Near-threshold production of a0(980)a_0(980)-mesons in πN\pi N and NN collisions and a0/f0a_0/f_0-mixing

We consider near-threshold $a_0(980)$-meson production in $\pi N$ and $NN$ collisions. An effective Lagrangian approach with one-pion exchange is applied to analyze different contributions to the cross section for different isospin channels. The Reggeon exchange mechanism is also evaluated for comparison. The results from $\pi N$ reactions are used to calculate the contribution of the $a_0$ meson to the cross sections and invariant $K \bar K$ mass distributions of the reactions $pp\to pn K^+\bar K^0$ and $pp\to pp K^+K^-$. It is found that the experimental observation of $a_0^+$ mesons in the reaction $pp\to pn K^+\bar K^0$ is much more promising than the observation of $a_0^0$ mesons in the reaction $pp\to pp K^+K^-$. Effects of isospin violation in the reactions $pN \to d a_0$, $pd \to \mathrm{^3He/^3H} a_0$, and $dd \to \mathrm{^4He} a_0$, which are induced by $a_0(980)$--$f_0(980)$ mixing, are also analyzed.Comment: 43 pages, including 16 eps figures, to be bublished in Phys. Atom. Nucl. (Yad. Fiz.) vol. 65, No. 11 (2002

t-3-Ethyl-r-2,c-6-bis­(4-methoxy­phen­yl)-1-nitro­sopiperidin-4-one

In the title mol­ecule, C21H24N2O4, the piperidine ring adopts a distorted boat conformation with the ethyl substituent in the axial position. The dihedral angle between the two benzene rings is 70.25 (9)°. An intra­molecular C—H⋯O inter­action is observed. In the crystal, mol­ecules are linked into a chain along the c axis by C—H⋯O hydrogen bonds and the chains are linked via weak C—H⋯π inter­actions

Aspects of a0-f0 mixing in the reaction pn->da0

Some aspects of a0-f0 mixing effects in the reaction ${\vec p} n\to da^0_0$ with perpendicular polarized proton beam are discussed. An angular--asymmetry parameter $A$ is defined to study those effects. It is shown that, for energies close to the production threshold, the angular--asymmetry parameter $A(\theta, \phi)$ is proportional to the a0-f0 mixing amplitude for arbitrary polar and azimuthal angles $\theta$ and $\phi$ of the outgoing $a_0$ meson. This statement is also valid for arbitrary energies, but then only at polar angles $\theta=0^0$ and $\theta=90^0$. The mass dependence of the differential cross section $d\sigma/dm_{\pi^0\eta}$ in the reaction $pn\to d\pi^0\eta$ in the presence of \mix mixing is also discussed.Comment: 17 pages, 3 Figure

Empirical Evaluation of Educational Service Quality in the Current Higher Education System

During the transition to the mixed education model during the Covid-19 pandemic, some issues have emerged in the matter of providing and supporting the quality of university education in all countries, including educational programs' relevance to the demands of the labor market, expectations of students and their families, digital transformation of the educational process, and economic stability of institution networks. The purpose of the research was to evaluate the quality of educational services in the higher education systems of Indonesia and Russia. The study systematized several essential factors for achieving educational service quality in the current higher education systems, given the limitations imposed by Covid-19. Following this objective, the study utilized a quantitative approach, adopting the SERVQUALmodel that measures the service quality across five service dimensions: tangibility, reliability, responsiveness, assurance, and empathy. The model aided the development of the questionnaire to assess the quality of the educational services of Indonesian and Russian universities. The questionnaire included 25 close-ended questions on two scales: one to measure the students' expectations regarding the quality of educational services and the other to measure the students' current perceptions. A snowball technique was used to recruit students from Indonesian and Russian universities as participants in the study. The students were asked to assess the educational services of their universities based on their initial expectations and current perceptions. Overall, the students of both countries revealed that they had high expectations from the educational services of their universities. However, the current perceptions of the Russian students regarding the quality of educational services provided by their universities are higher and more positive than the perceptions of the Indonesian students regarding the quality of educational services being delivered to them. The findings of the study have implications for education practitioners. Doi: 10.28991/ESJ-2022-SIED-05 Full Text: PD

