Observation of Devil's Staircase in the Novel Spin Valve System SrCo6_6O11_{11}

Using resonant soft x-ray scattering as a function of both temperature and magnetic field, we reveal a large number of almost degenerate magnetic orders in SrCo6O11. The Ising-like spins in this frustrated material in fact exhibit a so-called magnetic devil's staircase. It is demonstrated how a magnetic field induces transitions between different microscopic spin configurations, which is responsible for the magnetoresistance of SrCo6O11. This material therefore constitutes a unique combination of a magnetic devil's staircase and spin valve effects, yielding a novel type of magnetoresistance system.Comment: 5 pages, 5 figure

Tempo de demora intra-hospitalar das síndromes coronárias agudas

TITULO: Tempo de Demora Intra-hospitalar das Síndromes Coronárias Agudas. ENQUADRAMENTO: A doença coronária, por si só, mantém-se no primeiro lugar das causas de morte na União Europeia. O enfarte agudo do miocárdio (EAM) constitui uma importante causa de morbilidade e mortalidade, sobretudo ao nível dos países industrializados, e resulta, habitualmente, de um processo progressivo de aterosclerose coronária. Todos os anos em Portugal ocorrem cerca de 10.000 EAM. Em doentes com enfarte do miocárdio com supradesnivelamento do segmento ST, a reperfusão precoce é o tratamento de eleição. Manter o menor intervalo de tempo desde o início dos sintomas até à reperfusão é realçado nas guidelines atuais como uma prioridade. OBJECTIVOS: Determinar o tempo de demora intra-hospitalar das Síndromes Coronárias Agudas e analisar a influência de determinadas variáveis no tempo de demora intra-hospitalar, como a idade, o sexo, a forma de admissão (proveniência e tipo de transporte), a prioridade do Sistema de Triagem de Manchester (STM), a dor torácica, o tipo de Síndrome Coronária Aguda (SCA) e a Via Verde Coronária (VVC). MÉTODOS: É um estudo quantitativo e transversal. Amostra constituída por 204 indivíduos com diagnóstico médico de SCA, internados na UCIC do CHTV, EPE, no período compreendido de 1 de Janeiro de 2010 a 30 de Setembro de 2010. A recolha de dados teve por base o registo informático do Sistema ALERT®. RESULTADOS: Os doentes são maioritariamente do sexo masculino (70,1%) com uma média de idades de 69,75 anos (dp=12,74). 63,2% são provenientes do domicílio, 34,8% foram referenciados pelo centro de saúde/SUB. A ambulância sem médico e os meios próprios são o tipo de transporte mais utilizado (44,1% e 42,6% respetivamente). 96,1% dos indivíduos apresentaram dor torácica. 49,0% dos indivíduos foi diagnosticado EAM sem Supra-ST, 32,4% dos indivíduos foi diagnosticado EAM com Supra-ST e 18,6% dos indivíduos foi diagnosticado angina instável. O tempo médio de demora pré-hospitalar (DPH) foi de 1043,11 minutos e o tempo médio entre o início da dor torácica e a admissão no Serviço de Urgência (TDH) foi de 1044,13 minutos; o tempo médio entre a admissão e a realização de triagem (DAT) foi de 8,60 minutos; o tempo médio entre a triagem e a realização do eletrocardiograma (DT-ECG) foi de 34,09 minutos; o tempo médio entre a realização do eletrocardiograma e a primeira observação médica (D-ECGMédico) foi de 20,48 minutos; o tempo médio entre a primeira observação médica e a administração da primeira terapêutica (D-Médico-Terapêutica) foi de 20,25 minutos; o tempo médio entre a admissão e a alta/internamento do doente (DIH-SU) foi de 281,91 minutos, com um tempo mínimo de 6 minutos e máximo de 1500 minutos. 64,7% dos indivíduos fizeram o 1.º ECG no SU num tempo superior a 10 minutos e apenas 35,3% dos indivíduos fizeram o 1.º ECG no SU num tempo 10 minutos. 74,5% dos indivíduos foram triados através do fluxograma Dor Torácica, 70,6% dos indivíduos foram triados com a prioridade laranja e 72,7% dos indivíduos do sexo masculino e 70,5% dos indivíduos do sexo feminino entraram pela VVC. Relativamente ao DIH-SU, o tempo médio foi de 126,71 minutos (dp=141,023) nos indivíduos com EAM com Supra-ST, 340,76 minutos (dp=246,71) nos indivíduos com EAM sem Supra-ST e 396,61 minutos (dp=324,50) nos indivíduos com angina instável. CONCLUSÃO: Os indivíduos do sexo masculino têm um tempo de demora intrahospitalar inferior aos indivíduos do sexo feminino (p> 0,05). Os indivíduos do grupo etário <55 anos apresentam melhores valores médios do tempo entre a admissão e a alta/internamento (p> 0,05). Os indivíduos transferidos do domicílio apresentam melhores valores médios no tempo de demora intra-hospitalar que os indivíduos que são referenciados por outra Instituição de Saúde (p> 0,05). Os indivíduos transportados em ambulância com médico apresentam melhores tempos médios de demora intrahospitalar (p< 0,05). Os indivíduos