| Author (s): |
GULOTTA, Florencia A.; DIAZ VERGARA, Ladislao; MONTENEGRO, Mariana; FERREYRA Nancy F.; PAZ ZANINI, Verónica I.
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| Title: |
SELF-ASSEMBLED MULTILAYERS OF WATER GLUCOSE MODIFIED-CHITOSAN AND GLUCOSE OXIDASE FOR DETECTION OF GLUCOSE IN MILK SAMPLES |
| Abstract: |
Background: A crucial aspect of electrochemical enzymatic biosensor development is the immobilization of the enzymes, as it directly influences the sensitivity of the bioelectrode. Among the different methods used to incorporate enzymes on the surface of the transducers, layer-by-layer (LbL) self-assembly based on electrostatic interaction with polyelectrolytes of opposite charge stands out due to its simplicity and reproducibility. Aims: The aim of the work was to develop an electrochemical glucose biosensor by LbL assembly of a new functionalized chitosan polycation and the enzyme glucose oxidase (GOx). Methods: Chitosan was chemically functionalized with glucose by the Maillard reaction. The resulting polycation, named G-Chit, is soluble in the medium compatible with the enzyme. The bioelectrode was obtained by alternating adsorption of G-Chit and GOx onto carbon paste electrodes. By selecting the number of bilayer of G-Chit/GOX, the enzyme concentration, and the pH, the electroanalytical performance of the biosensor was optimized. The electrochemical responses were characterized by cyclic voltammetry and chronoamperometry. Results: Under optimized experimental conditions, the biosensor exhibited a sensitivity of (0.81 ± 0.03) µA mM-1 in a glucose concentration range of (0.18 to 1.75) mM. Discussion: Results indicated that catalytic response increases both with the number of G-Chit/GOx bilayers and the enzyme concentration, obtaining the best responses for 3 bilayers and 2 mg mL-1, respectively, while the optimum working pH value was 7.0. Conclusions: The analytical response of the biosensor was tested in milk samples with negligible matrix effects, suggesting a potential application in other dairy products. Results show that G-Chit appears promising for the immobilization of enzymes.
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| Keywords: |
Glucose biosensor, glucose-functionalized chitosan, carbon paste electrode.
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| Year: |
2022
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| Initial page: |
1
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| Final page: |
7
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| Link: |
Acessar |
| DOI: |
10.48141/SJS.v30.n34.2022.01_FERREYRA_pgs_01_07.pdf |
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| Author (s): |
QUINTERO, Cristián Andrés; VALLEJO, Mariana Guadalupe; BONTTI, Sergio; PATIŃO, Sol; PEREZ-GIRABEL, Rocío
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| Title: |
ADVANCES IN NATURAL EXTRACTS USED FOR ANTIBIOTIC-RESISTANT BACTERIA TREATMENT: THE GRAM-NEGATIVE CASES |
| Abstract: |
Background: Infectious diseases are a global problem, the second human cause of death. Infectious diseases caused by pathogenic bacteria have been treated with a high degree of efficacy. However, even when the 20th century was considered the “golden age” of antibiotics, bacteria developed a different resistance mechanism to antibiotics. In 2017, the WHO issued an alert about 12 bacteria with an urgent need to develop new antibiotics. Aims: The aim of the present review is to analyze the current knowledge of the antibacterial activity of natural extract-based treatments against the pathogens listed by WHO. Methods: A systematic review of the literature in PubMed was performed to search for publications describing the use of natural extracts as antibiotics over bacteria. We focused on the Gram-Negative group. The exclusion criteria consisted of limiting papers on natural extracts tested over the bacteria culture related to eight selected bacteria, according to an alert issued by WHO in 2017, and seven plant extracts. Results: All the Gram-Negative bacteria listed in 2017 by WHO have been treated, with different degrees of advance, with some of the plant extracts and plant-based compounds reviewed. In general, the first approach is using inhibition disks applied over the bacterial biofilm in solid culture media. Discussion: While Salmonellae and P. aeruginosa have been extensively studied, over N. gonorrhoeae, A. baumannii have been tested with fewer natural extracts. Edible herbs are more often used, as well as artemisa and wine byproducts. In all cases, they are in the early stages of study, not being tested in patients at present. Conclusions: Plant extracts and plant-based compounds are effective as antibacterial, with minimal effects on the host cell. Furthermore, they are sustainable, environmentally friendly, and renewable.
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| Keywords: |
natural extract, bacteria, pathogen, Antibiotic-resistant, infectious diseases. .
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| Year: |
2022
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| Initial page: |
8
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| Final page: |
27
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| Link: |
Acessar |
| DOI: |
10.48141/SJS.v30.n34.2022.02_QUINTERO_pgs_08_27.pdf |
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| Author (s): |
EDISHERASHVILI, Tamari
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| Title: |
ASSESSMENT OF THE IRRIGATION WEIR REMOVAL IN THE ENGURI RIVER |
| Abstract: |
Background: Dams are one of the biggest threats to aquatic biodiversity. They restrict the movement of migratory fish. The construction of barriers can cause the complete extinction of some species from the rivers. When a dam can no longer perform its function or research will determine the need to demolish it, dams are often removed. In the lower part of the Enguri River, Georgia, an irrigation weir is currently non-functional. Aims: This research aims to prove the need to demolish the dam construction on the 44th km of the Enguri River, as it negatively impacts biodiversity and creates an artificial barrier in the river. Methods: Visual inspection was used as a method to assess the morphology and habitat of the dam where it is located. The conversation method was used with Engurhesi LTD representatives to understand the current function of the dam. The Questions were related to the current function of the dam. Results: Based on the conservation with Engurhesi LTD representatives, the study has shown that there is no reason that an irrigation weir might be left in its current state on the Enguri River. Based on the studies, the damage to biodiversity is real and disturbing. Discussion: The irrigation weir on the Enguri River was left untended because of the construction of the Enguri dam. Currently, there is no reason to divert the river Enguri with the help of an irrigation weir as there is no excess water in this river. Conclusions: In conclusion, it can be said that it is necessary to remove the irrigation weir on the Enguri River to restore habitat and mitigate the threats to biodiversity.
