93 research outputs found

    Valorization, comparison and characterization of coconuts waste and cactus in a biorefinery context using NaClO2-C2H4O2 and sequential NaClO2-C2H4O2/autohydrolysis pretreatment

    Get PDF
    The search for new sources of lignocellulosic raw materials for the generation of energy and new compounds encourages the search for locations not well known and with a high potential for biomass availability as is the case of the Northeast Region of Brazil. Thus, the cactus (CAC), green coconut shell (GCS), mature coconut fibre and mature coconut shell were pretreated by NaClO2C2H4O2 and sequential NaClO2C2H4O2/autohydrolysis aiming at the obtention of high added-value compounds in the liquid fraction and solid phase. The yield of the solid phase was between 61.42 and 90.97% and the reduction up to 91.63% of lignin in the materials pretreated by NaClO2C2H4O2. After NaClO2C2H4O2/autohydrolysis pretreatment the obtained solids yield was between 43.57 and 52.08%, with a solubilization of the hemicellulose content up to 81.42%. For both pretreatments the cellulosic content remained almost unchanged. The pretreated solids were characterized by SEM, X-ray and crystallinity indexes showing significant modifications when submitted to pretreatments. These results were further confirmed by the enzymatic conversion yields of 81.6890.03 and 86.9790.36% of the LCMs pretreated by NaClO2C2H4O2 and pretreated by NaClO2C2H4O2/autohydrolysis, respectively. The resulting liquors had a total phenolic compounds content between 0.20 and 3.05 g/L, lignin recovered up to 7.40 g/L (absence of sulphur) and xylooligosaccharides between 16.13 and 20.37 g/L. Thus, these pretreatments showed an efficient fractionation of LCMs, especially in the GCS, being an important requirement for the generation of products and byproducts in the context of the biorefinery.The authors gratefully acknowledge the Brazilian research funding agencies CNPq and CAPES for financial support. Financial support from the Energy Sustainability Fund 2014-05 (CONACYT-SENER), Mexican Centre for Innovation in Bioenergy (CemieBio), Cluster of Bioalcohols (Ref. 249564) is gratefully acknowledged. We also gratefully acknowledge support for this research by the Mexican Science and Technology Council (CONACYT, Mexico) for the infrastructure project - INFR201601 (Ref. 269461) and CB-2015-01 (Ref. 254808).info:eu-repo/semantics/publishedVersio

    The Ketogenic Diet Is an Effective Adjuvant to Radiation Therapy for the Treatment of Malignant Glioma

    Get PDF
    INTRODUCTION: The ketogenic diet (KD) is a high-fat, low-carbohydrate diet that alters metabolism by increasing the level of ketone bodies in the blood. KetoCal® (KC) is a nutritionally complete, commercially available 4:1 (fat:carbohydrate+protein) ketogenic formula that is an effective non-pharmacologic treatment for the management of refractory pediatric epilepsy. Diet-induced ketosis causes changes to brain homeostasis that have potential for the treatment of other neurological diseases such as malignant gliomas. METHODS: We used an intracranial bioluminescent mouse model of malignant glioma. Following implantation animals were maintained on standard diet (SD) or KC. The mice received 2×4 Gy of whole brain radiation and tumor growth was followed by in vivo imaging. RESULTS: Animals fed KC had elevated levels of β-hydroxybutyrate (p = 0.0173) and an increased median survival of approximately 5 days relative to animals maintained on SD. KC plus radiation treatment were more than additive, and in 9 of 11 irradiated animals maintained on KC the bioluminescent signal from the tumor cells diminished below the level of detection (p<0.0001). Animals were switched to SD 101 days after implantation and no signs of tumor recurrence were seen for over 200 days. CONCLUSIONS: KC significantly enhances the anti-tumor effect of radiation. This suggests that cellular metabolic alterations induced through KC may be useful as an adjuvant to the current standard of care for the treatment of human malignant gliomas

    Characterization of the ketogenic diet in mice

    No full text

    Effect of intravenous dexmedetomidine (1µg/kg) in obtunding the pressor response to laryngoscopy and tracheal intubation compared to intravenous preservative free 2% lignocaine (1.5mg/kg)

