2,724 research outputs found
Application of calibration masks to TV vidicon tube
Photographic application method devised for overlaying test pattern masks on TV camera vidicon tubes prints the mask within 0.0076 cm of the vertical and horizontal center lines of the tube face. Entire process, including mask fabrication and alignment procedure, requires less than 10 minutes
Spin Dynamics of the Magnetoresistive Pyrochlore Tl_2Mn_2O_7
Neutron scattering has been used to study the magnetic order and spin
dynamics of the colossal magnetoresistive pyrochlore Tl_2Mn_2O_7. On cooling
from the paramagnetic state, magnetic correlations develop and appear to
diverge at T_C (123 K). In the ferromagnetic phase well defined spin waves are
observed, with a gapless ( meV) dispersion relation E=Dq^{2} as
expected for an ideal isotropic ferromagnet. As T approaches T_C from low T,
the spin waves renormalize, but no significant central diffusive component to
the fluctuation spectrum is observed in stark contrast to the
La(Ca,Ba,Sr)MnO system. These results argue strongly that the
mechanism responsible for the magnetoresistive effect has a different origin in
these two classes of materials.Comment: 4 pages (RevTex), 4 figures (encapsulated postscript), to be
published in Phys. Rev. Let
Spin Excitation Spectrum of LaMnO
As an effective model to describe perovskite-type manganates (La,)MnO,
the double-exchange model on a cubic lattice is investigated. Spin excitation
spectrum of the model in the ground state is studied using the spin wave
approximation. Spin wave dispersion relation observed in the inelastic neutron
scattering experiment of LaPbMnO is reproduced. Effective
values for the electron bandwidth as well as Hund's coupling is estimated from
the data.Comment: 10 pages LaTeX including 4 PS figure
Metabolic consequences of ileal interruption of the enterohepatic circulation of bile acids
The enterohepatic circulation of bile acids comprises a tightly regulated process of hepatic bile acid secretion, intestinal reabsorption and transport back to the liver. Disruption of this process has significant consequences for both gastrointestinal, liver and whole-body homeostasis and therefore offers opportunities for therapeutic intervention. In this review we discuss the effects of (pharmacological) interruption of the enterohepatic circulation at different levels. Recently, several studies have been published on ileal interruption of the enterohepatic circulation of bile acids, targeting the apical-sodium dependent bile acid transporter (ASBT, SLC10A2), as therapy for various diseases. However, ambiguous results have been reported and in-depth mechanistic insights are lacking. Here we discuss these novel studies and review the current knowledge and literature on the consequences of ASBT inhibition and its potential effects on physiology and metabolism
The Apical Sodium-Dependent Bile Acid Transporter in Cholangiocytes Is Not Required for the Generation of Bile Flow in Mice
Editorial:FGF21 as a therapeutic target for obesity and insulin resistance: from rodent models to humans
Obesity is a global pandemic that requires the urgent development of therapies and
prevention strategies. To define new pharmacologic therapies or nutritional approaches it
is mandatory to find new targets. Fibroblast growth factor 21 (FGF21) is considered a
potential target to treat obesity, due to its favorable metabolic activity, signalling pathways
and regulatory mechanisms. It is well-documented that FGF21 is induced by a wide range
of biological stress conditions and a key signal that communicates and coordinates the
physiologic response to restore the metabolic homeostasis in different tissues (1). FGF21 is
elevated in pathological conditions such as obesity, insulin resistance, or fatty liver disease
where an impairment of its signalling has been described (2). On the other hand, FGF21
analogues tested in overweight/obese patients with type 2 diabetes or NAFLD/NASH can
reduce dyslipidaemia and steatosis, but improvements in glycaemic control or body weight
were not globally restored (3). This suggests that pharmacologic effects of FGF21 are
different from its physiological effects. In this Research Topic “FGF21 as a therapeutic
target for obesity and insulin resistance: from rodent models to humans”, we include
publications related to new advances involving FGF21, its signalling pathway, and its
potential as a target to treat obesityinfo:eu-repo/semantics/publishedVersio
The Apical Sodium-Dependent Bile Acid Transporter in Cholangiocytes Is Not Required for the Generation of Bile Flow in Mice
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