Determining the free fall acceleration is a common practice in Physics didactic laboratories. In this work, we present an experimental proposal to measure the acceleration of gravity based on an problem from professor Moysés Nussenzveig’s Mechanics textbook. This determination is carried out using the movement of a glider on an inclined air track, and has discrepancy of the order of 0.5%.

A determinação da aceleração de queda livre é uma prática comum em laboratórios didáticos de Física. Neste trabalho, apresentamos uma proposta experimental para medir a aceleração da gravidade baseada em um exercício do livro didático de Mecânica do professor Moysés Nussenzveig. Essa determinação é realizada através do movimento de um carro sobre um trilho de ar inclinado, e possui discrepância da ordem de 0,5%.

Abstract Glyphosate is a herbicide commonly used in agriculture for weed control. Current agricultural production demands vast amounts of this product, which are applied by ground or aerial spraying. The concomitant aerial currents promote glyphosate drift to vegetated or urban areas. In this context, we hypothesized that the lichens, Parmotrema tinctorum and Usnea barbata, could be sensitive to the action of glyphosate and therefore be used to bio-indicate the presence of this herbicide in areas affected by drift. Since living organisms respond in different ways to the action of herbicides, our interest was also to indicate biological markers responsive to the action of glyphosate, through concentrations and exposure times of the thallus, besides identifying the most sensitive species. We evaluated the effect of different concentrations (0.0, 4.8, 9.6, and 19.2 mg L-1) and exposure times (24, 48, and 72 hours) to glyphosate on the morphoanatomy, photobiont vitality, photosynthetic efficiency, and oxidative metabolism of the thalli. We found that the lichens, P. tinctorum and U. barbata, respond to glyphosate stress, with prospects for use in the biomonitoring of pollutant dispersal from plantation areas. When using P. tinctorum as a bioindicator, lichen morphoanatomy, photobiont vitality, and photosynthetic pigment concentration were efficient biomarkers for the effect of concentration and exposure time. For U. barbata, the lichenic morphoanatomy and the activity of SOD and APX enzymes were essential tools to indicate the herbicide action. Parmotrema tinctotum, however, was characterized as more sensitive in bio-indicating the presence of this herbicide to diagnose the air quality in urban areas or vegetation sectors adjacent to agricultural environments.

Resumo O glifosato é um herbicida comumente utilizado na agricultura para o controle de ervas daninhas, contudo, a produção agrícola atual demanda quantidades gigantescas deste produto, que são aplicadas por pulverizações terrestres ou aéreas, que acompanhadas de correntes aéreas, promovem a deriva do glifosato para áreas vegetacionais ou urbanas. Neste contexto, nós levantamos a hipótese de que os líquens Parmotrema tinctorum e Usnea barbata pudessem ser sensíveis à ação do glifosato e, portanto, bioindicar a presença deste herbicida em áreas afetadas por deriva. Como os organismos vivos respondem de diferentes formas à ação dos herbicidas, nosso interesse foi também de indicar marcadores biológicos responsivos à ação do glifosato, por meio de concentrações e tempos de exposição dos talos, além de identificar a espécie mais sensível. Para isso, nós avaliamos o efeito de diferentes concentrações (0.0, 4.8, 9.6 e 19.2 mg L-1) e tempos de aexposição (24, 48 e 72 horas) ao glifosato, sobre a morfoanatomia, vitalidade do fotobionte, eficiência fotossintética e metabolismo oxidativo dos talos. Nós verificamos que os liquens P. tinctorum e U. barbata respondem ao estresse por glifosato, com perspectivas para serem utilizados no biomonitoramento da dispersão de poluentes a partir de áreas de plantio. Contudo, para o uso de P. tinctorum como bioindicador, a morfoanatomia liquênica, a vitalidade do fotobionte e a concentração de pigmentos fotossintéticos consistiram em biomarcadores eficientes para o efeito de concentração e tempo de exposição. Para U. barbata, a morfoanatomia liquênica, bem como a atividade das enzimas SOD e APX constituíram ferramentas importantes para evidenciar a ação do herbicida. A espécie P. tinctotum, contudo, foi caracterizada como mais sensível, sendo indicada para bioindicar a presença deste herbicida e para diagnosticar a qualidade do ar em áreas urbanas ou fragmentos vegetacionais imersos em matrizes agrícolas.

