Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 408
Filtrar
1.
Phys Rev Lett ; 127(13): 130504, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34623868

RESUMO

We propose a scalable analog quantum simulator for quantum electrodynamics in two spatial dimensions. The setup for the U(1) lattice gauge field theory employs interspecies spin-changing collisions in an ultracold atomic mixture trapped in an optical lattice. We engineer spatial plaquette terms for magnetic fields, thus solving a major obstacle toward experimental realizations of realistic gauge theories in higher dimensions. We apply our approach to the pure gauge theory of compact QED and discuss how the phenomenon of confinement of electric charges can be described by the quantum simulator.

2.
Sci Rep ; 9(1): 6692, 2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-31040308

RESUMO

Using an effective genetic algorithm, we uncover the structure of a metastable Al41Sm5 phase that supplements its family sharing similar short-range orders. The phase evolves upon heating an amorphous Al-9.7 at.% Sm ribbon, produced by melt-spinning. The dynamical phase selection is discussed with respect to the structural connections between the short-range packing motifs in the amorphous precursor and those observed in the selected phases. The phase elucidated here is one of several newly discovered large-unit-cell phases found to form during devitrification from the glass in this binary system, further illustrating the power and efficiency of our approach, the important role of structural hierarchy in phase selection, and the richness of the metastable phase landscape accessible from the glassy structure.

3.
Med J Malaysia ; 72(4): 236-240, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28889135

RESUMO

OBJECTIVES: Percutaneous coronary intervention (PCI) of total chronic total occlusion (CTO) still remains a major challenge in interventional cardiology. There is only insignificant knowledge reported in the literature about age differences in CTO recanalization. We analyzed in this study the issue of the impact of age on procedural characteristics, complications and short-term outcome. METHODS: Between 2012-2016 we included 440 patients. They underwent PCI for at least one CTO. Antegrade and retrograde CTO techniques were applied. The retrograde approach was used only after failed antegrade intervention. Continuous data are presented as the mean ± standard deviation; categorical data are presented as numbers and percentages unless otherwise specified. We used Twosamplet- t-test with equal variance to test the significant differences of the variables between the two cohorts. RESULTS: Procedural success proved independently of age. There was no significant interaction between age and procedural success (p=0.5). Complication rates were low in both groups (2.7% vs. 4%; p=0,4) with no difference in statistical significance. CONCLUSIONS: Our study suggests that in an aging society patients with severe coronary artery disease and chronical total occlusions an interventional therapy should be used more intensively. It can be performed safe and feasible.


Assuntos
Oclusão Coronária/cirurgia , Intervenção Coronária Percutânea , Fatores Etários , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Intervenção Coronária Percutânea/efeitos adversos , Intervenção Coronária Percutânea/métodos , Estudos Retrospectivos , Resultado do Tratamento
4.
Neth Heart J ; 25(5): 304-311, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28244014

RESUMO

BACKGROUND: Percutaneous coronary intervention (PCI) of total chronic coronary occlusion (CTO) still remains a major challenge. Insignificant data are reported in the literature about gender differences in CTO-PCI in the era of new drug-eluting stents. In this study we analysed the impact of gender on procedural characteristics, complications and acute results. METHODS: Between 2010-2015 we included 780 consecutive patients. They underwent PCI for at least one CTO. Antegrade and retrograde CTO techniques were applied. RESULTS: Patients undergoing CTO-PCI were mainly men (84%). Male patients were younger (66.9 years ±10.6 vs. 61.1 years ±10.4; p < 0.001), more often smokers, but less frequently had a history of coronary artery disease (24.4% vs. 32.7%; p = 0.085) compared with female patients. Female patients more often had diabetes mellitus (29.6% vs. 26.7%; p = 0.55) and hypertension (82.7% vs. 80.7%; p = 0.55). There were no differences with respect to the amount of contrast fluid, fluoroscopy time and examination time as well as to the length of the stent or the number of the stents. The stent diameter was slightly smaller in women, which was not surprising because the lumen calibre tends to be smaller in women than in men (3.0 mm (2.5-3) vs. 3.0 mm (3-3.5); p < 0.001). The success rates were 81.0% in women and 80.1% in men. There was no significant interaction between gender and procedural success and complication rates. CONCLUSIONS: Our retrospective study suggests that women and men have a comparable success rate at a low complication rate after recanalisation of CTO.

