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1.
Nat Mater ; 21(12): 1352-1356, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36138146

RESUMO

Conductivities are key material parameters that govern various types of transport (electronic charge, spin, heat and so on) driven by thermodynamic forces. Magnons, the elementary excitations of the magnetic order, flow under the gradient of a magnon chemical potential1-3 in proportion to a magnon (spin) conductivity. The magnetic insulator yttrium iron garnet is the material of choice for efficient magnon spin transport. Here we report a giant magnon conductivity in thin yttrium iron garnet films with thicknesses down to 3.7 nm when the number of occupied two-dimensional subbands is reduced from a large number to a few, which corresponds to a transition from three-dimensional to two-dimensional magnon transport. We extract a two-dimensional magnon spin conductivity around 1 S at room temperature, comparable to the (electronic) conductivity of the high-mobility two-dimensional electron gas in GaAs quantum wells at millikelvin temperatures4. Such high conductivities offer opportunities to develop low-dissipation magnon-based spintronic devices.

2.
Opt Express ; 26(24): 31554-31566, 2018 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-30650739

RESUMO

We experimentally demonstrate a disruptive approach to control magnetooptical nonreciprocal effects. It has been known that the combination of a magneto-optically (MO) active substrate and extraordinary transmission (EOT) effects through deep-subwavelength nanoslits of a noble metal grating, leads to giant enhancements of the magnitude of the MO effects that would normally be obtained on just the bar substrate. This was demonstrated both in the transmission configuration, where the OET is directly observed, as well as in reflection configuration, where an increase of a transmitted power results in a decrease in reflected power. We show here that even more than just an enhancement, the MO effects can also undergo a sign reversal by achieving a hybridization of the different types of resonances at play in these EOT nanogratings. By tuning the geometrical profile of the grating's slits, one can engineer - for a fixed wavelength and fixed magnetization - the transverse MO Kerr effect (TMOKE) reflectivity of such a magnetoplasmonic system to be enhanced, extinguished or inversely enhanced. We have fabricated gold gratings with varying nanoslit widths on a Bi-substituted gadolinium iron garnet and experimentally confirmed such a behavior using a customized magneto-optic Mueller matrix ellipsometer. This demonstration allows new design paradigms for integrated nonreciprocal circuits and biochemical sensors with increased sensitivity and reduced footprint.

3.
Diabetes Obes Metab ; 18(11): 1110-1119, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27333970

RESUMO

AIMS: To test whether adjusting insulin and glucagon in response to exercise within a dual-hormone artificial pancreas (AP) reduces exercise-related hypoglycaemia. MATERIALS AND METHODS: In random order, 21 adults with type 1 diabetes (T1D) underwent three 22-hour experimental sessions: AP with exercise dosing adjustment (APX); AP with no exercise dosing adjustment (APN); and sensor-augmented pump (SAP) therapy. After an overnight stay and 2 hours after breakfast, participants exercised for 45 minutes at 60% of their maximum heart rate, with no snack given before exercise. During APX, insulin was decreased and glucagon was increased at exercise onset, while during SAP therapy, subjects could adjust dosing before exercise. The two primary outcomes were percentage of time spent in hypoglycaemia (<3.9 mmol/L) and percentage of time spent in euglycaemia (3.9-10 mmol/L) from the start of exercise to the end of the study. RESULTS: The mean (95% confidence interval) times spent in hypoglycaemia (<3.9 mmol/L) after the start of exercise were 0.3% (-0.1, 0.7) for APX, 3.1% (0.8, 5.3) for APN, and 0.8% (0.1, 1.4) for SAP therapy. There was an absolute difference of 2.8% less time spent in hypoglycaemia for APX versus APN (p = .001) and 0.5% less time spent in hypoglycaemia for APX versus SAP therapy (p = .16). Mean time spent in euglycaemia was similar across the different sessions. CONCLUSIONS: Adjusting insulin and glucagon delivery at exercise onset within a dual-hormone AP significantly reduces hypoglycaemia compared with no adjustment and performs similarly to SAP therapy when insulin is adjusted before exercise.


