Enhancing the Plasma-Resistance Properties of Li2O-Al2O3-SiO2 Glasses for the Semiconductor Etch Process via Alkaline Earth Oxide Incorporation.

To develop plasma-resistant glass materials suitable for semiconductor etching processes, we introduced alkaline earth oxides (ROs) into a Li2O-Al2O3-SiO2 (LAS) glass. Analysis of glass properties with respect to the additives revealed that among the analyzed materials, the LAS material in which Li2O was partially replaced by MgO (MLAS) exhibited the most favorable characteristics, including a low dielectric constant (6.3) and thermal expansion coefficient (2.302 × 10-6/°C). The high performance of MLAS is attributed to the high ionic field strength of Mg2+ ions, which restricts the movement of Li+ ions under the influence of electric fields and thermal vibrations at elevated temperatures. When exposed to CF4/O2/Ar plasma, the etching speed of RO-doped glasses decreased compared with that of quartz and LAS glass, primarily owing to the generation of a high-sublimation-point fluoride layer on the surface. Herein, MLAS demonstrated the slowest etching speed, indicating exceptional plasma resistance. X-ray photoelectron spectroscopy analysis conducted immediately after plasma etching revealed that the oxidation-to-fluorination ratio of Li was the lowest for MLAS. This observation suggests that the presence of Mg2+ ions in the plasma discharge inhibits the migration of Li+ ions toward the surface, thereby contributing to the excellent plasma resistance of MLAS.

Fabrication of Highly Porous and Pure Zinc Oxide Films Using Modified DC Magnetron Sputtering and Post-Oxidation.

Porous films of metals and metal oxides exhibit larger surface areas and higher reactivities than those of dense films. Therefore, they have gained growing attention as potential materials for use in various applications. This study reports the use of a modified direct current magnetron sputtering method to form porous Zn-ZnO composite films, wherein a subsequent wet post-oxidation process is employed to fabricate pure porous ZnO films. The porous Zn-ZnO composite films were initially formed in clusters, and evaluation of their resulting properties allowed the optimal conditions to be determined. An oxygen ratio of 0.3% in the argon gas flow resulted in the best porosity, while a process pressure of 14 mTorr was optimal. Following deposition, porous ZnO films were obtained through rapid thermal annealing in the presence of water vapor, and the properties and porosities of the obtained films were analyzed. An oxidation temperature of 500 °C was optimal, with an oxidation time of 5 min giving a pure ZnO film with 26% porosity. Due to the fact that the films produced using this method are highly reliable, they could be employed in applications that require large specific surface areas, such as sensors, supercapacitors, and batteries.

Downregulation of spleen tyrosine kinase in hepatocellular carcinoma by promoter CpG island hypermethylation and its potential role in carcinogenesis.

Spleen tyrosine kinase (SYK) has predominantly been studied in hematopoietic cells, where it is involved in immunoreceptor-mediated signaling. However, SYK expression has been shown in numerous non-hematopoietic cells, and its downregulation has been shown to be involved in tumor formation and progression. SYK methylation has been demonstrated to identify a subset of hepatocellular carcinoma (HCC) cases with poor prognosis, but little is known regarding the biological role of SYK in HCC. We found that SYK methylation is a common event in HCC, and is inversely associated with its expression. We established stable HCC cell lines with inducible SYK expression vectors, and compared the differential RNA expression profiles of HCC cell lines with or without the induction of SYK. Gene ontology analysis revealed that the SYK-regulated genes were enriched for genes involved in cell adhesion. Accordingly, we found that the induction of SYK expression increased the adhesion of cells to fibronectin and decreased cell migration and invasion, and that cessation of SYK overexpression increased cell migration and invasion. Our findings suggest that SYK is involved in regulating cell to matrix adhesions, and that SYK loss affects the migration, and invasion of HCC cells.

Prognostic implications of and relationship between CpG island hypermethylation and repetitive DNA hypomethylation in hepatocellular carcinoma.

PURPOSE: This study aims to determine the relationship between CpG island DNA hypermethylation and global genomic DNA hypomethylation and their prognostic implications in hepatocellular carcinoma. The association of DNA methylation changes with clinicopathologic factors and the chronological ordering of DNA methylation changes along multistep hepatocarcinogenesis were also assessed. EXPERIMENTAL DESIGN: Hepatocellular carcinoma (n = 20) and nonneoplastic liver samples (n = 72) were analyzed for their methylation status at 41 CpG island loci and 3 repetitive DNA elements (LINE-1, ALU, and SAT2) using MethyLight or combined bisulfite restriction analysis. After selection of 19 CpG island loci showing cancer-specific DNA methylation, another set of 99 hepatocellular carcinoma samples was analyzed for these loci. RESULTS: The number of methylated genes in hepatocellular carcinoma was significantly higher in hepatocellular carcinoma patients with a cirrhotic liver than in hepatocellular carcinoma patients with a noncirrhotic liver (9.9 versus 7.0, P = 0.001). Hepatocellular carcinoma from female patients showed a higher number of methylated genes than hepatocellular carcinoma from male patients (11.2 versus 8.4, P = 0.006). The genes CRABP1 and SYK showed significant association between CpG island hypermethylation and patients' poor survival. SAT2 hypomethylation occurred earlier than LINE-1 or ALU hypomethylation along the multistep hepatocarcinogenesis. Depending on the type of CpG island locus, a direct, inverse, or no relationship between CpG island hypermethylation and repetitive DNA hypomethylation was observed in hepatocellular carcinomas. CONCLUSION: The varying relationships between the hypermethylation of individual CpG island loci and the hypomethylation of repetitive elements suggests that they are not mechanically linked. SYK and CRABP1 hypermethylation may serve as useful tumor markers for prognostication of hepatocellular carcinoma patients.

