Publications by authors named "Tam Ho"

We disclose a broad platform for copper-catalyzed atom transfer radical addition (ATRA) of electron-deficient olefins. Catalytic Cu(dtbbpy)(OTf) enables radical addition of electron-deficient alkyl halides to acrylates, acrylamides, and vinyl sulfones in fair to excellent yields. The resultant ATRA products can be used in a variety of telescoped reactions, including substitution with basic amine nucleophiles to afford α-amino esters.

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Herein, we report mechanistic investigations into the Cu-catalyzed three-component carboamination of alkenes with α-halo carbonyls and aryl amines via an oxocarbenium intermediate. Monitoring the reaction reveals the formation of transient atom transfer radical addition (ATRA) intermediates with both electron-neutral and deficient vinyl arenes as well as unactivated alkenes. Based on our experimental studies and density functional theory calculations, the oxocarbenium is generated through atom transfer and subsequent intramolecular substitution.

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Currently, numerous glycosides have been synthesized and used in clinical applications, neutraceuticals, cosmetics, and food processing. Structurally, a glycoside is composed of aglycone attaching to one or several sugar moieties so-called glycone. It is found that biochemical or biopharmaceutical properties of glycoside are mainly determined by its sugar part and thereby alternation of this glycone resulting in novel structure and characteristics as well.

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Background: Surgery is a common treatment for pelvic organ prolapse (POP); however, risk of recurrence and reoperation is high, resulting in a negative impact on quality of life and sexual function.

Aim: To examine the long-term effects of POP surgery and endogenous circulating ovarian hormones on the vagina and bladder.

Methods: Our animal model simulated surgical injury of the vagina and bladder during POP surgery.

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The synthesis of α-haloboronic esters via atom transfer radical addition (ATRA) is constrained due to its limited range of compatible substrates or the need to manipulate the olefin coupling partners. Herein, we present a novel approach for their synthesis via Cu-catalyzed ATRA to vinyl boronic esters. The catalyst is proposed to mediate a traditionally inefficient halogen atom transfer of the α-boryl radical intermediate, thus significantly expanding the range of participating substrates relative to established methods.

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Previous literature suggests that kidney transplant recipients (KTRs) do not use the majority of opioid tablets prescribed after transplant surgery. This study analyzed the effectiveness of a new pain management guidance in KTRs after discharge from transplant surgery at a renal transplant center. The single center pre-, post- study compared the number of opioid refill requests, patient-reported pain control, multimodal analgesic agents, and opioid tablets prescribed at discharge in both pre- and post- cohorts.

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Despite the growing number of older people who live alone and in poverty, the intersection of these two social risk factors and the impacts on older adults' health and well-being have not been widely examined. This qualitative study explores the challenges and strengths of 47 older people who live alone and in poverty in Hong Kong. Thematic analysis was used to identify eight themes related to challenges: (i) social isolation and loneliness, (ii) self-esteem and self-efficacy, (iii) declining mobility, health and activity levels, (iv) high medical expenses, (v) age discrimination and long wait times for medical health services, (vi) age discrimination, retirement, and wanting part-time employment, (vii) not enough gender-specific social participation activities, and (viii) housing insecurity.

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Vicinal diamines are a common motif found in biologically active molecules. The hydroamination of allyl amine derivatives is a powerful approach for the synthesis of substituted 1,2-diamines. Herein, the rhodium-catalyzed hydroamination of primary and secondary allylic amines using diverse amine nucleophiles, including primary, secondary, acyclic, and cyclic aliphatic amines to access a wide range of unsymmetrical vicinal diamines, is presented.

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This paper describes the route, from simulations toward experiments, for optimizing the magnetoelectric (ME) geometries for vortex magnetic field sensors. The research is performed on the base of the Metglas/Piezoelectric (PZT) laminates in both open and closed magnetic circuit (OMC and CMC) geometries with different widths (), lengths (), and diameters (). Among these geometries, the CMC laminates demonstrate advantages not only in their magnetic flux distribution, but also in their sensitivity and in their independence of the position of the vortex center.