Assuntos
Técnicas Biossensoriais/instrumentação , Diabetes Mellitus Tipo 1/tratamento farmacológico , Exercício Físico/fisiologia , Glucagon/administração & dosagem , Hipoglicemiantes/administração & dosagem , Sistemas de Infusão de Insulina , Insulina/administração & dosagem , Pâncreas Artificial , Adolescente , Adulto , Técnicas Biossensoriais/métodos , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Estudos Cross-Over , Diabetes Mellitus Tipo 1/sangue , Relação Dose-Resposta a Droga , Feminino , Glucagon/efeitos adversos , Humanos , Hipoglicemia/induzido quimicamente , Hipoglicemia/prevenção & controle , Hipoglicemiantes/efeitos adversos , Insulina/efeitos adversos , Masculino , Pessoa de Meia-Idade , Pâncreas Artificial/efeitos adversos , Adulto Jovem
4.
Paediatr Anaesth ; 26(8): 823-30, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27247166

RESUMO

BACKGROUND: Percutaneous cannulation of the femoral artery in the pediatric age group can be technically challenging, especially when performed by residents in training. OBJECTIVE: We examined whether the use of real-time ultrasound guidance is superior to a palpation landmark technique for femoral artery catheterization in children undergoing heart surgery. METHODS: Patients were prospectively randomized into two groups. In the palpation group, the femoral artery was cannulated using the traditional landmark method of palpation of arterial pulse. In the ultrasound group, cannulation was guided by real-time scanning with an ultrasound probe. Ten minutes were set as time limit for the resident's trials during which the time taken for attempted cannulation (primary outcome), number of attempts, number of successful cannulations on first attempt, and success rate were compared between the two groups. Adverse events were monitored on postoperative days 1 and 3. RESULTS: A total of 106 patients were included in the study. The time taken for attempted femoral artery cannulation was shorter (301 ± 234 vs 420 ± 248 s; difference in mean: 119; 95% confidence interval (CI) of difference: 26-212; P = 0.012) and the number of attempts was lower [1 (1-10) vs 2 (1-5); difference in median: 1, 95% CI of difference: 0.28-1.72; P = 0.003] in the ultrasound group compared with the palpation group. The number of successful cannulations on first attempt was higher in the ultrasound group compared with palpation group [24/53 (45%) vs 13/53 (25%); odds ratio (OR): 2.54, 95% CI: 1.11-5.82; P = 0.025]. The number of patients who had successful cannulation was 31 of 55 (58%) in the palpation group and 40 of 53 (75%) in the ultrasound group (OR: 2.18, 95% CI: 0.95-5.01; P = 0.06). None of the patients had adverse events at days 1 and 3. CONCLUSIONS: Ultrasound-guided femoral arterial cannulation in children when performed by anesthesia residents is superior to the palpation technique based on the reduction of the time taken for attempted cannulation and the number of attempts, and improvement in first attempt success.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Cateterismo Periférico/métodos , Artéria Femoral , Internato e Residência , Palpação/métodos , Ultrassonografia de Intervenção/métodos , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Estudos Prospectivos
5.
Phys Rev Lett ; 113(2): 027601, 2014 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-25062233

RESUMO

We report the observation of the spin Peltier effect (SPE) in the ferrimagnetic insulator yttrium iron garnet (YIG), i.e., a heat current generated by a spin current flowing through a platinum (Pt)|YIG interface. The effect can be explained by the spin transfer torque that transforms the spin current in the Pt into a magnon current in the YIG. Via magnon-phonon interactions the magnetic fluctuations modulate the phonon temperature that is detected by a thermopile close to the interface. By finite-element modeling we verify the reciprocity between the spin Peltier and spin Seebeck effect. The observed strong coupling between thermal magnons and phonons in YIG is attractive for nanoscale cooling techniques.

6.
Neurosurg Focus ; 37(1 Suppl): 1, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24983719

RESUMO

We report the case of a 62-year-old female who presented for stent-assistant coiling of an incidental 11-mm complex bilobed left superior hypophyseal internal carotid artery aneurysm. A microcatheter was navigated into the aneurysm and trapped by a 37-mm stent. Using three-dimensional and two-dimensional coils, the elongated aneurysm was coiled. The bigger lobe was coiled first followed by the smaller lobe. Minimal residual filling of the smaller lobe will be re-evaluated at 6-month follow up. The patient tolerated the procedure well and no complications were encountered. The video can be found here: http://youtu.be/TrXfsaICQVo .


