278 research outputs found

    Anion dependence of camel-shape capacitance at the interface between mercury and ionic liquids studied using pendant drop method

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    The electrocapillarity and zero-frequency differential capacitance, Cd, have been studied using pendant drop method, at the Hg interface of an ionic liquid (IL), 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide, [C2mim+][TFSA−], and have been compared with those of [C2mim+]BF, an IL with the common cation and a different anion, to focus on the anion dependence of zero-frequency Cd. The Hg interface of [C2mim+][TFSA−], the IL of the larger anion in the present study, exhibits greater zero-frequency Cd than that of [C2mim+]BF, the IL of the smaller anion. This behavior contradicts a simple expectation in which larger ion leads to smaller Cd. This apparent contradiction is explained by proximity of the charged moiety of TFSA− to the electrode surface compared with that of BF. The potential dependence of zero-frequency Cd for the two ILs both exhibits one-hump camel shape around the potential of zero charge (Epzc), which has been predicted to be specific behavior of the electrical double layer of ILs by theory and simulation. The humps are located at potentials more negative than Epzc. From a mean-field lattice-gas theory for the EDL in ILs, this negative shift can be interpreted that the charged moiety for C2mim+ is more easily condensed in the EDL than those for BF and TFSA−

    Thermodynamic stability of H2 + tetrahydrofuran mixed gas hydrate in nonstoichiometric aqueous solutions

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    Phase equilibria (pressure - temperature relations) of the H2 + tetrahydrofuran mixed gas hydrate system have been measured for various concentrations of tetrahydrofuran aqueous solutions. The three-phase equilibrium lines obtained in the present study are shifted to the low-temperature or high-pressure side from that of the stoichiometric THF solution. Each three-phase equilibrium line of H2 + tetrahydrofuran hydrate converges at the three-phase equilibrium line of the pure tetrahydrofuran hydrate. At the cross point on the lines, the tetrahydrofuran concentration of mother aqueous solution agrees with each other. The Raman spectra of H 2 and tetrahydrofuran for the H2 + tetrahydrofuran mixed gas hydrate do not change with the variation of tetrahydrofuran mole fraction from 0.010 to 0.130 in the aqueous solution. © 2007 American Chemical Society.Shunsuke Hashimoto, Takeshi Sugahara, Hiroshi Sato et al. Thermodynamic Stability of H2 + Tetrahydrofuran Mixed Gas Hydrate in Nonstoichiometric Aqueous Solutions. Journal of Chemical & Engineering Data, 52 (1), 517-520, March 1, © 2007 American Chemical Society. https://doi.org/10.1021/je060436

    Phase equilibria for H2 + CO2 + H2O system containing gas hydrates

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    Isothermal phase equilibrium (pressure-composition in the gas phase) for the ternary system of H2 + CO2 + H2O has been investigated in the presence of gas hydrate phase. Three-phase equilibrium pressure increases with the H2 composition of gas phase. The Raman spectra suggest that H2 is not enclathrated in the hydrate-cages and behaves only like the diluent gas toward the formation of CO2 hydrate. This fact is also supported by the thermodynamic analysis using Soave-Redlich-Kwong equation of state. © 2005 Elsevier B.V. All rights reserved

    Reformulation of Boundary String Field Theory in terms of Boundary State

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    We reformulate bosonic boundary string field theory in terms of boundary state. In our formulation, we can formally perform the integration of target space equations of motion for arbitrary field configurations without assuming decoupling of matter and ghost. Thus, we obtain the general form of the action of bosonic boundary string field theory. This formulation may help us to understand possible interactions between boundary string field theory and the closed string sector.Comment: 13 page

    Effect of Impeller Agitation on Preparation of Tetra- n

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    The slurries-containing tetra-n-butyl ammonium bromide (TBAB) solution and its semiclathrate hydrate have attracted a lot of interest as latent heat transport media. These hydrate slurries contain some microparticles of crystal, and the size and shape of these hydrate particles could affect the mobility of slurries. Hence, it is essential to investigate the efficient hydrate-slurry preparation methods and the effect of hydrate particles on the fluid property of slurries for the application to latent heat transport media. In the present study, the effect of agitation on particle size distribution and aggregation of particles was studied to prepare easily flowing TBAB hydrate slurries that were suitable for fluid transport. First of all, the effects of impeller rotational speed and impeller type on the particle size and frequency of aggregation were investigated. The results suggested that the particle size distribution and the frequency of particle aggregation are strongly affected by the intensity of shear rate and its uniformity, which was controllable with impeller type and its rotation speed

    Verrucous carcinoma of the esophagus with complete response after chemoradiotherapy

