Measurement setup for Nernst and Seebeck effect at high temperatures and magnetic fields tested on elemental bismuth and full-Heusler compounds

In this work, a measurement setup to study the Seebeck and Nernst effect at high temperatures and high magnetic fields is introduced and discussed. The measurement system allows for simultaneous measurements of both thermoelectric effects up to 700 K and magnetic fields up to 12 T. Based on theoretical concepts, measurement equations are derived that counteract constant spurious offset voltages and, therefore, inhibit systematic errors in the measurement setup. The functionality is demonstrated on polycrystalline samples of elemental bismuth as well as various full-Heusler materials, exhibiting an anomalous Nernst effect. In all samples, the measured Seebeck and Nernst coefficients align excellently with the reported values. This allows future research to substantially extend the measured temperature and field intervals, commonly limited to temperatures below room temperature. For the first time, the thermoelectric and thermomagnetic properties of these materials are reported up to temperatures of 560 K.

Relationship between ectopic calcifications and bone fragility depicted on computed tomography scan in 70 patients with systemic sclerosis

Background

A higher risk of osteoporotic fracture was described in systemic sclerosis patients than in healthy patients.

Objective

To evaluate the relation between osteoporotic fracture risk measured by the scanographic bone attenuation coefficient of the first lumbar vertebra (SBAC-L1) on computed tomography (CT) scan and the presence of ectopic calcifications: vascular, valvular and spinal.

Methods

This monocentric retrospective study was performed on patients followed between 2000 and 2014 at Nancy University Hospital. Systemic sclerosis patients, according to ACR/EULAR 2013 criteria, followed from 2000 to 2014 and who underwent, during their follow-up, a CT including the first lumbar vertebra were included. The SBAC-L1 was measured with a threshold set at 145 Hounsfield units (HU). Vascular and spinal calcifications were studied on CT. For vascular calcifications, the Agatston score was used. Valvular calcifications were studied on echocardiography.

Results

A total of 70 patients were included (mean age: 62.3 (±15.6) years, women 88.5%). The mean SBAC-L1 was 157.26 (±52.1) HU, and 35 patients (50%) presented an SBAC-L1 ⩽ 145 HU. The reproducibility of the calcification evaluation was good, with kappa coefficients varying between 0.63 and 1. In univariate analysis, spinal and vascular calcifications were associated with an SBAC-L1 ⩽ 145 HU, with ORs of 13.6 (1.6-113.3) and 8 (95%CI: 2.5-25.5), respectively. In multivariate analysis, the SBAC-L1 was not associated with the presence of any ectopic calcifications. The SBAC-L1 decreased with age (p = 0.0001).

Conclusion

Patients with systemic sclerosis with an SBAC-L1 ⩽ 145 HU were older, but they did not have more ectopic calcification.

Trial registration

The ethics committee of Nancy Hospital agreed with this study (referral file number 166). This study was designed in accordance with the general ethical principles outlined in the Declaration of Helsinki.

AB0948 Osteoporotic screening and prevalence of severe osteoporotic fractures in a population of psoriatic arthritis initiating a biologic treatment

Background

Osteoporosis is a common complication of Rheumatic diseases. The association between osteoporosis and rheumatoid arthritis is clearly demonstrated while this association is still debated as well as for the screening of osteoporosis by Dual-Energy X-Ray Absorptiometry (DEXA) or to demonstrate an increased risk of fracture on radiography in a population of Psoriatic Arthritis (PsA). The prevalence of fragility fractures reported on medical reports ranged between 12% and 40% in PsA patients. Only a few studies evaluated the prevalence of vertebral fracture (VF) on spine radiographs. To our knowledge no study has evaluated the contribution of radiographic or CT assessment of the spine on the prevalence of fragility fracture reported in medical records.

Objectives

To determine Psoriatic Arthritis patient’s characteristics screened for osteoporosis by DEXA in a population initiating a biologic treatment (bDMARD) and to estimate the prevalence of severe osteoporotic fractures on medical reports and after imaging modalities scoring (X-ray or CT-scan).

Methods

Patients with psoriasis should satisfy the CASPAR or ASAS criteria and have been screened during their follow up for a bDMARD. Osteoporotic screening was defined by a BMD testing (DEXA). Vertebral fractures were scored according to Genant’s method on spine X-ray or sagittal CT-scan images. Clinical and demographic data and the presence of previous severe osteoporotic fracture reported in the medical records were collected.

Results

On 417 PsA patients screened for bDMARDs during 2008-2019, 89 patients (21.3%) were assessed for osteoporosis by DEXA. Increased age, female sex, menopause, previous severe fracture, disease duration, presence of inflammatory bowel disease, current and previous corticosteroid and bDMARDs uses were significantly associated with osteoporotic screening. On DEXA, 7 patients (7.9%) were classified as osteoporotic. The prevalence of severe osteoporotic fracture was 6.7% in medical reports and increased to 23.6% after scoring spine radiographies or TAP-CT images. In univariate analysis the presence of severe osteoporotic fractures was associated with age (p=0.013), scanographic bone attenuation coefficient (p=0.005) and Lumbar T-score (p=0.039).

Conclusion

Less than a quarter of PsA patients initiating a bDMARD is screened for osteoporosis. The prevalence of osteoporosis on DEXA and severe osteoporotic fractures on medical records are inferior to 10%. After systematic imaging evaluation, this prevalence increases at 23.6%.

