| 1. |
- Cossarizza, A., et al.
(author)
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Guidelines for the use of flow cytometry and cell sorting in immunological studies (second edition)
- 2019
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In: European Journal of Immunology. - : Wiley. - 0014-2980 .- 1521-4141. ; 49:10, s. 1457-1973
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Journal article (peer-reviewed)abstract
- These guidelines are a consensus work of a considerable number of members of the immunology and flow cytometry community. They provide the theory and key practical aspects of flow cytometry enabling immunologists to avoid the common errors that often undermine immunological data. Notably, there are comprehensive sections of all major immune cell types with helpful Tables detailing phenotypes in murine and human cells. The latest flow cytometry techniques and applications are also described, featuring examples of the data that can be generated and, importantly, how the data can be analysed. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid, all written and peer-reviewed by leading experts in the field, making this an essential research companion.
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| 2. |
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| 3. |
- Barucca, G., et al.
(author)
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The potential of Λ and Ξ- studies with PANDA at FAIR
- 2021
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In: European Physical Journal A. - : Springer Nature. - 1434-6001 .- 1434-601X. ; 57:4
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Journal article (peer-reviewed)abstract
- The antiproton experiment PANDA at FAIR is designed to bring hadron physics to a new level in terms of scope, precision and accuracy. In this work, its unique capability for studies of hyperons is outlined. We discuss ground-state hyperons as diagnostic tools to study non-perturbative aspects of the strong interaction, and fundamental symmetries. New simulation studies have been carried out for two benchmark hyperon-antihyperon production channels: p¯ p→ Λ¯ Λ and p¯ p→ Ξ¯ +Ξ-. The results, presented in detail in this paper, show that hyperon-antihyperon pairs from these reactions can be exclusively reconstructed with high efficiency and very low background contamination. In addition, the polarisation and spin correlations have been studied, exploiting the weak, self-analysing decay of hyperons and antihyperons. Two independent approaches to the finite efficiency have been applied and evaluated: one standard multidimensional efficiency correction approach, and one efficiency independent approach. The applicability of the latter was thoroughly evaluated for all channels, beam momenta and observables. The standard method yields good results in all cases, and shows that spin observables can be studied with high precision and accuracy already in the first phase of data taking with PANDA.
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| 4. |
- Barucca, G., et al.
(author)
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Study of excited Ξ baryons with the P¯ ANDA detector
- 2021
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In: European Physical Journal A. - : Springer Nature. - 1434-6001 .- 1434-601X. ; 57:4
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Journal article (peer-reviewed)abstract
- The study of baryon excitation spectra provides insight into the inner structure of baryons. So far, most of the world-wide efforts have been directed towards N∗ and Δ spectroscopy. Nevertheless, the study of the double and triple strange baryon spectrum provides independent information to the N∗ and Δ spectra. The future antiproton experiment P¯ANDA will provide direct access to final states containing a Ξ¯ Ξ pair, for which production cross sections up to μb are expected in p¯p reactions. With a luminosity of L= 10 31 cm- 2 s- 1 in the first phase of the experiment, the expected cross sections correspond to a production rate of ∼106events/day. With a nearly 4 π detector acceptance, P¯ANDA will thus be a hyperon factory. In this study, reactions of the type p¯p → Ξ¯ +Ξ∗ - as well as p¯p → Ξ¯ ∗ +Ξ- with various decay modes are investigated. For the exclusive reconstruction of the signal events a full decay tree fit is used, resulting in reconstruction efficiencies between 3 and 5%. This allows high statistics data to be collected within a few weeks of data taking.
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| 5. |
- Chahla, J., et al.
