454 research outputs found
Infection Prevention and the Protective Effects of Unidirectional Displacement Flow Ventilation in the Turbulent Spaces of the Operating Room
Background: Unidirectional displacement flow (UDF) ventilation systems in operating rooms are characterized by a uniformity of velocity 80% and protect patients and operating room personnel against exposure to hazardous substances. However, the air below the surgical lights and in the surrounding zone is turbulent, which impairs the ventilation systemâs effect.
Aim: We first used the recovery time (RT) as specified in International Organization for Standardization 14644 to determine the particle reduction capacity in the turbulent spaces of an operating room with a UDF system. Methods: The uniformity of velocity was analyzed by comfort-level probe grid measurements in the protected area below a hemispherical closed-shaped and a semi-open column-shaped surgical light (tilt angles: 0/15/30) and in the surrounding zone of a research operating room. Thereafter, RTs were calculated.
Results: At a supply air volume of 10,500 m3/h, the velocity, reported as average uniformity+standard deviation, was uniform in the protected area without lights (95.8% + 1.7%), but locally turbulent below the hemispherical closedshaped (69.3% + 14.6%), the semi-open column-shaped light (66.9% + 10.9%), and in the surrounding zone (51.5%+17.6%). The RTs ranged between 1.1 and 1.7 min below the lights and 3.5+0.28 min in the surrounding zone and depended exponentially on the volume flow rate.
Conclusions: Compared to an RT of 20 min as required for operating rooms with mixed dilution flow, particles here were eliminated 12â18 times more quickly from below the surgical lights and 5.7 times from the surrounding zone. Thus, the effect of the lights was negligible and the UDFâs retained its strong protective effect
Sodium, renin, aldosterone, catecholamines, and blood pressure in diabetes mellitus
Sodium, renin, aldosterone, catecholamines, and blood pressure in diabetes mellitus. Interrelations among plasma renin activity (PRA), aldosterone and Cortisol levels, blood volume, exchangeable sodium, urinary catecholamines, and blood pressure were studied in 35 normal subjects and 60 age-matched non-azotemic patients with diabetes mellitus (60% with hypertension, 15% with orthostatic hypotension). Basal PRA, plasma aldosterone, cortisol, blood volume, plasma potassium, and urinary electrolytes were comparable in diabetic and normal subjects. Diabetic patients, however, had a 10% increase in body sodium (P < 0.01), and 8% of them showed normal postural PRA responses and subnormal aldosterone responses; 22% had subnormal PRA and normal aldosterone responses, and 17% had subnormal responses of PRA and aldosterone. Non-PRA-related aldosterone responses could not be explained by ACTH or electrolytes. Orthostatic decreases in blood pressure correlated (P < 0.01) with both catecholamine excretion and basal PRA. This suggests that in diabetes mellitus, body sodium is increased. Basal PRA and plasma aldosterone are usually normal, but their postural responses are frequently impaired. Absent aldosterone responses, despite normal PRA responsiveness, may reflect an adrenal abnormality or an ineffective form of renin. Marked postural aldosterone stimulation, unrelated to PRA, ACTH, or electrolytes, points to a potent unknown factor in aldosterone control. Low levels of free peripheral catecholamines and PRA may be complementary factors contributing to postural hypotension.Sodium, rĂ©nine, aldostĂ©rone, catĂ©cholamines et pression artĂ©rielle dans le diabĂštĂ© sucrĂ©. Les inter-relations entre l'activitĂ© rĂ©nine plasmatique (PRA), les concentrations d'aldostĂ©rone et de cortisol, le volume sanguin, le sodium Ă©changeable, les catĂ©cholamines urinaires et la pression artĂ©rielle ont Ă©tĂ© Ă©tudiĂ©es chez 35 sujets normaux et 60 malades atteints de diabĂ©tĂ©, sans insuffisance rĂ©nale et dont les Ăąges Ă©taient appariĂ©s (60% avaient une hypertension et 15% une hypotension orthostatique). La PRA de base, l'aldostĂ©rone et le Cortisol plasmatiques, le volume sanguin, le potassium