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1.
Cochrane Database Syst Rev ; 5: CD013204, 2023 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-37204002

RESUMEN

BACKGROUND: The finding that exercise is inversely related to metabolic syndrome after transplantation is novel and suggests that exercise interventions might provide a means for reducing metabolic syndrome complications in liver transplantation recipients. The use of exercise for increasing the physical activity daily levels by more frequent, higher intensity, and longer duration of training sessions, or the sum of these components may be necessary to counteract the effects of the pretransplant reduced activity, metabolic disturbances, and post-transplant immunosuppression, as well as improve physical function and aerobic capacity following liver transplantation. Regular physical activity has a long-term positive impact on recovery following various surgical procedures including transplantation, giving people the opportunity to return to an active life with their families, in society, and in their professional life. Likewise, specific muscle strength training may attenuate the loss of strength after liver transplantation. OBJECTIVES: To evaluate the benefits and harms of exercise-based interventions in adults after liver transplantation compared to no exercise, sham interventions, or another type of exercise. SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search date was 2 September 2022. SELECTION CRITERIA: We included randomised clinical trials in liver transplantation recipients comparing any type of exercise with no exercise, sham interventions, or another type of exercise. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were 1. all-cause mortality; 2. serious adverse events; and 3. health-related quality of life. Our secondary outcomes were 4. a composite of cardiovascular mortality and cardiac disease; 5. aerobic capacity; 6. muscle strength; 7. morbidity; 8. non-serious adverse events; and 9. cardiovascular disease post-transplantation. We assessed risk of bias of the individual trials using RoB 1, described the interventions using the TIDieR checklist, and used GRADE to assess certainty of evidence. MAIN RESULTS: We included three randomised clinical trials. The trials randomised 241 adults with liver transplantation, of which 199 participants completed the trials. The trials were conducted in the USA, Spain, and Turkey. They compared exercise versus usual care. The duration of the interventions ranged from two to 10 months. One trial reported that 69% of participants who received the exercise intervention were adherent to the exercise prescription. A second trial reported a 94% adherence to the exercise programme, with participants attending 45/48 sessions. The remaining trial reported a 96.8% adherence to the exercise intervention during the hospitalisation period. Two trials received funding; one from the National Center for Research Resources (US) and the other from Instituto de Salud Carlos III (Spain). The remaining trial did not receive funding. All trials were at an overall high risk of bias, derived from high risk of selective reporting bias and attrition bias in two trials. The results on all-cause mortality showed a higher risk of death in the exercise group versus the control group, but these results are very uncertain (risk ratio (RR) 3.14, 95% confidence interval (CI) 0.74 to 13.37; 2 trials, 165 participants; I² = 0%; very low-certainty evidence). The trials did not report data on serious adverse events excluding mortality or non-serious adverse events. However, all trials reported that there were no adverse effects associated with exercise. We are very uncertain on whether exercise compared with usual care has a beneficial or harmful effect on health-related quality of life assessed using the 36-item Short Form Physical Functioning subscale at the end of the intervention (mean difference (MD) 10.56, 95% CI -0.12 to 21.24; 2 trials, 169 participants; I² = 71%; very low-certainty evidence). None of the trials reported data on composite of cardiovascular mortality and cardiovascular disease, and cardiovascular disease post-transplantation. We are very uncertain if there are differences in aerobic capacity in terms of VO2peak at the end of the intervention between groups (MD 0.80, 95% CI -0.80 to 2.39; 3 trials, 199 participants; I² = 0%; very low-certainty evidence). We are very uncertain if there are differences in muscle strength at end of the intervention between groups (MD 9.91, 95% CI -3.68 to 23.50; 3 trials, 199 participants; I² = 44%; very low-certainty evidence). One trial measured perceived fatigue using the Checklist Individual Strength (CIST). Participants in the exercise group showed a clinically important lower degree of fatigue perception than participants in the control group, with a mean reduction of 40 points in the CIST (95% CI 15.62 to 64.38; 1 trial, 30 participants).  We identified three ongoing studies. AUTHORS' CONCLUSIONS: Based on very low-certainty evidence in our systematic review, we are very uncertain of the role of exercise training (aerobic, resistance-based exercises, or both) in affecting mortality, health-related quality of life, and physical function (i.e. aerobic capacity and muscle strength) in liver transplant recipients. There were few data on the composite of cardiovascular mortality and cardiovascular disease, cardiovascular disease post-transplantation, and adverse event outcomes. We lack larger trials with blinded outcome assessment, designed according to the SPIRIT statement and reported according to the CONSORT statement.