Assuntos
Doenças das Artérias Carótidas/terapia , Artéria Carótida Interna , Embolização Terapêutica/métodos , Aneurisma Intracraniano/terapia , Feminino , Humanos , Pessoa de Meia-Idade , Hipófise , Stents
7.
World Neurosurg ; 184: e754-e764, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38350598

RESUMO

BACKGROUND: With continued evolution in stereotactic techniques and an expanding armamentarium of surgical therapeutic options, non-craniotomy stereotactic procedures in neuro-oncology are becoming increasingly complex, often requiring multi-trajectory approaches. Here we demonstrate that the ClearPoint SmartFrame Array (Solana Beach, California, USA), a second-generation magnetic resonance imaging-compatible stereotactic frame, supports such non-craniotomy, multi-trajectory (NCMT) stereotactic procedures. METHODS: We previously published case reports demonstrating the feasibility of NCMT through the ClearPoint SmartFrame Array. Here we prospectively followed the next 10 consecutive patients who underwent such multi-trajectory procedures to further establish procedural safety and clinical utility. RESULTS: Ten patients underwent complex, multi-trajectory stereotactic procedures, including combinations of needle biopsy ± cyst drainage and laser interstitial thermal therapy targeting geographically distinct regions of neoplastic lesions under the same anesthetic event. The median maximal radial error of stereotaxis was 1.0 mm. In all cases, definitive diagnosis was achieved, and >90% of the intended targets were ablated. The average stereotaxis time for the multi-trajectory procedure was 119 ± 22.2 minutes, comparing favorably to our previously published results of single-trajectory procedures (80 ± 9.59 minutes, P = 0.125). There were no procedural complications. Post-procedure, the neurologic condition of 1 patient improved, while the remaining 9 patients remained stable. All patients were discharged home, with a median hospital stay of 1 day (range: 1-12 days). With a median follow-up of 376 days (range: 155-1438 days), there were no 30-day readmissions or wound complications. CONCLUSIONS: Geographically distinct regions of brain cancer can be safely and accurately accessed through the ClearPoint Array frame in NCMT stereotactic procedures.


Assuntos
Neoplasias Encefálicas , Terapia a Laser , Humanos , Terapia a Laser/métodos , Técnicas Estereotáxicas , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/cirurgia , Procedimentos Neurocirúrgicos/métodos , Imageamento por Ressonância Magnética/métodos
8.
Transplantation ; 108(3): 777-786, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-37899481

RESUMO

BACKGROUND: Chronic lung allograft dysfunction (CLAD) is the leading cause of death beyond the first year after lung transplantation. The development of donor-specific antibodies (DSA) is a recognized risk factor for CLAD. Based on experience in kidney transplantation, we hypothesized that belatacept, a selective T-cell costimulatory blocker, would reduce the incidence of DSA after lung transplantation, which may ameliorate the risk of CLAD. METHODS: We conducted a pilot randomized controlled trial (RCT) at 2 sites to assess the feasibility and inform the design of a large-scale RCT. All participants were treated with rabbit antithymocyte globulin for induction immunosuppression. Participants in the control arm were treated with tacrolimus, mycophenolate mofetil, and prednisone, and participants in the belatacept arm were treated with tacrolimus, belatacept, and prednisone through day 89 after transplant then converted to belatacept, mycophenolate mofetil, and prednisone for the remainder of year 1. RESULTS: After randomizing 27 participants, 3 in the belatacept arm died compared with none in the control arm. As a result, we stopped enrollment and treatment with belatacept, and all participants were treated with standard-of-care immunosuppression. Overall, 6 participants in the belatacept arm died compared with none in the control arm (log rank P = 0.008). We did not observe any differences in the incidence of DSA, acute cellular rejection, antibody-mediated rejection, CLAD, or infections between the 2 groups. CONCLUSIONS: We conclude that the investigational regimen used in this pilot RCT is associated with increased mortality after lung transplantation.


Assuntos
Transplante de Pulmão , Tacrolimo , Humanos , Abatacepte/uso terapêutico , Tacrolimo/efeitos adversos , Ácido Micofenólico/uso terapêutico , Prednisona/uso terapêutico , Projetos Piloto , Imunossupressores/efeitos adversos , Terapia de Imunossupressão , Anticorpos , Transplante de Pulmão/efeitos adversos , Rejeição de Enxerto/prevenção & controle , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto
9.
Phys Rev Lett ; 111(21): 217204, 2013 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-24313523

RESUMO

We report on the electrical detection of the dynamical part of the spin-pumping current emitted during ferromagnetic resonance using inverse spin Hall effect methods. The experiment is performed on a YIG|Pt bilayer. The choice of yttrium iron garnet (YIG), a magnetic insulator, ensures that no charge current flows between the two layers and only the pure spin current produced by the magnetization dynamics is transferred into the adjacent strong spin-orbit Pt layer via spin pumping. To avoid measuring the parasitic eddy currents induced at the frequency of the microwave source, a resonance at half the frequency is induced using parametric excitation in the parallel geometry. Triggering this nonlinear effect allows us to directly detect on a spectrum analyzer the microwave component of the inverse spin Hall effect voltage. Signals as large as 30 µV are measured for precession angles of a couple of degrees. This direct detection provides a novel efficient means to study magnetization dynamics on a very wide frequency range with great sensitivity.

