Publications by authors named "Kevin Lam"

Background: Subcortical ischemic vascular cognitive impairment (SIVCI) is the most common form of vascular cognitive impairment. White matter hyperintensities (WMH) secondary to SIVCI often result in impaired executive function. Cognitive reserve is a property of the brain that allows for preserved cognitive performance given brain injury or disease.

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Background: Subcortical ischemic vascular cognitive impairment (SIVCI) is the most common form of vascular cognitive impairment. White matter hyperintensities (WMH) are hallmarks of SIVCI and are associated with impaired executive function. Cognitive reserve is a property of the brain that moderates an individual’s ability to maintain cognitive performance given brain injury or pathology.

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Purpose: To assess the association of serum vitamin D level and the live birth rate in women undergoing frozen embryo transfer (FET).

Methods: This is a retrospective cohort study involving 1489 infertile women who had frozen embryo transfer at two tertiary reproductive medicine centres from 2019 to 2021. Only the first frozen embryo transfer was included for women who had repeated transfers during the period.

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Background: Subcortical ischemic vascular cognitive impairment (SIVCI) is highly prevalent in older individuals. White matter hyperintensities (WMH) are a defining feature of SIVCI. There are sex differences in SIVCI, with females having higher volume and faster WMH progression than males.

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Objective: To explore the role of local public health organisations in antimicrobial stewardship (AMS) and antimicrobial resistance (AMR) surveillance.

Methods: A scoping review was conducted. Peer-reviewed and grey literature from countries within the organisation for economic co-operation and development was searched between 1999 and 2023 using the concepts of local public health, AMR and AMS.

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Traditional etherification methods, although staples in synthetic chemistry, often fall short in the efficient construction of sterically hindered dialkyl ethers, especially under mild and practical conditions. Recent advances have attempted to address these limitations, typically relying on transition metal catalysts, external reductants, or harsh reaction conditions. In this work, we disclose a novel electrochemical approach that enables the synthesis of sterically hindered ethers from economically relevant and readily accessible alcohols without the need for sacrificial oxidants.

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Article Synopsis
  • A new electrochemical method is introduced for safer cyanation reactions using 5-aminotetrazole as a cyanide source, avoiding toxic cyanide salts.
  • This method successfully generates both electrophilic and nucleophilic cyanide sources and allows for the synthesis of various compounds like cyanamides, heterocycles, and aromatic nitriles.
  • The process has been adapted for flow electrosynthesis, showcasing its scalability and potential for large-scale use.*
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Invasive membrane protrusions play a central role in a variety of cellular processes. Unlike filopodia, invasive protrusions are mechanically stiff and propelled by branched actin polymerization. However, how branched actin filaments are organized to create finger-like invasive protrusions is unclear.

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Purpose: Given the potential role of light and its wavelength on ocular growth, this study investigated the effect of short-term exposure to red, cyan and blue light on ocular biometry in humans.

Methods: Forty-four young adults and 20 children, comprising emmetropes and myopes, underwent 2-h sessions of cyan (507 nm), red (638 nm) and broadband white light on three separate days via light-emitting glasses. Additionally, young adults were exposed to blue light (454 nm) on an additional day.

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Biological soil amendments of animal origin (BSAAOs) are widely used in urban agriculture to improve soil quality. Although BSAAO use is regulated due to risks for introducing foodborne pathogens, effects on antimicrobial-resistant (AMR) bacteria are not well established. Here, we aimed to explore the impacts of BSAAOs on levels of resident AMR bacteria in leafy vegetable production environments (i.

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The active silicon cell of a solar photovoltaic (PV) panel is covered by an ethylenevinylacetate (EVA) adhesive and a protective top glass layer. Separating this glass-EVA layer from the underlying silicon represents a bottleneck for recycling PV panels. Previous work has shown that the EVA-Si bond can be weakened by applying a continuous source of heat to melt the EVA.

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In this letter, we disclose the anodic oxidation of oxamic acids in the presence of EtN·3HF as a practical, scalable, and robust method to rapidly access carbamoyl fluorides from readily available and stable precursors. The simplicity of this method also led us to develop the first flow electrochemical preparation of carbamoyl fluorides, demonstrating scale-up feasibility as a proof of concept.

