Navegando por Palavras-chave "Lactic acid"
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- ItemAcesso aberto (Open Access)Associação entre maturação sexual e limiar de lactato em meninas de 10-15 anos(Universidade Federal de São Paulo (UNIFESP), 2010-08-25) Nicoláo, Ana Lúcia Anauate [UNIFESP]; Barros Neto, Turibio Leite de [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)The lactate thresholds are used to assess the aerobic capacity in different ages. Studies show that children and adolescents present less lactate blood concentrations [la] than adults under certain effort loads. There are evidences that this is related to their maturational development. Objective: To verify the association between the sexual maturation and the lactate threshold in some adolescent soccer players ranging from 12 to 15 years old. Method: The sample was related to the intentional and not probabilistic type involving 36 girls, from 12 to 15 years old, members of the soccer schools held by the Mayority of São Paulo. The body weight, height and the sum of two skinfolds – calf and triceps were obtained from the sample. A physician directly observed the sexual maturation of the genitals and pubic hair development through the Tanner index. To determine the lactate threshold a progressive test, a 3 x 800 m in running track, was performed by adolescents, their effort intensity was controlled by pre-established heart rate zones and the [la] were measured at the end of each run. The velocity corresponding to [la] of 2,5 mmol.L-1 (V2,5) was obtained through the linear interpolation. The multiple linear regression was used to better understand the nature of these associations between the variables, considering the lactate threshold (V2,5) as a dependent variable and the age (years), the body weight index (kg/m2), height (cm) and the sum of the skinfolds (mm) as independent variables. Result: The growth variables and the sexual maturation have little association with the lactate threshold in the youngest and pre-adolescent girls. It is important to take in consideration the sexual maturation influence on the threshold lactate. Conclusion: Taking in account the group homogeneity and being the range between 12 and 15 years old a period susceptible to many modifications, the maturational development and not the chronological age showed to be responsible for a significant difference in the analyzed variables.
- ItemSomente MetadadadosChallenges and opportunities in lactic acid bioprocess design-From economic to production aspects(Elsevier Science Bv, 2018) Oliveira, Regiane Alves de; Komesu, Andrea [UNIFESP]; Rossell, Carlos Eduardo Vaz; Maciel Filho, RubensLactic acid is an already consolidated bioproduct in the world market. It has many applications, such as: the production of biodegradable polymers, substitution of plastics from oil, and new uses in medicine. Besides this, new applications are being discovered every year, especially in chemical industries as a building-block molecule. The lactic acid market is in constant growth and the fact that the final products are able to comply with environmental laws as green, renewable and biodegradable products contributes to the tendency of continuous growth in the next few years. With all of this in mind, this paper will explore the main aspects of the sector, as well as market tendencies, production chain, and innovation. (C) 2018 Elsevier B.V. All rights reserved.
- ItemAcesso aberto (Open Access)Comparison of lactate values obtained from different sites and their clinical significance in patients with severe sepsis(Associacao Paulista Medicina, 2011-01-06) Nascente, Ana Paula Metran [UNIFESP]; Assunção, Murillo [UNIFESP]; Guedes, Carla Janaina [UNIFESP]; Freitas, Flavio Geraldo Rezende [UNIFESP]; Mazza, Bruno Franco [UNIFESP]; Jackiu, Miriam [UNIFESP]; Machado, Flavia Ribeiro; Universidade Federal de São Paulo (UNIFESP)CONTEXT AND OBJECTIVE: The ideal site for lactate collection has not been clearly established. This study aimed to evaluate associations between lactate levels in arterial blood (Lart), peripheral venous blood (Lper) and central venous blood (Lean) in patients with severe sepsis or septic shock.DESIGN AND SETTING: Cross-sectional analytical study in an tertiary university hospital.METHOD: Samples from patients with a central venous catheter and from healthy volunteers (control group) were collected. Blood was drawn simultaneously for measurements of Lart, Lper and Lcen, and the first sample was collected less than 24 hours after the onset of organ dysfunction. The results were analyzed using Pearson correlation, Bland-Altman and McNemar tests.RESULTS: A total of 238 samples were collected from 32 patients. The correlation results were r = 0.79 (P < 0.0001) for Lart/Lper and r = 0.84 (P < 0.0001) for Lart/Lcen. Bland-Altman showed large limits of agreement: -3.2 +/- 4.9 (-12.8 to 6.4) and -0.8 +/- 5.9 (-12.5 to 10.8), for Lper and Lcen respectively. lathe control group, there was greater correlation (r = 0.9009, P = 0.0004) and agreement: -0.7 +/- 1.2 (-3.1 to 1.7). Regarding clinical intervention, there was good agreement between Lart/Lcen (96.3%; three disagreements), with worst results for Lart/Lper (87.0%) with 10 cases of disagreement (P = 0.04). In eight patients (80.0%) Lper was higher than Lart.CONCLUSION: Lcen, and not Lper, can replace Lart with good correlation and clinical agreement. Lper tends to overestimate Lart, thus leading to unnecessary therapeutic interventions.
