1,721,041 research outputs found
Effects of seed layers on the characteristics of (Pb,La)(Zr,Ti)O-3 thin films prepared by electron cyclotron resonance plasma enhanced chemical vapor deposition
No full textThe effects of seed layers on the characteristics of La-doped lead zirconate titanate (PLZT) thin films prepared by electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR PECVD) were investigated. The seed layers used were lead oxide, titanate, lead titanate and La-doped lead titanate. PLZT films with stoichiometric composition and perovskite single phase were fabricated using titanate, lead titanate and La-doped lead titanate as seed layers. Among them, PLT was the most effective seed layer in regard to surface morphology, crystallinity and electrical properties of the PLZT films. The effects of seed layers were very remarkable on the Pt/SiO2/Si substrate, however, less significant on the Pt/Ti/SiO2/Si substrate because the Ti atoms out-diffused from the Ti underlayer to the substrate surface and exhibited seed-like characteristics for the formation of perovskite phase nuclei.The authors acknowledge the support of Samsung Electronics Co. for this research
Colorectal Cancer in Octogenarian and Nonagenarian Patients: Clinicopathological Features and Survivals
Full text linkPURPOSE: Elderly population will comprise a substantial proportion of colorectal cancer (CRC) patients. We examined patients older than 80 years according to their clinical and pathological characteristics to fully understand the elderly patients. METHODS: CRC patients, 60 years or older at diagnosis, admitted between 2009 and 2014 at our hospital were enrolled. The patients were divided into 2 groups: elderly (aged > 80 years, n = 133), and controls (aged 60 to 79 years, n = 596). Patient's demographics, risk factors for prognosis of CRC, Clinicopathological parameters, treatment, and survival rates were compared.
RESULTS: The mean ages were 83.9 and 64.8 years, respectively. Male-to-female ratio and tumor sidedness were comparable in both groups. Prognostic factors found in univariate analysis; differentiation, stage, lymphovascular invasion, and carcinoembryonic antigen showed no statistical difference. The microsatellite instability status and number of retrieved lymph nodes were also similar (17.2 vs 21.6, P = 0.505). A significant difference was found in the treatment approach for chemotherapy as the elderly patients with stage III and IV tend to have omitted adjuvant (43.6% vs. 92.8%, P < 0.001) or palliative (35.8% vs. 89.4%, P = 0.016) chemotherapy. Except in stage I, elderly patients showed significantly lower overall survival rates.
CONCLUSION: Current study shows far-elderly patients with CRC were less likely to receive standard treatments, which might have resulted in an inferior outcome. As the number of elderly patients with CRC increase, our results provide a basis for further clinical and molecular investigations of elderly CRC patients
(Pb,La)(Zr,Ti)O-3 thin films prepared by electron cyclotron resonance plasma enhanced chemical vapor deposition for the charge storage capacitor of a gigabit-scale dynamic random access memory
No full textPerovskite single phase (Pb,La)(Zr,Ti)O-3 (PLZT) (0-22/60/40) thin films with a stoichiometric composition were successfully fabricated on Pt/Ti/SiO2/Si substrates at 490 degrees C by the electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR PECVD). The characteristics of PLZT films for various La concentrations were investigated for the application to the charge storage capacitor of a gigabit-scale dynamic random access memory (DRAM). The La doped films showed paraelectric-like slim loop P-V hysteresis curves and almost no frequency dependence of permittivity. The doping of La caused the film surface to be very smooth. After rapid thermal annealing at 650 degrees C for 1 min, the capacitance as well as the leakage current characteristics of the films were greatly improved. The 50-nm-thick PLZT(5.5/56/44) film had an effective capacitance of 133 fF/mu m(2) and an SiO2 equivalent thickness of 0.26 nm
A comparative study on the nucleation and growth of ECR-PECVD PLZT ((Pb,La)(Zr,Ti)O-3) thin films on Pt/SiO2/Si substrates and on Pt/Ti/SiO2/Si substrates
