Development and application of spectrophotometric method for the determination of cefaclor in pharmaceutical formulations

A simple, fast and sensitive spectrophotometric method for the determination of cefaclor in pharmaceutical raw and dosage forms based on reaction with ninhydrin is developed, optimized and validated. The purple color (Ruhemenn's purple) that resulted from the reaction was stabilized and measured at 560 nm. Beer's law is obeyed in the concentration range of 4-80 µg mL-1 with molar absorptivity of 1.42 × 10(5) L mole-1 cm-1. All variables including the reagent concentration, heating time, reaction temperature, color stability period, and cefaclor/ninhydrin ratio were studied in order to optimize the reaction conditions. No interference was observed from common pharmaceutical adjuvant. The developed method is easy to use, accurate and highly cost-effective for routine studies relative to HPLC and other techniques.

Chemical stability of enalapril maleate drug substance and tablets by a stability-indicating liquid chromatographic method

The chemical stability of enalapril drug substance and tablets was studied by a stability-indicating liquid chromatographic method. Stress testing was performed on drug substance under various conditions. Accelerated stability testing was carried out for different formulations of enalapril tablets. Chromatographic separation was achieved on a RP-18 column, using a mobile phase of methanol phosphate buffer at 1.0 mL min"1 and UV detection. Degradation of the drug substance was greater under hydrolytic conditions. After 180 days of accelerated stability testing most enalapril tablets showed more than 10% of degradation. Enalapril drug substance and tablets showed instability under stress and accelerated testing respectively, with possible implications on the therapeutic activity.

Development and validation of a novel stability indicating RP-UPLC method for simultaneous determination of nizatidine, methylparaben and propylparaben in oral liquid pharmaceutical formulation

A selective and accurate stability-indicating gradient reverse phase ultra performance liquid chromatographic method has been developed and validated for the simultaneous determination of nizatidine, methylparaben and propylparaben in pharmaceutical oral liquid formulation. The separation was achieved on Acquity UPLC TM HSS T3 1.8 µm column by using mobile phase containing a gradient mixture of solvent A (0.02 Mol L-1 KH2PO4, pH 7.5) and B (60:40 v/v mixture of methanol and acetonitrile) at flow rate of 0.4 mL min-1. Drug product was exposed to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. The developed method was validated as per international ICH guidelines with respect to specificity, linearity, accuracy, precision and robustness.

Preparation of nano-MgO using ultrasonic method and its characteristics

MgO is an important inorganic material, which can be used in many aspects, such as catalyst, toxic-waste remediation agent, adsorbent, and others. In order to make use of MgO, nano-MgO was prepared by ultrasonic method using Mg (CH3COO)2.2H2O as precursor, NaOH aqueous solution as precipitant in this paper. Effect factors on MgO nano-particle size were investigated. Characteristics of samples were measured by TGA, XRD, TEM, and others techniques. The results showed that the size of nano-MgO about 4 nm could be obtained under the following conditions (ultrasonic time 20 min, ultrasonic power 250 W, titration rate of NaOH 0.25 mL/min, NaOH concentration 0.48 mol/L, calcinations temperature 410 °C, calcination time 1.5 h, heating rate of calcination 5 °C/min). It was a very simple and effective method to prepare nano-MgO.

Relationships and estimates of longitudinal growth stress in Eucalyptus dunnii at different ages

The objective of this study was to obtain estimates of longitudinal growth stresses in standing trees of the Eucalyptus dunnii Maiden at eight, thirteen, fifteen and nineteen years of age and to determine their relationships with wood characteristics. The longitudinal growth stresses were indirectly measured by the "CIRAD-Forêt" method and estimated from both the dynamic modulus of elasticity and the modulus of elasticity in tension parallel to the grain. The longitudinal residual strain (LRS) and the estimates of the longitudinal growth stresses tended to increase with the age of the material. The LRS correlated positively and significantly with all the growth stresses estimates. The largestes magnitudes were at 13, 15 and 19 years of age. The basic density presented high, positive and significant correlations with the dynamic modulus of elasticity, estimated in the longitudinal direction, for wood saturated and at 12% moisture content, for all the ages assessed. All the growth stresses estimates presented high, positive and significant correlations between themselves.

Determinação do módulo de elasticidade em madeira laminada colada por meio de ensaio não destrutivo (''stress wave timer'')

As vigas estruturais de madeira são formas racionais do emprego da madeira na construção de estruturas, sendo obtidas pela associação de peças serradas e permitindo a utilização de tábuas com seções e comprimentos variados, além de combinações com madeira de qualidade diferenciada. Para atingir a resistência máxima de uma viga de madeira laminada colada, pode-se utilizar a classificação mecânica das peças por meio dinâmico. O objetivo deste estudo foi estabelecer correlação entre os métodos estático e dinâmico de classificação de vigas de madeira laminada. O trabalho foi desenvolvido com o emprego de peças de madeira serrada de Pinus taeda e adesivo resorcina fenolformaldeído. O processo de fabricação das vigas envolveu a classificação das peças, usinagem de emendas, formação das lamelas, montagem e prensagem das vigas. Já os ensaios envolveram a determinação do módulo de elasticidade por meio do ''stress wave method'' e de uma máquina universal de ensaios. Os resultados foram analisados pela análise de regressão do estabelecimento da equação de ajuste de correlação. O sistema de classificação visual utilizado na seleção de peças foi insuficiente para se atingirem os valores máximos de módulo de elasticidade; o posicionamento correto das lamelas por meio do método dinâmico de classificação teve como consequência direta o aumento do módulo de elasticidade da viga, e houve baixa correlação entre as formas de obtenção do módulo de elasticidade das vigas, não sendo possível a elaboração de equação adequada entre os métodos testados.

Genetic transformation of Eucalyptus camaldulensis by agrobalistic method

Eucalyptus stands in the setting of worldwide forestry due to its adaptability, rapid growth, production of high-quality and low cost of wood pulp fibers. The eucalyptus convetional breeding is impaired mainlly by the long life cycle making the genetic transformation systems an important tool for this purpose. However, this system requires in vitro eficient protocols for plant induction, regeneration and seletion, that allow to obtain transgenic plants from the transformed cell groups. The aim of this work was to evaluate the callus formation and to optimize the leaves and callus genetic transformation protocol by using the Agrobacterium tumefaciens system. Concerning callus formation, two different culture media were evaluated: MS medium supplemented with auxin, cytokinin (M1) and the MS medium with reduced nitrogen concentration and supplemented with auxin, cytokinin coconut water (M2). To establish the leave genetic transformation, those were exposed to agrobiolistics technique (gene gun), to tissue injury, and A. tumesfasciens EHA 105 contening the vetor pCambia 3301 (35S::GUS::NOS), for gene transference and to establish the callus transformation thoses were exposed only to A. tumefasciens. For both experiments, the influence of different infection periods was evaluated. The M2 medium provided the best values for callus sizea and fresh and dry weight. The leaves genetic transformation using the agrobiolistics technique was effective, the gus gene transient expression could be observed. No significant differences were obtained in the infection periods (4, 6 and 8 minutes). The callus genetic transformation with A. tumefaciens also promotend the gus gene transient expression on the callus co-cultiveted for 15 e 30 minutes. The transformed callus was transfered to a regeneration and selection medium and transformed plants were obtained.

Efficiency of distinct data mining algorithms for classifying stress level in piglets from their vocalization

Among the challenges of pig farming in today's competitive market, there is factor of the product traceability that ensures, among many points, animal welfare. Vocalization is a valuable tool to identify situations of stress in pigs, and it can be used in welfare records for traceability. The objective of this work was to identify stress in piglets using vocalization, calling this stress on three levels: no stress, moderate stress, and acute stress. An experiment was conducted on a commercial farm in the municipality of Holambra, São Paulo State , where vocalizations of twenty piglets were recorded during the castration procedure, and separated into two groups: without anesthesia and local anesthesia with lidocaine base. For the recording of acoustic signals, a unidirectional microphone was connected to a digital recorder, in which signals were digitized at a frequency of 44,100 Hz. For evaluation of sound signals, Praat® software was used, and different data mining algorithms were applied using Weka® software. The selection of attributes improved model accuracy, and the best attribute selection was used by applying Wrapper method, while the best classification algorithms were the k-NN and Naive Bayes. According to the results, it was possible to classify the level of stress in pigs through their vocalization.