- ItemAcesso aberto (Open Access)Efeito do treinamento aeróbio na regulação hormonal e metabólica em ratos(Universidade Federal de São Paulo (UNIFESP), 2008-06-25) Costa, Carlos Alberto Nannini [UNIFESP]; Dâmaso, Ana Raimunda [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Objective: Observe metabolic behavior and physiological adjustments promoted by a protocol of physical activities in aquatic way with the use of additional loads varying between 3 and 5% of body weight. Methods: Thirty adult male Wistar rats were randomly divided into two groups: the Trained Group (TG) and Control Group (CG). The 15 animals of the TG, which underwent physical training, were subdivided into three subgroups: GT1, GT2 and GT3. They underwent 5 weekly swimming sessions during 60 minutes, respectively totaling 3, 6 and 12 weeks of training. Insulin concentration doses, IGF, glucose and lactate at different periods and stages of protocol were used as tools to interpret possible adaptations. ANOVA ONE-WAY for unpaired data was the statistical method for glucose, insulin and IGF analysis. ANOVA TWO-WAY, statistic SAS for PC 6.08 (SAS Institute, Cary, NC) was used for plasmatic lactate. Results: No significant changes in plasmatic concentrations occurred. Conclusion: Current analysis showed that experimental model used does not induce physiological adjustments and hormone adaptations when these are analyzed by the above-mentioned methods and biochemical variables. Other researches should be undertaken involving long-term experiments coupling distinct techniques and approaches.
- ItemAcesso aberto (Open Access)Evaluation of Hybrid Short Path Evaporation to Concentrate Lactic Acid and Sugars from Fermentation(North Carolina State Univ Dept Wood & Paper Sci, 2018) Oliveira, Regiane Alves de; Komesu, Andrea [UNIFESP]; Rossell, Carlos Eduardo Vaz; Maciel, Maria Regina Wolf; Maciel Filho, RubensLactic acid is an important organic compound that finds various applications in the chemical, pharmaceutical, food, and medical industries. Many of these applications require lactic acid with high purity. Hybrid short path evaporation (HSPE) is a separation process well studied in the petrochemical sector that is mainly used to obtain compounds with high purity. It is also a process offering small residence time, low pressure, and environmentally friendliness. The concentration process of lactic acid was studied by using HSPE in the presence of high total reducing sugar content remaining from sugarcane molasses fermentation. In this work, the influence of operational conditions, such as evaporator temperature (86.4 degrees C to 153.6 degrees C), internal condenser temperature (7.95 degrees C to 18 degrees C), and feed flow rate (8.27 to 21.7 mL/min), on lactic acid concentration and mass percentages were evaluated. The results showed that all variables influenced the process. Mathematical models were developed for the mass percentage and concentration of the total reducing sugar in the distilled stream and for the mass percentage at residue stream. Under the best operational conditions, the concentration of lactic acid (approximate to 247.7 g/L) was 2.5 times higher than the initial fermentation broth (approximate to 100.1 g/L).
- ItemSomente MetadadadosEvaluation of lactic acid purification from fermentation broth by hybrid short path evaporation using factorial experimental design(Elsevier B.V., 2014-11-05) Komesu, Andrea; Martins, Patricia Fazzio [UNIFESP]; Lunelli, Betania Hoss; Oliveira, Johnatt; Maciel Filho, Rubens; Wolf Maciel, Maria Regina; Universidade Estadual de Campinas (UNICAMP); Universidade Federal de São Paulo (UNIFESP)This work describes the evaluation of lactic acid purification from fermentation broth by hybrid short path evaporation. the proposed hybrid purification process consists of an evaporation system composed by a cylindrical wiped film evaporator with two condensers, one located internally and other externally to the evaporator. Through factorial experimental design, the influence of operation conditions as feed flow rate, agitation, condenser and evaporator temperature on residue and distilled percentages, lactic acid purity and recovery were studied. Models were developed in order to describe the response of interest as function of operating conditions. the results showed that with a high operating pressure (in terms of short path evaporation), with a pressure of 1000 Pa, and one step of separation, lactic acid purity around 89.7% was obtained which was about 18 times lactic acid concentration higher than the initial content in raw material. (C) 2014 Elsevier B.V. All rights reserved.
- ItemAcesso aberto (Open Access)Obtenção do ácido lático a partir do glicerol: uma revisão(Universidade Federal de São Paulo, 2022-02-01) Oliveira, Viviane Gundes [UNIFESP]; Concha, Viktor Oswaldo Cárdenas [UNIFESP]; http://lattes.cnpq.br/0661599261187131; http://lattes.cnpq.br/1139457439982588Visto que nos últimos anos houve um crescimento da produção de biodiesel devido a necessidade de substituição dos combustíveis fósseis não renováveis por combustíveis provenientes de fontes renováveis, surgiu um aumento do excedente de produção de glicerol na indústria. A partir desse acréscimo, começaram a ser estudadas formas de utilização industrial para aproveitamento desse subproduto, que pode ser a produção de ácidos orgânicos, seja por via química ou fermentativa. Um dos ácidos que podem ser obtidos através do glicerol é o ácido lático, o ácido carboxílico mais abundante da natureza e com diversas aplicações nas indústrias alimentícia, cosmética e farmacêutica. Além disso, o ácido lático é precursor de uma nova geração de materiais plásticos biodegradáveis como o poli ácido lático (PLA). Este trabalho teve como objetivo explorar a produção de ácidos orgânicos, especialmente do ácido lático por síntese química (catálise heterogênea) a partir do glicerol, e ao mesmo tempo abordar os conceitos de processos químicos na produção do ácido lático através da montagem de diagrama de blocos e um balanço de massa preliminar do processo.
