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1.
Environ Res ; 247: 118120, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38199476

RESUMO

Photo-catalysts based on BiVO4 (BV) and Eco-graphene (EG) were synthesized and obtained in a single step with high-quality properties. These nanostructures (NEs) were obtained through a green chemistry route and by adding 2, 3, and 5 wt% of a homemade EG. The BV/X EG NEs (where X = corresponds to the weight % of EG) demonstrated high photocatalytic activity, obtaining Sulfamethoxazole degradation percentages of 40, 45, 52, and 57 for BV, BV/2 EG, BV/3 EG, and BV/5 EG respectively, using a blue LED light. In addition, it was observed that the presence of EG slightly affected the surface area and porosity of BV. Moreover, it was observed that the presence of EG stabilized the scheelite monoclinic phase (m-s), and decreased the crystal size and band-gap values of BV-based samples. It was detected that EG contents increased the BV reduction, creating oxygen vacancies and V4+ states, which favored electron transfer, enhanced the photo-catalytic activity, and decreased the recombination rate. The adsorption influence of the BV/EG system was also studied. Finally, the stability tests of these materials after four cycles of reuse allowed keeping practically the full degradation capacity, demonstrating that these NEs represent a promising material driven by visible light that can be used for wastewater decontamination in the presence of drugs.


Assuntos
Grafite , Nanoestruturas , Grafite/química , Sulfametoxazol , Adsorção , Luz
2.
Rev. int. med. cienc. act. fis. deporte ; 23(93): 87-100, nov.- dec. 2023. tab
Artigo em Inglês | IBECS | ID: ibc-229998

RESUMO

The aim of the study was to analyse, using the Spanish version of the ACSQ-1, the use of coping strategies considering gender, age, type of sport and sport modality, as well as the correlations themselves. The sample consisted of 334 Colombian elite athletes (156 men and 178 women) with a mean age of 27 years (M = 27.10, SD = 6.57). The most commonly used strategies were emotional calming and cognitive restructuring, with mental withdrawal being the least used. Men had higher values than women for emotional calm and cognitive restructuring. Younger athletes had higher values than older athletes for mental withdrawal and seeking social support. Paralympic athletes showed higher values than Olympic athletes in emotional calmness and cognitive restructuring, and nodifferences were found depending on the sport modality. Significant correlations were found between most strategies (AU)


El objetivo del estudio fue analizar, empleando la versión española del ACSQ-1, el uso de estrategias de afrontamiento considerando sexo, edad, tipo dedeporte y modalidad deportiva, así como las propias correlaciones. La muestra estuvo compuesta por 334 deportistas de élite colombianos (156 hombres y 178 mujeres) con una media de edad de 27 años (M = 27,10, DE = 6,57). Las estrategias más empleadas fueron la calma emocional y la reestructuración cognitiva, siendo la menos usada el retraimiento mental. Los hombres presentaron mayores valores que las mujeres en calma emocional y reestructuración cognitiva. Los deportistas de menos edad presentaron mayores valores que los de más en retraimiento mental y búsqueda de apoyo social. Los deportistas de modalidades paralímpicas mostraron mayores valores que los de olímpicas en calma emocional y reestructuración cognitiva, no encontrándose diferencias en función de la modalidad deportiva. Se encontraron correlaciones significativas entre la mayor parte de estrategias (AU)


Assuntos
Humanos , Masculino , Feminino , Adulto , Adaptação Psicológica , Esportes , Atletas/psicologia , Fatores Sexuais , Fatores Etários , Colômbia
3.
Phys Rev Lett ; 130(19): 193601, 2023 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-37243649

RESUMO

With a levitodynamics experiment in the strong and coherent quantum optomechanical coupling regime, we demonstrate that the oscillator acts as a broadband quantum spectrum analyzer. The asymmetry between positive and negative frequency branches in the displacement spectrum traces out the spectral features of the quantum fluctuations in the cavity field, which are thus explored over a wide spectral range. Moreover, in our two-dimensional mechanical system the quantum backaction, generated by such vacuum fluctuations, is strongly suppressed in a narrow spectral region due to a destructive interference in the overall susceptibility.

