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1.
Inorg Chem ; 62(8): 3629-3636, 2023 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-36780272

RESUMEN

Vacancy-ordered halide perovskites have received great interest in optoelectronic applications. In this work, we report the novel inorganic halide Cs10MnSb6Cl30 with a distinctive 10H (10-layer hexagonal) perovskite polytype structure with (hcccc)2 stacking. Cs10MnSb6Cl30 has 30% B-site vacancies ordered at both corner- and face-sharing sites, resulting in [MnSb6Cl30]10-n columns, i.e., a reduction of octahedral connectivity to 1D. This results in enhanced photoluminescence in comparison to the previously reported 25% vacancy-ordered 3C polytype Cs4MnSb2Cl12 with 2D connectivity. This demonstrates not only the existence of the 10H perovskite structure in halides but also demonstrates the degree of B-site deficiency and stacking sequence variation as a direction to tune the optical properties of perovskite polytypes via vacancy rearrangements.

2.
Inorg Chem ; 61(7): 3230-3239, 2022 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-35138839

RESUMEN

We present the influence of positional isomerism on the crystal structure of fluorobenzylammonium copper(II) chloride perovskites A2CuCl4 by incorporating ortho-, meta-, and para-fluorine substitution in the benzylamine structure. Two-dimensional (2D) polar ferromagnet (3-FbaH)2CuCl4 (3-FbaH+ = 3-fluorobenzylammonium) is successfully obtained, which crystallizes in a polar orthorhombic space group Pca21 at room temperature. In contrast, both (2-FbaH)2CuCl4 (2-FbaH+ = 2-fluorobenzylammonium) and (4-FbaH)2CuCl4 (4-FbaH+ = 4-fluorobenzylammonium) crystallize in centrosymmetric space groups P21/c and Pnma at room temperature, respectively, displaying significant differences in crystal structures. These differences indicate that the position of the fluorine atom is a driver for the polar behavior in (3-FbaH)2CuCl4. Preliminary magnetic measurements confirm that these three perovskites possess dominant ferromagnetic interactions within the inorganic [CuCl4]∞ layers. Therefore, (3-FbaH)2CuCl4 is a polar ferromagnet, with potential as a type I multiferroic. This work is expected to promote further development of high-performance 2D copper(II) halide perovskite multiferroic materials.

3.
Inorg Chem ; 60(16): 12247-12254, 2021 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-34319709

RESUMEN

Mixed halide azetidinium lead perovskites AzPbBr3-xXx (X = Cl or I) were obtained by mechanosynthesis. With varying halide composition from Cl- to Br- to I-, the chloride and bromide analogues both form in the hexagonal 6H polytype while the iodide adopts the 9R polytype. An intermediate 4H polytype is observed for mixed Br/I compositions. Overall, the structure progresses from 6H to 4H to 9R perovskite polytype with varying halide composition. Rietveld refinement of the powder X-ray diffraction patterns revealed a linear variation in unit cell volume as a function of the average radius of the anion, which not only is observed within the solid solution of each polytype (according to Vegard's law) but also extends uniformly across all three polytypes. This is correlated to a progressive (linear) tuning of the bandgap from 3.43 to 2.00 eV. Regardless of halide, the family of azetidinium halide perovskite polytypes are highly stable, with no discernible change in properties over more than 6 months under ambient conditions.

4.
Molecules ; 26(21)2021 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-34770883

RESUMEN

A family of Ruddlesden-Popper (n = 1) layered perovskite-related phases, Az2PbClxBr4-x with composition 0 ≤ x ≤ 4 were obtained using mechanosynthesis. These compounds are isostructural with K2NiF4 and therefore adopt the idealised n = 1 Ruddlesden-Popper structure. A linear variation in unit cell volume as a function of anion average radius is observed. A tunable bandgap is achieved, ranging from 2.81 to 3.43 eV, and the bandgap varies in a second-order polynomial relationship with the halide composition.

5.
J Electrocardiol ; 48(1): 43-4, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25465863

RESUMEN

The 12-lead electrocardiogram (ECG) is a complex set of cardiac signals that require a high degree of skill and clinical knowledge to interpret. Therefore, it is imperative to record and understand how expert readers interpret the 12-lead ECG. This short paper showcases how eye tracking technology and audio data can be fused together and visualised to gain insight into the interpretation techniques employed by an eminent ECG champion, namely Dr Rory Childers.


