3,460 results on '"F B"'
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2. 6-18-O-PURINE NUCLEOTIDES. SYNTHESIS AND INFRARED BAND ASSIGNMENT.
- Author
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HOWARD FB and MILES HT
- Subjects
- Kinetics, Adenine Nucleotides, Aminohydrolases, Chemical Phenomena, Chemistry, Cyanides, Deuterium, Guanine Nucleotides, Infrared Rays, Nucleosides, Nucleotides, Oxygen Isotopes, Purine Nucleotides, Research, Solvents, Spectrum Analysis
- Published
- 1965
3. THE CONFIGURATION OF PHYTOENE.
- Author
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JUNGALWALA FB and PORTER JW
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- Carotenoids, Chemical Phenomena, Chemistry, Chromatography, Research, Spectrophotometry
- Published
- 1965
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4. WATER.
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BOTTCHER CJ and KLYNSTRA FB
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- Chemical Phenomena, Chemistry, Water
- Published
- 1963
5. THE MECHANISM OF ACTION OF THE RIBONUCLEASE-REACTIVATING ENZYME.
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VENETIANER P and STRAUB FB
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- Animals, Swine, Ascorbic Acid, Biochemical Phenomena, Chemical Phenomena, Chemistry, Chloromercuribenzoates, Enzyme Reactivators, Pancreas, Research, Ribonucleases
- Published
- 1964
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6. Mathematics in Chemistry: Indeterminate Forms and Their Meaning
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Segurado, Manuel A. P., Silva, Margarida F. B., and Castro, Rita
- Abstract
The mathematical language and its tools are complementary to the formalism in chemistry, in particular at an advanced level. It is thus crucial, for its understanding, that students acquire a solid knowledge in Calculus and that they know how to apply it. The frequent occurrence of indeterminate forms in multiple areas, particularly in Physical Chemistry, justifies the need to properly understand the limiting process in such cases. This article emphasizes the importance of the L'Hopital's rule as a practical tool, although often neglected, to obtain the more common indeterminate limits, through the use of some specific examples as the radioactive decay, spectrophotometric error, Planck's radiation law, second-order kinetics, or consecutive reactions. (Contains 4 notes and 7 figures.)
- Published
- 2011
- Full Text
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7. Estimating p-n Diode Bulk Parameters, Bandgap Energy and Absolute Zero by a Simple Experiment
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Ocaya, R. O. and Dejene, F. B.
- Abstract
This paper presents a straightforward but interesting experimental method for p-n diode characterization. The method differs substantially from many approaches in diode characterization by offering much tighter control over the temperature and current variables. The method allows the determination of important diode constants such as temperature coefficient of voltage, bandgap and indicates the existence of a unique temperature, hypothesized to be absolute zero, at which the voltage-temperature characteristics of the diode converge under different constant diode currents. (Contains 5 figures.)
- Published
- 2007
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8. African potato (Hypoxis hemerocallidea): a systematic review of its chemistry, pharmacology and ethno medicinal properties
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Matyanga, Celia M. J., Morse, Gene D., Gundidza, Mazuru, and Nhachi, Charles F. B.
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- 2020
- Full Text
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9. Implementation of science education programme for sustainable development in Ebonyi State: a prognostic analysis
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Nkwede, Joseph Okwesili, Udeuhele, Godwin I., Ogbaga, Emmanuel, Ikporo, F. B, and Oluka , B. N.
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Science education ,Biology ,Chemistry ,Physics ,Sustainable Development - Abstract
This paper assessed the degree of implementation of science education programme for sustainable development particularly in Ebonyi State, Nigeria. Four research questions guided the study. The study adopted programme evaluation design. The population of the study comprised of all the one thousand and eighty (1080) Science teachers from Abakaliki Education Zone of Ebonyi State and out of which one hundred and eight research subjects were selected as sample through proportionate random sampling technique. The instruments that were used for the data collection were checklist and observation schedule drawn from secondary schools science curriculum. The instruments used for were subjected to validation which was validated by experts from different science areas. The instrument were subjected to test of internal consistency using Kendel-W of Concordance for Checklist and Cronbach alpha for Observational Schedule. The reliability indices for Kendel W Concordance yielded 0.77 0.72 and 0.83 respectively and this was specifically for research question 1-3 and the reliability index for the Observational schedule using Cronbach alpha yielded an alpha index of 0.68. Research questions were answered using frequency and percentages. The study established among other things that; biology, chemistry and physics teachers used at secondary for the teaching of science subjects are not adequate with the specification of biology, chemistry and physics core curriculum to effectively teach the subjects. The study also shows that some of the science instructional materials, some teaching facilities such as classrooms and boards are not adequate with the specification of the facilities in the core curriculum. The study therefore recommended inter alia; that government should fund science programme adequately, since science is the key to development, government and school authorities should endeavour to provide adequate instructional material resources for the teaching and learning of sciences, workshops and seminars/conferences should be organized periodically by government for serving biology, chemistry and physics teachers.
- Published
- 2022
10. Soybean productivity with Trichoderma asperellum seed treatment in different regions of the Brazilian Cerrado
- Author
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A.F. Chagas Junior, Rodrigo Silva de Oliveira, Brigitte Sthepani Orozco Colonia, L. F. B. Chagas, and Albert Lennon Lima Martins
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chemistry.chemical_compound ,Agronomy ,chemistry ,Seed treatment ,Biology ,General Agricultural and Biological Sciences ,Productivity ,Trichoderma asperellum - Published
- 2021
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11. Gas exchange and leaf area of banana plants under salt stress inoculated with growth-promoting bacteria
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Ana J. O. Rodrigues, Beatriz de A. Araújo, Marlos A. Bezerra, Christiana de F. B. da Silva, Alan B. O. de Sousa, Cynthia M. R. Nogueira, ANA J. O. RODRIGUES, Instituto Federal de Educação, Ciência e Tecnologia do Ceará/Campus Crateús, BEATRIZ DE A. ARAÚJO, Universidade Federal do Ceará/Centro de Ciências Agrárias/Departamento de Engenharia Agrícola, MARLOS ALVES BEZERRA, CNPAT, CHRISTIANA DE FATIMA BRUCE DA SILVA, CNPAT, ALAN B. O. DE SOUSA, Universidade Federal do Ceará/Centro de Ciências Agrárias/Departamento de Engenharia Agrícola, and CYNTHIA M. R. NOGUEIRA, Universidade Federal do Ceará/Centro de Ciências Agrárias.
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Soil salinity ,Environmental Engineering ,growth ,Agriculture (General) ,Salt (chemistry) ,Bacillus sp ,Photosynthesis ,Limitações fotossintéticas ,Irrigation water ,salinity ,S1-972 ,Bacillus sphaericus ,chemistry.chemical_classification ,photosynthetic limitations ,Growth promoting ,Banana Prata ,biology ,Inoculation ,fungi ,food and beverages ,biology.organism_classification ,Salinity ,Horticulture ,chemistry ,Crescimento ,Photosynthetic limitations ,Agronomy and Crop Science ,Bacteria ,Salinidade - Abstract
Banana orchards in arid and semiarid regions require the use of irrigation. However, the presence of high concentration of salts in water can impair the development of plants, requiring the evaluation of new technologies to mitigate the effects of stress. The objective of this study was to evaluate gas exchange and leaf area in banana seedlings of the cultivar Prata Catarina inoculated with strains of Bacillus spp. under different electrical conductivities of irrigation water. The experiment was carried out in a greenhouse at Embrapa Tropical Agroindustry, Fortaleza, Ceará state, Brazil. The design used was in randomized blocks, in a 4 × 4 factorial scheme, with the first factor being the inoculation treatments: without any application; slow-release fertilizer; Strain 186 and Strain 109, and the second factor being the electrical conductivity of irrigation water (0.5; 1.5; 3.0; 4.5 dS m-1), in five blocks and each plot consisting of three plants. The electrical conductivity of irrigation water negatively influenced the gas exchange of banana cv. Prata Catarina in the vegetative stage, during the 89 days of cultivation. The Bacillus spp. strains 186 and 109 did not improve the gas exchange and leaf area of plants under salinity conditions.
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- 2021
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12. AgAu Hollow Nanoshells on Layered Graphene Oxide and Silica Submicrospheres as Plasmonic Nanozymes for Light-Enhanced Electrochemical H2O2 Sensing
- Author
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Susana I. Córdoba de Torresi, André H.B. Dourado, Maria Paula de Souza Rodrigues, Gabriela F. B. Davilla, Adriano M. R. P. da Silva, and Rafael Pires da Silva
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chemistry.chemical_compound ,Materials science ,chemistry ,ELETROQUÍMICA ,Graphene ,law ,Oxide ,General Materials Science ,Nanotechnology ,Electrochemistry ,Plasmon ,Nanoshell ,law.invention - Published
- 2021
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13. Addition of bismuth to Pt and Pd for electric power generation with selective cogeneration of acetate from ethanol in a fuel cell type reactor
- Author
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Francine Lima, J. Nandenha, E.H. Fontes, R. F. B. de Souza, and Almir Oliveira Neto
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Sodium borohydride ,chemistry.chemical_compound ,Lattice constant ,X-ray photoelectron spectroscopy ,Chemistry ,Linear sweep voltammetry ,Analytical chemistry ,chemistry.chemical_element ,Electrocatalyst ,Current density ,Power density ,Bismuth - Abstract
Pt/C, PtBi(95:5)/C, Pd/C, and PdBi(95:5)/C were synthesized by the sodium borohydride reducing method to produce metal nanoparticles with advanced electronic properties to enhance the ethanol oxidation reaction (EOR) mechanism. The Transmission Electron Microscopy (TEM) images and X-ray photoelectron spectroscopy (XPS) showed that a small Bi content does not affect the nanoparticle size PdBi/C; in contrast, it does affect the PtBi ones. The X-ray diffraction analysis revealed a lattice parameter modification by Bi dope in Pt crystalline structure. Furthermore, the ATR-FTIR results indicated the suppression of carbonate formation and increment in acetate production. The results of polarization and power density curves on DEFC, the material PtBi/C presented the more high power density, almost six times bigger than Pt/C. PtBi/C also has the highest current density (44 mW/cm2) and the lowest onset potential (−0.6 V) in linear sweep voltammetry experiments. It also has the highest final current density in current-time experiments. Hence, PtBi/C is a very promising electrocatalyst for DEFC.
