Statistical properties of a free-electron laser revealed by the Hanbury Brown and Twiss interferometry

We present a comprehensive experimental analysis of statistical properties of the self-amplified spontaneous emission (SASE) free-electron laser (FEL) FLASH at DESY in Hamburg by means of Hanbury Brown and Twiss (HBT) interferometry. The experiments were performed at the FEL wavelengths of 5.5 nm, 13.4 nm, and 20.8 nm. We determined the 2-nd order intensity correlation function for all wavelengths and different operation conditions of FLASH. In all experiments a high degree of spatial coherence (above 50%) was obtained. Our analysis performed in spatial and spectral domains provided us with the independent measurements of an average pulse duration of the FEL that were below 60 fs. To explain complicated behaviour of the 2-nd order intensity correlation function we developed advanced theoretical model that includes the presence of multiple beams and external positional jitter of the FEL pulses. By this analysis we determined that in most experiments several beams were present in radiating field and in one of the experiments external positional jitter was about 25% of the beam size. We envision that methods developed in our study will be used widely for analysis and diagnostics of the FEL radiation.Comment: 29 pages, 14 figures, 3 table

Characterization of Spatial Coherence of Synchrotron Radiation with Non-Redundant Arrays of Apertures

We present a method to characterize the spatial coherence of soft X-ray radiation from a single diffraction pattern. The technique is based on scattering from non-redundant arrays (NRA) of slits and records the degree of spatial coherence at several relative separations from one to 15 microns, simultaneously. Using NRAs we measured the transverse coherence of the X-ray beam at the XUV X-ray beamline P04 of the PETRA III synchrotron storage ring as a function of different beam parameters. To verify the results obtained with the NRAs additional Young's double pinhole experiments were conducted and show good agreement.Comment: 15 pages, 6 figures, 2 tables, 42 reference

Основные аспекты межгоспитальной транспортировки пациентов с политравмой, находящихся в критическом состоянии

Polytrauma is one of the main causes of death in modern medicine. It is characterized by the particular severity of clinical manifestations and attended by significant impairments of the body’s vital functions, by diagnostic difficulties, and treatment complexity. In Kuzbass, as many as 8 thousand victims annually die from severe injuries. Death rates amount 21—22% in specialized hospitals and up to 60% or more in unspecialized hospitals. On the basis of multidisciplinary medical centers, an effective network of health care facilities (HCF) is being set up to render a specialized medical aid to patients with polytrauma. The application of expensive medical diagnostic and therapeutic technologies reduces the rates of morbidity and disability among patients with polytrauma. A specialized medical aid cannot be rendered to all victims without solving the problems of their transportation to a specialized center. Of the greatest difficulty is the transportation of critically ill patients with polytrauma and unstable hemodynamics when artificial ventilation is used during transportation. The transportation service set up in the Center of Miners’ Health Care in the specialized polytrauma center is engaged in the development of the problems of safe transport of this category of victims. Organizational problems are to collect information on victims, to form a specialized team and to supply the latter with equipment. Therapeutic-and-diagnostic problems are to additionally evaluate the status of victims at the scene (in an unspecialized HCF, if required, in and around the area of an accident), to prepare a patient before transportation; to provide a complete set of intensive therapy during interhospital transportation of patients with polytrauma in relation to the predominant component of a damage. In the authors’ opinion, solution of this group of problems can enhance the efficiency of intensive care during transportation and reduce mortality rates in this category of patients. Политравма является одной из основных причин смертности в современной медицине. Она отличается особой тяжестью клинических проявлений, сопровождается значительными нарушениями жизненно важных функций организма, трудностью диагностики, сложностью лечения. В Кузбассе ежегодно погибает до 8 тыс пострадавших от тяжелых травм. В условиях специализированных стационаров летальность составляет 21—22%, не специализированных ЛПУ — она достигает 60% и более. На базе многопрофильных медицинских центров создается действенная сеть лечебных учреждений для оказания специализированной медицинской помощи пациентам с политравмой. Использование дорогостоящих медицинских диагностических и лечебных технологий позволяет снизить уровень летальности, инвалидности среди пациентов с политравмой. Оказание специализированной медицинской помощи всем пострадавшим невозможно без решения вопросов транспортировки в специализированный центр. Наибольшую сложность представляет транспортировка пациентов с политравмой, находящихся в критическом состоянии, с нестабильной гемодинамикой, с применением во время транспортировки ИВЛ. Созданная в «Центре охраны здоровья шахтеров» при специализированном центре политравмы служба транспортировки занимается разработкой вопросов безопасного транспорта этой категории пострадавших. Организационными: информация о пострадавших, формирование специализированной бригады и её оснащения. Лечебно-диагностическими: дополнительная оценка состояния пострадавших на месте (в неспециализированном ЛПУ, при необходимости — в зоне чрезвычайных происшествий); подготовка пациента перед транспортировкой; обеспечение полного комплекса интенсивной терапии во время межгоспитальной транспортировки у пациентов с политравмой в зависимости от доминирующего компонента повреждения. Решение этих вопросов позволит повысить эффективность интенсивной терапии при проведении транспортировки и снизить летальность у данной категории пациентов.

