Дифференциальная диагностика сифилитической и гнездной алопеции: клиническая картина, трихоскопические признаки

This paper describes a clinical case of secondary syphilis, which was manifested exclusively by syphilitic alopecia.We describe the details of the clinical picture, as well as a differential diagnosis of syphilitic alopecia and alopecia areata on the basis of trichoscopy data.For a patient with scalp lesions typical of syphilis (focal form of alopecia), the trichoscopic picture was represented by hairs broken at different heights from 1 to 5 mm, “empty” follicles (“yellow” dots), anisotrichosis due to the loss of terminal hair. The eyebrow trichoscopy showed “yellow dots”, vellus hairs, hair thinning due to the loss of bristly hair. A comparison of the trichoscopic pictures for alopecia areata and syphilitic areata have revealed the absence in the latter of a number of signs typical of the former, such as pencil-point, ex clamation-point, zigzag, monilethrix and tulip hairs.Patients with a clinical picture of focal, diffuse or mix ed alopecia should be tested for syphilis using serological methods.Описан случай вторичного периода сифилиса с единственным клиническим проявлением — сифилитической алопецией.Представлены особенности клинической картины, дифференциальной диагностики сифилитической и гнездной алопеции на основании данных трихоскопии.Приведены данные трихоскопической картины у пациента с поражением волосистой части головы при сифилисе (мелкоочаговой формы алопеции): обломанные на разной высоте от 1 до 5 мм во- лосы, «пустующие» фолликулы («желтые» точки), анизотрихоз вследствие выпадения части тер- минальных волос. Представлена трихоскопия бровей: «желтые точки», веллус, поредение за счет выпадения части щетинистых волос. При сравнении трихоскопической картины гнездной алопеции и сифилитической выявлено отсутствие ряда признаков, часто встречающихся при гнездной алопеции, таких как: конические волосы, волосы «по типу восклицательного знака», зигзагообразные волосы, волосы «по типу монилетрикса», тюльпаноподобные волосы.Обозначена актуальность и целесообразность скрининга пациентов с клинической картиной мелкоочаговой, диффузной, смешанной алопеции на сифилис с помощью серологических методов исследования крови

Is the mean-field approximation so bad? A simple generalization yelding realistic critical indices for 3D Ising-class systems

Modification of the renormalization-group approach, invoking Stratonovich transformation at each step, is proposed to describe phase transitions in 3D Ising-class systems. The proposed method is closely related to the mean-field approximation. The low-order scheme works well for a wide thermal range, is consistent with a scaling hypothesis and predicts very reasonable values of critical indices.Comment: 4 page

Dual boson approach to collective excitations in correlated fermionic systems

We develop a general theory of a boson decomposition for both local and non-local interactions in lattice fermion models which allows us to describe fermionic degrees of freedom and collective charge and spin excitations on equal footing. An efficient perturbation theory in the interaction of the fermionic and the bosonic degrees of freedom is constructed in so-called dual variables in the path-integral formalism. This theory takes into account all local correlations of fermions and collective bosonic modes and interpolates between itinerant and localized regimes of electrons in solids. The zero-order approximation of this theory corresponds to extended dynamical mean-field theory (EDMFT), a regular way to calculate nonlocal corrections to EDMFT is provided. It is shown that dual ladder summation gives a conserving approximation beyond EDMFT. The method is especially suitable for consideration of collective magnetic and charge excitations and allows to calculate their renormalization with respect to "bare" RPA-like characteristics. General expression for the plasmonic dispersion in correlated media is obtained. As an illustration it is shown that effective superexchange interactions in the half-filled Hubbard model can be derived within the dual-ladder approximation.Comment: Extended version, 17 pages, 5 figure

Dual boson approach with instantaneous interaction

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Importance of full Coulomb interactions for understanding the electronic structure of delta-Pu

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Lorentz breaking Effective Field Theory and observational tests

Analogue models of gravity have provided an experimentally realizable test field for our ideas on quantum field theory in curved spacetimes but they have also inspired the investigation of possible departures from exact Lorentz invariance at microscopic scales. In this role they have joined, and sometime anticipated, several quantum gravity models characterized by Lorentz breaking phenomenology. A crucial difference between these speculations and other ones associated to quantum gravity scenarios, is the possibility to carry out observational and experimental tests which have nowadays led to a broad range of constraints on departures from Lorentz invariance. We shall review here the effective field theory approach to Lorentz breaking in the matter sector, present the constraints provided by the available observations and finally discuss the implications of the persisting uncertainty on the composition of the ultra high energy cosmic rays for the constraints on the higher order, analogue gravity inspired, Lorentz violations.Comment: 47 pages, 4 figures. Lecture Notes for the IX SIGRAV School on "Analogue Gravity", Como (Italy), May 2011. V.3. Typo corrected, references adde

Dual fermion approach to nonlocal correlations in the Hubbard model

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Numerical study of the classical 2D discrete frustrated phi(4) model

Item does not contain fulltextThe two-dimensional discrete frustrated phi(4) model is studied by Monte Carlo simulations for two sets of the parameters of the model. Two phase transitions and a floating-incommensurate phase are observed for the case of stronger frustration. The phase transition from the floating-fluid phase to the floating - incommensurate phase is of Kosterlitz-Thouless type. A single phase transition from the floating-fluid phase to the ferro-phase is found for the case of weaker frustration