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Extracorporeal membrane oxygenation (ECMO) has strikingly progressed over the last 20 years in the management of adult and pediatric severe respiratory and cardiac dysfunctions refractory to conventional management. In this review, we will discuss the weaning strategies of veno-venous and veno-arterial ECMO including the bridge to recovery and bridge to transplant along with post-ECMO care. We will also discuss the futility and the management of bridge to nowhere from Indian perspectives. [ABSTRACT FROM AUTHOR]

Purpose: Extracorporeal membrane oxygenation (ECMO) use for severe coronavirus disease 2019 (COVID-19) patients has increased during the course of the pandemic. As uncertainty existed regarding patient's outcomes, early guidelines recommended against establishing new ECMO centers. We aimed to explore the epidemiology and outcomes of ECMO for COVID-19 related cardiopulmonary failure in five countries in the Middle East and India and to evaluate the results of ECMO in 5 new centers. Methods: This is a retrospective, multicenter international, observational study conducted in 19 ECMO centers in five countries in the Middle East and India from March 1, 2020, to September 30, 2020. We included patients with COVID-19 who received ECMO for refractory hypoxemia and severe respiratory acidosis with or without circulatory failure. Data collection included demographic data, ECMO-related specific data, pre-ECMO patient condition, 24 h post-ECMO initiation data, and outcome. The primary outcome was survival to home discharge. Secondary outcomes included mortality during ECMO, survival to decannulation, and outcomes stratified by center type. Results: Three hundred and seven COVID-19 patients received ECMO support during the study period, of whom 78 (25%) were treated in the new ECMO centers. The median age was 45 years (interquartile range IQR 37–52), and 81% were men. New center patients were younger, were less frequently male, had received higher PEEP, more frequently inotropes and prone positioning before ECMO and were less frequently retrieved from a peripheral center on ECMO. Survival to home discharge was 45%. In patients treated in new and established centers, survival was 55 and 41% (p = 0.03), respectively. Multivariable analysis retained only a SOFA score < 12 at ECMO initiation as associated with survival (odds ratio, OR 1.93 (95% CI 1.05–3.58), p = 0.034), but not treatment in a new center (OR 1.65 (95% CI 0.75–3.67)). Conclusions: During pandemics, ECMO may provide favorable outcomes in highly selected patients as resources allow. Newly formed ECMO centers with appropriate supervision of regional experts may have satisfactory results. [ABSTRACT FROM AUTHOR]

Purpose: Minimizing post-operational neurological deficits as a result of brain surgery has been one of the most pertinent endeavours of neurosurgical research. Studies have utilised fMRIs, EEGs and MEGs in order to delineate and establish eloquent areas, however, these methods have not been utilized by the wider neurosurgical community due to a lack of clinical endpoints. We sought to ascertain if there is a correlation between graph theory metrics and the neurosurgical notion of eloquent brain regions. We also wanted to establish which graph theory based nodal centrality measure performs the best in predicting eloquent areas. Methods: We obtained diffusion neuroimaging data from the Human Connectome Project (HCP) and applied a parcellation scheme to it. This enabled us to construct a weighted adjacency matrix which we then analysed. Our analysis looked at the correlation between PageRank centrality and eloquent areas. We then compared PageRank centrality to eigenvector centrality and degree centrality to see what the best measure of empirical neurosurgical eloquence was. Results: Areas that are considered neurosurgically eloquent tended to be predicted by high PageRank centrality. By using summary scores for the three nodal centrality measures we found that PageRank centrality best correlated to empirical neurosurgical eloquence. Conclusion: The notion of eloquent areas is important to neurosurgery and graph theory provides a mathematical framework to predict these areas. PageRank centrality is able to consistently find areas that we consider eloquent. It is able to do so better than eigenvector and degree central measures. [ABSTRACT FROM AUTHOR]

Droplet-based microfluidic biochips (or DMFBs) are rapidly becoming a revolutionizing lab-on-a-chip technology. Numerous application specific protocols bridging the cross-disciplinary fields necessitate DMFBs as their prime need. The main goal at the fluid level is to minimize bioassay schedule length. Also, for a safe assay outcome, contamination among droplet routes must be avoided. Size restriction of a chip and reconfigurable nature of the operational modules in DMFB introduce contaminated cells which necessarily require washing as an urgent need. As the sub-tasks of fluid level possess their own constraints for a successful DMFB design, rip-up and reiteration of sub-tasks may become unavoidable if all of those constraints are not satisfied mutually. To achieve a shorter time for chip realization a crucial need in fluid-level design is to avoid rip-up and re-iteration; hence, design convergence is to be incorporated that collectively considers the fluid-level sub-tasks, instead of solving them individually. Thus, this paper focuses on the fluid level of DMFBs while considering design convergence, contamination avoidance, and washing issues. Obtained results are compared with several existing benchmarks. [ABSTRACT FROM AUTHOR]

