A WISER way for simulating the performance of gratings.

Soft X-ray monochromators for synchrotron radiation sources have been continuously developed over the years, improving energy resolution and stability. Great effort has been made in improving the surface quality of the optics involved, reaching values permitting diffraction-limited images. Still, one problem has not been solved, nor fully understood, yet: groove placing errors. Nowadays, these are one of the major factors responsible for resolving the power reduction of diffraction-gratings-based X-ray monochromators. Despite decades of use of gratings, there is not yet a universally established method for predicting and simulating the effect of groove placing errors on monochromator performance. This is especially important in the new scenario of high-coherent X-ray sources, i.e. diffraction-limited storage rings and free-electron lasers. To address this problem, in this article an approach based on WISER (Wavefront propagatIon Simulation codE libRary) is presented. WISER is a physical optics simulation package, also available in the user-friendly Orange Synchrotron Radiation Suite - OASYS. Even though it was originally conceived to assess the focusing performance of X-ray mirrors in the presence of height defects, it perfectly simulates the performance of a periodic (or quasi-periodic) structure like a diffraction grating. In this article, the way to use WISER and its application to a specific case, e.g. the design of a monochromator for the upgrade of a beamline at the Advanced Light Source, are shown. A simple rule for estimating how well the grooves are placed on a grating, based on calculation of the Strehl ratio, is also presented.

The time-resolved atomic, molecular and optical science instrument at the Linac Coherent Light Source.

The newly constructed time-resolved atomic, molecular and optical science instrument (TMO) is configured to take full advantage of both linear accelerators at SLAC National Accelerator Laboratory, the copper accelerator operating at a repetition rate of 120 Hz providing high per-pulse energy as well as the superconducting accelerator operating at a repetition rate of about 1 MHz providing high average intensity. Both accelerators power a soft X-ray free-electron laser with the new variable-gap undulator section. With this flexible light source, TMO supports many experimental techniques not previously available at LCLS and will have two X-ray beam focus spots in line. Thereby, TMO supports atomic, molecular and optical, strong-field and nonlinear science and will also host a designated new dynamic reaction microscope with a sub-micrometer X-ray focus spot. The flexible instrument design is optimized for studying ultrafast electronic and molecular phenomena and can take full advantage of the sub-femtosecond soft X-ray pulse generation program.

[Appropriateness of the request for preoperative cardiological evaluation in non-cardiac surgery: 8-year experience in a high-volume cardiological center]. / Appropriatezza della richiesta di consulenza cardiologica preoperatoria nella chirurgia non cardiaca: esperienza di 8 anni di un centro cardiologico ad alto volume di attività.

BACKGROUND: In the last decades the population undergoing non-cardiac surgery has become more numerous and complex. Cardiovascular perioperative complications represent at least one third of the perioperative deaths. Despite the pivotal role of the cardiologist in the perioperative management, current guidelines are often hardly useful in different settings of clinical practice. Local clinical protocols contribute to fill these gaps, to define the role of each specialist in the perioperative context and to achieve the best medical outcome. METHODS: This single-center retrospective study analyzes the background of 33 463 preoperatory cardiologic visits, the adherence to scientific evidence in our institute and the impact of the implementation of a shared clinical protocol (CP) in terms of reduction of inappropriate requests of cardiological evaluations. RESULTS: Among all the patients, the mean age was 59 ± 18 years, 52.8% were male. Hypertension was the most prevalent disease followed by diabetes, chronic coronary syndrome and atrial fibrillation. The "low-risk surgery" category was the most represented (56.2%) and the vast majority of patients (70.1%) was totally free from predictors of perioperative cardiovascular events. After the introduction of the CP, the number of inappropriate evaluations decreased by 32%, mainly in the low-risk category. However, despite the overall reduction, almost two thirds of the evaluations were still deemed inappropriate according to the CP, mostly (82.9%) in the low-risk category and to a lesser degree (55%) in the moderate/high-risk category. CONCLUSIONS: The inappropriate use of the resources resulted in disappointing organizational performance, poor assistance quality and a huge number of inappropriate preoperatory evaluations. The implementation of a CP, developed on the basis of the local needs, is a useful tool to enhance the organizational standards for the cardiological evaluation of patients undergoing non-cardiac surgery. Regular verifications, a widespread knowledge of the guidelines and a more efficient system of management and surveillance may improve the appropriateness of these evaluations.

Special Issue "EUV and X-ray Wavefront Sensing".

X-ray optics are extensively used in synchrotron radiation and free-electron laser facilities, as well as in table-top laboratory sources [...].

