24,738 research outputs found
The use of scintigraphy to identify and localize the mammary sentinel lymph nodes in female dogs: prognostic value
The article has no abstract.
Isokinetics strength relation with fear of fall, falls and physical activity level in elderly women
Introduction: Low levels of physical activity (PA) in elderly has been related with the decline in physical and psychological functions, affecting the ability in the performance of activities of daily living (ADLs) and contributing to the occurrence of walking-related fall (Metz, Lee, Sui, Powell, Blair, 2010). The purpose of this study was to relate strength levels with fear of fall (FF), falls occurrence as well as with PA level on elderly women.
Methods: One hundred not institutionalized post-menopausal women (aged 66.17 ± 8.21 years) volunteered to participate on this research. The peak torque (PT) at 60Âș.s-1 ( 3 rep) and 180Âș.s-1 (20 rep) angular speeds in knee extension and flexion concentric actions were measured using an isokinetic dynamometer (Biodex System 3). Muscular fatigue was also estimated at 180Âș.s-1. To achieve the occurrence of falls during last year as well FF score, we applied a standardized Questionnaire that included socio-demographic, health and falls parameters. PA level was accessed by interview with Yale Physical Activity Questionnaire.
Descriptive statistics was performed using means and standard deviations. The Spearman correlation coefficient was used to investigate associations among quantitative independent variables.
Results: PT at 60Âș.s-1 in knee extension and flexion and PT at 180Âș.s-1 in knee flexion showed a positive association with vigorous index (r=,205 p=,041; r=,249 p=,013; r=,218 p=,029 respectively). Standing index presented also a positive correlation with PT at 60Âș.s-1 and PT 180Âș.s-1 in knee extension (r=,205 p=,041 and r=,314 p=,004).
FF registered a positive association with body mass (BM) and body mass index (BMI) (r=,205 p=,041 and r=,201 p=,045), and a negative association with PT in extension action on both angular velocities (r=-,241 p=,016 and r=-,203 p=,043).
Muscular fatigue showed a positive correlation with the number of falls during the last year (r=,201 p=,036).
Conclusions: Decreases of strength on lower limb is an important factor that contributes to falls occurrence once we registered a negative relation between PT on extension action and the FF.
Our data related higher values of BM and BMI with higher fear of falling confirming that overweight are common associated to disturb on gait function and mobility that represents also a risk factor for falls.
Present results suggest that more time of PA is needed to increase lower limb strength in the elderly
Decoration of nanovesicles with pH (low) insertion peptide (pHLIP) for targeted delivery
Acidity at surface of cancer cells is a hallmark of tumor microenvironments, which does not depend on tumor perfusion, thus it may serve as a general biomarker for targeting tumor cells. We used the pH (low) insertion peptide (pHLIP) for decoration of liposomes and niosomes. pHLIP senses pH at the surface of cancer cells and inserts into the membrane of targeted cells, and brings nanomaterial to close proximity of cellular membrane. DMPC liposomes and Tween 20 or Span 20 niosomes with and without pHLIP in their coating were fully characterized in order to obtain fundamental understanding on nanocarrier features and facilitate the rational design of acidity sensitive nanovectors. The samples stability over time and in presence of serum was demonstrated. The size, ζ-potential, and morphology of nanovectors, as well as their ability to entrap a hydrophilic probe and modulate its release were investigated. pHLIP decorated vesicles could be useful to obtain a prolonged (modified) release of biological active substances for targeting tumors and other acidic diseased tissues
Sclerostin does not play a major role in the pathogenesis of skeletal complications in type 2 diabetes mellitus
