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1.
Phys Rev Lett ; 123(23): 233601, 2019 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-31868492

RESUMEN

We investigate a Bose-Einstein condensate strongly coupled to an optical cavity via a repulsive optical lattice. We detect a stable self-ordered phase in this regime, and show that the atoms order through an antisymmetric coupling to the P band of the lattice, limiting the extent of the phase and changing the geometry of the emergent density modulation. Furthermore, we find a nonequilibrium phase with repeated intense bursts of the intracavity photon number, indicating nontrivial driven-dissipative dynamics.

2.
J Intern Med ; 284(3): 270-281, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29664160

RESUMEN

BACKGROUND: Hyponatremia is a common feature of acute illness and associated with increased mortality. This may be explained by a stress-mediated activation of the vasopressin system with an increase in free-water reabsorption. OBJECTIVES: To investigate whether the association between hyponatremia and mortality could be explained by activation of the vasopressin system. METHODS: We prospectively enrolled adult, medical patients seeking emergency care in three centres in Switzerland, France and the United States. We investigated associations between admission plasma sodium and copeptin, a stable portion of the vasopressin-precursor peptide, with 30-day mortality. We performed uni- and multivariate regression analysis. RESULTS: Of 6962 included patients, 18% had hyponatremia (sodium ≤135 mmol L-1 ), which doubled their risk for mortality compared to patients with normonatremia (8.3% vs. 3.8%). This association was confirmed in a multivariate-adjusted logistic regression analysis [adjusted odds ratio (OR) 1.47, 95% CI 1.12-1.93, P = 0.005]. Vasopressin levels, mirrored by copeptin, were also increased in nonsurvivors and strongly associated with mortality (adjusted OR 3.42, 95% CI 2.76-4.25, P < 0.001). The association between hyponatremia and mortality remained unchanged when adding copeptin levels to the regression model (fully adjusted OR 1.53, 95% CI 1.16-2.00, P = 0.002). CONCLUSION: This prospective study including medical patients upon emergency room admission found hyponatremia as well as an activation of the vasopressin system to be independently associated with mortality. This suggests that stress- and vasopressin-independent mechanisms are responsible for the association of low sodium levels with mortality.


Asunto(s)
Enfermedad Aguda/mortalidad , Hiponatremia/sangre , Hiponatremia/mortalidad , Vasopresinas/sangre , Adulto , Anciano , Estudios de Cohortes , Correlación de Datos , Comparación Transcultural , Servicio de Urgencia en Hospital , Femenino , Francia , Glicopéptidos/sangre , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Riesgo , Tasa de Secreción/fisiología , Sodio/sangre , Suiza , Estados Unidos
3.
J Appl Microbiol ; 125(4): 1216-1225, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29802665

RESUMEN

AIMS: A molecular method for a rapid detection of viable Legionella pneumophila of all serogroups in tap water samples was developed as an alternative to the reference method (ISO). Legionellae are responsible for Legionnaires' disease, a severe pneumonia in humans with high lethality. METHODS AND RESULTS: The developed method is based on a nutritional stimulation and detection of an increase in precursor 16S rRNA as an indicator for viability. For quantification, DNA was detected by qPCR. This method was compared to the ISO method using water samples obtained from public sports facilities in Switzerland. The sensitivity and specificity were 91 and 97%, respectively, when testing samples for compliance with a microbiological criterion of 1000 cell equivalents per l. CONCLUSION: The new method is sensitive and specific for Leg. pneumophila and allows results to be obtained within 8 h upon arrival, compared to one week or more by the ISO method. SIGNIFICANCE AND IMPACT OF THE STUDY: The method represents a useful tool for a rapid detection of viable Leg. pneumophila of all serogroups in water by molecular biology. It can be used as an alternative to the ISO method for official water analysis for legionellae and particularly when a short test time is required.


