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1.
Int J Clin Pract ; 75(5): e14005, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33400345

RESUMEN

OBJECTIVE: Delayed revascularisation in patients with ST-segment elevation myocardial infarction (STEMI) is associated with poor prognosis. The aim of this study is to investigate how the timeline in STEMI treatment was affected during the Covid-19 outbreak. METHOD: Consecutive 165 STEMI patients were enrolled in the study during the Covid-19 pandemic period (Pandemic period) and the prepandemic period (Control period). The time period until patients' leaving their current position after the onset of pain (home delay), the time from the onset of pain to the first medical contact (FMC delay), door-to-balloon time, procedure time and hospitalisation time were recorded. RESULTS: A total of 165 patients, 82 in the Pandemic period and 83 in the Control period, were included in the study. When compared with the control period, home delay [30 (5-6912) minutes vs 165 (10-360) minutes, P < .001] and FMC delay [61 (20-6932) minutes vs 190 (15-3660) minutes, P < .001] were significantly prolonged during the pandemic period. In addition, non-IRA PCI rate (8.8% vs 19.3% P = .043) and hospitalisation time [71 (15-170) vs 74.2 (37-329) hours, P = .045] were decreased. CONCLUSION: During the Covid-19 pandemic period, prolonged prehospital time parameters were observed in STEMI patients. Therefore, additional measures may be required to prevent unfavourable delays in STEMI patients during the outbreak.


Asunto(s)
COVID-19 , Intervención Coronaria Percutánea , Infarto del Miocardio con Elevación del ST , Humanos , Pandemias , SARS-CoV-2 , Infarto del Miocardio con Elevación del ST/epidemiología , Infarto del Miocardio con Elevación del ST/terapia
3.
Med Sci Monit ; 21: 2116-24, 2015 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-26198682

RESUMEN

BACKGROUND: Although myocardial bridging (MB) is defined as an angiographic phenomenon with a benign course, it has also been associated with adverse cardiovascular events. The effects of exercise on myocardial repolarization in patients with MB were tested in this study, with Tp-e and Tp-e/QT repolarization indexes. MATERIAL AND METHODS: A total of 50 patients in whom isolated MB was diagnosed at coronary angiography (CAG) (Group I) and 48 patients with normal CAG results (Group II) were included in this study. The participants underwent treadmill exercise stress testing according to the Bruce protocol. QT dispersion (QTd) was defined as the minimum QT interval subtracted from the maximum. The Tp-e interval was defined as the difference between the QT and the QT peak time period. QTd and Tp-e intervals were calculated for all patients before and after exercise testing and differences between groups were compared. RESULTS: At peak exercise, QTd and cQTd showed a significant increase in comparison to baseline values in the group of patients with myocardial bridges. Significant increases were also found with exercise in the Tp-e, cTp-e durations and Tp-e/QT ratio of the MB patient group in comparison to the baseline values. On the other hand, significant differences in QTd, cQTd, Tp-e, cTp-e intervals, and Tp-e/QT ratio during peak exercise in comparison with baseline values were not detected in the control group (p>0.05). CONCLUSIONS: Significant increases in QTd, cQTd, Tp-e and cTp-e intervals and Tp-e/QT ratio were detected in the MB patients during exercise testing.


Asunto(s)
Ejercicio Físico/fisiología , Puente Miocárdico/patología , Puente Miocárdico/fisiopatología , Anciano , Estudios de Casos y Controles , Angiografía Coronaria , Electrocardiografía , Prueba de Esfuerzo/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Miocardio/patología , Estudios Prospectivos
4.
Proc Natl Acad Sci U S A ; 108(29): 11784-9, 2011 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-21715661