plasmatique et les Ă©lectrolytes urinaires Ă©taient comparables chez les diabĂ©tiques et les sujets normaux. Les malades diabĂ©tiques, cependant, ont une augmentation de 10% de leur sodium corporel (P < 0,01). Huit pour cent d'entre eux ont une rĂ©ponse posturale de PRA normale et une rĂ©ponse de l'aldostĂ©rone infĂ©rieure Ă la normale, 22% ont une rĂ©ponse de PRA infĂ©rieure Ă la normale et une reponse de l'aldosterone normale, et 17% ont des rĂ©ponses de PRA et de l'aldostĂ©rone infĂ©rieures Ă la normale. Les rĂ©ponses de l'aldostĂ©rone sans rapport avec PRA ne peuvent pas ĂȘtre expliquĂ©es par l'ACTH ou les Ă©lectrolytes. Les diminutions de la pression artĂ©rielle liĂ©es Ă l'orthostatisme sont correlĂ©es (P < 0,01) Ă la fois avec l'excrĂ©tion de catĂ©cholamines et la PRA de base. Ceci suggĂ©re qu'au cours du diabĂ©te le sodium corporel est augmentĂ©. La PRA et l'aldosterone de base sont souvent normales mais leur rĂ©ponse posturale est souvent modifiĂ©e. L'absence de rĂ©ponse de l'aldosterone malgrĂ© une rĂ©ponse normale de PRA peut traduire une anomalie surrĂ©nale ou une forme de rĂ©nine inefficace. Une stimulation posturale importante de l'aldostĂ©rone non expliquĂ©e par la PRA, l'ACTH ou les Ă©lectrolytes oriente vers un facteur inconnu mais puissant du contrĂŽle de la sĂ©crĂ©tion d'aldostĂ©rone. Des concentrations basses de catĂ©cholamines libres et une PRA basse peuvent ĂȘtre des facteurs complĂ©mentaires qui participent Ă l'hypotension posturale
Sodium, renin, aldosterone, catecholamines, and blood pressure in diabetes mellitus
Sodium, renin, aldosterone, catecholamines, and blood pressure in diabetes mellitus. Interrelations among plasma renin activity (PRA), aldosterone and Cortisol levels, blood volume, exchangeable sodium, urinary catecholamines, and blood pressure were studied in 35 normal subjects and 60 age-matched non-azotemic patients with diabetes mellitus (60% with hypertension, 15% with orthostatic hypotension). Basal PRA, plasma aldosterone, cortisol, blood volume, plasma potassium, and urinary electrolytes were comparable in diabetic and normal subjects. Diabetic patients, however, had a 10% increase in body sodium (P < 0.01), and 8% of them showed normal postural PRA responses and subnormal aldosterone responses; 22% had subnormal PRA and normal aldosterone responses, and 17% had subnormal responses of PRA and aldosterone. Non-PRA-related aldosterone responses could not be explained by ACTH or electrolytes. Orthostatic decreases in blood pressure correlated (P < 0.01) with both catecholamine excretion and basal PRA. This suggests that in diabetes mellitus, body sodium is increased. Basal PRA and plasma aldosterone are usually normal, but their postural responses are frequently impaired. Absent aldosterone responses, despite normal PRA responsiveness, may reflect an adrenal abnormality or an ineffective form of renin. Marked postural aldosterone stimulation, unrelated to PRA, ACTH, or electrolytes, points to a potent unknown factor in aldosterone control. Low levels of free peripheral catecholamines and PRA may be complementary factors contributing to postural hypotension.Sodium, rĂ©nine, aldostĂ©rone, catĂ©cholamines et pression artĂ©rielle dans le diabĂštĂ© sucrĂ©. Les inter-relations entre l'activitĂ© rĂ©nine plasmatique (PRA), les concentrations d'aldostĂ©rone et de cortisol, le volume sanguin, le sodium Ă©changeable, les catĂ©cholamines urinaires et la pression artĂ©rielle ont Ă©tĂ© Ă©tudiĂ©es chez 35 sujets normaux et 60 malades atteints de diabĂ©tĂ©, sans insuffisance rĂ©nale et dont les Ăąges Ă©taient appariĂ©s (60% avaient une hypertension et 15% une hypotension orthostatique). La PRA de base, l'aldostĂ©rone et le Cortisol plasmatiques, le volume sanguin, le potassium plasmatique et les Ă©lectrolytes urinaires Ă©taient comparables chez les diabĂ©tiques et les sujets normaux. Les malades diabĂ©tiques, cependant, ont une augmentation de 10% de leur sodium corporel (P < 0,01). Huit pour cent d'entre eux ont une rĂ©ponse posturale de PRA normale et une rĂ©ponse de l'aldostĂ©rone infĂ©rieure Ă la normale, 22% ont une rĂ©ponse de PRA infĂ©rieure Ă la normale et une