113 research outputs found
Spin-state transition and phase separation in multi-orbital Hubbard model
We study spin-state transition and phase separation involving this transition
based on the milti-orbital Hubbard model. Multiple spin states are realized by
changing the energy separation between the two orbitals and the on-site Hund
coupling. By utilizing the variational Monte-Carlo simulation, we analyze the
electronic and magnetic structures in hole doped and undoped states. Electronic
phase separation occurs between the low-spin band insulating state and the
high-spin ferromagnetic metallic one. Difference of the band widths in the two
orbitals is of prime importance for the spin-state transition and the phase
separation.Comment: 5 pages, 5 figure
Where did the super-small sized large bowel advanced cancer come from?
Our study suggested that the super-small sized (less than 15 mm in maximum diameter) large bowel advanced cancers, which were sometimes found, were derived from the superficial depressed-type or flat elevation-type of the colorectal early cancers, not polyp-type of those
The role of melatonin as an antioxidant in the follicle
Melatonin (N-acetyl-5-methoxytryptamine) is secreted during the dark hours at night by pineal gland, and it regulates a variety of important central and peripheral actions related to circadian rhythms and reproduction. It has been believed that melatonin regulates ovarian function by the regulation of gonadotropin release in the hypothalamus-pituitary gland axis via its specific receptors. In addition to the receptor mediated action, the discovery of melatonin as a direct free radical scavenger has greatly broadened the understanding of melatonin's mechanisms which benefit reproductive physiology. Higher concentrations of melatonin have been found in human preovulatory follicular fluid compared to serum, and there is growing evidence of the direct effects of melatonin on ovarian function especially oocyte maturation and embryo development. Many scientists have focused on the direct role of melatonin on oocyte maturation and embryo development as an anti-oxidant to reduce oxidative stress induced by reactive oxygen species, which are produced during ovulation process. The beneficial effects of melatonin administration on oocyte maturation and embryo development have been confirmed by in vitro and in vivo experiments in animals. This review also discusses the first application of melatonin to the clinical treatment of infertile women and confirms that melatonin administration reduces intrafollicular oxidative damage and increase fertilization rates. This review summarizes our recent works and new findings related to the reported beneficial effects of melatonin on reproductive physiology in its role as a reducer of oxidative stress, especially on oocyte maturation and embryo development
Luteal blood flow in patients undergoing GnRH agonist long protocol
<p>Abstract</p> <p>Background</p> <p>Blood flow in the corpus luteum (CL) is closely related to luteal function. It is unclear how luteal blood flow is regulated. Standardized ovarian-stimulation protocol with a gonadotropin-releasing hormone agonist (GnRHa long protocol) causes luteal phase defect because it drastically suppresses serum LH levels. Examining luteal blood flow in the patient undergoing GnRHa long protocol may be useful to know whether luteal blood flow is regulated by LH.</p> <p>Methods</p> <p>Twenty-four infertile women undergoing GnRHa long protocol were divided into 3 groups dependent on luteal supports; 9 women were given ethinylestradiol plus norgestrel (Planovar) orally throughout the luteal phase (control group); 8 women were given HCG 2,000 IU on days 2 and 4 day after ovulation induction in addition to Planovar (HCG group); 7 women were given vitamin E (600 mg/day) orally throughout the luteal phase in addition to Planovar (vitamin E group). Blood flow impedance was measured in each CL during the mid-luteal phase by transvaginal color-pulsed-Doppler-ultrasonography and was expressed as a CL-resistance index (CL-RI).</p> <p>Results</p> <p>Serum LH levels were remarkably suppressed in all the groups. CL-RI in the control group was more than the cutoff value (0.51), and only 2 out of 9 women had CL-RI values < 0.51. Treatments with HCG or vitamin E significantly improved the CL-RI to less than 0.51. Seven of the 8 women in the HCG group and all of the women in the vitamin E group had CL-RI < 0.51.</p> <p>Conclusion</p> <p>Patients undergoing GnRHa long protocol had high luteal blood flow impedance with very low serum LH levels. HCG administration improved luteal blood flow impedance. This suggests that luteal blood flow is regulated by LH.</p
Amnion as a surrogate tissue reporter of the effects of maternal preeclampsia on the fetus
We described the study design, detailed analytical methods, and verification results in the supporting information file. (DOCX 21.2 MB
Development of 1 MJ Conduction-Cooled LTS Pulse Coil for UPS-SMES