8.
J Environ Manage ; 299: 113452, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34526276

RESUMO

Cadiz Bay is a shallow mesotidal lagoon with extensive populations of the seagrass Cymodocea nodosa at intertidal and shallow subtidal elevations. This work aims to understand the mechanisms behind the resilience of this species to gradual sea level rise by studying its acclimation capacity to depth along the shallow littoral, and therefore, to gradual variations in the light environment. To address this objective, these populations have been monitored seasonally over a 10 year period, representing the longest seasonal database available in the literature for this species. The monitoring included populations at 0.4, -0.08 and -0.5 m LAT. The results show that C. nodosa has a strong seasonality for demographic and shoot dynamic properties - with longer shoots and larger growth in summer (high temperature) than in winter (low temperature), but also some losses. Moreover, shoots have different leaf morphometry depending on depth, with small and dense shoots in the intertidal areas (0.4 m) and sparse large shoots in the subtidal ones (-0.08 and 0.5 m). These differences in morphometry and shoot dynamic properties, combined with the differences in shoot density, explain the lack of differences in meadow production balance (i.e. meadow growth - meadow losses) between the intertidal (0.4 m) and the deepest population (-0.5 m), supporting the long term resilience of Cymodocea nodosa in Cadiz Bay. This study contributes to the understanding of the mechanisms behind seagrass stability and resilience, which is particularly important towards predicting the effects of climate change on these key coastal ecosystems, and also highlights the value of continuous long-term monitoring efforts to evaluate seagrass trajectories.


Assuntos
Alismatales , Ecossistema , Aclimatação , Mudança Climática , Folhas de Planta
9.
Games Health J ; 10(5): 361-369, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34403592

RESUMO

Objective: To measure metabolic and physiological demand, subjective fatigue, and enjoyment during a signature 30-minute immersive virtual reality (IVR) adaptive cable resistance exergaming session. Methods: Fourteen healthy college-aged individuals (seven females) were initially acquainted with the IVR equipment and gameplay dynamics. Participants then underwent a 30-minute IVR exergaming session performing six different cable resistance exercises. A portable metabolic gas exchange analyzer concurrently assessed energy expenditure (EE) through indirect calorimetry while a chest-worn monitor captured heart rate (HR). Participants subsequently completed questionnaires, including the Borg scale for rating of perceived exertion (RPE), Physical Activity Enjoyment Scale (PACES), and Simulator Sickness Questionnaire (SSQ). Results: The mean EE, mean metabolic equivalent, and average total calories expended during the 30-minute session were 14.7 (standard deviation [SD] 2.8) kcal/minute, 12.9 (SD 0.5), and 440 (SD 84) kcals respectively. The mean HR was 176 (SD 3.1) beats per minute (bpm) with a mean max HR of 188 SD (SD 2.9) bpm. The combined training volume among all participants was 16,102 kg (SD 4137). Participants classified the IVR training session to be "somewhat hard-to-hard" with a RPE score of 14 (SD 1) while indicating the session to be "enjoyable" with a PACES score of 4.31 (SD 0.36). The participants did not report any cybersickness symptoms, demonstrating an average total SSQ score of 24.04 (SD 24.13). Conclusions: IVR exergaming incorporating cable resistance training elicits high EE and physiological demand with high enjoyment scores while attenuating perceived fatigue. The potential for IVR to elicit these acute training effects over long-term training periods warrants further investigation into its contribution to fitness and health.


Assuntos
Jogos de Vídeo , Realidade Virtual , Calorimetria Indireta , Exercício Físico , Feminino , Humanos , Esforço Físico , Adulto Jovem
10.
J Nutr Health Aging ; 24(7): 723-729, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32744568

RESUMO

OBJECTIVES: Diabetes mellitus (DM) and frailty are common in older patients with acute coronary syndromes (ACS). No data exists about its prognostic impact on long-term outcomes and their possible interaction in this setting. DESIGN: Observational prospective study. SETTING: Multicenter registry conducted in 44 hospitals in Spain. PARTICIPANTS: Consecutive patients with ACS aged 80≥years. MEASUREMENTS: A comprehensive geriatric evaluation was performed during hospitalization, including frailty assessment by the FRAIL score. The impact of DM and frailty on the incidence of mortality/readmission at 24 months was analysed by a Cox regression model. RESULTS: A total of 498 patients were included (mean age 84.3 years). Prevalence of previous DM was 199/498 (40.0%). The rate of frail patients was 135/498 (27.1%). The incidence of mortality/readmission was higher frail patients (HR 2.49) (both p<0.001). In contrast, DM was not significantly associated to a higher rate of outcomes (HR 1.23, p=0.060) in the whole cohort. Among non-frail patients, patients with DM had a similar incidence of mortality or readmission (p=0.959). In contrast, among frail patients, DM was significantly associated with a higher incidence of events (HR 1.51, p=0.034). CONCLUSIONS: Unlike frailty status, DM was not associated to poorer long-term outcome in elderly patients with ACS. Among frail patients the presence of DM seems to provide additional prognostic information.