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Background: Patient-derived xenograft (PDX) mouse tumour models can predict response to therapy in patients. Predictions made from PDX cultures (PDXC) would allow for more rapid and comprehensive evaluation of potential treatment options for patients, including drug combinations.

Methods: We developed a PDX library of BRAF-mutant metastatic melanoma, and a high-throughput drug-screening (HTDS) platform utilising clinically relevant drug exposures.

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Purpose: As cardiovascular implantable electronic devices (CIEDs) are increasingly indicated in older patients, and the burden of cancer is rising with the aging population, the management of patients with CIEDs who require radiotherapy (RT) is a timely concern. The objective of the study was to evaluate the management of, and malfunctions in, patients with CIEDs undergoing RT.

Methods: A retrospective study of patients with CIEDs receiving RT at Kingston Health Sciences Center from March 2007-April 2018 was conducted.

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Sustained exposure to an asynchronous multisensory signal causes perceived simultaneity to shift in the direction of the leading component of the adapting stimulus. This is known as temporal recalibration, and recent evidence suggests that it can occur very rapidly, even after a single asynchronous audiovisual (AV) stimulus. However, this form of rapid recalibration appears to be unique to AV stimuli, in contrast to recalibration following sustained asynchronies which occurs with audiotactile (AT) and visuotactile (VT) stimuli.

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We examined different encapsulation strategies for perovskite solar cells by testing the device stability under continuous illumination, elevated temperature (85 °C) and ambient humidity of 65 %. The effects of the use of different epoxies, protective layers and the presence of desiccant were investigated. The best stability (retention of ∼80 % of initial efficiency on average after 48 h) was obtained for devices protected by a SiO film and encapsulated with a UV-curable epoxy including a desiccant sheet.

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Hb Tarrant [α126(H9)Asp→Asn; HBA2: c.379G > A (or HBA1)], is a rare high oxygen affinity hemoglobin (Hb) variant that causes erythrocytosis, previously described in a few Mexican-American families. Here we report the first Chinese family with this Hb variant presenting with unexplained familial erythrocytosis.

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Objective: To assess the impact of individualised, reconciled evidence-based recommendations (IRERs) and multidisciplinary care in patients with chronic heart failure (CHF) on clinical guideline compliance for CHF and common comorbid conditions.

Design And Setting: A retrospective hospital clinical audit conducted between 1st July 2006 and February 2011.

Participants: A total of 255 patients with a diagnosis of CHF who attended the Multidisciplinary Ambulatory Consulting Services (MACS) clinics, at the Royal Adelaide Hospital, were included.

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Influenza infection predisposes patients to secondary bacterial pneumonia that contributes significantly to morbidity and mortality. Although this association is well documented, the mechanisms that govern this synergism are poorly understood. A window of hyporesponsiveness following influenza infection has been associated with a substantial increase in local and systemic IFN-γ concentrations.

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Purpose: To determine the efficacy of minocycline-rifampin-coated hemodialysis catheters in reducing catheter-related infections in patients requiring hemodialysis for acute renal failure.

Methods: Between May 2000 and March 2002, 66 patients were randomly assigned to receive a minocycline-rifampin-impregnated central venous catheter and 64 were randomly assigned to receive an unimpregnated catheter. Patients were followed prospectively until the catheter was removed.

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We have identified three novel, rarely expressed human genes that encode new members of the lipid transfer/lipopolysaccharide binding protein (LT/LBP) gene family based on sequence homology. BPI and other members of the LT/LBP family are structurally related proteins capable of binding phospholipids and lipopolysaccharides. Real-time PCR studies indicate that BPIL1 and BPIL3 are highly expressed in hypertrophic tonsils.

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Background: The authors published a pharmacokinetic- pharmacodynamic model for two drugs based on response surface methodology. Because of the complexity of the model, they performed a simulation study to answer two questions about use of the model: (1) which study design would be most satisfactory; and (2) how many patients would need to be studied to adequately describe an entire response surface.

Methods: Data were simulated using realistic variability for two hypothetical intravenous anesthetic drugs that interact synergistically and that could be given by computer-controlled infusion.

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