Smear layer removal by passive ultrasonic irrigation and 2 new mechanical methods for activation of the chelating solution

Machado Ricardo,da Silva Isadora,Comparin Daniel,de Mattos Bianca Araujo Marques,Alberton Luiz Rômulo,da Silva Neto Ulisses Xavier 대한치과보존학회 2021 Restorative Dentistry & Endodontics Vol.46 No.1

Objectives: The aim of this study was to compare smear layer removal by conventional application (CA), passive ultrasonic irrigation (PUI), EasyClean (EC), and XP-Endo Finisher (XPF), using 17% ethylenediaminetetraacetic acid (EDTA) after chemomechanical preparation, as evaluated with scanning electron microscopy (SEM). Materials and Methods: Forty-five single-rooted human mandibular premolars were selected for this study. After chemomechanical preparation, the teeth were randomly divided into 5 groups according to the protocol for smear layer removal, as follows: G1 (control): CA of distilled water; G2 (CA): CA of 17% EDTA; G3 (PUI): 17% EDTA activated by PUI; G4 (EC): 17% EDTA activated by EC; and G5 (XPF): 17% EDTA activated by XPF. SEM images (×1,000) were obtained from each root third and scored by 3 examiners. Data were evaluated using the Kruskal-Wallis and Dunn tests (p < 0.05). Results: In the apical third, there were no statistically significant differences among the groups (p > 0.05). In the cervical and middle thirds, the experimental groups performed better than the control group (p < 0.05); however, G2 presented better results than G3, G4, and G5 (p < 0.05), which showed no differences among one another (p > 0.05). Conclusions: No irrigation method was able to completely remove the smear layer, especially in the apical third. Using CA for the chelating solution performed better than any form of activation.

Safety Assessment and Botanical Standardization of an Edible Species from South America

Giseli Karenina Traesel,Camila Dias Machado,Cleide Adriane Signor Tirloni,Jacqueline Vergutz Menetrier,Francislaine Aparecida dos Reis Lı´vero,Emerson Luiz Botelho Lourenco,Silvia Aparecida Oesterreic 한국식품영양과학회 2017 Journal of medicinal food Vol.20 No.5

Tropaeolum majus L. (Tropaeolaceae), commonly known as nasturtium, is an important edible plant native to the Andean States and widely disseminated throughout South America. Despite the use of this species is quite widespread, there are no minimum quality control standards or data on its genotoxicity. So, the aim of this study was to present a detailed anatomical and histochemical study for Tropaeolum majus and provide genotoxicity parameters of a preparation routinely used in South American countries. First, three different Tropaeolum majus aqueous extracts (TMAEs) at concentrations of 1.5%, 7%, and 15% were prepared according to the popular use. Then, genetic toxicity of TMAE was evaluated on bacterial reverse mutation, genomic lesions, and micronucleus formation in male rats. Furthermore, a detailed anatomical and histochemical study of the leaves and stems of Tropaeolum majus were performed. No revertant colonies were found in any bacterial cultures examined. In the comet assay, TMAE showed no significant DNA damage in all tested doses. Micronucleus assay showed no significant increases in the frequency of inducing micronuclei in any dose examined. Light and electron microscope images of cross-section of leaves and stems from Tropaeolum majus revealed useful diagnostic features. The presented data showed significant safety parameters for the use of TMAE and provided important data for the quality control of this plant species.

Supplementation with Selenium Can Influence Nausea, Fatigue, Physical, Renal, and Liver Function of Children and Adolescents with Cancer

Maria Luiza dos Santos Vieira,Fernando Luiz Affonso Fonseca,Larissa Grossi Costa,Registila Libania Beltrame,Carolina Machado de Sousa Chaves,Jairo Cartum,Sarah Isabel P. M. do N. Alves,Ligia Ajaime Az 한국식품영양과학회 2015 Journal of medicinal food Vol.18 No.1

The drugs used in chemotherapy treatments have little specificity, attack tumor cells, and also injure proliferative tissues. Knowledge of the functions of micronutrients has greatly increased, especially of Selenium (Se) that presents immunomodulatory and antitumor functions. The present study evaluated the health-related quality of life of patients undergoing chemotherapy for the treatment of leukemias and lymphomas (LL) and solid tumors (ST) while receiving Selenium (Se) supplementation. This is a randomized, double-blind, crossover study that evaluated the quality of life (EORTC-QLQC30 questionnaire), renal and liver functions of patients supplemented with Se. There was no statistically significant alteration in LL patients. However, the fatigue and nausea scores after 30 days did decrease in this group as well as in the ST group. After 1 year supplementation with Selenium, a more noticeable decrease in the scores concerning fatigue and nausea could be observed in the ST group, when compared with the beginning of the study. The LL patients also presented a decrease in the fatigue scores and physical functions. The kidney function as well as liver function has improved after Selenium supplementation when compared with the placebo intake in LL and ST patients, more remarkably in the LL group. Supplementation with Selenium promotes the reduction of chemotherapy side effects in cancer patients, especially by improving the conditions of patients with fatigue, nausea, and impaired physical function. Renal and liver functions have also improved.