Assuntos
Síndrome Coronariana Aguda/complicações , Diabetes Mellitus/etiologia , Idoso Fragilizado/estatística & dados numéricos , Fragilidade/complicações , Síndrome Coronariana Aguda/mortalidade , Idoso de 80 Anos ou mais , Diabetes Mellitus/mortalidade , Feminino , Humanos , Masculino , Prevalência , Prognóstico , Estudos Prospectivos
11.
Osteoporos Int ; 31(10): 1935-1942, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32474650

RESUMO

FRAX® calculates the 10-year probability of major osteoporotic fractures (MOF), which are considered to have a greater clinical impact than other fractures. Our results suggest that, in postmenopausal women with severe osteoporosis, those treated with teriparatide had a 60% lower risk of FRAX®-defined MOF compared with those treated with risedronate. INTRODUCTION: The VERO trial was an active-controlled fracture endpoint clinical trial that enrolled postmenopausal women with severe osteoporosis. After 24 months, a 52% reduction in the hazard ratio (HR) of clinical fractures was reported in patients randomized to teriparatide compared with risedronate. We examined fracture results restricted to FRAX®-defined major osteoporotic fractures (MOF), which include clinical vertebral, hip, humerus, and forearm fractures. METHODS: In total, 1360 postmenopausal women (mean age 72.1 years) were randomized to receive subcutaneous daily teriparatide (20 µg) or oral weekly risedronate (35 mg). Patient cumulative incidence of ≥ 1 FRAX®-defined MOF and of all clinical fractures were estimated by Kaplan-Meier analyses, and the comparison between treatments was based on the stratified log-rank test. Additionally, an extended Cox model was used to estimate HRs at different time points. Incidence fracture rates were estimated at each 6-month interval. RESULTS: After 24 months, 16 (2.6%) patients in the teriparatide group had ≥ 1 low trauma FRAX®-defined MOF compared with 40 patients (6.4%) in the risedronate group (HR 0.40; 95% CI 0.23-0.68; p = 0.001). Clinical vertebral and radius fractures were the most frequent FRAX®-defined MOF sites. The largest difference in incidence rates of both FRAX®-defined MOF and all clinical fractures between treatments occurred during the 6- to 12-month period. There was a statistically significant reduction in fractures between groups as early as 7 months for both categories of clinical fractures analyzed. CONCLUSION: In postmenopausal women with severe osteoporosis, treatment with teriparatide was more efficacious than risedronate, with a 60% lower risk of FRAX®-defined MOF during the 24-month treatment period. Fracture risk was statistically significantly reduced at 7 months of treatment. CLINICAL TRIAL INFORMATION: ClinicalTrials.gov Identifier: NCT01709110 EudraCT Number: 2012-000123-41.


Assuntos
Conservadores da Densidade Óssea , Osteoporose Pós-Menopausa , Fraturas por Osteoporose , Idoso , Densidade Óssea , Conservadores da Densidade Óssea/uso terapêutico , Método Duplo-Cego , Feminino , Humanos , Osteoporose Pós-Menopausa/tratamento farmacológico , Fraturas por Osteoporose/epidemiologia , Fraturas por Osteoporose/etiologia , Fraturas por Osteoporose/prevenção & controle , Ácido Risedrônico/uso terapêutico , Teriparatida/uso terapêutico
12.
Acta pediatr. esp ; 78(3/4): e118-e121, mar.-abr. 2020. ilus
Artigo em Espanhol | IBECS | ID: ibc-202680

