343 research outputs found
Metals used in maxillofacial surgery
The goal of maxillofacial surgery is to restore the shape and functionality of maxillofacial region. In the past years, there has been a tremendous progress in this field because of significant advances in biotechnology that provided innovative biomaterials to efficiently reconstruct the maxillofacial injured region. By using appropriate selection of the implant biomaterial, it is possible to reconstruct the native tissue, both in form and function. The ideal biomaterial should mimic native tissues regarding density, strength, and modulus of elasticity. Autografts are currently the gold standard for replacement of missing tissues, but synthetic biomaterials have been widely used because they eliminate the discomfort to take the replacement tissue from the donor site. Among synthetic biomaterials, different metals may be utilized to efficiently reconstruct the maxillofacial injured region. This article makes an effort to summarize the most important metals in use in maxillofacial surgery, and point out advantages and disadvantage of each typ
AGN Feedback Compared: Jets versus Radiation
Feedback by Active Galactic Nuclei is often divided into quasar and radio
mode, powered by radiation or radio jets, respectively. Both are fundamental in
galaxy evolution, especially in late-type galaxies, as shown by cosmological
simulations and observations of jet-ISM interactions in these systems. We
compare AGN feedback by radiation and by collimated jets through a suite of
simulations, in which a central AGN interacts with a clumpy, fractal galactic
disc. We test AGN of and erg/s, considering jets
perpendicular or parallel to the disc. Mechanical jets drive the more powerful
outflows, exhibiting stronger mass and momentum coupling with the dense gas,
while radiation heats and rarifies the gas more. Radiation and perpendicular
jets evolve to be quite similar in outflow properties and effect on the cold
ISM, while inclined jets interact more efficiently with all the disc gas,
removing the densest in Myr, and thereby reducing the amount of
cold gas available for star formation. All simulations show small-scale inflows
of M/yr, which can easily reach down to the Bondi radius of
the central supermassive black hole (especially for radiation and perpendicular
jets), implying that AGN modulate their own duty cycle in a feedback/feeding
cycle.Comment: 21 pages, 15 figures, 2 table
3D simulations of the early stages of AGN jets: geometry, thermodynamics and backflow
We investigate the interplay between jets from Active Galactic Nuclei (AGNs)
and the surrounding InterStellar Medium (ISM) through full 3D, high resolution,
Adaptive Mesh Refinement simulations performed with the FLASH code. We follow
the jet- ISM system for several Myr in its transition from an early, compact
source to an extended one including a large cocoon. During the jet evolution,
we identify three major evolutionary stages and we find that, contrary to the
prediction of popular theoretical models, none of the simulations shows a
self-similar behavior. We also follow the evolution of the energy budget, and
find that the fraction of input power deposited into the ISM (the AGN coupling
constant) is of order of a few percent during the first few Myr. This is in
broad agreement with galaxy formation models employing AGN feedback. However,
we find that in these early stages, this energy is deposited only in a small
fraction (< 1%) of the total ISM volume. Finally we demonstrate the relevance
of backflows arising within the extended cocoon generated by a relativistic AGN
jet within the ISM of its host galaxy, previously proposed as a mechanism for
self-regulating the gas accretion onto the central object. These backflows tend
later to be destabilized by the 3D dynamics, rather than by hydrodynamic
(Kelvin- Helmholtz) instabilities. Yet, in the first few hundred thousand
years, backflows may create a central accretion region of significant extent,
and convey there as much as a few millions of solar masses.Comment: Accepted in MNRAS - 16 pages, 12 figures - Multimedia available on
the author's webpage: http://www.mpia.de/~ciel
Retrospective analysis of the correlation between the facial biotype and the inclination of the upper canine cusp axis to the occlusal plane
Permanent maxillary canines are the second most frequently impacted teeth and the prevalence of this clinical condition is estimated to be 1-2% in the general population. The diagnosis of maxillary canine impaction should be based on both clinical and radiographic examinations. The aim of this study was to evaluate the presence of a correlation between the facial biotype and the inclination of the upper cusp axis. A correlation between the total radicular length of the lateral incisors was also evaluated, by comparing the side of impaction with the healthy side. Twenty three patients with a diagnosis of unilateral upper cusp impaction were recruited. For each patient, dental casts and radiographic material (panoramic radiographs and lateral cephalograms) were examined. Statistical analyses were done with Spearman's rank correlation coefficient or Spearman's rho (V). X-ray examinations demonstrated that canine impaction was associated to other dental anomalies (32% of the sample). The mean S angle measurements were 22.9° ± 4.1°, and mean values of the T angle were 34.7°± 4.0°. The mean distance “d” value was 14.6 mm ± 1.2 mm. The mean values of the angle between the upper cusp axis and the perpendicular-to-Fh plane were 20.8 °± 2.6°. Among the 23 subjects recruited, 5 showed values included in the range 25°-45° and 1 an inclination > 45°. The results obtained in the present study demonstrate a significant inverse correlation between the MM angle and the inclination of the upper cusp axis to the perpendicular-to-Fh plan
Evolution of the Mass-Metallicity relations in passive and star-forming galaxies from SPH-cosmological simulations
We present results from SPH-cosmological simulations, including
self-consistent modelling of SN feedback and chemical evolution, of galaxies
belonging to two clusters and twelve groups. We reproduce the mass-metallicity
(ZM) relation of galaxies classified in two samples according to their
star-forming activity, as parametrized by their sSFR, across a redshift range
up to z=2.
