Publications by authors named "Nicolas Ho"

Hereditary spastic paraplegia (HSP) is a group of genetic motor neuron diseases resulting from length-dependent axonal degeneration of the corticospinal upper motor neurons. Due to the advancement of next-generation sequencing, more than 70 novel HSP disease-causing genes have been identified in the past decade. Despite this, our understanding of HSP physiopathology and the development of efficient management and treatment strategies remain poor.

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Bioequivalence (BE) is usually hard to achieve for extended-release (ER) dosage form products due to not only its complicated formulation but also to the BCS classification of the investigated drugs. Considering the difficulties in establishing full-scale IVIVC and limited in vivo pharmacokinetics data in the early stage of formulation development, we have selected BCS III drug metformin as a model drug to demonstrate a novel approach for the selection of BE formulations. Firstly, dissolution tests in both standard and biorelevant media were performed followed by identification of the most similar formulation WM to the reference product (GXR) based on principal component analysis (PCA) of the dissolution data.

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Ethnopharmacological Relevance: Radix Salvia Miltiorrhiza (Danshen) and Radix Pueraria Lobate (Gegen) are officially listed in the Chinese Pharmacopoeia and have long been used together as a Compound Chinese Traditional Medicine (CCTM) for treatment of coronary heart diseases, which are often co-administered with aspirin or warfarin to patients suffering from cardiovascular diseases.

Aim Of Study: Since significant pharmacokinetic and pharmacodynamic interactions between Danshen-Gegen (DG) formula and aspirin/warfarin have been observed in our previous rat studies, the current study was proposed aiming to further verify such pharmacokinetic and pharmacodynamic interactions in healthy human subjects and explore related mechanisms.

Materials And Methods: A 5-day, multiple dose, five-session clinical trial has been carried out (n = 14) with 2-week washout periods between sessions, during which the subjects would receive different combinations of the medications.

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Ethnopharmacological Relevance: According to Traditional Chinese Medicine theory, influenza is categorized as a warm disease or Wen Bing. The Wen Bing formulas, such as Yin-Qiao-San and Sang-Ju-Yin, are still first-line herbal therapies in combating variant influenza virus. To continue our study on the pharmacokinetic and pharmacodynamic interactions between Wen Bing formulas and oseltamivir (OS), the first-line western drug for the treatment of influenza, further interactions between OS and the eight single herbs and their relevant marker components from Wen Bing formulas were investigated in the current study.

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Piperine, an alkaloid from black pepper, has demonstrated beneficial effects in central nervous system, especially in epilepsy control. However, its therapeutic application remains limited due to the low aqueous solubility of piperine. Thus, the present study aimed to formulate piperine into a more solubilized form to enhance its oral bioavailability and facilitate its development as a potential anti-epileptic treatment.

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We have built and demonstrated a lateral shearing interferometer as a process engineering and control tool for the fabrication and characterization of direct-laser-written waveguide structures in chalcogenide glasses. Photoinduced change in refractive index of 0.154+/-0.

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A versatile mid-infrared hyperspectral imaging system is demonstrated by combining a broadly tunable external cavity quantum cascade laser and a microbolometer focal plane array. The tunable midinfrared laser provided high brightness illumination over a tuning range from 985 cm(-1) to 1075 cm(-1) (9.30-10.

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We demonstrate the design, fabrication, and characterization of single-mode low-loss waveguides for mid-infrared (MIR) wavelengths. Planar waveguide structures were fabricated from multilayer thin films of arsenic-based chalcogenide glasses followed by the creation of channel waveguides by using the photodarkening effect. Propagation losses as low as 0.

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Single-channel waveguides and Y couplers were fabricated in chalcogenide thin films by use of femtosecond laser pulses from a 25-MHz repetition rate Ti:sapphire laser. Refractive-index differentials (delta n > 10(-2)) were measured through interferometric microscopy and are higher than the typical values reported for oxide glasses. The dependence of the index differential on the peak intensity reveals the nonlinear nature of the photosensitivity in arsenic trisulfide below its bandgap energy, and the refractive-index change is correlated to the photoinduced structural changes inferred by Raman spectroscopy data.

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We present experimental results highlighting the physica mechanism responsible for the initial spectral broadening of femtosecond Ti:Sapphire pulses in a highly birefringent microstructured fiber having a small effective area. By rotating the input polarization and varying the injected power while monitoring the resulting changes in the output spectrum, we are bringing clear evidences that the initial broadening mechanism leading to a broadband supercontinuum is indeed the fission of higher-order solitons into redshifted fundamental solitons along with blueshifted nonsolitonic radiation.

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Chalcogenide glasses are promising candidates for all-optical switching and various nonlinear applications. However, we show that As2S3 thin films are photosensitive at wavelengths in the 1.5-microm telecommunication window.

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