49 research outputs found
Retraction notice on the article by A.S. Zotov et al. ‘Short-Term Results of Two Strategies in Thoracoscopic Ablation for Lone Atrial Fibrillation’ doi: 10.17816/clinpract110719
Editorial board of the journal informs authors about the retraction of the article Short-Term Results of Two Strategies in Thoracoscopic Ablation for Lone Atrial Fibrillation published in Journal of Clinical Practice 13(3) 2022 by A.S. Zotov, O.Yu. Pidanov, I.S. Osmanov, A.V. Troitsky, A.A. Silaev, E.R. Sakharov, V.N. Sukhotin, O.O. Shelest, R.I. Khabazov, D.A. Timashkov. The reason for the retraction is the publication ethics violation in terms of authorship criteria. Not all authors whose names appear on the article made substantial contributions to the study drafted/revised the manuscript and approved the version to be published.
Retraction made on January 09, 2023 with approve from the Editor-in-Chief
Abscess Formation Following Spilled Gallstones During Laparoscopic Cholecystectomy
A review of the English literature concerning spilled gallstones during laparoscopic cholecystectomy is compared with one institution's experience of four cases during 1,726 laparoscopic cholecystectomies performed over a four-year period. Strategies regarding management and treatment are discussed
Хирургические и патоморфологические результаты тотальной мезоректумэктомии с применением методики водоструйной диссекции при раке прямой кишки
Background. The paper presents our own experience of using a waterjet dissector ERBEJET2® in the course of surgical interventions for colorectal cancer. This experience is unique for Russia.Materials and methods. Waterjet dissection method associated with total mesorectumectomy was used by us in 20 patients suffering from rectal cancer. An average age of patients was 59.2 ± 13.9 years. In all the patients surgeries were performed for adenogenic colorectal cancer, morphologically verified at the preoperative stage. Resected preparations were studied on morphological level. For comparison, two control groups of 20 patients were selected, in which the rectum mobilization was performed by using monopolar coagulator and harmonic scalpel. The studied groups were matched by gender, age, location and the tumor extent. All the surgeries were performed by one surgical team.Results. Results of the study demonstrated advantages of waterjet dissection when performing total mesorectumectomy due to a minimum depth of tissue damage on the lateral margin of resection.Conclusion. Waterjet dissectors have taken their place in the extensive list of tools used when performing surgical interventions for colorectal cancer, that allows to expect an improvement of functional and oncological results of the surgical treatment.Введение. В работе приведен собственный, уникальный для России опыт применения водоструйного диссектора ERBEJET2® в ходе выполнения оперативных вмешательств по поводу рака прямой кишки.Материалы и методы. Методика водоструйной диссекции при выполнении тотальной мезоректумэктомии применена нами у 20 больных раком прямой кишки. Средний возраст пациентов составил 59,2 ± 13,9 года. У всех больных оперативные вмешательства выполняли по поводу аденогенного рака прямой кишки, морфологически верифицированного на предоперационном этапе. Удаленные препараты исследованы морфологически. Для сравнения были выбраны 2 контрольные группы по 20 пациентов, у которых мобилизацию прямой кишки проводили с применением монополярного коагулятора и гармонического скальпеля. Исследованные группы были сопоставимы по гендерному составу, возрасту, локализации и распространенности опухоли. Все оперативные вмешательства выполняла одна бригада хирургов.Результаты. Результаты исследования продемонстрировали преимущества метода водоструйной диссекции при выполнении тотальной мезоректумэктомии за счет минимальной глубины повреждения тканей по латеральному краю резекции.Заключение. Водоструйные диссекторы заняли свое место в обширном списке инструментария, применяющегося при выполнении оперативных вмешательств по поводу рака прямой кишки, позволяя рассчитывать на улучшение функциональных и онкологических результатов хирургического лечения
Extreme photometric and polarimetric variability of blazar S4 0954+65 at its maximum optical and γ-ray brightness levels
In 2022 the BL Lac object S4 0954+65 underwent a major variability phase, reaching its historical maximum brightness in the
optical and γ -ray bands. We present optical photometric and polarimetric data acquired by the Whole Earth Blazar Telescope
(WEBT) Collaboration from 2022 April 6 to July 6. Many episodes of unprecedented fast variability were detected, implying
an upper limit to the size of the emitting region as low as 10−4 parsec. The WEBT data show rapid variability in both the degree
and angle of polarization. We analyse different models to explain the polarization behaviour in the framework of a twisting
jet model, which assumes that the long-term trend of the flux is produced by variations in the emitting region viewing angle.
