Publications by authors named "Steven Tan"

Background Stroke is a prevalent ailment that impacts a substantial number of individuals globally, resulting in both physical impairment and mortality. One of its major causes is carotid artery stenosis. The symptoms and degree of stenosis are key indications for carotid endarterectomy (CEA).

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Background Abdominal aortic aneurysm (AAA) is a dangerous disorder characterised by abnormal enlargement of the abdominal aorta. The severity of the aneurysm and the presence of symptoms determine the necessary monitoring or treatment to prevent potential fatalities. The objective of this study is to estimate the perioperative mortality and long-term outcome of endovascular abdominal aneurysm repair (EVAR).

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Objectives Preoperative fasting plays a pivotal role in adequately preparing patients for anaesthesia and surgical procedures. However, it is imperative to consider not only the medical aspects but also patients' overall comfort, as this can significantly contribute to improved surgical outcome. The primary objective of this quality improvement project (QIP) is to provide healthcare professionals, including anaesthetists, surgeons, nurses, and stakeholders with information regarding insights required to embrace the concept of preoperative snack prescription as a strategy for enhancing patient-centred care.

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Sample homogeneity dictates whether analyzing a test portion of an entire sample can provide representative information about incurred mycotoxins. In this study, we evaluated particle-size-distribution-based homogeneity of laboratory mycotoxin samples using laser diffraction particle size analysis and International Organization for Standardization (ISO) Guide 35: 2017. Incurred whole corn, compound feed, peanut butter, and wheat flour (500 g each) were comminuted using wet, cryogenic, or dry milling.

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Successful goal-directed actions require constant fine-tuning of the motor system. This fine-tuning is thought to rely on an implicit adaptation process that is driven by sensory prediction errors (e.g.

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Significance: Understanding longitudinal changes in why individuals frequent low-vision clinics is crucial for ensuring that patient care keeps current with changing technology and changing lifestyles. Among other findings, our results suggest that reading remains a prevailing patient complaint, with shifting priorities toward technology-related topics.

Purpose: This study aimed to understand changes in patient priorities and patient care in low vision over the past decade.

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Coabalamin-dependent -demethylase in sp. strain MRG-PMF1 was found to catalyze the unprecedented allyl aryl ether cleavage reaction. To expand the potential biotechnological applications, the reaction mechanism of the allyl aryl ether C-O bond cleavage, proposed to utilize the reactive Co(I) supernucleophile species, was studied further from the anaerobic whole-cell biotransformation.

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Enzyme-linked immunosorbent assays (ELISAs) are a cornerstone of modern molecular detection, but the technique still faces notable challenges. One of the biggest problems is discriminating true signal generated by target molecules versus non-specific background. Here, we developed a Single-Molecule Colocalization Assay (SiMCA) that overcomes this problem by employing total internal reflection fluorescence microscopy to quantify target proteins based on the colocalization of fluorescent signal from orthogonally labeled capture and detection antibodies.

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To monitor co-exposure to toxic mycotoxins in dried fruits, it is advantageous to simultaneously determine multiple mycotoxins using a single extraction and liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis. In this study, we applied a stable isotope dilution and LC-MS/MS method to multi-mycotoxin analysis in dried fruits, selecting raisins, plums, figs, and cranberries for matrix extension. Samples were prepared using cryogenic grinding, followed by the fortification of carbon-13 (13C) uniformly labeled internal standards for twelve mycotoxins, and extraction using 50% acetonitrile.

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Background: While vaccine development is itself a challenge; ensuring optimal vaccine uptake at population level can present an even more significant challenge. Therefore, this study aimed to assess the Pakistani population's attitude and preferences towards the Coronavirus disease 2019 (COVID-19) vaccine.

Method: A cross-sectional study was carried out through an online self-administered questionnaire from 27 September 2020 to 11 October 2020.

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Gut metabolism of natural products is of great interest due to the altered biological activity of the metabolites. To study the gut metabolism of the dietary furanocoumarins, the biotransformation of was studied with human gut microbiota. The major components of , including xanthotoxin (), bergapten (), imperatorin (), isoimperatorin (), oxypeucedanin (), and byakangelicol (), were all metabolized by the human fecal sample, and each furanocoumarin was also biotransformed by sp.

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Integrin-based adhesion complexes link the cytoskeleton to the extracellular matrix (ECM) and are central to the construction of multicellular animal tissues. How biological function emerges from the tens to thousands of proteins present within a single adhesion complex remains unclear. We used fluorescent molecular tension sensors to visualize force transmission by individual integrins in living cells.

