Raman spectra soft modeling of the biodiesel oxidation through evolving factor analysis & multivariate curve resolution.

The oxidative stability of biodiesel is defined by its relative resistance to the action of oxygen at room temperature. Its determination is an essential reference to the quality of biofuel and a significant parameter to be determined. This parameter concerns the quality of the biodiesel to be supplied to the consumer, and its determination is fundamental to maintaining the engine's proper functioning. Raman spectroscopy allows the rapid obtaining of structural information regarding biodiesel quality and, when aided by multivariate analysis methods, allows a quantitative determination of specific properties. This work uses Raman spectroscopy, Multivariate Curve Resolution with Alternative Least Squares (MCR-ALS) method, and Evolving Factor Analysis (EFA) to study biodiesel's oxidation kinetics. Also, the vibrational modes C = C, CH2, and CH3 were identified as the main structural groups involved in this process, corroborating previous studies. The MCR-ALS & EFA combination allowed modeling of the degradation kinetics following an A â†’ B â†’ C mechanism, where A corresponds to the biodiesel (starting material), B is related to the hydroperoxide mixture, and C is the final product. The results also suggested that this process follows a first-order reaction, with kinetic constant values of k1 = 0.0056 min-1 and k2 = 0.0031 min-1.

Commercial characteristics of coffee seedlings produced with different sources of phosphorus and plant growth-promoting bacteria.

Considered the economic engine of many countries, the coffee culture represents an important component of the agricultural chain in Brazil. The growing values of commercialization, planting areas, and crop productivity require the acquisition of quality seedlings, which must receive adequate nutritional support through efficient fertilizers. Slow and controlled-release fertilizers, such as organominerals, gain prominence when it comes to increasing efficiency in the use of phosphorus, as well as plant growth-promoting bacteria (PGPB) with phosphate solubilizing characteristics. This study aimed to evaluate the effect of different sources of mineral and organomineral fertilizers, inoculated and non-inoculated with PGPB on the quality parameters of coffee seedlings. In general, the P sources used in the experiment positively interfered with the development of coffee seedlings. This proves that there is a need for nutritional supplementation for the good development of the seedlings. Among the sources used, the organomineral in granulated form showed better performance in coffee seedlings' growth and physiological parameters, proving to be a viable alternative to commonly used fertilizers. The addition of PGPB showed a significant advantage for seedling quality variables.

Nonlinear behavior of the impedance spectrum of a kerosene based ferrofluid.

We investigate the nonlinear behavior of the electric impedance of a kerosene-based ferrofluid (FF) sample subjected to an ac electric voltage of amplitude ranging from 10 mV to 3 V in the frequency range 6.3 mHz, 100 kHz. The FF sample was inserted between two parallel gold electrodes separated by 127 µm distance. The results show that even a sinusoidal voltage of amplitude low as 80 mV can give origin to nonlinear effects for frequency of the applied voltage smaller than 100 mHz. Our experimental data confirm the results obtained by solving numerically the equations of the Poisson-Nernst-Planck model. From this agreement it follows that the model based on the equation of continuity for the mobile ions, and the equation of Poisson for the actual potential across the sample, works well also in its non-linear version.

Ions, adsorption and electric response of a ferrofluid cell.

We show that the electric response of a cell in the shape of a slab containing a ferrofluid (magnetic particles in kerosene) can be interpreted by means of a model based on the adsorption of ions from limiting surfaces. We report on three samples, identical in all aspects, but limited by electrodes in gold, platinum and titanium. For frequency larger than 1 kHz, the spectra of the real and imaginary parts of the total electrical impedance of the cells are identical. From this result it follows that in this frequency range the response of the cell is independent of the electrodes, which can be considered as blocking. In the low frequency region, up to 0.3 mHz, the response of the cells depends on the electrodes, as discussed recently by Batalioto et al., Phys. Chem. Chem. Phys., 2021, 23, 2819. A simple generalization of the PNP model with ohmic boundary conditions works well only up to 10 mHz. For frequencies smaller than this value the reactance of the cells tends to increase again, indicating a capacity behaviour that could be related to the adsorption effect of the electrodes. A generalization of the ohmic PNP model containing surface capacitance in series is able to fit the data. From the value of the surface capacitance, the thickness of the surface layer is estimated to be on the molecular scale. From this result, we conclude that the adsorption phenomenon could be important for the description of the electrical properties of these systems. A simple generalization of the PNP model with boundary conditions derived by the Langmuir model is in reasonable agreement with our experimental data. The analysis is performed at the impedance level, taking into account a test based on the tangent of the loss angle of the system.

