68 research outputs found
KamLAND, terrestrial heat sources and neutrino oscillations
We comment on the first indication of geo-neutrino events from KamLAND and on
the prospects for understanding Earth energetics. Practically all models of
terrestrial heat production are consistent with data within the presently
limited statistics, the fully radiogenic model being closer to the observed
value ( geo-events). In a few years KamLAND should collect
sufficient data for a clear evidence of geo-neutrinos, however discrimination
among models requires a detector with the class and size of KamLAND far away
from nuclear reactors. We also remark that the event ratio from Thorium and
Uranium decay chains is well fixed , a constraint that
can be useful for determining neutrino oscillation parameters. We show that a
full spectral analysis, including this constraint, further reduces the
oscillation parameter space compared to an analysis with an energy threshold
.Comment: 12 pages, RevTeX file, 3 ps figures included in the correct order,
corrected some typos and added references. Accepted for publication on Phys.
Lett.
Local charge and spin currents in magnetothermal landscapes
A scannable laser beam is used to generate local thermal gradients in
metallic (Co2FeAl) or insulating (Y3Fe5O12) ferromagnetic thin films. We study
the resulting local charge and spin currents that arise due to the anomalous
Nernst effect (ANE) and the spin Seebeck effect (SSE), respectively. In the
local ANE experiments, we detect the voltage in the Co2FeAl thin film plane as
a function of the laser spot position and external magnetic field magnitude and
orientation. The local SSE effect is detected in a similar fashion by
exploiting the inverse spin Hall effect in a Pt layer deposited on top of the
Y3Fe5O12. Our findings establish local thermal spin and charge current
generation as well as spin caloritronic domain imaging
Whole-thorax irradiation induces hypoxic respiratory failure, pleural effusions and cardiac remodeling
To study the mechanisms of death following a single lethal dose of thoracic radiation, WAG/RijCmcr (Wistar) rats were treated with 15 Gy to the whole thorax and followed until they were morbid or sacrificed for invasive assays at 6 weeks. Lung function was assessed by breathing rate and arterial oxygen saturation. Lung structure was evaluated histologically. Cardiac structure and function were examined by echocardiography. The frequency and characteristics of pleural effusions were determined. Morbidity from 15 Gy radiation occurred in all rats 5 to 8 weeks after exposure, coincident with histological pneumonitis. Increases in breathing frequencies peaked at 6 weeks, when profound arterial hypoxia was also recorded. Echocardiography analysis at 6 weeks showed pulmonary hypertension and severe right ventricular enlargement with impaired left ventricular function and cardiac output. Histologic sections of the heart revealed only rare foci of lymphocytic infiltration. Total lung weight more than doubled. Pleural effusions were present in the majority of the irradiated rats and contained elevated protein, but low lactate dehydrogenase, when compared with serum from the same animal. Pleural effusions had a higher percentage of macrophages and large monocytes than neutrophils and contained mast cells that are rarely present in other pathological states. Lethal irradiation to rat lungs leads to hypoxia with infiltration of immune cells, edema and pleural effusion. These changes may contribute to pulmonary vascular and parenchymal injury that result in secondary changes in heart structure and function. We report that conditions resembling congestive heart failure contribute to death during radiation pneumonitis, which indicates new targets for therapy
Edge-on disk around the T Tauri star [MR81] Halpha 17 NE in CrA
Using the speckle camera SHARP at the 3.5m ESO NTT, K\"ohler and
collaborators found an object ~3.5 mag fainter in K only 1.3" north-east of the
T Tauri star [MR81] Ha 17 in the Corona Australis (CrA) star-forming region,
which could be either a brown dwarf or a T Tauri star with an edge-on disk. We
attempt to study this faint object in detail. We acquired deep VLT NACO
near-infrared images at three epochs to determine, whether [MR81] Ha 17 and the
nearby faint object are co-moving and to measure the infrared colors of both
objects. We obtained optical and infrared spectra of both objects with the VLT
using FORS and ISAAC, respectively, to determine spectral types and
temperatures as well as ages and masses. The T Tauri star [MR81] Ha 17 and the
