Circuit Structure and Control Method to Reduce Size and Harmonic Distortion of Interleaved Dual Buck Inverter

A new circuit structure and control method for a high power interleaved dual-buck inverter are proposed. The proposed inverter consists of six switches, four diodes and two inductors, uses a dual-buck structure to eliminate zero-cross distortion, and operates in an interleaved mode to reduce the current stress of switch. To reduce the total harmonic distortion at low output power, the inverter is controlled using discontinuous-current-mode control combined with continuous-current-mode control. The experimental inverter had a power-conversion efficiency of 98.5% at output power = 1300 W and 98.3% at output power = 2 kW, when the inverter was operated at an input voltage of 400 V-DC, output voltage of 220 V-AC/60 Hz, and switching frequency of 20 kHz. The total harmonic distortion was < 0.66%, which demonstrates that the inverter is suitable for high-power dc-ac power conversion.11Ysciescopu

Regulation of Expression of B7 by Murine Langerhans Cells: A Direct Relationship Between B7 mRNA Levels and the Level of Surface Expression of B7 by Langerhans Cells

Cultured BALB/c epidermal Langerhans cells express high levels of the costimulatory molecule B7 on their surfaces relative to levels expressed on fresh Langerhans cells. Quantitation of relative amounts of B7 mRNA in fresh epidermal cells and cultured epidermal cells following amplification of mRNA signals via reverse transcriptase – polymerase chain reaction, hybridization of PCR products with radiolabeled internal oligonucleotide probes, resolution of hybrids in non-denaturing polyacrylamide gels, and detection by autoradiography revealed dramatically (approximately one thousandfold) higher levels of B7 mRNA in cultured epidermal cells (10-40% 1-A+) as compared with fresh epidermal cells (1 – 4% I-A+). Levels of B7 mRNA in cultured epidermal cells were also substantially greater than those detected in a reference B lymphoma cell line (CH-1). Analysis of 87 mRNA expression in subpopulations of cultured epidermal cells demonstrated that essentially all of the B7 mRNA was present in Langerhans cells; cells bearing I-A and CD45 antigens. Cultured keratinocytes did not contain appreciable amounts of B7 mRNA. These results are consistent with previous data regarding surface expression of 87 by cLC and also demonstrate that fLC are essentially devoid of B7 mRNA and surface protein

Metastasis of Transitional Cell Carcinoma to the Lower Abdominal Wall 20 Years after Cystectomy

Iatrogenic implantation has been the main cause in the majority of cases of transitional call carcinoma (TCC) with metastasis to the abdominal wall. A 66-year-old woman had undergone radical cystectomy 20 years prior to presenting. Radiological investigations revealed one mass in the left lower abdominal wall and one mass in the right inguinal area. She underwent wide excision of the lesions that revealed metastasis of TCC. This report describes this case of a woman with bladder carcinoma who developed a metastasis in the anterior abdominal wall following an apparent disease-free interval of 20 years

Transition from Pemphigus Foliaceus to Pemphigus Vulgaris: Case Report with Literature Review

The transition between the main subtypes of pemphigus, pemphigus vulgaris (PV), and pemphigus foliaceus (PF) has rarely been reported. Moreover, the development of PV in a patient with PF is much more unusual than that of PF in a patient with PV. We report a 48-year-old man who presented with cutaneous lesions showing the typical clinical and histological features of PF. Five years later, his skin lesions became extensive and he developed oral erosions. His condition did not respond well to steroids and azathioprine. Histological examination of a vesicle disclosed suprabasal acantholysis in contrast to the subcorneal acantholysis discovered upon initial histological evaluation. Indirect immunofluorescence revealed IgG antikeratinocyte cell surface antibodies at a titer of 1:640. The titer was 1:160 at initial diagnosis. Upon immunoblotting, the patient's serum reacted with 130 kiloDalton (kDa) and 160 kDa proteins, suggesting desmoglein (Dsg) 3 and 1, respectively. We herein report an unusual case of PV that developed from PF during the disease's flare-up

Combined Treatment of an Intratumoral Injection of Dendritic Cells and Systemic Chemotherapy (Paclitaxel) for Murine Fibrosarcoma

A novel combined treatment of conventional chemotherapy with an intratumoral injection of syngeneic dendritic cells (DCs) has emerged as a potent cancer treatment strategy. In this study, we evaluated the synergistic effect of an intraperitoneal (i.p.) injection of a chemotherapeutic drug, paclitaxel, and an intratumoral (i.t.) injection of syngeneic bone marrow-derived DCs for the treatment of pre-existing fibrosarcoma. Subcutaneous tumors were established using MCA102 fibrosarcoma cells in syngeneic C57BL/6 mice. The results demonstrated that the combined treatment of paclitaxel chemotherapy and the injection of DCs led to complete tumor regression, in contrast to only partial eradication of the tumors with chemotherapy or DCs alone. Furthermore, the tumor-free mice were able to resist a repeat challenge with the same type of tumor. These findings suggest that a combination therapy of systemic chemotherapy along with the intratumoral administration of DCs is a potent treatment strategy for fibrosarcoma

Immunotherapy of Malignant Melanoma with Tumor Lysate-Pulsed Autologous Monocyte-Derived Dendritic Cells

PURPOSE: Dendritic cell (DC) vaccination for melanoma was introduced because melanoma carries distinct tumor-associated antigens. The purpose of this study was to investigate the efficacy and safety of DC vaccination for melanoma in Korea. MATERIALS AND METHODS: Five patients with stage IV and one with stage II were enrolled. Autologous monocyte-derived DCs (MoDCs) were cultured and pulsed with tumor-lysate, keyhole limpet hemocyanin, and cytokine cocktail for mature antigen-loaded DC. DC vaccination was repeated four times at 2-week intervals and 2-4×10⁷ DC were injected each time. RESULTS: Reduced tumor volume was observed by PET-CT in three patients after DC vaccination. Delayed type hypersensitivity responses against tumor antigen were induced in five patients. Tumor antigen-specific IFN-γ-producing peripheral blood mononuclear cells were detected with enzyme-linked immunosorbent spot in two patients. However, the overall clinical outcome showed disease progression in all patients. CONCLUSION: In this study, DC vaccination using tumor antigen-loaded, mature MoDCs led to tumor regression in individual melanoma patients. Further standardization of DC vaccination protocol is required to determine which parameters lead to better anti-tumor responses and clinical outcomes.ope

Neurotoxicity Screening in a Multipotent Neural Stem Cell Line Established from the Mouse Brain

Neural stem cells (NSCs) have mainly been applied to neurodegeneration in some medically intractable neurologic diseases. In this study, we established a novel NSC line and investigated the cytotoxic responses of NSCs to exogenous neurotoxicants, glutamates and reactive oxygen species (ROS). A multipotent NSC line, B2A1 cells, was established from long-term primary cultures of oligodendrocyte-enriched cells from an adult BALB/c mouse brain. B2A1 cells could be differentiated into neuronal, astrocytic and oligodendroglial lineages. The cells also expressed genotypic mRNA messages for both neural progenitor cells and differentiated neuronoglial cells. B2A1 cells treated with hydrogen peroxide and L-buthionine-(S,R)-sulfoximine underwent 30-40% cell death, while B2A1 cells treated with glutamate and kainate showed 25-35% cell death. Cytopathologic changes consisting of swollen cell bodies, loss of cytoplasmic processes, and nuclear chromatin disintegration, developed after exposure to both ROS and excitotoxic chemicals. These results suggest that B2A1 cells may be useful in the study of NSC biology and may constitute an effective neurotoxicity screening system for ROS and excitotoxic chemicals