324 research outputs found
Freeze-in Dirac neutrinogenesis: thermal leptonic CP asymmetry
We present a freeze-in realization of the Dirac neutrinogenesis in which the
decaying particle that generates the lepton-number asymmetry is in thermal
equilibrium. As the right-handed Dirac neutrinos are produced non-thermally,
the lepton-number asymmetry is accumulated and partially converted to the
baryon-number asymmetry via the rapid sphaleron transitions. The necessary
CP-violating condition can be fulfilled by a purely thermal kinetic phase from
the wavefunction correction in the lepton-doublet sector, which has been
neglected in most leptogenesis-based setup. Furthermore, this condition
necessitates a preferred flavor basis in which both the charged-lepton and
neutrino Yukawa matrices are non-diagonal. To protect such a proper Yukawa
structure from the basis transformations in flavor space prior to the
electroweak gauge symmetry breaking, we can resort to a plethora of model
buildings aimed at deciphering the non-trivial Yukawa structures.
Interestingly, based on the well-known tri-bimaximal mixing with a minimal
correction from the charged-lepton or neutrino sector, we find that a
simultaneous explanation of the baryon-number asymmetry in the Universe and the
low-energy neutrino oscillation observables can be attributed to the mixing
angle and the CP-violating phase introduced in the minimal correction.Comment: 28 pages and 7 figures; more discussions and one figure added, final
version published in the journa
, and neutrino mass in the 2HDM-III with right-handed neutrinos
Given that the two-Higgs-doublet model of type III (2HDM-III) has the
potential to address the anomalies while the resolution to the
deficits requires new degrees of freedom within this
framework, we consider in this paper a unified scenario where the low-scale
type-I seesaw mechanism is embedded into the 2HDM-III, so as to accommodate the
and anomalies as well as the neutrino mass.
We first revisit the anomalies and find that the current
world-averaged results can be addressed at level without violating
the bound from the branching ratio . The scenario predicts two sub-eV neutrino masses
based on a decoupled heavy Majorana neutrino and two nearly degenerate Majorana
neutrinos with mass around the electroweak scale. For the
anomalies, the same scenario can generate the required Wilson coefficients in
the direction , with
Yukawa couplings for the muon and the top quark.Comment: 32 pages, 4 figures; More discussions and references added, final
version to be published in JHE
Scotogenic Dirac neutrino model embedded with leptoquarks: one pathway to addressing all
If the leptoquarks proposed to account for the intriguing anomalies observed
in the -meson decays, and , as well as in
the anomalous magnetic moment of the muon, , can be embedded into
the scotogenic Dirac neutrino model, all these flavor anomalies, together with
the origin of neutrino masses and the nature of dark matter, would be
potentially addressed in a unified picture. Among the minimal seesaw, one-loop,
and two-loop realizations of the dimension-4 effective operator
for the Dirac neutrino masses, we show that plenty of
diagrams associated with the two-loop realizations of can
support the coexistence of leptoquarks and dark matter candidates. After a
simple match of these leptoquarks to those that can accommodate all the flavor
anomalies, we establish the scotogenic Dirac neutrino models embedded with
leptoquarks, which could address all the problems mentioned above.Comment: 17 pages, 16 tables, 9 figure
外用喜疗妥致严重皮肤反应1例
Objective: To explore the clinical characteristics, diagnosis and prognosis of local severe cutaneous reactions as result of the treatment with Hirudoid. Methods: One case of severe cutaneous reactions as result of the treatment with Hirudoid was reported and the relevant literatures were reviewed. Results: The site of puncture of left arm occurred non-leakage phlebitis with local pain after chemotherapy. The patient was applied the Hirudoid to the affected areas 2 times daily. After 2 days, local skin felt a kind of burning pain and it seems to be getting worse. The skin lesions began as pruritic red macules or papules. It became swelled and bleeding after scratching. We considered that the cutaneous reactions were an allergic response to Hirudoid. We discontinued the Hirudoid and desensitization treatment was used on cure, but it failed to respond to the medical treatment. A hot compress with 50% magnesium sulphate solution can reduce swelling and alleviate pain. Scales of skin peel off and weaved the new skin after 10 days. Conclusion: The case of local severe cutaneous reactions as result of the treatment with Hirudoid is very rare. A hot compress with 50% magnesium sulphate solution can help to relieve the discomfort. 目的 探讨外用喜疗妥致严重皮肤反应的临床特征及治疗和预后。方法 报道1例外用喜疗妥致严重皮肤反应患者的临床资料并结合相关文献进行分析。结果 患者,女,60岁,化疗后穿刺部位左侧手臂出现非渗漏性静脉炎,局部疼痛。给予喜疗妥每日2次外涂。2天后,患者突感涂抹局部烧灼样疼痛,并可见大片红色斑丘疹奇痒难忍,抓挠后充血肿胀。考虑喜疗妥过敏所致,立即停用喜疗妥,并应用脱敏治疗,效果不佳,局部颜色由红色渐变为暗紫色且肿痛剧烈,给予50%硫酸镁溶液湿热敷。3天后患者症状逐渐减轻,肿胀消退,10天后患处皮肤全部脱落并被新的完好皮肤覆盖。结论 外用喜疗妥致严重皮肤反应非常罕见,50%硫酸镁溶液热敷患处皮肤,可以缓解肿痛,消除症状
