Frequency-Dependent Dielectric Permittivity in Poisson-Nernst-Planck Model.

The approaches developed for studying the polarization of molecules and the dynamics of ions in dielectric materials are usually considered separately. The two effects are often believed to take place in different frequency ranges. The low frequency response is usually dominated by ionic migration, whereas the high frequency response is played by molecular polarization. The goal here is to clarify the interplay between free and bound charge densities and their influences on permittivity and impedance profiles by proposing a version of the Poisson-Nernst-Planck (PNP) model that allows to include the effect of a frequency-dependent (and thus not instantaneous) polarizability.

Polarization-Modulated Bent-Core Liquid Crystal Thin Films without Layer Undulation.

Spatial confinement is known to affect molecular organizations of soft matter. We present an important manifestation of this statement for thin films of bent-core smectic liquid crystals. Prior freeze-fracture transmission electron microscopy (FFTEM) studies carried out on nitro-substituted bent-core mesogens (n-OPIMB-NO_{2}) revealed an undulated smectic layer structure with an undulation periodicity of ∼8 nm. We report cryogenic TEM measurements on ∼100 nm thick 8-OPIMB-NO_{2} films. In contrast to FFTEM results, our studies show only density modulation with periodicity b=16.2 nm, and no smectic layer undulation. We show that the discrepancy between the FFTEM and cryogenic transmission electron microscopy (cryo-TEM) results can be attributed to the different sample thicknesses used in the experiments. FFTEM monitors cracked surfaces of a relatively thick (5-10 µm) frozen sample, whereas cryo-TEM visualizes the volume of a thin (0.1 µm) film that was quenched from its partially fluid phase. These results have importance in possible photovoltaics and organic electronics applications where submicron thin films are used.

Stability of anterior open bite treatment with bonded spurs associated with high-pull chincup.

OBJECTIVE: To evaluate the stability of anterior open bite (AOB) treatment with bonded spurs associated with high-pull chincup (BS/HPCC). METHODS: The experimental group consisted of 25 Class I AOB patients (15 female, 10 male) treated with BS/HPCC for 1 year. Cephalograms were analysed at pre-treatment (T1), post-treatment (T2) and at the 3-year post-treatment (T3) stage with the patients mean ages of 8.10, 9.14 and 12.18 years, respectively. The control group consisted of 23 subjects (13 female, 10 male) with normal occlusion, with comparable ages at the 3 stages (8.45, 9.45 and 12.50 years at T1, T2 and T3, respectively). T tests were used for intergroup comparisons at T1 and to compare the changes during the 3-year post-treatment period (T2-T3). Intragroup comparison in the treated group was evaluated with dependent t tests between T1 and T2. Correlations between the overbite changes in the T2-T3 period, the pre-treatment AOB severity and the amount of correction achieved during treatment were evaluated with Pearson's correlation coefficient. RESULTS: No statistically significant relapse of the AOB was found at T3. Only 1 patient had a clinically significant AOB relapse. Neither the pre-treatment AOB severity nor the amount of correction was related to overbite changes during the 3-year post-treatment period. CONCLUSIONS: There was no statistically significant relapse of the AOB, and the clinical stability of AOB correction 3-year post-treatment was of 96%.

Effects of testosterone administration (and its 5-alpha-reduction) on parenchymal organ volumes in healthy young men: findings from a dose-response trial.

Animal data shows that testosterone administration increases the volume of some parenchymal organs. However, the effects of exogenous testosterone on solid abdominal organs in humans remain unknown. The present study evaluated the effects of testosterone administration on the volume of liver, spleen and kidneys in a dose-response trial. Young healthy men aged 18-50 years participating in the 5α-Reductase (5aR) Trial. All participants received monthly injections of 7.5 mg leuprolide acetate to suppress endogenous testosterone secretion and weekly injections of 50, 125, 300 or 600 mg of testosterone enanthate, and were randomized to receive either 2.5 mg dutasteride (5 α-reductase inhibitor) or placebo daily for 20 weeks. Liver, spleen and kidney volumes were measured at baseline and the end of treatment using 1.5-Tesla magnetic resonance imaging. The dose-effect of testosterone on changes in the volume of parenchymal organs was evaluated by linear regression model. The association between changes in total testosterone (TT) levels and changes in organ volumes were assessed. Testosterone administration increased liver volume dose-dependently (17.4 cm3 per 100 mg of weekly testosterone enanthate; p = 0.031); the increase in liver volume was positively associated with changes in TT levels (R2  = 0.08, p = 0.024). A dose-dependent, but non-significant, increase in kidney volumes was also seen. Inclusion of dutasteride use into the models showed an independent association of randomization to dutasteride group with liver volume increase. In conclusion, Testosterone administration increased the liver volume in a dose-dependent manner. The potential changes in parenchymal organs should be considered when interpreting apparent changes in lean mass in response to anabolic interventions.

Elastic anisotropy effects on the electrical responses of a thin sample of nematic liquid crystal.