References

[1]Chandran S, Aldei A, Johnson SR, Cheung AM, Salonen D, Gladman DD. Prevalence and risk factors of low bone mineral density in psoriatic arthritis: A systematic review. Seminars in Arthritis and Rheumatism. oct 2016

[2]Riesco M, Manzano F, Font P, García A, Nolla JM. Osteoporosis in psoriatic arthritis: an assessment of densitometry and fragility fractures. Clinical Rheumatology. déc 2013

[3]Pedreira PG, Pinheiro MM, Szejnfeld VL. Bone mineral density and body composition in postmenopausal women with psoriasis and psoriatic arthritis. Arthritis Res Ther. févr 2011

[4]Del Puente A, Esposito A, Costa L, Benigno C, Del Puente A, Foglia F, et al. Fragility Fractures in Patients with Psoriatic Arthritis. The Journal of Rheumatology Supplement. 1 nov 2015

[5]van der Weijden MAC, van der Horst-Bruinsma IE, van Denderen JC, Dijkmans BAC, Heymans MW, Lems WF. High frequency of vertebral fractures in early spondylarthropathies. Osteoporos Int. juin 2012

[6]Pickhardt PJ, Pooler BD, Lauder T, del Rio AM, Bruce RJ, Binkley N. Opportunistic Screening for Osteoporosis Using Abdominal Computed Tomography Scans Obtained for Other Indications. Ann Intern Med. 16 avr 2013

[7]Kwok TSH, Sutton M, Yang Ye J, Pereira D, Chandran V, Gladman DD. Prevalence and factors associated with osteoporosis and bone mineral density testing in psoriatic arthritis. Arthritis Care & Research. 16 déc 2020

[8]Gulati AM et al. Osteoporosis in psoriatic arthritis: a cross-sectional study of an outpatient clinic population. RMD Open. juin 2018

Disclosure of Interests

None declared

Physical properties of {Ti,Zr,Hf}2Ni2Sn compounds

Physical properties, i.e. electrical resistivity (4.2-800 K), Seebeck coefficient (300-800 K), specific heat (2-110 K), Vickers hardness and elastic moduli (RT), have been defined for single-phase compounds with slightly nonstoichiometric compositions: Ti_2.13Ni₂Sn_0.87, Zr_2.025Ni₂Sn_0.975, and Hf_2.055Ni₂Sn_0.945. From X-ray single crystal and TEM analyses, Ti_2+xNi₂Sn_1-x, x ∼ 0.13(1), is isotypic with the U₂Pt₂Sn-type (space group P4₂/mnm, ternary ordered version of the Zr₃Al₂-type), also adopted by the homologous compounds with Zr and Hf. For all three polycrystalline compounds (relative densities >95%) the electrical resistivity of the samples is metallic-like with dominant scattering from static defects mainly conditioned by off-stoichiometry. Analyses of the specific heat curves C_pvs. T and C_p/T vs. T² reveal Sommerfeld coefficients of γ_Ti2Ni2Sn = 14.3(3) mJ mol^-1 K^-2, γ_Zr2Ni2Sn = 10(1) mJ mol^-1 K^-2, γ_Hf2Ni2Sn = 9.1(5) mJ mol^-1 K^-2 and low-temperature Debye-temperatures: θLTD = 373(7)K, 357(14)K and 318(10)K. Einstein temperatures were in the range of 130-155 K. Rather low Seebeck coefficients (<15 μV K^-1), power factors (pf < 0.07 mW mK^-2) and an estimated thermal conductivity of λ < 148 mW cm^-1 K^-1 yield thermoelectric figures of merit ZT < 0.007 at ∼800 K. Whereas for polycrystalline Zr₂Ni₂Sn elastic properties were determined by resonant ultrasound spectroscopy (RUS): E = 171 GPa, ν = 0.31, G = 65.5 GPa, and B = 147 GPa, the accelerated mechanical property mapping (XPM) mode was used to map the hardness and elastic moduli of T₂Ni₂Sn. Above 180 K, Zr₂Ni₂Sn reveals a quasi-linear expansion with CTE = 15.4 × 10^-6 K^-1. The calculated density of states is similar for all three compounds and confirms a metallic type of conductivity. The isosurface of elf shows a spherical shape for Ti/Zr/Hf atoms and indicates their ionic character, while the [Ni₂Sn]^n- sublattice reflects localizations around the Ni and Sn atoms with a large somewhat diffuse charge density between the closest Ni atoms.

OP0282 RITUXIMAB ASSOCIATED WITH SEVERE COVID-19 AMONG PATIENTS WITH INFLAMMATORY ARTHRITIDES: A 1-YEAR MULTICENTER STUDY IN 1116 SUCCESSIVE PATIENTS RECEIVING BIOLOGIC AGENTS

Background:

At a time when vaccines are being prioritized for individuals most at risk, there is currently no clear evidence that risk of SARS-CoV-2 infection is higher for patients with than without inflammatory arthritides (IA). Biologic use was not associated with worse COVID-19 outcomes for yet but the case of rituximab (RTX) remains an issue, given its immunological long term effect, the role of humoral response against SARS-CoV-2 and its indirect effect on T-cell response. A potential association between rituximab and worse COVID-19 outcomes was raised by case reports and retrospective, declarative studies (with few data on the total number of patients exposed).

Objectives:

To address differently the issue of the risk of COVID-19 related to RTX and limit biases, we examined the occurrence of severe COVID-19 in all patients receiving intravenous biologic agents at day-hospitals during the pandemic in France.

Methods:

From 1st September 2019 to 1st January 2021, we analyzed patients with IA prospectively treated with intravenous biologic agents (RTX, abatacept, infliximab or tocilizumab) in 7 clinical centers in France. We obtained the list of patients receiving intravenous biologic agents in each center from the pharmacist of the hospitals. Therefore, all consecutive patients receiving 1 of the 4 drugs at the time of the study were included in each center. Patients with no follow-up after September 2020 were systematically contacted by phone. The occurrence of a severe COVID -19 (i.e. resulting in death, hospitalization or increase in length of hospitalization related to COVID-19) was the primary outcome criteria.

Results:

In total, 1116 patients receiving intravenous biologic agents were included: 449 with infliximab, 392 RTX, 170 tocilizumab and 105 abatacept. From 1st September 2019, the median follow-up time was 15 months (interquartile range 14-16). In total, 10 cases of severe COVID-19 occurred, 9 treated with RTX and 1 with infliximab (supplementary Table 1). Four deaths occurred in our cohort during follow-up but none was related to COVID-19 (1 patient treated by tocilizumab, 1 by RTX and 2 by infliximab). In univariate analysis, the proportion of severe COVID-19 was significantly higher for patients receiving RTX than other biologic agents (9/392 vs 1/724, p=0.0003, OR [95%CI] 17.0 [2.1-134.6]). To take into account potential confounders, we performed multivariate analysis accounting for baseline parameters that differed between RTX and other biologic groups. RTX remained significantly associated with risk of severe COVID-19 (p=0.019) (Table 1).

