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1.
PLoS One ; 17(8): e0271926, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36001643

RESUMEN

Both psychedelic drug experiences and near-death experiences can occasion changes in perspectives on death and dying, but there have been few direct comparisons of these phenomena. This study directly compared psychedelic occasioned and non-drug experiences which altered individuals' beliefs about death. Individuals who reported an experience that altered their beliefs about death occasioned by either a psychedelic drug or a near-death or other non-ordinary experience completed an online survey. Circumstances of the experience, mystical and near-death subjective features, changes in attitudes about death, and other persisting effects were evaluated. The study sample (n = 3192) included five groups: non-drug near-death or other non-ordinary experiences (n = 933), and drug experiences occasioned by lysergic acid diethylamide (LSD) (n = 904), psilocybin (n = 766), ayahuasca (n = 282), or N,N-dimethyltryptamine (DMT) (n = 307). Analyses of differences in experiences were adjusted statistically for demographic differences between groups. Compared to the psychedelic groups, the non-drug group was more likely to report being unconscious, clinically dead, and that their life was in imminent danger. The groups were remarkably similar in the reported changes in death attitudes attributed to the experience, including a reduced fear of death and high ratings of positive persisting effects and personal meaning, spiritual significance, and psychological insight. Although both psychedelic and non-drug participants showed robust increases on standardized measures of mystical and near-death experiences, these measures were significantly greater in the psychedelic participants. Non-drug participants were more likely to rate their experiences as the single most meaningful of their lives. Comparing across psychedelic substances, ayahuasca and DMT groups tended report stronger and more positive enduring consequences of the experience than the psilocybin and LSD groups, which were largely indistinguishable. These data provide a detailed characterization and comparison of psychedelic occasioned and non-drug experiences that changed attitudes about death and suggest the importance of future prospective psychedelic administration studies.


Asunto(s)
Banisteriopsis , Alucinógenos , Humanos , Dietilamida del Ácido Lisérgico , N,N-Dimetiltriptamina , Trastornos Fóbicos , Psilocibina
2.
Sci Rep ; 11(1): 13697, 2021 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-34211063

RESUMEN

Microbial keratitis occurs from the infection of the cornea by fungi and or bacteria. It remains one of the most common global causes of irreversible blindness accounting for 3.5% (36 million) of blind people as of 2015. This paper looks at the use of a bacteria binding polymer designed to bind Staphylococcus aureus and remove it from the corneal surface. Mechanical unbinding measurements were used to probe the interactions of a thermo-active bacteria-binding polymer, highly-branched poly(N-isopropyl acrylamide), functionalised with modified vancomycin end groups (HB-PNIPAM-Van) to bacteria placed on rabbit corneal surfaces studied ex-vivo. This was conducted during sequential temperature phase transitions of HB-PNIPAM-Van-S. aureus below, above and below the lower critical solution temperature (LCST) in 3 stages, in-vitro, using a novel micro-bead force spectroscopy (MBFS) approach via atomic force microscopy (AFM). The effect of temperature on the functionality of HB-PNIPAM-Van-S. aureus showed that the polymer-bacteria complex reduced the work done in removing bacterial aggregates at T > LCST (p < 0.05), exhibiting reversibility at T < LCST (p < 0.05). At T < LCST, the breaking force, number of unbinding events, percentage fitted segments in the short and long range, and the percentage of unbinding events occurring in the long range (> 2.5 µm) increased (p < 0.05). Furthermore, the LCST phase transition temperature showed 100 × more unbinding events in the long-range z-length (> 2.5 µm) compared to S. aureus aggregates only. Here, we present the first study using AFM to assess the reversible mechanical impact of a thermo-active polymer-binding bacteria on a natural corneal surface.


Asunto(s)
Resinas Acrílicas/química , Córnea/microbiología , Microscopía de Fuerza Atómica/métodos , Staphylococcus aureus/aislamiento & purificación , Vancomicina/análogos & derivados , Animales , Transición de Fase , Conejos , Temperatura
3.
Langmuir ; 29(22): 6597-605, 2013 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-23642168

