3D-modeling Capabilities in Assessing Resectability of Pancreatic Head Tumors

Background. Pancreatic head cancer ranks 6–7th among oncologic diseases and 4–5th among causes of mortality, with only 5% of patients achieving 5-year survival rate to date. Despite the successes of modern diagnostics and surgical treatment, the problem of early detection, staging of oncologic process and, as a consequence, combined treatment of pancreatic head cancer remains actual.Objective: increasing the accuracy of diagnostics and estimation of resectability of the pancreatic head cancer on the basis of the complex use of the radiation methods of investigation with pancreaticoduodenal zone 3D-reconstructions.Material and methods. The study included 93 patients (44 (47.31%) males and 49 (52.69%) females) with complicated pancreatoduodenal masses treated from 2019 to 2022 at the Surgical Department of the City Mariinsky Hospital. The patients’ age varied from 44 to 90 years, the mean age was 67±0.74 years. All patients underwent magnetic resonance imaging (MRI) on an Ingenia MR tomograph (Philips Medical Systems, Netherlands) with a magnetic field induction of 3 Tesla. The native examination of the abdomen and retroperitoneum, supplemented with MR-cholangiopancreatography protocol, and dynamic contrast enhancement with data collection in arterial, portal, and delayed phases were carried out. T2-weighted images were then performed using turbospin-echo technology, including fat-suppressed images, to evaluate structural changes and the presence of fluid in fascial spaces. Patients also underwent endoscopic ultrasound of the pancreaticoduodenal zone using the push and pull method, and abdominal multislice computed tomography (MSCT). To build 3D models, we used free 3D-slicer and Mimics programs, which allowed to build semi-automatic model for further evaluation of anatomo-topographic relations.Results. MSCT 3D modeling revealed tumor invasion into the superior mesenteric vein in 6 (23.06%) patients, whereas MRI models showed tumor invasion in 4 (15.38%) patients, intraoperatively the results were confirmed in 5 patients (19.23%). According to both MSCT and MRI modeling data, the invasion of the ventral trunk occurred in 1 (5.2%) case, which was confirmed intraoperatively. Inferior vena cava invasion on MSCT and MRI models was detected in 3 (11.54%) patients, whereas intraoperatively – in 4 (15.38%) patients. The MSCT and MRI 3D models coincided with the data on invasion of the ventral trunk in 1 (3.85%) patient and the superior mesenteric artery in 2 (7.69%) patients, which was fully confirmed intraoperatively.Conclusion. 3D modeling on the basis of MRI and MSCT studies is an informative method in preoperative staging of pancreatic head cancer and its resectability. This method allows to objectively determine the localization and prevalence of the tumor process on adjacent anatomical structures, as well as visually demonstrate the metastatic lesion of regional lymph nodes. By the parameters of diagnostic efficiency, 3D models are maximally close to the intraoperative picture, which allows planning both the volume and the course of surgical intervention

A Large-Scale FPGA-Based Trigger and Dead-Time Free DAQ System for the Kaos Spectrometer at MAMI

The Kaos spectrometer is maintained by the A1 collaboration at the Mainz Microtron MAMI with a focus on the study of (e,e'K^+) coincidence reactions. For its electron-arm two vertical planes of fiber arrays, each comprising approximately 10 000 fibers, are operated close to zero degree scattering angle and in close proximity to the electron beam. A nearly dead-time free DAQ system to acquire timing and tracking information has been installed for this spectrometer arm. The signals of 144 multi-anode photomultipliers are collected by 96-channel front-end boards, digitized by double-threshold discriminators and the signal time is picked up by state-of-the-art F1 time-to-digital converter chips. In order to minimize background rates a sophisticated trigger logic was implemented in newly developed Vuprom modules. The trigger performs noise suppression, signal cluster finding, particle tracking, and coincidence timing, and can be expanded for kinematical matching (e'K^+) coincidences. The full system was designed to process more than 4 000 read-out channels and to cope with the high electron flux in the spectrometer and the high count rate requirement of the detectors. It was successfully in-beam tested at MAMI in 2009.Comment: Contributed to 17th IEEE Real Time Conference (RT10), Lisbon, 24-28 May 201

Health status assessment of related kidney donors in the late postoperative period