faint nearby object have a projected separation of 1369.58 mas, i.e. 178 AU at
130 pc. They share the same proper motion (~5 sigma), so that they most
certainly form a bound binary pair. The apparently fainter component [MR81] Ha
17 NE has a spectral type of M2e, while the apparently brighter component
[MR81] Ha 17 SW, the previously known T Tauri star, has a spectral type of
M4-5e. We can identify a nearly edge-on disk around [MR81] Ha 17 NE by visual
inspection, which has a diameter of at least 30 to 50 AU. We are able to detect
strong emission lines in [MR81] Ha 17 NE, which are almost certainly due to
ongoing accretion. The NE object is detectable only by means of its scattered
light. If both objects are coeval (2-3 Myr) and located at the same distance
(~130 pc as CrA), then the apparently fainter [MR81] Ha 17 NE is more massive
(primary) component with a nearly edge-on disk and the apparently brighter
component [MR81] Ha 17 SW is less massive (com- panion). Both are low-mass T
Tauri stars with masses of ~0.5 and 0.23 \pm 0.05 solar masses, respectively.Comment: A&A in pres
The Impact of Insulin Pump Therapy on Glycemic Profiles in Patients with Type 2 Diabetes: Data from the OpT2mise Study
Background: The OpT2mise randomized trial was designed to compare the effects of continuous subcutaneous insulin infusion (CSII) and multiple daily injections (MDI) on glucose profiles in patients with type 2 diabetes. Research Design and Methods: Patients with glycated hemoglobin (HbA1c) levels of â„8% (64 mmol/mol) and â€12% (108 mmol/mol) despite insulin doses of 0.7-1.8 U/kg/day via MDI were randomized to CSII (n=168) or continued MDI (n=163). Changes in glucose profiles were evaluated using continuous glucose monitoring data collected over 6-day periods before and 6 months after randomization. Results: After 6 months, reductions in HbA1c levels were significantly greater with CSII (-1.1±1.2% [-12.0±13.1 mmol/mol]) than with MDI (-0.4±1.1% [-4.4±12.0 mmol/mol]) (P<0.001). Similarly, compared with patients receiving MDI, those receiving CSII showed significantly greater reductions in 24-h mean sensor glucose (SG) (treatment difference, -17.1 mg/dL; P=0.0023), less exposure to SG >180 mg/dL (-12.4%; P=0.0004) and SG >250 mg/dL (-5.5%; P=0.0153), and more time in the SG range of 70-180 mg/dL (12.3%; P=0.0002), with no differences in exposure to SG<70 mg/dL or in glucose variability. Changes in postprandial (4-h) glucose area under the curve >180 mg/dL were significantly greater with CSII than with MDI after breakfast (-775.9±1,441.2 mg/dL/min vs. -160.7±1,074.1 mg/dL/min; P=0.0015) and after dinner (-731.4±1,580.7 mg/dL/min vs. -71.1±1,083.5 mg/dL/min; P=0.0014). Conclusions: In patients with suboptimally controlled type 2 diabetes, CSII significantly improves selected glucometrics, compared with MDI, without increasing the risk of hypoglycemia
Intraventricular dyssynchrony in light chain amyloidosis: a new mechanism of systolic dysfunction assessed by 3-dimensional echocardiography
<p>Abstract</p> <p>Background</p> <p>Light chain amyloidosis (AL) is a rare but often fatal disease due to intractable heart failure. Amyloid deposition leads to diastolic dysfunction and often preserved ejection fraction. We hypothesize that AL is associated with regional systolic dyssynchrony. The aim is to compare left ventricular (LV) regional synchrony in AL subjects versus healthy controls using 16-segment dyssynchrony index measured from 3-dimension-al (3D) echocardiography.</p> <p>Methods</p> <p>Cardiac 3D echocardiography full volumes were acquired in 10 biopsy-proven AL subjects (60 ± 3 years, 5 females) and 10 healthy controls (52 ± 1 years, 5 females). The LV was subdivided into 16 segments and the time from end-diastole to the minimal systolic volume for each of the 16 segments was expressed as a percent of the cycle length. The standard deviations of these times provided a 16-segment dyssynchrony index (16-SD%). 16-SD% was compared between healthy and AL subjects.</p> <p>Results</p> <p>Left ventricular ejection fraction was comparable (control vs. AL: 62.4 ± 0.6 vs. 58.6 ± 2.8%, p = NS). 16-SD% was significantly higher in AL versus healthy subjects (5.93 ± 4.4 vs. 1.67 ± 0.87%, p = 0.003). 16-SD% correlated with left ventricular mass index (R 0.45, p = 0.04) but not to left ventricular ejection fraction.</p> <p>Conclusion</p> <p>Light chain amyloidosis is associated with left ventricular regional systolic dyssynchrony. Regional dyssynchrony may be an unrecognized mechanism of heart failure in AL subjects.</p
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