Qiyin Fang

Qiyin Fang
McMaster University | McMaster · Department of Engineering Physics

PhD

About

159
Publications
46,083
Reads
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2,096
Citations
Citations since 2016
56 Research Items
1047 Citations
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2016201720182019202020212022050100150
2016201720182019202020212022050100150

Publications

Publications (159)
Article
Cytoplasmic and membrane-bound BCL-2 family proteins regulate apoptosis, a form of programmed cell death, via dozens of binary protein interactions confounding measurement of the effects of inhibitors in live cells. In cancer, apoptosis is frequently dysregulated, and cell survival depends on antiapoptotic proteins binding to and inhibiting proapop...
Article
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Objective: In colonoscopy, it is desirable to accurately localize the position of the endoscope’s distal tip. Current tip localization techniques are not sufficient for recording the position and movement of the tip, nor is its rotation measured. We hypothesize that integration of multiple tracking modalities can effectively record the endoscope’s...
Article
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Objectives: Primary stability is a fundamental prerequisite in predicting the prognosis of a mini-implant (MI) as a skeletal anchorage. This study aims to evaluate the influence of implant site preparation technology on the primary stability of MI. Methods: A total of 108 bovine cortical bone samples were fabricated to three thicknesses (0.5, 1.0,...
Article
Mn²⁺ was shown to be incorporated as a co-dopant in glycothermally synthesized Ce:YAG-based nanophosphors to enhance the red component of the emission spectrum. Structural characterization showed a preferential inclusion of Mn²⁺ in the Y site. AlIV/AlVI ratios were found to decrease from 0.25 in Ce:YAG nanophosphors to 0.11 with the addition of Mn²...
Article
Full-text available
Phytoplankton monitoring is essential for better understanding and mitigation of phytoplankton bloom formation. We present a microfluidic cytometer with two imaging modalities for onsite detection and identification of phytoplankton: a lensless imaging mode for morphological features, and a fluorescence imaging mode for autofluorescence signal of p...
Article
In the wake of the COVID-19 pandemic, those planning and conducting research involving older adults have faced many challenges, in part because of the public health measures in place. This article details the early steps and corresponding strategies implemented by our multidisciplinary team to pivot our large-scale aging and mobility study. Based o...
Article
The papers in this special section focus on biophotonics. This is an emerging and widely growing field of advanced biomedical technologies that has opened up new horizons for extensive transfer of state-of-the-art technologies coming from the areas of quantum electronics, lasers, fiber optics and electro-optics to the life sciences and medicine. Th...
Article
Invar 36 (FeNi36) is a weldable nickel alloy, known for its low thermal expansion properties, that contains 36% of nickel and 64% iron. The laser-based powder bed fusion process is often associated with defects and flaws that should be controlled for production quality. Spatter formation and delamination are two phenomena that could be observed in...
Article
Skin erythema may present due to many causes. One of the common causes is prolonged exposure to sunrays. Other than sun exposure, skin erythema is an accompanying sign of dermatologic diseases, such as psoriasis and acne. Quantifying skin erythema in patients enables the dermatologist to assess the patient's skin health. Quantitative assessment of...
Article
Skin cancer (SC) is a widely spread disease in the USA, Canada, and Australia. Skin cancer patients are mostly of advanced age and therefore more likely to be treated with radiation therapy as many are comorbid and not surgical candidates. However, radiation therapy has side effects, which may range from skin erythema to skin necrosis. As erythema...
Preprint
Fluorescence lifetime imaging microscopy (FLIM) can detect Fӧrster resonance energy transfer (FRET) to measure protein-protein interactions in live cells. Traditional FLIM-FRET uses relative intensities to represent protein expression, consequently limiting users to a qualitative comparison of resulting binding curves. In our quantitative Fast FLIM...
Article
Full-text available
It is highly demanding to identify healthy and non-healthy species in a heterogeneous environment such as human tissues. In such a case, one identifier, such as a spectral fingerprint, might be inadequate. Therefore, additional identification is required, for instance, a polarization measurement In view of that, the development of a spectropolarime...
