Parámetros fisicoquímicos para la síntesis de ácido láctico ó etanol de la bacteria (corynebacterium glutamicum)

El interés por obtener productos para la industria de biocombustibles a partir de desechos agrícolas, conduce a las investigaciones en la búsqueda de sistemas microbianos resistentes y costo-efectivos. La Corynebacterium glutamicum, es un microorganismo usado para producir amino-ácidos, crece en gran variedad de sustratos y es resistente durante la fermentación, a variaciones en el pH, temperatura, presión osmótica y acumulación de alcohol, características que lo hacen candidato a ser mejorado para la síntesis de ácido láctico y etanol. Aún se desconocen aspectos de su fisiología que aumenten su eficiencia en convertir azúcares (C5 y C6) en estos dos metabolitos. Por tanto, este trabajo se basó en estudiar e identificar los parámetros fisicoquímicos que tuvieron un mayor efecto sobre el crecimiento bacteriano y la síntesis de ácido láctico. Para lograr este objetivo, ocho variables fueron evaluadas en un modelo estadístico producido en erlenmeyer, con estos resultados se hallaron las condiciones óptimas que fueron evaluadas en un cultivo por lotes en biorreactor. La temperatura, la concentración de biotina y azúcar fueron las variables con mayor impacto (p and lt; 0,05) sobre el cultivo. Usando las condiciones óptimas, 36 °C; 6,1 mg/L de biotina y 50 g/L de glucosa, se obtuvo una max de 0,394 h-1, 16 g/L de ácido láctico a las 15 h del proceso con un rendimiento del 32%; observándose un mayor consumo de sustrato durante el crecimiento y poca disponibilidad para la fermentación, que sugiriendo una alimentación del cultivo al final de la fase exponencial que aumente los rendimientos de producción

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Contribution a l'etude du comportement des ions Ag+ en presence de mineraux sulfures

SIGLECNRS T 58170 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

PARÁMETROS FISICOQUÍMICOS PARA LA SÍNTESIS DE ÁCIDO LÁCTICO Ó ETANOL DE LA BACTERIA (Corynebacterium glutamicum)

El interés por obtener productos para la industria de biocombustibles a partir de desechos agrícolas, conduce a las investigaciones en la búsqueda de sistemas microbianos resistentes y costo-efectivos. La Corynebacterium glutamicum, es un microorganismo usado para producir amino-ácidos, crece en gran variedad de sustratos y es resistente durante la fermentación, a variaciones en el pH, temperatura, presión osmótica y acumulación de alcohol, características que lo hacen candidato a ser mejorado para la síntesis de ácido láctico y etanol. Aún se desconocen aspectos de su fisiología que aumenten su eficiencia en convertir azúcares (C5 y C6) en estos dos metabolitos. Por tanto, este trabajo se basó en estudiar e identificar los parámetros fisicoquímicos que tuvieron un mayor efecto sobre el crecimiento bacteriano y la síntesis de ácido láctico. Para lograr este objetivo, ocho variables fueron evaluadas en un modelo estadístico producido en erlenmeyer, con estos resultados se hallaron las condiciones óptimas que fueron evaluadas en un cultivo por lotes en biorreactor. La temperatura, la concentración de biotina y azúcar fueron las variables con mayor impacto (p< 0,05) sobre el cultivo. Usando las condiciones óptimas, 36 °C; 6,1 mg/L de biotina y 50 g/L de glucosa, se obtuvo una max de 0,394 h-1, 16 g/L de ácido láctico a las 15 h del proceso con un rendimiento del 32%; observándose un mayor consumo de sustrato durante el crecimiento y poca disponibilidad para la fermentación, que sugiriendo una alimentación del cultivo al final de la fase exponencial que aumente los rendimientos de producción

Investigations of low-frequency noise of GaN based heterostructure field-effect transistors

NRC publication: Ye