(author)
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The posteromedial corner of the knee: an international expert consensus statement on diagnosis, classification, treatment, and rehabilitation
- 2021
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In: Knee Surgery, Sports Traumatology, Arthroscopy. - : Springer Science and Business Media LLC. - 0942-2056 .- 1433-7347. ; 29, s. 2976-2986
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Journal article (peer-reviewed)abstract
- Purpose: To establish recommendations for diagnosis, classification, treatment, and rehabilitation of posteromedial corner (PMC) knee injuries using a modified Delphi technique. Methods: A list of statements concerning the diagnosis, classification, treatment and rehabilitation of PMC injuries was created by a working group of four individuals. Using a modified Delphi technique, a group of 35 surgeons with expertise in PMC injuries was surveyed, on three occasions, to establish consensus on the inclusion or exclusion of each statement. Experts were encouraged to propose further suggestions or modifications following each round. Pre-defined criteria were used to refine item lists after each survey. The final document included statements reaching consensus in round three. Results: Thirty-five experts had a 100% response rate for all three rounds. A total of 53 items achieved over 75% consensus. The overall rate of consensus was 82.8%. Statements pertaining to PMC reconstruction and those regarding the treatment of combined cruciate and PMC injuries reached 100% consensus. Consensus was reached for 85.7% of the statements on anatomy of the PMC, 90% for those relating to diagnosis, 70% relating to classification, 64.3% relating to the treatment of isolated PMC injuries, and 83.3% relating to rehabilitation after PMC reconstruction. Conclusion: A modified Delphi technique was applied to generate an expert consensus statement concerning the diagnosis, classification, treatment, and rehabilitation practices for PMC injuries of the knee with high levels of expert agreement. Though the majority of statements pertaining to anatomy, diagnosis, and rehabilitation reached consensus, there remains inconsistency as to the optimal approach to treating isolated PMC injuries. Additionally, there is a need for improved PMC injury classification. Level of evidence: Level V. © 2020, European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).
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| 6. |
- Kunze, K. N., et al.
(author)
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A guide to appropriately planning and conducting meta-analyses: part 3. Special considerations-the network meta-analysis
- 2023
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In: Knee Surgery Sports Traumatology Arthroscopy. - 0942-2056. ; 31:7, s. 2544-2549
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Research review (peer-reviewed)abstract
- The meta-analysis has become one of the predominant studies designs in orthopaedic literature. Within recent years, the network meta-analysis has been implicated as a powerful approach to comparing multiple treatments for an outcome of interest when conducting a meta-analysis (as opposed to two competing treatments which is typical of a traditional meta-analysis). With the increasing use of the network meta-analysis, it is imperative for readers to possess the ability to independently and critically evaluate these types of studies. The purpose of this article is to provide the necessary foundation of knowledge to both properly conduct and interpret the results of a network meta-analysis.
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| 7. |
- Parmar, Priyanka, et al.
(author)
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Association of maternal prenatal smoking GFI1-locus and cardiometabolic phenotypes in 18,212 adults
- 2018
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In: EBioMedicine. - : Elsevier BV. - 2352-3964. ; 38, s. 206-216
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Journal article (peer-reviewed)abstract
- Background: DNA methylation at the GFI1-locus has been repeatedly associated with exposure to smoking from the foetal period onwards. We explored whether DNA methylation may be a mechanism that links exposure to maternal prenatal smoking with offspring's adult cardio-metabolic health. Methods: We meta-analysed the association between DNA methylation at GFI1-locus with maternal prenatal smoking, adult own smoking, and cardio-metabolic phenotypes in 22 population-based studies from Europe, Australia, and USA (n= 18,212). DNA methylation at the GFI1-locus was measured in whole-blood. Multivariable regression models were fitted to examine its association with exposure to prenatal and own adult smoking. DNA methylation levels were analysed in relation to body mass index (BMI), waist circumference (WC), fasting glucose (FG), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), diastolic, and systolic blood pressure (BP). Findings: Lower DNA methylation at three out of eight GFI1-CpGs was associated with exposure to maternal prenatal smoking, whereas, all eight CpGs were associated with adult own smoking. Lower DNA methylation at cg14179389, the strongest maternal prenatal smoking locus, was associated with increased WC and BP when adjusted for sex, age, and adult smoking with Bonferroni-corrected P < 0.012. In contrast, lower DNA methylation at cg09935388, the strongest adult own smoking locus, was associated with decreased BMI, WC, and BP (adjusted 1 x 10(-7) < P < 0.01). Similarly, lower DNA methylation at cg12876356, cg18316974, cg09662411, and cg18146737 was associated with decreased BMI and WC (5 x 10(-8) < P < 0.001). Lower DNA methylation at all the CpGs was consistently associated with higher TG levels. Interpretation: Epigenetic changes at the GFI1 were linked to smoking exposure in-utero/in-adulthood and robustly associated with cardio-metabolic risk factors. Fund: European Union's Horizon 2020 research and innovation programme under grant agreement no. 633595 DynaHEALTH.
