Determination of water content in grains with microwave oven / Determinação do teor de água em grãos com forno micro-ondas

The determination of water content is essential for the maintenance of grain quality, and an evaluation of alternative methods for quantification allows to increase the efficiency of the process and bring benefits to the productive sector. The study aimed to analyze the efficiency of using microwave ovens to determine the water content in grains. The studywas carried out in a completely randomized design in a 5x6 factorial scheme, with fivespecies (peanut, sunflower, corn, soybean and wheat) and six microwave drying periods (0.5, 1, 1.5, 2, 2.5, and 3 min), with four replications. Data were subjected to descriptive analysis to characterize the samples, and regression analysis to analyze differences between methods as a function of drying time. The determination of water content in peanut, sunflower,corn,soybean and wheat grains in microwave is technically feasible, showing correlation with the determination in an oven by the standard method. The drying time in the microwave influences the water removal capacity of the grains. For peanut, sunflower,corn,soybean and wheat grains, the microwave drying time of 3 min showed greater similarity with the determination by the standard method.(AU)

A determinação do conteúdo de água é fundamental para manutenção da qualidade de grãos, sendo que a avaliação de métodos alternativos para quantificação permite elevar a eficiência do processo e ocasionar benefícios ao setor produtivo. O estudo teve como objetivo analisar a eficiência da utilização de forno micro-ondas para determinação do teor de água em grãos. O estudo foi conduzido em delineamento inteiramente casualizado em esquema fatorial 5x6, sendo cincoespécies (amendoim, girassol, milho, soja e trigo) e seis períodos de secagem em micro-ondas (0,5; 1; 1,5; 2; 2,5 e 3 min), com quatro repetições. Osdados foram submetidos a análise descritiva para caracterização das amostras, e análise de regressão para análise das diferenças entre métodos em função do tempo de secagem. A determinação do teor de água em grãos de amendoim, girassol,milho,soja e trigo em micro-ondas é tecnicamente viável, apresentando correlação com a determinação em estufa pelo método padrão. O tempo de secagem no micro-ondas influencia na capacidade de remoção de água dos grãos. Para os grãos de amendoim, girassol,milho,soja e trigo, o tempo de secagem por micro-ondas de 3 min apresentou maior similaridade com a determinaçãopelo método padrão.(AU)

Microwave-assisted extraction and content determination of astilbin in Lysiphyllum strychnifolium stems

Abstract Lysiphyllum strychnifolium (Craib) A. Schmitz. (in Thai name, Ya nang daeng) has been traditionally used to treat fever, alcohol intoxication, cancer, allergies, and blood toxins. It can be used as a health-promoting herbal tea and contains hydroalcoholic extracts. The purpose of the present study was to develop a microwave-assisted extraction method for astilbin in L. strychnifolium stems. HPLC was used to determine astilbin content. Three extraction conditions were optimized: types of solvent, microwave power levels, and the number of extraction cycles. Water:methanol (40:60) was the best solvent for astilbin extraction from L. strychnifolium stems using 450 watts and six microwave-assisted extraction cycles. This technique offers important advantages over conventional methods, such as shorter extraction times, substantial energy savings, and a reduced environmental burden.

Transurethral microwave thermotherapy for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia.

