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2.
Sci Rep ; 13(1): 14366, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37658090

RESUMEN

Superconducting microwave resonators are crucial elements of microwave circuits, offering a wide range of potential applications in modern science and technology. While conventional low-T[Formula: see text] superconductors are mainly employed, high-T[Formula: see text] cuprates could offer enhanced temperature and magnetic field operating ranges. Here, we report the realization of [Formula: see text] superconducting coplanar waveguide resonators, and demonstrate a continuous evolution from a lossy undercoupled regime, to a lossless overcoupled regime by adjusting the device geometry, in good agreement with circuit model theory. A high-quality factor resonator was then used to perform electron spin resonance measurements on a molecular spin ensemble across a temperature range spanning two decades. We observe spin-cavity hybridization indicating coherent coupling between the microwave field and the spins in a highly cooperative regime. The temperature dependence of the Rabi splitting and the spin relaxation time point toward an antiferromagnetic coupling of the spins below 2 K. Our findings indicate that high-Tc superconducting resonators hold great promise for the development of functional circuits. Additionally, they suggest novel approaches for achieving hybrid quantum systems based on high-T[Formula: see text] superconductors and for conducting electron spin resonance measurements over a wide range of magnetic fields and temperatures.

3.
Phys Rev Lett ; 130(10): 106201, 2023 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-36962050

RESUMEN

Squeezing of the quadratures of the electromagnetic field has been extensively studied in optics and microwaves. However, previous works focused on the generation of squeezed states in a low impedance (Z_{0}≈50 Ω) environment. We report here on the demonstration of the squeezing of bosonic edge magnetoplasmon modes in a quantum Hall conductor whose characteristic impedance is set by the quantum of resistance (R_{K}≈25 kΩ), offering the possibility of an enhanced coupling to low-dimensional quantum conductors. By applying a combination of dc and ac drives to a quantum point contact, we demonstrate squeezing and observe a noise reduction 18% below the vacuum fluctuations. This level of squeezing can be improved by using more complex conductors, such as ac driven quantum dots or mesoscopic capacitors.

4.
J Hosp Infect ; 135: 132-138, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36918068

RESUMEN

BACKGROUND: Extended-spectrum beta-lactamase-producing Enterobacterales (eESBL) have high prevalence in hospitals, but real-time monitoring of nosocomial acquisition through conventional typing methods is challenging. Moreover, patient-to-patient transmission varies between the main species, namely Escherichia coli and Klebsiella pneumoniae, which draws into question the relevance of applying identical preventive measures. AIM: To detect eESBL cross-transmission events (CTEs) using the quantitative antibiogram (QA) method in combination with epidemiological data (combined QA method), and to determine the effectiveness of standard or contact precautions for eESBL species. METHODS: First, a validation set was used to compare the relevance of the combined QA method with a combination of pulsed-field gel electrophoresis and epidemiological data (combined PFGE method). Next, a 4-year retrospective analysis was conducted to detect eESBL CTEs in hospitalized patients. Two species were screened - ESBL E. coli (ESBL-Ec) and ESBL K. pneumoniae (ESBL-Kp). During the study, standard precautions alone were applied to patients with ESBL-Ec, whereas contact precautions were applied for patients with ESBL-Kp. FINDINGS: As a proof of concept, use of the combined QA method and the combined PFGE method for the detection of CTEs gave identical results for E. coli, and similar results for at least 75% of K. pneumoniae. Overall, 722 patients with ESBL-Ec isolates and 280 patients with ESBL-Kp isolates were included in the retrospective analysis. Nine and 23 CTEs were identified for E. coli and K. pneumoniae, respectively, involving 20 (2.7%) and 36 (12.8%) patients, respectively. CONCLUSION: The combined QA method constitutes a rapid tool for epidemiological surveillance to detect CTEs. In the study hospital, standard precautions are sufficient to prevent acquisition of ESBL-Ec, whereas contact precautions must be implemented to prevent acquisition of ESBL-Kp.