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- 2021
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14. Thiophosphonium–Alkyne Cycloaddition Reactions: A Heavy Congener of the Carbonyl–Alkyne Metathesis
- Author
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Milica Feldt, Pawel Löwe, Lukas F. B. Wilm, Fabian Dielmann, and Maike B. Röthel
- Subjects
chemistry.chemical_classification ,Chemistry ,Heteroatom ,Substituent ,Alkyne ,Featured Article ,Medicinal chemistry ,Cycloaddition ,Inorganic Chemistry ,chemistry.chemical_compound ,Salt metathesis reaction ,Alkyne metathesis ,Reactivity (chemistry) ,Physical and Theoretical Chemistry ,Acetonitrile - Abstract
While the metathesis reaction between alkynes and thiocarbonyl compounds has been thoroughly studied, the reactivity of alkynes with isoelectronic main group R2E=S compounds is rarely reported and unknown for [R2P=S]+ analogues. We show that thiophosphonium ions, which are the isoelectronic phosphorus congeners to thiocarbonyl compounds, undergo [2 + 2]-cycloaddition reactions with different alkynes to generate 1,2-thiaphosphete ions. The four-membered ring species are in an equilibrium state with the corresponding P=C–C=S heterodiene structure and thus undergo hetero-Diels–Alder reactions with acetonitrile. Heteroatom and substituent effects on the energy profile of the 1,2-thiaphosphete formation were elucidated by means of quantum chemical methods., We show that thiophosphonium ions, which are the isoelectronic phosphorus congeners to thiocarbonyl compounds, undergo [2 + 2]-cycloaddition reactions with different alkynes to generate 1,2-thiaphosphete ions. The four-membered ring species are in an equilibrium state with the corresponding P=C−C=S heterodiene structure and thus undergo hetero-Diels−Alder reactions with acetonitrile. Heteroatom and substituent effects on the energy profile of the 1,2-thiaphosphete formation were elucidated by means of quantum chemical methods.
- Published
- 2021
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15. Aqueous two‐phase systems in Latin America: perspective and future trends
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Cassamo Ussemane Mussagy, Guillermo Picó, Marco Rito-Palomares, Hector Marcelo Fernandez-Lahore, Jorge F. B. Pereira, Álvaro S. Lima, Juan A. Asenjo, Mirna González-González, Escuela de Medicina y Ciencias de la Salud, Nacional University of Rosario, Tiradentes University (UNIT), Universidade Estadual Paulista (UNESP), Universidade de São Paulo (USP), Pólo II – Pinhal de Marrocos, Jacobs University, and University of Chile
- Subjects
trends ,Latin Americans ,applications ,Renewable Energy, Sustainability and the Environment ,Chemistry ,General Chemical Engineering ,Organic Chemistry ,Perspective (graphical) ,bioprocess ,Pollution ,ATPS ,Inorganic Chemistry ,Fuel Technology ,Phase (matter) ,Economic geography ,Bioprocess ,Waste Management and Disposal ,Biotechnology - Abstract
Made available in DSpace on 2022-04-28T19:44:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Aqueous two-phase systems (ATPS) have been demonstrated to be a simple and robust worldwide applied bioprocessing technology. From high value microscopic to macroscopic biological molecules obtained from a wide broad of matrices, ATPS have shown a high efficiency capacity for their concentration, enrichment, recovery, and purification. Particularly in Latin America, four relevant countries have paved the way and played important leading roles in this transformation history. This perspective article aims to present a critical analysis of the practical evolution of the main implementations of ATPS in Argentina, Brazil, Chile, and Mexico. Special attention is given to novel applications of this biphasic bioprocess that are being explored to accomplish visionary therapeutic tasks for the healthcare, biotechnology, and pharmaceutical sectors, as well as other environmental purposes. © 2021 Society of Chemical Industry (SCI). Tecnologico de Monterrey Escuela de Medicina y Ciencias de la Salud Institute of Biotechnological and Chemistry Processes Faculty of Biochemical and Pharmaceutical Sciences Nacional University of Rosario Tiradentes University (UNIT) Department of Engineering of Bioprocesses and Biotechnology School of Pharmaceutical Sciences São Paulo State University (UNESP) School of Pharmaceutical Sciences University of São Paulo Univ. Coimbra CIEPQPF Department of Chemical Engineering Rua Sílvio Lima Pólo II – Pinhal de Marrocos Department of Life Science & Chemistry Focus Area Health Jacobs University Centre for Biotechnology and Bioengineering University of Chile Department of Engineering of Bioprocesses and Biotechnology School of Pharmaceutical Sciences São Paulo State University (UNESP)
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- 2021
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16. A purified lectin with larvicidal activity from a woodland mushroom, Agaricus semotus Fr
- Author
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Taiwo Scholes Adewole, Titilayo Oluwaseun Agunbiade, Isaiah O. Adedoyin, F. B. Adewoyin, and Adenike Kuku
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Mushroom ,Chromatography ,biology ,Size-exclusion chromatography ,Lectin ,biology.organism_classification ,General Biochemistry, Genetics and Molecular Biology ,chemistry.chemical_compound ,chemistry ,Sephadex ,Agaricus semotus ,otorhinolaryngologic diseases ,biology.protein ,Chelation ,Sodium dodecyl sulfate ,General Agricultural and Biological Sciences ,Polyacrylamide gel electrophoresis - Abstract
This study investigated the larvicidal activity on Culex quinquefasciatus of lectin purified from fresh fruiting bodies of woodland mushroom, Agaricus semotus. A. semotus lectin (ASL) was purified via ion-exchange chromatography on DEAE-cellulose A-25 and size exclusion chromatography on Sephadex G-100 matrix. Molecular weight (16.6 kDa) was estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The effects of temperature, pH, metal chelation- and larvicidal activity of ASL were also investigated. The ASL indifferently agglutinated the erythrocytes of the human ABO blood system and was stable at acidic pH and below 50 °C whereas 66% of its activity was lost at 60 °C with complete inactivation at 70 °C. ASL is a metalloprotein requiring barium ion as chelation of metals by 50 mM EDTA rendered the lectin inactive, while the addition of BaCl2, among other metal salts, restored the activity. ASL showed larvicidal activity against C. quinquefasciatus larvae after 24 h with a mortality of 5 and 95% at 5 and 25 mg/mL respectively, and LC50 of 13.80 mg/mL. This study concluded that purified A. semotus lectin showed impressive larvicidal activity, which could be exploited in its development as an insecticidal agent.
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- 2021
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17. Investigation into Small Molecule Isomeric Glucuronide Metabolite Differentiation Using In Silico and Experimental Collision Cross-Section Values
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John R F B Connolly, Claire Beaumont, David Higton, Gordon J. Dear, Johannes P. C. Vissers, Jordi Munoz-Muriedas, Alison Webb, and Cris Lapthorn
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Analyte ,Ion-mobility spectrometry ,Chemistry ,In silico ,Metabolite ,fungi ,Mass spectrometry ,Small molecule ,Ion ,chemistry.chemical_compound ,Structural Biology ,Computational chemistry ,Glucuronide ,Spectroscopy - Abstract
Identifying isomeric metabolites remains a challenging and time-consuming process with both sensitivity and unambiguous structural assignment typically only achieved through the combined use of LC-MS and NMR. Ion mobility mass spectrometry (IMMS) has the potential to produce timely and accurate data using a single technique to identify drug metabolites, including isomers, without the requirement for in-depth interpretation (cf. MS/MS data) using an automated computational pipeline by comparison of experimental collision cross-section (CCS) values with predicted CCS values. An ion mobility enabled Q-Tof mass spectrometer was used to determine the CCS values of 28 (14 isomeric pairs of) small molecule glucuronide metabolites, which were then compared to two different in silico models; a quantum mechanics (QM) and a machine learning (ML) approach to test these approaches. The difference between CCS values within isomer pairs was also assessed to evaluate if the difference was large enough for unambiguous structural identification through in silico prediction. A good correlation was found between both the QM- and ML-based models and experimentally determined CCS values. The predicted CCS values were found to be similar between ML and QM in silico methods, with the QM model more accurately describing the difference in CCS values between isomer pairs. Of the 14 isomeric pairs, only one (naringenin glucuronides) gave a sufficient difference in CCS values for the QM model to distinguish between the isomers with some level of confidence, with the ML model unable to confidently distinguish the studied isomer pairs. An evaluation of analyte structures was also undertaken to explore any trends or anomalies within the data set.
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- 2021
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18. Synthesis of Heterobimetallic Complexes through Chemoselective 2,4-Metalation of a Thiazolium Salt
- Author
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Lukas F. B. Wilm, Patrick D. Dutschke, Sebastian Termühlen, Alexander Hepp, and F. Ekkehardt Hahn
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Inorganic Chemistry ,chemistry.chemical_classification ,Metalation ,Chemistry ,Organic Chemistry ,Polymer chemistry ,Salt (chemistry) ,Physical and Theoretical Chemistry - Published
- 2021
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19. Phenotypic Correlations and Integration of Nitrogen, Potassium and Press Mud Fertilizers in Relation to Sugarcane Yield and Quality
- Author
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Farrag F. B. Abu-Ellail and Anwar H. Sasy
- Subjects
Yield (engineering) ,Agronomy ,chemistry ,media_common.quotation_subject ,Potassium ,chemistry.chemical_element ,Quality (business) ,General Medicine ,Nitrogen ,media_common ,Mathematics - Published
- 2021
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20. Thermometry by vibrational Raman spectroscopy of nitrogen: Identification and impact of spatial averaging effects
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Malte F. B. Stodt, Udo Fritsching, and Johannes Kiefer
- Subjects
symbols.namesake ,Materials science ,chemistry ,Principal component analysis ,symbols ,Analytical chemistry ,chemistry.chemical_element ,General Materials Science ,Identification (biology) ,Raman spectroscopy ,Nitrogen ,Spectroscopy - Published
- 2021
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21. Regioselective Double Oxidative Addition of Bis‐NHC Precursors
- Author
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Matthias D. Böhme, Alexander Hepp, Lukas F. B. Wilm, and F. Ekkehardt Hahn
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Inorganic Chemistry ,Chemistry ,Regioselectivity ,Medicinal chemistry ,Oxidative addition - Published
- 2021
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22. Effects of Organic and Inorganic Fertilizers on the Growth and Yield of Kenaf (Hibiscus cannabinus L.) Production in South Western Nigeria
- Author
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A. K. Adebayo, A. O. Togun, F. B. Anjorin, and S. O. Olanipekun
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Yield (engineering) ,biology ,Agronomy ,Chemistry ,General Medicine ,Fiber ,biology.organism_classification ,Hibiscus ,Kenaf - Abstract
Farmers use Inorganic Fertilizers (IF) to improve kenaf yield in Nigeria. However, the detrimental effects of mineral fertilizers and its high cost calls for the use of organic fertilizers that are locally available and environment friendly. Combination of Organic Fertiliser (OF) with IF may reduce the bulkiness of OF while harnessing the benefit of both for higher yields. Field trials were conducted at Ibadan and Ilora in 2013 and 2014 to investigate the effects of combined fertilizers on the growth and yield of kenaf. Organic and IF (NPK 20:10:10) fertilizers as: (i) 160 kg ha-1 (sole organic), (ii) 100 kg ha-1 (sole IFl), (iii) Organic and IF at 50:50 ratio and (iv) control (no fertilizer). The experiment was laid out in Randomized Complete block design (RCBD) and replicated three times. Results showed that plant height (220.17 cm, 216.80 cm) and stem diameter (2.27 cm, 1.16 cm). Bast fiber (2.27 t/ha, 2.27 t/ha) and seed yield (1.69 t/ha, 1.78 t/ha) in Ibadan and Ilora respectively were significantly higher in plots with combined fertilizer. Combined fertilizers had the highest fiber and seed yield above sole application and control (no fertilizer application). Hence it is recommended for kenaf cultivation in Southwest Nigeria.