Ultrafast structural changes direct the first molecular events of vision

視覚に関わるタンパク質の超高速分子動画 --薄暗いところで光を感じる仕組み--. 京都大学プレスリリース. 2023-03-23.Vision is initiated by the rhodopsin family of light-sensitive G protein-coupled receptors (GPCRs). A photon is absorbed by the 11-cis retinal chromophore of rhodopsin, which isomerizes within 200 femtoseconds to the all-trans conformation, thereby initiating the cellular signal transduction processes that ultimately lead to vision. However, the intramolecular mechanism by which the photoactivated retinal induces the activation events inside rhodopsin remains experimentally unclear. Here we use ultrafast time-resolved crystallography at room temperature to determine how an isomerized twisted all-trans retinal stores the photon energy that is required to initiate the protein conformational changes associated with the formation of the G protein-binding signalling state. The distorted retinal at a 1-ps time delay after photoactivation has pulled away from half of its numerous interactions with its binding pocket, and the excess of the photon energy is released through an anisotropic protein breathing motion in the direction of the extracellular space. Notably, the very early structural motions in the protein side chains of rhodopsin appear in regions that are involved in later stages of the conserved class A GPCR activation mechanism. Our study sheds light on the earliest stages of vision in vertebrates and points to fundamental aspects of the molecular mechanisms of agonist-mediated GPCR activation

Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR

Relationship of edge localized mode burst times with divertor flux loop signal phase in JET

A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM

PERSPECTIVAS DEL PROCESO DE GLOBALIZACIÓN Y SU INFLUENCIA SOBRE LOS DERECHOS HUMANOS ECONÓMICOS, SOCIALES Y CULTURALES

El escenario internacional se encuentra en constante transformación debido a lo que se ha denominado el proceso de “globalización”. Este afecta las relaciones internaciones interestatales e influye en la vida cotidiana de los individuos. El Derecho Internacional y más específicamente el Derecho Internacional de los Derechos Humanos no es ajeno a este proceso. La investigación afirma que nos encontramos frente a una etapa de transnacionalización de los Derechos Humanos, que permite que los individuos cuenten con mayor protección en ámbitos supranacionales. También hace especial mención a los derechos Económicos Sociales y Culturales, analiza el debate sobre el pluralismo jurídico y la eficacia diferencial. En la metodología empleada se revisan fuentes documentales y se realiza un análisis de algunos derechos particulares previstos en el Pacto de Derechos Económicos, Sociales y Culturales. Los planteamientos permiten afirmar que el proceso de globalización ha determinado la transnacionalización de los Derechos Humanos, surgiendo de dicho fenómeno consecuencias positivas y negativas en cuanto a su cumplimiento