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1.
Front Med (Lausanne) ; 9: 967887, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36314033

RESUMO

Introduction: A substantial proportion of individuals with low cardiovascular risk receive inappropriate statin prescription for primary prevention of cardiovascular disease (CVD) instead of the evidence-based recommendations to promote healthy lifestyle behaviors. This study reports on the structured process performed to design targeted de-implementation strategies to reduce inappropriate prescription of statins and to increase healthy lifestyle promotion in low cardiovascular risk patients in Primary Care (PC). Methods: A formative study was conducted based on the Theoretical Domains Framework and the Behavior Change Wheel (BCW). It comprised semi-structured interviews with PC professionals to define the problem in behavioral terms; focus groups with Family Physicians and patients to identify the determinants (barriers and facilitators) of inappropriate statin prescription and of healthy lifestyle promotion practice; mapping of behavioral change interventions operationalized as de-implementation strategies for addressing identified determinants; and consensus techniques for prioritization of strategies based on perceived effectiveness, feasibility and acceptability. Results: Identified key determinants of statin prescription and healthy lifestyle promotion were: the lack of time and clinical inertia, external resources, patients' preferences and characteristics, limitation of available clinical tools and guidelines, social pressures, fears about negative consequences of not treating, and lack of skills and training of professionals. Fourteen potential de-implementation strategies were mapped to the identified determinants and the following were prioritized: 1) non-reflective decision assistance strategies based on reminders and decision support tools for helping clinical decision-making; 2) decision information strategies based on the principles of knowledge dissemination (e.g., corporative diffusion of evidence-based Clinical Practice Guidelines and Pathways for CVD primary prevention); 3) reflective decision-making restructuring strategies (i.e., audit and feedback provided along with intention formation interventions). Conclusions: This study supports the usefulness of the BCW to guide the design and development of de-implementation strategies targeting the determinants of clinicians' decision-making processes to favor the abandonment of low-value practices and the uptake of those recommended for CVD primary prevention in low-risk patients. Further research to evaluate the feasibility and effectiveness of selected strategies is warranted. Clinical trial registration: Sanchez A. De-implementation of Low-value Pharmacological Prescriptions (De-imFAR). ClinicalTrials.gov, Identifier: NCT04022850. Registered July 17, 2019. In: ClinicalTrials.gov. Bethesda (MD): U.S. National Library of Medicine (NLM). Available from: https://www.clinicaltrials.gov/ct2/show/NCT04022850.

2.
Chem Asian J ; 16(4): 315-321, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33372401

RESUMO

We have quantum chemically studied the structure and nature of alkali- and coinage-metal bonds (M-bonds) versus that of hydrogen bonds between A-M and B- in archetypal [A-M⋅⋅⋅B]- model systems (A, B=F, Cl and M=H, Li, Na, Cu, Ag, Au), using relativistic density functional theory at ZORA-BP86-D3/TZ2P. We find that coinage-metal bonds are stronger than alkali-metal bonds which are stronger than the corresponding hydrogen bonds. Our main purpose is to understand how and why the structure, stability and nature of such bonds are affected if the monovalent central atom H of hydrogen bonds is replaced by an isoelectronic alkali- or coinage-metal atom. To this end, we have analyzed the bonds between A-M and B- using the activation strain model, quantitative Kohn-Sham molecular orbital (MO) theory, energy decomposition analysis (EDA), and Voronoi deformation density (VDD) analysis of the charge distribution.

3.
Chemphyschem ; 21(16): 1805-1813, 2020 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-32602631

RESUMO

We have quantum chemically studied the structure and nature of 1-substituted 3-trimethylsilyl cyclobutenes and 2,2-disubstituted-7-trimethylsilyl bycyclo[4.2.0]octa-1(6),3-dienes comparing their reactivity to archetypal 3-substituted cyclobutene systems using density functional theory at M06-2X(PCM)/TZ2P level. We wish to understand how the ring opening reaction is affected by a substituent not directly connected to the σ Carbon-Carbon breaking bond. To this end, we have analyzed the reaction profiles considering second order perturbation energies and natural steric analysis within NBO framework.

