10,637 research outputs found
Determination of and Extraction of from Semileptonic Decays
By globally analyzing all existing measured branching fractions and partial
rates in different four momentum transfer-squared bins of decays, we obtain the product of the form factor and magnitude of
CKM matrix element to be . With this
product, we determine the semileptonic form factor
in conjunction with the value of
determined from the SM global fit. Alternately, with the product together with
the input of the form factor calculated in lattice QCD recently, we
extract , where the error is
still dominated by the uncertainty of the form factor calculated in lattice
QCD. Combining the
extracted from all existing measurements of decays and
together, we find the most
precisely determined to be , which improves
the accuracy of the PDG'2014 value by
Effective potential for composite operators and for an auxiliary scalar field in a Nambu-Jona-Lasinio model
We derive the effective potentials for composite operators in a
Nambu-Jona-Lasinio (NJL) model at zero and finite temperature and show that in
each case they are equivalent to the corresponding effective potentials based
on an auxiliary scalar field. The both effective potentials could lead to the
same possible spontaneous breaking and restoration of symmetries including
chiral symmetry if the momentum cutoff in the loop integrals is large enough,
and can be transformed to each other when the Schwinger-Dyson (SD) equation of
the dynamical fermion mass from the fermion-antifermion vacuum (or thermal)
condensates is used. The results also generally indicate that two effective
potentials with the same single order parameter but rather different
mathematical expressions can still be considered physically equivalent if the
SD equation corresponding to the extreme value conditions of the two potentials
have the same form.Comment: 7 pages, no figur
Preparation of productive and highly purified mogrosides from Siraitia grosvenorii
The mogrosides of Siraitia grosvenorii are natural sweetener and potential chemopreventive agents. In order to obtain high-yield and good-quality mogrosides, the flash extraction method was employed to extract mogrosides from S. grosvenorii. The extraction parameters were optimized by Taguchi’s experimental design, and the total yield of mogrosides was 8.6% under the optimum conditions. After purification by the chromatography column, the purity of mogrosides was greater than 92%. The separation technique described here may be applicable to commercial production of high-quality mogrosides.Key words: Flash extraction, mogrosides, mogroside V, purification, Taguchi’s experimental design
Plant Natural Product Formononetin Protects Rat Cardiomyocyte H9c2 Cells against Oxygen Glucose Deprivation and Reoxygenation via Inhibiting ROS Formation and Promoting GSK-3β Phosphorylation
The opening of mitochondrial permeability transition pore (mPTP) is a major cause of cell death in ischemia reperfusion injury. Based on our pilot experiments, plant natural product formononetin enhanced the survival of rat cardiomyocyte H9c2 cells during oxygen glucose deprivation (OGD) and reoxygenation. For mechanistic studies, we focused on two major cellular factors, namely, reactive oxygen species (ROS) and glycogen synthase kinase 3β (GSK-3β), in the regulation of mPTP opening. We found that formononetin suppressed the formation of ROS and superoxide in a concentration-dependent manner. Formononetin also rescued OGD/reoxygenation-induced loss of mitochondrial membrane integrity. Further studies suggested that formononetin induced Akt activation and GSK-3β (Ser9) phosphorylation, thereby reducing GSK-3β activity towards mPTP opening. PI3K and PKC inhibitors abolished the effects of formononetin on mPTP opening and GSK-3β phosphorylation. Immunoprecipitation experiments further revealed that formononetin increased the binding of phosphor-GSK-3β to adenine nucleotide translocase (ANT) while it disrupted the complex of ANT with cyclophilin D. Moreover, immunofluorescence revealed that phospho-GSK-3β (Ser9) was mainly deposited in the space between mitochondria and cell nucleus. Collectively, these results indicated that formononetin protected cardiomyocytes from OGD/reoxygenation injury via inhibiting ROS formation and promoting GSK-3β phosphorylation.published_or_final_versio
Purification of Z-Ligustilide by AgNO3-Impregnated Silica Gel
OBJECTIVE To investigate the application of AgNO3-impregnated silica gel in a format of column chromatography for the isolation and purification of Z-ligustilide from the essential oil of Ligusticum chuanxiong Hort.. METHODS AgNO3(2%) was impregnated to the common silica gel to generate a new column chromatographic media. The essential oil was eluted with the mobile phase (petroleum ether: acetoacetate=98.5∶1.5), and detected by TLC and UV-Vis spectrometer. The product Z-ligustilide was characterized by GC-MS and HPLC techniques. RESULTS Z-Ligustilide with the purity of 98.87% was effectively purified. CONCLUSION The present study describes a method for rapid isolation of highly pure Z-ligustilide at low cost, allowing future scale-up for modern industrial production
phi3 theory with F_4 flavor symmetry in 6-2\epsilon dimensions: 3-loop renormalization and conformal bootstrap
We consider theory in with global symmetry. The beta function is calculated up to 3 loops, and a stable unitary IR fixed point is observed. The anomalous dimensions of operators quadratic or cubic in are also computed. We then employ conformal bootstrap technique to study the fixed point predicted from the perturbative approach. For each putative scaling dimension of (, we obtain the corresponding upper bound on the scaling dimension of the second lowest scalar primary in the representation which appears in the OPE of . In , we observe a sharp peak on the upper bound curve located at equal to the value predicted by the 3-loop computation. In , we observe a weak kink on the upper bound curve at =
Topological Properties of Spatial Coherence Function
Topology of the spatial coherence function is considered in details. The
phase singularity (coherence vortices) structures of coherence function are
classified by Hopf index and Brouwer degree in topology. The coherence flux
quantization and the linking of the closed coherence vortices are also studied
from the topological properties of the spatial coherence function.Comment: 9 page
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