232 research outputs found
Structure of hadron resonances with a nearby zero of the amplitude
We discuss the relation between the analytic structure of the scattering
amplitude and the origin of an eigenstate represented by a pole of the
amplitude.If the eigenstate is not dynamically generated by the interaction in
the channel of interest, the residue of the pole vanishes in the zero coupling
limit. Based on the topological nature of the phase of the scattering
amplitude, we show that the pole must encounter with the
Castillejo-Dalitz-Dyson (CDD) zero in this limit. It is concluded that the
dynamical component of the eigenstate is small if a CDD zero exists near the
eigenstate pole. We show that the line shape of the resonance is distorted from
the Breit-Wigner form as an observable consequence of the nearby CDD zero.
Finally, studying the positions of poles and CDD zeros of the KbarN-piSigma
amplitude, we discuss the origin of the eigenstates in the Lambda(1405) region.Comment: 7 pages, 3 figures, v2: published versio
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Improved Constraints on Sterile Neutrino Mixing from Disappearance Searches in the MINOS, MINOS+, Daya Bay, and Bugey-3 Experiments.
Searches for electron antineutrino, muon neutrino, and muon antineutrino disappearance driven by sterile neutrino mixing have been carried out by the Daya Bay and MINOS+ collaborations. This Letter presents the combined results of these searches, along with exclusion results from the Bugey-3 reactor experiment, framed in a minimally extended four-neutrino scenario. Significantly improved constraints on the ΞΈ_{ΞΌe} mixing angle are derived that constitute the most constraining limits to date over five orders of magnitude in the mass-squared splitting Ξm_{41}^{2}, excluding the 90% C.L. sterile-neutrino parameter space allowed by the LSND and MiniBooNE observations at 90% CL_{s} for Ξm_{41}^{2}<13ββeV^{2}. Furthermore, the LSND and MiniBooNE 99% C.L. allowed regions are excluded at 99% CL_{s} for Ξm_{41}^{2}<1.6βeV^{2}
Phonon-assisted carrier transport through a lattice-mismatched interface
We showed the distinctive unconventional junction effect of MoS2 junctions: a lattice mismatched MoS2. It is unique to observe the difference originated from the atomic interrelation at the interface. The results revealed the dominant scattering source at the conventional naturally stepwise junction, while the misorientationally stacked layer exhibited effectively decoupled behavior and a significantly smaller junction resistance via phonon assist carrier. Therefore, our finding in this paper clearly shows the different mechanisms in carrier transport at both junction interface of MoS2
Ξ±-Adducin Gly460Trp Gene Mutation and Essential Hypertension in a Chinese Population: A Meta-Analysis including 10960 Subjects
BACKGROUND: The Ξ±-adducin Gly460Trp (G460W) gene polymorphism may be associated with susceptibility to essential hypertension (EH), but this relationship remains controversial. In an attempt to resolve this issue, we conducted a meta-analysis. METHODS: Twenty-three separated studies involving 5939 EH patients and 5021 controls were retrieved and analyzed. Four ethnicities were included: Han, Kazakh, Mongolian, and She. Eighteen studies with 5087 EH patients and 4183 controls were included in the Han subgroup. Three studies with 636 EH patients and 462 controls were included in the Kazakh subgroup. The Mongolian subgroup was represented by only one study with 100 EH patients and 50 controls; similarly, only one study with 116 EH patients and 326 controls was available for the She subgroup. The pooled and ethnic group odds ratios (ORs) along with the corresponding 95% confidence intervals (95% CI) were assessed using a random effects model. RESULTS: There was a significant association between the Ξ±-adducin G460W gene polymorphism and EH in the pooled Chinese population under both an allelic genetic model (OR: 1.12, 95% CI: 1.04-1.20, Pβ=β0.002) and a recessive genetic model (OR: 1.40, 95% CI: 1.16-1.70, Pβ=β0.0005). In contrast, no significant association between the Ξ±-adducin G460W gene polymorphism and EH was observed in the dominant genetic model (OR: 0.88, 95% CI: 0.72-1.09, Pβ=β0.24). In stratified analysis by ethnicity, significantly increased risk was detected in the Han subgroup under an allelic genetic model (OR: 1.13, 95% CI: 1.04-1.23, Pβ=β0.003) and a recessive genetic model (OR: 1.43, 95% CI: 1.17-1.75, Pβ=β0.0006). CONCLUSIONS: In a Chinese population of mixed ethnicity, the Ξ±-adducin G460W gene polymorphism was linked to EH susceptibility, most strongly in Han Chinese
Comparison of hormonal receptor and HER-2 status between breast primary tumours and relapsing tumours: clinical implications of progesterone receptor loss
