Publications by authors named "James Piper"

Two molecular cytology approaches, (i) time-gated immunoluminescence assay (TGiA) and (ii) Raman-active immunolabeling assay (RiA), have been developed to detect prostate cancer (PCa) cells in urine from five prostate cancer patients. For TGiA, PCa cells stained by a biocompatible europium chelate antibody-conjugated probe were quantitated by automated time-gated microscopy (OSAM). For RiA, PCa cells labeled by antibody-conjugated Raman probe were detected by Raman spectrometer.

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Surface modification and functionalization is typically required to engineer upconversion nanoparticles (UCNPs) for biosensing and bioimaging applications. Nevertheless, despite various antibody conjugation methods having been applied to UCNPs, no consensus has been reached on the best choice, as the results from individual studies are largely unable to be compared due to inadequate assessment of the properties of the conjugated products. Here, we introduce a systematic approach to quantitatively evaluate the biological activity of antibody-conjugated UCNPs.

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Water-in-oil-in-water (w/o/w) double emulsion (DE) encapsulation has been widely used as a promising platform technology for various applications in the fields of food, cosmetics, pharmacy, chemical engineering, materials science, and synthetic biology. Unfortunately, DEs formed by conventional emulsion generation approaches in most cases are highly polydisperse, making them less desirable for quantitative assays, controlled biomaterial synthesis, and entrapped ingredient release. Microfluidic devices can generate monodisperse DEs with controllable size, morphology, and production rate, but these generally require multistep fabrication processes and use of different solvents or bulky external instrumentation to pattern channel wettability.

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Introduction: Our purpose was to define and categorize patient complaints within a hand surgery practice over a 10-year period. In addition, we aimed to define surgeon and patient factors associated with formal complaints.

Methods: All patients who filed a complaint with our institution's patient advocacy service against six hand surgeons in an academic practice over a 10-year period were recorded and categorized using the Patient Complaint Analysis System.

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Background: Formal patient complaints are associated with increased malpractice litigation and can have adverse occupational consequences for surgeons. Our purpose was to define and categorize patient complaints within an academic pediatric orthopaedic surgery practice over a 10-year period. We further aimed to define risk factors associated with patient complaints.

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Yeast has been engineered for cost-effective organic acid production through metabolic engineering and synthetic biology techniques. However, cell growth assays in these processes were performed in bulk at the population level, thus obscuring the dynamics of rare single cells exhibiting beneficial traits. Here, we introduce the use of monodisperse picolitre droplets as bioreactors to cultivate yeast at the single-cell level.

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Upconversion nanoparticles (UCNPs) exhibit unique optical properties such as photo-emission stability, large anti-Stokes shift, and long excited-state lifetimes, allowing significant advances in a broad range of applications from biomedical sensing to super-resolution microscopy. In recent years, progress on nanoparticle synthesis led to the development of many strategies for enhancing their upconversion luminescence, focused in particular on heavy doping of lanthanide ions and core-shell structures. In this article, we investigate the non-linear emission properties of fully Yb-based core-shell UCNPs and their impact on the super-resolution performance of stimulated excitation-depletion (STED) microscopy and super-linear excitation-emission (uSEE) microscopy.

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Lanthanide-based upconversion nanoparticles (UCNPs) generally require high power laser excitation. Here, we report wide-field upconversion microscopy at single-nanoparticle sensitivity using incoherent excitation of a 970 nm light-emitting diode (LED). We show that due to its broad emission spectrum, LED excitation is about 3 times less effective for UCNPs and generates high background compared to laser illumination.

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Upconversion nanoparticles (UCNPs) are becoming increasingly popular as biological markers as they offer photo-stable imaging in the near-infrared (NIR) biological transparency window. Imaging at NIR wavelengths benefits from low auto-fluorescence background and minimal photo-damage. However, as the diffraction limit increases with the wavelength, the imaging resolution deteriorates.

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Efficient DNA mutation detection methods are required for diagnosis, personalized therapy development, and prognosis assessment for diseases such as cancer. To address this issue, we proposed a straightforward approach by combining active plasmonic nanostructures, surface-enhanced Raman spectroscopy (SERS), and polymerase chain reaction (PCR) with a statistical tool to identify and classify BRAF wild type (WT) and V600E mutant genes. The nanostructures provide enhanced sensitivity, while PCR offers high specificity toward target DNA.

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Time-resolved luminescence detection using long-lived probes with lifetimes in the microsecond region have shown great potential in ultrasensitive and multiplexed bioanalysis. In flow cytometry, however, the long lifetime poses a significant challenge to measure wherein the detection window is often too short to determine the decay characteristics. Here we report a time-resolved microfluidic flow cytometer (tr-mFCM) incorporating an acoustic-focusing chip, which allows slowing down of the flow while providing the same detection conditions for every target, achieving accurate lifetime measurement free of autofluorescence interference.

