7 research outputs found
Design and experimental validation of a magnetic device for stem cell culture
Cell culture of bone and tendon tissues requires mechanical stimulation of the cells in order to mimic their physiological state. In the present work, a device has been conceived and developed to generate a controlled magnetic field with a homogeneous gradient in the working space. The design requirement was to maximize the magnetic flux gradient, assuring a minimum magnetizing value in a 15 mm Ă 15 mm working area, which highly increases the normal operating range of this sort of devices. The objective is to use the machine for two types of biological tests: magnetic irradiation of biological samples and force generation on paramagnetic particles embedded in scaffolds for cell culture. The device has been manufactured and experimentally validated by evaluating the force exerted on magnetic particles in a viscous fluid. Apart from the magnetic validation, the device has been tested for irradiating biological samples. In this case, viability of human dental pulp stem cells has been studied in vitro after electromagnetic field exposition using the designed device. After three days of irradiation treatment, cellular microtissues showed a 59% increase in the viable cell number. Irradiated cells did not show morphological differences when compared with control cells
Bioactive potential of silica coatings and its effect on the adhesion of proteins to titanium implants
There is an ever-increasing need to develop dental implants with ideal characteristics to achieve specific and desired biological response in the scope of improve the healing process post-implantation. Following that premise, enhancing and optimizing titanium implants through superficial treatments, like silica sol-gel hybrid coatings, are regarded as a route of future research in this area. These coatings change the physicochemical properties of the implant, ultimately affecting its biological characteristics. Sandblasted acid-etched titanium (SAE-Ti) and a silica hybrid sol-gel coating (35M35G30T) applied onto the Ti substrate were examined. The results of in vitro and in vivo tests and the analysis of the protein layer adsorbed to each surface were compared and discussed.
In vitro analysis with MC3T3-E1 osteoblastic cells, showed that the sol-gel coating raised the osteogenic activity potential of the implants (the expression of osteogenic markers, the alkaline phosphatase (ALP) and IL-6 mRNAs, increased). In the in vivo experiments using as model rabbit tibiae, both types of surfaces promoted osseointegration. However, the coated implants demonstrated a clear increase in the inflammatory activity in comparison with SAE-Ti. Mass spectrometry (LCâMS/MS) analysis showed differences in the composition of protein layers formed on the two tested surfaces. Large quantities of apolipoproteins were found attached predominantly to SAE-Ti. The 35M35G30T coating adsorbed a significant quantity of complement proteins, which might be related to the material intrinsic bioactivity, following an associated, natural and controlled immune response.
The correlation between the proteomic data and the in vitro and in vivo outcomes is discussed on this experimental work
Fat modification in afuegalâl pitu cheese during ripening by capillary gas chromatography
Osseointegration mechanisms: a proteomic approach
The prime objectives in the development of biomaterials for dental applications are to improve the quality of osseointegration
and to short the time needed to achieve it. Design of implants nowadays involves changes in the surface characteristics to
obtain a good cellular response. Incorporating osteoinductive elements is one way to achieve the best regeneration possible
post-implantation. This study examined the osteointegrative potential of two distinct biomaterials: sandblasted acid-etched
titanium and a silica solâgel hybrid coating, 70% MTMOS-30% TEOS. In vitro, in vivo, and proteomic characterisations of
the two materials were conducted. Enhanced expression levels of ALP and IL-6 in the MC3T3-E1 cells cultured with coated
discs, suggest that growing cells on such surfaces may increase mineralisation levels. 70M30T-coated implants showed
improved bone growth in vivo compared to uncoated titanium. Complete osseointegration was achieved on both. However,
coated implants displayed osteoinductive properties, while uncoated implants demonstrated osteoconductive characteristics.
Coagulation-related proteins attached predominantly to SAE-Ti surface. Surface properties of the material might drive the
regenerative process of the affected tissue. Analysis of the proteins on the coated dental implant showed that few proteins
specifically attached to its surface, possibly indicating that its osteoinductive properties depend on the silicon delivery from
the implant
The miniJPAS survey: a preview of the Universe in 56 colours
International audienceThe Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) will soon start to scan thousands of square degrees of the northern extragalactic sky with a unique set of optical filters from a dedicated m telescope, JST, at the Javalambre Astrophysical Observatory. Before the arrival of the final instrument (a 1.2 Gpixels, 4.2deg field-of-view camera), the JST was equipped with an interim camera (JPAS-Pathfinder), composed of one CCD with a 0.3deg field-of-view and resolution of 0.23 arcsec pixel. To demonstrate the scientific potential of J-PAS, with the JPAS-Pathfinder camera we carried out a survey on the AEGIS field (along the Extended Groth Strip), dubbed miniJPAS. We observed a total of deg, with the J-PAS filters, which include narrow band (NB, Angstrom) and two broader filters extending to the UV and the near-infrared, complemented by the SDSS broad band (BB) filters. In this paper we present the miniJPAS data set, the details of the catalogues and data access, and illustrate the scientific potential of our multi-band data. The data surpass the target depths originally planned for J-PAS, reaching between and for the NB filters and up to for the BB filters ( in a ~arcsec aperture). The miniJPAS primary catalogue contains more than sources extracted in the detection band with forced photometry in all other bands. We estimate the catalogue to be complete up to for point-like sources and up to for extended sources. Photometric redshifts reach subpercent precision for all sources up to , and a precision of % for about half of the sample. (Abridged
The miniJPAS survey: A preview of the Universe in 56 colors
