24 results on '"Roberta R. Rodrigues"'
Search Results
2. Structural Evidence for Pnictogen-Centered Lewis Acidity in Cationic Platinum-Stibine Complexes Featuring Pendent Amino or Ammonium Groups
- Author
-
Roberta R. Rodrigues and François P. Gabbaï
- Subjects
pnictogen bonding ,platinum ,catalysis ,Organic chemistry ,QD241-441 - Abstract
As part of our continuing interest in the chemistry of cationic antimony Lewis acids as ligands for late transition metals, we have now investigated the synthesis of platinum complexes featuring a triarylstibine ligand substituted by an o-[(dimethylamino)methyl]phenyl group referred to as ArN. More specifically, we describe the synthesis of the amino stibine ligand Ph2SbArN (L) and its platinum dichloride complex [LPtCl]Cl which exists as a chloride salt and which shows weak coordination of the amino group to the antimony center. We also report the conversion of [LPtCl]Cl into a tricationic complex [LHPt(SMe2)]3+ which has been isolated as a tris-triflate salt after reaction of [LPtCl]Cl with SMe2, HOTf and AgOTf. Finally, we show that [LHPt(SMe2)][OTf]3 acts as a catalyst for the cyclization of 2-allyl-2-(2-propynyl)malonate.
- Published
- 2021
- Full Text
- View/download PDF
3. Preferential Direction of Electron Transfers at a Dye–Metal Oxide Interface with an Insulating Fluorinated Self-Assembled Monolayer and MgO
- Author
-
Nathan I. Hammer, Kayla Foell, Leigh Anna Hunt, Hammad Cheema, Dinesh Nugegoda, Jared H. Delcamp, and Roberta R. Rodrigues
- Subjects
Electron transfer reactions ,Materials science ,Interface (Java) ,Event (relativity) ,Oxide ,Self-assembled monolayer ,02 engineering and technology ,Electron ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,7. Clean energy ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Metal ,chemistry.chemical_compound ,General Energy ,chemistry ,Photoinduced charge separation ,Chemical physics ,visual_art ,visual_art.visual_art_medium ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
Slowing nondesirable electron transfer reactions at metal oxide–dye interfaces is important for many technologies. In particular, after an interfacial photoinduced charge separation event at a meta...
- Published
- 2021
- Full Text
- View/download PDF
4. Pyridyl CO2 Fixation Enabled by a Secondary Hydrogen Bonding Coordination Sphere
- Author
-
Roberta R. Rodrigues, Qing Li, Jared H. Delcamp, Jacqueline N. Gayton, Glake Hill, and Lakeeta Sanders
- Subjects
Chemistry ,Materials science ,Coordination sphere ,Chemical physics ,Hydrogen bond ,General Chemical Engineering ,Carbon fixation ,Multiple applications ,General Chemistry ,InformationSystems_MISCELLANEOUS ,QD1-999 - Abstract
Reversible CO2 binders under ambient conditions are of significant interest for multiple applications in sensing and capture technologies. In this paper, a general systematic way to evaluate CO2 re...