Asunto(s)
Agua Dulce/microbiología , Legionella pneumophila/aislamiento & purificación , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , ADN Bacteriano/genética , Humanos , Legionella pneumophila/clasificación , Legionella pneumophila/genética , Legionella pneumophila/crecimiento & desarrollo , Enfermedad de los Legionarios/microbiología , Viabilidad Microbiana , ARN Ribosómico 16S/genética , Sensibilidad y Especificidad , Microbiología del Agua
4.
J Water Health ; 16(1): 138-149, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29424727

RESUMEN

Water resources situated in areas with underlying karst geology are particularly vulnerable to fecal pollution. In such vulnerable systems, microbial source tracking (MST) methods are useful tools to elucidate the pathways of both animal and human fecal pollution, leading to more accurate water use risk assessments. Here, we describe the application of a MST toolbox using both culture-dependent bacteriophage and molecular-dependent 16S rRNA assays at spring and well sites in the karstic St Imier Valley, Switzerland. Culture-dependent and molecular-dependent marker performance varied significantly, with the 16S rRNA assays displaying greater sensitivity than their phage counterpart; HF183 was the best performing human wastewater-associated marker while Rum2Bac was the best performing ruminant marker. Differences were observed in pollution regimes between the well and spring sampling sites, with the spring water being more degraded than the well site. Our results inform the choice of marker selection for MST studies and highlight differences in microbial water quality between well and spring karst sites.


Asunto(s)
Agua Potable/microbiología , Monitoreo del Ambiente/métodos , Microbiología del Agua , Recursos Hídricos , Animales , Bacteriófagos/aislamiento & purificación , Humanos , Reacción en Cadena de la Polimerasa , Medición de Riesgo , Suiza , Virus/aislamiento & purificación , Calidad del Agua
5.
Br J Dermatol ; 174(5): 1061-7, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26574236

RESUMEN

BACKGROUND: Long-term results following liposuction in patients with lipoedema are available only for an average period of 4 years. OBJECTIVE: To find out whether the improvement of complaints persists for a further 4 years. METHODS: In a single-centre study, 85 patients with lipoedema had already been examined after 4 years. A mail questionnaire - often in combination with clinical controls - was repeated after another 4 years (8 years after liposuction). RESULTS: Compared with the results after 4 years, the improvement in spontaneous pain, sensitivity to pressure, oedema, bruising and restriction of movement persisted. The same held true for patient self-assessment of cosmetic appearance, quality of life and overall impairment. Eight years after surgery, the reduction in the amount of conservative treatment (combined decongestive therapy, compression garments) was similar to that observed 4 years earlier. CONCLUSION: These results demonstrate for the first time the long-lasting positive effects of liposuction in patients with lipoedema.


Asunto(s)
Lipectomía/métodos , Lipedema/terapia , Adulto , Anciano , Contusiones/etiología , Contusiones/terapia , Técnicas Cosméticas , Femenino , Humanos , Persona de Mediana Edad , Trastornos del Movimiento/etiología , Trastornos del Movimiento/terapia , Dolor/etiología , Dolor/prevención & control , Presión , Calidad de Vida , Factores de Tiempo , Resultado del Tratamiento , Adulto Joven
6.
Nanotechnology ; 27(19): 195303, 2016 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-27040175

RESUMEN

Advanced synthesis of semiconductor nanowires (NWs) enables their application in diverse fields, notably in chemical and electrical sensing, photovoltaics, or quantum electronic devices. In particular, indium arsenide (InAs) NWs are an ideal platform for quantum devices, e.g. they may host topological Majorana states. While the synthesis has been continously perfected, only a few techniques have been developed to tailor individual NWs after growth. Here we present three wet chemical etch methods for the post-growth morphological engineering of InAs NWs on the sub-100 nm scale. The first two methods allow the formation of self-aligned electrical contacts to etched NWs, while the third method results in conical shaped NW profiles ideal for creating smooth electrical potential gradients and shallow barriers. Low temperature experiments show that NWs with etched segments have stable transport characteristics and can serve as building blocks of quantum electronic devices. As an example we report the formation of a single electrically stable quantum dot between two etched NW segments.