Patient characteristicsRituximab (n= 392)Other bDMARDs (n= 724)Univariate analysis, p-valueMultivariate analysis, p-valueMedian age (years), — [IQR]64 [56-71]57.3 [47.0-67.0]< 0.00010.51Female — n (%)285 (72.7)426 (58.8)< 0.00010.58IA diagnosis< 0.00010.12Median follow-up from 1st September to last news14 [13-15]15 [14-16]< 0.00010.86Confirmed severe COVID-19 cases —n (%)9 (2.3)1 (0.1)0.00030.019Comorbidities** (history of) — n (%) Cardiovascular disease60 (15.4)167 (23.1)0.00250.77 Chronic lung disease,92 (23.5)84 (11.6)0.00010.88Median BMI (kg/m2) — [IQR]25.8 [23.2-29.4]27.3 [23.4-31.2]0.0150.80Treatments — n (%) Methotrexate179 (45.8)322 (44.5)0.71 Leflunomide41 (10.5)39 (5.4)0.00230.43 Hydroxychloroquine35 (8.9)24 (3.3)0.00010.15 Glucocorticoids127 (41.8)100 (19.4)< 0.00010.36 Median dose (mg/day) — [IQR]1 [0-5]0 [0-0]< 0.0001

No significant difference in terms of baseline gammaglobulins (p=0.46) or number of previous RTX infusions (p=0.57) was observed among patients receiving RTX with or without a severe COVID-19.

Conclusion:

The present results highly indicate increased risk of severe COVID-19 with RTX. Among patients with inflammatory arthritides, those receiving RTX should be prioritized for vaccination against SARS-CoV-2, sufficiently long before infusion/reinfusion and the immunization checked, or an alternative targeted therapy proposed.

Acknowledgements:

We thank Dr. Karine Demesmay and all the pharmacists who helped us for this study.

Disclosure of Interests:

Renaud FELTEN Speakers bureau: Abbvie, Biogen, BMS, Lilly, Novartis, Pfizer, Pierre-Marie Duret: None declared, Elodie BAUER: None declared, Marc Ardizzone: None declared, H Julien Djossou: None declared, Jean-Hugues Salmon: None declared, Cassandre Fabre: None declared, Julia Walther: None declared, Isabelle CHARY VALCKENAERE: None declared, marion geoffroy: None declared, Laurent Messer: None declared, Francis Berenbaum: None declared, Martin SOUBRIER: None declared, Jérémie SELLAM Speakers bureau: MSD, Pfizer, Abbvie, Roche, BMS, Lilly, Janssen, Novartis, Galapagos, Sandoz, Fresenius Kabi, Grant/research support from: Roche, MSD, Pfizer, Jacques-Eric Gottenberg: None declared

Relationship between calcifications and structural lesions on hand radiography and axial calcifications on CT-scan: A retrospective study in systemic sclerosis

The objectives of this study were to describe the prevalence and characteristics of radiographic lesions of the hands, and calcifications of the spine on computer tomography scans (CT-scans), and to investigate the relationships between radiographic and CT-scan abnormalities and clinical features in a population of patients with systemic sclerosis (SSc).Subjects underwent X-ray examination of the hands, and thoracic or thoraco-abdominal and pelvic CT scan or lumbar CT scan in the year. Structural lesions on hand X ray was scored and spinal calcifications were evaluated in the anterior, intracanal and posterior segments. Intra and inter-reliability was tested for radiography and CT- scan. Prognostic factors considered were interstitial pulmonary lesions on the CT scan, pulmonary arterial hypertension (PAH) and death.This study involved 77 SSc patients, 58 (75%) with limited cutaneous SSc (lcSSc) and 19 (25%) with diffuse SSc (dSSc). The prevalences of radiographic lesions of the hand were 28.6% for periarticular calcifications and 26% for calcinosis. On CT scan, 64 (83%) patients exhibited at least 1 calcification. Spine calcifications were depicted in 80.5%, 27.3%, and 35.1% at the anterior, intracanal and posterior segments respectively. Calcifications were mainly localized on thoracic spine. Inter reader reliabilities were good for hands and moderate for spine respectively. Spine calcifications and periarticular calcifications in the hands were associated (P = .012). Calcinosis in the hands was related to PAH (P = .02). Posterior calcification segment and foraminal calcifications were associated with interstitial lung disease (ILD) (P = .029) and death (P = .001).More than 80% of systemic sclerosis patients presented spine calcifications. A significant association between hands and spinal calcifications were confirmed and some localization in the posterior segment considered as a bad prognostic factor.

THU0393 INFLAMMATORY BOWEL DISEASES AMONG SECUKINUMAB-TREATED PATIENTS: 24 CASES FROM THE MISSIL REGISTRY

Background:

An alert regarding about the tolerance of Interleukin 17 (IL-17) inhibitors has been issued from data of randomized controlled trials showing cases of de novo inflammatory bowel diseases (IBD). In a recent analysis of pooled data from 21 clinical trials, cases of IBD events (including Crohn’s disease (CD), ulcerative colitis (UC) and inflammatory bowel disease unclassified (IBDU)) were uncommon (1). Yet, real-world data are lacking.

Objectives:

To describe real-world data about patients treated by IL-17 inhibitors developing new onset IBD (CD or UC).

Methods:

A French national registry called MISSIL was started in February 2018 to collect the cases of patients treated by IL-17 inhibitors developing new onset IBD. This registry is conducted by rheumatologist, dermatologist and gastroenterologist learned societies specialized on immune-mediated inflammatory diseases. In France, secukinumab (SEK) has been granted market authorization since June 2016 and ixekizumab since April 2018.

