30 research outputs found

    Temperature dependence of a Raman CO2 densimeter from 23 degrees C to 200 degrees C and 7.2 to 248.7 MPa : Evaluation of density underestimation by laser heating

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    Unintended local temperature enhancement by excitation laser might change Raman spectral features and potentially lead to misinterpretation of the data. To evaluate robustness of Raman CO2 densimeters in the presence of laser heating, we investigate the relation between temperature (T, degrees C), density (rho, g/cm(3)), and Fermi diad split (Delta, cm(-1)) using a high-pressure optical cell at 23 degrees C to 200 degrees C and 7.2-248.7 MPa. Results indicate that Delta decreases concomitantly with increasing temperature for a constant density in all density regions investigated. This result suggests that the density estimated based on Delta might be underestimated if the fluid is heated locally by the laser. Combining results of earlier studies with those of the present study indicates that the temperature dependence of Delta (|( partial differential Delta/ partial differential T)(rho)|) has a maximum value around 0.6-0.7 g/cm(3). Consequently, at very high densities such as 1.1-1.2 g/cm(3), |( partial differential Delta/ partial differential T)(rho)| is small. Thus, Delta at such densities is less affected by laser heating. However, at densities below approximately 0.7 g/cm(3), although |( partial differential Delta/ partial differential T)(rho)| becomes smaller at lower densities, the relative density decrease becomes larger even for a small density decrease because the density itself becomes smaller. Therefore, at such densities, a density decrease of more than 10% was observed for some fluid inclusions, even at typical laser powers for inclusion analysis. Finally, to accurately estimate the density even in the presence of laser heating, we show that it is effective to estimate the intercept Delta from the correlation between Delta and laser power and substitute it into Delta-rho relations

    Seasonal home range and habitat selection patterns of sika deer Cervus nippon in southern Hokkaido, Japan

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    In 1980 and 1981, eight and nine individual sika deer Cervus nippon were reintroduced in southern Hokkaido, Japan, respectively, to address population declines in this species during 1900s. As recent population growth has led to human-wildlife conflicts, this study investigated the responses of sika deer to resource availability and geomorphic factors during the summer and winter seasons in southern Hokkaido. Global positioning system-collared data collected from 2016 to 2018 were used to assess the home range patterns and habitat selection of 14 female sika deer located in Mount Esan and Shiriuchi. The core home range size was defined using a 50% kernel density estimation that indicated a larger home range in winter than summer for all deer. Habitat selection was assessed using generalized linear mixed models. The results showed variation in habitat selection between resident deer of Mount Esan and Shiriuchi, as well as migratory deer in Shiriuchi during summer. Resident deer in Mount Esan and Shriuchi preferred areas closer to crops during summer. Interaction effects revealed that migratory deer utilized natural grassland close to forest edge habitat in Shiriuchi. By contrast, resident deer in Shiriuchi selected forest edge habitat and natural grasslands close to crops. In winter, low elevation was the most important habitat factor for all deer across the study area. Thus, sika deer habitat selection depends on resource availability in summer and topographic factors in the winter

    Gold Ultrathin Nanorods with Controlled Aspect Ratios and Surface Modifications: Formation Mechanism and Localized Surface Plasmon Resonance

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    We synthesized gold ultrathin nanorods (AuUNRs) by slow reductions of gold­(I) in the presence of oleylamine (OA) as a surfactant. Transmission electron microscopy revealed that the lengths of AuUNRs were tuned in the range of 5–20 nm while keeping the diameter constant (∼2 nm) by changing the relative concentration of OA and Au­(I). It is proposed on the basis of time-resolved optical spectroscopy that AuUNRs are formed via the formation of small (<2 nm) Au spherical clusters followed by their one-dimensional attachment in OA micelles. The surfactant OA on AuUNRs was successfully replaced with glutathionate or dodecanethiolate by the ligand exchange approach. Optical extinction spectroscopy on a series of AuUNRs with different aspect ratios (ARs) revealed a single intense extinction band in the near-IR (NIR) region due to the longitudinal localized surface plasmon resonance (LSPR), the peak position of which is red-shifted with the AR. The NIR bands of AuUNRs with AR < 5 were blue-shifted upon the ligand exchange from OA to thiolates, in sharp contrast to the red shift observed in the conventional Au nanorods and nanospheres (diameter >10 nm). This behavior suggests that the NIR bands of thiolate-protected AuUNRs with AR < 5 are not plasmonic in nature, but are associated with a single-electron excitation between quantized states. The LSPR band was attenuated by thiolate passivation that can be explained by the direct decay of plasmons into an interfacial charge transfer state (chemical interface damping). The LSPR wavelengths of AuUNRs are remarkably longer than those of the conventional AuNRs with the same AR, demonstrating that the miniaturization of the diameter to below ∼2 nm significantly affects the optical response. The red shift of the LSPR band can be ascribed to the increase in the effective mass of electrons in AuUNRs

