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1.
Nano Lett ; 23(4): 1451-1458, 2023 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-36748796

RESUMEN

Existing barriers to efficient deep ultraviolet (UV) light-emitting diodes (LEDs) may be reduced or overcome by moving away from conventional planar growth and toward three-dimensional nanostructuring. Nanorods have the potential for enhanced doping, reduced dislocation densities, improved light extraction efficiency, and quantum wells free from the quantum-confined Stark effect. Here, we demonstrate a hybrid top-down/bottom-up approach to creating highly uniform AlGaN core-shell nanorods on sapphire repeatable on wafer scales. Our GaN-free design avoids self-absorption of the quantum well emission while preserving electrical functionality. The effective junctions formed by doping of both the n-type cores and p-type caps were studied using nanoprobing experiments, where we find low turn-on voltages, strongly rectifying behaviors and significant electron-beam-induced currents. Time-resolved cathodoluminescence measurements find short carrier liftetimes consistent with reduced polarization fields. Our results show nanostructuring to be a promising route to deep-UV-emitting LEDs, achievable using commercially compatible methods.

2.
BMC Health Serv Res ; 22(1): 1313, 2022 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-36329472

RESUMEN

BACKGROUND: Emerging evidence suggests that access to chiropractic care may reduce the likelihood of initiating an opioid prescription for spinal pain; however, the impact of chiropractic care for patients already prescribed opioids is uncertain. We undertook a sequential explanatory mixed methods study to evaluate the association between initiating chiropractic care and continued opioid use among adult patients attending an Ontario community health centre (CHC) and receiving opioid therapy for chronic non-cancer spinal pain. METHODS: We conducted a retrospective cohort study of 210 patient records between January 1, 2014 and December 31, 2020. We used generalized estimating equations, adjusted for patient demographics, co-morbidities, visit frequency, and calendar year, to evaluate the association between receipt versus non-receipt of chiropractic services and continued opioid use (e.g., unique opioid fills, number of refills, and dosages) up to one year following the index chiropractic visit. We also completed follow-up interviews with 14 patients and nine general practitioners from the CHC and integrated these data with our quantitative findings. RESULTS: Over 12-month follow-up, there were lower rates of opioid fills (incidence rate ratio [IRR] = 0.66; 95% confidence interval [CI], 0.52-0.83) and refills (IRR = 0.27; 95% CI, 0.17-0.42) among chiropractic recipients (n = 49) versus non-recipients (n = 161). Although patients who did and did not receive chiropractic care began the study with the same dose of opioids, recipients were less likely to be prescribed higher-dose opioids (i.e., ≥ 50 mg morphine equivalents daily) compared to non-recipients at three months (odds ratio [OR] = 0.14; 95% CI, 0.04-0.47), six months (OR = 0.14; 95% CI, 0.05-0.40), nine months (OR = 0.19; 95% CI, 0.07-0.57), and 12 months (OR = 0.22; 95% CI, 0.08-0.62). Interviews suggested that patient self-efficacy, limited effectiveness of opioids for chronic pain, stigma regarding use of opioids, and access to chiropractic treatment were important influencing factors. CONCLUSION: We found that continued prescription opioid use among patients with chronic non-cancer spinal pain who received chiropractic care was lower than in patients who did not receive chiropractic care. Four themes emerged in our qualitative interviews to help provide a richer understanding of this association. Randomized controlled trials are needed to establish the effect of chiropractic care on opioid use for chronic spinal pain.


