Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 5 de 5
Filter
Add more filters










Database
Language
Publication year range
1.
Sci Rep ; 14(1): 3382, 2024 Feb 09.
Article in English | MEDLINE | ID: mdl-38336984

ABSTRACT

Temperature-dependent dc-magnetization and ac-susceptibility curves have been recorded for series of single and double layered Ruddlesden-Popper multicomponent perovskites with chemical formula A2BO4 and A3B2O7, respectively, with (La, Sr) on A-sites and up to 7 different cations on the B-sites (Ti, Cr, Mn, Fe, Co, Ni, Cu). The phase purity and chemical homogeneity of the compounds were investigated by X-ray diffraction and energy dispersive X-ray spectroscopy. Independently of the composition, spin glassiness is observed in both systems. Scaling analyses suggest the materials undergo spin glass phase transitions at low temperatures. Yet, qualitative differences are observed between the single-layered and double-layered systems, which are discussed in the light of the spatial dimensionality and magnetic interaction in layered oxide perovskites.

2.
J Phys Condens Matter ; 29(15): 155402, 2017 Apr 20.
Article in English | MEDLINE | ID: mdl-28192279

ABSTRACT

Combining theory with experiments, we study the phase stability, elastic properties, electronic structure and hardness of layered ternary borides AlCr2B2, AlMn2B2, AlFe2B2, AlCo2B2, and AlNi2B2. We find that the first three borides of this series are stable phases, while AlCo2B2 and AlNi2B2 are metastable. We show that the elasticity increases in the boride series, and predict that AlCr2B2, AlMn2B2, and AlFe2B2 are more brittle, while AlCo2B2 and AlNi2B2 are more ductile. We propose that the elasticity of AlFe2B2 can be improved by alloying it with cobalt or nickel, or a combination of them. We present evidence that these ternary borides represent nanolaminated systems. Based on SEM measurements, we demonstrate that they exhibit the delamination phenomena, which leads to a reduced hardness compared to transition metal mono- and diborides. We discuss the background of delamination by analyzing chemical bonding and theoretical work of separation in these borides.

3.
Int J Clin Pract ; 69(6): 703-9, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25707918

ABSTRACT

BACKGROUND: Accidental falls during hospitalisation have a range of complications and more information is needed to improve prevention. We investigated patterns of in-hospital fall-related major injuries in the period 2000-2012 and the association between chronic conditions and in-hospital fall-related major injuries. METHODS: Using administrative databases, patients aged 65+ years with in-hospital falls causing fractures or head injuries with need for surgery or intensive observation were identified as cases and were individually matched with five controls. Joinpoint regression was used to examine time trends and conditional logistic regression was used to analyse odds ratio (OR) for in-hospital falls-related major injuries according to a range of comorbidities. RESULTS: Four thousand seven hundred and fifty-four cases were identified from 2000 to 2012 and the most common injury was femur fracture (61.55%). For individuals aged 65-74 and 75+ years, the incidence of in-hospital falls-related major injuries per 100,000 hospital days increased significantly in 2000-2012 (average annual change: 3.2%, CI: 0.6-5.8) and 2007-2012 (average annual change: 11.4%, CI: 5.7-17.5), respectively. Significantly increased OR for in-hospital fall-related major injuries were found for individuals with dementia (OR = 2.34, CI: 1.87-2.92), osteoporosis (OR = 1.68, CI: 1.43-1.99), stroke (OR = 1.63, CI: 1.41-1.88), depression (OR = 1.24, CI: 1.09-1.41), chronic obstructive pulmonary disease (OR = 1.18, CI: 1.01-1.39) and Parkinson disease (OR = 1.17, CI: 1.01-1.34). CONCLUSIONS: In-hospital falls-related major injuries increased significantly during the study period. Elderly with dementia, osteoporosis, stroke, depression, chronic obstructive pulmonary disease and Parkinson disease were associated with increased OR for in-hospital fall-related major injuries. Increased focus on patients with these comorbidities is warranted to decrease the increasing incidence in in-hospital major injuries.


Subject(s)
Accidental Falls/statistics & numerical data , Craniocerebral Trauma/etiology , Fractures, Bone/etiology , Hospitalization/statistics & numerical data , Aged , Aged, 80 and over , Case-Control Studies , Chronic Disease , Denmark/epidemiology , Female , Humans , Incidence , Male , Regression Analysis , Risk Factors
4.
J Phys Condens Matter ; 23(5): 055301, 2011 Feb 09.
Article in English | MEDLINE | ID: mdl-21406905

ABSTRACT

The thickness dependence of the Fe magnetic hyperfine field and the interfacial intermixing of Fe(0.82)Ni(0.18)/Co superlattices, with the same thickness for FeNi and Co layers, have been investigated. A local concentration model using the magnetic hyperfine field values from the [Fe(0.82)Ni(0.18)](1 - x)Co(x) alloys has been used to interpret the field distribution in the superlattices and the Co concentration profiles over the superlattices. A relationship between the Fe magnetic hyperfine field and the Fe magnetic moment has been determined for the unordered [Fe(0.82)Ni(0.18)](1 - x)Co(x) and Fe(1 - x)Co(x) alloys. The magnetic hyperfine fields have been explained using two Fermi contact terms: (i) the core electron term proportional to the Fe magnetic moment with a proportionality constant of - 13 T/µ(B) and (ii) a valence electron term linearly dependent on the Co concentration. The direction of the magnetic moments is found to be in the sample plane except for the 1/1 superlattice, where an angle of about 45° is found.

5.
Scand J Med Sci Sports ; 18(6): 756-64, 2008 Dec.
Article in English | MEDLINE | ID: mdl-18208434

ABSTRACT

Physical training is important in the treatment of patients with cystic fibrosis (CF). Optimal types of training and intensity are unknown. The aim of the study was to evaluate the effect on muscular strength after 6 months of endurance training (ET) and/or resistance training (RT). Twenty patients (eight females) participated, 16-35 years, with mean forced expiratory volume in 1 s 91% of the predicted. ET or RT for 30-45 min three times a week for 3 months was followed by a mixed program for another 3 months. Heart rate recording, diaries and frequent personal contacts were used for monitoring. Vitamin E and cytokines were analyzed. Fifteen tests of muscular strength were used. Handgrip strength in females and quadriceps strength in males were significantly decreased compared with healthy age- and sex-matched controls and positively associated with lung function. Sixteen patients completed the program. By ET, quadriceps strength was further decreased and after 6 months quadriceps isometric strength was also decreased in females. There was a tendency toward different effects on the serum levels of IL-6 and vitamin E by the different types of training. CF patients showed no improvements in muscular strength after 6 months of controlled training, suggesting a physiological muscular impairment despite normal anthropometry, but associated with lung function.


Subject(s)
Cystic Fibrosis/rehabilitation , Muscle Strength/physiology , Physical Fitness/physiology , Adult , Exercise Test , Female , Humans , Male , Monitoring, Physiologic/methods , Sweden , Young Adult
SELECTION OF CITATIONS
SEARCH DETAIL
...