5.
Int J Cardiol ; 230: 228-231, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28041697

RESUMO

BACKGROUND: Percutaneous coronary intervention (PCI) of total chronic coronary occlusion (CTO) still remains a major challenge in interventional cardiology. To predict the probability of a successful intervention different scoring systems are available. We analyzed in this study the validity of two scoring systems, the Japanese CTO score (J-CTO score) and the newly developed Clinical and Lesion-related score (CL Score). METHODS: Between 2012 and 2015 we included 379 consecutive patients. They underwent PCI for at least one CTO. Antegrade and retrograde CTO techniques were applied. The retrograde approach was used only after failed antegrade intervention. RESULTS: Patients undergoing CTO PCI were mainly men (84%). The overall procedural success rate was 84% (±0.4). The mean J-CTO score was 2.9 (±1.3) and the mean CL score was 4.3 (±1.7). The CL score predicted more precisely the interventional results than the J-CTO score. CONCLUSIONS: Our study suggests that the previously presented CL score is superior to the J-CTO score in identifying CTO lesions with a likelihood for successful recanalization. Generally it appears to be a helpful tool for selecting patients and identifying the appropriate operator.


Assuntos
Oclusão Coronária/cirurgia , Intervenção Coronária Percutânea/métodos , Sistema de Registros , Medição de Risco/métodos , Doença Crônica , Angiografia Coronária , Oclusão Coronária/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença
6.
Data Brief ; 6: 492-4, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26900594

RESUMO

In this article, we describe data on (1) compositions for both as-cast and heat treated specimens were summarized in Table 1; (2) the determined enthalpy of mixing of liquid phase is listed in Table 2; (3) thermodynamic database of the Co-Pr system in TDB format for the research articled entitle Chemical partitioning for the Co-Pr system: First-principles, experiments and energetic calculations to investigate the hard magnetic phase W.

8.
Euro Surveill ; 19(5)2014 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-24524235

RESUMO

The prevalence of influenza A and B virus-specific IgG was determined in sera taken between 2008 and 2010 from 1,665 children aged 0-17 years and 400 blood donors in Germany. ELISA on the basis of whole virus antigens was applied. Nearly all children aged nine years and older had antibodies against influenza A. In contrast, 40% of children aged 0-4 years did not have any influenza A virus-specific IgG antibodies. Eightysix percent of 0-6 year-olds, 47% of 7-12 year-olds and 20% of 13-17 year-olds were serologically naïve to influenza B viruses. By the age of 18 years, influenza B seroprevalence reached approximately 90%. There were obvious regional differences in the seroprevalence of influenza B in Germany. In conclusion, seroprevalences of influenza A and influenza B increase gradually during childhood. The majority of children older than eight years have basal immunity to influenza A, while comparable immunity against influenza B is only acquired at the age of 18 years. Children aged 0-6 years, showing an overall seroprevalence of 67% for influenza A and of 14% for influenza B, are especially at risk for primary infections during influenza B seasons.


Assuntos
Anticorpos Antivirais/sangue , Vírus da Influenza A/imunologia , Vírus da Influenza B/imunologia , Influenza Humana/epidemiologia , Adolescente , Criança , Pré-Escolar , Feminino , Alemanha/epidemiologia , Humanos , Imunoglobulina G/sangue , Lactente , Influenza Humana/sangue , Influenza Humana/imunologia , Masculino , Prevalência , Estudos Soroepidemiológicos , Adulto Jovem
9.
Eur J Clin Microbiol Infect Dis ; 33(6): 1019-27, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24413899

RESUMO

Post-infectious sequelea such as Guillain Barré syndrome (GBS), reactive arthritis (RA), and inflammatory bowel disease (IBD) may arise as a consequence of acute Campylobacter-enteritis (AE). However, reliable seroprevalence data of Campylobacter-associated sequelae has not been established. The objectives of this study were, first, to identify the most specific and sensitive test antigen in an optimized ELISA assay for diagnosing a previous Campylobacter-infection and, second, to compare the prevalence of anti-Campylobacter antibodies in cohorts of healthy blood donors (BD), AE, GBS, RA, and IBD patients with antibodies against known GBS, RA and IBD triggering pathogens. Optimized ELISAs of single and combined Campylobacter-proteins OMP18 and P39 as antigens were prepared and sera from AE, GBS, RA and IBD patients and BD were tested for Campylobcter-specific IgA and IgG antibodies. The results were compared with MIKROGEN™-recomLine Campylobacter IgA/IgG and whole cell lysate-immunoblot. Antibodies specific for Helicobacter pylori, Mycoplasma pneumoniae, Yersinia enterocolitica, and Borrelia afzelii were tested with commercial immunoblots. ROC plot analysis revealed AUC maxima in the combination of OMP18 and P39 for IgA and in the P39-antigen for IgG. As a result, 34-49 % GBS cases, 44-62 % RA cases and 23-40 % IBD cases were associated with Campylobacter-infection. These data show that Campylobcater-seropositivity in these patient groups is significantly higher than other triggering pathogens suggesting that it plays an important role in development of GBS and RA, and supports the hypothesis that recurrent acute campylobacteriosis triggers IBD.