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- 2021
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23. Selective Targeting of Integrin αvβ8 by a Highly Active Cyclic Peptide
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Markus Schwaiger, Katja Steiger, Luciana Marinelli, Markus Nieberler, Johannes Notni, Horst Kessler, Salvatore Di Maro, Michael Weinmüller, Francesco Saverio Di Leva, Oleg V. Maltsev, Hans-Jürgen Wester, Ute Reuning, Alexander Wurzer, Udaya Kiran Marelli, Roswitha Beck, Andreas F. B. Räder, Florian Reichart, Tobias G. Kapp, Reichart, Florian, Maltsev, Oleg V, Kapp, Tobias G, Räder, Andreas F B, Weinmüller, Michael, Marelli, Udaya Kiran, Notni, Johanne, Wurzer, Alexander, Beck, Roswitha, Wester, Hans-Jürgen, Steiger, Katja, Di Maro, Salvatore, Di Leva, Francesco Saverio, Marinelli, Luciana, Nieberler, Marku, Reuning, Ute, Schwaiger, Marku, Kessler, Horst, Reichart, F., Maltsev, O. V., Kapp, T. G., Rader, A. F. B., Weinmuller, M., Marelli, U. K., Notni, J., Wurzer, A., Beck, R., Wester, H. -J., Steiger, K., Di Maro, S., Di Leva, F. S., Marinelli, L., Nieberler, M., Reuning, U., Schwaiger, M., and Kessler, H.
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Boron Compounds ,Integrins ,Integrin ,Medizin ,Gallium Radioisotopes ,Peptide ,Molecular Dynamics Simulation ,Peptides, Cyclic ,Proof of Concept Study ,01 natural sciences ,03 medical and health sciences ,Cell Line, Tumor ,Drug Discovery ,Humans ,Cancer, Integrins, Peptide synthesis, Medicinal Chemistry, Molecular Imaging ,Receptor ,Fluorescent Dyes ,030304 developmental biology ,chemistry.chemical_classification ,0303 health sciences ,biology ,Chemistry ,Ligand (biochemistry) ,Highly selective ,Orders of magnitude (mass) ,Cyclic peptide ,0104 chemical sciences ,Cell biology ,Molecular Docking Simulation ,010404 medicinal & biomolecular chemistry ,Microscopy, Fluorescence ,Drug Design ,biology.protein ,Molecular Medicine ,Radiopharmaceuticals - Abstract
Integrins play important roles in physiological and pathophysiological processes. Among the RGD-recognizing integrin subtypes, the αvβ8 receptor is emerging as an attractive target because of its involvement in various illnesses, such as autoimmune diseases, viral infections, and cancer. However, its functions have, so far, not been investigated in living subjects mainly because of the lack of a selective αvβ8 ligand. Here, we report the design and potential medical applications of a cyclic octapeptide as the first highly selective small-molecule ligand for αvβ8. Remarkably, this compound displays low nanomolar αvβ8 binding affinity and a strong discriminating power of at least 2 orders of magnitude versus other RGD-recognizing integrins. Peptide functionalization with fluorescent or radioactive labels enables the selective imaging of αvβ8-positive cells and tissues. This new probe will pave the way for detailed characterization of the distinct (patho)physiological role of this relatively unexplored integrin, providing a basis to fully exploit the potential of αvβ8 as a target for molecular diagnostics and personalized therapy regimens.
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- 2019
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24. Effect of the hydroxamate group in the antitumoral activity and toxicity toward normal cells of new copper(II) complexes
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Jackson A. L. C. Resende, Roberto Weider de Assis Franco, Milton M. Kanashiro, Marcelo da Silva Mathias, Nathália F. B. Azeredo, Franz Viana Borges, Christiane Fernandes, and Adolfo Horn
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Cisplatin ,0303 health sciences ,U937 cell ,Stereochemistry ,Chemistry ,030302 biochemistry & molecular biology ,Metals and Alloys ,General Biochemistry, Genetics and Molecular Biology ,Biomaterials ,03 medical and health sciences ,chemistry.chemical_compound ,Annexin ,Apoptosis ,Cell culture ,medicine ,Amine gas treating ,Propidium iodide ,General Agricultural and Biological Sciences ,Cytotoxicity ,030304 developmental biology ,medicine.drug - Abstract
The synthesis, physico–chemical characterization and cytotoxicity of four copper(II) coordination complexes, i.e. [Cu(HBPA)Cl2] (1), [Cu(BHA)2] (2), [Cu(HBPA)(BHA)Cl] CH3OH (3) and [Cu(HBPA)2]Cl2·4H2O (4), are reported. HBPA is the tridentate ligand N-(2-hydroxybenzyl)-N-(2-pyridylmethyl)amine and HBHA is the benzohydroxamic acid. The reaction between the HBHA and CuCl2.2H2O has resulted in the new complex (2) and the reaction between complex (1) and HBHA has resulted in the new complex (3). X-ray diffraction studies for complex (3) indicated the effective coordination of HBHA as BHA−. Their cytotoxicity was evaluated against three human tumoral cell lines (Colo-205, NCI-H460 and U937) and PBMC (peripheral blood mononuclear cells), using the MTT cytotoxic assay. The results toward PBMC reveal that the new copper(II) complex (2) presents lower toxicity toward normal cells. Furthermore, complex (2) presents IC50 values lower than cisplatin toward NCI-H460 and the best selectivity index obtained towards NCI-H460 (SI = 2.2) and U937 cell lines (SI = 2.0), as a result of the presence of two molecules of HBHA in its structure. Complex (3) presents IC50 values lower than cisplatin toward NCI-H460, Colo-205 and comparable to cisplatin toward U937. The evaluation of the cell death type promoted by complexes (2) and (4) was investigated toward NCI-H460 revealing better results than the standard drug cisplatin, according to the Annexin V and propidium iodide (PI) labeling experiment. Based on the studies here performed, HBHA seems to be related to lower toxicity toward PBMC and HBPA is improving directly the cytotoxity.
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- 2021
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25. Research Note: Effects of the in ovo injection of organic zinc, manganese, and copper and posthatch holding time before placement on broiler body temperature during grow out
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K.E.C. Elliott, L.L. Lindsey, O.C. Olojede, E. J. Kim, Patrick D. Gerard, E. D. Peebles, and T. F. B. Oliveira
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Male ,Litter (animal) ,Time Factors ,animal structures ,Zygote ,chemistry.chemical_element ,Zinc ,Management and Production ,Biology ,broiler ,In ovo ,Body Temperature ,Random Allocation ,feed and water restriction ,03 medical and health sciences ,Animal science ,Animals ,Incubation ,Hatchling ,030304 developmental biology ,Manganese ,0303 health sciences ,Hatching ,Temperature ,0402 animal and dairy science ,Broiler ,04 agricultural and veterinary sciences ,General Medicine ,040201 dairy & animal science ,holding time ,chemistry ,Animal Science and Zoology ,Flock ,posthatch ,Chickens ,Copper - Abstract
Effects of the in ovo injection of organic microminerals (OM) (zinc, manganese, and copper) and posthatch holding time (HT) on the daily body temperature (bt) of broilers during grow out were determined. The hatching eggs from a Ross 708 breeder flock at 32 wk of age were incubated under standard commercial conditions. At 17 d of incubation, eggs were randomly allocated to 3 in ovo OM injection treatment (TRT) groups, and at 21 d of incubation, male hatchlings were randomly allocated to 2 posthatch HT treatment groups. Eggs were either not injected or were in ovo injected with diluent only or diluent containing the OM mixture. A 0-hour HT group had immediate access to water and feed, and a 24-hour HT (24HT) group contained birds that were kept in transport baskets in their pens without access to feed and water for 24 h before being released. Fifteen male birds were placed in each of 36 litter floor pens in a temperature-controlled facility. Approximately 2 birds in each of 6 replicate pens belonging to each TRT-HT combination had temperature transponders inserted subcutaneous in the mid-dorsal region of the neck. All birds were brooded under standard commercial conditions and had ad libitum access to feed and water after their respective HT. The bt of the same birds were determined daily at the same time each day beginning at hatch and ending on 39 d of posthatch age (AGE). There were no significant main or interactive effects involving TRT or HT for bt. However, there was a significant (P ≤ 0.0001) main effect because of AGE. A general increase in bt occurred during the 39 d grow out period. At hatch, bt was 40.54 ± 0.056°C and at AGE 39 was 41.46 ± 0.055°C. Under standard brooding conditions, a general increase in bt occurred in the Ross 708 broilers. However, these birds did not exhibit a significant bt response to TRT or a 24HT before placement.