10.
Diabetes Obes Metab ; 15(12): 1065-70, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23602044

RESUMO

Since the discovery of insulin, great progress has been made to improve the accuracy and safety of automated insulin delivery systems to help patients with type 1 diabetes achieve their treatment goals without causing hypoglycaemia. In recent years, bioengineering technology has greatly advanced diabetes management, with the development of blood glucose meters, continuous glucose monitors, insulin pumps and control systems for automatic delivery of one or more hormones. New insulin analogues have improved subcutaneous absorption characteristics, but do not completely eliminate the risk of hypoglycaemia. Insulin effect is counteracted by glucagon in non-diabetic individuals, while glucagon secretion in those with type 1 diabetes is impaired. The use of glucagon in the artificial pancreas is therefore a logical and feasible option for preventing and treating hypoglycaemia. However, commercially available glucagon is not stable in aqueous solution for long periods, forming potentially cytotoxic fibrils that aggregate quickly. Therefore, a more stable formulation of glucagon is needed for long-term use and storage in a bi-hormonal pump. In addition, a model of glucagon action in type 1 diabetes is lacking, further limiting the inclusion of glucagon into systems employing model-assisted control. As a result, although several investigators have been working to help develop bi-hormonal systems for patients with type 1 diabetes, most continue to utilize single hormone systems employing only insulin. This article seeks to focus on the attributes of glucagon and its use in bi-hormonal systems.


Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Glucagon/administração & dosagem , Hipoglicemiantes/administração & dosagem , Insulinas/administração & dosagem , Pâncreas Artificial , Glicemia/metabolismo , Previsões , Humanos , Hiperglicemia/prevenção & controle , Hipoglicemia/prevenção & controle
11.
J Neurosurg Case Lessons ; 5(2)2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36624633

RESUMO

BACKGROUND: Current technologies that support stereotactic laser ablation (SLA) of geographically distinct lesions require placement of multiple bolts or time-consuming, intertrajectory adjustments. OBSERVATIONS: Two geographically distinct nodular lesions were safely biopsied and laser ablated in a 62-year-old woman with recurrent glioblastoma using the ClearPoint Array frame, a novel magnetic resonance imaging-compatible stereotactic frame designed to support independent parallel trajectories without intertrajectory frame adjustment. LESSONS: Here, the authors provide a proof-of-principle case report demonstrating that geographically distinct lesions can be safely biopsied and ablated through parallel trajectories supported by the ClearPoint Array frame without intertrajectory adjustment.