Assuntos
Artrite Reativa/epidemiologia , Infecções por Campylobacter/complicações , Infecções por Campylobacter/epidemiologia , Síndrome de Guillain-Barré/epidemiologia , Doenças Inflamatórias Intestinais/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antibacterianos/sangue , Infecções por Campylobacter/diagnóstico , Estudos de Coortes , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Estudos Soroepidemiológicos , Adulto Jovem
10.
Pharmacopsychiatry ; 47(1): 22-8, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24222011

RESUMO

INTRODUCTION: This survey aims to contribute to the current discussion about neuroenhancement by comparing cognitive enhancer(s) (CE) users with CE non-users with a focus on their characteristics and attitudes. METHODS: An online survey was sent out to all undergraduate and graduate students of the University of Zürich who allow such e-mails (n=8642), accompanied by advertisement for the survey in lectures. 1765 students completed the survey, which was about healthy people's use of Ritalin, Adderall and/or Modasomil to increase concentration and/or alertness. A complementary paper-and-pencil survey (n=97 students, response rate: 95.1%) was also carried out in order to compare data. RESULTS: Non-therapeutic CE users (6.2%) were more often male, considered religion to be of less importance and had more experience with drugs. CE had been taken for study purposes by 4.7% of all students. CE users had tried Ritalin most often, which about half of them received from friends and colleagues. The CE users had more reasons for and fewer concerns about taking CE than non-users. The most common reasons for both groups were "the effects of learning quicker" and "for finishing more work in less time". The most common concerns for both groups were "the worries about possible side effects" and "the goal of CE to achieve more", and "an unnatural interference of such products with our bodies" (CE-users) or "the gut feeling of not using such products" (CE non-users). DISCUSSION: The comparison of CE users with CE non-users reveals insights about their attitudes, which will add to the understanding of why students take or could imagine taking such products.


Assuntos
Cognição/efeitos dos fármacos , Psicotrópicos/farmacologia , Estudantes/psicologia , Feminino , Inquéritos Epidemiológicos , Humanos , Modelos Logísticos , Masculino , Suíça , Universidades
11.
Digestion ; 88(3): 161-4, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24080585

RESUMO

BACKGROUND: Barrett esophagus (BE) is a major risk factor for adenocarcinoma of the distal esophagus. Reliable detection of BE during upper endoscopy is therefore mandatory. According to most guidelines, diagnosis of BE requires both endoscopy and histology for confirmation. However, since adenocarcinomas were also described in patients with indeterminate BE, i.e. endoscopic visible columnar metaplasia but no histological confirmation of goblet cells or vice versa, debate has risen on the risk of malignancy and the need for endoscopic surveillance in such patients. PATIENTS AND METHODS: The study was aimed to assess long-term follow-up data on 209 patients with indeterminate BE (on histopathology or endoscopy) initially examined between 1999 and 2000. Patients or referring physicians were contacted concerning the most recent endoscopic and histopathological results. RESULTS: Follow-up data could be assessed in 149/209 patients (65.1%) after a mean follow-up period of 9.4 years (SD ±2.4 years). Neoplasia was not reported for any patient. The previous endoscopic-histopathological diagnoses could be confirmed in 3 patients only. In the group with endoscopic diagnosis of BE but no histopathological confirmation, BE was described histopathologically in 1 patient during follow-up. CONCLUSION: Persistence of indeterminate BE is poor during long-term follow up. The risk of cancer appears to be negligible. Hence, surveillance of these patients appears equivocal.


Assuntos
Adenocarcinoma/patologia , Esôfago de Barrett/patologia , Neoplasias Esofágicas/patologia , Lesões Pré-Cancerosas/patologia , Adenocarcinoma/diagnóstico , Esôfago de Barrett/diagnóstico , Neoplasias Esofágicas/diagnóstico , Esofagoscopia , Feminino , Seguimentos , Células Caliciformes/patologia , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Lesões Pré-Cancerosas/diagnóstico , Prognóstico
12.
Phys Rev Lett ; 110(20): 205505, 2013 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-25167428

RESUMO

By analyzing the angular correlations in scanning electron nanodiffraction patterns from a melt-spun Zr(36)Cu(64) glass, the dominant local order was identified as icosahedral clusters. Mapping the extent of this icosahedral short-range order demonstrates that the medium-range order in this material is consistent with a face-sharing or interpenetrating configuration. These conclusions support results from atomistic modeling and a structural basis for the glass formability of this system.