The electrical responses of a nematic liquid crystal cell are investigated by means of the elastic continuum theory. The nematic medium is considered as a parallel circuit of a resistance and a capacitance and the electric current profile across the sample is determined as a function of the elastic constants. In the reorientation process of the nematic director, the resistance and capacitance of the sample are determined by taking into account the elastic anisotropy. A nonmonotonic profile for the current is observed in which a minimum value of the current may be used to estimate the elastic constants values. This scenario suggests a theoretical method to determine the values of the bulk elastic constants in a single planar aligned cell just by changing the direction of applied electrical field and measuring the resulting electrical current.

Formulação de ração para frangos de corte de crescimento lento utilizando valores de energia metabolizável dos ingredientes determinada com linhagens de crescimento lento e rápido / Feed formulation for slow-growing broilers using metabolizable energy values of food determined with strains of slow-and-fast-growing

Com este trabalho, objetivou-se avaliar o efeito da formulação de rações para frangos de corte de crescimento lento, com a utilização de valores de energia metabolizável (EMAn) dos alimentos determinados por linhagens de crescimento rápido e lento, sobre o desempenho, características de carcaça, biometria de órgãos digestórios e valores energéticos das rações experimentais. Utilizaram-se 72 pintos de um dia, machos, da linhagem Isa Label, distribuídos em delineamento de blocos ao acaso, com dois tratamentos (energia dos alimentos) e seis repetições de seis animais cada. As médias foram comparadas pelo teste de Tukey a 5% de probabilidade. Os tratamentos consistiram na formulação de rações baseadas na energia do milho e no farelo de soja determinados com frangos Cobb (EMAn Cobb) e Isa Label (EMAn Isa Label). O experimento foi conduzido na fase inicial, e as aves consumiram as dietas por 28 dias. A formulação da dieta baseada na EMAn Cobb e Isa Label não afetou o desempenho, a biometria de órgãos digestórios e as características de carcaça de aves de crescimento lento. Porém, a dieta formulada com a EMAn Isa Label resultou em melhor conversão calórica e menor deposição de gordura abdominal na carcaça das aves. EMAn da ração semelhante ao nível calculado foi determinada com a formulação baseada na EMAn do milho e do farelo de soja determinada com a linhagem Isa Label (2.750 x 2.728 kcal/kg). Os valores de EMAn do milho e do farelo de soja determinados com aves Isa Label não afetam o desempenho dos frangos de crescimento lento, porém resultam em menor gordura abdominal, atendendo aos anseios dos consumidores de aves alternativas...

We conducted this work aiming to evaluate the effect of using the metabolizable energy of food, determined by different strains (AMEn Cobb and AMEn Isa Label), on diet formulation for slow growing broilers on the performance, carcass characteristics, biometrical morphometry measures of digestive organs and energetic values of the experimental diets. A total of 72 male broiler chickens, Isa Label, were used and the experiment followed a randomized blocks design with two treatments (feedstuff energy), and six replicates of six birds each. The averages were compared by Tukey test at 5% probability. The treatments consisted in formulating diets using the energy of corn and soybean meal determined by Cobb and Isa Label strains. The experiment was conducted in the starter phase and the birds consumed the diets for 28 days. The diet formulated based on AMEn Cobb or Isa Label did not affect the performance, biometrical and morphometry measures of digestive organs and carcass characteristics. However, the diet formulated according to AMEn Isa Label resulted in better caloric conversion, bioeconomic energetic conversion and lower deposition of abdominal fat. AMEn of the diets similar to those calculated levels were determined with the formulation based on AMEn of corn and soybean meal determined for the line Isa Label (2.750 x 2.728 kcal/kg). Values of AMEn of corn and soybean meal determined with Isa Label strains not affect the performance of slow growing broilers, but resulted in lower abdominal fat according to the desires of consumers for alternative poultry...

Antiviral activities of extracts and phenolic components of two Spondias species against dengue virus

In recent years, the search for natural plant products to fight viral diseases has been increasing. In this work, two Spondias species, namely S. mombin and S. tuberosa, found in Ceará state (Brazil), and their main phenolic components were evaluated against dengue virus. In vitro antiviral tests were performed against type-2 dengue virus by the MTT method and standard cytopathic effect reduction assay in C6/36 cells. Cytotoxicity was also evaluated by MTT. The presence of phenolic compounds quercetin, rutin, and ellagic acid in plant extracts was characterized by HPLC analysis. Both Spondias species extracts and components were nontoxic to the cells whereas rutin and quercetin displayed relevant antiviral activity with IC50 of 362.68 µg/mL and 500 µg/mL, respectively.

Objective assessment of knee osteroarthritis in parachuters by bioimpedance spectroscopy.

The aim of the present study was to derive an objective and noninvasive assessment of osteoarthritis of the knee joint by bioimpedance spectrocopy (BIS). The study was performed in Brazilian Military Parachuters and intends to contribute to the improvement of the early diagnosis of joint degeneration. Twelve male volunteers (24 knee joints) participated in the study. A novel index (ID) to assess the disease was proposed from the raw bioimpedance parameter. This index was compared with a subjective rating (Dejour scale) performed by 3 therapists. The results indicated that the values of ID were significantly different (p0.001) between the control group (class 1 of Dejour) and the pathological group (class 2 or higher). A Spearman correlation of -0.81 between the values of ID and the therapists rating was detected. Despite the need of increasing the sample size, the novel technique seems to be capable of supplying an objective and non-invasive tool for helping the diagnosis of the knee osteoarthritis.

