195 research outputs found
A model of maxilla resection to test new hybrid implants:macroporous titanium and tissue engineering elements
Maxillary bone loss in commonly found in humans, due to bone ageing, tooth loos, periodontal disease and, more severely, to trauma, radiotherapy and tumor resection. Masillofacial reconstructive surgery is a still unmet clinical demand, available therapies include grafting of autologous or heterologous bone tissue and/or the implantation of metallic plates, buy these treatments are still unable to resume form and function. The emrgence of 3D-printing technology applied to metal alloys now allows the manufacturing of customized, patient-tailored prosthetic implants. However, poor bone quiality at the implant site due to ageing or disease still hamper proper osseointegration. By combining Electron Beam Melting metal sintering and tissue engineering, we are developing hybrid maxillofacial implants, wher a metal framework of Ti6Al4V alloy confers both and appropiaate shape and mechanical stabilty, while stem cells and osteogenic molecules stimulate bone growth into the metal framework, thus pormoting osseointegration. We hereby present the in vitro work driving to the development of our hybrid maxillofacial prostheses, as well as the setting up of an in vivo model of complete maxilla full resection, created in order to test the prostheses in a preclinical studyUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Langerhans cell histiocytosis in the maxillofacial area in adults : report of three cases
Langerhans cell histiocytosis (LCH) is a disease of unknown etiology, characterized by proliferation of pathological Langerhans cells within different organs. It mainly affects children, but adult cases also occur, with an incidence rate of one to two per million. The head and neck are affected in almost 90% of cases. Diagnosis is made by means of histopathological analysis, and imaging studies are necessary in order to determine extent of the disease. There are no controlled trials proposing an optimal treatment protocol for LCH. Prognosis in adults is generally good due to the slow evolution of the disease and its favourable response to treatment. In our report, we present three cases of LCH in patients aged 16, 24, and 28 years respectively, with primary manifestation in the maxillofacial area. A literature review was also conducted
Verrucous carcinoma of the oral mucosa: an epidemiological and follow-up study of patients treated with surgery in 5 last years
Introduction: Oral Verrucous Carcinoma (OVC) is described apart of the Squamous Cell Carcinoma (SCC) due to
its specific properties. The objective of our study is to show our series of cases of OVC and to compare with the
SCC in terms of clinical manifestations, epidemiology, histopathology, treatment and follow-up.
Material and Methods: This is a retrospective study of all the OVC treated in our department between January-
2007 and December-2011. The analyzed variables were sex, age, localization in the oral cavity, histopathology,
number of biopsies needed to diagnose OVC, TNM classification, treatment and recurrences during follow-up.
Results: Our sample was composed by n=14 patients, 57% female, with a mean age of 69.14 years. The most com
-
mon localization was buccal mucosa (n=5). Seven patients were diagnosed of OVC with the first biopsy. TNM
classification was: pT1: 7 patients, pT2: 3 patients, pT3: 3 patients, pT4: 1 patient. No cervical metastases were
observed either in cervical neck dissection or during the follow-up of the patients. The treatment was surgery with
clinical resection margins up to 1 cm in all cases, followed by radiotherapy in selected cases. Only n=1 patient
(7.69%) presented a recurrence after 34 months of follow-up. The overall survival rate was 92.85%.
Conclusions: In our population, OVC represents the 6.16% of all oral cavity and oropharynx cancer, and is more
frequent in female patients above 70 years old. It uses to rise over a previous lesion, and usually affects the buccal
mucosa. In patients with high suspicious lesions, more than one biopsy may be needed to diagnose OVC. No pa
-
tient showed cervical dissemination. In our experience, treatment based on local resection, without cervical neck
dissection, could be a good option for these patients
Gingival neurofibroma in a neurofibromatosis type 1 patient : case report
Neurofibroma is a benign peripheral nerve sheath tumour. It is one of the most frequent tumours of neural origin and its presence is one of the clinical criteria for the diagnosis of type 1 neurofibromatosis (NF-I). Neurofibromatosis type 1 is an autosomal dominantly inherited disease due to an alteration in the long arm of chromosome 17. About 50% of NF-I patients have no family history of the disease. NF-I patients have skin lesions (café au lait spots and neurofibromas) as well as bone malformations and central nervous system tumours. Diagnosis is based on a series of clinical criteria. Gingival neurofibroma in NF-I is uncommon. Treatment of neurofibromas is surgical resection. The aim of this paper is to report a case of NF-I with gingival involvement and to review the literature
Computer programming teaching in learning High School Physics
Este trabajo desarrolla una propuesta didáctica para introducir actividades de programación por
ordenador en la resolución de problemas de Física. Tal propuesta persigue un doble objetivo: por una parte
facilitar, a través de la programación de simulaciones de Física, la asimilación de los contenidos de esta materia
y, por otra, iniciar a los alumnos en la programación y en el pensamiento computacional. En este artículo se
fundamenta teóricamente la propuesta, se presenta el material desarrollado para su implementación en el aula y
se describe una intervención a modo de estudio piloto realizada en varios institutos, junto con su evaluación
mediante cuestionarios dirigidos a los profesores y estudiantes participantes. Los resultados obtenidos muestran
una positiva percepción de la propuesta desarrollada.This paper develops a didactic proposal to introduce computer programming activities in physics
problem solving. Such proposal has two objectives. The first one is to facilitate the assimilation of the physics
contents through programming physics simulations. The second one is to initiate students in programming and
computational thinking. In this paper our proposal is theoretically founded and the material developed for the
classroom is presented. A scale intervention performed in several high schools is described and evaluated by
means of two opinion questionnaires fulfilled by the enrolled students and teachers. The results obtained show a
positive percepcion of the developed proposal
Constraining the regular Galactic Magnetic Field with the 5-year WMAP polarization measurements at 22 GHz
[ABRIDGED] The knowledge of the regular component of the Galactic magnetic
field gives important information about the structure and dynamics of the Milky
Way, as well as constitutes a basic tool to determine cosmic rays trajectories.