Принципы наблюдения за пульмонологическими больными подросткового возраста в поликлинике

While organizing medical care for respiratory patients prevention, outpatient surveillance and rehabilitation measures are of prior importance. We analyzed outpatient medical histories of adolescents being surveyed for respiratory pathology. The expert analysis founds serious defects in records of medical history and physical data, quality of clinical, laboratory, and instrumental examinations, and patients' surveillance. When using a screening system 3 groups of the patients were selected: the 1-st group had risk factors for lung pathology development, the 2 -nd group consisted of adolescents with first diagnosed lung disease, and the 3 -rd group included chronic respiratory patients. Proper measures were determined for each group. Rehabilitation monitoring is necessary for early detection of chronic respiratory patients who need preventive measures and rehabilitation. A functional-and-organizing model for outpatient rehabilitation of adolescents and an automatic screening system for multifactorial assessment of health were created.В организации медицинской помощи пациентам с болезнями органов дыхания (БОД) приоритетное значение отводится профилактике, диспансеризации, системе реабилитации. Были проанализированы амбулаторные карты подростков, состоящих на диспансерном учете с БОД. В результате проведенного экспертного анализа выявлены серьезны е недостатки по сбору жалоб, описания физического статуса больных, по качеству клинико-лабораторного и инструментального обследования пациентов, диспансеризации . С помощью скрининговой системы сформированы 3 потока пациентов: 1-й — угрожаемые по патологии легких; 2 -й — больные подростки со впервые выявленным заболеванием легких, 3-й — больные с хроническим и БОД. Для каждого потока определялся характер проводимых мероприятий. Реабилитационный мониторинг необходим для раннего выявления пациентов с БОД, нуждающихся в оздоровительных мероприятиях и реабилитации. Разработана функционально-организационная модель восстановительного лечения подростков на амбулаторно-поликлиническом этапе, система автоматизированного скрининга многофакторной оценки здоровья

Реконструкция желчных протоков после неудачной лапароскопической холецистэктомии (обзор литературы)

   Today, the incidence of iatrogenic bile duct injury in laparoscopic cholecystectomy averages 0.4 % worldwide. In Russia, it accounted for 0.6 % in 2020. Side-to-side hepaticojejunostomy is the operation of choice with complete injury of the common bile duct. It is considered the safest operation, which preserves blood supply, provides wider anastomosis, ensures complete rehabilitation in 75–98 % of cases. Even in the centers of hepatobiliary surgery, the development of strictures after hepaticojejunostomy with traditional access after iatrogenic injury to the bile ducts occurs in 10–20 % of cases. Bile leakage develops in 3.0–3.3 % of cases. The success of reconstructive surgery largely depends on the precision technique of performing anastomosis, which can be ensured mainly by the quality of imaging. The possibility of laparoscopic hepaticojejunostomy after a common bile duct injury is currently a subject of debate, and only few publications report on its successful performance. Most surgeons prefer open anastomosis due to insufficient space for laparoscopic instruments. Although the advantages of laparoscopic surgery over traditional interventions are essential for this category of patients no less than for the others. Robotic laparoscopic surgery with its additional space for instruments in the complete absence of tremor, a twenty-fold increase in three-dimensional image, which increases the accuracy of tissue dissection and the precision of anastomotic sutures, can be an excellent option for working on thin tubular structures in the porta hepatis.   На сегодня частота ятрогенной травмы желчных протоков при лапароскопической холецистэктомии в среднем в мире составляет 0,4 %. В России в 2020 году — 0,6 %. Гепатикоеюностомия «бок в бок» является операцией выбора при полном повреждении общего желчного протока, считается наиболее безопасной, позволяет сохранить кровоснабжение, обеспечить формирование более широкого анастомоза, добиться полноценной реабилитации у 75–98 % пациентов. Даже в центрах гепатобилиарной хирургии развитие стриктур после гепатикоеюностомии традиционным доступом после ятрогенного повреждения желчных протоков происходит в 10–20 % случаев. Подтекание желчи развивается у 3,0–3,3 % пациентов. Успех реконструктивной операции во многом зависит от прецизионной техники выполнения анастомоза, которая может быть обеспечена главным образом качеством визуализации. Возможность лапароскопической гепатикоеюностомии после травмы общего желчного протока в настоящее время является предметом дискуссии, и в литературе существует небольшое количество публикаций о ее успешном исполнении. Большинство хирургов предпочитают открытое наложение анастомоза, ссылаясь на недостаточное рабочее пространство для лапароскопических инструментов, хотя данная категория пациентов не менее других нуждается в преимуществах лапароскопической хирургии перед традиционными вмешательствами. Роботическая лапароскопическая хирургия с ее дополнительными степенями свободы работы инструментов при полном отсутствии тремора, двадцатикратным увеличением при трехмерном изображении, повышающим точность рассечения тканей и прецизионность швов анастомоза, может стать отличным вариантом для работы на тонких трубчатых структурах в воротах печени