All the models can reproduce the average trend of the polarization degree, and can account for its general anticorrelation with
the flux, but the dispersion of the data requires the presence of intrinsic mechanisms, such as turbulence, shocks, or magnetic
reconnection. The WEBT optical data are compared to γ -ray data from the Fermi satellite. These are analysed with both fixed
and adaptive binning procedures. We show that the strong correlation between optical and γ -ray data without measurable delay
assumes different slopes in faint and high brightness states, and this is compatible with a scenario where in faint states we mainly
see the imprint of the geometrical effects, while in bright states the synchrotron self-Compton process dominates
ВОЗМОЖНОСТИ РЕКОНСТРУКЦИИ МОЧЕВЫДЕЛИТЕЛЬНОЙ СИСТЕМЫ ПОСЛЕ ТОТАЛЬНЫХ ЭКЗЕНТЕРАЦИЙ МАЛОГО ТАЗА У ПАЦИЕНТОВ С МЕСТНО-РАСПРОСТРАНЕННЫМИ ПЕРВИЧНЫМИ И РЕЦИДИВНЫМИ ОПУХОЛЯМИ ПРЯМОЙ КИШКИ
The investigators analyzed the world literature on and the immediate and late results of 14 total small pelvic exenterations with different urinary tract reconstruction modalities. Postoperative complications occurred in 57.1 % of patients; postoperative mortality was 7.1 %. Late results were followed up in 12 patients. Overall survival at 10 to 48 months after surgery (median 26 months) was 83.3 %; relapse-free survival was 75 %. Urine derivation was made via orthotopic bladder plasty in 5 patients, Bricker operation in 6, and bilateral ureterocutaneostomy in 3. Functional results were regarded as good in all the patients after orthotopic bladder plasty. Thus, adequate urinary tract reconstruction allows one to expect the quality of life to be better without a negative impact on oncological results.Проведен обзор мировой литературы и проанализированы непосредственные и отдаленные результаты 14 тотальных экзентераций малого таза с различными вариантами реконструкции мочевыделительной системы. Послеоперационные осложнения имели место у 57,1 % больных, послеоперационная летальность составила 7,1 %. Отдаленные результаты прослежены у 12 пациентов. Общая выживаемость в сроки от 10 до 48 мес после операции (медиана 26 мес) составила 83,3 %, безрецидивная выживаемость — 75 %. Деривация мочи была обеспечена путем выполнения ортотопической пластики мочевого пузыря у 5 больных, операции Брикера – у 6, билатеральной уретерокутанеостомии – у 3 пациентов. Функциональные результаты оцениваются как хорошие у всех пациентов после ортотопической пластики мочевого пузыря. Таким образом, выполнение полноценной реконструкции мочевыделительной системы позволяет рассчитывать на улучшение качества жизни больных без отрицательного влияния на онкологические результаты
Multimessenger Characterization of Markarian 501 during Historically Low X-Ray and γ-Ray Activity
We study the broadband emission of Mrk 501 using multiwavelength observations from 2017 to 2020 performed with a multitude of instruments, involving, among others, MAGIC, Fermi's Large Area Telescope (LAT), NuSTAR, Swift, GASP-WEBT, and the Owens Valley Radio Observatory. Mrk 501 showed an extremely low broadband activity, which may help to unravel its baseline emission. Nonetheless, significant flux variations are detected at all wave bands, with the highest occurring at X-rays and very-high-energy (VHE) 3-rays. A significant correlation (>3σ) between X-rays and VHE 3-rays is measured, supporting leptonic scenarios to explain the variable parts of the emission, also during low activity. This is further supported when we extend our data from 2008 to 2020, and identify, for the first time, significant correlations between the Swift X-Ray Telescope and Fermi-LAT. We additionally find correlations between high-energy 3-rays and radio, with the radio lagging by more than 100 days, placing the 3-ray emission zone upstream of the radio-bright regions in the jet. Furthermore, Mrk 501 showed a historically low activity in X-rays and VHE 3-rays from mid-2017 to mid-2019 with a stable VHE flux (>0.2 TeV) of 5% the emission of the Crab Nebula. The broadband spectral energy distribution (SED) of this 2 yr long low state, the potential baseline emission of Mrk 501, can be characterized with one-zone leptonic models, and with (lepto)-hadronic models fulfilling neutrino flux constraints from IceCube. We explore the time evolution of the SED toward the low state, revealing that the stable baseline emission may be ascribed to a standing shock, and the variable emission to an additional expanding or traveling shock. © 2023. The Author(s). Published by the American Astronomical Society
