70 research outputs found
Human Tracking across Heterogeneous Systems Based on Mobile Agent Technologies
In a human tracking system, expanding a monitoring range of one system is complicating the management of devices and increasing its cost. Therefore, we propose a method to realize a wide-range human tracking by connecting small systems. In this paper, we examined an agent deploy method and information contents across the heterogeneous human tracking systems. By implementing the proposed method, we can construct a human tracking system across heterogeneous systems, and the system can track a target continuously between systems
Phase equilibrium temperature and dissociation enthalpy in the tri-n-butylalkylphosphonium bromide semiclathrate hydrate systems
Semiclathrate hydrate (SCH) is one of the phase change materials suitable for cold storage. The thermodynamic properties of SCHs, such as an equilibrium temperature and a dissociation enthalpy, depend on the size and shape of guest substances. In this study, to reveal the effect of cation size and shape on the thermodynamic properties, tri-n-butylalkylphosphonium bromide (P444R-Br) SCHs, where the alkyl group was n-propyl (R = 3), n-butyl (R = 4), n-pentyl (R = 5), i-butyl (R = i-4), i-pentyl (R = i-5), or allyl (R = Al)), were investigated. The branched alkyl groups (R = i-4 or i-5) raised the equilibrium temperature, whereas the shorter alkyl groups (R = 3 or Al) lowered one. Except for P4445-Br and P444(Al)-Br SCHs, the other P444R-Br SCHs had the same orthorhombic structure. Among the orthorhombic systems in the present study, the semiclathrate hydrate with a higher equilibrium temperature had a larger dissociation enthalpy
Quasi-elastic neutron scattering studies on fast dynamics of water molecules in tetra-n-butylammonium bromide semiclathrate hydrate
The dynamics of the water molecules in tetra-n-butyl-d36-ammonium bromide semiclathrate hydrate were investigated by quasi-elastic neutron scattering (QENS). The QENS results clearly revealed afast reorientation motion of water molecules in the temperature range of 212–278 K. The mean jumpdistance of hydrogen atoms was within 1.5‒2.0 Å. The relaxation time of water reorientation wasestimated to be 100‒410 ps with activation energy of 10.2±5.8 kJ·mol-1. The activation energy wasin good agreement with the cleavage energy of hydrogen bonds. Such a short relaxation time ofwater reorientation is possibly due to strong interaction between a bromide anion and its surroundingwater molecules (similar to so-called negative hydration), which suggests a unique strategy fordesigning efficient, safe, and inexpensive proton conductors having the framework of semiclathratehydrates.Shimada Jin, Tani Atsushi, Yamada Takeshi, et al. "Quasi-elastic neutron scattering studies on fast dynamics of water molecules in tetra-n-butylammonium bromide semiclathrate hydrate", Applied Physics Letters 123, 50 (2023) https://doi.org/10.1063/5.0157560
Phase Equilibrium Relations of Semiclathrate Hydrates Based on Tetra- n-butylphosphonium Formate, Acetate, and Lactate
Phase equilibrium (temperature-composition) relations of tetra-n-butylphosphonium formate (TBP-For), acetate (TBP-Ace), and lactate (TBP-Lac) semiclathrate hydrate systems have been measured. The highest equilibrium temperatures of TBP-For, TBP-Ace, and TBP-Lac semiclathrate hydrates were 280.9, 284.6, and 283.8 K at the atmospheric pressure, respectively, where the composition of tetra-n-butylphosphonium carboxylate was approximately 0.035 ± 0.001 (mole fraction) in every system. The dissociation enthalpies of tetra-n-butylphosphonium carboxylate semiclathrate hydrates were measured by differential scanning calorimetry. The dissociation enthalpies of TBP-For, TBP-Ace, and TBP-Lac semiclathrate hydrates were (187 ± 3), (193 ± 3), and (177 ± 3) J·g-1, respectively.Jin Shimada, Masami Shimada, Takeshi Sugahara, et al. Phase Equilibrium Relations of Semiclathrate Hydrates Based on Tetra-n-butylphosphonium Formate, Acetate, and Lactate. Journal of Chemical & Engineering Data, 63 (9), 3615-3620, September 13, © 2018 American Chemical Society. https://doi.org/10.1021/acs.jced.8b0048
Thermodynamic Properties of Tetra-n-butylphosphonium Dicarboxylate Semiclathrate Hydrates
Semiclathrate hydrate (SCH) is one of the phase change materials suitable for cold energy storage. Thermodynamic properties of SCHs, such as an equilibrium temperature and the dissociation enthalpy, depend on the size and shape of the guest substances. In the present study, to reveal the effects of steric conformations of the guest anions on the thermodynamic properties of SCHs, tetra-n-butylphosphonium dicarboxylate (TBP-DC) SCHs, where the anion was oxalate (TBP-Oxa), malonate (TBP-Mal), succinate (TBP-Suc), glutarate (TBP-Glu), maleate (TBP-Male), or fumarate (TBP-Fum), were investigated. TBP-Oxa, -Mal, -Suc, and -Fum SCHs had similar equilibrium temperatures, whereas the equilibrium temperatures of TBP-Glu and -Male SCHs were higher. This suggests that the size and conformation of glutarate and maleate anions are appropriate for the cage structures of SCHs. Moreover, we compared the equilibrium temperatures of TBP-Suc, -Male, and -Fum SCHs because TBP-Suc, -Male, and -Fum have similar anion structures. The equilibrium temperature of TBP-Suc SCH was similar to that of TBP-Fum SCH, whereas TBP-Male SCH showed a higher equilibrium temperature. This result implies that the succinate anion is accommodated in the trans conformation, similar to the fumarate anion, in the hydrate cages.Jin Shimada, Moe Yamada, Atsushi Tani et al. Thermodynamic Properties of Tetra-n-butylphosphonium Dicarboxylate Semiclathrate Hydrates. Journal of Chemical & Engineering Data, 67 (1), 67-73, January 13, © 2022 American Chemical Society. https://doi.org/10.1021/acs.jced.1c0074
