Publications by authors named "Jose Vallejos"

Objective: A narrative overview of regional academic research collaborations to address the increasing burden and gaps in care for patients at risk of, and who suffer from, stroke in Latin America (LA).

Materials And Methods: A summary of experiences and knowledge of the local situation is presented. No systematic literature review was performed.

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Unlabelled: Background and purpose; Chile has been one of the most affected countries by the COVID-19 pandemic, with one of the highest case rates per population. This has affected the epidemiological behaviour of various pathologies. We analyze the impact of the pandemic on the number of admissions due to stroke, its severity and mortality in Santiago, Chile.

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Unlabelled: Of importance to the biological properties of proteins produced in cell culture systems are the complex post-translational modifications that are affected by variations in process conditions. Protein oxidation, oxidative modification to intracellular proteins that involves cleavage of the polypeptide chain, and modifications of the amino acid side chains can be affected by such process variations. Dissolved oxygen is a parameter of increasing interest since studies have shown that despite the necessity of oxygen for respiration, there may also be some detrimental effects of oxygen to the cell.

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In this study, we perform mass transfer characterization (k(L) a) on a novel mechanically driven/stirred Process Scouting Device, PSD, (SuperSpinner D 1000®, SSD) and demonstrate that this novel device can be viewed as disposable bioreactor. Using patch-based optical sensors, we were able to monitor critical cell culture environmental conditions such as dissolved oxygen (DO) and pH in SSD for comparison to a 1 L standard spinner (SS) flask. We also coupled these mass transfer studies with mixing time studies where we observed relative high mixing times (5.

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During the past decade, novel disposable cell culture vessels (generally referred to as Process Scouting Devices or PSDs) have become increasingly popular for laboratory scale studies and seed culture generation. However, the lack of engineering characterization and online monitoring tools for PSDs makes it difficult to elucidate their oxygen transfer capabilities. In this study, a mass transfer characterization (k(L)a) of sensor enabled static and rocking T-flasks is presented and compared with other non-instrumented PSDs such as CultiFlask 50®, spinner flasks, and SuperSpinner D 1000®.

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Approximately 25%-40% of ischemic strokes are considered of unknown cause (ie, cryptogenic). The available information on associated risk factors, functional outcome, and recurrence of this subtype of stroke is limited, especially for the Chilean population. We conducted a prospective cohort study of 380 patients aged ≥ 18 years admitted consecutively to a stroke unit with demonstrated ischemic stroke.

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The bioprocess development cycle is a complex task that requires a complete understanding of the engineering of the process (e.g., mass transfer, mixing, CO(2) removal, process monitoring, and control) and its affect on cell biology and product quality.

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A rare congenital myocardial defect, known as left ventricular hypertrabeculation/non-compaction (LVHT), has been occasionally described associated with thrombus formation with a potential systemic embolic risk, but its association with ischemic strokes remains controversial. We report a case of ischemic stroke in a patient with severe LVHT and ventricular dysfunction as a possible etiologic synergistic association. In absence of other embolic sources, a severe LVTH associated with ventricular dysfunction could constitute a potential source of brain embolism, especially in patients with high suspicion of an embolic mechanism of ischemic stroke.

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Routine cell culture is done in small-scale disposable vessels (typically 0.1-100 mL volumes) in academia and industry. Despite their wide use in bioprocess development (i.

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A novel optical sensor was used to study mixing and mean circulation time in a model minibioreactor (12.5 mL stirred vessel, equipped with a paddle impeller). Rotational rates in the range of 10-1,000 rpm corresponding to Reynolds number between 14 and 1,350 were studied.

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A novel confocal optical system to study mixing time in small-scale bioreactors is presented. The system is designed to monitor fluorescence upon tracer addition from a localized confocal volume of 0.21 mL within a glass vessel.

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