Carbonaceous materials are currently of great importance because they are used in electrochemical devices capable of storing energy from renewable sources of electricity generation. In this work, a search on the characteristics of precursors, synthesis methods and characterization of carbonaceous materials with electrochemical applications was carried out. As a result of this review is obtained that distillery vinasse and torula liquor are potential sources of carbon for the synthesis of those materials. Also those synthesis methods using templates lead to improved electrical properties, clays are the most commonly used templates for synthesis, but it is evidenced the possibility of using zeolites chemically modified with these ends. The doping with nitrogen, phosphorus and some metal oxides leads to an improvement of the electrical properties of the obtained materials.
The aim of this work was the optimization of lipid production by an oleaginous yeast strain using agroindustrial by-products obtained from the dairy and sugar industries as carbon sources. Screening (Plackett-Burman) and optimization (Box-Behnken) designs were used to determine the influence of the components of the culture medium on the percentage of accumulated lipids and the biomass concentration, as well as to optimize the composition of the culture medium, respectively. The triglycerides concentration was determined by the sulfo-phospho-vanillin method. The regression equations obtained during optimization predicted maximum values of lipid accumulation of 65 % and biomass concentration of 13 mg/mL, results comparable to those obtained by other researchers and which point to the industrial applicability of this strain in technological systems aimed at biodiesel production.
The present work calculates the likeness of the N, N’-((1, 3-fenilenbis theoretically (azanediil)) bis(carbonotioil)) bis(furan-2-carboxamida) as ionoforo of a selective electrode to ions lead (II). For it was calculated it the energy of union ionoforo-Pb2+, the same as for the main reported interferences: Cu2+, Hg2+, Zn2+, Ni2+, Co2+, Ca2+ and Cd2+. The geometries and energy were optimized using the Theory of the Functional one of the Density with the functional M06L and three combinations of different base groups. For the calculation of the solvation energy the pattern SMD was used. The relative energy obtained by the first two combinations of base groups differs with the experimental results. However, the third combination ratifies the experimental evidence of the preference of this ionoforo toward the ions Cu2+ and Pb2+ and the smallest selectivity toward the rest of the interferences, except for the ions Ni2+ whose relative energy are bigger than those of any other ion.
The aim of the present work was to determine some quality parameters and to evaluate the stability of hydroethanolic to 70% extract of leaves of Spondias mombin L. (Anacardiaceae), stored at room temperature for one year. This specie is used traditionally for the treatment of diverse diseases because to its activity as antibacterial, anti-inflammatory and antioxidant. The leaves were collected in different stages of the cycle of life and it was used the maceration method. High-performance liquid chromatography (HPLC) analysis showed the presence of important phytoconstituents such as gallic acid and derivates and quercetin 3-O- glucosides. The parameters: organoleptic characteristics, pH, relative density, total solids, fixed solids, volatile solids, total phenolic and total flavonoids content were determined; the confidence intervals were established. The obtained data from the extract to the study of stability, related with these parameters, allow to assure stable behaviour during one year, from a physical-chemical standpoint.
The waters coming from the Guaos-Gascon Hydrographic Basin, located in the western part of the city of Santiago de Cuba, are used as area of disposition of residual products of the human activity, affecting its natural composition and increasing the pollutant load that reaches Santiaguera Bay. To carry out this study were analyzed 24 physical-chemical and 3 microbiological in eight monitoring stations, between the months of February and April of the year 2017, The results obtained are compared with the Cuban Standards drinking water, supply, fishing and bathing, finding, that they don't fulfill the same ones. These hydraulic currents are affected by pathogenic germs: total coliforms, fecal and E. coli. The Quality Index for Surface Waters is determined and is statistically compared with previous studies, there being differences between them, observing a temporary decrease, confirming an increase in contamination.
The teaching of the Organic Chemistry for the career of Pharmaceutical Sciences of the Universidad de Oriente is sustained in relationships interdisciplinary and interdisciplinary con it bases on its principle rector: relationship structure-property-applications. The present work shows the results obtained of implementation of integrative seminars in the Pharmaceutical Organic Chemistry I and Chemistry Organic Pharmacist II for a bigger contribution in the pharmaceutical professional's formation. The methods were used: historical-logical, system focus, analysissynthesis, inductive-deductive and specialist criterion. Abilities related with the profession are shown, expressed in the analytic programs of each subject, their correspondence with the seminars and the results reached with this class type during the courses 2018-2019 and 20192020. The integration of the contents of the Pharmaceutical Organic Chemistry was achieved I and II, as well as with other subjects of the career, being demonstrated the narrow linking between the Organic Chemistry and the pharmaceutical specialty.
Radiotracers are very important in the oil industry. The extraction with trioctylamine (TOA) and tributylphosphate (TBF) has been used to obtain a radiotracer in organic phase from the eluent of the 99Mo/99mTc generator. In this work we studied the influence of the phase separation method in the extraction of technetium 99 metastable pertechnetate (). Centrifugation was necessary to obtain adequate separation. The formulation TBF-TOA-cyclohexane was optimized for the extraction of 600 MBq activity of, perspective for industrial scale applications. Additionally, with 7.53%TBF-0.77%TOA-cyclohexane formulation, the highest extraction yield (96.86%) was achieved. A laboratory installation that simulates a continuous horizontal gravitational separator (oil-water layer), was constructed and evaluated.
