We demonstrate dynamic surface-enhanced Raman scattering (SERS) imaging with 3 dimensional mapping in a living cell by combining a confocal Raman spectrometer and dual-focus dark-field microscopy. Gold nanoparticles acting as a probe traveling through the living cell, are tracked by dual-focus dark-field imaging, with position feedback to the confocal Raman spectrometer in order to record evolving SERS signals from the same gold nanoparticle moving through the cell. Simultaneous detection of motion and the SERS spectrum enables the visualization of the SERS pathways.
View Article and Find Full Text PDFSurface morphology of materials is routinely analysed by an atomic force microscope and scanning tunneling microscope (STM) down to subnanometer precision. However, it is still challenging to investigate the surface chemistry simultaneously, which requires specific capability of force or tunneling spectroscopy in ultrahigh vacuum environment and liquid Helium temperature. Here we demonstrate the simultaneous chemical and structural analysis of individual carbon nanotubes (CNTs) by STM-based tip-enhanced Raman spectroscopy (STM-TERS) with 1.
View Article and Find Full Text PDFWe report, for the first time, the saturated excitation (SAX) of fluorescent proteins for subdiffraction-limited imaging of living cells in three-dimensions. To achieve saturation, a bright yellow and green fluorescent protein (Venus and EGFP) that exhibits a strong nonlinear fluorescence response to the high excitation intensity at the laser focus is used. Harmonic demodulation of the fluorescence signal produced by a modulated excitation light extracts the nonlinear fluorescence signals.
View Article and Find Full Text PDFSaturated excitation (SAX) microscopy utilizes the nonlinear relation between fluorescence emission and excitation under saturated excitation to improve the spatial resolution of confocal microscopy. In this study, we theoretically and experimentally investigate the saturation of fluorescence excitation under modulated excitation to optimize the excitation conditions for SAX microscopy. Calculation of the relationships between fluorescence and excitation intensity with different modulation frequencies reveals that the lifetime of the triplet state of the fluorescent probe strongly affects the strength of the demodulated fluorescence signals.
View Article and Find Full Text PDFObjectives: The purpose of this study was to evaluate the lesion frequency and incremental added benefit with "true whole-body" (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) of distal lower extremities. We compared this field of view with the typical whole-body view, from head to upper thighs, in numerous patients with known or suspected malignancy.
Methods: True whole-body (18)F-FDG PET/CT, from the top of the head to the bottom of the feet, was performed on 4574 consecutively registered patients with known or suspected malignancy.
We show that scattering from a single gold nanoparticle is saturable for the first time. Wavelength-dependent study reveals that the saturation behavior is governed by depletion of surface plasmon resonance, not the thermal effect. We observed interesting flattening of the point spread function of scattering from a single nanoparticle due to saturation.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
October 2013
The title dinuclear complex, [Fe2Br4(C13H9N4)2], which lies on an inversion center, features two approximately planar bis-(pyridin-2-yl)pyrazole (bpypz(-)) ligands [maximum deviation = 0.082 (3) Å] and four bromide ions. Each Fe(III) ion is octa-hedrally coordinated by four N atoms of two bpypz(-) ligands and two Br ions.
View Article and Find Full Text PDFBackground: Accurate detection and monitoring of disease-related biomarkers is important in understanding pathophysiology. We devised a rapid immunoreaction system that uses submicrometer polymer-coated fluorescent ferrite (FF) beads containing both ferrites (magnetic iron oxide) and fluorescent europium complexes.
Methods: FF beads were prepared by encapsulation of hydrophobic europium complexes into the polymer layers of affinity magnetic beads using organic solvent.
System level understanding of the cell requires detailed description of the cell state, which is often characterized by the expression levels of proteins. However, understanding the cell state requires comprehensive information of the cell, which is usually obtained from a large number of cells and their disruption. In this study, we used Raman spectroscopy, which can report changes in the cell state without introducing any label, as a non-invasive method with single cell capability.
View Article and Find Full Text PDFThe purpose of this study was to determine the physiological and biochemical properties of hindlimb muscles after hypoventilation (HPO) induced by bilateral phrenic nerve denervation. Male Wistar rats (10 weeks-old) underwent HPO by the phrenic nerve denervation at the cervical level or sham surgery. Analyses were performed 4, 8, and 12 weeks after the surgery.
View Article and Find Full Text PDFWe report the simultaneous imaging of protonated and deprotonated forms of carbonylcyanide p-trifluoromethoxy-phenylhydrazone (FCCP) molecules in live cells by Raman microscopy. Nitriles, structure-sensitive Raman tags, are used to detect the two distinct molecular structures, demonstrating the potential of Raman microscopy for structure-based imaging of bioactive small molecules.
View Article and Find Full Text PDFThe electronic properties of single walled carbon nanotubes (SWNTs) can change with a slight deformation, such as the one caused by the pressure of one SWNT crossing over the other in an "X" shape. The effect, however, is extremely localized. We present a tip-enhanced Raman investigation of the extremely localized semiconductor-to-metal transition of SWNTs in such a situation, where we can see how the Fano interaction, which is a Raman signature of metallic behavior, grows towards the junction and is localized within a few nanometers of its vicinity.