7.
Nano Lett ; 15(7): 4585-90, 2015 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-26086240

RESUMEN

Semiconducting nanowires (NWs) are a versatile, highly tunable material platform at the heart of many new developments in nanoscale and quantum physics. Here, we demonstrate charge pumping, that is, the controlled transport of individual electrons through an InAs NW quantum dot (QD) device at frequencies up to 1.3 GHz. The QD is induced electrostatically in the NW by a series of local bottom gates in a state of the art device geometry. A periodic modulation of a single gate is enough to obtain a dc current proportional to the frequency of the modulation. The dc bias, the modulation amplitude and the gate voltages on the local gates can be used to control the number of charges conveyed per cycle. Charge pumping in InAs NWs is relevant not only in metrology as a current standard, but also opens up the opportunity to investigate a variety of exotic states of matter, for example, Majorana modes, by single electron spectroscopy and correlation experiments.

8.
Phys Rev Lett ; 115(21): 216801, 2015 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-26636862

RESUMEN

We report the observation of two fundamental subgap transport processes through a quantum dot (QD) with a superconducting contact. The device consists of a carbon nanotube contacted by a Nb superconducting and a normal metal contact. First, we find a single resonance with position, shape, and amplitude consistent with the theoretically predicted resonant Andreev tunneling (AT) through a single QD level. Second, we observe a series of discrete replicas of resonant AT at a separation of ~145 µeV, with a gate, bias, and temperature dependence characteristic for boson-assisted, inelastic AT, in which energy is exchanged between a bosonic bath and the electrons. The magnetic field dependence of the replica's amplitudes and energies suggest that two different bosons couple to the tunnel process.

9.
Phys Rev Lett ; 115(22): 227003, 2015 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-26650317

RESUMEN

Cooper pair splitting (CPS) is a process in which the electrons of the naturally occurring spin-singlet pairs in a superconductor are spatially separated using two quantum dots. Here, we investigate the evolution of the conductance correlations in an InAs CPS device in the presence of an external magnetic field. In our experiments the gate dependence of the signal that depends on both quantum dots continuously evolves from a slightly asymmetric Lorentzian to a strongly asymmetric Fano-type resonance with increasing field. These experiments can be understood in a simple three-site model, which shows that the nonlocal CPS leads to symmetric line shapes, while the local transport processes can exhibit an asymmetric shape due to quantum interference. These findings demonstrate that the electrons from a Cooper pair splitter can propagate coherently after their emission from the superconductor and how a magnetic field can be used to optimize the performance of a CPS device. In addition, the model calculations suggest that the estimate of the CPS efficiency in the experiments is a lower bound for the actual efficiency.

10.
Eur J Neurol ; 22(1): 203-6, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24589025

RESUMEN

BACKGROUND AND PURPOSE: Detection of autoantibodies against neuronal surface antigens and their correlation with the pattern and severity of symptoms led to the definition of new autoimmune-mediated forms of encephalitis and was essential for the initiation of immunotherapies including plasma exchange. The elimination of autoantibodies using selective immunoadsorption (IA) is a pathophysiologically guided therapeutic approach but has not yet been evaluated in a separate analysis. METHODS: A retrospective analysis was performed of patients with autoimmune encephalitis who were treated with tryptophan IA in six neurological clinics between 2009 and 2013. The modified Rankin scale (mRS) was used to evaluate neurological status before and after IA. RESULTS: Data on 13 patients were documented. Twelve patients were positive for specific autoantibodies (NMDA-R, GABA, GAD, Lgl1). Patients received a series of a median of six IA treatments. Median mRS of all patients was 3.0 before IA and 2.0 after IA (P < 0.001). Eleven patients improved by at least one point in mRS after IA. CONCLUSION: For autoimmune-mediated forms of encephalitis rapid elimination of autoantibodies with selective IA seems to be an effective therapeutic option as part of multimodal immune therapy.