International audienceThe Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) will scan thousands of square degrees of the northern sky with a unique set of 56 filters using the dedicated 2.55 m Javalambre Survey Telescope (JST) at the Javalambre Astrophysical Observatory. Prior to the installation of the main camera (4.2âdeg2 field-of-view with 1.2 Gpixels), the JST was equipped with the JPAS-Pathfinder, a one CCD camera with a 0.3âdeg2 field-of-view and plate scale of 0.23 arcsec pixelâ1. To demonstrate the scientific potential of J-PAS, the JPAS-Pathfinder camera was used to perform miniJPAS, a âŒ1 deg2 survey of the AEGIS field (along the Extended Groth Strip). The field was observed with the 56 J-PAS filters, which include 54 narrow band (FWHMââŒâ145 Ă
) and two broader filters extending to the UV and the near-infrared, complemented by the u,âg,âr,âi SDSS broad band filters. In this miniJPAS survey overview paper, we present the miniJPAS data set (images and catalogs), as we highlight key aspects and applications of these unique spectro-photometric data and describe how to access the public data products. The data parameters reach depths of magABâââ22â23.5 in the 54 narrow band filters and up to 24 in the broader filters (5Ï in a 3âł aperture). The miniJPAS primary catalog contains more than 64â000 sources detected in the r band and with matched photometry in all other bands. This catalog is 99% complete at râ=â23.6 (râ=â22.7) mag for point-like (extended) sources. We show that our photometric redshifts have an accuracy better than 1% for all sources up to râ=â22.5, and a precision of â€0.3% for a subset consisting of about half of the sample. On this basis, we outline several scientific applications of our data, including the study of spatially-resolved stellar populations of nearby galaxies, the analysis of the large scale structure up to zââŒâ0.9, and the detection of large numbers of clusters and groups. Sub-percent redshift precision can also be reached for quasars, allowing for the study of the large-scale structure to be pushed to zâ>â2. The miniJPAS survey demonstrates the capability of the J-PAS filter system to accurately characterize a broad variety of sources and paves the way for the upcoming arrival of J-PAS, which will multiply this data by three orders of magnitude.Key words: surveys / techniques: photometric / astronomical databases: miscellaneous / stars: general / galaxies: general / cosmology: observationsâ miniJPAS data and associated value added catalogs are publicly available http://archive.cefca.es/catalogues/minijpas-pdr20191
Global Retinoblastoma Presentation and Analysis by National Income Level
This cross-sectional analysis reports the retinoblastoma stage at
diagnosis across the world during a single year, investigates
associations between clinical variables and national income level, and
investigates risk factors for advanced disease at diagnosis.
Key PointsQuestionIs the income level of a country of residence
associated with the clinical stage of presentation of patients with
retinoblastoma? FindingsIn this cross-sectional analysis that included
4351 patients with newly diagnosed retinoblastoma, approximately half of
all new retinoblastoma cases worldwide in 2017, 49.1\% of patients from
low-income countries had extraocular tumor at time of diagnosis compared
with 1.5\% of patients from high-income countries. MeaningThe clinical
stage of presentation of retinoblastoma, which has a major influence on
survival, significantly differs among patients from low-income and
high-income countries, which may warrant intervention on national and
international levels.
ImportanceEarly diagnosis of retinoblastoma, the most common intraocular
cancer, can save both a child's life and vision. However, anecdotal
evidence suggests that many children across the world are diagnosed
late. To our knowledge, the clinical presentation of retinoblastoma has
never been assessed on a global scale. ObjectivesTo report the
retinoblastoma stage at diagnosis in patients across the world during a
single year, to investigate associations between clinical variables and
national income level, and to investigate risk factors for advanced
disease at diagnosis. Design, Setting, and ParticipantsA total of 278
retinoblastoma treatment centers were recruited from June 2017 through
December 2018 to participate in a cross-sectional analysis of
treatment-naive patients with retinoblastoma who were diagnosed in 2017.
Main Outcomes and MeasuresAge at presentation, proportion of familial
history of retinoblastoma, and tumor stage and metastasis. ResultsThe
cohort included 4351 new patients from 153 countries; the median age at
diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976
patients (45.4\%) were female. Most patients (n=3685 {[}84.7\%]) were
from low- and middle-income countries (LMICs). Globally, the most common
indication for referral was leukocoria (n=2638 {[}62.8\%]), followed by
strabismus (n=429 {[}10.2\%]) and proptosis (n=309 {[}7.4\%]). Patients
from high-income countries (HICs) were diagnosed at a median age of 14.1
months, with 656 of 666 (98.5\%) patients having intraocular
retinoblastoma and 2 (0.3\%) having metastasis. Patients from low-income
countries were diagnosed at a median age of 30.5 months, with 256 of 521
(49.1\%) having extraocular retinoblastoma and 94 of 498 (18.9\%) having
metastasis. Lower national income level was associated with older
presentation age, higher proportion of locally advanced disease and
distant metastasis, and smaller proportion of familial history of
retinoblastoma. Advanced disease at diagnosis was more common in LMICs
even after adjusting for age (odds ratio for low-income countries vs
upper-middle-income countries and HICs, 17.92 {[}95\% CI, 12.94-24.80],
and for lower-middle-income countries vs upper-middle-income countries
and HICs, 5.74 {[}95\% CI, 4.30-7.68]). Conclusions and RelevanceThis
study is estimated to have included more than half of all new
retinoblastoma cases worldwide in 2017. Children from LMICs, where the
main global retinoblastoma burden lies, presented at an older age with
more advanced disease and demonstrated a smaller proportion of familial
history of retinoblastoma, likely because many do not reach a
childbearing age. Given that retinoblastoma is curable, these data are
concerning and mandate intervention at national and international
levels. Further studies are needed to investigate factors, other than
age at presentation, that may be associated with advanced disease in
LMICs