Imaging Molecules from Within: Ultra-fast, {\AA}ngstr\"om Scale Structure Determination of Molecules via Photoelectron Holography using Free Electron Lasers

A new scheme based on (i) upcoming brilliant X-ray Free Electron Laser (FEL) sources, (ii) novel energy and angular dispersive, large-area electron imagers and (iii) the well-known photoelectron holography is elaborated that provides time-dependent three-dimensional structure determination of small to medium sized molecules with {\AA}ngstr\"om spatial and femtosecond time resolution. Inducing molecular dynamics, wave-packet motion, dissociation, passage through conical intersections or isomerization by a pump pulse this motion is visualized by the X-ray FEL probe pulse launching keV photoelectrons within few femtoseconds from specific and well-defined sites, deep core levels of individual atoms, inside the molecule. On their way out the photoelectrons are diffracted generating a hologram on the detector that encodes the molecular structure at the instant of photoionization, thus providing 'femtosecond snapshot images of the molecule from within'. Detailed calculations in various approximations of increasing sophistication are presented and three-dimensional retrieval of the spatial structure of the molecule with {\AA}ngstr\"om spatial resolution is demonstrated. Due to the large photo-absorption cross sections the method extends X-ray diffraction based, time-dependent structure investigations envisioned at FELs to new classes of samples that are not accessible by any other method. Among them are dilute samples in the gas phase such as aligned, oriented or conformer selected molecules, ultra-cold ensembles and/or molecular or cluster objects containing mainly light atoms that do not scatter X-rays efficiently.Comment: 18 pages, 11 figure

Visualization of Geometric Images in Robotics Clubs

Исследование основано на оценке эффективности компьютерной визуализации с точки зрения развития способностей и возможностей школьников. Оно позволяет с применением практических примеров улучшить восприятие и изучение учениками геометрических изображений, а так же их строение.The research is based on assessing the effectiveness of computer visualization in terms of the development of the abilities and capabilities of schoolchildren. It allows, using practical examples, to improve the perception and study of geometric images by students, as well as their structure

Observation of Resonant Diffusive Radiation in Random Multilayered Systems

Diffusive Radiation is a new type of radiation predicted to occur in randomly inhomogeneous media due to the multiple scattering of pseudophotons. This theoretical effect is now observed experimentally. The radiation is generated by the passage of electrons of energy 200KeV-2.2MeV through a random stack of films in the visible light region. The radiation intensity increases resonantly provided the Cherenkov condition is satisfied for the average dielectric constant of the medium. The observed angular dependence and electron resonance energy are in agreement with the theoretical predictions. These observations open a road to application of diffusive radiation in particle detection, astrophysics, soft X-ray generation and etc.. `Comment: 4pages, 4figure

Educational needs and opportunities for adaptation of students with disabilities and persons with health limitations in the tertiary education system

The article is devoted to the definition consideration of the educational needs of persons with health limitations (hereinafter – HL) and disabled persons in the tertiary education system; the aspects in which these needs are expressed. The article highlights the adaptation possibilities of disabled people in the tertiary education system, as well as the specifics of the organization and goals of an educational institution for teaching people with HL. The authors identify the barriers of social relations faced by students with HL, disabled students and their teachers at universities; analyze the degree of involvement of a student with HL in the educational process. The paper pays attention to the main approaches to the organization of educational activities of persons with HL and disabled people, namely: competence-based, project-based and activity-based approaches. The main types of inclusion, identified on the basis of medical indicators, as conditions for organizing the training of students with HL and disabled students are considered. It is determined that the education organization at the university of students with HL allows to adapt educational programs to the special needs of students, depending on the state of health of students with HL and of disabled students

Update on the LLRF operations status at the European XFEL

The European XFEL (EuXFEL) is a free-electron laser in the X-ray range for users. Its high availability is one of the key aspects of the machine. In 2022, it entered in the sixth year of operation. The EuXFEL linac is based on the TESLA superconducting RF technology, operating at 1.3 GHz with an RF pulse length of 650 $\mu$s and a repetition rate of 10 Hz. The LLRF system is based on the MicroTCA standard and relies on a high level of automation. In this contribution, we review the LLRF operation at the EuXFEL and the development of new tools and features to improve the monitoring and extend the usability of the LLRF system.Comment: Talk presented at LLRF Workshop 2022 (LLRF2022, arXiv:2208.13680

Pancreatic Perivascular Epithelial Cell Tumor (PEComa) with Liver Metastasis: a Case Report and Literature Review

Aim: to present a clinical case of pancreatic PEComa with liver metastases with an emphasis on morphological features, radiology diagnostic methods and features of treatment tactics, allowing practitioners to get an idea about this rare mesenchymal tumors composed of “perivascular epithelioid cells”, and a review of literature data on pancreatic PEComa, including 32 author's cases.General statements. A 22-year-old woman who was surgically treated for pancreatic head PEComa with infiltration of the duct of Wirsung, common bile duct, duodenal wall, focal invasion into the blood and lymphatic vessels, and perineural space infiltration. Synchronously, metastases were detected in both liver lobes, for which she took Everolimus for 6 years under the control of radiology methods with dose adjustment and frequency of administration. At the A.V. Vishnevsky National Medical Research Center of Surgery, the patient underwent right-sided hemihepatectomy and atypical resection of II-III liver segments.Conclusion. To determine clearer criteria for the diagnosis and differential diagnosis of PEComa, to identify criteria for the malignancy of these tumors, to develop treatment tactics and further dynamic monitoring, a set of statistical data of significant group and randomized clinical trials are needed. Pancreatic PEComas in this group are extremely rare and often have a benign course. The presented clinical case demonstrates the most malignant form of this tumor with localization in the pancreas and liver metastases

Cystic Form of Duodenal Dystrophy (Clinical Case)

Aim: the reason for the publication was the rare occurrence, as well as the non-specificity of symptoms of the cystic form of duodenal dystrophy. The listed features of this disease lead to difficulties in its differential diagnosis and the choice of the optimal method of treatment.General statements. The report is devoted to the description of a case of successful treatment of a cystic form of duodenal dystrophy — a chronic inflammation of the pancreatic tissue, ectopic in the wall of the duodenum. A 47-year-old patient was admitted to the clinic with complaints of persistent abdominal pain, periodic vomiting, general weakness, weight loss of 20 kg in three months. With the help of computed tomography, the diagnosis was established, the tumor process was rejected, and chronic pancreatitis was detected in the orthotopic pancreas. Due to the presence of changes in the main pancreas, the patient underwent pancreatoduodenal resection. The features of the operation were pronounced infiltrative changes and pronounced vitreous tissue edema, which made it difficult to mobilize the hepatic flexure of the colon and duodenum.Conclusion. Pancreatoduodenal resection is the optimal surgical intervention for the combination of cystic form of duodenal dystrophy with sub-/decompensated duodenal stenosis

XUV digital in-line holography using high-order harmonics

A step towards a successful implementation of timeresolved digital in-line holography with extreme ultraviolet radiation is presented. Ultrashort XUV pulses are produced as high-order harmonics of a femtosecond laser and a Schwarzschild objective is used to focus harmonic radiation at 38 nm and to produce a strongly divergent reference beam for holographic recording. Experimental holograms of thin wires are recorded and the objects reconstructed. Descriptions of the simulation and reconstruction theory and algorithms are also given. Spatial resolution of few hundreds of nm is potentially achievable, and micrometer resolution range is demonstrated.Comment: 8 pages, 8 figure