Asunto(s)
Autoanticuerpos/sangre , Encefalitis/inmunología , Encefalitis/terapia , Técnicas de Inmunoadsorción , Triptófano/metabolismo , Adulto , Anciano , Encefalitis Antirreceptor N-Metil-D-Aspartato/terapia , Proteínas del Citoesqueleto/inmunología , Encefalitis/sangre , Femenino , Glutamato Descarboxilasa/inmunología , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven , Ácido gamma-Aminobutírico/inmunología
11.
Scand J Rheumatol ; 44(5): 359-62, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25974288

RESUMEN

OBJECTIVES: We aimed to determine how loss of response (LOR) to adalimumab (ADA) in juvenile idiopathic arthritis (JIA) may be related to anti-ADA antibodies (AAA). METHOD: AAA and ADA levels were measured in 23 consecutive patients with JIA responding significantly to treatment with ADA. RESULTS: Six out of 23 (26%) patients developed AAA and had low ADA levels. Five out of six AAA-positive patients experienced LOR. In these patients use of concomitant methotrexate (MTX) was significantly lower. CONCLUSIONS: The occurrence of AAA is a frequent event associated with LOR. Monitoring of AAA and serum ADA levels should be considered in JIA patients under ADA therapy.


Asunto(s)
Adalimumab/inmunología , Adalimumab/uso terapéutico , Anticuerpos Antiidiotipos/sangre , Antirreumáticos/inmunología , Antirreumáticos/uso terapéutico , Artritis Juvenil/tratamiento farmacológico , Adalimumab/sangre , Adolescente , Anticuerpos Antiidiotipos/inmunología , Antirreumáticos/sangre , Artritis Juvenil/sangre , Artritis Juvenil/inmunología , Biomarcadores/sangre , Niño , Quimioterapia Combinada , Femenino , Humanos , Masculino , Metotrexato/uso terapéutico , Índice de Severidad de la Enfermedad , Insuficiencia del Tratamiento , Resultado del Tratamiento , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores
12.
Environ Sci Technol ; 49(12): 7142-51, 2015 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-25871525

RESUMEN

Microbial contamination of groundwater represents a significant health risk to resource users. Culture-dependent Bacteroides phage and molecular-dependent Bacteroidales 16S rRNA assays are employed in microbial source tracking (MST) studies globally, however little is known regarding how these important groups relate to each other in the environment and which is more suitable to indicate the presence of waterborne fecal pollution and human enteric viruses. This study addresses this knowledge gap by examining 64 groundwater samples from sites with varying hydrogeological properties using a MST toolbox containing two bacteriophage groups (phage infecting GB-124 and ARABA-84), and two Bacteroidales 16S rRNA markers (Hf183 and BacR); those were compared to fecal indicator bacteria, somatic coliphage, Bacteroidales 16S rRNA marker AllBac, four human enteric viruses (norovirus GI and II, enterovirus and group A rotavirus) and supplementary hydrogeological/chemical data. Bacteroidales 16S rRNA indicators offered a more sensitive assessment of both human-specific and general fecal contamination than phage indicators, but may overestimate the risk from enteric viral pathogens. Comparison with hydrogeological and land use site characteristics as well as auxiliary microbiological and chemical data proved the plausibility of the MST findings. Sites representing karst aquifers were of significantly worse microbial quality than those with unconsolidated or fissured aquifers, highlighting the vulnerability of these hydrogeological settings.


