3,662 research outputs found

    A minimal U(1)′U(1)^\prime extension of MSSM in light of the B decay anomaly

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    Motivated by the RKR_K and RK∗R_{K^*} anomalies from B decays, we extend the minimal supersymmetric model with a non-universal anomaly-free U(1)′U(1)^\prime gauge symmetry, coupling non-universally to the lepton sector as well as the quark sector. In particular, only the third generation quarks are charged under this U(1)′U(1)^\prime, which can easily evade the dilepton bound from the LHC searches. An extra singlet is introduced to break this U(1)′U(1)^\prime symmetry allowing for the μ\mu-term to be generated dynamically. The relevant constraints of Bs−BˉsB_s-\bar{B}_s mixing, D0−Dˉ0D^0-\bar{D}^0 mixing and the LHC dilepton searches are considered. We find that in the allowed parameter space this U(1)′U(1)^\prime gauge interaction can accommodate the RKR_K and RK∗R_{K^*} anomalies and weaken considerably the Z′Z^\prime mass limits while remaining perturbative up to the Planck scale.Comment: 12 pages,2 figure

    Triaqua-1κ3 O-μ-cyanido-1:2κ2 N:C-penta­cyanido-2κ5 C-tetra­kis­(dimethyl­formamide-1κO)-1-holmium(III)-2-iron(III) monohydrate

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    In the bimetallic cyanide-bridged title complex, [Fe0.98HoRu0.02(CN)6(C3H7NO)4(H2O)3]·H2O, the HoIII ion is in a slightly distorted square-anti­prismatic arrangement formed by seven O atoms from four dimethyl­formamide (DMF) mol­ecules and three water mol­ecules, and one N atom from a bridging cyanide group connected with the FeIII atom which is octa­hedrally coordinated by six cyanide groups. In the crystal, mol­ecules are held together through O—H⋯N and O—H⋯O hydrogen-bonding inter­actions to form a three-dimensional framework. Elemental analysis of one of the precursors and the crystal shows that there is a slight contamination of Fe by Ru. The Fe site displays, therefore, small substitutional disorder with site-occupancy factors Fe/Ru = 0.98:0.02. The two methyl groups of two dimethyl­formamide ligands are positionally disordered with site-occupancy factors of 0.44 (3):0.56 (3) and 0.44 (3):0.56 (3)

    Qualitative and quantitative analysis of catechin and quercetin in flavonoids extracted from Rosa roxburghii Tratt

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    Purpose: To perform a qualitative and quantitative analysis of catechin and quercetin in flavonoids extracted from Rosa roxburghii Tratt.Methods: Total flavonoids were determined using ultraviolet spectrophotometry (UV) at 500 nm. The optimal gradient program started with 15 % methanol and was kept within a period of 0 – 20 min, while 25 % methanol was kept within 20 – 33 min. Subsequently, the concentration of methanol was reduced to 15 % and was held for 10 min until the next injection. Mass spectrometry spray voltage was 4,000 V, ionization temperature 350 °C, atomizer pressure 35 psi, nitrogen flow rate 8 L/min, and mass scan range 200 – 800 m/z. The detection wavelength used for catechin and quercetin was 270 and 368 nm, respectively.Results: Based on the UV results, Rosa roxburghii Tratt content was 73.85 %, which is in agreement with the national standard. Liquid chromatography-mass spectrometry (LC-MS) results indicate that Rosa roxburghii Tratt flavonoids contained quercetin, 34.26 %, with relative standard deviation (RSD) of 2.88 % and catechin content of 2.97 % with RSD of 1.49 %.Conclusion: The proposed measurement method for determining the content of flavonoids in Rosa roxburghii Tratt has the advantage of simplicity, feasibility, good repeatability, and rapid and accurate analysis.Keywords: Rosa roxburghii Tratt, Flavonoids, Catechin, Querceti

    Poly[(acetato-κ2 O,O′)aqua­(μ4-1H-benzimidazole-5,6-dicarboxyl­ato-κ5 N 3:O 5,O 5′:O 5,O 6:O 6′)praseodymium(III)]

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    In the title complex, [Pr(C9H4N2O4)(C2H3O2)(H2O)]n, the PrIII ion is coordinated by five O atoms and one N atom from four benzimidazole-5,6-dicarboxyl­ate ligands, two O atoms from an acetate ligand and one water mol­ecule, giving a tricapped trigonal-prismatic geometry. The benzimidazole-5,6-dicarboxyl­ate and acetate ligands connect the PrIII ions, forming a layer in the ac plane; the layers are further linked by N—H⋯O and O—H⋯O hydrogen bonding and π–π stacking inter­actions between neighboring pyridine rings [the centroid–centroid distance is 3.467 (1) Å], assembling a three-dimensional supra­molecular network. The acetate methyl group is disordered over two positions with site-occupancy factors of 0.75 and 0.25

    A polymorph of diaqua­bis(pyrazine-2-carboxyl­ato-κ2 N 1,O)copper(II)

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    The title compound, [Cu(C5H3N2O2)2(H2O)2], is a new polymorph of the previously reported compound [Klein et al. (1982 ▶). Inorg. Chem. 21, 1891–1897]. The CuII atom, lying on an inversion center, is coordinated by two N atoms and two O atoms from two pyrazine-2-carboxyl­ate ligands and by two water mol­ecules in a distorted octa­hedral geometry with the water mol­ecules occupying the axial sites. Inter­molecular O—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds connect the complex mol­ecules into a two-dimensional layer parallel to (10), whereas the previously reported polymorph exhibits a three-dimensional hydrogen-bonded network

    Effects of painful stimulation and acupuncture on attention networks in healthy subjects

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    Pain is a subjective sensory and emotional experience, and it has been reported that many different brain regions are regulated by pain, and that pain can impact attention. Acupuncture is an important treatment component of Chinese traditional medicine, and has been used for thousands of years to treat a wide variety of conditions. Although several studies have shown that acupuncture improves consciousness, the precise impact of both acupuncture and painful stimulation on attention is unclear. Are all of the attention networks modulated, or do these stimuli act on a specific network? Is the effect of painful stimulation similar to that of acupuncture? We administered the attention network test to 30 participants (15 males) to investigate the relative efficiencies of three independent attention networks (alerting, orienting, and executive control networks) under three conditions: baseline, after painful stimulation, and after acupuncture. The degree of pain experienced was assessed on a horizontally oriented visual analogue scale. The results showed that painful stimulation and acupuncture had similar effects on the orienting and executive control networks; however, there was a significantly different effect between the three conditions on the alerting network. In conclusion, (1) painful stimulation can selectively impact attention; (2) acupuncture can also selectively impact attention; i.e., both have selective influences on the alerting and executive control networks, but not on the orienting network; (3) the effects of acupuncture and painful stimulation are not identical. The mechanisms by which painful stimulation and acupuncture influence attention warrant further research
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