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2.
Sci Rep ; 13(1): 14366, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37658090

RESUMO

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.
Artigo em Inglês | MEDLINE | ID: mdl-36962050

RESUMO

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.
Artigo em Inglês | MEDLINE | ID: mdl-36918068

RESUMO

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.


Assuntos
Infecção Hospitalar , Infecções por Escherichia coli , Gammaproteobacteria , Infecções por Klebsiella , Humanos , Escherichia coli , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/prevenção & controle , Estudos Retrospectivos , beta-Lactamases , Infecções por Escherichia coli/epidemiologia , Hospitais , Klebsiella pneumoniae , Testes de Sensibilidade Microbiana , Infecções por Klebsiella/epidemiologia
5.
Nat Commun ; 13(1): 4625, 2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35941153

RESUMO

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.
Artigo em Inglês | MEDLINE | ID: mdl-34198001

RESUMO

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.


Assuntos
Infecções Comunitárias Adquiridas , Staphylococcus aureus Resistente à Meticilina , Infecções dos Tecidos Moles , Infecções Estafilocócicas , Infecções Comunitárias Adquiridas/epidemiologia , Feminino , Hospitais , Humanos , Recém-Nascido , Staphylococcus aureus Resistente à Meticilina/genética , Gravidez , Infecções Estafilocócicas/tratamento farmacológico
7.
Phys Rev Lett ; 124(3): 036802, 2020 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-32031865

RESUMO

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.
Artigo em Inglês | MEDLINE | ID: mdl-29799266

RESUMO

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.
Artigo em Inglês | MEDLINE | ID: mdl-27353582

RESUMO

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.


Assuntos
Aedes/anatomia & histologia , Aedes/classificação , Mosquitos Vetores , Asas de Animais/anatomia & histologia , Animais , Cidades , Entomologia/métodos , Feminino , Masculino , Filipinas , Análise Espacial
10.
J Psychiatr Ment Health Nurs ; 18(5): 394-402, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21539684

RESUMO

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.


Assuntos
Hospitais Psiquiátricos/estatística & dados numéricos , Transtornos Mentais/enfermagem , Auditoria de Enfermagem , Isolamento de Pacientes/estatística & dados numéricos , Restrição Física/estatística & dados numéricos , Adolescente , Adulto , Fatores Etários , Idoso , Transtorno Bipolar/epidemiologia , Transtorno Bipolar/enfermagem , Transtorno Bipolar/psicologia , Canadá , Estudos Transversais , Feminino , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Transtornos Mentais/epidemiologia , Transtornos Mentais/psicologia , Pessoa de Meia-Idade , Isolamento de Pacientes/psicologia , Transtornos da Personalidade/epidemiologia , Transtornos da Personalidade/enfermagem , Transtornos da Personalidade/psicologia , Transtornos Psicóticos/epidemiologia , Transtornos Psicóticos/enfermagem , Transtornos Psicóticos/psicologia , Restrição Física/psicologia , Estudos Retrospectivos , Fatores de Risco , Esquizofrenia/epidemiologia , Esquizofrenia/enfermagem , Estatística como Assunto , Revisão da Utilização de Recursos de Saúde , Adulto Jovem
11.
Rev Med Interne ; 32(1): 33-8, 2011 Jan.
Artigo em Francês | MEDLINE | ID: mdl-20801559

RESUMO

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.


Assuntos
Eritroblastos , Síndromes Mielodisplásicas , Aplasia Pura de Série Vermelha , Distribuição por Idade , Transfusão de Sangue , Diagnóstico Diferencial , Eritroblastos/patologia , Eritropoetina/uso terapêutico , Medicina Baseada em Evidências , França/epidemiologia , Humanos , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/epidemiologia , Síndromes Mielodisplásicas/fisiopatologia , Síndromes Mielodisplásicas/terapia , Prognóstico , Aplasia Pura de Série Vermelha/diagnóstico , Aplasia Pura de Série Vermelha/epidemiologia , Aplasia Pura de Série Vermelha/fisiopatologia , Aplasia Pura de Série Vermelha/terapia , Fatores de Risco , Distribuição por Sexo
12.
Rev Med Interne ; 32(5): e66-8, 2011 May.
Artigo em Francês | MEDLINE | ID: mdl-20633965

RESUMO

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.


Assuntos
Síndrome Hipereosinofílica/genética , Síndrome Hipereosinofílica/patologia , Mutação/genética , Proteínas de Fusão Oncogênica/genética , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Linfócitos T/patologia , Fatores de Poliadenilação e Clivagem de mRNA/genética , Antineoplásicos/uso terapêutico , Benzamidas , Doença Crônica , Rearranjo Gênico do Linfócito T/genética , Testes Genéticos , Humanos , Síndrome Hipereosinofílica/tratamento farmacológico , Mesilato de Imatinib , Masculino , Pessoa de Meia-Idade , Piperazinas/uso terapêutico , Pirimidinas/uso terapêutico , Resultado do Tratamento
13.
Clin Exp Immunol ; 150(2): 340-8, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17822443

RESUMO

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.


Assuntos
Citocinas/biossíntese , Dinoprostona/biossíntese , Macrófagos Alveolares/imunologia , Serotonina/imunologia , Animais , Asma/imunologia , Linhagem Celular , Dinoprostona/imunologia , Relação Dose-Resposta Imunológica , Humanos , Interleucina-10/biossíntese , Óxido Nítrico/biossíntese , Ratos , Agonistas do Receptor 5-HT1 de Serotonina , Agonistas do Receptor 5-HT2 de Serotonina , Antagonistas do Receptor 5-HT2 de Serotonina , Fator de Necrose Tumoral alfa/metabolismo
14.
Ann Dermatol Venereol ; 133(10): 788-90, 2006 Oct.
Artigo em Francês | MEDLINE | ID: mdl-17072196

RESUMO

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.


Assuntos
Crioglobulinemia/complicações , Hepatite C Crônica/complicações , Linfoma de Células B/complicações , Púrpura/complicações , Neoplasias Esplênicas/complicações , Humanos , Masculino , Pessoa de Meia-Idade
17.
Med Trop (Mars) ; 62(6): 589-93, 2002.
Artigo em Francês | MEDLINE | ID: mdl-12731301
19.
Med Trop (Mars) ; 60(2): 171-8, 2000.
Artigo em Francês | MEDLINE | ID: mdl-11100446

RESUMO

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.


Assuntos
Mordeduras e Picadas/etiologia , Mordeduras e Picadas/prevenção & controle , Tubarões , Clima Tropical , Animais , Mordeduras e Picadas/epidemiologia , Humanos , Prevenção Primária/métodos , Trabalho de Resgate/métodos , Fatores de Risco , Tubarões/anatomia & histologia , Tubarões/classificação , Tubarões/fisiologia , Viagem
20.
Am J Respir Cell Mol Biol ; 23(4): 572-7, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11017925

RESUMO

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.


Assuntos
Mediadores da Inflamação/metabolismo , Leucotrieno D4/fisiologia , Macrófagos Alveolares/metabolismo , Animais , Sequência de Bases , Linhagem Celular , Quimiocina CCL3 , Quimiocina CCL4 , Primers do DNA , Ensaio de Imunoadsorção Enzimática , Proteínas Inflamatórias de Macrófagos/biossíntese , Proteínas Inflamatórias de Macrófagos/metabolismo , Óxido Nítrico/biossíntese , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/metabolismo
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