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Metastasis requires tumor cells to navigate through a stiff stroma and squeeze through confined microenvironments. Whether tumors exploit unique biophysical properties to metastasize remains unclear. Data show that invading mammary tumor cells, when cultured in a stiffened three-dimensional extracellular matrix that recapitulates the primary tumor stroma, adopt a basal-like phenotype.

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Article Synopsis
  • Integrin-based adhesions are essential for cell migration, with talin acting as a molecular clutch that connects integrins to the actomyosin cytoskeleton.
  • The Kank protein family is identified as novel components of focal adhesions, accumulating at specific regions and binding to talin to enhance its activation.
  • Kank proteins reduce the strength of the integrin-talin connection to the actomyosin, leading to decreased cell migration speed by promoting slippage in adhesion complexes.
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Autofocusing and feature detection are two essential processes for performing automated biological cell manipulation tasks. In this paper, we have introduced a technique capable of focusing on a holding pipette and a mammalian cell under a bright-field microscope automatically, and a technique that can detect and track the presence and orientation of the polar body of an oocyte that is rotated at the tip of a micropipette. Both algorithms were evaluated by using mouse oocytes.

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A very important step of Pre-implantation genetic diagnosis (PGD) is embryo biopsy, in which process the zona pellucida (ZP) is cut open partially and a part of cellular material is extracted from the embryo. Recognition of the ZP is necessary not only for embryo biopsy, but also for other applications such as zona pellucida thickness variation (ZPTV), embryo dissection, etc. The ZP opening position is closely related to the cell survival rate after the biopsy.

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Three-dimensional (3-D) positioning and orientation of embryos/oocytes is necessary to facilitate micromanipulation tasks such as cell injection and cellular structural biopsy commonly performed under a microscope. Conventional cell orientation is performed manually by using a vacuum equipped micropipette to aspirate and release the cell, which is a trial-and-error approach. The conventional method relies heavily on the skill of the operator; it also suffers from low precision, low success rate and low controllability.

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Focal adhesions (FAs) are micron-sized protein assemblies that coordinate cell adhesion, migration, and mechanotransduction. How the many proteins within FAs are organized into force sensing and transmitting structures is poorly understood. We combined fluorescent molecular tension sensors with super-resolution light microscopy to visualize traction forces within FAs with <100 nm spatial resolution.

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Photopolymerizable hydrogels derived from naturally occurring polymers have attracted significant interest in tissue-engineering applications due to their excellent biocompatibility, hydrophilic nature favourable for cell ingrowth and ability to be cured in situ through a minimally invasive procedure. In this study, we developed a composite hydrogel consisting of photocrosslinkable methacrylated glycol chitosan (MeGC) and semi-interpenetrating collagen (Col) with a riboflavin photoinitiator under blue light. The incorporation of Col in MeGC hydrogels enhanced the compressive modulus and slowed the degradation rate of the hydrogels.

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Objectives: This study aimed to examine differences in autonomic responses to stress, pain perception, and the role of negative affect in these responses in individuals with irritable bowel syndrome (IBS) according to Traditional Chinese Medicine (TCM) classifications.

Design: Fifty-nine female patients with IBS age 18-65 years diagnosed by TCM practitioners as showing primarily an excess (n=32) or an overlap (n=27) pattern (mixed excess and deficiency) were assessed for symptom differences, heart rate, and skin conductance responses to a psychosocial stressor and pain perception. SETTINGS/LOCATIONS: University of California in Los Angeles, California.

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Bone morphogenetic proteins (BMPs) are believed to be the most potent osteoinductive factors. However, BMPs are highly pleiotropic molecules and their supra-physiological high dose requirement leads to adverse side effects and inefficient bone formation. Thus, there is a need to develop alternative osteoinductive growth factor strategies that can effectively complement BMP activity.

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Pseudomonas syringae pv. tomato, the causal agent of bacterial speck of tomato, has recently become an increasing problem in California due to the evolution and prevalence of highly aggressive race 1 strains. In resistant plant genotypes, the type III effectors AvrPto and AvrPtoB are recognized by the tomato proteins Pto and Prf.

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The so-called functional somatic syndromes comprise a group of disorders that are primarily symptom-based, multisystemic in presentation and probably involve alterations in mind-brain-body interactions. The emerging neurobiological models of allostasis/allostatic load and of the emotional motor system show striking similarities with concepts used by Traditional Chinese Medicine (TCM) to understand the functional somatic disorders and their underlying pathogenesis. These models incorporate a macroscopic perspective, accounting for the toll of acute and chronic traumas, physical and emotional stressors and the complex interactions between the mind, brain and body.

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