It can also provide clear windows where primordial magnetic fields could be
detected. We want to obtain the regular (large scale) pattern of the magnetic
field distribution of the Milky Way that better fits the polarized synchrotron
emission as seen by the 5-year WMAP data at 22 GHz. We have done a systematic
study of a number of Galactic magnetic field models: axisymmetric, bisymmetric,
logarithmic spiral arms, concentric circular rings with reversals and
bi-toroidal. We have explored the parameter space defining each of these models
using a grid-based approach. In total, more than one million models are
computed. The model selection is done using a Bayesian approach. For each
model, the posterior distributions are obtained and marginalised over the
unwanted parameters to obtain the marginal 1-D probability distribution
functions. In general, axisymmetric models provide a better description of the
halo component, although attending to their goodness-of-fit, the rest of the
models cannot be rejected. In the case of disk component, the analysis is not
very sensitive for obtaining the disk large scale structure, because of the
effective available area (less than 8% of the whole map and less than 40% of
the disk). Nevertheless, within a given family of models, the best-fit
parameters are compatible with those found in the literature. The family of
models that better describes the polarized synchrotron halo emission is the
axisymmetric one, with magnetic spiral arms with a pitch angle of ~24 degrees,
and a strong vertical field of 1 microG at z ~ 1 kpc. When a radial variation
is fitted, models require fast variations.Comment: 14 pages, 9 figures. Accepted for publication in A&
QUIJOTE scientific results - III. Microwave spectrum of intensity and polarization in the Taurus Molecular Cloud complex and L1527
ABSTRACT: We present new intensity and polarization observations of the Taurus Molecular Cloud (TMC) region in the frequency range 10–20 GHz with the multifrequency instrument (MFI) mounted on the first telescope of the Q-U-I-JOint TEnerife (QUIJOTE) experiment. From the combination of the QUIJOTE data with the WMAP 9-yr data release, the Planck second data release, the DIRBE maps, and ancillary data, we detect an anomalous microwave emission (AME) component with flux density SAME,peak = 43.0 ± 7.9 Jy in the TMC and SAME,peak = 10.7 ± 2.7 Jy in the dark cloud nebula L1527, which is part of the TMC. In the TMC the diffuse AME emission peaks around a frequency of 19 GHz, compared with an emission peak about a frequency of 25 GHz in L1527. In the TMC, the best constraint on the level of AME polarization is obtained at the Planck channel of 28.4 GHz, with an upper limit πAME < 4.2 per cent (95 per cent C.L.), which reduces to πAME < 3.8 per cent (95 per cent C.L.) if the intensity of all the free–free, synchrotron and thermal dust components are negligible at this frequency. The same analysis in L1527 leads to πAME < 5.3 per cent (95 per cent C.L.) or πAME < 4.5 per cent (95 per cent C.L.) under the same assumption. We find that in the TMC and L1527 on average about 80 per cent of the H II gas should be mixed with thermal dust. Our analysis shows how the QUIJOTE-MFI 10–20 GHz data provide key information to properly separate the synchrotron, free–free, and AME components.This work has been partially funded by the Spanish Ministry of Economy and Competitiveness (MINECO) under the projects AYA2007-68058-C03-01, AYA2010-21766-C03-02, AYA2012-39475-C02-01, AYA2014-60438-P: ESP2015- 70646.C2-1-R, AYA2015-64508-P and the Consolider-Ingenio project CSD2010-00064 (EPI: Exploring the Physics of Inflation)
Magnetic Fields in the Milky Way
This chapter presents a review of observational studies to determine the
magnetic field in the Milky Way, both in the disk and in the halo, focused on
recent developments and on magnetic fields in the diffuse interstellar medium.
I discuss some terminology which is confusingly or inconsistently used and try
to summarize current status of our knowledge on magnetic field configurations
and strengths in the Milky Way. Although many open questions still exist, more
and more conclusions can be drawn on the large-scale and small-scale components
of the Galactic magnetic field. The chapter is concluded with a brief outlook
to observational projects in the near future.Comment: 22 pages, 5 figures, to appear in "Magnetic Fields in Diffuse Media",
eds. E.M. de Gouveia Dal Pino and A. Lazaria
Detection of Spectral Variations of Anomalous Microwave Emission with QUIJOTE and C-BASS
Anomalous Microwave Emission (AME) is a significant component of Galactic
diffuse emission in the frequency range -GHz and a new window into
the properties of sub-nanometre-sized grains in the interstellar medium. We
investigate the morphology of AME in the diameter
Orionis ring by combining intensity data from the QUIJOTE experiment at ,
, and GHz and the C-Band All Sky Survey (C-BASS) at GHz,
together with 19 ancillary datasets between and GHz. Maps of
physical parameters at resolution are produced through Markov Chain
Monte Carlo (MCMC) fits of spectral energy distributions (SEDs), approximating
the AME component with a log-normal distribution. AME is detected in excess of
at degree-scales around the entirety of the ring along
photodissociation regions (PDRs), with three primary bright regions containing
dark clouds. A radial decrease is observed in the AME peak frequency from
GHz near the free-free region to GHz in the outer
regions of the ring, which is the first detection of AME spectral variations
across a single region. A strong correlation between AME peak frequency,
emission measure and dust temperature is an indication for the dependence of
the AME peak frequency on the local radiation field. The AME amplitude
normalised by the optical depth is also strongly correlated with the radiation
field, giving an overall picture consistent with spinning dust where the local
radiation field plays a key role.Comment: 19 pages, 7 figures, accepted for publication by MNRA
- …