Publications by authors named "James Kwan"

The abatement of aromatic pollutants in water requires their oxidation to nontoxic products by resource-intensive reactions with hydroxyl radicals (•OH). We elucidate the mechanisms of •OH-induced aromatic ring degradation by combining kinetic measurements, electron paramagnetic resonance spectroscopy, density functional theory calculations, and kinetic modelling. We demonstrate that benzyl alcohol, a model aromatic compound, is oxidized by •OH radicals, generated by ultrasonic irradiation in an O2-rich environment, into aromatic compounds (benzaldehyde and phenol derivatives) and C1-C2 oxygenates (formic acid, glyoxal, and oxalic acid).

View Article and Find Full Text PDF

To retrospectively analyze clinical outcomes of patients with "treatment-resistant" neovascular age-related macular degeneration or diabetic macular edema who were switched to intravitreal faricimab injections (IFIs) using a "real-world" treat-and-extend (TAE) protocol. Seventy-one eyes from 62 patients receiving antivascular endothelial growth factor injections were evaluated before and after switching to IFI. Demographic and clinical data were collected.

View Article and Find Full Text PDF

Efficient energy transfer management in catalytic processes is crucial for overcoming activation energy barriers while minimizing costs and CO emissions. We exploit here a concept of CuO particle design with multiple gas-stabilizing sites, engineered to function as cavitation nuclei and catalysts. This concept facilitates the selective and efficient acoustic energy transfer directly to the catalyst surface, avoiding the undesired dissipation of acoustic energy into the bulk solution while demonstrating superior cavitation properties at lower acoustic pressure amplitudes.

View Article and Find Full Text PDF

Since its advent in 2011, black titanium oxide (B-TiO) has garnered significant attention due to its exceptional optical characteristics, notably its enhanced absorption spectrum ranging from 200 to 2000 nm, in stark contrast to its unmodified counterpart. The escalating urgency to address global climate change has spurred intensified research into this material for sustainable hydrogen production through thermal, photocatalytic, electrocatalytic, or hybrid water-splitting techniques. The rapid advancements in this dynamic field necessitate a comprehensive update.

View Article and Find Full Text PDF

The design and development of supported catalysts for the oxygen evolution reaction (OER) is a promising pathway to reducing iridium loading in proton exchange membrane water electrolysers. However, supported catalysts often suffer from poor activity and durability, particularly when deployed in membrane electrode assemblies. In this work, we deploy iridium coated hollow titanium dioxide particles as OER catalysts to achieve higher Ir mass activities than the leading commercial catalysts.

View Article and Find Full Text PDF

Introduction: Entrustable professional activities (EPAs) are one way to assess competencies, and are designed to bridge the gap between theoretical competencies and real world clinical practice.

Aims: This was a systematic review which aims to answer the question: "Which EPAs related to Emergency Medicine are described for medical schools?".

Methods: We included original qualitative, interventional and observational studies (cross-sectional, case-control, and cohort studies) that described EPAs relevant to Emergency Medicine for Medical School.

View Article and Find Full Text PDF

Background: The International Federation for Emergency Medicine (IFEM) published its model curriculum for medical student education in emergency medicine in 2009. Because of the evolving principles of emergency medicine and medical education, driven by societal, professional, and educational developments, there was a need for an update on IFEM recommendations. The main objective of the update process was creating Intended Learning Outcomes (ILOs) and providing tier-based recommendations.

View Article and Find Full Text PDF

Ultrasonic irradiation holds potential for the selective oxidation of non-volatile organic substrates in the aqueous phase by harnessing hydroxyl radicals as chemical initiators. Here, a mechanistic description of hydroxyl radical-initiated glyoxal oxidation is constructed by gleaning insights from photolysis and radiation chemistry to explain the yields and kinetic trends for oxidation products. The mechanistic description and kinetic measurements reported herein reveal that increasing the formation rate of hydroxyl radicals by changing the ultrasound frequency increases both the rates of glyoxal consumption and the selectivity towards C acid products over those from C-C cleavage.

View Article and Find Full Text PDF

The TATA-box binding protein (TBP) is the sole transcription factor common in the initiation complexes of the three major eukaryotic RNA Polymerases (Pol I, II and III). Although TBP is central to transcription by the three RNA Pols in various species, the emergence of TBP paralogs throughout evolution has expanded the complexity in transcription initiation. Furthermore, recent studies have emerged that questioned the centrality of TBP in mammalian cells, particularly in Pol II transcription, but the role of TBP and its paralogs in Pol I transcription remains to be re-evaluated.

View Article and Find Full Text PDF

Purpose: To compare the effectiveness and efficiency of a glued (sutureless) technique for amniotic membrane transplantation (AMT) with a traditional sutured one in the setting of acute Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN).

Methods: This retrospective cohort study evaluated all patients diagnosed with SJS/TEN between 2008 and 2020 within our hospital network who received AMT in the acute phase according to our protocol and had at least one ophthalmic follow-up in the chronic phase. Primary outcomes included best-corrected visual acuity (BCVA) at the most recent visit, presence of a severe ocular complication (SOC) via predefined criteria, time to procedure and duration of procedure.

View Article and Find Full Text PDF

Overexposure to antibiotics originating in wastewater has profound environmental and health implications. Conventional treatment methods are not fully effective in removing certain antibiotics, such as the commonly used antibiotic, tetracycline, leading to its accumulation in water catchments. Alternative antibiotic removal strategies are garnering attention, including sonocatalytic oxidative processes.

View Article and Find Full Text PDF

Welcome to this special issue on Cavitation-Enhanced Drug Delivery and Immunotherapy-a rapidly evolving area that has been buoyed in recent years by the development of methods harnessing the activity of ultrasound-stimulated bubbles known as cavitation [...

