A kinetic model for hydrolysis of whey proteins by cardosin a extracted from Cynara Cardunculus

The enzymatic hydrolysis of the major whey proteins, namely b-lactoglobulin (b-Lg) and a-lactalbumin (a-La), was experimentally studied using whey as substrate; an aspartic protease (cardosin A), previously extracted from the flowers of Cynara cardunculus and purified by gel filtration and ion exchange chromatographies, was used for this purpose. Sweet whey was incubated for 24 h at various enzyme:substrate ratios, at controlled pH (5.2 and 6.0) and temperature (55 C); the hydrolyzates were assayed by gel permeation chromatography and electrophoresis. A mechanistic model was proposed for the kinetics, which basically leads to a double-substrate, single-enzyme Michaelis–Menten rate expression containing four adjustable parameters; these parameters were estimated by applying multiresponse, nonlinear regression analysis to the experimental data, so that the model would yield good fits. The best estimates obtained for Km were markedly lower for a-La than for b-Lg, so cardosin A shows a higher affinity for a-La than for b-Lg. The experimental results also suggest that b-Lg is rather resistant to enzyme-mediated hydrolysis under all experimental conditions tested. The highest activity (measured by kcat) of cardosin A was recorded toward a-La (i.e. 0.013 s 1) at pH 5.2. Furthermore, the specificity ratio (kcat=Km), obtained toward each whey protein, indicated that cardosin A possesses a higher catalytic efficiency for hydrolysis of a-La than of b-Lg; the highest value for this ratio was recorded for a-La at pH 5.2, and was close to that reported elsewhere for cardosin A acting on caseins and casein-like substrates

Some resesarch on control of vibrations in civil engineering under covicocepad project

Some information is provided on the latest R&D within COVICOCEPAD project approved in the framework of Eurocores program. It addresses the use of TMD’s TLD’s, base isolation devices, MR dampers and a hybrid technique using both devices together. Some results are provided associated with calibration of a MR damper at FEUP, as well as its inclusion in a small scale laboratory set-up with proper equations of motion of the controlled smart structure. Applications of TMD’s devices to two civil engineering structures under dynamic and seismic actions are also outlined

Biochemical diagnosis of medullary thyroid carcinoma: basal calcitonin and provocative tests

Calcitonin is a hormone secreted by the parafollicular thyroid cells. Diagnosis of medullary thyroid carcinoma (MTC) should be considered when high basal calcitonin levels or high calcitonin levels after specific provocative test are found. In this context, calcitonin is considered a relevant tumor marker for diagnosis and follow-up of MTC. In this manuscript, we review some issues related to the usefulness of measuring basal calcitonin in patients with thyroid nodules. The current available provocative tests for calcitonin are discussed. Finally, we comment on some aspects related to the assays for calcitonin measurement.A calcitonina é um hormônio secretado pelas células parafoliculares tiroideanas. O diagnóstico de carcinoma medular de tiróide (CMT) pode ser suspeitado a partir do encontro de níveis aumentados de calcitonina basal ou após testes de estímulos específicos. Neste sentido, a calcitonina caracteriza-se como um importante marcador tumoral para o diagnóstico e seguimento de pacientes portadores de CMT. Neste artigo, revisamos alguns tópicos referentes à utilidade da dosagem de calcitonina basal em pacientes portadores de nódulos de tiróide para rastreamento de CMT. Comentamos a respeito dos principais testes de estímulo para secreção de calcitonina disponíveis e finalizamos com algumas observações sobre os ensaios para dosagem de calcitonina.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Fleury - Centro de Medicina DiagnósticaUNIFESP, EPM, Fleury - Centro de Medicina DiagnósticaSciEL

Optimization of raw ewes’ milk high-pressure pre-treatment for improved production of raw milk cheese

Serra da Estrela protected designation of origin (PDO) cheese is manufactured with raw milk from Bordaleira and/or Churra Mondegueira da Serra da Estrela sheep breeds. Several socioenvironmental shortcomings have reduced production capacity; hence, treatments that may contribute to its efficient transformation into cheese are welcome. High-pressure processing (HPP) milk pre-treatment may contribute to a cheese yield increment, yet optimization of processing conditions is warranted. An initial wide-scope screening experiment allowed for pinpointing pressure intensity, holding time under pressure and time after HPP as the most important factors influencing curd yield. Based on this, a more targeted screening experiment allowed for selecting the range of experimental conditions to be used for an experimental design study that revealed an HPP treatment at 121 MPa for 30 min as the optimum for milk processing to improve curd yield (>9%) and effectively maintain the beneficial cheese microbiota; the optimum was validated in a final experimental framework.info:eu-repo/semantics/publishedVersio