com dor torácica apresentam piores tempos médios de demora intra-hospitalar que os indivíduos sem dor torácica, à exceção do tempo entre a triagem e o ECG (p< 0,05). Os indivíduos com EAM com Supra-ST são os indivíduos que apresentam melhores tempos médios de demora intra-hospitalar (p< 0,001). Os indivíduos que entraram na VVC são os indivíduos que apresentam melhores tempos médios de demora intra-hospitalar (p< 0,001). PALAVRAS-CHAVE: Síndrome coronária aguda, Tempo de demora intra-hospitalar, Triagem de Manchester, Dor torácica, Tipo de SCA, Via Verde Coronária, ECG.ABSTRACT TITLE: In-hospital delay time in Acute Coronary Syndrome FRAMEWORK: Coronary heart disease alone remains in the first cause of death in the European Union. The acute myocardial infarction (AMI) is an important cause of morbidity and mortality, especially at the level of industrialized countries, and usually results of a progressive process of coronary atherosclerosis. Every year in Portugal occur, about 10000 AMI. In patients with ST-segment elevation myocardial infarction, the early reperfusion therapy is the treatment of choice. Keep the shortest time interval from symptom onset to reperfusion is emphasized in current guidelines as a priority. OBJECTIVES: Determining the time delay of thein-hospital management of Acute Coronary Syndromes and analyze the influence of certain variables in the in-hospital delay time, such as age, sex, the form of admission (provenance and type of transport), the priority of the Manchester Triage System, chest pain, the type of Acute Coronary Syndrome (ACS) and VVC. METHODS: It is a quantitative cross-sectional, retrospective study. Sample of 204individuals, with diagnosis of acute coronary syndrome (ACS), hospitalized in the Coronary Care Unit of CHTV, EPE from the period 1 January 2010 to 30 September 2010. Data collection was based on the computer record ALERT ®System. RESULTS: Patients are mostly male (70.1%) with average age of 69,75. 63.2% came from home, 34.8% were referred by a health center. The type of transport used were, ambulance without doctor and by own means (44.1% and 42.6% respectively). 96.1%ofindividuals had chest pain. 49.0% of individuals were diagnosed with Non-STsegment elevation myocardial infarction, 32.4% of individuals were diagnosed with STsegment elevation myocardial infarction and 18.6%of individuals diagnosed unstable angina. The pre-hospital delay time average was 1043.11 minutes and the time of the beginning of chest pain and admission to hospital average was 1044.13 minutes; time average between admission and triage was 8.60 minutes; time between triage and application of ECG averaged 34.09 minutes; time between execution of ECG and the first medical observation averaged 20.48 minutes; time between the first observation and the first medical therapeutic averaged 20.25 minutes. The average time between admission and discharge/hospitalization was 281.91 minutes, with a minimum time of 6 minutes and a maximum of 1500 minutes. 64.7%of individual shad the first ECG in the emergency room at a time over 10 minutes and only 35.3% of individual shad the first ECG in the emergency room at a time 10 minutes. 74.5% of individuals were triaged through the flowchart chest pain, 70.6% of individuals were triaged with the priority orange and 72.7% of males and 70.5% of females entered the VVC. For the time between admission and discharge/hospitalization, the average time was 126.71 minutes (sd = 141.03) in individuals with ST-segment elevation myocardial infarction, 340.76 minutes (sd = 246.71) in individuals with Non-ST-segment elevation myocardial infarction and 396.61 minutes (sd = 324.50) in patients with unstable angina. CONCLUSION: The males have a lower in-hospital delay time than females (p>0.05). Individuals in the age group <55 year shave better average time between admission and discharge/hospitalization (p>0.05). Individuals transferred from home show better average in-hospital delay time than individuals that are referenced by other Health Institutions (p>0.05). Individuals transported by ambulance with a doctor have better average in-hospital delay time (p<0.05). Individuals with chest pain have worse average in-hospital delay time than individuals without chest pain, except for the time between triage and ECG (p <0.05). Individuals with ST-segment elevation myocardial infarction are the individuals with the best average in-hospital delay time (p <0.001). Individuals who entered the VVC are individuals who have better average in-hospital delay time (p <0.001). KEY WORDS: Acute coronary syndrome, in- hospital delay time, Manchester Triage system, chest pain, type of ACS, via verde coronária. Sd= standard deviation