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    Background : Verrucous carcinoma of the esophagus (VCE) is a rare tumor that is difficult to diagnose. In most cases, biopsies show nonspecific inflammatory and hyperkeratotic changes and do not show malignant findings. Most VCEs are slowly growing, locally advanced tumors with few metastases. Treatments for VCE are the same as for normal esophageal cancer, involving combined chemotherapy, surgical resection, and radiation therapy. However, it has been reported that VCE has a poor response to radiation or chemoradiotherapy (CRT). A case of VCE with complete response (CR) after CRT is presented. Case presentation : A 70-year-old man was found to have white, irregular esophageal mucosa 4 years earlier. He had been followed up as an outpatient as having candidal esophagitis. However, his tumor grew gradually, and biopsy was performed by endoscopic mucosal resection (EMR). He was finally diagnosed with VCE. He had no metastases to distant organs, but some lymph node metastases were suspected. The tumor invaded his left bronchus. The esophagostomy and gastrostomy were constructed as emergent procedures. The patient then underwent definitive CRT. 4 weeks after the end of CRT, two-stage esophagectomy was performed. First, he underwent esophagectomy with thoracic lymph node dissection. A latissimus dorsi flap was patched to the bronchus after primary suture of the hole. 6 weeks later, reconstruction of the gastric tube was performed through the antethoracic route. The pathological findings showed CR to CRT, with no proliferative cancer cells in the specimen. The patient has had no recurrence for three and half years after the resection. Conclusions : We presented a locally advanced VCE that achieved CR to CRT. In cases that have some difficulty for local resection, CRT might be an appropriate treatment for VCE

    Overexpression of Adenovirus E1A Reverses Transforming Growth Factor-β-induced Epithelial-mesenchymal Transition in Human Esophageal Cancer Cells

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    The epithelial-mesenchymal transition (EMT), a normal biological process by which epithelial cells acquire a mesenchymal phenotype, is associated with migration, metastasis, and chemoresistance in cancer cells, and with poor prognosis in patients with esophageal cancer. However, therapeutic strategies to inhibit EMT in tumor environments remain elusive. Here, we show the therapeutic potential of telomerase-specific replication- competent oncolytic adenovirus OBP-301 in human esophageal cancer TE4 and TE6 cells with an EMT phenotype. Transforming growth factor-β (TGF-β) administration induced the EMT phenotype with spindleshaped morphology, upregulation of mesenchymal markers and EMT transcription factors, migration, and chemoresistance in TE4 and TE6 cells. OBP-301 significantly inhibited the EMT phenotype via E1 accumulation. EMT cancer cells were susceptible to OBP-301 via massive autophagy induction. OBP-301 suppressed tumor growth and lymph node metastasis of TE4 cells co-inoculated with TGF-β-secreting fibroblasts. Our results suggest that OBP-301 inhibits the TGF-β-induced EMT phenotype in human esophageal cancer cells. OBP-301-mediated E1A overexpression is a promising antitumor strategy to inhibit EMT-mediated esophageal cancer progression

    Subtotal esophagectomy and concurrent reconstruction with free jejunal flap for primary esophageal cancer after pancreatoduodenectomy

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    Background Pancreatoduodenectomy and subtotal esophagectomy are widely considered the most invasive and difficult surgical procedures in gastrointestinal surgery. Subtotal esophagectomy after pancreatoduodenectomy is expected to be extremely difficult due to complicated anatomical changes, and selecting an appropriate intestinal reconstruction method will also be a difficult task. Therefore, perhaps because the method is considered impossible, there have been few reports of subtotal esophagectomy after pancreatoduodenectomy. Case presentation A 73-year-old man with a history of pancreatoduodenectomy was diagnosed with superficial thoracic esophageal squamous cell carcinoma. Definitive chemoradiation therapy was recommended at another hospital; however, he visited our department to undergo surgery. We performed the robot-assisted thoracoscopic subtotal esophagectomy. There were some difficulties with the reconstruction: the gastric tube could not be used, the reconstruction was long, and the organs reconstructed in the previous surgery had to be preserved. However, the concurrent reconstruction was achieved with the help of a free jejunal flap and vascular reconstruction. All reconstructions from the previous surgery, including the remnant stomach, were preserved via regional abdominal lymph node dissection. After reconstruction, intravenous indocyanine green showed that circulation in the reconstructed intestines was preserved. On postoperative day 1, no recurrent nerve paralysis was observed during laryngoscopy. The patient could start oral intake smoothly 2 weeks after surgery and did not exhibit any postoperative complications related to the reconstruction. The patient was transferred to another hospital on postoperative day 21. Conclusions Owing to the free jejunal flap interposition method, we safely performed one stage subtotal esophagectomy and concurrent reconstruction, preservation of the remnant stomach, and pancreaticobiliary reconstruction in patients with a history of pancreatoduodenectomy. We believe that this method is acceptable and useful for patients undergoing complicated reconstruction
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