- Published
- 2020
5. Copper-based redox shuttles supported by preorganized tetradentate ligands for dye-sensitized solar cells
- Author
-
Hammad Cheema, Jonah W. Jurss, Joseph M Lee, Jared H. Delcamp, Roberta R. Rodrigues, Lizhu Chen, Natalie S Taylor, and Ryan C. Fortenberry
- Subjects
Biphenyl ,chemistry.chemical_element ,Photochemistry ,Redox ,Copper ,law.invention ,Inorganic Chemistry ,chemistry.chemical_compound ,Electron transfer ,Dye-sensitized solar cell ,chemistry ,law ,Solar cell ,Organic dye ,Chelation - Abstract
Three copper redox shuttles ([Cu(1)]2+/1+, [Cu(2)]2+/1+, and [Cu(3)]2+/1+) featuring tetradentate ligands were synthesized and evaluated computationally, electrochemically, and in dye-sensitized solar cell (DSC) devices using a benchmark organic dye, Y123. Neutral polyaromatic ligands with limited flexibility were targeted as a strategy to improve solar-to-electrical energy conversion by reducing voltage losses associated with redox shuttle electron transfer events. Inner-sphere electron transfer reorganization energies (λ) were computed quantum chemically and compared to the commonly used [Co(bpy)3]3+/2+ redox shuttle which has a reported λ value of 0.61 eV. The geometrically constrained biphenyl-based Cu redox shuttles investigated here have lower reorganization energies (0.34-0.53 eV) and thus can potentially operate with lower driving forces for dye regeneration (ΔGreg) in DSC devices when compared to [Co(bpy)3]3+/2+-based devices. The rigid tetradentate ligand design promotes more efficient electron transfer reactions leading to an improved JSC (14.1 mA cm-2), higher stability due to the chelate effect, and a decrease in VlossOC for one of the copper redox shuttle-based devices.
- Published
- 2020
- Full Text
- View/download PDF
6. Synthesis of a tetratopic bisphosphine ligand derived from pyrimidine and its incorporation into gold and silver coordination polymers
- Author
-
Roberta R. Rodrigues, Eric W. Reinheimer, Christopher L. Dorsey, and Todd W. Hudnall
- Subjects
Inorganic Chemistry ,Materials Chemistry ,Physical and Theoretical Chemistry - Published
- 2023
- Full Text
- View/download PDF
7. Thienopyrroledione-Based Photosensitizers as Strong Photoinduced Oxidants: Oxidation of Fe(bpy)32+ in a >1.3 V Dye-Sensitized Solar Cell
- Author
-
Jared H. Delcamp, Roberta R. Rodrigues, Austin Dorris, Nathan I. Hammer, and Adithya Peddapuram
- Subjects
Dye-sensitized solar cell ,Materials science ,Materials Chemistry ,Electrochemistry ,Energy Engineering and Power Technology ,Chemical Engineering (miscellaneous) ,Electrical and Electronic Engineering ,Photochemistry ,Visible spectrum - Abstract
The design of visible light absorbing organic dyes as strong photoinduced oxidants is needed for many potential applications in energy production and storage. To access more positive potentials, th...
- Published
- 2019
- Full Text
- View/download PDF
8. Highly Active Ruthenium CNC Pincer Photocatalysts for Visible-Light-Driven Carbon Dioxide Reduction
- Author
-
Sanjit Das, Charles Edwin Webster, Jared H. Delcamp, Roberta R. Rodrigues, Elizabeth T. Papish, Chance M. Boudreaux, Eric W. Reinheimer, Robert W. Lamb, and Fengrui Qu
- Subjects
010405 organic chemistry ,chemistry.chemical_element ,010402 general chemistry ,Photochemistry ,01 natural sciences ,0104 chemical sciences ,Pincer movement ,Ruthenium ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Physical and Theoretical Chemistry ,Carbon monoxide ,Visible spectrum ,Electrochemical reduction of carbon dioxide - Abstract
Five ruthenium catalysts described herein facilitate self-sensitized carbon dioxide reduction to form carbon monoxide with a ruthenium catalytic center. These catalysts include four new and one previously reported CNC pincer complexes featuring a pyridinol derived N-donor and N-heterocyclic carbene (NHC) C-donors derived from imidazole or benzimidazole. The complexes have been characterized fully by spectroscopic and analytic methods, including X-ray crystallography. Introduction of a 2,2'-bipyridine (bipy) coligand and phenyl groups on the NHC ligand was necessary for rapid catalysis. [(CNC)Ru(bipy)(CH
- Published
- 2019
- Full Text
- View/download PDF
9. Iron Redox Shuttles with Wide Optical Gap Dyes for High-Voltage Dye-Sensitized Solar Cells
- Author
-