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The sensitive and simultaneous detection of cytokines will provide new insights into the physiological process and disease pathways due to the complex nature of cytokine networks. However, the key challenge is the lack of probes that can simultaneously detect multiple cytokines in a single sample. In this contribution, we proposed an alternative approach for sensitive cytokine detection in a multiplex manner by the use of a new set of surface-enhanced Raman spectroscopy (SERS) nanotags.

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Sub-diffraction microscopy enables bio-imaging with unprecedented clarity. However, most super-resolution methods require complex, costly purpose-built systems, involve image post-processing and struggle with sub-diffraction imaging in 3D. Here, we realize a conceptually different super-resolution approach which circumvents these limitations and enables 3D sub-diffraction imaging on conventional confocal microscopes.

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We describe simple direct conjugation of a single TEGylated Europium chelate to DNA that binds to intracellular rRNA and is then detected using a homogeneous luminescent in situ hybridisation (LISH) technique. As a proof-of-principle, was selected as a model for our study to show the ability of this probe to bind to intracellular 16S ribosomal rRNA. A highly purified Europium chelate conjugated oligonucleotide probe complementary to an rRNA sequence-specific was prepared and found to be soluble and stable in aqueous solution.

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Objectives: Mammalian targets of rapamycin inhibitors (mTORi) are considered second-line immunosuppression agents because of associated increases in rejection and impaired wound healing. Recent reports indicate mTORi have been linked to improved survival, decreased inflammatory response in pancreatitis, and antiproliferative and antiangiogenic activity. Mammalian targets of rapamycin inhibitors have not been extensively analyzed in pancreas transplant recipients.

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Background: The decision to utilize portal or systemic venous drainage in pancreas transplantation is surgeon- and center-dependent. Information regarding the superior method is based on single-center reports and animal models.

Methods: UNOS data on adults receiving pancreas and kidney-pancreas transplants from 1987 to 2016 were analyzed (n = 29 078).

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Deep tissue imaging in the second near-infrared (NIR-II) window holds great promise for physiological studies and biomedical applications. However, inhomogeneous signal attenuation in biological matter hampers the application of multiple-wavelength NIR-II probes to multiplexed imaging. Here, we present lanthanide-doped NIR-II nanoparticles with engineered luminescence lifetimes for in vivo quantitative imaging using time-domain multiplexing.

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Follicular dendritic cell (FDC) sarcoma is a very rare neoplasm which commonly involves the lymph nodes and less commonly involves extranodal organs such as the liver. Most cases of FDC sarcoma are idiopathic, however some cases are associated with other disease states. Management of FDC sarcoma is primarily focused on surgical resection of the mass, and secondarily focused on radiotherapy, chemotherapy and/or biologic pharmacotherapy.

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Lanthanide-doped glasses and crystals are attractive for laser applications because the metastable energy levels of the trivalent lanthanide ions facilitate the establishment of population inversion and amplified stimulated emission at relatively low pump power. At the nanometre scale, lanthanide-doped upconversion nanoparticles (UCNPs) can now be made with precisely controlled phase, dimension and doping level. When excited in the near-infrared, these UCNPs emit stable, bright visible luminescence at a variety of selectable wavelengths, with single-nanoparticle sensitivity, which makes them suitable for advanced luminescence microscopy applications.

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Prostate cancer is one of the male killing diseases and early detection of prostate cancer is the key for better treatment and lower cost. However, the number of prostate cancer cells is low at the early stage, so it is very challenging to detect. In this study, we successfully designed and developed upconversion immune-nanohybrids (UINBs) with sustainable stability in a physiological environment, stable optical properties and highly specific targeting capability for early-stage prostate cancer cell detection.

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We describe the application of a synthetically developed tetradentate β-diketonate-europium chelate with high quantum yield (39%), for sensitive immunodetection of prostate cancer cells (DU145). MIL38 antibody, a mouse monoclonal antibody against Glypican 1, conjugated directly to the chelate via lysine residues, resulted in soluble (hydrophilic) and stable immunoconjugates. Indirect labeling of the antibody by a europium chelated secondary polyclonal antibody and a streptavidin/biotin pair was also performed.

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We report a patient with previous biliary symptoms and endoscopic interventions who presented with clinical features suggestive of choledocholithiasis. Open surgical exploration disclosed three gallbladders with copious stones and varying degrees of acute and chronic inflammation. Literature review revealed only 16 previously reported cases.

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The ultimate frontier in nanomaterials engineering is to realize their composition control with atomic scale precision to enable fabrication of nanoparticles with desirable size, shape and surface properties. Such control becomes even more useful when growing hybrid nanocrystals designed to integrate multiple functionalities. Here we report achieving such degree of control in a family of rare-earth-doped nanomaterials.

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Compared with routine microscopy imaging of a few analytes at a time, rapid scanning through the whole sample area of a microscope slide to locate every single target object offers many advantages in terms of simplicity, speed, throughput, and potential for robust quantitative analysis. Existing techniques that accommodate solid-phase samples incorporating individual micrometer-sized targets generally rely on digital microscopy and image analysis, with intrinsically low throughput and reliability. Here, we report an advanced on-the-fly stage scanning method to achieve high-precision target location across the whole slide.

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