Jaewon Lee

Phase III Trial of Two Versus Four Additional Cycles in Patients Who Are Nonprogressive After Two Cycles of Platinum-Based Chemotherapy in Non–Small-Cell Lung Cancer

PURPOSEnThis trial was conducted to determine the optimal duration of chemotherapy in Korean patients with advanced non-small-cell lung cancer (NSCLC).nnnPATIENTS AND METHODSnPatients with stages IIIB to IV NSCLC who had not progressed after two cycles of chemotherapy were randomly assigned to receive either four (arm A) or two (arm B) more cycles of third-generation, platinum-doublet treatment.nnnRESULTSnOf the 452 enrolled patients, 314 were randomly assigned to the groups. One-year survival rates were 59.0% in arm A and 62.4% in arm B, and the difference of 3.4% (95% CI, -8.0 to 4.8) met the predefined criteria for noninferiority. The median time to progression (TTP), however, was 6.2 months (95% CI, 5.7 to 6.7 months) in arm A and 4.6 months (95% CI, 4.4 to 4.8 months) in arm B, the difference of which is statistically significant (P = .001). The frequencies of hematologic and nonhematologic toxicities were similar in the two arms.nnnCONCLUSIONnThis study confirms the noninferiority of overall survival with four cycles compared with six cycles of chemotherapy for the first-line treatment of advanced NSCLC and supports the current American Society of Clinical Oncology guidelines. Notably, patients receiving six cycles of chemotherapy compared with four cycles showed a favorable TTP, suggesting that further investigation of the new strategies of maintenance therapy with less toxic agents after three to four cycles of induction chemotherapy might be warranted to improve survival, with consideration of both ethnicity and pharmacogenomic signatures.

Effect of annealing temperature on dielectric constant and bonding structure of low-k SiCOH thin films deposited by plasma enhanced chemical vapor deposition

We investigated the effect of annealing temperature on the properties of SiCOH films deposited by plasma-enhanced chemical vapor deposition using or a mixture of Si–O containing and hydrocarbon precursors, decamethyl-cyclopentasiloxane (DMCPSO-C10H30O5Si5) and cyclohexane (CHex-C6H12). These SiCOH films were deposited at pressures of 0.6 and 1.5 Torr and the as-deposited SiCOH films were subjected to annealing temperatures from 25 to 500 °C in a furnace for 1 h in N2 ambient at a pressure of 1 atm. The relative dielectric constants, k, of the SiCOH films deposited at 0.6 and 1.5 Torr were 2.76 and 2.26, respectively, before the annealing process. The subsequent annealing of the SiCOH film at 500 °C further reduced the k values to as low as 2.31 and 1.85, respectively. Decreases in the refractive index, hardness, and modulus were observed as the annealing temperature increased to 450 °C. However, further increasing annealing temperature to 500 °C caused the refractive index, hardness, and modulus to increase again. Trends of decreases in both the hardness and modulus with increasing annealing temperature were found. The refractive index and the film thickness retention also decreased with increasing annealing temperature. The change in the k value as a function of the annealing temperature was correlated with the change in the Fourier transform infrared absorption peaks of C–Hx, Si–CH3, and Si–O related groups. As the annealing temperature increased, the intensity of both the CHx and Si–CH3 peaks decreased, respectively. In particular, the C–H2 (asymmetric and symmetric) peaks provide direct evidence of the presence of ethylene groups in the SiCOH films. Thus the decrease in intensity of the peaks corresponding to the CHx groups and Si–O cage structure in the SiCOH films was considered to be responsible for lowering they dielectric constant, refractive index, hardness and modulus of the films. The leakage current density of the SiCOH films at 1 MV/cm is obtained ~10-8 A/cm2 with the 450 °C annealed films, which can be considered as an acceptable leakage current level for the interconnect application.

Algorithm for Fault Detection and Classification Using Wavelet Singular Value Decomposition for Wide-Area Protection

An algorithm for fault detection and classification method for wide-area protection in Korean transmission systems is proposed. The modeling of 345-kV and 765-kV Korean power system transmission networks using the Electro Magnetic Transient Program - Restructured Version (EMTP- RV) is presented and the algorithm for fault detection and classification in transmission lines is developed. The proposed algorithm uses the Wavelet Transform (WT) and Singular Value Decomposition (SVD). The Singular value of Approximation coefficient (SA) and part Sum of Detail coefficient (SD) are introduced. The characteristics of the SA and SD at the fault conditions are analyzed and used in the algorithm for fault detection and classification. The validation of the proposed algorithm is verified by various simulation results.

