Lower doses of dacarbazine (modified BEACODD) as a safer strategy with equal effectiveness in an intensive treatment protocol of Hodgkin's lymphoma: a preliminary retrospective analysis of a single public center in Brazil.

The German Hodgkin Study Group developed the escalated BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone) protocol as a treatment strategy for advanced-stage Hodgkin's lymphoma. In Brazil, as well as in other countries, procarbazine has been replaced with dacarbazine due to the limited availability of procarbazine. The Hematology Center at Irmandade da Santa Casa de Misericórdia in São Paulo adopted and modified the escalated BEACOPP protocol, substituting prednisone with dexamethasone and incorporating two different doses of dacarbazine: 375 mg/m2/day on Day 8 or the original dose of 250 mg/m2/day on Days 2 and 3. This adjustment was made in response to the anticipated toxicity profile. This study aimed to compare the two different doses in the protocols (375 mg/m2/cycle versus 500 mg/m2/cycle) administered to patients with advanced Hodgkin's lymphoma in similar periods. This retrospective study analyzed the data of 31 patients at a single center in Brazil from 2019 to 2021. Seventeen of the 31 patients received 500 mg/m2/cycle (500 Group), while 14 received 375 mg/m2/cycle (375 Group). At the end of the protocol, 71% of the patients in the 375 Group and 76% in the 500 Group achieved complete remission. On analyzing the number of cycles that patients presented with febrile neutropenia, the 500 Group had three times more events (17.9%) than the 375 Group (6.09% - p-value = 0.04). In the 500 Group, 47.1% needed to change the protocol to ABVD (doxorubicin hydrochloride, bleomycin sulfate, vinblastine sulfate, and dacarbazine) due to toxicity. In this limited cohort from a single public center in Brazil, the use of 375 mg/m2 of dacarbazine per cycle of the modified escalated BEACOPP protocol emerged as a safer strategy, maintaining treatment efficacy without compromising response in patients with advanced Hodgkin's lymphoma.

Clinical characteristics and outcomes of Brazilian patients with duodenal-type follicular lymphoma: a multicenter retrospective study.

Duodenal-type follicular lymphoma (DFL) is a rare subtype classified by the 5th edition of the WHO and international consensus classifications of lymphoid neoplasms, typically presenting as localized disease with favorable outcomes. This multicenter retrospective study examines 53 Brazilian DFL patients with a median age of 58.2 years (33-85), with males comprising 50% (n = 27). According to Lugano GI tract classification, 40 patients (75%) were stage I. Median follow-up was 2.9 years (range 0.1-11). Incidental diagnosis occurred in 28 patients (52.8%) during routine endoscopy; 24 patients (45%) presented mild gastrointestinal symptoms. Treatments included watchful waiting (32 patients, 60.4%), rituximab monotherapy (15 patients, 28.3%), radiotherapy (three patients, 5.7%), and chemoimmunotherapy (three patients, 5.7%). Three patients experienced disease progression; watchful waiting showed three spontaneous remissions. No deaths occurred during follow-up. This study, the first from Latin America, demonstrates a good prognosis across treatments, highlighting Watchful waiting's effectiveness.

Mechanical Strain, Temperature, and Misalignment Effects on Data Communication between Piezoceramic Ultrasonic Transducers.

Acoustic waves can be used for wireless telemetry as an alternative to situations where electrical or optical penetrators are unsuitable. However, the response of the ultrasonic transducer can be greatly affected by temperature variations, mechanical deformations, misalignment between transducers, and multiple layers in the propagation zone. Therefore, this work sought to quantify such influences on communication between ultrasonic transducers. The experimental measurements were performed at the frequency where power transfer is maximized. Moreover, there were four experimental models, each with its own performed setup. The ultrasonic transducers are attached to both sides of a 6 mm thick stainless-steel plate for configuring just one barrier. Multiple layers of transducers are attached to the outer side of two plates immersed in an acoustic fluid with a 100 mm thick barrier. In both cases, the S21 parameter was used to quantify the influence of the physical barrier because it correlates with the power flow between ports that return after a given excitation. The results showed that when a maximum deformation of 1250 µm/m was applied, the amplitude of the S21 parameter varied around +0.7 dB. Furthermore, increasing the temperature from 30 to 100 °C slightly affected the S21 (+0.8 dB), but the signal decayed quickly for temperatures beyond 100 °C. Additionally, the ultrasonic communication with a multiple layer was found to occur under misalignment with an intersection area of up to 40%. None of the factors evaluated resulted in insufficient power transfer, except for a large misalignment between the transducers. Such results indicate that this type of communication can be a robust alternative, with a minimum alignment of 40% between transducers and electrical penetrators.

