Assessment of nose protector for sport activities: finite element analysis

There has been a significant increase in the number of facial fractures stemming from sport activities in recent years, with the nasal bone one of the most affected structures. Researchers recommend the use of a nose protector, but there is no standardization regarding the material employed. Clinical experience has demonstrated that a combination of a flexible and rigid layer of ethylene vinyl acetate (EVA) offers both comfort and safety to practitioners of sports. The aim of the present study was the investigation into the stresses generated by the impact of a rigid body on the nasal bone on models with and without an EVA protector. For such, finite element analysis was employed. A craniofacial model was constructed from images obtained through computed tomography. The nose protector was modeled with two layers of EVA (1 mm of rigid EVA over 2 mm of flexible EVA), following the geometry of the soft tissue. Finite element analysis was performed using the LS Dyna program. The bone and rigid EVA were represented as elastic linear material, whereas the soft tissues and flexible EVA were represented as hyperelastic material. The impact from a rigid sphere on the frontal region of the face was simulated with a constant velocity of 20 m s-1 for 9.1 mu s. The model without the protector served as the control. The distribution of maximal stress of the facial bones was recorded. The maximal stress on the nasal bone surpassed the breaking limit of 0.130.34 MPa on the model without a protector, while remaining below this limit on the model with the protector. Thus, the nose protector made from both flexible and rigid EVA proved effective at protecting the nasal bones under high-impact conditions.

Learned helplessness in the rat: Effect of response topography in a within-subject design

Three experiments investigated learned helplessness in rats manipulating response topography within-subject and different intervals between treatment and tests among groups. In Experiment 1, rats previously exposed to inescapable shocks were tested under an escape contingency where either jumping or nose poking was required to terminate shocks: tests were run either 1, 14 or 28 days after treatment. Most rats failed to jump, as expected, but learned to nose poke, regardless of the interval between treatment and tests and order of testing. The same results were observed in male and female rats from a different laboratory (Experiment 2) and despite increased exposure to the escape contingencies using a within-subject design (Experiment 3). Furthermore, no evidence of helplessness reversal was observed, since animals failed to jump even after having learned to nose-poke in a previous test session. These results are not consistent with a learned helplessness hypothesis, which claims that shock (un)controllability is the key variable responsible for the effect. They are nonetheless consistent with the view that inescapable shocks enhance control by irrelevant features of the relationship between the environment and behavior. (C) 2010 Elsevier B.V. All rights reserved.

Quality of life assessment septoplasty in patients with nasal obstruction

Naasal obstruction is a common complaint in the population. When caused by a deviated nasal septum, septoplasty is the procedure of choice for treating these patients. NOSE is a tool for assessing the disease-specific quality of life related to nasal obstruction. Aim: To assess the impact of septoplasty on patients with nasal obstruction secondary to deviated nasal septum based on the disease-specific quality-of-life questionnaire. Design: Prospective. Methods: Patients undergoing septoplasty with/without turbinectomy after no clinical improvement with medical treatment were assessed by the NOSE questionnaire before and 3 months after surgery. We evaluated the surgical improvement based on total score, the magnitude of the surgery in the disease-specific quality of life and the correlation between the preoperative score and postoperatively improvement. Results: Fourty-six patients were included in the study. There was a statistically significant improvement in the preoperative NOSE score (md = 75, IQR = 26) and after three months (md = 10, IQR = 20) (p < 0.001.T-Wilcoxon). The standardized response mean was 3.07. We found a strong correlation between the preoperative score in the NOSE questionnaire and improvements in the postoperative period (r = -0.789, p < 0.001, Spearman). No difference was found in improvement scores by gender. (p = 0.668, U-Mann-Whitney). Conclusion: Septoplasty resulted in a statistically significant improvement in the disease-specific QOL questionnaire.