Ryan C. Fortenberry, Jonathon Watson, Roberta R. Rodrigues, Leigh Anna Hunt, Jonah W. Jurss, Christine Curiac, Nathan I. Hammer, Jared H. Delcamp, and Anthony Devdass
- Subjects
General Chemical Engineering ,Ether ,02 engineering and technology ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Redox ,law.invention ,chemistry.chemical_compound ,law ,Photovoltaics ,Solar cell ,Environmental Chemistry ,General Materials Science ,Alkyl ,chemistry.chemical_classification ,business.industry ,Aryl ,High voltage ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Dye-sensitized solar cell ,General Energy ,chemistry ,0210 nano-technology ,business - Abstract
A series of iron polypyridyl redox shuttles were synthesized in the 2+ and 3+ oxidation states and paired with a series of wide optical gap organic dyes with weak aryl ether electron-donating groups. High voltage dye-sensitized solar cell (HV-DSC) devices were obtained through controlling the redox shuttle energetics and dye donor structure. The use of aryl ether donor groups, in place of commonly used aryl amines, allowed for the lowering of the dye ground-state oxidation potential which enabled challenging to oxidize redox shuttles based on Fe2+ polypyridyl structures to be used in functional devices. By carefully designing a dye series that varies the number of alkyl chains for TiO2 surface protection, the recombination of electrons in TiO2 to the oxidized redox shuttle could be controlled, leading to HV-DSC devices of up to 1.4 V.
- Published
- 2021
10. Pyridyl CO
- Author
-
Jacqueline N, Gayton, Qing, Li, Lakeeta, Sanders, Roberta R, Rodrigues, Glake, Hill, and Jared H, Delcamp
- Subjects
Article - Abstract
Reversible CO2 binders under ambient conditions are of significant interest for multiple applications in sensing and capture technologies. In this paper, a general systematic way to evaluate CO2 receptors with π-systems is put forward. A series of receptors (five pyridine-based and one triazine-based) are evaluated as CO2 binders in terms of number of hydrogen bonding sites, strength of hydrogen bond donors, and number of nucleophilic sites. The binding of CO2 to the receptors was probed by computational models, absorption spectroscopy, fluorescence spectroscopy, cyclic voltammetry, and 1H NMR studies. Multiple solvents with varying ionic strength additives are probed to analyze the effects on CO2-bound intermediates. The receptors were screened progressively down-selecting through the different analytical techniques arriving at a promising pyridine receptor, which shows evidence of CO2 binding with each of the analytical techniques. The diaminopyridine motif demonstrates reversible CO2 binding and has convenient substitution sites for derivatization to incorporate into functional sensor systems.
- Published
- 2020
11. Precious metal-free solar-to-fuel generation: SSM-DSCs powering water splitting with NanoCOT and NiMoZn electrocatalysts
- Author
-
Hammad Cheema, Jared H. Delcamp, Shanlin Pan, Pravin S. Shinde, Roberta R. Rodrigues, and Jonathon Watson
- Subjects
Materials science ,Precious metal ,02 engineering and technology ,010402 general chemistry ,7. Clean energy ,01 natural sciences ,Catalysis ,law.invention ,Graphene electrode ,law ,Solar cell ,Materials Chemistry ,Electrolysis of water ,Metals and Alloys ,General Chemistry ,021001 nanoscience & nanotechnology ,6. Clean water ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Chemical engineering ,Electrode ,Organic dye ,Ceramics and Composites ,Water splitting ,0210 nano-technology - Abstract
A precious metal-free sequential series multijunction dye-sensitized solar cell (SSM-DSC)-powered water electrolysis system is demonstrated using NanoCOT and NiMoZn electrodes. A stable 3.9% solar-to-hydrogen (STH) efficiency is achieved using a recently reported black organic dye and graphene electrodes for DSCs.
- Published
- 2020
12. Near-infrared unsymmetrical squaraine core-based sensitizers for co-sensitized high-photocurrent dye-sensitized solar cells
- Author
-
Jonathon Watson, Roberta R. Rodrigues, and Jared H. Delcamp
- Subjects
General Energy ,General Engineering ,General Physics and Astronomy ,General Materials Science ,General Chemistry - Published
- 2022
- Full Text
- View/download PDF
13. Photocatalytic Reduction of CO2 to CO and Formate: Do Reaction Conditions or Ruthenium Catalysts Control Product Selectivity?
