4,344 research outputs found
Pressure-driven magnetic moment collapse in the ground state of MnO
The zero temperature Mott transition region in antiferromagnetic, spin S=5/2
MnO is probed using the correlated band theory LSDA+U method. The first
transition encountered is an insulator-insulator volume collapse within the
rocksalt structure that is characterized by an unexpected Hund's rule violating
`spin-flip' moment collapse. This spin-flip to S=1/2 takes fullest advantage of
the anisotropy of the Coulomb repulsion, allowing gain in the kinetic energy
(which increases with decreasing volume) while retaining a sizable amount of
the magnetic exchange energy. While transition pressures vary with the
interaction strength, the spin-flip state is robust over a range of interaction
strengths and for both B1 and B8 structures
Association of Small Dense LDL with Coronary Artery Disease and Diabetes in Urban Asian Indians - The Chennai Urban Rural Epidemiology Study (CURES-8)
Objective: Earlier studies in Europeans have identified small dense LDL to be associated with coronary artery
disease and diabetes. In this study we assessed the association of small dense LDL with diabetes and CAD in
Asian Indians.
Methods: Study subjects were selected from the Chennai Urban Rural Epidemiology Study (CURES), a
population based study on representative sample of Chennai city in southern India. Group 1:non-diabetic
subjects (n=30); Group 2: diabetic subjects without CAD (n=30); Group 3:diabetic subjects with CAD (n=30).
LDL subfractions were estimated using LipoPrint LDL system. LDL subfractions 3 and above, defined as
small dense LDL was summed up to determine the overall small LDL. 75th percentile of the overall small
dense LDL in non-diabetic subjects was used as a cut-off for defining elevated levels of small dense LDL.
Results: The mean age of the study subjects was not significantly different among groups. Overall small
dense LDL was significantly higher in diabetic subjects with CAD (16.7 ± 11.1 mg/dl, p<0.05) and without
CAD (11.1 ± 8.0 mg/dl, p<0.05) compared to non-diabetic subjects without CAD (7.2 ± 6.8 mg/dl). Small
dense LDL showed a positive correlation with fasting plasma glucose (r=0.252, p=0.023), HbA1c (r=0.281,
p=0.012), total cholesterol (r=0.443, p<0.001), triglycerides(r=0.685, p<0.001), LDL(r=0.342, p=0.002), total
cholesterol/HDL ratio (r=0.660, p=<0.001) and triglycerides/HDL ratio(r=0.728, p<0.001) and a negative
correlation with HDL cholesterol (r= -0.341, p=0.002) and QUICKI values (r= -0.260, p=0.019). ROC curves
constructed to predict elevated small dense LDL ((9.0 mg/dl) revealed that triglycerides/HDL ratio and total
cholesterol/HDL ratio had higher AUC values compared to other parameters. A triglycerides/HDL ratio of
3.0 had the optimum sensitivity (80.0%) and specificity (78.0%) for detecting elevated small dense LDL.
Conclusion: This data suggests that in Asian Indians, small dense LDL is associated with both diabetes and
CAD and that a triglycerides/HDL ratio (3.0 could serve a surrogate marker of small dense LDL
Forecasting Stock Time-Series using Data Approximation and Pattern Sequence Similarity
Time series analysis is the process of building a model using statistical
techniques to represent characteristics of time series data. Processing and
forecasting huge time series data is a challenging task. This paper presents
Approximation and Prediction of Stock Time-series data (APST), which is a two
step approach to predict the direction of change of stock price indices. First,
performs data approximation by using the technique called Multilevel Segment
Mean (MSM). In second phase, prediction is performed for the approximated data
using Euclidian distance and Nearest-Neighbour technique. The computational
cost of data approximation is O(n ni) and computational cost of prediction task
is O(m |NN|). Thus, the accuracy and the time required for prediction in the
proposed method is comparatively efficient than the existing Label Based
Forecasting (LBF) method [1].Comment: 11 page
Electrochromic device response controlled by an in situ polymerized ionic liquid based gel electrolyte
Polymer electrolytes were synthesized by two different approaches and applied to electrochromic
devices based on electrodeposited tungsten oxide (WO3) or poly(3,4-ethylenedioxythiophene)
(PEDOT) films as the cathode, and a Prussian blue (PB) film as the anode. The first method involved
the entrapping of an ionic liquid in a polymer host (poly(methylmethacrylate) or PMMA) and the
second approach relied on the in situ thermal polymerization of methylmethacrylate (MMA) in the
hydrophobic ionic liquid, yielding a solidified transparent gel. The effect of in situ solid polymer
electrolyte formation on device performance characteristics was realized in terms of a larger
coloration efficiency of 119 cm2 C21 (l = 550 nm) achieved for the WO3–PB (MMA) device, as
compared to a value of 54 cm2 C21 obtained for the WO3–PB (PMMA) device. Similar enhancements
in electrochromic coloring efficiency, reflectance contrast, and faster switching kinetics were obtained
for the PEDOT–PB (MMA) device. The strategy of introducing an electrolyte to the electrochromic
device in a liquid state and then subjecting the same to gradual polymerization allows greater
accessibility of the electrolyte ions to the active sites on the electrochromic electrodes and superior
interfacial contact. As a consequence, larger optical contrast and faster kinetics are achieved in the
MMA based devices. While PEDOT films were amorphous, PB films were semi-crystalline but only in
the case of WO3; the hexagonal structure of WO3, equipped with three/four/six-coordinated voids was
found to affect bleaching kinetics favorably. The performance of PMMA based electrolyte is limited
by high resistance at the electrode–electrolyte interface, and a smaller number of ions available for
oxidation and reduction. Large area (y10 cm 6 4 cm) devices were also fabricated using this simple
wet chemistry method and their ability to color uniformly without any pinholes was demonstrated
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