Helicobacter pylori infection appears essential for stomach carcinogenesis: Observations in Semarang, Indonesia

The gastric cancer incidence in Semarang, Indonesia, is exceedingly low: only approximately 1/100th of the level in Japan. To elucidate the reason, we carried out an ecological study recruiting 69 male and 102 female participants from the general populace in January 2005. Positive urea breath tests were 0% for both men and women, and Helicobacter pylori (H. pylori) IgG antibodies were found in 2% (0–5, 95% confidence interval) of men and 2% (0–4) of women, significantly lower than the 62% (58–65) and 57% (53–60), respectively, in Japan. Furthermore, there were no positive findings with the pepsinogen tests in Semarang, again significant in comparison with the 23% (22–25) and 22% (20–23) in Japan. Variation in smoking levels and consumption of NaCl, vegetables and fruit were found, but not to an extent that would allow explanation of the major differences in gastric cancer incidence. We may conclude that the very low prevalence of H. pylori infection and thus chronic atrophic gastritis account for the rarity of stomach cancer in Semarang, Indonesia. (Cancer Sci 2005; 96: 873–875

Double In Situ Approach for the Preparation of Polymer Nanocomposite with Multi-functionality

A novel one-step synthetic route, the double in situ approach, is used to produce both TiO2nanoparticles and polymer (PET), and simultaneously forming a nanocomposite with multi-functionality. The method uses the release of water during esterification to hydrolyze titanium (IV) butoxide (Ti(OBu)4) forming nano-TiO2in the polymerization vessel. This new approach is of general significance in the preparation of polymer nanocomposites, and will lead to a new route in the synthesis of multi-functional polymer nanocomposites

SIC/SIC composite thruster for a non-toxic liquid propellant rocket engine

Combustion chamber and nozzle for a non-toxic liquid rocket engine made by Tyrano ZMI SiC fiber reinforced SiC matrix composite were tested under sea level combustion tests. Combustion chamber and nozzle are the key hot parts for small liquid propellant engine, since chamber wall needs to be cooled by fuel rich low temperature gas. To create fuel rich low temperature gas, excess amount of fuel is consumed. Consequently, high temperature heat resisting material is indispensable to have better performance rocket engine. Nb based alloy are commonly used in combustion chamber and nozzle for a liquid propellant rocket engine for a satellite maneuver system with the maximum operating temperature around 1300°C. In this study, SiC/SiC combustion chamber with nozzle were examined and its performance was demonstrated by sea level static combustion tests in air and under vacuum. Tyrano ZMI SiC fiber (Ube Industry) was used as reinforcing fiber and carbon interface was selected to have higher temperature resistance. Fiber preform was fabricated by tri-axial braiding technique and carbon interface and SiC matrix were formed by chemical vapor infiltration (CVI). After CVI process, further densification was conducted by polymer infiltration and pyrolysis (PIP) process until no gas leak was detected under low pressure of 0.2 MPa. Largest inner diameter of the chamber was designed as 65 mm and the smallest inner diameter of 26 mm as a nozzle throat. Nozzle was designed with opening area ratio of 25 to investigate manufacturability. The combustion chamber and nozzle attached with a core engine as shown in Figure 1. Non-toxic fuel, ethanol, and oxidizer, N2O, were supplied through the showerhead type injection into combustion chamber. Sea level static combustion tests were conducted both in air and under vacuum (1.3 kPa). The engine combustion tests were successful (30s in air and 19 s in vacuum) and no damage could be found. The performance of the engine improved to specific impulse of 290s with assumption of nozzle area ratio 100. The maximum surface temperature reached to 1250°C, where the inner wall temperature could be calculated about 1600°C. Prototype engine development program successfully completed and we are preparing to start real application project of this engine system as a final stage of solid propellant satellite launcher Please click Additional Files below to see the full abstract

Contribuition to development of self-compacting concrete

Orientador: Vladimir Antonio PaulonDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia CivilResumo: A presente dissertação tem como objetivo o desenvolvimento da especialidade da tecnologia do concreto de elevado desempenho, o concreto auto-adensável. A tendência do mercado em construir cada vez mais estruturas arrojadas exige o desenvolvimento de tecnologias que coadunem com a realidade técnico-econômica da obra. A concretagem destas estruturas, quando realizada em formas irregulares e em armação densa, ocasiona, na maioria das vezes, problemas no adensamento, formando descontinuidade e/ou segregação na peça concretada. Contudo, quando executada em concreto auto-adensável, estas ocorrências tendem a diminuir. Este trabalho apresenta a confrontação da metodologia de avaliação do concreto autoadensável no estado fresco com o método da caixa L e o utilizado atualmente na Alemanha conforme a norma DIN 1045 -2 DAfStb- Richtlinie Selbstverdichtender Beton (SVB-Richtlinie), com o propósito de levar para a prática procedimentos simples e de fácil análise do controle de trabalhabilidade do concreto, e também a aplicação do concreto auto-adensável em estruturas de escala real para analisar a segregação do concreto quando lançados a 4,00 metros de altura.Abstract: This study concerns a special kind of high performance concrete technology development, called self-compacting concrete. The growing market tendency to build bold structures requires construction technology development, which fits real technical-economical needs. The concrete placing in irregular shape structures, and reinforced concrete structures, most of time brings compacting problems and result on segregation, and/or not satisfactory concrete surfacing. However, the use of self-compacting concrete can reduce these problems. The main objective of this research is to compare L box method and the German standard DIN 1045 -2 DAfStb- Richtlinie Selbstverdichtender Beton (SVB-Richtlinie) for fresh self compacting concrete workability analysis, in order to propose the L box method as an practical and easy way test to control the fresh concrete quality. This study also provides an accurate description of self-compaction concrete history, its development and the advantages reached by the structures based on concrete selfcompacting concrete, as well. Furthermore this research sets a real beam and column structure concrete applications from 4,00 m high filling to analyze segregation behavior.MestradoEdificaçõesMestre em Engenharia Civi

Layered double hydroxide composite monoliths with three-dimensional hierarchical channels: structural control and adsorption behavior

Hierarchically porous layered double hydroxide (LDH) materials have potential in anion-exchange, adsorption and catalysis applications, because of their large surface areas and liquid transportation capabilities. The preparation of monolithic LDH-Al(OH)3 composites with hierarchical µm/nm-scale channels and their adsorption behavior is reported. Monolithic gels were synthesized via sol-gel processing, from metal salt precursor solutions. m-scale macrochannels spontaneously formed by inducing phase separation during sol-gel transition. nm-scale mesochannels were accommodated as interstices between primary/secondary particles. In this study, these hierarchical channel sizes were controlled. The macrochannel size was controlled by tuning the degree of phase separation. The mesochannel size was controlled independently, by tuning the crystallite size of LDH under different solvothermal conditions. The relationship between pore characteristics and adsorption behavior of tailored hierarchically porous LDH-Al(OH)3 monolithic gels were investigated by using dye molecules as adsorbates. Monolithic gels with larger macrochannels and mesochannels exhibit faster adsorption rate and higher affinity, respectively. LDH-Al(OH)3 monolithic gels with hierarchical channels may have potential in some applications such as biosensing, water purification and catalysis.The study was supported by a Grant-in-Aid for Scientific Research (B) (No. 22360276) and a Grant-in-Aid for Young Scientists (B) (No. 24750206), from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan Society for the Promotion of Science (JSPS)