In this work, we studied the formation of hierarchical porous cartridges by means of bacterial cellulose impregnation with the zeolites A and X. Cellulose was successfully produced by Komagataeibacter genus and the zeolites were obtained by hydrothermal route. The composites were formed using both oxidized and non-oxidized cellulose. Different characterization techniques were used to analyze the resulting materials like powder X-ray diffraction, spectroscopic techniques (infrared vibrational spectroscopy and nuclear magnetic resonance), electron microscopy, thermal analyses, as well as ionic exchange experiments. The results show that the composites present layers with large voids among them, formed by cellulose nanofibrils tangling the particles in the oxidized samples, and shiftings in the bands referent to the carboxilyc groups and hydrogen bondings. The oxidation step for the cellulose seems to be important for the hierarchization and a positive effect on the cartridges is found for Ca2+ ionic exchange tests. Thus, these components can be successfully mixed to form cartridges with potential use at gas and liquid adsorption technologies.

ABSTRACT Objectives: To evaluate the impact of COVID-19 on clinical and surgical practice, educational activities, health and lifestyle behavior of Brazilian urology residents. Materials and Methods: A web-based survey was sent to 468 Brazilian urology residents from postgraduate years (PGY) 3 to 5 to collect data on clinical practice and training after 4 months of COVID-19. We also assessed health-related and behavior changes, rate of infection by SARS-CoV-2, deployment to the front line of COVID-19, residents’ concerns, and access to personal protective equipment (PPE). Results: Massive reductions in elective and emergency patient consultations, diagnostic procedures and surgeries were reported across the country, affecting PGY 3 to 5 alike. Most in-person educational activities were abolished. The median damage to the urological training expected for 2020 was 6.0 [3.4 – 7.7], on a scale from 0 to 10, with senior residents estimating a greater damage (P< 0.001). Educational interventions developed included online case-based discussions, subspeciality conferences and lectures, and grand rounds. Most senior residents favored extending residency to compensate for training loss and most younger residents favored no additional training (p< 0.001). Modifications in health and lifestyle included weight gain (43.8%), reduced physical activity (68.6%), increased alcoholic intake (44.9%) and cigarette consumption (53.6%), worsening of sexual life (25.2%) and feelings of sadness or depression (48,2%). Almost half were summoned to work on the COVID-19 front-line and 24.4% had COVID-19. Most residents had inadequate training to deal with COVID-19 patients and most reported a shortage of PPE. Residents’ concerns included the risk of contaminating family members, being away from residency program, developing severe COVID-19 and overloading colleagues. Conclusions: COVID-19 had a massive impact in Brazilian urology residents´ training, health and lifestyle behavior, which may reflect what happened in other medical specialties. Studies should confirm these findings to help developing strategies to mitigate residents’ losses.

ABSTRACT Introduction: Nocturnal enuresis is a highly incident chronic disorder that generates countless problems to the child and their parents. Bed-wetting has significant negative impacts on self-esteem and the performance of children. The aim of the current study is to assess the quality of life of enuretic children, as well as its association to sex and age. Patients and Methods: Thirty-nine enuretic children (23 boys) and 49 healthy children (27 boys) without any history of previous treatment for enuresis or voiding dysfunction were included. Age ranged between 6 and 11 years old. The “AUQEI” questionnaire was applied in a private environment to all children by the same researcher (psychologist) to evaluate quality of life. Results: Enuretic children displayed loss in quality of life when compared to non-enuretic (35.9% of enuretic x 16.3% of non-enuretic, p=0.035). They were mostly affected in their daily activities (p=0.02). No significant differences were found in the association of sex and gender with quality of life. These results suggest that, children with nocturnal enuresis have 2.87 times more chances of having loss in quality of life compared to non-enuretic. Conclusions: Enuresis has a great impact in quality of life of children. This impact is not related to the age or sex of the child.