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| Keywords: |
Dam removal, biodiversity, river restoration, fish passage.
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| Year: |
2022
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| Initial page: |
28
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| Final page: |
31
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| Link: |
Acessar |
| DOI: |
10.48141/SJS.v30.n34.2022.03_EDISHERASHVILI_pgs_28_31.pdf |
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| Author (s): |
ATÇEKEN, Nazente; KOZALAK, Gül; ÖZGÜL, R. Köksal; SYED, Hamzah
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| Title: |
THE TREND TOWARDS PHENOME-WIDE ASSOCIATION STUDIES (PheWASs) IN COVID-19 RESEARCH |
| Abstract: |
Background: Coronavirus Disease-2019 (COVID-19) appears in individuals asymptomatically and in various symptomatic forms. Symptomatic diversity can result in diagnosis failures, hospitalization, admission to intensive care, multi-organ failure, and death. The causes and risk factors of the severity of disease symptoms are uncertain. This uncertainty can only be resolved by elucidating the effects of host genes and genetic variations on different phenotypes. Aim: This review aimed to emphasize the importance of large-scale genotype-phenotype correlation studies in elucidating the phenotypic diversity in COVID-19 disease. Methods: All publications related to Phenome-Wide Association Study (PheWAS) in the PubMed database were searched. PheWAS studies applied to COVID-19 patients have been identified. In addition, studies applied to the genome-wide association study (GWAS)- Electronic health records (EHRs) data and additionally matched to the gene expression data were systematically reviewed. The latest PheWAS methodology and its importance in Large-scale genotype-phenotype correlations are discussed within the context of published COVID-19 studies. Results: According to our PubMed search data, there are few PheWAS studies on COVID-19 disease. This review explains the use of PheWAS studies applied to health records and GWAS data, and colocalization studies applied to expression quantitative trait locus (eQTL) analysis to understand the phenotypic variability of COVID-19. Discussion; Although there is a very limited number of PheWAS studies on COVID-19 diseases, these studies have obtained important data. At the current stage, there is a need for such studies in COVID-19 research. Conclusions: PheWAS is an ideal method for large-scale genotype-phenotype correlation studies that can reveal genetic diversity and phenotypic diversity in the pathophysiology of the disease.
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| Keywords: |
Phenome-wide association study (PheWAS), Genome-wide association study (GWAS), Electronic health records (EHRs), Large-scale genotype-phenotype correlation, COVID-19.
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| Year: |
2022
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| Initial page: |
32
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| Final page: |
46
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| Link: |
Acessar |
| DOI: |
10.48141/SJS.v30.n34.2022.04_ATÇEKEN_pgs_32_46.pdf |
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| Author (s): |
DELMONDES, Paulo Gabriel Dias; CARVALHO, Carlos Vitor de Alencar
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| Title: |
MANAGEMENT MODEL FOR CONSTRUCTION WASTE PRODUCED IN THE CITY OF RIO DE JANEIRO |
| Abstract: |
Background: A new management model for construction and demolition waste (CDW) was proposed for the city of Rio de Janeiro, hence waste the city planning area estimated generation; the results were compared with the data published by COMLURB and SNIS through the statistics tests was proved that CDW had been dispersed, which support the hypothesis that the current model cause dispersion of the rubble. Aim: This study proposes a new management model for CDW to the city, according to regions where occur the higher production of rubble. Methods: The estimation of rubble was obtained through the issued licenses from 2006 to 2020 published by SMPU. The quantification of rubble in the city was carried out by adopting the generation indicator from licensed construction activities. The amount of CDW published by COMLURB and SNIS was compared through statistics tests ANOVA and T-Test, the second period from 2006 to 2020 and 2011 to 2020. To measure the area to implant a CDW recycling plant, criteria from production capacity were used. Results: ANOVA test to data from 2006 to 2020 and 2011 to 2020, according to a confidence interval of 95%, found the P value 0.589 and 0.022, respectively, it was verified that the significant difference is between data from COMLURB and Estimated. The T-test was applied from the same period in data from SNIS and estimated the P values 0.399 and 0.014. Discussion: The data from Estimating between 2006 and 2020 showed the best representation. The Área de Planejamento – AP (Planning Area) 4 was where 50.70% of the total rubble, after the AP 3 with 17.66%, the AP 5 was estimated at 16.59%, last of all, AP 2 and AP 1 were calculated the generation of 8.28% and 6.77%, respectively. Therefore, sizing the CDW recycling producing 361,99.00 tons per year demands an area of 32,397.50 m˛. Conclusions: It was concluded that the receipt of CDW in transfer stations managed by COMLURB is not allowed; therefore, the need to create a construction waste recycling plant was presented, to this end, it is necessary to have an available area of approximately 32,397.50 m˛.
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| Keywords: |
construction waste, recycling, quantification, waste transfer stations, landfill.
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| Year: |
2022
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| Initial page: |
47
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| Final page: |
65
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| Link: |
Acessar |
| DOI: |
10.48141/SJS.v30.n34.2022.05_DELMONDES_pgs_47_65.pdf |
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