Article
Full-text available
It is highly demanding to identify healthy and non-healthy species in a heterogeneous environment such as human tissues. In such a case, one identifier, such as a spectral fingerprint, might be inadequate. Therefore, additional identification is required, for instance, a polarisation measurement. In view of that, the development of a spectropolarim...
Article
We report the development of a three-dimensional optical model to predict the propagation of light through multilayer optical fluorescence sensors employing total internal reflection. The ray-tracing-based model visualizes the propagation of light from a light source through the optical sensor allowing optimization of the optical path, optical prop...
Article
Full-text available
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Article
Protein-protein interactions can be measured in live cells, at nanometer scale, using Fluorescence Lifetime Imaging Microscopy (FLIM) enabled Firster Resonance Energy Transfer (FRET). There are growing interests in exploring protein-protein interactions in drug discovery applications. Traditional single point confocal microscopes, however, are slow...
Article
Continuous measurement of dissolved oxygen (DO) variation is important in water monitoring and biomedical applications, which require low-cost and low-maintenance sensors capable of automated operation. A frequency-domain optofluidic DO sensor with total internal reflection (TIR) design has been developed based on fluorescence quenching of Rutheniu...
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Screening and surveillance for gastrointestinal (GI) cancers by endoscope guided biopsy is invasive, time consuming, and has the potential for sampling error. Tissue endogenous fluorescence spectra contain biochemical and physiological information, which may enable real-time, objective diagnosis. We first briefly reviewed optical biopsy modalities...
Article
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Urine testing is a powerful clinical diagnostic tool. The noninvasive collection of samples and wide range of diagnostic targets found in urine makes urinalysis well suited for point-of-care (PoC) monitoring applications. Complete urinalysis testing faces many limitations due to the large quantity of samples processed, the time required for testing...
Article
Currently, the spinning disk confocal microscope is the most popular fast confocal imaging system. However, these instruments require a high pixel density camera detector, limiting their use in many applications. We have designed a multiplexed confocal scheme that performs raster scanning of a ${32 \times 32}$32×32 foci array in which the output im...
Article
Luminescence lifetime imaging systems are typically complex and expensive instruments targeting bench-top applications. We present a low-cost approach for video frame rate luminescence lifetime imaging on the microsecond scale based on a cellphone camera. The luminescence lifetime is mapped by measuring the phase shift of optical fringes captured b...
Article
Full-text available
Urine testing is an essential clinical diagnostic tool. The presence of urine sediments, typically analyzed through microscopic urinalysis or cell culture, can be indicative of many diseases, including bacterial, parasitic, and yeast infections, as well as more serious conditions like bladder cancer. Current urine analysis diagnostic methods are us...
Article
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An optical phantom model with stable oxygen saturation (StO2) and optical properties (OPs) is the key for quick and accurate calibration of spectral imaging devices. Toward this goal, we have developed gel-based phantoms using Agarose, polystyrene microsphere, purified hemoglobin, and yeast. Theoretical values of OPs were calculated by applying Bee...
Article
The streak camera is a picosecond resolution photodetector with parallel input capability; however, the degree of multiplexing is limited by crosstalk and temporal uncertainty in the sweeping field. We introduced a fixed time delay between adjacent fibers to reduce crosstalk in the synchroscan mode. The fixed delay and a tunable electronic delay be...
Article
The development of compact and low-cost dissolved oxygen (DO) sensors is essential for the continuous in situ monitoring of environmental water quality and wastewater treatment processes. The optical detection of dynamic and reversible quenching of fluorescent dyes by oxygen has been used for DO sensing. In this paper, we have optimized a multila...
Article
Full-text available
Background: The postpartum period is a vulnerable time for the pelvic floor. Early implementation of pelvic floor muscle exercises, appropriately termed as pelvic floor muscle training (PFMT), in the postpartum period has been advocated because of its established effectiveness. The popularity of mobile health (mHealth) devices highlights their per...
