3,173 research outputs found
Development of dark Ti(C,O,N) coatings prepared by reactive sputtering
Accepted manuscriptDirect current reactive magnetron sputtering was implemented to successfully deposit dark Ti(C,O,N) thin films on silicon substrates. A titanium target was sputtered while a mixture of oxygen and nitrogen was injected into the deposition chamber, independently from an acetylene source. The deposition parameters were chosen as a function of pre-existing knowledge about sputtered Ti–O–N and Ti–C–O films. Tuning the oxygen/(nitrogen+carbon) ratio allowed obtaining a large spectrum of properties. In particular, the colour of the films was characterized by spectral reflectance spectroscopy, and expressed in the CIE 1976 L*a*b* colour space. An accurate control of the reactive gas mixture flow rate allowed obtaining intrinsic, stable and attractive dark colour for decorative applications. Surprisingly, the coatings with the lowest content of carbon
and the highest content of oxygen presented the darkest tones. Composition analysis by electron probe microanalysis was done to quantify the titanium and metalloid concentrations in the films. X-ray diffraction experiments revealed the evolution of the film structure from a fcc structure for the lowest (O2+N2) flow rates to an amorphous one for the highest flow rates.Fundação para a Ciência e Tecnologia (FCT) - SFRH/BPD/27114/2006 and
PTDC/CTM/69362/2006. CRUP (Acção
Integrada Luso-francesa No. F-2307). GRICES/CNRS collaboration
(Proc. 4.1.1 França
Relationship between 1,25-Dihydroxyvitamin D and Body Composition in Middle-Aged Sedentary Adults: The FIT-AGEING Study
Vitamin D deficiency is a worldwide health problem that, in addition to its well-known
negative effects on musculoskeletal health, has been related to a wide range of acute and chronic
age-related diseases. However, little is known about the association of body composition with the
active, hormonal form of vitamin D, 1,25-dihydroxyvitamin D plasma levels (1,25(OH)2D). Therefore,
the aim of this study was to investigate the association of 1,25(OH)2Dwith body composition including
lean and fat body mass as well as bone mineral density (BMD) in middle-aged sedentary adults. Atotal
of 73 (39 women) middle-aged sedentary adults (53.7 5.1 years old) participated in the current study.
We measured weight and height, and we used dual energy X-ray absorptiometry to measure lean body
mass, fat body mass and BMD. Body mass index (BMI), lean mass index (LMI), and fat mass index (FMI)
were calculated. 1,25(OH)2D was measured using a DiaSorin Liaison®immunochemiluminometric
analyzer. The results showed a negative association of 1,25(OH)2D with BMI, LMI and BMD
( = -0.274, R2 = 0.075, p = 0.019; = -0.268, R2 = 0.072, p = 0.022; and = -0.325, R2 = 0.105,
p = 0.005, respectively), which persisted after controlling for age and sex. No significant differences in
1,25(OH)2D across body weight status were observed after controlling for the same covariates. In
summary, our results suggest that 1,25(OH)2D could be negatively associated with BMI, LMI and
BMD whereas no association was found with FMI in middle-aged sedentary adultsA.D.-l.-O. is funded by the Spanish Ministry of Education (FPU15/03960). L.G.-M. is supported by
a fellowship from “la Caixa” Foundation (ID 100010434) and the fellowship code is LCF/BQ/PR19/11700007.
F.J.A.-G. is funded by the Spanish Ministry of Education (FPU14/04172), the University of Granada Plan Propio
de Investigación 2016-Excellence actions: Unit of Excellence on Exercise and Health (UCEES)-and Plan Propio de
Investigación 2018-Programa Contratos-Puente
Aislamiento de un extracto de BMP y estudio anatomopatológico del fenómeno de inducción ósea tras su implante en defectos óseos
El objetivo del presente trabajo fue determinar el potencial osteogénico de
la proteína morfogenética ósea (BMP) en la reparación de grandes defectos diafisarios.
Además, se investiga la acción coadyuvante de la fibronectina (FN). La BMP fue extraída
a partir de hueso cortical bovino. Se utilizaron un total de 108 ratas Sprague Dawley. En
cada animal, se resecó un segmento de diáfisis femoral de 1.5 cm, siendo inmovilizado el
defecto óseo con una aguja en omega. Se rellenó el defecto implantando 25 mg de BMP
con o sin 0.5 mg de FN en una cápsula de gelatina (36 animales en ambos grupos). Los
resultados se compararon con los obtenidos en otro grupo (36 animales) en el que sólo se
implantó FN que sirvió como grupo control. El proceso de reparación se evaluó mediante
métodos histológicos y ultraestructurales. La aparición del fenómeno de inducción ósea
con reconstrucción del defecto óseo fue mayor en el grupo con implante de BMP más FN
(23 animales, 64%) que en el grupo en el que sólo se implantó BMP (20 animales, 56%).
Ningún animal del grupo control manifestaba signos de inducción ósea.The aim of the present work was to evaluate the osteogenic potential of
Bone Morphogenetic Protein (BMP) for reparation of large segmental bone defects. In addition,
the coadjuvant efect of fibronectin (FN) was investigated. BMP was partially purified
from bovine cortical bone. A total of 108 Sprague Dawley rats were used in the experiment.
Diaphyseal segments of the femur (1.5 cm) were removed in each animal, manteinant
the bone defect with a wire. A gelatine capsula containing 25 mg of BMP without or
with 0.5 mg of FN, were implanted into the bone defect (36 animal in each group).
Results were compared to those obtained in a control group (36 animals) in which FN
alone was implanted. The bone repair process was assessed by histologic and ultrastructural
methods. Bone induction with reconstruction of the defect was found more of ten in
the group with both BMP and FN implanted (23 animals, 64%) than in the group with
BMP implant alone (20 animals, 56%). Animals of the control group showed no bone induction.