The aim of the study is to demonstrate that the biotinylated 19 base oligonucleotide probe of the gag gene H1Gag1584 can be used as a molecular recognition element for the detection of HIV-1 proviral DNA, in two electrochemical detection systems of free laber. Two free leber electrochemical detection systems were evaluated: an impedimetric DNA genosensor using a self-assembled biotin monolayer (SAM) and a voltammetric DNA genosensor by modifying a new epoxy graphite transducer with graphene oxide. The results obtained in this study showed that the biotinylated 19-base oligonucleotide probe of the gag gene H1Gag1584 can be used as a molecular recognition element for the detection of HIV-1 proviral DNA, in two electrochemical detection systems of free labels.
Sida pyramidata Cav., well-known in Cuba as Yerba de aura, is traditionally used as a decoction of leaf sprouts to treat digestive disorders and diseases of the uterus. So far there are no reports of phytochemical studies on the plant that scientifically justify the attributed pharmacological properties. The objective of this work was to identify the secondary metabolites of biological and therapeutic interest present in the Sida pyramidata Cav. species. Phytochemical screening, performed on plant leaf extracts and applied thin layer chromatography, allowed to verify the presence of several families of secondary metabolites with pharmacological interest such as: saponins, essential oils, alkaloids, phenols and coumarins; being these with more abundance in the ethanol extract. The abundance of saponins, essential oils and alkaloids in Sida pyramidata Cav. It could be responsible for the pharmacological activity attributed to the plant.
In this work, were developed membranes of polyvinyl alcohol (PVA) loaded with a cuban natural zeolite for their potential application in CO2 adsorption. Those were characterized by scanning electron microscopy, FTIR spectroscopy with ATR and thermogravimetric analysis. It could be proven that it is possible to obtain membranes of PVA/zeolite that are flexible, homogeneous and with appropriate thermal stability. The importance of the quantity of water was evaluated added in the physical characteristics of the membranes. It could settle down that there are not significant interactions between the polymer and the zeolite in the compound materials. It was demonstrated that their thermal behavior depends on the quantity of added zeolite. The results obtained in the studies of static adsorption from CO2 to 25 oC suggest that the compound membranes PVA/zeolite can be good candidates like adsorbents of this gas for its employment in the purification of the air.
This work evaluates the physical and physicochemical parameters of the “Festival” strawberry variety, obtained under the edaphoclimatic conditions of Humpata, Province of Huila, Angola, followed by its transformation into sweet of adequate quality. The analyzes carried out were: the mass was determined on analytical balance and the transversal and longitudinal diameters with a caliper. Other analyzes were: total acidity titratable by volumetry, pH by potentiometry, total soluble solids by refractometry, moisture and ash by gravimetry. The study carried out showed that the pH of the pulp was 3.41; and in the sweet it was 3.31. The titratable acidity in the strawberry pulp was 0.186 g/100 ml and in the sweet 0.096 g/100 ml; the ascorbic acid content in the pulp was 18.60 mg/100g. The average content of soluble solids in the pulp was 9.51oBrix and for the sweet 68.83oBrix. These chemical characteristics of the pulp and the sweet provide information about their nutritional values.
Polyacrylamide hydrogels were produced by simultaneous synthesis and crosslinking, induced by gamma radiation in a 60Co irradiator, from a monomeric solution of 1, 26 M acrylamide. Obtained hydrogels are modified chemically by incomplete basic hydrolysis, using potassium hydroxide to achieve a poly (acrylamide-co-potassium acrylate) copolymer. The swelling process of samples in distilled water fits first order kinetic models, and second order kinetics in conditions of both acid and basic pH at constant ionic force. The best swelling values are obtained for samples irradiated at 10 kGy and modified with potassium hydroxide for 1 h, thus achieving a weight gain of over 1000 times its weight in distilled water, whereas in pH buffers the optimum absorption capacity for an agricultural-used hydrogel was slightly exceeded, increasing its weight 60 times over.
This work describes the process of preparation of particles polymeric submicrometric of n-butilo butylcyanoacrylate loaded with 5-Fluorouracil, designed as a liberation system controlled to treat carcinoma in skin, able to improve the therapeutic value of this cytostatic one, overcoming this way the disadvantages of its use in formulations that contain it free. The departure monomer was synthesized and characterized by means of technical spectroscopic. The particles were obtained by means of polymerization in emulsion and they were characterized to FT-GO, RMN-1H, RMN-13C and MALDI-TOF. The particle size, morphology and characteristic electrokinetics were analyzed by means of DLS, SEM and potential zed. Two methodologies were employees to load the particles with the cytostatic one: superficial adsorption and absorption or encapsulation in the main polymeric. The load processes were followed using UV or HPLC. The nanosphere was stable and of smaller diameter at 500nm. The efficiency of encapsulation of the 5Fluorouracil was of 30% for both methodologies.
