Radix Paeoniae Alba (RPA) is the root of Paeonia lactiflora Pallas, which belongs to the Ranunculaceae family. RPA has been commonly used in traditional medicine to tonify the blood, to alleviate pain, and to treat inflammation and cancer. A recent study reported that RPA inhibits hepatocellular carcinoma cell growth and induces their apoptosis. 1)Several constituents isolated from RPA have also been found to have immunologically active.2,3) However, details of the mechanism underlying the activity of RPA are not understood.Apoptosis is a highly regulated process that involves the activation of a series of molecular events that lead to cell death, and is characterized by morphologic changes, chromatin condensation, and apoptotic bodies, which are associated with DNA cleavage and ladder formation. 4,5) There are two major apoptotic pathways, namely, intrinsic and extrinsic apoptosis signaling, in cells responsive to apoptotic stimuli. [6][7][8][9] The intrinsic apoptosis pathway involves mitochondrial signaling, and caspase-9 has been suggested to be the predominant initiator caspase in this pathway. 7,9) In contrast, the extrinsic apoptosis pathway is mediated by death receptors, such as, Fas receptors and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), and the extrinsic pathway is initiated by caspase-8. 6,8) The activated initiator caspases-8 and -9 starts a proteolytic cascade by cleaving downstream effector caspases, such as, caspase-3, -6, and -7.7) Of these, caspase-3 is believed to be the main executioner caspase and its activation has been shown to be essential for both intrinsic and extrinsic apoptotic cell death. 10,11) To study the mechanism underlying the anticancer activities of RPA, we examined the antiproliferative effect of RPA extracts (RPAE) in HL-60, a human promyelocytic leukemia cell line. Our results demonstrated that RPAE induces apoptosis in a dose-dependent manner in HL-60 cells. We further demonstrate that the apoptotic effects induced by RPAE are accompanied by intrinsic pathway features, i.e., the release of cytochrome c into cytosol and the activation of procaspase-9, but not by extrinsic pathway features, and eventual caspase-3 activation. MATERIALS AND METHODS Culture ConditionsHuman leukemia HL-60 cells were purchased from the American Type Culture Collection. Cells were placed in 75 cm 2 tissue culture flasks and grown at 37°C under a humidified, 5% CO 2 atmosphere in RPMI 1640 medium (Gibco BRL) supplemented with 10% fetal bovine serum and 2 mM glutamine, 10000 units/ml of penicillin, 10 mg/ml of streptomycin, and 2.5 mg/ml of amphotericin B.Preparation of Herbal Extract Radix Paeoniae Alba was identified by Min-Kyo Shin, keeper of the herbarium at the Department of Physiology, School of Oriental Medicine, Wonkwang University (Voucher samples were preserved for reference; Ref. No. Omcphy 2001-80). To produce the extract, 200 g of RPA was added to 1800 ml of water, boiled for 2 h, filtered, and concentrated to 200 ml. The sterile extract (41.97 g) was store...

This paper describes the heteroepitaxial growth of single-crystalline 3C-SiC (cubic silicon carbide) thin films on Si (100) wafers by atmospheric pressure chemical vapor deposition (APCVD) at 1350 o C for micro/ nanoelectromechanical system (M/NEMS) applications, in which hexamethyldisilane (HMDS, Si2(CH3)6) was used as a safe organosilane single-source precursor. The HMDS flow rate was 0.5 sccm and the H2 carrier gas flow rate was 2.5 slm. The HMDS flow rate was important in obtaing a mirror-like crystalline surface. The growth rate of the 3C-SiC film in this work was 4.3 μm/h. A 3C-SiC epitaxial film grown on the Si (100) substrate was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), reflection high energy electron diffraction (RHEED), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and Raman scattering, respectively. These results show that the main chemical components of the grown film were single-crystalline 3C-SiC layers. The 3C-SiC film had a very good crystal quality without twins, defects or dislocations, and a very low residual stress.

This paper describes the characteristics of cubic silicon carbide (3C-SiC) films grown on a carbonized Si(100) substrate, using hexamethyldisilane (HMDS, Si 2 (CH 3 ) 6 ) as a safe organosilane single precursor in a nonflammable H 2 /Ar (H 2 in Ar) mixture carrier gas by atmospheric pressure chemical vapor deposition (APCVD) at 1280°C. The growth process was performed under various conditions to determine the optimized growth and carbonization condition. Under the optimized condition, grown film has a single crystalline 3C-SiC with well crystallinity, small voids, low residual stress, low carrier concentration, and low RMS. Therefore, the 3C-SiC film on the carbonized Si (100) substrate is suitable to power device and MEMS fields.Keywords : Crystalline 3C-SiC, Carbonization, CVD, Hexamethyldisilane 1 Tokai Carbon Korea Anseong, Gyeonggi-do, 456-843, Korea 2 School of Electrical Engineering, University of Ulsan 93 Daehak-ro, Namgu, Ulsan 680-749, Korea + Corresponding author: gschung@ulsan.ac.kr (Received : Apr. 2, 2013, Revised : May. 13, 2013, Accepted : May. 17, 2013 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License(http://creativecommons.org/licenses/bync/3.0)which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

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