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BACKGROUND: Same day discharge (SDD) following atrial fibrillation (AF) ablation procedure has emerged as routine practice, and primarily driven by operator discretion. However, the impacts of SDD on clinical outcomes, healthcare system costs, and patient reported outcomes (PROs) have not been systematically studied. METHODS: We retrospectively analyzed patients undergoing routine AF ablation procedures with SDD versus overnight observation (NSDD). After propensity adjustment we compared postprocedure adverse events (AEs), healthcare system costs, and changes in PROs. RESULTS: We identified 310 cases, with 159 undergoing SDD and 151 staying at least one midnight in the hospital (NSDD). Compared with NSDD, SDD patients were similar age (mean 64 vs. 66, p = 0.3), sex (26% female vs. 27%, p = 0.8), and with lower mean CHADS2-VA2Sc scores (2.0 vs. 2.7; p < 0.011). The primary outcome of AEs was noninferior in SDD versus NSDD patients (odds ratio 0.45, 95% confidence interval 0.21-0.99; noninferiority margin of 10%). There were also no differences in overall cost to the healthcare system between SDD and NSDD (p = 0.11). PROs numerically favored SDD (p = NS for all scores). CONCLUSIONS: Physician selection for SDD appears at least as safe as NSDD with respect to clinical outcomes and SDD is not significantly less costly to the health system. There is a trend towards more favorable, general PROs among SDD patients. Routine SDD should be strongly considered for patients undergoing routine AF ablation procedures.
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Fibrilação Atrial , Ablação por Cateter , Alta do Paciente , Medidas de Resultados Relatados pelo Paciente , Humanos , Fibrilação Atrial/cirurgia , Fibrilação Atrial/economia , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/fisiopatologia , Feminino , Masculino , Estudos Retrospectivos , Ablação por Cateter/economia , Ablação por Cateter/efeitos adversos , Pessoa de Meia-Idade , Idoso , Resultado do Tratamento , Fatores de Tempo , Alta do Paciente/economia , Custos Hospitalares , Fatores de Risco , Análise Custo-Benefício , Tempo de Internação/economia , Procedimentos Cirúrgicos Ambulatórios/economia , Procedimentos Cirúrgicos Ambulatórios/efeitos adversosRESUMO
INTRODUCTION: Spin - the beautification of study results to emphasise benefits or minimise harms - is a deceptive reporting strategy with the potential to affect clinical decision-making adversely. Few studies have investigated the extent of spin in systematic reviews. Here, we sought to address this gap by evaluating the presence of the nine most severe forms of spin in the abstracts of systematic reviews on treatments for postoperative nausea and vomiting (PONV). PONV has the potential to increase hospital costs and patient burden, adversely affecting outcomes. METHODS: We developed search strategies for MEDLINE and Embase to identify systematic reviews focused on PONV. Following title and abstract screening of the reviews identified during the initial search, those that met inclusion criteria were evaluated for the presence of spin and received a revised AMSTAR-2 (A Measurement Tool to Assess Systematic Reviews) appraisal by two investigators in a masked, duplicate manner. Study characteristics for each review were also extracted in duplicate. RESULTS: Our systematic search returned 3513 studies, of which 130 systematic reviews and meta-analyses were eligible for data extraction. We found that 29.2% of included systematic reviews contained spin (38/130). Eight of the nine types of spin were identified, with spin type 3 ('selective reporting of or overemphasis on efficacy outcomes or analysis favouring the beneficial effect of the experimental intervention') being the most common. Associations were found between spin and funding source. Spin was more likely in the abstracts of privately funded than nonfunded studies, odds ratio (OR) 2.81 [95% confidence interval (CI), 0.66 to 11.98]. In the abstracts of studies not mentioning funding spin was also more likely than in nonfunded studies, OR 2.30 (95% CI, 0.61 to 8.70). Neither of these results were statistically significant. Significance was found in the association between the presence of spin and AMSTAR-2 ratings: 'low' quality studies were less likely to contain spin than 'high' quality, OR 0.24 (95% CI, 0.07 to 0.88): 'critically low' studies were also less likely to contain spin than 'high' quality studies, OR 0.21 (95% CI, 0.07 to 0.65). There were no other associations between spin and the remaining extracted study characteristics or AMSTAR-2 ratings. CONCLUSION: Spin was present in greater than 29% of abstracts of systematic reviews and meta-analyses regarding PONV. Various stakeholders must take steps to improve the reporting quality of abstracts on PONV.
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High coincidence-to-accidental ratio (CAR) is crucial for photon-pair sources (PPSs) integrated with pump reject filters (PRFs) in silicon, but CAR values currently reported for integrated PPS/PRF chips still fall short of those achieved using stand-alone sources with external PRFs. Here we report measured and modelled CAR values for a micro-ring resonator PPS integrated with a PRF consisting of a three-stage, cascaded (via their through ports), contra-directional coupler (CDC) that compare favorably even with some stand-alone sources. CDC-based PRFs provide the benefits of compact area and wide reject bands without a need for tuning, in comparison to prior-art implementations.
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Plants utilize multiple isoforms of villin, an F-actin regulating protein with an N-terminal gelsolin-like core and a distinct C-terminal headpiece domain. Unlike their vertebrate homologues, plant villins have a much longer linker polypeptide connecting the core and headpiece. Moreover, the linker-headpiece connection region in plant villins lacks sequence homology to the vertebrate villin sequences. It is unknown to what extent the plant villin headpiece structure and function resemble those of the well-studied vertebrate counterparts. Here we present the first solution NMR structure and backbone dynamics characterization of a headpiece from plants, villin isoform 4 from Arabidopsis thaliana. The villin 4 headpiece is a 63-residue domain (V4HP63) that adopts a typical headpiece fold with an aromatics core and a tryptophan-centered hydrophobic cap within its C-terminal subdomain. However, V4HP63 has a distinct N-terminal subdomain fold as well as a novel, high mobility loop due to the insertion of serine residue in the canonical sequence that follows the variable length loop in headpiece sequences. The domain binds actin filaments with micromolar affinity, like the vertebrate analogues. However, the V4HP63 surface charge pattern is novel and lacks certain features previously thought necessary for high-affinity F-actin binding. Utilizing the updated criteria for strong F-actin binding, we predict that the headpiece domains of all other villin isoforms in A. thaliana have high affinity for F-actin.
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Actinas/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/química , Proteínas dos Microfilamentos/metabolismo , Isoformas de Proteínas/metabolismo , Sequência de Aminoácidos , Proteínas de Arabidopsis/química , Biopolímeros/química , Biopolímeros/metabolismo , Cromatografia em Gel , Proteínas dos Microfilamentos/química , Simulação de Dinâmica Molecular , Ressonância Magnética Nuclear Biomolecular , Ligação Proteica , Isoformas de Proteínas/química , Propriedades de SuperfícieRESUMO
Manipulating the composition of a mixed alkylthiol self-assembled monolayer (SAM) modified gold surface using both electrochemical and electroless methods is demonstrated. Through the use of fluorophore labeled thiolated DNA and in situ fluorescence microscopy with a gold single crystal bead electrode, a procedure was developed to study and quantify the selective desorption of an alkylthiolate SAM. This method enabled a self-consistent measurement of the removal of the SAM from the 111 surface compared to the 100 surface region at various potentials. A 20-fold increase in the electrochemical removal and replacement of the SAM from the 111 surface over the 100 surface was realized at -0.8 V/AgAgCl. A related procedure was developed for the solution-based electroless removal of the SAM using NaBH4 achieving a similar selectivity at the same potential. Unfortunately, in the electroless process fine control over the reducing potential was difficult to achieve. In addition, working in the presence of O2 complicates the solution potential measurement due to depolarization by the reduction of O2, resulting in a less clear relationship between selectivity and measured solution potential. Interestingly, the electrochemical method was not disturbed by the presence of O2. In preparation for work with Au nanorods, electrochemical measurements were performed in electrolyte that included 1 mM CTAB and was found to not interfere with this method. Preliminary results are promising for using this methodology for treatment of acid-terminated alkylthiol modified Au nanorods.
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Silicon microcavity-based optical trapping of Au nanoparticles with diameters as small as ≈24 nm is achieved using optical powers <1 mW. By comparing measured and modeled histograms of transmission time series data obtained when a particle is trapped in the cavity, it is shown that the influence of backaction on the transmitted light dynamics alone can be used to determine the size of trapped particles with nanometer precision.
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Guided mode resonance (GMR) enhanced second- and third-harmonic generation (SHG and THG) is demonstrated in an azo-polymer resonant waveguide grating (RWG), comprised of a poled azo-polymer layer on top of a textured SU8 substrate with a thin intervening layer of TiO2. Strong SHG and THG outputs are observed by matching either in-coming fundamental- or out-going harmonic-wavelength to the GMR wavelengths of the azo-polymer RWG. Without the azo-polymer coating, pure TiO2 RWGs, do not generate any detectable SHG using a fundamental beam peak intensity of 2 MW/cm(2). Without the textured TiO2 layer, a planar poled azo-polymer layer results in 3650 times less SHG than the full nonlinear RWG structure under identical excitation conditions. Rigorous coupled-wave analysis calculations confirm that this enhancement of the nonlinear conversion is due to strong local electric fields that are generated at the interfaces of the TiO2 and azo-polymer layers when the RWG is excited at resonant wavelengths associated with both SHG and THG conversion processes.
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Relaxation dynamics is universal in science and engineering; its study serves to parameterize a system's response and to help identify a microscopic model of the processes involved. When measured data for a phenomenon cannot be fitted using one exponential, the choice of an alternative function to describe the decay becomes nontrivial. Here, we contrast two different, but fundamentally related approaches to fitting nontrivial decay curves; exponential decomposition and the gamma probability density function.
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Substâncias Luminescentes/química , Cinética , Modelos TeóricosRESUMO
Neuroblastoma is the most common type of extracranial solid tumor in children and can often result in death if not treated. High-intensity focused ultrasound (HIFU) is a non-invasive technique for treating tissue that is deep within the body. It avoids the use of ionizing radiation, avoiding long-term side-effects of these treatments. The goal of this project was to develop the rendering component of an augmented reality (AR) system with potential applications for image-guided HIFU treatment of neuroblastoma. Our project focuses on taking 3D models of neuroblastoma lesions obtained from PET/CT and displaying them in our AR system in near real-time for use by physicians. We used volume ray casting with raster graphics as our preferred rendering method, as it allows for the real-time editing of our 3D radiologic data. Some unique features of our AR system include intuitive hand gestures and virtual user interfaces that allow the user to interact with the rendered data and process PET/CT images for optimal visualization. We implemented the feature to set a custom transfer function, set custom intensity cutoff points, and region-of-interest extraction via cutting planes. In the future, we hope to incorporate this work as part of a complete system for focused ultrasound treatment by adding ultrasound simulation, visualization, and deformable registration.
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Introduction: Early identification of residents who may require remediation could help prevent problems for both individual residents and their programs. Our aim in this project was to identify whether residents prone to challenges with professionalism could be identified early. Methods: For 3 years we tracked onboarding tasks completed by residents between official match and the first day of residency to develop a tool that would help identify residents who may be at risk for problems with timely chart completion and subsequent remediation. We compared residents' "at risk" scores with in-training exam (ITE) scores to differentiate between professionalism (task completion issues) and medical knowledge. Results: Our at-risk tool successfully predicted timely chart completion rates and need for remediation within our residency program (Fischer's exact P<.001), but was not predictive of ITE scores. Discussion: Using readily accessible information, we can identify residents at risk for poor task completion performance, who may benefit from extra support and development in the area of organizational skill. Early identification may increase opportunities for early intervention.
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Biopsies play a crucial role in diagnosis of various diseases including cancers. In this study, we developed an augmented reality (AR) system to improve biopsy procedures and increase targeting accuracy. Our AR-guided biopsy system uses a high-speed motion tracking technology and an AR headset to display a holographic representation of the organ, lesions, and other structures of interest superimposed on real physical objects. The first application of our AR system is prostate biopsy. By incorporating preoperative scans, such as computed tomography (CT) or magnetic resonance imaging (MRI), into real-time ultrasound-guided procedures, this innovative AR-guided system enables clinicians to see the lesion as well as the organs in real time. With the enhanced visualization of the prostate, lesion, and surrounding organs, surgeons can perform prostate biopsies with an increased accuracy. Our AR-guided biopsy system yielded an average targeting accuracy of 2.94 ± 1.04 mm and can be applied for real-time guidance of prostate biopsy as well as other biopsy procedures.
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While minimally invasive laparoscopic surgery can help reduce blood loss, reduce hospital time, and shorten recovery time compared to open surgery, it has the disadvantages of limited field of view and difficulty in locating subsurface targets. Our proposed solution applies an augmented reality (AR) system to overlay pre-operative images, such as those from magnetic resonance imaging (MRI), onto the target organ in the user's real-world environment. Our system can provide critical information regarding the location of subsurface lesions to guide surgical procedures in real time. An infrared motion tracking camera system was employed to obtain real-time position data of the patient and surgical instruments. To perform hologram registration, fiducial markers were used to track and map virtual coordinates to the real world. In this study, phantom models of each organ were constructed to test the reliability and accuracy of the AR-guided laparoscopic system. Root mean square error (RMSE) was used to evaluate the targeting accuracy of the laparoscopic interventional procedure. Our results demonstrated a registration error of 2.42 ± 0.79 mm and a procedural targeting error of 4.17 ± 1.63 mm using our AR-guided laparoscopic system that will be further refined for potential clinical procedures.
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Background: Catheter ablation is an effective treatment for atrial fibrillation (AF) but incurs significant financial costs to payers. Reducing variability may improve cost effectiveness. Objectives: We aimed to measure (1) the components of direct and indirect costs for routine AF ablation procedures, (2) the variability of those costs, and (3) the main factors driving ablation cost variability. Methods: Using data from the University of Utah Health Value Driven Outcomes system, we were able to measure direct, inflation-adjusted costs of uncomplicated, routine AF ablation to the healthcare system. Direct costs were considered costs incurred by pharmacy, disposable supplies, patient labs, implants, and other services categories (primarily anesthesia support) and indirect costs were considered within imaging, facility, and electrophysiology lab management categories. Results: A total of 910 patients with 1060 outpatient ablation encounters were included from January 1, 2013, to December 31, 2020. Disposable supplies accounted for the largest component of cost with 44.8 ± 9.7%, followed by other services (primarily anesthesia support) with 30.4 ± 7.7% and facility costs with 16.1 ± 5.6%; pharmacy, imaging, and implant costs each contributed <5%. Direct costs were larger than indirect costs (82.4 ± 5.6% vs 17.6 ± 5.6%). Multivariable regression showed that procedure operator was the primary factor associated with AF ablation overall cost (up to 12% differences depending on operator). Conclusions: Direct costs and other services (primarily anesthesia) drive the majority costs associated with AF ablations. There is significant variability in costs for these routine, uncomplicated AF ablation procedures. The procedure operator, and not patient characteristic, is the main driver for cost variability.
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We report coupling of the excitonic photon emission from photoexcited PbSe colloidal quantum dots (QDs) into an optical circuit that was fabricated in a silicon-on-insulator wafer using a CMOS-compatible process. The coupling between excitons and sub-µm sized silicon channel waveguides was mediated by a photonic crystal microcavity. The intensity of the coupled light saturates rapidly with the optical excitation power. The saturation behaviour was quantitatively studied using an isolated photonic crystal cavity with PbSe QDs site-selectively located at the cavity mode antinode position. Saturation occurs when a few µW of continuous wave HeNe pump power excites the QDs with a Gaussian spot size of 2 µm. By comparing the results with a master equation analysis that rigorously accounts for the complex dielectric environment of the QD excitons, the saturation is attributed to ground state depletion due to a non-radiative exciton decay channel with a trap state lifetime ~ 3 µs.
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Coloides/química , Chumbo/química , Pontos Quânticos , Compostos de Selênio/química , Silício/química , Eletroquímica/métodos , Radiação Eletromagnética , Desenho de Equipamento , Hélio/química , Teste de Materiais , Microscopia Eletrônica de Varredura/métodos , Modelos Estatísticos , Neônio/química , Distribuição Normal , Fótons , SolventesRESUMO
Phantoms are invaluable tools broadly used for research and training purposes designed to mimic tissues and structures in the body. In this paper, polyvinyl chloride (PVC)-plasticizer and silicone rubbers were explored as economical materials to reliably create long-lasting, realistic kidney phantoms with contrast under both ultrasound (US) and X-ray imaging. The radiodensity properties of varying formulations of soft PVC-based gels were characterized to allow adjustable image intensity and contrast. Using this data, a phantom creation workflow was established which can be easily adapted to match radiodensity values of other organs and soft tissues in the body. Internal kidney structures such as the medulla and ureter were created using a two-part molding process to allow greater phantom customization. The kidney phantoms were imaged under US and X-ray scanners to compare the contrast enhancement of a PVC-based medulla versus a silicone-based medulla. Silicone was found to have higher attenuation than plastic under X-ray imaging, but poor quality under US imaging. PVC was found to exhibit good contrast under X-ray imaging and excellent performance for US imaging. Finally, the durability and shelf life of our PVC-based phantoms were observed to be vastly superior to that of common agar-based phantoms. The work presented here allows extended periods of usage and storage for each kidney phantom while simultaneously preserving anatomical detail, contrast under dual-modality imaging, and low cost of materials.
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Cardiac catheterization is a delicate strategy often used during various heart procedures. However, the procedure carries a myriad of risks associated with it, including damage to the vessel or heart itself, blood clots, and arrhythmias. Many of these risks increase in probability as the length of the operation increases, creating a demand for a more accurate procedure while reducing the overall time required. To this end, we developed an adaptable virtual reality simulation and visualization method to provide essential information to the physician ahead of time with the goal of reducing potential risks, decreasing operation time, and improving the accuracy of cardiac catheterization procedures. We additionally conducted a phantom study to evaluate the impact of using our virtual reality system prior to a procedure.
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A novel method for patterning optically active colloidal PbSe nanocrystals on Si surfaces is reported. Oleate-capped PbSe nanocrystals were found to adhere preferentially to H-terminated Si surfaces over oxide and alkyl-terminated Si surfaces. Scanning probe lithography was used to oxidize locally a dodecyl monolayer on the Si surface of a silicon-on-insulator wafer prepatterned with photonic crystal microcavities. Aqueous HF was then used to remove the oxide and expose H-terminated Si areas, yielding patterned PbSe nanocrystals on the Si surface after exposure to a nanocrystal solution. This patterning technique allows for the selective deposition of PbSe nanocrystals at the main antinode of the silicon-based microcavities. More than a 10-fold photoluminescence enhancement due to the cavity-nanocrystal coupling was observed.
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The feasibility of using a parametric down-conversion process to generate squeezed electromagnetic states in three dimensional photonic crystal microcavity structures is investigated for the first time. The spectrum of the squeezed light is theoretically calculated by using an open cavity quantum mechanical formalism. The cavity communicates with two main channels, which model vertical radiation losses and coupling into a single-mode waveguide respectively. The amount of squeezing is determined by the correlation functions relating the field quadratures of light coupled into the waveguide. All of the relevant model parameters are realistically estimated for structures made in Al0.3Ga0.7As, using finite-difference time-domain simulations. Squeezing up to approximately 30% below the shot noise level is predicted for 10 mW average power, 80 MHz repetition, 500 ps excitation pulses using in a [111] oriented wafer.
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Desenho Assistido por Computador , Cristalização/métodos , Modelos Teóricos , Dispositivos Ópticos , Simulação por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Luz , Fótons , Espalhamento de RadiaçãoRESUMO
This work demonstrates that arbitrary types of spatially modulated second-order susceptibility (chi((2)) structures such as 1D and 2D, periodic and quasi-periodic structures can be obtained by using the combination of corona poling and direct laser writing (DLW) techniques. The fabrication technique is based on the photodepoling of azo-dye molecules caused by one-photon or two-photon absorption during the DLW process. Polarization and second harmonic generation (SHG) images of the fabricated structures were measured by electrostatic force microscope and SHG mapping techniques, respectively. Furthermore, quasi-phase-matched (QPM) enhanced SHG from a 1D periodically poled azo-copolymer planar waveguide is demonstrated using an optical parametric oscillator laser by scanning wavelength from 1500 to 1600 nm. The resonant wavelength of the QPM enhanced SHG is peaked at 1537 nm with FWHM is congruent to 2.5 nm.
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Compostos Azo/química , Desenho Assistido por Computador , Modelos Teóricos , Óptica e Fotônica/instrumentação , Oscilometria/instrumentação , Polímeros/química , Simulação por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Dinâmica não LinearRESUMO
The p-i-n quantum dot (QD) solar cells were fabricated through the single-step deposition of both of its p-type and light absorbing quantum layers. The hole transport and light absorbing layers of these devices were made by the p- and n-type PbS QDs, which were functionalized with mercaptopropionic acid and different halide, hybrid, and perovskite ligands, respectively. Fabrication of such p-i-n devices by the single-step deposition of pre-exchanged colloidal QDs had not been fully investigated so far because of the low progression of ligand exchange processes, weak colloidal stability of pre-exchanged QDs in desired solvents, and remaining of the ligand exchange products along with particles. However, we showed that the type of ligand complexes, amino acid products of ligand exchange, and protic solvents are highly effective for increasing the ligand exchange progression and preparation of high colloidal stability QDs with superior photoluminescence properties. As well, the surface chemistry investigations by the means of Fourier transform infrared, nuclear magnetic resonance, X-ray photoelectron spectroscopy, X-ray diffraction, inductively coupled plasma optical emission spectrometry, carbon-hydrogen-nitrogen-sulfur elemental analysis, zeta potential, and high-resolution transmission electron microscopy were led to the presentation of new concepts about the theoretical and experimental ligand weight percentages, the mechanisms of solution-phase ligand exchange processes, and formation of ligands adlayer on the (111) facets of QDs. The pre-exchanged colloidal QDs showed very good desirability for the single-step deposition of dense, defects-free, and smooth QD layers. Regarding that, the p-i-n solar cells were successfully fabricated by the single-step deposition of both of the QD layers. Especially, the highest power conversion efficiency value of 6.40% was recorded for the devices in which the light absorbing layer was prepared by the composite-like QD-perovskite structures.