BACKGROUND: Transurethral resection of the prostate (TURP) has been the gold-standard treatment for alleviating urinary symptoms and improving urinary flow in men with symptomatic benign prostatic hyperplasia (BPH). However, the morbidity of TURP approaches 20%, and less invasive techniques have been developed for treating BPH. Transurethral microwave thermotherapy (TUMT) is an alternative, minimally-invasive treatment that delivers microwave energy to produce coagulation necrosis in prostatic tissue. This is an update of a review last published in 2012. OBJECTIVES: To assess the effects of transurethral microwave thermotherapy for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia. SEARCH METHODS: We performed a comprehensive search using multiple databases (the Cochrane Library, MEDLINE, Embase, Scopus, Web of Science, and LILACS), trials registries, other sources of grey literature, and conference proceedings published up to 31 May 2021, with no restrictions by language or publication status. SELECTION CRITERIA: We included parallel-group randomized controlled trials (RCTs) and cluster-RCTs of participants with BPH who underwent TUMT. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed studies for inclusion at each stage and undertook data extraction and risk of bias and GRADE assessments of the certainty of the evidence (CoE). We considered review outcomes measured up to 12 months after randomization as short-term and beyond 12 months as long-term. Our main outcomes included: urologic symptoms scores, quality of life, major adverse events, retreatment, and ejaculatory and erectile function. MAIN RESULTS: In this update, we identified no new RCTs, but we included data from studies excluded in the previous version of this review. We included 16 trials with 1919 participants, with a median age of 69 and moderate lower urinary tract symptoms. The certainty of the evidence for most comparisons was moderate-to-low, due to an overall high risk of bias across studies and imprecision (few participants and events). TUMT versus TURP Based on data from four studies with 306 participants, when compared to TURP, TUMT probably results in little to no difference in urologic symptom scores measured by the International Prostatic Symptom Score (IPSS) on a scale from 0 to 35, with higher scores indicating worse symptoms at short-term follow-up (mean difference (MD) 1.00, 95% confidence interval (CI) -0.03 to 2.03; moderate certainty). There is likely to be little to no difference in the quality of life (MD -0.10, 95% CI -0.67 to 0.47; 1 study, 136 participants, moderate certainty). TUMT likely results in fewer major adverse events (RR 0.20, 95% CI 0.09 to 0.43; 6 studies, 525 participants, moderate certainty); based on 168 cases per 1000 men in the TURP group, this corresponds to 135 fewer (153 to 96 fewer) per 1000 men in the TUMT group. TUMT, however, probably results in a large increase in the need for retreatment (risk ratio (RR) 7.07, 95% CI 1.94 to 25.82; 5 studies, 337 participants, moderate certainty) (usually by repeated TUMT or TURP); based on zero cases per 1000 men in the TURP group, this corresponds to 90 more (40 to 150 more) per 1000 men in the TUMT group. There may be little to no difference in erectile function between these interventions (RR 0.63, 95% CI 0.24 to 1.63; 5 studies, 337 participants; low certainty). However, TUMT may result in fewer cases of ejaculatory dysfunction compared to TURP (RR 0.36, 95% CI 0.24 to 0.53; 4 studies, 241 participants; low certainty). TUMT versus sham Based on data from four studies with 483 participants we found that, when compared to sham, TUMT probably reduces urologic symptom scores using the IPSS at short-term follow-up (MD -5.40, 95% CI -6.97 to -3.84; moderate certainty). TUMT may cause little to no difference in the quality of life (MD -0.95, 95% CI -1.14 to -0.77; 2 studies, 347 participants; low certainty) as measured by the IPSS quality-of-life question on a scale from 0 to 6, with higher scores indicating a worse quality of life. We are very uncertain about the effects on major adverse events, since most studies reported no events or isolated lesions of the urinary tract. TUMT may also reduce the need for retreatment compared to sham (RR 0.27, 95% CI 0.08 to 0.88; 2 studies, 82 participants, low certainty); based on 194 retreatments per 1000 men in the sham group, this corresponds to 141 fewer (178 to 23 fewer) per 1000 men in the TUMT group. We are very uncertain of the effects on erectile and ejaculatory function (very low certainty), since we found isolated reports of impotence and ejaculatory disorders (anejaculation and hematospermia). There were no data available for the comparisons of TUMT versus convective radiofrequency water vapor therapy, prostatic urethral lift, prostatic arterial embolization or temporary implantable nitinol device. AUTHORS' CONCLUSIONS: TUMT provides a similar reduction in urinary symptoms compared to the standard treatment (TURP), with fewer major adverse events and fewer cases of ejaculatory dysfunction at short-term follow-up. However, TUMT probably results in a large increase in retreatment rates. Study limitations and imprecision reduced the confidence we can place in these results. Furthermore, most studies were performed over 20 years ago. Given the emergence of newer minimally-invasive treatments, high-quality head-to-head trials with longer follow-up are needed to clarify their relative effectiveness. Patients' values and preferences, their comorbidities and the effects of other available minimally-invasive procedures, among other factors, can guide clinicians when choosing the optimal treatment for this condition.

Performing thermal ablations for hepatomas - is it a worthy skill for hepatologists?

INTRODUCTION AND OBJECTIVES: The role of hepatologists in the management of hepatocellular carcinoma (HCC) is not well defined. We conducted a cross-sectional study to assess the feasibility of hepatology-directed HCC treatment. PATIENTS: We evaluated 107 patients with newly diagnosed HCC, undergoing locoregional therapy as the first therapy between January 2017 and February 2019. RESULTS: The hepatologist directly participated in most of the microwave ablations. This descriptive cross-sectional study reveals the feasibility of the hepatologist-directed thermal ablation therapy, with decent outcome including response rate. CONCLUSIONS: Hepatologists can play a key role in the management of HCC in the current era of multidisciplinary team approach. Training fellows in performing ultrasound guided thermal ablation techniques would be one step forward in this direction.

