The Post-AGB Star IRAS 07253-2001: Pulsations, Long-Term Brightness Variability and Spectral Peculiarities

The observations and comprehensive study of intermediate initial mass stars at the late stages of evolution, and after the asymptotic giant branch (AGB) in particular, are of crucial importance to identify the common properties for the stars of given group and to reveal binaries among them. This work aims to investigate photometric and spectral peculiarities of a poorly studied post-AGB candidate and infrared source IRAS 07253-2001. We present the new multicolour $UBVR_{C}I_{C}YJHK$ photometry obtained with the telescopes of the Caucasian mountain observatory and analyse it together with the data acquired by the All Sky Automated Survey for SuperNovae. We report on the detection of multiperiod brightness variability caused by pulsations. A beating of close periods, the main one of 73 days and additional ones of 68 and 70 days, leads to amplitude variations. We have also detected a long-term sine trend in brightness with a period of nearly 1800 days. We suppose it to be orbital and IRAS 07253-2001 to be binary. Based on new low-resolution spectroscopic data obtained with the 2.5-m telescope of the Caucasian mountain observatory in 2020 and 2023 in the $\lambda$3500-7500 wavelength range we have identified spectral lines and compiled a spectral atlas. We have found the [N II], [Ni II] and [S II] forbidden emission lines in the spectrum and discuss their origin. The H$\alpha$ line has a variable double-peaked emission component. We have derived preliminary estimates of the star's parameters and detected a variation of radial velocity with a peak-to-peak amplitude of about 30 km s$^{-1}$.Comment: 19 pages, 11 figures, 6 tables, Table 2 is only available in electronic form, accepted to Astrophysical Bulleti

QCD in the nuclear medium and effects due to Cherenkov gluons

The equations of in-medium gluodynamics are proposed. Their classical lowest order solution is explicitly shown for a color charge moving with constant speed. For nuclear permittivity larger than 1 it describes emission of Cherenkov gluons resembling results of classical electrodynamics. The values of the real and imaginary parts of the nuclear permittivity are obtained from the fits to experimental data on the double-humped structure around the away-side jet obtained at RHIC. The dispersion of the nuclear permittivity is predicted by comparing the RHIC, SPS and cosmic ray data. This is important for LHC experiments. Cherenkov gluons may be responsible for the asymmetry of dilepton mass spectra near rho-meson, observed in the SPS experiment with excess in the low-mass wing of the resonance. This feature is predicted to be common for all resonances. The "color rainbow" quantum effect might appear according to higher order terms of in-medium QCD if the nuclear permittivity depends on color.Comment: 29 p., 4 figs; for "Phys. Atom. Nucl." volume dedicated to 80th birthday of L.B. Okun; minor corrections on pp. 11 and 13 in v

ЭФФЕКТИВНОСТЬ НИЗКОИНТЕНСИВНОГО ЛАЗЕРНОГО ИЗЛУЧЕНИЯ ДЛЯ ПРОФИЛАКТИКИ И ЛЕЧЕНИЯ РАДИАЦИОННО-ИНДУЦИРОВАННОГО МУКОЗИТА ПОЛОСТИ РТА И ГЛОТКИ

