1,660 research outputs found
Myocardial injury associated with coronavirus disease 2019 in pregnancy.
OBJECTIVE:Coronavirus disease 2019 (COVID-19) is associated with cardiac injury1-3 and bradycardia4 in the non-pregnant population. The incidence of these complications in pregnancy is unknown. The objective of this study was to determine the rate of abnormal serum cardiac biomarkers or bradycardia among pregnant and immediately postpartum women admitted for treatment of severe or critical COVID-19 in a large integrated health system in New York. STUDY DESIGN:This is a retrospective review of all pregnant and immediately postpartum women hospitalized for COVID-19 at 7 hospitals within Northwell Health, the largest academic health system in New York state, from March 1 to April 30, 2020. Women who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by polymerase chain reaction (PCR) assay and who met the National Institute of Health (NIH) criteria for severe or critical illness5 were included. Women with a positive PCR test who were admitted for a reason other than treatment of COVID-19 (eg, labor) were excluded. The Northwell Health Institutional Review Board approved the study as minimal-risk research using data collected for routine clinical practice and waived the requirement for informed consent. Clinical records were manually reviewed. Data collected included demographics, medical comorbidities, pregnancy characteristics, laboratory and imaging results, medications administered, and clinical outcomes. Laboratory and imaging studies were ordered at the discretion of the attending physician. The primary outcomes evaluated were elevated cardiac troponins (I, T, or high sensitivity), elevated brain natriuretic peptide (BNP), bradycardia (defined as \u3c 60 beats per minute, bpm), and maternal heart rate (HR) nadir. Descriptive statistics were used to characterize the data. RESULTS:A total of 31 women met inclusion criteria; 20 (65%) had cardiac biomarkers measured during hospitalization (Table). Cardiac troponins and BNP were elevated in 22% (n=4/18) and 30% (n=3/10) of these patients, respectively. Four patients had transthoracic echocardiograms performed and all were reported as normal. No patients had preexisting cardiovascular disease or hypertension. Two maternal mortalities in this cohort were previously reported;6 both patients had elevated cardiac troponins and one also had an elevated BNP. The nadir HR ranged from 30-92 bpm and bradycardia occurred in one-third of patients (n=10/31). Half of women with elevated troponin and three-fourths of women with elevated BNP had an episode of bradycardia recorded during their hospital course. CONCLUSION:Myocardial injury as demonstrated by abnormal cardiac biomarkers and bradycardia may be common among pregnant women with severe or critical COVID-19. In this study, one-fifth of patients who had troponin levels measured were found to have elevations (one-eighth of the overall study population). Among patients who had brain natriuretic peptide levels measured, 30% were elevated (10% of the overall study population). One third of women had bradycardia. This study is limited by a small sample size. Laboratory testing and imaging was not uniform due to the retrospective nature of the study. Sampling bias was unavoidable because the decision to measure cardiac markers or perform imaging studies was made by the patient\u27s care team, based on clinical presentation rather than a formal protocol. Few studies have evaluated the risk of cardiac injury or arrhythmia among pregnant women with COVID-19. It is also unknown whether there are long-term sequelae that affect maternal health or future pregnancy outcomes. This is an important area of focus for future research
Studying the stability of equilibrium solutions in the planar circular restricted four-body problem
The Newtonian circular restricted four-body problem is considered.We have obtained nonlinear algebraic equations, determining equilibrium solutions in the rotating frame, and found six possible equilibrium configurations of the system. Studying the stability of equilibrium solutions, we have proved that the radial equilibrium solutions are unstable while the bisector equilibrium solutions are stable in Liapunov’s sense if the mass parameter μ belongs (0, μ0), where μ0 is 0 a sufficiently small number, and μ ≠ μj , j = 1, 2, 3. We have also proved that for μ = μ1 and μ = μ3 the resonance conditions of the third and the fourth orders, respectively, are fulfilled and for these values of μ the bisector equilibrium are unstable and stable in Liapunov’s sense, respectively. All symbolic and numerical calculations are done with the computer algebra system Mathematica.Розглядається кругова зрiзана проблема ньютонiвської динамiки для чотирьох тiл. Отримано нелiнiйнi алгебраїчнi рiвняння, що визначають рiвноважнi розв’язки вiдносно обертаючої системи вiдлiку, та знайдено шiсть рiвноважних конфiгурацiй системи. При вивченнi стiйкостi рiвноважних розв’язкiв доведено, що радiальнi рiвноважнi розв’язки є нестiйкими, проте бiсекторнi рiвноважнi розв’язки є стiйкими за Ляпуновим, якщо параметр маси μ належить (0, μ0), де μ0 - досить мале число, і μ ≠ μj , j = 1, 2, 3. Також доведено, що для μ = μ1 та μ = μ3 умови резонансу вiдповiдно третього та четвертого порядкiв виконано, iдля цих значень µ бiсекторнi рiвноважнi розв’язки є вiдповiдно нестiйкими та стiйкими за Ляпуновим. Усi символьнi та числовi обчислення виконано за допомогою системи комп’ютерної алгебри "Математика"
Cholinergic signals preserve haematopoietic stem cell quiescence during regenerative haematopoiesis.