- Author
-
Roberta R. Rodrigues, Elizabeth T. Papish, Jared H. Delcamp, and Chance M. Boudreaux
- Subjects
010405 organic chemistry ,Energy Engineering and Power Technology ,chemistry.chemical_element ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Redox ,0104 chemical sciences ,Ruthenium ,Catalysis ,Solvent ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Electrochemistry ,Photocatalysis ,Chemical Engineering (miscellaneous) ,Photosensitizer ,Formate ,Electrical and Electronic Engineering ,Selectivity - Abstract
The photocatalytic reduction of CO2 can generate a number of products with CO and HCO2– being two of the most commonly observed. Frequently, the selective formation of one of these products is presumed to be the result of catalyst design. However, several common variables are present when exploring the photocatalytic CO2 reduction reaction. In order to better understand the origin of selectivity in this reaction, the choices of solvent, electron and proton source, photosensitizer (PS), and catalyst were evaluated in photocatalytic CO2 reduction reactions. Intriguingly, highly selective catalysts for CO or HCO2– under one set of conditions can be transformed by these environmental choices into becoming highly selective for the opposite product while retaining high turnover numbers. This highlights the importance of carefully considering reaction conditions before ascribing catalyst selectivity to an inherent molecular design property.
- Published
- 2018
- Full Text
- View/download PDF
14. Nickel(<scp>ii</scp>) pincer complexes demonstrate that the remote substituent controls catalytic carbon dioxide reduction
- Author
-
Nalaka P. Liyanage, Yujie Sun, Roberta R. Rodrigues, Dalton B. Burks, Jared H. Delcamp, Shakeyia Davis, Xuan Liu, Charles Edwin Webster, Robert W. Lamb, and Elizabeth T. Papish
- Subjects
010405 organic chemistry ,Chemistry ,Ligand ,Metals and Alloys ,Substituent ,chemistry.chemical_element ,Protonation ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,Catalysis ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Pincer movement ,Nickel ,chemistry.chemical_compound ,Materials Chemistry ,Ceramics and Composites ,Pincer ligand ,Electrochemical reduction of carbon dioxide - Abstract
The first example of a CNC pincer ligand with a central pyridinol ligand is reported in a nickel(ii) complex. This metal complex can be protonated or deprotonated reversibly in situ to switch on or off the photocatalytic performance towards CO2 reduction. The O- substituent appears essential for catalysis.
- Published
- 2018
- Full Text
- View/download PDF
15. Sequential series multijunction dye-sensitized solar cells (SSM-DSCs): 4.7 volts from a single illuminated area
- Author
-
Roberta R. Rodrigues, Jared H. Delcamp, and Hammad Cheema
- Subjects
Materials science ,Photon ,Series (mathematics) ,Renewable Energy, Sustainability and the Environment ,business.industry ,Photon management ,Energy conversion efficiency ,Volt ,Ranging ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Pollution ,Potential energy ,0104 chemical sciences ,Dye-sensitized solar cell ,Nuclear Energy and Engineering ,Environmental Chemistry ,Optoelectronics ,0210 nano-technology ,business - Abstract
Sequential series multijunction dye-sensitized solar cells (SSM-DSCs), which are mechanically stacked single illuminated area DSC devices wired in series, are reported to have exceptionally high photovoltages (Voc) ranging from 1.9–4.7 V from 2–5 stacked subcells. The use of multiple photoactive films under one area within the SSM-DSC framework is made possible by fine-tuning the thickness of TiO2 in each device and by judicious dye selection to allow for excellent light distribution among the films, termed as “photon management”. The SSM-DSC approach allows for incorporation of materials designed to use the maximal potential energy of photons in each region of the solar spectrum. Importantly, SSM-DSCs were observed to maintain high Voc under low-light conditions, rendering these systems very attractive for indoor applications. Additionally, an SSM-DSC was found to have a solar-to-fuel conversion efficiency of 2% (2.7% including H2 production) for the reduction of CO2 to CO with IrO2 and Au2O3 electrocatalysts, without an external bias.