Ética médica en la práctica clínica / Medical ethics in clinical practice

La actividad médica se puede ver en dos contextos diferentes, tanto en la práctica clínica como en la investigación científica. El concepto de práctica clínica es todo acto realizado sobre un paciente con el objetivo de diagnosticar o tratar enfermedades. Por otro lado, la investigación clínica cuestiona diferentes aspectos relacionados con la salud humana. Este estudio busca inicialmente esclarecer los aspectos y componentes que orientan la relación y comunicación médico-paciente, definiendo los valores éticos de esta práctica, donde el profesional médico modela su carácter, mediante una relación entre los principios abordados en el ámbito de la ética de los profesionales de la salud. La demostración de una adecuada y sana relación de los profesionales médicos con sus pacientes es necesaria y fundamental a través del respeto y principalmente a través del principio de autonomía, ya que todo ser humano debe ser reconocido como fin y dueño de sí mismo, donde las actividades médicas comprenden procesos que involucran vida, salud e integridad física. Así, el presente trabajo abordará los diversos aspectos de la ética médica, en relación con el contexto de la práctica clínica del médico.

The medical activity can be seen in different contexts, both in clinical practice and in scientific research. The concept of clinical practice is every act performed on a patient with the objective of diagnosing or treating illnesses. On the other hand, clinical research questions different aspects related to human health. This study initially seeks to clarify the aspects and components that guide the doctor-patient relationship and communication, defining the ethical values of this practice, from which the medical professional models its character, through a relationship between the principles addressed in the scope of their ethics. health professionals. The demonstration of an adequate and healthy relationship between medical professionals and their patients is necessary and fundamental through respect and mainly through the principle of autonomy, since every human being must be recognized as an end and duen of symbolism, hence medical activities include processes that involve life, health and physical integrity. Thus, this work will address the various aspects of medical ethics, in relation to the context of the clinical practice of the doctor.

Free ions in kerosene-based ferrofluid detected by impedance spectroscopy.

The influence of the free ions on the electric response of cells filled with kerosene-based ferrofluids in the low-frequency region is explored. The experimental investigations have been performed on cells limited by different types of electrodes, with the same kind of ferrofluid, by means of the impedance spectroscopy technique. The electrodes considered in our study are made of titanium, platinum, gold, brass and surgical steel. The analysis of the spectra of the real and imaginary parts of the electric impedance of the cell data has been done by means of a simplified version of the Poisson-Nernst-Planck model, in which only the carriers of a given sign are mobile. The agreement between the theoretical predictions and the experimental data is rather good on the whole frequency range. From the analysis of the data in the low-frequency range, dominated by the properties of the electrodes, we discovered that only gold electrodes behave in a manner different from the other electrodes. From the best fit of the experimental data the free-ions density is determined as well as their diffusion coefficient in kerosene. The estimated dielectric constant of the kerosene is in good agreement with the values reported in the literature. In the framework of our model, the surface conductivity of the electrodes has been also determined.

Magnetic, structural and cation distribution studies on [Formula: see text] (x = 0.00, 0.02, 0.04, 0.06 and 0.1) nanoparticles.

We synthesized and characterized the colloidal suspensions of [Formula: see text] nanoparticles with x = 0.00, 0.02, 0.04, 0.06 and 0.1. The effect of the Fe3+ ion replacement by Nd3+ on the crystal structure is in-depth studied. The samples were characterized by the following techniques: X-ray diffraction (XRD), UV-Vis spectrophotometry, transmission electronic microscopy (TEM), small-angle X-ray scattering (SAXS), magnetization as a function of applied magnetic field (M-H loops) and magnetization as a function of temperature in zero-field-cooled and field-cooled regimes (ZFC-FC). From XRD cation distribution, structural parameters were extracted. The increasing in the bandgap is interpreted as a result of the higher interatomic separation with the doping. TEM micrographs reveal a polydisperse size and shape distribution of particles. The results for the volume-weighted average diameter measured by SAXS are consistent with those determined by XRD. From the M-H loops we found that the superparamagnetic (SPM) regime contributes with 95-97% for all samples, while only 3-5% contribution comes from the paramagnetic (PM) regime. The saturation magnetization increases in a steady manner upon increasing the Nd3+ ion molar ratio from 0.00 up to 0.06, reaching the maximum value of 105.8±0.4 Am2/kg at x = 0.06. It is worth to mention that the result for the saturation magnetization value are higher than that of the bulk material.

Major seminal plasma proteome of rabbits and associations with sperm quality.

