Soft Magnetic Properties of Bulk Nanocrystalline Fe-(Zr, Hf)-B Alloys Produced by Extruding Amorphous Powders

The Bulk Fe_Zr_7B_3 and Fe_Hf_7B_4 alloys were prepared by extruding amorphous powders through utilizing a softening phenomenon of an amorphous alloy near the crystallization temperature. The extruded bulk alloys are composed of an amorphous phase containing a small amount of bcc phase in an as-extruded state and the structure changes to a mostly single bcc phase with grain sizes from 10 to 25 nm by annealing at 923 K. The soft magnetic properties of the bulk alloys are better for the alloys containing a smaller volume fraction of bcc phase in as-extruded state. The Fe_Zr_7B_3 alloy extruded at pressure of 860 MPa and temperature of 673 K has a high relative density above 99 %, and exhibits the permeabilities (μ_e) of 2350, flux density (B_) of 1.59 T and the coercivity (H_c) of 26 A/m

Characterization of a Murine Anti-laminin-1 Monoclonal Antibody (AK8) Produced by Immunization with Mouse-derived Laminin-1

Laminin-1 is a structural glycoprotein that forms an integral part of the scaffolding of basement membranes, and plays an important role during embryonic development. We have recently demonstrated a significant association between anti-laminin-1 antibodies (Abs) and reproductive failure, such as recurrent spontaneous abortions and infertility-associated endometriosis in both human and mouse studies. In the present study, we established an IgM (μ,κ) monoclonal anti-laminin-1 Ab (AK8) by immunizing mice with mouse Engelbreth-Holm-Swarm sarcoma (EHS)-derived laminin-α1. The AK8 monoclonal antibody (mAb) reacted with particular peptide sequences from the globular G domain of mouse laminin-α1 chain of using ELISA and Western blot techniques. The peptide tertiary structure of the epitope recognized by AK8 mAb was predicted using eight synthesized domain peptide sequences and three consensus sequences obtained by phage displayed random peptide library. Basement membranes of endometrium of pregnant mice and humans were immunostained with AK8 mAb. Thus, AK8 mAb recognized a common structure present in the G domain of the laminin-1 chain in both mice and humans. The passive immunization of mice with AK8 mAb may represent a suitable animal model for anti-laminin-1 Ab-mediated reproductive failure

No significant difference found in PET/MRI CBF values reconstructed with CT-atlas-based and ZTE MR attenuation correction

Abstract Background Accurate attenuation correction (AC) is one of the most important issues to be addressed in quantitative brain PET/MRI imaging. Atlas-based MRI AC (AB-MRAC), one of the representative MRAC methods, has been used to estimate the skull attenuation in brain scans. The zero echo time (ZTE) pulse sequence is also expected to provide a better MRAC estimation in brain PET scans. The difference in quantitative measurements of cerebral blood flow (CBF) using H2 15O-PET/MRI was compared between the two MRAC methods, AB and ZTE. Method Twelve patients with cerebrovascular disease (4 males, 43.2 ± 11.7 years) underwent H2 15O-PET/MRI studies with a 3-min PET scan and MRI scans including the ZTE sequence. Eleven of them were also studied under the conditions of baseline and 10 min after acetazolamide administration, and 2 of them were followed up after several months interval. A total of 25 PET images were reconstructed as dynamic data using 2 sets of reconstruction parameters to obtain the image-derived input function (IDIF), the time-activity curves of the major cerebral artery extracted from images, and CBF images. The CBF images from AB- and ZTE-MRAC were then compared for global and regional differences. Results The mean differences of IDIF curves at each point obtained from AB- and ZTE-MRAC dynamic data were less than 5%, and the differences in time-activity curves were very small. The means of CBF from AB- and ZTE-MRAC reconstructions calculated using each IDIF showed differences of less than 5% for all cortical regions. CBF images from AB-MRAC tended to show greater values in the parietal region and smaller values in the skull base region. Conclusion The CBF images from AB- and ZTE-MRAC reconstruction showed no significant differences in regional values, although the parietal region tended to show greater values in AB-MRAC reconstruction. Quantitative values in the skull base region were very close, and almost the same IDIFs were obtained

Cerebral Oxidative Stress in Early Alzheimer’s Disease Evaluated by ⁶⁴Cu-ATSM PET/MRI: A Preliminary Study

Oxidative stress imaging using diacetyl-bis (N4-methylthiosemicarbazone) (Cu-ATSM) was applied to the evaluation of patients with early Alzheimer’s disease (eAD). Ten eAD patients (72 ± 9 years) and 10 age-matched healthy controls (HCs) (73 ± 9 years) participated in this study. They underwent dynamic PET/MRI using 11C-PiB and 64Cu-ATSM with multiple MRI sequences. To evaluate cerebral oxidative stress, three parameters of 64Cu-ATSM PET were compared: standardized uptake value (SUV), tracer influx rate (Kin), and a rate constant k3. The input functions were estimated by the image-derived input function method. The relative differences were analyzed by statistical parametric mapping (SPM) using SUV and Kin images. All eAD patients had positive and HC subjects had negative PiB accumulation, and MMSE scores were significantly different between them. The 64Cu-ATSM accumulation tended to be higher in eAD than in HCs for both SUV and Kin. When comparing absolute values, eAD patients had a greater Kin in the posterior cingulate cortex and a greater k3 in the hippocampus compared with lobar cortical values of HCs. In SPM analysis, eAD had an increased left operculum and decreased bilateral hippocampus and anterior cingulate cortex compared to HCs. 64Cu-ATSM PET/MRI and tracer kinetic analysis elucidated cerebral oxidative stress in the eAD patients, particularly in the cingulate cortex and hippocampus