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To compare cognitive function among frail and prefrail older adults.
Cross-sectional clinical study.
Fifty-one non-institutionalized older individuals participated in this study.
Cognitive functions were evaluated through Mini-Mental State Examination (Global Cognition), Digit Span Forward (short-term memory), Digit Span Backward (working memory), Verbal Fluency Test (semantic memory/executive function). Data were compared using parametric and non-parametric bivariate tests. Binary logistic regression was used to test a frailty prediction model. Statistical significance was defined as p ≤ 0.01 to compare groups. In the regression model, the p value was set to be ≤0.05.
Statistically significant differences were observed in global cognition, and short-term memory between frail and prefrail individuals (p ≤ 0.01). Global cognition explained 14–19% of frailty's model.
According to our findings, the evaluation of cognitive functions among older persons with frailty and prefrailty provides important complementary information to better manage frailty and its progression.
The effect of heavy metal in fish has been the focus of extensive research for many years. However, the combined effect of heavy metals and nanomaterials is still a new subject that needs to be studied. The aim of this study was to examine histopathologic alterations in the gills of Nile tilapia (Oreochromis niloticus) to determine possible effects of lead (Pb), carbon nanotubes, and Pb+carbon nanotubes on their histological integrity, and if this biological system can be used as a tool for evaluating water quality in monitoring programs. For this, tilapia were exposed to Pb, carbon nanotubes and Pb+carbon nanotubes for 4 days. The main alterations observed were epithelial structure, hyperplasia and displacement of epithelial cells, and alterations of the structure and occurrence of aneurysms in the secondary lamella. The most severe alterations were related to the Pb+carbon nanotubes. We conclude that the oxidized multi-walled carbon nanotubes enhanced the acute lead toxicity in Nile tilapias. This work draws attention to the implications of carbon nanomaterials released in the aquatic environment and their interaction with classical pollutants.
Patients with a deletion at chromosome 22q11.2 (22q11DS) have 30% lifetime risk of developing a psychosis. People fulfilling clinical criteria for ultra-high risk (UHR) for psychosis have 30% risk of developing a psychosis within 2 years. Both high-risk groups show white-matter (WM) abnormalities in microstructure and volume compared to healthy controls (HC), which have been related to psychotic symptoms. Comparisons of WM pathology between these two groups may specify WM markers related to genetic and clinical risk factors.
Fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD) and mean diffusivity (MD) were assessed using diffusion tensor magnetic resonance imaging (MRI), and WM volume with structural MRI, in 23 UHR patients, 21 22q11DS patients, and 33 HC.
Compared to UHR patients 22q11DS patients had (1) lower AD and RD in corpus callosum (CC), cortical fasciculi, and anterior thalamic radiation (ATR), (2) higher FA in CC and ATR, and (3) lower occipital and superior temporal gyrus WM volume. Compared to HC, 22q11DS patients had (1) lower AD and RD throughout cortical fasciculi and (2) higher FA in ATR, CC and inferior fronto-occipital fasciculus. Compared to HC, UHR patients had (1) higher mean MD, RD, and AD in CC, ATR and cortical fasciculi, (2) no differences in FA.
UHR and 22q11DS patients share a susceptibility for developing psychosis yet were characterized by distinct patterns of WM alterations relative to HC. While UHR patients were typified by signs suggestive of aberrant myelination, 22q11DS subjects showed signs suggestive of lower axonal integrity.
We examined whether culturing embryos with linoleic acid (LA) in semi-defined medium reduces lipid accumulation and improves cryosurvival after vitrification. Embryos were cultured with LA (100 μM) and a semi-defined medium was used during in vitro culture (IVC), in which the fetal calf serum was substituted by bovine serum albumin (BSA). There was a reduction (P < 0.05) in the embryonic development rate (Control: 25.8% versus LA: 18.5%), but the proposed system was effective in promoting the decrease (P = 0.0130) in the intracellular lipid content (Control: 27.3 ± 0.7 versus LA: 24.6 ± 0.7 arbitrary fluorescence units of embryos stained with the fluorescent dye Nile Red), consequently increasing (P = 0.0490) the embryo survival after 24h of culture post-warming (Control: 50.0% versus LA: 71.7%). The results question the criteria used to evaluate the efficiency of an in vitro production system specifically with relation to the maximum number of blastocysts produced and suggest that might be more appropriate to improve the desired characteristics of embryos generated in accordance with the specific purpose of in vitro embryo production, commercial or scientific. In conclusion, supplying LA to serum-free culture medium was found to adversely affect the rates of embryo development to the blastocyst stage, but significantly reduced embryo lipid accumulation and improved cryopreservation survival.
