Indications for sharp continuous phase transitions at finite temperatures connected with the apparent metal-insulator transition in two-dimensional disordered systems

In a recent experiment, Lai et al. [Phys. Rev. B 75, 033314 (2007)] studied the apparent metal-insulator transition (MIT) of a Si quantum well structure tuning the charge carrier concentration $n$. They observed linear temperature dependences of the conductivity $\sigma(T,n)$ around the Fermi temperature and found that the corresponding $T \to 0$ extrapolation $\sigma_0(n)$ exhibits a sharp bend just at the MIT. Here, reconsidering the data published by Lai et al., it is shown that this sharp bend is related to a peculiarity of $\sigma(T=const.,n)$ clearly detectable in the whole $T$ range up to 4 K, the highest measuring temperature in that work. Since this peculiarity seems not to be smoothed out with increasing $T$ it may indicate a sharp continuous phase transition between the regions of apparent metallic and activated conduction to be present at finite temperature. Hints from the literature of such a behavior are discussed. Finally, a scaling analysis illuminates similarities to previous experiments and provides understanding of the shape of the peculiarity and of sharp peaks found in $d log_{10} \sigma / d n (n)$.Comment: Revised version (quantitative determination of exponent beta added), accepted for publication by Physical Review B. Revtex, 10 pages, 9 figure

Evaluating a p-th order cohomology operation

A certain p-th order cup product is detected by a p-th order cohomology operation . The result is applied to finite H-spaces, to show that several properties of compact Lie groups do not hold for arbitrary torsion free finite H-spaces

Changes in mucosa laryngopharyngeal vascularization after radiotherapy and concomitant chemotherapy observed with narrow band imaging. Description of two cases

Introducción y objetivo: La imagen de banda estrecha o Narrow Band Imaging (NBI) es un sistema de mejora de imagen utilizado en la detección de anomalías vasculares en la mucosa y submucosa con neoplasia. En 2011 Ni estableció los cinco tipos de patrones de imágenes en la mucosa laríngea relacionándolos con los hallazgos histopatológicos de las lesiones. Sin embargo, estos patrones se ven modificados por tratamientos previos de cirugía láser, radioterapia y quimioterapia. Nuestro objetivo es describir las imágenes tipo con NBI obtenidas en pacientes tratados con el esquema terapéutico de radioterapia y quimioterapia concomitante. Descripción: Imágenes de NBI en paciente de 68 años con carcinoma epidermoide no queratinizante supraglótico estadio III tratado con radioterapia y quimioterapia concomitante a los tres meses y al año posterior al tratamiento. Imágenes de NBI en paciente de 50 años con carcinoma epidermoide no queratinizante de nasofaringe estadio II tratado con radioterapia y quimioterapia concomitante a los tres meses y al año posterior al tratamiento. Resultados: Los patrones obtenidos no se identifican con ninguno de los establecidos previamente por Ni. Las imágenes difieren en función del tiempo transcurrido desde el tratamiento. Conclusiones: Es importante conocer las alteraciones observadas en la mucosa y submucosa de pacientes tratados con radioterapia y quimioterapia concomitante ya que difieren de los patrones característicos descritos por Ni asociados a la presencia de neoplasia.Introduction and objective: Narrow Band Imaging (NBI) is an image enhancement system used to detect vascular anomalies in the mucosa and submucosa of neoplasms. In 2011 Ni established the five types of imaging patterns in the laryngeal mucosa relating them to the histopathological findings of the lesions. However, these patterns are modified by previous treatments of laser surgery, radiotherapy and chemotherapy. Our objective is to describe the NBI type images obtained in patients treated with the therapeutic regimen of radiotherapy and concomitant chemotherapy. Description: NBI images in a 68-yearold patient with stage III supraglottic non-keratinizing squamous cell carcinoma treated with radiotherapy and concomitant chemotherapy at three months and the year after treatment. NBI images in a 50-year-old patient with stage II nasopharynx non-keratinizing squamous cell carcinoma treated with radiotherapy and concomitant chemotherapy at three months and the year after treatment. Results: The obtained patterns are not identified with any of those previously established by Ni. The images differ depending on the time elapsed since the treatment. Conclusions: It is important to know the alterations observed in the mucosa and submucosa of patients treated with radiotherapy and concomitant chemotherapy since they differ from the characteristic patterns described by Ni associated with the presence of neoplasia

Activation of р-450-depended monooxygenases changing immunotoxicity of phosphoroorganic compounds due to their metabolism character

It was established that the application of the monooxygenase system inductors (MSI) of phenobarbital and benzonal up to acute poisoning of animals by trichlorfom in a dose of 1,0 LD50, metabolized in the organism till production of compounds with higher toxicity caused its immunotoxic properties increase. The experiment was carried out on outbred white rats. the acute dimethyldichlorvinylphosphate (1,0 LD50) poisoning, biotransformation of which proceeded with formation of less-toxic and non-toxic compounds after MSI introduction, caused its decrease of suppression influence on immunity system indice

The Nature of the Chemical Process. 1. Symmetry Evolution - Revised Information Theory, Similarity Principle and Ugly Symmetry

Three laws of information theory have been proposed. Labeling by introducing nonsymmetry and formatting by introducing symmetry are defined. The function L (L=lnw, w is the number of microstates, or the sum of entropy and information, L=S+I) of the universe is a constant (the first law of information theory). The entropy S of the universe tends toward a maximum (the second law law of information theory). For a perfect symmetric static structure, the information is zero and the static entropy is the maximum (the third law law of information theory). Based on the Gibbs inequality and the second law of the revised information theory we have proved the similarity principle (a continuous higher similarity-higher entropy relation after the rejection of the Gibbs paradox) and proved the Curie-Rosen symmetry principle (a higher symmetry-higher stability relation) as a special case of the similarity principle. Some examples in chemical physics have been given. Spontaneous processes of all kinds of molecular interaction, phase separation and phase transition, including symmetry breaking and the densest molecular packing and crystallization, are all driven by information minimization or symmetry maximization. The evolution of the universe in general and evolution of life in particular can be quantitatively considered as a series of symmetry breaking processes. The two empirical rules - similarity rule and complementarity rule - have been given a theoretical foundation. All kinds of periodicity in space and time are symmetries and contribute to the stability. Symmetry is beautiful because it renders stability. However, symmetry is in principle ugly because it is associated with information loss.Comment: 29 pages, 14 figure

A finite loop space not rationally equivalent to a compact Lie group

We construct a connected finite loop space of rank 66 and dimension 1254 whose rational cohomology is not isomorphic as a graded vector space to the rational cohomology of any compact Lie group, hence providing a counterexample to a classical conjecture. Aided by machine calculation we verify that our counterexample is minimal, i.e., that any finite loop space of rank less than 66 is in fact rationally equivalent to a compact Lie group, extending the classical known bound of 5.Comment: 8 page

Removing pose from face images

This paper proposes a novel approach to pose removal from face images based on the inherent symmetry that is present in faces. In order for face recognition systems and expression classification systems to operate optimally, subjects must look directly into the camera. The removal of pose from face images after their capture removes this restriction. To obtain a pose-removed face image, the frequency components at each position of the face image, obtained through a wavelet transformation, are examined. A cost function based on the symmetry of this wavelet transformed face image is minimized to achieve pose removal.Experimental results are presented that demonstrate that the proposed algorithm improves upon existing techniques in the literature