cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.14278922.v1
title: ALCOHOL BASED SOLUTIONS FOR HAND AND SURFACE SANITATION IN THE PREVENTION OF COVID-19: INFORMATIVE COMPENDIUM REGARDING THE INVOLVED CHEMISTRY

description: The recent coronavirus pandemic has already victimized hundreds of thousands of people around the world, and until this moment does not exist any medicine for healing or vaccine to avoid the contamination. Therefore, the actions of social isolation associated with the use of masks and surface and hand sanitation are the most effective actions to avoid the virus dissemination. The hands are one of the main vectors of contagious, and should be washed constantly and sanitized with some disinfectant agent. Among the recommendations, the formulations based on ethyl alcohol and isopropyl alcohol are the most used, being the efficiency of these formulations based on the alcohol type, the concentration, the applied volume, and the contact time. The gel disinfectants are preferred by the population due to the facile and safer manipulation. However, due to the pandemic, the main gelling agent has become sparse and, in the function of this, some countries authorized the utilization of alternative formulations. The World Health Organization recommends two formulations, being one based on ethyl alcohol (80 Vol%) and the second on isopropyl alcohol (75 Vol%), destined for the local manufacture and with a fast and effective action.
DOI: 10.6084/m9.figshare.14278924
title: EVALUATING OF DIFFICULTIES OF UNDERGRADUATE ON THE REPORT OF CHEMISTRY LAB EXPERIMENTAL

description: Scientific reports are important tools for show results of experimental activities undertaken at undergraduate level. The aims of this research were detecting difficulties of undergraduate students in the elaboration of reports in the experimental chemistry subjects of students of the Science: Biology and Chemistry course at the Federal University of Amazonas in different periods (2nd to 10th). Results and discussion and theoretical bibliographic were topics reported with the most difficulty. The students showed little reading habit, however, which increases with the time they spend in university, also reflecting the retention rate in the experimental subjects. These results point to possibilities to reduce the difficulties in the elaboration of experimental reports by intervention alternatives more appropriate to the desired learning process, based on the students’ reality. Detecting these points becomes an important to assist them in the learning process of academic writing.
DOI: 10.6084/m9.figshare.14278925
title: STANDARDIZATION OF GLUTATHIONE REDUCTASE MEASURE IN Aegla singularis (ANOMURA, CRUSTACEA) USING DCCR EXPERIMENTAL PLANNING

description: Glutathione Reductase (GR) plays a key role in the maintenance of GSH homeostasis, variations in its activity may indicate damage from environmental contaminants. Experimental planning is a strategy to reduces time and cost in enzymatic assays. In this work, DCCR experimental planning was used to standardize and to validate the measure of GR in Aegla singularis bioindicator. Samples of A. singularis were collected in three watersheds with different percentages of naturalness and land uses. At all, were selected 7 streams, in which collections were performed at one upstream (most preserved) and one downstream (less preserved) point. Effects of temperature, reading time, substrate (GSSG) and protein concentration in GR reaction medium were evaluated, being that the two latter variables were optimized by DCCR. GR was not affected by temperature (15 to 30 °C) or reading time (6 and 10 minutes). Increased concentrations of proteins from biological extract had negative correlation with GR, whereas higher concentrations of GSSG resulted in higher GR activity. Environmental validation showed that GR in Aeglawas influenced primarily by the watershed of origin. DCCR planning was efficient to optimizing the use of GR as a biomarker of environmental quality.
DOI: 10.6084/m9.figshare.14278925.v1
title: STANDARDIZATION OF GLUTATHIONE REDUCTASE MEASURE IN Aegla singularis (ANOMURA, CRUSTACEA) USING DCCR EXPERIMENTAL PLANNING

description: Glutathione Reductase (GR) plays a key role in the maintenance of GSH homeostasis, variations in its activity may indicate damage from environmental contaminants. Experimental planning is a strategy to reduces time and cost in enzymatic assays. In this work, DCCR experimental planning was used to standardize and to validate the measure of GR in Aegla singularis bioindicator. Samples of A. singularis were collected in three watersheds with different percentages of naturalness and land uses. At all, were selected 7 streams, in which collections were performed at one upstream (most preserved) and one downstream (less preserved) point. Effects of temperature, reading time, substrate (GSSG) and protein concentration in GR reaction medium were evaluated, being that the two latter variables were optimized by DCCR. GR was not affected by temperature (15 to 30 °C) or reading time (6 and 10 minutes). Increased concentrations of proteins from biological extract had negative correlation with GR, whereas higher concentrations of GSSG resulted in higher GR activity. Environmental validation showed that GR in Aeglawas influenced primarily by the watershed of origin. DCCR planning was efficient to optimizing the use of GR as a biomarker of environmental quality.
DOI: 10.6084/m9.figshare.14278926.v1
title: MULTIVARIATE ANALYSIS OF DIGITAL IMAGES AS AN ALTERNATIVE TO MONITOR DYE DEGRADATION BY THE FENTON PROCESS