The objective of this paper was characterize of the chemical point of view, the soils at the emplacement of hazardous waste depository, at Juragua, Cuba, as part of the Environmental Baseline. It was possible to establish the reference levels of the following heavy metals (MP): copper (Cu), zinc (Zn); chromium (Cr); nickel (Ni); lead (Pb); cadmium (Cd) and manganese (Mn), by the method of Direct Aspiration by Atomic Absorption Spectroscopy (AAS) in air - acetylene flame, according to procedures. Mercury (Hg) was determined using a direct mercury analyzer (DMA - 80), according to the standard procedure. The confidence intervals for the mean with a probability of 95%, were established and are of great importance for the evaluation of the environmental impact of the installation in the soil. These results are within the range reported as natural values and should be considered as references values for the study area.
In the work the elaborated educational tasks are shown, from the treatment of chemical contents with historical focus, and that they favor the formation of values ethical-professionals in the students of the careers of Degree in Education with chemical profile (Biology-chemistry and Chemistry) of the Universidad de Oriente, what constitutes the objective of the investigation. Theoretical, empiric methods and the percentage calculation were used for the qualitative and quantitative valuation of the results; as well as the triangulation of data. With the application of the educational tasks it is contributed to the development of values: love to the science and the profession, responsibility before the study and in their labor practice, sense of ownership and professional identity, demonstrated starting from the attitudes and responsible behavior, and reflected in the way of professional performance.
The validation of a stripping voltammetric method for the cadmium quantification in wastewater using the built potentiostat is presented. Stability of current intensity was observed in KCl 1 mol/L and in acetic acid/acetate buffer, setting 10s as the sampling time. At pH 5 and -1300 mV an increasing of the peak current was observed, and the electrodeposition time did not show significative influence. The linear range was 6·10-5 - 5·10-4 mol/L. The detection and quantification limits were 10-5 mol/L and 5·10-5 mol/L. The method presented coefficients of variation for repeatability between 3 and 3, 9% and with statistical homogeneity in different days. The recovery percentage was 102 ± 4,83 %. The associated uncertainty with concentration was 1,3∙10-5 – 1,2∙10-6 mol/L. The quantification of samples of wastewater showed a cadmium concentration of 199 ± 8,9 mg/L, with a variation coefficient of 4,5 %.
Phytochemical investigations suggest that Gymnanthes lucida Sw. (aite) is a potential candidate for obtaining antioxidant principles. Total phenolic and flavonoid content were quantified and in vitro antioxidant capacity was assessed in extracts, ellagitannins, and coumarins isolated from the leaf and bark by three methods: 2,2-diphenyl-1-pricrylhydrazyl (DPPH) and 2,2´-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radicals scavenging activities and ferric reducing power. The highest phenolic and flavonoid content was observed in the leaf extract which also exhibited the highest activity among the extracts DPPH (IC50=12,82 ± 0,12 μg/mL), ABTS (IC50=13,83 ± 3,45 μg/mL), and reducing power (104% compared to ascorbic acid). Ellagic acid (EA) showed the highest activity, with DPPH (IC50=11,75 ± 0,53 μg/mL), ABTS (IC50=11,28 ± 0,28 μg/mL), and reducing power (107 % compared to ascorbic acid). Results suggest that G. lucida is a natural source of antioxidants where EA is the main secondary metabolite of the leaf responsible for the activity.
The establishment of a reference material is necessary for the quality control tests that arecarried out on drugs, guaranteeing reliable and traceable measurements. A new candidatereference material for Nimotuzumab was developed at the Center for MolecularImmunology with the aim of replacing the current one before its expiration. In this work,was determined the secondary structure and thermal stability of materials by circulardichroism in the ultraviolet distant and three-dimensional folding by means of the nearultraviolet and intrinsic fluorescence. Both materials presented a predominance of β sheets(~ 42%) and thermodynamic stability of ~ 71 o C. The three-dimensional folding showedvery similar spectra in terms of the position of the absorption bands of the aromaticresidues and the intensity of fluorescence emission for the Tyr (336 nm) and for the Trp(337 nm).
Specific contrast agents facilitate the use of Magnetic Resonance Imaging (MRI) in the early diagnosis of Alzheimer's disease (AD). In the present work, a procedure for the synthesis of a potential MRI contrast agent based on PEGylated Gd2O3 particles is developed for conjugation to Amylovis®, a family of compounds that has shown a high affinity for the pathological structures present in AD. The products obtained were characterized by FT-IR, ICP, TGA, DLS and SEM. Amylovis-functionalized Gd2O3 particles showed a spherical morphology, with an average hydrodynamic diameter of 2.5 μm. These particles presented an adequate value of the ratio between the longitudinal (r1) and transversal (r2) relaxivities (r2/r1 = 2.4). This suggests that once these particles have a hydrodynamic diameter smaller than 200 nm, they could be used as a potential contrast agent for MRI.
