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1.
Phys Chem Chem Phys ; 23(10): 5992-5998, 2021 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-33666602

RESUMEN

The LiNi0.33Mn0.33Co0.33O2 compound is one of the most interesting cathode materials for Li-ion batteries. Li diffusion in this material directly influences charging/discharging times (and consequently power densities), maximum capacities, stress formation and possible side reactions. In the present study Li tracer self-diffusion is investigated in polycrystalline sintered bulk samples with an average grain size of about 50 nm in the temperature range between 110 and 350 °C. For analysis, stable 6Li tracers are used in combination with Secondary Ion Mass Spectrometry (SIMS). The diffusivities can be described by the Arrhenius law with an activation enthalpy of (0.85 ± 0.03) eV, which is interpreted as the migration energy of a single Li vacancy. Lithium diffuses via structural vacancies whose concentration is fixed by a Li deficiency of about 10%. An extrapolation of the diffusivities to room temperature gives significantly lower values than the diffusivities obtained by electrochemical measurements in literature.

2.
BMC Genomics ; 13: 99, 2012 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-22429863

RESUMEN

BACKGROUND: Sugar beet (Beta vulgaris sp. vulgaris) crops account for about 30% of world sugar. Sugar yield is compromised by reproductive growth hence crops must remain vegetative until harvest. Prolonged exposure to cold temperature (vernalization) in the range 6 °C to 12 °C induces reproductive growth, leading to bolting (rapid elongation of the main stem) and flowering. Spring cultivation of crops in cool temperate climates makes them vulnerable to vernalization and hence bolting, which is initiated in the apical shoot meristem in processes involving interaction between gibberellin (GA) hormones and vernalization. The underlying mechanisms are unknown and genome scale next generation sequencing approaches now offer comprehensive strategies to investigate them; enabling the identification of novel targets for bolting control in sugar beet crops. In this study, we demonstrate the application of an mRNA-Seq based strategy for this purpose. RESULTS: There is no sugar beet reference genome, or public expression array platforms. We therefore used RNA-Seq to generate the first reference transcriptome. We next performed digital gene expression profiling using shoot apex mRNA from two sugar beet cultivars with and without applied GA, and also a vernalized cultivar with and without applied GA. Subsequent bioinformatics analyses identified transcriptional changes associated with genotypic difference and experimental treatments. Analysis of expression profiles in response to vernalization and GA treatment suggested previously unsuspected roles for a RAV1-like AP2/B3 domain protein in vernalization and efflux transporters in the GA response. CONCLUSIONS: Next generation RNA-Seq enabled the generation of the first reference transcriptome for sugar beet and the study of global transcriptional responses in the shoot apex to vernalization and GA treatment, without the need for a reference genome or established array platforms. Comprehensive bioinformatic analysis identified transcriptional programmes associated with different sugar beet genotypes as well as biological treatments; thus providing important new opportunities for basic scientists and sugar beet breeders. Transcriptome-scale identification of agronomically important traits as used in this study should be widely applicable to all crop plants where genomic resources are limiting.


Asunto(s)
Beta vulgaris/genética , Frío , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Giberelinas/farmacología , Reguladores del Crecimiento de las Plantas/farmacología , Transcriptoma , Biología Computacional/métodos , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Redes Reguladoras de Genes , Genotipo , Anotación de Secuencia Molecular , Datos de Secuencia Molecular , Brotes de la Planta/genética , ARN Mensajero/química , ARN de Planta/química , Análisis de Secuencia de ARN
3.
Lancet Diabetes Endocrinol ; 6(5): 382-391, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29519744