Asunto(s)
Cardiología/historia , Competencia Clínica , Documentación/historia , Electrocardiografía/historia , Movimientos Oculares , Historia del Siglo XXI , Estados Unidos
6.
J Electrocardiol ; 47(6): 895-906, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25110276

RESUMEN

INTRODUCTION: It is well known that accurate interpretation of the 12-lead electrocardiogram (ECG) requires a high degree of skill. There is also a moderate degree of variability among those who interpret the ECG. While this is the case, there are no best practice guidelines for the actual ECG interpretation process. Hence, this study adopts computerized eye tracking technology to investigate whether eye-gaze can be used to gain a deeper insight into how expert annotators interpret the ECG. Annotators were recruited in San Jose, California at the 2013 International Society of Computerised Electrocardiology (ISCE). METHODS: Each annotator was recruited to interpret a number of 12-lead ECGs (N=12) while their eye gaze was recorded using a Tobii X60 eye tracker. The device is based on corneal reflection and is non-intrusive. With a sampling rate of 60Hz, eye gaze coordinates were acquired every 16.7ms. Fixations were determined using a predefined computerized classification algorithm, which was then used to generate heat maps of where the annotators looked. The ECGs used in this study form four groups (3=ST elevation myocardial infarction [STEMI], 3=hypertrophy, 3=arrhythmias and 3=exhibiting unique artefacts). There was also an equal distribution of difficulty levels (3=easy to interpret, 3=average and 3=difficult). ECGs were displayed using the 4x3+1 display format and computerized annotations were concealed. RESULTS: Precisely 252 expert ECG interpretations (21 annotators×12 ECGs) were recorded. Average duration for ECG interpretation was 58s (SD=23). Fleiss' generalized kappa coefficient (Pa=0.56) indicated a moderate inter-rater reliability among the annotators. There was a 79% inter-rater agreement for STEMI cases, 71% agreement for arrhythmia cases, 65% for the lead misplacement and dextrocardia cases and only 37% agreement for the hypertrophy cases. In analyzing the total fixation duration, it was found that on average annotators study lead V1 the most (4.29s), followed by leads V2 (3.83s), the rhythm strip (3.47s), II (2.74s), V3 (2.63s), I (2.53s), aVL (2.45s), V5 (2.27s), aVF (1.74s), aVR (1.63s), V6 (1.39s), III (1.32s) and V4 (1.19s). It was also found that on average the annotator spends an equal amount of time studying leads in the frontal plane (15.89s) when compared to leads in the transverse plane (15.70s). It was found that on average the annotators fixated on lead I first followed by leads V2, aVL, V1, II, aVR, V3, rhythm strip, III, aVF, V5, V4 and V6. We found a strong correlation (r=0.67) between time to first fixation on a lead and the total fixation duration on each lead. This indicates that leads studied first are studied the longest. There was a weak negative correlation between duration and accuracy (r=-0.2) and a strong correlation between age and accuracy (r=0.67). CONCLUSIONS: Eye tracking facilitated a deeper insight into how expert annotators interpret the 12-lead ECG. As a result, the authors recommend ECG annotators to adopt an initial first impression/pattern recognition approach followed by a conventional systematic protocol to ECG interpretation. This recommendation is based on observing misdiagnoses given due to first impression only. In summary, this research presents eye gaze results from expert ECG annotators and provides scope for future work that involves exploiting computerized eye tracking technology to further the science of ECG interpretation.


Asunto(s)
Arritmias Cardíacas/diagnóstico , Inteligencia Artificial , Electrocardiografía/métodos , Movimientos Oculares/fisiología , Fijación Ocular/fisiología , Percepción Visual/fisiología , Adulto , Competencia Clínica , Femenino , Humanos , Masculino , Lectura
7.
Br J Dermatol ; 169 Suppl 2: 32-8, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23786618