RESUMEN

A comprehensive study of the adsorption of the compounds involved in the reaction of dehydration of fructose to 5-hydroxymethyl furfural (HMF) on the zeolite H-BEA with SiO2/Al2O3 = 18 has been carried out. Furthermore, a method for the estimation of the real adsorption loading from the experimentally measured excess adsorption is developed and applied to calculate the adsorption isotherms both in the case of single-solute and multisolute mixtures. It was found that zeolite H-BEA adsorbs HMF and levulinic acid from water mixtures to greater extent than sugars and formic acid, which prefer to partition in the aqueous phase. HMF and levulinic acid adsorption isotherms could be fitted in a Redlich-Peterson isotherm model, while the adsorption of formic acid is better fitted using the Freundlich model and sugars via the Henry model. Adsorption loadings decreased with increasing temperature (0, 25, and 40 °C), which is characteristic of an exothermic process. From the temperature dependence of the isotherms, the limiting heat of adsorption at zero coverage was determined using van't Hoff equation. Given the importance and the complexity of multicomponent systems, several experiments of adsorption of multisolute solutions have been carried out. In most of the cases, the ideal adsorbed solution theory (IAST) has been proven to satisfactorily predict adsorption from multisolute mixtures using as input the single-solute isotherms.

4.
Langmuir ; 27(19): 11990-8, 2011 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-21861473

RESUMEN

Materials were synthesized for the recovery of n-butanol from dilute aqueous solutions, as may be useful for applications in biofuel-water separations. These materials are composed of hydrophobic, cavity-containing calixarenes covalently bound directly to porous, hydrophilic silica supports through a Si linker atom rather than a flexible organic linker, as is common, at surface coverages of up to ∼0.25 calixarenes/nm(2) (∼250 µmol calix/g matl). The calixarene ring size, upper rim groups, bridging group (calixarene vs thiacalixarene), and surface density were varied. The materials were characterized by NMR, UV-vis, and TGA. The absolute butanol uptake reached ∼0.16 mmol butanol per gram of material at equilibrium concentrations below 0.12 M and increased monotonically with the calixarene surface density. The background adsorption onto the silica surface was small at high calixarene loading. At 298 K, the free energy of adsorption in the calixarene cavities became more favorable by 3 kJ/mol as the surface area of the hydrophobic calixarene upper rim groups increased from H to methyl to tert-butyl, consistent with adsorption driven by van der Waals interactions. A thiacalix[4]arene-SiO(2) material, containing polarizable sulfur bridges and a larger, more conformationally mobile calixarene structure, had slightly stronger adsorption still. All materials except this thiacalixarene exhibited fully reversible adsorption into solution. As a representative material, the adsorption of n-butanol from aqueous solution at a tert-butylcalix[4]arene site was accompanied by a negligible enthalpy change but a small, favorable entropy change of +50 ± 20 J/mol/K, indicating that adsorption is driven by desolvation. Butanol desorbed from tert-butylcalix[4]arene materials at ∼150 °C into the gas phase, well within the range of stability of calixarenes (<300 °C), indicating that these materials have promise as regenerable adsorbents.


Asunto(s)
1-Butanol/química , Calixarenos/química , Adsorción , Estructura Molecular , Tamaño de la Partícula , Soluciones , Estereoisomerismo , Propiedades de Superficie , Termodinámica , Agua/química
5.
Neurology ; 71(23): 1907-13, 2008 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-18971443

RESUMEN

The US health care crisis is of great concern to American neurologists. The United States has the world's most expensive health care system yet one-sixth of Americans are uninsured. The cost and volume of procedures is expanding, while reimbursement for office visits is declining. Pharmaceutical costs, durable goods, and home health care are growing disproportionately to other services. Carriers spend more for their own administration and profit than on payments to physicians. This first article on the US health care system identifies problems and proposes solutions, many of which are championed by the American Academy of Neurology through its legislative and regulatory committees.


Asunto(s)
Atención a la Salud , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Seguro de Costos Compartidos , Atención a la Salud/economía , Atención a la Salud/métodos , Atención a la Salud/estadística & datos numéricos , Femenino , Humanos , Lactante , Masculino , Mala Praxis/estadística & datos numéricos , Registros Médicos/estadística & datos numéricos , Persona de Mediana Edad , Médicos , Dinámica Poblacional , Mecanismo de Reembolso , Estados Unidos , Adulto Joven
6.
Neurology ; 71(23): 1914-20, 2008 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-18971444

RESUMEN

In the search for a universal, high quality, affordable health care system, Americans seek to identify and correct a series of current problems. In part one of this two-part series, we presented problems along with some suggested actions. This second part presents other health care systems in Europe and Canada. These different systems provide universal care and at a lower cost than in the United States. Further domestic proposals are presented from the Massachusetts plan and positions from US presidential candidates. These systems and proposals raise ideas about possible changes in the US health care system. Knowledge of these issues and other health care systems will help foster a meaningful dialog about changes in the US health care system.