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- 2021
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26. Development of new dinuclear Fe(<scp>iii</scp>) coordination compounds with in vitro nanomolar antitrypanosomal activity
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Wanderley de Souza, Sergio Henrique Seabra, Bruna Barriquel Segat, Nathália F. B. Azeredo, Jackson A. L. C. Resende, Felipe Figueirôa Moreira, Renato Augusto DaMatta, Marcelo Monteiro Marques, Cristina Pinheiro Santiago, Adolfo Horn, Letícia Maria Pequeno Madureira, Dalber R.S. Candela, Juliana de Araujo Portes, Giovanni F. Caramori, and Christiane Fernandes
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Chagas disease ,chemistry.chemical_classification ,biology ,Chemistry ,Stereochemistry ,biology.organism_classification ,medicine.disease ,Leishmania ,Coordination complex ,Inorganic Chemistry ,Benznidazole ,medicine ,Trypanosoma cruzi ,Nifurtimox ,Cytotoxicity ,IC50 ,medicine.drug - Abstract
Chagas disease is a neglected tropical disease caused by the protozoan pathogen Trypanosoma cruzi. The disease is a major public health problem affecting about 6 to 7 million people worldwide, mostly in Latin America. The available therapy for this disease is based on two drugs, nifurtimox and benznidazole, which exhibit severe side effects, including resistance, severe cytotoxicity, variable efficacy and inefficiency in the chronic phase. Therefore, new drugs are urgently needed. Coordination compounds may be an interesting alternative for antiparasite therapy against Leishmania spp., Toxoplasma gondii and T. cruzi. Herein, we tested the in vitro effect on T. cruzi epimastigotes (Y strain) of two new μ-oxo Fe(III) dinuclear complexes: [(HL1)(Cl)Fe(μ-O)Fe(Cl)(HL2)](Cl)2·(CH3CH2OH)2·H2O (1) and [(HL2)(Cl)Fe(μ-O)Fe(Cl)(HL2)](Cl)2·H2O (2) where HL1 and HL2 are ligands which contain two pyridines, amine and alcohol moieties with a naphthyl pendant unit yielding a N3O coordination environment. Complexes (1) and (2), which are isomers, were completely characterized, including X-ray diffraction studies for complex (1). Parasites were treated with the complexes and the outcome was analyzed. Complex (1) exhibited the lowest IC50 values, which were 99 ± 3, 97 ± 2 and 110 ± 39 nM, after 48, 72 and 120 h of treatment, respectively. Complex (2) showed IC50 values of 118 ± 5, 122 ± 6 and 104 ± 29 nM for the same treatment times. Low cytotoxicity to the host cell LLC-MK2 was found for both complexes, resulting in impressive selectivity indexes of 106 for complex (1) and 178 for (2), after 120 h of treatment. Treatment with both complexes reduced the mitochondrial membrane potential of the parasite. Ultrastructural analysis of the parasite after treatment with complexes showed that the mitochondria outer membrane presented swelling and abnormal disposition around the kinetoplast; in addition, reservosomes presented anomalous spicules and rupture. The complexes showed low nanomolar IC50 values affecting mitochondria and reservosomes, essential organelles for the survival of the parasite. The low IC50 and the high selectivity index show that both complexes act as a new prototype of drugs against T. cruzi and may be used for further development in drug discovery to treat Chagas disease.
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- 2021
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27. Heterobimetallic complexes composed of bismuth and lithium carboxylates as polyurethane catalysts – alternatives to organotin compounds
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Fabian Dielmann, Lukas F. B. Wilm, Emre Levent, Oliver Sala, and Pawel Löwe
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inorganic chemicals ,Quantum chemical ,food and beverages ,chemistry.chemical_element ,equipment and supplies ,Pollution ,Combinatorial chemistry ,Catalysis ,Bismuth ,chemistry.chemical_compound ,chemistry ,Environmental Chemistry ,Lithium ,Polyurethane - Abstract
Organotin compounds are important catalysts for the synthesis of polyurethanes consisting of aliphatic isocyanates and polyols. Due to their toxicity, however, it has been a long-standing goal to develop more environmentally benign catalysts. Bismuth octoates and neodecanoates are such well-known alternatives, but their catalytic activity is insufficient for many applications. Herein we show that the catalytic activity of bismuth carboxylates can be enhanced significantly by the addition of lithium carboxylates. Structural and spectroscopic results reveal the spontaneous formation of heterobimetallic complexes consisting of two bismuth and four lithium carboxylates that show dynamic behaviour in solution. The mechanism of the bismuth-catalyzed urethane reaction was elucidated in detail using quantum chemical calculations, paving the way for a rational catalyst design.
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- 2021
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28. Predicting stable binding modes from simulated dimers of the D76N mutant of β2-microglobulin
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Filipe E. P. Rodrigues, João N. M. Vitorino, Nuno F. B. Oliveira, Rui J. S. Loureiro, Miguel Machuqueiro, and Patrícia F. N. Faísca
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Dimer ,Intermolecular force ,Mutant ,Biophysics ,Protein aggregation ,Biochemistry ,Computer Science Applications ,Hydrophobic effect ,chemistry.chemical_compound ,Molecular dynamics ,chemistry ,Structural Biology ,Docking (molecular) ,Chemical physics ,Genetics ,Protein oligomerization ,TP248.13-248.65 ,Biotechnology - Abstract
The D76N mutant of the β 2 m protein is a biologically motivated model system to study protein aggregation. There is strong experimental evidence, supported by molecular simulations, that D76N populates a highly dynamic conformation (which we originally named I 2 ) that exposes aggregation-prone patches as a result of the detachment of the two terminal regions. Here, we use Molecular Dynamics simulations to study the stability of an ensemble of dimers of I 2 generated via protein–protein docking. MM-PBSA calculations indicate that within the ensemble of investigated dimers the major contribution to interface stabilization at physiological pH comes from hydrophobic interactions between apolar residues. Our structural analysis also reveals that the interfacial region associated with the most stable binding modes are particularly rich in residues pertaining to both the N- and C-terminus, as well residues from the BC- and DE-loops. On the other hand, the less stable interfaces are stabilized by intermolecular interactions involving residues from the CD- and EF-loops. By focusing on the most stable binding modes, we used a simple geometric rule to propagate the corresponding dimer interfaces. We found that, in the absence of any kind of structural rearrangement occurring at an early stage of the oligomerization pathway, some interfaces drive a self-limited growth process, while others can be propagated indefinitely allowing the formation of long, polymerized chains. In particular, the interfacial region of the most stable binding mode reported here falls in the class of self-limited growth.
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- 2021
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29. Polymeric micelles using cholinium-based ionic liquids for the encapsulation and release of hydrophobic drug molecules
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Daniel T. Kamei, Isabelle S. Kurnik, Marlus Chorilli, Natália A. D'Angelo, André Moreni Lopes, António A. Vicente, Jorge F. B. Pereira, Priscila Gava Mazzola, Universidade do Minho, Universidade Estadual Paulista (Unesp), Universidade Estadual de Campinas (UNICAMP), University of California, CIEPQPF, and University of Minho
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Polymers ,Ciências Biológicas [Ciências Naturais] ,Biomedical Engineering ,Ionic Liquids ,cholinium-based ionic liquids ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,Lower critical solution temperature ,chemistry.chemical_compound ,Phase (matter) ,Molecule ,General Materials Science ,Micelles ,Drug Carriers ,Science & Technology ,Aqueous solution ,Polymeric micelles ,Hydrophobic drug ,encapsulation and release of hydrophobic drug molecules ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,3. Good health ,chemistry ,Ionic liquid ,Drug delivery ,0210 nano-technology ,Hydrophobic and Hydrophilic Interactions - Abstract
We generated stable amphiphilic copolymer-based polymeric micelles (PMs) with temperature-responsive properties utilizing Pluronic® L35 and a variety of ionic liquids (ILs) to generate different aqueous two-phase micellar systems (ATPMSs). The partitioning of the hydrophobic model compound curcumin (CCM) into the PM-rich phase and the drug delivery capabilities of the PMs were investigated. ATPMSs formed using more hydrophobic ILs (i.e., [Ch][Hex] [Ch][But] > [Ch][Pro] > [Ch][Ac] [Ch]Cl) were the most effective in partitioning (KCCM) and recovering (RECRich) CCM into the PM-rich phase (15.2 < KCCM < 22.0 and 90% < RECRich < 95%, respectively). Moreover, using 1.2 M [Ch][But] and 0.2 M [Ch][Hex] ILs yielded higher encapsulation efficiency (EE) (94.1 and 96.0%, respectively) and drug loading (DL) capacity (14.8 and 16.2%, respectively), together with an increase in the average hydrodynamic diameter of the PMs (DH) (42.5 and 45.6 nm, respectively). The CCMPM formulations were stable at 4.0, 25.0, and 37.0 °C and the release of CCM was faster with the less hydrophobic ILs (i.e., [Ch]Cl and [Ch][Ac]). Furthermore, due to the lower critical solution temperature properties of Pluronic® L35, the PMs exhibit temperature responsiveness at 37.0 °C. In vitro cytotoxicity assays were also performed to determine the potency of CCMPM formulations, and a 1.8-fold decrease in IC50 values was observed between the CCMPMs/[Ch][Hex] and CCMPMs/[Ch]Cl formulations for PC3 cells. The lower IC50 value for the [Ch][Hex] version corresponded to a greater potency compared to the [Ch]Cl version, since a lower concentration of CCM was required to achieve the same therapeutic effect. The ATPMSs investigated in this study serve as a novel platform for Pluronic® L35/PBS buffer (pH 7.4) + IL-based ATPMS development. The unique properties reported here may be useful in applications such as controlled-release drug delivery systems (DDS), encapsulation, and bioseparations., This study was funded by the Coordination for Higher Level Graduate Improvements (CAPES/Brazil, finance code 001), the National Council for Scientific and Technological Development (CNPq/Brazil) and the State of São Paulo Research Foundation (FAPESP/Brazil, processes #2014/16424-7, #2017/10789-1, #2018/10799-0, #2018/05111-9, #2019/05624-9, #2019/08549-8, and #2020/03727-2)., info:eu-repo/semantics/publishedVersion
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- 2021
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30. Evaluation of Some Sugar Beet Varieties under Water Salinity Stress in New Reclaimed Land
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M. S. El-Kady, E. H. S. El-Laboudy, and Farrag F. B. Abu-Ellail
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Irrigation ,Sucrose ,Field experiment ,fungi ,Biology ,biology.organism_classification ,Salinity ,chemistry.chemical_compound ,Horticulture ,chemistry ,Germination ,Sugar beet ,Sugar ,Water content - Abstract
In line with sustainable agriculture that depends on modern methods and new sources of non-traditional irrigation, a field experiment was conducted at a privet farm behind Cairo-Alexandria Desert Road, Giza, Egypt during two seasons to evaluate five sugar beet varieties under water salinity stress condition. The present work included 15 treatments; represent five sugar beet varieties: viz. Multi-germs (Amina, Farida, and Faten) and Mono-germs (Unners and Sharleston), in combinations with two salinity treatments (Magic-Sal (13% humic acid + 20% carboxylic acid) and Sal-Wax (50% carboxylic acid) components) compared to control application. Results indicated that salinity treatments help in early stages to increase the emergency percentage of sugar beet varieties under high salinity water stress. As compared to control treatment, salinity treatments significantly increase proline accumulation, leaf relative water content (LRWC %),and root yield, but, it caused a reduction in quality parameters (sucrose, purity, and extractable sugar percentages) in both seasons. On the other hand, variety (Amina) overpassed the other varieties under salinity water stress with respect to germination ratio, proline content, LRWC%,and root yield (ton/fed) in both seasons. While, Sharelston variety surpassed significantly the other studied varieties with respect to sucrose, purity, and extractable sugar percentage (ES%) in both seasons.The distribution of stomata density of leaf increased as salinity water stress level increased. Results also showed that five sugar beet varieties under two salinity treatments (Magic-Sal or Sal-Wax) had positive effects and increased stomata area, but stomata density and its index as well as stomata closure% decreased compared with non-use.
