333 research outputs found

    Spin cast ferroelectric beta poly(vinylidene fluoride) thin films via rapid thermal annealing

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    We describe a method of fabricating ferroelectric beta-type poly(vinylidene fluoride) (PVDF) thin films on Au substrate by the humidity controlled spin casting combined with rapid thermal treatment. Our method produces thin uniform ferroelectric PVDF film with ordered beta crystals consisting of characteristic needlelike microdomains. A capacitor with a 160 nm thick ferroelectric PVDF film exhibits the remanent polarization and coercive voltage of similar to 7.0 mu C/cm(2) and 8 V, respectively, with the temperature stability of up to 160 degrees C. A ferroelectric field effect transistor also shows a drain current bistablility of 100 at zero gate voltage with +/- 20 V gate voltage sweep. (C) 2008 American Institute of Physicsopen485

    The Antioxidant Activity and Their Major Antioxidant Compounds from Acanthopanax senticosus and A. koreanum

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    The antioxidant activity and chlorogenic acid and caffeic acid contents were investigated from different parts of Acanthopanax senticosus and A. koreanum. Antioxidant activity was assessed by various in vitro assays such as DPPH, ABTS, FRAP, reducing power assays and ORAC, and the chlorogenic acid and caffeic acid were validated by HPLC chromatography. Among the various extracts, the fruit extracts of A. senticosus and A. koreanum exhibited strongest antioxidant activities including ABTS, FRAP, reducing power and ORAC, however, strongest DPPH radical scavenging activity was observed from the leaf extract of A. senticosus. In addition, the antioxidant activities of various extracts were correlated with total phenolic and proanthocyanidin contents. The major phenolic contents from various parts of these plants observed that leaf extract of A. senticosus expressed higher levels of chlorogenic acid (14.86 mg/dry weigh g) and caffeic acid (3.09 mg/dry weigh g) than other parts. Therefore, these results suggest that the leaf of A. senticosus may be an excellent natural source for functional foods and pharmaceutical agents, and the validated method was useful for the quality control of A. senticosus

    Case Report Squamous cell carcinoma of the small bowel manifesting as a jejunal perforation: a case report

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    Abstract: Squamous cell carcinoma arising from the small intestine is rare and difficult to identify as a primary or metastatic feature. We report a case of small intestinal squamous cell carcinoma manifesting as subacute peritonitis due to perforation. An 80-year-old man was admitted to our hospital with intermittent postprandial abdominal pain. He was diagnosed with acute peritonitis due to gastrointestinal perforation. During explorative laparotomy, a perforation site was detected in the jejunum and segmental resection to correct the perforation was performed including the perforation site located at the 70 cm inside the jejunum from the Treitz ligament. The pathology results revealed squamous cell carcinoma in the resected segment of the jejunum with two perforation sites

    PVP2004-3033 NUMERICAL PREDICTION OF HOMOLOGOUS CURVES FOR THE SMART MCP

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    ABSTRACT A procedure for generating prefiminary homologous curves, which are used as an input for the safety analysis of SMART, was developed. A commercial code for the computational fluid dynamics was adopted as a tool for the procedure. To generate homologous curves, we define the homologous variables and construct a computational matrix. Computations were performed according to the matrix, and the results were compared and analyzed for the representative computational points among the matrix. A modification method to obtain the homologous curves from the results was suggested by using the similarity laws and the complete curves were generated. The curves were compared with available experimental data and the validity of the procedure was investigated

    Suppression of STAT3 and HIF-1 Alpha Mediates Anti-Angiogenic Activity of Betulinic Acid in Hypoxic PC-3 Prostate Cancer Cells

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    Background: Signal transducer and activator of transcription 3 (STAT3) is a transcription factor that regulates various cellular processes such as cell survival, angiogenesis and proliferation. In the present study, we examined that betulinic acid (BA), a triterpene from the bark of white birch, had the inhibitory effects on hypoxia-mediated activation of STAT3 in androgen independent human prostate cancer PC-3 cells. Methodology/Principal Findings: BA inhibited the protein expression and the transcriptional activities of hypoxia-inducible factor-1a (HIF-1a) under hypoxic condition. Consistently, BA blocked hypoxia-induced phosphorylation, DNA binding activity and nuclear accumulation of STAT3. In addition, BA significantly reduced cellular and secreted levels of vascular endothelial growth factor (VEGF), a critical angiogenic factor and a target gene of STAT3 induced under hypoxia. Furthermore, BA prevented in vitro capillary tube formation in human umbilical vein endothelial cells (HUVECs) maintained in conditioned medium of hypoxic PC-3 cells, implying anti-angiogenic activity of BA under hypoxic condition. Of note, chromatin immunoprecipitation (ChiP) assay revealed that BA inhibited binding of HIF-1a and STAT3 to VEGF promoter. Furthermore, silencing STAT3 using siRNA transfection effectively enhanced the reduced VEGF production induced by BA treatment under hypoxia. Conclusions/Significance: Taken together, our results suggest that BA has anti-angiogenic activity by disturbing th

    Transvaginal Endoscopic Appendectomy

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    Since Kalloo and colleagues first reported the feasibility and safety of a peroral transgastric approach in the porcine model in 2004, various groups have reported more complex natural orifice transluminal endoscopic surgery (NOTES) procedures, such as the cholecystectomy, splenectomy and liver biopsy, in the porcine model. Natural orifice access to the abdominal cavity, such as transgastric, transvesical, transcolonic, and transvaginal, has been described. Although a novel, minimally invasive approach to the abdominal cavity is a peroral endoscopic transgastric approach, there are still some challenging issues, such as the risk of infection and leakage, and the method of gastric closure. Hybrid-NOTES is an ideal first step in humans. Human hybrid transvaginal access has been used for years by many surgeons for diagnostic and therapeutic purposes. Here, we report a transvaginal flexible endoscopic appendectomy, with a 5-mm umbilical port using ultrasonic scissors in a 74-year-old woman with acute appendicitis

    Primary Large Cell Neuroendocrine Carcinoma of the Breast: Radiologic and Pathologic Findings

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    Some breast neoplasms are classified as primary neuroendocrine carcinomas because they are positive for neuroendocrine markers. Although neuroendocrine carcinomas can originate from various organs of the body, primary neuroendocrine carcinomas of the breast are extremely rare. The diagnosis of primary neuroendocrine carcinoma of the breast can only be made if nonmammary sites are confidently excluded or if an in situ component can be found. Here we report a primary large-cell neuroendocrine carcinoma (LCNL) involving the left breast. Breast ultrasonography revealed a lobulated, heterogeneous, low-echoic mass in the left breast, and the lesion ap-peared as a well-defined, highly-enhancing mass on a chest computed tomography scan. Ultrasound-guided core needle biopsy was performed on the mass, and primary LCNC was confirmed by histopathologic examination
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