description: The present work proposed the application of a multivariate regression model based on image data to monitor the decolorization process. Thus, a PLS regression based on the color histogram was applied to monitor the methylene blue degradation by the Fenton reaction. The results obtained by the digital imaging and UV-Vis methods were compared and the initial (Cº) and final (C) methylene blue concentrations, as well as the kinetic parameters, coefficients of determination (R2), half time degradation (t½), intercept (ρ), and slope (σ), were evaluated. From our results, the digital imaging and UV-Vis methods have equivalent potential to monitor the color removal profile, similar kinetic term, and low measurement errors. While the coefficient of determination (R(2)) of all PLS models and kinetics curves are close to 1.00, the half time degradation (t½) parameter ranged between 0.29 to 1.39 min for the UV-Vis model, and 0.80 min to 2.17 min for the digital imaging model. Furthermore, the efficiency of methylene blue removal ranged between 92.04% and 97.78% for the UV-Vis model and 91.30% to 93.72% for the digital imaging model. Then, based on statistical comparison tests, it was concluded that the digital imaging method is an alternative to monitor dye degradation processes.
DOI: 10.6084/m9.figshare.14278926
title: MULTIVARIATE ANALYSIS OF DIGITAL IMAGES AS AN ALTERNATIVE TO MONITOR DYE DEGRADATION BY THE FENTON PROCESS

description: The present work proposed the application of a multivariate regression model based on image data to monitor the decolorization process. Thus, a PLS regression based on the color histogram was applied to monitor the methylene blue degradation by the Fenton reaction. The results obtained by the digital imaging and UV-Vis methods were compared and the initial (Cº) and final (C) methylene blue concentrations, as well as the kinetic parameters, coefficients of determination (R2), half time degradation (t½), intercept (ρ), and slope (σ), were evaluated. From our results, the digital imaging and UV-Vis methods have equivalent potential to monitor the color removal profile, similar kinetic term, and low measurement errors. While the coefficient of determination (R(2)) of all PLS models and kinetics curves are close to 1.00, the half time degradation (t½) parameter ranged between 0.29 to 1.39 min for the UV-Vis model, and 0.80 min to 2.17 min for the digital imaging model. Furthermore, the efficiency of methylene blue removal ranged between 92.04% and 97.78% for the UV-Vis model and 91.30% to 93.72% for the digital imaging model. Then, based on statistical comparison tests, it was concluded that the digital imaging method is an alternative to monitor dye degradation processes.
DOI: 10.6084/m9.figshare.14278927
title: SPECIATION ANALYSIS OF ARSENIC IN RICE USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY COUPLED WITH HYDRIDE GENERATION ATOMIC FLUORESCENCE SPECTROMETRY (HPLC-HG-AFS)

description: The aim of this work was to develop a method using high performance liquid chromatography coupled with hydride generation atomic fluorescence spectrometry (HPLC-HG-AFS) for the determination and speciation analysis of the inorganic and organic species of arsenic found most often in rice samples: As(V), As(III), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA). The best chromatographic resolution was obtained using pH 6.2, a phosphate buffer mobile phase concentration of 20 mmol L-1 and flow rate of 0.57 mL min-1, HCl concentration of 5.55% (v/v), and NaBH4 concentration of 0.90% (w/v). The accuracy of the method was confirmed by the low relative error values obtained for analysis of a certified reference material (NIST 1568b): 6.63% (total inorganic As), 3.44% (DMA), 0% (MMA), and 0.53% (total As). In recovery tests, the proposed method achieved satisfactory recoveries in the range 86-110%.
DOI: 10.6084/m9.figshare.14278928
title: PREPARATION OF HYDRAZONE AND N-ACYLHYDRAZONE USING COMMERCIAL DRUGS AS REAGENTS: PRACTICAL CLASSES OF BIOACTIVE COMPOUND SYNTHESIS