Diacetylcurcumin: a novel strategy against Enterococcus faecalis biofilm in root canal disinfection.

Aim: We evaluated Diacetylcurcumin (DAC), a derivative of curcumin, for its antibacterial and antibiofilm properties against Enterococcus faecalis. Methods: Minimum inhibitory concentration (MIC) and minimum bactericidal concentration were determined, along with antibiofilm potential and toxicity in Galleria mellonella. Additionally, in silico computational analysis was performed to understand its mechanisms of action. Results & conclusion: DAC demonstrated significant antibacterial effects, with MIC and MBC values of 15.6 and 31.25 µg/ml, respectively, and reduced biofilm formation. A synergistic effect, reducing biofilm by 77%, was observed when combined with calcium hydroxide. G. mellonella toxicity tests confirmed DAC's safety at tested concentrations, suggesting its potential for use in root canal disinfection products.

Diacetylcurcumin (DAC) comes from turmeric, a natural spice often used in food. DAC may have the ability to fight germs, including the bacteria Enterococcus faecalis. We tested DAC's ability to kill E. faecalis and stopping the formation of films of the bacteria. We found that a small amount of DAC did kill E. faecalis. When used with calcium hydroxide, DAC works even better to reduce the formation of bacterial films by 77%. DAC is safe to be used on teeth, so may be a useful ingredient for preserving mouth health.

Fabry-Perot Cavity Optimization for Absolute Strain Sensing Using Finite Element Analysis.

The finite element method (FEM) was used to investigate the optical-mechanical behavior of a Fabry-Perot Interferometer (FPI) composed of a capillary segment spliced between two sections of standard optical fiber. The developed FEM model was validated by comparing it with theory and with previously published experimental data. The model was then used to show that the absolute strain on the host substrate is usually smaller than the strain measurement obtained with the sensor. Finally, the FEM model was used to propose a cavity geometry that can be produced with repeatability and that yields the correct absolute strain experienced by the host substrate, without requiring previous strain calibration.

Peripheral lymphocyte subsets as predicting factors for molecular recurrence after imatinib discontinuation in a phase 2 imatinib discontinuation trial in patients with chronic myeloid leukemia.

INTRODUCTION: Treatment-free remission (TFR) is successful in half of the patients with chronic myeloid leukemia who discontinue Imatinib (IM) after sustained molecular response. METHODS: In a prospective trial, we used pioglitazone for 3 months before stopping IM in 30 patients. Percentages of peripheral blood lymphocyte subsets were assessed before and after treatment. The relation of these data with duration of IM treatment and TRF were examined. RESULTS: The median time of IM treatment was 117.6 months. After discontinuation, 11 patients had molecular recurrence after 5.2 months (2.4 - 30). The observation time for those remaining in TFR was 46 (26 - 56) months. The independent factors for the maintenance of TFR were the duration of IM treatment and the percentage of double-positive T cells at IM stop. CONCLUSION: A longer treatment with imatinib was associated with a longer TFR after discontinuation. Pioglitazone could act as an immunomodulator, increasing DP T cells which may contribute to prevent relapse.

Ultrasonic Energy and Data Transfer through a Metal-Liquid Multi-Layer Channel Enhanced by Automatic Gain and Carrier Control.

Ultrasonic communication and power transfer are attractive solutions when conventional electromagnetic-based or wired connections are unfeasible. Most ultrasonic communication applications concern a single-solid barrier. Nevertheless, some relevant scenarios can be composed of several fluid-solid media, through which communication and power transfer are intended. Due to its multi-layer nature, insertion loss and, consequently, the system efficiency considerably decrease. This paper presents an ultrasonic system capable of simultaneously power transferring and transmitting data through a set of two flat steel plates separated by a fluid layer using a pair of co-axially aligned piezoelectric transducers on opposite sides of the barrier. The system is based on frequency modulation and adopts a novel technique for automatic gain and automatic carrier control. The modems used herein were developed specifically for this application, rendering the system able to transfer data at a rate of 19,200 bps, using the frequency shift keying (FSK) modulation scheme and simultaneously transferring 66 mW of power through two flat steel plates (5 mm) separated by a fluid layer (100 mm), which completely supplied a pressure and temperature sensor. The proposed automatic gain control allowed a higher data transmission rate and the automatic carrier control reduced power consumption. The former reduced the transmission error from 12% to 5%, while the latter reduced the global power consumption from 2.6 W to 1.2 W. The proposed system is promising for monitoring applications such as oil wellbore structural health monitoring systems.

Ultrasonic Power and Data Transfer through Multiple Curved Layers Applied to Pipe Instrumentation.

Ultrasonic power and data transfer through multilayered curved walls was investigated using numerical and experimental analysis. The acoustic channel used in this paper was formed by two concentric pipes filled with water, aiming for applications that involve powering and monitoring sensors installed behind the pipe walls. The analysis was carried out in the frequency and time domains using numerical and experimental models. Power and data were effectively simultaneously transferred through the channel. A remote temperature and pressure sensor was powered and interrogated throughout all the layers, and the power insertion loss was 10.72 dB with a data transmission rate of 1200 bps using an amplitude modulated scheme with Manchester coding. The efficiency of the channel was evaluated through an experimental analysis of the bit error rate (BER) with different values of signal-to-noise ratio (SNR), showing a decrease in the number of errors compared with detection without Manchester coding.

Passive Downhole Pressure Sensor Based on Surface Acoustic Wave Technology.

A passive surface acoustic wave (SAW) pressure sensor was developed for real-time pressure monitoring in downhole application. The passive pressure sensor consists of a SAW resonator, which is attached to a circular metal diaphragm used as a pressure transducer. While the membrane deflects as a function of pressure applied, the frequency response changes due to the variation of the SAW propagation parameters. The sensitivity and linearity of the SAW pressure sensor were measured to be 8.3 kHz/bar and 0.999, respectively. The experimental results were validated with a hybrid analytical-numerical analysis. The good results combined with the robust design and packaging for harsh environment demonstrated it to be a promising sensor for industrial applications.

Derivation of acoustoelastic Lamb wave dispersion curves in anisotropic plates at the initial and natural frames of reference.

The propagation speed of ultrasonic waves in pre-stressed media can be evaluated either at the natural or initial frames of reference. In this paper general equations that can be applied to the partial wave technique are presented in order to obtain the dispersion spectra of acoustoelastic Lamb waves in anisotropic plates in either frame of reference. Employing these equations, dispersion curves for the fundamental modes in a pre-stressed transversely isotropic aluminum plate were numerically obtained in both reference frames under longitudinal and transverse loading with the material transverse axis along each of the Cartesian directions, as well as the propagation along a non-principal direction. Results confirm that due to the material natural anisotropy, the speed variation depends not only on the pre-stress direction but also on the material orientation as well as on the polarization of the propagating mode. Similar to bulk waves, the relationship between the speed at the natural and initial frames is a function of the load direction.

Psychiatric comorbidity in diabetes type 1: a cross-sectional observational study.