A 1 MW, 1 s UPS-SMES is being developed for a protection from a momentary voltage drop and an instant power failure. As a key technology of the UPS-SMES, we developed a prototype LTS pulse coil with a stored energy of 100 kJ and conducted cooling and excitation tests in 2005. The operation test of the prototype UPS-SMES using this 100 kJ coil with power converters have been performed in 2006. A 1 MJ coil was designed before the fabrication of the 100 kJ prototype coil. The superconductor, the electric insulation technique, the winding method, and the cooling structure used for the 100 kJ coil were based upon the 1 MJ coil design. The successful performance test results of the prototype 100 kJ coil validated the design concept and fabrication technique of the 1 MJ coil. According to the achievement of the prototype 100 kJ UPS-SMES, the 1 MJ conduction-cooled LTS pulse coil has been fabricated successfully. The successful experimental results of the 100 kJ prototype coil with power converters and the fabrication procedure of the 1 MJ full size coil are described
Adult Intussusception Caused by an Inverted Meckel Diverticulum
Adult intussusception caused by an inverted Meckel diverticulum is rare. We report a 55-year-old Japanese man with intussusception. He was admitted to our hospital with vomiting and abdominal pain. The abdomen was hard with tenderness and muscle guarding. Computed tomography scanning demonstrated a typical inhomogeneous target-shaped mass in the right abdomen. We diagnosed intussusception and performed emergency surgery. At laparotomy, ileocolic intussusception was observed and the ileocecal segment was resected. The surgical specimen comprised an 84 cm segment of resected ileocecum with an elongated polypoid lesion measuring 11 × 2 cm within the ileal lumen. Histopathological examination demonstrated that the polypoid lesion was an inverted Meckel diverticulum. Postoperatively, the patient made an uneventful recovery
Abdominoperineal Resection for Unexpected Distal Intramural Spreading of Rectal Cancer
Introduction: In rectal cancer, distal intramural spread may sometimes occur, but a maximum extent of distal spread of > 6 cm is very rare. Case Presentation: A 65-year-old Japanese male with an advanced rectal cancer tumor with para-aortic lymph node metastasis was admitted. We performed a low anterior resection with lymphadenectomy, but the intraoperative frozen-section analysis of margins revealed malignant cell positivity; we, therefore, performed an abdominoperineal resection. Pathological findings showed that the maximum extent of distal spread was 6 cm. After 12 courses of FOLFOX4 as adjuvant chemotherapy, abdominal computed tomography revealed whole lymph node metastases, including Virchow’s node. Though FOLFIRI + panitumumab was started, he was not eligible for additional chemotherapy after 10 cycles. Conclusion: An intraoperative frozen pathology examination was helpful for the additional resection, when unexpected distal spreading had occurred in rectal cancer. The evidence of a distal negative margin should not be underestimated
Efficacy of salvage therapies for advanced acral melanoma after anti-PD-1 monotherapy failure: a multicenter retrospective study of 108 Japanese patients
BackgroundAnti-programmed cell death protein 1 (PD-1) monotherapy is one of the standard systemic therapies for advanced melanoma; however, the efficacy of salvage systemic therapies after PD-1 monotherapy failure (PD-1 MF), particularly in acral melanoma (AM), the main clinical melanoma type in Japanese patients, is unclear. This study aimed to investigate the efficacy of salvage systemic therapies in Japanese patients with AM after PD-1 MF.Patients and methodsThe study included 108 patients with advanced AM (palm and sole, 72; nail apparatus, 36) who underwent salvage systemic therapy at 24 Japanese institutions. We mainly assessed the objective response rate (ORR), progression-free survival (PFS), and overall survival (OS).ResultsThirty-six (33%) patients received ipilimumab, 23 (21%) received nivolumab and ipilimumab (nivo/ipi), 10 (9%) received cytotoxic chemotherapy, 4 (4%) received BRAF and MEK inhibitors (BRAFi/MEKi), and the remaining 35 (32%) continued with PD-1 monotherapy after disease progression. The ORRs in the ipilimumab, nivo/ipi, cytotoxic chemotherapy, and BRAFi/MEKi groups were 8, 17, 0, and 100%, respectively. The nivo/ipi group showed the longest OS (median, 18.9 months); however, differences in ORR, PFS, and OS between the groups were insignificant. The OS in the nivo/ipi group was higher in the palm and sole groups than in the nail apparatus group (median: not reached vs. 8.7 months, p < 0.001). Cox multivariate analysis demonstrated that nail apparatus melanoma independently predicted unfavorable PFS and OS (p = 0.006 and 0.001). The total OS (from PD-1 monotherapy initiation to death/last follow-up) was insignificant between the groups.ConclusionNivo/ipi was not more effective than cytotoxic chemotherapy and ipilimumab after PD-1 MF in patients with advanced AM. The prognosis after PD-1 MF would be poorer for nail apparatus melanoma than for palm and sole melanoma
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