Group-III-nitride semiconductors have shown enormous potential as light sources for full-colour displays, optical storage and solid-state lighting. Remarkably, InGaN blue- and green-light-emitting diodes (LEDs) emit brilliant light although the threading dislocation density generated due to lattice mismatch is six orders of magnitude higher than that in conventional LEDs. Here we explain why In-containing (Al,In,Ga)N bulk films exhibit a defect-insensitive emission probability. From the extremely short positron diffusion lengths (<4 nm) and short radiative lifetimes of excitonic emissions, we conclude that localizing valence states associated with atomic condensates of In–N preferentially capture holes, which have a positive charge similar to positrons. The holes form localized excitons to emit the light, although some of the excitons recombine at non-radiative centres. The enterprising use of atomically inhomogeneous crystals is proposed for future innovation in light emitters even when using defective crystals. [ABSTRACT FROM AUTHOR]

Nonpolar (1100) m-plane gallium nitride has been grown heteroepitaxially on (100) γ-LiAlO2 by several groups. Previous attempts to grow m-plane GaN by hydride vapor phase epitaxy (HVPE) yielded films unsuitable for subsequent device regrowth because of the high densities of faceted voids intersecting the films' free surfaces. We report here on the growth of planar m-plane GaN films on (100) γ-LiAlO2 and elimination of bulk and surface defects. The morphology achieved is smooth enough to allow for fabrication of m-plane GaN templates and free-standing substrates for nonpolar device regrowth. The GaN films were grown in a horizontal HVPE reactor at 860-890°C. Growth rates ranged from 30 µm/h to 240 µm/h, yielding free-standing films up to 250-µm thickness. The m-plane GaN films were optically specular and mirror-like, with undulations having 50-200-nm peak-to-valley heights over millimeter length scales. Atomic force microscopy revealed a striated surface morphology, similar to that observed in m-plane GaN films grown by molecular beam epitaxy (MBE). Root-mean-square (RMS) roughness was 0.636 nm over 25-µm² areas. Transmission electron microscopy (TEM) was performed on the m-plane GaN films to quantify microstructural defect densities. Basal-plane stacking faults of 1 x 105 cm-1 were observed, while 4 x 109 cm-2 threading dislocations were observed in the g = 0002 diffraction condition. [ABSTRACT FROM AUTHOR]

Green synthesis of iron oxide nanoparticles (Fe NPs) was prepared using Delonix regia flower extract, and their Photo Fenton like oxidation was performed. The synthesized Fe–NPs were characterized using XRD, FESEM, FETEM, FT-IR, and VSM confirmed the formation both of Magnetite (Fe3O4) and Hematite (α-Fe2O3) nanoparticles. The prepared catalyst was used for the photo Fenton like degradation of Methylene blue (MB) and Congo red (CR) dyes. The optimization of various operational parameters, such as the influence of concentration of catalyst, H2O2, initial dye and initial pH was executed. The results showed that under optimum conditions, about 99% decolorization of both MB and CR dye was accomplished within 10 min. The catalyst was removed by an external magnet, and reuse study showed that there is no notable decrease in the efficacy of the catalyst was observed up to five cycles. The results are exemplifying that the biogenic prepared Fe NPs having high potential for the photo-assisted degradation of both MB and CR in the existence of H2O2. [ABSTRACT FROM AUTHOR]

Deep ultraviolet light-emitting diode structures with a peak wavelength of 275 nm, as well as individual AlGaN:Mg layers, were grown by metalorganic chemical vapor deposition on (0001) silicon carbide. Control of the Mg profile in the devices reduced unwanted Mg-related emission at 320 nm to 1/224th of that emitted at the peak wavelength. An additional peak at 410 nm was observed to be related to oxygen incorporation in the film and confirmed with secondary ion mass spectroscopy (SIMS). Also investigated in an effort to improve hole injection were aluminum content, layer thickness, V/III ratio, activation temperature, and properties of the GaN:Mg contact layer and transparent contact metal stack. By optimizing this and other layers of the device, output powers of 0.84 mW at 1.3 A were obtained from packaged devices, with forward voltages as low as 4.9 V at 20 mA. [ABSTRACT FROM AUTHOR]