Results:

24 cases under SEK were reported between February 2018 and January 2020: 3 patients with psoriasis and 21 patients with spondylwoarthritis. There were 20 patients with new onset CD and 4 with UC. Mean age was 51.7 ± 15.7 years old and 12/24 were female; 10 presented an axial spondyloarthritis, 5 a peripheral spondyloarthritis and 6 both,13/17 were HLA-B27 positive,7/19 had a radiographic sacroiliitis and 11/17 a MRI sacroiliitis. Only 2 were biological Disease-modifying antirheumatic drug (bDMARD)-naïve. Crohn’s disease was mainly located at the ileum, colon and rectum. The median time to onset of symptoms was 2 (1-6) months. The main symptoms were diarrhea, nausea and vomiting and loss of weight. Median CRP at the onset of symptoms was 68 mg/L (41-140.5); 21 patients underwent biopsies, 12 were in favor of CD. IL-17 inhibitors were consistently stopped. Patients were treated by corticosteroids (16/24), mesalazine (7/24), methotrexate (3/24), thiopurines (2/24), infliximab (9/243), adalimumab (3/24), golimumab (2/24), ustekinumab (5/24). The evolution was favorable under treatment with complete resolution (4/24), improvement (11/24) or stabilization (5/24). 3 patients worsened under treatment and 1 died (massive myocardial infarction).

Conclusion:

IBD flare in patients treated with IL-17 inhibitors are rare and lead to discuss the potential iatrogenic role of IL-17 inhibitor drugs. Further cases are needed to better characterize this complication. A case-control study will be conducted to identify patients at risk to develop IBD under IL-17 inhibitor.

References:

[1]Reich et al. Incidence rates of inflammatory bowel disease in patients with psoriasis, psoriatic arthritis and ankylosing spondylitis treated with secukinumab: a retrospective analysis of pooled data from 21 clinical trials. Ann Rheum Dis. 2019;78:473-479

Disclosure of Interests:

Jean-Guillaume Letarouilly Grant/research support from: Research grant from Pfizer, Benjamin Pariente: None declared, Delphine Staumont-Sallé Speakers bureau: Lilly, Novartis, Philippe Goupille Grant/research support from: AbbVie, Amgen, Biogen, BMS, Celgene, Chugai, Lilly, Janssen, Medac, MSD France, Nordic Pharma, Novartis, Pfizer, Sanofi and UCB, Consultant of: AbbVie, Amgen, Biogen, BMS, Celgene, Chugai, Lilly, Janssen, Medac, MSD France, Nordic Pharma, Novartis, Pfizer, Sanofi and UCB, Speakers bureau: AbbVie, Amgen, Biogen, BMS, Celgene, Chugai, Lilly, Janssen, Medac, MSD France, Nordic Pharma, Novartis, Pfizer, Sanofi and UCB, Pascal Claudepierre Speakers bureau: Janssen, Novartis, Lilly, Stephane Varin: None declared, Sylvain Lanot: None declared, Emmanuelle Dernis Speakers bureau: Lilly, Novartis, Tristan Pascart Speakers bureau: Novartis, Lilly, Beatrice Banneville Speakers bureau: Lilly, Novartis, Pauline Baudart: None declared, Bruno Gombert: None declared, Elodie BAUER: None declared, Laurianne Plastaras: None declared, Sébastien Barbarot: None declared, Renaud FELTEN: None declared, Loïc Le Dantec: None declared, Nathalie Sultan-Bichat: None declared, Céline Girard: None declared, Arnaud Constantin Grant/research support from: Study was sponsored by Sanofi Genzyme, Consultant of: Consulting fees from Abbvie, BMS, Celgene, Gilead, Janssen, Lilly, Novartis, Pfizer, Roche, Sanofi, UCB, Daniel Wendling: None declared, Philippe Gaudin Speakers bureau: Lilly, Denis Jullien Speakers bureau: Lilly, Novartis, Thao Pham Speakers bureau: Novartis, Janssen, Lilly, Rene-Marc Flipo Speakers bureau: Novartis, Janssen, Lilly

Structural and magnetic properties of the Yb2Pd2(In1-x Sn x ) system: a synchrotron x-ray and neutron powder diffraction investigation

The structural properties of the Yb₂Pd₂(In_1-x Sn _x ) system were investigated at room temperature by synchrotron x-ray powder diffraction. All the inspected compositions (x  =  0.0, 0.3, 0.4, 0.5, 0.6, 0.8, 0.9) crystallize in the tetragonal space group P4/mbm; the cell parameters exhibit a non-linear dependence on composition, whereas cell volume changes more regularly, with a minimum at x  =  0.8. Samples with Sn content x  =  0.5, 0.6, 0.9 were also analysed by neutron diffraction down to 0.5 K. No evidence for a structural transition can be detected at low temperature, whereas an antiferromagnetic ordering is observed, characterized by a propagation vectors k  =  (0,0,½). Magnetic moments order in the tetragonal ab-plane and the magnetic structure belongs to the Shubnikov magnetic space group P4/mbm.

Study of vertebral fracture and Scanographic Bone Attenuation Coefficient in rheumatoid arthritis and ankylosing spondylitis vs. controls

The objective of this study is to identify the prevalence of vertebral fractures (VFs) and to measure the scanographic bone attenuation coefficient of the first lumbar vertebra (SBAC-L1) based CT-scan, a biomarker of bone fragility in patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS) and in a control group. This monocentric and retrospective study included patients with RA and AS, based on ACR/EULAR or New-York criteria, respectively. A control group was constituted. All of the patients received a CT-scan. VFs were determined via CT-scans according to the Genant classification, and the SBAC-L1 was measured in Hounsfield units (HU). SBAC-L1 ≤145 HU (fracture threshold) defined patients at risk of VFs. 244 patients were included (105 RA, 83 AS, 56 controls). Of the 4.365 vertebrae studied, 66 osteoporotic VFs were found in 36 patients: 18 (17.1%) RA, 13 (15.7%) AS and 5 (8.9%) controls. The mean SBAC-L1 was 142.2 (±48.4) HU for RA, 142.8 (±48.2) for AS, both of which were significantly lower than that of the control group (161.8 (±42.7) HU). Of the 36 patients with VFs and rheumatism, 28% had a T-score ≤-2.5 SD and 71.4% a SBAC-L1 ≤145 HU. A T-score ≤-2.5 SD and a SBAC-L1 ≤145 HU were associated with VF (OR = 3.07 (CI 95%: 1.07; 8.81), and 2.31 (CI 95%: 1.06; 5.06)), respectively. The SBAC-L1 was significantly lower in the RA and AS groups than in the control group. Furthermore, SBAC-L1 ≤145 HU was associated with a higher risk of VFs, with an odds ratio similar to that of a DXA.