Asunto(s)
Quiropráctica , Dolor Crónico , Trastornos Relacionados con Opioides , Adulto , Humanos , Dolor Crónico/tratamiento farmacológico , Analgésicos Opioides/efectos adversos , Estudios Retrospectivos , Ontario/epidemiología , Trastornos Relacionados con Opioides/tratamiento farmacológico , Prescripciones de Medicamentos , Centros Comunitarios de Salud
3.
J Manipulative Physiol Ther ; 45(4): 235-247, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-36008170

RESUMEN

OBJECTIVE: The purpose of this study was to examine the association between receipt of chiropractic services and initiating a prescription for opioids among adult patients with noncancer spinal pain in a Canadian community health center. METHODS: In this sequential explanatory mixed methods analysis, we conducted a retrospective study of 945 patient records (January 2014 to December 2020) and completed interviews with 14 patients and 9 general practitioners. We used Cox proportional hazards regression analyses, adjusted for patient demographics, comorbidities, visit frequency, and calendar year to evaluate the association between receipt of chiropractic care and time to first opioid prescription up to 1 year after presentation. Qualitative data were analyzed thematically and integrated with our quantitative findings. RESULTS: There were 24% of patients (227 of 945) with noncancer spinal pain who received a prescription for opioids. The risk of initiating a prescription for opioids at 1 year after presentation was 52% lower in chiropractic recipients vs nonrecipients (hazard ratio [HR], 0.48; 99% confidence interval [CI], 0.29-0.77) and 71% lower in patients who received chiropractic services within 30 days of their index visit (HR, 0.29; 99% CI, 0.13-0.68). Patients whose index visit date was in a more recent calendar year were also less likely to receive opioids (HR, 0.86; 99% CI, 0.76-0.97). Interviews suggested that self-efficacy, access to chiropractic services, opioid stigma, and treatment impact were influencing factors. CONCLUSION: Patients with noncancer spinal pain who received chiropractic care were less likely to obtain a prescription for opioids than patients who did not receive chiropractic care.


Asunto(s)
Analgésicos Opioides , Quiropráctica , Adulto , Analgésicos Opioides/uso terapéutico , Canadá , Centros Comunitarios de Salud , Prescripciones de Medicamentos , Humanos , Dolor , Estudios Retrospectivos
4.
J Manipulative Physiol Ther ; 40(9): 635-642, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29229053

RESUMEN

OBJECTIVE: The purpose of this study was to evaluate a chiropractic service for back pain patients integrated within a publicly funded, multidisciplinary, primary care community health center in Cambridge, Ontario, Canada. METHODS: Patients consulting for back pain of any duration were referred by their medical doctor or nurse practitioner for chiropractic treatment at the community health center. Patients completed questionnaires at baseline and at discharge from the service. Data were collected prospectively on consecutive patients between January 2014 and January 2016. RESULTS: Questionnaire data were obtained from 93 patients. The mean age of the sample was 49.0 ± 16.27 years, and 66% were unemployed. More than three-quarters (77%) had had their back pain for more than a month, and 68% described it as constant. According to the Bournemouth Questionnaire, Bothersomeness, and global improvement scales, a majority (63%, 74%, and 93%, respectively) reported improvement at discharge, and most (82%) reported a significant reduction in pain medication. More than three-quarters (77%) did not visit their primary care provider while under chiropractic care, and almost all (93%) were satisfied with the service. According to the EuroQol 5 Domain questionnaire, more than one-third of patients (39%) also reported improvement in their general health state at discharge. CONCLUSION: Implementation of an integrated chiropractic service was associated with high levels of improvement and patient satisfaction in a sample of patients of low socioeconomic status with subacute and chronic back pain.


Asunto(s)
Centros Comunitarios de Salud/organización & administración , Prestación Integrada de Atención de Salud/organización & administración , Personal de Salud/organización & administración , Accesibilidad a los Servicios de Salud/estadística & datos numéricos , Dolor de la Región Lumbar/rehabilitación , Manipulación Quiropráctica , Adulto , Anciano , Canadá , Servicios de Salud Comunitaria/normas , Servicios de Salud Comunitaria/tendencias , Femenino , Encuestas de Atención de la Salud , Humanos , Dolor de la Región Lumbar/diagnóstico , Masculino , Persona de Mediana Edad , Ontario , Evaluación de Resultado en la Atención de Salud , Estudios Prospectivos
5.
Pacing Clin Electrophysiol ; 39(7): 642-51, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27027856