A combined approach for the treatment of cervical vertigo.

BACKGROUND: Cervical vertigo is a diagnosis commonly made at both otorhinolaryngologist and chiropractic offices. Hypothesized non-vascular mechanisms are reviewed. Therapeutic approaches have been suggested in the literature, ranging from cervical immobilization to vertebral manipulation. OBJECTIVE: To characterize the patient population with cervical vertigo and observe therapeutic results of a treatment protocol by using distinct conservative modalities. METHODS: Fifteen subjects with cervical vertigo were selected from patients presenting with dizziness at an otorhinolaryngology medical office. Diagnosis was based on specific criteria and results of an otoneurologic examination. All patients were submitted to a treatment protocol, including spinal manipulation, manual therapy on affected muscle groups, analgesic electrotherapy, labyrinth sedation, surface electromyography biofeedback, and an exercise program. Evolution of dizziness complaints and related musculoskeletal dysfunction was observed. RESULTS: Musculoskeletal complaints were present in 93% of the patients, mainly cervical pain, shoulder-girdle pain, and tension-type headache. Median duration of musculoskeletal symptoms was 7.5 years, whereas the median duration of dizziness before the beginning of treatment was 52 days. Treatment duration averaged 5 sessions and 41 days. At the end of treatment, 60% of patients reported remission, 20% reported consistent improvement of vertigo. Remission of musculoskeletal symptoms was observed in 26.7% of patients, and improvement was observed in 60% of patients. CONCLUSION: Chronic, nontraumatic, cervical and shoulder-girdle dysfunction was an important causal and perpetuating factor of cervical vertigo in the population studied, and a consistent improvement was observed with the use of a conservative treatment protocol involving multiple modalities for patients with cervical vertigo. Further controlled studies are needed to access its validity.

[Perceptions of nulliparous women about prematurity]. / Percepções de mães primigestas diante da prematuridade.

This study was made in a neonatal intensive care unit in a school hospital at Porto Alegre/RS, trying to identify the reactions of nuliparous mothers about prematurity. Ten (10) interviews with mothers of premature infants was made. The most commonly reactions were: fear, guilty, anxiety, negation, angry and depression. The mother's feeling about the team, are also observed, and classified in: positive (tranquility, safety, trust, regardless) and negative (doubt, indifference, guilty, envy and fear). A plane of nursing care was made to mothers of premature infants in neonatal intensive care unit (NICU), with the objective of humanization and improving the assistance.

[Ankylosis of deciduous teeth]. / Anquilose de dentes decíduos.

The authors reviewed the literature concerning ankylosis of deciduous teeth, with emphasis on the diagnosis, the incidence, the aetiology and the treatment of this manifestation, illustrated with representative clinical cases.

[Anterior open bite. Concept, etiology, characteristics, classification and clinical cases]. / Mordida aberta anterior. Conceito, etiologia, características, classificação e casos clínicos.

The preoccupation with vertical abnormalities, and particularly anterior open bites, led the authors to establish its concept, to review the literature concerning aetiology and treatment, to propose a classification and to present three case reports of this condition.

[Thumbsucking and malocclusion--presentation of a clinical case]. / Hábito de sucção do polegar e má oclusão--apresentação de um caso clínico.

The digital sucking habit have been significantly related with the malocclusions. These problems can be observed as in the deciduous and mixed as in the permanent dentition. Frequency, length, and intensity of the habit generate as a consequence: anterior open bite, retrusion of the mandible, protrusion of the maxilla, excessive overjet, labial version of the upper incisors, uprighting of the lower incisors, posterior cross bites, sometimes associated to a ogival palate, diastema between the upper incisors, and any others facial characteristics. According to various authors, when the habit persist for an extended period after the age of four years, is considered how malocclusion cause. In this case is requered the professional interference. The presentation of this study has the objective to show the clinic conduct for preventive orthodontics in face to cases who exhib harmful habits.

[Hawley appliance and its clinical use]. / A placa de Hawley e sua utilizacao clinica.

The authors presented considerations on the Hawley appliance, describing its main characteristics and modifications. It is also showed the advantages of its use, as well as its main indications: a) slight tooth inclinations and rotations; b) extrusion of posterior teeth; c) space maintener and d) as retention after orthodontic treatment.

[Impressions in orthodontic finishing]. / Moldagem com finalidade ortodontica.

The authors review the subject and recommend a sequence to be followed during the impression taking, starting always in the lower arch, due to its comfort and less possibility of provoking nausea, this way acquiring the patient's trust.

[Importance of intermediate panoramic radiography in orthodontic treatment]. / Importância das radiografias panorâmicas intermediárias em tratamentos ortodônticos.

The authors justify the importance of the panoramic radiographs taken in the intermediary phases of the orthodontic treatment presenting a clinical case of a late developing supranumerary pre-molar.