446 research outputs found
Synoptic Sky Surveys and the Diffuse Supernova Neutrino Background: Removing Astrophysical Uncertainties and Revealing Invisible Supernovae
The cumulative (anti)neutrino production from all core-collapse supernovae
within our cosmic horizon gives rise to the diffuse supernova neutrino
background (DSNB), which is on the verge of detectability. The observed flux
depends on supernova physics, but also on the cosmic history of supernova
explosions; currently, the cosmic supernova rate introduces a substantial
(+/-40%) uncertainty, largely through its absolute normalization. However, a
new class of wide-field, repeated-scan (synoptic) optical sky surveys is coming
online, and will map the sky in the time domain with unprecedented depth,
completeness, and dynamic range. We show that these surveys will obtain the
cosmic supernova rate by direct counting, in an unbiased way and with high
statistics, and thus will allow for precise predictions of the DSNB. Upcoming
sky surveys will substantially reduce the uncertainties in the DSNB source
history to an anticipated +/-5% that is dominated by systematics, so that the
observed high-energy flux thus will test supernova neutrino physics. The
portion of the universe (z < 1) accessible to upcoming sky surveys includes the
progenitors of a large fraction (~ 87%) of the expected 10-26 MeV DSNB event
rate. We show that precision determination of the (optically detected) cosmic
supernova history will also make the DSNB into a strong probe of an extra flux
of neutrinos from optically invisible supernovae, which may be unseen either
due to unexpected large dust obscuration in host galaxies, or because some
core-collapse events proceed directly to black hole formation and fail to give
an optical outburst.Comment: 11 pages, 6 figure
Pyeloplasty effectiveness in cases of ureteropelvic junction obstruction in children: methodology and assessment parameters
The article presents the analysis of published data (Scopus, Web of Science, PubMed/MedLine, The Cochrane Library, and eLIBRARY databases) devoted to the study of existing criteria for assessment of pyeloplasty effectiveness. Published sources most often refer to the dynamics of reduction of the renal collecting system (RCS) and postoperative renal functional status as the assessment criteria. However, there are no consistent values, which could be employed as assessment criteria indicating success as soon as they are registered. The tools used to estimate RCS reduction are not standardized in terms of research techniques, projection of RCS dilatation measurement, and the locations between which renal and pelvic anatomic structures are measured. A variety of approaches to measuring the anteroposterior renal pelvis dimension in children with hydronephrosis tends to blur the analysis of actual pyeloplasty results. This review of published sources demonstrates the lack of agreement as regards the criteria for assessment of pyeloplasty effectiveness. There is a pressing need for appropriate steps to harmonize ultrasonography methods, to standardize the anatomic landmarks for measurement, and to define the criteria to be used to assess the effectiveness of pyeloplasty
Ренин-ангиотензиновая система: роль в развитии и прогрессии почечно-клеточного рака (обзор литературы)
Renal cell carcinoma (RCC) is one of the most common forms of malignant epithelial tumors of this localization. The development of new approaches to the diagnosis, prognosis and treatment of RCC is an topical issue of molecular medicine. The renin-angiotensin system (RAS) is not only an important component of the central and humoral mechanisms of controlling blood pressure and hydroelectrolytic balance, but also refers to the body systems involved in complex carcinogenesis pathways. Researches on the role of RAS in tumor progression are currently the priority. The data on the role of RAS in the development and progression of malignant tumors in the kidneys are being discussed. In this article, we present an overview of data on the role of RAS in the emergence and development of RCC, an analysis of the molecular mechanisms of development and progression of RCC, the prospects for using indicators of the RAS: angiotensin-converting enzymes (ACE), ACE2 and angiotensin II receptors as markers of diagnosis and monitoring of neoplastic transformation processes in the kidney. The prospects for the use of new, effective anticancer drugs with a targeted effect on definite indicators of the RAS of RCC were analyzed.Почечно-клеточный рак (ПКР) – одна из наиболее частых форм злокачественных эпителиальных опухолей данной локализации. Разработка новых подходов к диагностике, прогнозу и лечению ПКР является актуальной проблемой молекулярной медицины. Ренин-ангиотензиновая система (РАС) – не только важный компонент центральных и гуморальных механизмов контроля артериального давления и водно-электролитного баланса, но и относится к числу систем организма, вовлеченных в сложные пути канцерогенеза. Исследования, касающиеся роли РАС в опухолевой прогрессии, в настоящее время являются одними из приоритетных. Обсуждаются данные о роли РАС в развитии и прогрессии злокачественных новообразований в почках. В настоящей статье представлены обзор данных о роли РАС в возникновении и развитии ПКР, анализ молекулярных механизмов развития и прогрессирования ПКР, перспектив использования показателей РАС (ангиотензинпревращающих ферментов (АПФ), АПФ2 и рецепторов ангиотензина II) в качестве маркеров диагностики и мониторинга процессов неопластической трансформации в почке. Проанализированы перспективы использования новых, эффективных противоопухолевых препаратов с таргетным действием на отдельные показатели РАС при ПКР.