Dependence of brittle-to-ductile transition on crystallographic direction in diamond turning of single-crystal silicon

The objective of this paper is to show the dependence relationship between the crystallographic orientations upon brittle-to-ductile transition during diamond turning of monocrystalline silicon. Cutting tests were performed using a -5 degrees rake angle round nose diamond tool at different machining scales. At the micrometre level, the feedrate was kept constant at 2.5 micrometres per revolution (mu m/r), and the depth of cut was varied from 1 to 5 mu m. At the submicrometre level, the depth of cut was kept constant at 500 nm and the feedrate varied from 5 to 10 mu m/r. At the micrometre level, the uncut shoulder generated with an interrupted cutting test procedure provided a quantitative measurement of the ductile-to-brittle transition. Results show that the critical chip thickness in silicon for ductile material removal reaches a maximum of 285 nm in the [100] direction and a minimum of 115 nm in the [110] direction, when the depth of cut was 5 mu m. It was found that when a submicrometre depth of cut was applied, microcracks were revealed in the [110] direction, which is the softer direction in silicon. Micro Raman spectroscopy was used to estimate surface residual stress after machining. Compressive residual stress in the range 142 MPa and smooth damage free surface finish was probed in the [100] direction for a depth of cut of 5 mu m, whereas residual stresses in the range 350 MPa and brittle damage was probed in the [110] direction for a depth of cut of 500 nm.

Orthodontic measurements and nasal respiratory function after surgically assisted rapid maxillary expansion: an acoustic rhinometry and rhinomanometry study

The present study sought to assess nasal respiratory function in adult patients with maxillary constriction who underwent surgically assisted rapid maxillary expansion (SARME) and to determine correlations between orthodontic measurements and changes in nasal area, volume, resistance, and airflow. Twenty-seven patients were assessed by acoustic rhinometry, rhinomanometry, orthodontic measurements, and use of a visual analogue scale at three time points: before surgery; after activation of a preoperatively applied palatal expander; and 4 months post-SARME. Results showed a statistically significant increase (p < 0.001) in all orthodontic measurements. The overall area of the nasal cavity increased after surgery (p < 0.036). The mean volume increased between assessments, but not significantly. Expiratory and inspiratory flow increased over time (p < 0.001). Airway resistance decreased between assessments (p < 0.004). Subjective analysis of the feeling of breathing exclusively through the nose increased significantly from one point in time to the next (p < 0.05). There was a statistical correlation between increased arch perimeter and decreased airway resistance. Respiratory flow was the only variable to behave differently between sides. The authors conclude that the SARME procedure produces major changes in the oral and nasal cavity; when combined, these changes improve patients' quality of breathing.

THE INTERSTELLAR MAGNETIC FIELD CLOSE TO THE SUN. II.

The magnetic field in the local interstellar medium (ISM) provides a key indicator of the galactic environment of the Sun and influences the shape of the heliosphere. We have studied the interstellar magnetic field (ISMF) in the solar vicinity using polarized starlight for stars within 40 pc of the Sun and 90 degrees of the heliosphere nose. In Frisch et al. (Paper I), we developed a method for determining the local ISMF direction by finding the best match to a group of interstellar polarization position angles obtained toward nearby stars, based on the assumption that the polarization is parallel to the ISMF. In this paper, we extend the analysis by utilizing weighted fits to the position angles and by including new observations acquired for this study. We find that the local ISMF is pointed toward the galactic coordinates l, b = 47 degrees +/- 20 degrees, 25 degrees +/- 20 degrees. This direction is close to the direction of the ISMF that shapes the heliosphere, l, b = 33 degrees +/- 4 degrees, 55 degrees +/- 4 degrees, as traced by the center of the "Ribbon" of energetic neutral atoms discovered by the Interstellar Boundary Explorer (IBEX) mission. Both the magnetic field direction and the kinematics of the local ISM are consistent with a scenario where the local ISM is a fragment of the Loop I superbubble. A nearby ordered component of the local ISMF has been identified in the region l approximate to 0 degrees -> 80 degrees and b approximate to 0 degrees -> 30 degrees, where PlanetPol data show a distance-dependent increase of polarization strength. The ordered component extends to within 8 pc of the Sun and implies a weak curvature in the nearby ISMF of +/- 0 degrees.25 pc(-1). This conclusion is conditioned on the small sample of stars available for defining this rotation. Variations from the ordered component suggest a turbulent component of +/- 23 degrees. The ordered component and standard relations between polarization, color excess, and H-o column density predict a reasonable increase of N(H) with distance in the local ISM. The similarity of the ISMF directions traced by the polarizations, the IBEX Ribbon, and pulsars inside the Local Bubble in the third galactic quadrant suggest that the ISMF is relatively uniform over spatial scales of 8-200 pc and is more similar to interarm than spiral-arm magnetic fields. The ISMF direction from the polarization data is also consistent with small-scale spatial asymmetries detected in GeV-TeV cosmic rays with a galactic origin. The peculiar geometrical relation found earlier between the cosmic microwave background dipole moment, the heliosphere nose, and the ISMF direction is supported by this study. The interstellar radiation field at +/- 975 angstrom does not appear to play a role in grain alignment for the low-density ISM studied here.