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| 8. |
- Pruneski, J. A., et al.
(author)
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Supervised machine learning and associated algorithms: applications in orthopedic surgery
- 2023
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In: Knee Surgery Sports Traumatology Arthroscopy. - : Springer Science and Business Media LLC. - 0942-2056 .- 1433-7347. ; 31:4, s. 1196-1202
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Journal article (peer-reviewed)abstract
- Supervised learning is the most common form of machine learning utilized in medical research. It is used to predict outcomes of interest or classify positive and/or negative cases with a known ground truth. Supervised learning describes a spectrum of techniques, ranging from traditional regression modeling to more complex tree boosting, which are becoming increasingly prevalent as the focus on "big data" develops. While these tools are becoming increasingly popular and powerful, there is a paucity of literature available that describe the strengths and limitations of these different modeling techniques. Typically, there is no formal training for health care professionals in the use of machine learning models. As machine learning applications throughout medicine increase, it is important that physicians and other health care professionals better understand the processes underlying application of these techniques. The purpose of this study is to provide an overview of commonly used supervised learning techniques with recent case examples within the orthopedic literature. An additional goal is to address disparities in the understanding of these methods to improve communication within and between research teams.
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| 9. |
- Fazey, Ioan, et al.
(author)
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Transforming knowledge systems for life on Earth : Visions of future systems and how to get there
- 2020
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In: Energy Research & Social Science. - : Elsevier. - 2214-6296 .- 2214-6326. ; 70
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Journal article (peer-reviewed)abstract
- Formalised knowledge systems, including universities and research institutes, are important for contemporary societies. They are, however, also arguably failing humanity when their impact is measured against the level of progress being made in stimulating the societal changes needed to address challenges like climate change. In this research we used a novel futures-oriented and participatory approach that asked what future envisioned knowledge systems might need to look like and how we might get there. Findings suggest that envisioned future systems will need to be much more collaborative, open, diverse, egalitarian, and able to work with values and systemic issues. They will also need to go beyond producing knowledge about our world to generating wisdom about how to act within it. To get to envisioned systems we will need to rapidly scale methodological innovations, connect innovators, and creatively accelerate learning about working with intractable challenges. We will also need to create new funding schemes, a global knowledge commons, and challenge deeply held assumptions. To genuinely be a creative force in supporting longevity of human and non-human life on our planet, the shift in knowledge systems will probably need to be at the scale of the enlightenment and speed of the scientific and technological revolution accompanying the second World War. This will require bold and strategic action from governments, scientists, civic society and sustained transformational intent.
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| 10. |
- Kay, J., et al.
(author)
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A guide to appropriately planning and conducting meta-analyses-Part 1: indications, assumptions and understanding risk of bias
- 2023
-
In: Knee Surgery Sports Traumatology Arthroscopy. - : Springer Science and Business Media LLC. - 0942-2056 .- 1433-7347.
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Journal article (peer-reviewed)abstract
- A meta-analysis is the quantitative synthesis of data from two or more individual studies and are as a rule an important method of obtaining a more accurate estimate of the direction and magnitude of a treatment effect. However, it is imperative that the meta-analysis be performed with proper, rigorous methodology to ensure validity of the results and their interpretation. In this article the authors will review the most important questions researchers should consider when planning a meta-analysis to ensure proper indications and methodologies, minimize the risk of bias, and avoid misleading conclusions.
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| 11. |
- Khorana, A., et al.
(author)
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Choosing the appropriate measure of central tendency: mean, median, or mode?
