Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
1.
J Mater Res ; 39(1): 150-164, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38223565

RESUMEN

A new integrated deposition system taking advantage of magnetron sputtering and electron cyclotron-plasma enhanced chemical vapour deposition (IMS ECR-PECVD) is presented that mitigates the drawbacks of each fabrication system. This tailor-made system provides users with highly homogeneous and pure thin films with less undesired hydrogen and well-controlled rare-earth concentration compared to existing methods of rare-earth doping, such as metalorganic powders, sputtering, and ion implantation. We established the first comprehensive report on the deposition parameters of argon flow and sputtering power to achieve desired rare-earth concentrations in a wide composition range of terbium (Tb) doped-silicon oxide (Tb:SiOx) matrices including silicon-rich (x < 2), oxygen-rich (x > 2), and stoichiometric silicon oxide (x = 2). The deposition parameters to fabricate crystalline structure (Tb2Si2O7) in oxygen-rich samples are reported where Tb ions are optically active. IMS ECR-PECVD pushes the solubility limit of the rare-earth dopant in silicon films to 17 at.% for the desired future nanophotonic devices. Supplementary Information: The online version contains supplementary material available at 10.1557/s43578-023-01207-2.

2.
Nanotechnology ; 30(31): 314003, 2019 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-30970339

RESUMEN

Amorphous hydrogenated silicon carbonitride (a-SiCN:H) thin films were grown using electron cyclotron resonance chemical vapour deposition using a mixture of methane, nitrogen, and silane as precursors. The origin of the variation of macroscopic properties such as hardness (H), elastic modulus (E), photoluminescence (PL), and the optical band gap was investigated through their correlation with the microscopic features of a-SiCN:H thin films as a function of the process parameters, including the deposition temperature and methane gas flow rate. From a microstructural perspective, the thin films were investigated using x-ray photoelectron spectroscopy, Rutherford backscattering spectrometry, elastic recoil detection, transmission electron microscopy, and x-ray diffraction. It is verified that an increase of the substrate temperature resulted in the substitution of hydrogen atoms mainly by carbon atoms, causing the density of the silicon carbide-related structures to increase in the amorphous structure of the a-SiCN:H thin films. Hardness and elastic modulus were found to increase with the deposition temperature and decreased with an increase of the methane gas flow during the deposition, resulting in higher carbon content in the films. The observed changes are ascribed to the reduced density of the weak hydrogen terminated bonds and the variation of the relative bond density of Si-C to Si-N bonds. In addition, the thin films were depth profiled using a slow positron beam to investigate the role of vacancies. The observed increase of the positronium formation with increasing deposition temperature was found to correlate with the variation of PL, where an enhancement of the visible emission originating from carbon-related defects was observed. A set of optimized process parameters to fabricate a-SiCN:H thin films with improved visible emission and hardness properties is suggested.

3.
Artículo en Inglés | MEDLINE | ID: mdl-29732162

RESUMEN

Hashimoto's encephalopathy (HE) is rarely reported with only a few hundred cases published. Diagnosis is made in patients with an appropriate clinical picture and high antithyroperoxidase (anti-TPO) antibodies after infectious, toxic and metabolic causes of encephalopathy have been excluded. There is little objective data on the neurocognitive impairment in patients with HE and their improvement with treatment. We present the case of a 28-year-old woman with HE. Approach to management was novel as objective neuropsychological assessment was used to assess her clinical condition and response to treatment. Intravenous immunoglobulin (IVIg) as the first-line treatment instead of steroids. She responded well. The case illustrates that a different approach is required for the diagnosis and treatment of HE. A new diagnostic criteria is proposed that includes neurocognitive assessment, serum and CSF antibodies, an abnormal EEG and exclusion of other causes of encephalopathy. Furthermore, treatment should be tailored to the patient. LEARNING POINTS: Neurocognitive assessment should be carried out to assess the extent of brain involvement in suspected Hashimoto's encephalopathy pre- and post- treatment.Treatment of Hashimoto's encephalopathy should be tailored to the patient.Unifying diagnostic criteria for Hashimoto's encephalopathy must be established.