Asunto(s)
Atención a la Salud , Reforma de la Atención de Salud , Política de Salud , Modelos Organizacionales , Programas Nacionales de Salud/organización & administración , Planificación en Salud Comunitaria , Atención a la Salud/economía , Atención a la Salud/métodos , Atención a la Salud/estadística & datos numéricos , Apoyo a la Planificación en Salud , Humanos , Programas Nacionales de Salud/economía , Estados Unidos
7.
Lancet ; 360(9342): 1280-6, 2002 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-12414202

RESUMEN

BACKGROUND: Young people with physical disabilities often have difficulty attaining independence in adult life and consequently need lifelong support from parents and from health-care and social-care services. There are concerns about the organisation and cost-effectiveness of such services and their ability to meet the independence training and serious health needs of these young people. Our aim was to compare a young adult team (YAT) approach with the ad hoc service approach in four locations in England, in terms of their ability to enhance the participation in society of these young people and their cost. METHODS: We did a retrospective cohort study, in which we interviewed 254 physically disabled young people. 124 healthy controls were given a questionnaire. We interviewed with standardised measures and used logistic regression analysis to test for effects of ad hoc and YAT services. The Mantel-Haenszel chi2 statistic was used to test for differences in resource use between areas in which the YAT and ad hoc services were available. FINDINGS: The absence of pain, fatigue, and stress increased the odds of participation two-fold to four-fold. After adjustment for these factors, young people cared for by multidisciplinary YAT teams were 2.54 times (95% CI 1.30-4.98) more likely than those who used ad hoc services to participate in society. Resource use did not differ between the two service types. INTERPRETATION: A YAT approach costs no more to implement than an ad hoc approach, and is more likely to enhance participation in society of young people with physical disabilities.


Asunto(s)
Personas con Discapacidad/rehabilitación , Grupo de Atención al Paciente , Adolescente , Adulto , Estudios de Cohortes , Femenino , Humanos , Masculino , Análisis de Regresión , Estudios Retrospectivos , Encuestas y Cuestionarios
9.
Muscle Nerve ; 24(9): 1134-41, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11494265

RESUMEN

Previous studies demonstrated age- and height-related slowing of nerve conduction velocity (NCV) and reduction in nerve response amplitude. Unfortunately, many studies examined discontinuous populations, preventing regression analysis. The correlation coefficients of available studies vary widely, preventing clear conclusions. We retrospectively examined 3969 clinically normal subjects ranging in age from 20 to 95 years from a total of 22,420 electrodiagnostic studies done between 1986 and 1998. The correlation of NCV with height was stronger than with age. Regression equations using both factors account for 12--27% of the variance. Responses were seen in the majority of patients aged 70 years and older, but the percentage of normals who had no response increased with advancing age. Age was strongly inversely correlated with the amplitudes of both sensory and motor responses, accounting for 7--16% of the variance. Regression equations using both height and age improved this correlation, accounting for 7--22% of the variance. Therefore, both height and age must be taken into consideration when normal values are developed.


Asunto(s)
Envejecimiento/fisiología , Estatura/fisiología , Electrofisiología/normas , Conducción Nerviosa/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Humanos , Persona de Mediana Edad , Neuronas Motoras/fisiología , Enfermedades del Sistema Nervioso/diagnóstico , Enfermedades del Sistema Nervioso/fisiopatología , Neuronas Aferentes/fisiología , Nervio Peroneo/citología , Nervio Peroneo/fisiología , Estudios Retrospectivos , Nervio Sural/citología , Nervio Sural/fisiología , Nervio Cubital/citología , Nervio Cubital/fisiología
10.
Brain Inj ; 15(2): 149-65, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11260765

RESUMEN

The purpose of this pilot study was to investigate the lack of knowledge and misconceptions concerning brain injury, as perceived by those with experience of the condition. Using a qualitative research method, 19 semi-structured interviews were conducted with brain-injured individuals, caregivers and professionals who provide social rehabilitation after brain injury. Interviews were analysed using Interpretative Phenomenological Analysis. According to participants, inaccurate and inadequate knowledge about brain injury is common among the general public and among health professionals without expertise in the field of brain injury. The major themes that emerged from the analysis were: inaccurate beliefs about recovery time and possible extent of recovery from brain injury; lack of awareness of the diversity ofproblems it can cause, particularly the existence of behavioural and cognitive sequelae; misconceptions about the capabilities of brain-injured people depending on the visibility or invisibility of their disability: and misidentification of brain-injured individuals as mentally ill or learning disabled. Results are discussed in terms of a theory of illness cognition. Posibilities for further research are discussed, and it is concluded that the results of this study could help guide future information provision to all who may come into contact with brain injury.


Asunto(s)
Actitud Frente a la Salud , Lesiones Encefálicas , Cognición , Personal de Salud , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Recuperación de la Función
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