Article
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Background: Medication non-adherence can lead to significant morbidity and mortality. This 4-week feasibility study aims to demonstrate that the eDosette intervention can be implemented with older adults in primary care. Method: Fifty-six older adults from four primary care sites in Southwestern Ontario, Canada participated. The intervention involv...
Conference Paper
Full-text available
Surveillance and assessment of radiation-induced erythema is an important aspect of managing skin toxicity in radiation therapy treated patients. Upon receiving the early fractions of radiation, an inflammatory response and vascular dilation takes place due to damage of basal cells in the skin’s epidermal layer. This process of skin reddening known...
Conference Paper
Full-text available
This work describes a procedure to characterize a developed acousto-optic tunable filter (AOTF) based hyperspectral imaging (HSI) system, operating in the visible-near infrared (VNIR) spectrum. The developed AOTF-HSI system consists of an AOTF (11 x 12 mm aperture), a set of optics, and a computer. The AOTF-HSI setup includes a complementary metal...
Article
Ultrafast lasers are promising tools for surgical applications requiring precise tissue cutting. Shallow ablation depth and slow rate as well as collateral damage are common barriers limiting the use of laser in clinical applications. Localized cooling with water and/or air jet is known to reduce collateral thermal damage. We studied the influence...
Article
Full-text available
Erythema is an inflammatory condition of the skin that is commonly used as a feature to monitor the progression of cutaneous diseases or treatment induced side effects. In radiation therapy, skin erythema is routinely assessed visually by an expert using standardized grading criteria. However, visual assessment (VA) is subjective and commonly used...
Article
Concentration of Dissolved oxygen (DO) is an important indicator of water quality. Fluorescence quenching is a commonly used optical method to measure DO. Steady-state fluorescence intensity measurements are easy to be influenced by acquisition artifacts, which makes determination of absolution DO values difficult. We developed a miniaturized, opto...
Conference Paper
Full-text available
The incessant innovations of hyperspectral imaging (HSI) and data mining algorithms create necessity for developing reliable means of assessment and comparison. In medical applications of HSI, for instance, one of such means is tissue-equivalent phantoms. These phantoms are designed to mimic the spectral behavior of real living tissues. In this wor...
Conference Paper
Full-text available
We document a comparison of an acousto-optic tunable filter (AOTF), and a liquid crystal tunable filter (LCTF) based on hyperspectral imaging (HSI). The purpose of this work is to highlight each tunable filter, in order to ease filter choice in HSI design. Three factors are evaluated including spectral resolution, and image quality. The results ver...
Article
Full-text available
The acousto-optic tunable filter (AOTF) is one of the most used techniques for hyperspectral imaging (HSI), and is capable of fast and random wavelength access, high diffraction efficiency, and good spectral resolution. Typical AOTF-HSI works with linearly polarized light; hence, its throughput is limited for randomly polarized applications such as...
Article
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Purpose: One of the major problems in breast cancer surgery is defining surgical margins and establishing complete tumor excision within a single surgical procedure. The goal of this work is to establish instrumentation that can differentiate between tumor and normal breast tissue with the potential to be implemented in vivo during a surgical proc...
Article
Aqueous-based coatings using combinations of polydopamine (PDA) (as bioadhesive) and grafted polyethylene glycol (PEG) (as antifouling agent) have been reported to reduce biofouling on multiple material surfaces. However, the achievable PEG grafting density and antifouling performance are limited, leaving exposed PDA to provide sites for attachment...
Article
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Three-dimensional electrodes that are controllable over multiple lengthscales are very important for use in bioanalytical systems that integrate solid-phase devices with solution-phase samples. Here we present a fabrication method based on all-solution-processing and thin film wrinkling using smart polymers that is ideal for rapid prototyping of tu...