12.
Lancet Respir Med ; 11(9): 791-803, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37348524

RESUMO

BACKGROUND: There is a clinical need for therapeutics for COVID-19 patients with acute hypoxemic respiratory failure whose 60-day mortality remains at 30-50%. Aviptadil, a lung-protective neuropeptide, and remdesivir, a nucleotide prodrug of an adenosine analog, were compared with placebo among patients with COVID-19 acute hypoxaemic respiratory failure. METHODS: TESICO was a randomised trial of aviptadil and remdesivir versus placebo at 28 sites in the USA. Hospitalised adult patients were eligible for the study if they had acute hypoxaemic respiratory failure due to confirmed SARS-CoV-2 infection and were within 4 days of the onset of respiratory failure. Participants could be randomly assigned to both study treatments in a 2 × 2 factorial design or to just one of the agents. Participants were randomly assigned with a web-based application. For each site, randomisation was stratified by disease severity (high-flow nasal oxygen or non-invasive ventilation vs invasive mechanical ventilation or extracorporeal membrane oxygenation [ECMO]), and four strata were defined by remdesivir and aviptadil eligibility, as follows: (1) eligible for randomisation to aviptadil and remdesivir in the 2 × 2 factorial design; participants were equally randomly assigned (1:1:1:1) to intravenous aviptadil plus remdesivir, aviptadil plus remdesivir matched placebo, aviptadil matched placebo plus remdesvir, or aviptadil placebo plus remdesivir placebo; (2) eligible for randomisation to aviptadil only because remdesivir was started before randomisation; (3) eligible for randomisation to aviptadil only because remdesivir was contraindicated; and (4) eligible for randomisation to remdesivir only because aviptadil was contraindicated. For participants in strata 2-4, randomisation was 1:1 to the active agent or matched placebo. Aviptadil was administered as a daily 12-h infusion for 3 days, targeting 600 pmol/kg on infusion day 1, 1200 pmol/kg on day 2, and 1800 pmol/kg on day 3. Remdesivir was administered as a 200 mg loading dose, followed by 100 mg daily maintenance doses for up to a 10-day total course. For participants assigned to placebo for either agent, matched saline placebo was administered in identical volumes. For both treatment comparisons, the primary outcome, assessed at day 90, was a six-category ordinal outcome: (1) at home (defined as the type of residence before hospitalisation) and off oxygen (recovered) for at least 77 days, (2) at home and off oxygen for 49-76 days, (3) at home and off oxygen for 1-48 days, (4) not hospitalised but either on supplemental oxygen or not at home, (5) hospitalised or in hospice care, or (6) dead. Mortality up to day 90 was a key secondary outcome. The independent data and safety monitoring board recommended stopping the aviptadil trial on May 25, 2022, for futility. On June 9, 2022, the sponsor stopped the trial of remdesivir due to slow enrolment. The trial is registered with ClinicalTrials.gov, NCT04843761. FINDINGS: Between April 21, 2021, and May 24, 2022, we enrolled 473 participants in the study. For the aviptadil comparison, 471 participants were randomly assigned to aviptadil or matched placebo. The modified intention-to-treat population comprised 461 participants who received at least a partial infusion of aviptadil (231 participants) or aviptadil matched placebo (230 participants). For the remdesivir comparison, 87 participants were randomly assigned to remdesivir or matched placebo and all received some infusion of remdesivir (44 participants) or remdesivir matched placebo (43 participants). 85 participants were included in the modified intention-to-treat analyses for both agents (ie, those enrolled in the 2 x 2 factorial). For the aviptadil versus placebo comparison, the median age was 57 years (IQR 46-66), 178 (39%) of 461 participants were female, and 246 (53%) were Black, Hispanic, Asian or other (vs 215 [47%] White participants). 431 (94%) of 461 participants were in an intensive care unit at baseline, with 271 (59%) receiving high-flow nasal oxygen or non-invasive ventiliation, 185 (40%) receiving invasive mechanical ventilation, and five (1%) receiving ECMO. The odds ratio (OR) for being in a better category of the primary efficacy endpoint for aviptadil versus placebo at day 90, from a model stratified by baseline disease severity, was 1·11 (95% CI 0·80-1·55; p=0·54). Up to day 90, 86 participants in the aviptadil group and 83 in the placebo group died. The cumulative percentage who died up to day 90 was 38% in the aviptadil group and 36% in the placebo group (hazard ratio 1·04, 95% CI 0·77-1·41; p=0·78). The primary safety outcome of death, serious adverse events, organ failure, serious infection, or grade 3 or 4 adverse events up to day 5 occurred in 146 (63%) of 231 patients in the aviptadil group compared with 129 (56%) of 230 participants in the placebo group (OR 1·40, 95% CI 0·94-2·08; p=0·10). INTERPRETATION: Among patients with COVID-19-associated acute hypoxaemic respiratory failure, aviptadil did not significantly improve clinical outcomes up to day 90 when compared with placebo. The smaller than planned sample size for the remdesivir trial did not permit definitive conclusions regarding safety or efficacy. FUNDING: National Institutes of Health.


Assuntos
COVID-19 , Insuficiência Respiratória , Adulto , Humanos , Feminino , Pessoa de Meia-Idade , Masculino , COVID-19/complicações , SARS-CoV-2 , Resultado do Tratamento , Tratamento Farmacológico da COVID-19 , Insuficiência Respiratória/tratamento farmacológico , Insuficiência Respiratória/etiologia , Oxigênio
13.
Diabet Med ; 29(8): 1067-73, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22150642

RESUMO

BACKGROUND: Because declining glucose levels should be detected quickly in persons with Type 1 diabetes, a lag between blood glucose and subcutaneous sensor glucose can be problematic. It is unclear whether the magnitude of sensor lag is lower during falling glucose than during rising glucose. METHODS: Initially, we analysed 95 data segments during which glucose changed and during which very frequent reference blood glucose monitoring was performed. However, to minimize confounding effects of noise and calibration error, we excluded data segments in which there was substantial sensor error. After these exclusions, and combination of data from duplicate sensors, there were 72 analysable data segments (36 for rising glucose, 36 for falling). We measured lag in two ways: (1) the time delay at the vertical mid-point of the glucose change (regression delay); and (2) determination of the optimal time shift required to minimize the difference between glucose sensor signals and blood glucose values drawn concurrently. RESULTS: Using the regression delay method, the mean sensor lag for rising vs. falling glucose segments was 8.9 min (95%CI 6.1-11.6) vs. 1.5 min (95%CI -2.6 to 5.5, P<0.005). Using the time shift optimization method, results were similar, with a lag that was higher for rising than for falling segments [8.3 (95%CI 5.8-10.7) vs. 1.5 min (95% CI -2.2 to 5.2), P<0.001]. Commensurate with the lag results, sensor accuracy was greater during falling than during rising glucose segments. CONCLUSIONS: In Type 1 diabetes, when noise and calibration error are minimized to reduce effects that confound delay measurement, subcutaneous glucose sensors demonstrate a shorter lag duration and greater accuracy when glucose is falling than when rising.