ABSTRACT Objectives To evaluate the impact of COVID-19 on clinical practice, income, health and lifestyle behavior of Brazilian urologists during the month of April 2020. Materials and Methods A 39-question, web-based survey was sent to all urologist members of the Brazilian Society of Urology. We assessed socio-demographic, professional, health and behavior parameters. The primary goal was to evaluate changes in urologists’ clinical practice and income after two months of COVID-19. We also looked at geographical differences based on the incidence rates of COVID-19 in different states. Results Among 766 urologists who completed the survey, a reduction ≥ 50% of patient visits, elective and emergency surgeries was reported by 83.2%, 89.6% and 54.8%, respectively. An income reduction of ≥ 50% was reported by 54.3%. Measures to reduce costs were implemented by most. Video consultations were performed by 38.7%. Modifications in health and lifestyle included weight gain (32.9%), reduced physical activity (60.0%), increased alcoholic intake (39.9%) and reduced sexual activity (34.9%). Finally, 13.5% of Brazilian urologists were infected with SARS-CoV-2 and about one third required hospitalization. Urologists from the highest COVID-19 incidence states were at a higher risk to have a reduction of patient visits and non-essential surgeries (OR=2.95, 95% CI 1.86 – 4.75; p< 0.0001) and of being infected with SARS-CoV-2 (OR=4.36 95%CI 1.74-10.54, p=0.012). Conclusions COVID-19 produced massive disturbances in Brazilian urologists’ practice, with major reductions in patient visits and surgical procedures. Distressing consequences were also observed on physicians’ income, health and personal lives. These findings are probably applicable to other medical specialties.

Abstract We present a general investigation of a Long-Period Grating (LPG) for transverse strain measurement. The transverse strain sensing characteristics, for instance, the load intensity and azimuthal angle, are analyzed with the data set generated by the LPG sensor and probed by artificial neural network (ANN). Furthermore, we evaluate and compare the predictive performance of the interrogation model considering the square correlation coefficient (R2), root mean square error (RMSE) and mean absolute percentage error (MAPE). The results indicate that the ANN model could be successfully employed to estimate the load intensity and azimuthal angle using a single LPG sensor.

An alternating magnetic field (AMF)-stimuli responsive nanodevice based on magnetic nanoparticles (MNP) functionalized with water-soluble carboxylate-substituted pillar[5]arene (CP[5]A), namely MNP-CP[5]A, as a multiplatform for cancer treatment has been designed. MNP-CP[5]A was loaded with doxorubicin (DOX), showing a loading capacity of 9.5 mg g-1. The nanodevice demonstrated good colloidal stability, superparamagnetic behavior, and was capable to generate detectable heat in solution induced by AMF application. DOX release, monitored by ultraviolet-visible (UV-Vis) spectroscopy, was investigated by varying the temperature (37 and 45 °C) without AMF and in the presence of AMF (frequency (f) = 307 kHz, field amplitude (H) = 200 Oe, 45 °C) at pH = 7.4. Thermo-induced DOX release without AMF was 1.9% (1.8 μg mL-1) and 2.3% (3.3 μg mL-1) at 37, and 45 °C within 50 min, respectively. In an AMF DOX release increased to 5.7% (8.2 μg mL-1) within 50 min. Therefore, MNP-CP[5]A-DOX works as a chemo-hyperthermia nanodevice.

The mesoporous material Al-Mobil Composition of Matter No. 41 (Al-MCM-41) was successfully obtained from kaolin, a low cost raw material, by means of hydrothermal route. The process of synthesis of Al-MCM-41 was based on calcination of kaolin, dealumination by acid treatment, hydrothermal synthesis in alkaline medium and surfactant extraction. The characterization of the obtained mesoporous material was carried out by techniques such as: X-ray diffraction, infrared vibrational spectroscopy, 29Si and 27Al solid state nuclear magnetic resonance, scanning electron microscopy, transmission electron microscopy and N2 adsorption-desorption. The X-ray diffraction at low angles allowed the determination of the cell parameter, which was 4.02 nm. The analyses of scanning and transmission electron microscopy revealed important morphological properties of the synthesized material. N2 adsorption/desorption showed a Brunauer-Emmett-Teller (BET) specific surface area of 1,303 m2 g-1, pore volume of 1.23 cm3 g-1 and average diameter of 2.45 nm. The mesoporous material presented a maximum adsorption capacity of 316 mg g-1 for the cationic dye methylene blue (MB) in a concentration typical of industrial effluents, which makes it a potential adsorbent for MB removal from wastewaters.

Abstract Steady increase in prices of petroleum-based fuels and growing environmental concerns are boosting attention to alternative fuels. In this context, biodiesel has drawn attention as an alternative fuel, especially as a substitute to traditional diesel. Biodiesel is commonly produced from triacylglycerols and alcohol through transesterification reaction. Knowledge of equilibrium phase distribution of key components in transesterification systems is essential for a better understanding of the reaction pathway and for guiding the design and optimization of reactors and the products separation. This study reports experimental results and thermodynamic modeling of the liquid-liquid equilibrium of systems composed of soybean oil + monoacylglycerols + diacylglycerols + ethyl oleate + oleic acid + ethanol at 303.15 and 318.15 K. Experimental data were well correlated using NRTL, with a maximum deviation of 0.688%. As for UNIFAC, the deviations between predicted and experimental data ranged from 3.13 to 9.21%.

