474 research outputs found
SUSY SU(5) GUT Flavor Model for Fermion Masses and Mixings with Adjoint, Large
We propose an flavor model based on supersymmetric (SUSY) SU(5) GUT.
The first and third generations of \textbf{10} dimensional representations in
SU(5) are all assigned to be of . The second generation of
\textbf{10} is to be of . Right-handed neutrinos of singlet
\textbf{1} and three generations of are all assigned to be
of . The VEVs of two sets of flavon fields are allowed a
moderate hierarchy, that is . Tri-Bimaximal (TBM) mixing can be produced
at both leading order (LO) and next to next to leading order (NNLO) in neutrino
sector. All the masses of up-type quarks are obtained at LO. We also get the
bottom-tau unification and the popular Georgi-Jarlskog
relation as well as a new mass relation
in which the novel Clebsch-Gordan (CG) factor arises
from the adjoint field . The GUT relation leads to a sizable mixing
angle and the correct quark mixing matrix
can also be realised in the model. The resulting CKM-like mixing
matrix of charged leptons modifies the vanishing in TBM
mixing to a large , in excellent
agreement with experimental results. A Dirac CP violation phase
is required to make the deviation from
small. We also present some phenomenological numerical
results predicted by the model.Comment: 36 pages, 12 figures, major revison to the previous editio
Production of proton-rich nuclei around Z=84-90 in fusion-evaporation reactions
Within the framework of the dinuclear system model, production cross sections
of proton-rich nuclei with charged numbers of Z=84-90 are investigated
systematically. Possible combinations with the Si, S, Ar
bombarding the target nuclides Ho, Tm, Yb,
Lu, Hf and Ta are analyzed thoroughly. The
optimal excitation energies and evaporation channels are proposed to produce
the proton-rich nuclei. The systems are feasible to be constructed in
experiments. It is found that the neutron shell closure of N=126 is of
importance during the evaporation of neutrons. The experimental excitation
functions in the Ar induced reactions can be nicely reproduced. The
charged particle evaporation is comparable with neutrons in cooling the excited
proton-rich nuclei, in particular for the channels with and proton
evaporation. The production cross section increases with the mass asymmetry of
colliding systems because of the decrease of the inner fusion barrier. The
channels with pure neutron evaporation depend on the isotopic targets. But it
is different for the channels with charged particles and more sensitive to the
odd-even effect.Comment: 15 pages, 10 figures. arXiv admin note: text overlap with
arXiv:0803.1117, arXiv:0707.258
Astrocytic and Oligodendrocytic P2X7 Receptors Determine Neuronal Functions in the CNS
P2X7 receptors are members of the ATP-gated cationic channel family with a preferential
localization at the microglial cells, the resident macrophages of the brain. However,
these receptors are also present at neuroglia (astrocytes, oligodendrocytes) although
at a considerably lower density. They mediate necrosis/apoptosis by the release of
pro-inflammatory cytokines/chemokines, reactive oxygen species (ROS) as well as
the excitotoxic (glio)transmitters glutamate and ATP. Besides mediating cell damage
i.e., superimposed upon chronic neurodegenerative processes in Alzheimer’s Disease,
Parkinson’s Disease, multiple sclerosis, and amyotrophic lateral sclerosis, they may also
participate in neuroglial signaling to neurons under conditions of high ATP concentrations
during any other form of neuroinflammation/neurodegeneration. It is a pertinent open
question whether P2X7Rs are localized on neurons, or whether only neuroglia/microglia
possess this receptor-type causing indirect effects by releasing the above-mentioned
signaling molecules. We suggest as based on molecular biology and functional evidence
that neurons are devoid of P2X7Rs although the existence of neuronal P2X7Rs cannot
be excluded with absolute certainty
Vinegar amount in the process affected the components of vinegar-baked Radix Bupleuri and its hepatoprotective effect
Application comparison of improved endotracheal tube and ordinary endotracheal tube among critically ill patients