RESUMEN

BACKGROUND: Nonsustained ventricular tachycardia (NSVT) detected by ambulatory Holter (Holter NSVT) is a major risk factor for sudden cardiac death in hypertrophic cardiomyopathy (HCM). We hypothesized that the prognostic utility of Holter NSVT in HCM would improve with prolonged monitoring and a higher heart rate cut-off for detection. METHODS: We enrolled 60 patients (44 ± 14 years) with HCM, who had a prophylactic implantable cardioverter defibrillator (ICD). Positive Holter NSVT (prior to implant) was defined as ≥3 beats at ≥120 beats per minute (bpm). We assessed the prevalence of rapid NSVT (RNSVT) detected by their ICD within 12 months of its implant, defined as 4-16 beats at ≥150-200 bpm. The primary outcome was appropriate ICD therapy (antitachycardia pacing and shocks) for sustained ventricular arrhythmia (VA). RESULTS: Holter NSVT was detected in 34 patients. RNSVT occurred in 21 (35%) patients of whom five did not have Holter NSVT. Over a median follow-up of 61 (interquartile range 29, 129) months after ICD implant, nine patients had VA. RNSVT, but not Holter NSVT, was significantly associated with VA (hazard ratio 6.2, 95% confidence interval [1.3-30], P = 0.01) by multivariable Cox regression analysis that included conventional risk factors. Receiver operating characteristic analysis for RNSVT (area under curve 0.80, P = 0.005) showed that the occurrence of ≥2 episodes of RNSVT discriminated patients for VA optimally (sensitivity 78%, specificity 84%, positive predictive value 47%, negative predictive value 96%). CONCLUSIONS: In this pilot study, RNSVT detected by continuous monitoring independently predicted VA in HCM and offered superior discrimination of VA risk compared to conventional risk factors, including Holter NSVT. Future studies are needed to validate these findings in a larger, unselected HCM cohort.


Asunto(s)
Cardiomiopatía Hipertrófica/complicaciones , Cardiomiopatía Hipertrófica/diagnóstico , Diagnóstico por Computador/métodos , Electrocardiografía Ambulatoria/métodos , Taquicardia Ventricular/complicaciones , Taquicardia Ventricular/diagnóstico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Reproducibilidad de los Resultados , Medición de Riesgo/métodos , Sensibilidad y Especificidad , Adulto Joven
6.
Circulation ; 127(24): 2383-92, 2013 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-23775193

RESUMEN

BACKGROUND: The benefit of implantable cardioverter-defibrillators (ICDs) among elderly patients is controversial and may be attenuated by nonarrhythmic death. We examined the impact of age on device-delivered therapies and outcomes after primary or secondary prevention ICD. METHODS AND RESULTS: In a prospective, inclusive registry of 5399 ICD recipients in Ontario, Canada (February 2007 to September 2010), device-delivered therapies and complications were determined at routine clinic visits. Among primary prevention ICD recipients aged 18 to 49 (n=317), 50 to 59 (n=769), 60 to 69 (n=1336), 70 to 79 (n=1242), and ≥80 (n=275) years, mortality increased with age, as follows: 2.1, 3.0, 5.4, 6.9, and 10.2 deaths per 100 person-years, respectively (P<0.001). Secondary prevention ICD recipients aged 18 to 49 (n=114), 50 to 59 (n=244), 60 to 69 (n=481), 70 to 79 (n=462), and ≥80 (n=159) years also exhibited increasing mortality, as follows: 2.2, 3.8, 6.1, 8.7, and 15.5 deaths per 100 person-years, respectively (P<0.001). However, rates of appropriate shock were similar across age groups: from 6.7 (18-49 years) to 4.2 (≥80 years) per 100 person-years after primary prevention ICDs (P=0.139) and from 11.4 (18-49 years) to 11.9 (≥80 years) per 100 person-years after secondary prevention ICDs (P=0.993). Covariate-adjusted competing risk analysis demonstrated higher risk of death (Ptrend<0.001 for both primary and secondary prevention) but no significant decline in appropriate shocks with older age after primary (P=0.130) or secondary (P=0.810) prevention ICD implantation. CONCLUSIONS: Whereas elderly patients exhibited increased mortality after ICD implantation, rates of appropriate device shocks were similar across age groups. Decisions regarding ICD candidacy should not be based on age alone but should consider factors that predispose to mortality despite defibrillator implantation.