Motivation of student radiographers in learning situations based on role-play simulation: A multicentric approach involving trainers and students

INTRODUCTION

Role-play simulation is implemented in different radiography institutions. This tool develops Knowledge, Skills and Competences (KSC) in students. The aim of this study was to identify the strategies implemented by trainers in order to encourage student motivational dynamics and to find those that resonate with students.

METHODS

Three role-play simulation sessions using a grid were observed in two different radiography institutions that have a simulation centre (two French institutions and one Swiss). In order to identify explicitly or implicitly the motivational strategies used, four interviews with trainers were conducted. To understand students' opinions about these strategies, seven interviews with radiography students were done.

RESULTS

Defining motivation was not easy. The trainers used various strategies to motivate students, not all of which were verbalized in interviews. Although students said they were stressed prior to participating in role-play simulation, this study shows that such simulation sessions are effective to develop high motivational dynamics for students.

CONCLUSION

This study has identified three main areas of improvement: exploring students' expectations, give importance to patients briefing so that they can fully perform their role and improving the authenticity of the environment. The latter issue can only be addressed through access to up-to-date equipment in training institutions.

A global cline in a colour polymorphism suggests a limited contribution of gene flow towards the recovery of a heavily exploited marine mammal

Evaluating how populations are connected by migration is important for understanding species resilience because gene flow can facilitate recovery from demographic declines. We therefore investigated the extent to which migration may have contributed to the global recovery of the Antarctic fur seal (Arctocephalus gazella), a circumpolar distributed marine mammal that was brought to the brink of extinction by the sealing industry in the eighteenth and nineteenth centuries. It is widely believed that animals emigrating from South Georgia, where a relict population escaped sealing, contributed to the re-establishment of formerly occupied breeding colonies across the geographical range of the species. To investigate this, we interrogated a genetic polymorphism (S291F) in the melanocortin 1 receptor gene, which is responsible for a cream-coloured phenotype that is relatively abundant at South Georgia and which appears to have recently spread to localities as far afield as Marion Island in the sub-Antarctic Indian Ocean. By sequencing a short region of this gene in 1492 pups from eight breeding colonies, we showed that S291F frequency rapidly declines with increasing geographical distance from South Georgia, consistent with locally restricted gene flow from South Georgia mainly to the South Shetland Islands and Bouvetøya. The S291F allele was not detected farther afield, suggesting that although emigrants from South Georgia may have been locally important, they are unlikely to have played a major role in the recovery of geographically more distant populations.

Strong antisymmetric spin-orbit coupling and superconducting properties: the case of noncentrosymmetric LaPtSi

In this work we aim to analyze the effect of a strong antisymmetric spin-orbit coupling (ASOC) on the superconductivity of noncentrosymmetric LaPtSi. We study the energy gap structure of polycrystalline LaPtSi by using magnetic penetration depth measurements down to 0.02T _c. We observed a dirty s-wave behavior, which provides compelling evidence that the spin-singlet component of the mixed pairing state is highly dominant. This is consistent with previous results in the sense that the mere presence of a strong ASOC does not lead to unconventional behaviors. Our result also downplays LaPtSi as a good candidate for realizing time-reversal invariant topological superconductivity.

Breakdown of the coherence effects and Fermi liquid behavior in YbAl3 nanoparticles

A change in the Kondo lattice behavior of bulk YbAl₃ has been observed when the alloy is shaped into nanoparticles (≈12 nm). Measurements of the electrical resistivity show inhibited coherence effects and deviation from the standard Fermi liquid behavior (T ²-dependence). These results are interpreted as being due to the effect of the disruption of the periodicity of the array of Kondo ions provoked by the size reduction process. Additionally, the ensemble of randomly placed nanoparticles also triggers an extra source of electronic scattering at very low temperatures (≈15 K) due to quantum interference effects.

Boron-phil and boron-phob structure units in novel borides Ni3Zn2B and Ni2ZnB: experiment and first principles calculations

The crystal structures of two novel borides in the Ni-Zn-B system, τ₅-Ni₃Zn₂B and τ₆-Ni₂ZnB, were determined by single crystal X-ray diffraction (XRSC) in combination with selected area electron diffraction in a transmission electron microscope (SAED-TEM) and electron probe microanalysis (EPMA). Both compounds crystallize in unique structure types (space group C2/m, a = 1.68942(8) nm, b = 0.26332(1) nm, c = 0.61904(3) nm, β = 111.164(2)°, R_F = 0.0219 for Ni₃Zn₂B, and space group C2/m, a = 0.95296(7) nm, b = 0.28371(2) nm, c = 0.59989(1) nm, β = 93.009(4)°, R_F = 0.0163 for Ni₂ZnB). Both compounds have similar building blocks: two triangular prisms centered by boron atoms are arranged along the c-axis separated by Zn layers, which form empty octahedra connecting the boron centered polyhedra. Consistent with the (Ni+Zn)/B ratio, isolated boron atoms are found in τ₅-Ni₃Zn₂B, while B-B pairs exist in τ₆-Ni₂ZnB. The crystal structure of Ni₂ZnB is closely related to that of τ₄-Ni₃ZnB₂, i.e. Ni₂ZnB can be formed by removing the nearly planar nickel layer in Ni₃ZnB₂ and shifting the origin of the unit cell to the center of the B-B pair. The electrical resistivity and specific heat of τ₅-Ni₃Zn₂B reveal the metallic behavior of this compound with an anomaly at low temperature, possibly arising from a Kondo-type interaction. Further analysis on the lattice contribution of the specific heat reveals similarity with τ₄-Ni₃ZnB₂ with some indications of lattice softening in τ₅-Ni₃Zn₂B, which could be related to the increasing metal content and the absence of B-B bonding in τ₅-Ni₃Zn₂B. For the newly found phases, τ₅-Ni₃Zn₂B and τ₆-Ni₂ZnB as well as for τ₃-Ni₂₁Zn₂B₂₀ and τ₄-Ni₃ZnB₂ density functional theory (DFT) calculations were performed by means of the Vienna Ab initio Simulation Package (VASP). Total energies and forces were minimized in order to determine the fully relaxed structural parameters, which agree very well with experiment. Energies of formations in the range of -25.2 to -26.9 kJ mol^-1 were calculated and bulk moduli in the range of 179.7 to 248.9 GPa were derived showing hardening by increasing the B concentration. Charge transfer is discussed in terms of Bader charges resulting in electronic transfer from Zn to the system and electronic charge gain by B. Ni charge contributions vary significantly with crystallographic position depending on B located in the neighbourhood. The electronic structure is presented in terms of densities of states, band structures and contour plots revealing Ni-B and Ni-Zn bonding features.