Análise microestrutural e propriedades mecânicas de cerâmicas vítreas cristalizadas por energia de micro-ondas / Microstructural characterization and mechanical properties of glassceramics crystallized by microwave energy

O objetivo deste trabalho foi verificar a viabilidade de um processo alternativo de cristalização por meio de energia de micro-ondas, e estabelecer um protocolo de cristalização para três vitrocerâmicas comerciais; além de avaliar o efeito deste processo na microestrutura e propriedades mecânicas das mesmas. A hipótese nula foi que a cristalização por meio de energia de micro-ondas não afetou as características microestruturais e consequentemente as propriedades destes materiais cerâmicos. Foram confeccionados 180 discos a partir de blocos de três diferentes vitrocerâmicas: dissilicato de lítio (IPS e.max CAD, Ivoclar Vivadent) e silicatos de lítio reforçados por zircônia (I ­ Suprinity, Vita Zahnfabrik; II ­ Celtra, Dentsply), seguindo as dimensões da norma ISO 6872 (12 x 1,2 mm). Foram testadas três temperaturas de cristalização em forno de micro-ondas (700ºC, 770ºC e 850ºC), e os testes de flexão biaxial, MEV e DRX foram utilizados para definir qual a temperatura em que as cerâmicas apresentaram melhor comportamento. Os testes de densidade, translucidez, rugosidade superficial, dureza Vickers e desgaste de três e dois corpos foram realizados com as amostras cristalizadas apenas nas temperaturas selecionadas para cada cerâmica. Para o grupo DL-mo, a temperatura de cristalização foi 850ºC, e a resistência do material aumentou (422,4 ± 63,53). Para os grupos SLZ1-mo e SLZ2-mo, a temperatura de cristalização foi 770ºC, com resistências aproximadamente semelhantes ao grupo convencional (302,8 ± 37,86 e 268,7 ± 44,85 respectivamente). Os testes de translucidez e densidade mostraram uma relação estatística em que as cerâmicas com maior densidade possuem maior translucidez, como as SLZ1-mo e SLZ2-mo. O teste de rugosidade não apresentou diferença estatística para os parâmetros Ra e Rsm, apenas para Rz. Para o teste de desgaste de três corpos, o grupo cristalizado em micro-ondas sofreu menor taxa de desgaste (0.22 ± 0.71) do que o grupo convencional (0.62 ± 0.4); enquanto para o teste de desgaste de dois corpos a forma de cristalização não foi uma variável estatisticamente significante. SLZ1 apresentou maior taxa de desgaste, independentemente da forma de cristalização (1.30 ± 1.79). Concluiu-se que o processo de cristalização é viável para vitrocerâmicas, e que diferentes temperaturas de cristalização resultam em diferentes microestruturas e propriedades mecânicas. A temperatura de cristalização para DL, utilizando energia de micro-ondas, é 850ºC e para SLZ1 e SLZ2 é 770ºC. Cerâmicas cristalizadas em forno de micro-ondas apresentam menor taxa de desgaste, maior resistência à flexão, maiores módulos de Weibull, e consequentemente maior longevidade(au)

The aim of this study was to verify the viability of an alternative process of crystallization using microwave energy and to establish a crystallization protocol for three commercial glass-ceramics; besides evaluating the effect of this process on the microstructure and mechanical properties of them. The null hypothesis was that the crystallization by microwave energy did not affect the microstructural characteristics and consequently the mechanical properties of these ceramic materials. 180 discs were made from blocks of three different glass-ceramics: lithium disilicate (IPS e.max CAD, Ivoclar Vivadent) and lithium silicates reinforced by zirconia (I - Suprinity, Vita Zahnfabrik; II - Celtra, Dentsply); according to ISO 6872 (dimensions: 12 x 1.2 mm). Three crystallization temperatures were tested in a microwave oven (700ºC, 770ºC and 850ºC), and the biaxial flexure, SEM and XRD tests were performed to define the temperature in which the ceramics presented their best behavior. Density, translucency, surface roughness, Vickers hardness and three and two-body wear tests were performed with the crystallized samples only at the selected temperatures for each ceramic. For DL-mo group, the crystallization temperature was 850ºC and material's resistance increased (422.4 ± 63.53). For SLZ1-mo and SLZ2-mo groups, the crystallization temperature was 770ºC, with resistances approximately similar to the conventional group (302.8 ± 37.86 and 268.7 ± 44.85 respectively). Translucency and density tests showed that the higher the density, the higher the translucency. The roughness test showed no statistical difference for Ra and Rsm parameters, only for Rz. For the three-body wear test, the microwave crystallized group suffered lower wear rate (0.22 ± 0.71) than the conventional group (0.62 ± 0.4); while for the two-body wear test the crystallization approach was not a statistically significant variable. SLZ1 presented higher wear rates, regardless of the crystallization approach (1.30 ± 1.79). It was concluded that the crystallization process is viable for glass ceramics, and that different crystallization temperatures result in different microstructures and mechanical properties. The crystallization temperature for DL using microwave energy is 850ºC and for SLZ1 and SLZ2 is 770ºC. Microwave oven crystallized ceramics have a lower wear rate, higher flexural resistance, higher Weibull modulus, and consequently higher longevity(AU)