Ultrafast spin-switching of a ferrimagnetic alloy at room temperature traced by resonant magneto-optical Kerr effect using a seeded free electron laser

Ultrafast magnetization reversal of a ferrimagnetic metallic alloy GdFeCo was investigated by time-resolved resonant magneto-optical Kerr effect measurements using a seeded free electron laser. The GdFeCo alloy was pumped by a linearly polarized optical laser pulse, and the following temporal evolution of the magnetization of Fe in GdFeCo was element-selectively traced by a probe free electron laser pulse with a photon energy tuned to the Fe M-edge. The results have been measured using rotating analyzer ellipsometry method and confirmed magnetization switching caused by ultrafast heating

Association of bone morphogenetic protein-2 gene polymorphisms with susceptibility to ossification of the posterior longitudinal ligament of the spine and its severity in Chinese patients

A case–control study was conducted to examine the association between two single nucleotide polymorphisms (SNPs) in exon 2 of the bone morphogenetic protein-2 gene (BMP-2) and ossification of the posterior longitudinal ligament (OPLL), and to investigate whether SNPs of the Ser37Ala (T/G) and the Ser87Ser (A/G) in the BMP-2 gene are associated with genetic susceptibility to OPLL and its severity in Chinese subjects. The Ser87Ser (A/G) SNP has been implicated in bone mineral density (BMD) and increases the risk of OA in women. The Ser37Ala (T/G) SNP is associated with BMD and the rate of bone loss in osteoporosis and osteoporosis fractures. A total of 57 OPLL patients and 135 non-OPLL controls were studied. Radiographs of the cervical spine were analyzed to determine the presence and the severity of OPLL. The association of two SNPs with the occurrence and the extent of OPLL were statistically evaluated. There was a significant association between the Ser37Ala (T/G) polymorphism and the occurrence of OPLL in the cervical spine. However, no significant association was found between the Ser37Ala (T/G) polymorphism and the more number of ossified cervical vertebrae in OPLL patients. There was a significant association between the Ser87Ser (A/G) polymorphism and the more number of ossified cervical vertebrae in OPLL patients. However, there was no statistical difference between the Ser87Ser (A/G) SNP and the occurrence of OPLL in the cervical spine. In addition, the Ser87Ser (A/G) polymorphism in male patients and in female patients showed no statistical difference between cases and controls. The present results demonstrate that BMP-2 Gene is not only a factor associated with the occurrence of OPLL, but also a factor related to more extensive OPLL. The “G” allele in the Ser37Ala (T/G) polymorphism is associated with the occurrence of OPLL, but not more extensive OPLL in the cervical spine. The “G” allele in the Ser87Ser (A/G) polymorphism promotes the extent of OPLL, whereas the “A” allele in the Ser87Ser (A/G) polymorphism restricts ectopic ossification in the cervical spine at least in Chinese subjects

Photoinduced transient states of antiferromagnetic orderings in La1 3Sr2 3FeO3 and SrFeO3 delta thin films observed through time resolved resonant soft x ray scattering

The relationship between the magnetic interaction and photoinduced dynamics in antiferromagnetic perovskites is investigated in this study. In La1 3Sr2 3FeO3 thin films, commensurate spin ordering is accompanied by charge disproportionation, whereas SrFeO3 amp; 8722; amp; 948; thin films show incommensurate helical antiferromagnetic spin ordering due to increased ferromagnetic coupling compared to La1 3Sr2 3FeO3. To understand the photoinduced spin dynamics in these materials, we investigate the spin ordering through time resolved resonant soft x ray scattering. In La1 3Sr2 3FeO3, ultrafast quenching of the magnetic ordering within 130 fs through a nonthermal process is observed, triggered by charge transfer between the Fe atoms. We compare this to the photoinduced dynamics of the helical magnetic ordering of SrFeO3 amp; 8722; amp; 948;. We find that the change in the magnetic coupling through optically induced charge transfer can offer an even more efficient channel for spin order manipulatio

Design and Validation of a Novel Method to Measure Cross-Sectional Area of Neck Muscles Included during Routine MR Brain Volume Imaging

Low muscle mass secondary to disease and ageing is an important cause of excess mortality and morbidity. Many studies include a MR brain scan but no peripheral measure of muscle mass. We developed a technique to measure posterior neck muscle cross-sectional area (CSA) on volumetric MR brain scans enabling brain and muscle size to be measured simultaneously.We performed four studies to develop and test: feasibility, inter-rater reliability, repeatability and external validity. We used T1-weighted MR brain imaging from young and older subjects, obtained on different scanners, and collected mid-thigh MR data.After developing the technique and demonstrating feasibility, we tested it for inter-rater reliability in 40 subjects. Intraclass correlation coefficients (ICC) between raters were 0.99 (95% confidence intervals (CI) 0.98-1.00) for the combined group (trapezius, splenius and semispinalis), 0.92 (CI 0.85-0.96) for obliquus and 0.92 (CI 0.85-0.96) for sternocleidomastoid. The first unrotated principal component explained 72.2% of total neck muscle CSA variance and correlated positively with both right (r = 0.52, p = .001) and left (r = 0.50, p = .002) grip strength. The 14 subjects in the repeatability study had had two MR brain scans on three different scanners. The ICC for between scanner variation for total neck muscle CSA was high at 0.94 (CI 0.86-0.98). The ICCs for within scanner variations were also high, with values of 0.95 (CI 0.86-0.98), 0.97 (CI 0.92-0.99) and 0.96 (CI 0.86-0.99) for the three scanners. The external validity study found a correlation coefficient for total thigh CSA and total neck CSA of 0.88.We present a feasible, valid and reliable method for measuring neck muscle CSA on T1-weighted MR brain scans. Larger studies are needed to validate and apply our technique with subjects differing in age, ethnicity and geographical location