Article
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Glioma itself accounts for 80% of all malignant primary brain tumors, and glioblastoma multiforme (GBM) accounts for 55% of such tumors. Diffuse reflectance and fluorescence spectroscopy have the potential to discriminate healthy tissues from abnormal tissues and therefore are promising noninvasive methods for improving the accuracy of brain tissue...
Article
Optical spectroscopy of human tissue has been widely applied within the field of biomedical optics to allow rapid, in vivo characterization and analysis of the tissue. When designing an instrument of this type, an imaging spectrometer is often employed to allow for simultaneous analysis of distinct signals. This is especially important when perform...
Article
Full-text available
Current instruments used to detect specific protein-protein interactions in live cells for applications in high-content screening (HCS) are limited by the time required to measure the lifetime. Here, a 32 × 1 single-photon avalanche diode (SPAD) array was explored as a detector for fluorescence lifetime imaging (FLIM) in HCS. Device parameters and...
Article
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Optofluidic devices combining micro-optical and microfluidic components bring a host of new advantages to conventional microfluidic devices. Aspects, such as optical beam shaping, can be integrated on-chip and provide high-sensitivity and built-in optical alignment. Optofluidic microflow cytometers have been demonstrated in applications, such as po...
Article
Dissolved oxygen (DO) is an important indicator for water quality and is also used in point of care applications. Fluorescence signal from Ruthenium (Ru(dpp) 3 ²⁺ ) based fluorophores can be quenched by oxygen such that the reduction of fluorescence signal is proportionally to oxygen concentration. This mechanism allows an optical method to measure...
Article
Full-text available
Time-resolved fluorescence (TRF) and diffuse reflectance (DR) spectroscopy are two optical biopsy modalities that have been studied in tumor diagnosis. Combination of TRF and DR spectroscopy allows us to obtain more features such as fluorescence intensity, lifetime, and optical properties, thus potentially improving the tissue diagnostic accuracy....
Article
Changes in the composition of type I and type III collagen in tissue can shed light on various diseases. However, many of the current collagen detection techniques require invasive and destructive tissue sampling. In this study, a low cost, low complexity light emitting diode (LED) based system was developed to realize both non-invasive detection a...
Article
Full-text available
The ability to recover the intrinsic fluorescence of biological fluorophores is crucial to accurately identify the fluorophores and quantify their concentrations in the media. Although some studies have successfully retrieved the fluorescence spectral shape of known fluorophores, the techniques usually came with heavy computation costs and did not...
Article
Full-text available
Confocal microscopy has several advantages over wide-field microscopy, such as out-of-focus light suppression, 3D sectioning, and compatibility with specialized detectors. While wide-field microscopy is a faster approach, multiplexed confocal schemes can be used to make confocal microscopy more suitable for high-throughput applications, such as hig...
Article
Silicon nitride thin films are deposited by plasma-enhanced chemical vapor deposition on (100) and (111) CaF2 crystalline substrates. Delaminated wavy buckles formed during the release of internal compressive stress in the films and the stress releasing processes are observed macroscopically and microscopically. The stress release patterns start fr...
Article
Early detection and treatment of high-grade dysplasia (HGD) in Barrett's esophagus may reduce the risk of developing esophageal adenocarcinoma. Confocal endomicroscopy (CLE) has shown advantages over routine white-light endoscopic surveillance with biopsy for histological examination; however, CLE is compromised by insufficient contrast and by intr...
Article
High-grade dysplasia (HGD) in Barrett's esophagus (BE) poses increased risk for developing esophageal adenocarcinoma. To date, early detection and treatment of HGD regions are still challenging due to the sampling error from tissue biopsy and relocation error during the treatment after histopathological analysis. In this study, CP-A (metaplasia) an...
Article
Counting of E. coli DH5α cell suspensions in phosphate buffered saline is performed using a micro-flow cytometer based on a photonic-microfluidic integrated device. Side-scattered light signals are used to count the E. coli cells. A detection efficiency of 92% is achieved when compared with the expected count from a haemocytometer. The detection ef...