Oral mucositis is the most common and significant complication of chemoradiation therapy for oral and pharyngeal cancer. There are no standard methods for preventing and treating this disease. Patients with severe adverse events need expensive supportive care and unplanned treatment breaks. The objective of the study was to assess and optimize the effectiveness of low level laser therapy (LLLT) for prevention and treatment of chemoradiation-induced oral mucositis in patients with oral and pharyngeal cancer. Material and Methods. Forty-eight patients who received chemoradiation therapy for oral and pharyngeal cancer were enrolled. All patients were randomly divided into two groups. Group I patients (n=28) received standard treatment of chemoradiation-induced complications. Group II patients (n=20) were treated with low level laser therapy (LLLT) at a wavelength of 635 nm, three times a week for three minutes prior to radiation therapy session. Results. In the LLLT group, a statistically significant decrease in the frequency and severity of oral mucositis as well as decrease in pain were observed as compared to the group with standard treatment (χ2 =64,14, р<0,0001). No significant difference in the onset of symptoms and duration of severe mucositis were found. LLLT is an effective method capable of decreasing the frequency and severity of adverse events associated with concurrent chemoradiation therapy. Key words: radiation-induced mucositis, oral and pharyngeal cancer, low level laser therapy, chemoradiation therapy.><0,0001). No significant difference in the onset of symptoms and duration of severe mucositis were found. LLLT is an effective method capable of decreasing the frequency and severity of adverse events associated with concurrent chemoradiation therapy. При проведении лучевой/химиолучевой терапии опухолей полости рта и глотки наиболее частым и клинически значимым побочным эффектом лечения является мукозит – повреждение слизистой оболочки полости рта и глотки. В качестве одного из нефармакологических методов его профилактики и лечения используется низкоэнергетическое лазерное излучение (НИЛИ). Целью исследования было изучение эффективности НИЛИ красного диапазона для профилактики и лечения мукозита слизистой оболочки полости рта и глотки. Материалы и методы. В протокол включены 48 пациентов, получавших лучевую/химиолучевую терапию по поводу злокачественных новообразований полости рта, ротоглотки и носоглотки, которые случайным образом были разделены на две группы. В первой группе (28 пациентов) проводилась коррекция осложнений химиолучевого лечения в соответствии со стандартами клиники. Во второй группе (20 пациентов) дополнительно использовалось воздействие на слизистую оболочку низкоинтенсивным лазерным излучением (длина волны 635 нм, мощность 5 мВт) 3 раза в нед в течение 3 мин перед сеансом облучения, начиная с первого дня лечения. Результаты. В группе воздействия НИЛИ отмечалось статистически значимое снижение частоты и тяжести мукозита, а также снижение выраженности болевого синдрома по сравнению с группой стандартной коррекции мукозита. Статистически значимых различий по критерию появления первых симптомов побочных эффектов и по критерию продолжительности мукозита наиболее тяжелой степени выявлено не было. НИЛИ является эффективным и доступным методом, позволяющим существенно снизить частоту и тяжесть побочных эффектов лучевой и химиолучевой терапии.

Long-term multiwavelength monitoring and reverberation mapping of NGC 2617 during a changing-look event

We present the results of photometric and spectroscopic monitoring campaigns of the changing look AGN NGC~2617 carried out from 2016 until 2022 and covering the wavelength range from the X-ray to the near-IR. The facilities included the telescopes of the SAI MSU, MASTER Global Robotic Net, the 2.3-m WIRO telescope, Swift, and others. We found significant variability at all wavelengths and, specifically, in the intensities and profiles of the broad Balmer lines. We measured time delays of ~ 6 days (~ 8 days) in the responses of the H-beta (H-alpha) line to continuum variations. We found the X-ray variations to correlate well with the UV and optical (with a small time delay of a few days for longer wavelengths). The K-band lagged the B band by 14 +- 4 days during the last 3 seasons, which is significantly shorter than the delays reported previously by the 2016 and 2017--2019 campaigns. Near-IR variability arises from two different emission regions: the outer part of the accretion disc and a more distant dust component. The HK-band variability is governed primarily by dust. The Balmer decrement of the broad-line components is inversely correlated with the UV flux. The change of the object's type, from Sy1 to Sy1.8, was recorded over a period of ~ 8 years. We interpret these changes as a combination of two factors: changes in the accretion rate and dust recovery along the line of sight.Comment: 14 pages, 15 figures, accepted by the MNRA

THE DEVELOPMENT OF ACCESSIBLE URBAN ENVIRONMENT USING THE PROJECT «MOBILE APPLICATION “CITY WITHOUT LIMITS”» AS AN EXAMPLE

In this article questions about accessibility of urban environment for disabled people with limitation of movement are considered, moreover the project providing conditions for comfortable movement in city space for specified groups of the population is represented.Выражаем благодарность команде разработчиков приложения, команде «Атмосфера» и волонтерам проекта «Город без границ»