RESUMEN

In human skin fibroblasts in vitro, procollagen-1 and NAD(+)/NADH were reduced in three strains of adult fibroblasts compared with neonatal fibroblasts. The levels of both procollagen-1 and NAD(+)/NADH were increased in the adult fibroblasts by treatment for 24 (NAD energy) or 48 h (procollagen-1) with a complex containing niacinamide, Pal-KTTKS peptide and an olive oil fatty acid derivative (Olivem(®)), especially in combination with a natural extract from dill (Lys'lastine V(®)). In one of the adult fibroblast strains evaluated, these changes in procollagen-1 and NAD(+)/NADH in response to the complex of bioactives were in parallel with increased expression of mRNA biomarkers related primarily to dermal matrix and basement membrane structure, including COL1A1, COL3A1, COL5A1, COL14A1, ELN and LOXL2, in addition to SOD2, NAMPT and TGFBR3; MMP1 was decreased in expression. In general, these mRNA biomarker effects were maintained or boosted by the addition of Lys'lastine V, particularly at 1%, and were similar to the fold changes in mRNA expression in neonatal compared with adult fibroblasts. These results indicate that the complex of niacinamide, Pal-KTTKS and Olivem, especially with addition of Lys'lastine V, increases the NAD(+)/NADH bioenergy level of adult skin fibroblasts in parallel with increased expression of skin structure biomarkers in vitro to levels similar to those in younger fibroblasts. Thus, niacinamide, Pal-KTTKS, Olivem and Lys'lastine V are promising bioactive candidates for inclusion in cosmetic formulations.


Asunto(s)
Metabolismo Energético/fisiología , Niacinamida/farmacología , Oligopéptidos/farmacología , Aceites de Plantas/farmacología , Envejecimiento de la Piel/fisiología , Piel/efectos de los fármacos , Adulto , Células Cultivadas , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Femenino , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Humanos , Recién Nacido , Masculino , Persona de Mediana Edad , NAD/genética , NAD/metabolismo , Aceite de Oliva , Extractos Vegetales/farmacología , ARN Mensajero/metabolismo , Piel/citología , Piel/metabolismo
8.
Br J Dermatol ; 166 Suppl 2: 16-9, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22670614

RESUMEN

The use of global gene expression profiling, also known as transcriptomics or genomics, provides a means to identify key pathways affected in ageing skin that can be improved with appropriate cosmetic compounds. Aspects of skin ageing that can be addressed include matrix production, barrier, lipid synthesis, antioxidant capacity and hyperpigmentation. Gene expression profiling together with in vitro human skin cell cultures for compound screening and verification have led to the identification of cosmetic compounds and an understanding of the biological effects of compounds such as niacinamide, Pal-KTTKS, hexamidine, retinyl propionate and sodium dehydroacetate. In addition, understanding of the decreased antioxidant capacity of aged skin has led to the identification of new antiageing ingredients, olive-derived fatty acid ethoxylates, which have been shown to restore antioxidant enzymes in skin keratinocytes and fibroblasts. Gene expression profiling of age spots has also provided an understanding of the role of undecylenoyl phenylalanine in reducing melanin production by an adrenergic receptor mechanism in melanocytes. The use of these compounds in cosmetic formulations for skin care can aid improvements in the appearance of aged skin, including the improved appearance of fine lines, wrinkles and age spots.


Asunto(s)
Cosméticos/farmacología , Genómica/métodos , Trastornos de la Pigmentación/tratamiento farmacológico , Envejecimiento de la Piel/genética , Antioxidantes/farmacología , Cosméticos/química , Ácidos Grasos/farmacología , Humanos , Aceite de Oliva , Aceites de Plantas/farmacología , Receptores Adrenérgicos beta/fisiología , Envejecimiento de la Piel/efectos de los fármacos , Pigmentación de la Piel/efectos de los fármacos , Pigmentación de la Piel/genética , Transcripción Genética/genética , Regulación hacia Arriba
9.
Chem Mater ; 34(5): 2458-2467, 2022 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-35431437

