Variables Affecting Delignification of Corn Wastes Using Urea for Total Reducing Sugars Production.

In this work, a combination of mechanical and chemical pretreatments using urea on corn residues (leaves and stems) was evaluated to obtain total reducing sugars (TRSs). The residues were characterized via high-performance liquid chromatography (HPLC) to quantify biomass composition. During the mechanical pretreatment, the particle size of the biomass was reduced to 0.5, 1, and 2 mm. The chemical pretreatment was performed with urea solution at different concentrations (2, 5, and 10% w/v) and a fixed biomass-to-solvent ratio of 1:25 (g/mL) as well as stirring at 150 rpm for 20 h. The effect of temperature on the pretreatment results was evaluated by varying such operating variables in 30 and 50 °C. After both pretreatments, hydrolysis was carried out in an autoclave using sulfuric acid at 1% v/v at 121 °C for 1 h. The content of TRS was quantified using 3,5-dinitrosalicylic acid (DNS) method and biomass after pretreatment was characterized via Fourier transform infrared (FT-IR). For both leaves and stems, the HPLC technique reported the presence of 47.4 g of cellulose, 40.04 g of hemicellulose, and 26.38 g of lignin. It was found that the highest amount of TRS (36.50 g/L) was obtained with a urea concentration of 2% at 50 °C using a particle size of 0.5 mm. The production of TRS was significantly higher for pretreated biomass than that for raw corn residues, confirming the importance of both mechanical and chemical pretreatments to reach better delignification results.

Estudio Observacional: Dermatofibrosarcoma Protuberans, Serie de casos / Observational Study: Dermatofibrosarcoma Protuberans, Case Series

Introducción: El dermatofibrosarcoma protuberans(DFSP), es uno de los tumores cutáneos menos frecuentes, se clasifica dentro de los sarcomas fibrohistociticos y está caracterizado por un crecimiento lento y progresivo. Métodos: Se realizó una serie de casos retrospectiva de los pacientes con DFSP atendidos en el Centro de la Piel (CEPI) entre 2010 y 2019, se tomó en cuenta la información demográfica, características clínicas, tratamiento y su evolución. Resultados: Seis pacientes fueron diagnosticados y tratados por DFSP en el período evaluado, existió un predominio de mujeres (4 mujeres, 2 hombres) con una media de edad de 58.2 (DE =19,6), tres de ellos presentaron lesiones en forma de placa indurada y los restantes presentaron nódulo único, la localización de las lesiones fueron en hombro, cuello e hipogastrio. El tratamiento más utilizado fue la escisión amplia, ninguno de los pacientes presentó recidivas al primer y quinto año del seguimiento. Conclusión: Es necesario el reconocimiento de las características clínicas típicas de DFSP ya que podría pasar como una tumoración benigna de piel, por lo cual se debe apoyar con el estudio histopatológico frente a la sospecha de este tipo de lesión

Introduction: Dermatofibrosarcoma protuberans (DFSP) is one of the rare tumors found in the fibrohistocytic sarcomas and it is characterized by slow and progressive growth. Methods:A retrospective study of six cases treated at the Skin Center (CEPI) between 2010 and 2019 was carried out. We have take into account demographic information, characteristics, treatment and evolution of the lesions. Results:Six patients were diagnosed and treated by DFSP. There was a predominance of women (4 women, 2 men) with a mean age of 58.2 (SD = 19.6), three of them presented lesions in the form of indurated plaque and the rest presented a unique nodule. The locations of the lesions were the shoulder, neck and hypogastrium. The most commonly used treatment was wide excision, none of the patients presented recurrences at the first and fifth year of follow-up. Conclusion:Recognition of the typical clinical characteristics of DFSP is necessary since it could be mistaken as a benign tumor of the skin. The diagnosis must be always done by histopathological confirmation

Environmental and Safety Assessments of Industrial Production of Levulinic Acid via Acid-Catalyzed Dehydration.

These days, there is a need to develop novel and emerging processing pathways that permit production of value-added substances and fuels considering sustainability aspects. In this sense, levulinic acid (LA) is one of the most promising biorefinery products. This paper presents environmental and safety assessments of LA production via acid-catalyzed dehydration (ACD) of biomass. The process was modeled by using Aspen Plus process simulation software based on a capacity of 132 000 tons per annum of banana rachis (main raw material). Likewise, environmental and safety assessments were developed. Parameters such as heats of reaction, explosivity, toxicity of substances, and operational conditions along with extended mass and energy balances were used to perform safety and environmental analyses. In this regard, the modeled topology showed an inherent safety index (ISI) score of 24 with an equal contribution of 12 points for both chemical inherent safety index (CIS) and process inherent safety index (PIS). ACD showed a good safety performance, with moderate concerns related to the handling of formic acid. Moreover, the waste reduction algorithm (WAR) was used to assess environmental performance and estimate potential environmental impacts (PEIs) of the simulated topology. It was performed considering four case studies to determine the influence of mass streams (case 1), product streams (case 2), energy streams (case 3), and simultaneous products and energy contribution (case 4). This analysis showed that for this process, the total inletting flow of impacts that enter was less than the amount of these that leave the system according to a generation rate of the PEI for case 1 (-1.89 × 102 PEI/h) and case 3 (-1.83 × 102 PEI/h). From the environmental viewpoint, the major concern is associated with the photochemical oxidation potential category because of the handling of volatile organic compounds through the process.

The Adenosine A3 Receptor Regulates Differentiation of Glioblastoma Stem-Like Cells to Endothelial Cells under Hypoxia.

Glioblastoma (GBM) is a neoplasm characterized by an extensive blood vessel network. Hypoxic niches of GBM can induce tumorigenic properties of a small cell subpopulation called Glioblastoma stem-like cells (GSCs) and can also increase extracellular adenosine generation which activates the A3 adenosine receptor (A3AR). Moreover, GSCs potentiates the persistent neovascularization in GBM. The aim of this study was to determine if A3AR blockade can reduce the vasculogenesis mediated by the differentiation of GSCs to Endothelial Cells (ECs) under hypoxia. We evaluated the expression of endothelial cell markers (CD31, CD34, CD144, and vWF) by fluorescence-activated cell sorting (FACS), and vascular endothelial growth factor (VEGF) secretion by ELISA using MRS1220 (A3AR antagonist) under hypoxia. We validate our results using U87MG-GSCs A3AR knockout (GSCsA3-KO). The effect of MRS1220 on blood vessel formation was evaluated in vivo using a subcutaneous GSCs-tumor model. GSCs increased extracellular adenosine production and A3AR expression under hypoxia. Hypoxia also increased the percentage of GSCs positive for endothelial cell markers and VEGF secretion, which was in turn prevented when using MRS1220 and in GSCsA3-KO. Finally, in vivo treatment with MRS1220 reduced tumor size and blood vessel formation. Blockade of A3AR decreases the differentiation of GSCs to ECs under hypoxia and in vivo blood vessel formation.