RESUMEN

We introduce an ultrasensitive label-free detection technique based on asymmetric Fano resonances in plasmonic nanoholes with far reaching implications for point-of-care diagnostics. By exploiting extraordinary light transmission phenomena through high-quality factor (Q(solution) ∼ 200) subradiant dark modes, we experimentally demonstrate record high figures of merits (FOMs as high as 162) for intrinsic detection limits surpassing that of the gold standard prism coupled surface-plasmon sensors (Kretschmann configuration). Our experimental record high sensitivities are attributed to the nearly complete suppression of the radiative losses that are made possible by the high structural quality of the fabricated devices as well as the subradiant nature of the resonances. Steep dispersion of the plasmonic Fano resonance profiles in high-quality plasmonic sensors exhibit dramatic light intensity changes to the slightest perturbations within their local environment. As a spectacular demonstration of the extraordinary sensitivity and the quality of the fabricated biosensors, we show direct detection of a single monolayer of biomolecules with naked eye using these Fano resonances and the associated Wood's anomalies. To fabricate high optical-quality sensors, we introduce a high-throughput lift-off free evaporation fabrication technique with extremely uniform and precisely controlled nanofeatures over large areas, leading to resonance line-widths comparable to that of the ideally uniform structures as confirmed by our time-domain simulations. The demonstrated label-free sensing platform offers unique opportunities for point-of-care diagnostics in resource poor settings by eliminating the need for fluorescent labeling and optical detection instrumentation (camera, spectrometer, etc.) as well as mechanical and light isolation.


Asunto(s)
Técnicas Biosensibles/métodos , Nanoestructuras/ultraestructura , Conformación Proteica , Proteínas/ultraestructura , Resonancia por Plasmón de Superficie/métodos , Nanoestructuras/química , Proteínas/química , Análisis Espectral
5.
Nanoscale ; 2024 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-39171500

RESUMEN

In nanophotonics, nanohole arrays (NHAs) are periodic arrangements of nanoscale apertures in thin films that provide diverse optical functionalities essential for various applications. Fully studying NHAs' optical properties and optimizing performance demands understanding both materials and geometric parameters, which presents a computational challenge due to numerous potential combinations. Efficient computational modeling is critical for overcoming this challenge and optimizing NHA-based device performance. Traditional approaches rely on time-consuming numerical simulation processes for device design and optimization. However, using a deep learning approach offers an efficient solution for NHAs design. In this work, a deep neural network within the forward modeling framework accurately predicts the optical properties of NHAs by using device structure data such as periodicity and hole radius as model inputs. We also compare three deep learning-based inverse modeling approaches-fully connected neural network, convolutional neural network, and tandem neural network-to provide approximate solutions for NHA structures based on their optical responses. Once trained, the DNN accurately predicts the desired result in milliseconds, enabling repeated use without wasting computational resources. The models are trained using over 6000 samples from a dataset obtained by finite-difference time-domain (FDTD) simulations. The forward model accurately predicts transmission spectra, while the inverse model reliably infers material attributes, lattice geometries, and structural parameters from the spectra. The forward model accurately predicts transmission spectra, with an average Mean Squared Error (MSE) of 2.44 × 10-4. In most cases, the inverse design demonstrates high accuracy with deviations of less than 1.5 nm for critical geometrical parameters. For experimental verification, gold nanohole arrays are fabricated using deep UV lithography. Validation against experimental data demonstrates the models' robustness and precision. These findings show that the trained DNN models offer accurate predictions about the optical behavior of NHAs.