Asunto(s)
Infección Hospitalaria , Infecciones por Escherichia coli , Gammaproteobacteria , Infecciones por Klebsiella , Humanos , Escherichia coli , Infección Hospitalaria/epidemiología , Infección Hospitalaria/prevención & control , Estudios Retrospectivos , beta-Lactamasas , Infecciones por Escherichia coli/epidemiología , Hospitales , Klebsiella pneumoniae , Pruebas de Sensibilidad Microbiana , Infecciones por Klebsiella/epidemiología
5.
Nat Commun ; 13(1): 4625, 2022 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-35941153

RESUMEN

After almost twenty years of intense work on the celebrated LaAlO3/SrTiO3system, the recent discovery of a superconducting two-dimensional electron gas (2-DEG) in (111)-oriented KTaO3-based heterostructures injects new momentum to the field of oxides interface. However, while both interfaces share common properties, experiments also suggest important differences between the two systems. Here, we report gate tunable superconductivity in 2-DEGs generated at the surface of a (111)-oriented KTaO3 crystal by the simple sputtering of a thin Al layer. We extract the superfluid stiffness of the 2-DEGs and show that its temperature dependence is consistent with a node-less superconducting order parameter having a gap value larger than expected within a simple BCS weak-coupling limit model. The superconducting transition follows the Berezinskii-Kosterlitz-Thouless scenario, which was not reported on SrTiO3-based interfaces. Our finding offers innovative perspectives for fundamental science but also for device applications in a variety of fields such as spin-orbitronics and topological electronics.

6.
Infect Dis Now ; 51(6): 540-546, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34198001

RESUMEN

OBJECTIVE: We aimed to report a community outbreak of an uncommon methicillin-resistant Staphylococcus aureus (MRSA) originating in a maternity ward. PATIENTS AND METHODS: Cases were defined by epidemiological, clinical, and microbiological investigations. Microbiological investigations included phenotypic analysis, molecular typing, and whole-genome sequencing. To control the outbreak, we applied both national recommendations to prevent in-hospital transmission and the French High Council for Public Health guidelines on the management of community-acquired MRSA infections. RESULTS: Between March and July 2016, seven patients with MRSA infections were identified: six skin and soft tissue infections and one pulmonary infection, including six microbiologically confirmed infections. Infections occurred in community settings, but a link with the same maternity ward was found for all patients. All MRSA strains had a t690 spa type, were tetracycline-resistant, and produced Panton-Valentine leukocidin. All isolates belonged to the sequence type 88 (ST88). CONCLUSION: This outbreak highlights the largely underestimated risk of healthcare-associated infections in maternity wards. Healthcare workers should be aware of the importance of standard hygiene precautions and use of alcohol-based hand sanitizers for neonates and mothers.


Asunto(s)
Infecciones Comunitarias Adquiridas , Staphylococcus aureus Resistente a Meticilina , Infecciones de los Tejidos Blandos , Infecciones Estafilocócicas , Infecciones Comunitarias Adquiridas/epidemiología , Femenino , Hospitales , Humanos , Recién Nacido , Staphylococcus aureus Resistente a Meticilina/genética , Embarazo , Infecciones Estafilocócicas/tratamiento farmacológico
7.
Phys Rev Lett ; 124(3): 036802, 2020 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-32031865

RESUMEN

We present conductance-matrix measurements of a three-terminal superconductor-semiconductor hybrid device consisting of two normal leads and one superconducting lead. Using a symmetry decomposition of the conductance, we find that antisymmetric components of pairs of local and nonlocal conductances qualitatively match at energies below the superconducting gap, and we compare this finding with symmetry relations based on a noninteracting scattering matrix approach. Further, the local charge character of Andreev bound states is extracted from the symmetry-decomposed conductance data and is found to be similar at both ends of the device and tunable with gate voltage. Finally, we measure the conductance matrix as a function of magnetic field and identify correlated splittings in low-energy features, demonstrating how conductance-matrix measurements can complement traditional single-probe measurements in the search for Majorana zero modes.