reponse de l'aldosterone normale, et 17% ont des rĂ©ponses de PRA et de l'aldostĂ©rone infĂ©rieures Ă la normale. Les rĂ©ponses de l'aldostĂ©rone sans rapport avec PRA ne peuvent pas ĂȘtre expliquĂ©es par l'ACTH ou les Ă©lectrolytes. Les diminutions de la pression artĂ©rielle liĂ©es Ă l'orthostatisme sont correlĂ©es (P < 0,01) Ă la fois avec l'excrĂ©tion de catĂ©cholamines et la PRA de base. Ceci suggĂ©re qu'au cours du diabĂ©te le sodium corporel est augmentĂ©. La PRA et l'aldosterone de base sont souvent normales mais leur rĂ©ponse posturale est souvent modifiĂ©e. L'absence de rĂ©ponse de l'aldosterone malgrĂ© une rĂ©ponse normale de PRA peut traduire une anomalie surrĂ©nale ou une forme de rĂ©nine inefficace. Une stimulation posturale importante de l'aldostĂ©rone non expliquĂ©e par la PRA, l'ACTH ou les Ă©lectrolytes oriente vers un facteur inconnu mais puissant du contrĂŽle de la sĂ©crĂ©tion d'aldostĂ©rone. Des concentrations basses de catĂ©cholamines libres et une PRA basse peuvent ĂȘtre des facteurs complĂ©mentaires qui participent Ă l'hypotension posturale
Low-energy quasiparticle excitations in dirty d-wave superconductors and the Bogoliubov-de Gennes kicked rotator
We investigate the quasiparticle density of states in disordered d-wave
superconductors. By constructing a quantum map describing the quasiparticle
dynamics in such a medium, we explore deviations of the density of states from
its universal form (), and show that additional low-energy
quasiparticle states exist provided (i) the range of the impurity potential is
much larger than the Fermi wavelength [allowing to use recently developed
semiclassical methods]; (ii) classical trajectories exist along which the
pair-potential changes sign; and (iii) the diffractive scattering length is
longer than the superconducting coherence length. In the classically chaotic
regime, universal random matrix theory behavior is restored by quantum
dynamical diffraction which shifts the low energy states away from zero energy,
and the quasiparticle density of states exhibits a linear pseudogap below an
energy threshold .Comment: 4 pages, 3 figures, RevTe
Spin and Charge Structure Factor of the 2-d Hubbard Model
The spin and charge structure factors are calculated for the Hubbard model on
the square lattice near half-filling using a spin-rotation invariant six-slave
boson representation. The charge structure factor shows a broad maximum at the
zone corner and is found to decrease monotonically with increasing interaction
strength and electron density and increasing temperature. The spin structure
factor develops with increasing interaction two incommensurate peaks at the
zone boundary and along the zone diagonal. Comparison with results of Quantum
Monte Carlo and variational calculations is carried out and the agreement is
found to be good. The limitations of an RPA-type approach are pointed out.Comment: 18 pages, revtex, 13 postscript figures, submitted to Phys. Rev.
The Evolution of Early-type Red Galaxies with the GEMS Survey: Luminosity-size and Stellar Mass-size Relations Since z=1
We combine HST/ACS imaging from the GEMS survey with redshifts and rest-frame
quantities from COMBO-17 to study the evolution of morphologically early-type
galaxies with red colors since z=1. We use a new large sample of 728 galaxies
with centrally-concentrated radial profiles (Sersic n>2.5) and rest-frame U-V
colors on the red sequence. By appropriate comparison with the local relations
from SDSS, we find that the luminosity-size (L-R) and stellar mass-size (M-R)
relations evolve in a manner that is consistent with the passive aging of
ancient stars. By itself, this result is consistent with a completely passive
evolution of the red early-type galaxy population. If instead, as demonstrated
by a number of recent surveys, the early-type galaxy population builds up in
mass by a factor of 2 since z=1, our results imply that new additions to the
early-type galaxy population follow similar L-R and M-R correlations, compared
to the older subset of early-type galaxies. Adding early-type galaxies to the
red sequence through disk fading appears to be consistent with the data.