Efeito da forma de aquecimento em parâmetros de qualidade e identidade de óleos vegetais / Effect of the heating means in quality and identity parameters of vegetable oils

Objetivou-se com este trabalho avaliar parâmetros de identidade e qualidade de óleo de abacate produzido nacionalmente, comparativamente a azeite de oliva e óleo de arroz, após aquecimento em bloco digestor ou micro-ondas. Avaliaram-se amostras sem aquecimento (controle) e aquecidas por 1:30 h em bloco digestor ou 3 min em micro-ondas. Determinaram-se a acidez e os índices iodo e refração. Os resultados indicaram que houve aumento de acidez, redução no índice de iodo e índice de refração após o aquecimento. Apesar do maior valor de acidez após o aquecimento, o óleo de abacate sofreu menor elevação em relação ao controle (cerca de 4 vezes) do que as demais amostras. O impacto do aquecimento foi maior no óleo de arroz, seguido do azeite de oliva. O aquecimento por micro-ondas afetou mais a qualidade das amostras que o aquecimento em bloco digestor.(AU)

Determinação de protocolo para descristalização de mel em micro-ondas / Standard to melt honey with microwaves

O presente estudo teve como objetivo obter um protocolo para descristalização do mel de forma a não alterar os parâmetros físico-químicos. Para o estudo, foram utilizadas amostras de mel que estavam cristalizadas nos locais de compra, sendo estas submetidas em micro-ondas a diferentes níveis de potência (Mínima, Média e Alta) e tempos (5, 10, 15 e 20 segundos). As amostras de mel apresentaram valores de 2,57 a 3,58 mg.kg de hidroximetilfurfural (HMF). Além da análise de HMF, foram avaliados também o teor de umidade, Teste de Fiehe, Prova de Lugol e Lund, sendo obtidos resultados dentro do preconizado na legislação brasileira. Um protocolo adequado para descristalizaçao de mel em micro-ondas foi obtido com uso de potência média e com tempo de 15 segundos.(AU)

Determinação de protocolo para descristalização de mel em micro-ondas / Standard to melt honey with microwaves

O presente estudo teve como objetivo obter um protocolo para descristalização do mel de forma a não alterar os parâmetros físico-químicos. Para o estudo, foram utilizadas amostras de mel que estavam cristalizadas nos locais de compra, sendo estas submetidas em micro-ondas a diferentes níveis de potência (Mínima, Média e Alta) e tempos (5, 10, 15 e 20 segundos). As amostras de mel apresentaram valores de 2,57 a 3,58 mg.kg de hidroximetilfurfural (HMF). Além da análise de HMF, foram avaliados também o teor de umidade, Teste de Fiehe, Prova de Lugol e Lund, sendo obtidos resultados dentro do preconizado na legislação brasileira. Um protocolo adequado para descristalizaçao de mel em micro-ondas foi obtido com uso de potência média e com tempo de 15 segundos.

Efeito da forma de aquecimento em parâmetros de qualidade e identidade de óleos vegetais / Effect of the heating means in quality and identity parameters of vegetable oils

Objetivou-se com este trabalho avaliar parâmetros de identidade e qualidade de óleo de abacate produzido nacionalmente, comparativamente a azeite de oliva e óleo de arroz, após aquecimento em bloco digestor ou micro-ondas. Avaliaram-se amostras sem aquecimento (controle) e aquecidas por 1:30 h em bloco digestor ou 3 min em micro-ondas. Determinaram-se a acidez e os índices iodo e refração. Os resultados indicaram que houve aumento de acidez, redução no índice de iodo e índice de refração após o aquecimento. Apesar do maior valor de acidez após o aquecimento, o óleo de abacate sofreu menor elevação em relação ao controle (cerca de 4 vezes) do que as demais amostras. O impacto do aquecimento foi maior no óleo de arroz, seguido do azeite de oliva. O aquecimento por micro-ondas afetou mais a qualidade das amostras que o aquecimento em bloco digestor.

Método de obtenção de matéria seca e composição química de volumosos / Dry matter obtainiment method and chemical composition of roughages

Objetivou-se avaliar a influência do método de secagem sobre a composição nutricional de diferentes volumosos. Foram utilizadas quatro gramíneas (Urochloa brizantha cv. Marandu, Urochloa brizantha cv. MG4, Cynodon dactylon cv. Coastcross e Panicum maximum cv. Áries), uma leguminosa forrageira, o estilosante (Stylosanthes cv. Campo Grande) e duas silagens (Zea mays e Triticum aestivum cv. BRS Umbu). Os métodos de secagem se basearam no uso da estufa de ventilação forçada e de forno de micro-ondas. O delineamento estatístico utilizado foi um arranjo fatorial 2 x 8 (2 métodos de secagem e 8 volumosos) com 4 repetições. O método de secagem não influenciou o conteúdo de matéria seca das forragens. A secagem em forno micro-ondas elevou os teores de fibra em detergente neutro nos volumosos avaliados. Houve interação entre o método de secagem e tipo de forragem avaliada, com relação à proteína bruta (estilosante), extrato etéreo (MG4, estilosante e Áries) e nitrogênio insolúvel em detergente neutro (Coastcross, MG4, Marandu e estilosante). O forno de micro-ondas pode ser utilizado como instrumento para obtenção da matéria seca em alimentos volumosos, porém, a técnica pode afetar a composição da forragem avaliada.

It was aimed determinate the influence of drying methods on nutritional composition of different roughages. The experimental material were four grass species (Urochloa brizantha cv. Marandu, Urochloa brizantha cv. MG4, Cynodon dactylon cv. Coastcross e Panicum maximum cv. Áries), one forage legume (Stylosanthes cv. Campo Grande) and two silages (Zea mays e Triticum aestivum cv. BRS Umbu). The drying methods were based on use of forced air oven or microwave oven. The experimental design were a 2 x 8 factorial arrangement (2 drying methods and 8 roughages) with 4 repetitions. There was no effect of drying method on roughages dry matter content. Microwave oven drying increased neutral detergent fiber. There was an interaction between drying method and evaluated roughage. Increased contents of crude protein (estilosante), neutral detergent insoluble nitrogen (Coastcross, MG4, Marandu e estilosante) and ether extract (MG4, estilosante e Áries) were observed when roughages were dried using microwave oven. The microwave oven usage is an alternative to obtain the dry matter content of roughages; however this technic may affect the sample composition.

Método de obtenção de matéria seca e composição química de volumosos / Dry matter obtainiment method and chemical composition of roughages

Objetivou-se avaliar a influência do método de secagem sobre a composição nutricional de diferentes volumosos. Foram utilizadas quatro gramíneas (Urochloa brizantha cv. Marandu, Urochloa brizantha cv. MG4, Cynodon dactylon cv. Coastcross e Panicum maximum cv. Áries), uma leguminosa forrageira, o estilosante (Stylosanthes cv. Campo Grande) e duas silagens (Zea mays e Triticum aestivum cv. BRS Umbu). Os métodos de secagem se basearam no uso da estufa de ventilação forçada e de forno de micro-ondas. O delineamento estatístico utilizado foi um arranjo fatorial 2 x 8 (2 métodos de secagem e 8 volumosos) com 4 repetições. O método de secagem não influenciou o conteúdo de matéria seca das forragens. A secagem em forno micro-ondas elevou os teores de fibra em detergente neutro nos volumosos avaliados. Houve interação entre o método de secagem e tipo de forragem avaliada, com relação à proteína bruta (estilosante), extrato etéreo (MG4, estilosante e Áries) e nitrogênio insolúvel em detergente neutro (Coastcross, MG4, Marandu e estilosante). O forno de micro-ondas pode ser utilizado como instrumento para obtenção da matéria seca em alimentos volumosos, porém, a técnica pode afetar a composição da forragem avaliada.(AU)

It was aimed determinate the influence of drying methods on nutritional composition of different roughages. The experimental material were four grass species (Urochloa brizantha cv. Marandu, Urochloa brizantha cv. MG4, Cynodon dactylon cv. Coastcross e Panicum maximum cv. Áries), one forage legume (Stylosanthes cv. Campo Grande) and two silages (Zea mays e Triticum aestivum cv. BRS Umbu). The drying methods were based on use of forced air oven or microwave oven. The experimental design were a 2 x 8 factorial arrangement (2 drying methods and 8 roughages) with 4 repetitions. There was no effect of drying method on roughages dry matter content. Microwave oven drying increased neutral detergent fiber. There was an interaction between drying method and evaluated roughage. Increased contents of crude protein (estilosante), neutral detergent insoluble nitrogen (Coastcross, MG4, Marandu e estilosante) and ether extract (MG4, estilosante e Áries) were observed when roughages were dried using microwave oven. The microwave oven usage is an alternative to obtain the dry matter content of roughages; however this technic may affect the sample composition.(AU)

Effects of microwave ablation or its combination with whole-body chemotherapy on serum vascular endothelial growth factor levels in patients with stage IIIB/IV NSCLC.

