Use of FBG optical sensors for structural health monitoring: Practical application

This paper describes the development of FBG Optical sensors for their practical application on structural health monitoring. The sensors were installed on the Tsing Ma Bridge for a trial run. The results using FBG sensors were in excellent agreement with those acquired by the bridge WASHMS

Corticofugal Gating of Auditory Information in the Thalamus: An In Vivo Intracellular Recording Study

In the present study, we investigated the auditory responses of the medial geniculate (MGB) neurons, through in vivo intracellular recordings of anesthetized guinea pigs, while the auditory cortex was electrically activated. Of the 63 neurons that received corticofugal modulation of the membrane potential, 30 received potentiation and 33 received hyperpolarization. The corticofugal potentiation of the membrane potential (amplitude, mean ± SD, 8.6 ± 5.5 mV; duration, 125.5 ± 75.4 msec) facilitated the auditory responses and spontaneous firing of the MGB neurons. The hyperpolarization of -11.3 ± 4.9 mV in amplitude and 210.0 ± 210. 1 msec in duration suppressed the auditory responses and spontaneous firing of the MGB neurons. Four of the five neurons that were histologically confirmed to be located in the lemniscal MGB received corticofugal facilitatory modulation, and all of the four neurons that were confirmed to be located in the non-lemniscal MGB received corticofugal inhibitory modulation. The present intracellular recording provides novel results on how the corticofugal projection gates the sensory information in the thalamus: via the spatially selective depolarization of lemniscal MGB neurons and hyperpolarization of non-lemniscal MGB neurons. It is speculated that the systematic selectivity of facilitation and inhibition over the lemniscal and non-lemniscal MGB is related to the attention shift within the auditory modality and across the sensory modalities.published_or_final_versio

Dorsal column is not involved in the mechanism of the hypotensive effect by simulating acupuncture on rat hindlimb

The present study investigated the role of the dorsal column (DC) in the mechanism of the hypotensive effect induced by simulating acupuncture on rat hindlimb. The femoral arterial pressure and electrocardiogram (ECG) of rats were recorded when the hypothalamic paraventricular nucleus (PVN) was electrically stimulated with or without DC lesion. Stimulation of the deep peroneal nerve (DPN) decreased the pressor response elicited by electrical stimulation of the PVN. Thirty minutes after micro-dissection of the right DC, the inhibitory effect of stimulating the right or left DPN on the pressor response induced by stimulation of the contralateral PVN was not altered. Of 6 rats tested, the inhibitory effect of stimulating the right or left DPN could still be observed five days after the right DC was destroyed. The pain responses of both hindlimbs of the rats with the right DC destroyed showed no obvious difference when compared with the sham control rats. These data suggest that the DC is not involved in the inhibitory effect of stimulating the DPN on the pressor response induced by the PVN activation.published_or_final_versio

An in vivo intracellular study of auditory thalamic neurons

The intrinsic electrophysiological properties of medial geniculate body (MGB) neurons and their responses to noise bursts/pure tones were examined in the pentobarbital anesthetized guinea pig through intracellular recording. Discharge rate was calculated in the absence of acoustic stimuli over varied membrane potentials which were changed by intracellular injection of current or through automatic drifting. The non-acoustically-driven firing rate was 45.8±23.3 Hz (mean±S.D., n=8) at membrane potentials of -45 mV, 30.6±19.4 Hz (n=14) at -50 mV, 18.0±12.9 Hz (n=14) at -55 mV, and significantly decreased to 5.7±7.4 Hz at -60 mV, and to 0.7±1.5 Hz (n=10) at -65 mV (ANOVA, P<0.001). The maximum non-acoustically-driven rate observed in the present study was 160 Hz. The auditory responsiveness of the MGB neurons was examined at membrane potentials over a range of -45 to -75 mV: the higher the membrane potential, the greater the responsiveness and vice versa. A putative non-low-threshold calcium spike (non-LTS) burst was observed in the present study. It showed significantly longer inter-spike intervals (11.6±6.0 ms, P<0.001, t -test) than those associated with the putative LTS bursts (6.7±2.4 ms, P<0.001, t-test). The dependence of the temporal structure of the spikes/spike bursts on the stimulus may provide insight into the temporal coding of sound information in the auditory system. © 2003 Elsevier Ltd. All rights reserved.published_or_final_versio

