145 research outputs found

    Magnetic Proximity Effect in Perovskite Superconductor/Ferromagnet Multilayers

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    YBa2Cu3O7/La2/3Ca1/3MnO3\mathrm{YBa_2Cu_3O_7/La_{2/3}Ca_{1/3}MnO_3} superconducting/ferromagnetic (SC/FM) multilayers have been studied by neutron reflectometry. Evidence for a characteristic difference between the structural and magnetic depth profiles is obtained from the occurrence of a structurally forbidden Bragg peak in the FM state. The comparison with simulated reflectivity curves allows us to identify two possible magnetization profiles: a sizable magnetic moment within the SC layer antiparallel to the one in the FM layer (inverse proximity effect), or a ``dead'' region in the FM layer with zero net magnetic moment. The former scenario is supported by an anomalous SC-induced enhancement of the off-specular reflection, which testifies to a strong mutual interaction of SC and FM order parameters.Comment: 4 pages, 2 figures, submitted to PR

    Alteration of Multiple Leukocyte Gene Expression Networks is Linked with Magnetic Resonance Markers of Prognosis After Acute ST-Elevation Myocardial Infarction

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    Prognostic relevant pathways of leukocyte involvement in human myocardial ischemic-reperfusion injury are largely unknown. We enrolled 136 patients with ST-elevation myocardial infarction (STEMI) after primary angioplasty within 12 h after onset of symptoms. Following reperfusion, whole blood was collected within a median time interval of 20 h (interquartile range: 15-25 h) for genome-wide gene expression analysis. Subsequent CMR scans were performed using a standard protocol to determine infarct size (IS), area at risk (AAR), myocardial salvage index (MSI) and the extent of late microvascular obstruction (lateMO). We found 398 genes associated with lateMO and two genes with IS. Neither AAR, nor MSI showed significant correlations with gene expression. Genes correlating with lateMO were strongly related to several canonical pathways, including positive regulation of T-cell activation (p = 3.44 x 10(-5)), and regulation of inflammatory response (p = 1.86 x 10(-3)). Network analysis of multiple gene expression alterations associated with larger lateMO identified the following functional consequences: facilitated utilisation and decreased concentration of free fatty acid, repressed cell differentiation, enhanced phagocyte movement, increased cell death, vascular disease and compensatory vasculogenesis. In conclusion, the extent of lateMO after acute, reperfused STEMI correlated with altered activation of multiple genes related to fatty acid utilisation, lymphocyte differentiation, phagocyte mobilisation, cell survival, and vascular dysfunction

    Suunnitteluprosessiohje

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    Tämän opinnäytetyön aiheena oli suunnitteluprosessiohje. Opinnäytetyön tavoitteena oli tehdä Suomen Imurikeskus Oy:lle vakioidut toimintatavat laitteistojen suunnittelun kululle, ja selvittää mahdollinen kehitysvaihtoehto tiedonhallinnalle. Opinnäytetyössä käytiin lävitse Suomen Imurikeskus Oy:n laitteistojen valmistuksen eri vaiheita suunnittelijoiden osalta. Tämän perusteella kehitettiin vakioidut toimintatavat suunnitteluprosessiohjeeseen. Kehitysvaihtoehtona tiedonhallinnalle harkittiin Vertex Systems Oy:n Vertex Flow PDM/PLM -ohjelmistoa ja ohjelmistoon käytiin tutustumassa Vertex Systems Oy:n järjestämssä PLM-päivässä Tampereella. Lopputuloksena saatiin valmistettua Suomen Imurikeskus Oy:n käyttöön toimiva suunnitteluprosessiohje laitteistojen suunnitteluun. Suunnitteluprosessiohje sisältää ohjeistuksen laitteistojen suunnittelun eri vaiheille.The purpose of this thesis was to create engineering process manual for Suomen Imurikeskus Oy. The manual is meant to clarify the correct procedures for the process of appliance planning and alternative options for data management. In this thesis different phases of manufacturing were examined from Suomen Imurikeskus Oy’s designers point of view. Based on the thesis some standardized procedures were created for the engineering process manual. Vertex Systems' Vertex Flow PDM/PLM software was considered as an option for data management and the software was familiarized by visiting PLM-fair hosted by Vertex Systems Oy in Tampere. End result of the thesis was an engineering process manual for appliance planning to Suomen Imurikeskus Oy use. Engineering process manual includes instructions to different steps of appliance planning

    Consensus-based technical recommendations for clinical translation of renal ASL MRI

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    OBJECTIVES: This study aimed at developing technical recommendations for the acquisition, processing and analysis of renal ASL data in the human kidney at 1.5 T and 3 T field strengths that can promote standardization of renal perfusion measurements and facilitate the comparability of results across scanners and in multi-centre clinical studies. METHODS: An international panel of 23 renal ASL experts followed a modified Delphi process, including on-line surveys and two in-person meetings, to formulate a series of consensus statements regarding patient preparation, hardware, acquisition protocol, analysis steps and data reporting. RESULTS: Fifty-nine statements achieved consensus, while agreement could not be reached on two statements related to patient preparation. As a default protocol, the panel recommends pseudo-continuous (PCASL) or flow-sensitive alternating inversion recovery (FAIR) labelling with a single-slice spin-echo EPI readout with background suppression and a simple but robust quantification model. DISCUSSION: This approach is considered robust and reproducible and can provide renal perfusion images of adequate quality and SNR for most applications. If extended kidney coverage is desirable, a 2D multislice readout is recommended. These recommendations are based on current available evidence and expert opinion. Nonetheless they are expected to be updated as more data become available, since the renal ASL literature is rapidly expanding