4.
J Org Chem ; 84(17): 10593-10605, 2019 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-31348647

RESUMO

Catalytic enantioselective 1,3-dipolar cycloaddition between imino esters and electrophilic alkenes, employing chiral metal complexes derived from copper(I) and silver(I) salts and (S)-DM- or (S)-DTBM-Segphos as ligands produces diastereodivergently exo- or endo-cycloadducts, respectively. The effect of the functional group of the dipolarophile and the fine tuning of the catalyst plays an important role in promoting reverse diastereoselectivities. The origins of experimentally observed enantioselectivity and diastereoselectivity data, as well as the origin of the observed switched endo/exo ratios, are also explained by means of density functional theory calculations.

5.
Chemistry ; 25(38): 9035-9044, 2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-31033030

RESUMO

The development of π-extended phosphorus heterocycles has been rapidly increasing because of their unique optoelectronics properties, which are very often considered to be a consequence of special hyperconjugative interactions. However, the latter interactions have primarily been investigated within the five-membered species, phospholes, and they are often conceptually extrapolated to the rest of π-extended phosphorus heterocycles (including six-membered P-heterocycles) despite evident structural differences. Herein, we report, for the first time, a detailed investigation that sheds light on the hyperconjugative effects of a series of phosphorus heterocyclic systems by means of EDA and NBO calculations within a DFT framework. Our results lay the foundations for the future design of π-extended phosphorus heterocycles with improved optoelectronics properties.

6.
ChemistryOpen ; 8(1): 49-57, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30652065

RESUMO

A detailed computational study of the Diels-Alder reaction of cyclopentadiene with acrylonitrile, methylacrylate and their α-methylated counterparts methacrylonitrile and methyl methacrylate at the M06-2X(PCM)/TZVP level of theory has been performed. We want to understand the excellent exo-selectivities observed experimentally due the presence of this substituent. To this end, analysis of the reaction coordinate by means of activation strain model of chemical reactivity (ASM-distortion interaction model) including solvation effects and NBO second order perturbation energy have been carried out.

7.
J Org Chem ; 83(24): 15101-15109, 2018 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-30457861

RESUMO

All possible demethylation reactions of a diverse family of quaternary alkaloids by means of DFT calculations are here described. We aim to develop a rational model that allows the explanation of the high selectivity observed experimentally and predicts the occurrence of new alkaloid derivatives. To this end, we have performed a detailed analysis of the initial reagents and products. In addition, as a proof of concept, an experimentally unknown demethylation reaction of coralyne has been carried out, thus verifying the reliability of the theoretical model presented here.

8.
Chemistry ; 24(32): 8092-8097, 2018 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-29600546

RESUMO

1,3-Dipolar cycloadditions (1,3-DC) between imino esters (as precursors of N-metallated azomethine ylides) and π-deficient alkenes are promoted by cooperative asymmetric Lewis acid/Brønsted base catalysis. The components of these catalytic pairs are silver salts derived from enantiopure commercially available BINOL-based phosphoric acids and Cinchona alkaloids. Chiral phosphoric silver(I) salts promote HOMO raising of in situ formed 1,3-dipoles, whereas protonated cinchona alkaloids generate a LUMO lowering for the dipolarophiles resulting in a global acceleration of the 1,3-DC. The best results were obtained with BINOL-derived silver phosphate and hydrocinchonine. Matching between both cooperative metallo- and organocatalyst results in an enhanced enantiomeric excess, superior to that reached by both separate components. NOESY experiments and DFT calculations are compatible with a non-covalent interaction (hydrogen bond) between both catalysts, which results in close contacts and mutually coupled chiral environments.

9.
Environ Int ; 115: 133-141, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29567433

RESUMO

Bacteriophages are ubiquitously distributed prokaryotic viruses that are more abundant than bacteria. As a consequence of their life cycle, phages can kidnap part of their host's genetic material, including antibiotic resistance genes (ARGs), which released phage particles transfer in a process called transduction. The spread of ARGs among pathogenic bacteria currently constitutes a serious global health problem. In this study, fresh vegetables (lettuce, spinach and cucumber), and cropland soil were screened by qPCR for ten ARGs (blaTEM, blaCTX-M-1 group, blaCTX-M-9 group, blaOXA-48, blaVIM, mecA, sul1, qnrA, qnrS and armA) in their viral DNA fraction. The presence of ARGs in the phage DNA was analyzed before and after propagation experiments in an Escherichia coli host strain to evaluate the ability of the phage particles to infect a host. ARGs were found in the phage DNA fraction of all matrices, although with heterogeneous values. ARG prevalence was significantly higher in lettuce and soil, and the most common overall were ß-lactamases. After propagation experiments, an increase in ARG densities in phage particles was observed in samples of all four matrices, confirming that part of the isolated phage particles were infectious. This study reveals the abundance of free, replicative ARG-containing phage particles in vegetable matrices and cropland soil. The particles are proposed as vehicles for resistance transfer in these environments, where they can persist for a long time, with the possibility of generating new resistant bacterial strains. Ingestion of these mobile genetic elements may also favor the emergence of new resistances, a risk not previously considered.