A Controlled Study of Sorbent Suspension Dialysis in Chronic Liver Disease and Hepatic Encephalopathy

To investigate the role of extracorporeal detoxification in cirrhotic patients with advanced hepatic encephalopathy not responding to medical treatment, 20 patients were randomized to receive six hours of additional sorbent dialysis or ongoing standardized medical treatment. Following treatment, the clinical stage of encephalopathy remained unchanged in both groups. Abnormal sensory evoked potentials improved following sorbent dialysis (N70 latency, 128 ms before versus 110 ms after treatment, P<0,05; cervico-cranial transmission, 7.7 ms versus 6.8 ms, P<0.01) indicating improvement in important aspects of cerebral function. In contrast, brain function remained unchanged following medical treatment (N70 latency, 114 ms versus 113 ms; cervico-cranial transmission, 7.7 ms versus 7.2 ms, P=NS, respectively). Serum benzodiazepine levels decreased significantly after sorbent dialysis but not after medical treatment. Biocompatibility of sorbent dialysis was limited and clinical complications occurred in a proportion of patients. In conclusion, a six-hour treatment with sorbent suspension dialysis did not ameliorate the clinical stage of HE but improved neurophysiologic function in cirrhotic patients who had not responded to conventional medical treatment.

The half Heusler system Ti1+xFe1.33−xSb–TiCoSb with Sb/Sn substitution: phase relations, crystal structures and thermoelectric properties

Phase equilibria for Heusler Phase Ti_1+xFe_1.33−xSb at 800 °C and calculated isosurfaces (ϒ = 0.42) of the electron localization function in TiFe_1.25Sb.

Mechanical properties of non-centrosymmetric CePt3Si and CePt3B

Elastic moduli, hardness (both at room temperature) and thermal expansion (4.2-670 K) have been experimentally determined for polycrystalline CePt₃Si and its prototype compound CePt₃B as well as for single-crystalline CePt₃Si. Resonant ultrasound spectroscopy was used to determine elastic properties (Young's modulus E and Poisson's ratio ν) via the eigenfrequencies of the sample and the knowledge of sample mass and dimensions. Bulk and shear moduli were calculated from E and ν, and the respective Debye temperatures were derived. In addition, ab initio DFT calculations were carried out for both compounds. A comparison of parameters evaluated from DFT with those of experiments revealed, in general, satisfactory agreement. Positive and negative thermal expansion values obtained from CePt₃Si single crystal data are fairly well explained in terms of the crystalline electric field model, using CEF parameters derived recently from inelastic neutron scattering. DFT calculations, in addition, demonstrate that the atomic vibrations keep almost unaffected by the antisymmetric spin-orbit coupling present in systems with crystal structures having no inversion symmetry. This is opposite to electronic properties, where the antisymmetric spin-orbit interaction has shown to distinctly influence features like the superconducting condensate of CePt₃Si.

Structures and processes necessary for providing effective home treatment to severely mentally ill persons: a naturalistic study

BACKGROUND

Home treatment for severely mentally ill persons is becoming increasingly popular. This research aims to identify structures and processes in home treatment that impact on patient-related outcomes.

METHODS

We analysed 17 networks that provide home treatment to severely mentally ill persons using a naturalistic approach. The networks were similar with regard to central components of home treatment such as case management, 24 h crisis hotline and home visits, but differed in all other aspects such as the multidisciplinary teams, time spent with patients, etc. To determine treatment outcome, patients' psychosocial functioning was measured using the Health of the Nation Outcome Scales (HoNOS). Structures and processes were assessed using claims data and questionnaires answered by the different networks. Primary outcome was highlighted by the change in HoNOS scores from the start of home treatment compared with 6 months later. We sought to explain this outcome through patient and network characteristics using regression analysis. Data on 3,567 patients was available.

RESULTS

On average, psychosocial functioning improved by 0.84 across networks between t0 and t1. There were more similarities than differences between the networks with regard to the structures and processes that we tested. A univariate regression analysis found staff's prior experience in mental health care and the effort that they invested in their work correlated positively with patient outcome. This needs to be interpreted under considering that univariate analysis does not show causal relationship. A high case load per case manager, increased and longer patient contact and more family intervention were correlated with worse patient outcome, probably indicating that sicker patients receive more care and intervention.

CONCLUSION

Home treatment networks succeed in delivering care tailored to the needs of patients. In order to improve the quality of care in home treatment, this study suggests employing experienced staff who is ready to invest more effort in their patients. Further research needs to consider a longer follow-up time.