Asunto(s)
Enfermedades Cardiovasculares , Trasplante de Hígado , Síndrome Metabólico , Humanos , Adulto , Trasplante de Hígado/efectos adversos , Calidad de Vida , Enfermedades Cardiovasculares/prevención & control , Síndrome Metabólico/complicaciones , Terapia por Ejercicio/efectos adversos , Fatiga/etiología
2.
J Chem Phys ; 154(22): 224106, 2021 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-34241192

RESUMEN

Controlling the thermochemistry and kinetics of chemical reactions is a central problem in chemistry. Among factors permitting this control, the substituent effect constitutes a remarkable example. Here, we develop a model accounting for the effect of a substituent on the potential energy surface of the substrate (i.e., substituted molecule). We show that substituents affect the substrate by exerting forces on the nuclei. These substituent-induced forces are able to develop a work when the molecule follows a given reaction path. By applying a simple mechanical model, it becomes possible to quantify this work, which corresponds to the energy variation due to the effect of the substituent along a specific pathway. Our model accounts for the Hammett equation as a particular case, providing the first non-empirical scale for the σ and ρ constants, which, in the developed model, are related to the forces exerted by the substituents (σ) and the reaction path length (ρ), giving their product (σ · ρ) the well-known variation on the reaction energy due to the substituent.

3.
Org Lett ; 20(16): 4902-4906, 2018 08 17.
Artículo en Inglés | MEDLINE | ID: mdl-30070487

RESUMEN

Addition of an organolithium compound to a BN-phenanthrene with embedded B and N atoms is proposed to result in coordination of RLi to the boron atom. This coordination, supported by NMR spectroscopy and DFT calculations, increases the nucleophilicity of the system in the ß position to the N atom and is therefore a useful tool for promoting regioselective C-H functionalization of BN aromatics.

4.
J Am Chem Soc ; 140(1): 264-276, 2018 01 10.
Artículo en Inglés | MEDLINE | ID: mdl-29172489

RESUMEN

Reaction of [Pd(IPr)2] (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) and O2 leads to the surprising discovery that at low temperature the initial reaction product is a highly labile peroxide complex cis-[Pd(IPr)2(η2-O2)]. At temperatures ≳ -40 °C, cis-[Pd(IPr)2(η2-O2)] adds a second O2 to form trans-[Pd(IPr)2(η1-O2)2]. Squid magnetometry and EPR studies yield data that are consistent with a singlet diradical ground state with a thermally accessible triplet state for this unique bis-superoxide complex. In addition to reaction with O2, cis-[Pd(IPr)2(η2-O2)] reacts at low temperature with H2O in methanol/ether solution to form trans-[Pd(IPr)2(OH)(OOH)]. The crystal structure of trans-[Pd(IPr)2(OOH)(OH)] is reported. Neither reaction with O2 nor reaction with H2O occurs under comparable conditions for cis-[Pd(IMes)2(η2-O2)] (IMes = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene). The increased reactivity of cis-[Pd(IPr)2(η2-O2)] is attributed to the enthalpy of binding of O2 to [Pd(IPr)2] (-14.5 ± 1.0 kcal/mol) that is approximately one-half that of [Pd(IMes)2] (-27.9 ± 1.5 kcal/mol). Computational studies identify the cause as interligand repulsion forcing a wider C-Pd-C angle and tilting of the NHC plane in cis-[Pd(IPr)2(η2-O2)]. Arene-arene interactions are more favorable and serve to further stabilize cis-[Pd(IMes)2(η2-O2)]. Inclusion of dispersion effects in DFT calculations leads to improved agreement between experimental and computational enthalpies of O2 binding. A complete reaction diagram is constructed for formation of trans-[Pd(IPr)2(η1-O2)2] and leads to the conclusion that kinetic factors inhibit formation of trans-[Pd(IMes)2(η1-O2)2] at the low temperatures at which it is thermodynamically favored. Failure to detect the predicted T-shaped intermediate trans-[Pd(NHC)2(η1-O2)] for either NHC = IMes or IPr is attributed to dynamic effects. A partial potential energy diagram for initial binding of O2 is constructed. A range of low-energy pathways at different angles of approach are present and blur the distinction between pure "side-on" or "end-on" trajectories for oxygen binding.