6.
Anatol J Cardiol ; 28(1): 19-28, 2024 01 02.
Artículo en Inglés | MEDLINE | ID: mdl-37888785

RESUMEN

BACKGROUND: Atrial fibrillation (AF) is strongly associated with an increased risk of ischemic events. Anticoagulation focuses on reducing the risk of embolism. Guideline recommended CHA2DS2-VASc scoring system is most widely used; however, different scoring systems do exist. Thus, we sought to assess the impact of anticoagulant treatment and different scoring systems on the development of stroke, myocardial infarction, and all-cause mortality in patients with nonvalvular AF. METHODS: The present study was designed as a prospective cohort study. The enrollment of the patients was conducted between August 1, 2015, and January 1, 2016. The follow-up period was defined as the time from enrollment to the end of April 1, 2017, which also provided at least 12 months of prospective follow-up for each patient. RESULTS: A total of 1807 patients with AF were enrolled. During the follow-up, 2.7% (48) of patients had stroke, 0.8% (14) had myocardial infarction, and 7.5% (136) died. The anticoagulation and risk factors in AF (ATRIA) score had a better accuracy for the prediction of stroke compared to other scoring systems (0.729, 95% CI, 0.708-0.750, P <.05). Patients under low-dose rivaroxaban treatment had significantly worse survival (logrank P <.001). Age, CHA2DS2-VASc score, R2CHADS2 score, ATRIA score, chronic heart failure, prior stroke, and being under low-dose rivaroxaban treatment were independent predictors of clinical endpoint (P <.001). CONCLUSION: Low-dose rivaroxaban treatment was independently and strongly associated with the combined clinical endpoint. Furthermore, the ATRIA score proved to be a stronger predictor of stroke in the Turkish population.


Asunto(s)
Fibrilación Atrial , Infarto del Miocardio , Accidente Cerebrovascular , Humanos , Fibrilación Atrial/complicaciones , Fibrilación Atrial/tratamiento farmacológico , Fibrilación Atrial/epidemiología , Estudios Prospectivos , Rivaroxabán/uso terapéutico , Incidencia , Turquía/epidemiología , Accidente Cerebrovascular/epidemiología , Accidente Cerebrovascular/prevención & control , Accidente Cerebrovascular/complicaciones , Anticoagulantes/uso terapéutico , Infarto del Miocardio/epidemiología , Infarto del Miocardio/complicaciones
7.
Small ; 9(24): 4207-14, 2013 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-23766297

RESUMEN

The microfluidic isolation of target cells using adhesion-based surface capture has been widely explored for biology and medicine. However, high-throughput processing can be challenging due to interfacial limitations such as transport, reaction, and non-specific fouling. Here, it is shown that antibody-functionalized capture surfaces with discontinuous permeability enable efficient target cell capture at high flow rates by decreasing fouling. Experimental characterization and theoretical modeling reveal that "wall effects" affect cell-surface interactions and promote excess surface accumulation. These issues are partially circumvented by reducing the transport and deposition of cells near the channel walls. Optimized microfluidic devices can be operated at higher cell concentrations with significant improvements in throughput.


Asunto(s)
Inmunoensayo/métodos , Microfluídica/instrumentación , Nanoporos , Adsorción , Línea Celular Tumoral , Diseño de Equipo , Humanos , Leucocitos/citología , Masculino , Técnicas Analíticas Microfluídicas , Nanotecnología , Tamaño de la Partícula , Permeabilidad , Silicio/química , Propiedades de Superficie
8.
Cureus ; 15(3): e36253, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37069863

RESUMEN

Hereditary hyperferritinemia-cataract syndrome (HHCS) is a rare genetic condition characterized by persistent hyperferritinemia (usually ferritin >1,000 ng/mL) without tissue iron overload, with or without early-onset slow-progressing bilateral nuclear cataract. It was first identified as a new genetic disorder in 1995, and since then genetic sequencing studies have been carried out to identify associated mutations in affected families. New mutations around the world are still being reported in the iron-responsive element (IRE) of the L-ferritin gene (FTL) to this day. Many clinicians remain unaware of this rare condition. The co-occurrence of FTL mutations and hereditary hemochromatosis (HH) mutations, especially H63D, on the HFE gene has been reported in the literature, which often leads to a diagnosis of HH, missed diagnosis of HHCS, incorrect treatment with phlebotomies and the occurrence of associated iatrogenic iron deficiency anemia. We herein report the case of a 40-year-old woman with spontaneous facial freckling, bilateral cataracts, homozygosity for HFE H63D mutation, iron deficiency anemia, and hyperferritinemia, who has been treated with phlebotomy and iron chelation therapy to no avail. Eleven years after being diagnosed and treated for HH, a reevaluation of her clinical presentation, laboratory results, medical imaging, and family history led to the recognition that her case is explained not by HH, but by an alternative diagnosis, HHCS. Our main objective in this report is to increase clinical awareness about HHCS, an often-unknown differential diagnosis of hyperferritinemia without iron overload, and to prevent adverse medical interventions in HHCS patients.