Learning suction graspability considering grasp quality and robot reachability for bin-picking
Deep learning has been widely used for inferring robust grasps. Although
human-labeled RGB-D datasets were initially used to learn grasp configurations,
preparation of this kind of large dataset is expensive. To address this
problem, images were generated by a physical simulator, and a physically
inspired model (e.g., a contact model between a suction vacuum cup and object)
was used as a grasp quality evaluation metric to annotate the synthesized
images. However, this kind of contact model is complicated and requires
parameter identification by experiments to ensure real world performance. In
addition, previous studies have not considered manipulator reachability such as
when a grasp configuration with high grasp quality is unable to reach the
target due to collisions or the physical limitations of the robot. In this
study, we propose an intuitive geometric analytic-based grasp quality
evaluation metric. We further incorporate a reachability evaluation metric. We
annotate the pixel-wise grasp quality and reachability by the proposed
evaluation metric on synthesized images in a simulator to train an
auto-encoder--decoder called suction graspability U-Net++ (SG-U-Net++).
Experiment results show that our intuitive grasp quality evaluation metric is
competitive with a physically-inspired metric. Learning the reachability helps
to reduce motion planning computation time by removing obviously unreachable
candidates. The system achieves an overall picking speed of 560 PPH (pieces per
hour).Comment: 18 pages, 2 tables, 7 figure
Cyclooxygenase-2 is Involved in the Progression of Thyroid Cancer
Although the inducible form of cyclooxygenase (COX), COX-2, is highly expressed in various cancers and it is also involved in cancer progression, its role in thyroid cancer is not fully understood. We assessed in the situ cyclooxygenase expression in normal thyroids (n=6), Graves\u27 thyroids (n=6), thyroid adenomas (n=12), thyroid follicular (n=15) and papillary carcinomas (n=30). In comparison to the constitutive expression of COX-1, COX-2 was highly expressed in thyroid cancers (90.0% of thyroid papillary carcinomas and 73.3% of thyroid follicular carcinomas) and moderately in thyroid adenomas (25.5%), but barely expressed in normal and Graves\u27 thyroid tissues. This quantitative assessment employed immunohistochemical methods. Thereafter we compared the effect of COX-2 inhibition on a human follicular thyroid carcinoma cell line (WRO), and a human papillary carcinoma cell line (NPA), using selective COX-2 inhibitor(NS-398). The treatment with 50 μM NS-398 suppressed the growth of the COX-2 expressing cells, NPA cells (37.7%;p<0.01) and WRO cells (10.1%;p<0.05). Moreover, at concentrations ? 100 μM, NS-398 induced cell death a mitochondrial dysfunction. In addition, 50 μM of NS-398 inhibited the activation of extracellular signal-regulated kinase in NPA cells after the stimulation with fetal bovine serum. Our results indicate that COX-2 is involved in the progression of thyroid cancer
An isomorphous replacement method for efficient de novo phasing for serial femtosecond crystallography.
SACLAのX線自由電子レーザーを用いた新規タンパク質立体構造決定に世界で初めて成功. 京都大学プレスリリース. 2015-09-14.Serial femtosecond crystallography (SFX) with X-ray free electron lasers (XFELs) holds great potential for structure determination of challenging proteins that are not amenable to producing large well diffracting crystals. Efficient de novo phasing methods are highly demanding and as such most SFX structures have been determined by molecular replacement methods. Here we employed single isomorphous replacement with anomalous scattering (SIRAS) for phasing and demonstrate successful application to SFX de novo phasing. Only about 20,000 patterns in total were needed for SIRAS phasing while single wavelength anomalous dispersion (SAD) phasing was unsuccessful with more than 80,000 patterns of derivative crystals. We employed high energy X-rays from SACLA (12.6 keV) to take advantage of the large anomalous enhancement near the LIII absorption edge of Hg, which is one of the most widely used heavy atoms for phasing in conventional protein crystallography. Hard XFEL is of benefit for de novo phasing in the use of routinely used heavy atoms and high resolution data collection
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