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- 2021
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31. Effect of N-fixing Bacteria on Nitrogen Fertilizer Requirements for some Sugar Beet Varieties
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B. S. I. Makhlouf, E. H. S. El-Laboudy, and Farrag F. B. Abu-Ellail
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biology ,chemistry.chemical_element ,Sowing ,engineering.material ,Azospirillum brasilense ,biology.organism_classification ,Nitrogen ,Animal science ,Human fertilization ,chemistry ,engineering ,Sugar beet ,Fertilizer ,Leaf area index ,Sugar - Abstract
Two field trials were carried out at Tamiya Agricultural Research Station, (latitude of 29.58°N and longitude of 30.96°E), Fayoum Governorate,Egypt, during 2018/2019 and 2019/2020 seasons to study the relative importance of nitrogen-fixing bacteria i.e. Bacillus polymyxa (BC)and Azospirillum brasilense(AZS) as a soil drench under mineral nitrogen fertilizer levels and their effects on some sugar beet varieties. A split-plot design was used. Four treatments of nitrogen fertilization (80 kg N/fed ”control”, 60 kg N/fed + soil drench with BC, 60 kg N/fed + soil drench with AZS and 60 kg N/fed + soil drench with a mixture of BC and AZS) were occupied the main plots, whereas, six varieties (Beta303, Sirona, Panther,Des9003, Athospoly and Maximus) were distributed randomly in the sub-plots. Adding 60 kg N/fed + soil drench with a mixture of AZS and BC was adequate to produce the economical values of extractable sugar%, root and sugar yields/fed. Varieties Sirona and Maximus had the highest values of root and sugar yields/fed. Significant interactions effects among nitrogen treatments and varieties on the studied traits were discussed. Root and sugar yields/fed were significantly and positively correlated with leaf area index and crop growth rate, root diameter and its fresh weight/plant, in both seasons. Under the environmental conditions of this study, it was found that sowing Sirona and/or Maximus varieties under fertilization of 60 kg N/fed in combination with a mixture of BC and AZS at 5L/fed twice as a soil drench could be recommended to achieve the economical root and sugar yields/fed.
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- 2021
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32. Phase-selective laser–induced breakdown spectroscopy in flame spray pyrolysis for iron oxide nanoparticle synthesis
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Malte F. B. Stodt, Chenyang Liu, Johannes Kiefer, Lutz Mädler, Shuiqing Li, and Udo Fritsching
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education.field_of_study ,Materials science ,Mechanical Engineering ,General Chemical Engineering ,Population ,Iron oxide ,Atomic emission spectroscopy ,Nanoparticle ,Combustion ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,Particle ,Laser-induced breakdown spectroscopy ,Physical and Theoretical Chemistry ,Thermal spraying ,education - Abstract
The flame spray pyrolysis of iron oxide nanoparticles using the new reference nozzle SpraySyn is a key step towards the understanding of the coupling of physicochemical steps such as precursor atomization, spray evaporation, combustion, particle formation and growth. Owing to the countless available solvents and precursors, systematic investigations are necessary to fully understand the impact of precursor formulation on the reaction route and, hence, the particle properties. In this work, the recently developed phase-selective laser-induced breakdown spectroscopy (PS-LIBS) technique is applied to an external mixing spray flame reactor in order to study iron oxide particle formation along the axial centerline of the spray under varying precursor solutions. The addition of 2-ethylhexanoic acid (EHA) to precursors is investigated and significant differences in the evolution of the atomic emission spectra are observed, enabling the differentiation between droplet-to-particle and gas-to-particle routes in situ. The observations from PS-LIBS are in good agreement with TEM images and XRD, where haematite (α-Fe2O3), maghemite (γ-Fe2O3), and magnetite (Fe3O4) were observed. Raman spectroscopy (RS) in particle-free spray-flames revealed a significant gas-phase temperature difference of about ΔT∼500 K under addition of EHA to the spray and demonstrated accurate temperature measurements up to droplet rates of 103 Hz. The experimental results allow deep insights into the spray flame combustion and particle nucleation kinetics. Moreover, they can be coupled with population balance models and be used for the validation of numerical simulations.
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- 2021
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33. Electroreduction of CO2 Catalyzed by Nickel Imidazolin-2-ylidenamino-Porphyrins in Both Heterogeneous and Homogeneous Molecular Systems
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Maryam Abdinejad, Heinz-Bernhard Kraatz, Fabian Dielmann, and Lukas F. B. Wilm
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Materials science ,Renewable Energy, Sustainability and the Environment ,business.industry ,General Chemical Engineering ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,Molecular systems ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Catalysis ,Renewable energy ,Nickel ,Chemical engineering ,chemistry ,Homogeneous ,Environmental Chemistry ,Current (fluid) ,0210 nano-technology ,business ,Electrochemical reduction of carbon dioxide - Abstract
Electrocatalytic carbon dioxide reduction to value-added chemicals is an important strategy to store renewable energy. Despite recent advances, the current level of performance of these systems doe...
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- 2020
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34. Reversible and irreversible fluorescence activity of the Enhanced Green Fluorescent Protein in pH: Insights for the development of pH-biosensors
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Carolina Falaschi Saponi, Timothy M. Ryan, Fernando Lucas Primo, Nathalia Vieira dos Santos, Tamar L. Greaves, Jorge F. B. Pereira, Universidade Estadual Paulista (Unesp), RMIT University, Australian Synchrotron, and CIEPQPF
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Models, Molecular ,Circular dichroism ,Protein Conformation ,Green Fluorescent Proteins ,Biosensing Techniques ,02 engineering and technology ,Enhanced green fluorescent protein ,Green Fluorescent Protein ,Biochemistry ,Fluorescence ,Green fluorescent protein ,Structure-Activity Relationship ,03 medical and health sciences ,X-Ray Diffraction ,Structural Biology ,Intrinsic fluorescence of proteins ,Protein stability ,Neutral ph ,Molecular Biology ,Small-angle X-ray scattering (SAXS) ,030304 developmental biology ,chemistry.chemical_classification ,0303 health sciences ,Chemistry ,Adverse conditions ,Circular Dichroism ,Biomolecule ,General Medicine ,Hydrogen-Ion Concentration ,021001 nanoscience & nanotechnology ,Circular dichroism (CD) ,Biophysics ,0210 nano-technology ,Biosensor - Abstract
Made available in DSpace on 2020-12-12T01:37:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-12-01 Australian Nuclear Science and Technology Organisation Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Enhanced Green Fluorescent Protein (EGFP) is a biomolecule with intense and natural fluorescence, with biological and medical applications. Although widely used as a biomarker in research, its application as a biosensor is limited by the lack of in-depth knowledge regarding its structure and behavior in adverse conditions. This study is focused on addressing this need by evaluating EGFP activity and structure at different pH using three-dimensional fluorescence, circular dichroism and small-angle X-ray scattering. The focus was on the reversibility of the process to gain insights for the development of biocompatible pH-biosensors. EGFP was highly stable at alkaline pH and quenched from neutral-to-acidic pH. Above pH 6.0, the fluorescence loss was almost completely reversible on return to neutral pH, but only partially reversible from pH 5.0 to 2.0. This work updates the knowledge regarding EGFP behavior in pH by accounting for the recent data on its structure. Hence, it is evident that EGFP presents the required properties for use as natural, biocompatible and environmentally friendly neutral to acidic pH-biosensors. Department of Engineering of Bioprocesses and Biotechnology School of Pharmaceutical Sciences São Paulo State University (UNESP), Rodovia Araraquara-Jaú/Km 01 School of Science College of Science Engineering and Health RMIT University, 124 La Trobe Street Australian Synchrotron, 800 Blackburn Road Univ Coimbra CIEPQPF Department of Chemical Engineering, Rua Sílvio Lima, Pólo II – Pinhal de Marrocos Department of Engineering of Bioprocesses and Biotechnology School of Pharmaceutical Sciences São Paulo State University (UNESP), Rodovia Araraquara-Jaú/Km 01 FAPESP: 18/06576-5 FAPESP: 2014/16424-7 FAPESP: 2014/19793-3 FAPESP: 2016/07529-5 FAPESP: 2018/01858-2 FAPESP: 2018/20833-0 FAPESP: 2018/50009-8
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- 2020
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35. Evaluation of Insecticidal Activity of Thyme, Oregano, and Cassia Volatile Oils on Cat Flea
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Diefrey Ribeiro Campos, Marco A. A. de Sousa, Jéssica Karoline de Oliveira Chaves, Katherina Coumendouros, Gabriela Carmelinda Martins dos Santos, Yara Peluso Cid, F. B. Scott, Douglas Siqueira de Almeida Chaves, Cecília Lopes da Conceição, and Lilia Aparecida Salgado de Morais
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Larva ,Flea ,biology ,010405 organic chemistry ,Cat flea ,Flea control ,biology.organism_classification ,01 natural sciences ,Cinnamaldehyde ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,chemistry.chemical_compound ,chemistry ,Cassia ,Carvacrol ,Food science ,General Pharmacology, Toxicology and Pharmaceutics ,Thymol - Abstract
The aim of the present study was to evaluate the insecticidal effect of the cassia, thyme and oregano volatile oils against the immature and adult flea’s stages. For this purpose, the tested samples were chemically characterized by GC-FID and GC-MS. The mortality of larvae and adult fleas, eggs, and pupae of Ctenocephalides felis felis was performed through in vitro tests at different concentration levels. Inhibition of development and residual efficacy were also determined. The chemical characterization of the cassia, thyme, and oregano volatile oils presented cinnamaldehyde (91%), thymol (44.7%), and carvacrol (76.2%), respectively, as major constituents. In general, the samples showed insecticidal activity for both immature and adult flea’s stages. The best LC50 values for adults were obtained by oregano volatile oils (33.5 and 21.8 μg·cm−2, respectively, 24 and 48 h). Cassia volatile oils showed the best results against larvae (17.2 and 10.3 μg·cm−2, respectively, 24 and 48 h), eggs (3 μg.cm−2), and pupae (34.6 μg·cm−2), as well as the lowest value for inhibition of development (2.3 μg·cm−2). The oregano and thyme volatile oils showed residual efficacy greater than 80% for 6 days while cassia showed this result for 4 days. The results demonstrated the potential of volatile oils for flea control in all stages of the life cycle, with emphasis on cassia. The residual effects of the volatile oils are promising for the development of new and environmentally friendly phyto-pesticides for veterinary uses.