13.
Praxis (Bern 1994) ; 101(17): 1089-97, 2012 Aug 22.
Artigo em Alemão | MEDLINE | ID: mdl-22915511

RESUMO

Patients with a severe eating disorder (anorexia, bulimia, other) are rarely subject of systematic studies. However, many of these patients are in need of in-patient treatment on specialized wards applying interdisciplinary treatment modalities. Updated criteria based on which hospitalisation should occur are provided by the recently issued S3-guideline for the treatment of eating disorders. We retrospectively assessed 26 consecutive patients with a severe eating disorder who were admitted to a psychosomatic/internal medicine university hospital in terms of their somatic, psychological, and social characteristics. Based on the S3-guideline, we conclude that hospitalization of these patients, within a multidisciplinary treatment setting, complies with evidenced-based criteria.


Assuntos
Anorexia Nervosa/terapia , Bulimia Nervosa/terapia , Fidelidade a Diretrizes , Adolescente , Adulto , Anorexia Nervosa/diagnóstico , Anorexia Nervosa/psicologia , Índice de Massa Corporal , Peso Corporal , Bulimia Nervosa/diagnóstico , Bulimia Nervosa/psicologia , Comorbidade , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/psicologia , Transtorno Depressivo/terapia , Feminino , Hospitais Universitários , Humanos , Transtornos Mentais/diagnóstico , Transtornos Mentais/psicologia , Transtornos Mentais/terapia , Pessoa de Meia-Idade , Admissão do Paciente , Determinação da Personalidade/estatística & dados numéricos , Psicometria , Suíça , Adulto Jovem
15.
Eur Respir J ; 38(1): 147-53, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21148226

RESUMO

Pneumonia is an important cause of influenza-associated morbidity and mortality. Influenza vaccination has been shown to reduce morbidity and mortality during influenza seasons. Protection from severe pneumonia may contribute to the beneficial effect of influenza vaccination. Therefore, we investigated the impact of prior influenza vaccination on disease severity and mortality in patients with community-acquired pneumonia (CAP). Analysis from an observational, multicentre cohort study initiated by the German competence network for CAP was performed. Patients were analysed separately as an influenza season and off-season cohort. Associations between vaccination status and outcome parameters were evaluated by multivariate analyses. In the season cohort (2,368 patients) CAP in vaccinated patients was significantly less severe according to most analysed parameters (CURB index ≥ 1: OR 0.76, 95% CI 0.60-0.98; procalcitonin ≥ 2.0 ng·mL(-1): OR 0.53, 95% CI 0.35-0.81; procalcitonin ≥ 0.5 ng·mL(-1): OR 0.71, 95% CI 0.51-0.99) and these patients showed a significantly better overall survival within the 6-month follow-up period (HR 0.63, 95% CI 0.45-0.89). Within the off-season cohort (2,632 patients) there was no significant influence of vaccination status on CAP severity or disease outcome. In conclusion, prior influenza vaccination was associated with less severe clinical course and improved overall long-term survival in patients with CAP during influenza seasons.


Assuntos
Infecções Comunitárias Adquiridas/fisiopatologia , Vacinas contra Influenza/uso terapêutico , Influenza Humana/complicações , Pneumonia/fisiopatologia , Idoso , Estudos de Coortes , Infecções Comunitárias Adquiridas/mortalidade , Feminino , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Pneumonia/mortalidade , Estações do Ano , Resultado do Tratamento , Vacinação
16.
Phys Rev Lett ; 105(21): 215502, 2010 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-21231320

RESUMO

Synchrotron x-ray diffraction and high-resolution electron microscopy revealed the origin of different strain hardening behaviors (and dissimilar tensile ductility) in nanocrystalline Ni and nanocrystalline Co. Planar defect accumulations and texture evolution were observed in Co but not in Ni, suggesting that interfacial defects are an effective passage to promote strain hardening in truly nanograins. Twinning becomes less significant in Co when grain sizes reduce to below ~15 nm. This study offers insights into achieving excellent mechanical properties in nanocrystalline materials.