Infective and nonbacterial thrombotic endocarditis in patients with post-COVID-19 viral-immune myocarditis
The possibility of heart inflammation (both myocardial and endocardial) months after a coronavirus disease 2019 (COVID-19) has not been practically studied, especially since approaches to the treatment of myocarditis in combination with various endocarditis forms have not been developed.Aim. To study the prevalence and mechanisms of SARS-CoV-2-associated endocardial injury in patients with morphologically verified post-COVID-19 myocarditis, as well as to develop approaches to comprehensive therapy.Material and methods. The study included 18 patients with severe morphologically verified post-COVID-19 myocarditis (men, 9; 51,1±9,4 years; 35 to 66 years). Patients with prior verified myocarditis/myocardial infarction, rheumatic heart disease, and systemic immune diseases were excluded. The average time after COVID-19 was 6,5 [3.5; 10] months The diagnosis of myocarditis was confirmed by endomyocardial biopsy (including immunohistochemical examination with antibodies to CD3, CD20, CD45, CD68, and to SARS-CoV-2 antigens; polymerase chain reaction for SARS-CoV-2 RNA, DNA of cardiotropic viruses). The blood level of anticardiac antibodies was determined by indirect immunofluorescence. In addition, echocardiography, magnetic resonance imaging (n=8), cardiac multislice tomography (n=1), and coronary angiography (n=14) were performed.Results. Biopsy revealed active (n=12) and borderline (n=3) lymphocytic myocarditis, eosinophilic (n=2) and giant cell (n=1) myocarditis. In 4 patients, nonbacterial thrombotic endocarditis (NBTE) with parietal and intravascular thrombosis was diagnosed, and in one patient — infective endocarditis (IE) of the bicuspid aortic valve. Myocardial persistence of SARS-CoV-2 was detected in 72% of cases (in 3 patients — with NBTE; in 1 — with IE; in 9 — without endocarditis). Titers of anticardiac antibodies increased by 3-4 times in 94% of patients. Patients with endocarditis were characterized by larger heart chambers, lower ejection fraction (27,5±6,6 vs 36,0±13,4%), more severe pulmonary hypertension, and valvular regurgitation. Intraventricular thrombosis according to echocardiography/magnetic resonance imaging and cardiac embolism was not observed. Treatment in all patients included methylprednisolone at an average dose of 24 mg a day. In 10 patients, the result was monitored for at least 3 months as follows: the ejection fraction was 46,0±12,7% and 44,3±7,3% in patients with and without endocarditis, respectively.Conclusion. Endocarditis in patients with post-COVID-19 myocarditis was detected in 28% (1 patient — IE; 4 — NBTE). The key mechanisms of post-COVID-19 myocarditis and NBTE are long-term (up to 18 months) myocardial persistence of SARS-Cov-2 and the development of an autoimmune reaction. Endocarditis was diagnosed in more severe patients, including those with giant cell and eosinophilic myocarditis. The effectiveness of steroid therapy in combination with anticoagulants in patients with NBTE requires further study. In case of IE, steroids can also be used in the treatment of myocarditis (in combination with antibiotics and immunoglobulin)
The development and application of a new tool to assess the adequacy of the content and timing of antenatal care
Abstract
Background: Current measures of antenatal care use are limited to initiation of care and number of visits. This
study aimed to describe the development and application of a tool to assess the adequacy of the content and
timing of antenatal care.
Methods: The Content and Timing of care in Pregnancy (CTP) tool was developed based on clinical relevance for
ongoing antenatal care and recommendations in national and international guidelines. The tool reflects minimal
care recommended in every pregnancy, regardless of parity or risk status. CTP measures timing of initiation of care,
content of care (number of blood pressure readings, blood tests and ultrasound scans) and whether the
interventions were received at an appropriate time. Antenatal care trajectories for 333 pregnant women were then
described using a standard tool (the APNCU index), that measures the quantity of care only, and the new CTP tool.
Both tools categorise care into 4 categories, from ‘Inadequate’ (both tools) to ‘Adequate plus’ (APNCU) or
‘Appropriate’ (CTP). Participants recorded the timing and content of their antenatal care prospectively using diaries.
Analysis included an examination of similarities and differences in categorisation of care episodes between the
tools.