View Article and Find Full Text PDFSaturated excitation (SAX) microscopy offers high-depth discrimination predominantly due to nonlinearity in the fluorescence response induced by the SAX. Calculation of the optical transfer functions and the edge responses for SAX microscopy revealed the contrast improvement of high-spatial frequency components in the sample structure and the effective reduction of background signals from the out-of-focus planes. Experimental observations of the edge response and x-z cross-sectional images of stained HeLa cells agreed well with theoretical investigations.
View Article and Find Full Text PDFBackground: Ion beam has been used in cancer treatment, and has a unique preferable feature to deposit its main energy inside a human body so that cancer cell could be killed by the ion beam. However, conventional ion accelerator tends to be huge in its size and its cost. In this paper a future intense-laser ion accelerator is proposed to make the ion accelerator compact.
View Article and Find Full Text PDFAim: Maximum standardized uptake value on (18) F-fluorodeoxyglucose positron emission tomography was evaluated as a predictive surrogate marker in developing treatment strategies for recurrent or metastatic endometrial stromal sarcoma.
Methods: Clinical information was obtained from records of patients with recurrent or metastatic endometrial stromal sarcoma who underwent surgery or biopsy following (18)F-fluorodeoxyglucose positron emission tomography. Pathological features - including estrogen receptor, progesterone receptor and Ki-67 expression - were immunohistochemically evaluated.
Acta Crystallogr Sect E Struct Rep Online
October 2013
The title dinuclear complex mol-ecule, [Cu2(C13H9N4)2(PF6)2], lies about an inversion center. The Cu(II) atom shows a square-pyramidal coordination geometry with the basal plane formed by four N atoms of the two bis-chelating 3,5-bis-(pyridin-2-yl)pyrazolate ions and with one F atom of the hexa-fluoro-phosphate ion in the apical position. Mol-ecules are stacked in a column along the a axis through C-H⋯F hydrogen bonds.
View Article and Find Full Text PDFTip-enhanced Raman scattering microscopy is a powerful technique for analysing nanomaterials at high spatial resolution far beyond the diffraction limit of light. However, imaging of intrinsic properties of materials such as individual molecules or local structures has not yet been achieved even with a tip-enhanced Raman scattering microscope. Here we demonstrate colour-coded tip-enhanced Raman scattering imaging of strain distribution along the length of a carbon nanotube.
View Article and Find Full Text PDFBy using the optical frequency dependence of surface-plasmon polaritons, color images can be reconstructed from holograms illuminated with white light. We report details on the color selectivity of the color holograms. The selectivity is tuned by the thickness of a dielectric film covering a plasmonic metal film.
View Article and Find Full Text PDFIn polycrystalline materials, grain growth occurs at elevated temperatures to reduce the total area of grain boundaries with high energy. The grain growth rate usually slows down with annealing time, making it hard to obtain grains larger than a millimeter in size. We report a crystal growth method that employs only a cyclic heat treatment to obtain a single crystal of more than several centimeters in a copper-based shape-memory alloy.
View Article and Find Full Text PDFAim: Renal damage has been reported as an important complication during combination treatment of peginterferon (PEG IFN), ribavirin (RBV) and telaprevir (TVR) for chronic hepatitis C. However, very little is known about this complication. We investigated the role TVR plays in renal damage during this triple therapy.
View Article and Find Full Text PDFCase Rep Gastroenterol
September 2013
A 21-year-old man with a history of sudden rectal hemorrhage was referred to our hospital. Examination disclosed thrombocytopenia and hepatosplenomegaly. A liver biopsy specimen demonstrated Gaucher cells in Glisson's capsule.
View Article and Find Full Text PDFProlactin is not only a pituitary hormone but an immunoregulatory hormone secreted from lymphocytes. Prolactin induction in relation to hepatitis C virus (HCV) infection has not been elucidated. The serum levels of prolactin were examined in 232 HCV-infected subjects positive for anti-HCV antibody and 65 healthy controls negative for it, who were recruited in the cohort study.
View Article and Find Full Text PDFWe present a simple plasmonic method that enables tuning of accessibility to the dipole-forbidden transition states of matter. This technique is realized by well-controlled plasmonic dimers, which can confine optical fields on the order of molecular dimensions. As an example, the approach is applied to activate invisible noncenter phonon modes of defect-free graphene in resonance Raman spectra.
View Article and Find Full Text PDFMetal nanoparticles have recently emerged as ubiquitous surface-enhanced Raman scattering (SERS) agents for nano-imaging and nano-analysis. These applications make use of the unique optical properties of metal nanoparticles to enhance the efficiency of Raman scattering, whereas the small size of the nanoparticles localizes the enhanced Raman scattering at the nanoscale. In this perspective, we review the recent progress in SERS nano-imaging and nano-spectroscopy using metal nanoparticles applied especially to biological samples and nanomaterials.
View Article and Find Full Text PDFBackground: Hepatic steatosis is often seen in patients with chronic hepatitis C (CH-C). It is still unclear whether these patients have an impaired mitochondrial β-oxidation. In this study we assessed mitochondrial β-oxidation in CH-C patients by investigating ketogenesis during fasting.
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