RESUMEN

BACKGROUND: We aimed to assess 24-month outcomes of wearing an organic light-emitting sleep mask as an intervention to treat and prevent progression of non-central diabetic macular oedema. METHODS: CLEOPATRA was a phase 3, single-blind, parallel-group, randomised controlled trial undertaken at 15 ophthalmic centres in the UK. Adults with non-centre-involving diabetic macular oedema were randomly assigned (1:1) to wearing either a light mask during sleep (Noctura 400 Sleep Mask, PolyPhotonix Medical, Sedgefield, UK) or a sham (non-light) mask, for 24 months. Randomisation was by minimisation generated by a central web-based computer system. Outcome assessors were masked technicians and optometrists. The primary outcome was the change in maximum retinal thickness on optical coherence tomography (OCT) at 24 months, analysed using a linear mixed-effects model incorporating 4-monthly measurements and baseline adjustment. Analysis was done using the intention-to-treat principle in all randomised patients with OCT data. Safety was assessed in all patients. This trial is registered with Controlled-Trials.com, number ISRCTN85596558. FINDINGS: Between April 10, 2014, and June 15, 2015, 308 patients were randomly assigned to wearing the light mask (n=155) or a sham mask (n=153). 277 patients (144 assigned the light mask and 133 the sham mask) contributed to the mixed-effects model over time, including 246 patients with OCT data at 24 months. The change in maximum retinal thickness at 24 months did not differ between treatment groups (mean change -9·2 µm [SE 2·5] for the light mask vs -12·9 µm [SE 2·9] for the sham mask; adjusted mean difference -0·65 µm, 95% CI -6·90 to 5·59; p=0·84). Median compliance with wearing the light mask at 24 months was 19·5% (IQR 1·9-51·6). No serious adverse events were related to either mask. The most frequent adverse events related to the assigned treatment were discomfort on the eyes (14 with the light mask vs seven with the sham mask), painful, sticky, or watery eyes (14 vs six), and sleep disturbance (seven vs one). INTERPRETATION: The light mask as used in this study did not confer long-term therapeutic benefit on non-centre-involving diabetic macular oedema and the study does not support its use for this indication. FUNDING: The Efficacy and Mechanism Evaluation Programme, a Medical Research Council and National Institute for Health Research partnership.


Asunto(s)
Adaptación a la Oscuridad , Retinopatía Diabética/complicaciones , Edema Macular/prevención & control , Fototerapia , Anciano , Progresión de la Enfermedad , Femenino , Humanos , Edema Macular/complicaciones , Edema Macular/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Fototerapia/instrumentación , Fototerapia/métodos , Retina/diagnóstico por imagen , Retina/patología , Tomografía de Coherencia Óptica , Resultado del Tratamiento
4.
Trials ; 15: 458, 2014 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-25417120

RESUMEN

BACKGROUND: This study will evaluate hypoxia, as a novel concept in the pathogenesis of diabetic macular oedema (DMO). As the oxygen demand of the eye is maximum during dark-adaptation, we hypothesize that wearing light-masks during sleep will cause regression and prevent the development and progression of DMO. The study protocol comprises both an efficacy and mechanistic evaluation to test this hypothesis. METHOD/DESIGN: This is a phase III randomised controlled single-masked multicentre clinical trial to test the clinical efficacy of light-masks at preventing dark-adaptation in the treatment of non-central DMO. Three hundred patients with non-centre-involving DMO in at least one eye will be randomised 1:1 to light-masks and control masks (with no light) to be used during sleep at night for a period of 24 months. The primary outcome is regression of non-central oedema by assessing change in the zone of maximal retinal thickness at baseline on optical coherence tomography (SD-OCT). Secondary outcomes will evaluate the prevention of development and progression of DMO by assessing changes in retinal thickness in different regions of the macula, macular volume, refracted visual acuity and level of retinopathy. Safety parameters will include sleep disturbance. Adverse events and measures of compliance will be assessed over 24 months. Participants recruited to the mechanistic sub-study will have additional retinal oximetry, multifocal electroretinography (ERG) and microperimetry to evaluate the role of hypoxia by assessing and comparing changes induced by supplemental oxygen and the light-masks at 12 months. DISCUSSION: The outcomes of this study will provide insight into the pathogenesis of DMO and provide evidence on whether a simple, non-invasive device in the form of a light-mask can help prevent the progression to centre-involving DMO and visual impairment in people with diabetes.


Asunto(s)
Adaptación a la Oscuridad , Retinopatía Diabética/terapia , Edema Macular/terapia , Máscaras , Fototerapia/instrumentación , Proyectos de Investigación , Protocolos Clínicos , Retinopatía Diabética/diagnóstico , Retinopatía Diabética/metabolismo , Retinopatía Diabética/fisiopatología , Electrorretinografía , Inglaterra , Diseño de Equipo , Humanos , Edema Macular/diagnóstico , Edema Macular/metabolismo , Edema Macular/fisiopatología , Oximetría , Consumo de Oxígeno , Fototerapia/efectos adversos , Valor Predictivo de las Pruebas , Método Simple Ciego , Factores de Tiempo , Tomografía de Coherencia Óptica , Resultado del Tratamiento , Agudeza Visual , Pruebas del Campo Visual , Gales
5.
Nat Biotechnol ; 32(4): 356-63, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24633243