Differences in hormone receptor and HER-2 status between primary tumour and corresponding relapse could have a substantial impact on clinical management of patients. The aim of this study was to evaluate change in expression of hormone receptors and HER-2 status between primary tumour and corresponding local recurrence or distant metastasis. We analysed 140 primary tumours and related recurrent or metastatic samples. Hormone receptors status was evaluated by immunohistochemistry, while HER-2 status by immunohistochemistry and silver in situ hybridisation. A change in HER-2 was rare; 3.7% of cases by immunohistochemistry and only 0.7% by silver in situ hybridisation analysis. A change in estrogen and progesterone receptors was seen in 6.4% and 21.4% of cases, respectively. Estrogen receptor change was not affected by adjuvant therapy, whereas progesterone receptor was influenced by adjuvant chemotherapy associated to hormone therapy (Pβ=β0.0005). A change in progesterone receptor was more frequent in distant metastases than in local recurrences (Pβ=β0.03). In the setting of estrogen receptor positive tumours, patients with progesterone receptor loss in local recurrence had a statistically significant lower median metastasis free survival compared to others patients; progesterone receptor positive, 112Β months; progesterone receptor negative, 24Β months (Pβ=β0.005). A change between primary tumour and corresponding relapse is frequent for progesterone receptor, infrequent for estrogen receptor and rare for HER-2. In cases with changes in HER-2, it is worthwhile reassessing HER-2 status with both immunohistochemistry and in situ hybridisation analysis. Progesterone receptor loss seems to be influenced by therapy and to correlate with a worse prognosis
Successful Cognitive Aging in Rats: A Role for mGluR5 Glutamate Receptors, Homer 1 Proteins and Downstream Signaling Pathways
Normal aging is associated with impairments in cognition, especially learning and memory. However, major individual differences are known to exist. Using the classical Morris Water Maze (MWM) task, we discriminated a population of 24-months old Long Evans aged rats in two groups - memory-impaired (AI) and memory-unimpaired (AU) in comparison with 6-months old adult animals. AI rats presented deficits in learning, reverse memory and retention. At the molecular level, an increase in metabotropic glutamate receptors 5 (mGluR5) was observed in post-synaptic densities (PSD) in the hippocampus of AU rats after training. Scaffolding Homer 1b/c proteins binding to group 1 mGluR facilitate coupling with its signaling effectors while Homer 1a reduces it. Both Homer 1a and 1b/c levels were up-regulated in the hippocampus PSD of AU animals following MWM task. Using immunohistochemistry we further demonstrated that mGluR5 as well as Homer 1b/c stainings were enhanced in the CA1 hippocampus sub-field of AU animals. In fact mGluR5 and Homer 1 isoforms were more abundant and co-localized in the hippocampal dendrites in AU rats. However, the ratio of Homer 1a/Homer 1b/c bound to mGluR5 in the PSD was four times lower for AU animals compared to AI rats. Consequently, AU animals presented higher PKCΞ³, ERK, p70S6K, mTOR and CREB activation. Finally the expression of immediate early gene Arc/Arg3.1 was shown to be higher in AU rats in accordance with its role in spatial memory consolidation. On the basis of these results, a model of successful cognitive aging with a critical role for mGluR5, Homer 1 proteins and downstream signalling pathways is proposed here
The Promigratory Activity of the Matricellular Protein Galectin-3 Depends on the Activation of PI-3 Kinase
Expression of galectin-3 is associated with sarcoma progression, invasion and metastasis. Here we determined the role of extracellular galectin-3 on migration of sarcoma cells on laminin-111. Cell lines from methylcholanthrene-induced sarcomas from both wild type and galectin-3β/β mice were established. Despite the presence of similar levels of laminin-binding integrins on the cell surface, galectin-3β/β sarcoma cells were more adherent and less migratory than galectin-3+/+ sarcoma cells on laminin-111. When galectin-3 was transiently expressed in galectin-3β/β sarcoma cells, it inhibited cell adhesion and stimulated the migratory response to laminin in a carbohydrate-dependent manner. Extracellular galectin-3 led to the recruitment of SHP-2 phosphatase to focal adhesion plaques, followed by a decrease in the amount of phosphorylated FAK and phospho-paxillin in the lamellipodia of migrating cells. The promigratory activity of extracellular galectin-3 was inhibitable by wortmannin, implicating the activation of a PI-3 kinase dependent pathway in the galectin-3 triggered disruption of adhesion plaques, leading to sarcoma cell migration on laminin-111
Evolution of the Reactor Antineutrino Flux and Spectrum at Daya Bay
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Measurement of electron antineutrino oscillation based on 1230Β days of operation of the Daya Bay experiment
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