100 research outputs found

    Mode separation of a single-frequency bi-modal elastic wave pulse by a phononic crystal

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    Multiple wave modes in a signal can be effectively separated by frequency filtering or frequency-based methods as long as the modes propagate at different frequencies. However, they cannot be applied for the separation of multiple modes that propagate at the same frequency. This work shows that two wave modes contained in a single-frequency bi-modal signal can be separated if a specially engineered phononic crystal (PC) is employed. For demonstration, guided elastic wave experiments were performed in a thin aluminum plate in the middle of which a PC is inserted for mode separation. (C) 2011 American Institute of Physics. [doi:10.1063/1.3662446clos

    Excellent treatment outcomes in children younger than 18 months with stage 4 nonamplified neuroblastoma

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    PurposeAlthough the prognosis is generally good in patients with intermediate-risk neuroblastoma, no consensus has been reached on the ideal treatment regimen. This study analyzed treatment outcomes and toxicities in patients younger than 18 months with stage 4 MYCN nonamplified neuroblastoma.MethodsWe retrospectively analyzed 20 patients younger than 18 months newly diagnosed with stage 4 MYCN nonamplified neuroblastoma between January 2009 and December 2015. Patients received 9 cycles of chemotherapy and surgery, with or without local radiotherapy, followed by 12 cycles of differentiation therapy with 13-cis-retinoic acid. Chemotherapy consisted of alternating cycles of cisplatin, etoposide, doxorubicin, and cyclophosphamide (CEDC) and ifosfamide, carboplatin, and etoposide (ICE) regimens.ResultsThe most common primary tumor site was the abdomen (85%), and the most common metastatic sites were the lymph nodes (65%), followed by the bones (60%), liver (55%), skin (45%), and bone marrow (25%). At the end of induction therapy, 14 patients (70%) achieved complete response, with 1 achieving very good partial response, 4 achieving partial response, and 1 showing mixed response. Nine patients (45%) received local radiotherapy. At a median follow-up of 47 months (range, 17–91 months), none of these patients experienced relapse, progression, or secondary malignancy, or died. Three years after chemotherapy completion, none of the patients had experienced grade ≥3 late adverse effects.ConclusionPatients younger than 18 months with stage 4 MYCN nonamplified neuroblastoma showed excellent outcomes, without significant late adverse effects, when treated with alternating cycles of CEDC and ICE, followed by surgery and differentiation therapy

    Inverted bi-prism phononic crystals for one-sided elastic wave transmission applications

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    This work presents the realization of one-sided wave transmission by using a specially engineered phononic crystal structure. It is an inverted bi-prism phononic crystal engineered for a horizontally incident elastic wave at a specific frequency. The incident wave along one direction is shown to be totally reflected by the bi-prism while the incident wave along the opposite direction transmitted through it with refraction, also evident from experiments. An application of the proposed bi-prism may be found in thin elastic strips. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4721485clos

    Primary leiomyosarcoma of the pancreas

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    Primary sarcomas of the pancreas are extremely rare, accounting for 0.1% of malignant pancreatic (non-islet) neoplasms. Pancreatic leiomyosarcoma is a highly aggressive malignancy that spreads in a similar manner to gastric leiomyosarcoma, i.e., by adjacent organ invasion, hematogenous spread, and lymph node metastasis. These tumors are large at the time of diagnosis and are usually found at an advanced stage. We report a case of a 70-year-old female with intermittent right upper quadrant abdominal discomfort. Radiological, histopathological, and immunohistochemical studies revealed the tumor to be a primary leiomyosarcoma of the pancreas. Herein, we describe a patient with a primary leiomyosarcoma of the pancreas who presented with clinical and radiological findings indicative of a mass in the pancreatic head

    Undifferentiated carcinoma of the pancreas with osteoclast-like giant cells

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    Undifferentiated carcinoma with osteoclast-like giant cells is a rare neoplasm of the exocrine pancreas. Some similar cases have been reported, but the histogenesis of these tumors varies and is controversial. We report here on a case of undifferentiated carcinoma of the pancreas with osteoclast-like giant cells. A 77-year old woman presented with abdominal pain and anorexia. Abdominal computed tomography and magnetic resonance imaging showed an approximately 10 × 5 cm highly attenuated mass arising from the tail of the pancreas and invading the spleen and adjacent bowel loop. The initial impression was a malignant endocrine tumor or solid-pseudopapillary tumor of the pancreas. The patient underwent a distal pancreatectomy with splenectomy and left hemicolectomy. The histopathology and immunohistochemistry helped make the diagnosis that of an undifferentiated carcinoma with osteoclast-like giant cells of the pancreas

    Prognostic factors in children with extracranial germ cell tumors treated with cisplatin-based chemotherapy

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    PurposeTo evaluate the outcomes and prognostic factors in children with extracranial germ cell tumors (GCTs) treated at a single institution.MethodsSixty-six children diagnosed with extracranial GCTs between 1996 and 2012 were included in the study. Primary treatment was surgical excision, followed by six cycles of cisplatin-based chemotherapy. The survival rates were compared according to the International Germ Cell Cancer Cooperative Group classification used for GCTs in adults to validate the classification guidelines for GCTs in children.ResultsThe median patient age was 4.4 years. In 34 patients (51.5%), the primary tumor site was the gonad. Extragonadal GCTs were detected in 32 patients. The 5-year overall survival and event-free survival (EFS) were 92.0%±3.5% and 90.4%±3.7%, respectively. In univariate analysis, tumor histology, metastasis, and elevated alpha-fetoprotein were not prognostic factors in children with extracranial GCTs. However, EFS was poorer in patients with mediastinal disease (n=12, 66.7%±13.6 %) than in those with nonmediastinal disease (n=54, 96.0%±2.8%) (P=0.001). The 5-year EFS was lower in patients older than 10 years, (n=21, 80.0%±8.9%) compared with those younger than 10 years (n=45, 95.2%±3.3%) (P=0.04). Multivariate analysis identified the mediastinal tumor site as the only independent prognostic factor.ConclusionThe prognosis of children with extracranial GCTs was favorable. However, nongerminomatous mediastinal tumors were associated with poor survival in children. Further research is needed to improve the prognosis of children with malignant mediastinal GCTs
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