    Get PDF
    Background: Haemodynamic variation during layngoscopy/intubation is always a matter of concern for Anesthesiologists. A stable circulatory system is the wish of all performing general anaesthesia. Hence an acceptable and easy method needs to be established to prevent the haemodynamic variations. Our aim was to evaluate the effect of intravenous Dexmedetomidine (1µg/kg) infusion in obtunding the pressor response to laryngoscopy and tracheal intubation compared to intravenous preservative free 2% Lignocaine (1.5mg/kg).Methods: In this study, 60 patients, aged between 18-60 years belonging to ASA I and II are included. They were randomly divided into 2 groups, each comprising of 30. In group D, patients were given Dexmedetomidine 1µg/kg IV infusion over 10min and in group L, patient were given Lignocaine 1.5mg/kg IV.Results: In group D, the systolic, diastolic, mean arterial pressure and heart rate decreased significantly, from baseline, at first, second, third, fourth and fifth minute post intubation. In group L, the systolic, diastolic, mean arterial pressure and heart rate increased from baseline at first and second minute and then decreased at third, fourth and fifth minute post intubation.Conclusions: When compared between the two groups all the hemodynamic parameters showed statistical significance. There are no significant side effects and severe haemodynamic variability like hypotension and bradycardia. Therefore we concluded that Dexmedetomidine is superior to lignocaine in blunting the hemodynamic response to laryngoscopy and endotracheal intubation without any significant side effects.

    Brain Metabolic Changes in Mice On the Ketogenic Diet

    No full text

    Theoretical study on molecules of interstellar interest. II. Radical cation of compact polycyclic aromatic hydrocarbons

    No full text
    Radical cations of polycyclic aromatic hydrocarbons have been postulated to be molecular carriers of diffuse spectroscopic features observed in the interstellar medium. Several important observations made by stellar and laboratory spectroscopists motivated us to undertake a detailed theoretical study attempting to validate the recorded data. In continuation of our work on this subject, we here focus on a detailed theoretical study of the doublet ground (X&#732;) and low-lying excited (&#195;, B&#732; and C&#732;) electronic states of the radical cation of phenanthrene, pyrene, and acenaphthene molecule. A multistate and multimode theoretical model in a diabatic electronic basis is developed here through extensive ab initio quantum chemistry calculations. Employing this model, first-principles nuclear dynamics calculations are carried out to unravel the spectral assignment, time-dependent dynamics, and photostability of the mentioned electronic states of the radical cations. The theoretical results compare well with the observed experimental data

    Theoretical study on molecules of interstellar interest. I. Radical cation of noncompact polycyclic aromatic hydrocarbons

    No full text
    Polycyclic aromatic hydrocarbons (PAHs), in particular, their radical cation (PAH+), have long been postulated to be the important molecular species in connection with the spectroscopic observations in the interstellar medium. Motivated by numerous important observations by stellar as well as laboratory spectroscopists, we undertook detailed quantum mechanical studies of the structure and dynamics of electronically excited PAH+ in an attempt to establish possible synergism with the recorded data. In this paper, we focus on the quantum chemistry and dynamics of the doublet ground (X̃) and low-lying excited (Ã, B̃, and C̃) electronic states of the radical cation of tetracene, pentacene, and hexacene molecule. This study is aimed to unravel photostability, spectroscopy, and time-dependent dynamics of their excited electronic states. In order to proceed with the theoretical investigations, we construct suitable multistate and multimode Hamiltonians for these systems with the aid of extensive ab initio calculations of their electronic energy surfaces. The diabatic coupling surfaces are derived from the calculated adiabatic electronic energies. First principles nuclear dynamics calculations are then carried out employing the constructed Hamiltonians and with the aid of time-independent and time-dependent quantum mechanical methods. The theoretical results obtained in this study are found to be in good accord with those recorded in experiments. The lifetime of excited electronic states is estimated from their time-dependent dynamics and compared with the available data

    A facile stereocontrolled synthesis of taxol CD rings

    No full text
    The crucial highly functionalized CD substructure of taxol has been synthesized featuring a stereocontrolled Boord reaction and stereoselective Sharpless allylic oxidation sequence leading to oxetane formation

    First and stereocontrolled entry to C-7 hydroxy functionality of taxanes employing Boord reaction

    No full text
    Synthesis of a highly functionalized taxol skeleton core making use of Diels-Alder and a novel oxygen bridge opening strategies leading to functionalized C-ring is described
    • …
    corecore