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.

Estimation of transpiration of the 'Valencia' orange young plant using thermal dissipation probe method

Most studies on measures of transpiration of plants, especially woody fruit, relies on methods of heat supply in the trunk. This study aimed to calibrate the Thermal Dissipation Probe Method (TDP) to estimate the transpiration, study the effects of natural thermal gradients and determine the relation between outside diameter and area of xylem in 'Valencia' orange young plants. TDP were installed in 40 orange plants of 15 months old, planted in boxes of 500 L, in a greenhouse. It was tested the correction of the natural thermal differences (DTN) for the estimation based on two unheated probes. The area of the conductive section was related to the outside diameter of the stem by means of polynomial regression. The equation for estimation of sap flow was calibrated having as standard lysimeter measures of a representative plant. The angular coefficient of the equation for estimating sap flow was adjusted by minimizing the absolute deviation between the sap flow and daily transpiration measured by lysimeter. Based on these results, it was concluded that the method of TDP, adjusting the original calibration and correction of the DTN, was effective in transpiration assessment.

Fuzzy modeling of broiler performance, raised from 1 to 21 days, subject to heat stress

ABSTRACT Given the need to obtain systems to better control broiler production environment, we performed an experiment with broilers from 1 to 21 days, which were submitted to different intensities and air temperature durations in conditioned wind tunnels and the results were used for validation of afuzzy model. The model was developed using as input variables: duration of heat stress (days), dry bulb air temperature (°C) and as output variable: feed intake (g) weight gain (g) and feed conversion (g.g-1). The inference method used was Mamdani, 20 rules have been prepared and the defuzzification technique used was the Center of Gravity. A satisfactory efficiency in determining productive responses is evidenced in the results obtained in the model simulation, when compared with the experimental data, where R2 values ​​calculated for feed intake, weight gain and feed conversion were 0.998, 0.981 and 0.980, respectively.

Modified method for bronchial suture by Ramirez Gama compared to separate stitches suture: experimental study

OBJECTIVE: To experimentally compare two classic techniques described for manual suture of the bronchial stump.METHODS: We used organs of pigs, with isolated trachea and lungs, preserved by refrigeration. We dissected 30 bronchi, which were divided into three groups of ten bronchi each, of 3mm, 5mm, and 7mm, respectively. In each, we performed the suture with simple, separated, extramucosal stitches in five other bronchi, and the technique proposed by Ramirez and modified by Santos et al in the other five. Once the sutures were finished, the anastomoses were tested using compressed air ventilation, applying an endotracheal pressure of 20mmHg.RESULTS: the Ramirez Gama suture was more effective in the bronchi of 3, 5 and 7 mm, and there was no air leak even after subjecting them to a tracheal pressure of 20mmHg. The simple interrupted sutures were less effective, with extravasation in six of the 15 tested bronchi, especially in the angles of the sutures. These figures were not significant (p = 0.08).CONCLUSION: manual sutures of the bronchial stumps were more effective when the modified Ramirez Gama suture was used in the caliber bronchi arms when tested with increased endotracheal pressure.

Increased oxidative stress markers may be a promising indicator of risk for primary ovarian insufficiency: a cross-sectional case control study