8.
Phys Rev Lett ; 120(19): 196402, 2018 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-29799266

RESUMEN

We investigate the 1/3 monolayer α-Pb/Si(111) surface by scanning tunneling spectroscopy (STS) and fully relativistic first-principles calculations. We study both the high-temperature sqrt[3]×sqrt[3] and low-temperature 3×3 reconstructions and show that, in both phases, the spin-orbit interaction leads to an energy splitting as large as 25% of the valence-band bandwidth. Relativistic effects, electronic correlations, and Pb-substrate interaction cooperate to stabilize a correlated low-temperature paramagnetic phase with well-developed lower and upper Hubbard bands coexisting with 3×3 periodicity. By comparing the Fourier transform of STS conductance maps at the Fermi level with calculated quasiparticle interference from nonmagnetic impurities, we demonstrate the occurrence of two large hexagonal Fermi sheets with in-plane spin polarizations and opposite helicities.

9.
J Vector Borne Dis ; 53(2): 127-35, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27353582

RESUMEN

BACKGROUND & OBJECTIVES: Aedes aegypti (L.) is an efficient vector for arboviral diseases such as dengue. The wings of Ae. aegypti has been extensively studied in order to investigate population heterogeneity and structure by utilizing a landmark based geometric morphometrics (GMs) approach. The aim of this study was to examine and assess the wing geometry of Ae. aegypti in Metropolitan Manila. METHODS: In total, 312 Ae. aegypti mosquitoes were collected from 98 sampling points using a mosquito light-trap from May 2014 to January 2015. A complete coverage of the wing was achieved by removing wing scales with chemical and physical treatment, leading to identification of 26 landmarks. Geometric morphometric analyses were employed and the spatial distance pattern was estimated using isolation by distance (IBD) and spatial autocorrelation (SA). RESULTS: The results of the GM analyses revealed population heterogeneity and structuring in Ae. aegypti populations for both sexes using principal component and canonical variate analyses respectively. Moreover, IBD and SA only detected significant spatial structure in male Ae. aegypti populations while female population structures were homogeneous throughout the geographical area. INTERPRETATION & CONCLUSION: The newly modified wing preparation procedure was able to capture a complete coverage of the wings of Ae. aegypti, thus providing a stronger separation power for very close populations in an urban area. It is also noteworthy that the results of IBD and SA supported the findings of GM in the population structuring of male and female Ae. aegypti. The outcome of the study increases our understanding of the vector, which would be useful in developing effective control strategies.


Asunto(s)
Aedes/anatomía & histología , Aedes/clasificación , Mosquitos Vectores , Alas de Animales/anatomía & histología , Animales , Ciudades , Entomología/métodos , Femenino , Masculino , Filipinas , Análisis Espacial
10.
J Psychiatr Ment Health Nurs ; 18(5): 394-402, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21539684

RESUMEN

Seclusion with or without restraint is a measure used to manage patients with challenging behaviours. Although controversial, the intervention remains poorly documented, especially in Canadian psychiatric hospitals. The purpose of this study is to assess the prevalence of the measure and identify any correlated demographic characteristics and psychiatric disorders. Episodes of seclusion with or without restraint were extracted from a computerized, hospital-based system introduced specifically to track such interventions. Of 2721 patients hospitalized during that time, 23.2% (n = 632) were secluded with or without restraint, and 17.5% (n = 476) were secluded with restraint. Younger age, schizophrenia or other psychosis, bipolar and personality disorder, and longer stay in hospital are predictors of an episode of seclusion with or without restraint. Younger age, bipolar and personality disorders and a longer stay in hospital are predictors of an episode of seclusion with restraint. For patients who spent longer in seclusion and under restraint, there is a positive association with longer stay in hospital. In this inpatient psychiatric facility, seclusion with or without restraint thus appears to be common. More research is warranted to better identify the principal factors associated with seclusion and restraint and help reduce resort to these measures.