Poly[dinitrato[μ3-2,4,6-tris(4-pyridyl)-1,3,5-triazine]cobalt(II)]
The solvothermal reaction of Co(NO3)2 and 2,4,6-tris(4-pyridyl)-1,3,5-triazine in dimethylformamide/ethanol mixed solvent afforded the title coordination polymer, [Co(NO3)2(C18H12N6)]n, in which the CoII atom is seven-coordinated by pyridyl groups of three different ligands and two chelating nitrate anions. The complex displays a nano-sized porous metal–organic framework that belongs to a (10,3) topological network
Bis(μ-carboxylatoethylphosphonato)bis[aqua(2,2′-bipyridine)manganese(II)]
The title compound, [Mn2(HO3PCH2CH2COO)2(C8H8N2)2(H2O)2], was obtained by hydrothermal synthesis. The manganese(II) ions are six-coordinate and are linked by two 2-carboxyethylphosphonate ligands, forming a centrosymmetric dimer. The Mn ions adopts a distorted octahedral coordination geometry. The dimers are further linked by O—H⋯O hydrogen bonds and π–π stacking interactions [centroid–centroid distance 4.2754 (4) Å]
Nanotube ferroelectric tunnel junctions with giant tunneling electroresistance ratio
Low-dimensional ferroelectric tunnel junctions are appealing for the
realization of nanoscale nonvolatile memory devices due to their inherent
advantage of device miniaturization. Those based on current mechanisms still
have restrictions including low tunneling electroresistance (TER) effects and
complex heterostructures. Here, we introduce an entirely new TER mechanism to
construct the nanotube ferroelectric tunnel junction with ferroelectric
nanotubes as the tunneling region. When rolling a ferroelectric monolayer into
a nanotube, due to the coexistence of its intrinsic ferroelectric polarization
with the flexoelectric polarization induced by bending, there occurs
metal-insulator transition depending on radiative polarization states. For the
pristine monolayer, its out-of-plane polarization is tunable by an in-plane
electric field, the conducting states of the ferroelectric nanotube can thus be
tuned between metallic and insulating via axial electric means. Using
{\alpha}-In2Se3 as an example, our first-principles density functional theory
calculations and nonequilibrium Green's function formalism confirm the
feasibility of the TER mechanism and indicate an ultrahigh TER ratio exceeding
9.9*10^10% of the proposed nanotube ferroelectric tunnel junctions. Our
findings provide a promising approach based on simple homogeneous structures
for high density ferroelectric microelectronic devices with excellent ON/OFF
performance.Comment: 15 pages, 5 figure
Dendrobium officinale
Background. Dendrobium officinale (DO) Kimura et Migo is a precious Chinese herb that is considered beneficial for health due to its antioxidant and antidiabetes properties, and so on. In this research, we try to determine the preventive effect of DO on the early complications of STZ-induced diabetic rats. Methods. Type 1 diabetic rats were produced with a single intraperitoneal injection of STZ (50 mg/kg). DO (1 g/kg/day) was then orally administered for 5 weeks. Blood glucose, TC, TG, BUN, CREA, and GSH-PX levels were determined, and electroretinographic activity and hypoalgesia were investigated. Pathological sections of the eyes, hearts, aortas, kidneys, and livers were analyzed. Results. Treatment with DO significantly attenuated the serum levels of TC, TG, BUN, and CREA, markedly increased the amplitudes of ERG a- and b-waves and Ops, and reduced the hypoalgesia and histopathological changes of vital organs induced by hyperglycemia. The protective effect of DO in diabetic rats may be associated with its antioxidant activity, as evidenced by the marked increase in the serum level of glutathione peroxidase. However, DO had no significant effect on blood glucose levels and bodyweight of diabetic rats. Conclusions. DO supplementation is an effective treatment to prevent STZ-induced diabetic complications
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