9.
Nat Mater ; 11(1): 69-75, 2011 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-22081082

RESUMEN

Engineered optical metamaterials present a unique platform for biosensing applications owing to their ability to confine light to nanoscale regions and to their spectral selectivity. Infrared plasmonic metamaterials are especially attractive because their resonant response can be accurately tuned to that of the vibrational modes of the target biomolecules. Here we introduce an infrared plasmonic surface based on a Fano-resonant asymmetric metamaterial exhibiting sharp resonances caused by the interference between subradiant and superradiant plasmonic resonances. Owing to the metamaterial's asymmetry, the frequency of the subradiant resonance can be precisely determined and matched to the molecule's vibrational fingerprints. A multipixel array of Fano-resonant asymmetric metamaterials is used as a platform for multispectral biosensing of nanometre-scale monolayers of recognition proteins and their surface orientation, as well as for detecting chemical binding of target antibodies to recognition proteins.


Asunto(s)
Técnicas Biosensibles , Nanoestructuras/química , Mapeo Peptídico/métodos , Fenómenos Electromagnéticos , Nanotecnología/métodos , Proteínas/química , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie
10.
Proc Natl Acad Sci U S A ; 106(46): 19227-32, 2009 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-19880744

RESUMEN

Infrared absorption spectroscopy enabling direct access to vibrational fingerprints of the molecular structure is a powerful method for functional studies of bio-molecules. Although the intrinsic absorption cross-sections of IR active modes of proteins are nearly 10 orders of magnitude larger than the corresponding Raman cross-sections, they are still small compared to that of fluorescence-label based methods. Here, we developed a new tool based on collective excitation of plasmonic nanoantenna arrays and demonstrated direct detection of vibrational signatures of single protein monolayers. We first tailored the geometry of individual nanoantennas to form resonant structures that match the molecular vibrational modes. The tailored nanoantennas are then arranged in such a way that their in-phase dipolar coupling leads to a collective excitation of the ensemble with strongly enhanced near fields. The combined collective and individual plasmonic responses of the antenna array play a critical role in attaining signal enhancement factors of 10(4)-10(5). We achieved measurement of the vibrational spectra of proteins at zeptomole levels for the entire array, corresponding to only 145 molecules per antenna. The near-field nature of the plasmonic enhancement of the absorption signals is demonstrated with progressive loading of the nanoantennas with varying protein film thicknesses. Finally, an advanced model based on nonequilibrium Green's function formalism is introduced, which explains the observed Fano-type absorption line-shapes and tuning of the absorption strengths with the antenna resonance.


Asunto(s)
Fibroínas/química , Nanoestructuras/química , Espectrofotometría Infrarroja/métodos , Espectrometría Raman/métodos , Resonancia por Plasmón de Superficie/métodos , Sensibilidad y Especificidad , Vibración
11.
Nano Lett ; 11(4): 1685-9, 2011 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-21438605

RESUMEN

We introduce an approach enabling construction of a scalable metamaterial media supporting multispectral plasmon induced transparency. The composite multilayered media consist of coupled meta-atoms with radiant and subradiant hybridized plasmonic modes interacting through the structural asymmetry. A perturbative model incorporating hybridization and mode coupling is introduced to explain the observed novel spectral features. The proposed scheme is demonstrated experimentally by developing a lift-off-free fabrication scheme that can automatically register multiple metamaterial layers in the transverse plane. This metamaterial which can simultaneously enhance nonlinear processes at multiple frequency domains could open up new possibilities in optical information processing.


