654 research outputs found
Classifications of dense languages
Let X be a finite alphabet containing more than one letter. A dense language over X is a language containing a disjunctive language. A language L is an n-dense language if for any distinct n words w(1), w(2),..., w(n) is an element of X+, there exist two words u, v is an element of X* such that uw(1)v, uw(2)v,... uw(n)v is an element of L. In this paper we classify dense languages into strict n- dense languages and study some of their algebraic properties. We show that for each n >= 0, the n- dense language exists. For an n- dense language L, n not equal 1, the language L boolean AND Q is a dense language, where Q is the set of all primitive words over X. Moreover, for a given n >= 1, the language L is such that L boolean AND Q is an element of D-n(X), then L is an element of D-m( X) for some m, n = 0, can be split into disjoint union of infinitely many n- dense languages
Magnetic resonance imaging of glutamate in neuroinflammation
AbstractInflammation in central nervous system (CNS) is one of the most severe diseases, and also plays an impellent role in some neurodegenerative diseases. Glutamate (Glu) has been considered relevant to the pathogenesis of neuroinflammation. In order to diagnose neuroinflammation incipiently and precisely, we review the pathobiological events in the early stages of neuroinflammation, the interactions between Glu and neuroinflammation, and two kinds of magnetic resonance techniques of imaging Glu (chemical exchange saturation transfer and magnetic resonance spectroscopy)
Transport Properties of Electron-doped Sr1-xLaxCuOδ Superconducting Thin Films
An important, still open question in solid state physics is the mechanism of high-temperature superconductivity observed in cuprate compounds, discovered 28 years ago. They are characterized by a layered structure - superconducting CuO2 planes separated by doping layers. Superconductivity emerges from an insulating antiferromagnetic state by doping the CuO2 planes with holes or electrons. Structurally, the simplest cuprate family is only composed of CuO2 planes separated by Sr planes and it might be considered as a model cuprate. However, it appeared that such compound is difficult to prepare: no single crystals were produced to date. Ceramic samples are prepared under high pressure. Epitaxial films are also difficult to synthesize. We have studied Sr1-xLaxCuOδ (SLCO) compound which is electron-doped by partial substitution Sr2+/La3+. As most of research is focused on hole-doped cuprates, our goal was to make stable superconducting SLCO thin films to perform the first measurements of magnetic and electrical transport properties of this "model" cuprate family. C-axis oriented films were deposited by rf magnetron sputtering technique on heated substrates suitable for epitaxial growth. We determined basic superconducting properties of these films, namely the critical temperature and upper critical fields, and the temperature and field dependence of the critical currents. Normal state transport properties were also investigated. In particular a strong temperature dependence of the Hall number was observed, with a change of sign., indicating that two types of carriers are present. Negative in-plane magnetoresistance was also detected, indicative of some remaining antiferromagnetism. Any theory that concerns the mechanism of superconductivity of cuprates must be able to explain these properties
Zero-bias anomalies on SrLaCuO thin films
High-impedance contacts made on the surface of SrLaCuO
superconducting thin films systematically display a zero-bias anomaly. We
consider two-level systems (TLS) as the origin of this anomaly. We observe that
the contribution of some TLS to the contact resistance is weakened by a
magnetic field. We show that this could result from the increase of the TLS
relaxation rate in the superconducting state, due to its ability to create
pairs of quasiparticles out of the condensate, when located close to the
surface of the film
Final state interactions in the decay
In this article, we study the final-state rescattering effects in the decay
, the numerical results indicate the corrections are
comparable with the contribution from the naive factorizable amplitude, and the
total amplitudes can accommodate the experimental data.Comment: 11 pages, 1 figure, revised version, to appear in EPJ
A_4 Symmetry and Lepton Masses and Mixing
Stimulated by Ma's idea which explains the tribimaximal neutrino mixing by
assuming an A_4 flavor symmetry, a lepton mass matrix model is investigated. A
Frogatt-Nielsen type model is assumed, and the flavor structures of the masses
and mixing are caused by the VEVs of SU(2)_L-singlet scalars \phi_i^u and
\phi_i^d (i=1,2,3), which are assigned to {\bf 3} and ({\bf 1}, {\bf 1}',{\bf
1}'') of A_4, respectively.Comment: 13 pages including 1 table, errors in Sec.7 correcte
Performance Comparison between Consequent-Pole and Inset Modular Permanent Magnet Machines
This paper proposes some consequent-pole modular
permanent magnet machines with different flux gap widths
and slot/pole number combinations. The corresponding inset
modular permanent magnet machines having the same
magnet volume are also presented for comparison. It has been
demonstrated that the output torques of the consequent pole
modular machines are always higher than those of the inset
modular machines regardless of flux gap widths and slot/pole
number combinations. Other electromagnetic performances
such as back-EMF, cogging torque, and iron losses, etc. are
calculated by 2D FEA software and compared as well. The
advantages and disadvantages of consequent and inset
modular permanent magnet machines are summarized in this
paper
Construction and functional analysis of nattokinase-producing cucumber obtained by the CRISPR-Cas9 system
Nattokinase (NK) is effective in the prevention and treatment of cardiovascular disease. Cucumber is rich in nutrients with low sugar content and is safe for consumption. The aim of this study was to construct a therapeutic cucumber that can express NK, which can prevent and alleviate cardiovascular diseases by consumption. Because the Bitter fruit ( Bt ) gene contributes to bitter taste but has no obvious effect on the growth and development of cucumber, so the NK-producing cucumber was constructed by replacing the Bt gene with NK by using CRISPR/Cas9. The pZHY988-Cas9-sgRNA and pX6-LHA-U6-NK-T-RHA vectors were constructed and transformed into Agrobacterium tumefaciens EHA105, which was transformed into cucumber by floral dip method. The crude extract of NK-producing cucumber had significant thrombolytic activity in vitro . In addition, treatment with the crude extract significantly delayed thrombus tail appearance, and the thrombin time of mice was much longer than that of normal mice. The degrees of coagulation and blood viscosity as well as hemorheological properties improved significantly after crude extract treatment. These findings show that NK-producing cucumber can effectively alleviate thrombosis and improve blood biochemical parameters, providing a new direction for diet therapy against cardiovascular diseases
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