Asunto(s)
Bacteroides/genética , Bacteroidetes/genética , Biomarcadores/análisis , Heces/virología , Agua Subterránea/virología , Contaminación del Agua/análisis , Calidad del Agua , Heces/microbiología , Agua Subterránea/microbiología , Agua Subterránea/normas , Humanos , ARN Ribosómico 16S/genética
13.
Neuroradiology ; 57(12): 1203-9, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26293130

RESUMEN

INTRODUCTION: Limbic encephalitis (LE) associated with voltage-gated potassium channel-complex antibodies (VGKC-LE) is frequently non-paraneoplastic and associated with marked improvement following corticosteroid therapy. Mesial temporal lobe abnormalities are present in around 80 % of patients. If associated or preceded by faciobrachial dystonic seizures, basal ganglia signal changes may occur. In some patients, blurring of the supratentorial white matter on T2-weighted images (SWMB) may be seen. The purpose of this study was to evaluate the incidence of SWMB and whether it is specific for VGKC-LE. METHODS: Two experienced neuroradiologists independently evaluated signal abnormalities on FLAIR MRI in 79 patients with LE while unaware on the antibody type. RESULTS: SWMB was independently assessed as present in 10 of 36 (28 %) compared to 2 (5 %) of 43 non-VGKC patients (p = 0.009). It was not related to the presence of LGI1 or CASPR2 proteins of VGKC antibodies. MRI showed increased temporomesial FLAIR signal in 22 (61 %) VGKC compared to 14 (33 %) non-VGKC patients (p = 0.013), and extratemporomesial structures were affected in one VGKC (3 %) compared to 11 (26 %) non-VGKC patients (p = 0.005). CONCLUSION: SWMB is a newly described MRI sign rather specific for VGKC-LE.


Asunto(s)
Cerebro/patología , Imagen de Difusión Tensora/métodos , Encefalitis Límbica/inmunología , Encefalitis Límbica/patología , Canales de Potasio con Entrada de Voltaje/inmunología , Sustancia Blanca/patología , Adulto , Anciano , Anciano de 80 o más Años , Autoanticuerpos/inmunología , Cerebro/inmunología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Sustancia Blanca/inmunología , Adulto Joven
14.
Acta Neurol Scand ; 130(2): 97-102, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24720783

RESUMEN

BACKGROUND: To minimize the risk of progressive multifocal leucoencephalopathy (PML), treatment with natalizumab is often stopped after 2 years, but evidence upon rebound of disease activity is limited and controversial. OBJECTIVE: To evaluate effects of natalizumab discontinuation on clinical disease activity within twelve months after cessation. METHODS: We retrospectively analyzed data of 201 patients with MS who discontinued natalizumab between 2007 and 2012. Mean change scores of annualized relapse rate (ARR) and expanded disability status scale (EDSS) were calculated for detection of rebound disease activity after twelve months. RESULTS: Natalizumab exposure did not exceed 2 years in 50.2% of patients, and the most common reasons for discontinuation were a long treatment period and concern of PML (56%). A total of 11.9% experienced a rebound phenomenon within twelve months. Mean ARR prenatalizumab was lower (P = 0.001, 95% CI -1.0-0.000) and treatment response to natalizumab poorer (P < 0.001, 95% CI 0.4-1.3) in patients with rebound compared to those without, but rebound was not associated with brief exposure to natalizumab (P = 0.159, 95% CI -9.3-1.5). 86.1% of patients switched to another therapy. Patients without rebound were found more often in the group starting an alternative treatment early (P = 0.013). CONCLUSION: Our data suggest that rebound of MS disease activity affects a subgroup of patients (11.9%), especially those with low disease activity before natalizumab therapy and a longer treatment gap after its withdrawal.


Asunto(s)
Anticuerpos Monoclonales Humanizados/administración & dosificación , Síndrome de Abstinencia a Sustancias/etiología , Adulto , Femenino , Humanos , Masculino , Esclerosis Múltiple/tratamiento farmacológico , Natalizumab , Estudios Retrospectivos
15.
J Dairy Sci ; 97(3): 1305-12, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24440268

