Water-in-oil emulsions separation using an ultrasonic standing wave coalescence chamber.

The offshore extraction of crude oil produces stable water in oil emulsion. To separate this emulsion into oil and water phases, the oil/water interfacial film is commonly destroyed by the addition of chemical demulsifiers. The use of an ultrasonic standing wave force field could be an alternative to reduce the dosage of chemical demulsifiers in the coalescence process. In this work, an ultrasonic separator of water in crude oil emulsions is investigated through the use of a high frequency ultrasonic standing wave coalescence chamber. The coalescing chamber uses the acoustic radiation force to induce the coalescence of water droplets at the pressure nodes of a standing wave field. Due to temperature fluctuations, the excitation frequency is controlled to maintain the resonance in the coalescence chamber and the voltage amplitude is controlled to deliver a given acoustic power. Experimental tests using standardized emulsions of water in oil were carried out in a laboratory processing plant. The effects of ultrasound application, flow rate, initial water content, demulsifier dosage and chamber inlet temperature were analyzed. The results show that the use of the acoustic radiation force improves the emulsion separation in all the conditions analyzed, when compared with the gravitational separation technique.

Efficacy of low-level laser therapy as an auxiliary tool for management of acute side effects of head and neck radiotherapy.

INTRODUCTION: Head and neck radiotherapy (HNRT) is associated with acute and chronic side effects, some of which result in great morbidity. The aim of this study was to determine the efficacy of low-level laser therapy (LLLT) as an oral care tool for the management of these effects. MATERIALS AND METHODS: Clinical information was collected from 216 patients undergoing HNRT; these individuals were divided into a control group without laser therapy (n = 108) and a laser group (n = 108). The intervention of the laser group was performed in a different period to the control group and was applied three times weekly. All data were analyzed by a descriptive statistical analysis. RESULTS: The presence and severity of mucositis were similar between the groups. However, the laser group showed a lower frequency of interruption of oncologic therapy related to mucositis (p = 0.030) and the need of nasogastric tube nutrition during the HNRT (p = 0.027). In addition, trismus was less intense in the laser group (p = 0.023). CONCLUSIONS: The introduction of laser therapy in the supportive care for patients undergoing HNRT showed benefits for the patient and the medical system, reducing morbidity and costs associated with side-effects.

Numerical Characterization of Piezoceramics Using Resonance Curves.

Piezoelectric materials characterization is a challenging problem involving physical concepts, electrical and mechanical measurements and numerical optimization techniques. Piezoelectric ceramics such as Lead Zirconate Titanate (PZT) belong to the 6 mm symmetry class, which requires five elastic, three piezoelectric and two dielectric constants to fully represent the material properties. If losses are considered, the material properties can be represented by complex numbers. In this case, 20 independent material constants are required to obtain the full model. Several numerical methods have been used to adjust the theoretical models to the experimental results. The continuous improvement of the computer processing ability has allowed the use of a specific numerical method, the Finite Element Method (FEM), to iteratively solve the problem of finding the piezoelectric constants. This review presents the recent advances in the numerical characterization of 6 mm piezoelectric materials from experimental electrical impedance curves. The basic strategy consists in measuring the electrical impedance curve of a piezoelectric disk, and then combining the Finite Element Method with an iterative algorithm to find a set of material properties that minimizes the difference between the numerical impedance curve and the experimental one. Different methods to validate the results are also discussed. Examples of characterization of some common piezoelectric ceramics are presented to show the practical application of the described methods.

Tongue squamous cell carcinoma in young nonsmoking and nondrinking patients: 3 clinical cases of orthodontic interest.

Oral squamous cell carcinoma traditionally affects older men who smoke and drink. A change in this profile has been reported because of an increased incidence in young nonsmoking and nondrinking patients. The purpose of this article was to describe a series of young nonsmoking and nondrinking patients diagnosed with tongue squamous cell carcinoma who had recently received orthodontic treatment or evaluation. Details regarding diagnosis, treatment, follow-up, and disease evolution are presented, with a review of the pertinent literature. Orthodontists often treat young adults, who have frequent dental appointments and long-term follow-ups. Thus, practitioners should pay special attention to young patients during dental consultations, since the incidence of malignant oral lesions in this segment of the population seems to be increasing.

Evaluation of an educational video to improve the understanding of radiotherapy side effects in head and neck cancer patients.

PURPOSE: Side effects of head and neck radiotherapy are common and can interfere with treatment. However, scientific information on a patient's understanding of these complications is scarce and confusing. Therefore, the aim of this study was to assess the effect of an educational video on improving the understanding of head and neck cancer patients undergoing radiotherapy about treatment complications. METHODS: A 6-min video about head and neck radiotherapy side effects was produced by a multidisciplinary oncology team. A controlled clinical study was performed with two groups: the control group (N = 19), which received verbal information, and the video group (N = 19), which received verbal information and watched the video. Two questionnaires were given to both groups, one before the beginning of radiotherapy and the other after finishing radiotherapy. RESULTS: Thirty-eight patients were included in the study (mean age of 59.7 years in the video group and 57.9 in the control group). Thirty-one patients had an education level less than high school education. All patients of the video group answered correctly why they were undergoing radiotherapy. On the other hand, three patients of the control group did not know the reason for the treatment. More patients of the video group demonstrated better knowledge about radiotherapy side effects than patients of the control group. Only one patient of the video group had doubts about the treatment, compared to seven of the control group. CONCLUSIONS: The present study showed that an educational video may improve patient understanding of head and neck radiotherapy and its side effects despite their education level.

Simultaneous low (1 Hz)- and high (10 Hz)-frequency bilateral transcranial magnetic stimulation in a patient with severe depression and crohn disease.

We present a case report in which electroconvulsive therapy had a good effect for the treatment of depression in association with Crohn disease, but adverse effects limited its use. Repetitive transcranial magnetic stimulation was tried both in a conventional way (high frequency over the left dorsolateral prefrontal cortex) and in a bilateral sequential way (high frequency in the same region followed in the same session by low frequency on the right side). Finally, bilateral simultaneous stimulation (high frequency over the left and low frequency over the right side) was tried and resulted in a response similar to that of electroconvulsive therapy.

Criterios de evaluación odontológica pre-radioterapia y necesidad de tratamiento de las enfermedades orales post-radioterapia en cabeza y cuello / Pre-radiotherapy dental evaluation criteria and treatment needs of oral side effects after head and neck radiotherapy

El objetivo de esta revisión es presentar criterios de evaluación odontológica pre-radioterapia y cuáles son las principales necesidades de tratamiento de estos pacientes después del tratamiento de radiación. Fueron revisados artículos en inglés, español y portugués entre 1995 y 2009 indexados en Pubmed y Scielo. Las palabras claves fueron: cáncer oral y radioterapia, complicaciones de la radioterapia en cabeza y cuello, evaluación oral pre-radioterapia. Los efectos colaterales de la radioterapia en la región de cabeza y cuello pueden ser temporales o tardíos. Aquellos que son tardíos, como la caries de radiación y la osteorradionecrosis pueden estar directamente relacionados con el hecho de no haber realizado una evaluación odontológica previa y pueden afectar severamente la calidad de vida del paciente.La participación del cirujano-dentista en el equipo multidisciplinario y la evaluación odontológica de los pacientes que serán sometidos a radioterapia en la región de cabeza y cuello son de vital importancia en mejorar la calidad de vida post-operatoria de estos pacientes.

The objective of this review is to present pre-radiotherapy evaluation criteria and the main needs for treatment of these patients after the radiation therapy. Were revised articles in English, Spanish and Portuguese language between 1995 and 2009 indexed in Pubmed and Scielo. The keywords were oral cancer and radiotherapy, complications in head and neck radiotherapy, oral pre-radiotherapy evaluation.The adverse complications of radiotherapy in head and neck area could be temporary or late. The late effects, such as radiation caries and osteorradionecrosis could be directly associated with the fact that previous dental evaluation was not performed and can severely affect the post-operatory quality of life. The participation of the dentist in the multidisciplinary team and dental evaluation of the patients that will receive radiotherapy in the head and neck area are of vital importance to improve the post-operatory quality of life of these patients.