RESUMEN

Two-dimensional (2D) organic-inorganic hybrid copper halide perovskites have drawn tremendous attention as promising multifunctional materials. Herein, by incorporating ortho-, meta-, and para-chlorine substitutions in the benzylamine structure, we first report the influence of positional isomerism on the crystal structures of chlorobenzylammonium copper(II) chloride perovskites A2CuCl4. 2D polar ferromagnets (3-ClbaH)2CuCl4 and (4-ClbaH)2CuCl4 (ClbaH+ = chlorobenzylammonium) are successfully obtained. They both adopt a polar monoclinic space group Cc at room temperature, displaying significant differences in crystal structures. In contrast, (2-ClbaH)2CuCl4 adopts a centrosymmetric space group P 21/ c at room temperature. This associated structural evolution successfully enhances the physical properties of the two polar compounds with high thermal stability, discernible second harmonic generation (SHG) signals, ferromagnetism, and narrow optical band gaps. These findings demonstrate that the introduction of chlorine atoms into the interlayer organic species is a powerful tool to tune crystal symmetries and physical properties, and this inspires further exploration of designing high-performance multifunctional copper-based materials.

10.
Skin Res Technol ; 17(3): 366-72, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21492241

RESUMEN

BACKGROUND: The measurement of transepidermal water loss (TEWL) is used to monitor changes in the stratum corneum's permeability to water vapor. This measurement is widely used in the cosmetics industry and in dermatology research. However, only limited work has been undertaken to assess the comparability of results from different TEWL meters over an extended range of measurements. METHODS: This study compared the results of TEWL measurements between two commonly used open-chamber and closed-chamber TEWL devices. Five hundred and forty measurements were taken in 17 participants on the dorsum and palm of both hands on two different days and the order of the devices was randomized. RESULTS: The results showed that the open TEWL meter's capacity for measuring high values of TEWL was restricted, and that the closed-chamber TEWL meter was less sensitive to differences in the lower range of measurements. CONCLUSION: Both devices have their strengths for different applications, but their results cannot be directly compared. We were unable to find a statistical model that would allow us to transform the measurements made on one device for a comparison with the results generated by the other device.


Asunto(s)
Agua Corporal/metabolismo , Dermatología/instrumentación , Examen Físico/instrumentación , Pérdida Insensible de Agua/fisiología , Agua/análisis , Adulto , Diseño de Equipo , Análisis de Falla de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
11.
PLoS One ; 16(4): e0249297, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33909630

RESUMEN

BACKGROUND: Prognosis in Palliative care Study (PiPS) models predict survival probabilities in advanced cancer. PiPS-A (clinical observations only) and PiPS-B (additionally requiring blood results) consist of 14- and 56-day models (PiPS-A14; PiPS-A56; PiPS-B14; PiPS-B56) to create survival risk categories: days, weeks, months. The primary aim was to compare PIPS-B risk categories against agreed multi-professional estimates of survival (AMPES) and to validate PiPS-A and PiPS-B. Secondary aims were to assess acceptability of PiPS to patients, caregivers and health professionals (HPs). METHODS AND FINDINGS: A national, multi-centre, prospective, observational, cohort study with nested qualitative sub-study using interviews with patients, caregivers and HPs. Validation study participants were adults with incurable cancer; with or without capacity; recently referred to community, hospital and hospice palliative care services across England and Wales. Sub-study participants were patients, caregivers and HPs. 1833 participants were recruited. PiPS-B risk categories were as accurate as AMPES [PiPS-B accuracy (910/1484; 61%); AMPES (914/1484; 61%); p = 0.851]. PiPS-B14 discrimination (C-statistic 0.837) and PiPS-B56 (0.810) were excellent. PiPS-B14 predictions were too high in the 57-74% risk group (Calibration-in-the-large [CiL] -0.202; Calibration slope [CS] 0.840). PiPS-B56 was well-calibrated (CiL 0.152; CS 0.914). PiPS-A risk categories were less accurate than AMPES (p<0.001). PiPS-A14 (C-statistic 0.825; CiL -0.037; CS 0.981) and PiPS-A56 (C-statistic 0.776; CiL 0.109; CS 0.946) had excellent or reasonably good discrimination and calibration. Interviewed patients (n = 29) and caregivers (n = 20) wanted prognostic information and considered that PiPS may aid communication. HPs (n = 32) found PiPS user-friendly and considered risk categories potentially helpful for decision-making. The need for a blood test for PiPS-B was considered a limitation. CONCLUSIONS: PiPS-B risk categories are as accurate as AMPES made by experienced doctors and nurses. PiPS-A categories are less accurate. Patients, carers and HPs regard PiPS as potentially helpful in clinical practice. STUDY REGISTRATION: ISRCTN13688211.