- ItemAcesso aberto (Open Access)Randomized clinical efficacy of superficial peeling with 85% lactic acid versus 70% glycolic acid(Sociedade Brasileira de Dermatologia, 2013-12-01) Prestes, Paula Souza; Oliveira, Márcia Motta Maia de; Leonardi, Gislaine Ricci [UNIFESP]; Methodist University of Piracicaba Health Sciences College; aff02; Universidade Federal de São Paulo (UNIFESP)BACKGROUND: Peeling is a procedure which aims to accelerate the process of skin exfoliation. OBJECTIVES:Development of formulations containing lactic acid at 85% or glycolic acid at 70% and the evaluation of these formulations on clinical efficacy in reduction of fine wrinkles.METHODS:Preliminary stability tests were carried out and an in vivo study was performed with three groups with 9 representatives each. One was the control group, which used only sunscreen; another one used lactic acid+sunscreen, and the last group used acid glycolic+sunscreen. Clinical efficacy was assessed with a CCD color microscope, through the digitization of images before and after treatment. The applications were carried out by a dermatologist, once a mont h every 30 days, during 3 months. The area with wrinkles was calculated by planimetry point counting, in accordance with Mandarin-de-Lacerda.RESULTS:The formulations were stable in the visual and Ph evaluation. There was no improvement in the control group; for lactic acid, there was significant improvement after the second peeling application on the outer lateral area of the right eye and after the third application on the outer lateral area of the left eye. For the glycolic acid group, there was significant improvement in the outer lateral area of the left eye after the first application, and of the right eye region, after three applications. The formulations used must be kept under refrigeration and should be manipulated every 30 days.CONCLUSIONS:Both peelings were effective in reducing fine wrinkles of the outer lateral eye area after three applications (p≤0.05%). It was observed that peeling efficacy in the external-lateral region of one eye might be different compared with that in skin of the external-lateral region of the other eye, relative to the speed of skin improvement.
- ItemAcesso aberto (Open Access)Seleção de solventes para a extração do ácido lático em soluções aquosas por meio do modelo UNIFAC(Universidade Federal de São Paulo, 2022-02-02) Cunha, Richard da Silva [UNIFESP]; Silva, Luciana Yumi Akisawa [UNIFESP]; http://lattes.cnpq.br/6845759105423166O ácido lático é uma substância muito utilizada nos diversos setores da indústria mundial. De fato, sua importância é observada no âmbito alimentício, cosmético, farmacêutico, têxtil etc. A produção de ácido lático pode ser feita por via química (sintética) ou via fermentativa (através de microrganismos produtores da substância), sendo esta a mais utilizada mundialmente devido sua vantagem econômica e sua maior facilidade de aplicação. Entretanto, há a necessidade de separá-lo do mosto/meio fermentativo utilizando-se de métodos eficientes, viáveis economicamente, menos nocivos ao meio ambiente e de fácil aplicação. Um dos métodos de separação mais promissores é o de extração líquido-líquido, que envolve a adição de um solvente com características desejáveis, como elevada seletividade, maior afinidade com o soluto que se deseja extrair, menor custo, menor toxicidade aos microrganismos etc. Uma etapa muito importante no projeto da extração líquido-líquido é a seleção de solventes. No entanto, a seleção de solventes por meio da determinação experimental de dados de equilíbrio líquido-líquido, demanda tempo, envolve custos e gera resíduos. Assim, uma alternativa promissora, é realizar a seleção de solventes com auxílio dos modelos termodinâmicos, que permitem a estimativa dos coeficientes de atividade e por conseguinte a determinação do coeficiente de partição, seletividade e capacidade do solvente. De fato, neste presente trabalho fora realizada a seleção de solventes usando o modelo termodinâmico UNIFAC que é um modelo de contribuição de grupos. Foram coletados 51 solventes da literatura para o cálculo de seus parâmetros: coeficiente de atividade a diluição infinita, seletividade e potencial do solvente, estes parâmetros relacionam-se com o índice de desempenho do solvente (PI – “Performance Index”) em extrair o ácido lático; além disso, foram calculados os valores dos coeficientes de partição octanol-água (Kow) para cada um dos solventes, para averiguar a respectiva toxicidade às bactérias fermentadoras. Com os valores calculados, observou-se que os solventes: p-cimeno, pineno e Limoneno (hidrocarbonetos), pentilcicloexanol, 1-decanol e 2-etil-nonanol (álcoois) apresentam maiores valores de log (Kow) consequentemente, menores riscos de toxicidade para as bactérias fermentadoras, embora possuam (todos eles) baixos valores de PI.