597 research outputs found
Novel anti-obesity quercetin-derived Q2 prevents metabolic disorders in rats fed with high-fat diet
Objective: Obesity is often accompanied by an increased morbidity and mortality due to an increase of the cardiovascular disease risk factors, diabetes mellitus and dyslipidemia. Research is constantly working on protective molecules against obesity. In the present study, a novel Quercetin derivative Q2 was synthesized to overcome the poor bioavailability and low stability of Quercetin, a natural flavonoid with antioxidative and antiobesity properties.
Methods: Rats were fed (12ws) with normodiet (fat:INS; 6.2%), High Fat Diet (fat:60%), HFDINS; +INS; Q2 in water (500INS; nM). Metabolic and anthropometric parameters were measured. 3T3-L1 preadipocytes were incubated with Q2 (1-25μM) and the differentiation program was evaluated by lipid accumulation through ORO staining. Gene and protein expression levels were assessed by RT-PCR and Western blot analysis.
Results: Compared to HFD, HFDINS; +INS; Q2 rats showed reduced body weight, abdominal obesity, dyslipidemia and improved glucose tolerance. This is associated to lower adipose and liver modifications compared to hypertrophy and steatosis observed in HFD. In 3T3-L1 cells, lipid accumulation was significantly impaired by treatment with Q2. Indeed, Q2 significantly decreased the expression of the main adipogenic markers, c/EBPα and PPARγ both at mRNA and protein level.
Conclusions: Our results indicate that Q2 markedly decreases differentiation of 3T3-L1 preadipocytes and contributes to prevent metabolic disorders as well as adipose and liver alterations typical of severe obesity induced by a HFD
Models and experimental results from the wide aperture Nb-Ti magnets for the LHC upgrade
MQXC is a Nb-Ti quadrupole designed to meet the accelerator quality
requirements needed for the phase-1 LHC upgrade, now superseded by the high
luminosity upgrade foreseen in 2021. The 2-m-long model magnet was tested at
room temperature and 1.9 K. The technology developed for this magnet is
relevant for other magnets currently under development for the high-luminosity
upgrade, namely D1 (at KEK) and the large aperture twin quadrupole Q4 (at CEA).
In this paper we present MQXC test results, some of the specialized heat
extraction features, spot heaters, temperature sensor mounting and voltage tap
development for the special open cable insulation. We look at some problem
solving with noisy signals, give an overview of electrical testing, look at how
we calculate the coil resistance during at quench and show that the heaters are
not working We describe the quench signals and its timing, the development of
the quench heaters and give an explanation of an Excel quench calculation and
its comparison including the good agreement with the MQXC test results. We
propose an improvement to the magnet circuit design to reduce voltage to ground
values by factor 2. The program is then used to predict quench Hot-Spot and
Voltages values for the D1 dipole and the Q4 quadrupole.Comment: 8 pages, Contribution to WAMSDO 2013: Workshop on Accelerator Magnet,
Superconductor, Design and Optimization; 15 - 16 Jan 2013, CERN, Geneva,
Switzerlan
Testing Beam-Induced Quench Levels of LHC Superconducting Magnets
In the years 2009-2013 the Large Hadron Collider (LHC) has been operated with
the top beam energies of 3.5 TeV and 4 TeV per proton (from 2012) instead of
the nominal 7 TeV. The currents in the superconducting magnets were reduced
accordingly. To date only seventeen beam-induced quenches have occurred; eight
of them during specially designed quench tests, the others during injection.
There has not been a single beam- induced quench during normal collider
operation with stored beam. The conditions, however, are expected to become
much more challenging after the long LHC shutdown. The magnets will be
operating at near nominal currents, and in the presence of high energy and high
intensity beams with a stored energy of up to 362 MJ per beam. In this paper we
summarize our efforts to understand the quench levels of LHC superconducting
magnets. We describe beam-loss events and dedicated experiments with beam, as
well as the simulation methods used to reproduce the observable signals. The
simulated energy deposition in the coils is compared to the quench levels
predicted by electro-thermal models, thus allowing to validate and improve the
models which are used to set beam-dump thresholds on beam-loss monitors for Run
2.Comment: 19 page
Tomograms and other transforms. A unified view
A general framework is presented which unifies the treatment of wavelet-like,
quasidistribution, and tomographic transforms. Explicit formulas relating the
three types of transforms are obtained. The case of transforms associated to
the symplectic and affine groups is treated in some detail. Special emphasis is
given to the properties of the scale-time and scale-frequency tomograms.
Tomograms are interpreted as a tool to sample the signal space by a family of
curves or as the matrix element of a projector.Comment: 19 pages latex, submitted to J. Phys. A: Math and Ge
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