1,060 research outputs found

    Temperature-dependent evolutions of excitonic superfluid plasma frequency in a srong excitonic insulator candidate, Ta2_2NiSe5_5

    Get PDF
    We investigate an interesting anisotropic van der Waals material, Ta2_{2}NiSe5_{5}, using optical spectroscopy. Ta2_{2}NiSe5_{5} has been known as one of the few excitonic insulators proposed over 50 years ago. Ta2_{2}NiSe5_{5} has quasi-one dimensional chains along the aa-axis. We have obtained anisotropic optical properties of a single crystal Ta2_{2}NiSe5_{5} along the aa- and cc-axes. The measured aa- and cc-axis optical conductivities exhibit large anisotropic electronic and phononic properties. With regard to the aa-axis optical conductivity, a sharp peak near 3050 cm1^{-1} at 9 K, with a well-defined optical gap (ΔEI\Delta^{EI} \simeq 1800 cm1^{-1}) and a strong temperature-dependence, is observed. With an increase in temperature, this peak broadens and the optical energy gap closes around \sim325 K(TcEIT_c^{EI}). The spectral weight redistribution with respect to the frequency and temperature indicates that the normalized optical energy gap (ΔEI(T)/ΔEI(0)\Delta^{EI}(T)/\Delta^{EI}(0)) is 1(T/TcEI)21-(T/T_c^{EI})^2. The temperature-dependent superfluid plasma frequency of the excitonic condensation in Ta2_{2}NiSe5_{5} has been determined from measured optical data. Our findings may be useful for future research on excitonic insulators.Comment: 17 pages, 5 figure

    P2X7 receptor regulates leukocyte infiltrations in rat frontoparietal cortex following status epilepticus

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>In the present study, we investigated the roles of P2X7 receptor in recruitment and infiltration of neutrophil during epileptogenesis in rat epilepsy models.</p> <p>Methods</p> <p>Status epilepticus (SE) was induced by pilocarpine in rats that were intracerebroventricularly infused with either saline, 2',3'-O-(4-benzoylbenzoyl)-adenosine 5'-triphosphate (BzATP), adenosine 5'-triphosphate-2',3'-dialdehyde (OxATP), or IL-1Ra (interleukin 1 receptor antagonist) prior to SE induction. Thereafter, we performed immunohistochemical studies for myeloperoxidase (MPO), CD68, interleukin-1β (IL-1β), monocyte chemotactic protein-1 (MCP-1) and macrophage inflammatory protein-2 (MIP-2).</p> <p>Results</p> <p>In saline-infused animals, neutrophils and monocytes were observed in frontoparietal cortex (FPC) at 1 day and 2 days after SE, respectively. In BzATP-infused animals, infiltrations of neutrophils and monocytes into the FPC were detected at 12 hr and 1 day after SE, respectively. In OxATP-infused animals, neutrophils and monocytes infiltrated into the FPC at 1 day and 2 days after SE, respectively. However, the numbers of both classes of leukocytes were significantly lower than those observed in the saline-infused group. In piriform cortex (PC), massive leukocyte infiltration was detected in layers III/IV of saline-infused animals at 1-4 days after induction of SE. BzATP or OxATP infusion did not affect neutrophil infiltration in the PC. In addition, P2X7 receptor-mediated MCP-1 (released from microglia)/MIP-2 (released from astrocytes) regulation was related to SE-induced leukocyte infiltration in an IL-1β-independent manner.</p> <p>Conclusions</p> <p>Our findings suggest that selective regulation of P2X7 receptor-mediated neutrophil infiltration may provide new therapeutic approaches to SE or epilepsy.</p

    Effects of Particle Size and Cement Replacement of LCD Glass Powder in Concrete

    Get PDF
    The high quality liquid crystal display (LCD) processing waste glass (LPWG) generated from the manufacturing process of Korea’s LCD industries, having the world’s highest technological level and production, was finely ground into particles smaller than cement particles (higher fineness than OPC) to verify their applicability and performance as a replacement for cement. For a concrete mix having a W/B ratio of 0.44, cement was replaced with LPWG glass powder (LGP) at ratios of 5, 10, 15, and 20% (LGP12) and 5 and 10% (LGP5) according to the particle size to prepare test cylinder specimens, which were tested with respect to air contents, slump in fresh concrete, and compressive strength and splitting tensile strength of hardened concrete. The microstructure of the concrete specimens was analyzed through Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), and a Mercury Intrusion Porosimetry (MIP). Replacement of cement with LGP for cement could effectively decrease the quantity of cement used due to the excellent performance of LGP. It may positively contribute to the sustainable development of the cement industry as well as waste recycling and environment conservation on a national scale

    Effects of creatine and β-guanidinopropionic acid and alterations in creatine transporter and creatine kinases expression in acute seizure and chronic epilepsy models