OBJECTIVE: This study aims to investigate the prevalence of psychiatric disorders, i.e., the presence of signs and symptoms of anxiety and depression in type 1 diabetic patients, as well as to investigate the prevalence of psychiatric disorders in insulin dependent patients. METHODS: A cross-sectional observational study of 110 diabetic outpatients (mean = 58.3, SD = 14.5; 50 male and 60 female) was conducted in a public health clinic with patients diagnosed with diabetes mellitus who were under the medical supervision of an endocrinologist. The patients were evaluated through the Mini International Neuropsychiatric Interview and the Hospital Anxiety and Depression Scale(HADS). RESULTS: With respect to anxiety symptoms, we found a prevalence of 60% (n = 66) among patients, while in depression symptoms we found a prevalence of 53.6% (n = 59) concerning the 110 patients evaluated. More specifically, we found 28.2% (n = 31) of patients without depression or anxiety, 13.6% (n = 15) of patients with depression, 16.4% (n = 18) of patients with anxiety and 41.8% (n = 46) of patients with depression combined with anxiety. The most remarkable data were generalized anxiety disorder (22.7%), dysthymia (18.2%), panic disorder (8.2%) and social phobia (5.5%). CONCLUSION: The need for accurate assessments about the presence of symptoms related to psychopathology in patients with type 1 diabetes is evident.

Psychiatric comorbidity in diabetes type 1: a cross-sectional observational study / Comorbidade psiquiátrica no diabetes tipo 1: um estudo transversal observacional

Objective This study aims to investigate the prevalence of psychiatric disorders, i.e., the presence of signs and symptoms of anxiety and depression in type 1 diabetic patients, as well as to investigate the prevalence of psychiatric disorders in insulin dependent patients. Methods A cross-sectional observational study of 110 diabetic outpatients (mean = 58.3, SD = 14.5; 50 male and 60 female) was conducted in a public health clinic with patients diagnosed with diabetes mellitus who were under the medical supervision of an endocrinologist. The patients were evaluated through the Mini International Neuropsychiatric Interview and the Hospital Anxiety and Depression Scale(HADS). Results With respect to anxiety symptoms, we found a prevalence of 60% (n = 66) among patients, while in depression symptoms we found a prevalence of 53.6% (n = 59) concerning the 110 patients evaluated. More specifically, we found 28.2% (n = 31) of patients without depression or anxiety, 13.6% (n = 15) of patients with depression, 16.4% (n = 18) of patients with anxiety and 41.8% (n = 46) of patients with depression combined with anxiety. The most remarkable data were generalized anxiety disorder (22.7%), dysthymia (18.2%), panic disorder (8.2%) and social phobia (5.5%). Conclusion The need for accurate assessments about the presence of symptoms related to psychopathology in patients with type 1 diabetes is evident. .

Objetivo Elementos relacionados à saúde mental do paciente diabético tipo 1 são encontrados em várias pesquisas. O objetivo desse estudo é avaliar sinais e sintomas depressivos nesse grupo de pacientes, como também investigar as principais prevalências psiquiátricas que os acometem. Métodos Pesquisa realizada em 110 pacientes diabéticos atendidos em ambulatórios (média = 58.3, D = 14.5; 50 masculinos e 60 femininos) conduzida em Postos de Saúde Pública nos momentos de consulta médica com endocrinologista. A avaliação transcorreu com as escalas Mini International Neuropsychiatric Interview and Hospital Anxiety and Depression Scale (HADS). Resultados Os sintomas de ansiedade tiveram prevalência de 60% (n = 66), enquanto para depressão encontramos resultados de 53.6% (n = 59), considerando que 110 pacientes foram avaliados. Mais especificamente, nós encontramos 28,2 (n. 31) pacientes sem depressão ou ansiedade, 13,6 (n. 15) pacientes com depressão, 16,4 pacientes (n. 18) com ansiedade e 41,8 (n. 46) pacientes com depressão combinada com ansiedade. Outros transtornos comórbidos tiveram prevalência de ansiedade generalizada (22,7%), distimia (18,2%), pânico (8,2%) e fobia social (5,5%). Conclusão Sintomas ansiosos e depressivos são comuns em pacientes diabéticos do tipo 1, porém há prevalência de psicopatologias diversas nesse grupo de pacientes, levando em conta novas necessidades de pesquisas futuras para validar protocolos de tratamentos mais adequados para diabéticos do tipo 1. .