Asunto(s)
Arritmias Cardíacas/mortalidad , Arritmias Cardíacas/prevención & control , Desfibriladores Implantables/estadística & datos numéricos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Arritmias Cardíacas/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ontario/epidemiología , Prevención Primaria , Estudios Prospectivos , Sistema de Registros , Estudios Retrospectivos , Prevención Secundaria , Tasa de Supervivencia , Resultado del Tratamiento , Adulto Joven
7.
ACS Appl Opt Mater ; 1(11): 1836-1846, 2023 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-38037651

RESUMEN

Supraparticle (SP) microlasers fabricated by the self-assembly of colloidal nanocrystals have great potential as coherent optical sources for integrated photonics. However, their deterministic placement for integration with other photonic elements remains an unsolved challenge. In this work, we demonstrate the manipulation and printing of individual SP microlasers, laying the foundation for their use in more complex photonic integrated circuits. We fabricate CdSxSe1-x/ZnS colloidal quantum dot (CQD) SPs with diameters from 4 to 20 µm and Q-factors of approximately 300 via an oil-in-water self-assembly process. Under a subnanosecond-pulse optical excitation at 532 nm, the laser threshold is reached at an average number of excitons per CQD of 2.6, with modes oscillating between 625 and 655 nm. Microtransfer printing is used to pick up individual CQD SPs from an initial substrate and move them to a different one without affecting their capability for lasing. As a proof of concept, a CQD SP is printed on the side of an SU-8 waveguide, and its modes are successfully coupled to the waveguide.

8.
Indian Pacing Electrophysiol J ; 12(1): 24-6, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22368379

RESUMEN

Abrupt changes in heart rate, particularly short-long-short sequences in the ventricular cycle length (CL), might precede initiation of ventricular tachycardia/fibrillation (VT/VF). These changes may be facilitated or caused by pacing activity in patients with pacemakers or implantable-cardioverter defibrillators (ICDs). We describe a patient with two episodes of acquired VT precipitated by short-long-short sequences and diagnosed from the ICD recordings. In such cases, the knowledge of the device parameters is extremely important for a correct diagnosis and management.

9.
BMJ Case Rep ; 14(4)2021 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-33827866

RESUMEN

A two-stage revision total hip replacement (THR) remains the gold standard for treating chronic periprosthetic joint infection. The goals for the first stage are twofold: (1) remove infected tissue/implants, obtaining tissue samples for culture; (2) deliver local antibiotics and maintain hip function with a prosthesis with antibiotic-loaded acrylic cement. With extensive bone loss prefabricated spacers are not sufficient, therefore customised spacers are required. The current technique, coating cephalomedually femoral nail in cement, is complex, time consuming, functions poorly and causes wear debris from excessive friction at the femoral/acetabular articulation. We report a technique to create a custom made composite spacer using a short femoral nail, standard Exeter femoral stem (Stryker), Trident acetabular cup (Stryker) and polymethyl methacrylate (PMMA) bone cement with antibiotics. This technique restores hip biomechanics and gives a stable articulation, even in the presence of abductor deficiency, due to dual mobility bearings.


Asunto(s)
Artroplastia de Reemplazo de Cadera , Prótesis de Cadera , Infecciones Relacionadas con Prótesis , Acetábulo/diagnóstico por imagen , Acetábulo/cirugía , Antibacterianos/uso terapéutico , Cementos para Huesos , Prótesis de Cadera/efectos adversos , Humanos , Infecciones Relacionadas con Prótesis/tratamiento farmacológico , Infecciones Relacionadas con Prótesis/cirugía , Reoperación
11.
Anal Biochem ; 402(1): 83-90, 2010 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-20307487

RESUMEN

Here we describe bacterial genotyping by direct linear analysis (DLA) single-molecule mapping. DLA involves preparation of restriction digest of genomic DNA labeled with a sequence-specific fluorescent probe and stained nonspecifically with intercalator. These restriction fragments are stretched one by one in a microfluidic device, and the distribution of probes on the fragments is determined by single-molecule measurement of probe fluorescence. Fluorescence of the DNA-bound intercalator provides information on the molecule length. Because the probes recognize short sequences, they encounter multiple cognate sites on 100- to 300-kb-long DNA fragments. The DLA maps are based on underlying DNA sequences of microorganisms; therefore, the maps are unique for each fragment. This allows fragments of similar lengths that cannot be resolved by standard DNA sizing techniques to be readily distinguished. DNA preparation, data collection, and analysis can be carried out in as little as 5h when working with monocultures. We demonstrate the ability to discriminate between two pathogenic Escherichia coli strains, O157:H7 Sakai and uropathogenic 536, and we use DLA mapping to identify microorganisms in mixtures. We also introduce a second color probe to double the information used to distinguish molecules and increase the length range of mapped fragments.


Asunto(s)
Bacterias/genética , Dermatoglifia del ADN/métodos , ADN Bacteriano/genética , Genoma Bacteriano , Técnicas de Tipificación Bacteriana/métodos , Escherichia coli/genética , Técnicas Analíticas Microfluídicas/métodos , Reproducibilidad de los Resultados
12.
Europace ; 12(3): 441-2, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19897504

RESUMEN

The introduction of new pacing algorithms for preserving intrinsic atrioventricular conduction has made the interpretation of normal pacemaker function at times challenging. Electrocardiographic (ECG) findings in a patient with apparent pacemaker malfunction is presented and interpretation given. During this process, the managed ventricular pacing algorithm is described to interpret the ECG findings and the potential pitfalls of this algorithm is discussed.


Asunto(s)
Bloqueo Atrioventricular , Estimulación Cardíaca Artificial/efectos adversos , Estimulación Cardíaca Artificial/métodos , Electrocardiografía , Anciano de 80 o más Años , Algoritmos , Bloqueo Atrioventricular/diagnóstico , Bloqueo Atrioventricular/fisiopatología , Bloqueo Atrioventricular/terapia , Humanos , Marcapaso Artificial
13.
Clin Chem ; 55(12): 2121-9, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19815611

RESUMEN

BACKGROUND: Epidemiologic studies require identification or typing of microbial strains. Macrorestriction DNA mapping analyzed by pulsed-field gel electrophoresis (PFGE) is considered the current gold standard of genomic typing. This technique, however, is difficult to implement because it is labor-intensive and difficult to automate, it requires a long time to obtain results, and results often vary between laboratories. METHODS: We used direct linear analysis (DLA), which uses a single reagent set and long fragments of microbial genomic DNA to identify various microbes. In this technique, an automated system extracts fragments exceeding 100 kb from restriction enzyme digests of genomic DNA from microbial isolates and hybridizes them with a sequence-dependent fluorescent tag. These fragments are then stretched in a microfluidics chip, and the patterns of the distribution of the tags are discerned with fluorescence confocal microscopy. The tag pattern on each DNA fragment is compared with a database of known microbial DNA sequences or with measured patterns of other microbial DNAs. RESULTS: We used DLA to type 71 Staphylococcus aureus strains. Of these, 9 had been sequenced, 10 were representative of the major pulsed-field types present in the US, and 52 were isolated recently in a hospital in Cambridge, MA. Matching DNA fragments were identified in different samples by a clustering algorithm and were used to quantify the similarities of the strains. CONCLUSIONS: DLA-based strain typing is a powerful technique with a resolution comparable to macrorestriction mapping with PFGE, but DLA is faster, more automated, and more reproducible.


Asunto(s)
ADN Bacteriano/genética , Colorantes Fluorescentes , Staphylococcus aureus/genética , Técnicas de Tipificación Bacteriana , Genoma Bacteriano , Técnicas Analíticas Microfluídicas , Microscopía Confocal , Análisis de Secuencia por Matrices de Oligonucleótidos , Reproducibilidad de los Resultados , Staphylococcus aureus/clasificación , Staphylococcus aureus/aislamiento & purificación
15.
J Can Chiropr Assoc ; 63(2): 64-79, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31564745

RESUMEN

OBJECTIVE: To evaluate costs and consequences of a new back pain service provided by chiropractors integrated into a Community Health Centre in Cambridge, Ontario. The study sample included 95 consecutive patients presenting between January 2014 to January 2016 with a mixture of sub-acute and chronic back pain. METHODS: A secondary cost-utility analysis was performed and conducted from the perspective of the healthcare institution. Cost-utility was calculated as cost per quality-adjusted life year (QALY) gained over a time horizon of 90 days. RESULTS: According to the EuroQol 5 Domain questionnaire, nearly 70% of patients improved. The mean number of treatment sessions was 8.4, and an average of 0.21 QALYs were gained at an average cost per QALY of $1,042. Seventy-seven percent of patients did not visit their primary care provider over the 90-day period, representing potential cost savings to the institution of between $2,022.23 and $6,135.82. CONCLUSION: Adding chiropractic care to usual medical care was associated with improved outcomes at a reasonable cost in a sample of complex patients with sub-acute and chronic back pain. Future comparative cost-effectiveness studies are needed.


OBJECTIF: Évaluer les coûts et les conséquences d'un nouveau service pour soulager les maux de dos offert par des chiropraticiens intégrés à un centre de santé communautaire à Cambridge, en Ontario. L'échantillon de l'étude comprenait 95 patients qui se sont présentés consécutivement entre janvier 2014 et janvier 2016 et qui étaient atteints de diverses douleurs dorsales subaiguës et chroniques. MÉTHODES: Une analyse coût-utilité secondaire a été effectuée du point de vue de l'établissement de santé. Le coût-utilité a été calculé en tant que coût par année de vie ajustée en fonction de la qualité (AVAQ) obtenu sur une période de 90 jours. RÉSULTATS: Selon les résultats du questionnaire EuroQol 5 Domain, près de 70 % des patients ont observé une amélioration de leurs symptômes. Le nombre moyen de séances de traitement était de 8,4 et une moyenne de 0,21 AVAQ a été obtenue à un coût moyen par AVAQ de 1 042 $. Soixante-dix-sept pour cent des patients n'ont pas consulté leur fournisseur de soins primaires au cours de la période de 90 jours, ce qui représente des économies potentielles de l'ordre de 2 022,23 $ à 6 135,82 $ pour l'établissement. CONCLUSION: L'ajout de soins chiropratiques aux soins médicaux habituels a entraîné une amélioration des résultats à un coût raisonnable pour un échantillon de patients ayant des besoins complexes et présentant des douleurs dorsales subaiguës et chroniques. De futures études comparatives coût-efficacité sont nécessaires.