4.
Ann Clin Biochem ; 54(6): 702-706, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28068804

RESUMEN

Background A logical consequence of the introduction of robotics and high-capacity analysers has seen a consolidation to larger units. This requires new structures and quality systems to ensure that laboratories deliver consistent and comparable results. Methods A spreadsheet program was designed to accommodate results from up to 12 different instruments/laboratories and present IQC data, i.e. Levey-Jennings and Youden plots and comprehensive numerical tables of the performance of each item. Input of data was made possible by a 'data loader' by which IQC data from the individual instruments could be transferred to the spreadsheet program on line. Results A set of real data from laboratories is used to populate the data loader and the networking software program. Examples are present from the analysis of variance components, the Levey-Jennings and Youden plots. Conclusions This report presents a software package that allows the simultaneous management and detailed monitoring of the performance of up to 12 different instruments/laboratories in a fully interactive mode. The system allows a quality manager of networked laboratories to have a continuous updated overview of the performance. This software package has been made available at the ACB website.


Asunto(s)
Técnicas de Laboratorio Clínico/normas , Informe de Investigación , Programas Informáticos , Humanos , Control de Calidad , Proyectos de Investigación
6.
Int J Med Sci ; 5(1): 9-17, 2008 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-18219370

RESUMEN

The use of MDRD-eGFR to diagnose Chronic Kidney Disease (CKD) is based on the assumption that the algorithm will minimize the influence of age, gender and ethnicity that is observed in S-Creatinine concentration and thus allow a single cut-off at which further diagnostic and therapeutic actions should be considered. This hypothesis is tested in a retrospective analysis of outpatients (N=93,404) and hospitalised (N=35,572) patients in UK and Sweden, respectively. An algorithm based on the same model as the MDRD-eGFR algorithm was derived from simultaneously measured S-Creatinine concentrations and Iohexol GFR in a subset of 565 patients. The combined uncertainty of using this algorithm was estimated to about 15 % which is about three times that of the S-Creatinine concentration results. The diagnostic performance of S-Creatinine concentration was evaluated using the Iohexol clearance as the reference procedure. It was shown that the diagnostic capacity of MDRD-eGFR, as it stands, has no added value compared to S-Creatinine. The gender and age differences of the S-Creatinine concentrations in the dataset persist after applying the MDRD-eGFR algorithm. Thus, a general use of the MDRD-eGFR does not seem justified. Furthermore the claim that the eGFR is adjusted for body area is misleading; the algorithm does not include any body size marker. It is thus a dangerous marker for guiding drug administration.


Asunto(s)
Creatinina/sangre , Tasa de Filtración Glomerular/fisiología , Fallo Renal Crónico/diagnóstico , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Algoritmos , Estudios de Cohortes , Medios de Contraste/farmacocinética , Femenino , Humanos , Pacientes Internos , Yohexol/farmacocinética , Fallo Renal Crónico/epidemiología , Fallo Renal Crónico/fisiopatología , Masculino , Tasa de Depuración Metabólica , Persona de Mediana Edad , Pacientes Ambulatorios , Curva ROC , Valores de Referencia , Estudios Retrospectivos , Sensibilidad y Especificidad , Distribución por Sexo , Suecia/epidemiología , Reino Unido/epidemiología
7.
Ann Clin Biochem ; 43(Pt 1): 77-9, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16390614

RESUMEN

Thyroid function tests are the most commonly requested endocrine investigations in both primary and secondary care. Attention to detail is vital, as the appropriate interpretation may point to conditions other than thyroid disease itself. We describe two cases of hypopituitarism masquerading as borderline thyroid function tests.


Asunto(s)
Hipopituitarismo/diagnóstico , Enfermedades de la Tiroides/diagnóstico , Enfermedades de la Tiroides/fisiopatología , Glándula Tiroides/fisiología , Glándula Tiroides/fisiopatología , Adulto , Anciano , Diagnóstico Diferencial , Femenino , Humanos , Hipopituitarismo/sangre , Masculino , Pruebas de Función de la Tiroides
8.
Ann Clin Biochem ; 42(Pt 2): 162; author reply 162-3, 2005 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15832469
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...