Analysis and application of digital spectral warping in analog and mixed-signal testing

Spectral warping is a digital signal processing transform which shifts the frequencies contained within a signal along the frequency axis. The Fourier transform coefficients of a warped signal correspond to frequency-domain 'samples' of the original signal which are unevenly spaced along the frequency axis. This property allows the technique to be efficiently used for DSP-based analog and mixed-signal testing. The analysis and application of spectral warping for test signal generation, response analysis, filter design, frequency response evaluation, etc. are discussed in this paper along with examples of the software and hardware implementation

Cerenkov generation of high-frequency confined acoustic phonons in quantum wells

We analyze the Cerenkov emission of high-frequency confined acoustic phonons by drifting electrons in a quantum well. We find that the electron drift can cause strong phonon amplification (generation). A general formula for the gain coefficient, alpha, is obtained as a function of the phonon frequency and the structure parameters. The gain coefficient increases sharply in the short-wave region. For the example of a Si/SiGe/Si device it is shown that the amplification coefficients of the order of hundreds of 1/cm can be achieved in the sub-THz frequency range.Comment: 4 pages, 2 figures. Submitted to AP

Stimulation of reparation in a linear wound model in rats by Bischofit gel

The article is to evaluate Bischofit gel reparative activity in a linear wound model in rat

The cardio- and endothelial protective effects of ethyl methyl hydroxyl pyridine malate in modeling L-name induced nitric oxide deficiency

Currently, endothelial dysfunction is considered as a predictor of a number of pathologies, including arterial hypertension, ischemic heart disease, chronic heart failure, and is also a pathogenetic component of organ damage in diabetes, hypo estrogenic and other conditions. The purpose of the study is an experimental study of the cardio and vasoprotective effects of etoxidol under conditions of endothelial dysfunctio

КОНЦЕПТУАЛЬНАЯ МОДЕЛЬ МЕХАНИЗМОВ ОБЕСПЕЧЕНИЯ КАЧЕСТВА ОБСЛУЖИВАНИЯ В СЕТЯХ С КОММУТАЦИЕЙ ПАКЕТОВ

The paper presents analysis and generalization of the quality of service mechanisms in packetswitched networks. Decomposition of the quality of service mechanisms is presented. Each QoS control mechanism can be split into four components. Each component is responsible for the defined subtask. A method of formalization is offered in which each QoS mechanism component is presented by function of defined arguments. Presented method is used for simulation of QoS mechanisms in the next generation networks.Анализируются и обобщаются принципы работы механизмов обеспечения качества обслуживания в сетях с коммутацией пакетов. Проводится декомпозиция и выделяются четыре компонента механизмов обеспечения качества обслуживания. Описываются особенности каждого из компонентов. Предлагается способ формализации для построения имитационных моделей механизмов обеспечения качества обслуживания в сетях нового поколения, при котором каждый из компонентов представляется функцией от определенных параметров

Clinical course, costs and predictive factors for response to treatment in carpal tunnel syndrome: The PALMS study protocol

Background Carpal tunnel syndrome (CTS) is the most common neuropathy of the upper limb and a significant contributor to hand functional impairment and disability. Effective treatment options include conservative and surgical interventions, however it is not possible at present to predict the outcome of treatment. The primary aim of this study is to identify which baseline clinical factors predict a good outcome from conservative treatment (by injection) or surgery in patients diagnosed with carpal tunnel syndrome. Secondary aims are to describe the clinical course and progression of CTS, and to describe and predict the UK cost of CTS to the individual, National Health Service (NHS) and society over a two year period. Methods/Design In this prospective observational cohort study patients presenting with clinical signs and symptoms typical of CTS and in whom the diagnosis is confirmed by nerve conduction studies are invited to participate. Data on putative predictive factors are collected at baseline and follow-up through patient questionnaires and include standardised measures of symptom severity, hand function, psychological and physical health, comorbidity and quality of life. Resource use and cost over the 2 year period such as prescribed medications, NHS and private healthcare contacts are also collected through patient self-report at 6, 12, 18 and 24 months. The primary outcome used to classify treatment success or failures will be a 5-point global assessment of change. Secondary outcomes include changes in clinical symptoms, functioning, psychological health, quality of life and resource use. A multivariable model of factors which predict outcome and cost will be developed. Discussion This prospective cohort study will provide important data on the clinical course and UK costs of CTS over a two-year period and begin to identify predictive factors for treatment success from conservative and surgical interventions