ДОНОРОВ МЕДИЦИНСКИЙ ОТБОРДОНОРОВ СКРИНИНГДОНОРЫ ТКАНЕЙДОНОРЫ ОРГАНОВНЕФРЭКТОМИЯПОЧЕК ТРАНСПЛАНТАЦИЯПЕРЕСАДКА ПОЧКИПОЧЕЧНАЯ ТРАНСПЛАНТАЦИЯТРАНСПЛАНТАЦИОННАЯ ТОЛЕРАНТНОСТЬПОЧЕЧНАЯ НЕДОСТАТОЧНОСТЬПОЧКИ, НЕДОСТАТОЧНОСТЬ ФУНКЦИИПОСЛЕОПЕРАЦИОННЫЙ ПЕРИОДЦель. Изучить состояние здоровья живых доноров почки на основании степени восстановления функции почки и общего физического статуса донора. Материал и методы. 37 родственных доноров почек перенесли нефрэктомию в период с 2014 по 2017 год. Средний возраст составил 48,3±9,7 года (М±сигма), мужчин было 19 (51%), женщин – 18 (49%). В позднем послеоперационном периоде (1,9±1,1 года (М±сигма)) изучали уровни протеинурии и скорости клубочковой фильтрации (СКФ). Качество жизни доноров почек оценивали с помощью опросника Medical Outcomes Study-Short Form-36. Результаты. Средняя СКФ до операции составила 78,9±24,5 мл/мин на 1,73 м{2} и снизилась до 49,8±11,2 мл/мин на 1,73 м{2} на 2-е сутки после операции. При выписке (15,2±7,0 LYZ) средняя СКФ увеличивалась до 53,4±8,0 мл/мин на 1,73 м{2} и практически достигла предоперационного уровня через 1,9±1,1 года. Отмечено повышение креатинина и увеличение протеинурии в ранние сроки с нормализацией этих показателей в отдаленные сроки. Это свидетельствует о том, что единственная почка с нормальной функцией способна компенсировать отсутствие контралатеральной. Кроме того, наше исследование показало, что в позднем послеоперационном периоде не было статистически значимой разницы ни по СКФ, ни по качеству жизни между донорами разных возрастных групп. Таким образом, при адекватной селекции пары донор-реципиент на основе комплексного обследования, трансплантация почки является не только эффективным методом лечения терминальной стадии хронической почечной недостаточности, но и безопасна для здоровья и дальнейшей почечной функции донора. Заключение. У прижизненных доноров отмечается постепенное восстановление почечной функции, согласно СКФ, при выписке (день 15,2±7,0) и в позднем послеоперационном периоде (1,9±1,1 года) практически до предоперационного уровня. Физический и психологический компоненты здоровья доноров разных возрастных групп были сопоставимы.Objective. To analyze the health status of living kidney donors based on the degree of restoration of the kidney function and the general physical status of the donor. Methods. 37 related kidney donors underwent nephrectomy between 2014 and 2017. The average age was 48.3±9.7 (М±sigma) years, with 19 men (51%) and 18 (49%) women. In the late postoperative period (1,9±1,1 years (М±sigma), the levels of proteinuria, and glomerular filtration rate (GFR) were studied. The life quality of kidney donors was assessed using the Medical Outcomes Study-Short Form-36 questionnaire. Results. The average GFR before the operation was 78,9±24,5 ml/min per 1.73 m{2}, and fell to 49,8±11,2 ml/min per 1.73 m{2} on the 2nd day after the operation. Upon discharge (15,2±7,0 day), average GFR increased to 53,4±8,0 ml/min per 1.73 m{2}, and almost reached pre-operation levels 1,9±1,1 years after the operation. This suggests that a single normally-functioning kidney is capable of taking on the load from the missing kidney. Furthermore, our study showed that, in the late postoperative period, there was no statistically significant difference in either GFR or quality of life between the donors of different age groups (p>0.05). Our research showed that if adequate protocols are used for living donor selection, donor-recipient kidney transplantation is not only an effective method for treating terminal stage of chronic end stage of renal disease, but is also safe for health and the subsequent renal function of the donor. Conclusions. In living donors, a gradual restoration of renal function is observed, according to GFR, at discharge (day 15.2±7.0) and in the late postoperative period (1.9±1.1 years), almost reaching the preoperative level. The physical and psychological health components of donors of different age groups were comparable