RESUMO

La erupción variceliforme de Kaposi (EVK) es la diseminación cutánea del virus herpes simple (VHS), siendo la etiología más frecuente el VHS tipo 1. Suele presentarse en pacientes con enfermedades cutáneas de base o por lesiones agudas de la barrera epidérmica. La sospecha clínica se confirma mediante reacción en cadena de la polimerasa, aislamiento del virus en cultivo o mediante anticuerpos monoclonales realizados de una muestra extraída de las lesiones cutáneas. La complicación más frecuente es la sobreinfección bacteriana por Staphylococcus aureus y el tratamiento de elección es aciclovir oral o intravenoso, en función de la gravedad. En la literatura, son múltiples los artículos que asocian la dermatitis atópica con la EVK. Pero estas dos patologías no siempre vienen de la mano, por lo que su diagnóstico en ocasiones puede suponer todo un reto para el pediatra. Presentamos una actualización de los conocimientos de esta enfermedad a raíz de un caso recientemente diagnosticado en nuestro servicio


The variceliform eruption of Kaposi (EVK) is the cutaneous dissemination of the herpes simplex virus (HSV), the most frequent etiology being HSV type 1. It usually occurs in patients with underlying skin diseases or due to a lesion in the epidermal barrier. Clinical suspicion is confirmed by polymerase chain reaction, virus isolation in culture or by monoclonal antibodies made from a sample of skin lesions. The most frequent complication is bacterial superinfection due to Staphylococcus aureus and the treatment of choice is oral or intravenous acyclovir, depending on the severity. In literature, there are many articles that associate atopic dermatitis with the EVK. But these two pathologies do not always come hand in hand, so their diagnosis can sometimes be a challenge for the pediatrician. We present an update on the knowledge of this disease following a case recently diagnosed in our service


Assuntos
Humanos , Masculino , Lactente , Erupção Variceliforme de Kaposi/diagnóstico , Erupção Variceliforme de Kaposi/virologia , Doença de Mão, Pé e Boca/virologia , Doença de Mão, Pé e Boca/diagnóstico , Erupção Variceliforme de Kaposi/tratamento farmacológico , Combinação Amoxicilina e Clavulanato de Potássio/uso terapêutico , Aciclovir/uso terapêutico , Enterovirus/isolamento & purificação , Herpesvirus Humano 1/isolamento & purificação
13.
Leukemia ; 34(10): 2648-2659, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32107471

RESUMO

Myelofibrosis (MF) occurs as part of the natural history of polycythemia vera (PV) and essential thrombocythemia (ET), and remarkably shortens survival. Although JAK2V617F and CALR allele burden are the main transformation risk factors, inflammation plays a critical role by driving clonal expansion toward end-stage disease. NF-κB is a key mediator of inflammation-induced carcinogenesis. Here, we explored the involvement of miR-146a, a brake in NF-κB signaling, in MPN susceptibility and progression. rs2910164 and rs2431697, that affect miR-146a expression, were analyzed in 967 MPN (320 PV/333 ET/314 MF) patients and 600 controls. We found that rs2431697 TT genotype was associated with MF, particularly with post-PV/ET MF (HR = 1.5; p < 0.05). Among 232 PV/ET patients (follow-up time=8.5 years), 18 (7.8%) progressed to MF, being MF-free-survival shorter for rs2431697 TT than CC + CT patients (p = 0.01). Multivariate analysis identified TT genotype as independent predictor of MF progression. In addition, TT (vs. CC + CT) patients showed increased plasma inflammatory cytokines. Finally, miR-146a-/- mice showed significantly higher Stat3 activity with aging, parallel to the development of the MF-like phenotype. In conclusion, we demonstrated that rs2431697 TT genotype is an early predictor of MF progression independent of the JAK2V617F allele burden. Low levels of miR-146a contribute to the MF phenotype by increasing Stat3 signaling.


Assuntos
MicroRNAs/genética , Transtornos Mieloproliferativos/genética , Mielofibrose Primária/genética , Idoso , Alelos , Animais , Citocinas/genética , Progressão da Doença , Feminino , Genótipo , Humanos , Inflamação/genética , Inflamação/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Mutação/genética , Transtornos Mieloproliferativos/patologia , NF-kappa B/genética , Policitemia Vera/genética , Policitemia Vera/patologia , Transdução de Sinais/genética , Trombocitemia Essencial/genética , Trombocitemia Essencial/patologia
14.
Phys Rev Lett ; 124(2): 023601, 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-32004051

RESUMO

Recent optomechanical experiments have observed nonclassical properties in macroscopic mechanical oscillators. A key indicator of such properties is the asymmetry in the strength of the motional sidebands produced in the probe electromagnetic field, which is originated by the noncommutativity between the oscillator ladder operators. Here we extend the analysis to a squeezed state of an oscillator embedded in an optical cavity, produced by the parametric effect originated by a suitable combination of optical fields. The motional sidebands assume a peculiar shape, related to the modified system dynamics, with asymmetric features revealing and quantifying the quantum component of the squeezed oscillator motion.

15.
Foot (Edinb) ; 40: 27-33, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31055210

RESUMO

PURPOSE: Surgical treatment of moderate hallux valgus (HV) onwards by Chevron osteotomy and all variants described to date including the recent extended distal Chevron osteotomy (EDCO), yields improvable outcome but with recurrence rate. A new modification of this technique is needed to achieve better results. METHODS: 34 consecutive female patients suffering from moderate HV underwent a new minimally extended distal Chevron osteotomy (MEDCO) with percutaneous soft tissue release (PSTR). Outcome was assessed using pre-post operative VAS-Pain, AOFAS Hallux Score and radiological measurements. Mean age was 53.7 years, follow-up 2.7 years and satisfaction score 8. RESULTS: VAS improved from 7 to 1 (p < 0.001) and AOFAS score from 64 to 90.7 (p < 0.001). Comparing postoperative HV and intermetatarsal (IM) angles of previous studies (either employing a Chevron osteotomy alone or a double Chevron-Akin) with our results, an improvement from 15.6/14.8 to 9.1 and 8.2 /8.8 to 5.6 respectively (p < 0.05) was achieved. Complication and recurrence rates were both 5.8%, lower than the documented rates of other techniques. CONCLUSION: The modified technique in the present study was found to be a more effective and reliable method of correcting hallux valgus when compared to other previous procedures. It provides a higher level of satisfaction and excellent outcomes with low complication and recurrence rates. Furthermore, the percutaneous lateral incision improved the cosmetic results by avoiding formation of a dorsal first web space scar. Medial incision is also shorter than the one used for EDCO. LEVEL OF EVIDENCE: Level IV, case series.


Assuntos
Hallux Valgus/cirurgia , Osteotomia/métodos , Feminino , Hallux Valgus/diagnóstico por imagem , Humanos , Pessoa de Meia-Idade , Medição da Dor , Satisfação do Paciente , Complicações Pós-Operatórias/prevenção & controle , Recidiva , Índice de Gravidade de Doença
16.
QJM ; 112(3): 183-188, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30380132

RESUMO

BACKGROUND: The clinical effect of peri-operative bridging therapy in atrial fibrillation (AF) patients remains unclear given that it may increase bleeding risk without providing significant benefits. We aimed to investigate peri-procedural events in relation to peri-operative use of bridging therapy in AF patients under Vitamin K Antagonists (VKAs). METHODS: We included AF patients stable the previous 6 months on VKAs. During a median follow-up of 6.5 years (IQR 4.3-7.9), we recorded all invasive procedures and the peri-operative clinical management. All peri-procedural events (ischaemic stroke/transient ischaemic attack/systemic embolism, clinically relevant non-major bleeding and major bleeding) and severe peri-procedural events (ischaemic stroke/transient ischaemic attack/systemic embolism and major bleeding) suffered until the 30-days post-intervention period were recorded. RESULTS: We included 1361 patients (48.7% male, median age 76 [IQR 71-81] years). There were 1100 (70.9%) procedures performed using bridging therapy. The rate of any (4.5% vs. 0.7%, P < 0.001) and severe (2.3% vs. 0.0%, P = 0.002) peri-procedural events were higher in patients receiving bridging therapy. Adjusted logistic regressions demonstrated that the bleeding risk of the procedure was related with higher risk of severe peri-procedural events (OR 3.51, 95% CI 1.54-8.01) and peri-procedural events (OR 2.77, 95% CI 1.56-4.91). Importantly, the use of bridging therapy was also independently associated with higher risk of any peri-procedural events (OR 4.32, 95% CI 1.28-14.51). CONCLUSIONS: In this study including AF patients under VKA therapy, the use of bridging therapy as part of the clinical management during an invasive procedure was independently associated with higher risk of any peri-procedural event.