We aimed to analyze the changes of serum vascular endothelial growth factor (VEGF) before and after microwave ablation (MWA) in patients with stage IIIB-IV non-small cell lung cancer (NSCLC), and to observe the effects of MWA combined with chemotherapy on short-term therapeutic efficacy and long-term survival. Concentrations of serum VEGF in 20 healthy subjects were considered as controls. Changes of serum VEGF were detected by ELISA before and after MWA (1 and 7 days after treatment). Seven days after MWA, patients were divided into a combination chemotherapy group of 22 subjects and a MWA alone group of 18 subjects. Serum VEGF was measured 1 month after MWA and 4 cycles after chemotherapy (3 months) to evaluate term effects; and 1- and 2-year survival rates. Serum VEGF concentrations declined sharply 1 day after MWA, and were significantly different from the levels before treatment. Subsequently, VEGF rebounded 7 days after ablation, higher than that before treatment. At 1 and 3 months, serum VEGF levels in both treatment groups were remarkably lower than that before treatment; efficiency, or for the 1-year survival rate. However, the 2-year survival rates were significantly different between the two groups. We demonstrated that after MWA, the serum VEGF concentration undergoes a process of increasing, which might promote metastasis and recurrence of NSCLC. MWA combined with whole-body chemotherapy appears to be an effective method to increase the disease control rate, reduce the probability of metastasis and recurrence, and thus improve long-term survival.

Prevalence of fatigue reported by physiotherapists operating diathermy equipment for microwave.

OBJECTIVE: To Analyze the association between prevalence of fatigue referred by physical therapists and their occupational exposure to radiation emitted by therapeutic microwave diathermy equipment. METHODS: A Cross-sectional study conducted in 193 physical therapists from four cities of the west of Paraná State, Brazil. A specified structured web questionnaire was applied for collecting data about microwave diathermy exposition and potential confounders, plus the Multidimensional Assessment of Fatigue (MAF). Statistical analysis included logistic regression and Student's t-test. RESULTS: The prevalence of fatigue in the category exposed to microwave diathermy was higher (15.0%) than in non-exposed (2.9%). On multivariate logistic regression, a significant independent association between exposure to microwave diathermy and prevalence of fatigue was observed (odds ratio 4.93; 95% confidence interval 1.04 - 23.25; p = 0.04). The Student's t-test showed significant difference between the number of hours exposed to diathermy microwave, being 3,839.1 within physical therapists who referred fatigue and 497.6 within others (p = 0.004). CONCLUSION: The results demonstrate a significant and independent association between occupational exposure of physical therapists to radiation of microwave diathermy and prevalence of fatigue. Therefore, occupational safety guidelines aimed at these professionals as a prevention of possible adverse effects, as well as the replication of this study are suggested.

Prevalence of fatigue reported by physiotherapists operating diathermy equipment for microwave / Prevalência de fadiga referida por fisioterapeutas que operam equipamentos de diatermia por micro-ondas

Objective: To Analyze the association between prevalence of fatigue referred by physical therapists and their occupational exposure to radiation emitted by therapeutic microwave diathermy equipment. Methods: A Cross-sectional study conducted in 193 physical therapists from four cities of the west of Paraná State, Brazil. A specified structured web questionnaire was applied for collecting data about microwave diathermy exposition and potential confounders, plus the Multidimensional Assessment of Fatigue (MAF). Statistical analysis included logistic regression and Student's t-test. Results: The prevalence of fatigue in the category exposed to microwave diathermy was higher (15.0%) than in non-exposed (2.9%). On multivariate logistic regression, a significant independent association between exposure to microwave diathermy and prevalence of fatigue was observed (odds ratio 4.93; 95% confidence interval 1.04 - 23.25; p = 0.04). The Student's t-test showed significant difference between the number of hours exposed to diathermy microwave, being 3,839.1 within physical therapists who referred fatigue and 497.6 within others (p = 0.004). Conclusion: The results demonstrate a significant and independent association between occupational exposure of physical therapists to radiation of microwave diathermy and prevalence of fatigue. Therefore, occupational safety guidelines aimed at these professionals as a prevention of possible adverse effects, as well as the replication of this study are suggested. .

Objetivo: Analisar a associação entre a prevalência de fadiga referida por fisioterapeutas e a exposição desses profissionais à radiação emitida por equipamentos terapêuticos de diatermia por micro-ondas. Metodologia: Foi realizado estudo de corte transversal com 193 fisioterapeutas de quatro municípios da região Oeste do Estado do Paraná, Brasil. Foi aplicado, via eletrônica, questionário estruturado especialmente para a coleta de dados sobre a exposição ocupacional à radiação emitida por equipamentos de diatermia por micro-ondas e potenciais fatores de confusão, acrescido do questionário de Avaliação Multidimensional de Fadiga. A análise estatística incluiu regressão logística e teste t de Student. Resultados: A prevalência de fadiga na categoria expostos a micro-ondas foi maior (15,0%) do que em não expostos (2,9%). Na regressão logística multivariada foi observada associação independente significante entre a exposição ocupacional de fisioterapeutas à radiação de diatermia por micro-ondas e a prevalência de fadiga (odds ratio 4,93; intervalo de confiança de 95% 1,04 - 23,25; p = 0,04). O teste t de Student mostrou diferença significante entre o número total de horas de exposição à radiação de diatermia por micro-ondas, sendo de 3.891,1 entre os fisioterapeutas que referiram fadiga e de 497,6 entre os que não referiram (p = 0,004). Conclusão: Os resultados demonstraram associação significante entre a exposição ocupacional de fisioterapeutas à radiação emitida por equipamentos de diatermia por micro-ondas e fadiga, portanto, são sugeridas orientações de segurança ocupacional, dirigidas a esses profissionais, como medida preventiva ...