RESUMEN

The objective of this study was to characterize Staphylococcus aureus isolates from Swiss raw milk cheeses that had been found to be contaminated with coagulase-positive staphylococci and to estimate the frequency of the various genotypes, in particular the mastitis-associated Staph. aureus genotype B (GTB). The isolates were also tested for staphylococcal enterotoxin (SE) genes and other virulence factors. From 623 coagulase-positive staphylococci isolated from 78 contaminated raw milk cheeses, 609 were found to be Staphylococcus aureus. Genotyping of all Staph. aureus isolates was performed by PCR amplification of the 16S-23S rRNA intergenic spacer region, as this method was used previously to differentiate between mastitis subtypes associated with their clinical outcome. In total, 20 different genotypes were obtained and the 5 most frequently occurring genotypes were distributed in 6.4% or more of the samples. The enterotoxin-producing Staph. aureus GTB, known for its high contagiousness and increased pathogenicity in Swiss mastitis herds, was found to be the most abundant subtype at the sample level (71.8%) as well as among the isolates (62.0%). A subset of 107 isolates of the different genotypes were analyzed for the presence of SE genes and revealed 9 different SE gene patterns, with sed being most frequently detected and 26% being PCR-negative for SE genes. Almost all isolates of the major contaminant GTB contained the SE gene pattern sed, sej, ser, with half of them additionally carrying sea. Production of SE in vitro was consistent with the SE genes detected in most of the cases; however, some isolated GTB did not produce SEA. Staphylococcus aureus Protein A (spa) typing revealed 30 different subtypes and most GTB isolates belonged to the bovine spa type t2953; GTB/t2953 was linked among other subtypes to SE production in cheese and staphylococcal intoxication cases. Furthermore, 1 of the 623 isolates was a methicillin-resistant Staph. aureus, which was an seh-carrying Staph. aureus spa type tbl 0635 (non-GTB). We conclude that control and reduction of enterotoxigenic Staph. aureus GTB in dairy herds in Switzerland will not only prevent economic losses at the farm level but also improve the safety of raw milk cheeses; distribution of methicillin-resistant Staph. aureus via raw milk cheese is of less concern.


Asunto(s)
Queso/microbiología , Leche/microbiología , Staphylococcus aureus/genética , Staphylococcus aureus/aislamiento & purificación , Animales , Bovinos , Enterotoxinas/análisis , Enterotoxinas/genética , Femenino , Análisis de los Alimentos , Contaminación de Alimentos/análisis , Microbiología de Alimentos , Genotipo , Reacción en Cadena de la Polimerasa , Suiza
16.
Nat Commun ; 15(1): 1068, 2024 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-38316779

RESUMEN

Combining superconducting resonators and quantum dots has triggered tremendous progress in quantum information, however, attempts at coupling a resonator to even charge parity spin qubits have resulted only in weak spin-photon coupling. Here, we integrate a zincblende InAs nanowire double quantum dot with strong spin-orbit interaction in a magnetic-field resilient, high-quality resonator. The quantum confinement in the nanowire is achieved using deterministically grown wurtzite tunnel barriers. Our experiments on even charge parity states and at large magnetic fields, allow us to identify the relevant spin states and to measure the spin decoherence rates and spin-photon coupling strengths. We find an anti-crossing between the resonator mode in the single photon limit and a singlet-triplet qubit with a spin-photon coupling strength of g/2π = 139 ± 4 MHz. This coherent coupling exceeds the resonator decay rate κ/2π = 19.8 ± 0.2 MHz and the qubit dephasing rate γ/2π = 116 ± 7 MHz, putting our system in the strong coupling regime.

17.
Euro Surveill ; 18(18): 20469, 2013 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-23725774

RESUMEN

From 24 April to 31 July 2011, nine cases of listeriosis were registered in the cantons of Aargau, Basel-Land and Zurich, Switzerland. In six of the cases, infection with Listeria monocytogenes was laboratory confirmed, while three remained suspected cases. The suspected cases were family members of confirmed cases with identical or similar symptoms. All confirmed cases were infected with a L. monocytogenes strain belonging to serovar 1/2a: all had an indistinguishable pulsotype by pulsed-field gel electrophoresis (PFGE). The same strain was detected in samples of cooked ham that were on sale from a particular retailer. Two samples of ham tested contained 470 and 4,800 colony-forming units (CFU) L. monocytogenes per gram respectively. Data of shopper cards from two confirmed cases could be evaluated: both cases had purchased the contaminated ham. The outbreak initiated a product recall and alert actions at national and European level, through the Rapid Alert System for Food and Feed (RASFF). Following the RASFF alert, the company producing the contaminated ham was inspected by the responsible authorities. Their investigations showed that the ham was not contaminated in the production plant, but in the premises of a company to which slicing and packing was outsourced.