The present study was conducted to describe the major seminal plasma proteome of rabbits and potential associations between seminal proteins and semen criteria. Semen samples were collected from 18 New Zealand adult rabbits, and seminal plasma proteins were analyzed by 2-D SDS-PAGE and tandem mass spectrometry. Sperm motility, vigor, concentration, morphology and membrane sperm viability were evaluated. Rabbits ejaculated 364 ±â€¯70 million sperm/ml, with 81 ±â€¯6.1% motile cells, 3.8 ±â€¯0.2 vigor and 66.7 ±â€¯2.5% sperm with normal morphology. Based on the viability and acrosome integrity assay, there were 65.8 ±â€¯2.5% live sperm with intact acrosome and most spermatozoa had both intact acrosome and functional membrane. On average, 2-D gels of rabbit seminal plasma had 232 ±â€¯69.5 spots, as determined by PDQuest software (Bio Rad, USA). Mass spectrometry allowed the identification of 137 different proteins. The most abundant proteins in rabbit seminal plasma were hemoglobin subunit zeta-like, annexins, lipocalin, FAM115 protein and albumin. The intensity of the spots associated with these five proteins represented 71.5% of the intensity of all spots detected in the master gel. Multiple regression models were estimated using sperm traits as dependent variables and seminal plasma proteins as independent ones. Also, sperm motility had positive association with beta-nerve growth factor and cysteine-rich secretory protein 1-like and a negative one with galectin-1. The percentage of rabbit sperm with intact membrane was related to seminal plasma protein FAM115 complex and tropomyosin. Then, the population of morphologically normal sperm in rabbit semen was positively linked to carcinoembryonic antigen-related cell adhesion molecule 6-like and down regulated by seminal plasma isocitrate dehydrogenase. Based on another regression model, the variation in the percentage of live sperm with intact acrosome was partially explained by the amount of leukocyte elastase inhibitor and the peptidyl-prolyl cis-trans isomerase A in the rabbit seminal fluid. The current study reports the identification of 137 proteins of rabbit seminal plasma. Major proteins of seminal secretion relate primarily to prevention of damages caused by lipid peroxide radicals and oxidative stress, membrane functionality, transport of lipids to the sperm membrane and temperature regulation. Moreover, finding seminal plasma proteins as indicators of semen parameters will improve assisted reproductive technologies.

Molecular dynamics simulation and binding free energy studies of novel leads belonging to the benzofuran class inhibitors of Mycobacterium tuberculosis Polyketide Synthase 13.

In this work, the binding mechanism of new Polyketide Synthase 13 (Pks13) inhibitors has been studied through molecular dynamics simulation and free energy calculations. The drug Tam1 and its analogs, belonging to the benzofuran class, were submitted to 100 ns simulations, and according to the results obtained for root mean square deviation, all the simulations converged from approximately 30 ns. For the analysis of backbone flotation, the root mean square fluctuations were plotted for the Cα atoms; analysis revealed that the greatest fluctuation occurred in the residues that are part of the protein lid domain. The binding free energy value (ΔGbind) obtained for the Tam16 lead molecule was of -51.43 kcal/mol. When comparing this result with the ΔGbind values for the remaining analogs, the drug Tam16 was found to be the highest ranked: this result is in agreement with the experimental results obtained by Aggarwal and collaborators, where it was verified that the IC50 for Tam16 is the smallest necessary to inhibit the Pks13 (IC50 = 0.19 µM). The energy decomposition analysis suggested that the residues which most interact with inhibitors are: Ser1636, Tyr1637, Asn1640, Ala1667, Phe1670, and Tyr1674, from which the greatest energy contribution to Phe1670 was particularly notable. For the lead molecule Tam16, a hydrogen bond with the hydroxyl of the phenol not observed in the other analogs induced a more stable molecular structure. Aggarwal and colleagues reported this hydrogen bonding as being responsible for the stability of the molecule, optimizing its physic-chemical, toxicological, and pharmacokinetic properties.

Isomeric effects tuning the electron transport in carotenoid derivatives: from ohmic to rectifier behavior.

Single-molecules have been widely investigated in the last decades due to their promises as devices in molecular electronics. One of the advantages in the use of natural compounds in molecular electronics is the economy of material and molecular synthesis, which makes the process both cheaper and self-sustaining. Although many studies have considered electronic transport in single molecules, there are few studies associated with isomeric effects in biologically appealing systems. In the present work, we have studied ballistic electron transport in two isomeric forms of a retinol molecule: 11-cis and all-trans-retinol. The molecules were connected between two Au(111) electrodes and calculations were performed with the NEGF-DFT methodology. Current-voltage, differential conductance, and rectification curves were obtained and compared for two structures. While 11-cis-retinol shows a more symmetrical current-voltage curve, all-trans-retinol acts as molecular diode for low applied voltages. Our results suggest that a simple isomeric effect modulates the molecular device from nanowires to diodes with potential applications as field-effect transistors.