    Regimen-Related Mucosal Injury of the Gut Increased the Incidence of CMV Disease after Allogeneic Bone Marrow Transplantation

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    Cytomegalovirus (CMV) infection is one of the major causes of morbidity in patients undergoing allogeneic stem cell transplantation (alloSCT). The incidences of CMV antigenemia and CMV disease in 43 patients who received allogeneic bone marrow transplantation (BMT) using a reduced-intensity conditioning (RIC) regimen, which mainly consisted of fluclarabine, busulfan and total body irradiation, were compared with those in 68 patients who received a myeloablative conditioning (MAC) regimen, and risk factors for CMV antigenemia and CMV disease were identified. Before engraftment, grade 3-4 mucosal injury due to the conditioning regimen was significantly decreased in RIC patients (stomatitis: P = 0.02; diarrhea: P < 0.01). Rate of engraftment, incidences of acute graft-versus-host disease (aGVHD) and rate of corticosteroid administration were not different in RIC patients and MAC patients. Although the incidences of CMV antigenemia were not significantly different in RIC patients and MAC patients (64.1% vs. 57.8%, logrank, P = 0.59), the incidence of CMV disease was significantly decreased in RIC patients (5.4% vs. 20.3%, logrank, P = 0.04). CMV seropositivity in the patients (P < 0.01) and corticosteroid administration (P < 0.01) were revealed by multivariate analysis to be significant risk factors for CMV antigenemia. Grade II-IV aGVHD (P = 0.02) and grade 3-4 diarrhea before engraftment (P = 0.04) were revealed to be risk factors for CMV disease. The present study is the first study to show that severe diarrhea before engraftment is a significant risk factor for CMV disease. In summary, risk of CMV disease was significantly decreased in patients without severe mucosal injury of the gut due to the conditioning regimen before engraftment

    Successful treatment of acute myelogenous leukemia with favorable cytogenetics by reduced-intensity stem cell transplantation

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    Acute myelogenous leukemia (AML) with favorable cytogenetics responds well to chemotherapy. If the leukemia relapses, allogenic hematopoietic stem transplantation (allo-HSCT) is considered as a treatment option. Since the efficacy of reduced-intensity stem cell transplantation (RIST) for AML with favorable cytogenetics has not been established, we retrospectively analyzed the outcomes of allo-HSCT in AML patients according to cytogenetic risks. The outcome of allo-HSCT for AML patients with favorable cytogenetics seemed to be superior to that for AML patients with intermediate cytogenetics. In AML patients with favorable cytogenetics, the 3-year overall survival (OS) and relapse-free survival (RFS) rates were 88% and 76%, respectively, in the RIST group. Both the 3-year OS and RFS rates were 81% in the conventional stem cell transplantation (CST) group. The outcome of RIST for AML patients with favorable cytogenetics was comparable to that for patients who received CST despite the more advanced age and greater organ dysfunction in RIST group than in CST group. None of the patients died within 90 days after RIST. Moreover, there was no relapse in patients with favorable cytogenetics who were in hematological remission prior to RIST. Thus, RIST for AML patients with favorable cytogenetics in remission is safe and effective

    HB vaccine to prevent viral reactivation in allogeneic hematopoietic stem cell transplantation recipients with previous HBV infection

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    HBV-reverse seroconversion (RS) following allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a frequent late-onset complication in recipients with previous HBV infection. We conducted post-transplant HB vaccine intervention in 38 allo-HSCT recipients with previous HBV infection. Firstly, we followed the recipients without any intervention (historical control) until 2003; hence we commenced HB vaccination. Out of the patients who underwent transplantation after 2003, 13 recipients were immunized by a standard 3-dose regimen after immunosuppressant cessation (vaccine group), while 12 recipients were observed without any intervention (non-vaccine group). Eight of the 13 historical control group recipients and 3 of the 12 non-vaccine group recipients, but none of the 13 vaccine group recipients, suffered HBV-RS. Cumulative risks of HBV-RS at 3 years post-HSCT in the historical control, non-vaccine and vaccine groups were 41%, 39% and 0% respectively (P = 0.022). We therefore conclude that intervention with HB vaccines is significantly effective in preventing post-HSCT HBV-RS
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