Asunto(s)
Hospitales Psiquiátricos/estadística & datos numéricos , Trastornos Mentales/enfermería , Auditoría de Enfermería , Aislamiento de Pacientes/estadística & datos numéricos , Restricción Física/estadística & datos numéricos , Adolescente , Adulto , Factores de Edad , Anciano , Trastorno Bipolar/epidemiología , Trastorno Bipolar/enfermería , Trastorno Bipolar/psicología , Canadá , Estudios Transversales , Femenino , Humanos , Tiempo de Internación/estadística & datos numéricos , Masculino , Trastornos Mentales/epidemiología , Trastornos Mentales/psicología , Persona de Mediana Edad , Aislamiento de Pacientes/psicología , Trastornos de la Personalidad/epidemiología , Trastornos de la Personalidad/enfermería , Trastornos de la Personalidad/psicología , Trastornos Psicóticos/epidemiología , Trastornos Psicóticos/enfermería , Trastornos Psicóticos/psicología , Restricción Física/psicología , Estudios Retrospectivos , Factores de Riesgo , Esquizofrenia/epidemiología , Esquizofrenia/enfermería , Estadística como Asunto , Revisión de Utilización de Recursos , Adulto Joven
11.
Rev Med Interne ; 32(1): 33-8, 2011 Jan.
Artículo en Francés | MEDLINE | ID: mdl-20801559

RESUMEN

Myelodysplastic syndrome with erythroid hypoplasia or erythroblastopenia has not yet been clearly defined, and in most patients it is mistaken for acquired pure red cell aplasia. Including one additional patient reported in this article, a literature review revealed only 50 cases over the last 20 years. These patients were predominantly elderly males, all required regular packed red cell transfusions, and they had a poor prognosis, mainly because of acute transformation. The mechanisms of erythroid aplasia remain unclear. However, recent data suggest the association of an intrinsic stem cell defect with immunological implication.


Asunto(s)
Eritroblastos , Síndromes Mielodisplásicos , Aplasia Pura de Células Rojas , Distribución por Edad , Transfusión Sanguínea , Diagnóstico Diferencial , Eritroblastos/patología , Eritropoyetina/uso terapéutico , Medicina Basada en la Evidencia , Francia/epidemiología , Humanos , Síndromes Mielodisplásicos/diagnóstico , Síndromes Mielodisplásicos/epidemiología , Síndromes Mielodisplásicos/fisiopatología , Síndromes Mielodisplásicos/terapia , Pronóstico , Aplasia Pura de Células Rojas/diagnóstico , Aplasia Pura de Células Rojas/epidemiología , Aplasia Pura de Células Rojas/fisiopatología , Aplasia Pura de Células Rojas/terapia , Factores de Riesgo , Distribución por Sexo
12.
Rev Med Interne ; 32(5): e66-8, 2011 May.
Artículo en Francés | MEDLINE | ID: mdl-20633965

RESUMEN

We report a 49-year-old man suffering from chronic hypereosinophilia whose biological tests revealed a gene rearrangement between FIP1L1 and PDGFRA as well as a T-cell clonality. After 1 year of therapy with imatinib mesylate (100 mg daily), the patient was clinically asymptomatic, the fusion transcript was undetectable using RTQ-PCR and no lymphoproliferative disorders occurred. This unique combination raises the question of the physiopathology of such a grey zone hypereosinophilia and their management.


Asunto(s)
Síndrome Hipereosinofílico/genética , Síndrome Hipereosinofílico/patología , Mutación/genética , Proteínas de Fusión Oncogénica/genética , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/genética , Linfocitos T/patología , Factores de Escisión y Poliadenilación de ARNm/genética , Antineoplásicos/uso terapéutico , Benzamidas , Enfermedad Crónica , Reordenamiento Génico de Linfocito T/genética , Pruebas Genéticas , Humanos , Síndrome Hipereosinofílico/tratamiento farmacológico , Mesilato de Imatinib , Masculino , Persona de Mediana Edad , Piperazinas/uso terapéutico , Pirimidinas/uso terapéutico , Resultado del Tratamiento
13.
Clin Exp Immunol ; 150(2): 340-8, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17822443