- 2023
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In: Knee Surgery Sports Traumatology Arthroscopy. - : Springer Science and Business Media LLC. - 0942-2056 .- 1433-7347. ; 31:1, s. 12-15
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Journal article (peer-reviewed)abstract
- Mean, median, and mode are among the most basic and consistently used measures of central tendency in statistical analysis and are crucial for simplifying data sets to a single value. However, there is a lack of understanding of when to use each metric and how various factors can impact these values. The aim of this article is to clarify some of the confusion related to each measure and explain how to select the appropriate metric for a given data set. The authors present this work as an educational resource, ensuring that these common statistical concepts are better understood throughout the Orthopedic research community.
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| 12. |
- Kunze, J., et al.
(author)
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Optical study of competition between ordering and metallicity in La(2-2x)Sr(1+2x)Mn(2)O(7)
- 2003
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In: Physical Review B Condensed Matter. - 0163-1829 .- 1095-3795. ; 67
-
Journal article (peer-reviewed)abstract
- We study by spectroscopic ellipsometry the optical in-plane anisotropies in La(2-2x)Sr(1+2x)Mn(2)O(7) with 0.32less than or equal toxless than or equal to0.40 above and below the metal to insulator (MI) transition. Spectral-weight changes in the optical conductivity occur at a cross-over temperature T(’)=280 K for all dopings. Local ordering of orbital and charge degrees of freedom sets in doping dependently at temperatures of 145 Kless than or equal toT(*)less than or equal to310 K. Below the MI transition we observe for all dopings except x=0.36 a vanishing of the charge ordering and an isotropic and metallic state at low frequencies, whereas the local orbital ordering persists. For x=0.36 we observe two different characteristic developments of the ordering processes, one being compatible with the parabolic doping dependence on T(*) established by the other doping levels and the second showing ordering at a temperature slightly above the MI transition. We argue that our observations are compatible with a phase separation scenario.
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| 13. |
- Kunze, K. N., et al.
(author)
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A guide to appropriately planning and conducting meta-analyses: part 2-effect size estimation, heterogeneity and analytic approaches
- 2023
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In: Knee Surgery Sports Traumatology Arthroscopy. - : Springer Science and Business Media LLC. - 0942-2056 .- 1433-7347. ; 31:5, s. 1629-1634
-
Research review (peer-reviewed)abstract
- Meta-analyses by definition are a subtype of systematic review intended to quantitatively assess the strength of evidence present on an intervention or treatment. Such analyses may use individual-level data or aggregate data to produce a point estimate of an effect, also known as the combined effect, and measure precision of the calculated estimate. The current article will review several important considerations during the analytic phase of a meta-analysis, including selection of effect estimators, heterogeneity and various sub-types of meta-analytic approaches.
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| 14. |
- Kunze, M, et al.
(author)
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Recommendations to Improve Tick-Borne Encephalitis Surveillance and Vaccine Uptake in Europe
- 2022
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In: Microorganisms. - : MDPI AG. - 2076-2607. ; 10:7
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Journal article (peer-reviewed)abstract
- There has been an increase in reported TBE cases in Europe since 2015, reaching a peak in some countries in 2020, highlighting the need for better management of TBE risk in Europe. TBE surveillance is currently limited, in part, due to varying diagnostic guidelines, access to testing, and awareness of TBE. Consequently, TBE prevalence is underestimated and vaccination recommendations inadequate. TBE vaccine uptake is unsatisfactory in many TBE-endemic European countries. This review summarizes the findings of a scientific workshop of experts to improve TBE surveillance and vaccine uptake in Europe. Strategies to improve TBE surveillance and vaccine uptake should focus on: aligning diagnostic criteria and testing across Europe; expanding current vaccine recommendations and reducing their complexity; and increasing public education of the potential risks posed by TBEV infection.
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| 15. |
- Nesti, Cedric, et al.