Determinação do teor de umidade em grãos empregando radiação micro-ondas / Determination of grain moisture content using microwave radiation

A determinação de umidade em grãos é um parâmetro de qualidade importante, uma vez que o teor de água presente no alimento tem influência tanto no armazenamento quanto na comercialização do produto. Os métodos usados como referência na determinação de umidade em grãos empregam a perda por dessecação em estufa (LOD). Apesar de ser de fácil execução, esse método dispende cerca de 24h de aquecimento, normalmente, em 105°C, para obtenção do resultado. No presente estudo, é proposta a determinação da perda por dessecação assistida por radiação micro-ondas (MALOD) para amostras de grãos moídos de arroz branco, arroz integral, ervilha, feijão branco, feijão carioca, feijão preto, grão-de-bico, lentilha e milho, buscando reduzir o tempo de análise. Parâmetros como potência irradiada, massa de amostra, influência do recipiente e tempo de irradiação com micro-ondas foram avaliados e os resultados obtidos foram comparados com a LOD (sugerido pelo MAPA) e, também, por radiação infravermelha (IRLOD). Verificou-se que não houve diferença significativa do teor de umidade empregando massas de amostra entre 2 e 15g por LOD, porém, para MALOD, ocorreram hot spots (carbonização da amostra) com massas superiores a 2g. Resultados similares de umidade foram encontrados entre os diferentes recipientes (pesa-filtros e frascos de polipropileno), optando-se pela utilização dos frascos de polipropileno, devido à diminuição do tempo de pré-condicionamento. A MALOD apresentou concordância entre 94% e 102% com o método oficial, sendo que apenas 50min foram suficientes para determinar a umidade para todos os grãos, perfazendo uma redução do tempo de análise de até 29 vezes.(AU)

The determination of moisture in grains is an important quality parameter, since the water content in food has an influence on both storage and commercialization of product. The methods often used for determination of moisture in grains are based on the loss on drying in an oven (LOD). Although it is easy to perform, this method spent about 24h of heating, usually at 105°C, to obtain the result. In the present study is proposed the determination of the loss on drying assisted by microwave radiation (MALOD) for samples of grounded grains of white rice, brown rice, peas, beans, bean, black beans, chick-peas, lentils and corn, in order to reduce the analysis time. Parameters such as irradiated power, sample mass, container and influence of irradiation time with microwave were evaluated and the results were compared with those obtained by LOD (suggested by MAPA) and also by infrared radiation (IRLOD). It was found that there was no significant difference in moisture content in samples between 2 and 15g using LOD, but there were hot spots for MALOD (carbonization of the sample) with masses higher than 2g. Similar results for moisture content were found by the use of different containers (glass weighing bottle and polypropylene flasks) and the polypropylene cups were selected due to the reduction of conditioning time of flasks. The agreement of MALOD with the official method was between 94% and 102% and only 50min were enough to determine the moisture of all grains, making a reduction of analysis time by 29 times.(AU)

The therapeutic effect of a pulsed electromagnetic field on the reproductive patterns of male Wistar rats exposed to a 2.45-GHz microwave field.

INTRODUCTION: Environmental exposure to man-made electromagnetic fields has been steadily increasing with the growing demand for electronic items that are operational at various frequencies. Testicular function is particularly susceptible to radiation emitted by electromagnetic fields. OBJECTIVES: This study aimed to examine the therapeutic effects of a pulsed electromagnetic field (100 Hz) on the reproductive systems of male Wistar rats (70 days old). METHODS: The experiments were divided into five groups: microwave sham, microwave exposure (2.45 GHz), pulsed electromagnetic field sham, pulsed electromagnetic field (100 Hz) exposure, and microwave/pulsed electromagnetic field exposure. The animals were exposed for 2 hours/day for 60 days. After exposure, the animals were sacrificed, their sperm was used for creatine and caspase assays, and their serum was used for melatonin and testosterone assays. RESULTS: The results showed significant increases in caspase and creatine kinase and significant decreases in testosterone and melatonin in the exposed groups. This finding emphasizes that reactive oxygen species (a potential inducer of cancer) are the primary cause of DNA damage. However, pulsed electromagnetic field exposure relieves the effect of microwave exposure by inducing Faraday currents. CONCLUSIONS: Electromagnetic fields are recognized as hazards that affect testicular function by generating reactive oxygen species and reduce the bioavailability of androgen to maturing spermatozoa. Thus, microwave exposure adversely affects male fertility, whereas pulsed electromagnetic field therapy is a non-invasive, simple technique that can be used as a scavenger agent to combat oxidative stress.

