Polaron and bipolaron dispersion curves in one dimension for intermediate coupling

Bipolaron energies are calculated as a function of wave vector by a variational method of Gurari appropriate for weak or intermediate coupling strengths, for a model with electron-phonon interactions independent of phonon wave vectors and a short-ranged Coulomb repulsion. It is assumed that the bare electrons have a constant effective mass. A two-parameter trial function is taken for the relative motion of the two electrons in the bipolaron. Energies of bipolarons are compared with those of two single polarons as a function of wave vector for various parameter values. Results for effective masses at the zone center are also obtained. Comparison is made with data of other authors for bipolarons in the Hubbard-Holstein model, which differs mainly from the present model in that it has a tight-binding band structure for the bare electrons.Comment: 11 pages including six figures. Physical Review B, to be publishe

Modification of a charged-Bose-gas model for observed room-temperature superconductivity in narrow channels through films of oxidised atactic polypropylene

Reasons have been found for thinking that the minimum diameter of channels of a given length to support superconductivity at room temperature through films of oxidised atactic polypropylene (OAPP) is considerably larger than found in a model for Bose condensation in an array of nanofilaments [D.M. Eagles, Phil. Mag. 85, 1931 (2005)] used previously. This model was introduced to interpret experimental results dating from 1988 on OAPP. The channels are thought to be of larger diameter than believed before because, for an N-S-N system where the superconductor consists of an array of single-walled carbon nanotubes, the resistance, for good contacts, is R_Q/2N, where N is the number of nanotubes and R_Q=12.9 kOhm [See e.g. M. Ferrier et al., Solid State Commun. 131, 615 (2004)]. We assume this would be 2R_Q/N for a triplet superconductor with all spins in the same direction and no orbital degeneracy, which may be the case for nanofilaments in OAPP. Hence one may infer a minimum number of filaments for a given resistance. In the present model, the E(K) curve for the bosons is taken to be of a Bogoliubov form, but with a less steep initial linear term in the dispersion at T_c than occurs at low T. This form is different from the simple linear plus quadratic dispersion, with a steeper initial slope, used in my 2005 paper. A combination of theory and experimental data has been used to find approximate constraints on parameters appearing in the theory.Comment: Publication details added. Correction to bracketing in Eq. (1), which was incorrect in v1 of preprint and in the published articl

Комбинированная пластика при посттравматическом остеомиелите большеберцовой кости (клиническое наблюдение)

The article presents a clinical case of successful complex surgical management of a 62-year-old patient with chronic post-traumatic tibial osteomyelitis. A two-stage surgical treatment was aimed to sanitize a chronic purulent focus in the tibia lower third and to perform a complex reconstructive surgery aimed to correct bone and soft tissue defects. The reconstructive stage of the discussed complex surgical treatment consisted in combined plasty: a cavity in the bone was filled with bone grafts obtained from the iliac crest; and a skin and soft tissue defect was corrected with an islet sural musculocutaneous flap on the distal feeding pedicle. As a result, the surgeons could effectively correct tibia and soft tissues defects with good functional and cosmetic results.В статье представлено клиническое наблюдение успешного комплексного хирургического лечения пациентки, 62 лет, с хроническим посттравматическим остеомиелитом большеберцовой кости. Продемонстрировано двухэтапное хирургическое лечение, включающее вмешательство, направленное на санацию хронического гнойного очага в нижней трети большеберцовой кости, и сложную реконструктивно-восстановительную операцию для ликвидации костной полости и дефекта мягких тканей. Реконструктивный этап комплексного хирургического лечения заключался в выполнении комбинированной пластики: костная пластика аутоспонгиозой, полученной из гребня подвздошной кости, и мягкотканная пластика островковым суральным кожно-мышечным лоскутом на дистальной питающей ножке, в результате чего удалось полностью ликвидировать дефект большеберцовой кости, мягких и покровных тканей с хорошими функциональными и косметическими результатами

ОСОБЕННОСТИ ДИАГНОСТИКИ И ЛЕЧЕНИЯ РАКА ПОЧКИ В РОССИИ: ПРЕДВАРИТЕЛЬНЫЕ РЕЗУЛЬТАТЫ МНОГОЦЕНТРОВОГО КООПЕРИРОВАННОГО ИССЛЕДОВАНИЯ

An interim analysis of the database comprising information on 7813 kidney cancer (KC) patients who had been treated or followed up in 25 health care facilities of Russia yielded some patient characteristics, the specific features of the tumor process, and main approaches to surgical and medical treatments. Such characteristics as a male-to-female patient ratio, stage distribution in patients, detection rate of different histological types of KC and different tumor grades, proportion of organ-saving and organ-removing interventions, drug treatments for metastatic KC are considered.В статье, по данным промежуточного анализа базы данных, включающей информацию о 7813 больных раком почки (РП), которые получали лечение и/или находились под наблюдением в 25 лечебных учреждениях России, представлены некоторые показатели, характеризующие пациентов, включенных в исследование, особенности опухолевого процесса и основные подходы к хирургическому и лекарственному лечению. Рассмотрены такие характеристики, как соотношение заболевших мужчин и женщин, постадийное распределение больных, частота выявления различных гистологических типов РП и различной степени дифференцировки опухоли, доля органосохраняющих и органоуносящих вмешательств, методы лекарственного лечения при метастатическом РП

SOME SPECIFIC FEATURES OF THE DIAGNOSIS AND TREATMENT OF KIDNEY CANCER IN RUSSIA: PRELIMINARY RESULTS OF A MULTICENTER COOPERATIVE STUDY

An interim analysis of the database comprising information on 7813 kidney cancer (KC) patients who had been treated or followed up in 25 health care facilities of Russia yielded some patient characteristics, the specific features of the tumor process, and main approaches to surgical and medical treatments. Such characteristics as a male-to-female patient ratio, stage distribution in patients, detection rate of different histological types of KC and different tumor grades, proportion of organ-saving and organ-removing interventions, drug treatments for metastatic KC are considered

SOME SPECIFIC FEATURES OF THE DIAGNOSIS AND TREATMENT OF KIDNEY CANCER IN RUSSIA: PRELIMINARY RESULTS OF A MULTICENTER COOPERATIVE STUDY

An interim analysis of the database comprising information on 7813 kidney cancer (KC) patients who had been treated or followed up in 25 health care facilities of Russia yielded some patient characteristics, the specific features of the tumor process, and main approaches to surgical and medical treatments. Such characteristics as a male-to-female patient ratio, stage distribution in patients, detection rate of different histological types of KC and different tumor grades, proportion of organ-saving and organ-removing interventions, drug treatments for metastatic KC are considered