To better understand the differences between coronal cloud prominences and channel prominences, we systematically identified and analyzed coronal cloud prominences recorded in SDO/AIA images at 304 Å from 2010 May 20 through 2012 April 28. For the 225 cases identified, their numbers vary directly with the sunspot number. Their durations are typically less than 3 days. Their most frequent maximum height is 90,000 + and - 10,000 km. We offer our hypothesis that many coronal cloud prominences originate from some of the mass of previously erupted filaments ejected high out of their filament channels; subsequently part of this mass falls and collects in leaky magnetic troughs among coronal magnetic fields which constrain the leaked mass to slowly drain downward along curved trajectories where it appears as coronal rain. Currently there is inadequate evidence for a convincing correspondence between either coronal cloud prominences or channel prominences with stellar prominences detected to date.
We describe the preliminary design of a magnetograph and visible-light imager instrument to study the solar dynamo processes through observations of the solar surface magnetic field distribution. The instrument will provide measurements of the vector magnetic field and of the line-of-sight velocity in the solar photosphere. As the magnetic field anchored at the solar surface produces most of the structures and energetic events in the upper solar atmosphere and significantly influences the heliosphere, the development of this instrument plays an important role in reaching the scientific goals of The Atmospheric and Space Science Coordination (CEA) at the Brazilian National Institute for Space Research (INPE). In particular, the CEA's space weather program will benefit most from the development of this technology. We expect that this project will be the starting point to establish a strong research program on Solar Physics in Brazil. Our main aim is acquiring progressively the know-how to build state-of-the-art solar vector magnetograph and visible-light imagers for space-based platforms to contribute to the efforts of the solar-terrestrial physics community to address the main unanswered questions on how our nearby Star works.
During the last years carbon-based nanostructures (such as, fullerenes, carbon nanotubes and graphene) have been object of intense investigations. The great interest in these nanostructures can be attributed to their remarkable electrical and mechanical properties. Their inorganic equivalent structures do exist and are based on boron nitride (BN) motifs. BN fullerenes, nanotubes and single layers have been already synthesized. Recently, the fracture patterns of single layer graphene and multi-walled carbon nanotubes under stress have been studied by theoretical and experimental methods. In this work we investigated the fracturing process of defective carbon and boron nitride nanotubes under similar stress conditions. We have carried out fully atomistic molecular reactive molecular dynamics simulations using the ReaxFF force field. The similarities and differences between carbon and boron nitride fracture patterns are addressed.
In this work we report the structural and optical properties of ion implanted GaN. Potential acceptors such as Ca and Er were used as dopants. Ion implantation was carried out with the substrate at room temperature and 550 °C, respectively. The lattice site location of the dopants was studied by Rutherford backscattering/channeling combined with particle induced X-ray emission. Angular scans along both  and  directions show that 50% of the Er ions implanted at 550 oC occupy substitutional or near substitutional Ga sites after annealing. For Ca we found only a fraction of 30% located in displaced Ga sites along the  direction. The optical properties of the ion implanted GaN films have been studied by photoluminescence measurements. Er- related luminescence near 1.54 μm is observed under below band gap excitation at liquid helium temperature. The spectra of the annealed samples consist of multiline structures with the sharpest lines found in GaN until now. The green and red emissions were also observed in the Er doped samples after annealing.
In this work we report the structural and optical properties of ion
implanted GaN. Potential acceptors such as Ca and Er were used as dopants.
Ion implantation was carried out with the substrate at room temperature and
550 °C, respectively. The lattice site location of the dopants was studied
by Rutherford backscattering/channeling combined with particle induced X-ray
emission. Angular scans along both  and  directions show that
50% of the Er ions implanted at 550 °C occupy substitutional or near
substitutional Ga sites after annealing. For Ca we found only a fraction of
30% located in displaced Ga sites along the  direction. The optical
properties of the ion implanted GaN films have been studied by
photoluminescence measurements. Er- related luminescence near 1.54 µm is
observed under below band gap excitation at liquid helium temperature. The
spectra of the annealed samples consist of multiline structures with the
sharpest lines found in GaN until now. The green and red emissions were also
observed in the Er doped samples after annealing.
