RF magnetron sputtered (BiDy)3(FeGa)5O12:Bi2O3 composite garnet-oxide materials possessing record magneto-optic quality in the visible spectral region

Bismuth-substituted iron garnets are considered to be the most promising magneto-optical materials because of their excellent optical transparency and very high magneto-optical figures of merit in the near-infrared spectral region. However, the practical application of garnets in the visible and short-wavelength infrared parts of spectrum is currently limited, due to their very high optical absorption (especially in sputtered films) in these spectral regions. In this paper, we identify the likely source of excess absorption observed in sputtered garnet films in comparison with epitaxial layers and demonstrate (Bi,Dy)(3)(Fe,Ga)(5)O(12): Bi(2)O(3) composites possessing record MO quality in the visible region

Studies and application of bent crystals for beam steering at 70-GeV IHEP accelerator

This report overviews studies accomplished in the U70 proton synchrotron of IHEP-Protvino during the recent two decades. Major attention is paid to a routine application of bent crystals for beam extraction from the machine. It has been confirmed experimentally that efficiency of beam extraction with a crystal deflector of around 85% is well feasible for a proton beam with intensity up to 1012 protons per cycle. Another trend is to use bent crystals for halo collimation in a high energy collider. New promising options emerge for, say, LHC and ILC based on the "volume reflection" effect, which has been discovered recently in machine study runs at U70 of IHEP (50 GeV) and SPS of CERN (400 GeV).Comment: 12 pages, 14 figure

Crystal collimation experiment on 70-GeV proton accelerator

The first proof-of-principle experiment on "crystal collimation" was performed with 70-GeV protons on IHEP accelerator. A bent crystal installed in the ring as a primary element upstream of a collimator has reduced the radiation levels downstream in the accelerator by a factor of two. The measurements agree with Monte Carlo predictions

Перелом Гоффа: обзор иностранной литературы

The Hoffa fracture is an extremely rare injury of one or two condyles of the femur in the frontal plane, more often associated with injury to other structures of the knee joint area. The main cause of the Hoffa fracture is considered to be a high-energy injury (road accident in 80.5% of cases). The isolated Hoffa fracture accounts for 0.65% of all femoral fractures. To date, there is no consensus on surgical approach or optimal technique of internal fixation for the frontal fracture of the femoral condyles. There is also a large percentage of mistakes in the X-ray diagnosis of this pathology. The existing classifications have not found wide application in clinical practice, being difficult and inapplicable for solving the issue of treatment tactics and preoperative planning. The aim of the study is to present modern views on the diagnosis, principles and techniques of surgical treatment of patients with the Hoffa fractures based on the analysis of the literature. Based on the analyzed literature, conclusions are drawn about the need for careful collection of injury anamnesis, increased surgeon caution in the presence of this injury clinical picture and the simultaneous absence of pathology on standard knee joint X-rays, the need to perform an additional examination in the form of lateral (non-standard) projections of the knee joint X-rays, CT or MRI. During preoperative planning, preference should be given to minimally invasive technologies, including arthroscopically-associated methods of treatment.Перелом Гоффа (ПГ) это крайне редкая травма одного или двух мыщелков бедренной кости во фронтальной плоскости, чаще ассоциированная с повреждением других структур области коленного сустава. Основной причиной ПГ считается высокоэнергетическая травма. На долю изолированного перелома Гоффа приходится 0,65% всех переломов бедренной кости. На сегодняшний день не существует единого мнения о хирургическом доступе или оптимальной технике внутренней фиксации при фронтальном переломе мыщелков бедренной кости. Также существует большой процент ошибок при рентгенологической диагностике данной патологии. Существующие классификации не нашли широкого применения в клинической практике, являясь громоздкими и неприменимыми для решения вопроса о тактике лечения и предоперационного планирования. Цель обзора на основании анализа литературы представить современные взгляды на диагностику, принципы и технику хирургического лечения пациентов с переломами Гоффа. На основе анализа литературы сделаны выводы о необходимости тщательного сбора анамнеза травмы, повышенной настороженности хирурга при наличии клинической картины данного повреждения и одновременного отсутствия патологии на стандартных рентгенограммах коленного сустава, необходимости выполнять дополнительное обследование в виде боковых (нестандартных) проекций рентгенографии коленного сустава, СКТ или МРТ. Во время предоперационного планирования следует отдавать предпочтение малоинвазивным технологиям, в том числе артроскопически-ассоциированным методам лечения

Pancreatopleural fistula as a complication of necrotizing pancreatitis (clinical case)

Acute pancreatitis is a disease that is accompanied by systemic inflammatory response syndrome and polysystemic dysfunction. Often acute pancreatitis leads to damage to various organs, including: pleura, mediastinum, cardiovascular structures. These complications cause difficulties in diagnosing and treating patients. In this review, we discuss the complications of acute pancreatitis, focusing on the diagnosis and treatment of pancreatopleural fistulas. Pancreatopleural fistula is a rather rare complication observed in patients with both acute and chronic pancreatitis due to traumatic or iatrogenic damage to the pancreatic duct. Conservative treatment with ocreatid combined with stenting of the pancreatic duct currently makes it possible to achieve closure of the fistula in 31-45% of cases, surgical intervention – in 80-90% of cases. The clinical case presented in this article demonstrates the successful treatment of this difficult complication of acute pancreatitis. The authors emphasized the need for timely diagnosis of this condition, as delaying adequate treatment can worsen the prognosis of recovery of patients with pancreatopleural fistulae

Determination of surface defects by using the wavefront scanner

The possibility of changes in the polarization state of the laser beam reflected from inhomogeneity with the refractive index gradient is theoretically shown, which allows separating the phase shifts related with relief inhomogeneities and local changes of the surface refractive index. Modification of the wavefront scanner for analyzing the wavefront of the laser beam reflected from the samples’ surface is considered. The main idea of the method is to use the focused laser beams with different polarizations for illuminating separate areas of the surface. The results of detecting test surfaces with different structures by the wavefront scanner are presented

Proton Extraction from IHEP Accelerator Using Bent Crystals

IHEP Protvino has pioneered the wide practical use of bent crystals as optical elements in high-energy beams for beam extraction and deflection on permanent basis since 1989. In the course of IHEP experiments, crystal channeling has been developed into efficient instrument for particle steering at accelerators, working in predictable, reliable manner with beams of very high intensity over years. Crystal systems extract 70 GeV protons from IHEP main ring with efficiency of 85% at intensity of 1.E12, basing on multi-pass mechanism of channeling proposed theoretically and realised experimentally at IHEP. Today, six locations on the IHEP 70-GeV main ring of the accelerator facility are equipped by crystal extraction systems, serving mostly for routine applications rather than for research and allowing a simultaneous run of several particle physics experiments, thus significantly enriching the IHEP physics program. The long successful history of large-scale crystal exploitation at IHEP should help to incorporate channeling crystals into accelerator systems worldwide in order to create unique systems for beam delivery. We report recent results from the research and exploitation of crystal extraction systems at IHEP.Comment: Invited talk at the International workshop "Relativistic Channeling and Related Coherent Phenomena", Frascati (Rome) 23-26 March 200

Measurement of RudsR_{\text{uds}} and RR between 3.12 and 3.72 GeV at the KEDR detector

Using the KEDR detector at the VEPP-4M $e^+e^-$ collider, we have measured the values of $R_{\text{uds}}$ and $R$ at seven points of the center-of-mass energy between 3.12 and 3.72 GeV. The total achieved accuracy is about or better than $3.3\%$ at most of energy points with a systematic uncertainty of about $2.1\%$. At the moment it is the most accurate measurement of $R(s)$ in this energy range