- Published
- 2017
- Full Text
- View/download PDF
16. A High-Voltage Molecular-Engineered Organic Sensitizer-Iron Redox Shuttle Pair: 1.4 V DSSC and 3.3 V SSM-DSSC Devices
- Author
-
Roberta R. Rodrigues, Hammad Cheema, and Jared H. Delcamp
- Subjects
Materials science ,Ligand ,business.industry ,Doping ,Iron redox ,High voltage ,General Medicine ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,7. Clean energy ,01 natural sciences ,Redox ,Catalysis ,0104 chemical sciences ,Molecular engineering ,Dye-sensitized solar cell ,Optoelectronics ,0210 nano-technology ,business ,Voltage - Abstract
The development of high voltage solar cells is an attractive way to use sunlight for solar-to-fuel devices, multijunction solar-to-electric systems, and to power limited-area consumer electronics. By designing a low-oxidation-potential organic dye (RR9)/redox shuttle (Fe(bpy)33+/2+ ) pair for dye-sensitized solar-cell (DSSC) devices, the highest single device photovoltage (1.42 V) has been realized for a DSSC not relying on doped TiO2 . Additionally, Fe(bpy)33+/2+ offers a robust, readily tunable ligand platform for redox potential tuning. RR9 can be regenerated with a low driving force (190 mV), and by utilizing the RR9/Fe(bpy)33+/2+ redox shuttle pair in a subcell for a sequential series multijunction (SSM)-DSSC system, one of the highest known three subcell photovoltage was attained for any solar-cell technology (3.34 V, >1.0 V per subcell).
- Published
- 2017
17. Phosphaalkene vs. phosphinidene: the nature of the P-C bond in carbonyl-decorated carbene → PPh adducts
- Author
-
Christopher L. Dorsey, Chelsee A. Arceneaux, Roberta R. Rodrigues, and Todd W. Hudnall
- Subjects
Chemistry ,Metals and Alloys ,General Chemistry ,Photochemistry ,Medicinal chemistry ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Adduct ,chemistry.chemical_compound ,Phosphinidene ,Materials Chemistry ,Ceramics and Composites ,Dichlorophenylphosphine ,Phosphaalkene ,Carbene - Abstract
Treatment of dichlorophenylphosphine with two equivalents of carbonyl-decorated carbenes results in a two-electron reduction of the phosphorus centre concomitant with carbene oxidation to afford novel phosphaalkenes as confirmed via crystallographic, spectroscopic, and DFT analyses.
- Published
- 2013
18. 'Candidatus Liberibacter asiaticus' infection alters the reflectance profile in asymptomatic citrus plants.
- Author
-
Vieira JG, Santana ED, Conceição FG, Iost Filho FH, de Pazini JB, Rodrigues R, and Yamamoto PT
- Abstract
Background: Huanglongbing (HLB) is the primary and most destructive disease affecting citrus, caused by a pathogen transmitted by an insect vector, Diaphorina citri. There are no curative methods for the disease, and rapid and accurate methods are needed for early detection in the field, even before symptoms appear. These will facilitate the faster removal of infected trees, preventing the spread of the bacteria through commercial citrus orchards., Results: It was possible to determine ranges of hyperspectral bands that demonstrated significant differences in relative reflectance between treatments consisting of healthy and infected plants from the first days of evaluation, when plants infected with 'Candidatus Liberibacter asiaticus' (CLas) were still in the asymptomatic stage of the disease. From the Week 2 of evaluation [58 days after infection (DAI) of plants] until the last week, spectral differences were detected in the red edge region (660-750 nm). From the Week 6 onwards (86 DAI), spectral differences between healthy and symptomatic plants were observed in bands close to the visible region (520-680 nm)., Conclusion: Spectral differences were detected in the leaves of C. sinensis infected by CLas before the appearance of symptoms, making it feasible to use the hyperspectral sensor to monitor the disease. Our results indicate the need for future studies to validate the use of hyperspectral sensors for managing and detecting HLB in commercial citrus orchards, contributing to the integrated management of the disease. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)
- Published
- 2024
- Full Text
- View/download PDF
19. Effect of an 'implementation intention' intervention on adherence to oral anti-diabetic medication in Brazilians with type 2 diabetes.