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- 2020
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36. Application of Chemometric Techniques for Validation of Computational Methods Applied in Molecular Modeling of 6α-Hidroxyvouacapan-7β, 17β-Lactone with Antiproliferative Activity in Leukemia Cells
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Davi do Socorro Barros Brasil, Rosivaldo S. Borges, Igor V. F. dos Santos, Williams Jorge da Cruz Macêdo, Vitor H. S. Sanches, Renato Araújo da Costa, Adonay S. de Carvalho, Elenilze F. B. Ferreira, Cleison C. Lobato, Cleydson B. R. Santos, Kelton L. B. Santos, and Rai C. Silva
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chemistry.chemical_classification ,Computational Mathematics ,Leukemia ,Molecular model ,Biochemistry ,Chemistry ,medicine ,General Materials Science ,General Chemistry ,Electrical and Electronic Engineering ,Condensed Matter Physics ,medicine.disease ,Lactone - Abstract
Hidroxyvouacapan-6α-7β, 17β-lactone (HVL) is a synthetic derivative of 6α, 7β-dihydroxyvouacapan-17β-oic acid (ADV) which was isolated from the fruits of Pterodon polygalaeflorus Benth. Both compounds showed anti-inflammatory and analgesic activities. According to studies conducted by Euzébio et al. in 2009 and 2010, ADV, HVL and some derivatives showed antiproliferative activity in different line of cancer cells, including the K562 leukemia. In this paper, we propose a combination of quantum-chemical methods, multivariate analysis and statistical to assess semi-empirical (AM1, PM3 and ZINDO), Hartree-Fock (HF) and DFT (B3LYP) methods in different basis set for determining which method better describes in sign and magnitude the geometric parameters of HVL compared to crystallographic data. PCA results were based on three main components, explaining 88.79% of the total variance for the geometrical parameters O2C6, O4C17C14C, C16O1C12, C6C7O3C17 and O3C7C8C14. DFT (B3LYP) method corresponded well with experimental data in hierarchical cluster analysis (HCA). The experimental and theoretical angles were analyzed by linear regression and statistical parameter (correlation coefficients, significance and predictability) were evaluated.
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- 2020
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37. Methane conversion to higher value-added product and energy co-generation using anodes OF PdCu/C in a solid electrolyte reactor: alkaline fuel cell type monitored by differential mass spectroscopy
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Araceli Jardim da Silva, A. Oliveira Neto, Andrezza S. Ramos, Monique C.L. Santos, R. F. B. de Souza, C.M. Godoi, and T. L. Tagomori
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Alkaline fuel cell ,010405 organic chemistry ,Chemistry ,Methyl formate ,Inorganic chemistry ,General Chemistry ,Electrolyte ,010402 general chemistry ,01 natural sciences ,Methane ,0104 chemical sciences ,Potassium formate ,chemistry.chemical_compound ,Dimethyl ether ,Partial oxidation ,Methanol - Abstract
PdxCuy/C catalysts combinations were employed to CH4 partial oxidation in mild condition using a solid electrolyte reactor—alkaline fuel cell type. The differential mass spectroscopy on line method was used to monitor the oxidation products obtained as methanol, dimethyl ether, methyl formate and potassium formate. It was observed that as the electrical potential of the reactor increases, the generation of products decreases. The best results for conversion of methane into methanol and energy co-generation was obtained from Pd90Cu10/C and Pd50Cu50/C due to better H2O activation effects and adsorption site for CH4 oxidation.
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- 2020
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38. Electrooxidation of Acetaldehyde on Pt(111) Surface Modified by Random Defects and Tin Decoration
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B. A. F. Previdello, V. Del Colle, Amaury F. B. Barbosa, and Germano Tremiliosi-Filho
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Chemistry ,Acetaldehyde ,chemistry.chemical_element ,Reaction intermediate ,Photochemistry ,Electrochemistry ,DIÓXIDO DE CARBONO ,Catalysis ,Acetic acid ,chemistry.chemical_compound ,Adsorption ,Platinum ,Tin - Abstract
Acetaldehyde oxidation was studied on well-ordered Pt(111), stepped Pt(554), and disordered Pt(111). Random superficial defects of the {110}-type were electro-generated on well-ordered Pt(111) surface by successive potential cycling at 0.05 V s−1 between 0.05 and 1.3 V in 0.1 M HClO4 solution. In general, well-ordered Pt(111) is more active than stepped or disordered platinum surfaces for acetaldehyde oxidation. The reaction follows a dual pathways mechanism, leading each pathway to CO2 and acetic acid, respectively, as final products. The CO2 is produced via adsorbed CO and CHx reaction intermediates. Acetic acid comes from the adsorbed acetaldehyde oxidation. Additionally, acetaldehyde was also investigated on well-ordered Pt(111) and disordered Pt(111) surfaces, both modified by deposited tin submonolayers. An outstanding performance was observed when both, well-ordered and disordered Pt(111) surfaces, were modified by Sn. It was observed an extraordinary displacement of the onset potential for more negative potentials and an increased production of CO2 and acetic acid.
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- 2020
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39. Deep Eutectic Solvents: An Alternative Medium for the Preparation of Organosulfur Compounds
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G Jacob Raquel, Hartwig Daniela, Bettanin Luana, F. B. Aquino Thalita, J Lenardao Eder, and E.R. Nascimento José
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010405 organic chemistry ,Chemistry ,Geography, Planning and Development ,General Earth and Planetary Sciences ,Organic chemistry ,010402 general chemistry ,01 natural sciences ,Organosulfur compounds ,0104 chemical sciences ,Water Science and Technology ,Eutectic system - Abstract
Deep Eutectic Solvent (DES) as a “green solvent” has been used as an alternative to replace Volatile Organic Compounds (VOCs) and traditional Ionic Liquids (ILs). In recent years, DES has gained much attention due to its excellent properties such as low cost, easy preparation, high viscosity, low vapor pressure, low volatility, high thermal stability, biodegradability and non-toxicity, among others. Other classes of compounds with increased interest are organosulfur compounds due to their applicability as synthetic intermediates in organic reactions and their high importance in pharmaceutical and agrochemical industries. This review describes the recent advances in the preparation of organosulfur compounds using DES as an alternative solvent, focusing on several types of organic reactions, including aromatic substitution reactions (SNAr), condensation, cyclocondensation, cyclization, ring-opening, thia-Michael addition, one-pot reactions and heterocyclodehydrations.
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- 2020
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40. Simultaneous biofiltration of H2S and NH3 using compost mixtures from lignocellulosic waste and chicken manure as packing material
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Daniel Felipe Forero, Diana Vela-Aparicio, Mario A. Hernández, Iván O. Cabeza, and Pedro F. B. Brandão
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Compost ,Health, Toxicology and Mutagenesis ,Hydrogen sulfide ,General Medicine ,010501 environmental sciences ,engineering.material ,Contamination ,Pulp and paper industry ,01 natural sciences ,Pollution ,Husk ,Ammonia ,chemistry.chemical_compound ,chemistry ,Biofilter ,engineering ,Environmental Chemistry ,Environmental science ,Chicken manure ,Bagasse ,0105 earth and related environmental sciences - Abstract
Biofiltration offers an efficient and economical alternative for the elimination of offensive odors caused by hydrogen sulfide, ammonia, and volatile organic compounds. Considering that packing materials affect the performance and represent the main installation cost, the purpose of this work was to evaluate the biofiltration of H2S and NH3 comparing three composted mixtures made from chicken manure and lignocellulosic residues (pruning waste, sugarcane bagasse, and rice husk) used as packing material. A range of gas concentrations similar to those of a municipal WWTP was used in the biofiltration of a contaminated stream performed on a laboratory scale. The results indicate that at low concentrations of H2S (6-36 ppm) and NH3 (0-1 ppm), the three biofilters showed 100% removal efficiency. Now, at the maximum levels of gas concentrations of H2S (250 ppm) and NH3 (19 ppm) while the removal efficiency of H2S remained higher than 90% in all cases, the removal efficiency of NH3 remained higher than 90% only in the sugarcane bagasse biofilter. Compost mixtures with sugarcane bagasse and rice husk are highly reliable as packing material for biofiltration at high concentration of H2S. Specifically, the sugarcane bagasse mixture had the highest removal efficiency (99% H2S and 95% NH3) and the highest elimination capacity (15 g H2S/m3h and 0.6 g NH3/m3h), making it a better option for the elimination of both gases. These results represent a contribution to the construction of a low-price elimination system of offensive odors in WTTPs and other industries.