Abstract This paper presents a modification for the already consolidated analytical model that calculates the gain and ripple in multi-pump Raman amplifiers by considering energy conservation. The original analytical model precisely computes the pump-pump interaction to the C- and L-band for a WDM input signal. However, when this method is used to amplify a large bandwidth, as the entire C and a part of the L band, the increase in the number of pump lasers impacts the obtained results. The error, if compared with results obtained by a numerical method, becomes significant. An analysis in terms of energy is proposed to minimize the discrepancy between analytical and numerical results. An improvement is observed to the gain results.

Neste estudo teve-se como objetivo avaliar o efeito do fotoperíodo sobre o ciclo de vida e a morfometria da concha de Dysopeas muibum Marcus & Marcus, 1968 em condições de laboratório. Para tal, foram acompanhados o crescimento da concha, a liberação de filhotes e a mortalidade de 40 espécimes submetidos a condições naturais de temperatura, umidade relativa do ar e fotoperíodo, e 80 submetidos a condições controladas (40 com dias longos e 40 com dias curtos), desde o nascimento até 180 dias de vida, quando foram aferidas as medidas da concha. Verificou-se que o fotoperíodo não teve efeito sobre o padrão de crescimento indeterminado, a relação entre reprodução e crescimento, a iteroparidade e a baixa mortalidade antes e após a maturidade sexual. As condições controladas de temperatura, umidade relativa do ar e fotoperíodo favoreceram o crescimento, maiores valores conquiliomorfométricos e o rápido alcance da maturidade sexual, enquanto a diminuição do comprimento do dia favoreceu a fecundidade.

This study aimed to evaluate the effect of photoperiod on the life cycle and shell morphology of Dysopeas muibum Marcus & Marcus, 1968 under laboratory conditions. To this end, we conducted monitoring growth of the shell, the release of puppies and mortality of 40 specimens undergo natural conditions of temperature, relative humidity and photoperiod, and 80 undergo controlled conditions (40 with long days, and 40 with short days), from birth to 180 days, when the measures of the shell were taken. It was found that the photoperiod had no effect on the indeterminate growth, the relationship between reproduction and growth, iteroparidade and low mortality before and after sexual maturity. The controlled conditions of temperature, relative humidity and photoperiod favored growth, conchiliomorphometrics values higher and fast reach sexual maturity, while the decrease in day length favored fecundity.

OBJETIVO: verificar a prevalência e fatores de risco associados à sibilância em lactentes no primeiro ano de vida.MÉTODOS: estudo transversal, onde foi aplicado o questionário padronizado e validado (Estudio Internacional de Sibilancias en Lactantes-EISL) aos pais de lactentes com idade entre 12 e 15 meses que procuraram 26 das 85 unidades de atenção básica, no período 2006 a 2007. A variável dependente, sibilância, foi definida utilizando os seguintes padrões: ocasional (até dois episódios de sibilância) e recorrente (três ou mais episódios). As variáveis independentes foram apresentadas usando distribuição de frequências, utilizadas para comparar os grupos. As medidas de associações foram baseadas em razão de chances (odds ratio-OR), com intervalo de confiança de 95% (IC95%), com análise bivariada, seguida de análise multivariada (OR ajustada).RESULTADOS: um total de 1.029 (37,7%) lactentes apresentou sibilância nos primeiros 12 meses de vida e destes, 16,2% tiveram sibilância recorrente. Os principais fatores de risco associados à sibilância foram: história familiar de asma (ORa = 2,12; IC95%: 1,76-2,54); seis ou mais episódios de resfriado (ORa = 2,38; IC95%: 1,91-2,97) e pneumonia (ORa = 3,02; IC95%: 2,43-3,76) e sibilância recorrente foram: asma na família (ORa = 1,73; IC95%: 1,22-2,46); início precoce de sibilância (ORa = 1,83; IC95%: 1,75-3,75); sintomas noturnos (ORa = 2,56; IC95%: 1,75-3,75); mais de 6 resfriados (ORa = 1,83; IC95%: 1,75-3,75)CONCLUSÃO: os principais fatores de risco associados à sibilância foram as infecções respiratórias e história de asma na família. Conhecer os fatores de risco dessa enfermidade deve ser uma prioridade para a saúde pública, que poderá desenvolver estratégias de controle e tratamento.