(author)
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Hemicolectomy versus appendectomy for patients with appendiceal neuroendocrine tumours 1-2 cm in size : a retrospective, Europe-wide, pooled cohort study
- 2023
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In: The Lancet Oncology. - : Elsevier. - 1470-2045 .- 1474-5488. ; 24:2, s. 187-194
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Journal article (peer-reviewed)abstract
- BackgroundAwareness of the potential global overtreatment of patients with appendiceal neuroendocrine tumours (NETs) of 1–2 cm in size by performing oncological resections is increasing, but the rarity of this tumour has impeded clear recommendations to date. We aimed to assess the malignant potential of appendiceal NETs of 1–2 cm in size in patients with or without right-sided hemicolectomy.MethodsIn this retrospective cohort study, we pooled data from 40 hospitals in 15 European countries for patients of any age and Eastern Cooperative Oncology Group performance status with a histopathologically confirmed appendiceal NET of 1–2 cm in size who had a complete resection of the primary tumour between Jan 1, 2000, and Dec 31, 2010. Patients either had an appendectomy only or an appendectomy with oncological right-sided hemicolectomy or ileocecal resection. Predefined primary outcomes were the frequency of distant metastases and tumour-related mortality. Secondary outcomes included the frequency of regional lymph node metastases, the association between regional lymph node metastases and histopathological risk factors, and overall survival with or without right-sided hemicolectomy. Cox proportional hazards regression was used to estimate the relative all-cause mortality hazard associated with right-sided hemicolectomy compared with appendectomy alone. This study is registered with ClinicalTrials.gov, NCT03852693.Findings282 patients with suspected appendiceal tumours were identified, of whom 278 with an appendiceal NET of 1–2 cm in size were included. 163 (59%) had an appendectomy and 115 (41%) had a right-sided hemicolectomy, 110 (40%) were men, 168 (60%) were women, and mean age at initial surgery was 36·0 years (SD 18·2). Median follow-up was 13·0 years (IQR 11·0–15·6). After centralised histopathological review, appendiceal NETs were classified as a possible or probable primary tumour in two (1%) of 278 patients with distant peritoneal metastases and in two (1%) 278 patients with distant metastases in the liver. All metastases were diagnosed synchronously with no tumour-related deaths during follow-up. Regional lymph node metastases were found in 22 (20%) of 112 patients with right-sided hemicolectomy with available data. On the basis of histopathological risk factors, we estimated that 12·8% (95% CI 6·5 –21·1) of patients undergoing appendectomy probably had residual regional lymph node metastases. Overall survival was similar between patients with appendectomy and right-sided hemicolectomy (adjusted hazard ratio 0·88 [95% CI 0·36–2·17]; p=0·71).InterpretationThis study provides evidence that right-sided hemicolectomy is not indicated after complete resection of an appendiceal NET of 1–2 cm in size by appendectomy, that regional lymph node metastases of appendiceal NETs are clinically irrelevant, and that an additional postoperative exclusion of metastases and histopathological evaluation of risk factors is not supported by the presented results. These findings should inform consensus best practice guidelines for this patient cohort.
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| 16. |
- Pfeiffer, L., et al.
(author)
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DNA methylation of lipid-related genes affects blood lipid levels
- 2015
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In: Circ Cardiovasc Genet. ; 8:2, s. 334-42
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Journal article (peer-reviewed)abstract
- BACKGROUND: Epigenetic mechanisms might be involved in the regulation of interindividual lipid level variability and thus may contribute to the cardiovascular risk profile. The aim of this study was to investigate the association between genome-wide DNA methylation and blood lipid levels high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, and total cholesterol. Observed DNA methylation changes were also further analyzed to examine their relationship with previous hospitalized myocardial infarction. METHODS AND RESULTS: Genome-wide DNA methylation patterns were determined in whole blood samples of 1776 subjects of the Cooperative Health Research in the Region of Augsburg F4 cohort using the Infinium HumanMethylation450 BeadChip (Illumina). Ten novel lipid-related CpG sites annotated to various genes including ABCG1, MIR33B/SREBF1, and TNIP1 were identified. CpG cg06500161, located in ABCG1, was associated in opposite directions with both high-density lipoprotein cholesterol (beta coefficient=-0.049; P=8.26E-17) and triglyceride levels (beta=0.070; P=1.21E-27). Eight associations were confirmed by replication in the Cooperative Health Research in the Region of Augsburg F3 study (n=499) and in the Invecchiare in Chianti, Aging in the Chianti Area study (n=472). Associations between triglyceride levels and SREBF1 and ABCG1 were also found in adipose tissue of the Multiple Tissue Human Expression Resource cohort (n=634). Expression analysis revealed an association between ABCG1 methylation and lipid levels that might be partly mediated by ABCG1 expression. DNA methylation of ABCG1 might also play a role in previous hospitalized myocardial infarction (odds ratio, 1.15; 95% confidence interval=1.06-1.25). CONCLUSIONS: Epigenetic modifications of the newly identified loci might regulate disturbed blood lipid levels and thus contribute to the development of complex lipid-related diseases.