Asunto(s)
Comercio , Contaminación de Alimentos/análisis , Listeria monocytogenes/aislamiento & purificación , Listeriosis/epidemiología , Productos de la Carne/microbiología , Anciano , Animales , Ensayo de Unidades Formadoras de Colonias , Seguridad de Productos para el Consumidor/legislación & jurisprudencia , Brotes de Enfermedades , Electroforesis en Gel de Campo Pulsado , Contaminación de Alimentos/legislación & jurisprudencia , Contaminación de Alimentos/prevención & control , Manipulación de Alimentos/métodos , Manipulación de Alimentos/normas , Humanos , Listeriosis/complicaciones , Listeriosis/diagnóstico , Productos de la Carne/análisis , Productos de la Carne/normas , Porcinos , Suiza/epidemiología
18.
Phys Rev Lett ; 109(15): 157002, 2012 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-23102354

RESUMEN

The two electrons of a Cooper pair in a conventional superconductor form a spin singlet and therefore a maximally entangled state. Recently, it was demonstrated that the two particles can be extracted from the superconductor into two spatially separated contacts via two quantum dots in a process called Cooper pair splitting (CPS). Competing transport processes, however, limit the efficiency of this process. Here we demonstrate efficiencies up to 90%, significantly larger than required to demonstrate interaction-dominated CPS, and on the right order to test Bell's inequality with electrons. We compare the CPS currents through both quantum dots, for which large apparent discrepancies are possible. The latter we explain intuitively and in a semiclassical master equation model. Large efficiencies are required to detect electron entanglement and for prospective electronics-based quantum information technologies.

20.
Mutat Res ; 743(1-2): 25-35, 2012 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-22249113

RESUMEN

Twelve chemical compounds have been selected for the European NewGeneris study on the basis of their potential to damage DNA, in order to establish adequate and reliable biomarkers of exposure. These genotoxic chemicals include heterocyclic amines, organochlorines, polycyclic aromatic hydrocarbons, mycotoxins, lipid peroxidation products and alcohol. Damage in somatic cells such as lymphocytes could give rise to cancer, while damage in germ cells could not only give rise to cancer but also to heritable defects. The alkaline Comet assay, with and without metabolic activation, as well as the neutral Comet assay were used to assess DNA integrity in spermatozoa and lymphocytes after in vitro treatment with low, middle and high doses of each chemical. DNA-reactive aldehydes generated by lipid peroxidation, food mutagens such as heterocyclic amines, nitrosamine and benzo[a]pyrene produced the highest amounts of DNA damage, even without metabolic activation. Damage seen with the neutral Comet assay - detecting primarily double-strand breaks - was lower than with the alkaline assay. In general, there was increased damage in the spermatozoa by comparison with the lymphocytes, with altered slopes in the dose-response curves. The Comet assay with sperm was generally very sensitive in assessing genotoxic damage, with the Comet parameters being good biomarkers of induced DNA damage. Establishing reliable biomarkers of exposure for the evaluation of dietary/environmental carcinogens is of utmost importance to protect our health and the health of our offspring.


Asunto(s)
Contaminantes Atmosféricos/toxicidad , Biomarcadores/análisis , Ensayo Cometa/métodos , Contaminación de Alimentos , Mutágenos/análisis , Benzo(a)pireno/toxicidad , Daño del ADN , Estudios de Factibilidad , Humanos , Linfocitos/efectos de los fármacos , Masculino , Hidrocarburos Policíclicos Aromáticos/toxicidad , Espermatozoides/efectos de los fármacos
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