Heart applications of 4D flow.

Four-dimensional (4D) flow sequences are an innovative type of MR sequences based upon phase contrast (PC) sequences which are a type of application of Angio-MRI together with the Time of Flight (TOF) sequences and Contrast-Enhanced Magnetic Resonance Acquisition (CE-MRA). They share the basic principles of PC, but unlike PC sequences, 4D flow has velocity encoding along all three flow directions and three-dimensional (3D) anatomic coverage. They guarantee the analysis of flow with multiplanarity on a post-processing level, which is a unique feature among MR sequences. Furthermore, this technique provides a completely new level to the in vivo flow analysis as it allows measurements in never studied districts such as intracranial applications or some parts of the heart never studied with echo-color-doppler, which is its sonographic equivalent. Furthermore, this technique provides a completely new level to the in vivo flow analysis as it allows accurate measurement of the flows in different districts (e.g., intracranial, cardiac) that are usually studied with echo-color-doppler, which is its sonographic equivalent. Of note, the technique has proved to be affected by less inter and intra-observer variability in several application. 4D-flow basic principles, advantages, limitations, common pitfalls and artefacts are described. This review will outline the basis of the formation of PC image, the construction of a 4D-flow and the huge impact the technique is having on the cardiovascular non-invasive examination. It will be then studied how this technique has had a huge impact on cardiovascular examinations especially on a central heart level.

A cantilevered liquid-nitrogen-cooled silicon mirror for the Advanced Light Source Upgrade.

This paper presents a novel cantilevered liquid-nitrogen-cooled silicon mirror design for the first optic in a new soft X-ray beamline that is being developed as part of the Advanced Light Source Upgrade (ALS-U) (Lawrence Berkeley National Laboratory, USA). The beamline is optimized for photon energies between 400 and 1400 eV with full polarization control. Calculations indicate that, without correction, this design will achieve a Strehl ratio greater than 0.85 for the entire energy and polarization ranges of the beamline. With a correction achieved by moving the focus 7.5 mm upstream, the minimum Strehl ratio is 0.99. This design is currently the baseline plan for all new ALS-U insertion device beamlines.

Compensation of heat load deformations using adaptive optics for the ALS upgrade: a wave optics study.

A realistic wave optics simulation method has been developed to study how wavefront distortions originating from heat load deformations can be corrected using adaptive X-ray optics. Several planned soft X-ray and tender X-ray insertion-device beamlines in the Advanced Light Source upgrade rely on a common design principle. A flat, first mirror intercepts the white beam; vertical focusing is provided by a variable-line-space monochromator; and horizontal focusing comes from a single, pre-figured, adaptive mirror. A variety of scenarios to cope with thermal distortion in the first mirror are studied by finite-element analysis. The degradation of the intensity distribution at the focal plane is analyzed and the adaptive optics that correct it is modeled. The range of correctable wavefront errors across the operating range of the beamlines is reported in terms of mirror curvature and spatial frequencies. The software developed is a one-dimensional wavefront propagation package made available in the OASYS suite, an adaptable, customizable and efficient beamline modeling platform.

Adaptive shape control of wavefront-preserving X-ray mirrors with active cooling and heating.

This article describes the development and testing of a novel, water-cooled, active optic mirror system (called "REAL: Resistive Element Adjustable Length") that combines cooling with applied auxiliary heating, tailored to the spatial distribution of the thermal load generated by the incident beam. This technique is theoretically capable of sub-nanometer surface figure error control even at high power density. Tests conducted in an optical metrology laboratory and at synchrotron X-ray beamlines showed the ability to maintain the mirror profile to the level needed for the next generation storage rings and FEL mirrors.

Complex Plug-Prosthesis Interaction During Percutaneous Closure of Mitral Paravalvular Leak: The Butterfly Effect.

This case shows how interaction between imaging experts and interventionists allowed us to overcome the challenge of plug-prosthesis interaction in a complex procedure.

Population inversion X-ray laser oscillator.

Oscillators are at the heart of optical lasers, providing stable, transform-limited pulses. Until now, laser oscillators have been available only in the infrared to visible and near-ultraviolet (UV) spectral region. In this paper, we present a study of an oscillator operating in the 5- to 12-keV photon-energy range. We show that, using the [Formula: see text] line of transition metal compounds as the gain medium, an X-ray free-electron laser as a periodic pump, and a Bragg crystal optical cavity, it is possible to build X-ray oscillators producing intense, fully coherent, transform-limited pulses. As an example, we consider the case of a copper nitrate gain medium generating ∼ 5 × [Formula: see text] photons per pulse with 37-fs pulse length and 48-meV spectral resolution at 8-keV photon energy. Our theoretical study and simulation of this system show that, because of the very large gain per pass, the oscillator saturates and reaches full coherence in four to six optical-cavity transits. We discuss the feasibility and design of the X-ray optical cavity and other parts of the oscillator needed for its realization, opening the way to extend X-ray-based research beyond current capabilities.