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| 17. |
- Wahl, Simone, et al.
(author)
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Epigenome-wide association study of body mass index, and the adverse outcomes of adiposity
- 2017
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In: Nature. - : NATURE PUBLISHING GROUP. - 0028-0836 .- 1476-4687. ; 541:7635, s. 81-
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Journal article (peer-reviewed)abstract
- Approximately 1.5 billion people worldwide are overweight or affected by obesity, and are at risk of developing type (2) diabetes, cardiovascular disease and related metabolic and inflammatory disturbances(1,2). Although the mechanisms linking adiposity to associated clinical conditions are poorly understood, recent studies suggest that adiposity may influence DNA methylation(3-6), a key regulator of gene expression and molecular phenotype(7). Here we use epigenome-wide association to show that body mass index (BMI; a key measure of adiposity) is associated with widespread changes in DNA methylation (187 genetic loci with P < 1 x 10(-7), range P = 9.2 x 10(-8) to 6.0 x 10(-46); n = 10,261 samples). Genetic association analyses demonstrate that the alterations in DNA methylation are predominantly the consequence of adiposity, rather than the cause. We find that methylation loci are enriched for functional genomic features in multiple tissues (P < 0.05), and show that sentinel methylation markers identify gene expression signatures at 38 loci (P < 9.0 x 10(-6), range P = 5.5 x 10(-6) to 6.1 x 10(-35), n = 1,785 samples). The methylation loci identify genes involved in lipid and lipoprotein metabolism, substrate transport and inflammatory pathways. Finally, we show that the disturbances in DNA methylation predict future development of type 2 diabetes (relative risk per 1 standard deviation increase in methylation risk score: 2.3 (2.07-2.56); P = 1.1 x 10(-54)). Our results provide new insights into the biologic pathways influenced by adiposity, and may enable development of new strategies for prediction and prevention of type 2 diabetes and other adverse clinical consequences of obesity.
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| 18. |
- Galizia, C. G., et al.
(author)
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Relationship of visual and olfactory signal parameters in a food-deceptive flower mimicry system
- 2005
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In: Behavioral Ecology. - : Oxford University Press (OUP). - 1045-2249 .- 1465-7279. ; 16:1, s. 159-168
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Journal article (peer-reviewed)abstract
- Pollinators such as bees are attracted to flowers by their visual display and their scent. Although most flowers reinforce visits by providing pollen and/or nectar, there are species-notably from the orchid family-that do not but do resemble rewarding species. These mimicry relationships provide ideal opportunities for investigating the evolution of floral signals and their impact on pollinator behavior. Here, we have reanalyzed a case of specialized food mimicry between the orchid Orchis israelitica and its model, the lily Bellevalia flexuosa. Based on current knowledge of insect sensory physiology, we were able to characterize both the visual and olfactory signals of model and mimic, as well as of two phylogenetically related orchids. By using a color vision model, we mapped each species' visual signals to the perceptual space of honeybees and found an apparent shift of the mimic's visual signals towards the model. We confirm that visual mimicry is present. We analyzed the flower odors by using gas chromatography/mass spectroscopy. We related these signals to the perceptual space of the pollinators by testing the scent extracts physiologically, using in vivo brain imaging. We found no evidence of olfactory mimicry. The results indicate that evolutionary pressure acts on the visual, but not olfactory, traits of O. israelitica toward a higher similarity to its model. Apparently, odor mismatch does not prevent a bee from landing on a flower that has the expected visual display. The results therefore argue for the dominance of visual stimuli in short-distance flower choice. The orchid may still depend on long-distance olfactory attraction originating from neighboring model plants.