Desempenho de bezerras de corte em pastagem de azevém recebendo farelo de arroz com ou sem monensina / Beef heifers performance in ryegrass pasture supplemented with rice bran with or without monensin

Foi estudado o desempenho de bezerras de corte em pastagem de azevém (Lolium multiflorum Lam.), com animais exclusivamente em pastejo ou recebendo farelo de arroz integral (FAI) em nível de 0,8% do peso corporal, associado ou não à monensina. O método de pastejo foi contínuo com número variável de animais. O delineamento experimental foi o inteiramente ao acaso, com medidas repetidas no tempo, com três tratamentos e três repetições de área. O uso de FAI associado ou não à monensina não expressou alteração na área pélvica das bezerras, na taxa de lotação e no ganho de peso por área. As bezerras que receberam FAI, com ou sem monensina, apresentaram maior ganho diário de peso corporal, peso corporal, escore de condição corporal e relação peso corporal:altura. O fornecimento de suplementação energética para bezerras de corte é uma alternativa viável em sistemas de produção que visam à redução da idade ao primeiro acasalamento.(AU)

The experiment was carried out with the objective of evaluating beef cattle heifer performance when exclusively grazing Italian ryegrass (Lolium multiflorum Lam.) pasture or supplemented with whole rice bran (WRB), equivalent to 0.8% of body weight, associated or not with monensin. The grazing method was "put-and-take" stocking, in a completely randomized experimental design, with replicated measures over time, with three treatments and three replications of area. The use of WRB, associated or not with monensin, did not affect heifers' pelvic area, stocking rate and area weight gain. Animals fed WRB, with or without monensin, showed greater average daily gain, body weight, body condition score, and body weight:height ratio. Energetic supplementation for beef heifers is one viable option in production systems seeking age reduction at the first mating.(AU)

Serum protein concentration in low-dose total body irradiation of normal and malnourished rats.

Among the radiotherapeutics' modalities, total body irradiation (TBI) is used as treatment for certain hematological, oncological and immunological diseases. The aim of this study was to evaluate the long-term effects of low-dose TBI on plasma concentration of total protein and albumin using prematurely and undernourished rats as animal model. For this, four groups with 9 animals each were formed: Normal nourished (N); Malnourished (M); Irradiated Normal nourished (IN); Irradiated Malnourished (IM). At the age of 28 days, rats of the IN and IM groups underwent total body gamma irradiation with a source of cobalt-60. Total protein and Albumin in the blood serum was quantified by colorimetry. This research indicates that procedures involving low-dose total body irradiation in children have repercussions in the reduction in body-mass as well as in the plasma levels of total protein and albumin. Our findings reinforce the periodic monitoring of total serum protein and albumin levels as an important tool in long-term follow-up of pediatric patients in treatments associated to total body irradiation.

Uso de suplementos para acasalamento de bezerras Angus aos 14 meses de idade / Use of supplements for mating Angus heifers at 14 months

O experimento foi conduzido com o objetivo de avaliar o desenvolvimento de novilhas de corte em três sistemas alimentares: exclusivamente em pastagem de azevém (Lolium multiflorum Lam.) ou em pastagem de azevém e recebendo 0,93% do peso corporal de grão de milho inteiro ou grão de aveia branca como suplemento. O delineamento experimental foi o inteiramente ao acaso, com medidas repetidas no tempo. A utilização da pastagem de azevém, com ou sem uso de grão de milho ou aveia como suplemento, possibilita desenvolvimento reprodutivo para que as bezerras sejam acasaladas aos 14 meses de idade. O peso corporal ao início da utilização da pastagem é determinante para que as bezerras atinjam adequado desenvolvimento reprodutivo no início da estação de acasalamento.(AU)

The experiment was carried out to evaluate the development of beef heifers in three feeding systems: exclusively on ryegrass pasture (Lolium multiflorum Lam.) or in ryegrass pasture and receiving 0.93% of body weight of corn whole grain or oats grain as a supplement. The experimental design was completely randomized with repeated measures in time. The utilization of ryegrass pasture, with or without the use of corn or oats grain as a supplement, provides reproductive development of heifers in order for them to be mated at 14 months of age. The body weight at the beginning of pasture utilization is crucial for heifers to reach adequate reproductive development at the beginning of the mating season.(AU)

Temperature dependence of the Soret coefficient of ionic colloids.