Assuntos
Bacteriófagos/genética , Resistência Microbiana a Medicamentos/genética , Microbiologia do Solo , Verduras/virologia , Agricultura , Bacteriófagos/efeitos dos fármacos , Genes Virais/genética
10.
Chem Asian J ; 13(9): 1138-1147, 2018 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-29437289

RESUMO

We have theoretically studied the non-identity SN 2 reactions of Mn OH(n-1) +CH3 Cl (M+ =Li+ , Na+ , K+ , and MgCl+ ; n=0, 1) in the gas phase and in THF solution at the OLYP/6-31++G(d,p) level using polarizable continuum model (PCM) implicit solvation. We want to explore and understand the effect of the metal counterion M+ and solvation on the reaction profile and the stereoselectivity of these processes. To this end, we have explored the potential energy surfaces of the backside (SN 2-b) and frontside (SN 2-f) pathways. To explain the computed trends, we have carried out analyses with an extended activation strain model (ASM) of chemical reactivity that includes the treatment of solvation effects.

11.
Chemphyschem ; 18(23): 3390-3401, 2017 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-28981213

RESUMO

The reactivity of nitrogen mustard mechlorethamine (mec) with purine bases towards formation of mono- (G-mec and A-mec) and dialkylated (AA-mec, GG-mec and AG-mec) adducts has been studied using density functional theory (DFT). To gain a complete overview of DNA-alkylation processes, direct chloride substitution and formation through activated aziridinium species were considered as possible reaction paths for adduct formation. Our results confirm that DNA alkylation by mec occurs via aziridine intermediates instead of direct substitution. Consideration of explicit water molecules in conjunction with polarizable continuum model (PCM) was shown as an adequate computational method for a proper representation of the system. Moreover, Runge-Kutta numerical kinetic simulations including the possible bisadducts have been performed. These simulations predicted a product ratio of 83:17 of GG-mec and AG-mec diadducts, respectively.


Assuntos
DNA/química , Mecloretamina/química , Purinas/química , Alquilação , Teoria Quântica
12.
Chemistry ; 23(69): 17487-17496, 2017 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-28922496

RESUMO

The reaction mechanism associated with the synthesis of phosphorus-based heteropolyaromatic architectures was investigated by DFT calculations at the B3LYP-D3/6-311+G(D) level of theory. The aim of this study is to provide essential information for the future development of improved polycyclic organophosphorus materials. To that end, the impact of the structure of the initial reactant and/or the intermediates structure on the mechanistic features and energetic profiles of the phosphorus cyclization process was studied. Moreover, the reactivity parameters were analyzed in detail in a conceptual DFT framework and the underlying reactivity trends were extracted. Thus, these findings provide important insights for a rational design of polycyclic phosphorus compounds.

13.
J Org Chem ; 82(12): 6298-6312, 2017 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-28534638

RESUMO

Diastereoselective multicomponent reactions of enantioenriched 4-nitroprolinates, obtained by enantiocatalyzed 1,3-dipolar cycloaddition (1,3-DC) of imino esters and nitroalkenes, with α,ß-unsaturated aldehydes and electrophilic alkenes proceed with total periselectivity depending on the structure of the aldehyde employed. This process evolves through a [3 + 2] 1,3-DC when cinnamaldehyde is used in the presence of an azomethine ylide, giving the corresponding highly substituted pyrrolizidines with endo selectivity. However, in the case of the α,ß-unsaturated aldehyde, which contains a hydrogen atom at the γ position, an amine-aldehyde-dienophile (AAD) [4 + 2] cycloaddition takes place by formation of an intermediate 1-amino-1,3-diene, affording highly functionalized cyclohexenes with high endo diastereoselectivity. This AAD process only occurred when a nitro group is bonded to the 4-position of the initial enantiomerically enriched pyrrolidine ring. DFT calculations have been carried out with the aim of explaining this different behavior between pyrrolidines with or without a nitro group, demonstrating the strong nitro-group-dependent periselectivity. The results of these computational studies also support the experimentally obtained absolute configuration of the final adducts.

