1,644 research outputs found
Location and course of the mandibular canal in dentate patients: morphometric study using cone-beam computed tomography
Background: The morphometric characteristics of the mandibular canal (MC) may vary according to the characteristics of the population studied. Correct location of the MC is fundamental for the indication and planning of different dental treatments, and it is therefore essential to have clinical parameters indicating its approximate location. The aim of this study was to describe the location and course of the MC by morphometric relations in the mandibular body, from the mental foramen to distal of the first molar, in dentate adult patients.
Materials and methods: We analysed 55 cone-beam computed tomography (CBCT) of male and female patients, aged over 18 years and with fully dentate to the first molar. In each CBCT we selected five coronal sections (A–E) of the mandibular body at different levels using the teeth as references. We determined different morphometric measurements in each section to relate the MC with the corticals of the mandibular body (m1, m2, m3, m4), their orientation to lingual (F) and the thickness of the mandibular corticals (B1, B2 and B3).
Results: The distance between the MC and the alveolar crests was greater in males than in females in all the sections. In general, in all the hemiarches, the MC courses away from the vestibular cortical of the mandible (and in some cases significantly towards the lingual cortical) from anterior to posterior in the mandibular body. In the left hemiarch of dentate females the MC describes a descent in the molar zone within the mandibular body. Any intervention in the mandible must be carried out with extreme caution to avoid damaging the vasculo-nervous bundle which passes through the MC.
Conclusions: Cone-beam computed tomography is the best tool currently available for the planning and execution of surgical procedures, and is the only tool in clinical use which allows the precise course of the MC to be identified
Effective Hamiltonians in quantum optics: a systematic approach
We discuss a general and systematic method for obtaining effective
Hamiltonians that describe different nonlinear optical processes. The method
exploits the existence of a nonlinear deformation of the usual su(2) algebra
that arises as the dynamical symmetry of the original model. When some physical
parameter, dictated by the process under consideration, becomes small, we
immediately get a diagonal effective Hamiltonian that correctly represents the
dynamics for arbitrary states and long times. We extend the technique to su(3)
and su(N), finding the corresponding effective Hamiltonians when some resonance
conditions are fulfilled.Comment: 13 Pages, no figures, submitted for publicatio
The optimal age for performing surgery on patients with MEN 2B syndrome
Multiple endocrine neoplasia (MEN) syndromes are characterized by the association of various endocrine neoplasias. Prophylactic thyroidectomy is the treatment of choice for patients with RET gene mutations. The age at which patients undergo prophylactic thyroidectomy may vary depending on the position of the RET gene codon. In cases of MEN 2B, when the mutation is carried in codons 883, 918 or 922, prophylactic thyroidectomy is performed prior to 6 months of age, due to the increased aggressiveness of these heterozygosities, which are capable of determining the onset of medullary cancer during the first months of life. We present two heterozygous twin patients with MEN 2B syndrome who were born 32 weeks premature, and who underwent prophylactic thyroidectomy at 7 months of age. The patients were carriers of the mutation at codon 918. We suggested the early surgery at 7 months as, due to their prematurity, the patients were required to gain weight to improve their condition prior to surgery. The two patients had medullary thyroid carcinoma without lymph node involvement. In conclusion, for a truly prophylactic thyroidectomy, such patients should undergo surgery within the first month of life, particularly if these patients are carriers of the mutation in codons 883, 918 or 922
Redshift and Shear Calibration: Impact on Cosmic Shear Studies and Survey Design
The cosmological interpretation of weak lensing by large-scale structures
requires knowledge of the redshift distribution of the source galaxies. Current
lensing surveys are often calibrated using external redshift samples which span
a significantly smaller sky area in comparison to the lensing survey, and are
thus subject to sample variance. Some future lensing surveys are expected to be
calibrated in the same way, in particular the fainter galaxy populations where
the entire color coverage, and hence photometric redshift estimate, could be
challenging to obtain. Using N-body simulations, we study the impact of this
sample variance on cosmic shear analysis and show that, to first approximation,
it behaves like a shear calibration error 1+/-epsilon. Using the Hubble Deep
Field as a redshift calibration survey could therefore be a problem for current
lensing surveys. We discuss the impact of the redshift distribution sampling
error and a shear calibration error on the design of future lensing surveys,
and find that a lensing survey of area Theta square degrees and limiting
magnitude m_lim}, has a minimum shear and redshift calibration accuracy
requirements given by epsilon = epsilon_0 10^{beta(m_lim-24.5)} / sqrt(Theta/
200). Above that limit, lensing surveys would not reach their full potential.
