Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
1.
Nano Lett ; 21(19): 8266-8273, 2021 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-34569802

RESUMEN

Single atom magnets offer the possibility of magnetic information storage in the most fundamental unit of matter. Identifying the parameters that control the stability of their magnetic states is crucial to design novel quantum magnets with tailored properties. Here, we use X-ray absorption spectroscopy to show that the electronic configuration of dysprosium atoms on MgO(100) thin films can be tuned by the proximity of the metal Ag(100) substrate onto which the MgO films are grown. Increasing the MgO thickness from 2.5 to 9 monolayers induces a change in the dysprosium electronic configuration from 4f9 to 4f10. Hysteresis loops indicate long magnetic lifetimes for both configurations, however, with a different field-dependent magnetic stability. Combining these measurements with scanning tunneling microscopy, density functional theory, and multiplet calculations unveils the role of the adsorption site and charge transfer to the substrate in determining the stability of quantum states in dysprosium single atom magnets.

2.
BMJ Open ; 12(5): e054869, 2022 05 30.
Artículo en Inglés | MEDLINE | ID: mdl-35636784

RESUMEN

OBJECTIVES: To assess the applicability of risk factors for severe COVID-19 defined in the general population for patients on haemodialysis. SETTING: A retrospective cross-sectional study performed across thirty four haemodialysis units in midlands of the UK. PARTICIPANTS: All 274 patients on maintenance haemodialysis who tested positive for SARS-CoV-2 on PCR testing between March and August 2020, in participating haemodialysis centres. EXPOSURE: The utility of obesity, diabetes status, ethnicity, Charlson Comorbidity Index (CCI) and socioeconomic deprivation scores were investigated as risk factors for severe COVID-19. MAIN OUTCOMES AND MEASURES: Severe COVID-19, defined as requiring supplemental oxygen or respiratory support, or a C reactive protein of ≥75 mg/dL (RECOVERY trial definitions), and its association with obesity, diabetes status, ethnicity, CCI, and socioeconomic deprivation. RESULTS: 63.5% (174/274 patients) developed severe disease. Socioeconomic deprivation associated with severity, being most pronounced between the most and least deprived quartiles (OR 2.81, 95% CI 1.22 to 6.47, p=0.015), after adjusting for age, sex and ethnicity. There was no association between obesity, diabetes status, ethnicity or CCI with COVID-19 severity. We found no evidence of temporal evolution of cases (p=0.209) or clustering that would impact our findings. CONCLUSION: The incidence of severe COVID-19 is high among patients on haemodialysis; this cohort should be considered high risk. There was strong evidence of an association between socioeconomic deprivation and COVID-19 severity. Other risk factors that apply to the general population may not apply to this cohort.


Asunto(s)
COVID-19 , Diabetes Mellitus , COVID-19/epidemiología , Estudios Transversales , Diabetes Mellitus/epidemiología , Humanos , Obesidad/epidemiología , Diálisis Renal , Estudios Retrospectivos , Factores de Riesgo , SARS-CoV-2 , Reino Unido/epidemiología
3.
ACS Nano ; 15(10): 16162-16171, 2021 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-34546038

RESUMEN

Single lanthanide atoms and molecules are promising candidates for atomic data storage and quantum logic due to the long lifetime of their magnetic quantum states. Accessing and controlling these states through electrical transport requires precise knowledge of their electronic configuration at the level of individual atomic orbitals, especially of the outer shells involved in transport. However, no experimental techniques have so far shown the required sensitivity to probe single atoms with orbital selectivity. Here we resolve the magnetism of individual orbitals in Gd and Ho single atoms on MgO/Ag(100) by combining X-ray magnetic circular dichroism with multiplet calculations and density functional theory. In contrast to the usual assumption of bulk-like occupation of the different electronic shells, we establish a charge transfer mechanism leading to an unconventional singly ionized configuration. Our work identifies the role of the valence electrons in determining the quantum level structure and spin-dependent transport properties of lanthanide-based nanomagnets.

4.
Diabetes Metab Syndr ; 13(4): 2431-2435, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31405655

RESUMEN

BACKGROUND: Diabetes in Sudan is real health challenge for health authorities especially optimum glycemic control and complications in particular diabetic septic foot. This is study aimed to assess knowledge of individuals with diabetes about self-foot care. METHODS: This is descriptive cross sectional, health facility-based study conducted in diabetes center in Khartoum, Sudan. The study recruited 150 individuals with diabetes. Data was collected using a standardized pretested questionnaire. RESULTS: Among the participants 64.7% were females and 35.3% were males, 36% of the participants were between the age of 51-60 years old. Good glycemic control (HbA1c) were achieved by 41.3% only. The participants who had good knowledge about diabetic foot self-care were 46.7%, poor knowledge 29.3% and moderate knowledge 24%. Good self-practice toward diabetic foot self-care was reported by 42.6%, moderate by 36.7% and poor practice by 20.7%. The awareness and practices significantly correlated with an increase in ages (≥51 years), higher level of education, medium income, unemployment, longer duration of diabetes > 10years, family history, controlled diabetes mellitus and education about diabetes complications and diabetic foot care (P value < 0.05). CONCLUSIONS: Only (46.7%) of participants address good awareness and practices about self-foot care. Accordingly, there is a great need to provide continuous health education to the patients about diabetic foot self-care and this knowledge-application gap must be narrowed down.


Asunto(s)
Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 2/complicaciones , Pie Diabético/terapia , Conocimientos, Actitudes y Práctica en Salud , Educación del Paciente como Asunto , Autocuidado/estadística & datos numéricos , Autocuidado/normas , Adulto , Estudios Transversales , Pie Diabético/etiología , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Pronóstico , Sudán/epidemiología , Encuestas y Cuestionarios
5.
J Epidemiol Glob Health ; 5(4): 405-7, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26025183

RESUMEN

Cardiovascular disease is stabilizing in high-income countries and has continued to rise in low-to-middle-income countries. Association of lipid profile with lipoprotein lipase gene was studied in case and control subject. The family history, hypertension, diabetes mellitus, smoking and alcohol consumption were the most risk factors for early-onset of coronary heart disease (CHD). Sudanese patients had significantly (P<0.05) lower TC and LDL-C levels compared to controls. Allele frequency of LPL D9N, N291S and S447X carrier genotype was 4.2%, 30.7% and 7.1%, respectively. We conclude that lipoprotein lipase polymorphism was not associated with the incidence of CHD in Sudan.


Asunto(s)
Enfermedad Coronaria/genética , Lipoproteína Lipasa/genética , Estudios de Casos y Controles , Enfermedad Coronaria/epidemiología , Femenino , Humanos , Lípidos/sangre , Masculino , Polimorfismo Genético , Factores de Riesgo , Sudán/epidemiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA