On the Flexural Rigidity of Reinforced Concrete Beams

It is general that the ordinary straight-line theory does not meet with success for evaluating the flexural rigidity of reinforced concrete beams. The co-operation of concrete between two successive cracks with the tensile reinforcement should be taken into account for its exact calculation. In this study, from the tensile loading test results on axially reinforced concrete prisms the mechanical behaviour of co-operation between concrete and reinforcement in tensile zone of beam is primarily discussed ; and the behaviour discussed is introduced into the development of the theoretical equation of flexural rigidity of cracked beams. The theory developed was verified by the experiments on simply supported reinforced concrete beams. Furthermore, some prospective way of clarifying the opening-up of crack width as well as the spacing between two successive cracks of beams is also discussed on the basis of tensile behaviour of axially reinforced concrete prisms

Multicanonical Monte Carlo Calculation of the First-order Phase Transition of Lennard-Jones Fluids

The liquid-solid phase transition was investigated by the multicanonical Monte Carlo method for a bulk Lennard-Jones fluid system that consists of 256 argon particles. The reliability of the multicanonical weight factor we determined was confirmed by the flatness of the histogram obtained by the multicanonical Monte Carlo production run. The first-order phase transition between solid and liquid phase was observed around 130 K from the change in thermodynamic properties as a function of temperature. Besides, the small change between two solid structures was also observed at 60 K from the radial distribution function, from the heat capacity and from conventional canonical Monte Carlo calculation at 60 K. Neither of them is not f. c. c. structure which is known as the most stable

Mechanical Properties of Simply Supported Prestressed Concrete Beams under Repeated Over-Loadings

Results of an experimental investigation on the mechanical behavior of simply supported prestressed concrete beams under repeated over-loading are described. This load was characterized by higher maximum load near the failure and the relatively slow loading velocity counting at most 100 cycles to the failure. Differences between the dynamic properties of grouted beams and of non-grouted beams under these loadings are also discussed. Test results give many interesting suggestions for the theoretical approach on the load-deformation relation of prestressed concrete baems subject to repeated over-loadings. It must be noticed that the deformation-dependent change of dissipated energy for the prestressed concrete beam is quite different from that for steel structure and of U-shaped curves

Molecular Imaging in Endoscopy

During the last decade, researchers have made great progress in the development of new image processing technologies for gastrointestinal endoscopy. However, diagnosis using conventional endoscopy with white light optical imaging is essentially limited, and ultimately, we still rely on the histopathological diagnosis from biopsy specimens. Molecular imaging represents the most novel imaging methods in medicine, and the future of endoscopic diagnosis is likely to be impacted by a combination of biomarkers and technology. Endoscopic molecular imaging can be defined as the visualization of molecular characteristics with endoscopy. These innovations will allow us not only to locate a tumor or dysplastic lesion but also to visualize its molecular characteristics and the activity of specific molecules and biological processes that affect tumor behavior and/or its response to therapy. In the near future, these promising technologies will play a central role in endoluminal oncology

Molecular Imaging in Endoscopic Oncology

The goal of our study is to develop a molecular imaging in gastrointestinal tract using infrared fluorescence endoscope (IRFE) and labeled antibodies with indocyanine green (ICG)-derivative in detecting cancerous tissue. IRFE consisted of an infrared endoscope equipped with excitation (710-790 nm) and barrier (810-920 nm) filters. We have developed ICG-N-hydroxy sulfo succinimide ester (ICG-sulfo-OSu) and 3-ICG-acyl-1,3-thiazolidine-2-thione (ICG-ATT) as an infrared fluorescent-labeling reagent. ICG-derivative-labeled anti-human carcinoembryonic antigen (CEA) antibody and MUC1 antibody were prepared. Freshly resected specimens with gastric cancer were observed by IRFE after reaction with ICG-derivative labeled antibodies. It resulted in positive fluorescence at the tumor location by IRFE, and the immnofluorescent images correlated well with the tumor sites. The immunohistochemical studies suggested the intensity of IR fluorescence of ICGATT-MUC1 stronger than ICG-sulfo-OSu. We conclude that an anti-CEA or MUC1 antibody with affinity for cancerous lesions and labeled with ICG-derivative can be imaged with this IRFE. Specific antibodies labeled with ICG-derivative with the reinforcing agent and electronic device can visualize cancer proteins generating a strong enough fluorescent signal