RESUMEN

Serotonin, well known for its role in depression, has been shown to modulate immune responses. Interestingly, the plasma level of serotonin is increased in symptomatic asthmatic patients and the use of anti-depressants, known to reduce serotonin levels, provokes a decrease in asthma symptoms and an increase in pulmonary function. Thus, we tested the hypothesis that serotonin affects alveolar macrophage (AM) cytokine production, altering the cytokine network in the lung and contributing to asthma pathogenesis. AMs were treated with different concentrations of serotonin (10(-11)-10(-9) M) or 5-HT(1) and 5-HT(2) receptor agonists for 2 h prior stimulation. T helper 1 (Th1) and Th2 cytokines, prostaglandin-E(2) (PGE(2)) and nitric oxide (NO) were measured in cell-free supernatants. Serotonin significantly inhibited the production of tumour necrosis factor (TNF) and interleukin (IL)-12, whereas IL-10, NO and PGE(2) production were increased. These immunomodulatory effects of serotonin were mimicked by 5-HT(2) receptor agonist but were not abrogated by 5-HT(2) receptor antagonist, suggesting the implication of other 5-HT receptors. Inhibitors of cyclooxygenase and antibody to PGE(2) abrogated the inhibitory and stimulatory effect of serotonin on TNF and IL-10 production, respectively, whereas NO synthase inhibitor eliminated serotonin-stimulated IL-10 increase. Furthermore, PGE(2) significantly increased AM IL-10 and NO production. These results suggest that serotonin alters the cytokine network in the lung through the production of PGE(2). The reduction of Th1-type cytokine by serotonin may contribute to asthma pathogenesis.


Asunto(s)
Citocinas/biosíntesis , Dinoprostona/biosíntesis , Macrófagos Alveolares/inmunología , Serotonina/inmunología , Animales , Asma/inmunología , Línea Celular , Dinoprostona/inmunología , Relación Dosis-Respuesta Inmunológica , Humanos , Interleucina-10/biosíntesis , Óxido Nítrico/biosíntesis , Ratas , Agonistas del Receptor de Serotonina 5-HT1 , Agonistas del Receptor de Serotonina 5-HT2 , Antagonistas del Receptor de Serotonina 5-HT2 , Factor de Necrosis Tumoral alfa/metabolismo
14.
Ann Dermatol Venereol ; 133(10): 788-90, 2006 Oct.
Artículo en Francés | MEDLINE | ID: mdl-17072196

RESUMEN

BACKGROUND: Splenic lymphoma with villous lymphocytes is occasionally associated with chronic hepatitis C infection. Antiviral hepatitis C therapy has been recently reported to be efficacious against splenic lymphoma with villous lymphocytes. We report a new case revealed by cutaneous symptoms. CASE REPORT: A 53-year-old patient with arthritis and neuropathy of the lower limbs consulted for vascular purpura on both legs. The blood picture showed an increase in villous lymphocytes leading to a diagnosis of splenic lymphoma with villous lymphocytes. Histologic examination of a cutaneous biopsy specimen showed thrombosis of the superficial dermal vessels, associated with cryoglobulinemia with renal and neurologic failure, a satellite of hepatitis C virus infection. The patient was treated with interferon, ribavirin and plasmapheresis. DISCUSSION: Vascular purpura, often associated with cryoglobulinemia, may reveal chronic hepatitis C infection. The efficacy of interferon and ribavirin treatment for splenic lymphoma with villous lymphocytes associated with hepatitis C infection has already been documented, and results in remission of cryoglobulinemia and lymphoma as well a eradication of viral load in 78% patients.


