Modelling the growth of lactic acid bacteria at different temperatures

ABSTRACT Mathematical models are widely used to predict the shelf life of foods. Lactic acid bacteria (LAB), particularly Lactobacillus plantarum, Weissella viridescens and Lactobacillus sakei, are the main spoilage bacteria of refrigerated, vacuum-packed meat products, stored in modified atmosphere, and their growth determines the shelf life length of these products. The objective of this study was to model the growth of L. plantarum, W. viridescens and L. sakei under different isothermal cultivation conditions and establish secondary models to describe the effect of temperature on the growth parameters of these bacteria. The LAB growth was evaluated in culture medium at temperatures of 4, 8, 12, 16, 20 and 30 ºC. The fit of Baranyi and Roberts (BAR) and Gompertz (GO) primary models to the growth curves of LAB was compared by statistical indices, in which the BAR model showed slightly better fits to the experimental data. The BAR growth parameters were used to establish the secondary models, µmax and Nmax were established for the three LAB. The power model described the influence of temperature on the parameter λ for L. plantarum, and other bacteria showed no lag phase. The growth of LAB was strongly influenced by storage temperature and the obtained models allow predicting the growth of these bacteria within the temperature range from 4 to 30 ºC.

Correção do dorso nasal baixo ou em sela com enxerto composto de cartilagem conchal fragmentada fixa ao pericôndrio envolvidos à fáscia da mastóide / Correction of low or saddle nasal dorsum with a composite graft of fragmented conchal cartilage fixed to the perichondrium wrapped in mastoid fascia

Introdução: A rinoplastia de aumento em muitos casos torna-se mais difícil que a rinoplastia de redução. Enxertos dorsais sólidos realizados com cartilagem costal têm sido muito utilizados para aumento dorsal, porém estão associados com altos índices de revisão, por isso, muitos autores passaram a utilizar cartilagem em cubos envoltos por fáscia. A fáscia da mastoide, conectada ao pericôndrio da cartilagem conchal auricular, pode formar um enxerto composto para o aumento do dorso nasal, sendo também uma opção de tratamento. O objetivo é demonstrar a possibilidade do uso de cartilagem da concha auricular fragmentada fixa ao seu pericôndrio, e envoltos na fáscia da mastoide, formando um enxerto composto para aumento do dorso nasal. Métodos: Tratase de um estudo retrospectivo de 9 pacientes operados entre 2012 e 2016 no Hospital de Base da Faculdade de Medicina de São José do Rio Preto, em que foi realizado aumento do dorso nasal com cartilagem conchal fragmentada fixa ao seu pericôndrio e envolto à fáscia da mastoide. Resultados: Os pacientes foram acompanhados de 6 a 48 meses. Foram questionados quanto à satisfação do procedimento nasal e sensibilidade auricular, com avaliação positiva dos pacientes e cirurgiões. Conclusão: A cartilagem conchal parece ser uma alternativa de grande valia para procedimentos de aumento de dorso nasal. Esta cartilagem envolta com fáscia da mastoide parece ser uma alternativa vantajosa em comparação ao uso de outras fáscias, com baixa morbidade e taxa de complicações, podendo ser uma grande opção para tratamento do nariz em sela.

Introduction: In many cases, augmentation rhinoplasty is more difficult than reduction rhinoplasty. Solid dorsal grafts performed with costal cartilage have been widely used for dorsal augmentation; however, they are associated with high rates of revision. Thus, many authors began to use cartilage cut into cubes wrapped in fascia. The mastoid fascia, connected to the perichondrium of the auricular conchal cartilage can form a composite graft to augment the nasal dorsum, which is also a treatment option. The objective is to demonstrate the possibility of using fragmented auricular conchal cartilage fixed to its perichondrium and wrapped in mastoid fascia to form a composite graft for augmentation of the nasal dorsum. Methods: This is a retrospective study of 9 patients who underwent operation between 2012 and 2016 at the Base Hospital of the Faculty of Medicine of São José do Rio Preto, in which the nasal dorsum was augmented with fragmented conchal cartilage fixed to its perichondrium and wrapped in the mastoid fascia. Results: The patients were followed up for up 6 to 48 months. They were questioned about their satisfaction with the nasal procedure and hearing sensitivity, and provided a positive evaluation of the surgeons. Conclusion: The conchal cartilage seems a highly valuable alternative graft for nasal dorsum augmentation procedures. The technique of using cartilage wrapped in mastoid fascia seems to be an advantageous alternative when compared with those using cartilage wrapped in other fasciae: it has low morbidity and complications rates and can be a great option for saddle nose treatment.

Modeling the Growth of Byssochlamys fulva on Solidified Apple Juice at Different Temperatures

The aim of this study was to establish primary and secondary models to describe the growth kinetics of Byssochlamys fulva on solidified apple juice at different temperatures. B. fulva was inoculated on solidified apple juice at 10, 15, 20, 25 and 30 °C. Linear-with-breakpoint, Baranyi and Roberts, and Huang primary models (without upper asymptote) were fitted to the data, and they showed good ability to describe the growth kinetics. B. fulva showed longer adaptation time on apple juice than on culture medium, but growth rates were similar as reported in the literature. The dependence of µmax and λ parameters on temperature was described with Square Root and Arrhenius-Davey secondary models, respectively. These models were important to establish process/storage conditions and apple juice shelf life.

Tensión arterial media como indicador precoz de hipertensión en el embarazo / Mean arterial pressure as early indicator of hypertension in pregnancy

Se estudia la Tensión Arterial Media (TAM) y su evolución en pacientes que tuvieron hipertensión (HTA) en el embarazo. Se consideraron TAM y Tensión Arterial Diastólica (TAD). Se correlacionó con la edad gestacional en la que aparecen por primera vez y aquella cuando los valores de tensión arterial en términos absolutos definen la enfermedad. Se analizaron medias, rangos, desvíos, curvas. La población se randomizó en dos grupos: uno de HTA (N=50) y otro de embarazadas normales (N=50), siendo significativa la relación de aumento de TAM en el grupo de HTA respecto al control en el intervalo de 26 semanas. Se observó la tendencia según curva, a la aparición de TAM=90 mm Hg alrededor de la semana 23 de gestación, mientras que la TAD=90 mm Hg., lo hizo alrededor de la semana 35 en el grupo de HTA, mientras que en el control no sucedió. Se concluye que la TAM es un indicador fidedigno y precoz de HTA ya que antecede a la aparición de signos tardíos