description: Several scientific works demonstrate the chemical and medicinal importance of hydrazone compounds. In this regard, the present paper proposes some practical classes of chemoinformatics and organic chemistry, using investigative and illustrative strategies, to teach the synthesis of a hydrazone and a N-acylhydrazone with proven biological activity. The motivating element used for the development of this didactic material was the use of commercial drugs, such as hydralazine and isoniazid, as alternative reagents for the synthesis of the target compounds. The sequence of experimental classes was planned to demonstrate the role of chemistry in the development of new drugs, to estimulate the curiosity of undergraduate students and to facilitate learning and the assimilation of the contents.
DOI: 10.6084/m9.figshare.14278927.v1
title: SPECIATION ANALYSIS OF ARSENIC IN RICE USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY COUPLED WITH HYDRIDE GENERATION ATOMIC FLUORESCENCE SPECTROMETRY (HPLC-HG-AFS)

description: The aim of this work was to develop a method using high performance liquid chromatography coupled with hydride generation atomic fluorescence spectrometry (HPLC-HG-AFS) for the determination and speciation analysis of the inorganic and organic species of arsenic found most often in rice samples: As(V), As(III), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA). The best chromatographic resolution was obtained using pH 6.2, a phosphate buffer mobile phase concentration of 20 mmol L-1 and flow rate of 0.57 mL min-1, HCl concentration of 5.55% (v/v), and NaBH4 concentration of 0.90% (w/v). The accuracy of the method was confirmed by the low relative error values obtained for analysis of a certified reference material (NIST 1568b): 6.63% (total inorganic As), 3.44% (DMA), 0% (MMA), and 0.53% (total As). In recovery tests, the proposed method achieved satisfactory recoveries in the range 86-110%.
DOI: 10.6084/m9.figshare.14278928.v1
title: PREPARATION OF HYDRAZONE AND N-ACYLHYDRAZONE USING COMMERCIAL DRUGS AS REAGENTS: PRACTICAL CLASSES OF BIOACTIVE COMPOUND SYNTHESIS

description: Several scientific works demonstrate the chemical and medicinal importance of hydrazone compounds. In this regard, the present paper proposes some practical classes of chemoinformatics and organic chemistry, using investigative and illustrative strategies, to teach the synthesis of a hydrazone and a N-acylhydrazone with proven biological activity. The motivating element used for the development of this didactic material was the use of commercial drugs, such as hydralazine and isoniazid, as alternative reagents for the synthesis of the target compounds. The sequence of experimental classes was planned to demonstrate the role of chemistry in the development of new drugs, to estimulate the curiosity of undergraduate students and to facilitate learning and the assimilation of the contents.
DOI: 10.6084/m9.figshare.14278931
title: INFLUENCE OF AGITATION AND AERATION ON XYLITOL PRODUCTION BY THE YEAST Starmerella meliponinorum

description: The production of xylitol from pentose-fermenting yeast is closely related to the amount of oxygen present in the culture medium. This study evaluated the effects of agitation and aeration in xylitol production using the yeast Starmerella meliponinorum FRP.09, previously isolated and selected due to its capacity to produce ethanol and xylitol from xylose. Fermentations were conducted in 125 mL flasks with 15 mL of culture medium and shaken at 150 rpm and 200 rpm without forced aeration and compared to fermentation in a static system. To assess the forced aeration, bioreactor was used with an air flow of 0.1 vvm and agitation of 100 rpm, 0.25 vvm / 150 rpm and 0.5 vvm / 200 rpm. Higher agitation and airflow significantly increased the xylose consumption. The yeast S. meliponinorum FRP.09 achieved the best xylitol yield of 0.6 g of xylitol per g of xylose consumed, when the fermentation was conducted with an air flow/rotation speed of 0.5 vvm / 200 rpm in bioreactor and 150 rpm in the fermentation flasks.
DOI: 10.6084/m9.figshare.14278932
title: DIDACTIC SEQUENCE FOR THE PROMOTION OF PRACTICAL AND MULTIDISCIPLINARY STUDY WITH ACCESSIBLE MATERIALS

description: Innovation and multidisciplinarity are the way to accelerate improvements in education, as well as the search for contextualized content. The multidisciplinarity between chemistry and Biology, allows to explore various contents, one of them is the environment. Works that offer alternatives to simpler experiments are of great help professors. In this context, this study suggests a didactic sequence using easily accessible materials to address chemical and Microbiological concepts of soil. The proposal is aimed at high school students and early undergraduate students. The contents were: hydrogen potentials (pH), mixture separation methods, soil liquid and gas phases and soil microbial population extraction involving bacterial DNA. Thus, the work shows a low cost alternative for the teaching of concepts related to soil, being a contextualized, multidisciplinary, dynamic and attractive proposal.
DOI: 10.6084/m9.figshare.14278933.v1
title: QUANTIFICATION OF CRAMBE BIODIESEL CONTENT IN DIESEL BLENDS USING MIR SPECTROSCOPY END VARIABLES SELECTION.