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- 2020
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41. High CO tolerance of Pt nanoparticles synthesized by sodium borohydride in a time-domain NMR spectrometer
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L.C. de Queiroz, Andrezza S. Ramos, R. F. B. de Souza, Monique C.L. Santos, Walter Ricardo Brito, M.B. Machado, J. Nandenha, C.M. Godoi, E.H. Fontes, and Almir Oliveira Neto
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chemistry.chemical_classification ,Materials science ,Renewable Energy, Sustainability and the Environment ,Reducing agent ,Inorganic chemistry ,Energy Engineering and Power Technology ,chemistry.chemical_element ,Nanoparticle ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,NMR spectra database ,Sodium borohydride ,chemistry.chemical_compound ,Fuel Technology ,chemistry ,Compounds of carbon ,Cyclic voltammetry ,0210 nano-technology ,Platinum ,Carbon monoxide - Abstract
The CO poisoning effect was overcome using a novel synthesis method. This method consists of using sodium borohydride reducing agent assisted by magnetic field and radiofrequency pulses in the time-domain NMR spectrometer. This synthesis was useful to disperse the Pt nanoparticles over the carbon support and to compress the lattice strain of the Pt crystalline structure. Besides that, Pt/C MFP90° showed a multi-CO oxidation component in cyclic voltammetry, and this can avoid the poisoning effect by creating a large availability of CO species to be adsorbed, desorbed, and re-adsorbed. Pt/C MFP90° has also shown the best performance in the PEMFC regarding H2 and CO + H2 experiments.
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- 2020
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42. Stability evaluation of emulsion developed with extracts of Aloe vera (Aloe vera L.), Calendula (Calendula officinalis L.), Camomila (Matricaria chamomilla L.) and Asiatic centella (Centella asiatica L.)
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F. B. Marcondes, J. Kotowy, Trajano Felipe Barrabas Xavier da Silva, and N. C. Lubi
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Active ingredient ,calendula officinalis ,Wax ,Centella ,matricaria chamomilla ,centella asiática ,biology ,Traditional medicine ,Chemistry ,lcsh:A ,stability study ,biology.organism_classification ,Aloe vera ,Matricaria chamomilla ,aloe vera ,Calendula officinalis ,glycolic extracts ,visual_art ,Emulsion ,visual_art.visual_art_medium ,Calendula ,lcsh:General Works - Abstract
The emulsions are cosmetic and pharmaceutical forms developed for topical use, ideal for the incorporation of active ingredients such as plant extracts, because of a great affinity with the skin when compared with other formulations. However, they are thermodynamically unstable systems and sometimes the addition of active principles can destabilize the system. The Stability study is a tool for the development of products, because when submitting a formulation to different tests, one can evaluate behaviors that indicate storage conditions or even make commercialization impossible. The study used the glycolic extracts of Aloe vera L. which presents mucílago in its composition, used in cosmetology and treatment of burns, Calendula officinalis L. which possesses cicatrizing and anti-inflammatory property, Matricaria Chamomilla L. which has anti-inflammatory feature and antiseptic, and Centella Asiatica L. which has anti-inflammatory, healing and calming properties. The extracts were incorporated into an emulsion and evaluated separately. The choice of extracts was made at random. After the evaluation of the physical-chemical stability and organoleptic characteristics, which lasted 60 days, it was possible to conclude that the emulsion developed with non-ionic self-emulsifying wax (Polavax) is very unstable when added with the glycolic extracts of Aloe vera L., Calendula officinalis L., Matricaria chamomilla L. and Centella asiatica L., not tolerating large temperature variations with changes in viscosity and pH.
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- 2020
43. The influence of time and irrigant refreshment on biofilm removal from lateral morphological features of simulated root canals
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W. J. van der Meer, Prashant K. Sharma, L.W.M. van der Sluis, Xenos Petridis, Thais Cristina Pereira, Rene J. B. Dijkstra, F. B. de Andrade, Personalized Healthcare Technology (PHT), and Man, Biomaterials and Microbes (MBM)
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Time Factors ,sodium hypochlorite ,Root canal ,IRRIGANTES DO CANAL RADICULAR ,Dentistry ,irrigation ,Lateral canal ,chemistry.chemical_compound ,medicine ,General Dentistry ,optical coherence tomography ,Root Canal Irrigants ,Chemistry ,business.industry ,removal ,Lateral root ,Biofilm ,Basic Research – Technical ,biochemical phenomena, metabolism, and nutrition ,medicine.anatomical_structure ,Sodium hypochlorite solution ,Sodium hypochlorite ,Original Article ,Dental Pulp Cavity ,biofilms ,business ,Root Canal Preparation - Abstract
Aim: To evaluate the effect of irrigant refreshment and exposure time of a 2% sodium hypochlorite solution (NaOCl) on biofilm removal from simulated lateral root canal spaces using two different flow rates. Methodology: A dual-species biofilm was formed by a Constant Depth Film Fermenter (CDFF) for 96 h in plug inserts with anatomical features resembling an isthmus or lateral canal-like structures. The inserts were placed in a root canal model facing the main canal. NaOCl 2% and demineralized water (control group) were used as irrigant solutions. Both substances were applied at a flow rate of 0.05 and 0.1 mL s−1. The samples were divided into three groups with zero, one or two refreshments in a total exposure time of 15 min. A three-way analysis of variance (anova) was performed to investigate the interaction amongst the independent variables and the effect of consecutive irrigant refreshment on percentage of biofilm removal. A Tukey post hoc test was used to evaluate the effect of each independent variable on percentage biofilm removal in the absence of statistically significant interactions. Results: For the lateral canal, NaOCl removed significantly more biofilm irrespective of the number of refreshments and exposure time (P = 0.005). There was no significant effect in biofilm removal between the consecutive irrigant refreshments measured in the same biofilm. For the isthmus, NaOCl removed significantly more biofilm irrespective of the number of refreshments and exposure time; both NaOCl and a high flow rate removed significantly more biofilm when the exposure time was analysed (P = 0.018 and P = 0.029, respectively). Evaluating the effect of consecutive irrigant refreshment on the same biofilm, 2% NaOCl, 0.1 mL s−1 flow rate and one or two refreshments removed significant more biofilm (P = 0.04, 0.034 and 0.003
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- 2020
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44. Antifungal Effectiveness of Pyrolytic Oil Obtained from Triplochiton scleroxylon (De. Wild) Sawdust on Selected Wood Species
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F. B. Okanlawon, J. K. Abiola, O. A. Olatunji, and O. A. Adegoke
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Antifungal ,Triplochiton scleroxylon ,medicine.drug_class ,Chemistry ,visual_art ,medicine ,visual_art.visual_art_medium ,General Medicine ,Pyrolytic carbon ,Sawdust ,Pulp and paper industry ,Pyrolysis - Abstract
The present study was carried out to investigate the effectiveness of pyrolytic oil obtained from Triplochion scleroxylon sawdust which used as a preservative against fungi attack on Alstonia bonnei, Ceiba pentandra, Pterocarpus osun, Terminalia randii, Triplochiton scleroxylon wood. The wood samples used for the experiment were dimensioned into 20 x 20 x 60 mm and soaked for 72 hours to obtain appreciable absorption. The percentage absorption after soaking and weight loss after exposure to termite were determined. Data were analyzed using simple statistics and analysis of variance at α0.05. The highest and lowest percentage absorption was recorded for Terminalia randii and Alstonia bonnie with 23.20 % and 13.10 % respectively. Analysis of variance result indicates the significant difference in wood species used. The result obtained for weight loss revealed significant differences in wood species as well as in fungi also. The result further showed that those are taken as control recorded the highest weight loss to white and brown rot fungi. Pyrolytic oil possesses a great potential in the prevention of fungi attack as it contained phenolic compound.
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- 2020
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45. Isolation and identification of Lactobacillus spp. (Lactobacillaceae) resistant to Cd(II) and As(III) from fermented cocoa
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María Camila Lara-Morales, Ana María Guzmán-Beltrán, Pedro F. B. Brandão, Elianna Castillo, and Claudia Milena Rodríguez-López
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QH301-705.5 ,Microorganism ,chemistry.chemical_element ,Fermentación ,law.invention ,03 medical and health sciences ,Probiotic ,Minimum inhibitory concentration ,law ,Theobroma cacao ,Toxic elements ,Food science ,Biology (General) ,Lactobacilos ,Arsenic ,030304 developmental biology ,0303 health sciences ,Cadmium ,Elementos tóxicos ,biology ,030306 microbiology ,Chemistry ,biology.organism_classification ,Salinity ,Lactobacilli ,Fermentation ,General Agricultural and Biological Sciences ,Bacteria - Abstract
RESUMEN El objetivo de este estudio fue aislar e identificar a partir de cacao fermentado en Caldas Colombia, bacterias con potencial de aplicación en procesos biotecnológicos, como la detoxificación de cadmio (Cd(II)) y arsénico (As(III)) en el organismo humano. En total se recuperaron 36 aislados de los cuales se recuperaron 11 en presencia de 1,0 mg/L de Cd(II) y 25 en presencia de 0,1 mg/L de As(III). Su identificación molecular determinó que la mayoría de los aislados son del género Lactobacillus. Los ensayos de crecimiento en presencia de diferentes concentraciones de los elementos evaluados permitió determinar que gran parte de los aislamientos presentan resistencia a mayores concentraciones de As(III) (300 mg/L) que de Cd(II) (10 mg/L). En ensayos de tolerancia a la acidez (pH 2,5) se encontró que la cepa tipo Lactobacillus plantarum JCM 1055, junto con los aislamientos nativos L. plantarum A19, A26 y C16, mostraron la mayor tolerancia, por lo que se seleccionaron para evaluar su tolerancia a condiciones de salinidad. Las bacterias evaluadas mostraron crecimiento en concentraciones de hasta 4 g/L de sales biliares. Se concluye que los L. plantarum evaluados en este trabajo tienen un gran potencial para futuros ensayos en los que se busque demostrar la disminución de la bioaccesibilidad de Cd(II) y As(III) en condiciones in vitro del sistema digestivo humano debido a su resistencia a altas concentraciones de estos elementos y su tolerancia a condiciones de acidez y salinidad. Esto, junto con el reconocido potencial probiótico que tienen estos microorganismos, permitirá a futuro su uso en procesos biológicos de mitigación de Cd(II) y As(III). ABSTRACT The aim of this study was to isolate and identify from fermented cocoa in Caldas Colombia, bacteria with potential application in biotechnological processes such as detoxification of cadmium (Cd(II)) and arsenic (As(III)) in the human organism. In total, 36 isolates were obtained, from which 11 were recovered in the presence of 1.0 mg/L of Cd(II) and 25 in presence of 0.1 mg/L of As(III). Molecular identification showed most isolates belong to the genera Lactobacillus. Minimum inhibitory concentration assays, in presence of different concentrations of the elements, allowed to determine that the majority of isolates have resistance to higher concentration of As(III) (300 mg/L) than Cd(II) (10 mg/L). Acidity tolerance assays at pH 2.5 showed that type strain Lactobacillus plantarum JCM 1055, and native isolates L. plantarum A19, A26, and C16, presented the highest tolerance, thus they were selected to evaluate their tolerance to salinity conditions. The evaluated bacteria could grow in bile salts up to 4 g/L. It is concluded that the evaluated L. plantarum have great potential to be used in assays in which bioaccessibility of Cd(II) and As(III) is diminished under in vitro conditions of the human digestive system, due to its resistance to high concentrations of the elements and tolerance to acidic and high bile salt conditions. These facts, together with the recognized probiotic potential of these microorganisms, may allow their future use in biological processes to mitigate Cd(II) and As(III).