Single crystalline colorless α-Al2O3 samples were
implanted with several fluences of Fe+ ions in the range of
1×1016 to 5×1017 Fe+ cm-2 at
room temperature. Optical absorption and luminescence measurements were
carried out before and after annealing in reducing and oxidizing
atmospheres. The structural changes were studied with RBS/channeling and
x-ray diffraction. After implantation, the damage induces a brownish
coloration in the samples for fluences below 2×1017
Fe+ cm-2. The optical spectra are characterized by
an absorption band centered at 200 nm. This band is strongly reduced after
annealing at 1100 °C in reducing atmosphere and a new well-defined band
develops around 350 nm. This new band shifts to lower values with the
implanted fluence, which is an indication of its correlation with the
dimensions of the iron precipitates formed in the implanted region. The
existence of these precipitates was confirmed by x-ray diffraction and TEM.
The samples implanted with fluences above 1×1016 Fe+
cm-2 annealed in oxidizing atmosphere display different
optical absorption spectra, with respect to those annealed in reducing
atmosphere, characterized by an increase in the intensity of the peak at 200
nm. Luminescence measurements show the presence of F and F+
centers in the samples. The existence of these defects can be explained by
the need of charge compensation and strain release due to the formation of
mixed iron oxide or metallic precipitates.
The thermal stability of ion irradiated 1.7 μm thick AZ-1350J photoresist films was investigated using the RBS and ERDA techniques to measure the composition of the irradiated and annealed films. The films have been irradiated with He, N and Ar ions at energies from 380 to 760 keV and fluences between 2 × 1015 and 1016 ions cm−2. A considerable increase in the thermal stability of the He irradiated film is observed from ≈200°C – when the non-irradiated film starts to decompose – to 400°C after the irradiation. The FTIR spectroscopy and the SEM observations were used to study the chemical structural changes and the surface morphology of the irradiated samples. The results are discussed in terms of the energy density deposited by the ions, the large loss of H during irradiation, and the resulting increase in cross-linking density.
An aspartic proteinase precursor, herein named BYC
(Boophilus Yolk pro-Cathepsin) was isolated from eggs of the hard
tick, Boophilus microplus. As judged by electrophoresis on sodium
dodecyl sulfate polyacrylamide slab gel (SDS–PAGE),
purified BYC presented 2 bands of 54 and 49 kDa, bearing the same
NH2-terminal amino acid sequence. By Western blot
analysis, BYC was also found in the haemolymph, indicating an extraovarian
site of synthesis. Several organs were incubated in culture medium with
[35S] methionine, and only the gut and fat body
showed synthesis of BYC polypeptides.
Protein sequencing of both the NH2-terminal and an internal
sequence obtained after cyanogen bromide (CNBr) cleavage
of BYC revealed homology with several aspartic proteinase precursors.
Incubation at pH 3·5 resulted in autoproteolysis of
BYC, which produced the mature form of the enzyme, that displayed
pepstatin-sensitive hydrolytic activity against
haemoglobin. Western blot analysis using anti-BYC monoclonal antibodies
showed proteolytic processing of BYC during
embryogenesis and suggested activation of the enzyme during development.
role of BYC in degradation of vitellin, the
major yolk protein of tick eggs, is discussed.
Single-crystal sapphire (α–Al2O3) was implanted at room temperature with 200 keV erbium ions to a fluence of 8 × 1013 cm–2. Ion channeling using 1.6 MeV He+ shows that the crystal suffers little damage for this low dose implant. Angular scans through axial and planar directions in the crystal indicate that 70% of the Er atoms reside on displaced octahedral sites in the α–Al2O3 lattice. As pure Al2O3 has a high density of free octahedral sites, this explains why high concentrations of Er can be dissolved in this material. Smaller fractions of Er are found on tetrahedral (20%) and random (10%) sites. The samples exhibit strongly peaked photoluminescence spectra around 1.5 μm, due to intra-4f transitions in Er3+, indicating the existence of well-defined sites for the luminescing Er3+ ions. It is concluded that the octahedral site is the dominating optically active site in the lattice.
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