30 research outputs found

    High-pressure dc magnetic measurements on a bisdiselenazolyl radical ferromagnet using a vibrating-coil SQUID magnetometer

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    The high-pressure magnetic properties of the iodo-substituted bisdiselenazolyl radical ferromagnet IBPSSEt have been studied by vibrating-coil SQUID magnetometry. The magnetic state at a pressure (P) of approximately 2 GPa has the highest Curie temperature (TC) of 27.5 K, and displays an ideal three-dimensional (3D) ferromagnetic interaction network. The value of TC observed by ac magnetic susceptibility measurements is consistent with that obtained from dc measurements below approximately 4 GPa. Field-cooled dc measurements at more elevated pressures reveal a slow evolution of magnetic ordering, so that atP >6 GPa the structure may be described in terms of a 1D ferromagnetic chain with predominantly antiferromagnetic lateral (interchain) interactions, in accord with the results of density functional theory calculations

    Relationship of magnetic ordering and crystal structure in lanthanide ferromagnets Gd, Tb, Dy, and Ho at high pressures

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    The pressure dependence of the magnetic ordering temperatures for the lanthanide ferromagnets Gd, Tb, Dy, and Ho has been investigated in the pressure region up to 18 GPa by two types of magnetic measurements using a superconducting quantum interference device (SQUID). The present magnetic measurements enabled us to investigate the pressure dependence of the magnetization intensity at low magnetic fields as well as the magnetic ordering temperatures. Their results are interpreted in the light of such previous experiments as magnetic susceptibility, magnetization, electrical resistance, neutron diffraction, and Mössbauer spectroscopy measurements. All of the magnetic orderings in the above four elements were suppressed down to less than the detection level, being related to the structural transition. The ferromagnetic ordering in Gd, Tb, Dy, and Ho is stabilized in the hcp structure. The magnetic anomalies due to the helimagnetic ordering of Tb and Dy disappear at the Sm-to-dhcp transition and the hcp-to-Sm transition, respectively, while that of Ho disappears in the Sm-type phase near the Sm-to-dhcp transition

    Hydrostatic Compression Effects on Fifth-Group Element Superconductors V, Nb, and Ta Subjected to High-Pressure Torsion

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    In fifth-group element superconductors V, Nb, and Ta, the increase in superconducting transition temperature (Tc) was attempted by using both high-pressure torsion (HPT) and additional hydrostatic pressure (HP) compression. The former brings about the grain refinement and strain accumulation in the unit-cell level. The additional compression for severely strained superconductors triggers strengthening intergrain-contact and/or structural deformation in the unit-cell level. The manner of the appearance of the above two effects depends on the kind of elements: First, in V, there is no prominent effect of HPT, comparing to the hydrostatic compression effects on its non-strained material. Next, in Ta, the effect of strengthening intergrain-contact appears at small hydrostatic compression, resulting in temporal increase in Tc. Finally, Nb exhibits prominent increase in Tc by both effects and, in particular, the structural deformation in the unit-cell level promotes the increase in Tc. Thus, the accumulation of residual strain in the level of starting material can be a promising work to manipulate Tc under HP compression

    CNVs in Three Psychiatric Disorders

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    BACKGROUND: We aimed to determine the similarities and differences in the roles of genic and regulatory copy number variations (CNVs) in bipolar disorder (BD), schizophrenia (SCZ), and autism spectrum disorder (ASD). METHODS: Based on high-resolution CNV data from 8708 Japanese samples, we performed to our knowledge the largest cross-disorder analysis of genic and regulatory CNVs in BD, SCZ, and ASD. RESULTS: In genic CNVs, we found an increased burden of smaller (500 kb) exonic CNVs in SCZ/ASD. Pathogenic CNVs linked to neurodevelopmental disorders were significantly associated with the risk for each disorder, but BD and SCZ/ASD differed in terms of the effect size (smaller in BD) and subtype distribution of CNVs linked to neurodevelopmental disorders. We identified 3 synaptic genes (DLG2, PCDH15, and ASTN2) as risk factors for BD. Whereas gene set analysis showed that BD-associated pathways were restricted to chromatin biology, SCZ and ASD involved more extensive and similar pathways. Nevertheless, a correlation analysis of gene set results indicated weak but significant pathway similarities between BD and SCZ or ASD (r = 0.25–0.31). In SCZ and ASD, but not BD, CNVs were significantly enriched in enhancers and promoters in brain tissue. CONCLUSIONS: BD and SCZ/ASD differ in terms of CNV burden, characteristics of CNVs linked to neurodevelopmental disorders, and regulatory CNVs. On the other hand, they have shared molecular mechanisms, including chromatin biology. The BD risk genes identified here could provide insight into the pathogenesis of BD