5.
J Chem Theory Comput ; 13(2): 727-736, 2017 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-28080052

RESUMEN

Control of absorption spectra in chromophores is a fundamental aspect of many photochemical and photophysical processes as it constitutes the first step of the global photoinduced process. Here we explore the use of mechanical forces to modulate the light absorption process. Specifically, we develop a computational formalism for determining the type of mechanical forces permitting a global tuning of the absorption spectrum. This control extends to the excitation wavelength, absorption bands overlap, and oscillator strength. The determination of these optimal forces permits us to rationally guide the design of new mechano-responsive chromophores. Pyrene has been chosen as the case study for applying these computational tools because significant absorption spectra information is available for the chromophore as well as for different strained derivatives. Additionally, pyrene presents a large flexibility, which makes it a good system to test the inclusion of force probes as the strategy to exert forces on the system.

6.
J Chem Theory Comput ; 11(8): 3740-5, 2015 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-26574456

RESUMEN

Photoreactivity can be influenced by mechanical forces acting over a reacting chromophore. Nevertheless, the specific effect of the external forces in the photoreaction mechanism remains essentially unknown. Conical intersections are key structures in photochemistry, as they constitute the funnels connecting excited and ground states. These crossing points are well known to provide valuable information on molecular photoreactivity, including crucial aspects as potential photoproducts which may be predicted by just inspection of the branching plane vectors. Here, we outline a general framework for understanding the effect of mechanical forces on conical intersections and their implications on photoreactivity. Benzene S1/S0 conical intersection topology can be dramatically altered by applying less than 1 nN force, making the peaked pattern of the intersection become a sloped one, also provoking the transition state in the excited state to disappear. Both effects can be related to an increase in the photostability as the conical intersection becomes more accessible, and its topology in this case favors the recovery of the initial reactant. The results indicate that the presence of external forces acting over a chromophore have to be considered as a potential method for photochemical reactivity control.


Asunto(s)
Benceno/química , Estrés Mecánico , Teoría Cuántica , Termodinámica
7.
Nutr Hosp ; 31(5): 2313-23, 2015 May 01.
Artículo en Español | MEDLINE | ID: mdl-25929408

RESUMEN

The World Health Organization has proposed that health be promoted and protected through the development of an environment that enables sustainable actions at individual, community, national and global levels. Indeed, food-based dietary guidelines, i.e., food pyramids, have been developed in numerous countries to disseminate nutritional information to the general population. However, wider recommendations are needed, with information on an active, healthy lifestyle, not just healthy eating. The objective of the present work is to propose a three-dimensional pyramid as a new strategy for promoting adequate nutrition and active healthy lifestyles in a sustainable way. Indeed, the Iberomerican Nutrition Foundation (FINUT) pyramid of healthy lifestyles has been designed as a tetrahedron, its three lateral faces corresponding to the binomials food and nutrition, physical activity and rest, and education and hygiene. Each lateral face is divided into two triangles. These faces show the following: 1. food-based guidelines and healthy eating habits as related to a sustainable environment; 2. recommendations for rest and physical activity and educational, social and cultural issues; 3. selected hygiene and educational guidelines that, in conjunction with the other two faces, would contribute to better health and provide measures to promote environmental sustainability. The new FINUT pyramid is addressed to the general population of all ages and should serve as a guide for living a healthy lifestyle within a defined social and cultural context. It includes an environmental and sustainability dimension providing measures that should contribute to the prevention of non-communicable chronic diseases.