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- 2020
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46. Evaluation of different conventional lipid extraction techniques’ efficiency in obtaining oil from oleaginous seeds
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Angélica F. B. Piccioli, Cintia S. F. Ferreira, Jesuí Vergílio Visentainer, Victor Hugo Maldonado da Cruz, Patrícia D. S. Santos, Oscar Oliveira Santos, Roberta da Silveira, and Rafael L. G. Priori
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chemistry.chemical_classification ,food.ingredient ,Chemistry ,General Chemical Engineering ,food and beverages ,Fatty acid ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Biochemistry ,Sunflower ,Industrial and Manufacturing Engineering ,0104 chemical sciences ,food ,Lipid extraction ,Materials Chemistry ,Acid hydrolysis ,Food science ,0210 nano-technology ,Canola ,Polyunsaturated fatty acid - Abstract
Vegetable oils present great economic importance as they can be used and marketed by different industries based on their properties. Currently, several techniques can be employed to extract oils from seeds. However, novel techniques are not easily applicable in any environment. Thus, this study aimed to evaluate the efficiency of simple techniques; Bligh and Dyer, Soxhlet, and acid hydrolysis, in extracting oil from canola, flaxseed, soybean, and sunflower seeds. The sum of fatty acids found in extracted oils indicated Bligh and Dyer as the most efficient method among those assessed. Furthermore, the lower content of polyunsaturated fatty acids quantified in oils obtained by Soxhlet or acid hydrolysis may result from oxidation triggered using high temperatures required by both methods. Different lipid extraction methodologies were compared for the determination of fatty acid content in seeds.
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- 2020
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47. Improved GROMOS 54A7 Charge Sets for Phosphorylated Tyr, Ser, and Thr to Deal with pH-Dependent Binding Phenomena
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Miguel Machuqueiro, Inês Pires, and Nuno F. B. Oliveira
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Threonine ,chemistry.chemical_classification ,Binding Sites ,Biomolecule ,Protonation ,Hydrogen-Ion Concentration ,Molecular Dynamics Simulation ,Electrostatics ,SH2 domain ,Force field (chemistry) ,Computer Science Applications ,Partial charge ,chemistry ,Computational chemistry ,Serine ,Tyrosine ,Molecule ,Phosphorylation ,Physical and Theoretical Chemistry - Abstract
Phosphorylation is a ubiquitous post-translational modification in proteins, and the phosphate group is present constitutively or transiently in most biological building blocks. These phosphorylated biomolecules are involved in many high-affinity binding/unbinding events that rely predominantly on electrostatic interactions. To build accurate models of these molecules, we need an improved description of the atomic partial charges for all relevant protonation states. In this work, we showed that the commonly used protocols to derive atomic partial charges using well-solvated molecules are inadequate to model the protonation equilibria in binding events. We introduced a protocol based on PB/MC calculations with a single representative conformation (of both protonation states) and used the resulting pKa estimations to help manually curate the atomic partial charges. The final charge set, which is fully compatible with the GROMOS 54A7 force field, proved to be very effective in modeling the protonation equilibrium in different phosphorylated peptides in the free (tetrapeptides, pentapeptides, and pY1021) and protein-complexed forms (pY1021/PLC-γ1 complex). This was particularly important in the case of the pY1021 bound to the SH2 domain of PLC-γ1, where only our curated charge set captured the correct protonation equilibrium at the neutral to slightly acidic pH range. The binding/unbinding phenomena in that pH range are biologically relevant, and to improve our models, we need to go beyond the commonly used protocols and obtain revised force field parameters for these molecules.
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- 2020
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48. The Kinetics, Mechanism and Effect of Contact Time on the Adsorption of Cadmium and Glyphosate to Alfisol
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O. A. Adegoke, O. A. Okon Akan, F. B. Okanlawon, and O. A. Olatunji
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Psychiatry and Mental health ,Cadmium ,chemistry.chemical_compound ,Adsorption ,chemistry ,Contact time ,Glyphosate ,Alfisol ,Inorganic chemistry ,Kinetics ,chemistry.chemical_element ,Mechanism (sociology) - Abstract
This study was carried out using Alfisol as an adsorbent to adsorb Cadmium and Glyphosate both of which are common inorganic and organic contaminants. The soil samples were air-dried and allowed to pass through 2mm sieve before use while its analysis was done following the standard procedures. The kinetic data were tested with pseudo-first-order and pseudo-second-order models, and it was concluded that both adsorbates adsorption followed the pseudo-second-order kinetics, while the nature and the mechanism of adsorption processes were studied by using an intraparticle diffusion model. A complete linear plot of intraparticle diffusion was obtained for glyphosate which suggests that intraparticle diffusion was the rate-controlling step in its adsorption but the opposite is the case for cadmium adsorption. The peak removal of cadmium occurred after 50 minutes with equilibrium attained over 250 minutes while peak glyphosate removal was achieved after 30 minutes. It can be concluded that Alfisol can be effectively used for the adsorption of both Cadmium and Glyphosate thus showcasing a potential environmental remediation process.
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- 2020
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49. Pigmentantes naturais em dietas de codornas japonesas a base de arroz integral descascado e não polido
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E. Gopinger, E. G. Xavier, Débora Cristina Nichelle Lopes, R. C. Dias, V. F. B. Roll, Martha Lopes Schuch de Castro, Fernando Rutz, Suelen Nunes da Silva, Caroline Bavaresco, and J. Schafhauser
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Meal ,food.ingredient ,biology ,Chemistry ,Soybean meal ,General Medicine ,biology.organism_classification ,Pigment ,food ,Animal science ,Yolk ,visual_art ,visual_art.visual_art_medium ,Sugar beet - Abstract
Desenvolveu-se um experimento a fim de verificar o efeito da inclusão de pigmentos naturais, feno de alfafa (FA), colorífico de urucum (U) e beterraba (B), em uma dieta a base de arroz integral descascado e não-polido e farelo de soja sobre a coloração das gemas dos ovos de codornas. Foram utilizadas 100 codornas japonesas com 70 dias de idade. Os tratamentos foram T1: dieta controle (arroz integral descascado e não-polido em substituição total ao milho); T2: T1 + de 4% FA; T3: T1 + de 8% FA; T4: T1 + de 12% FA; T5: T1 + 4% de U; T6: T1 + 8% de U; T7: T1 +12% de U; T8: T1 + 4% de B; T9: T1 + 8% de B; e T10: T1 + 12% de B. Ao final de 15 dias foram verificadas as colorações das gemas dos ovos com colorímetro. O feno de alfafa promoveu diminuição da luminosidade e a cor variou do verde ao amarelado. Houve também aumento da saturação da cor com o aumento dos níveis de feno de alfafa na dieta (P
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- 2020
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50. Produção e análise marginal em vacas de leite submetidas a níveis de ureia na dieta à base de silagem de sorgo
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P.T. Viana, H. de A. Santana Júnior, L.A.P. Raduns, F. B. L. Mendes, G. Abreu Filho, R.H. Alves, E.O. Cardoso Santana, and B.H.R. Weiss
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Silage ,General Medicine ,Biology ,Sorghum ,biology.organism_classification ,Cattle feeding ,chemistry.chemical_compound ,Animal science ,medicine.anatomical_structure ,chemistry ,Latin square ,Lactation ,Urea ,medicine ,Composition (visual arts) ,Dairy cattle - Abstract
Objetivou-se avaliar as características produtivas, nutricionais e econômicas de vacas de leite submetidas a níveis de ureia com dietas à base de silagem de sorgo. Foram utilizadas 05 vacas lactantes ¾ Holandês x ¼ Gir Leiteiro, no terço médio de lactação, com idade média de 60 meses e peso corporal médio de 518 kg ± 52 kg, que foram distribuídas em cinco tratamentos, em delineamento experimental de quadrado latino 5x5. Os tratamentos (U-50, U-75, U-100, U-125 e U-150) foram constituídos de diferentes níveis de ureia no concentrado (5,7; 8,6; 11,4; 14,3 e 17,1 g de ureia/kg de MS do concentrado, respectivamente). Adotou-se como nível de significância 0,05. Não houve efeito dos níveis de ureia no consumo alimentar, digestibilidade e parâmetros metabólicos de vacas de leite. Não foram observadas diferenças significativas na produção de leite corrigida para 3,5% de gordura. A composição do leite não sofreu efeitos significativos. O custo total com volumoso, concentrado e alimentação não sofreu efeitos significativos. A receita bruta com a venda de leite não sofreu efeito significativo, apresentando média de BRL 28,65. A taxa de retorno marginal não apresentou diferenças significativas. Os diferentes níveis de ureia não afetaram a produção de vacas de leite. Conclui-se que na dieta de vacas de leite à base de silagem de sorgo pode-se realizar a inclusão de ureia no concentrado com níveis de 5,7 a 17,1 g/kg do concentrado, sem redução do desempenho produtivo dos animais.
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- 2020
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