Клиническое наблюдение редкого варианта поражения лабиринта: опухоль эндолимфатического мешка

Endolymphatic sac tumors are rare neoplasms originating from the endolymphatic epithelium of the intraosseous part of the endolymphatic duct and sac, typically characterized by slow growth and local destructive changes. We present a case of an endolymphatic sac tumor in a 28-year-old man who consulted an otoneurologist with complaints of progressive hearing loss and dizziness attacks and was referred for a CT scan of the temporal bones and MRI of the inner ear with delayed contrast enhancement. The data of otoneurological and radiological examinations before and after surgical treatment and the results of surgical treatment with histological verification of the tumor are presented. The objective of this case presentation is to demonstrate the usefulness of CT and MRI methods in detecting an endolymphatic sac tumor, to compare the results of otoneurological and radiological examinations and intraoperative and histological data followed by surgery. Radiological examination revealed a neoplasm of the right temporal bone with typical imaging characteristics of endolymphatic sac tumor. Surgery was performed, the mass was removed completely, and the endolymphatic sac tumor was histologically verified. Radiologic presentation includes a typically located area of bone destruction in the petrous part of the temporal bone in the area of the vestibular aqueduct, possibly with the spread of the tumor into the cerebellopontine angle, with a heterogeneous structure, with uneven contrast enhancement. Due to the rarity of this pathology, diagnosis in the early stages is often difficult, and for the correct interpretation of radiologic findings in patients with hearing loss and dizziness, knowledge of the normal anatomy of the temporal bone and awareness of rare variants of its lesions are of key importance. Timely examination of patients with suspected temporal bone lesions and correct diagnosis are the key to successful treatment and maintaining the quality of life in this group of patients.Опухоли эндолимфатического мешка — это редкие новообразования, исходящие из эндолимфатического эпителия внутрикостной части эндолимфатического протока и мешка, типичными для них являются медленный рост и локальные деструктивные изменения. Нами представлено наблюдение опухоли эндолимфатического мешка у мужчины 28 лет, который обратился к отоневрологу с жалобами на прогрессирующее снижение слуха и приступы головокружения и был направлен на лучевое обследование в объеме МСКТ височных костей и МРТ внутреннего уха с отсроченным контрастированием. Приведены данные отоневрологического, лучевого обследования до и после оперативного лечения и результаты оперативного лечения с гистологической верификацией опухоли. Цель данного наблюдения — продемонстрировать возможности лучевой диагностики (КТ и МРТ) в выявлении опухоли эндолимфатического мешка, сопоставить результаты отоневрологического и лучевого обследования и интраоперационные и гистологические данные. При лучевом обследовании выявлено новообразование височной кости с типичными визуализационными характеристиками опухоли эндолимфатического мешка. Проведено оперативное лечение, образование удалено, верифицирована опухоль эндолимфатического мешка. Лучевая семиотика ОЭМ включает наличие типично расположенной зоны остеодеструкции в каменистой части височной кости в зоне расположения водопровода преддверия, возможно распространение опухолевого компонента в область мостомозжечкового угла, гетерогенной структуры, с неравномерным накоплением контрастного препарата. В связи с редкостью данной патологии диагностика на ранних стадиях часто затруднена, а для верной интерпретации изменений при лучевом обследовании пациентов со снижением слуха и головокружением, знание нормальной лучевой анатомии височной кости и информированность о редких вариантах ее патологии имеют ключевое значение. Своевременное обследование пациентов с подозрением на образование височной кости и правильная постановка диагноза являются залогом успешного лечения и сохранения качества жизни у данной группы пациентов