Incoherent Photoproduction of η\eta-mesons from the Deuteron near Threshold

Incoherent photoproduction of the $\eta$-meson on the deuteron is studied for photon energies from threshold to 800 MeV. The dominant contribution, the $\gamma$N-$\eta$N amplitude, is described within an isobar model. The final state interaction derived from the CD-Bonn potential is included and found to be important for the description of the production cross section close to threshold. Possible effects from the $\eta N$ final state interaction are discussed.Comment: 11 pages, revtex, including 6 figure

Photoproduction of mesons off nuclei

Recent results for the photoproduction of mesons off nuclei are reviewed. These experiments have been performed for two major lines of research related to the properties of the strong interaction. The investigation of nucleon resonances requires light nuclei as targets for the extraction of the isospin composition of the electromagnetic excitations. This is done with quasi-free meson photoproduction off the bound neutron and supplemented with the measurement of coherent photoproduction reactions, serving as spin and/or isospin filters. Furthermore, photoproduction from light and heavy nuclei is a very efficient tool for the study of the interactions of mesons with nuclear matter and the in-medium properties of hadrons. Experiments are currently rapidly developing due to the combination of high quality tagged (and polarized) photon beams with state-of-the-art 4pi detectors and polarized targets

ABC Effect in Basic Double-Pionic Fusion --- Observation of a new resonance?

We report on a high-statistics measurement of the basic double pionic fusion reaction $pn \to d\pi^0\pi^0$ over the energy region of the so-called ABC effect, a pronounced low-mass enhancement in the $\pi\pi$-invariant mass spectrum. The measurements were performed with the WASA detector setup at COSY. The data reveal the ABC effect to be associated with a Lorentzian shaped energy dependence in the integral cross section. The observables are consistent with a resonance with $I(J^P) =0(3^+)$ in both $pn$ and $\Delta\Delta$ systems. Necessary further tests of the resonance interpretation are discussed

Scalar-isovector K K-bar production close to threshold

The reaction pp -> d K^+ K^0-bar has been investigated at excess energies Q = 47.4 and 104.7 MeV above the K^+ K^0-bar threshold at COSY-Juelich. Coincident dK^+ pairs were detected with the ANKE spectrometer, and events with a missing K^0-bar invariant-mass subsequently identified. The joint analysis of invariant-mass and angular distributions reveals s-wave dominance between the two kaons, in conjunction with a p-wave between the deuteron and the kaon pair, i.e. K K-bar production via the a_0^+(980) channel. Integration of the differential distributions yields total cross sections of sigma(pp -> d K^+ K^0-bar) = (38 +/- 2(stat) +/- 14(syst)) nb and 190 +/- 4(stat) +/- 39(syst)) nb for the low and high Q values, respectively.Comment: 7 pages, 6 figures; accepted for publication in Eur.Phys.J.