16.
Heart Rhythm ; 5(3): 387-90, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18243813

RESUMEN

BACKGROUND: Defibrillation threshold (DFT) testing has traditionally been a routine part of implantable cardioverter-defibrillator (ICD) implantation, despite a lack of compelling evidence that it predicts or improves outcomes. In the past, when devices were much less reliable, DFT testing seemed prudent; however, modern ICD systems have such a high rate of successful defibrillation that many electrophysiologists now question whether DFT testing is still worthwhile, particularly since DFT testing may now be the highest acute risk component of ICD implantation. OBJECTIVE: The purpose of this study was to systematically document complications directly attributable to intraoperative DFT testing. METHODS: We obtained data on DFT-related complications from all 21 adult ICD implant centers in Canada, covering the period from January 1, 2000, to September 30, 2006. RESULTS: There were a total of 19,067 ICD implants in Canada during the study period. There were three DFT testing-related deaths, five DFT testing-related strokes, and 27 episodes that required prolonged resuscitation. Two patients had significant clinical sequelae after prolonged resuscitation. CONCLUSIONS: The risk of severe complications from intraoperative DFT testing appears small, even allowing for the underestimation of its true rate with the current study methodology. These slight but measurable risks must be considered when assessing the risk-benefit ratio of the procedure. Additional data from ongoing prospective ICD registries and/or clinical trials are required.


Asunto(s)
Desfibriladores Implantables/normas , Técnicas Electrofisiológicas Cardíacas/efectos adversos , Anciano de 80 o más Años , Canadá/epidemiología , Umbral Diferencial , Diseño de Equipo , Análisis de Falla de Equipo , Seguridad de Equipos , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Conducta de Reducción del Riesgo , Procedimientos Innecesarios
17.
Materials (Basel) ; 11(10)2018 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-30248983

RESUMEN

Europium is the most-studied and least-well-understood rare earth ion (REI) dopant in GaN. While attempting to increase the efficiency of red GaN light-emitting diodes (LEDs) by implanting Eu⁺ into p-type GaN templates, the Strathclyde University group, in collaboration with IST Lisbon and Unipress Warsaw, discovered hysteretic photochromic switching (HPS) in the photoluminescence spectrum of doubly doped GaN(Mg):Eu. Our recent work, summarised in this contribution, has used time-, temperature- and light-induced changes in the Eu intra-4f shell emission spectrum to deduce the microscopic nature of the Mg-Eu defects that form in this material. As well as shedding light on the Mg acceptor in GaN, we propose a possible role for these emission centres in quantum information and computing.

18.
Heart Rhythm ; 15(4): 524-529, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29198903

RESUMEN

BACKGROUND: The Riata lead advisory was announced in 2011 and has posed unique management challenges because of cable externalization and insulation abrasion, in some cases leading to sudden loss of defibrillation. OBJECTIVE: The purpose of this study was to provide further data on the rate of electrical failure in a population of patients with a Riata lead under advisory. METHODS: Using the Canadian Registry of Electronic Device Outcomes, prospective follow-up data were collected on 1352 Riata leads under advisory in 17 implantable cardioverter-defibrillator (ICD) implantation centers in Canada. Data on electrical and structural failure were collected, as well as periprocedural complications related to lead revision (abandonment or extraction). RESULTS: Of the 1352 leads included in this 12-month follow-up cohort, 110 leads were revised. Mean follow-up time was 10.4 ± 1.5 years. The 12-year rate of electrical failure for the 8Fr lead was 9.45%, whereas the 10-year failure rate for the 7Fr lead was 7.25% and was not found to be accelerating. Of the leads revised because of advisory only (patient preference, advisory related, electrical or structural failure), the majority were abandoned (n = 54 [76.0%]), whereas 17 (24.0%) were extracted using power tools. The rate of major complications in each group was 5.6% and 5.9%, respectively. CONCLUSION: This report provides further data on the risk of electrical lead failure over a long lead dwell time. The risk of failure exceeds the risk of periprocedural major complications, indicating that the risk-to-benefit ratio is favorable to revise the lead in appropriate clinical scenarios.


