Low-energy M1 states in deformed nuclei: spin-scissors or spin-flip?

The low-energy $M1$ states in deformed $^{164}$Dy and spherical $^{58}$Ni are explored in the framework of fully self-consistent Quasiparticle Random-Phase Approximation (QRPA) with various Skyrme forces. The main attention is paid to orbital and spin $M1$ excitations. The obtained results are compared with the prediction of the low-energy {\it spin-scissors} $M1$ resonance suggested within Wigner Function Moments (WFM) approach. A possible relation of this resonance to low-energy spin-flip excitations is analyzed. In connection with recent WFM studies, we consider evolution of the low-energy spin-flip states in $^{164}$Dy with deformation (from the equilibrium value to the spherical limit). The effect of tensor forces is briefly discussed. It is shown that two groups of $1^+$ states observed at 2.4-4 MeV in $^{164}$Dy are rather explained by fragmentation of the orbital $M1$ strength than by the occurrence of the collective spin-scissors resonance. In general, our calculations do not confirm the existence of this resonance.Comment: 7 pages, 7 figures, submitted to Physics of Atomic Nuclei. arXiv admin note: text overlap with arXiv:2102.13580. As compared with the previous version, Ref. [1] was removed, Ref [33] was replaced, description of Fig. 3 was modifie

Molecular Structure of Pyrazinamide: A Critical Assessment of Modern Gas Electron Diffraction Data from Three Laboratories

Otlyotov AA, Girichev, Georgiy V, Rykov AN, Glodde T, Vishnevskiy Y. Molecular Structure of Pyrazinamide: A Critical Assessment of Modern Gas Electron Diffraction Data from Three Laboratories. JOURNAL OF PHYSICAL CHEMISTRY A. 2020;124(25):5204-5211.Accuracy and precision of molecular parameters determined by modern gas electron diffraction have been investigated. Diffraction patterns of gaseous pyrazinamide have been measured independently in three laboratories, in Bielefeld (Germany), Ivanovo (Russia), and Moscow (Russia). All data sets have been analyzed in equal manner using a highly controlled background elimination procedure and flexible restraints in molecular structure refinement. In detailed examination and comparison of the obtained results we have determined the average experimental precision of 0.004 angstrom for bond lengths and 0.2 degrees for angles. The corresponding average deviations of the refined parameters from the ae-CCSD(T)/cc-pwCVTZ theoretical values were 0.003 angstrom and 0.2 degrees. The average precision for refined amplitudes of interatomic vibrations was determined to be 0.005 angstrom. It is recommended to take into account these values in calculations of total errors for refined parameters of other molecules with comparable complexity

Microscopic analysis of dipole electric and magnetic strengths in 156^{156}Gd

The dipole electric ($E1$) and magnetic ($M1$) strengths in strongly deformed $^{156}$Gd are investigated within a fully self-consistent Quasiparticle Random Phase Approximation (QRPA) with Skyrme forces SV-bas, SLy6 and SG2. We inspect, on the same theoretical footing, low-lying dipole states and the isovector giant dipole resonance in $E1$ channel and orbital scissors resonance as well as spin-flip giant resonance in $M1$ channel. Besides, $E1$ toroidal mode and low-energy spin-flip $M1$ excitations are considered. The calculations show a good agreement with available experimental data, except for the recent NRF measurements of M. Tamkas et al for $M1$ strength at 4-6 MeV, where, in contradiction with our calculations and previous $(p,p')$ data, almost no $M1$ strength was observed.Comment: 8 pages, 4 figure

Influence of Antipodally Coupled Iodine and Carbon Atoms on the Cage Structure of 9,12-I2-closo-1,2-C2B10H10 : An Electron Diffraction and Computational Study