Using the galaxy number counts from the Hubble Ultra-Deep Field, we find
(epsilon_0,beta)=(0.015,-0.18) and (epsilon_0,beta)=(0.011,-0.23) for ground
and space based surveys respectively. Lensing surveys with no or limited
redshift information and/or poor shear calibration accuracy will loose their
potential to analyse the cosmic shear signal in the sub-degree angular scales,
and therefore complete photometric redshift coverage should be a top priority
for future lensing surveys.Comment: Accepted version to Astroparticle Physic
Effects of fat and/or methionine hydroxy analog added to a molasses-urea-based supplement on ruminal and postruminal digestion and duodenal flow of nutrients in beef steers consuming low-quality lovegrass hay
Five crossbred beef steers (initial BW = 338.6 ± 7.8 kg) fitted with ruminal and duodenal cannulas were used in a 5 × 5 Latin square design experiment to evaluate the effects of methionine hydroxy analog (MHA) and/or yellow grease (fat) added to a molassesurea- based supplement on intake and characteristics of digestion. Steers were fed low-quality hay (long-stem lovegrass Eragrostis curvula: 3.3% CP, 76.8% NDF; DM basis) ad libitum and supplemented with 0.91 kg/d (as fed) of 1 of 4 supplements in a 2 × 2 + 1 factorial arrangement of treatments. Supplemental treatments were 1) control (no supplement, NC); 2) molassesurea liquid supplement (U); 3) U containing (as-fed basis) 1.65% MHA (UM); 4) U containing (as-fed basis) 12% fat (UF); and 5) U containing (as-fed basis) 1.65% MHA and 12% fat (UMF). Total and forage OM intake (kg/d and as % of BW) increased (P \u3c 0.01) with molasses-urea, decreased (P ≤ 0.04) with MHA, and were not affected (P = 0.61) with fat supplementation. Total tract NDF digestibility increased (P = 0.01) with molasses-urea supplementation, and was less (P = 0.01) for fat than for nonfat supplementation. Total and microbial N flowing to the duodenum increased (P = 0.01) with molasses-urea supplementation. Although, total N flowing to duodenum was not affected (P = 0.27), microbial N decreased (P = 0.01), and nonammonia nonmicrobial N (NANMN) increased (P = 0.01) with fat supplementation. Extent of in situ OM and NDF digestibility at 96 h increased (P = 0.01) with molasses-urea supplementation, but were not affected (P ≥ 0.14) by either MHA or fat supplementation. Duodenal flow of total AA, essential AA, and nonessential AA increased (P ≤ 0.02) with molasses-urea supplementation. Total and nonessential serum AA concentration decreased (P \u3c 0.01) with molasses-urea supplementation. Total ruminal VFA concentration increased (P = 0.01) with molasses-urea supplementation, and was not affected (P ≥ 0.14) by MHA or fat supplementation. Fat can be used in molasses-urea liquid supplements for cattle consuming low-quality forage to increase energy intake without negatively affecting forage intake or characteristics of digestion. However, adding MHA did not further improve the response to urea supplementation of cattle consuming low-quality forage. Conversely, the inclusion of MHA on urea supplement decreased forage intake
Optimus: plataforma digital dedicada a la recomendaci?n y gesti?n de recolocaci?n de servicios de telefon?a m?vil pospago
En Lima Metropolitana, los clientes de telefon?a m?vil pospago no hacen uso de todos los beneficios adquiridos mediante contrato con las empresas operadoras, adem?s de verse envueltos en gestiones complejas para realizar solicitudes de recolocaci?n. Por ello, se identific? una oportunidad para implementar la plataforma digital B2C denominada Optimus, que permita evaluar sus necesidades, comparar la oferta comercial existente, recomendar la mejor opci?n de plan y gestionar su recolocaci?n. Para tal efecto, se plante? como objetivo determinar la factibilidad econ?mica y t?cnica del modelo de negocio, considerando dos fases estrat?gicas: la primera, de penetraci?n, con el objetivo de incrementar la cuota de mercado; y la segunda, de posicionamiento basado en liderazgo de costos. Realizada la investigaci?n de mercado, los resultados se?alaron que el 43% de las personas que conforman el mercado potencial estar?an dispuestas a pagar por los servicios de Optimus, con un ticket m?ximo de S/80,00. Finalmente, se evalu? la viabilidad econ?mica tomando en cuenta los escenarios pesimista, esperado y optimista, circunscritos a las variables de ingresos (precio, cantidad y
volumen) y a diversos costos, en especial el de autorizaci?n de representatividad legal (carta poder), que genera gran impacto en el costo de ventas