The sympathetic nervous system has been evolutionary selected to respond to stress and activates haematopoietic stem cells via noradrenergic signals. However, the pathways preserving haematopoietic stem cell quiescence and maintenance under proliferative stress remain largely unknown. Here we found that cholinergic signals preserve haematopoietic stem cell quiescence in bone-associated (endosteal) bone marrow niches. Bone marrow cholinergic neural signals increase during stress haematopoiesis and are amplified through cholinergic osteoprogenitors. Lack of cholinergic innervation impairs balanced responses to chemotherapy or irradiation and reduces haematopoietic stem cell quiescence and self-renewal. Cholinergic signals activate α7 nicotinic receptor in bone marrow mesenchymal stromal cells leading to increased CXCL12 expression and haematopoietic stem cell quiescence. Consequently, nicotine exposure increases endosteal haematopoietic stem cell quiescence in vivo and impairs hematopoietic regeneration after haematopoietic stem cell transplantation in mice. In humans, smoking history is associated with delayed normalisation of platelet counts after allogeneic haematopoietic stem cell transplantation. These results suggest that cholinergic signals preserve stem cell quiescence under proliferative stress
Thermodynamics and dynamics of the formation of spherical lipidic vesicles
We propose a free energy expression accounting for the formation of spherical
vesicles from planar lipidic membranes and derive a Fokker-Planck equation for
the probability distribution describing the dynamics of vesicle formation. We
found that formation may occur as an activated process for small membranes and
as a transport process for sufficiently large membranes. We give explicit
expressions for the transition rates and the characteristic time of vesicle
formation in terms of the relevant physical parameters.Comment: 14pgs, 6 figures, sendo to Jour. Phys. Bio
Bottom Production
We review the prospects for bottom production physics at the LHC.Comment: 74 pages, Latex, 71 figures, to appear in the Report of the ``1999
CERN Workshop on SM physics (and more) at the LHC'', P. Nason, G. Ridolfi, O.
Schneider G.F. Tartarelli, P. Vikas (conveners
Respiratory syncytial virus: diagnosis, prevention and management.
Respiratory syncytial virus (RSV) is responsible for a large burden of disease globally and can present as a variety of clinical syndromes in children of all ages. Bronchiolitis in infants under 1 year of age is the most common clinical presentation hospitalizing 24.2 per 1000 infants each year in the United Kingdom. RSV has been shown to account for 22% of all episodes of acute lower respiratory tract infection in children globally. RSV hospitalization, that is, RSV severe disease, has also been associated with subsequent chronic respiratory morbidity. Routine viral testing in all children is not currently recommended by the United Kingdom National Institute for Health and Care Excellence (NICE) or the American Academy of Pediatrics (AAP) guidance and management is largely supportive. There is some evidence for the use of ribavirin in severely immunocompromised children. Emphasis is placed on prevention of RSV infection through infection control measures both in hospital and in the community, and the use of the RSV-specific monoclonal antibody, palivizumab, for certain high-risk groups of infants. New RSV antivirals and vaccines are currently in development. Ongoing work is needed to improve the prevention of RSV infection, not only because of the acute morbidity and mortality, but also to reduce the associated chronic respiratory morbidity after severe infection
Metadata for ATLAS
This document provides an overview of the metadata, which are needed to characterize ATLAS event data at different levels (a complete run, data streams within a run, luminosity blocks within a run, individual events)
The ATLAS SCT grounding and shielding concept and implementation
This paper presents a complete description of Virgo, the French-Italian gravitational wave detector. The detector, built at Cascina, near Pisa (Italy), is a very large Michelson interferometer, with 3 km-long arms. In this paper, following a presentation of the physics requirements, leading to the specifications for the construction of the detector, a detailed description of all its different elements is given. These include civil engineering infrastructures, a huge ultra-high vacuum (UHV) chamber (about 6000 cubic metres), all of the optical components, including high quality mirrors and their seismic isolating suspensions, all of the electronics required to control the interferometer and for signal detection. The expected performances of these different elements are given, leading to an overall sensitivity curve as a function of the incoming gravitational wave frequency. This description represents the detector as built and used in the first data-taking runs. Improvements in different parts have been and continue to be performed, leading to better sensitivities. These will be detailed in a forthcoming paper
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