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>In order to confirm the roles of creatine (Cr) in epilepsy, we investigated the anti-convulsive effects of Cr, creatine transporter (CRT) and creatine kinases (CKs) against chemical-induced acute seizure activity and chronic epileptic seizure activity.</p> <p>Results</p> <p>Two hr after pilocarpine (PILO)-seizure induction, ubiquitous mitochondrial CK (uMtCK) immunoreactivity was unaltered as compared to control level. However, brain-type cytoplasm CK (BCK) immunoreactivity was decreased to 70% of control level. CRT immunoreactivity was decreased to 60% of control level. Following Cr or Tat-CK treatment, uMtCK or CRT immunoreactivity was unaffected, while BCK immunoreactivity in Cr treated group was increased to 3.6-fold of control levels. β-Guanidinopropionic acid (GPA, a competitive CRT inhibitor) reduced BCK and CRT expression. In addition, Cr and tat-BCK treatment delayed the beginning of seizure activity after PILO injection. However, GPA treatment induced spontaneous seizure activity without PILO treatment. In chronic epilepsy rats, both uMtCK and CRT immunoreactivities were reduced in the hippocampus. In contrast, BCK immunoreactivity was similar to that observed in control animals. Cr-, GPA and tat-BCK treatment could not change EEG.</p> <p>Conclusion</p> <p>Cr/CK circuit may play an important role in sustaining or exacerbating acute seizure activity, but not chronic epileptic discharge.</p

    The combination effect of sodium butyrate and 5-Aza-2'-deoxycytidine on radiosensitivity in RKO colorectal cancer and MCF-7 breast cancer cell lines

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The overall level of chromatin compaction is an important mechanism of radiosensitivity, and modification of DNA methylation and histone deacetylation may increase radiosensitivity by altering chromatin compaction. In this study, we investigated the effect of a demethylating agent, a histone deacetylase(HDAC) inhibitor, and the two agents combined on radiosensitivity in human colon and breast cancer cell lines.</p> <p>Methods</p> <p>In this study, we used RKO colorectal cancer cell line and MCF-7 breast cancer cell lines and normal colon cell lines. On each of the cell lines, we used three different agents: the HDAC inhibitor sodium butyrate(SB), the demethylating agent 5-Aza-2'-deoxycytidine(5-aza-DC), and radiation. We then estimated the percentage of the cell survival using the XTT method and experimented to determine if there was an augmentation in the therapeutic effect by using different combinations of the two or three of the treatment methods.</p> <p>Results</p> <p>After treatment of each cell lines with 5-aza-DC, SB and 6 grays of radiation, we observed that the survival fraction was lower after the treatment with 5-aza-DC or SB than with radiation alone in RKO and MCF-7 cell lines(p < 0.001). The survival fraction was lowest when the two agents, 5-aza-DC and SB were combined with radiation in both RKO and MCF-cell lines.</p> <p>Conclusion</p> <p>In conclusion, 5-aza-DC and SB can enhance radiosensitivity in both MCF-7 and RKO cell lines. The combination effect of a demethylating agent and an HDAC inhibitor is more effective than that of single agent treatment in both breast and colon cancer cell lines.</p

    Proteomic analysis of pregnancy-related proteins from pig uterus endometrium during pregnancy

    Get PDF
    Many important molecular events associated with implantation and development occur within the female reproductive tract, especially within the uterus endometrium, during pregnancy periods. The endometrium includes the mucosal lining of the uterus, which provides a suitable site for implantation and development of a fertilized egg and fetus. To date, the molecular cascades in the uterus endometrium during pregnancy periods in pigs have not been elucidated fully. In this study, we compared the functional regulated proteins in the endometrium during pregnancy periods with those in non-pregnant conditions and investigated changes in expression patterns during pregnancy (days 40, 70, and 93) using two-dimensional gel electrophoresis (2-DE) and western blotting. The functional regulated proteins were identified and discovered from differentially expressed proteins in the uterus endometrium during pregnancy. We discovered 820 protein spots in a proteomic analysis of uterus endometrium tissues with 2-DE gels. We identified 63 of the 98 proteins regulated differentially among non-pregnant and pregnant tissues (matched and unmatched spots). Interestingly, 10 of these 63 proteins are development-, cytoskeleton- and chaperon-related proteins such as transferrin, protein DJ-1, transgelin, galectin-1, septin 2, stathmin 1, cofilin 1, fascin 1, heat shock protein (HSP) 90β and HSP 27. The specific expression patterns of these proteins in the endometrium during pregnancy were confirmed by western blotting. Our results suggest that the expressions of these genes involved in endometrium function and endometrium development from early to late gestation are associated with the regulation of endometrium development for maintaining pregnancy

    A Case of Duodenal Anisakiasis with Duodenal Ulcer

    Get PDF
    Humans can be incidentally parasitized by third-stage larvae of Anisakis species following the ingestion of raw or undercooked seafood. Acute gastric anisakiasis is one of the most frequently encountered complaints in Korea. However, duodenal anisakiasis with duodenal ulcer had not been reported in Korea, despite the habit of eating raw fish. In this case, a 47-year-old man was hospitalized because of sharp epigastric pain and repeated vomiting after eating raw fish 3 days previously. On admission, esophagogastroduodenoscopic examination revealed an active duodenal bulb ulcer. At 5 mm away from the ulcer margin, a whitish linear worm was found with half of its body penetrating the duodenal mucosa. Herein, we report this case of duodenal anisakiasis accompanied by duodenal ulcer
    corecore