Because of the comparable electron scattering abilities of carbon and boron, the electron diffraction structure of the C2v-symmetric molecule closo-1,2-C2B10H12 (1), one of the building blocks of boron cluster chemistry, is not as accurate as it could be. On that basis, we have prepared the known diiodo derivative of 1, 9,12-I2-closo-1,2-C2B10H10 (2), which has the same point-group symmetry as 1 but in which the presence of iodine atoms, with their much stronger ability to scatter electrons, ensures much better structural characterization of the C2B10 icosahedral core. Furthermore, the influence on the C2B10 geometry in 2 of the antipodally positioned iodine substituents with respect to both carbon atoms has been examined using the concerted application of gas electron diffraction and quantum chemical calculations at the MP2 and density functional theory (DFT) levels. The experimental and computed molecular geometries are in good overall agreement. Molecular dynamics simulations used to obtain vibrational parameters, which are needed for analyzing the electron diffraction data, have been performed for the first time for this class of compound. According to DFT calculations at the ZORA-SO/BP86 level, the 11B chemical shifts of the boron atoms to which the iodine substituents are bonded are dominated by spin-orbit coupling. Magnetically induced currents within 2 have been calculated and compared to those for [B12H12]2-, the latter adopting a regular icosahedral structure with Ih point-group symmetry. Similar total current strengths are found but with a certain anisotropy, suggesting that spherical aromaticity is present; electron delocalization in the plane of the hetero atoms in 2 is slightly hindered compared to that for [B12H12]2-, presumably because of the departure from ideal icosahedral symmetry

КОМОРБИДНОСТЬ И ПРОГНОЗИРОВАНИЕ РИСКА ВОЗНИКНОВЕНИЯ ПОСЛЕОПЕРАЦИОННЫХ ИНФЕКЦИОННЫХ ОСЛОЖНЕНИЙ У БОЛЬНЫХ ТУБЕРКУЛЕЗНЫМ СПОНДИЛИТОМ

Goal of the study: to study co-morbidity and risk of post-operative infectious complications in tuberculous spondylitis patients with concurrent non-specific spinal osteomyelitis as per ASA, PITSS scales and Charlson score.Materials and methods. Surgical treatment of 41 patients with infectious spondylitis was retrospectively analyzed. Patients were divided into 2 groups. Tuberculous spondylitis patients were included into group 1 – 24 (58.5%), and those suffering from non-specific spinal osteomyelitis were included into group 2 (17.0-41.5%) More than half of tuberculous spondylitis patients were HIV positive (13/54.3%) and 16 out of 24 patients (66.7%) had generalized form of tuberculosis. The survival forecast for the patients after surgery was estimated by Charlson score, ASA score was used for evaluation of surgical and anesthetic risks, and risk of postoperative complications was assessed by PITSS (Postoperative infection treatment score for the spine) (2012).Results. Early and late infectious complications were detected in 4 (9.7%) of patients with ASA at 3-4 scores, Charlson score exceeding 5 and high risk as per PITSS (more than 21 scores). Tuberculous spondylitis patients had Charlson score exceeding 5 and high risk as per ASA (4 scores) more often compared to those suffering from non-specific spinal osteomyelitis. The majority of infectious spondylitis patients (28/57.5%) had medium and high risk of postoperative complications development as per PITSS. HIV positive tuberculous spondylitis patients had two fold risk of postoperative complications development compared to those HIV negative (χ2 = 4.53, OR = 2.76, p = 0.0012). Цель исследования: изучение коморбидности и риска возникновения послеоперационных инфекционных осложнений у больных туберкулезным спондилитом (ТС) и неспецифическим остеомиелитом позвоночника (НОП) по шкалам ASA, PITSS и индексу коморбидности Чарлсона (ИКЧ).Материалы и методы. Проведен ретроспективный анализ хирургического лечения 41 пациента с инфекционными спондилитами (ИС). Пациенты были разбиты на 2 группы. Больные ТС вошли в 1-ю группу - 24 (58,5%), 2-ю группу (17,0-41,5%) составили пациенты с НОП. Более половины больных ТС (13/54,3%) имели ВИЧ-инфекцию, у 16/24 (66,7%) пациентов имелся генерализованный туберкулез. Прогноз выживаемости больных после проведенного оперативного лечения рассчитан по ИКЧ, дана оценка степени риска операции и наркоза по шкале ASA, проведено прогнозирование риска послеоперационных осложнений по шкале PITSS (Postoperative infection treatment score for the spine) (2012).Результаты. Ранние и поздние инфекционные осложнения выявлены у 4 (9,7%) больных с риском по ASA 3-4 cт., ИКЧ более 5 баллов и PITSS высокой степени риска (более 21 балла). У больных ТС ИКЧ более 5 баллов и высокая степень риска по ASA (4 ст.) встречались чаще, чем среди больных НОП (p ≤ 0,05). Большинство пациентов с ИС (28/57,5%) имели средний и высокий риск развития ПОО по шкале PITSS. У ВИЧ-позитивных пациентов с ТС риск их возникновения был в 2 раза выше, чем у ВИЧ-негативных пациентов (χ2 = 4,53, OR = 2,76, p = 0,0012)

