469 research outputs found

    Tailoring Low-field Strain Properties of [0.97Bi1/2(Na0.78K0.22)1/2TiO3-0.03LaFeO3]-Bi1/2(Na0.82K0.18)1/2TiO3 Lead-Free Relaxor/Ferroelectric Composites

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    We investigated the effect of Bi1/2(Na0.82K0.18)1/2TiO3 (BNKT) modification on the ferroelectric and electric-field-induced strain (EFIS) properties of lead-free 0.97Bi1/2(Na0.82K0.18)1/2TiO3-0.03LaFeO3 (BNKTLF) ceramics as a function of BNKT content (x= 0, 0.1, 0.2, 0.3, 0.5, and 1). BNKT-modified BNKTLF powders were synthesized using a conventional solid-state reaction method. As the BNKT content x increased from 0 to 1 the normalized electric-field-induced strain (Smax/Emax) was observed to increase at relatively low fields, i.e., below the poling field. Moreover, BNKTLF-30BNKT showed about 460 pm/V as low as at 3 kV/mm, which is a considerably high value among the lead-free systems reported so far. Consequently, it was confirmed that ceramic-ceramic composite, a mixture of an ergodic relaxor matrix and embedded ferroelectric seeds, is a salient way to make lead-free piezoelectrics practical with enhanced EFIS at low field as well as less hysterical.ope

    Successful Salvage Unrelated Umbilical Cord Blood Transplantation with Two Units After Engraftment Failure with Single Unit in Severe Aplastic Anemia

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    Severe aplastic anemia (SAA) patients without an HLA-matched sibling donor need alternative treatment options. Umbilical cord blood transplantation (UCBT) has become an alternative means for treating various diseases, but it has not been proved to be a satisfactory method to treat SAA. Here, we report the case of a girl who underwent successful two-unit UCBT after engraftment failure with a single unit. Two-unit UCBT is proposed to have better engraftment potential and to offer a better chance of survival, according to some reports. Increased cell dose and graft-versus-graft reaction could contribute to these advantages. With this promising result, two-unit UCBT could be an alternative treatment option for patients with SAA without an HLA-matched donor

    Retrospective Analysis of Peripheral Blood Stem Cell Transplantation for the Treatment of High-Risk Neuroblastoma

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    Disease relapse after autologous peripheral blood stem cell transplantation (APBSCT) is the main cause of treatment failure in high-risk neuroblastoma (NBL). To reduce relapse, various efforts have been made such as CD34+ selection and double APBSCT. Here the authors reviewed the clinical features and outcomes of high-risk NBL patients and analyzed their survival. The medical records of 36 patients with stage III or IV NBL who underwent APBSCT at Seoul National University Children's Hospital between May 1996 and May 2004 were reviewed. Total 46 APBSCTs were performed in 36 patients. Disease free survival (DFS) and overall survival of all patients were 47.7% and 68.8%, respectively. The patients were allocated to three groups according to the APBSCT type. The DFS of CD34+ non-selected single APBSCT patients (N=13), CD34+ selected single APBSCT patients (N=14), and CD34+ selected double APBSCT patients (N=9) were 55.6%, 40.6%, and 50.0%, respectively, which were not significantly different. Thus the survival was not found to be affected by CD34+ selection or transplantation number. To improve long-term survival, various efforts should be made such as chemotherapy dose intensification, more effective tumor purging, and control of minimal residual disease via the use of differentiating and immune-modulating agents

    Improved survival in patients with recurrent Wilms tumor: the experience of the Seoul National University Children's Hospital

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    The survival in cases with relapsed Wilms tumor is dismal. Recently, however the introduction of new therapeutic agents and experimental strategies has improved the survival. We analysed the survival of patients with relapsed Wilms tumor according to the treatment period. During the early period 1983-1993, patients who had received two drugs were treated with doxorubicin and the others were treated with cisplatin and etoposide, whereas during the late period 1994-2004, patients were treated with combinations of cyclophosphamide/etoposide and carboplatin/etoposide. During the early period, 8 of 57 experienced relapse, and 8 of 41 relapsed during the late period. Only 2 patients treated during the early period survived in complete response (CR), whereas during the late period, 5 patients remained alive in CR, and 3 of those received high-dose chemotherapy (HDC) with autologous peripheral stem cell rescue (SCR). The estimated 5 yr event-free survival rate was 37.5% in the entire study group, 50% for patients in the late period, and 25% for patients in the early period (p=0.38). The survival in patients with relapsed Wilms tumor dramatically improved during the late period and HDC with SCR was one of the effective salvage strategies

    Concurrent Langerhans Cell Histiocytosis and B-Lineage Lymphoid Proliferation in the Bone Marrow