RESUMEN

If immunized with an antigen of interest, transgenic mice with large portions of unrearranged human immunoglobulin loci can produce fully human antigen-specific antibodies; several such antibodies are in clinical use. However, technical limitations inherent to conventional transgenic technology and sequence divergence between the human and mouse immunoglobulin constant regions limit the utility of these mice. Here, using repetitive cycles of genome engineering in embryonic stem cells, we have inserted the entire human immunoglobulin variable-gene repertoire (2.7 Mb) into the mouse genome, leaving the mouse constant regions intact. These transgenic mice are viable and fertile, with an immune system resembling that of wild-type mice. Antigen immunization results in production of high-affinity antibodies with long human-like complementarity-determining region 3 (CDR3H), broad epitope coverage and strong signatures of somatic hypermutation. These mice provide a robust system for the discovery of therapeutic human monoclonal antibodies; as a surrogate readout of the human antibody response, they may also aid vaccine design efforts.


Asunto(s)
Anticuerpos Monoclonales/genética , Ingeniería Genética/métodos , Región Variable de Inmunoglobulina/genética , Transgenes/genética , Secuencia de Aminoácidos , Animales , Anticuerpos Monoclonales/inmunología , Linfocitos B/inmunología , Linfocitos B/fisiología , Cromosomas Artificiales Bacterianos/genética , Femenino , Humanos , Masculino , Ratones , Ratones Transgénicos , Datos de Secuencia Molecular
6.
Eur J Pain ; 13(5): 524-32, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-18691920

RESUMEN

The effect on human skin of over-exposure to solar ultraviolet radiation (UVR) has been well described. The erythema produced is commonly referred to as 'sunburn'. Recently UVR induced inflammation has been utilised as a human model of sub-acute pain. Our aim was to characterise the sensory phenotype of UVB inflammation in human volunteers. We delivered UVB to small areas of volar forearm skin in healthy volunteers and found that the degree of inflammation and concomitant increase in sensitivity to cutaneous stimuli were UVB dose and time dependent. We directly compared UVB induced inflammation and the more established thermal burn and topical capsaicin pain models. UVB inflammation produced precisely demarcated erythematous lesions without secondary flare. Both thermal burns and topical capsaicin produced large areas of flare, indistinguishable in character from the primary lesions. Moreover, UVB inflammation induced large reductions in mechanical pain threshold restricted to the primary lesion site, whereas the more established inflammatory pain models produced not only primary hypersensitivity but also significant areas of secondary mechanical hypersensitivity. Taken together these findings suggest that UVB inflammation, at least using moderate doses produces sensory changes primarily by sensitising peripheral pain processing in the relative absence of alterations in central pain processing.


Asunto(s)
Hiperalgesia/fisiopatología , Inflamación/fisiopatología , Piel/fisiopatología , Quemadura Solar/fisiopatología , Rayos Ultravioleta/efectos adversos , Adulto , Quemaduras/etiología , Quemaduras/patología , Quemaduras/fisiopatología , Capsaicina/efectos adversos , Femenino , Calor/efectos adversos , Humanos , Hiperalgesia/etiología , Hiperalgesia/patología , Inflamación/etiología , Inflamación/patología , Masculino , Modelos Neurológicos , Nociceptores/fisiología , Nociceptores/efectos de la radiación , Umbral del Dolor/fisiología , Umbral del Dolor/efectos de la radiación , Dosis de Radiación , Células Receptoras Sensoriales/fisiología , Células Receptoras Sensoriales/efectos de la radiación , Fármacos del Sistema Sensorial/efectos adversos , Piel/patología , Piel/efectos de la radiación , Quemadura Solar/etiología , Quemadura Solar/patología , Factores de Tiempo , Adulto Joven
7.
J Med Humanit Bioeth ; 6(1): 28-37, 1985.
Artículo en Inglés | MEDLINE | ID: mdl-11658642

RESUMEN

KIE: Standard arguments for and against sex preselection, i.e., choosing the sex of one's child prior to conception, are reviewed. Sex preselection is then considered from a feminist perspective which attempts to maximize clusters of values rather than unnecessarily trying to choose the most important value. From this perspective, a reasonable stance would be not to opt for a girl or a boy, but to plan and welcome each child.^ieng


Asunto(s)
Preselección del Sexo , Valores Sociales , Toma de Decisiones , Servicios de Planificación Familiar , Femenino , Humanos , Cooperación Internacional , Internacionalidad , Hombres , Métodos , Prejuicio , Riesgo , Medición de Riesgo , Análisis para Determinación del Sexo , Cambio Social , Mujeres , Derechos de la Mujer
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