OBJECTIVE:to investigate the prevalence and risk factors associated with wheezing in infants in the first year of life.METHODS:this was a cross-sectional study, in which a validated questionnaire (Estudio Internacional de Sibilancias en Lactantes - International Study of Wheezing in Infants - EISL) was applied to parents of infants aged between 12 and 15 months treated in 26 of 85 primary health care units in the period between 2006 and 2007. The dependent variable, wheezing, was defined using the following standards: occasional (up to two episodes of wheezing) and recurrent (three or more episodes of wheezing). The independent variables were shown using frequency distribution to compare the groups. Measures of association were based on odds ratio (OR) with a confidence interval of 95% (95% CI), using bivariate analysis, followed by multivariate analysis (adjusted OR [aOR]).RESULTS:a total of 1,029 (37.7%) infants had wheezing episodes in the first 12 months of life; of these, 16.2% had recurrent wheezing. Risk factors for wheezing were family history of asthma (OR = 2.12; 95% CI: 1.76-2.54) and six or more episodes of colds (OR = 2.38; 95% CI: 1.91-2.97) and pneumonia (OR = 3.02; 95% CI: 2.43-3.76). For recurrent wheezing, risk factors were: familial asthma (aOR = 1.73; 95% CI: 1.22-2.46); early onset wheezing (aOR = 1.83; 95% CI: 1.75-3.75); nocturnal symptoms (aOR = 2.56; 95% CI: 1.75-3.75), and more than six colds (aOR = 2.07; 95% CI 1.43- .00).CONCLUSION:the main risk factors associated with wheezing in Fortaleza were respiratory infections and family history of asthma. Knowing the risk factors for this disease should be a priority for public health, in order to develop control and treatment strategies.

We analyzed the ecology of Hydrodynastes gigas, one of the largest snakes of South America, studying 342 specimens obtained during 21 years of field sampling including road sampling, intensive searches and opportunistic encounter methods. Females attained sexual maturity at larger relative body size than males, and were largest, had biggest heads and more ventral scales. Males had larger tails and more subcaudal scales than females. This sexual dimorphism, common among snakes, would be related to an increment in its reproductive potential. The females' reproductive cycle was seasonal and annual; while in males it was continuous and annual. The reproductive potential was high, 16.3 eggs/female/year, with a clear tendency to be higher in larger females. Hydrodynastes gigas is a diurnal snake and preys on all kinds of common vertebrates in wetlands habitats, including amphibians, reptiles, fish, mammals and birds, in order of importance. Individuals were active throughout the year, being one of the 4 most abundant species of snakes in the floodplains of large South American rivers. Due to its abundance, generalist diet, higher size and reproductive potential, we suggest that this species is an important predator in South America's aquatic ecosystems.

Analizamos la ecología de Hydrodynastes gigas, una de las serpientes de mayor tamaño en Sudamérica. Estudiamos 342 ejemplares obtenidos durante 21 años de muestreos en rutas, búsquedas intensivas y capturas ocasionales. Las hembras maduraron sexualmente con mayor tamaño corporal que los machos, adicionalmente fueron más largas, tuvieron cabezas más grandes y más escamas ventrales. Los machos tuvieron mayor longitud de cola y más escamas subcaudales. Este dimorfismo sexual, común en serpientes, puede estar relacionado con el aumento del potencial reproductivo. El ciclo reproductivo fue estacional y anual en hembras, mientras que fue continuo y anual en machos. El potencial reproductivo fue alto, 16.3 huevos/hembra/año, con una tendencia a ser mayor en hembras más grandes. Hydrodynastes gigas es diurna y se alimenta de todo tipo de vertebrados frecuentes en los humedales que habita, incluyendo anfibios, reptiles, peces, mamíferos y aves, en orden de importancia. Los individuos se mantuvieron activos todo el año, siendo una de las 4 especies de serpientes más abundantes en las planicies de inundación de grandes ríos sudamericanos. Su abundancia, dieta generalista, gran tamaño y capacidad reproductiva sugieren que esta especie es un importante depredador en los ecosistemas acuáticos de Sudamérica.