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Analysing dynamics of a single biomolecule using high-resolution imaging techniques has been had significant attentions to understand complex biological system. Among the many approaches, vertical nanopillar arrays in contact with the inside of cells have been reported as a one of useful imaging applications since an observation volume can be confined down to few-tens nanometre theoretically. However, the nanopillars experimentally are not able to obtain super-resolution imaging because their evanescent waves generate a high optical loss and a low signal-to-noise ratio. Also, conventional nanopillars have a limitation to yield 3D information because they do not concern field localization in z-axis. Here, we developed novel hybrid nanopillar arrays (HNPs) that consist of SiO2 nanopillars terminated with gold nanodisks, allowing extreme light localization. The electromagnetic field profiles of HNPs are obtained through simulations and imaging resolution of cell membrane and biomolecules in living cells are tested using one-photon and 3D multiphoton fluorescence microscopy, respectively. Consequently, HNPs present approximately 25 times enhanced intensity compared to controls and obtained an axial and lateral resolution of 110 and 210 nm of the intensities of fluorophores conjugated with biomolecules transported in living cells. These structures can be a great platform to analyse complex intracellular environment.

Decommissioning and closure of Canada's Underground Research Laboratory (URL) involved installing a full-scale 5 m diameter by 12 m long seal in the main access shaft. The seal consisted of clay and concrete components spanning a major water-bearing fracture zone (FZ2) located at a depth of around 275 m that isolates two hydrogeochemical regimes. This paper presents results of coupled hydromechanical (H-M) numerical modelling that simulated measured performance of the seal. Parameters for the H-M modeling were determined from previously measured laboratory test data. Results from the modeling were compared with field data for water uptake and total pressures in the system. They show that hydration of the clay seal was dominated by the groundwater flow from FZ2. The simulations showed good agreement with field readings and provide an improved understanding of various interrelated physical processes that take place during hydration. Key words: shaft seal, hydromechanical (H-M) performance, swelling pressure, soil suction, soil water retention curve. La desaffectation et la fermeture du laboratoire souterrain de recherche (LRS) du Canada impliquaient l'installation d'un scellement a pleine echelle de 5 m de diametre sur 12 m de long dans le puits d'acces principal. Le scellement consistait en des composants d'argile et de beton couvrant une zone de fracture aquifere majeure (FZ2) situee a une profondeur de 275 m qui isole deux regimes hydrogeochimiques. Cet article presente les resultats d'une modelisation numerique couplee hydro-mecanique (H-M) qui simule les performances mesurees du scellement. Les parametres pour la modelisation H-M ont ete determines a partir de donnees prealablement mesurees lors d'essais de laboratoire. Les resultats de la modelisation ont ete compares aux donnees de terrain pour l'absorption d'eau et les pressions totales dans le systeme. Ils montrent que l'hydratation du scellement d'argile etait dominee par le flux d'eau souterraine provenant de FZ2. Les simulations ont montre une bonne concordance avec les lectures sur le terrain et ont permis de mieux comprendre les differents processus physiques interdepen-dants qui se produisent pendant l'hydratation. Mots-cles : scellement de puits, performance hydromecanique (H-M), pression de gonflement, succion du sol, courbe de retention d'eau., 1. Introduction During closure of the Underground Research Laboratory (URL) in south-eastern Manitoba, Atomic Energy of Canada Limited (AECL) constructed a composite concrete-clay-concrete seal in the main access shaft to [...]

We recently developed a novel hyperspectral excitation-resolved near-infrared fluorescence imaging system (HER-NIRF) based on a continuous-wave wavelength-swept laser. In this study, this technique is applied to measure the distribution of the therapeutic agent dimethyl sulfoxide (DMSO) by utilizing solvatochromic shift in the spectral profile of albumin-bound Indocyanine green (ICG). Using wide-field imaging in turbid media, complex dynamics of albumin-bound ICG are measured in mixtures of dimethyl sulfoxide (DMSO) and water. Phantom experiments are conducted to evaluate the performance of the HER-NIRF system. The results show that the distribution of DMSO can be visualized in the wide-field reflection geometry. One of the main purposes of the DMSO is to act as a carrier for other drugs, enhancing their effects by facilitating skin penetration. Understanding the solubility and permeability of drugs in vivo is very important in drug discovery and development. Hence, this HER-NIRF technique has great potential to advance the utilization of the therapeutic agent DMSO by mapping its distribution via the solvatochromic shift of ICG. By customizing the operational wavelength range, this system can be applied to any other fluorophores in the near-infrared region and utilized for a wide variety of drug delivery studies. [ABSTRACT FROM AUTHOR]