Recurrent pancreatitis after renal transplantation in a child.

A five-yr-old girl, who was a renal transplant recipient, presented with nausea, vomiting, epigastric discomfort, papules, and vesicles on her body. She was diagnosed with acute pancreatitis and varicella zoster infection because her serum amylase and lipase levels were positive. Fourteen months later, she was readmitted with nausea, vomiting, and epigastric pain similar to the previous symptoms and was diagnosed with acute pancreatitis. This case report indicates that acute pancreatitis can be one of a number of complications following pediatric renal transplantation and can recur because of various causes.

[Epidemiologic investigation on an outbreak of salmonellosis in Yeongcheon-si, 2004].

OBJECTIVES: An outbreak of salmonellosis occurred among the students and staff of D primary school in Yeongcheon-si, 2004. This investigation was carried out to prevent any recurrence of this outbreak and to study the infection source and transmission of the salmonellosis. METHODS: The authors conducted a questionnaire survey among 1,205 students and staff members from D primary school about the ingestion of the school lunch and drinking water, and the manifestation of their symptoms. The author examined rectal swabs, the tap water and microorganism cultures, and we also investigated the dining facility and water supply facility. RESULTS: The diarrheal cases were defined as the confirmed cases or the persons who had diarrhea more than one time with symptoms such as fever, vomiting and tenesmus. The diarrheal attack rate was 28.0%. Ingestion of fried bean curd with egg had a significantly high association with the diarrheal attack rate (p<0.05), and the relative risk of the fried bean curd with egg was 10.68 (95% CI=3.88-29.41), as was determined by logistic regression analysis. The bacterial counts in the tap water of the food preparation room and toilet (first floor) exceeded the maximum permissible counts. S. Enteritidis bacteria were only cultured from the fried bean curd with egg of all the supplied foods on September 3, 2004. CONCLUSIONS: The major cause of salmonellosis was presumed to be the contaminated bean curd via contaminated tap water due to a water leak of a school water pipe. This contaminated bean curd was under prepared, which allowed the S. Enteritidis to survive and multiply prior to its ingestion.

[Investigation of a series of brucellosis cases in Gyeongsangbuk-do during 2003-2004].

OBJECTIVES: We conducted an investigation on 14 cases of brucellosis in Gyeongsangbuk-do during 2003-2004 to understand the source of infection and the transmission routes of brucellosis. METHODS: The authors visited the each of the health centers and we examined the patients, their written epidemiologic questionnaire and the occurrence of bovine brucellosis. We visited the patients' living and work areas, and we examined their occupations, the date they developed symptoms, the progress of their symptoms, whether or not they were treated, their current status, whether or not they consumed raw milk and raw meat, and if their work was related to cattle breeding and the related details. We reviewed the results of the blood tests and medical records and we examined the cattle's barn. RESULTS: There were 3 patients in 2003 and 11 patients in 2004. All of their brucella antibody titer exceeded 1:160. The patients' symptoms were fever, myalgia, malaise, chills and an influenza-like illness, but the clinical signs were absent on the medical records. Brucella abortus were cultured from 3 of the patients' blood samples. CONCLUSIONS: When the authors discovered the transmission routes, they were divided into 4 different sorts. The first route was related to cattle birth such that patients touched the calves or placentas that were infected with the Brucella species. The second route was related to performing artificial insemination on the cattle and the semen that was used for artificial insemination. The third route was due to the ingestion of raw meat and milk. The last route was due to sexual intercourse between the patients.

Interleukin-8 and tumor necrosis factor-alpha are increased in minimal change disease but do not alter albumin permeability.

AIMS: Minimal change disease (MCD) is the most common primary nephrotic syndrome in children. Some suggested that interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-alpha) are involved in the pathogenesis of MCD. This study was done to see changes of plasma and urinary IL-8, TNF-alpha, and their effects on determination of permeability of glomerular basement membrane (BM) contributed by heparan sulfate proteoglycan (HSPG). METHODS: Study patients consisted of 19 biopsy-proven MCD children aged 2-15 years old. Both plasma, urinary IL-8 and TNF-alpha were measured. Employing the Millicell system, IL-8 and TNF-alpha were screened for the permeability factors. We examined whether IL-8 and TNF-alpha regulated BM HSPG gene expression and HS synthesis in the glomerular epithelial cells (GECs). RESULTS: Urinary IL-8 during relapse was significantly increased when compared with that of during remission or controls (13,996 +/- 2,811 vs. 2,941 +/- 373, 5,331 +/- 640 ng/mg.cr) (p < 0.05). Urinary TNF-alpha during relapse was also significantly increased (364.4 +/- 51.2 vs. 155.3 +/- 20.8, 36.0 +/- 4.5 ng/mg.cr) (p < 0.05). Plasma IL-8 during relapse was significantly increased compared to that during remission(1.19 +/- 0.62 vs. 0.51 +/- 0.42 ng/ml) (p < 0.05). However, the negative results were obtained in the permeability assay using the Millicell system. No difference was seen in BM HSPG gene expression and HS synthesis in the GECs. CONCLUSION: Therefore, it seems that both IL-8 and TNF-alpha may not play a disease-specific role in the pathogenesis of MCD.