945 research outputs found
Design, Modeling, Microfabrication and Characterization of the Micro Gas Chromatography Columns
Effective Focal Area Dimension Optimization of Shear Horizontal Point-Focusing EMAT Using Orthogonal Test Method
To overcome the shortcomings of low energy conversion efficiency of electromagnetic acoustic transducers (EMATs), point-focusing shear horizontal (PFSH) wave EMAT is used to focus the wave energy into a specific area. Many factors will affect the capability of the focusing transducer, and in addition to considering the signal intensity, the detection accuracy is also required to be investigated. Specifically, to simplify the test process, we use the orthogonal test method to study the effect of different influence parameters on signal intensity and focal area dimensions. Seven factors are selected, and three results are determined in the test. Range analysis shows that for signal amplitude M , the top three impact factors are the coil width w , coil turns n , and focal length lF (equal to bandwidth factor α ). Moreover, magnet number m and frequency fc dominate the effective focal length lfd , and aperture angle Ξ determines the effective focal width wfd . To enable higher signal intensity and smaller focal area dimensions, it is necessary to consider various factors on the PFSH-EMAT focusing performance. The testâs signal intensity with optimized parametersâ combination at the focal point is nearly 144.42% higher than the average of all the tests, lfd decreased by 37.84%, and wfd decreased by 50.59%. The experiment also verified that focusing EMAT with optimized parameters has a better focusing performance
Effect of phosphatidylethanolamine and phosphatidylserine on antioxidant capacity, oxidative stability and color reversion of camellia seed oil
Non-hydratable phospholipids as pro-oxidants are likely to cause a decrease in the quality of vegetable oils. The influence of phosphatidylethanolamine (PE) and phosphatidylserine (PS) on the oxidative stability, antioxidant capacity and color reversion of refined camellia seed oil (RCSO) was evaluated in this work. The PE/PS addition could improve the oxidative stability and antioxidant capacity, but was not a key factor in the color reversion of RCSO. The results clearly showed that PE and PS were not prooxidants but antioxidants in camellia seed oil, and the findings of the present study would be useful for extending the shelf-life of camellia seed oil and for retaining phospholipids during moderate refining
Studies of the electric dipole transitions of deformed rare-earth nuclei
Spectrum and electric dipole transition rates and relative intensities in
Sm, Gd, Dy are studied in the framework of
the interacting boson model with s,p,d,f bosons. It is found that E1 transition
data among the low-lying levels are in good agreement with the SU(3) dynamical
symmetry of the spdf interacting boson model proposed by Engel and Iachello to
describe collective rotation with octupole vibration. These results show that
these nuclei have SU(3) dynamic symmetry to a good approximation. Also in this
work many algebraic expressions for electric dipole transitions in the SU(3)
limit of the spdf-IBM have been obtained. These formulae together with the
formulae given previously exhaust nearly all the E1 transitions for low-lying
negative parity states. They are useful in analyzing experimental data.Comment: 26 pages, 1 figur
Recognizing basal cell carcinoma on smartphoneâcaptured digital histopathology images with a deep neural network
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154530/1/bjd18026.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154530/2/bjd18026_am.pd
Regulation of TMPRSS6 by BMP6 and iron in human cells and mice.
Mutations in transmembrane protease, serine 6 (TMPRSS6), encoding matriptase-2, are responsible for the familial anemia disorder iron-refractory iron deficiency anemia (IRIDA). Patients with IRIDA have inappropriately elevated levels of the iron regulatory hormone hepcidin, suggesting that TMPRSS6 is involved in negatively regulating hepcidin expression. Hepcidin is positively regulated by iron via the bone morphogenetic protein (BMP)-SMAD signaling pathway. In this study, we investigated whether BMP6 and iron also regulate TMPRSS6 expression. Here we demonstrate that, in vitro, treatment with BMP6 stimulates TMPRSS6 expression at the mRNA and protein levels and leads to an increase in matriptase-2 activity. Moreover, we identify that inhibitor of DNA binding 1 is the key element of the BMP-SMAD pathway to regulate TMPRSS6 expression in response to BMP6 treatment. Finally, we show that, in mice, Tmprss6 mRNA expression is stimulated by chronic iron treatment or BMP6 injection and is blocked by injection of neutralizing antibody against BMP6. Our results indicate that BMP6 and iron not only induce hepcidin expression but also induce TMPRSS6, a negative regulator of hepcidin expression. Modulation of TMPRSS6 expression could serve as a negative feedback inhibitor to avoid excessive hepcidin increases by iron to help maintain tight homeostatic balance of systemic iron levels
Singular perturbation of reduced wave equation and scattering from an embedded obstacle
We consider time-harmonic wave scattering from an inhomogeneous isotropic
medium supported in a bounded domain ().
{In a subregion , the medium is supposed to be lossy and have a
large mass density. We study the asymptotic development of the wave field as
the mass density } and show that the wave field inside
will decay exponentially while the wave filed outside the medium will
converge to the one corresponding to a sound-hard obstacle
buried in the medium supported in . Moreover, the
normal velocity of the wave field on from outside is shown to
be vanishing as . {We derive very accurate estimates
for the wave field inside and outside and on in terms of
, and show that the asymptotic estimates are sharp. The implication of
the obtained results is given for an inverse scattering problem of
reconstructing a complex scatterer.
Charmless Decays Based on the six-quark Effective Hamiltonian with Strong Phase Effects II
We provide a systematic study of charmless decays (
and denote pseudoscalar and vector mesons, respectively) based on an
approximate six-quark operator effective Hamiltonian from QCD. The calculation
of the relevant hard-scattering kernels is carried out, the resulting
transition form factors are consistent with the results of QCD sum rule
calculations. By taking into account important classes of power corrections
involving "chirally-enhanced" terms and the vertex corrections as well as weak
annihilation contributions with non-trivial strong phase, we present
predictions for the branching ratios and CP asymmetries of decays into
PP, PV and VV final states, and also for the corresponding polarization
observables in VV final states. It is found that the weak annihilation
contributions with non-trivial strong phase have remarkable effects on the
observables in the color-suppressed and penguin-dominated decay modes. In
addition, we discuss the SU(3) flavor symmetry and show that the symmetry
relations are generally respected
Comparison of Differential Pulse Voltammetry (DPV)-a new method of carbamazepine analysis-with Fluorescence Polarization Immunoassay (FPIA)
Carbamazepine is a widely used anti-epileptic drug with narrow therapeutic range. Many methods have been developed for monitoring the serum drug level. Differential pulse voltammetry (DPV), an electrochemical method advantaged by simple, inexpensive, and relatively short analysis time, has recently been developed for carbamazepine detection. We used a newly developed DPV method with glassy carbon as a working electrode to determine the carbamazepine level. The performance of DPV is compared with the widely used fluorescence polarization immunoassay (FPIA) technique in precision, accuracy, linearity and detection limit. The precision, linearity and accuracy of the DPV and FPIA techniques were comparable at most clinical used levels. The detection limit was 1 mu g/mL for the DPV technique and 0.5 mu g/mL for the FPIA technique. The performance of the DPV technique was within the FDA guidelines for bioanalytical methods, which ensures the clinical applicability of the DPV technique. The DPV technique may have the potential to be a good alternative for carbamazepine analysis
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