Its slope shows irrelevant evolution in the passive sample, being steeper in
groups than in clusters. However, the sub-sample of high-mass passive galaxies
only is characterized by a steep increase of the slope with redshift, from
which it can be inferred that the bulk of the slope evolution of the ZM
relation is driven by the more massive passive objects. (...ABRIDGED...)
The ZM relation for the star-forming sample reveals an increasing scatter
with redshift, indicating that it is still being built at early epochs. The
star-forming galaxies make up a tight sequence in the SFR-M_* plane at high
redshift, whose scatter increases with time alongside with the consolidation of
the passive sequence. We also confirm the anti-correlation between sSFR and
stellar mass, pointing at a key role of the former in determining the galaxy
downsizing, as the most significant means of diagnostics of the star formation
efficiency. Likewise, an anti-correlation between sSFR and metallicity can be
established for the star-forming galaxies, while on the contrary more active
galaxies in terms of simple SFR are also metal-richer.
We discuss these results in terms of the mechanisms driving the evolution
within the high- and low-mass regimes at different epochs: mergers,
feedback-driven outflows and the intrinsic variation of the star formation
efficiency.Comment: Emended list of author
A propósito del artículo: Esquema de ayuno intermitente y reducción de medidas antropométricas, perfil lipídico, presión arterial y riesgo cardiovascular: About the article: Intermittent fasting scheme and reduction of anthropometric measurements, lipid profile, blood pressure and cardiovascular risk
Dear Editor:We have read with great interest the article "Intermittent fasting scheme and reduction of anthropometric measurements, lipid profile, blood pressure and cardiovascular risk" published by Dr Javier Wong-Gonzáles et al, in number 1, volume 22 of your magazine; where the purpose of the research focuses on the assessment of the efficacy of intermittent fasting as a strategy for the modification of anthropometric parameters and cardiovascular risk variables; We would like to contribute the importance of defining the times of the day in which the periods of food intake and abstinence are framed during intermittent fasting, since the induced metabolic effects are highly dependent on circadian fluctuations.Estimado señor editor:Hemos leído con gran interés el artículo “Esquema de ayuno intermitente y reducción de medidas antropométricas, perfil lipídico, presión arterial y riesgo cardiovascular” publicado por el Dr Javier Wong-Gonzáles et al, en el número 1, volumen 22 de su revista; donde el propósito de la investigación se centra en la valoración de la eficacia del ayuno intermitente como estrategia para la modificación de parámetros antropométricos y variables de riesgo cardiovascular; quisiéramos aportar la importancia de definir los momentos del día en los que se enmarcan los periodos de ingesta y abstinencia de alimentos durante el ayuno intermitente, puesto que los efectos metabólicos inducidos son altamente dependientes de las fluctuaciones circadianas. 
Mean Platelet Volume in Neonatal Sepsis: Meta-Analysis of Observational Studies
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Mean Platelet Volume in Neonatal Sepsis: Meta-Analysis of Observational Studies
by Carlos J. Toro-Huamanchumo 1ORCID,Cielo Cabanillas-Ramirez 2,3ORCID,Carlos Quispe-Vicuña 3,4ORCID,Jose A. Caballero-Alvarado 5ORCID,Darwin A. León-Figueroa 3,6ORCID,Nicolás Cruces-Tirado 7 andJoshuan J. Barboza 3,8,*ORCID
1
Escuela de Medicina, Universidad Cesar Vallejo, Trujillo 13007, Peru
2
Escuela de Medicina, Universidad Peruana de Ciencias Aplicadas, Lima 15023, Peru
3
Unidad de Revisiones Sistemáticas y Meta-Análisis, Tau-Relaped Group, Trujillo 13007, Peru
4
Sociedad Científica San Fernando, Universidad Nacional Mayor de San Marcos, Lima 15081, Peru
5
Facultad de Medicina, Universidad Privada Antenor Orrego, Trujillo 13007, Peru
6
Facultad de Medicina Humana, Universidad de San Martín de Porres, Chiclayo 14000, Peru
7
Facultad de Ciencias de la Salud, Universidad Señor de Sipán, Chiclayo 14006, Peru
8
Vicerrectorado de Investigación, Universidad Norbert Wiener, Lima 15046, Peru
*
Author to whom correspondence should be addressed.
Children 2022, 9(12), 1821; https://doi.org/10.3390/children9121821
Received: 5 October 2022 / Revised: 21 November 2022 / Accepted: 22 November 2022 / Published: 25 November 2022
(This article belongs to the Section Pediatric Infectious Diseases)
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Abstract
Introduction: Early onset neonatal sepsis (EONS), particularly in preterm sepsis, is a potentially fatal issue. Evaluation of mean platelet volume (MPV) as an EONS predictor was the goal. Methods: Four databases were used to conduct a systematic evaluation of cohort and case–control studies. Up till the end of October 2022, 137 articles were found utilizing the search method. Following the review, 12 studies were included. Leukocytes, MPV, platelets, gender, birth weight, gestational age, mortality, and C-reactive protein (CRP) were all taken into account while analyzing the prediction of EONS. Inverse-variance methodology and the random-effects model were used. Using GRADE, the evidence’s quality was evaluated. Results: Neonatal patients with sepsis had significantly higher MPV levels than do neonates without sepsis (MD 1.26; 95% CI 0.89–1.63; p < 0.001). An increased MPV during the first 24 h postpartum was associated with high CRP values and high risk of neonatal mortality. In the investigations, the MPV cutoff for sepsis patients was 9.95 (SD 0.843). Overall certainty of the evidence was very low. Conclusions: The increased MPV during the first 24 h postpartum may be predictive of EONS and mortality. Future studies are warranted.
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