    Kidney transplantation recovers the reduction level of serum sulfatide in ESRD patients via processes correlated to oxidative stress and platelet count

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    Sulfatide is a major component of glycosphingolipids in lipoproteins. Recently, we reported that a low serum level of sulfatide in hemodialysis patients might be related to the high incidence of cardiovascular diseases. However, the serum kinetics of sulfatide in kidney disease patients and the function of endogenous serum sulfatide are still unclear. To obtain novel knowledge concerning these issues, we investigated the serum kinetics of sulfatide in 5 adult kidney transplant recipients. We also analyzed the correlated factors influencing the serum sulfatide level, using multiple regression analysis. Kidney transplantation caused a dramatic increase of serum sulfatide without an alteration of its composition in all recipients in a time-dependent manner; however, the recovery speed was slower than that of the improvement of kidney function and the serum sulfatide reached a nearly normal level after 1 year. Multiple regression analysis showed that the significant correlated factor influencing the serum sulfatide level was log duration (time parameter) throughout the observation period, and the correlated factors detected in the stable phase were the decrease of serum concentration of malondialdehyde (an oxidative stress marker) as well as the elevation of platelet count. The current study results demonstrated the gradual but reliable recovery of the serum sulfatide level in kidney transplant recipients for the first time, suggesting a close correlation between serum sulfatide and kidney function. The recovery of serum sulfatide might derive from the attenuation of systemic oxidative stress. The normal level of serum sulfatide in kidney transplant recipients might affect platelet function, and contribute to the reduction of cardiovascular disease incidence.ArticleGLYCOCONJUGATE JOURNAL. 28(3-4):125-135 (2011)journal articl

    N-butyl cyanoacrylate is very effective for massive haemorrhage during the perinatal period.

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    OBJECTIVE: The liquid embolic agent n-butyl cyanoacrylate (NBCA) is a tissue adhesive used as an immediate and permanent embolic agent when mixed with oil-based contrast medium. In this study, the preservation of fertility with TAE using NBCA for massive haemorrhage during pregnancy or the peripartum period and the utility of this therapy were investigated. METHODS: Cases from January 2005 to October 2010 in which TAE was performed for massive haemorrhage in pregnant women, particularly during the peripartum period, were investigated. RESULTS: TAE was performed in 27 pregnant women. The embolic agent used was GS only in five cases, NBCA only in 19 cases, and additional embolization with NBCA when the effect with GS was insufficient in three cases, one each of abruptio placentae, cervical pregnancy, and uterine atony.A comparison of mean blood loss when each embolic agent was used for haemostasis showed a significant difference between cases in which GS only was used and cases in which NBCA only was used. In a comparison of mean transfusion volume, a significant difference was seen between cases in which both GS and NBCA were used and cases in which NBCA only was used. In a postoperative follow-up survey, menses resumed in eight patients, including four patients who later became pregnant and three who delivered. CONCLUSIONS: TAE with NBCA, which has an embolic effect unrelated to clotting dysfunction for massive haemorrhage during the peripartum period, is a minimally invasive and very effective treatment method for patients with severe DIC

    Uterine artery embolization with NBCA.

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    <p>(1) A catheter is inserted from the left or right femoral artery, arteriography of surrounding arteries is performed, and extravasation of the contrast medium is confirmed (inside circle). (2) The catheter is selectively advanced in arteries in which extravasation is confirmed, and the prepared NBCA mixture is injected. The flow of the injected NBCA mixture along the vessel could be confirmed while watching the contrast effect on perspective images (arrow) (3). The NBCA mixture hardens with time and embolises the site of bleeding. It can be visualised as a transparent solid substance on perspective images (arrow) (4). Contrast medium is used again after embolisation, but no obvious extravasation is seen, and reliable haemostasis has been achieved (inside circle).</p
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