Asunto(s)
Desfibriladores Implantables/estadística & datos numéricos , Predicción , Sistema de Registros , Arritmias Cardíacas/terapia , Canadá , Análisis de Falla de Equipo , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos
19.
Am Heart J ; 154(5): 899-907, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17967596

RESUMEN

BACKGROUND: Sudden cardiac death (SCD) is a devastating complication of hypertrophic cardiomyopathy (HCM). The optimal strategy for the primary prevention of SCD in HCM remains controversial. METHODS: Using a Markov model, we compared the health benefits and cost-effectiveness of 3 strategies for the primary prevention of SCD: implantable cardioverter/defibrillator (ICD) insertion, amiodarone therapy, or no therapy. We modeled hypothetical cohorts of 45-year-old patients with HCM with no history of cardiac arrest but at significant risk of SCD (3%/y). RESULTS: Over a lifetime, compared with no therapy, ICD therapy increased quality-adjusted survival by 4.7 quality-adjusted life years (QALYs) at an additional cost of $142,800 ($30,000 per QALY), whereas amiodarone increased quality-adjusted survival by 2.8 QALYs at an additional cost of $104,900 ($37,300 per QALY). Compared with no therapy, ICD therapy would cost < $50,000 per QALY for patients (i) aged 25, with > or = 1 risk factors for SCD, and (ii) aged 45 or 65, with > or = 2 risk factors for SCD. CONCLUSIONS: An ICD strategy is projected to yield the greatest increase in quality-adjusted life expectancy of the 3 treatment strategies evaluated. Combined consideration of age and the number of risk factors for SCD may allow more precise tailoring of ICD therapy to its expected benefits.


Asunto(s)
Cardiomiopatía Hipertrófica/mortalidad , Muerte Súbita Cardíaca/prevención & control , Desfibriladores Implantables/economía , Cardioversión Eléctrica/instrumentación , Esperanza de Vida/tendencias , Prevención Primaria/economía , Adulto , Anciano , Cardiomiopatía Hipertrófica/economía , Cardiomiopatía Hipertrófica/terapia , Análisis Costo-Beneficio , Muerte Súbita Cardíaca/epidemiología , Cardioversión Eléctrica/economía , Humanos , Cadenas de Markov , Persona de Mediana Edad , Calidad de Vida , Tasa de Supervivencia
20.
J Interv Card Electrophysiol ; 19(1): 55-60, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17605095

RESUMEN

BACKGROUND: Atrial overdrive pacing algorithms may be effective in preventing or suppressing atrial fibrillation (AF). However, the maintenance of a heart rate incessantly faster than spontaneous could induce left ventricular (LV) dysfunction and promote heart failure (HF) on the long term. OBJECTIVE: This post hoc analysis examined the effects of a new overdrive algorithm on the incidence of HF-related adverse events in 411 patients enrolled in the ADOPT-A trial. MATERIALS AND METHODS: The AF Suppression algorithm was randomly programmed ON in 209 patients (treatment group) versus OFF in 202 patients (control group). The incidence of HF-related adverse events and HF-related deaths over a 6-month follow-up was compared between the two groups. Patients with versus without HF-related clinical events were also compared to each other within each group. RESULTS: There were eight HF-related adverse clinical events (3.8%) in the treatment group and 11 (5.4%) in the control group, including four HF-related deaths (1.9 vs. 2.0%) in each group during follow-up. Baseline NYHA functional class in patients with versus without HF-related adverse events was 1.4 +/- 0.5 versus 1.5 +/- 0.7 in the control, and 1.5 +/- 0.8 versus 1.5 +/- 0.6 in the treatment group. LV ejection fraction (EF) was 49 +/- 7% in patients with, versus 57 +/- 12% in patients without HF-related adverse events, in the control group, and 43 +/- 14% in patients with, versus 56 +/- 13% in patients without HF-related adverse events, in the treatment group. LVEF was lowest and similar in both groups among patients who died from HF (35 +/- 10% in the control and 38 +/- 27% in the treatment group). CONCLUSIONS: In ADOPT-A, HF-related clinical events and deaths were related to LV dysfunction and not to atrial pacing overdriven by the AF suppression algorithm.


Asunto(s)
Fibrilación Atrial/terapia , Gasto Cardíaco Bajo/epidemiología , Marcapaso Artificial , Anciano , Algoritmos , Estimulación Cardíaca Artificial , Femenino , Humanos , Incidencia , Masculino , Prevalencia , Método Simple Ciego , Resultado del Tratamiento
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