Asunto(s)
Cuidadores/psicología , Personal de Salud/psicología , Neoplasias/patología , Cuidados Paliativos , Pacientes/psicología , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Humanos , Entrevistas como Asunto , Masculino , Persona de Mediana Edad , Neoplasias/terapia , Pronóstico , Estudios Prospectivos , Factores de Riesgo
12.
PLoS One ; 16(4): e0249763, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33909658

RESUMEN

PURPOSE: The Palliative Prognostic (PaP) score; Palliative Prognostic Index (PPI); Feliu Prognostic Nomogram (FPN) and Palliative Performance Scale (PPS) have all been proposed as prognostic tools for palliative cancer care. However, clinical judgement remains the principal way by which palliative care professionals determine prognoses and it is important that the performance of prognostic tools is compared against clinical predictions of survival (CPS). METHODS: This was a multi-centre, cohort validation study of prognostic tools. Study participants were adults with advanced cancer receiving palliative care, with or without capacity to consent. Key prognostic data were collected at baseline, shortly after referral to palliative care services. CPS were obtained independently from a doctor and a nurse. RESULTS: Prognostic data were collected on 1833 participants. All prognostic tools showed acceptable discrimination and calibration, but none showed superiority to CPS. Both PaP and CPS were equally able to accurately categorise patients according to their risk of dying within 30 days. There was no difference in performance between CPS and FPN at stratifying patients according to their risk of dying at 15, 30 or 60 days. PPI was significantly (p<0.001) worse than CPS at predicting which patients would survive for 3 or 6 weeks. PPS and CPS were both able to discriminate palliative care patients into multiple iso-prognostic groups. CONCLUSIONS: Although four commonly used prognostic algorithms for palliative care generally showed good discrimination and calibration, none of them demonstrated superiority to CPS. Prognostic tools which are less accurate than CPS are of no clinical use. However, prognostic tools which perform similarly to CPS may have other advantages to recommend them for use in clinical practice (e.g. being more objective, more reproducible, acting as a second opinion or as an educational tool). Future studies should therefore assess the impact of prognostic tools on clinical practice and decision-making.


Asunto(s)
Neoplasias/terapia , Cuidados Paliativos/métodos , Médicos/normas , Anciano , Técnicas de Apoyo para la Decisión , Femenino , Humanos , Masculino , Neoplasias/diagnóstico , Neoplasias/mortalidad , Relaciones Médico-Paciente , Valor Predictivo de las Pruebas , Estudios Prospectivos , Tasa de Supervivencia
13.
Mov Disord ; 25(7): 912-9, 2010 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-20461808

RESUMEN

A case-control study of genetic, environmental, and occupational risk factors for Parkinson's disease (PD) was carried out in five European countries (Italy, Malta, Romania, Scotland, and Sweden) to explore the possible contribution of interactions among host and environmental factors in sporadic PD. Whereas smoking habits confirmed its negative association with PD, a possible modulatory role of genetic polymorphisms was investigated to obtain further mechanistic insights. We recruited 767 cases of PD and 1989 age-matched and gender-matched controls. Participants completed an interviewer-administered questionnaire including the history of smoking habits. The polymorphisms of genes involved either in metabolism of compounds contained in tobacco smoke (CYP2D6, CYP1B1, GSTM1, GSTT1, GSTM3, GSTP1, NQO1, SOD2, EPHX and NAT2) or in dopaminergic neurotransmission (MAOA, MAOB, DAT1 and DRD2) were characterized by PCR based methods on genomic DNA. We found evidence of statistically significant gene-tobacco interaction for GSTM1, NAT2, and GSTP1, the negative association between tobacco smoking and PD being significantly enhanced in subjects expressing GSTM1-1 activity, in NAT2 fast acetylators, and in those with the GSTP1*B*C haplotype. Owing to the retrospective design of the study, these results require confirmation.