Yield, quality, alternate bearing and long-term yield index in pecan, as a response to mineral and organic nutrition
The pecan nut is produced in 57 countries in the world. Alternate bearing is one of the main biological problems that affect pecan cultivation. Mineral and organic fertilization is a good strategy to maintain and increase pecan nut production. In this study, several mineral and organic doses of fertilization were tested using a factorial arrangement 56 bounded to 25 treatments was used in structure Taguchi L25: nitrogen (N) 0 - 240 kg ha-1, phosphate (P2O5) 0 - 120 kg ha-1, potassium (K2O) 0 - 100 kg ha-1, calcium (CaO) 0 - 400 kg ha-1, liquid humus 0 - 3600 L ha-1 and solid humus 0 - 8000 kg ha-1. The study was carried out in Aldama city, Chihuahua (Mexico). An average yield of 2.4 t ha-1 was obtained, 157 nuts per kilogram and 58.9% of edible nut. The average alternate bearing intensity was 31.58%, and the long-term yield index (IRLP) was 9.59%. It is concluded that the factors whit the greatest impact on the analyzed variables were N and P2O5. In addition, it was found these mineral and organic fertilization systems help to reduce alternate bearing in pecan and simultaneously improve production and long-term productivity index. Optimal fertilization doses were defined: 181.4 kg ha-1 of N, 93.5 kg ha-1 of P2O5 and 3287.2 L ha-1 of liquid humus. Finally, the mineral fertilization complemented with organic fertilization is considered a good fertilization strategy for pecan trees, to increase production and with lower environmental impact
Functional divergence in the role of N-linked glycosylation in smoothened signaling
The G protein-coupled receptor (GPCR) Smoothened (Smo) is the requisite signal transducer of the evolutionarily conserved Hedgehog (Hh) pathway. Although aspects of Smo signaling are conserved from Drosophila to vertebrates, significant differences have evolved. These include changes in its active sub-cellular localization, and the ability of vertebrate Smo to induce distinct G protein-dependent and independent signals in response to ligand. Whereas the canonical Smo signal to Gli transcriptional effectors occurs in a G protein-independent manner, its non-canonical signal employs Gαi. Whether vertebrate Smo can selectively bias its signal between these routes is not yet known. N-linked glycosylation is a post-translational modification that can influence GPCR trafficking, ligand responsiveness and signal output. Smo proteins in Drosophila and vertebrate systems harbor N-linked glycans, but their role in Smo signaling has not been established. Herein, we present a comprehensive analysis of Drosophila and murine Smo glycosylation that supports a functional divergence in the contribution of N-linked glycans to signaling. Of the seven predicted glycan acceptor sites in Drosophila Smo, one is essential. Loss of N-glycosylation at this site disrupted Smo trafficking and attenuated its signaling capability. In stark contrast, we found that all four predicted N-glycosylation sites on murine Smo were dispensable for proper trafficking, agonist binding and canonical signal induction. However, the under-glycosylated protein was compromised in its ability to induce a non-canonical signal through Gαi, providing for the first time evidence that Smo can bias its signal and that a post-translational modification can impact this process. As such, we postulate a profound shift in N-glycan function from affecting Smo ER exit in flies to influencing its signal output in mice
Spanish Consensus Document on the Treatment Algorithm for Rosacea
Recent scientific evidence and the incorporation of new drugs into the therapeutic arsenal against rosacea have made it necessary to review and update treatment criteria and strategies. To this end, a panel of 15 dermatologists, all experts in rosacea, was formed to share experiences and discuss treatment options, response criteria, and changes to treatment. Based on a critical review of the literature and a discussion of the routine practices of Spanish dermatologists, the panel proposed and debated different options, with consideration of the experience of professionals and the preferences of patients or equality criteria. Following validation of the proposals, the final recommendations were formulated and, together with the evidence from the main international guidelines and studies, used to produce this consensus document. The goal of this consensus document is to provide dermatologists with practical recommendations for the management of rosacea.
