| 1. |
- Schaff, Florian, et al.
(författare)
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Six-dimensional real and reciprocal space small-angle X-ray scattering tomography.
- 2015
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 527:7578, s. 353-353
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Tidskriftsartikel (refereegranskat)abstract
- When used in combination with raster scanning, small-angle X-ray scattering (SAXS) has proven to be a valuable imaging technique of the nanoscale, for example of bone, teeth and brain matter. Although two-dimensional projection imaging has been used to characterize various materials successfully, its three-dimensional extension, SAXS computed tomography, poses substantial challenges, which have yet to be overcome. Previous work using SAXS computed tomography was unable to preserve oriented SAXS signals during reconstruction. Here we present a solution to this problem and obtain a complete SAXS computed tomography, which preserves oriented scattering information. By introducing virtual tomography axes, we take advantage of the two-dimensional SAXS information recorded on an area detector and use it to reconstruct the full three-dimensional scattering distribution in reciprocal space for each voxel of the three-dimensional object in real space. The presented method could be of interest for a combined six-dimensional real and reciprocal space characterization of mesoscopic materials with hierarchically structured features with length scales ranging from a few nanometres to a few millimetres--for example, biomaterials such as bone or teeth, or functional materials such as fuel-cell or battery components.
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| 2. |
- Stadler, Marietta, et al.
(författare)
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Effects of smoking cessation on beta cell function, insulin sensitivity, body weight and appetite.
- 2014
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Ingår i: European journal of endocrinology / European Federation of Endocrine Societies. - 1479-683X. ; 170, s. 219-227
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Tidskriftsartikel (refereegranskat)abstract
- Objective To stop smoking is commonly associated with significant weight gain, but the mechanisms for this are poorly understood. We assessed the effects of smoking cessation on body weight, insulin sensitivity, β-cell function, and appetite. Subjects and methods Twenty-seven long-term smokers (n=27; nine females/18 males, 28±1 years, 22.9±0.6kg/m2) attending an ambulatory smoking cessation program in a community hospital in Vienna, Austria were examined at baseline (Visit A; still smoking) and after a minimum of 3 months of smoking abstinence (Visit B; n=14); relapsed smokers were not followed up. Participants underwent 3-h oral glucose tolerance tests and body composition measurements at each study visit. Fasting (QUICKI) and dynamic (oral glucose insulin sensitivity (OGIS)) insulin sensitivity and β-cell secretion (insulinogenic index 140 (IGI40)) were calculated. Food intake was quantified with a free choice buffet. Fasting plasma concentrations of neuropeptide-Y (NPY), peptide-YY (PYY), glucagon-like peptide 1 (GLP1), leptin, ghrelin, and visfatin were measured. Results After >3 months' smoking abstinence, body weight, and fat mass were increased (+4 and +22% respectively, P<0.05) and fasting insulin sensitivity deteriorated (QUICKI: post, 0.37±0.02 vs baseline, 0.41±0.2; P<0.05), while OGIS remained unchanged throughout. IGI40 increased by 31% after >3 months' smoking abstinence (P<0.01). Carbohydrate ingestion increased after stopping smoking (P<0.05). NPY fasting levels were increased after >3 months (P<0.05), PYY, GLP1, leptin, ghrelin, and visfatin were unchanged. Conclusion Smoking cessation is associated with transient metabolic changes including increased β-cell secretion in response to glucose and fasting insulin resistance. These alterations may be associated with or contribute to the body weight gain after smoking cessation.
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| 3. |
- Ţuţueanu, A. E., et al.
(författare)
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Gradual emergence of superconductivity in underdoped La2-x Srx CuO4
- 2023
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Ingår i: Physical Review B. - 2469-9969 .- 2469-9950. ; 107:17
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Tidskriftsartikel (refereegranskat)abstract
- We present triple-axis neutron scattering studies of low-energy magnetic fluctuations in strongly underdoped La2-xSrxCuO4 with x=0.05, 0.06 and 0.07, providing quantitative evidence for a direct competition between these fluctuations and superconductivity. At dopings x=0.06 and x=0.07, three-dimensional superconductivity is found, while only a very weak signature of two-dimensional superconductivity residing in the CuO2 planes is detectable for x=0.05. We find a surprising suppression of the low-energy fluctuations by an external magnetic field at all three dopings. This implies that the response of two-dimensional superconductivity to a magnetic field is similar to that of a bulk superconductor. Our results provide direct evidence of a very gradual onset of superconductivity in cuprates.
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| 4. |
- Wittchen, Hans-Ulrich, et al.
(författare)
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The need for a behavioural science focus in research on mental health and mental disorders
- 2014
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Ingår i: International Journal of Methods in Psychiatric Research. - : Wiley-Blackwell. - 1049-8931 .- 1557-0657. ; 23, s. 28-40
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Tidskriftsartikel (refereegranskat)abstract
- Psychology as a science offers an enormous diversity of theories, principles, and methodological approaches to understand mental health, abnormal functions and behaviours and mental disorders. A selected overview of the scope, current topics as well as strength and gaps in Psychological Science may help to depict the advances needed to inform future research agendas specifically on mental health and mental disorders. From an integrative psychological perspective, most maladaptive health behaviours and mental disorders can be conceptualized as the result of developmental dysfunctions of psychological functions and processes as well as neurobiological and genetic processes that interact with the environment. The paper presents and discusses an integrative translational model, linking basic and experimental research with clinical research as well as population-based prospective-longitudinal studies. This model provides a conceptual framework to identify how individual vulnerabilities interact with environment over time, and promote critical behaviours that might act as proximal risk factors for ill-health and mental disorders. Within the models framework, such improved knowledge is also expected to better delineate targeted preventive and therapeutic interventions that prevent further escalation in early stages before the full disorder and further complications thereof develop. In contrast to conventional personalized medicine that typically targets individual (genetic) variation of patients who already have developed a disease to improve medical treatment, the proposed framework model, linked to a concerted funding programme of the Science of Behaviour Change, carries the promise of improved diagnosis, treatment and prevention of health-risk behaviour constellations as well as mental disorders.
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