Asunto(s)
Expresión Génica/genética , Enfermedad de Parkinson/epidemiología , Tabaquismo/epidemiología , Tabaquismo/genética , Anciano , Estudios de Casos y Controles , Femenino , Genotipo , Humanos , Masculino , Exposición Profesional/efectos adversos , Reacción en Cadena de la Polimerasa , Polimorfismo Genético/genética
14.
Occup Environ Med ; 67(6): 401-7, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19910296

RESUMEN

OBJECTIVES: Organic solvent exposure may be associated with cognitive impairment in later life although the evidence for this association is inconsistent. This study sought to examine the association between organic solvent exposure and cognitive function in later life. METHODS: A prospective longitudinal study set in Aberdeen, Scotland examined 336 men and women born in 1936 who participated in the 1947 Scottish Mental Survey. Cognitive function at age 67 years was measured using the Trail Making Test B (TMT B), the Digit Symbol (DS) test, and the Auditory Verbal Learning Test (AVLT). Occupational hygienists reviewed occupational histories, blind to cognitive function, and estimated lifetime solvent exposures. Multiple regression analyses were employed to explore the association between solvent exposure and cognitive performance after adjustment for confounders. RESULTS: After adjusting for childhood IQ, smoking, alcohol and sex, the solvent exposed group took on average almost 10 s longer than the unexposed group to complete the TMT B, a highly significant difference. For the DS test, after adjusting for childhood IQ, smoking and gender, the exposed group scored on average two points lower than the unexposed group, which was again highly significant. There was no evidence of an effect for cumulative solvent exposure on the TMT B or DS test. For the AVLT there were no significant differences associated with exposure. CONCLUSIONS: This study of subjects with generally low exposures, found no clear evidence of an association between solvent exposure and cognitive function.


Asunto(s)
Trastornos del Conocimiento/inducido químicamente , Enfermedades Profesionales/inducido químicamente , Solventes/toxicidad , Anciano , Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/epidemiología , Femenino , Estudios de Seguimiento , Humanos , Estudios Longitudinales , Masculino , Pruebas Neuropsicológicas , Enfermedades Profesionales/diagnóstico , Enfermedades Profesionales/epidemiología , Exposición Profesional/efectos adversos , Estudios Prospectivos , Escocia/epidemiología , Prueba de Secuencia Alfanumérica
15.
Occup Med (Lond) ; 60(1): 36-42, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19914970

RESUMEN

AIMS: The aims are to compare hearing loss between professional divers and offshore workers and to study whether hearing loss symptoms reflected physical disorder. A secondary objective was to study total threshold shift assessment as a method of detecting noise-induced hearing loss (NIHL). METHODS: Participants (151 divers and 120 offshore workers) completed a questionnaire for symptoms and screening audiometry. Audiograms were assessed for total threshold shift at 1, 2, 3, 4 and 6 kHz and the prevalence of referral (within population 5th centile) or warning levels (within population 20th centile) of hearing loss. Audiograms were assessed for an NIHL pattern at four levels by two occupational physicians. RESULTS: Hearing loss symptoms were commoner in divers at all levels of hearing loss regardless of differences between groups on audiometry. Hearing loss in offshore workers was within the population age-adjusted norm. Thirteen per cent of divers were within the 5th percentile for threshold shift for the population norm in contrast to 4% of offshore workers and this was predominantly left sided (OR 3.16, 95% CI 1.13-8.93). This difference was lost after adjustment for history of regular exposure to explosion or gunfire. Divers were more likely to have a pattern of severe NIHL on the left (OR 4.61, 95% CI 1.39-15.39, P < 0.05). Approximately 50% of participants with severe NIHL did not have a referral level of hearing loss. CONCLUSIONS: Divers suffer more NIHL than a control population. Current guidance on the assessment of total threshold shift for the detection of significant NIHL was inadequate in the sample studied.


Asunto(s)
Audiometría/métodos , Buceo/efectos adversos , Industria Procesadora y de Extracción , Pérdida Auditiva Provocada por Ruido/diagnóstico , Ruido en el Ambiente de Trabajo/efectos adversos , Enfermedades Profesionales/diagnóstico , Adulto , Audiometría/normas , Pérdida Auditiva Provocada por Ruido/fisiopatología , Humanos , Persona de Mediana Edad , Variaciones Dependientes del Observador , Enfermedades Profesionales/etiología , Petróleo , Factores de Riesgo , Umbral Sensorial/fisiología
16.
J Cell Biol ; 103(6 Pt 1): 2091-102, 1986 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-3097026