Análise química e microbiológica de laranja antes e após cocção em microondas / Chemical and microbiological analysis of orange before and after cooking in microwave

No Brasil há um número crescente de novos casos de câncer, sendo a segunda causa de morte em nível mundial. Os diferentes estágios da doença levam o paciente ao desinteresse pelos alimentos devido às alterações que ocorrem em seu organismo. Esse trabalho teve como objetivo realizar análise química e microbiológica da laranja antes e após cocção em micro-ondas em 20, 30 e 40 segundos. As laranjas de suco foram descascadas e cortadas em 8 partes e, após, foram realizados os tratamentos térmicos em diferentes tempos. A seguir, foram efetuadas as análises químicas e microbiológicas. Os resultados obtidos mostraram que a vitamina C permaneceu inalterada no tratamento térmico de 20 segundos, além de haver uma concentração de 8% de proteínas. As análises microbiológicas não demonstraram contaminação representativa, de acordo com a legislação. Com isso, conclui-se que o tratamento térmico de 20 segundos foi mais apropriado, levando em consideração o aspecto microbiológico, organoléptico e químico.(AU)

In Brazil there is a growing number of new cases of the cancer and it the second cause of death the worldwide level. The differents stages of disease lead the patient at the selflessness toward nutriment, owing at the alteration that occur in his organism. This work had like objective to realize chemistry and biological analyses of orange, before and after cooking in microwaves at 20, 30 and 40 seconds. The oranges of juice were peel and cut in 8 parts and thermal treatments were realizing at differents times, then effected the chemistry and biological analyses. The results showed that, the vitamin C stood unaffected in thermal treatment of 20 seconds, besides there was a concentration of 8% protein. The microbiological analyses don 't demonstrate representative contamination, of according with the legislation. Therefore, it is conclude that thermal treatment of 20 seconds was the most appropriate take into consideration the microbiological, organoleptics and chemistry aspects. (AU)

Hot water bath treatments assisted by microwave energy to delay postharvest ripening and decay in strawberries (Fragaria × ananassa).

BACKGROUND: A lab-scale approach using microwave (MW)-assisted hot water treatments was developed and tested to assess the potential of this heating method to delay postharvest ripening and decay in strawberries. Strawberries (Fragaria × ananassa) immersed in water were exposed to microwaves at a frequency of 2450 MHz for 3 min at 514 W or 1 min 50 s at 763 W to reach an average temperature of 43.8 ± 0.6 °C at the fruit centre. Another batch was treated in hot water at 45 °C for 15 min, and a final batch was not treated (control). RESULTS: After 9 days of refrigerated storage (3 °C and 90% relative humidity), all heat-treated strawberries showed significant retention of quality parameters such as colour and firmness and significantly lower yeast and mould populations (P < 0.05). CONCLUSION: Strawberries subjected to MW-assisted hot water treatments showed significantly better retention of lightness compared with conventionally treated berries. A short (1 min 50 s) treatment at 763 W was the best choice to prevent strawberry decay.

The therapeutic effect of a pulsed electromagnetic field on the reproductive patterns of male Wistar rats exposed to a 2.45-GHz microwave field

INTRODUCTION: Environmental exposure to man-made electromagnetic fields has been steadily increasing with the growing demand for electronic items that are operational at various frequencies. Testicular function is particularly susceptible to radiation emitted by electromagnetic fields. OBJECTIVES: This study aimed to examine the therapeutic effects of a pulsed electromagnetic field (100 Hz) on the reproductive systems of male Wistar rats (70 days old). METHODS: The experiments were divided into five groups: microwave sham, microwave exposure (2.45 GHz), pulsed electromagnetic field sham, pulsed electromagnetic field (100 Hz) exposure, and microwave/pulsed electromagnetic field exposure. The animals were exposed for 2 hours/day for 60 days. After exposure, the animals were sacrificed, their sperm was used for creatine and caspase assays, and their serum was used for melatonin and testosterone assays. RESULTS: The results showed significant increases in caspase and creatine kinase and significant decreases in testosterone and melatonin in the exposed groups. This finding emphasizes that reactive oxygen species (a potential inducer of cancer) are the primary cause of DNA damage. However, pulsed electromagnetic field exposure relieves the effect of microwave exposure by inducing Faraday currents. CONCLUSIONS: Electromagnetic fields are recognized as hazards that affect testicular function by generating reactive oxygen species and reduce the bioavailability of androgen to maturing spermatozoa. Thus, microwave exposure adversely affects male fertility, whereas pulsed electromagnetic field therapy is a non-invasive, simple technique that can be used as a scavenger agent to combat oxidative stress.