La Organización Mundial de la Salud (World Health Organization: OMS) ha propuesto que la salud debe ser promovida y protegida a través del desarrollo de un medio ambiente que permita acciones sostenibles a nivel individual, comunitario, nacional y global. De hecho, se han desarrollado en numerosos países guías alimentarias (por ejemplo, las pirámides de alimentos) para divulgar información nutricional a la población general. Sin embargo, se necesitan recomendaciones más amplias sobre estilos activos de vida saludable, no restringidos únicamente a los alimentos. El objetivo de este trabajo es la propuesta de una pirámide tridimensional como una nueva estrategia para promover una nutrición adecuada y estilos activos de vida saludable de manera sostenible. En efecto, se ha diseñado la pirámide FINUT (Fundación Iberoamericana de Nutrición) sobre estilos de vida saludable como un tetraedro cuyas tres caras laterales se corresponden a los binomios alimentación y nutrición, actividad física y descanso, y educación e higiene. Cada cara lateral está dividida en dos triángulos. Estas caras muestran lo siguiente: 1. guías alimentarias y hábitos de alimentación saludable en relación a un medio ambiente sostenible; 2. recomendaciones sobre descanso y actividad física y temas de educación, sociales y culturales relacionados; 3. guías seleccionadas sobre higiene y educación que, en conjunto con las otras dos caras, puedan contribuir a una mejor salud para la población en un planeta sostenible. La nueva pirámide FINUT se dirige a la población general de todas las edades y debería servir como una guía para un estilo de vida saludable en un contexto social y cultural definido. La pirámide incluye una dimensión ambiental y sostenible que proporciona medidas para contribuir a la prevención de las enfermedades crónicas no transmisibles.


Asunto(s)
Dieta , Guías como Asunto , Estilo de Vida , Política Nutricional , Algoritmos , Conducta Alimentaria , Promoción de la Salud , Humanos , Organización Mundial de la Salud
8.
Adv Nutr ; 5(3): 358S-67S, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24829489

RESUMEN

The WHO has proposed that health be promoted and protected through the development of an environment that enables sustainable actions at individual, community, national, and global levels. Indeed, food-based dietary guidelines, i.e., food pyramids, have been developed in numerous countries to disseminate nutritional information to the general population. However, wider recommendations are needed, with information on an active healthy lifestyle, not just healthy eating. The objective of the present work is to propose a three-dimensional pyramid as a new strategy for promoting adequate nutrition and active healthy lifestyles in a sustainable way. Indeed, the Iberoamerican Nutrition Foundation (FINUT) pyramid of healthy lifestyles has been designed as a tetrahedron, with its 3 lateral faces corresponding to the facets of food and nutrition, physical activity and rest, and education and hygiene. Each lateral face is divided into 2 triangles. These faces show the following: 1) food-based guidelines and healthy eating habits as related to a sustainable environment; 2) recommendations for rest and physical activity and educational, social, and cultural issues; and 3) selected hygiene and educational guidelines that, in conjunction with the other 2 faces, would contribute to better health for people in a sustainable planet. The new FINUT pyramid is addressed to the general population of all ages and should serve as a guide for living a healthy lifestyle within a defined social and cultural context. It includes an environmental and sustainability dimension providing measures that should contribute to the prevention of noncommunicable chronic diseases.


Asunto(s)
Conductas Relacionadas con la Salud , Promoción de la Salud , Estilo de Vida , Política Nutricional , Enfermedad Crónica , Humanos , Factores Socioeconómicos
9.
J Chem Theory Comput ; 10(1): 312-23, 2014 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-26579912

RESUMEN

A new methodology to calculate efficiently the absorption spectrum of a single molecule when subjected to mechanical stress is presented. As example, the developed methodology was applied to cis- and trans-azobenzene, commonly used as photoswitch in a wide variety of applications. The results show that both (1)(n,π*) and (1)(π,π*) optical transitions can be efficiently modulated by applying an external force. A structural analysis was performed to evaluate the role of each internal coordinate in the excitation process, taking into account the application of external forces at different positions of azobenzene. Moreover, stress-strain curves were calculated in order to determine the maximum applicable forces within the elastic region, highlighting notable differences between the mechanical properties of cis- and trans-azobenzene conformers. The optomechanical work obtained by elongation and compression steps is calculated for a single azobenzene molecule and compared to available experimental data. Finally, the implications derived from the application of azobenzene as main chain component of a linear polymer acting as a photoinduced motor are discussed.