Engineering students can use the words “calculus” and “love” in the same sentence: using active learning the impossible can happen

Teaching Calculus can be one of the most challenging practices in the engineering context for a number of reasons, namely: taught at the beginning of engineering courses, introducing to the student in a critical phase of his/her transition between high school and university, not understanding the meaning of some contents in relation to Engineering. The disciplines of Calculus are responsible for high failure rates and students’ dropout. Lectures are predominantly used to teach Calculus in engineering context, with rigid contents centered on the blackboard and in the book. Therefore, students have low interaction with teachers and they have difficult to build their own knowledge and to understand the importance of mathematical methods, and procedures. However, project based learning was used to teach Calculus to engineering students. Students were asked to choose a phenomenon of their Engineering area of knowledge and explain why and how it needs integrals and derivatives to be explained. 127 students from six engineering courses were involved in the experiment. The students were organized in teams and tutored by other professors. This paper aims to describe the experience and analyze the outcomes terms of the perception of learning and development of transversal competences. The evaluation was based on content analysis of the reports delivered by the students. 100% of the groups evaluated the experience as positive. The students used adjectives such as "excellent", "extraordinary" to characterize the experience. In addition, students reported the following learning outcomes: knowledge and understanding; analysis; problem-solving; creativity/originality; communication and presentation; evaluation; planning and organization; interactive and group competences. Some groups reported that, in this project, they created prototypes that they will keep on researching and developing to take these ideas to the market. Yet, in this experience, the failure rate of this disciplThis work has been partially supported by projects COMPETE-POCI-01-0145-FEDER-007043 and FCT-UID-CEC-00319-2013, from Portugal

Necrose tubular aguda comprovada por biopsia em paciente com dengue e rabdomiolise

Resultados de histologia renal são muito escassos em pacientes com rabdomiólise e injúria renal aguda (IRA) associada a dengue. Descrevemos caso de dengue complicado por rabdomiólise e IRA no qual a biópsia renal mostrou necrose tubular aguda (NTA) e deposição renal de mioglobina. Paciente de 28 anos que apresentou dengue complicado por IRA grave e rabdomiólise é descrito. Ele necessitou de diálise por três semanas. A biópsia renal mostrou NTA, com imunohistoquímica fortemente positiva para mioglobina nos túbulos renais. O paciente recebeu alta com recuperação da função renal. Em conclusão, descrevemos caso de dengue complicado por IRA e rabdomiólise, em que a biópsia renal mostrou NTA e deposição de mioglobina. Sugerimos que creatinofosfoquinase deve ser monitorizada em pacientes com dengue para permitir o diagnóstico precoce de rabdomiólise e a instituição de medidas protetoras para o rim.Renal histology results are very scarce in dengue-associated rhabdomyolysis patients developing acute kidney injury (AKI). We report a case of dengue fever-induced AKI associated to rhabdomyolysis with a renal biopsy showing acute tubular necrosis (ATN) and renal deposition of myoglobin. A 28-year-old patient who presented dengue fever (DF) complicated by severe AKI and rhabdomyolysis is described. The patient required hemodialysis for three weeks. A renal biopsy revealed ATN with positive staining for myoglobin in the renal tubuli. The patient was discharged with recovered renal function. In conclusion, this case report described a biopsy proven ATN associated to DF-induced rhabdomyolysis, in which renal deposition of myoglobin was demonstrated. We suggest that serum creatine phosphokinase should be monitored in DF patients to allow for an early diagnosis of rhabdomyolysis and the institution of renal protective measures

The effect of method, standard and sample components on the total antioxidant capacity of commercial waters assessed by optical conventional assays

The total antioxidant capacity (TAC) of 28 flavoured water samples was assessed by ferric reducing antioxidant potential (FRAP), oxygen radical absorbance capacity (ORAC), trolox equivalent antioxidant capacity (TEAC) and total reactive antioxidant potential (TRAP) methods. It was observed that flavoured waters had higher antioxidant activity than the corresponding natural ones. The observed differences were attributed to flavours, juice and vitamins. Generally, higher TAC contents were obtained on lemon waters and lower values on guava and raspberry flavoured waters. Lower and higher TACs were obtained by TRAP and ORAC method, respectively. Statistical analysis suggested that vitamins and flavours increased the antioxidant content of the commercial waters