Yang-Yang thermodynamics on an atom chip

We investigate the behavior of a weakly interacting nearly one-dimensional (1D) trapped Bose gas at finite temperature. We perform in situ measurements of spatial density profiles and show that they are very well described by a model based on exact solutions obtained using the Yang-Yang thermodynamic formalism, in a regime where other, approximate theoretical approaches fail. We use Bose-gas focusing [Shvarchuck etal., Phys. Rev. Lett. 89, 270404 (2002)] to probe the axial momentum distribution of the gas, and find good agreement with the in situ results.Comment: extended introduction and conclusions, and minor changes throughout; accepted for publication in Phys. Rev. Let

The Hybrid Approach to Intervention of Chronic Total Occlusions

The "hybrid" approach to chronic total occlusion (CTO) percutaneous coronary intervention (PCI) was developed to provide guidance on optimal crossing strategy selection. Dual angiography remains the cornerstone of clinical decision making in CTO PCI. Four angiographic parameters are assessed: (a) morphology of the proximal cap (clear-cut or ambiguous); (b) occlusion length; (c) distal vessel size and presence of bifurcations beyond the distal cap; and (d) location and suitability of location and suitability of a retrograde conduit (collateral channels or bypass grafts) for retrograde access. Antegrade wire escalation is favored for short (<20 mm) occlusions, usually escalating rapidly from a soft tapered-tip polymer-jacketed guidewire to a stiff polymer-jacketed or tapered-tip guidewire. Antegrade dissection/re-entry is favored in long (≥20 mm long) occlusions, trying to minimize the dissection length by re-entering into the distal true lumen immediately after the occlusion. Primary retrograde approach is preferred for lesions with an ambiguous proximal cap, poor distal target, good interventional collaterals, and heavy calcification,as well as chronic kidney disease. The "hybrid" approach advocates early change between strategies to enable CTO crossing in the most efficacious, efficient, and safe way. Several early studies are demonstrating high success and low complication rates with use of the "hybrid" approach, supporting its expanding use in CTO PCI

Box traps on an atom chip for one-dimensional quantum gases

We present the implementation of tailored trapping potentials for ultracold gases on an atom chip. We realize highly elongated traps with box-like confinement along the long, axial direction combined with conventional harmonic confinement along the two radial directions. The design, fabrication and characterization of the atom chip and the box traps is described. We load ultracold ($\lesssim1 \mu$K) clouds of $^{87}$Rb in a box trap, and demonstrate Bose-gas focusing as a means to characterize these atomic clouds in arbitrarily shaped potentials. Our results show that box-like axial potentials on atom chips are very promising for studies of one-dimensional quantum gases.Comment: 9 pages 4 figure

Relationship between infarct tissue characteristics and left ventricular remodeling in patients with versus without early revascularization for acute myocardial infarction as assessed with contrast-enhanced cardiovascular magnetic resonance imaging

Left ventricular (LV) remodeling following myocardial infarction (MI) is the result of complex interactions between various factors, including presence or absence of early revascularization. The impact of early revascularization on the relationship between infarct tissue characteristics and LV remodeling is incompletely known. Therefore, we investigated in patients with versus without successful early revascularization for acute MI potential relations between infarct tissue characteristics and LV remodeling with contrast-enhanced (CE) cardiovascular magnetic resonance (CMR). Patients with versus without successful early revascularization underwent CE-CMR for tissue characterization and assessment of LV remodeling including end-diastolic and end-systolic volumes, LV ejection fraction, and wall motion score index (WMSI). CE-CMR images were analyzed for infarct tissue characteristics including core-, peri- and total-infarct size, transmural extent, and regional scar scores. In early revascularized patients (n = 46), a larger area of infarct tissue correlated significantly with larger LV dimensions and a more reduced LV function (r = 0.39-0.68; all P ≤ 0.01). Multivariate analyses identified peri-infarct size as the best predictor of LV remodeling parameters (R2 = 0.44-0.62). In patients without successful early revascularization (n = 47), there was no correlation between infarct area and remodeling parameters; only peri-infarct size versus WMSI (r = 0.33; P = 0.03) and transmural extent versus LVEF (r = -0.27; P = 0.07) tended to be related. A correlation between infarct tissue characteristics and LV remodeling was found only in patients with early successful revascularization. Peri-infarct size was found to be the best determinant of LV remodeling. Our findings stress the importance of taking into account infarct tissue characteristics and success of revascularization when LV remodeling is studie

Stimulus-induced gamma power predicts the amplitude of the subsequent visual evoked response

The efficiency of neuronal information transfer in activated brain networks may affect behavioral performance. Gamma-band synchronization has been proposed to be a mechanism that facilitates neuronal processing of behaviorally relevant stimuli. In line with this, it has been shown that strong gamma-band activity in visual cortical areas leads to faster responses to a visual go cue. We investigated whether there are directly observable consequences of trial-by-trial fluctuations in non-invasively observed gamma-band activity on the neuronal response. Specifically, we hypothesized that the amplitude of the visual evoked response to a go cue can be predicted by gamma power in the visual system, in the window preceding the evoked response. Thirty-three human subjects (22 female) performed a visual speeded response task while their magnetoencephalogram (MEG) was recorded. The participants had to respond to a pattern reversal of a concentric moving grating. We estimated single trial stimulus-induced visual cortical gamma power, and correlated this with the estimated single trial amplitude of the most prominent event-related field (ERF) peak within the first 100 ms after the pattern reversal. In parieto-occipital cortical areas, the amplitude of the ERF correlated positively with gamma power, and correlated negatively with reaction times. No effects were observed for the alpha and beta frequency bands, despite clear stimulus onset induced modulation at those frequencies. These results support a mechanistic model, in which gamma-band synchronization enhances the neuronal gain to relevant visual input, thus leading to more efficient downstream processing and to faster responses