Микробиологический спектр нозокомиальной инфекции у больных с инфекционными спондилитами, перенесших сепсис

In 2015—2017, a cohort study of 72 cases of infectious spondylitis (is) with severe sepsis was conducted, which amounted, to 5,8% of all operated, patients. The study showed, that Gram. (+) bacteria -52 (55,9%) prevailed, in crops from all media. Gram. (-) bacteria were detected, in 1\3 cases 37(39.8%), and Candida infection in 4 (4,3%).The main traced, sources of NI in patients with is where bedsores (13\18,1%), infection with surgical intervention, fistula (14\19,4), uroinfection (22\30,6%), subclavian catheters (7\55.5%). Gram. (+) bacteria was 26,8% (15 cases) and was mainly found, in wounds and. catheters. Gram. (-) bacteria more prevalent in ulcers in the urine culture (56,4 per cent). In 10 cases (17,8%) the crops were sterile. An increase in the role of S. epidermitis and. K. pneumoniae in the etiology of sepsis was found, in bacteriological typing of media. High resistance of nosocomial strains of Staphylococcus spp is noted. Gram. (-) bacteria to fluoroquin.alon.es and. cephalosporins 3—4 generations, which excludes the possibility of their empirical use in the treatment of severe sepsis in patients with is.В период 2015—2017 гг. проведено когортное исследование 72 случаев инфекционного спондилита с тяжелым, сепсисом, что составило 5,8% от. всех оперированных в больных. Как показало исследование, в посевах преобладали грамположительные бактерии — 52(55,9%). Грам-отрицательные бактерии выявлены в 1/3 случаев — 37 (39,8%), а кандидозная инфекция — в 4 (4,3%).Основными факторами риска возникновения сепсиса у больных инфекционными спондилитами были пролежни (13/18,1%), инфекция области хирургического вмешательства и свищи (14/19,4), уроинфекции (22/30,6%), подключичные катетеры (7/55,5%). Грамположительные бактерии составили 26,8% (15 случаев) и в основном обнаруживались в ранах и катетерах. Грамотрицательные бактерии чаще выявлялись в пролежнях и в посевах мочи (56,4%). В 10 случаях (17,8%) посевы. были стерильны.При бактериологическом, типировании установлено увеличение роли S. epidermitis и K. pneumoniae в этиологии сепсиса по сравнению с предыдущим, десятилетием.. Отмечается высокая резистентность нозокомиальных штаммов Staphylococcus spp. и грамотрицательной микрофлоры, к фторхиналонам и цефалоспоринам 3—4 поколения, что исключает, возможность их эмпирического применения в терапии тяжелых сепсисов у больных инфекционными спондилитами

Влияние эволюции лучевых методов диагностики на хирургическое представление о фазах и стадиях острого панкреатита

In modern pancreatology, diagnostics of acute pancreatitis is one of the most complex and urgent problems. In recent decades, the incidence of acute pancreatitis (AP) has more than doubled and now it exceeds 25% among acute surgical diseases. Pancreonecrosis accounts for about 20–35% of all complications. General and postoperative mortality reaches 15–45%. Modern radiology methods in patients with AP and pancreatic necrosis aid in determination of disease form and its complications. In this article, the importance of radiological methods for treatment planning is reviewed. Close attention is paid to the interpretation of computer tomography (CT) data using various CT-scales and classifications. High incidence among young and healthy people highlights socio-economic significance of AP. Therefore, in this literature review, we focus on the publications and clinical cases of acute pancreatitis. В современной панкреатологии проблема диагностики острого панкреатита – одна из наиболее сложных и актуальных. За последние десятилетия заболеваемость острым панкреатитом увеличилась более чем в 2 раза и превышает 25% в структуре острых хирургических заболеваний. Панкреонекроз составляет около 20–35% среди всех осложнений. Общая и послеоперационная летальность достигает 15–45%. Применение современных методов лучевой диагностики у больных острым панкреатитом и панкреонекрозом позволяет определить форму болезни и выявить ее осложнения. В данном обзоре литературы рассматривается значение лучевых методов диагностики в планировании лечебной тактики у больных острым панкреатитом. Пристальное внимание уделено интерпретации данных компьютерной томографии с применением различных КТ-шкал и классификаций. Высокая заболеваемость лиц молодого и трудоспособного возраста придает этой проблеме важное социально-экономическое значение. Поэтому в настоящем обзоре проанализированы данные литературы и клинические случаи острого панкреатита.