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| 19. |
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| 20. |
- Lundgren, A., et al.
(author)
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Resonance-Mode Electrochemical Impedance Measurements of Silicon Dioxide Supported Lipid Bilayer Formation and Ion Channel Mediated Charge Transport
- 2011
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In: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 83:20, s. 7800-7806
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Journal article (peer-reviewed)abstract
- A single-chip electrochemical method based on impedance measurements in resonance mode has been employed to study lipid monolayer and bilayer formation on hydrophobic alkanethiolate and SiO(2) substrates, respectively. The processes were monitored by temporally resolving changes in interfacial capacitance and resistance, revealing information about the rate of formation, coverage, and defect density (quality) of the layers at saturation. The resonance-based impedance measurements were shown to reveal significant differences in the layer formation process of bilayers made from (i) positively charged lipid 1-palmitoyl-2-oleoyl-sn-glycero-3-ethylphosphocholine (POEPC), (ii) neutral lipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) on SiO(2), and (iii) monolayers made from POEPC on hydrophobic alkanethiolate substrates. The observed responses were represented with an equivalent circuit, suggesting that the differences primarily originate from the presence of a conductive aqueous layer between the lipid bilayers and the SiO(2). In addition, by adding the ion channel gramicidin D to bilayers supported on SiO(2), channel-mediated charge transport could be measured with high sensitivity (resolution around 1 pA).
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| 21. |
- Neuber, G., et al.
(author)
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Generalized magneto-optical ellipsometry in ferromagnetic metals
- 2004
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In: Thin Solid Films. - 0040-6090 .- 1879-2731. ; 455, s. 39-42
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Journal article (peer-reviewed)abstract
- We present spectral generalized magneto-optical ellipsometry as an optical tool to investigate magnetic and electronic properties of ferromagnetic materials. The advantage of the simultaneous observation of the dielectric and the magnetic responses within one measurement procedure is crucial for materials with coupled degrees of freedom near a phase transition or during annealing procedures to improve the film quality by removing grain boundaries. Moreover, we show the implementation of this technique within an UHV-cryostat for a temperature range between 4.2 and 800 K and fields up to 40 mT. Examplary measurements on iron and Permalloy demonstrate the comfortable application of this technique. (C) 2003 Elsevier B.V. All rights reserved.
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| 22. |
- Neuber, G., et al.
(author)
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Temperature-dependent spectral generalized magneto-optical ellipsometry
- 2003
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In: Applied Physics Letters. - 0003-6951 .- 1077-3118. ; 83, s. 4509-4511
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Journal article (peer-reviewed)abstract
- We present a setup for temperature-dependent spectral generalized magneto-optical ellipsometry (SGME). This technique gives access to the electronic as well as the magnetic properties of ferromagnetic materials within one single magneto-optical measurement. It also allows the determination of the orientation of the magnetization. We show spectra of the real and the imaginary part of the refractive index N as well as the magneto-optical coupling parameter Q of permalloy and iron films for in-plane magnetization. Our findings demonstrate the relevance of SGME for the understanding of the interplay between electronic and magnetic properties of ferromagnetics. (C) 2003 American Institute of Physics.
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| 23. |
- Rauer, R., et al.