目的 探讨改良气管导管与传统气管导管优越性比较。方法 对25例需要长期呼吸机支持治疗患者随机分为A、B两组,A组(n=12)使用改良气管导管,B组(n=13)使用传统的气管导管,两组患者分别在留管时间、ICU住院时间、憋气缓解率以及更换气管导管费用方面进行比较。结果 两组患者在GCS评分及留管时间方面无统计学意义,P>0.05,但在更换导管费用、ICU入住时间以及憋气缓解率方面,改良气管导管明显优于传统气管导管,P<0.05。结论 改良气管导管可以大大减少头端贴壁的几率,从而减少重症患者憋气发生,同时可以减少患者入住ICU的时间,大大减少住院费用。Objective: To explore the advantages of improved endotracheal tube and to compare it with traditional endotracheal tube. Methods: 25 patients requiring long-term mechanical ventilation patients were randomly divided into two groups: group A and group B. Group A (n=12) use improved endotracheal tube, and traditional endotracheal tube was used for Group B (n=13). The indwelling time, ICU hospitalization time, suffocation remission rate and replacement cost of the endotracheal tube were respectively compared between two groups. Results: GCS score and indwelling catheter time between two groups have no statistical significance, P > 0.05. Improved tracheal catheter is much better than traditional tracheal catheter with regards to catheter replacement cost, time of ICU stay and remission rate of suffocation, P<0.05. Conclusion: The improvement of the endotracheal tube can greatly reduce the rate of head end to stick wall, thus decreasing occurrence of severe shortness of breath, shortening the stay time of the patients in ICU at the same time, and greatly reducing the cost of hospitalization.
Using scanning electron microscopy and molecular data to discover a new species from old herbarium collections: The case of Phlomoides henryi (Lamiaceae, Lamioideae)
Phlomoides is one of the largest genera of Lamiaceae with approximately 150–170 species distributed mainly in Eurasia. In this study, we describe and illustrate a new species, P. henryi, which was previously misidentified as P. bracteosa, from Yunnan Province, southwest China. Molecular phylogenetic analyses revealed that P. henryi is found within a clade in which most species lack basal leaves. In this clade, the new species is morphologically distinct from P. rotata in having an obvious stem and, from the rest, by having transparent to white trichomes inside the upper corolla lip. In addition, micro-features of trichomes on the calyx and leaf epidermis can differentiate the new species from other species grouped in the same clade and a key, based on trichome morphology for these species, is provided. The findings demonstrate that the use of scanning electron microscopy can reveal inconspicuous morphological affinities amongst morphologically similar species and play an important role in the taxonomic study of the genus Phlomoides
JCMT POL-2 and ALMA polarimetric observations of 6000-100 au scales in the protostar B335: linking magnetic field and gas kinematics in observations and MHD simulations
We present our analysis of the magnetic field structures from 6000 au to 100
au scales in the Class 0 protostar B335 inferred from our JCMT POL-2
observations and the ALMA archival polarimetric data. To interpret the
observational results, we perform a series of (non-)ideal MHD simulations of
the collapse of a rotating non-turbulent dense core, whose initial conditions
are adopted to be the same as observed in B335, and generate synthetic
polarization maps. The comparison of our JCMT and simulation results suggests
that the magnetic field on a 6000 au scale in B335 is pinched and well aligned
with the bipolar outflow along the east-west direction. Among all our
simulations, the ALMA polarimetric results are best explained with weak
magnetic field models having an initial mass-to-flux ratio of 9.6. However, we
find that with the weak magnetic field, the rotational velocity on a 100 au
scale and the disk size in our simulations are larger than the observational
estimates by a factor of several. An independent comparison of our simulations
and the gas kinematics in B335 observed with the SMA and ALMA favors strong
magnetic field models with an initial mass-to-flux ratio smaller than 4.8. We
discuss two possibilities resulting in the different magnetic field strengths
inferred from the polarimetric and molecular-line observations, (1)
overestimated rotational-to-gravitational energy in B335 and (2) additional
contributions in the polarized intensity due to scattering on a 100 au scale.Comment: Accepted by Ap
- …