description: Mid-Infrared absorption spectroscopy associate with the Partial Least Squares regression is the official method to monitor Brazilian commercial diesel quality. This method, however, uses solvents and a large number of samples for the construction of the calibration curves, which generates waste and increases the time needed for the analysis. In order to develop a non-destructive method, being possible to recover the sample after its quantification, decrease the quantity of samples and make use of a single calibration curve, in this study we used the oilseed crambe, which is not used in human food, for the methyl biodiesel production and PLS analysis for their content determination in mixtures with diesel at a concentration range of 1.00 to 30.00 (% v/v). The global model for crambe methyl biodiesel obatined RMSEC = 0.26 (% v/v), RMSECV = 0.35 (% v/v) and RMSEP = 0.41 (% v/v). Complementary, variable selection method iPLS was applied in the global model in order to reduce the spectral range required to regression construction and to improve the RMSEP, RMSECV and RMSEC values.
DOI: 10.6084/m9.figshare.14278931.v1
title: INFLUENCE OF AGITATION AND AERATION ON XYLITOL PRODUCTION BY THE YEAST Starmerella meliponinorum

description: The production of xylitol from pentose-fermenting yeast is closely related to the amount of oxygen present in the culture medium. This study evaluated the effects of agitation and aeration in xylitol production using the yeast Starmerella meliponinorum FRP.09, previously isolated and selected due to its capacity to produce ethanol and xylitol from xylose. Fermentations were conducted in 125 mL flasks with 15 mL of culture medium and shaken at 150 rpm and 200 rpm without forced aeration and compared to fermentation in a static system. To assess the forced aeration, bioreactor was used with an air flow of 0.1 vvm and agitation of 100 rpm, 0.25 vvm / 150 rpm and 0.5 vvm / 200 rpm. Higher agitation and airflow significantly increased the xylose consumption. The yeast S. meliponinorum FRP.09 achieved the best xylitol yield of 0.6 g of xylitol per g of xylose consumed, when the fermentation was conducted with an air flow/rotation speed of 0.5 vvm / 200 rpm in bioreactor and 150 rpm in the fermentation flasks.
DOI: 10.6084/m9.figshare.14278932.v1
title: DIDACTIC SEQUENCE FOR THE PROMOTION OF PRACTICAL AND MULTIDISCIPLINARY STUDY WITH ACCESSIBLE MATERIALS

description: Innovation and multidisciplinarity are the way to accelerate improvements in education, as well as the search for contextualized content. The multidisciplinarity between chemistry and Biology, allows to explore various contents, one of them is the environment. Works that offer alternatives to simpler experiments are of great help professors. In this context, this study suggests a didactic sequence using easily accessible materials to address chemical and Microbiological concepts of soil. The proposal is aimed at high school students and early undergraduate students. The contents were: hydrogen potentials (pH), mixture separation methods, soil liquid and gas phases and soil microbial population extraction involving bacterial DNA. Thus, the work shows a low cost alternative for the teaching of concepts related to soil, being a contextualized, multidisciplinary, dynamic and attractive proposal.
DOI: 10.6084/m9.figshare.14278933
title: QUANTIFICATION OF CRAMBE BIODIESEL CONTENT IN DIESEL BLENDS USING MIR SPECTROSCOPY END VARIABLES SELECTION.

description: Mid-Infrared absorption spectroscopy associate with the Partial Least Squares regression is the official method to monitor Brazilian commercial diesel quality. This method, however, uses solvents and a large number of samples for the construction of the calibration curves, which generates waste and increases the time needed for the analysis. In order to develop a non-destructive method, being possible to recover the sample after its quantification, decrease the quantity of samples and make use of a single calibration curve, in this study we used the oilseed crambe, which is not used in human food, for the methyl biodiesel production and PLS analysis for their content determination in mixtures with diesel at a concentration range of 1.00 to 30.00 (% v/v). The global model for crambe methyl biodiesel obatined RMSEC = 0.26 (% v/v), RMSECV = 0.35 (% v/v) and RMSEP = 0.41 (% v/v). Complementary, variable selection method iPLS was applied in the global model in order to reduce the spectral range required to regression construction and to improve the RMSEP, RMSECV and RMSEC values.
DOI: 10.6084/m9.figshare.14278934
title: TWO NEW AZAPHENANTHRENE ALKALOIDS FROM Anaxagorea dolichocarpa Sprague & Sandwith