Photoacoustic imaging has emerged as a promising biomedical imaging technique that enables visualization of the optical absorption characteristics of biological tissues in vivo. Among the different photoacoustic imaging system configurations, optical-resolution photoacoustic microscopy stands out by providing high spatial resolution using a tightly focused laser beam, which is typically transmitted through optical fibers. Achieving high-quality images depends significantly on optical fluence, which is directly proportional to the signal-to-noise ratio. Hence, optimizing the laser-fiber coupling is critical. Conventional coupling systems require manual adjustment of the optical path to direct the laser beam into the fiber, which is a repetitive and time-consuming process. In this study, we propose an automated laser-fiber coupling module that optimizes laser delivery and minimizes the need for manual intervention. By incorporating a motor-mounted mirror holder and proportional derivative control, we successfully achieved efficient and robust laser delivery. The performance of the proposed system was evaluated using a leaf-skeleton phantom in vitro and a human finger in vivo, resulting in high-quality photoacoustic images. This innovation has the potential to significantly enhance the quality and efficiency of optical-resolution photoacoustic microscopy. [ABSTRACT FROM AUTHOR]

Extended measurement ranges with coherent ranging necessitate an increase in the digitizer sampling rate. Subsampled coherent ranging can reduce the sampling rate, but it has been demonstrated in a short range below around 10 cm. Herein, programmable optical Vernier‐sampled coherent ranging over several tens of meters with a reduced sampling rate using a newly developed stepped‐frequency‐swept laser (stepped‐FSL) is proposed. The measurable range of three‐dimensional subsampled coherent ranging can be extended by increasing the coherence length of the stepped‐FSL. The proposed stepped‐FSL sequentially emits a discrete frequency output by applying a programmable voltage signal to an electro‐optic modulator. The free spectral range of the stepped‐FSL output can be rapidly and akinetically adjusted by changing the number of steps in the programmable voltage signal. The proposed system realizes an extended measurable range (over 20 m) and a high repetition rate (200 kHz). A low sampling rate of 10 MS s−1 is sufficient for operation at a subsampled interference frequency of 1 MHz. This rate is an order of magnitude lower than that of the conventional coherent ranging using an FSL. Experimental results demonstrate that the programmable optical Vernier‐sampled coherent ranging can be improved by leveraging novel optical subsampling with a stepped‐FSL. [ABSTRACT FROM AUTHOR]

In recent years, bone tissue engineering (BTE) has made significant progress in promoting the direct and functional connection between bone and graft, including osseointegration and osteoconduction, to facilitate the healing of damaged bone tissues. Herein, we introduce a new, environmentally friendly, and cost-effective method for synthesizing reduced graphene oxide (rGO) and hydroxyapatite (HAp). The method uses epigallocatechin-3-O-gallate (EGCG) as a reducing agent to synthesize rGO (E-rGO), and HAp powder is obtained from Atlantic bluefin tuna (Thunnus thynnus). The physicochemical analysis indicated that the E-rGO/HAp composites had exceptional properties for use as BTE scaffolds, as well as high purity. Moreover, we discovered that E-rGO/HAp composites facilitated not only the proliferation, but also early and late osteogenic differentiation of human mesenchymal stem cells (hMSCs). Our work suggests that E-rGO/HAp composites may play a significant role in promoting the spontaneous osteogenic differentiation of hMSCs, and we envision that E-rGO/HAp composites could serve as promising candidates for BTE scaffolds, stem-cell differentiation stimulators, and implantable device components because of their biocompatible and bioactive properties. Overall, we suggest a new approach for developing cost-effective and environmentally friendly E-rGO/HAp composite materials for BTE application. [ABSTRACT FROM AUTHOR]