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    We present three cases of concurrent Langerhans cell histiocytosis (LCH) and B-lineage lymphoid cell infiltrations and/or nodules in the bone marrow. The first patient was a 25-month-old boy who presented with LCH on the right shoulder and multiple osteolytic lesions. Bone marrow biopsy showed the presence of LCH and two large lymphoid nodules of B-lineage, which were located in the paratrabecular region. Both LCH and the lymphoid nodules resolved after treatment with prednisone, vinblastine, methotrexate, and cyclophosphamide. The second patient was a 7-month-old girl who presented with LCH in the scalp and bone marrow. In spite of the treatment, a follow-up bone marrow analysis performed after 16 months showed LCH and increased B-lineage lymphoid cells in the interstitial area, The third patient was a 26-month-old girl, and imaging studies revealed reddish skin lesions and multiple osteolytic lesions. Skin biopsy and bone marrow biopsy did not show the presence of LCH; however, we initiated the treatment on the basis of the results of imaging studies. The follow-up study after 6 months showed the presence of LCH and large, patchy infiltration of B-lymphoid cells. We report three rare cases of concurrent bone marrow involvement of LCH and B-lineage lymphoid proliferation, which strongly suggest lymphoid malignancy. Further, clonal changes should be studied to elucidate the common pathogenic mechanism between the two diseases. (Korean J Lab Med 2009;29:402-5)Licci S, 2008, ANN HEMATOL, V87, P855, DOI 10.1007/s00277-008-0489-5SWERDLOW SH, 2008, WHO CLASSIFICATION T, P358Feldman AL, 2005, LANCET ONCOL, V6, P435Adu-Poku K, 2005, J CLIN PATHOL, V58, P104, DOI 10.1136/jcp.2003.015537Thiele J, 1999, J CLIN PATHOL, V52, P294

    Selective Leaching of Zinc from Spent Zinc-Carbon Battery with Ammoniacal Ammonium Carbonate

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    This paper describes the ammoniacal ammonium carbonate leaching behavior of zinc and manganese from spent zinc-carbon batteries. For selective extraction of Zn from the spent zinc-carbon battery, leaching tests were carried out as a function of process parameters such as concentration of (NH 4 ) 2 CO 3 , ammonia, temperature, time and pulp density. Physical methods of separation such as crushing was applied to reduce the material to 10-20 mm size followed by magnetic separation to separate iron with a recovery about 10 mass% leaving most of Zn and Mn in the non-magnetic fraction. Non-magnetic fraction was further subjected to sieving to separate 2.46 mm over and under size fractions. The oversize material was processed by eddy current separation to recover zinc sheet and carbon rods and plastics. The under size material with chemical composition of Zn 15.5 mass%, Mn 17.5 mass%, and Fe 1.4 mass% was used for leaching studies. Under the optimum leaching conditions (2.0 kmol/m 3 (NH 4 ) 2 CO 3 and 4.0 kmol/m 3 ammonia, 40 C, 100 g/L pulp density, 30 min and 250 rpm), the leaching efficiency of zinc and manganese was 80.2% and less than 0.1%, respectively, indicating the selective recovery of zinc from the spent zinc-carbon battery. An overall zinc recovery is about 88%

    Primary Calcified T-Cell Lymphoma of the Urinary Bladder: A Case Report

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    Primary malignant lymphoma of the urinary bladder is extremely rare, and to our knowledge, no case described in the radiologic literature has been accompanied by calcification. We report a case in which the condition was associated with calcification, and describe the pelvic CT and MR imaging findings

    Successful mobilization using a combination of plerixafor and G-CSF in pediatric patients who failed previous chemomobilization with G-CSF alone and possible complications of the treatment

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    Peripheral blood stem cell (PBSC) mobilization, which uses plerixafor (AMD 3100), a newly developed specific inhibitor of the CXCR4 receptor, in combination with granulocyte-colony stimulating factor(G-CSF), has been shown to enhance the stem cell mobilization in adult patients, but pediatric data are scarce. We documented our experience with this drug in 6 Korean pediatric patients who had failed in chemomobilization, using G-CSF, alone. All patients were mobilized CD34+ cells (median, 11.08 × 106/kg: range, 6.34-28.97 × 106/kg) successfully within 2 to 3 cycles of apheresis, without complications. A total of 7 autologous transplantations were performed, including 1 tandem transplantation. However, 2 patients with brain tumors showed severe pulmonary complications, including spontaneous pneumomediastinum. This is the first study of PBSC mobilization with plerixafor in Asian pediatric patients. Furthermore our study suggests that mobilization with plerixafor may be effective in Korean pediatric patients, who have previously been heavily treated and have failed PBSC mobilization with classical chemomobilization, using G-CSF. However, further studies are needed to examine the possible complications of autologous transplantation, using a mobilized plerixafor product in children
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