Observation of the magnetic domain structures in Cu0,47_{0,47}Ni0,53_{0,53} thin films at low temperatures

We report on the first experimental visualization of domain structure in films of weakly ferromagnetic Cu$_{0,47}$Ni$_{0,53}$ alloy with different thickness at liquid helium temperatures. Improved high-resolution Bitter decoration technique was used to map the magnetic contrast on the top of the films well below the Curie temperature T$_{Curie}$ ($\sim$ 60 K). In contrast to magnetic force microscopy, this technique allowed visualization of the domain structure without its disturbance while the larger areas of the sample were probed. Maze-like domain patterns, typical for perpendicular magnetic anisotropy, were observed. The average domain width was found to be about 100 nm.Comment: 4 pages, 5 figures, will be published in JETP Let

Numerical approximation of the Euler-Poisson-Boltzmann model in the quasineutral limit

This paper analyzes various schemes for the Euler-Poisson-Boltzmann (EPB) model of plasma physics. This model consists of the pressureless gas dynamics equations coupled with the Poisson equation and where the Boltzmann relation relates the potential to the electron density. If the quasi-neutral assumption is made, the Poisson equation is replaced by the constraint of zero local charge and the model reduces to the Isothermal Compressible Euler (ICE) model. We compare a numerical strategy based on the EPB model to a strategy using a reformulation (called REPB formulation). The REPB scheme captures the quasi-neutral limit more accurately

Transition Radiation Spectra of Electrons from 1 to 10 GeV/c in Regular and Irregular Radiators

We present measurements of the spectral distribution of transition radiation generated by electrons of momentum 1 to 10 GeV/c in different radiator types. We investigate periodic foil radiators and irregular foam and fiber materials. The transition radiation photons are detected by prototypes of the drift chambers to be used in the Transition Radiation Detector (TRD) of the ALICE experiment at CERN, which are filled with a Xe, CO2 (15 %) mixture. The measurements are compared to simulations in order to enhance the quantitative understanding of transition radiation production, in particular the momentum dependence of the transition radiation yield.Comment: 18 pages, 15 figures, submitted to Nucl. Instr. Meth. Phys. Res.

Transition Radiation Spectroscopy with Prototypes of the ALICE TRD

We present measurements of the transition radiation (TR) spectrum produced in an irregular radiator at different electron momenta. The data are compared to simulations of TR from a regular radiator.Comment: 4 pages, 5 Figures, Proceedings for "TRDs for the 3rd millennium" (Sept. 4-7, 2003, Bari, Italy

Observation of the Triplet Spin-Valve Effect in a Superconductor-Ferromagnet Heterostructure

The theory of superconductor-ferromagnet (S-F) heterostructures with two ferromagnetic layers predicts the generation of a long-range, odd-in-frequency triplet pairing at non-collinear alignment (NCA) of the magnetizations of the F-layers. This triplet pairing has been detected in a Nb/Cu41Ni59/nc-Nb/Co/CoOx spin-valve type proximity effect heterostructure, in which a very thin Nb film between the F-layers serves as a normal conducting (nc) spacer. The resistance of the sample as a function of an external magnetic field shows that for not too high fields the system is superconducting at a collinear alignment of the Cu41Ni59 and Co layer magnetic moments, but switches to the normal conducting state at a NCA configuration. This indicates that the superconducting transition temperature Tc for NCA is lower than the fixed measuring temperature. The existence of a minimum Tc, at the NCA regime below that one for parallel or antiparallel alignments of the F-layer magnetic moments, is consistent with the theoretical prediction of a singlet superconductivity suppression by the long-range triplet pairing generation.Comment: 7 pages, 4 fgures, Submitted to Physical Review Letter

Position Reconstruction in Drift Chambers operated with Xe, CO2 (15%)

We present measurements of position and angular resolution of drift chambers operated with a Xe,CO$_2$(15%) mixture. The results are compared to Monte Carlo simulations and important systematic effects, in particular the dispersive nature of the absorption of transition radiation and non-linearities, are discussed. The measurements were carried out with prototype drift chambers of the ALICE Transition Radiation Detector, but our findings can be generalized to other drift chambers with similar geometry, where the electron drift is perpendicular to the wire planes.Comment: 30 pages, 18 figure