The major rivers within the City of Winnipeg are founded in glacial Lake Agassiz clay and silt sediments that have low shear strength. As such, riverbank instabilities are a common issue along many stretches of the rivers. The use of rockfill columns has become an increasingly utilized approach for stabilizing failing banks. Recent cases in Winnipeg have shown that movements can occur following installation of rockfill columns. Uncertainty regarding the magnitude of these movements that is required to mobilize shearing resistance in the rockfill columns has resulted in situations where the stability of riverbanks following remediation has been questioned. This has provided a need to improve our understanding about how much movement a stabilized slope must undergo before sufficient shear resistance of the rockfill column will be mobilized. The results of experimental testing conducted to assess the shear mobilization of rockfill column materials using a large-scale direct shear test apparatus are presented in this paper. The testing methodology is described along with the test results. The results show that the development of material specifications, construction, and placement methods and appropriate methods of analysis requires understanding of the stress--strain properties of the in situ soil and the rockfill material. Key words: rockfill columns, direct shear test, shear mobilization, shear strength. Les rivieres principales dans la ville de Winnipeg se trouvent par-dessus l'argile et les sediments silteux du lac glaciaire Agassiz, qui eux ont une faible resistance au cisaillement. Ainsi, les instabilites des berges est un probleme courant le long de plusieurs segments des rivieres. L'utilisation de colonnes de remblai rocheux est devenue une approche de plus en plus pratiquee pour la stabilisation des berges. Des cas recents a Winnipeg ont montre que des mouvements peuvent se produire suite a l'installation des colonnes de remblai rocheux. Les incertitudes reliees a la magnitude de ces mouvements requis pour mobiliser la resistance au cisaillement dans les colonnes de remblai rocheux ont amene a des situations ou la stabilite des berges suite a la restauration a ete remise en question. Ces situations ont demontre le besoin d'ameliorer nos connaissances sur les mouvements qu'une pente stabilisee doit subir avant qu'il y ait suffisamment de resistance au cisaillement de developpe dans la colonne de remblai rocheux. Dans cet article, des resultats d'essais experimentaux effectues pour evaluer la mobilisation en cisaillement des colonnes de remblai rocheux a l'aide d'un appareil a grande echelle d'essais de cisaillement direct sont presentes. La methodologie et les resultats des essais sont decrits. Les resultats demontrent que le developpement des caracteristiques des materiaux, les methodes de construction et de placement et les methodes d'analyse appropriees demande une comprehension des proprietes de contraintes--deformations du sol in-situ et du remblai rocheux. Mots-cles : colonnes de remblai rocheux, essai de cisaillement direct, mobilisation en cisaillement, resistance au cisaillement. [Traduit par la Redaction], Introduction Winnipeg's riverbanks consist predominantly of lacustrine clay--rich soils and alluvial (river) deposits of layered clays, silts, and sands. The lacustrine clay soils are relatively weak, resulting in instability along [...]

A simple configuration for simultaneous measurement of temperature and strain exploiting a temperature-insensitive birefringent interferometer based on a photonic crystal fiber incorporating an erbium-doped fiber (EDF) is investigated. The transmission peak power of the birefringent interferometer incorporating the EDF is changed by the temperature variation because the amplified spontaneous emission of the EDF strongly depends on temperature. The applied strain changes the peak wavelength of the birefringent interferometer connecting with the EDF, which can make it possible to discriminate concurrent sensitivities like temperature and strain. The temperature and strain sensitivities were -0.04dB/[degrees]C and 1.3 pm/[mu][epsilon], respectively. OCIS codes: 060.2310, 060.2370.

The development of scientific technology for art authentication has elicited multidimensional evidence to distinguish forgeries from original artwork. Here, we analyzed the three-dimensional morphology of cracks that contain information, such as the painting features of artworks, using optical coherence tomography. The forgeries were produced by an expert from original oil paintings with cracks that occur owing to paint drying, canvas aging, and physical damage. Parameters, such as shape, width, and depth, were compared based on the cross-sectional images of the original and fake cracks. The original cracks were rectangular and inverted, but the fake cracks were relatively simple inverted triangles. The original cracks were as deep as the thickness of the upper layer and mostly were "thin/deep" or "wide/shallow". The fake cracks were observed to be "'thin/shallow" or "wide/deep". This study aims to improve the understanding of crack characteristics and promote the development of techniques for determining art authenticity. [ABSTRACT FROM AUTHOR]

A practical scheme for a tunable multiwavelength Raman fiber ring laser based on a single fiber Bragg grating with a voltage-controllable coil heater is investigated. The number of phase-shifted regions within a single fiber grating determines the number of reflection peaks and the number of lasing wavelengths in the multiwavelength Raman fiber ring laser. A stable multiwavelength Raman fiber ring laser with low output peak-power fluctuation of less than 0.5 dB at room temperature is achieved. A multiwavelength Raman fiber ring laser with a high extinction ratio of more than 50 dB is realized. High flatness is obtained for three lasing peaks, and the lasing peak-power difference is measured to be less than 0.2 dB. A voltage-controllable coil heater with heating elements is used to effectively control three lasing wavelengths in the multiwavelength output, and the tunability of each lasing wavelength is measured to be 0.11 nm/V. OCIS codes: 060.2310, 060.2351, 060.3735.