Ba-filled Ni-Sb-Sn based skutterudites with anomalously high lattice thermal conductivity

Novel filled skutterudites BayNi4Sb12-xSnx (ymax = 0.93) have been prepared by arc melting followed by annealing at 250, 350 and 450 °C up to 30 days in vacuum-sealed quartz vials. Extension of the homogeneity region, solidus temperatures and structural investigations were performed for the skutterudite phase in the ternary Ni-Sn-Sb and in the quaternary Ba-Ni-Sb-Sn systems. Phase equilibria in the Ni-Sn-Sb system at 450 °C were established by means of Electron Probe Microanalysis (EPMA) and X-ray Powder Diffraction (XPD). With rather small cages Ni4(Sb,Sn)12, the Ba-Ni-Sn-Sb skutterudite system is perfectly suited to study the influence of filler atoms on the phonon thermal conductivity. Single-phase samples with the composition Ni4Sb8.2Sn3.8, Ba0.42Ni4Sb8.2Sn3.8 and Ba0.92Ni4Sb6.7Sn5.3 were used to measure their physical properties, i.e. temperature dependent electrical resistivity, Seebeck coefficient and thermal conductivity. The resistivity data demonstrate a crossover from metallic to semiconducting behaviour. The corresponding gap width was extracted from the maxima in the Seebeck coefficient data as a function of temperature. Single crystal X-ray structure analyses at 100, 200 and 300 K revealed the thermal expansion coefficients as well as Einstein and Debye temperatures for Ba0.73Ni4Sb8.1Sn3.9 and Ba0.95Ni4Sb6.1Sn5.9. These data were in accordance with the Debye temperatures obtained from the specific heat (4.4 K < T < 140 K) and Mössbauer spectroscopy (10 K < T < 290 K). Rather small atom displacement parameters for the Ba filler atoms indicate a severe reduction in the "rattling behaviour" consistent with the high levels of lattice thermal conductivity. The elastic moduli, collected from Resonant Ultrasonic Spectroscopy ranged from 100 GPa for Ni4Sb8.2Sn3.8 to 116 GPa for Ba0.92Ni4Sb6.7Sn5.3. The thermal expansion coefficients were 11.8 × 10(-6) K(-1) for Ni4Sb8.2Sn3.8 and 13.8 × 10(-6) K(-1) for Ba0.92Ni4Sb6.7Sn5.3. The room temperature Vickers hardness values vary within the range from 2.6 GPa to 4.7 GPa. Severe plastic deformation via high-pressure torsion was used to introduce nanostructuring; however, the physical properties before and after HPT showed no significant effect on the materials thermoelectric behaviour.

Magnetic phase diagram of superantiferromagnetic TbCu₂ nanoparticles

The structural state and static and dynamic magnetic properties of TbCu2 nanoparticles are reported to be produced by mechanical milling under inert atmosphere. The randomly dispersed nanoparticles as detected by TEM retain the bulk symmetry with an orthorhombic Imma lattice and Tb and Cu in the 4e and 8h positions, respectively. Rietveld refinements confirm that the milling produces a controlled reduction of particle sizes reaching ≃6 nm and an increase of the microstrain up to ≃0.6%. The electrical resistivity indicates a metallic behavior and the presence of a magnetic contribution to the electronic scattering which decreases with milling times. The dc-susceptibility shows a reduction of the Néel transition (from 49 K to 43 K) and a progressive increase of a peak (from 9 K to 15 K) in the zero-field-cooled magnetization with size reduction. The exchange anisotropy is very weak (a bias field of ≃30 Oe) and is due to the presence of a disordered (thin) shell coupled to the antiferromagnetic core. The dynamic susceptibility evidences a critical slowing down in the spin-disordered state for the lowest temperature peak associated with a spin glass-like freezing with a tendency of zv and β exponents to increase when the size becomes 6 nm (zv ≃ 6.6 and β ≃ 0.85). A Rietveld analysis of the neutron diffraction patterns 1.8 ≤ T ≤ 60 K, including the magnetic structure determination, reveals that there is a reduction of the expected moment (≃80%), which must be connected to the presence of the disordered particle shell. The core magnetic structure retains the bulk antiferromagnetic arrangement. The overall interpretation is based on a superantiferromagnetic behavior which at low temperatures coexists with a canting of surface moments and a mismatch of the antiferromagnetic sublattices of the nanoparticles. We propose a novel magnetic phase diagram where changes are provoked by a combination of the decrease of size and the increase of microstrain.

Reconstruction of a quadriceps tendon tear using Polyvinylidene fluoride sutures and patellar screw fixation: A biomechanical study

BACKGROUND

Acute quadriceps tendon tears are infrequent injuries requiring surgical treatment. Improved stability after surgical repair may allow for earlier weight-bearing and range of motion. Therefore, a new implant was tested and compared with the "gold standard", using transosseous sutures.

METHODS

Quadriceps tendon tears were constructed using a cadaveric model of 12 fresh matched-pair specimens (aged 61-97; mean age: 82 years). The biomechanical testing compared non-absorbable suture anchors (Polyvinylidene fluoride) versus transosseous absorbable sutures (Polydioxanon). Following anatomic reconstruction, the repaired specimens were loaded until they failed (testing machine: Hounsfield H10KM, Redhill, United Kingdom; maximum force: 1000 N; load speed: 25 mm/min; maximum test length: 150 mm; pre-load: 5 N). Values for load until tear displacement, maximum load until complete failure of the construct (pullout or breakage of the sutures or anchors) and stiffness of the reconstruction were recorded.

RESULTS

The stiffness found in the Polyvinylidene fluoride reconstruction (mean 9.83 N/mm) (standard deviation (SD) 7.75) showed a significant increase compared to the Polydioxanon reconstruction (mean 6.66 N/mm (SD 3.32); P=0.045). Transosseous fixation showed comparable results to the suture anchor system. There was no significant difference found in the maximum load to tear displacement (PVDF: 290.88 N (SD 106.01) vs. PDS: 266.75 N (SD 82.61); P=0.358).

CONCLUSIONS

Using the Polyvinylidene fluoride thread showed comparable results to the established method in reconstruction of ruptured quadriceps tendon. Stiffness of the Polyvinylidene fluoride thread reconstruction was even greater than Polydioxanon thread.

CLINICAL RELEVANCE

Improved stiffness may facilitate healing and is suggested as clinical relevance in reconstruction.