    Clinical characteristics and role of early cardiac magnetic resonance imaging in patients with suspected ST-elevation myocardial infarction and normal coronary arteries

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    A variety of conditions other than acute myocardial infarction may cause ST-elevation. Our objective was to evaluate the impact of cardiac magnetic resonance (CMR) on differential diagnosis from a prospective series of patients with suspected ST-elevation myocardial infarction (STEMI) and completely normal coronary arteries. Among 1,145 patients with suspected STEMI, 49 patients had completely normal coronary arteries and entered a prospective registry. CMR was done within 24 h, if possible, and included function analyses, T2-weighted imaging (T2 ratio), T1-weighted imaging before and after gadolineum administration (global relative enhancement; gRE), and late gadolineum enhancement (LGE). All patients were asked for a follow-up CMR after approximately 3 months. The incidence of patients with suspected STEMI and normal coronary arteries was 4.3% and mean age was 45 ± 14 years (STEMI group 64 ± 13 years; P < 0.001). 55% had a recent history of infection. Cardiac biomarkers showed a moderate elevation on admission. There was a significant change from baseline to follow-up for LV end-diastolic volumes (EDV) (P < 0.001), LV mass (P < 0.05), mean T2 ratio (P < 0.05), and LGE volume (P < 0.05). Major diagnostic groups were myocarditis (29%), pericarditis (27%), and takotsubo cardiomyopathy (10%). 18% were regarded as non-diagnostic. The study showed an incidence of 4.3% of patients with suspected STEMI and completely normal coronary arteries. Early CMR was valuable in the evaluation of the differential diagnoses and to exclude myocardial abnormalities in patients with uncertain aetiology. Further studies are needed for the assessment of long-term outcome

    Health-related qualify of life, angina type and coronary artery disease in patients with stable chest pain

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    Background: Health-related quality of life (HRQoL) is impaired in patients with stable angina but patients often present with other forms of chest pain. The aim of this study was to compare the pre-diagnostic HRQoL in patients with suspected coronary artery disease (CAD) according to angina type, gender, and presence of obstructive CAD. Methods: From the pilot study for the European DISCHARGE trial, we analysed data from 24 sites including 1263 patients (45.9% women, 61.1 ± 11.3 years) who were clinically referred for invasive coronary angiography (ICA; 617 patients) or coronary computed tomography angiography (CTA; 646 patients). Prior to the procedures, patients completed HRQoL questionnaires: the Short Form (SF)-12v2, the EuroQoL (EQ-5D-3 L) and the Hospital Anxiety and Depression Scale. Results: Fifty-five percent of ICA and 35% of CTA patients had typical angina, 23 and 33% had atypical angina, 18 and 28% had non-anginal chest discomfort and 5 and 5% had other chest discomfort, respectively. Patients with typical angina had the poorest physical functioning compared to the other angina groups (SF-12 physical component score; 41.2 ± 8.8, 43.3 ± 9.1, 46.2 ± 9.0, 46.4 ± 11.4, respectively, all age and gender-adjusted p &lt; 0.01), and highest anxiety levels (8.3 ± 4.1, 7.5 ± 4.1, 6.5 ± 4.0, 4.7 ± 4.5, respectively, all adjusted p &lt; 0.01). On all other measures, patients with typical or atypical angina had lower HRQoL compared to the two other groups (all adjusted p &lt; 0.05). HRQoL did not differ between patients with and without obstructive CAD while women had worse HRQoL compared with men, irrespective of age and angina type. Conclusions: Prior to a diagnostic procedure for stable chest pain, HRQoL is associated with chest pain characteristics, but not with obstructive CAD, and is significantly lower in women. Trial registration: Clinicaltrials.gov, NCT02400229

    Accuracy of cardiovascular magnetic resonance in myocarditis: comparison of MR and histological findings in an animal model

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    Background: Because Endomyocardial Biopsy has low sensitivity of about 20%, it can be performed near to myocardium that presented as Late Gadolinium Enhancement (LGE) in cardiovascular magnetic resonance (CMR). However the important issue of comparing topography of CMR and histological findings has not yet been investigated. Thus the current study was performed using an animal model of myocarditis. Results: In 10 male Lewis rats Experimental Autoimmune myocarditis was induced, 10 rats served as control. On day 21 animals were examined by CMR to compare topographic distribution of LGE to histological inflammation. Sensitivity, specificity, positive and negative predictive values for LGE in diagnosing myocarditis were determined for each segment of myocardium. Latter diagnostic values varied widely depending on topographic distribution of LGE and inflammation as well as on the used CMR sequence. Sensitivity of LGE was up to 76% (left lateral myocardium) and positive predictive values were up to 85% (left lateral myocardium), whereas sensitivity and positive predictive value dropped to 0 - 33% (left inferior myocardium). Conclusions: Topographic distribution of LGE and histological inflammation seem to influence sensitivity, specifity, positive and negative predictive values. Nevertheless, positive predictive value for LGE of up to 85% indicates that Endomyocardial Biopsy should be performed "MR-guided". LGE seems to have greater sensitivity than Endomyocardial Biopsy for the diagnosis of myocarditis
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