Comorbidity of depression and anxiety: association with poor quality of life in type 1 and 2 diabetic patients.

BACKGROUND: Diabetes is associates with depression and impairment in Quality of Life (QoL). OBJECTIVE: The objective is to define the frequencies of depressive and anxiety symptoms in a sample of patients diagnosed with type 1 and 2 diabetes, the amount of impairment of QoL and the weight of depression and anxiety in determining the QoL in such of patients. METHODS: A total of 210 patients were divided into two groups (type 1 and type 2). Patients completed the HADS and WHOQoL-bref. RESULTS: Groups showed a high prevalence of anxiety (type 1 = 60%, type 2 = 43.8%) and depression (type 1 = 52.4%, type 2 = 38.1%), both measures were significantly higher (p < 0.05) in diabetes type 1 patients. Type 1 patients also showed a QoL in the overall assessment and the physical, psychological and social relations domains. In both Type 1 and 2 diabetes poor QoL was found associated by anxiety and depression comorbidity. CONCLUSION: In overall diabetes patients depression and anxiety seems to be a determinant of poor QoL.

Transdiagnostic treatment using a unified protocol: application for patients with a range of comorbid mood and anxiety disorders.

OBJECTIVE: To evaluate the effectiveness of a unified cognitive-behavioral therapy protocol for group treatment of patients with a range of comorbid mood and anxiety disorders. METHODS: In this open-trial study, the unified protocol was followed for the psychotherapeutic treatment of 16 patients with comorbid mood and anxiety disorders, confirmed by the Mini International Neuropsychiatric Interview. Beck Depression and Anxiety Inventories, the World Health Organization Quality of Life evaluation instrument, and the ARIZONA scale of sexual function were used to evaluate progress in patients throughout the therapeutic process. RESULTS: All patients showed unipolar depressive disorder. Comorbidity with anxiety disorders was distributed as follows: generalized anxiety disorder, 13 (81.3%); panic disorder, 3 (18.8%); social anxiety disorder, 1 (6.3%); and post-traumatic stress disorder, 1 (6.3%). Improvement was observed in the signs and symptoms of depression (F = 78.62, p < 0.001) and anxiety (F = 19.64, p < 0.001), overall quality of life (F = 39.72, p < 0.001), physical domain (F = 28.15, p < 0.001)), psychological variables (F = 9.90, p = 0.007), social functioning (F = 36.86, p < 0.001), environmental variables (F = 27.63, p < 0.001), and sexuality (F = 13.13; p < 0.005). All parameters showed highly significant correlations (p < 0.01). CONCLUSION: An effort to establish one unified treatment protocol for a whole family of emotional disorders (primarily mood and anxiety disorders) showed benefits in the field of clinical psychology and for the treatment of patients. No other data were found in the literature describing the implementation of the unified protocol in a transdiagnostic group. Our results revealed statistically significant improvement in all variables, suggesting that the protocol proposed can become an important tool to improve quality of life, sexuality, and anxiety/depression symptoms in patients with different diagnoses.

Transdiagnostic treatment using a unified protocol: application for patients with a range of comorbid mood and anxiety disorders / Tratamento transdiagnóstico utilizando um protocolo unificado: aplicação em pacientes com diferentes transtornos de humor e ansiedade comórbidos