The variability patterns of the TeV blazar PG 1553 + 113 from a decade of MAGIC and multiband observations
PG 1553 + 113 is one of the few blazars with a convincing quasi-periodic emission in the gamma-ray band. The source is also a very high energy (VHE; >100 GeV) gamma-ray emitter. To better understand its properties and identify the underlying physical processes driving its variability, the MAGIC Collaboration initiated a multiyear, multiwavelength monitoring campaign in 2015 involving the OVRO 40-m and Medicina radio telescopes, REM, KVA, and the MAGIC telescopes, Swift and Fermi satellites, and the WEBT network. The analysis presented in this paper uses data until 2017 and focuses on the characterization of the variability. The gamma-ray data show a (hint of a) periodic signal compatible with literature, but the X-ray and VHE gamma-ray data do not show statistical evidence for a periodic signal. In other bands, the data are compatible with the gamma-ray period, but with a relatively high p-value. The complex connection between the low- and high-energy emission and the non-monochromatic modulation and changes in flux suggests that a simple one-zone model is unable to explain all the variability. Instead, a model including a periodic component along with multiple emission zones is required
Multi-messenger characterization of Mrk 501 during historically low X-ray and -ray activity
We study the broadband emission of Mrk 501 using multi-wavelength
observations from 2017 to 2020 performed with a multitude of instruments,
involving, among others, MAGIC, Fermi-LAT, NuSTAR, Swift, GASP-WEBT, and OVRO.
Mrk 501 showed an extremely low broadband activity, which may help to unravel
its baseline emission. Nonetheless, significant flux variations are detected at
all wavebands, with the highest occurring at X-rays and very-high-energy (VHE)
-rays. A significant correlation (3) between X-rays and VHE
-rays is measured, supporting leptonic scenarios to explain the
variable parts of the emission, also during low activity. This is further
supported when we extend our data from 2008 to 2020, and identify, for the
first time, significant correlations between Swift-XRT and Fermi-LAT. We
additionally find correlations between high-energy -rays and radio,
with the radio lagging by more than 100 days, placing the -ray emission
zone upstream of the radio-bright regions in the jet. Furthermore, Mrk 501
showed a historically low activity in X-rays and VHE -rays from
mid-2017 to mid-2019 with a stable VHE flux (0.2 TeV) of 5% the emission of
the Crab Nebula. The broadband spectral energy distribution (SED) of this
2-year-long low-state, the potential baseline emission of Mrk 501, can be
characterized with one-zone leptonic models, and with (lepto)-hadronic models
fulfilling neutrino flux constraints from IceCube. We explore the time
evolution of the SED towards the low-state, revealing that the stable baseline
emission may be ascribed to a standing shock, and the variable emission to an
additional expanding or traveling shock.Comment: 56 pages, 30 figures, 14 tables, submitted. Corresponding authors are
L. Heckmann, D. Paneque, S. Gasparyan, M. Cerruti, and N. Sahakya
Multi-year characterisation of the broad-band emission from the intermittent extreme BL Lac 1ES 2344+514