In contrast to previously reported elevations in serum sclerostin levels in diabetic patients, the present study shows that the impaired bone microarchitecture and cellular turnover associated with type 2 diabetes mellitus (T2DM)-like conditions in ZDF rats are not correlated with changes in serum and bone sclerostin expression. INTRODUCTION: T2DM is associated with impaired skeletal structure and a higher prevalence of bone fractures. Sclerostin, a negative regulator of bone formation, is elevated in serum of diabetic patients. We aimed to relate changes in bone architecture and cellular activities to sclerostin production in the Zucker diabetic fatty (ZDF) rat. METHODS: Bone density and architecture were measured by micro-CT and bone remodelling by histomorphometry in tibiae and femurs of 14-week-old male ZDF rats and lean Zucker controls (n = 6/group). RESULTS: ZDF rats showed lower trabecular bone mineral density and bone mass compared to controls, due to decreases in bone volume and thickness, along with impaired bone connectivity and cortical bone geometry. Bone remodelling was impaired in diabetic rats, demonstrated by decreased bone formation rate and increased percentage of tartrate-resistant acid phosphatase-positive osteoclastic surfaces. Serum sclerostin levels (ELISA) were higher in ZDF compared to lean rats at 9 weeks (+40 %, p < 0.01), but this difference disappeared as their glucose control deteriorated and by week 14, ZDF rats had lower sclerostin levels than control rats (-44 %, p < 0.0001). Bone sclerostin mRNA (qPCR) and protein (immunohistochemistry) were similar in ZDF, and lean rats at 14 weeks and genotype did not affect the number of empty osteocytic lacunae in cortical and trabecular bone. CONCLUSION: T2DM results in impaired skeletal architecture through altered remodelling pathways, but despite altered serum levels, it does not appear that sclerostin contributes to the deleterious effect of T2DM in rat bone
LoCuSS: The steady decline and slow quenching of star formation in cluster galaxies over the last four billion years
We present an analysis of the levels and evolution of star formation activity
in a representative sample of 30 massive galaxy clusters at 0.15<z<0.30 from
the Local Cluster Substructure Survey (LoCuSS), combining wide-field Spitzer
24um data with extensive spectroscopy of cluster members. The specific-SFRs of
massive (M>10^10 M_sun) star-forming cluster galaxies within r200 are found to
be systematically 28% lower than their counterparts in the field at fixed
stellar mass and redshift, a difference significant at the 8.7-sigma level.
This is the unambiguous signature of star formation in most (and possibly all)
massive star-forming galaxies being slowly quenched upon accretion into massive
clusters, their SFRs declining exponentially on quenching time-scales in the
range 0.7-2.0 Gyr. We measure the mid-infrared Butcher-Oemler effect over the
redshift range 0.0-0.4, finding rapid evolution in the fraction (f_SF) of
massive (M_K3M_sun/yr, of the
form f_SF (1+z)^7.6. We dissect the origins of the Butcher-Oemler effect,
revealing it to be due to the combination of a ~3x decline in the mean
specific-SFRs of star-forming cluster galaxies since z~0.3 with a ~1.5x
decrease in number density. Two-thirds of this reduction in the specific-SFRs
of star-forming cluster galaxies is due to the steady cosmic decline in the
specific-SFRs among those field galaxies accreted into the clusters. The
remaining one-third reflects an accelerated decline in the star formation
activity of galaxies within clusters. The slow quenching of star-formation in
cluster galaxies is consistent with a gradual shut down of star formation in
infalling spiral galaxies as they interact with the intra-cluster medium via
ram-pressure stripping or starvation mechanisms. We find no evidence for the
build-up of cluster S0 bulges via major nuclear star-burst episodes.Comment: 24 pages, 12 figures. Accepted for publication in Ap
Alfvenic Heating of Protostellar Accretion Disks
We investigate the effects of heating generated by damping of Alfven waves on
protostellar accretion disks. Two mechanisms of damping are investigated,
nonlinear and turbulent, which were previously studied in stellar winds
(Jatenco-Pereira & Opher 1989a, b). For the nominal values studied, f=delta
v/v_{A}=0.002 and F=varpi/Omega_{i}=0.1, where delta v, v_{A} and varpi are the
amplitude, velocity and average frequency of the Alfven wave, respectively, and
Omega_{i} is the ion cyclotron frequency, we find that viscous heating is more
important than Alfven heating for small radii. When the radius is greater than
0.5 AU, Alfvenic heating is more important than viscous heating. Thus, even for
the relatively small value of f=0.002, Alfvenic heating can be an important
source of energy for ionizing protostellar disks, enabling angular momentum
transport to occur by the Balbus-Hawley instability.Comment: 21 pages, 9 figures. Accepted for publication in Ap
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