Effects of methyl terminal and carbon bridging groups ratio on critical properties of porous organosilicate-glass films

Organosilicate glass-based porous low dielectic constant films with different ratios of terminal methyl to bridging organic (methylene, ethylene and 1,4-phenylene) groups are spin-on deposited by using a mixture of alkylenesiloxane with organic bridges and methyltrimethoxysilane, followed by soft baking at 120–200◦ C and curing at 430◦ C. The films’ porosity was controlled by using sacrificial template Brij® L4. Changes of the films’ refractive indices, mechanical properties, k-values, porosity and pore structure versus chemical composition of the film’s matrix are evaluated and compared with methyl-terminated low-k materials. The chemical resistance of the films to annealing in oxygen-containing atmosphere is evaluated by using density functional theory (DFT). It is found that the introduction of bridging groups changes their porosity and pore structure, increases Young’s modulus, but the improvement of mechanical properties happens simultaneously with the increase in the refractive index and k-value. The 1,4-phenylene bridging groups have the strongest impact on the films’ properties. Mechanisms of oxidative degradation of carbon bridges are studied and it is shown that 1,4-phenylene-bridged films have the highest stability. Methylene-and ethylene-bridged films are less stable but methylene-bridged films show slightly higher stability than ethylene-bridged films. © 2020 by the authors. Licensee MDPI, Basel, Switzerland

Cardiometabolic risk factors in predicting obstructive coronary artery disease in patients with non-ST-segment elevation acute coronary syndrome

Aim. To develop predictive models of obstructive coronary artery disease (OPCA) in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) based on the predictive potential of cardiometabolic risk (CMR) factors.Material and methods. This prospective observational cohort study included 495 patients with NSTE-ACS (median age, 62 years; 95% confidence interval [60; 64]), who underwent invasive coronary angiography (CAG). Two groups of persons were identified, the first of which consisted of 345 (69,6%) patients with OPCA (stenosis ≥50%), and the second — 150 (30,4%) without OPCA (<50%). The clinical and functional status of patients before CAG was assessed including 29 parameters. For data processing and analysis, the Mann-Whitney, Fisher, chi-squared tests and univariate logistic regression (LR) were used. In addition, for the development of predictive models, we used multivariate LR (MLR), support vector machine (SVM) and random forest (RF). The models was assessed using 4 metrics: area under the ROC-curve (AUC), sensitivity, specificity, and accuracy.Results. A comprehensive analysis of functional and metabolic status of patients made it possible to identify the CMR factors that have linear and nonlinear association with OPCA. Their weighting coefficients and threshold values with the highest predictive potential were determined using univariate LR. The quality metrics of the best predictive algorithm based on an ensemble of 10 MLR models were as follows: AUC — 0,82, specificity and accuracy — 0,73, sensitivity — 0,75. The predictors of this model were 7 categorical (total cholesterol (CS) ≥5,9 mmol/L, low-density lipoprotein cholesterol >3,5 mmol/L, waist-to-hip ratio ≥0,9, waist-to-height ratio ≥0,69, atherogenic index ≥3,4, lipid accumulation product index ≥38,5 cm*mmol/L, uric acid ≥356 pmol/L) and 2 continuous (high density lipoprotein cholesterol and insulin resistance index) variables.Conclusion. The developed algorithm for selecting predictors made it possible to determine their significant predictive threshold values and weighting coefficients characterizing the degree of influence on endpoints. The ensemble of MLR models demonstrated the highest accuracy of OPCA prediction before the CAG. The predictive accuracy of the SVM and RF models was significantly lower