Assuntos
Técnicas Biossensoriais/instrumentação , Glicemia/metabolismo , Diabetes Mellitus Tipo 1/sangue , Feminino , Humanos , Hipoglicemiantes/administração & dosagem , Insulina/administração & dosagem , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica/instrumentação
14.
Sci Rep ; 12(1): 7246, 2022 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-35508481

RESUMO

Nonlinear self-phase modulation is a universal phenomenon responsible, for example, for the formation of propagating dynamic solitons. It has been reported for waves of different physical nature. However its direct experimental observation for spin waves has been challenging. Here we show that exceptionally strong phase modulation can be achieved for spin waves in microscopic waveguides fabricated from nanometer-thick films of magnetic insulator, which support propagation of spin waves with large amplitudes corresponding to angles of magnetization precession exceeding 10°. At these amplitudes, the nonstationary nonlinear dynamic response of the spin system causes an extreme broadening of the spectrum of spin-wave pulses resulting in a strong spatial variation of the spin-wave wavelength and a temporal variation of the spin-wave phase across the pulse. Our findings demonstrate great complexity of nonlinear wave processes in microscopic magnetic structures and importance of their understanding for technical applications of spin waves in integrated devices.

15.
Euro Surveill ; 16(4)2011 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-21284922

RESUMO

From May 2009 to January 2010, the Virology Laboratory at the University Hospital of Bordeaux received more than 4,000 nasopharyngeal samples from the Aquitaine region (south-west France) for the diagnosis of pandemic influenza A(H1N1)2009. Eighty-three infected patients deteriorated and were admitted to intensive care units. Our study focused on 24 of these patients. Positivity for influenza A(H1N1)2009 was monitored by realtime PCR and duration of viral shedding was determined. The first available sample of each patient was analysed for bacterial, fungal and viral co-infection. We observed six bacterial (or bacterial/fungal) co-infections and one viral co-infection with respiratory syncytial virus. The samples were analysed for the presence of the neuraminidase H275Y (N1 numbering) mutation, which confers resistance to oseltamivir, by realtime PCR of the neuraminidase gene. No H275Y mutation was observed in any of the viral strains screened in this study. In parallel, a fragment of the haemagglutinin gene encoding amino acid residues 173 to 362 was sequenced to detect mutations that had been reported to increase the severity of the disease. Two patients were infected by strains bearing the D222G (H3 numbering) mutation. The viral shedding of A(H1N1)2009 in this study ranged from four to 28 days with a median of 11 days.


Assuntos
Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/virologia , Neuraminidase/genética , Pandemias , Eliminação de Partículas Virais , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antivirais/uso terapêutico , Criança , Pré-Escolar , Comorbidade , Feminino , França/epidemiologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Hospitais Universitários , Humanos , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Influenza Humana/diagnóstico , Influenza Humana/tratamento farmacológico , Influenza Humana/epidemiologia , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Oseltamivir/uso terapêutico , Reação em Cadeia da Polimerase , Fatores de Tempo , Adulto Jovem
16.
Turk J Gastroenterol ; 32(10): 808-818, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34787085

RESUMO

BACKGROUND: The aim of the study was to examine the impact of diagnostic status (i.e., having a clinical diagnosis of irritable bowel syndrome (IBS) or being symptomatic but undiagnosed on quality of life (QoL)). We also examined whether the relationships between QoL and variables such as symptom frequency, pain catastrophizing, visceral sensitivity, and psychological distress are moderated by diagnostic status. METHODS: The online sample comprised 404 participants (Mage = 33.59, SD = 12.43), of which 98 had been diagnosed with IBS and 306 were symptomatic but undiagnosed. RESULTS: The findings suggest that even after adjusting for symptom frequency, those diagnosed with IBS experience poorer QoL, relative to those without a diagnosis. Moreover, there was evidence that the relationship between specific QoL domains (namely, sex, food avoidance, and health worry) and psychological variables (namely, pain catastrophizing, and depression) was moderated by diagnostic status. CONCLUSION: The results indicate that diagnostic status in relation to IBS has psychological implications for QoL outcomes distinct from symptom frequency, age, and gender. This highlights a substantial gap in our current understanding of how a diagnosis of IBS can impact the lives of those suffering from IBS symptomology and calls into question the intended purpose of diagnosis.


Assuntos
Síndrome do Intestino Irritável , Qualidade de Vida , Humanos , Síndrome do Intestino Irritável/diagnóstico
17.
Epilepsy Res ; 176: 106725, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34304018

RESUMO

OBJECTIVE: High volume surgical epilepsy centers have reported a decrease in surgical resections and an increase in intracranial monitoring. Despite this increase in complexity, epilepsy surgery remains significantly underutilized. The goal of this study is to examine the utilization of and access to epilepsy surgery in the United States from 2006 to 2016. METHODS: We used administrative datasets from the National Inpatient Sample (NIS) and Center for Medicare and Medicaid Services (CMS) to report national estimates of epilepsy surgery and changes in surgery types. We also examined disparities and barriers in access to epilepsy surgery. RESULTS: Inpatient epilepsy admissions increased from 2.41 to 5.78 per 100,000 between 2006 and 2016, while surgical epilepsy admissions plateaued after 2011. Open resections comprised 75 % of all surgical cases from 2006 to 2011 then decreased each year to 50 % in 2016 with both temporal and extratemporal resections decreasing proportionally. Intracranial monitoring increased in the last two years of the study due to an increase in SEEG/depth electrode cases. The multivariate analysis showed that patients with Medicaid (OR 0.75, 95 % CI 0.67-0.83) and Medicare (OR 0.62, 95 % CI 0.54-0.70) were significantly less likely to undergo epilepsy surgery compared to those with private insurance. Black patients were less likely to undergo epilepsy surgery than White or Hispanic patients (OR 0.57, 95 % CI 0.49-0.67). No significant difference was found in epilepsy surgery rates after implementation of the Affordable Care Act (ACA) in 2014. CONCLUSION: This study identifies recent trends in epilepsy surgical approaches and suggests that improving access to care does not necessarily address disparities present in the treatment of epilepsy patients who need surgical care.


Assuntos
Epilepsia , Patient Protection and Affordable Care Act , Idoso , Epilepsia/epidemiologia , Epilepsia/cirurgia , Etnicidade , Disparidades em Assistência à Saúde , Humanos , Medicaid , Medicare , Estados Unidos
18.
N Engl J Med ; 354(2): 141-50, 2006 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-16407509

RESUMO

BACKGROUND: Conventional regimens of immunosuppressive drugs often do not prevent chronic rejection after lung transplantation. Topical delivery of cyclosporine in addition to conventional systemic immunosuppression might help prevent acute and chronic rejection events. METHODS: We conducted a single-center, randomized, double-blind, placebo-controlled trial of inhaled cyclosporine initiated within six weeks after transplantation and given in addition to systemic immunosuppression. A total of 58 patients were randomly assigned to inhale either 300 mg of aerosol cyclosporine (28 patients) or aerosol placebo (30 patients) three days a week for the first two years after transplantation. The primary end point was the rate of histologic acute rejection. RESULTS: The rates of acute rejection of grade 2 or higher were similar in the cyclosporine and placebo groups: 0.44 episode (95 percent confidence interval, 0.31 to 0.62) vs. 0.46 episode (95 percent confidence interval, 0.33 to 0.64) per patient per year, respectively (P=0.87 by Poisson regression). Survival was improved with aerosolized cyclosporine, with 3 deaths among patients receiving cyclosporine and 14 deaths among patients receiving placebo (relative risk of death, 0.20; 95 percent confidence interval, 0.06 to 0.70; P=0.01). Chronic rejection-free survival also improved with cyclosporine, as determined by spirometric analysis (10 events in the cyclosporine group and 20 events in the placebo group; relative risk of chronic rejection, 0.38; 95 percent confidence interval, 0.18 to 0.82; P=0.01) and histologic analysis (6 vs. 19 events, respectively; relative risk, 0.27; 95 percent confidence interval, 0.11 to 0.67; P=0.005). The risks of nephrotoxic effects and opportunistic infection were similar for patients in the cyclosporine group and the placebo group. CONCLUSIONS: Inhaled cyclosporine did not improve the rate of acute rejection, but it did improve survival and extend periods of chronic rejection-free survival. (ClinicalTrials.gov number, NCT00268515.).


