10,827 research outputs found
Early postnatal caloric restriction protects adult male intrauterine growth-restricted offspring from obesity.
Postnatal ad libitum caloric intake superimposed on intrauterine growth restriction (IUGR) is associated with adult-onset obesity, insulin resistance, and type 2 diabetes mellitus (T2DM). We hypothesized that this paradigm of prenatal nutrient deprivation-induced programming can be reversed with the introduction of early postnatal calorie restriction. Ten-month-old male rats exposed to either prenatal nutrient restriction with ad libitum postnatal intake (IUGR), pre- and postnatal nutrient restriction (IPGR), or postnatal nutrient restriction limited to the suckling phase (50% from postnatal [PN]1 to PN21) (PNGR) were compared with age-matched controls (CON). Visceral adiposity, metabolic profile, and insulin sensitivity by hyperinsulinemic-euglycemic clamps were examined. The 10-month-old male IUGR group had a 1.5- to 2.0-fold increase in subcutaneous and visceral fat (P < 0.0002) while remaining euglycemic, insulin sensitive, inactive, and exhibiting metabolic inflexibility (Vo(2)) versus CON. The IPGR group remained lean, euglycemic, insulin sensitive, and active while maintaining metabolic flexibility. The PNGR group was insulin sensitive, similar to IPGR, but less active while maintaining metabolic flexibility. We conclude that IUGR resulted in obesity without insulin resistance and energy metabolic perturbations prior to development of glucose intolerance and T2DM. Postnatal nutrient restriction superimposed on IUGR was protective, restoring metabolic normalcy to a lean and active phenotype
Evaluation of the first automated thyroglobulin assay
The aim of this study was to investigate technical and analytical performance of the first automated thyroglobulin (Tg) assay (DPC-Immulite(R); Diagnostic Products Corporation, Los Angeles, USA). In imprecision studies using several human serum pools ranging from 21 to 58 replicates, a coefficient of variation of 9.0 % was obtained at a mean Tg concentration of 0.84 ng/ml and of 6.1 % at a Tg concentration of 62.1 ng/ml. In a method comparison with a non-automated assay (BRAHMS LUMItest Tg(R), BRAHMS, Berlin, Germany) using 383 sera of 303 patients with thyroid carcinoma, regression analysis according to Passing and Bablock yielded in the following equation: Immulite Tg=1.6 x BRAHMS Tg - 0.1 ng/ml (Pearson's r=0.979). Sera obtained from 59 patients with thyroid carcinoma enabled comparative follow-up studies; in all cases qualitative agreement was found with regard to increase or decrease of serum Tg; in eight cases, however, Tg was detected with the Immulite assay but not with the BRAHMS assay. Further follow-up proved the presence of thyroid tissue in these patients. From these and further methodological data (dilution linearity, interference studies, carry-over study, high-dose hook properties, and short report time) it is concluded that the DPC-Immulite Tg assay meets the requirements of routine diagnostic use
Increased expression of apoptosis signalling receptors by alveolar macrophages in sarcoidosis
Efficient implementation of the Gutzwiller variational method
We present a self-consistent numerical approach to solve the Gutzwiller
variational problem for general multi-band models with arbitrary on-site
interaction. The proposed method generalizes and improves the procedure derived
by Deng et al., Phys. Rev. B. 79 075114 (2009), overcoming the restriction to
density-density interaction without increasing the complexity of the
computational algorithm. Our approach drastically reduces the problem of the
high-dimensional Gutzwiller minimization by mapping it to a minimization only
in the variational density matrix, in the spirit of the Levy and Lieb
formulation of DFT. For fixed density the Gutzwiller renormalization matrix is
determined as a fixpoint of a proper functional, whose evaluation only requires
ground-state calculations of matrices defined in the Gutzwiller variational
space. Furthermore, the proposed method is able to account for the symmetries
of the variational function in a controlled way, reducing the number of
variational parameters. After a detailed description of the method we present
calculations for multi-band Hubbard models with full (rotationally invariant)
Hund's rule on-site interaction. Our analysis shows that the numerical
algorithm is very efficient, stable and easy to implement. For these reasons
this method is particularly suitable for first principle studies -- e.g., in
combination with DFT -- of many complex real materials, where the full
intra-atomic interaction is important to obtain correct results.Comment: 19 pages, 7 figure
Spin Susceptibility of the Topological Superconductor UPt3 from Polarized Neutron Diffraction
Experiment and theory indicate that UPt3 is a topological superconductor in
an odd-parity state, based in part from temperature independence of the NMR
Knight shift. However, quasiparticle spin-flip scattering near a surface, where
the Knight shift is measured, might be responsible. We use polarized neutron
scattering to measure the bulk susceptibility with H||c, finding consistency
with the Knight shift but inconsistent with theory for this field orientation.
We infer that neither spin susceptibility nor Knight shift are a reliable
indication of odd-parity
Collisionless Magnetic Reconnection via Alfven Eigenmodes
We propose an analytic approach to the problem of collisionless magnetic
reconnection formulated as a process of Alfven eigenmodes' generation and
dissipation. Alfven eigenmodes are confined by the current sheet in the same
way that quantum mechanical waves are confined by the tanh^2 potential. The
dynamical time scale of reconnection is the system scale divided by the
eigenvalue propagation velocity of the n=1 mode. The prediction of the n=1 mode
shows good agreement with the in situ measurement of the
reconnection-associated Hall fields
Fermi Surface Evolution, Pseudo Gap and Stagger Gauge Field Fluctuation in Underdoped Cuprates
In the context of t-J model we show that in underdoped regime,beside the
usual long wave length gauge field fluctuation, an additional low energy
fluctuation, staggered gauge field fluctuation plays a crucial role in the
evolution of Fermi surface(FS) as well as the line shape of spectral function
for the cuprates. By including the staggered gauge field fluctuation we
calculate the spectral function of the electrons by RPA(random phase
approximation). The line shape of the spectral function near is very
broad in underdoped case and is quite sharp in overdoped case. For the spectral
function near , the quasiparticle peaks are always very sharp
in both underdoped and overdoped case. The temperature dependence of the
spectral function is also discussed in our present calculation. These results
fit well with the recent ARPES experiments. We also calculate the FS crossover
from a small four segment like FS to a large continuous FS. The reason of such
kind of FS crossover is ascribed to the staggered gauge field fluctuation which
is strong in underdoped regime and becomes much weaker in overdoped regime. The
pseudo gap extracted from the ARPES data can be also interpreted by the
calculation.Comment: 4 pages,6 eps figures include
Development and test of an open source autonomous sailing robot with accessibility, generality and extendability
This paper introduces the design of an open source autonomous sailing robot with emphasis on its accessibility, generality and extendability. To meet such requirements, a generic control box connecting an Arduino board and a Raspberry Pi computer was tailor-made so as to host the robot operating system (ROS) and to interact with versatile sensors and actuators. The goal of such a project is to create an accessible, generic and expendable platform of autonomous sailboats for wider education and research publicity and engagement. Autonomous sailing test for the developed sailboat was also conducted to validate its design
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