10.
J Phys Chem A ; 116(26): 7039-49, 2012 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-22667985

RESUMEN

The photochemistry and photophysics of a series of S-nitrosothiols (RSNOs) have been studied computationally. The photocleavage mechanism of the model compound CH(3)SNO to release CH(3)S· and ·NO was studied at the CASPT2 level resulting in a barrierless process when irradiating in the visible region (S(1)), in the near UV region (S(2)) and for photosensitized (T(1)) reaction. The absorption energy required to initiate photocleavage was calculated at the CASPT2 and B3P86 levels showing the possibility of the modulation of NO release by RSNO photoactivation as a function of the substituent R. Good correlations between the wavelengths of the lowest energy (1)(n,π*) and (1)(π,π*) transitions of aryl S-nitrosothiols and the corresponding Hammett constants of the substituents have been obtained.


Asunto(s)
Óxido Nítrico/química , Procesos Fotoquímicos , S-Nitrosotioles/química , Modelos Moleculares , Conformación Molecular , Termodinámica
11.
J Chem Theory Comput ; 8(9): 3293-302, 2012 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-26605736

RESUMEN

A methodology for the prediction of excitation energies for substituted chromophores on the basis of ground state structures has been developed. The formalism introduces the concept of "structural substituent excitation energy effect" for the rational prediction and quantification of the substituent effect in the excitation energy of a chromophore to an excited electronic state. This effect quantifies exclusively the excitation energy variation due to the structural changes of the chromophore induced by the substituent. Therefore, excitation bathochromic and hypsochromic shifts of substituted chromophores can be predicted on the basis of known ground and excited potential energy surfaces of a reference unsubstituted chromophore, together with the ground state minimum energy structure of the substituted chromophore. This formalism can be applied if the chemical substitution does not affect the nature of the electronic excitation, where the substituent effect can be understood as a force acting on the chromophore and provoking a structural change on it. The developed formalism provides a useful tool for quantitative and qualitative determination of the excitation energy of substituted chromophores and also for the analysis and determination of the structural changes affecting this energy. The proposed methodology has been applied to the prediction of the excitation energy to the first bright state of several S-nitrosothiols using the potential energy surfaces of methyl-S-nitrosothiol as a reference unsubstituted chromophore.

12.
ARS méd. (Santiago) ; 16(16): 33-44, 2008.
Artículo en Español | LILACS | ID: lil-515879

RESUMEN

Se aborda el tema desde la perspectiva del Derecho Constitucional, refiriéndose, por una parte, al carácter de personas que nuestra Carta Fundamental reconoce a los niños y adolescentes; sobre la base de la dignidad humana, los niños son personas titulares de los derechos garantizados por la Constitución y en los tratados internacionales vigentes y, en consecuencia, gozan de la dignidad que se reconoce por nuestra Carta Fundamental como inherente a todas las personas; el autor desarrolla algunas ideas en torno del principio consistente en que debe considerarse siempre el interés superior del niño, para terminar aplicando esas reflexiones al ámbito de la atención en la salud de los niños y adolescentes.


We present some thoughts about the challenges of the attention in the health of children and adolescents, from the point of view of the constitutional right. Our basic Charter recognizes the child as a person, with the same rights as an adult. This recognition stems from the fact that the full dignity as a human being is given to a child, and adolescent or an adult. The recognition afforded by our Charter is in line with International Treaties. The author presents some ideas on the principle of the best interest of the child and applies these ideas to the provision of health to children and adolescents.


Asunto(s)
Humanos , Adolescente , Niño , Salud del Adolescente , Salud Infantil , Jurisprudencia , Defensa del Niño/ética , Defensa del Niño/legislación & jurisprudencia , Atención a la Salud , Derechos del Paciente
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