Harmonical oscillator and electro-mechanical analogy: an interdiscinary experiment to high precision mass variation measurements

In general, the traditional Physics courses needs examples of the aplications of the Physics concepts in other areas such as Chemistry and Biology. This lacks tend to demotivate Chemistry and Biology students regarding to deal with Physical concepts developed in classroom. In this work, the analogy among mechanic and electric oscillators is investigated to be applied in Chemistry and Biology areas, showing to be valuable due to its aplication in techniques that aims to measure mass variation with high precision. This measure could be made in a direct or indirect way. These techniques are known as electrogravimetric techniques and they are important in biosensor aplications. Thus, this paper explores the electromechanic analogy in an interdisciplinary way involving areas like Physics, Chemistry and Biology. Based on this analogy, it is proposed an experiment that can be applied in different ways, i.e. by an basic approach or more deeper, depending on the students specific formation, in other words, Physics, Chemistry or Biology.

Simplified sample handing in mass spectrometry based protein research - focus on protein phosphorylation

The human genome comprises roughly 20 000 protein coding genes. Proteins are the building material for cells and tissues, and proteins are functional compounds having an important role in many cellular responses, such as cell signalling. In multicellular organisms such as humans, cells need to communicate with each other in order to maintain a normal function of the tissues within the body. This complex signalling between and within cells is transferred by proteins and their post-translational modifications, one of the most important being phosphorylation. The work presented here concerns the development and use of tools for phosphorylation analysis. Mass spectrometers have become essential tools to study proteins and proteomes. In mass spectrometry oriented proteomics, proteins can be identified and their post-translational modifications can be studied. In this Ph.D. thesis the objectives were to improve the robustness of sample handling methods prior to mass spectrometry analysis for peptides and their phosphorylation status. The focus was to develop strategies that enable acquisition of more MS measurements per sample, higher quality MS spectra and simplified and rapid enrichment procedures for phosphopeptides. Furthermore, an objective was to apply these methods to characterize phosphorylation sites of phosphopeptides. In these studies a new MALDI matrix was developed which allowed more homogenous, intense and durable signals to be acquired when compared to traditional CHCA matrix. This new matrix along with other matrices was subsequently used to develop a new method that combines multiple spectra from different matrises from identical peptides. With this approach it was possible to identify more phosphopeptides than with conventional LC/ESI-MS/MS methods, and to use 5 times less sample. Also, phosphopeptide affinity MALDI target was prepared to capture and immobilise phosphopeptides from a standard peptide mixture while maintaining their spatial orientation. In addition a new protocol utilizing commercially available conductive glass slides was developed that enabled fast and sensitive phosphopeptide purification. This protocol was applied to characterize the in vivo phosphorylation of a signalling protein, NFATc1. Evidence for 12 phosphorylation sites were found, and many of those were found in multiply phosphorylated peptides

Cuticular and Suberin Polymers of Edible Plants. Analysis by Gas Chromatographic-Mass Spectrometric and Solid State Spectroscopic Methods

Cutin and suberin are structural and protective polymers of plant surfaces. The epidermal cells of the aerial parts of plants are covered with an extracellular cuticular layer, which consists of polyester cutin, highly resistant cutan, cuticular waxes and polysaccharides which link the layer to the epidermal cells. A similar protective layer is formed by a polyaromatic-polyaliphatic biopolymer suberin, which is present particularly in the cell walls of the phellem layer of periderm of the underground parts of plants (e.g. roots and tubers) and the bark of trees. In addition, suberization is also a major factor in wound healing and wound periderm formation regardless of the plants’ tissue. Knowledge of the composition and functions of cuticular and suberin polymers is important for understanding the physiological properties for the plants and for nutritional quality when these plants are consumed as foods. The aims of the practical work were to assess the chemical composition of cuticular polymers of several northern berries and seeds and suberin of two varieties of potatoes. Cutin and suberin were studied as isolated polymers and further after depolymerization as soluble monomers and solid residues. Chemical and enzymatic depolymerization techniques were compared and a new chemical depolymerization method was developed. Gas chromatographic analysis with mass spectrometric detection (GC-MS) was used to assess the monomer compositions. Polymer investigations were conducted with solid state carbon-13 cross polarization magic angle spinning nuclear magnetic resonance spectroscopy (13C CP-MAS NMR), Fourier transform infrared spectroscopy (FTIR) and microscopic analysis. Furthermore, the development of suberin over one year of post-harvest storage was investigated and the cuticular layers from berries grown in the North and South of Finland were compared. The results show that the amounts of isolated cuticular layers and cutin monomers, as well as monomeric compositions vary greatly between the berries. The monomer composition of seeds was found to differ from the corresponding berry peel monomers. The berry cutin monomers were composed mostly of long-chain aliphatic ω-hydroxy acids, with various mid-chain functionalities (double-bonds, epoxy, hydroxy and keto groups). Substituted α,ω-diacids predominated over ω-hydroxy acids in potato suberin monomers and slight differences were found between the varieties. The newly-developed closed tube chemical method was found to be suitable for cutin and suberin analysis and preferred over the solvent-consuming and laborious reflux method. Enzymatic hydrolysis with cutinase was less effective than chemical methanolysis and showed specificity towards α,ω-diacid bonds. According to ₁₃C CP-MAS NMR and FTIR, the depolymerization residues contained significant amounts of aromatic structures, polysaccharides and possible cutan-type aliphatic moieties. Cultivation location seems to have effect on cuticular composition. The materials studied contained significant amounts of different types of biopolymers that could be utilized for several purposes with or without further processing. The importance of the so-called waste material from industrial processes of berries and potatoes as a source of either dietary fiber or specialty chemicals should be further investigated in detail. The evident impact of cuticular and suberin polymers, among other fiber components, on human health should be investigated in clinical trials. These by-product materials may be used as value-added fiber fractions in the food industry and as raw materials for specialty chemicals such as lubricants and emulsifiers, or as building blocks for novel polymers.

Effective diffusivity and convective mass transfer coefficient during the drying of bananas

In this article, a methodology is used for the simultaneous determination of the effective diffusivity and the convective mass transfer coefficient in porous solids, which can be considered as an infinite cylinder during drying. Two models are used for optimization and drying simulation: model 1 (constant volume and diffusivity, with equilibrium boundary condition), and model 2 (constant volume and diffusivity with convective boundary condition). Optimization algorithms based on the inverse method were coupled to the analytical solutions, and these solutions can be adjusted to experimental data of the drying kinetics. An application of optimization methodology was made to describe the drying kinetics of whole bananas, using experimental data available in the literature. The statistical indicators enable to affirm that the solution of diffusion equation with convective boundary condition generates results superior than those with the equilibrium boundary condition.

Chemical attributes of soil and dry mass accumulation of maize fertilized with cassava wastewater

The aim of this study was to evaluate chemical attributes alterations of a clay-loam textured soil and dry mass accumulation of maize submitted to application of cassava wastewater doses in three assessment periods. The experiment was conducted under greenhouse using a completely randomized experimental design in a factorial 5 × 3, with four replicates. The analyzed factors of research were doses of cassava wastewater (0; 12.6; 25.2; 50.4; 75.6 m3 ha-1) andassessment periods (20, 40 and 52 days after germination). The following parameters were determined: electric conductivity of soil saturation extract, pH in water, content of available P, content of exchangeable K+, Ca2+, Mg2+ and Na+of soil, dry mass of leaves and stem. The application of cassava wastewater on soil enables increase of pH, electric conductivity of saturation extract, contents of available P, contents of exchangeable K+ and Na+ and dry mass of leaves and stem. However, only pH and content of exchangeable K+ of soil, the electric conductivity of saturation extract and dry mass of leaves and stem are influenced by assessment period.

SOFTWARE TO ASSESS BEEF CATTLE BODY MASS THROUGH THE FUZZY BODY MASS INDEX

ABSTRACT The Body Mass Index (BMI) can be used by farmers to help determine the time of evaluation of the body mass gain of the animal. However, the calculation of this index does not reveal immediately whether the animal is ready for slaughter or if it needs special care fattening. The aim of this study was to develop a software using the Fuzzy Logic to compare the bovine body mass among themselves and identify the groups for slaughter and those that requires more intensive feeding, using "mass" and "height" variables, and the output Fuzzy BMI. For the development of the software, it was used a fuzzy system with applications in a herd of 147 Nellore cows, located in a city of Santa Rita do Pardo city – Mato Grosso do Sul (MS) state, in Brazil, and a database generated by Matlab software.

KINETICS OF MASS LOSS OF ARABICA COFFEE DURING ROASTING PROCESS

ABSTRACT Roasting is one of the most complex coffee processing steps due to simultaneous transfers of heat and mass. During this process, beans lose mass because of fast physical and chemical changes that will set color and flavor of the commercial coffee beverage. Therefore, we aimed at assessing the kinetics of mass loss in commercially roasted coffee beans according to heating throughout the processing. For that, we used samples of 350-g Arabica coffee processed grains with water content of 0.1217 kga kg-1, in addition to a continuous roaster with firing gas. The roaster had initial temperatures of 285, 325, 345 and 380 °C, decreasing during the process up to 255, 285, 305 and 335 °C respectively. Mass loss was calculated by the difference between grain weight before and after roasting. We observed a linear variation directly dependent on roaster temperature. For each temperature during the process was obtained a constant mass loss rate, which was reported by the Arrhenius model with r2 above 0.98. In a roaster in non-isothermal conditions, the required activation energy to start the mass loss in a commercial coffee roasting index was 52.27 kJ mol -1.

Teaching project: a low-cost swine model for chest tube insertion training

Objective: to describe and evaluate the acceptance of a low-cost chest tube insertion porcine model in a medical education project in the southwest of Paraná, Brazil. Methods: we developed a low-cost and low technology porcine model for teaching chest tube insertion and used it in a teaching project. Medical trainees - students and residents - received theoretical instructions about the procedure and performed thoracic drainage in this porcine model. After performing the procedure, the participants filled a feedback questionnaire about the proposed experimental model. This study presents the model and analyzes the questionnaire responses. Results: seventy-nine medical trainees used and evaluated the model. The anatomical correlation between the porcine model and human anatomy was considered high and averaged 8.1±1.0 among trainees. All study participants approved the low-cost porcine model for chest tube insertion. Conclusion: the presented low-cost porcine model for chest tube insertion training was feasible and had good acceptability among trainees. This model has potential use as a teaching tool in medical education.

Is liver transplantation associated with decreased bone mass in climacteric women?

PURPOSE: To evaluate whether climacteric women undergoing liver transplantation had higher prevalence of decreased bone mass than those without any liver disease. METHODS: A cross-sectional study with 48 women receiving follow-up care at a university hospital in Southeastern Brazil, from February 4th 2009 to January 5th 2011, was conducted. Of these women, 24 were 35 years or older and had undergone liver transplantation at least one year before study entry. The remaining 24 women had no liver disease and their ages and menstrual patterns were similar to those of transplanted patients. Laboratorial tests (follicle-stimulating hormone and estradiol) and bone density measurements of the lumbar spine and femur (equipment Hologic, Discovery WI) were performed. Statistical analysis was carried out by Fisher's exact test, simple Odds Ratio (OR), and multiple logistic regression. RESULTS: Mean age of the women included in the study was 52.8 (±10.7) years-old, 27.1% were premenopausal and 72.9% were peri/postmenopausal. Approximately 14.6% of these women exhibited osteoporosis and 35.4% had low bone mass. The following items were associated with decreased bone mass: being postmenopausal (OR=71.4; 95%CI 3.8 - 1,339.7; p<0.0001), current age over 49 years-old (OR=11.4; 95%CI 2.9 - 44.0; p=0.0002), and serum estradiol levels lower than 44.5 pg/mL (OR=18.3; 95%CI 3.4 - 97.0; p<0.0001). Having a history of liver transplantation was not associated with decreased bone mass (OR=1.4; 95%CI 0.4 - 4.3; p=0.56). CONCLUSION: Liver transplantation was not associated with decreased bone mass in this group of climacteric women.

Evaluation of common mental disorders in women with polycystic ovary syndrome and its relationship with body mass index

PURPOSE: To evaluate the prevalence of common mental disorders in women diagnosed with polycystic ovary syndrome as compared with paired controls without this syndrome. METHODS: Cross-sectional study with a Control Group examining women between the ages of 18 and 30 who did not use antidepressants and who sought the Gynecology Service of the researched sites. For every woman diagnosed with the polycystic ovary syndrome, another with the same age, educational status and presence or absence of sexual partners was sought without this diagnosis. In total, 166 patients agreed to participate, consisting of 95 diagnosed with polycystic ovary syndrome and 71 in the Control Group. The diagnosis of polycystic ovary syndrome was made by the presence of two from three criteria: oligomenorrhea or amenorrhea, clinical or biochemical hyperandrogenism and polycystic ovaries on transvaginal ultrasound, following exclusion of patients with Cushing's syndrome, congenital adrenal hyperplasia, and androgen-secreting tumors. Weight and height were measured to calculate the body mass index. The Self-Reporting Questionnaire, which evaluated 20 items, was used as an indicator of common mental disorders. A χ² analysis stratified by the category of body mass index was used to compare the prevalence of common mental disorders, between the groups of women with and without the polycystic ovary syndrome. RESULTS: There were no significant differences in age, education, presence of sexual partners, ethnicity, socioeconomic status, use of psychiatric medication, and search for consultation in mental health between the studied groups. The prevalence of obese women with indications of common mental disorders was significantly higher in women with polycystic ovary syndrome than in the Control Group. In the group with healthy body mass index, the incidence of common mental disorders was statistically significant different between women with polycystic ovary syndrome and normal controls (p=0.008). CONCLUSIONS: Women with diagnosis of this disease have an almost three-fold increased likelihood of common mental disorders as compared with those without polycystic ovary syndrome. Although obesity is often observed in polycystic ovary syndrome, even women with a healthy body mass index have an increased risk of psychiatric comorbidity.

Variations in the body mass index in Brazilian women undergoing adjuvant chemotherapy for breast cancer

PURPOSE:To evaluate variations in the body mass index in patients undergoing adjuvant chemotherapy for breast cancer, and to associate these changes with patient's age and adjuvant chemotherapy regimen.METHODS:We performed a retrospective cohort study in order to correlate any variation in the body mass index before and after adjuvant chemotherapy with patient's age and adjuvant chemotherapy regimen. Patients who received any form of prior hormone therapy, such as tamoxifen or aromatase inhibitors, were excluded. We selected data for 196 patients with stage I to III breast cancer who were treated by radical or conservative surgery and received adjuvant chemotherapy at the Cancer Institute of the State of São Paulo, Brazil.RESULTS:Before adjuvant chemotherapy, 67.8% of patients were classified as overweight or obese according to their body mass indices. Around 66.3% (95% CI 59.7–73.0) of the patients exhibited an increase in the body mass index after adjuvant chemotherapy. The average age of all patients was 56.3±11.3 years. Participants whose body mass index increased were younger than those with no increase (54.7±11.1 versus 59.3±11.2 years; p=0.007). Patients were treated with the following adjuvant chemotherapy regimens: doxorubicin, cyclophosphamide, and paclitaxel (AC-T, 129 patients, 65.8%); 5-fluoracil, doxorubicin, and cyclophosphamide (36 patients, 18.4%); cyclophosphamide, methotrexate, and 5-fluoracil (16 patients, 8.2%); docetaxel and cyclophosphamide (7 patients, 3.6%); and other regimen (8 patients, 4.1%). The AC-T regimen showed a statistically significant association with increase in the body mass index (p<0.001 by ANOVA).CONCLUSIONS:Most patients with breast cancer showed an increase in the body mass index after adjuvant chemotherapy, especially after the AC-T chemotherapy regimen.

Lobular Carcinoma in Situ with Atypical Mass Presentation: a Case Report

Lobular carcinoma in situ (LCIS) is associated with an increased risk of breast cancer and accounts for 1 to 2% of all breast cancers. LCIS diagnosis currently remains one of the major identifiable risk factors for subsequent breast cancer development. Imaging methods are becoming increasingly sensitive, and the consequent detection of small lesions and subtle abnormalities increases the chance of detection of in situ and invasive carcinomas, leading to a reduction in mortality. This report describes a case of a palpable complaint with abnormal imaging findings, including a solid LCIS mass.

Hydrodynamics Characteristics and Gas-Liquid Mass Transfer in a Three Phase Fluidized Bed Reactor

This paper presents the experimental characterization of hydrodynamics and gas-liquid mass transfer in a three-phase fluidized bed containing polystyrene and nylon particles. The influence of gas and liquid velocities on phase holdups and volumetric gas-liquid mass transfer coefficient was investigated for flow conditions similar to those applied in biotechnological process. The phase holdups were obtained by the pressure profile technique. The volumetric gas-liquid mass transfer coefficient was obtained adjusting the experimental concentration profiles of dissolved oxygen in the liquid phase with the predictions of the axial dispersion model. According to experimental results the liquid holdup increases with the gas velocity, whereas the solid holdup decreases. The gas holdup increases significantly with the increase in gas velocity, and it shows for the three-phase fluidized bed comparable values or larger than those of bubble column. The volumetric gas-liquid mass transfer coefficient increases significantly with an increase in the air velocity for both bubble column and fluidized beds. In addition, in the operational condition of high liquid velocity, the presence of low-density particles in the bed increased the gas-liquid mass transfer, and thus the volumetric mass transfer coefficient values obtained in the fluidized bed were comparable or larger than those of bubble column.

Accumulation of dry mass and macronutrients by sourgrass plants

The experiment was carried out aiming to analyze the dry mass production and distribution and the content and accumulation of macronutrients in sourgrass (Digitaria insularis) plants cultivated under mineral nutrition standard conditions. Plants grew in 7-liter pots filled with sand substrate and daily irrigated with nutrient solution, being maintained under greenhouse conditions. Treatments consisted of times of evaluation (21, 35, 49, 63, 77, 91, 105, 119, and 133 days after emergence - DAE) and were arranged in a completely randomized design with four replicates. Sourgrass showed small accumulation of dry mass (0.3 g per plant) and macronutrients (3.7 mg of N per plant, 0.4 mg of P per plant, 5.6 mg of K per plant, 0.9 mg of Ca per plant, 0.7 mg of Mg per plant, and 0.3 mg of S per plant) at vegetative growth stage (< 49 DAE). Those accumulations increased mainly after 77 DAE, reaching the maximum theoretical value at 143, 135, 141, 129, 125, 120, and 128 DAE, for dry mass (12.4 g per plant), N (163.2 mg per plant), P (27.1 mg per plant), K (260.5 mg per plant), Ca (47.6 mg per plant), Mg (30.9 mg per plant), and S (13.7 mg per plant), respectively. K and N were found with higher rates and, as a consequence, they were required and accumulated in greater amounts in plant tissues of sourgrass.

Wind Turbine Direct-Drive Permanent-Magnet Generator with Direct Liquid Cooling for Mass Reduction

Today’s electrical machine technology allows increasing the wind turbine output power by an order of magnitude from the technology that existed only ten years ago. However, it is sometimes argued that high-power direct-drive wind turbine generators will prove to be of limited practical importance because of their relatively large size and weight. The limited space for the generator in a wind turbine application together with the growing use of wind energy pose a challenge for the design engineers who are trying to increase torque without making the generator larger. When it comes to high torque density, the limiting factor in every electrical machine is heat, and if the electrical machine parts exceed their maximum allowable continuous operating temperature, even for a short time, they can suffer permanent damage. Therefore, highly efficient thermal design or cooling methods is needed. One of the promising solutions to enhance heat transfer performances of high-power, low-speed electrical machines is the direct cooling of the windings. This doctoral dissertation proposes a rotor-surface-magnet synchronous generator with a fractional slot nonoverlapping stator winding made of hollow conductors, through which liquid coolant can be passed directly during the application of current in order to increase the convective heat transfer capabilities and reduce the generator mass. This doctoral dissertation focuses on the electromagnetic design of a liquid-cooled direct-drive permanent-magnet synchronous generator (LC DD-PMSG) for a directdrive wind turbine application. The analytical calculation of the magnetic field distribution is carried out with the ambition of fast and accurate predicting of the main dimensions of the machine and especially the thickness of the permanent magnets; the generator electromagnetic parameters as well as the design optimization. The focus is on the generator design with a fractional slot non-overlapping winding placed into open stator slots. This is an a priori selection to guarantee easy manufacturing of the LC winding. A thermal analysis of the LC DD-PMSG based on a lumped parameter thermal model takes place with the ambition of evaluating the generator thermal performance. The thermal model was adapted to take into account the uneven copper loss distribution resulting from the skin effect as well as the effect of temperature on the copper winding resistance and the thermophysical properties of the coolant. The developed lumpedparameter thermal model and the analytical calculation of the magnetic field distribution can both be integrated with the presented algorithm to optimize an LC DD-PMSG design. Based on an instrumented small prototype with liquid-cooled tooth-coils, the following targets have been achieved: experimental determination of the performance of the direct liquid cooling of the stator winding and validating the temperatures predicted by an analytical thermal model; proving the feasibility of manufacturing the liquid-cooled tooth-coil winding; moreover, demonstration of the objectives of the project to potential customers.