description: A chemical investigation of Anaxagorea dolichocarpa Sprague & Sandwith, a member of Annonaceae family, was carried out. The ethanolic extract from the roots of this plant led, by chromatography tecniches, to isolation of the new azaphenanthrene alkaloids dolichocarpine (1) and 9-methoxyeupolauramine (2), besides the known alkaloids eupolauramine (3), 3-methoxyeupolauridine (4), eupolauramine (5) and 4-methylsampangine (6). The structures of isolated compounds were established by 1D and 2D NMR, HRESIMS, tandem MSn and IR data. The cytotoxicity of compounds 1 - 5 was evaluated against HCT-116 (human colorectal carcinoma) and L929 (murine fibroblast) cell lines.
DOI: 10.6084/m9.figshare.14278934.v1
title: TWO NEW AZAPHENANTHRENE ALKALOIDS FROM Anaxagorea dolichocarpa Sprague & Sandwith

description: A chemical investigation of Anaxagorea dolichocarpa Sprague & Sandwith, a member of Annonaceae family, was carried out. The ethanolic extract from the roots of this plant led, by chromatography tecniches, to isolation of the new azaphenanthrene alkaloids dolichocarpine (1) and 9-methoxyeupolauramine (2), besides the known alkaloids eupolauramine (3), 3-methoxyeupolauridine (4), eupolauramine (5) and 4-methylsampangine (6). The structures of isolated compounds were established by 1D and 2D NMR, HRESIMS, tandem MSn and IR data. The cytotoxicity of compounds 1 - 5 was evaluated against HCT-116 (human colorectal carcinoma) and L929 (murine fibroblast) cell lines.
DOI: 10.6084/m9.figshare.14278936
title: Novel PEG 4000 derivatives and its use in controlled release of drug indomethacin

description: The insertion of functional groups in polymer compounds may facilitate their interaction with different drugs. PEG polymers are widely used for their low melting point, low toxicity, drug compatibility, and hydrophilicity. They are used as pharmaceutical excipients for the formulation of conventional or modified released drugs and are designed to be upgraded as drug-modulating controllers at specific sites in the body. Indomethacin has been used in the controlled release of drugs because it is a drug that have good interaction with different polymers. The drug is a non-steroidal anti-inflammatory drug used in the treatment of rheumatoid arthritis, osteoarthritis, spondylitis, and other disorders. In this work, PEG 4000 had its chain modified by organic reactions and their derivatives were emulsified to form microparticles using polyvinyl alcohol as an emulsifier. Posteriorly were also incorporated with indomethacin. The samples were characterized to prove the influence of indomethacin on the morphology and thermal behavior of this polymer. The controlled release was performed in the time from 0 to 240 min using the Ultraviolet Spectroscopy to quantify indomethacin released from the polymer matrix for these 4 hours. Releases over the time were satisfactory as concentrations increased over time, which we can conclude that the structural modification of PEG 4000 was beneficial in the release of the indomethacin drug.
DOI: 10.6084/m9.figshare.14278936.v1
title: Novel PEG 4000 derivatives and its use in controlled release of drug indomethacin

description: The insertion of functional groups in polymer compounds may facilitate their interaction with different drugs. PEG polymers are widely used for their low melting point, low toxicity, drug compatibility, and hydrophilicity. They are used as pharmaceutical excipients for the formulation of conventional or modified released drugs and are designed to be upgraded as drug-modulating controllers at specific sites in the body. Indomethacin has been used in the controlled release of drugs because it is a drug that have good interaction with different polymers. The drug is a non-steroidal anti-inflammatory drug used in the treatment of rheumatoid arthritis, osteoarthritis, spondylitis, and other disorders. In this work, PEG 4000 had its chain modified by organic reactions and their derivatives were emulsified to form microparticles using polyvinyl alcohol as an emulsifier. Posteriorly were also incorporated with indomethacin. The samples were characterized to prove the influence of indomethacin on the morphology and thermal behavior of this polymer. The controlled release was performed in the time from 0 to 240 min using the Ultraviolet Spectroscopy to quantify indomethacin released from the polymer matrix for these 4 hours. Releases over the time were satisfactory as concentrations increased over time, which we can conclude that the structural modification of PEG 4000 was beneficial in the release of the indomethacin drug.