- Author
-
Trevisan DD, São-João T, Cornélio M, Jannuzzi F, de Sousa MR, Rodrigues R, and Lima MH
- Subjects
- Adult, Aged, Blood Glucose, Brazil, Diabetes Mellitus, Type 2 psychology, Female, Humans, Hypoglycemic Agents therapeutic use, Male, Middle Aged, Primary Health Care methods, Self Care, Treatment Outcome, Diabetes Mellitus, Type 2 drug therapy, Glycated Hemoglobin analysis, Hypoglycemic Agents administration & dosage, Intention, Medication Adherence
- Abstract
Objective: To evaluate the effects of an implementation intention intervention on adherence to an oral anti-diabetic medication regime, diabetes-related distress and on glycemic control in patients with type 2 diabetes mellitus., Methods: A randomized, parallel-group, single-center controlled trial was conducted among adults with type 2 diabetes being managed at the primary care level. The intervention group (IG, n = 45) received an 'implementation intention' intervention; the control group (CG, n = 45) received standard care. Primary outcomes were the taking of oral anti-diabetic medication, global adherence and level of glycated hemoglobin. The secondary outcome was diabetes-related distress. Data were gathered at baseline and after 15 weeks., Results: The IG showed improvements in adherence to an oral anti-diabetic medication regime (p < 0.0001), glycemic control (p < 0.0001) and diabetes-related distress (p < 0.0001) relative to the CG., Conclusions: The implementation intention intervention enhanced adherence to an oral anti-diabetic medication regime, which had positive effects on blood glucose levels and diabetes-related distress., Practice Implications: Adherence to an oral anti-diabetic medication regime can decrease blood glucose levels and diabetes-related distress and thus reduce complications of type 2 diabetes., Competing Interests: Declaration of Competing Interest None., (Copyright © 2019 Elsevier B.V. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
20. Avian influenza virus (H11N9) in migratory shorebirds wintering in the Amazon Region, Brazil.
- Author
-
de Araujo J, de Azevedo SM Jr, Gaidet N, Hurtado RF, Walker D, Thomazelli LM, Ometto T, Seixas MM, Rodrigues R, Galindo DB, da Silva AC, Rodrigues AM, Bomfim LL, Mota MA, Larrazábal ME, Branco JO, Serafini P, Neto IS, Franks J, Webby RJ, Webster RG, and Durigon EL
- Subjects
- Animals, Brazil, Influenza A virus classification, Phylogeny, Sympatry, Animal Migration, Charadriiformes virology, Influenza A virus isolation & purification, Seasons
- Abstract
Aquatic birds are the natural reservoir for avian influenza viruses (AIV). Habitats in Brazil provide stopover and wintering sites for water birds that migrate between North and South America. The current study was conducted to elucidate the possibility of the transport of influenza A viruses by birds that migrate annually between the Northern and Southern Hemispheres. In total, 556 orotracheal/cloacal swab samples were collected for influenza A virus screening using real-time RT-PCR (rRT-PCR). The influenza A virus-positive samples were subjected to viral isolation. Four samples were positive for the influenza A matrix gene by rRT-PCR. From these samples, three viruses were isolated, sequenced and characterized. All positive samples originated from a single bird species, the ruddy turnstone (Arenaria interpres), that was caught in the Amazon region at Caeté Bay, Northeast Pará, at Ilha de Canelas. To our knowledge, this is the first isolation of H11N9 in the ruddy turnstone in South America.