Asunto(s)
Crioglobulinemia/complicaciones , Hepatitis C Crónica/complicaciones , Linfoma de Células B/complicaciones , Púrpura/complicaciones , Neoplasias del Bazo/complicaciones , Humanos , Masculino , Persona de Mediana Edad
17.
Med Trop (Mars) ; 62(6): 589-93, 2002.
Artículo en Francés | MEDLINE | ID: mdl-12731301
19.
Med Trop (Mars) ; 60(2): 171-8, 2000.
Artículo en Francés | MEDLINE | ID: mdl-11100446

RESUMEN

Sightseeing travel in tropical zones is a growing industry. The risks incurred by travelers depend on the destination, duration of stay, individual behavior, and type of leisure activity. Water sports expose visitors to encounters with dangerous marine animals. Shark attacks are rare but always serious occurrences. Divers should handle any shark, regardless of size, with due precaution. Prevention of shark attack depends on avoiding encounters by not attracting the attention of the shark and knowing the proper attitude to adopt in case an encounter should occur. Active and passive protection can be used, but each method has advantages and disadvantages depending on the situation. Rescue operations are difficult due to the gravity of injuries and their occurrence in a marine environment. This along with the nature of the aggressor explain that many attacks are immediately fatal. Wounds are often deep with involvement of bone, blood vessels, and nerves. A possible source of complication in survivors is infection, which can involve uncommon microorganisms associated with bacteria in sharks mouth or marine environment.


Asunto(s)
Mordeduras y Picaduras/etiología , Mordeduras y Picaduras/prevención & control , Tiburones , Clima Tropical , Animales , Mordeduras y Picaduras/epidemiología , Humanos , Prevención Primaria/métodos , Trabajo de Rescate/métodos , Factores de Riesgo , Tiburones/anatomía & histología , Tiburones/clasificación , Tiburones/fisiología , Viaje
20.
Am J Respir Cell Mol Biol ; 23(4): 572-7, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11017925

RESUMEN

Cysteinyl leukotrienes (LTs), including LTC(4), LTD(4), and LTE(4), are well known to induce bronchoconstriction and increase bronchial hyperreactivity, mucus secretion, and vascular permeability. Interestingly, alveolar macrophages (AMs) express LTD(4) high-affinity receptor. These cells represent a major source of inflammatory mediators implicated in the pathophysiology of asthma. Thus, we investigated the immunomodulatory effects of LTD(4) on the production of inflammatory mediators such as macrophage inflammatory protein (MIP)- 1alpha, tumor necrosis factor (TNF), and nitric oxide (NO) by AMs. NR8383 cells, an AM cell line, were pretreated with LTD(4) (10(-11) M) for different periods of time and stimulated or not with lipopolysaccharide (LPS) for 2 h. Although LTD(4) treatment did not modulate the release of MIP-1alpha and TNF, this treatment (6 h) significantly increased the release of these mediators when AMs were further stimulated with LPS (increases of 47 and 21%, respectively). Further, LTD(4) pretreatment increased messenger RNA (mRNA) levels of MIP-1alpha and TNF. These effects of LTD(4) were abrogated by the presence of a LTD(4) receptor antagonist, Verlukast (MK-679), showing the specificity of LTD(4). Interestingly, LTD(4) treatment significantly increased the release of NO by LPS-stimulated AMs without modulating mRNA levels of the inducible NO synthase. Our data suggest that LTD(4) primes AMs to release more MIP-1alpha, TNF, and NO after stimulation. Thus, in addition to its potent bronchoconstrictor effect, LTD(4) may participate in the inflammatory process seen in asthma by potentiating the production of proinflammatory mediators by AMs during immunologic stimuli.


Asunto(s)
Mediadores de Inflamación/metabolismo , Leucotrieno D4/fisiología , Macrófagos Alveolares/metabolismo , Animales , Secuencia de Bases , Línea Celular , Quimiocina CCL3 , Quimiocina CCL4 , Cartilla de ADN , Ensayo de Inmunoadsorción Enzimática , Proteínas Inflamatorias de Macrófagos/biosíntesis , Proteínas Inflamatorias de Macrófagos/metabolismo , Óxido Nítrico/biosíntesis , Ratas , Ratas Sprague-Dawley , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Necrosis Tumoral alfa/biosíntesis , Factor de Necrosis Tumoral alfa/metabolismo
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