No full textPLZT (8/67/33) thin films were deposited on both Pt/SiO2/Si rind Pt/Ti/SiO2/Si substrates by electron cyclotron resonance chemical vapor deposition for various deposition times. The nucleation growth mechanism, and the thickness dependence of the dielectric constant of PLZT films on the substrate were investigated. At the initial stage of PLZT film deposition, the incorporation of Pb into the film is very difficult because of the high volatility of Pb oxide molecules on the Pt substrate, resulting in the formation of a Pb-deficient interfacial layer. The degree of Pb deficiency at the interface is more severe on the Pt/SiO2/Si substrate. For the Pt/SiO2/Si substrate, a very thick Pb-deficient interfacial layer forms and the non-perovskite phase becomes dominant. For the Pt/Ti/SiO2/Si substrate, Ti atoms which out-diffused to the substrate surface through the gain boundaries of the Pt layer facilitate the incorporation of Pb. which leads to the nucleation of a perovskite phase at the substrate grain boundaries and promotes the growth of the perovskite phase. The dielectric constant of the bulk PLZT film is 1420. However, the dielectric constant of the film decreases with decreasing film thickness due to the existence of the low dielectric interfacial layer. (C) 1998 Published by Elsevier Science Ltd. All rights reserved
Fabrication of perovskite (Pb,La)(Zr,Ti)O-3 thin films by electron cyclotron resonance plasma enhanced chemical vapor deposition
No full textLanthanum-modified lead zirconate titanate (PLZT) thin films were fabricated by electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR-PECVD) using MO sources. The composition of the PLZT films could be controlled by varying the flow rate of each MO source. Perovskite PLZT thin films with a smooth surface and fine grains were successfully fabricated on Pt/Ti/SiO2/Si at 450 degrees C. The deposition mechanism of the PLZT films in the ECR plasma was studied by examining the rate of incorporation of each cation into the film at various MO source flow rates. The microstructure of the deposited films and RTA treatment effects were also evaluated.The authors acknowledge the support of Samsung Electronics Co. for this research
Prognostic value of changes in serum carcinoembryonic antigen levels for preoperative chemoradiotherapy response in locally advanced rectal cancer
Full text linkBACKGROUND: Preoperative chemoradiotherapy (CRT) is a standard treatment modality for locally advanced rectal cancer. However, CRT alone cannot improve overall survival. Approximately 20% of patients with CRT-resistant tumors show disease progression. Therefore, predictive factors for treatment response are needed to identify patients who will benefit from CRT. We theorized that the prognosis may vary if patients are classified according to pre- to post-CRT changes in carcinoembryonic antigen (CEA) levels.
AIM: To identify patients with locally advanced rectal cancer for preoperative chemoradiotherapy based on carcinoembryonic antigen levels.
METHODS: We retrospectively included locally advanced rectal cancer patients who underwent preoperative CRT and curative resection between 2011 and 2017. Patients were assigned to groups A, B, and C based on pre- and post-CRT serum CEA levels: Both > 5; pre > 5 and post RESULTS: The cohort comprised 145 patients; of them, 27, 43, and 65 belonged to groups A, B, and C, respectively, according to changes in serum CEA levels before and after CRT. Pre- (P < 0.001) and post-CRT (P < 0.001) CEA levels and the ratio of down-staging (P = 0.013) were higher in Groups B and C than in Group A. The ratio of pathologic tumor regression grade 0/1 significantly differed among the groups (P = 0.003). Group C had the highest number of patients showing pCR (P < 0.001). Most patients with pCR showed pre- and post-CRT CEA levels < 5 ng/mL (P < 0.001, P = 0.008). Pre- and post-CRT CEA levels were important risk factors for pCR (OR = 18.71; 95%CI: 4.62-129.51, P < 0.001) and good response (OR = 5.07; 95%CI: 1.92-14.83, P = 0.002), respectively. Pre-CRT neutrophil-lymphocyte ratio and post-CRT T >/= 3 stage were also prognostic factors for pCR or good response.
CONCLUSION: Pre- and post-CRT CEA levels, as well as change in CEA levels, were prognostic markers for treatment response to CRT and may facilitate treatment individualization for rectal cancer
Prognostic reappraisal of postoperative carcinoembryonic antigen in T1-2N0 colorectal cancer
No full textBackground/Aim: The purpose of this study was to compare the prognostic value of preoperative carcinoembryonic antigen (CEA), preoperative CEA/tumor size and postoperative CEA in stage I colorectal cancer. Patients and Methods: We analyzed a total of 305 consecutive stage I colorectal cancer patients who underwent a radical surgery at our Department. The patients were divided into low and high preoperative CEA groups, low and high preoperative CEA/tumor size groups, and low and high postoperative CEA groups according to the optimal cut-off values. Results: Multivariate analysis showed that postoperative CEA was independently associated with OS and DFS. However, the preoperative CEA and preoperative CEA/tumor size were not. Conclusion: The prognostic value of postoperative CEA is better than preoperative CEA and preoperative CEA/tumor size in patients with stage I colorectal cancer. Moreover, the common 5 ng/ml cut-off was not optimal for risk stratification in stage I colorectal cancer
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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