(author)
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Magneto-optical investigation of spin polarisation of La0.71Ca0.3MnO3 and La0.7Sr0.3MnO3
- 2005
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In: Journal of Magnetism and Magnetic Materials. ; 290, s. 948-951
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Journal article (peer-reviewed)abstract
- We investigate the ferromagnetic phase of thin epitaxial films of the CMR manganites La0.7Ca0.3MnO3 and La0.7Sr0.3MnO3 by temperature-dependent spectral generalised magneto-optical ellipsometry (SGME). The phase transitions from a paramagnetic insulator to a ferromagnetic metal take place at T-C &AP; 265 K and T-C &AP; 335 K, respectively. The measurements covering a spectral range of 0.5-5eV are performed in the temperature range of 25-425 K. SGME allows a complete magneto-optical characterisation consisting of the determination of the diagonal components as well as the off-diagonal components ε(xx) of the dielectric tensor within a single measurement. Upon cooling through the Curie temperature, we observe the development of a Drude-like free-carrier response in ε(xx), indicating the release of previously bound charges. Meanwhile, ε(xx) exhibits a rising magneto-optical response. This reflects, via the increasing degree of spin polarisation of the bands involved in optical transitions, the emergence of ferromagnetism. We tentatively assign spectral features between 2.5 and 4.5 eV to transitions involving the Mn-d shell, especially the e(g) and t(2g) levels. © 2004 Elsevier B.V. All rights reserved.
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| 24. |
- Rauer, R., et al.
(author)
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Temperature-dependent spectral generalized magneto-optical ellipsometry for ferromagnetic compounds
- 2005
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In: Review of Scientific Instruments. - 0034-6748 .- 1089-7623. ; 76
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Journal article (peer-reviewed)abstract
- Spectral generalized magneto-optical ellipsometry is presented as an optical tool for the simultaneous measurement of the complex index of refraction n=n+ik, the complex magneto-optical coupling parameter Q=Q(r)+iQ(i) (i.e., the Voigt-parameter), and the orientation of the saturation magnetization M-s of isotropic ferromagnetic bulk materials. For wavelengths between 220 nm and 790 nm and at temperatures between 4.2 K and 800 K measurements on iron and permalloy demonstrate the comfortable application of this technique in order to resolve the spectral response of spin-polarized carriers and bands, which can provide valuable insight about the formation of the ferromagnetic state. (C) 2005 American Institute of Physics.
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| 25. |
- Wayment-Steele, H. K., et al.
(author)
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Effects of Al3+ on Phosphocholine and Phosphoglycerol Containing Solid Supported Lipid Bilayers
- 2016
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In: Langmuir. - : American Chemical Society (ACS). - 1520-5827 .- 0743-7463. ; 32:7, s. 1771-1781
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Journal article (peer-reviewed)abstract
- Aluminum has attracted great attention recently as it has been suggested by several studies to be associated with increased risks for Alzheimer's and Parkinson's disease. The toxicity of the trivalent ion is assumed to derive from structural changes induced in lipid bilayers upon binding, though the mechanism of this process is still not well understood. In the present study we elucidate the effect of Al3+ on supported lipid bilayers (SLBs) using fluorescence microscopy, the quartz crystal microbalance with dissipation (QCM-D) technique, dual-polarization interferometry (DPI), and molecular dynamics (MD) simulations. Results from these techniques show that binding of Al3+ to SLBs containing negatively charged and neutral phospholipids induces irreversible changes such as domain formation. The measured variations in SLB thickness, birefringence, and density indicate a phase transition from a disordered to a densely packed ordered phase.
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| 26. |
- Winfield, A. F. T., et al.
(author)
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Ethical Risk Assessment for Social Robots : Case Studies in Smart Robot Toys
- 2022
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In: Intelligent Systems, Control and Automation: Science and Engineering. - Cham : Springer Nature. ; , s. 61-76
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Book chapter (other academic/artistic)abstract
- Risk Assessment is a well known and powerful method for discovering and mitigating risks, and hence improving safety. Ethical Risk Assessment uses the same approach, but extends the scope of risk to cover ethical risks in addition to safety risks. In this paper we outline Ethical Risk Assessment (ERA), and set ERA within the broader framework of Responsible Robotics. We then illustrate ERA, first with a hypothetical smart robot teddy bear (RoboTed), and later with an actual smart robot toy (Purrble). Through these two case studies this paper demonstrates the value of ERA and how consideration of ethical risks can prompt design changes, resulting in more ethical and sustainable robots.
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