OBJECTIVE: To evaluate the effectiveness of a unified cognitive-behavioral therapy protocol for group treatment of patients with a range of comorbid mood and anxiety disorders. METHODS: In this open-trial study, the unified protocol was followed for the psychotherapeutic treatment of 16 patients with comorbid mood and anxiety disorders, confirmed by the Mini International Neuropsychiatric Interview. Beck Depression and Anxiety Inventories, the World Health Organization Quality of Life evaluation instrument, and the ARIZONA scale of sexual function were used to evaluate progress in patients throughout the therapeutic process. RESULTS: All patients showed unipolar depressive disorder. Comorbidity with anxiety disorders was distributed as follows: generalized anxiety disorder, 13 (81.3%); panic disorder, 3 (18.8%); social anxiety disorder, 1 (6.3%); and post-traumatic stress disorder, 1 (6.3%). Improvement was observed in the signs and symptoms of depression (F = 78.62, p < 0.001) and anxiety (F = 19.64, p < 0.001), overall quality of life (F = 39.72, p < 0.001), physical domain (F = 28.15, p < 0.001)), psychological variables (F = 9.90, p = 0.007), social functioning (F = 36.86, p < 0.001), environmental variables (F = 27.63, p < 0.001), and sexuality (F = 13.13; p < 0.005). All parameters showed highly significant correlations (p < 0.01). CONCLUSION: An effort to establish one unified treatment protocol for a whole family of emotional disorders (primarily mood and anxiety disorders) showed benefits in the field of clinical psychology and for the treatment of patients. No other data were found in the literature describing the implementation of the unified protocol in a transdiagnostic group. Our results revealed statistically significant improvement in all variables, suggesting that the protocol proposed can become an important tool to improve quality of life, sexuality, and anxiety/depression symptoms in patients with different diagnoses

OBJETIVO: Avaliar a eficácia de um protocolo unificado de terapia cognitivo-comportamental para tratamento em grupo de pacientes com diferentes transtornos de humor e ansiedade comórbidos. MÉTODOS: Neste estudo aberto, o protocolo unificado foi seguido no tratamento psicoterápico de 16 pacientes com transtornos de humor e ansiedade comórbidos, confirmados pelo Mini International Neuropsychiatric Interview. Os Inventários de Depressão e Ansiedade de Beck, o instrumento de avaliação de qualidade de vida da Organização Mundial da Saúde e a escala ARIZONA de função sexual foram utilizados para avaliar o progresso em pacientes ao longo de todo o processo terapêutico. RESULTADOS: Todos os pacientes tinham transtorno depressivo unipolar. A comorbidade com transtornos de ansiedade apresentou a seguinte distribuição: transtorno de ansiedade generalizada, 13 (81,3%); transtorno do pânico, 3 (18,8%); fobia social, 1 (6,3%); e transtorno do estresse pós-traumático, 1 (6,3%). Foi observada melhora nos sinais e sintomas de depressão (F = 78,62, p < 0,001) e ansiedade (F = 19,64, p < 0,001), na qualidade de vida geral (F = 39,72, p < 0,001), no domínio físico (F = 28,15, p < 0,001)), em variáveis psicológicas (F = 9,90, p = 0,007), funcionamento social (F = 36,86, p < 0,001), variáveis ambientais (F = 27,63, p < 0,001) e sexualidade (F = 13,13; p < 0,005). Todos os parâmetros demonstraram correlações altamente significativas (p < 0,01). CONCLUSÃO: O esforço para estabelecer um protocolo unificado de tratamento para toda uma família de transtornos emocionais (especialmente humor e ansiedade) mostrou benefícios na área da psicologia clínica e no tratamento dos pacientes. Não foram encontrados outros dados na literatura descrevendo a implementação do protocolo unificado em um grupo transdiagnóstico. Nossos resultados revelaram uma melhora estatisticamente significativa em todas as variáveis, sugerindo que o protocolo proposto pode se tornar uma ferramenta importante para melhorar qualidade de vida, sexualidade e sintomas de ansiedade/depressão em pacientes com diferentes diagnósticos

Prevalence of psychiatric disorders in patients with diabetes types 1 and 2.

BACKGROUND: Diabetes mellitus, classified into types 1 and 2, is a chronic disease that shows high comorbidity with psychiatric disorders. Insulin-dependent patients show a higher prevalence of psychiatric disorders than do patients with type 2 diabetes. METHODS: This research involved the participation of 200 subjects divided into 2 groups: 100 patients with diabetes type 1 and 100 patients with diabetes type 2. This study used the Mini International Neuropsychiatric Interview for the identification of psychiatric disorders. RESULTS: Of the 200 participants, 85 (42.5%) were found to have at least 1 psychiatric disorder. The most prevalent disorders were generalized anxiety disorder (21%), dysthymia (15%), social phobia (7%), current depression (5.5%), lifelong depression (3.5%), panic disorder (2.5%), and risk of suicide (2%). Other disorders with lower prevalence were also identified. The groups showed a statistically significant difference in the presence of dysthymia, current depression, and panic disorder, which were more prevalent in patients with diabetes type 1. CONCLUSION: The high prevalence of psychiatric disorders in diabetic patients points to the need for greater investment in appropriate diagnostic evaluation of patients that considers mental issues. The difference identified between the groups shows that preventive measures and therapeutic projects should consider the specific demands of each type of diabetes.

Gold nanoparticles on the surface of soda-lime glass: morphological, linear and nonlinear optical characterization.

Materials presenting high optical nonlinearity, such as materials containing metal nanoparticles (NPs), can be used in various applications in photonics. This motivated the research presented in this paper, where morphological, linear and nonlinear optical characteristics of gold NPs on the surface of bulk soda-lime glass substrates were investigated as a function of nanoparticle height. The NPs were obtained by annealing gold (Au) thin films previously deposited on the substrates. Pixel intensity histogram fitting on Atomic Force Microscopy (AFM) images was performed to obtain the thickness of the deposited film. Image analysis was employed to obtain the statistical distribution of the average height of the NPs. In addition, absorbance spectra of the samples before and after annealing were measured. Finally, the nonlinear refractive index (n2) and the nonlinear absorption index (α2) at 800 nm were obtained before and after annealing by using the thermally managed eclipse Z-scan (TM-EZ) technique with a Ti:Sapphire laser (150 fs pulses). Results show that both n2 and α2 at this wavelength change signs after the annealing and that the samples presented a high nonlinear refractive index.

Magnetic field measurements based on Terfenol coated photonic crystal fibers.

A magnetic field sensor based on the integration of a high birefringence photonic crystal fiber and a composite material made of Terfenol particles and an epoxy resin is proposed. An in-fiber modal interferometer is assembled by evenly exciting both eigenemodes of the HiBi fiber. Changes in the cavity length as well as the effective refractive index are induced by exposing the sensor head to magnetic fields. The magnetic field sensor has a sensitivity of 0.006 (nm/mT) over a range from 0 to 300 mT with a resolution about ±1 mT. A fiber Bragg grating magnetic field sensor is also fabricated and employed to characterize the response of Terfenol composite to the magnetic field.

Hydrostatic pressure sensing with high birefringence photonic crystal fibers.

The effect of hydrostatic pressure on the waveguiding properties of high birefringence photonic crystal fibers (HiBi PCF) is evaluated both numerically and experimentally. A fiber design presenting form birefringence induced by two enlarged holes in the innermost ring defining the fiber core is investigated. Numerical results show that modal sensitivity to the applied pressure depends on the diameters of the holes, and can be tailored by independently varying the sizes of the large or small holes. Numerical and experimental results are compared showing excellent agreement. A hydrostatic pressure sensor is proposed and demonstrated using an in-fiber modal interferometer where the two orthogonally polarized modes of a HiBi PCF generate fringes over the optical spectrum of a broad band source. From the analysis of experimental results, it is concluded that, in principle, an operating limit of 92 MPa in pressure could be achieved with 0.0003% of full scale resolution.

A magnetostrictive composite-fiber Bragg Grating sensor.

This paper presents a light and compact optical fiber Bragg Grating sensor for DC and AC magnetic field measurements. The fiber is coated by a thick layer of a magnetostrictive composite consisting of particles of Terfenol-D dispersed in a polymeric matrix. Among the different compositions for the coating that were tested, the best magnetostrictive response was obtained using an epoxy resin as binder and a 30% volume fraction of Terfenol-D particles with sizes ranging from 212 to 300 µm. The effect of a compressive preload in the sensor was also investigated. The achieved resolution was 0.4 mT without a preload or 0.3 mT with a compressive pre-stress of 8.6 MPa. The sensor was tested at magnetic fields of up to 750 mT under static conditions. Dynamic measurements were conducted with a magnetic unbalanced four-pole rotor.