RESUMEN

An in vitro system was developed that provides a quick microscopic assay for nuclear transport. The assay uses an extract of Xenopus eggs, normal or synthetic nuclei, and a fluorescently labeled nuclear protein, nucleoplasmin. This in vitro system accurately mimics in vivo nuclear transport, both in exclusivity and in the amount of accumulation observed (up to 17-fold). Selective accumulation of fluorescent nucleoplasmin is observed microscopically within 30 min with rat liver nuclei, Xenopus embryonic nuclei, regrown Xenopus sperm nuclei, or nuclei reconstituted in vitro from bacteriophage lambda DNA. This transport requires the signal domain of nucleoplasmin. Furthermore, the ability of nuclei to accumulate nucleoplasmin directly correlates with their ability to exclude the fluorescent non-nuclear proteins, FITC-immunoglobulin and phycoerythrin. An active transport model would predict that nuclear transport be temperature- and energy-dependent and that inhibition of transport by either low temperature or energy depletion would be reversible. Both predictions were confirmed in our system. Nucleoplasmin accumulation increases with temperature, while the protein is completely excluded at 0 degrees C. The effects of low temperature are reversible. As found for 125I-labeled nucleoplasmin (Newmeyer, D. D., J. M. Lucocq, T. R. Bürglin, and E. M. De Robertis, 1986, EMBO (Eur. Mol. Biol. Organ.) J., 5:501-510), transport of fluorescent nucleoplasmin is inhibited by ATP depletion. This effect is reversed by later ATP addition. Under ATP-depleted conditions non-nuclear proteins continue to be excluded. These results argue for a direct role of ATP in transport rather than for a simple role in preserving envelope integrity. In a first step towards defining the minimum requirements for a transport medium, egg extracts were depleted of membrane vesicles. Membrane-depleted extracts neither support transport nor maintain the integrity of the nuclear envelope.


Asunto(s)
Núcleo Celular/metabolismo , Proteínas Nucleares , Nucleoproteínas/metabolismo , Oocitos/metabolismo , Fosfoproteínas , Proteínas/metabolismo , Animales , Núcleo Celular/ultraestructura , Femenino , Fluoresceína-5-Isotiocianato , Fluoresceínas , Hígado/metabolismo , Microscopía Fluorescente , Nucleoplasminas , Oocitos/citología , Ratas , Tiocianatos , Xenopus
17.
J Cell Biol ; 104(2): 189-200, 1987 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-3805121

RESUMEN

Selective transport of proteins is a major mechanism by which biochemical differences are maintained between the cytoplasm and nucleus. To begin to investigate the molecular mechanism of nuclear transport, we used an in vitro transport system composed of a Xenopus egg extract, rat liver nuclei, and a fluorescently labeled nuclear protein, nucleoplasmin. With this system, we screened for inhibitors of transport. We found that the lectin, wheat germ agglutinin (WGA), completely inhibits the nuclear transport of fluorescently labeled nucleoplasmin. No other lectin tested affected nuclear transport. The inhibition by WGA was not seen when N-acetylglucosamine was present and was reversible by subsequent addition of sugar. When rat liver nuclei that had been incubated with ferritin-labeled WGA were examined by electron microscopy, multiple molecules of WGA were found bound to the cytoplasmic face of each nuclear pore. Gel electrophoresis and nitrocellulose transfer identified one major and several minor nuclear protein bands as binding 125I-labeled WGA. The most abundant protein of these, a 63-65-kD glycoprotein, is a candidate for the inhibitory site of action of WGA on nuclear protein transport. WGA is the first identified inhibitor of nuclear protein transport and interacts directly with the nuclear pore.


Asunto(s)
Lectinas/farmacología , Membrana Nuclear/metabolismo , Proteínas Nucleares , Nucleoproteínas/metabolismo , Fosfoproteínas , Aglutininas del Germen de Trigo/farmacología , Acetilglucosamina/farmacología , Animales , Transporte Biológico/efectos de los fármacos , Femenino , Hígado/metabolismo , Membrana Nuclear/efectos de los fármacos , Membrana Nuclear/ultraestructura , Nucleoplasminas , Oocitos/fisiología , Ratas , Extractos de Tejidos/farmacología , Xenopus
18.
J Cell Biol ; 114(1): 169-83, 1991 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2050741