Metabolomic Analysis of Patients with Chronic Myeloid Leukemia and Cardiovascular Adverse Events after Treatment with Tyrosine Kinase Inhibitors.

BACKGROUND: Cardiovascular adverse events (CV-AEs) are considered critical complications in chronic myeloid leukemia (CML) patients treated with second- and third-generation tyrosine kinase inhibitors (TKIs). The aim of our study was to assess the correlation between metabolic profiles and CV-AEs in CML patients treated with TKIs. METHODS: We investigated 39 adult CML patients in chronic-phase (mean age 49 years, range 24-70 years), with no comorbidities evidenced at baseline, who were consecutively identified with CML and treated with imatinib, nilotinib, dasatinib, and ponatinib. All patients performed Gas-Chromatography-Mass-Spectrometry-based metabolomic analysis and were divided into two groups (with and without CV-AEs). RESULTS: Ten CV-AEs were documented. Seven CV-AEs were rated as 3 according to the Common Toxicity Criteria, and one patient died of a dissecting aneurysm of the aorta. The patients' samples were clearly separated into two groups after analysis and the main discriminant metabolites were tyrosine, lysine, glutamic acid, ornithine, 2-piperdinecarboxylic acid, citric acid, proline, phenylalanine, threonine, mannitol, leucine, serine, creatine, alanine, and 4-hydroxyproline, which were more abundant in the CV-AE group. Conversely, myristic acid, oxalic acid, arabitol, 4-deoxy rithronic acid, ribose, and elaidic acid were less represented in the CV-AE group. CONCLUSIONS: CML patients with CV-AEs show a different metabolic profile, suggesting probable mechanisms of endothelial damage.

Post-Myocardial Infarction Ventricular Septal Defect Closure by a Percutaneous Septal Occluder Device After Unsuccessful Surgical Closure: Never Lose Hope.

Post myocardial infarction ventricular septal defect (VSD) is a life-threatening complication following ST elevation myocardial infarction (STEMI). Current guidelines recommend the urgent VSD closure for its significant mortality. Despite VSD is generally treated by surgical repair, surgeons often refrain from early surgery due to extremely poor results. We report the case of a 76-year-old women admitted to our hospital for a subacute myocardial infarction complicated by acute heart failure with VSD and apical thrombosis. The patient underwent an urgent surgical repair of VSD with a bovine pericardium patch and concomitant double saphenous vein graft for the left anterior descending and the first diagonal branch. After two days an early surgical patch dehiscence was observed and a percutaneous closure was planned. Due to the particular morphology of the unnatural anatomy of the septum generated by the dehiscence, we decided to close the defect using an off-label device for ventricular rupture. A 30/30 mm Amplatzer ASD-MF occluder was successfully implanted. At one-year follow up the patient was alive without significant residual shunt.

Kirkpatrick-Baez active optics system at FERMI: system performance analysis.

FERMI is the first and only seeded EUV-SXR free-electron laser (FEL) facility available to users; it operates at Elettra - Sincrotrone Trieste (Italy) and it presents five operating endstations. Three of them, namely LDM (Low Density Matter), DiProI (Diffraction and Projection Imaging) and MagneDyn (Magneto-Dynamical studies), use a Kirkpatrick-Baez (KB) active X-ray optics system to focus the FEL pulses into the experimental chambers. The present work reports on the final results of the upgraded KB Active Optics Systems (KAOS), which have been mechanically modified in order to improve stability and repeatability with respect to the original design. The results have been obtained on both the FERMI FEL lines, FEL1 and FEL2, and are particularly relevant for the latter as it is the low-wavelength line recently opened to users. After a thorough description of the new mechanical layout of the system and the aspects that have been improved after the refurbishment, a set of simulations of the optical performances are presented. The code used to simulate the behavior of KAOS is WISEr, a physical-optics-based tool, which is freely accessible, and integrated into the Oasys platform, that takes into account the specific surface metrology characterization of the beamline mirrors, including figure errors and microroughness power spectral density. The results of WISEr are then used as a reference for the actual optimization of the optical system. This procedure relies heavily on a wavefront sensor (WFS) mounted out of focus to optimize the refocusing mirrors alignment as well as their curvature bending (by minimization of the coefficients of the Zernike wavefront expansion). Moreover, the WFS data are used to reconstruct the focal spot parameters by means of a back-propagation of the electric field. Finally, these results are compared with those obtained after the FEL ablation of a PMMA layer positioned on the focal plane, and analyzed ex situ in a post-mortem fashion. The mechanically refurbished optical system and the multi-technique alignment approach, aimed at optimizing the mirrors' curvature, pitch and roll angles, allowed a focal spot of 1.8 µm × 2.4 µm at 4.14 nm wavelength (FEL2) to be inferred, confirmed by the PMMA ablation imprints.

