Are Japanese and European gastric cancer the same biological entity? An immunohistochemical study.

To examine the suggested biological difference between Japanese and British gastric cancers, immunohistochemistry was used to demonstrate eight markers of biological activity in a matched series of 40 Japanese and 33 British cases. There were no differences in the proportions of Japanese and British tumours positive to epidermal growth factor, epidermal growth factor receptor, transforming growth factor alpha, cripto or p53. A significantly greater proportion of British tumours were positive to c-erbB-2 whilst a significantly greater proportion of Japanese tumours were positive to nm23. British tumours had a significantly greater mean proliferating cell nuclear antigen proliferation index than Japanese tumours. These differences could be clinically significant

Quantitative Imaging of Protein-Protein Interactions by Multiphoton Fluorescence Lifetime Imaging Microscopy using a Streak camera

Fluorescence Lifetime Imaging Microscopy (FLIM) using multiphoton excitation techniques is now finding an important place in quantitative imaging of protein-protein interactions and intracellular physiology. We review here the recent developments in multiphoton FLIM methods and also present a description of a novel multiphoton FLIM system using a streak camera that was developed in our laboratory. We provide an example of a typical application of the system in which we measure the fluorescence resonance energy transfer between a donor/acceptor pair of fluorescent proteins within a cellular specimen.Comment: Overview of FLIM techniques, StreakFLIM instrument, FRET application

Studies on Functional Bacteria of Indonesian Tropical Forest Plants for Biorehabilitation of Degraded Lands

Forest degradations have left vast amount of damaged and abandoned lands in Indonesia. In this paper, we present our approaches in rehabilitation of adverse soils using functional bacteria isolated from plant species of Indonesian tropical rain forests. For these purposes, we collected bacteria from various bio-geo-climatically different forests and conducted bioassays to test these bacterial abilities in improving plant growth. Repeated seedling-based studies on Shorea spp., Alstonia scholaris, Acacia crassicarpa, and Agathis lorantifolia have revealed that many bacteria were able to promote plant growth at early stage in the nursery. Various plant responses towards inoculations suggested that although forest soils maintain highly diverse and potent bacteria, it is necessary to select appropriate approaches to obtain optimum benefits from these plant-bacteria interactions. Our ideas and futures studies for further management of these plant- bacteria interactions for biorehabilitation are also discussed

Effects of Long-Range Correlations on Nonmagnetic Mott Transitions in Hubbard model on Square Lattice

The mechanism of Mott transition in the Hubbard model on the square lattice is studied without explicit introduction of magnetic and superconducting correlations, using a variational Monte Carlo method. In the trial wave functions, we consider various types of binding factors between a doubly-occupied site (doublon, D) and an empty site (holon, H), like a long-range type as well as a conventional nearest-neighbor type, and add independent long-range D-D (H-H) factors. It is found that a wide choice of D-H binding factor leads to Mott transitions at critical values near the band width. We renew the D-H binding picture of Mott transitions by introducing two characteristic length scales, the D-H binding length l_{DH} and the minimum D-D distance l_{DD}, which we appropriately estimate. A Mott transition takes place at l_{DH}=l_{DD}. In the metallic regime (l_{DH}>l_{DD}), the domains of D-H pairs overlap with one another, thereby doublons and holons can move independently by exchanging the partners one after another. In contrast, the D-D factors give only a minor contribution to the Mott transition.Comment: 13 pages, 18 figures, submitted to J. Phys. Soc. Jp

Effect of Doublon-Holon Binding on Mott transition---Variational Monte Carlo Study of Two-Dimensional Bose Hubbard Models

To understand the mechanism of Mott transitions in case of no magnetic influence, superfluid-insulator (Mott) transitions in the S=0 Bose Hubbard model at unit filling are studied on the square and triangular lattices, using a variational Monte Carlo method. In trial many-body wave functions, we introduce various types of attractive correlation factors between a doubly-occupied site (doublon, D) and an empty site (holon, H), which play a central role for Mott transitions, in addition to the onsite repulsive (Gutzwiller) factor. By optimizing distance-dependent parameters, we study various properties of this type of wave functions. With a hint from the Mott transition arising in a completely D-H bound state, we propose an improved picture of Mott transitions, by introducing two characteristic length scales, the D-H binding length $\xi_{\rm dh}$ and the minimum D-D exclusion length $\xi_{\rm dd}$. Generally, a Mott transition occurs when $\xi_{\rm dh}$ becomes comparable to $\xi_{\rm dd}$. In the conductive (superfluid) state, domains of D-H pairs overlap with each other ($\xi_{\rm dh}>\xi_{\rm dd}$); thereby D and H can propagate independently as density carriers by successively exchanging the partners. In contrast, intersite repulsive Jastrow (D-D and H-H) factors have little importance for the Mott transition.Comment: 16 pages, 22 figures, submitted to J. Phys. Soc. Jp

Malta : a siege and a journey

MALTESE belongs to the Semitic language family. Other languages such as English and German belong to the Germanic group, while Latin, French, Italian, Portuguese and Spanish are members of the Romance language family. As members of their families, languages display similarities with other languages in their own language group. Thus, as a member of the Semitic language family, Maltese displays greater similarities with languages in the same group, such as Arabic, rather than with Germanic and Romance languages. But unlike Arabic, Maltese is written in Roman script.peer-reviewe

Field-Dependent Critical Current in Type-II Superconducting Strips: Combined Effect of Bulk Pinning and Geometrical Edge Barrier

Recent theoretical and experimental research on low-bulk-pinning superconducting strips has revealed striking dome-like magnetic-field distributions due to geometrical edge barriers. The observed magnetic-flux profiles differ strongly from those in strips in which bulk pinning is dominant. In this paper we theoretically describe the current and field distributions of a superconducting strip under the combined influence of both a geometrical edge barrier and bulk pinning at the strip's critical current Ic, where a longitudinal voltage first appears. We calculate Ic and find its dependence upon a perpendicular applied magnetic field Ha. The behavior is governed by a parameter p, defined as the ratio of the bulk-pinning critical current Ip to the geometrical-barrier critical current Is0. We find that when p > 2/pi and Ip is field-independent, Ic vs Ha exhibits a plateau for small Ha, followed by the dependence Ic-Ip ~ 1/Ha in higher magnetic fields.Comment: 4 pages, 2 figures, Fig. 1 revised, submitted to Phys. Rev.