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Background: Seven days of antibiotics are recommended in the setting of preterm premature rupture of membranes to promote latency. Azithromycin has generally replaced a 7-day course of erythromycin in current clinical practice. Azithromycin clears from plasma quickly and concentrates in local tissue, which is why daily dosing is not always needed, and local tissue, rather than plasma, concentrations are used to determine dosing.

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Article Synopsis
  • The study investigates whether low levels of 25-hydroxyvitamin D (25(OH)D) are linked to a higher risk of miscarriage in women experiencing threatened miscarriage.
  • It analyzed serum samples from 371 women, revealing a miscarriage rate of 12.1%, with no significant difference in rates between those deficient in vitamin D and those who were not.
  • Notably, while lower vitamin D levels did not correlate with miscarriages overall, women presenting earlier in their pregnancy (6 weeks or less) showed a higher miscarriage rate if they were non-deficient in vitamin D.
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Assembling molecular machines into crystals provides a way to harness their power on large length scales, but the development of a crystal analogue to a molecular motor remains a challenge. The molecule ()-5-(anthracen-9-ylmethylene)-3-butylthiazolidine-2,4-dione () has and isomers with strongly overlapping absorption spectra. This spectroscopic property allows both → and → photoisomerization reactions to be driven by a single light source, and simulations indicate this property can provide a route to robust oscillatory motion.

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Water-free reflux condensers, which use convective cooling from the surrounding air to condense vapors, avoid the need for cooling water, which is more sustainable than water-cooled condensers, and eliminates the risk of flooding, but these devices are newer and less familiar to many chemists, who may never have used them before. To facilitate the shift to water-free condensers, several types of water-free condensers (simple glass tube, Vigreux column, Condensyn, Findenser, and air-cooled Dimroth) were characterized using three different solvents (ethyl acetate, acetone, and tetrahydrofuran) under both gentle and vigorous refluxing conditions to compare their relative performance and determine the condensing capacity/failure point. In addition to experimentally quantifying the performance of each condenser both gravimetrically and via infrared thermal imaging, energy-balance models were developed to gain insight into which factors were most important in driving their performance.

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Organic molecules that undergo supercooling can provide the basis for novel stimuli-responsive materials, but the number of such compounds is limited. Results in this paper show that the stable organic radical 2,2,6,6-tetramethyl-1-piperidine-1-oxyl (TEMPO) can form a stable supercooled liquid (SCL). Upon melting and cooling back to room temperature, the TEMPO SCL can persist for months, even after mild physical agitation.

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Transgender women may have concerns of drug interactions between feminizing hormone therapy (FHT) and antiretrovirals, leading to nonadherence. This randomized, three-period crossover, open-label, phase I trial assessed the effects of doravirine (DOR) and tenofovir disoproxil fumarate (TDF) on the pharmacokinetics (PKs) of estradiol, spironolactone, and total testosterone and vice versa in healthy transgender women. Volunteers were randomized 1:1 into two sequences containing three treatment groups (DOR, lamivudine [3TC], and TDF alone; estradiol, spironolactone, and placebo; and DOR/3TC/TDF, estradiol, and spironolactone).

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2-Azidoanthracene (2N-AN) can act as a photochemical source of N gas when dissolved in an optically transparent polymer such as poly(methyl methacrylate) (PMMA). Irradiation at 365 or 405 nm of a 150 μm-thick polymer film submerged in water causes the rapid appearance of a surface layer of bubbles. The rapid appearance of surface bubbles cannot be explained by normal diffusion of N through the polymer and likely results from internal gas pressure buildup during the reaction.

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Purpose: This study aimed to optimize the non-invasive preimplantation genetic testing for aneuploidy (niPGT-A) in the laboratory by comparing two collection timing of the spent culture medium (SCM), two embryo rinsing protocols, and the use of conventional insemination instead of intracytoplasmic sperm injection (ICSI).

Methods: Results of two embryo rinsing methods (one-step vs sequential) and SCM collected on day 5 vs day 6 after retrieval were compared against trophectoderm (TE) biopsies as reference. Results from day 6 SCM in cycles fertilized by conventional insemination were compared with PGT-A using ICSI.

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