Asunto(s)
Modelos Químicos , Nanoestructuras/química , Nanoestructuras/ultraestructura , Resonancia por Plasmón de Superficie/métodos , Simulación por Computador , Luz , Dispersión de Radiación
12.
Nano Lett ; 11(9): 3694-700, 2011 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-21806006

RESUMEN

We experimentally demonstrate for the first time a very compact plasmonic hetero-oligomer structure where the multiple radiant and subradiant modes can be tailored independently. Unlike previous approaches based on collective excitations in complex plasmonic systems, we show precise engineering of resonances leading to simultaneous spectral overlap of multiple plasmonic modes with opposite radiative character. This asymmetric behavior combined with inherent spatial features of the structure leads to directional double Fano resonances as shown with numerical analysis. A model based on temporal coupled mode theory is also provided to describe the double Fano behavior.


Asunto(s)
Técnicas Biosensibles/métodos , Simulación por Computador , Dimerización , Electrones , Espectrometría de Masas/métodos , Microscopía Electrónica de Rastreo/métodos , Modelos Estadísticos , Nanotecnología/métodos , Óptica y Fotónica , Espectroscopía Infrarroja por Transformada de Fourier/métodos
13.
Nano Lett ; 11(12): 5219-26, 2011 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-22122330

RESUMEN

Analogues of many radio frequency (RF) antenna designs such as the half-wave dipole and Yagi-Uda have been successfully adapted to the optical frequency regime, opening the door for important advances in biosensing, photodetection, and emitter control. Examples of monopole antennas, however, are conspicuously rare given the element's extensive use in RF applications. Monopole antennas are attractive as they represent an easy to engineer, compact geometry and are well isolated from interference due the ground plane. Typically, however, the need to orient the antenna element perpendicular to a semi-infinite ground plane requires a three-dimensional structure and is incompatible with chip-based fabrication techniques. We propose and demonstrate here for the first time that monopole antenna elements can be fashioned out of single element nanoparticles fabricated in conventional planar geometries by using a small nanorod as a wire reflector. The structure offers a compact geometry and the reflector element provides a measure of isolation analogous to the RF counterpart. This isolation persists in the conductive coupling regime, allowing multiple monopoles to be combined into a single nanoparticle, yet still operate independently. This contrasts with several previous studies that observed dramatic variations in the spectral response of conductively coupled particles. We are able to account for these effects by modeling the system using circuit equations from standard RF antenna theory. Our model accurately describes this behavior as well as the detailed resonance tuning of the structure. As a specific practical application, the monopole resonances are precisely tuned to desired protein absorption bands, thereby enhancing their spectroscopic signatures. Furthermore, the accurate modeling of conductive coupling and demonstrated electronic isolation should be of general interest to the design of complex plasmonic circuits incorporating multiple antennas and other current carrying elements.

14.
North Clin Istanb ; 9(3): 286-289, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36199854

RESUMEN

A 58-year-old female patient presented at cardiology outpatient clinic with palpitation. The 12-lead electrocardiography on admission revealed monomorphic bigeminy premature ventricular contractions (PVCs) showed a left bundle-branch block configuration, monophasic R wave in lead I and aVL and precordial transition in V3 lead. Cardiac electrophysiological study was performed to patient. Activation mapping guided by three-dimensional electroanatomic system was done. The earliest ventricular activation was observed in the para-hisian region with the largest His potential (0.6 mV) during PVC. Due to the risk of atrioventricular (AV) block, radiofrequency (RF) ablation was planned to the region, where the His potential amplitude was lower (0.2 mV), the AV ratio was <1, and ventricular activation preceded the QRS onset by 37 ms. Subsequently, irrigated RF current was delivered in the distal His region with power starting at 15 W after PVC was suppressed, RF delivery was applied for a total of 90 s with gradually increasing power to 25 W. After ablation, under isoproterenol infusion, burst pacing from the right ventricle no PVCs/VTs was observed. A gradual RF energy application, a detailed activation mapping, and the distance from the largest His potential increase the likelihood of success in para-hisian PVC ablation.