Assuntos
Ciclosporina/administração & dosagem , Rejeição de Enxerto/prevenção & controle , Imunossupressores/administração & dosagem , Transplante de Pulmão , Doença Aguda , Administração por Inalação , Doença Crônica , Ciclosporina/efeitos adversos , Ciclosporina/uso terapêutico , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Humanos , Imunossupressores/efeitos adversos , Imunossupressores/uso terapêutico , Infecções/etiologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Análise de Regressão , Análise de Sobrevida
19.
Ann Thorac Surg ; 105(3): 893-900, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29394994

RESUMO

BACKGROUND: Lung disease is the leading cause of morbidity and death in scleroderma patients, but scleroderma is often considered a contraindication to lung transplantation because of concerns for worse outcomes. We evaluated whether 5-year survival in scleroderma patients after lung transplantation differed from other patients with restrictive lung disease. METHODS: This was a single-center, retrospective cohort study of all patients undergoing bilateral lung transplantation for scleroderma-related pulmonary disease between January 2006 and December 2014. This cohort was compared with patients undergoing bilateral lung transplantation for nonscleroderma group D restrictive disease. Primary outcomes reported were 1-year and 5-year survival. Diagnoses were identified by United Network of Organ Sharing listing and were confirmed by clinical examination and prelisting workup. RESULTS: We compared 26 patients who underwent BLT for scleroderma and 155 patients who underwent BLT for group D restrictive disease. Overall, the nonscleroderma cohort was younger, with lower lung allocation score but no difference in functional status. Donor characteristics were not different between the cohorts. Survival at 1 year was not different (73.1% vs 80.0%, p = 0.323). Long-term survival at 5 years was also not significantly different (65.4% vs 66.5%, p = 0.608). Multivariate Cox proportional hazards analysis found no differences in survival between scleroderma and nonscleroderma group D restrictive disease (hazard ratio, 2.19; p = 0.122). CONCLUSIONS: Despite being at high risk for extrapulmonary complications, patients undergoing bilateral lung transplantation for scleroderma have similar 1-year and 5-year survival as those with restrictive lung disease. Transplantation is a reasonable treatment option for a carefully selected population of candidates.


Assuntos
Pneumopatias/mortalidade , Pneumopatias/cirurgia , Transplante de Pulmão , Escleroderma Sistêmico/mortalidade , Escleroderma Sistêmico/cirurgia , Adulto , Idoso , Feminino , Humanos , Pneumopatias/etiologia , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Escleroderma Sistêmico/complicações , Taxa de Sobrevida , Resultado do Tratamento
20.
World Neurosurg ; 108: 988.e15-988.e20, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28830738

RESUMO

BACKGROUND: Dural arteriovenous fistula (DAVF) is an abnormal vascular connection between arterial and venous channels within dura mater. Although DAVFs have been linked to other types of intracranial tumors, this is the first case reporting the association between DAVF and an epidermoid tumor. CASE DESCRIPTION: A middle-aged patient with chronic headache presented with Borden type II DAVF draining into the right transverse sigmoid junction and was also found to have an epidermoid tumor over the right mastoid. The patient underwent staged embolization of the fistula through both transvenous and transarterial routes. Continuous intraoperative venous pressure monitoring confirmed marked reduction in intracranial venous pressure, and the patient's symptoms completely resolved. However, the fistula still remained. The residual DAVF was then surgically disconnected, and the epidermoid tumor was resected in the same procedure. CONCLUSIONS: This case demonstrates a DAVF can be associated with an epidermoid tumor. Tumor can compromise the venous outflow, which can then lead to intracranial venous hypertension and development of the DAVF. Venous pressure monitoring offers an objective method to verify resolution of venous hypertension, which might correlate with resolution of clinical symptoms.


Assuntos
Malformações Vasculares do Sistema Nervoso Central/diagnóstico por imagem , Cavidades Cranianas , Cisto Epidérmico/diagnóstico por imagem , Processo Mastoide/diagnóstico por imagem , Malformações Vasculares do Sistema Nervoso Central/complicações , Malformações Vasculares do Sistema Nervoso Central/terapia , Angiografia Cerebral , Imagem de Difusão por Ressonância Magnética , Embolização Terapêutica , Cisto Epidérmico/complicações , Cisto Epidérmico/cirurgia , Humanos , Pressão Intracraniana , Imageamento por Ressonância Magnética , Processo Mastoide/cirurgia , Pessoa de Meia-Idade , Monitorização Intraoperatória , Procedimentos Neurocirúrgicos , Pressão Venosa
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