Aims. The BL Lac 1ES 2344+514 is known for temporary extreme properties characterised by a shift of the synchrotron spectral energy distribution (SED) peak energy νsynch;p above 1 keV. While those extreme states have only been observed during high flux levels thus far, additional multi-year observing campaigns are required to achieve a coherent picture. Here, we report the longest investigation of the source from radio to very high energy (VHE) performed so far, focussing on a systematic characterisation of the intermittent extreme states. Methods.We organised a monitoring campaign covering a 3-year period from 2019 to 2021.Morethan ten instruments participated in the observations in order to cover the emission from radio to VHE. In particular, sensitive X-ray measurements by XMM-Newton, NuSTAR, and AstroSat took place simultaneously with multi-hour MAGIC observations, providing an unprecedented constraint of the two SED components for this blazar. Results. While our results confirm that 1ES 2344+514 typically exhibits νsynch;p > 1 keV during elevated flux periods, we also find periods where the extreme state coincides with low flux activity. A strong spectral variability thus happens in the quiescent state, and is likely caused by an increase in the electron acceleration efficiency without a change in the electron injection luminosity. On the other hand, we also report a strong X-ray flare (among the brightest for 1ES 2344+514) without a significant shift of νsynch;p. During this particular flare, the X-ray spectrum is among the softest of the campaign. It unveils complexity in the spectral evolution, where the common harder-when-brighter trend observed in BL Lacs is violated. By combining Swift-XRT and Swift-UVOT measurements during a low and hard X-ray state, we find an excess of the UV flux with respect to an extrapolation of the X-ray spectrum to lower energies. This UV excess implies that at least two regions significantly contribute to the infrared/optical/ultraviolet/X-ray emission. Using the simultaneous MAGIC, XMM-Newton, NuSTAR, and AstroSat observations, we argue that a region possibly associated with the 10 GHz radio core may explain such an excess. Finally, we investigate a VHE flare, showing an absence of simultaneous variability in the 0.3-2 keV band. Using time-dependent leptonic modelling, we show that this behaviour, in contradiction to single-zone scenarios, can instead be explained by a two-component model
Multi-year characterisation of the broad-band emission from the intermittent extreme BL Lac 1ES~2344+514
The BL Lac 1ES 2344+514 is known for temporary extreme properties (e.g., a
shift of the synchrotron SED peak energy above 1keV). While
those extreme states were so far observed only during high flux levels,
additional multi-year observing campaigns are required to achieve a coherent
picture. Here, we report the longest investigation of the source from radio to
VHE performed so far, focusing on a systematic characterisation of the
intermittent extreme states. While our results confirm that 1ES 2344+514
typically exhibits 1keV during elevated flux periods, we also
find periods where the extreme state coincides with low flux activity. A strong
spectral variability thus happens in the quiescent state, and is likely caused
by an increase of the electron acceleration efficiency without a change in the
electron injection luminosity. We also report a strong X-ray flare (among the
brightest for 1ES 2344+514) without a significant shift of .
During this particular flare, the X-ray spectrum is among the softest of the
campaign. It unveils complexity in the spectral evolution, where the common
harder-when-brighter trend observed in BL Lacs is violated. During a low and
hard X-ray state, we find an excess of the UV flux with respect to an
extrapolation of the X-ray spectrum to lower energies. This UV excess implies
that at least two regions contribute significantly to the
infrared/optical/ultraviolet/X-ray emission. Using the simultaneous MAGIC,
XMM-Newton, NuSTAR, and AstroSat observations, we argue that a region possibly
associated with the 10 GHz radio core may explain such an excess. Finally, we
investigate a VHE flare, showing an absence of simultaneous variability in the
0.3-2keV band. Using a time-dependent leptonic modelling, we show that this
behaviour, in contradiction to single-zone scenarios, can instead be explained
by a two-component model.Comment: Accepted for publication in Astronomy & Astrophysic