15.
J Arrhythm ; 38(3): 353-362, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35785368

RESUMEN

Aims: Galectin-3 is an inflammation biomarker that is associated with atrial fibrosis and plays a role in the development of atrial fibrillation (AF). Low voltage areas (LVAs) identified using an electroanatomical mapping system represent the presence of fibrotic tissue. The present study aimed to determine the relationship between coronary sinus (CS) serum sampling of galectin-3 levels and the presence and extent of LVA in patients with paroxysmal AF. Methods: A total of 115 consecutive paroxysmal AF patients underwent pulmonary vein isolation (PVI) included prospectively in the study. Voltage mapping was performed before PVI during sinus rhythm guided by multipolar high-density mapping catheter and LVAs were defined as regions where bipolar peak to peak voltage was <0.5 mV. Galectin-3 levels were measured via enzyme-linked immunosorbent assay. Results: CS serum sampling of galectin-3 levels was significantly higher in paroxysmal AF patients with LVA than those without LVA (16.5 ± 3.7 ng/ml vs. 10.2 ±2.7 ng/ml, respectively, p < .001). CS serum sampling of galectin-3 levels was significantly higher in paroxysmal AF patients with moderate and severe LVA than in paroxysmal AF patients with mild LVA (17 ± 3.5 ng/ml and 20.1 ± 1.3 ng/ml vs. 13.3 ± 2.3 ng/ml, respectively, p = .002). In the multivariate analysis female gender (odds ratio [OR] = 7.537, 95% confidence interval [CI]: 1.011-56.195; p = .049), left atrium volume (OR = 1.326, 95% CI: 1.052-1.67; p = .017), and CS serum sampling of galectin-3 levels (OR = 1.704, 95% CI: 1.169-2.483; p = .006) were significant and independent predictors for LVAs. Conclusion: In this study, we found that the CS serum sampling of galectin-3 levels increased with the extent of LVA and was an independent predictor for the presence of LVA.

16.
Opt Express ; 19(23): 22607-18, 2011 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-22109141

RESUMEN

We experimentally and numerically demonstrate a planar metamaterial consisting of two asymmetrically positioned π-structures in a single unit that exhibits plasmonic analogue of electromagnetically induced transparency (EIT). Through the coupling of the constituent nanorod elements, the proposed structure enables fine spectral tuning of the EIT-like behavior and controlling the location of near field enhancement. Originated from the asymmetric cascaded π-structures, we introduce a more compact system which possesses the EIT-like characteristics and as well as much smaller mode volumes. Due to these properties, the proposed metamaterials can be utilized for a wide range of applications including bio-chemical sensors, optical filters and modulators and enhancement of non-linear processes.

17.
Opt Express ; 19(12): 11202-12, 2011 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-21716349

RESUMEN

Our recent work has showed that diffractively coupled nanoplasmonic arrays for Fourier transform infrared (FTIR) microspectroscopy can enhance the Amide I protein vibrational stretch by up to 10(5) times as compared to plain substrates. In this work we consider computationally the impact of a microscope objective illumination cone on array performance. We derive an approach for computing angular- and spatially-averaged reflectance for various numerical aperture (NA) objectives. We then use this approach to show that arrays that are perfectly optimized for normal incidence undergo significant response degradation even at modest NAs, whereas arrays that are slightly detuned from the perfect grating condition at normal incidence irradiation exhibit only a slight drop in performance when analyzed with a microscope objective. Our simulation results are in good agreement with microscope measurements of experimentally optimized periodic nanoplasmonic arrays.

18.
Nano Lett ; 10(7): 2511-8, 2010 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-20560536

RESUMEN

The introduction of high-throughput and high-resolution nanofabrication techniques operating at low cost and low complexity is essential for the advancement of nanoplasmonic and nanophotonic fields. In this paper, we demonstrate a novel fabrication approach based on nanostencil lithography for high-throughput fabrication of engineered infrared plasmonic nanorod antenna arrays. The technique relying on deposition of materials through a shadow mask enables plasmonic substrates supporting spectrally sharp collective resonances. We show that reflectance spectra of these antenna arrays are comparable to that of arrays fabricated by electron beam lithography. We also show that nanostencils can be reused multiple times to fabricate a series of infrared nanoantenna arrays with identical optical responses. Finally, we demonstrate fabrication of plasmonic nanostructures in a variety of shapes with a single metal deposition step on different substrates, including nonconducting ones. Our approach, by enabling the reusability of the stencil and offering flexibility on the substrate choice and nanopattern design, could facilitate the transition of plasmonic technologies to the real-world applications.