Patients with a Combination of Atrial Fibrillation and Chronic Heart Failure in Clinical Practice: Comorbidities, Drug Treatment and Outcomes

Aim. To assess in clinical practice the structure of multimorbidity, cardiovascular pharmacotherapy and outcomes in patients with a combination of atrial fibrillation (AF) and chronic heart failure (CHF) based on prospective registries of patients with cardiovascular diseases (CVD).Materials and Methods. The data of 3795 patients with atrial fibrillation (AF) were analyzed within the registries RECVASA (Ryazan), RECVASA FP (Moscow, Kursk, Tula, Yaroslavl), REGION-PO and REGION-LD (Ryazan), REGION-Moscow, REGATA (Ryazan). The comparison groups consisted of 3016 (79.5%) patients with AF in combination with CHF and 779 (29.5%) patients with AF without CHF. The duration of prospective observation is from 2 to 6 years.Results. Patients with a combination of AF and CHF (n=3016, age was 72.0±10.3 years; 41.8% of men) compared with patients with AF without CHF (n=779, age was 70.3±12.0 years; 43.5% of men) had a higher risk of thromboembolic complications (CHA2DS2-VASc – 4.68±1.59 and 3.10±1.50; p<0.001) and hemorrhagic complications (HAS-BLED – 1.59±0.77 and 1.33±0.76; p<0.05). Patients with a combination of AF and CHF significantly more often (p<0.001) than in the absence of CHF were diagnosed with arterial hypertension (93.9% and 83.8%), coronary heart disease (87.9% and 53,5%), myocardial infarction (28.4% and 14.0%), diabetes mellitus (22.4% and 7.7%), chronic kidney disease (24.8% and 16.2%), as well as respiratory diseases (20.1% and 15.3%; p=0.002). Patients with AF in the presence of CHF, compared with patients without CHF, were more often diagnosed with a permanent form of arrhythmia (49.3% and 32.9%; p<0.001) and less often paroxysmal (22.5% and 46.2%; p<0.001) form  of  arrhythmia.  Ejection  fraction  ≤40%  (9.3%  and  1.2%;  p<0.001),  heart  rate  ≥90/min  (23.7% and 19.3%; p=0.008) and blood pressure ≥140/90 mm Hg (59.9% and 52.2%; p<0.001) were recorded with AF in the presence of CHF more often than in the absence of CHF. The frequency of proper cardiovascular pharmacotherapy was higher, albeit insufficient, in the presence of CHF (64.9%) than in the absence of it (56.1%), but anticoagulants were prescribed less frequently when AF and CHF were combined (38.8% and  49, 0%; p<0.001). The frequency of unreasonable prescription of antiplatelet agents instead of anticoagulants was 52.5% and 33.3% (p<0.001) in the combination of AF, CHF and coronary heart disease, as well as in the combination of AF with coronary heart disease but without CHF. Patients with AF and CHF during the observation period compared with those without CHF had higher mortality from all causes (37.6% and 30.3%; p=0.001), the frequency of non-fatal cerebral stroke (8.2% and 5.4%; p=0.032) and myocardial infarction (4.7% and 2.5%; p=0.036), hospitalizations for CVD (22.8% and 15.5%; p<0.001).Conclusion. Patients with a combination of AF and CHF, compared with the group of patients with AF without CHF, were older, had a higher risk of thromboembolic and hemorrhagic complications, they were more often diagnosed with other concomitant cardiovascular and chronic noncardiac diseases, decreased left ventricular ejection fraction, tachysystole, failure to achieve the target blood pressure level in the presence of arterial hypertension. The frequency of prescribing proper cardiovascular pharmacotherapy was higher, albeit insufficient, in the presence of CHF, while the frequency of prescribing anticoagulants was less. The  incidence of mortality from all causes, the development of non-fatal myocardial infarction   and cerebral stroke, as well as the incidence of hospitalizations for CVDs were higher in AF associated with CHF