Through comparison with models, the role of dissipationless merging is limited
to <1 major merger on average since z=1 for the most massive galaxies.
Predictions from models of gas-rich mergers are not yet mature enough to allow
a detailed comparison to our observations. We find tentative evidence that the
amount of luminosity evolution depends on galaxy stellar mass, such that the
least massive galaxies show stronger luminosity evolution compared to more
massive early types. This could reflect a different origin of low-mass
early-type galaxies and/or younger stellar populations; the present data is
insufficient to discriminate between these possibilities. (abridged)Comment: Submitted to ApJ, 23 pages, Latex using emulateapj5.sty and
onecolfloat.sty (included), 10 figures, version with full resolution figures
at http://www.astro.umass.edu/~dmac/Papers/ETevol.hires.p
The Digital Fish Library: Using MRI to Digitize, Database, and Document the Morphological Diversity of Fish
Museum fish collections possess a wealth of anatomical and morphological data that are essential for documenting and understanding biodiversity. Obtaining access to specimens for research, however, is not always practical and frequently conflicts with the need to maintain the physical integrity of specimens and the collection as a whole. Non-invasive three-dimensional (3D) digital imaging therefore serves a critical role in facilitating the digitization of these specimens for anatomical and morphological analysis as well as facilitating an efficient method for online storage and sharing of this imaging data. Here we describe the development of the Digital Fish Library (DFL, http://www.digitalfishlibrary.org), an online digital archive of high-resolution, high-contrast, magnetic resonance imaging (MRI) scans of the soft tissue anatomy of an array of fishes preserved in the Marine Vertebrate Collection of Scripps Institution of Oceanography. We have imaged and uploaded MRI data for over 300 marine and freshwater species, developed a data archival and retrieval system with a web-based image analysis and visualization tool, and integrated these into the public DFL website to disseminate data and associated metadata freely over the web. We show that MRI is a rapid and powerful method for accurately depicting the in-situ soft-tissue anatomy of preserved fishes in sufficient detail for large-scale comparative digital morphology. However these 3D volumetric data require a sophisticated computational and archival infrastructure in order to be broadly accessible to researchers and educators
The type II RAF inhibitor tovorafenib in relapsed/refractory pediatric low-grade glioma: the phase 2 FIREFLY-1 trial
\ua9 2023, The Author(s).BRAF genomic alterations are the most common oncogenic drivers in pediatric low-grade glioma (pLGG). Arm 1 (n = 77) of the ongoing phase 2 FIREFLY-1 (PNOC026) trial investigated the efficacy of the oral, selective, central nervous systemâpenetrant, type II RAF inhibitor tovorafenib (420 mg mâ2 once weekly; 600 mg maximum) in patients with BRAF-altered, relapsed/refractory pLGG. Arm 2 (n = 60) is an extension cohort, which provided treatment access for patients with RAF-altered pLGG after arm 1 closure. Based on independent review, according to Response Assessment in Neuro-Oncology High-Grade Glioma (RANO-HGG) criteria, the overall response rate (ORR) of 67% met the arm 1 prespecified primary endpoint; median duration of response (DOR) was 16.6 months; and median time to response (TTR) was 3.0 months (secondary endpoints). Other select arm 1 secondary endpoints included ORR, DOR and TTR as assessed by Response Assessment in Pediatric Neuro-Oncology Low-Grade Glioma (RAPNO) criteria and safety (assessed in all treated patients and the primary endpoint for arm 2, n = 137). The ORR according to RAPNO criteria (including minor responses) was 51%; median DOR was 13.8 months; and median TTR was 5.3 months. The most common treatment-related adverse events (TRAEs) were hair color changes (76%), elevated creatine phosphokinase (56%) and anemia (49%). Grade â„3 TRAEs occurred in 42% of patients. Nine (7%) patients had TRAEs leading to discontinuation of tovorafenib. These data indicate that tovorafenib could be an effective therapy for BRAF-altered, relapsed/refractory pLGG. ClinicalTrials.gov registration: NCT04775485
- âŠ