14.
Chemphyschem ; 17(23): 3932-3947, 2016 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-27642713

RESUMO

The reactivity of cisplatin towards different nucleophiles has been studied by using density functional theory (DFT). Water was considered first to analyze the factors that govern the transformation of cisplatin into more electrophilic aquated species by using an activation-strain model. It was found that the selectivity and reactivity of cisplatin is a delicate trade-off between strain and interaction energies and that the second chloride is a worse leaving group than the first. When similar studies were carried out with imidazole, guanine (G), and adenine (A), it was found that in general the second nucleophilic substitution reactions have lower activation barriers than the first ones. Finally, simulations of the structural restrictions imposed by the DNA scaffold in intra- and interstrand processes showed that the geometries of the reaction products are nonoptimal with respect to the unrestrained A and G nucleophiles, although the energetic cost is not considerable under physiological conditions, which thus permits nucleophilic substitution reactions that lead to highly distorted DNA.


Assuntos
Adenina/química , Cisplatino/química , DNA/química , Guanina/química , Imidazóis/química , Água/química , Teoria Quântica
15.
Org Lett ; 18(12): 2926-9, 2016 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-27268161

RESUMO

The synthesis of constrained spirocycles is achieved effectively by means of 1,3-dipolar cyclodditions employing α-imino γ-lactones as azomethine ylide precursors and nitroalkenes as dipolarophiles. The complex formed by (R,R)-Me-DuPhos 18 and AgF is the most efficient bifunctional catalyst. Final spiro-nitroprolinates cycloadducts are obtained in good to moderate yields and both high diastereo- and enantioselectivities. Density functional theory (DFT) calculations supported the expected absolute configuration as well as other stereochemical parameters.

16.
Beilstein J Org Chem ; 9: 2422-33, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24367409

RESUMO

The 1,3-dipolar cycloaddition between glycine-derived azlactones with maleimides is efficiently catalyzed by the dimeric chiral complex [(S a)-Binap·AuTFA]2. The alanine-derived oxazolone only reacts with tert-butyl acrylate giving anomalous regiochemistry, which is explained and supported by Natural Resonance Theory and Nucleus Independent Chemical Shifts calculations. The origin of the high enantiodiscrimination observed with maleimides and tert-butyl acrylate is analyzed using DFT computed at M06/Lanl2dz//ONIOM(b3lyp/Lanl2dz:UFF) level. Several applications of these cycloadducts in the synthesis of new proline derivatives with a 2,5-trans-arrangement and in the preparation of complex fused polycyclic molecules are described.

17.
Chemistry ; 19(41): 13761-73, 2013 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-23964002

RESUMO

Density functional theory and Car-Parrinello molecular dynamics simulations have been carried out for model aldol reactions involving aggregates of lithium enolates derived from acetaldehyde and acetone. Formaldehyde and acetone have been used as electrophiles. It is found that the geometries of the enolate aggregates are in general determined by the most favorable arrangements of the point charges within the respective Lin On clusters. The reactivity of the enolates follows the sequence monomer≫dimer>tetramer. In lithium aggregates, the initially formed aldol adducts must rearrange to form more stable structures in which the enolate and alkoxide oxygen atoms are within the respective Lin On clusters. Positive cooperative effects, similar to allosteric effects found in several proteins, are found for the successive aldol reactions in aggregates. The corresponding transition structures show in general sofa geometries.

18.
Org Lett ; 15(12): 2902-5, 2013 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-23755738

RESUMO

Chiral complexes formed by phosphoramidites such as (Sa,R,R)-9 and Cu(OTf)2 are excellent catalysts for the general 1,3-dipolar cycloaddition between azomethine ylides and nitroalkenes affording the corresponding tetrasubstituted proline esters mainly as exo-cycloadducts in high er at room temperature. The exo-cycloadducts can be obtained in enantiomerically pure form just after simple recrystallization. DFT calculations support the stereochemical results.


Assuntos
Complexos de Coordenação/química , Cobre/química , Nitrocompostos/química , Compostos Organofosforados/química , Catálise , Reação de Cicloadição , Estrutura Molecular , Estereoisomerismo
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