packard Image Point HX ultrasound system with standard imaging transducers. Echocardiography and an incremental physical exercise test were performed during the competitive season. Venous blood samples were drawn before and immediately after the maximal cycling exercise test for determination of somatomedin and hormonal concentrations. The basal concentration of IGF-I was statistically higher (p < 0.05) in athletes with left ventricular muscle hypertrophy (LVH) when compared to athletes with a normal upper limit of the left ventricular wall (LVN) (p < 0.05) and to the control group (CG) (p < 0.01). The IGF-I level increased significantly at maximal intensity of incremental exercise in CG (p < 0.01), LVN (p < 0.05) and LVH (p < 0.05) compared to respective values at rest. Long-term endurance training induced an increase in resting (p < 0.01) and post-exercise (p < 0.05) IGF-I/IGFBP-3 ratio in athletes with LVH compared to LVN. The testosterone (T) level was lower in LVH at rest compared to LVN and CG groups (p < 0.05). These results indicate that resting serum IGF-I concentration were higher in trained subjects with LVH compared to athletes without LVH. Serum IGF- I/IGFBP-3 elevation at rest and after exercise might suggest that IGF-I act as a potent stimulant of left ventricular hypertrophy in chronically trained endurance athlete

Prognostic value of low-dose dobutamine stress echocardiography in patients with aortic stenosis and impaired left ventricular function.

INTRODUCTION: The aim of this multicenter, prospective study was to evaluate the long-term prognostic value of low-dose dobutamine stress echocardiography (LDDSE) in patients with aortic stenosis (AS) and depressed left ventricular (LV) function. MATERIAL AND METHODS: The study group comprised 39 patients (34 male, mean age 59 +/-13 years) with AS (peak gradient > 25 mm Hg), LV ejection fraction (LVEF) </= 45% and low transaortic gradient (peak gradient </= 45 mm Hg, mean gradient </= 35 mm Hg). The qualification for subsequent therapeutic procedures was based on generally accepted indications. All patients underwent LDDSE and coronary angiography. Twelve months after LDDSE patients underwent control resting echocardiography and clinical evaluation. RESULTS: Twenty-seven (69.2%) patients had preserved contractile reserve. In this subgroup, true-severe AS was diagnosed in 12 patients, whereas pseudo-severe AS was found in 15 patients. Nine patients with true-severe AS, 2 patients with pseudo-severe AS and 7 patients without contractile reserve were referred for surgical treatment. The independent risk factors of death during follow-up were: aortic valve area (AVA) at peak stress < 0.8 cm(2) (OR 1.4; p = 0.003) and LVEF at rest < 35% (OR 6.8; p = 0.05). The independent risk factors of composite end-point (death or myocardial infarctions or pulmonary edema) were: AVA at stress < 0.8 cm(2) (OR 4.0; p = 0.03), absence of AVA increase during LDDSE (OR 5.7; p = 0.005), absence of contractile reserve (OR 4.5; p = 0.01) and presence of significant CAD (OR 6.9; p = 0.02). CONCLUSIONS: In patients with AS and depressed LVEF, LDDSE is a useful tool for long-term risk stratification

Influence of gender on diagnostic accuracy of rapid atrial and ventricular pacing stress echocardiography for the detection of coronary artery disease: a multicenter study (Pol-RAPSE final results).

BACKGROUND: Rapid cardiac pacing using a permanent pacemaker may be used as a nonpharmacologic stress during echocardiographic imaging for diagnosing coronary artery disease (CAD). We presented the final results of a national multicenter study, the Polish study on Rapid Pacing Stress Echocardiography (Pol-RAPSE), aimed at the assessment of the safety and accuracy of rapid cardiac pacing for the noninvasive diagnosis of CAD in women and men. METHODS: We have analyzed 149 tests performed in 100 patients with permanent pacemakers (27% ventricular pacing [VVI], 10% atrial pacing [AAI], 63% dual chamber pacing [DDD]) referred for stress echocardiography. All patients underwent coronary angiography as a reference for assessing the accuracy of rapid cardiac pacing stress echocardiography (RAPSE). Significant CAD was defined as luminal diameter reduction more than 50% in at least 1 major epicardial coronary artery. RESULTS: Peak stress was obtained in 73 patients using physiologic stimulation of right atrium by and mode or in 76 patients by VVI mode. Significant CAD was detected by angiography in 46% of women and 57% of men (P = not significant). The feasibility of the test was 98%. Overall accuracy of the test was slightly lower in women than in men (75% vs 88%, P = .04), although there were no significant differences in sensitivity, specificity, and positive and negative predictive values between the genders. In women (n = 48), the accuracy of RAPSE performed in AAI and VVI mode was 79% and 70% with no significant difference and in men was 89% and 87%, respectively (P = not significant). CONCLUSION: RAPSE is a safe and feasible modality for diagnosing CAD. The method offers slightly higher accuracy in men compared with women. Overall efficacy is satisfactory with both AAI and VVI pacing, although easier interpretation of peak AAI/DDD images results in a trend toward better accuracy