PURPOSE: The aim of this study was to evaluate serum levels of inducible nitric oxide synthase (INOS), myeloperoxidase (MPO), total antioxidant status (TAS), and total oxidative status (TOS) in women with primary ovarian insufficiency (POI) and to compare them with healthy fertile women. We also examined the possible risk factors associated with POI.METHODS: This cross-sectional case control study was conducted in Zekai Tahir Burak Women's Health Education and Research Hospital. The study population consisted of 44 women with POI (study group) and 36 healthy fertile women (control group). In all patients, serum levels of INOS, MPO, TAS, and TOS were determined. INOS and MPO levels were measured by enzyme-linked immunosorbent assay whereas colorimetric method was used for evaluating TAS and TOS levels. Age, body mass index (BMI), obstetric history, smoking status, family history, comorbidities, sonographic findings, complete blood count values, C-reactive protein and baseline hormone levels were also analyzed. Student's t-test or Mann-Whitney U test was used to compare continuous variables between the groups; categorical data were evaluated by using Pearson χ2 or Fisher exact test, when appropriate. Binary logistic regression method was used to identify risk factors for POI.RESULTS: We found significantly elevated levels of INOS (234.1±749.5 versus133.8±143.0; p=0.005), MPO (3,438.7±1,228.6 versus 2,481.9±1,230.1; p=0.001), and TOS (4.3±1.4 versus 3.6±1.4; p=0.02) in the sera of the study group when compared to the BMI-age matched control group. However, difference in serum levels of TAS were not significant between the 2 groups (1.7±0.2 versus 1.6±0.2; p=0.15). Logistic regression method demonstrated that BMI <25 kg/m2, nulliparity, family history of POI, smoking, and elevated serum levels of INOS, MPO, and TOS were independent risk factors for POI.CONCLUSION: We found an increase in INOS, MPO, and TOS in women with POI. These serum markers may be promising in early diagnosis of POI. Further large-scale studies are required to determine whether oxidative stress markers have a role in diagnosing POI.

Fecal cortisol metabolites as indicators of stress in crab-eating-fox (Cerdocyoun thous) in captivity

Abstract: Blood samples collection is a common method in biological research using domestic animals. However, most blood sampling techniques are complicated and highly invasive and may therefore not be appropriate for wildlife animals in research concerning stress. Thus, a non-invasive method to measure steroid hormones is critically needed. The first goal of this study was to determine how glucocorticoids concentrations are impacted by translocation and reproductive activity in crab-eating-fox (Cerdocyoun thous) in captivity. The physiological relevance of fecal glucocorticoid metabolites was further validated by demonstrating: (1) The translocation of a male to a females enclosure resulted in a 3.5-fold increase compared to baseline concentrations, (2) changes in adrenocortical activity, as reflected in concentrations of fecal cortisol metabolites during reproduction, gestation and lactation in females foxes, indicating that social interactions resulted in large increases of fecal glucocorticoids metabolites during the reproductive season. From these findings we conclude that fecal samples can be used for the non-invasive assessment of adrenocortical status in crab-eating-fox.

Method to obtain platelet-rich plasma from rabbits (Oryctolagus cuniculus )

Abstract: Platelet-rich plasma (PRP) is a product easy and inxpesnsive, and stands out to for its growth factors in tissue repair. To obtain PRP, centrifugation of whole blood is made with specific time and gravitational forces. Thus, the present work aimed to study a method of double centrifugation to obtain PRP in order to evaluate the effective increase of platelet concentration in the final product, the preparation of PRP gel, and to optimize preparation time of the final sample. Fifteen female White New Zealand rabbits underwent blood sampling for the preparation of PRP. Samples were separated in two sterile tubes containing sodium citrate. Tubes were submitted to the double centrifugation protocol, with lid closed and 1600 revolutions per minute (rpm) for 10 minutes, resulting in the separation of red blood cells, plasma with platelets and leucocytes. After were opened and plasma was pipetted and transferred into another sterile tube. Plasma was centrifuged again at 2000rpm for 10 minutes; as a result it was split into two parts: on the top, consisting of platelet-poor plasma (PPP) and at the bottom of the platelet button. Part of the PPP was discarded so that only 1ml remained in the tube along with the platelet button. This material was gently agitated to promote platelets resuspension and activated when added 0.3ml of calcium gluconate, resulting in PRP gel. Double centrifugation protocol was able to make platelet concentration 3 times higher in relation to the initial blood sample. The volume of calcium gluconate used for platelet activation was 0.3ml, and was sufficient to coagulate the sample. Coagulation time ranged from 8 to 20 minutes, with an average of 17.6 minutes. Therefore, time of blood centrifugation until to obtain PRP gel took only 40 minutes. It was concluded that PRP was successfully obtained by double centrifugation protocol, which is able to increase the platelet concentration in the sample compared with whole blood, allowing its use in surgical procedures. Furthermore, the preparation time is appropriate to obtain PRP in just 40 minutes, and calcium gluconate is able to promote the activation of platelets.