Desensitization of T lymphocyte function by CXCR3 ligands in human hepatocellular carcinoma

Aim: Despite the presence of lymphocyte infiltration, human hepatocellular carcinoma (HCC) is typically a rapidly progressive disease. The mechanism of regulation of lymphocyte migration is poorly understood. In this study, we investigated various factors regulating T cell migration in HCC patients. We examined serum CXC chemokine levels in HCC patients and demonstrated the production of CXC chemokines by HCC cell lines. We determined the effect of both HCC patient serum and tumor cell conditioned supernatant upon lymphocyte expression of chemokine receptor CXCR3 as well as lymphocyte migration. Lastly, we examined the chemotactic responses of lymphocytes derived from HCC patients. Methods: The serum chemokines IP-10 (CXCL10) and Mig (CXCL9) levels were measured by cytometric bead array (CBA) and the tumor tissue IP-10 concentration was measured by ELISA. The surface expression of CXCR3 on lymphocytes was determined by flow cytometry. The migratory function of lymphocytes to the corresponding chemokines was assessed using an in vitro chemotactic assay. Phosphorylation of extracellular signal-regulated kinase (ERK) was determined by Western blot analysis. Results: Increased levels of IP-10 and Mig were detected in HCC patient serum and culture supernatants of HCC cell lines. The IP-10 concentration in the tumor was significantly higher than that in the non-involved adjacent liver tissues. HCC cell lines secreted functional chemokines that induced a CXCR3-specific chemotactic response of lymphocytes. Furthermore, tumor-cell-derived chemokines induced initial rapid phosphorylation of lymphocyte ERK followed by later inhibition of ERK phosphorylation. The culture of normal lymphocytes with HCC cell line supernatants or medium containing serum from HCC patients resulted in a significant reduction in the proportion of lymphocytes exhibiting surface expression of CXCR3. The reduction in T cell expression of CXCR3 resulted in reduced migration toward the ligand IP-10, and both CD4 + and CD8 + T cells from HCC patients exhibited diminished chemotactic responses to IP-10 in vitro compared to T cells from healthy control subjects. Conclusion: This study demonstrates functional desensitization of the chemokine receptor CXCR3 in lymphocytes from HCC patients by CXCR3 ligands secreted by tumor cells. This may cause lymphocyte dysfunction and subsequently impaired immune defense against the tumor. © 2005 The WJG Press and Elsevier Inc. All rights reserved.published_or_final_versio

Effects of sensor errors on the performance of map matching

Author name used in this publication: Yongqi Chen2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

catena-Poly[[bis(1,3-propylenediamine)zinc(II)]-μ-naphthalene-2,6-dicarboxylato-κ2O2:O6]

The title compound, [Zn(C12H6O4)(C3H10N2)(2)](n), has been prepared from zinc(II), naphthalene-2,6-dicarboxylic acid (H(2)napdc) and 1,3-propylenediamine (pren). The Zn atom lies on a crystallographic centre of symmetry and is coordinated by two monodentate naphthalene-2,6-dicarboxylate ligands and two chelating 1,3-propylenediamine ligands in a distorted octahedral environment. The naphthalene-2,6-dicarboxylate ligands link the Zn atoms, forming a one-dimensional chain structure

Coalescence Behavior of Gold Nanoparticles

The tetraoctylammonium bromide (TOAB)-stabilized gold nanoparticles have been successfully fabricated. After an annealing of the as-synthesized nanoparticles at 300 °C for 30 min, the coalescence behavior of gold nanoparticles has been investigated using high-resolution transmission electron microscopy in detail. Two types of coalescence, one being an ordered combination of two or more particles in appropriate orientations through twinning, and the other being an ordered combination of two small particles with facets through a common lattice plane, have been observed

A spectrometric setup for synchronous total internal reflection fluorescence measurement at the solid/liquid interface

A spectrometric setup to perform total internal reflection fluorescence (TIRF) and synchronous TIRF measurements at solid/liquid interfaces is presented. The combination of TIRF and synchronous fluorescence was proposed to analyze simultaneously different components at interfaces. The TIRF excitation, emission and synchronous spectra of a water-soluble porphyrin were obtained from water/glass interface using this setup without the existence of a surfactant