RESUMEN

A family of proteins bearing novel N-acetylglucosamine residues has previously been found to be required to form functional nuclear pores. To begin to determine which of the proteins in this family are essential for pore function, antisera were raised to each of three members of the family, p62, p58, and p54. With these antisera, it was possible to deplete nuclear reconstitution extracts of the proteins and to test the depleted nuclei for nuclear transport. In the course of the experiments, it was found that the three proteins exist as a complex; antisera to any one, while specific on a protein blot, coimmunoprecipitated all three proteins. This complex of pore proteins is stable to 2 M salt, 2 M urea, and the detergent Mega 10, indicating the presence of specific and tight protein-protein interactions. By gel filtration, the complex has a molecular mass of 550-600 kD. Nuclei containing pores depleted of the complex are found to be defective for nuclear transport; moreover, we observe a strict linear correlation between the amount of complex present in nuclei and the amount of nuclear transport of which those nuclei are capable. Thus, the p62-p58-p54 complex defines a group of proteins with strong protein-protein interactions that form a unit of pore structure essential for pore function.


Asunto(s)
Glicoproteínas de Membrana/fisiología , Membrana Nuclear/metabolismo , Proteínas Nucleares/fisiología , Animales , Transporte Biológico , Técnica del Anticuerpo Fluorescente , Sueros Inmunes , Glicoproteínas de Membrana/inmunología , Proteínas de la Membrana/inmunología , Proteínas de la Membrana/fisiología , Peso Molecular , Membrana Nuclear/química , Proteínas de Complejo Poro Nuclear , Proteínas Nucleares/inmunología , Ratas
19.
Occup Med (Lond) ; 59(7): 509-11, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19690079

RESUMEN

BACKGROUND: Medical students may be at risk of sharps injuries for several reasons. These exposures can transmit a range of blood-borne pathogens including hepatitis B, hepatitis C and human immunodeficiency virus. AIMS: To evaluate medical students' knowledge regarding the prevention and management of sharps injuries and their experience of such exposures in the calendar year 2007. METHODS: A cross-sectional, web-based, survey of fourth and fifth year medical students enrolled at the University of Aberdeen in Scotland. All students were at the mid-point of their year of study. An invitation e-mail and two electronic reminders were sent, on specified days, to the study population. These contained a summary of the study and the link to the anonymous questionnaire. RESULTS: Of the 395 medical students e-mailed, 238 (60%) responded. When compared with fourth year medical students, final year students had higher mean knowledge scores for sharps injury management (P < 0.01). Of total, 18% reported resheathing used needles and 31% reported disposing of sharps for others, indicating poor compliance with standard precautions. In the event of an injury, 29% stated that they would scrub the wound. Only 44% were familiar with policies for reporting exposures. In all, 11% of students had experienced at least one contaminated sharps injury in 2007 and, of those, 40% had reported the most recent incident. CONCLUSIONS: Medical students are at risk of sharps injuries and their knowledge regarding the prevention and management of these exposures is limited: training on these issues should be increased.


Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Lesiones por Pinchazo de Aguja/prevención & control , Exposición Profesional/prevención & control , Gestión de Riesgos , Estudiantes de Medicina , Adulto , Estudios Transversales , Femenino , Humanos , Masculino , Medición de Riesgo , Escocia , Encuestas y Cuestionarios
20.
Technol Health Care ; 17(3): 269-79, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19641262

RESUMEN

The population is aging and with this, the incidence of age related diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD) are increasing. Assistive Technology (AT) is viewed as one of the possible solutions which can be used to meet the needs of persons suffering from PD. AT can enable a person to carry out a task which otherwise they would be unable to undertake independently. An AT can have many functions which range from helping people to use a computer, to monitoring someone's condition. Within this paper we attempt to categorize the different types of AT for persons with PD. Each of the technologies will be compared and contrasted and an overview of what is currently available presented. The paper concludes with some visionary comments on how the current levels of AT may change in the future.


Asunto(s)
Diseño de Equipo , Monitoreo Ambulatorio/instrumentación , Enfermedad de Parkinson/rehabilitación , Dispositivos de Autoayuda , Actividades Cotidianas , Teléfono Celular , Computadores , Humanos , Limitación de la Movilidad , Monitoreo Ambulatorio/métodos
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