The temperature dependence of the Soret coefficient S(T)(T) in electrostatically charged magnetic colloids is investigated. Two different ferrofluids, with different particles' mean dimensions, are studied. In both cases we obtain a thermophilic behavior of the Soret effect. The temperature dependence of the Soret coefficient is described assuming that the nanoparticles migrate along the ionic thermoelectric field created by the thermal gradient. A model based on the contributions from the thermoelectrophoresis and variation of the double-layer energy, without fitting parameters, is used to describe the experimental results of the colloid with the bigger particles. To do so, independent measurements of the ζ potential, mass diffusion coefficient, and Seebeck coefficient are performed. The agreement of the theory and the experimental results is rather good. In the case of the ferrofluid with smaller particles, it is not possible to get experimentally reliable values of the ζ potential and the model described is used to evaluate this parameter and its temperature dependence.

Single-molecular diodes based on opioid derivatives.

We propose an efficient single-molecule rectifier based on a derivative of opioid. Electron transport properties are investigated within the non-equilibrium Green's function formalism combined with density functional theory. The analysis of the current-voltage characteristics indicates obvious diode-like behavior. While heroin presents rectification coefficient R>1, indicating preferential electronic current from electron-donating to electron-withdrawing, 3 and 6-acetylmorphine and morphine exhibit contrary behavior, R<1. Our calculations indicate that the simple inclusion of acetyl groups modulate a range of devices, which varies from simple rectifying to resonant-tunneling diodes. In particular, the rectification rations for heroin diodes show microampere electron current with a maximum of rectification (R=9.1) at very low bias voltage of ∼0.6 V and (R=14.3)∼1.8 V with resistance varying between 0.4 and 1.5 M Ω. Once most of the current single-molecule diodes usually rectifies in nanoampere, are not stable over 1.0 V and present electrical resistance around 10 M. Molecular devices based on opioid derivatives are promising in molecular electronics.

A Molecular Dynamics of Cold Neutral Atoms Captured by Carbon Nanotube Under Electric Field and Thermal Effect as a Selective Atoms Sensor.

Here we analyzed several physical behaviors through computational simulation of systems consisting of a zig-zag type carbon nanotube and relaxed cold atoms (Rb, Au, Si and Ar). These atoms were chosen due to their different chemical properties. The atoms individually were relaxed on the outside of the nanotube during the simulations. Each system was found under the influence of a uniform electric field parallel to the carbon nanotube and under the thermal effect of the initial temperature at the simulations. Because of the electric field, the cold atoms orbited the carbon nanotube while increasing the initial temperature allowed the variation of the radius of the orbiting atoms. We calculated the following quantities: kinetic energy, potential energy and total energy and in situ temperature, molar entropy variation and average radius of the orbit of the atoms. Our data suggest that only the action of electric field is enough to generate the attractive potential and this system could be used as a selected atoms sensor.

Thermodynamic analysis of fuels in gas phase: ethanol, gasoline and ethanol - gasoline predicted by DFT method.

This paper presents a theoretical study using density functional theory to calculate thermodynamics properties of major molecules compounds at gas phase of fuels like gasoline, ethanol, and gasoline-ethanol mixture in thermal equilibrium on temperature range up to 1500 K. We simulated a composition of gasoline mixture with ethanol for a thorough study of thermal energy, enthalpy, Gibbs free energy, entropy, heat capacity at constant pressure with respect to temperature in order to study the influence caused by ethanol as an additive to gasoline. We used semi-empirical computational methods as well in order to know the efficiency of other methods to simulate fuels through this methodology. In addition, the ethanol influence through the changes in percentage fractions of chemical energy released in combustion reaction and the variations on thermal properties for autoignition temperatures of fuels was analyzed. We verified how ethanol reduces the chemical energy released by gasoline combustion and how at low temperatures the gas phase fuels in thermal equilibrium have similar thermodynamic behavior. Theoretical results were compared with experimental data, when available, and showed agreement. Graphical Abstract Thermodynamic analysis of fuels in gas phase.

A new species of gall midge associated with Diplopterys pubipetala (A.Juss.) Anderson and Davis (Malpighiaceae) from Altinópolis, São Paulo, Brazil.

Clinodiplosis bellum sp. nov. associated with Diplopterys pubipetala (A.Juss.) Anderson and Davis (Malpighiaceae) from Brazil are described. This is the first species of Clinodiplosis described to State of São Paulo and the first formal description of Diplopterys pubipetala (Malpighiaceae) as host plant of Cecidomyiidae species. Description and illustration of the Clinodiplosis bellum sp. nov. (Diptera: Cecidomyiidae) are given.