The results suggest that BMP augments the capacity of the host bed to sucessfully
regenerate large segmental bone defects. FN seens to increase bone induction. This
protein migth stabilize BMP locally improving contact between BMP and the surrounding
cells
Indicaciones Límite de las Fracturas de Húmero con Clavo Endomedular Cerrojado
El tratamiento de las fracturas diafisarias del húmero ha entrado en controversia
en los últimos años, como lo refleja la literatura internacional. La problemática
aumenta cuando se trata de fracturas diafisarias límites que alcanzan la zona metafisaria
superior e inferior. En un intento de mejora terapéutica este grupo de autores ha testado un
clavo cerrojado para el húmero diseñado por Seidel. El promedio de seguimiento ha sido de
12 meses con un mínimo de 6 meses. El número de casos evaluados ha sido 6. Siguiendo la
cotación de Stewart, 4 de los seis pacientes obtuvieron resultados buenos o excelentes. Todos
los pacientes consolidaron sus fracturas en un período de tiempo normal, entre 3 y 5 meses,
con una media de 4 meses, 4 de los seis pacientes no se inmovilizaron con yeso en ningún momento.
La bondad y sencillez del método hace augurar buenos resultados en otros grupos ampliando
sus indicaciones.Treatment of dyaphyseal fractures of the humerus has been the
source of considerable controversy in recent years. The problem increases in
dimension when one is dealing with limiting diaphyseal fractures that invole the
upper and lower metaphyseal zone. In an attempt to improve the therapy of this
circunstance, the members of this research team have tested a locking nail for the
humerus designed by Seidel. The mean follow-up time has been 12 months, with a
minimum of six months. The number of cases evaluated was 6. According to the
scale of Stewart, four of the cases obtained good or excellent results. All the patients
consolidated their fractures within a normal period of time -between 3 and 5
months-, with a mean of 4 months. Four of the 6 patients wer e not immobilized with
paster at any time. The goodness and simplicity of the method are suggestive of
promising results in other groups by broadening its indications
UWISH2 -- The UKIRT Widefield Infrared Survey for H2
We present the goals and preliminary results of an unbiased, near-infrared,
narrow-band imaging survey of the First Galactic Quadrant (10deg<l<65deg ;
-1.3deg<b<+1.3deg). This area includes most of the Giant Molecular Clouds and
massive star forming regions in the northern hemisphere. The survey is centred
on the 1-0S(1) ro-vibrational line of H2, a proven tracer of hot, dense
molecular gas in star-forming regions, around evolved stars, and in supernova
remnants. The observations complement existing and upcoming photometric surveys
(Spitzer-GLIMPSE, UKIDSS-GPS, JCMT-JPS, AKARI, Herschel Hi-GAL, etc.), though
we probe a dynamically active component of star formation not covered by these
broad-band surveys. Our narrow-band survey is currently more than 60% complete.
The median seeing in our images is 0.73arcsec. The images have a 5sigma
detection limit of point sources of K=18mag and the surface brightness limit is
10^-19Wm^-2arcsec^-2 when averaged over our typical seeing. Jets and outflows
from both low and high mass Young Stellar Objects are revealed, as are new
Planetary Nebulae and - via a comparison with earlier K-band observations
acquired as part of the UKIDSS GPS - numerous variable stars. With their
superior spatial resolution, the UWISH2 data also have the potential to reveal
the true nature of many of the Extended Green Objects found in the GLIMPSE
survey.Comment: 14pages, 8figures, 2tables, accepted for publication by MNRAS, a
version with higher resolution figures can be found at
http://astro.kent.ac.uk/~df
Calculation of The Band Gap Energy and Study of Cross Luminescence in Alkaline-Earth Dihalide Crystals
The band gap energy as well as the possibility of cross luminescence
processes in alkaline-earth dihalide crystals have been calculated using the ab
initio Perturbed-Ion (PI) model. The gap is calculated in several ways: as a
difference between one-electron energy eigenvalues and as a difference between
total energies of appropriate electronic states of the crystal, both at the HF
level and with inclusion of Coulomb correlation effects. In order to study the
possibility of ocurrence of cross luminescence in these materials, the energy
difference between the valence band and the upmost core band for some
representative crystals has been calculated. Both calculated band gap energies
and cross luminescence predictions compare very well with the available
experimental results.Comment: LaTeX file containing 8 pages plus 1 postscript figure. Final version
accepted for publication in The Journal of the Physical Society of Japan. It
contains a more complete list of references, as well as a more detailed
comparison with previous theoretical investigations on the subjec
Structure and chemical bonds in reactively sputtered black Ti–C–N–O thin films
The evolution of the nanoscale structure and the chemical bonds formed in Ti–C–N–O films grown by reactive sputtering were studied as a function of the composition of the reactive atmosphere by increasing the partial
pressure of an O2+N2 gas mixture from 0 up to 0.4 Pa, while that of acetylene (carbon source) was constant. The amorphisation of the films observed by transmission electron microscopy was confirmed by micro-
Raman spectroscopy, but it was not the only effect associated to the increase of the O2+N2 partial pressure. The chemical environment of titanium and carbon, analysed by X-ray photoemission spectroscopy, also
changes due to the higher affinity of Ti towards oxygen and nitrogen than to carbon. This gives rise to the appearance of amorphous carbon coexisting with poorly crystallized titanium oxynitride. The evolution of the films colour is explained on the basis of these structural changes.Fundação para a Ciência e a Tecnologia (FCT) - PTDC/CTM/69362/2006, SFRH/BPD/27114/2006CRUP (Acção Integrada Luso-francesa N° F-2307) and the GRICES/CNRS collaboration (Proc. 4.1.1 França
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