Multimodality Imaging Diagnosis of Multiple Ventricular Thrombosis and Massive Stroke after Gemcitabine and Cisplatin Chemotherapy for Urothelial Cancer.

Cancer and chemotherapy are known to be risk factors for developing coagulative disorders, venous thrombosis, adverse cardiovascular events, and cardiotoxicity. Combined modality gemcitabine-cisplatin chemotherapy is often administered to treat a few solid tumors. We report the unusual case of a man suffering from urothelial cancer and admitted for chemotherapy, who developed an ischemic stroke after the last chemotherapeutical cycle. During his hospital stay, at echocardiographic examination, left ventricular transient hypokinesia and two intraventricular thrombi were detected, without evidence of acute coronary syndrome. Multimodality imaging approach (i.e., transthoracic echo, transoesophageal echo, computed tomography, and cardiac magnetic resonance imaging) played a pivotal role for a clear diagnosis and prompt decision-making. This is the first report of an intraventricular-related arterial thromboembolic event in a patient treated with the combination gemcitabine-cisplatin.

Completeness condition for unambiguous profile reconstruction by sub-aperture stitching.

We describe the conditions required for a set of displaced sub-aperture measurements to contain sufficient information to reconstruct the stitched mirror profile removing all additive systematic errors of the measuring instrument, independent of the reference surface and of the guidance error of the linear stage used for the translation. We show that even-spaced stitching must be avoided and that the pitch error of the linear stage or the curvature of the reference must be measured, to avoid periodic errors and curvature errors in the reconstructed profile. We show that once these uncertainties are solved, the 1D profile can be reconstructed free of any additive systematic error. The theory is supported by computer simulations and by experimental results using two different instruments.

PhotonDiag2017 workshop: introductory overview.

This issue of the Journal of Synchrotron Radiation is a special issue including papers from the PhotonDiag2017 workshop. Here, a brief introduction is given.

Damage thresholds for blaze diffraction gratings and grazing incidence optics at an X-ray free-electron laser.

The Linac Coherent Light Source is upgrading its machine to high repetition rate and to extended ranges. Novel coatings, with limited surface oxidation, which are able to work at the carbon edge, are required. In addition, high-resolution soft X-ray monochromators become necessary. One of the big challenges is to design the mirror geometry and the grating profile to have high reflectivity (or efficiency) and at the same time survive the high peak energy of the free-electron laser pulses. For these reasons the experimental damage threshold, at 900 eV, of two platinum-coated gratings with different blazed angles has been investigated. The gratings were tested at 1° grazing incidence. To validate a model for which the damage threshold on the blaze grating can be estimated by calculating the damage threshold of a mirror with an angle of incidence identical to the angle of incidence on the grating plus the blaze angle, tests on Pt-coated substrates have also been performed. The results confirmed the prediction. Uncoated silicon, platinum and SiB3 (both deposited on a silicon substrate) were also investigated. In general, the measured damage threshold at grazing incidence is higher than that calculated under the assumption that there is no energy transport from the volume where the photons are absorbed. However, it was found that, for the case of the SiB3 coating, the grazing incidence condition did not increase the damage threshold, indicating that the energy transport away from the extinction volume is negligible.

Pharmacological Treatment of Vagal Hyperactivity, a Rare but Potentially Fatal Cause of Sudden Cardiac Death.

Vasovagal reaction, resulting in bradycardia and/or hypotension in response to a number of stimuli, is usually self-limiting, but potentially life-threatening exceptions have been described. Pharmacological treatment of proven efficacy is still lacking and the administered compounds are often chosen on the basis of either case reports or outdated small studies with a short-term follow up. In refractory cases, pacemaker implantation may be considered, although no responder patients represent a severe challenge for clinicians. The aim of this review is to examine the state of the art about this controversial issue.