- Published
- 2014
- Full Text
- View/download PDF
21. Synthetic and biological studies of tubulin targeting c2-substituted 7-deazahypoxanthines derived from marine alkaloid rigidins.
- Author
-
Scott R, Karki M, Reisenauer MR, Rodrigues R, Dasari R, Smith WR, Pelly SC, van Otterlo WAL, Shuster CB, Rogelj S, Magedov IV, Frolova LV, and Kornienko A
- Subjects
- Binding Sites, Cell Line, Tumor, Cell Survival drug effects, HeLa Cells, Humans, Hypoxanthines chemical synthesis, Hypoxanthines toxicity, MCF-7 Cells, Microscopy, Video, Molecular Docking Simulation, Protein Structure, Tertiary, Pyrimidines chemistry, Pyrroles chemistry, Structure-Activity Relationship, Tubulin metabolism, Tubulin Modulators toxicity, Alkaloids chemistry, Hypoxanthines chemistry, Tubulin chemistry, Tubulin Modulators chemical synthesis, Tubulin Modulators chemistry
- Abstract
C2-aryl- and C2-alkyl-7-deazahypoxanthines as analogues of marine alkaloid rigidins were prepared utilizing novel synthetic methods developed for the construction of the pyrrolo[2,3-d]pyrimidine ring system. The new compounds exhibited sub-micromolar to nanomolar antiproliferative potencies against a panel of cell lines including in vitro models for drug-resistant tumors, such as glioblastoma, melanoma and non-small-cell lung cancer. A selected representative C2-methyl-7-deazahypoxanthine was found to inhibit microtubule dynamics in cancer cells, lending evidence for tubulin targeting as a mode of action for these compounds in cancer cells. The results of the docking studies utilizing the colchicine site on β-tubulin were consistent with the observed structure-activity relationship data, including an important finding that derivatization at C2 with linear alkyl groups leads to the retention of activity, thus permitting the attachment of a biotin-containing linker for the subsequent proteomics assays. Because many microtubule-targeting compounds are successfully used to fight cancer in the clinic, the reported antitubulin rigidin analogues have significant potential as new anticancer agents., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2014
- Full Text
- View/download PDF
22. West Nile virus surveillance, Brazil, 2008-2010.
- Author
-
Ometto T, Durigon EL, de Araujo J, Aprelon R, de Aguiar DM, Cavalcante GT, Melo RM, Levi JE, de Azevedo Júnior SM, Petry MV, Neto IS, Serafini P, Villalobos E, Cunha EM, Lara Mdo C, Nava AF, Nardi MS, Hurtado R, Rodrigues R, Sherer AL, Sherer Jde F, Geraldi MP, de Seixas MM, Peterka C, Bandeira Dde S, Pradel J, Vachiery N, Labruna MB, de Camargo LM, Lanciotti R, and Lefrançois T
- Subjects
- Animals, Animals, Wild immunology, Birds immunology, Brazil epidemiology, Culicidae immunology, Enzyme-Linked Immunosorbent Assay methods, Horses immunology, Humans, Seroepidemiologic Studies, Antibodies, Viral blood, West Nile Fever diagnosis, West Nile Fever epidemiology, West Nile virus immunology
- Abstract
Background: West Nile virus (WNV) is an emergent pathogen that is widely distributed in North and Central America. The recent introduction in South America has focused attention on the spread of WNV across Southern American countries. The transmission network involves mosquitoes, birds, horses and humans., Methods: The serological evaluation of sera from 678 equids and 478 birds was performed using a WNV-specific blocking ELISA, and only the positive results were confirmed by plaque reduction neutralisation tests (PRNTs). Molecular analysis was performed on sera from 992 healthy equids and on 63 macerates of brains from equids that died of encephalitis and had previously tested negative for other pathogens. We also tested swabs from 928 birds. The samples analysed were collected in different biomes of Brazil., Results: We identified WNV antibodies by ELISA in thirteen equids and five birds, and PRNT90 confirmed WNV positivity in four equid samples collected in 2009 in an area between the Amazon and the Pantanal. None of the ELISA positive bird samples were confirmed by PRNT90, and all samples tested by RT-PCR were negative., Conclusion: WNV circulation is confirmed by this large scale survey even in the absence of detection of clinical cases.
