677 research outputs found
Relationship between Microstructure and Magnetic Domain Structure of Nd-Fe-B Melt-Spun Ribbon Magnets
The relation between the microstructure, observed using an electron probe microanalyzer, and the domain structure, observed using a Kerr microscope, was established to evaluate the effects of hot rolling and the addition of Ti-C on the c-axis orientation and the magnetization process of hot-rolled Nd-Fe-B-Ti-C melt-spun ribbons. The addition of Ti-C promotes the c-axis orientation and high coercivity in the ribbons. Elemental mapping suggests a uniform elemental distribution; however, an uneven distribution of Ti was observed in an enlarged grain with Ti-enriched points inside the grain. The reversal domains that nucleated at the Ti-enriched point inside the grain cause low coercivity
Protein Phosphatase 1δ with Nucleophosmin
Protein phosphorylation and dephosphorylation has been recognized as an essential mechanism in the regulation of cellular metabolism and function in various tissues. Serine and threonine protein phosphatases (PP) are divided into four categories: PP1, PP2A, PP2B, and PP2C. At least four isoforms of PP1 catalytic subunit in rat, PP1α, PP1γ1, PP1γ2, and PP1δ, were isolated. In the present study, we examined the localization and expression of PP1δ in human osteoblastic Saos-2 cells. Anti-PP1δ antibody recognized a protein present in the nucleolar regions in Saos-2 cells. Cellular fractionation revealed that PP1δ is a 37 kDa protein localized in the nucleolus. Nucleophosmin is a nucleolar phosphoprotein and located mainly in the nucleolus. Staining pattern of nucleophosmin in Saos-2 cells was similar to that of PP1δ. PP1δ and nucleophosmin were specifically stained as dots in the nucleus. Dual fluorescence images revealed that PP1δ and nucleophosmin were localized in the same regions in the nucleolus. Similar distribution patterns of PP1δ and nucleophosmin were observed in osteoblastic MG63 cells. The interaction of PP1δ and nucleophosmin was also shown by immunoprecipitation and Western analysis. These results indicated that PP1δ associate with nucleophosmin directly in the nucleolus and suggested that nucleophosmin is one of the candidate substrate for PP1δ
A new crystal plasticity constitutive equation based on crystallographic misorientation theory
Since plastic deformation of polycrystal sheet metal is greatly affected by its initial and plastic deformed textures, multi-scale finite element (FE) analysis based on homogenization with considering micro-polycrystal morphology is required [1]. We formulated a new crystal plasticity constitutive equation to introduce not only the effect of crystal orientation distribution, but also the size of crystal grain and/or the effect of crystal grain boundary for the micro-FE analysis. The hardening evolution equation based on strain gradient theory [2], [3] was modified to introduce curvature of crystal orientation based on crystallographic misorientation theory. We employed two-scale structure, such as a microscopic polycrystal structure and a macroscopic elastic/plastic continuum. Our analysis code predicts the plastic deformation of polycrystal metal in the macro-scale, and simultaneously the crystal texture and misorientation evolutions in the micro-scale. In this study, we try to reveal the relationship between the plastic deformation and the microscopic crystal misorientation evolution by using the homogenized FE procedure with the proposed crystal plasticity constitutive equation. The crystallographic misorientation evolution, which affects on the plastic deformation of FCC polycrystal metal, was investigated by using the multi-scale FE analysis. We confirmed the availability of our analysis code employing the new constitutive equation through the comparison of a uniaxial tensile problem with the numerical result and the experimental one
<i>Salmonella</i> Flagellum
Flagella-driven motility contributes to effective bacterial invasion. The bacterial flagellum of Salmonella enterica is a rotary motor powered by an electrochemical potential difference of protons across the cytoplasmic membrane. The flagellum is composed of several basal body rings and an axial structure consisting of the rod as a drive shaft, the hook as a universal joint and the filament as a helical propeller. The assembly of the axial structure begins with the rod, followed by the hook and finally the filament. A type III protein export apparatus is located at the flagellar base and transports flagellar axial proteins from the cytoplasm to the distal end of the growing flagellar structure where their assembly occurs. The protein export apparatus coordinates flagellar gene expression with assembly, allowing the hierarchy of flagellar gene expression to exactly parallel the flagellar assembly process. The basal body can accommodate a dozen stator complexes around a rotor ring complex in a load-dependent manner. Each stator unit conducts protons and pushes the rotor. In this book chapter, we will summarize our current understanding of the structure and function of the Salmonella flagellum
第4-5腰椎変性疾患に対する椎間cageのみでの低侵襲前方固定術(mini-ALIF)の臨床成績と放射線学的検討
Surgical treatment for degenerative spinal disorders is controversial, although lumbar fusion is considered an acceptable option for disabling lower back pain. Patients underwent instrumented minimally invasive anterior lumbar interbody fusion (mini-ALIF) using a retroperitoneal approach except for requiring multilevel fusions, severe spinal canal stenosis, high-grade spondylolisthesis, and a adjacent segments disorders. We retrospectively reviewed the clinical records and radiographs of 142 patients who received mini-ALIF for L4-5 degenerative lumbar disorders between 1998 and 2010. We compared preoperative and postoperative clinical data and radiographic measurements, including the modified Japanese Orthopaedic Association (JOA) score, visual analog scale (VAS) score for back and leg pain, disc height (DH), whole lumbar lordosis (WL), and vertebral wedge angle (WA). The mean follow-up period was 76 months. The solid fusion rate was 90.1% (128/142 patients). The average length of hospital stay was 6.9 days (range, 3-21 days). The mean blood loss was 63.7 ml (range, 10-456 ml). The mean operation time was 155.5 min (range, 96-280 min). The postoperative JOA and VAS scores for back and leg pain were improved compared with the preoperative scores. Radiological analysis showed significant postoperative improvements in DH, WL, and WA, and the functional and radiographical outcomes improved significantly after 2 years. The 2.8% complication rate included cases of wound infection, liquorrhea, vertebral body fractures, and a misplaced cage that required revision. Mini-ALIF was found to be associated with improved clinical results and radiographic findings for L4-5 disorders. A retroperitoneal approach might therefore be a valuable treatment option.博士(医学)・乙第1338号・平成26年5月28日Copyright © 日本脳神経外科学会 | The Japan Neurosurgical Society / 学会誌名(Neurologia medico-chirurgica)とJ-STAGEからの出典であ
CLINICOPATHOLOGICAL STUDY OF CEREBRAL SUBCORTICAL CAVERNOUS ANGIOMA AS EPILEPTOGENIC FOCUS
The authors conducted a comparative histological study of two groups of patients with cerebral subcortical cavernous angioma. One group was composed of 5 asymptomatic cases detected accidentally. The other group was composed of 4 patients presenting as epilepsy. The results obtained may be summarized as follows ; 1) Hemosiderin deposit and gliosis were seen in all cases examined ; 2) Granulomatous change was a histological finding associated with epileptogenesis ; 3) The histological changes, starting with proliferation of collagen fibers and leading to hyaline degeneration, calcification, and then hemangioma calcificans, seem to represent a course of spontaneous healing, when viewed from epileptogenesis
Type II DNA Topoisomerases Cause Spontaneous Double-Strand Breaks in Genomic DNA
Type II DNA topoisomerase enzymes (TOP2) catalyze topological changes by strand passage reactions. They involve passing one intact double stranded DNA duplex through a transient enzyme-bridged break in another (gated helix) followed by ligation of the break by TOP2. A TOP2 poison, etoposide blocks TOP2 catalysis at the ligation step of the enzyme-bridged break, increasing the number of stable TOP2 cleavage complexes (TOP2ccs). Remarkably, such pathological TOP2ccs are formed during the normal cell cycle as well as in postmitotic cells. Thus, this 'abortive catalysis' can be a major source of spontaneously arising DNA double-strand breaks (DSBs). TOP2-mediated DSBs are also formed upon stimulation with physiological concentrations of androgens and estrogens. The frequent occurrence of TOP2-mediated DSBs was previously not appreciated because they are efficiently repaired. This repair is performed in collaboration with BRCA1, BRCA2, MRE11 nuclease, and tyrosyl-DNA phosphodiesterase 2 (TDP2) with nonhomologous end joining (NHEJ) factors. This review first discusses spontaneously arising DSBs caused by the abortive catalysis of TOP2 and then summarizes proteins involved in repairing stalled TOP2ccs and discusses the genotoxicity of the sex hormones
Clinical Usefulness of Contrast-Enhanced Three-Dimensional Ultrasound Imaging with Sonazoid for Hepatic Tumor Lesions
An Electrically Adjustable 3-Terminal Regulator with Post-Fabrication Level-Trimming Function
This paper describes a new technique for 3-terminal regulators to adjust the output voltage level without additional terminals or extra off-chip components. By applying a serial control pattern using the intermediate voltage level between the supply voltage and the regulator output, the adjustment data in the internal nonvolatile memory are safely updated without noise disturbance. In an on-board test with a chip fabricated using a 0.35-¿m standard CMOS process, we confirm successful output voltage adjustment with sub-10mV precision.15th Asia and South Pacific Design Automation Conference (ASP-DAC 2010), January 18-21, 2010, Taipei, Taiwa
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