Conductive polymer gas sensor for quantitative detection of methanol in Brazilian sugar-cane spirit

A low-cost chemiresistive gas sensor is described, made by the deposition of a thin film of a conductive polymer, poly(2-dodecanoylsulfanyl-p-phenylenevinylene), doped with dodecylbenzenesulfonic acid (10%, w/w), onto interdigitated electrodes. The sensor exhibits linear electrical conductance changes in function of the concentration of methanol present in sugar-cane spirit in the range between 0.05% and 4.0%. Since the sensor is cheap, easy to fabricate, durable, presents low power consumption, and is not sensitive to ethanol, acetic acid or water, it can be used in portable equipments for monitoring methanol levels in distilled alcoholic beverages such as Brazilian sugar-cane spirit (cachaca). (C) 2011 Elsevier Ltd. All rights reserved.

Optical chemical sensors using polythiophene derivatives as active layer for detection of volatile organic compounds

Several studies on polythiophene gas sensors, based mainly on electrochemical and gravimetric principles can be found in the literature. However, other principles of gas detection, such as optical and thermal, are still little studied. Optical sensing is suitable for remote detection and offers great versatility at low cost. Here,we report on the use of thin films of seven polythiophene derivatives as active layer in optical sensors for the detection of six volatile organic compounds (n-hexane, toluene, tetrahydrofuran, chloroform, dichloromethane and methanol) and water vapor, in concentration range of 500-30,000 ppm. The results showed that it is possible to use different polythiophene derivatives to differentiate VOCs by optical sensing. Differentiation can be performed based on the presence or not of response to an analyte and the sensitivity value of the sensors for the analytes. Another important feature is the lack of the effect of humidity on the response of most films, which could be a major drawback in the application of these sensors. (C) 2011 Elsevier B.V. All rights reserved.

Intranasal tooth and associated rhinolith in a patient with cleft lip and palate

We report the case of a 9-year-old girl who presented with a complaint of a malodorous bloody discharge from the left naris. The patient had previously undergone a complete repair of left-sided cleft lip and palate. Clinical examination revealed hyperplasia of the nasal mucosa on the left side. X-ray examination of the nasal cavity demonstrated a radiopaque structure that resembled a tooth and a radiopaque mass similar to an odontoma that was adherent to the root of the suspected tooth. With the patient under general anesthesia, the structure was removed. On gross inspection, the structure was identified as a tooth with a rhinolith attached to the surface of its root. Microscopic examination revealed normal dentin and pulp tissue. A nonspecific inflammatory infiltrate was observed around the rhinolith, and areas of regular and irregular mineralization were seen. Some mineralized areas exhibited melanin-like brownish pigmentation. Areas of mucus with deposits of mineral salts were also observed. Rare cases of an intranasal tooth associated with a rhinolith have been described in the literature. We believe that this case represents only the second published report of an intranasal tooth associated with a rhinolith in a patient with cleft lip and palate

Resultados da ressecção de hemangiomas infantis nasais em fase proliferativa: abordagem segura para os tumores centrais da face