17.
MMW Fortschr Med ; 152(Suppl 4): 115-8, 2010 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-27372952
18.
Med Image Anal ; 13(6): 900-9, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19781977

RESUMO

This paper presents a novel data-driven method for image intensity normalisation, which is a prerequisite step for any kind of image comparison. The method involves a novel application of the Siddon algorithm that was developed initially for fast reconstruction of tomographic images and is based on a linear normalisation model with either one or two parameters. The latter are estimated by maximising the line integral, computed using the Siddon algorithm, in the 2D joint intensity distribution space of image pairs. The proposed normalisation method, referred to as Siddon Line Integral Maximisation (SLIM), was compared with three other methodologies, namely background ratio (BAR) scaling, linear fitting and proportional scaling, using a large number of synthesised datasets. SLIM was also compared with BAR normalisation when applied to phantom data and two clinical examples. The new method was found to be more accurate and less biased than its counterparts for the range of characteristics selected for the synthesised data. These findings were in agreement with the results from the analysis of the experimental and clinical data.


Assuntos
Algoritmos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Reconhecimento Automatizado de Padrão/métodos , Humanos , Interpretação de Imagem Assistida por Computador/instrumentação , Modelos Biológicos , Modelos Estatísticos , Imagens de Fantasmas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
19.
Med Microbiol Immunol ; 198(2): 93-101, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19194722

RESUMO

The objective of this study was to provide seroepidemiological information on influenza A and B antibodies in children and adolescents. Viral immunoglobulin G antibodies were determined retrospectively using enzyme-linked immunosorbent assays in a group of 1,111 children and adolescents. Sera (809) from healthy adult blood donors served as controls. In children, the prevalence of antibodies against influenza A was 82.0% and against influenza B 9.6%, whereas in adults the prevalence of antibodies against influenza A was calculated as 99.4% and against influenza B 56.7%. After decline of maternal antibodies during the first year of life, there was an increase of prevalence of influenza A antibodies up to 100% by the age of 12 years. In contrast, only 1-2% of children up to 9 years had influenza B antibodies increasing to 25% by the age of 18 years and to 70% among adults aged 30 years. Children aged 0-6 years had significantly lower concentrations and >12-15-year-old adolescents had significantly higher concentrations of antibodies against influenza A than adults. For all age groups of children and adolescents, significantly lower antibody concentrations against influenza B were measured in comparison to the blood donor control group. In conclusion, the annual influenza vaccination in children and adolescents may improve considerably the protection against influenza virus infection occurring during epidemics.


Assuntos
Anticorpos Antivirais/sangue , Vírus da Influenza A/imunologia , Vírus da Influenza B/imunologia , Influenza Humana/epidemiologia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Alemanha/epidemiologia , Humanos , Imunoglobulina G/sangue , Lactente , Influenza Humana/sangue , Influenza Humana/imunologia , Masculino , Prevalência , Estudos Soroepidemiológicos , Adulto Jovem
20.
Phys Med Biol ; 53(12): 3159-74, 2008 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-18495974

RESUMO

The increased intelligence, read-out speed, radiation hardness and potential large size of CMOS active pixel sensors (APS) gives them a potential advantage over systems currently used for verification of complex treatments such as IMRT and the tracking of moving tumours. The aim of this work is to investigate the feasibility of using an APS-based system to image the megavoltage treatment beam produced by a linear accelerator (Linac), and to demonstrate the logic which may ultimately be incorporated into future sensor and FPGA design to evaluate treatment and track motion. A CMOS APS was developed by the MI(3) consortium and incorporated into a megavoltage imaging system using the standard lens and mirror configuration employed in camera-based EPIDs. The ability to resolve anatomical structure was evaluated using an Alderson RANDO head phantom, resolution evaluated using a quality control (QC3) phantom and contrast using an in-house developed phantom. A complex intensity-modulated radiotherapy (IMRT) treatment was imaged and two algorithms were used to determine the field-area and delivered dose, and the position of multi-leaf collimator (MLC) leaves off-line. Results were compared with prediction from the prescription and found to agree within a single image frame time for dose delivery and 0.02-0.03 cm for the position of collimator leaves. Such a system therefore shows potential as the basis for an on-line verification system capable of treatment verification and monitoring patient motion.


Assuntos
Metais/química , Óxidos/química , Radioterapia de Intensidade Modulada/instrumentação , Estudos de Viabilidade , Humanos , Imagens de Fantasmas , Radioterapia de Alta Energia , Reprodutibilidade dos Testes , Semicondutores , Crânio
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA