296 research outputs found
Infrared point source variability between the Spitzer and MSX surveys of the Galactic mid-plane
We present a list of 552 sources with suspected variability, based on a
comparison of mid-infrared photometry from the GLIMPSE I and MSX surveys, which
were carried out nearly a decade apart. We were careful to address issues such
as the difference in resolution and sensitivity between the two surveys, as
well as the differences in the spectral responses of the instruments. We
selected only sources where the IRAC 8.0 and MSX 8.28 micron fluxes differ by
more than a factor of two, in order to minimize contamination from sources
where the difference in fluxes at 8 micron is due to a strong 10 micron
silicate feature. We present a subset of 40 sources for which additional
evidence suggests variability, using 2MASS and MIPSGAL data. Based on a
comparison with the variability flags in the IRAS and MSX Point-Source Catalogs
we estimate that at least a quarter of the 552 sources, and at least half of
the 40 sources are truly variable. In addition, we tentatively confirm the
variability of one source using multi-epoch IRAS LRS spectra. We suggest that
most of the sources in our list are likely to be Asymptotic Giant Branch stars.Comment: 47 pages, 12 Figures, 3 Tables, accepted for publication in A
Palmitic Acid Sophorolipid Biosurfactant: From Self-Assembled Fibrillar Network (SAFiN) To Hydrogels with Fast Recovery
Nanofibers are an interesting phase into which amphiphilic molecules can
self-assemble. Described for a large number of synthetic lipids, they were
seldom reported for natural lipids like microbial amphiphiles, known as
biosurfactants. In this work, we show that the palmitic acid congener of
sophorolipids (SLC16:0), one of the most studied families of biosurfactants,
spontaneously forms a self-assembled fiber network (SAFiN) at pH below 6
through a pH jump process. pH-resolved in-situ Small Angle X-ray Scattering
(SAXS) shows a continuous micelle-to-fiber transition, characterized by an
enhanced core-shell contrast between pH 9 and pH 7 and micellar fusion into
flat membrane between pH 7 and pH 6, approximately. Below pH 6, homogeneous,
infinitely long nanofibers form by peeling off the membranes. Eventually, the
nanofiber network spontaneously forms a thixotropic hydrogel with fast recovery
rates after applying an oscillatory strain amplitude out of the linear
viscoelastic regime (LVER): after being submitted to strain amplitudes during 5
min, the hydrogel recovers about 80% and 100% of its initial elastic modulus
after, respectively, 20 s and 10 min. Finally, the strength of the hydrogel
depends on the medium's final pH, with an elastic modulus fivefold higher at pH
3 than at pH 6.Comment: Philosophical Transactions of the Royal Society of London. A
(1887--1895), Royal Society, The, In pres
Electrochemical Synthesis, Characterisation, and Preliminary Biological Evaluation of an Anodic Aluminium Oxide Membrane with a pore size of 100 nanometres for a Potential Cell Culture Substrate
Abstract In this study we investigate the electrochemical synthesis and characterisation of a nanometre scale porous anodic alumin iu m o xide (AAO) membranes with a mean pore diameter of 100 n m. The membranes exhib it interesting properties such as controllable pore diameters, periodicity and density distribution. These properties can be preselected by adjusting the controlling parameters of a temperature controlled two-step anodization process. The surface features of the nanometre scale memb rane such as pore density, pore diameter and inter-pore d istance were quantified using field emission scanning electron microscopy (FESEM) and ato mic fo rce microscopy (AFM). A preliminary bio logical evaluation of the memb ranes was carried out to determine cell adhesion and morphology using the Cercopithecus aethiops[African green monkey -(Vero)] kidney epithelial cell line. Optical microscopy, FESEM and AFM investigations revealed the presence of focal adhesion sites over the surface of the porous membranes. The positive outcomes of the study, indicates that AAO memb ranes can be used as a viable tissue scaffold for potential tissue engineering applications in the future
An evaluation of the use of paediatric X-ray imaging in public health centres within primary health care in Malta
INTRODUCTION: Despite the possible harms of ionising radiation,
guidelines for the use of X-rays in children are
not available locally. International guidelines are
also limited.AIM: The aim of this study was to evaluate all X-rays
taken in paediatric patients in Primary HealthCare
in Malta over a period of six months.METHOD: A list of all X-rays taken in children aged 0-16
years during the period of July 2020 till December
2020 in all publicly funded Primary HealthCare
health centres in Malta was compiled using the
Radiology Information System (RIS), Picture
Archiving and Communication System (PACS)
and iSOFT Clinical Manager (iCM). A form was
designed using Microsoft Excel® to facilitate
collection of data. Patient demographics were
collected, and data was evaluated for the type
of X-ray ordered, reason for request and source
of referral, as well as the result of the X-rays and
any subsequent follow-up organised.RESULTS: Over the six-month period studied, 1176 children
were referred for X-ray imaging with 1324 X-rays
being taken. These were mostly 13-16 years of
age, with the majority being male. Most patients
were referred by general practitioners working
in health centres, with X-rays of the upper
limb being the most ordered radiographs. The
commonest reason for requesting an X-ray was
a history of trauma. In total, 75.8% of X-rays
ordered were reported as normal. Only 4.3% of
all requests referred to existing guidelines. With
reference to lower limb X-rays, Ottawa rules were
referred to in 11.4% of X-ray requests, with 78.6%
of these being reported as normal. Follow-up
visits were planned for 34% of children referred
for X-ray.CONCLUSION: The results of this evaluation show that most
X-rays in the paediatric population were taken
in view of trauma, and approximately 75% of
all X-rays taken were normal. Educating doctors
about the use of judicial x-ray imaging and
development of local guidelines might help to
reduce unnecessary investigations.peer-reviewe
SERCA directs cell migration and branching across species and germ layers
Branching morphogenesis underlies organogenesis in vertebrates and invertebrates, yet is incompletely understood. Here, we show that the sarco-endoplasmic reticulum Ca2+ reuptake pump (SERCA) directs budding across germ layers and species. Clonal knockdown demonstrated a cell-autonomous role for SERCA in Drosophila air sac budding. Live imaging of Drosophila tracheogenesis revealed elevated Ca2+ levels in migratory tip cells as they form branches. SERCA blockade abolished this Ca2+ differential, aborting both cell migration and new branching. Activating protein kinase C (PKC) rescued Ca2+ in tip cells and restored cell migration and branching. Likewise, inhibiting SERCA abolished mammalian epithelial budding, PKC activation rescued budding, while morphogens did not. Mesoderm (zebrafish angiogenesis) and ectoderm (Drosophila nervous system) behaved similarly, suggesting a conserved requirement for cell-autonomous Ca2+ signaling, established by SERCA, in iterative budding
Breast Mass Characterization Using 3‐Dimensional Automated Ultrasound as an Adjunct to Digital Breast Tomosynthesis
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135628/1/jum201332193.pd
Healthcare costs and utilization for Medicare beneficiaries with Alzheimer's
<p>Abstract</p> <p>Background</p> <p>Alzheimer's disease (AD) is a neurodegenerative disorder incurring significant social and economic costs. This study uses a US administrative claims database to evaluate the effect of AD on direct healthcare costs and utilization, and to identify the most common reasons for AD patients' emergency room (ER) visits and inpatient admissions.</p> <p>Methods</p> <p>Demographically matched cohorts age 65 and over with comprehensive medical and pharmacy claims from the 2003–2004 MEDSTAT MarketScan<sup>® </sup>Medicare Supplemental and Coordination of Benefits (COB) Database were examined: 1) 25,109 individuals with an AD diagnosis or a filled prescription for an exclusively AD treatment; and 2) 75,327 matched controls. Illness burden for each person was measured using Diagnostic Cost Groups (DCGs), a comprehensive morbidity assessment system. Cost distributions and reasons for ER visits and inpatient admissions in 2004 were compared for both cohorts. Regression was used to quantify the marginal contribution of AD to health care costs and utilization, and the most common reasons for ER and inpatient admissions, using DCGs to control for overall illness burden.</p> <p>Results</p> <p>Compared with controls, the AD cohort had more co-morbid medical conditions, higher overall illness burden, and higher but less variable costs (10,369; Coefficient of variation = 181 vs. 324). Significant excess utilization was attributed to AD for inpatient services, pharmacy, ER visits, and home health care (all p < 0.05). In particular, AD patients were far more likely to be hospitalized for infections, pneumonia and falls (hip fracture, syncope, collapse).</p> <p>Conclusion</p> <p>Patients with AD have significantly more co-morbid medical conditions and higher healthcare costs and utilization than demographically-matched Medicare beneficiaries. Even after adjusting for differences in co-morbidity, AD patients incur excess ER visits and inpatient admissions.</p
New genetic loci implicated in fasting glucose homeostasis and their impact on type 2 diabetes risk.
Levels of circulating glucose are tightly regulated. To identify new loci influencing glycemic traits, we performed meta-analyses of 21 genome-wide association studies informative for fasting glucose, fasting insulin and indices of beta-cell function (HOMA-B) and insulin resistance (HOMA-IR) in up to 46,186 nondiabetic participants. Follow-up of 25 loci in up to 76,558 additional subjects identified 16 loci associated with fasting glucose and HOMA-B and two loci associated with fasting insulin and HOMA-IR. These include nine loci newly associated with fasting glucose (in or near ADCY5, MADD, ADRA2A, CRY2, FADS1, GLIS3, SLC2A2, PROX1 and C2CD4B) and one influencing fasting insulin and HOMA-IR (near IGF1). We also demonstrated association of ADCY5, PROX1, GCK, GCKR and DGKB-TMEM195 with type 2 diabetes. Within these loci, likely biological candidate genes influence signal transduction, cell proliferation, development, glucose-sensing and circadian regulation. Our results demonstrate that genetic studies of glycemic traits can identify type 2 diabetes risk loci, as well as loci containing gene variants that are associated with a modest elevation in glucose levels but are not associated with overt diabetes
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