386 research outputs found

    Reduction of Dichlorosilane-Based Tungsten Silicide Resistivity by Amorphization and Its Applicability as an Electrode

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    The impact of ion implantation on dichlorosilane-based tungsten silicide is reported with an emphasis on structural changes and the formation of low-resistivity silicide. It was found that implantation to the as-deposited dichlorosilane-based tungsten layer with the hexagonal close-packed structure resulted in amorphization. After thermal annealing for crystallization, the amorphized silicide was converted to the large-grain-sized tetragonal structure in which the resistivity of the silicide was about 30% lower than that of the conventional structure. In addition, the surface of the implanted silicide was smoother than that of the conventional one. The resistivity after thermal activation depended on the implantation conditions: implantation species, energy, and dose. Among all implantation species tested, phosophorus ions were found to be the most effective in terms of device fabrication. For optimized device performance, the energy should be controlled to contain the ions in the silicide. With this condition, device performance was not adversely affected, and line resistance and dopant depletion were improved

    Selective Leaching of Zinc from Spent Zinc-Carbon Battery with Ammoniacal Ammonium Carbonate

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    This paper describes the ammoniacal ammonium carbonate leaching behavior of zinc and manganese from spent zinc-carbon batteries. For selective extraction of Zn from the spent zinc-carbon battery, leaching tests were carried out as a function of process parameters such as concentration of (NH 4 ) 2 CO 3 , ammonia, temperature, time and pulp density. Physical methods of separation such as crushing was applied to reduce the material to 10-20 mm size followed by magnetic separation to separate iron with a recovery about 10 mass% leaving most of Zn and Mn in the non-magnetic fraction. Non-magnetic fraction was further subjected to sieving to separate 2.46 mm over and under size fractions. The oversize material was processed by eddy current separation to recover zinc sheet and carbon rods and plastics. The under size material with chemical composition of Zn 15.5 mass%, Mn 17.5 mass%, and Fe 1.4 mass% was used for leaching studies. Under the optimum leaching conditions (2.0 kmol/m 3 (NH 4 ) 2 CO 3 and 4.0 kmol/m 3 ammonia, 40 C, 100 g/L pulp density, 30 min and 250 rpm), the leaching efficiency of zinc and manganese was 80.2% and less than 0.1%, respectively, indicating the selective recovery of zinc from the spent zinc-carbon battery. An overall zinc recovery is about 88%

    Prognostic Value of Postoperative CEA Clearance in Rectal Cancer Patients with High Preoperative CEA Levels

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    PURPOSE: We determined the prognostic value of carcinoembryonic antigen (CEA) clearance after tumor resection with serial evaluation of postoperative CEA levels in rectal cancer. METHODS: Between 1994 and 2004, we retrospectively reviewed 122 patients with rectal cancer whose serum CEA levels were measured on the preoperative day and postoperative days 7 and 30. Patients with preoperative CEA levels <5.0 ng/ml were excluded. An exponential trend line was drawn using the three CEA values. Patients were categorized into three groups based on R(2) values calculated through trend line, which indicates the correlation coefficient between exponential graph and measured CEA values: exponential decrease group (group 1: 0.9 < R(2) < or = 1.0), nearly exponential decrease group (group 2: 0.5 < R(2) < or = 0.9), and randomized clearance group (group 3: 0.5 < or = R(2)). We then analyzed the CEA clearance pattern as a prognostic indicator. RESULTS: With a median follow-up of 57 months, the 5-year overall survival was 62.3% vs. 48.1% vs. 25% and the 5-year disease-free survival was 58.6% vs. 52.7% vs. 25% among groups 1, 2, and 3 (P = 0.014, P = 0.027, respectively) in patients with stage III rectal cancer. For those with stage II rectal cancer, the 5-year overall survival rate of group 1 was significantly better than groups 2 and 3 (88.8% vs. 74.1%, respectively, P = 0.021). CONCLUSIONS: the postoperative pattern of CEA clearance is a useful prognostic determinant in patients with rectal cancer. Patients with a randomized pattern of CEA clearance after tumor resection should be regarded as having the possibility of a persistent CEA source and may require consideration of intensive follow-up or adjuvant therapy.ope

    Natural Food Additives and Preservatives for Fish-Paste Products: A Review of the Past, Present, and Future States of Research

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    Fish-paste products, also known as fish cakes or surimi-based products, are worldwide favorites. Surimi, a wet protein concentrate of fish muscle, is used as an intermediate raw material to produce surimi seafood. The flavor, texture, taste, shelf-life, and market value of surimi-based products depend on the source of the fish meat, type of applied heat treatment, and additives used to prepare the surimi. While preparing surimi with chemical additives, several problems have been observed, such as a lack of unique characteristics, inferior acceptability, and poor functionality. Various types of fish-paste products have been developed by using different ingredients (e.g., vegetables, seafood, herbs and oriental medicines, grains and roots including carrots, and functional food materials). However, a systematic review of fish-paste products prepared using natural food additives has not yet been performed. Therefore, the quality characteristics of fish-paste products and their functionalities were elucidated in this study. With the increasing demand for surimi seafood products, the functional properties, physiochemical properties, and shelf-life of surimi-based products need to be improved. This review will aid the preparation of new value-added products in the surimi industry

    Angiosarcomas of the Bilateral Breast and Heart: Which One is the Primary Site?

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    A 29-year-old pregnant woman with recurrent pericardial effusion and a cardiac tumor, diagnosed as an angiosarcoma, was treated with surgical resection of the tumor followed by radiotherapy. Immediately after completion of radiotherapy, she developed bilateral breast masses, which were also confirmed as angiosarcomas. We thought this might be the first case of bilateral angiosarcoma of the breast metastasizing to heart mimicking a primary cardiac angiosarcoma, although we could not conclude with certainty that angiosarcoma of the heart was not the primary site
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