72 research outputs found
Suppression of Structural Fatigue by Doping in Spinel Electrode Probed by In Situ Bending Beam Method
The onset of a Jahn-Teller effect at the surface of LiMn2O4 particles during cycling in the 4 V range was previously reported to
be one of the causes for the capacity fading. Furthermore, it has been reported that the Jahn-Teller effect in the 4 V range may be
suppressed by the substitution of the Mn ions by either Li or other transition metal ions. However, no direct evidence has yet been
reported. This study provides evidence for the onset of a Jahn-Teller effect in thin film 4 V LiMn2O4 and its suppression caused
by substituting the Mn ions with Co31 and Ni21 ions using in situ bending beam method ~BBM!. The deflectograms are measured
simultaneously with galvanostatic charge/discharge or cyclic voltammograms, and the onset of the Jahn-Teller effect is investigated
by means of the differential strain peak which is observed at around 3.90-3.95 V during cyclic voltammetry, and the slope
variation observed in the strain curves during galvanostatic charge/discharge. The suppression of the Jahn-Teller effect in the
doped spinel leads to the magnitude of the differential strain peak resulting from the Jahn-Teller effect being reduced in comparison
with the other two pairs of peaks, which correspond to the current peaks of the cyclic voltammogram.This work was supported by KOSEF through the Research Center for Energy Conversion and Storage (RCECS), Korea Science and Engineering Foundation (no. 2000-2-30100-012-3) and by the Ministry of Information and Communication of Korea (Support Project of University Information Technology Research Center supervised by KIPA). The authors thank Cheil Industries, Inc., for the supporting electrolytes
Comparison of sampling methods in assessing the microbiome from patients with ulcerative colitis
Background
Dysbiosis of ulcerative colitis (UC) has been frequently investigated using readily accessible stool samples. However, stool samples might insufficiently represent the mucosa-associated microbiome status. We hypothesized that luminal contents including loosely adherent luminal bacteria after bowel preparation may be suitable for diagnosing the dysbiosis of UC.
Methods
This study included 16 patients with UC (9 men and 7 women, mean age: 52.13 ± 14.09 years) and 15 sex- and age-matched healthy individuals (8 men and 7 women, mean age: 50.93 ± 14.11 years). They donated stool samples before colonoscopy and underwent luminal content aspiration and endoscopic biopsy during the colonoscopy. Then, the composition of each microbiome sample was analyzed by 16S rRNA-based next-generation sequencing.
Results
The microbiome between stool, luminal contents, and biopsy was significantly different in alpha and beta diversities. However, a correlation existed between stool and luminal contents in the Procrustes test (p = 0.001) and Mantel test (p = 0.0001). The stool microbiome was different between patients with UC and the healthy controls. Conversely, no difference was found in the microbiome of luminal content and biopsy samples between the two subject groups. The microbiome of stool and lavage predicted UC, with AUC values of 0.85 and 0.81, respectively.
Conclusion
The microbiome of stool, luminal contents, and biopsy was significantly different. However, the microbiome of luminal contents during colonoscopy can predict UC, with AUC values of 0.81. Colonoscopic luminal content aspiration analysis could determine microbiome differences between patients with UC and the healthy control, thereby beneficial in screening dysbiosis via endoscopy.
Trial registration: This trial was registered at
http://cris.nih.go.kr
. Registration No.: KCT0003352), Date: 2018–11-13.This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (No. 2020R1G1A100923411)
Evaluation of a competitive ELISA for antibody detection against avian influenza virus
Active serologic surveillance is necessary to control the spread of the avian influenza virus (AIV). In this study, we evaluated a commercially-available cELISA in terms of its ability to detect AIV antibodies in the sera of 3,358 animals from twelve species. cELISA detected antibodies against reference H1- through H15-subtype AIV strains without cross reactivity. Furthermore, the cELISA was able to detect antibodies produced following a challenge of the AIV H9N2 subtype in chickens, or following vaccination of the AIV H9 or H5 subtypes in chickens, ducks and geese. Next, we tested the sensitivity and specificity of the cELISA with sera from twelve different animal species, and compared these results with those obtained by the hemagglutination-inhibition (HI) test, the "gold standard" in AIV sera surveillance, a second commercially-available cELISA (IZS ELISA), or the agar gel precipitation (AGP) test. Compared with the HI test, the sensitivities and specificities of cELISA were 95% and 96% in chicken, 86% and 88% in duck, 97% and 100% in turkey, 100% and 87% in goose, and 91% and 97% in swine, respectively. The sensitivities and specificities of the cELISA in this study were higher than those of IZS ELISA for the duck, turkey, goose, and grey partridge sera samples. The results of AGP test against duck and turkey sera also showed significant correlation with the results of cELISA (R-value >0.9). In terms of flock sensitivity, the cELISA correlated better with the HI test than with commercially-available indirect ELISAs, with 100% flock sensitivity
25th annual computational neuroscience meeting: CNS-2016
The same neuron may play different functional roles in the neural circuits to which it belongs. For example, neurons in the Tritonia pedal ganglia may participate in variable phases of the swim motor rhythms [1]. While such neuronal functional variability is likely to play a major role the delivery of the functionality of neural systems, it is difficult to study it in most nervous systems. We work on the pyloric rhythm network of the crustacean stomatogastric ganglion (STG) [2]. Typically network models of the STG treat neurons of the same functional type as a single model neuron (e.g. PD neurons), assuming the same conductance parameters for these neurons and implying their synchronous firing [3, 4]. However, simultaneous recording of PD neurons shows differences between the timings of spikes of these neurons. This may indicate functional variability of these neurons. Here we modelled separately the two PD neurons of the STG in a multi-neuron model of the pyloric network. Our neuron models comply with known correlations between conductance parameters of ionic currents. Our results reproduce the experimental finding of increasing spike time distance between spikes originating from the two model PD neurons during their synchronised burst phase. The PD neuron with the larger calcium conductance generates its spikes before the other PD neuron. Larger potassium conductance values in the follower neuron imply longer delays between spikes, see Fig. 17.Neuromodulators change the conductance parameters of neurons and maintain the ratios of these parameters [5]. Our results show that such changes may shift the individual contribution of two PD neurons to the PD-phase of the pyloric rhythm altering their functionality within this rhythm. Our work paves the way towards an accessible experimental and computational framework for the analysis of the mechanisms and impact of functional variability of neurons within the neural circuits to which they belong
Torque Measurement of 3-DOF Haptic Master Operated by Controllable Electrorheological Fluid
This work presents a torque measurement method of 3-degree-of-freedom (3-DOF) haptic master featuring controllable electrorheological (ER) fluid. In order to reflect the sense of an organ for a surgeon, the ER haptic master which can generate the repulsive torque of an organ is utilized as a remote controller for a surgery robot. Since accurate representation of organ feeling is essential for the success of the robot-assisted surgery, it is indispensable to develop a proper torque measurement method of 3-DOF ER haptic master. After describing the structural configuration of the haptic master, the torque models of ER spherical joint are mathematically derived based on the Bingham model of ER fluid. A new type of haptic device which has pitching, rolling, and yawing motions is then designed and manufactured using a spherical joint mechanism. Subsequently, the field-dependent parameters of the Bingham model are identified and generating repulsive torque according to applied electric field is measured. In addition, in order to verify the effectiveness of the proposed torque model, a comparative work between simulated and measured torques is undertaken
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