View Article and Find Full Text PDF

Sonochemistry is the use of ultrasound to generate highly reactive radical species through the inertial collapse of a gas/vapour cavity and is a green alternative for hydrogen production, wastewater treatment, and chemical synthesis and modifications. Yet, current sonochemical reactors often are limited by their design, resulting in low efficacy and yields with slow reaction kinetics. Here, we constructed a novel sonochemical reactor design that creates cylindrically converging ultrasound waves to create an intense localised region of high acoustic pressure amplitudes (15 MPa) capable of spontaneously nucleating cavitation.

View Article and Find Full Text PDF

This case features a young healthy male who was diagnosed with immunoglobulin A (IgA) nephropathy after presenting with blurry vision that was caused by hypertensive retinopathy and papilledema. In this report, we examine the relationship between hypertension and increased intracranial pressure (ICP), along with the ocular signs of IgA nephropathy that may present in the setting of kidney disease.

View Article and Find Full Text PDF

A large number of transcription factors have been shown to bind and interact with mitotic chromosomes, which may promote the efficient reactivation of transcriptional programs following cell division. Although the DNA-binding domain (DBD) contributes strongly to TF behavior, the mitotic behaviors of TFs from the same DBD family may vary. To define the mechanisms governing TF behavior during mitosis in mouse embryonic stem cells, we examined two related TFs: Heat Shock Factor 1 and 2 (HSF1 and HSF2).

View Article and Find Full Text PDF
Article Synopsis
  • Transcription by RNA Polymerase II (Pol II) relies on the formation of a pre-initiation complex at the promoter, traditionally seen as dependent on the TATA-box binding protein (TBP).
  • Acute depletion of TBP in mouse embryonic stem cells does not significantly impact ongoing Pol II transcription, indicating a TBP-independent mechanism for transcriptional initiation.
  • While TBP affects RNA Polymerase III initiation, the TFIID complex remains functional with reduced factors, allowing Pol II transcription to continue efficiently without TBP.
View Article and Find Full Text PDF

We report the synthesis of hydroxyl-radical (˙OH) responsive fluorescent probes that utilise the 3,5-dihydroxybenzyl (DHB) functionality. 4-Methylumbeliferone-DHB (Umb-DHB) and resorufin-DHB (Res-DHB) in the presence of ˙OH radicals resulted in significant increases in their respective fluorescent emission intensities at 460 nm and 585 nm. The incubation of Res-DHB in HeLa cells followed by therapeutic ultrasound (1 MHz) resulted in a significant increase in fluorescence emission intensity thus permitting the ability to monitor ultrasound-induced ˙OH production in live cells.

View Article and Find Full Text PDF

Diabetic eye disease is strongly associated with the development of diabetic foot ulcers (DFUs). DFUs are a common and significant complication of diabetes mellitus (DM) that arise from a combination of micro- and macrovascular compromise. Hyperglycemia and associated metabolic dysfunction in DM lead to impaired wound healing, immune dysregulation, peripheral vascular disease, and diabetic neuropathy that predisposes the lower extremities to repetitive injury and progressive tissue damage that may ultimately necessitate amputation.

View Article and Find Full Text PDF

Introduction: Mortality risk prediction is an important part of the clinical assessment in the Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) patient. The SCORTEN and ABCD-10 scoring systems have been used as predictive clinical tools for assessing this risk. However, some of the metrics required in calculating these scores, such as the total body surface area (TBSA) involvement, are difficult to calculate.

View Article and Find Full Text PDF

Mycoplasma pneumoniae induced rash and mucositis (MIRM) is a relatively newly identified clinical entity which is characterized by mucocutaneous manifestations in the setting of Mycoplasma infection. Though a clinically distinct disease, MIRM exists on a diagnostic continuum with entities including erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis, and the recently described reactive infectious mucocutaneous eruption (RIME). In this systematic review, we discuss published findings on the epidemiology, clinical manifestations, diagnosis, and management of MIRM, with an emphasis on ocular disease.

View Article and Find Full Text PDF

Purpose: To present a semi-automated method of image alignment to aid in monitoring the progression of inherited retinal degenerations (IRDs).

Results: A 22-year-old woman presented with nyctalopia and a family history of retinitis pigmentosa (RP), but with no prior genetic testing. Fundus examination showed a sectoral retinal degeneration involving the inferior and nasal retina with rare, pigmented deposits.

View Article and Find Full Text PDF

Objective: To describe the relationship between history of atopic disease on systemic and ocular manifestations of Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN).

Methods: Retrospective chart review of patients with SJS/TEN patients. Those with and without prior atopic diagnosis were compared.

View Article and Find Full Text PDF

Purpose: We report two cases of refractile, peripheral, corneal stromal deposition in two patients with arterial tortuosity syndrome (ATS) and Ehlers-Danlos syndrome (EDS), two closely related connective tissue diseases (CTDs).

Observations: : A 21-year-old man with history of ATS and keratoectasia presented with bilateral peripheral corneal neovascularization with numerous whitish brown, refractile, deep stromal opacities that were circumferential along the inferotemporal cornea. After 3 years of follow-up, the corneal deposits did not progress, but the ectasia did, with significant bilateral corneal steepening and thinning for which the patient was recommended to undergo repeat corneal collagen cross linking.

View Article and Find Full Text PDF

Gold catalysts have attracted attention for enabling sustainable chemical processes under ambient conditions. This reactivity is attributed to the small size of the catalysts (<5 nm); however, their size also creates difficulty when removing from product streams and often require rare-metal additives to enhance reaction rate kinetics, thereby limiting the environmental benefits of these catalysts. Comparatively, submicron gold catalysts are easier to separate but are much less reactive under ambient conditions.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessionh0lr3o041v9pufbbk75bsncvqinm8k9a): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once