Results: According to the CTP tool, the care trajectory of 10,2% of the women was classified as inadequate, 8,4%
as intermediate, 36% as sufficient and 45,3% as appropriate. The assessment of quality of care differed significantly
between the two tools. Seventeen care trajectories classified as ‘Adequate’ or ‘Adequate plus’ by the APNCU were
deemed ‘Inadequate’ by the CTP. This suggests that, despite a high number of visits, these women did not receive
the minimal recommended content and timing of care.
Conclusions: The CTP tool provides a more detailed assessment of the adequacy of antenatal care than the
current standard index. However, guidelines for the content of antenatal care vary, and the tool does not at the
moment grade over-use of interventions as ‘Inappropriate’. Further work needs to be done to refine the content
items prior to larger scale testing of the impact of the new measure
Cytogenomic Profile of Uterine Leiomyoma: In Vivo vs. In Vitro Comparison
We performed a comparative cytogenomic analysis of cultured and uncultured uterine leiomyoma (UL) samples. The experimental approach included karyotyping, aCGH, verification of the detected chromosomal abnormalities by metaphase and interphase FISH, MED12 mutation analysis and telomere measurement by Q-FISH. An abnormal karyotype was detected in 12 out of 32 cultured UL samples. In five karyotypically abnormal ULs, MED12 mutations were found. The chromosomal abnormalities in ULs were present mostly by complex rearrangements, including chromothripsis. In both karyotypically normal and abnormal ULs, telomeres were ~40% shorter than in the corresponding myometrium, being possibly prerequisite to chromosomal rearrangements. The uncultured samples of six karyotypically abnormal ULs were checked for the detected chromosomal abnormalities through interphase FISH with individually designed DNA probe sets. All chromosomal abnormalities detected in cultured ULs were found in corresponding uncultured samples. In all tumors, clonal spectra were present by the karyotypically abnormal cell clone/clones which coexisted with karyotypically normal ones, suggesting that chromosomal abnormalities acted as drivers, rather than triggers, of the neoplastic process. In vitro propagation did not cause any changes in the spectrum of the cell clones, but altered their ratio compared to uncultured sample. The alterations were unique for every UL. Compared to its uncultured counterpart, the frequency of chromosomally abnormal cells in the cultured sample was higher in some ULs and lower in others. To summarize, ULs are characterized by both inter- and intratumor genetic heterogeneity. Regardless of its MED12 status, a tumor may be comprised of clones with and without chromosomal abnormalities. In contrast to the clonal spectrum, which is unique and constant for each UL, the clonal frequency demonstrates up or down shifts under in vitro conditions, most probably determined by the unequal ability of cells with different genetic aberrations to exist outside the body
Mathematical and Statistical Techniques for Systems Medicine: The Wnt Signaling Pathway as a Case Study
The last decade has seen an explosion in models that describe phenomena in
systems medicine. Such models are especially useful for studying signaling
pathways, such as the Wnt pathway. In this chapter we use the Wnt pathway to
showcase current mathematical and statistical techniques that enable modelers
to gain insight into (models of) gene regulation, and generate testable
predictions. We introduce a range of modeling frameworks, but focus on ordinary
differential equation (ODE) models since they remain the most widely used
approach in systems biology and medicine and continue to offer great potential.
We present methods for the analysis of a single model, comprising applications
of standard dynamical systems approaches such as nondimensionalization, steady
state, asymptotic and sensitivity analysis, and more recent statistical and
algebraic approaches to compare models with data. We present parameter
estimation and model comparison techniques, focusing on Bayesian analysis and
coplanarity via algebraic geometry. Our intention is that this (non exhaustive)
review may serve as a useful starting point for the analysis of models in
systems medicine.Comment: Submitted to 'Systems Medicine' as a book chapte
Accreting Millisecond X-Ray Pulsars
Accreting Millisecond X-Ray Pulsars (AMXPs) are astrophysical laboratories
without parallel in the study of extreme physics. In this chapter we review the
past fifteen years of discoveries in the field. We summarize the observations
of the fifteen known AMXPs, with a particular emphasis on the multi-wavelength
observations that have been carried out since the discovery of the first AMXP
in 1998. We review accretion torque theory, the pulse formation process, and
how AMXP observations have changed our view on the interaction of plasma and
magnetic fields in strong gravity. We also explain how the AMXPs have deepened
our understanding of the thermonuclear burst process, in particular the
phenomenon of burst oscillations. We conclude with a discussion of the open
problems that remain to be addressed in the future.Comment: Review to appear in "Timing neutron stars: pulsations, oscillations
and explosions", T. Belloni, M. Mendez, C.M. Zhang Eds., ASSL, Springer;
[revision with literature updated, several typos removed, 1 new AMXP added
Observation of associated near-side and away-side long-range correlations in √sNN=5.02 TeV proton-lead collisions with the ATLAS detector
Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02 TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1 μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos2Δϕ modulation for all ΣETPb ranges and particle pT
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