Technicolor Models with Color-Singlet Technifermions and their Ultraviolet Extensions

We study technicolor models in which all of the technifermions are color-singlets, focusing on the case in these fermions transform according to the fundamental representation of the technicolor gauge group. Our analysis includes a derivation of restrictions on the weak hypercharge assignments for the technifermions and additional color-singlet, technisinglet fermions arising from the necessity of avoiding stable bound states with exotic electric charges. Precision electroweak constraints on these models are also discussed. We determine some general properties of extended technicolor theories containing these technicolor sectors.Comment: 17 pages, latex, 2 figure

Surgery for lymph node metastases of medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) is a neuroendocrine malignancy of the thyroid C cells, and can commonly spread to cervical and mediastinal lymph nodes. MTC cells do not concentrate radioactive iodine and are not sensitive to hormonal manipulation, and therefore surgery is the only effective option for curative therapy, reduction in tumor burden or effective palliation. In patients undergoing preventative operations for hereditary MTC, central lymph node dissection should be considered if the calcitonin level is above 40 pg/ml. Systematic removal of at-risk or involved lymph node compartments should be performed in all patients with palpable primary tumors and recurrent disease, and a ‘berry-picking’ approach should be avoided. </jats:p

Shear Strength of Fiber Reinforced Reactive Powder Concrete I-Shaped Beam without Stirrup

Due to the high compressive strength of steel fiber reinforced (SFR) and Reactive Powder concrete (RPC), higher degree of prestressing is available for the beams using fiber reinforced reactive powder concrete. Hence, a slenderer structural component can be designed, which could save self-weight, work spacing, and potential reducing the costs. However, comparing to conventional reinforced concrete (RC) beams, studies on post-tensioning SFR-RPC beams subjected to shear failure are fewer. In this study, a series of shear tests for four large-scale beams (one SFR-RPC beam and three post-tensioning SFR-RPC beams) are made to quantify the effects of levels of prestressing on shear load capacity of SFR-RPC beams. Finally, the test results together with data published from existing literatures are compared to the design strength calculated in accordance to different standards. It is found that the current code provisions will underestimate the shear load capacity significantly. In addition, an analytical model is proposed to predict the shear load capacity of the test specimens. A good correlation is observed with a mean analytical model to experimental strength ratio of 1.02 and coefficient of variation of 0.12

Parton Distributions at Hadronization from Bulk Dense Matter Produced at RHIC

We present an analysis of $\Omega$, $\Xi$, $\Lambda$ and $\phi$ spectra from Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV in terms of distributions of effective constituent quarks at hadronization. Consistency in quark ratios derived from various hadron spectra provides clear evidence for hadron formation dynamics as suggested by quark coalescence or recombination models. We argue that the constituent quark distribution reflects properties of the effective partonic degrees of freedom at hadronization. Experimental data indicate that strange quarks have a transverse momentum distribution flatter than that of up/down quarks consistent with hydrodynamic expansion in partonic phase prior to hadronization. After the AMPT model is tuned to reproduce the strange and up/down quark distributions, the model can describe the measured spectra of hyperons and $\phi$ mesons very well where hadrons are formed through dynamical coalescence.Comment: 5 pages, 3 figures, two more paragraph added to address the referee's comment, figure updated to include the KET scale. Accepted version to appear in Phys. Rev.

Two-dimensional Superconductivity from Dimerization of Atomically Ordered AuTe2Se4/3 Cubes

The emergent phenomena such as superconductivity and topological phase transitions can be observed in strict two-dimensional crystalline matters. Artificial interfaces and one atomic thickness layers are typical 2D materials of this kind. Although having 2D characters, most bulky layered compounds, however, do not possess these striking properties. Here, we report the 2D superconductivity in bulky AuTe2Se4/3,where the reduction in dimensionality is achieved through inducing the elongated covalent Te-Te bonds. The atomic-resolution images reveal that the Au, Te and Se are atomically ordered in a cube, among which are Te-Te bonds of 3.18 A and 3.28 A. The superconductivity at 2.85 K is discovered, which is unraveled to be the quasi-2D nature owing to the BKT topological transition. The nesting of nearly parallel Fermi sheets could give rise to strong electron-phonon coupling. It is proposed to further depleting the thickness could result in more topologically-related phenomena.Comment: 16 pages, 5 figures,To be published in Nature Communication