Characterization of oxygen and nitrogen rapid thermal annealing processes for ultra-low- k SiCOH films

Rapid thermal annealing (RTA) processing under N 2 and O 2 ambient is suggested and characterized in this work for improvement of SiCOH ultra-low- k ( k = 2.4) film properties. Low- k film was deposited by plasma-enhanced chemical vapor deposition (PECVD) with decamethylcyclopentasiloxane and cyclohexane precursors. The PECVD films were treated by RTA processing in N 2 and O 2 environments at 550 °C for 5 min, and k values of 1.85 and 2.15 were achieved in N 2 and O 2 environments, respectively. Changes in the k value were correlated with the chemical composition of C–H x and Si–O related groups determined from the Fourier transform infrared (FTIR) analysis. As the treatment temperature was increased from 300 to 550 °C, the signal intensities of both the CH x and Si–CH 3 peaks were markedly decreased. The hardness and modulus of the film processed by RTA have been determined as 0.44 and 3.95 GPa, respectively. Hardness and modulus of RTA-treated films were correlated with D-group [O 2 Si–(CH 3 ) 2 ] and T-group [O 3 Si–(CH 3 )] fractions determined from the FTIR Si–CH 3 bending peak. The hardness and modulus improvement in this work is attributed to the increase of oxygen content in (O) x –Si–(CH 3 ) y by rearrangement.

A20 promotes metastasis of aggressive basal-like breast cancers through multi-monoubiquitylation of Snail1

Although the ubiquitin-editing enzyme A20 is a key player in inflammation and autoimmunity, its role in cancer metastasis remains unknown. Here we show that A20 monoubiquitylates Snail1 at three lysine residues and thereby promotes metastasis of aggressive basal-like breast cancers. A20 is significantly upregulated in human basal-like breast cancers and its expression level is inversely correlated with metastasis-free patient survival. A20 facilitates TGF-β1-induced epithelial–mesenchymal transition (EMT) of breast cancer cells through multi-monoubiquitylation of Snail1. Monoubiquitylated Snail1 has reduced affinity for glycogen synthase kinase 3β (GSK3β), and is thus stabilized in the nucleus through decreased phosphorylation. Knockdown of A20 or overexpression of Snail1 with mutation of the monoubiquitylated lysine residues into arginine abolishes lung metastasis in mouse xenograft and orthotopic breast cancer models, indicating that A20 and monoubiquitylated Snail1 are required for metastasis. Our findings uncover an essential role of the A20–Snail1 axis in TGF-β1-induced EMT and metastasis of basal-like breast cancers.

Using highly uniform and smooth selenium colloids as low-loss magnetodielectric building blocks of optical metafluids

We systematically analyzed the magnetodielectric resonances of Se colloids for the first time in an attempt to utilize them as building blocks for all-dielectric optical metafluids. By taking advantages of the synergistic properties of Se colloids, including their (i) high-refractive-index at optical frequencies, (ii) unprecedented structural uniformity, and (iii) ready availability, we were able to observe Kerker-type directional light scattering, resulting from the efficient coupling between strong electric and magnetic resonances, directly from Se colloidal suspensions. Thus, the use of Se colloids as a generic magnetodielectric building block suggests the opportunity for the production of fluidic low-loss optical antennas, which can be processed via spin-coating and painting.

Nanocomposite of LiFePO4 and mesoporous carbon for high power cathode of lithium rechargeable batteries.

A composite of LiFePO4 and MgO-templated disordered mesoporous carbon was prepared through infiltrating a LiFePO4 precursor solution into the mesoporous carbon and growing LiFePO4 nanocrystals in the pore of the carbon. Transmission electron microscope (TEM) and scanning electron microscope (SEM) analysis showed that LiFePO4 nanoparticles are embedded homogeneously in the mesoporous carbon without formation of big LiFePO4 particles out of the pores. The pores of the carbon are believed to suppress crystal growth of LiFePO4. The 3-dimensional conducting carbon network between the LiFePO4 nanoparticles led to excellent cycling stability and rate capability. The composite showed no fade of discharge capacity up to 100 cycles and 85% of the reversible capacity at 0.1 C was retained at 30 C.

Automatic End Point Detection of Plasma Etching Process Using the Multi-Way PCA of the Whole Optical Emission Spectrum

Automatic detection algorithm is needed for the real batch process and multi-way principal component analysis is developed to analyze the OES data and extract key component that capture the endpoint signal. The traditional endpoint detection technique uses a few manually selected wavelengths in the plasma etching process, which are adequate for large open area. As the integrated circuit devices continue to shrink in geometry and increase in device density, detecting the endpoint for small open area or multi-layer presents a serious challenge to process engineers. In this paper, a high-resolution optical emission spectroscopy system is used to provide the necessary sensitivity for detecting subtle endpoint signals. In the case study, we applied this algorithm to the open data sources and real etch process, which showed more reasonable features. This end point features can be used for the improved process monitoring afterwards

Carbon nanotube patterning with capillary micromolding of catalyst.

Patterning of multi-walled carbon nanotube (MWNT) in a plasma enhanced chemical vapor deposition (PECVD) chamber has been achieved by catalyst patterning using capillary micromolding process. Iron acetate catalyst nanoparticles were dissolved in ethanol and mold was fabricated with polydimethylsiloxane (PDMS). The ethanol solution containing catalyst nanoparticles was filled into the microchannel formed between PDMS mold and Si-wafer by capillary force. The capillary action of different solvents was simulated by commercial CFD-ACE+ simulation code to determine optimal solvents. Simulated result shows that the choice of solvent was critical in this capillary filling process. After the catalyst patterning, MWNT was grown at 700 approximately 800 degrees C by PECVD process using CH4 and Ar gas in a scale of approximately 10 micro-meters in a tubular inductively coupled plasma reactor. Grown CNTs were analyzed by FE-SEM and Raman Spectroscopy.