Las últimas evidencias científicas y la incorporación de nuevos fármacos al arsenal terapéutico de la rosácea hacen necesario revisar y actualizar los criterios y estrategias de tratamiento. Con este fin, un grupo de 15 dermatólogos expertos en esta enfermedad aportaron y discutieron acerca de las diferentes terapias y los criterios de respuesta y cambio de tratamiento. Partiendo de la revisión crítica de la bibliografía y de la exposición de los hábitos de los dermatólogos españoles en su práctica clínica, se formularon distintas propuestas que fueron debatidas teniendo en consideración tanto la experiencia profesional como las preferencias de los pacientes o los criterios de equidad. Una vez validadas las propuestas, se formularon las recomendaciones finales que, junto con la evidencia aportada por las principales guías y estudios internacionales, dieron lugar al presente documento. El objetivo de este consenso es ofrecer al dermatólogo un enfoque práctico para abordar la rosácea
Etiology and susceptbility to antimicrobials of urinary tract infections in patients of Rehabilitation Unit of a regional hospital
Objetivos: Conocer los resultados del estudio microbiológico de las muestras de orina de pacientes de la Unidad de
Rehabilitación de un hospital regional, incluyendo los datos locales de sensibilidad antibiótica.
Material y métodos: Se analizó la base de datos del Laboratorio de Microbiología del Hospital Universitario Virgen de
las Nieves con los estudios microbiológicos de las muestras de orinas realizados durante el año 2012. Se investigó la
etiología y la sensibilidad a los antibióticos de los uropatógenos más frecuentes presentes en 143 muestras de orina
obtenidas mediante sondaje o cateterismo. Los resultados del estudio de 9066 muestras de orina de micción media
de sujetos estudiados en Atención Primaria fueron utilizados como grupo control.
Resultados: El 50% de los pacientes neurológicos presentaron urocultivos positivos, frente al 23% de los controles.
E. coli fue el microorganismo más frecuentemente aislado en el grupo de enfermos neurológicos, al igual que en los
controles. En el estudio de resistencias E. coli presentó altas tasas de resistencia a ampicilina, cotrimoxazol, ciprofloxacino
y amoxicilina con ácido clavulánico.
Conclusiones: E. coli es el microorganismo más frecuentemente aislado en los dos grupos de pacientes estudiados.
Las resistencias a los antibióticos de los microorganismos procedentes de los dos grupos tienen patrones diferentes,
siendo globalmente menor a fosfomicina.Objectives: Knowing the results of microbiological tests of urine samples of patients from the Rehabilitation Unit of
a regional hospital, including local data of antibiotic susceptibility.
Material and methods: We analyzed the database of the Microbiology Laboratory of the Hospital Universitario
Virgen de las Nieves with microbiological studies conducted urine samples during 2012. We investigated the etiology
and antimicrobial susceptibility of uropathogens frequently present in 143 urine samples. The 9066 survey results
voiding urine mean in Primary Care study subjects were used as controls.
Results: The 50% of neurological patients had positive urine cultures, versus 23% of controls. E. coli was the most
frequently isolated organism group neurological patients, as in the controls. Resistance studies in E. coli showed high
rates of resistance to ampicillin, cotrimoxazole, ciprofloxacin and amoxicillin with clavulanic acid.
Conclusions: E. coli is the most frequently isolated microorganism in both groups of patients studied. The antibiotic
resistance of microorganisms from the two groups have different patterns, being globally less to fosfomycin
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