Assuntos
Fibrilação Atrial/terapia , Heparina de Baixo Peso Molecular/efeitos adversos , Assistência Perioperatória , Vitamina K/antagonistas & inibidores , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/efeitos adversos , Anticoagulantes/uso terapêutico , Feminino , Hemorragia/epidemiologia , Heparina de Baixo Peso Molecular/uso terapêutico , Humanos , Modelos Logísticos , Masculino , Prevalência , Fatores de Risco , Espanha/epidemiologia , Acidente Vascular Cerebral/prevenção & controle , Tromboembolia/epidemiologia , Tromboembolia/prevenção & controle
17.
Transl Cancer Res ; 8(2): 552-556, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35116787

RESUMO

BACKGROUND: This retrospective single center study aimed to describe circulating tumor DNA (ctDNA) comprehensive genomic profiling (CGP) utilization in a community practice for patients with advanced solid tumors. METHODS: All patients were included who were seen at the Scripps Hillcrest Oncology Clinic (San Diego, CA, USA) between September 2016 to March 2018 who had ctDNA assay testing performed. In this cohort, all ctDNA testing was performed to aid therapeutic decision making with wide variety in both the type of advanced solid tumor, as well as the line of therapy. RESULTS: Of the assays performed in the 41 patients included in this review, 42% of therapeutic actions following ctDNA assay results were influenced by the ctDNA result, including initiation of the corresponding Federal Drug Administration (FDA) approved therapy, placement on clinical trial, and initiation of off label-targeted options. In addition, CGP results guided clinicians away from futile or harmful treatments, such as EGFR inhibition in colorectal cancer patients with discovered KRAS mutations. No additional prognostic or therapeutic information was gathered in one quarter of patients for which ctDNA was drawn. Furthermore, discovered genomic alterations by ctDNA testing did not influence therapeutic action in 58% of cases. CONCLUSIONS: These results highlight the conundrum that having additional information regarding an individual's tumor biology does not yet translate into meaningful targeted therapy in the majority of cases. Further studies are needed regarding ctDNA utilization to help guide community oncologists who will continue to face the choice between targeted therapy, immunotherapy, and cytotoxic chemotherapy as science advances.

18.
PLoS One ; 13(3): e0193828, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29518121

RESUMO

Mathematical models simulating different and representative engineering problem, atomic dry friction, the moving front problems and elastic and solid mechanics are presented in the form of a set of non-linear, coupled or not coupled differential equations. For different parameters values that influence the solution, the problem is numerically solved by the network method, which provides all the variables of the problems. Although the model is extremely sensitive to the above parameters, no assumptions are considered as regards the linearization of the variables. The design of the models, which are run on standard electrical circuit simulation software, is explained in detail. The network model results are compared with common numerical methods or experimental data, published in the scientific literature, to show the reliability of the model.


Assuntos
Simulação por Computador , Engenharia , Modelos Teóricos , Corrosão , Elasticidade , Fricção , Microscopia de Força Atômica/instrumentação , Oxirredução , Oxigênio/química , Software , Temperatura , Titânio/química , Triterpenos
19.
Phys Rev Lett ; 120(2): 020503, 2018 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-29376724

RESUMO

The extraordinary sensitivity of the output field of an optical cavity to small quantum-scale displacements has led to breakthroughs such as the first detection of gravitational waves and of the motions of quantum ground-state cooled mechanical oscillators. While heterodyne detection of the output optical field of an optomechanical system exhibits asymmetries which provide a key signature that the mechanical oscillator has attained the quantum regime, important quantum correlations are lost. In turn, homodyning can detect quantum squeezing in an optical quadrature but loses the important sideband asymmetries. Here we introduce and experimentally demonstrate a new technique, subjecting the autocorrelators of the output current to filter functions, which restores the lost heterodyne correlations (whether classical or quantum), drastically augmenting the useful information accessible. The filtering even adjusts for moderate errors in the locking phase of the local oscillator. Hence we demonstrate the single-shot measurement of hundreds of different field quadratures allowing the rapid imaging of detailed features from a simple heterodyne trace. We also obtain a spectrum of hybrid homodyne-heterodyne character, with motional sidebands of combined amplitudes comparable to homodyne. Although investigated here in a thermal regime, the method's robustness and generality represents a promising new approach to sensing of quantum-scale displacements.

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