The In Vitro Genotoxic Effect of Tucuma (Astrocaryum aculeatum), an Amazonian Fruit Rich in Carotenoids

Olmiro Cezimbra de Souza Filho,Michele Rorato Sagrillo,Luiz Filipe Machado Garcia,Alencar Kolinski Machado,Francine Cadona,Euler Esteves Ribeiro,Marta Maria Medeiros Frescura Duarte,Ademir Farias More 한국식품영양과학회 2013 Journal of medicinal food Vol.16 No.11

Tucuma (Astrocaryum aculeatum) is an Amazonian fruit that presents high levels of carotenoids and other bioactive compounds such as quercetin. The extracts of tucuma peel and pulp present strong antioxidant activity which illustrate an elevated concentration that causes cytotoxic effects in human peripheral blood mononuclear cells (PBMCs). This study performed additional investigations to analyze the potential genotoxic effects of the tucuma extracts on PBMCs. The genotoxicity was evaluated by DNA fragmentation, Comet assay, and chromosomal instability G-band assays. The acute tucuma extract treatment showed genoprotective effects against DNA denaturation when compared with untreated PBMC cells. However, in the experiments with 24 and 72 h treatments to tucuma treatments, we observed low genotoxicity through a concentration of 100 lg/mL, some genotoxic effects related to intermediary concentrations (100–500 lg/mL), and more pronounced genotoxic effects on higher tucuma extract concentrations. After 24 h of treatment, the reactive oxygen species were similar among treatments and PBMC control groups. However, the caspase-1 activity related to the apoptosis and pyroptosis process increased significantly in higher tucuma concentrations. In summary, tucuma extracts, despite their higher antioxidant content and antioxidant activity, would present PBMCs genotoxic effects that are dependent on concentration and time exposition. These results need to be considered in future in vitro and in vivo studies of tucuma effects.

Impact of secondary droplet activation on the contrasting cloud microphysical relationships during the wet and dry seasons in the Amazon

Yeom, Jae Min,Yum, Seong Soo,Mei, Fan,Schmid, Beat,Comstock, Jennifer,Machado, Luiz A.T.,Cecchini, Micael A. Elsevier 2019 Atmospheric research Vol.230 No.-

<P><B>Abstract</B></P> <P>Cloud microphysical data obtained from aircraft measurements during the GoAmazon2014/5 campaign were analyzed to examine the differences in cloud microphysical properties and relationships between the wet and dry seasons and their implications on cloud microphysical processes. Basically, the distinct differences in cloud microphysical properties between the wet and dry seasons were considered to be due to higher concentration of aerosols and their larger sizes in the dry season, leading to higher droplet concentration. Analyses of cloud microphysical relationships and mixing diagrams strongly suggest homogeneous mixing for most cloud segments in both the wet and dry seasons: diluted cloud parcels with smaller liquid water content (L) and lower droplet concentration (N) generally had smaller mean volume of cloud droplets (V). However, in the dry season some cloud segments included cloud parcels that had high N of small cloud droplets, which led to a low correlation between N and V and also between N and L. These features are speculated to be due to secondary activation of cloud droplets from the cloud condensation nuclei in the entrained air, which seemed more likely to occur in the dry season due to more favorable conditions for such a process, including larger sizes of entrained aerosols, higher fluctuation of vertical velocity and lager turbulent dissipation rate.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Microphysical properties of Amazonian clouds in the wet and dry seasons are studied. </LI> <LI> Microphysical relationships for most cloud segments suggest homogeneous mixing. </LI> <LI> There is high likelihood of secondary droplet activation in the dry season. </LI> </UL> </P>

Nonisentropic Phenomenological Model of a Reciprocating Compressor

Willian Moreira Duarte,Juan Jose Garcia Pabon,Antônio Augusto Torres Maia,LUIZ MACHADO 대한설비공학회 2019 International Journal Of Air-Conditioning and Refr Vol.27 No.4

This paper presents the development of a numerical, iterative and nonisentropic model for the thermodynamic processes of a reciprocating compressor of a refrigeration system operating at steady state. The mathematical model was implemented using the scientific software Engineering Equation Solver (EES) and it is based on the application of the energy equations in four regions of the compressor: inlet duct and chambers of pre-compression, compression, and post-compression. The model was validated with experimental data collected from an open-drive reciprocating compressor, operating with the refrigerant R-134a at different suction and discharge pressures and with different compressor rotational speeds. Model validation was made comparing the values of the mass flow rate and the discharge temperature of the compressor generated by the model with their corresponding experimental values for 33 experimental tests, the mean relative difference was − 0.2% for the discharge temperature and 2.9% for mass flow rate. In this validation, the output variables of the model were calculated considering the uncertainties from the input variables. The theoretical mean standard uncertainty is 2% for discharge temperature and 6% for mass flow rate. An analysis of the capacitive and thermal performance of the compressor was made using the model, which demonstrates a decrease in the capacitive and thermal efficiencies for increasing the pressure ratio or clearance volume.

USING A HEAT PUMP AS AN ALTERNATIVE TO SUPPORT SOLAR COLLECTOR FOR WATER HEATING IN BRAZIL

ROBERTS VINICIUS DE MELO REIS,RAPHAEL NUNES OLIVEIRA,LUIZ MACHADO,RICARDO NICOLAU NASSAR KOURY 대한설비공학회 2012 International Journal Of Air-Conditioning and Refr Vol.20 No.3

With related greenhouse e®ect environmental issues linked to the constant problems of the °uctuations in oil prices, the use of solar energy is an important renewable energy source. Brazil is a country which is privileged considering the high rates of solar irradiation present throughout almost the entire national territory. Nevertheless, during certain times of the year, there is a solar energy de¯cit, which leads solar systems to require electrical resistance support at these times. The use of electrical resistance represents 23.5% of electric energy consumption and it presents a low residential energy e±ciency. The purpose of this work is an alternative technical design for reduction of electric energy consumption through the use of a solar energy system together with a generating heat pump for water heaters for households, as well as the ¯nancial feasibility study on the use of this system. One such heat pump has been designed, constructed and tested experimentally. The average performance coe±cient is equal to 2.10, a low value due to the use of a hermetic reciprocating compressor. Despite this low moderate price coe±cient of acquisition and installation of a heat pump, one can allow a return on investment in from 2.1 to 3.3 years, whereas the equipment has a useful life of about 20 years, this period of return on investment is interesting.