- Published
- 2013
- Full Text
- View/download PDF
23. Development of the SALdável programme to reduce salt intake among hypertensive Brazilian women: an intervention mapping approach.
- Author
-
Cornélio ME, Godin G, Rodrigues R, Agondi R, Spana T, and Gallani MC
- Subjects
- Brazil, Female, Humans, Feeding Behavior, Health Promotion methods, Hypertension diet therapy, Program Development methods, Self Efficacy, Sodium, Dietary adverse effects
- Abstract
Background: Despite strong evidence for a relationship between high salt intake and hypertension, plus the widespread recommendations for dietary salt restriction among hypertensive subjects, there are no nursing studies describing effective theory-based interventions., Aim: To describe a systematic process for development of a theory-based nursing intervention that is aimed at reducing salt intake among hypertensive women, by applying the 'intervention mapping' protocol., Methods: We developed our intervention following the six steps of the 'intervention mapping' protocol: assessing needs, creating a matrix of change objectives, selecting theoretical methods and practical applications, defining the intervention programme, organizing the adoption and implementation plan, and defining the evaluation plan., Results: Addition of salt during cooking is identified as the main source for salt consumption, plus women are identified as the people responsible for cooking meals at home. In our study, the motivational predictors of this behaviour were self-efficacy and habit. Guided practice, verbal persuasion, coping barriers, consciousness-raising and counter-conditioning were the theoretical methods we selected for enhancing self-efficacy and promoting habit change, respectively. Brainstorming, role-playing, cookbook use, measuring spoon use, label reading, hands-on skill-building activities and reinforcement phone calls were the chosen practical applications. We designed our intervention programme, and then organized the adoption and implementation plans. Finally, we generated a plan to evaluate our intervention., Conclusions: 'Intervention mapping' was a feasible methodological framework to guide the development of a theory-based nursing intervention for dietary salt reduction among hypertensive women.
- Published
- 2013
- Full Text
- View/download PDF
24. Cystic fibrosis and neonatal screening.
- Author
-
Rodrigues R, Gabetta CS, Pedro KP, Valdetaro F, Fernandes MI, Magalhães PK, Januário JN, and Maciel LM
- Subjects
- Antigens, Neoplasm blood, Biomarkers, Tumor blood, Black People, Cystic Fibrosis genetics, Cystic Fibrosis Transmembrane Conductance Regulator blood, Cystic Fibrosis Transmembrane Conductance Regulator genetics, DNA analysis, Humans, Immunohistochemistry, Incidence, Infant, Newborn, Lectins, C-Type blood, Pancreatitis-Associated Proteins, Prenatal Diagnosis, Trypsin blood, United States epidemiology, White People, Black or African American, Cystic Fibrosis diagnosis, Neonatal Screening
- Abstract
The clinical and diagnostic aspects of cystic fibrosis have been extensively reviewed, with an emphasis on neonatal screening. This systematic literature review involved a search for relevant contributions in the PubMed and SciELO databases. The first references to cystic fibrosis date to the Middle Ages. Cystic fibrosis is the most frequent autosomal recessive hereditary disease among Caucasians (1:2,000 to 3,500). More than 1,000 mutations lead to the disease, the most common being "F508, with 70% prevalence among Canadian, Northern European, and American Caucasians and 23 to 55% prevalence among Brazilians. The basic defect is in chloride ion secretion. Cystic fibrosis screening has long been controversial, and after almost three decades, there are few nationwide programs (most are regional or local). However, the U.S. Centers for Disease Control and Prevention (CDC) has concluded that screening for cystic fibrosis is justified. The lack of a specific screening test and the ethnic heterogeneity of the Brazilian population pose challenges for neonatal screening.
- Published
- 2008
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.