19.
Nano Lett ; 10(12): 4962-9, 2010 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-21053965

RESUMEN

Fast and sensitive virus detection techniques, which can be rapidly deployed at multiple sites, are essential to prevent and control future epidemics and bioterrorism threats. In this Letter, we demonstrate a label-free optofluidic nanoplasmonic sensor that can directly detect intact viruses from biological media at clinically relevant concentrations with little to no sample preparation. Our sensing platform is based on an extraordinary light transmission effect in plasmonic nanoholes and utilizes group-specific antibodies for highly divergent strains of rapidly evolving viruses. So far, the questions remain for the possible limitations of this technique for virus detection, as the penetration depths of the surface plasmon polaritons are comparable to the dimensions of the pathogens. Here, we demonstrate detection and recognition of small enveloped RNA viruses (vesicular stomatitis virus and pseudotyped Ebola) as well as large enveloped DNA viruses (vaccinia virus) within a dynamic range spanning 3 orders of magnitude. Our platform, by enabling high signal to noise measurements without any mechanical or optical isolation, opens up opportunities for detection of a broad range of pathogens in typical biology laboratory settings.


Asunto(s)
Técnicas Biosensibles , Líquidos Corporales/virología , Microfluídica/instrumentación , Nanoestructuras , Virus/aislamiento & purificación , Animales , Células Cultivadas , Cricetinae
20.
Cardiovasc J Afr ; 32(6): 292-296, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34128947

RESUMEN

BACKGROUND: The first clinical manifestation of the Wolff-Parkinson-White syndrome in previously asymptomatic individuals may be sudden cardiac death. The options for non-invasive risk stratification are limited in the current era beyond ambulatory rhythm monitoring and an exercise stress test. In our study, we sought to investigate whether there was a relationship between the shortest measured P- to delta-wave time interval (PDI) on the conduction properties of surface electrocardiogram and accessory pathways expressed as antegrade effective refractory period (APERP). METHODS: Demographic data, symptom status, electrocardiograms (ECG) and intra-cardiac recordings of invasive electrophysiology testing of 103 patients who underwent accessory pathway ablation procedures were collected. Exclusion criteria were: (1) intermittently occurring pre-excitation, which was detected in previous ECGs, (2) delta-wave resolution on treadmill test, (3) presence of multiple accessory pathways, and (4) accessory pathway locations other than the septum. The PDI was measured as the time interval from the beginning of the P wave to the earliest upstroke or downstroke of the delta wave on V1 and V2 derivations of the surface ECG, and the shortest measurement was recorded. RESULTS: Patients were grouped into two groups: group I, if APERP was < 240 ms and group II if APERP was ≥ 240 ms. PDI was significantly shorter in group II. By correlation analysis, a positive and moderate correlation between PDI and APERP (r = 0.598, p < 0.001) and PDI and age (r = 0.800, p < 0.001) was found, and a negative and moderate correlation between PDI and inducible AF (r = -492, p < 0.001). The best cut-off value for PDI to predict APERP ≥ 240 was 90.5 ms with a sensitivity of 80% and a specificity of 83%. CONCLUSIONS: Our results demonstrate that there was a strong correlation between the P- to delta-wave interval and universally accepted risk factors, such as low age, low APERP and atrial fibrillation inducibility. Further studies with larger patient groups and follow-up data are needed to appraise its predictive value.


Asunto(s)
Fibrilación Atrial , Síndrome de Wolff-Parkinson-White , Muerte Súbita Cardíaca/etiología , Electrocardiografía , Frecuencia Cardíaca , Humanos , Síndrome de Wolff-Parkinson-White/diagnóstico , Síndrome de Wolff-Parkinson-White/cirugía
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