Ba5{V,Nb}12Sb19+x, novel variants of the Ba5Ti12Sb19+x-type: crystal structure and physical properties

The novel compounds Ba5{V,Nb}12Sb19+x, initially found in diffusion zone experiments between Ba-filled skutterudite Ba0.3Co4Sb12 and group V transition metals (V,Nb,Ta), were synthesized via solid state reaction and were characterized by means of X-ray (single crystal and powder) diffraction, electron probe microanalysis (EPMA), and physical (transport and mechanical) properties measurements. Ba5V12Sb19.41 (a = 1.21230(1) nm, space group P4[combining overline]3m; RF(2) = 0.0189) and Ba5Nb12Sb19.14 (a = 1.24979(2) nm, space group P4[combining overline]3m; RF(2) = 0.0219) are the first representatives of the Ba5Ti12Sb19+x-type, however, in contrast to the aristotype, the structure of Ba5V12Sb19.41 shows additional atom disorder. Temperature dependent ADPs and specific heat of Ba5V12Sb19.41 confirmed the rattling behaviour of Ba1,2 and Sb7 atoms within the framework built by V and Sb atoms. Electrical resistivity of both compounds show an upturn at low temperature, and a change from p- to n-type conductivity above 300 K in Ba4.9Nb12Sb19.4. As expected from the complex crystal structure and the presence of defects and disorder, the thermal conductivity is suppressed and lattice thermal conductivity of ∼0.43 W m(-1) K(-1) is near values typical for amorphous systems. Vicker's hardness of (3.8 ± 0.1) GPa (vanadium compound) and (3.5 ± 0.2) GPa (niobium compound) are comparable to Sb-based filled skutterudites. However, the Young's moduli measured by nanoindentation for these compounds EI(Ba4.9V12Sb19.0) = (85 ± 2) GPa and EI(Ba4.9Nb12Sb19.4) = (79 ± 5) GPa are significantly smaller than those of skutterudites, which range from about 130 to 145 GPa.

The significance of caudate volume for age-related associative memory decline

Aging comes along with reduced gray matter (GM) volume in several cerebral areas and with cognitive performance decline in different cognitive domains. Moreover, regional GM volume is linked to specific cognitive sub processes in older adults. However, it remains unclear which regional changes in older individuals are directly associated with decreased cognitive performance. Moreover, most of the studies on this topic focused on hippocampal and prefrontal brain regions and their relation to memory and executive functioning. Interestingly, there are only a few studies that reported an association between striatal brain volume and cognitive performance. This is insofar surprising that striatal structures are (1) highly affected by age and (2) involved in different neural circuits that serve intact cognition. To address these issues, voxel-based morphometry (VBM) was used to analyze GM volume in 18 younger and 18 older adults. Moreover, several neuropsychological tests from different neuropsychological test batteries were applied to assess a broad range of cognitive domains. Older adults showed less GM volume than younger adults within frontal, striatal, and cerebellar brain regions. In the group of older adults, significant correlations were found between striatal GM volume and memory performance and between prefrontal/temporal GM volume and executive functioning. The only direct overlap between brain regions associated with regional atrophy and cognitive performance in older adults was found for the right caudate: older adults showed reduced caudate volume relative to younger adults. Moreover, caudate volume was positively correlated with associative memory accuracy in older adults and older adults showed poorer performances than younger adults in the respective associative memory task. Taken together, the current findings indicate the relevance of the caudate for associative memory decline in the aging brain.

Thermal, magnetic and electronic properties of non-centrosymmetric YbPt₂B

Ternary YbPt2B crystallizes in the non-centrosymmetric hexagonal CePt2B-type structure (space group P6(2)22). Electrical resistivity, specific heat and magnetic measurements reveal a magnetic instability at 5.6 K. Furthermore, a spin-reorientation of presumably a ferromagnetic type occurs around 1.5 K. The behaviour at low temperature is governed by a rather weak Kondo effect, T(K) ⩽ 1 K, in the presence of strong crystalline electric field splitting, with a doublet ground state. Besides, the complex magnetic behaviour presumably results from a Dzyaloshinskii-Moriya interaction triggered by the absence of inversion symmetry in the crystal structure. Scaling according to the de Gennes factor traces back magnetic ordering in YbPt2B to the Rudermann-Kittel-Kasuya-Yoshida (RKKY) interaction and the smooth evolution of the lattice constants and the unit cell volume of REPt2B (RE = rare earths) refers to the 4f(13) electronic configuration of Yb in YbPt2B.

On the constitution and thermodynamic modelling of the system Ti–Ni–Sn

Experimental and calculated phase equilibria for the system Ti–Ni–Sn.

Dent and Flint maize diversity panels reveal important genetic potential for increasing biomass production

Genetic and phenotypic analysis of two complementary maize panels revealed an important variation for biomass yield. Flowering and biomass QTL were discovered by association mapping in both panels. The high whole plant biomass productivity of maize makes it a potential source of energy in animal feeding and biofuel production. The variability and the genetic determinism of traits related to biomass are poorly known. We analyzed two highly diverse panels of Dent and Flint lines representing complementary heterotic groups for Northern Europe. They were genotyped with the 50 k SNP-array and phenotyped as hybrids (crossed to a tester of the complementary pool) in a western European field trial network for traits related to flowering time, plant height, and biomass. The molecular information revealed to be a powerful tool for discovering different levels of structure and relatedness in both panels. This study revealed important variation and potential genetic progress for biomass production, even at constant precocity. Association mapping was run by combining genotypes and phenotypes in a mixed model with a random polygenic effect. This permitted the detection of significant associations, confirming height and flowering time quantitative trait loci (QTL) found in literature. Biomass yield QTL were detected in both panels but were unstable across the environments. Alternative kinship estimator only based on markers unlinked to the tested SNP increased the number of significant associations by around 40% with a satisfying control of the false positive rate. This study gave insights into the variability and the genetic architectures of biomass-related traits in Flint and Dent lines and suggests important potential of these two pools for breeding high biomass yielding hybrid varieties.