INTRODUÇÃO: O hemangioma infantil é o tumor benigno mais comum da infância, predominando na região cervicofacial. É caracterizado por apresentar 3 fases distintas, observando-se frequentemente regressão espontânea dessas lesões. No entanto, sequelas residuais ou deformidades das estruturas anatômicas em crescimento podem ocorrer. A abordagem cirúrgica precoce e definitiva é indicada, em decorrência da localização dos hemangiomas nasais e seu potencial desfigurante, visando à obtenção de bons resultados estéticos e preservação anatômica. O objetivo do presente estudo foi analisar os resultados da abordagem cirúrgica definitiva para hemangiomas proliferativos nasais, com base em uma avaliação objetiva. MÉTODO: No período de 1997 a 2009, 20 pacientes portadores de hemangiomas nasais em fase proliferativa foram submetidos a tratamento cirúrgico. As lesões foram avaliadas segundo local de acometimento e tratamento realizado. Foram analisados índices de complicações e necessidade de procedimentos adicionais. Os resultados estéticos foram avaliados por avaliadores independentes. RESULTADOS: As lesões estavam localizadas na ponta nasal em 50% dos pacientes; no dorso, em 20%; em todas as subunidades, em 15%; nas áreas paranasais, em 10%; e na unidade alar, em 5%. A ressecção foi total em 60% dos pacientes e subtotal em 40%. O período médio de acompanhamento foi de 42,6 meses. A média de procedimentos cirúrgicos por paciente foi de 1,3 + 0,7. Nenhuma complicação importante foi observada. Os resultados foram positivamente avaliados quanto a redução do volume da lesão e melhora do contorno facial, corroborando a conduta proposta. CONCLUSÕES: No manejo dos hemangiomas nasais, o tratamento cirúrgico definitivo pode ser considerado uma alternativa segura e eficaz, com baixas taxas de complicação.

Enxerto composto auricular na reconstrução da asa nasal

O nariz ocupa o centro da face, o que torna pequenas assimetrias e imperfeições evidentes. Uma de suas subunidades é a asa nasal, região que exige não apenas resultados estéticos, mas também funcionais, em sua reconstrução, tornando-se um desafio ao cirurgião plástico. Neste artigo são descritos 3 casos em que foi utilizado enxerto composto auricular para reconstrução da asa nasal. Os enxertos apresentaram integração total, com resultados estéticos e funcionais adequados. Segundo revisão da literatura, não há diferença nos índices de complicação comparando-se os enxertos com os retalhos locais e, a longo prazo, a cartilagem auricular tende a manter-se no formato moldado, sofrendo raras distorções e mínima ou nenhuma absorção, diferentemente das cartilagens costais e dos enxertos ósseos. O enxerto composto auricular é uma técnica versátil e segura, com excelentes resultados na reconstrução da asa nasal e com baixa morbidade das áreas doadoras, cumprindo com eficiência seu objetivo reparador.

Effect of rapid maxillary expansion on the dimension of the nasal cavity and on facial morphology assessed by acoustic rhinometry and rhinomanometry

OBJECTIVE: To assess the effects of rapid maxillary expansion on facial morphology and on nasal cavity dimensions of mouth breathing children by acoustic rhinometry and computed rhinomanometry. METHODS: Cohort; 29 mouth breathing children with posterior crossbite were evaluated. Orthodontic and otorhinolaryngologic documentation were performed at three different times, i.e., before expansion, immediately after and 90 days following expansion. RESULTS: The expansion was accompanied by an increase of the maxillary and nasal bone transversal width. However, there were no significant differences in relation to mucosal area of the nose. Acoustic rhinometry showed no difference in the minimal cross-sectional area at the level of the valve and inferior turbinate between the periods analyzed, although rhinomanometry showed a statistically significant reduction in nasal resistance right after expansion, but were similar to pre-treatment values 90 days after expansion. CONCLUSION: The maxillary expansion increased the maxilla and nasal bony area, but was inefficient to increase the nasal mucosal area, and may lessen the nasal resistance, although there was no difference in nasal geometry. Significance: Nasal bony expansion is followed by a mucosal compensation.