In order to convey coal, ore and other raw materials for iron making, hundreds of conveyor-belts are working in a steel making plant. Because those facilities are weather-beaten, it is very difficult to apply a suitable maintenance service. In addition, conveyor-belts in a steel plant are distributed over a vast outdoor field. Therefore, it is almost impossible to carry out any condition monitoring by operators. In spite of the difficulty in applying a condition monitoring, it is urgently needed to develop an effective method for the detection of conveyor-belt trouble.
This paper presents a neural network parallel algorithm with SDNN/V (strictly digital neural networks with virtual slacks) enhanced with "virtual slack-neurons" for solving bipartite subgraph problems of combinatorial optimization problems, and the method to improve the quality of solutions by CS (constraint sets) programming based on SDNN/V. This problem is to divide a graph into two clusters so as to minimize the number of removed edges where edges in the same cluster are only removed from the given graph. Note that edges bridging between two clusters are not removed. This problem can be defined as a "set selection problem" with the "between-l-and-k-out-of-n" design rule in SDNN/V algorithm. The number of required neurons to solve this problem using SDNN/V algorithm is V, where V is the number of vertices, and the number of required sets is V+E, where E is the number of edges in a given graph as a bipartite subgraph problem. The 30-vertex with 50-edge graph problem used by other algorithm has been simulated to compare the authors' algorithm with other algorithms. The results of solving the bipartite subgraph problem using the authors' SDNN/V algorithm show that the computation steps in parallel execution is only 2 steps within O(1) time to converge to one of the solutions regardless of the problem size, and that the numbering order of each neuron such as sorted according to the number of sets assigned it has an effect on the quality of solutions in SDNN/V algorithm.
The potential for hepatic metastasis in nude mice was studied by the intrasplenic implantation method with five human pancreatic cancer cell lines, Capan-1, BxPC-3, AsPC-1, Panc-1, and MIAPaCa-2, especially in relation to serine protease expression, including urokinase-type plasminogen activator and pancreatic trypsinogen 1 (cationic form). The inhibitory effect of a serine protease inhibitor agent, FOY-305, on hepatic metastasis was also a assessed. As a result, the potential for hepatic metastasis was well correlated with expression of pancreatic trypsinogen 1 in these cell lines, and the incidence of metastasis was significantly decreased by FOY-305. These findings suggest that pharmacologic inhibition of serine protease activity may be a new strategy for the therapy of pancreatic cancer metastasis.
Abstract Purpose: The RNA interference effect is an alternative to antisense DNA as an experimental method of down-regulating a specific target protein. Although the RNA interference effect, which is mediated by small interfering RNA (siRNA) or micro-RNA, has potential application to human therapy, the hydrodynamic method usually used for rapid administration of oligonucleotides is unsuitable for use in humans. In this study, we have investigated the antitumor activity of a synthetic siRNA, B717, which is sequence specific for the human bcl-2 oncogene, complexed with a novel cationic liposome, LIC-101. Experimental Design: In a mouse model of liver metastasis, we administered B717/LIC-101 by bolus intravenous injection, adjusting the rate and volume of administration to what is feasible in human therapy. In a mouse model bearing prostate cancer in which the cells were inoculated under the skin, B717/LIC-101 was administered subcutaneously around the tumor. Results: The B717/LIC-101 complex inhibited the expression of bcl-2 protein and the growth of tumor cell lines in vitro in a sequence-specific manner in the concentration range of 3 to 100 nmol/L. Furthermore, the complex had a strong antitumor activity when administered intravenously in the mouse model of liver metastasis. B717 (siRNA) was shown to be delivered to tumor cells in the mouse liver, but only when complexed with LIC-101. The complex also inhibited tumor cell growth in the mouse model bearing prostate cancer. Conclusions: By combining siRNA with our cationic liposome, we overcame the difficulty of administering siRNA to animals in ways that can be applied in human therapy. Although our siRNA/liposome complex is not yet in clinical trials, it is expected to provide a novel siRNA therapy for cancer patients.
A novel method for the synthesis of RNA oligomers with 2-cyanoethoxymethyl (CEM) as the 2'-hydroxyl protecting group has been developed. The new method allows the synthesis of oligonucleotides with an efficiency and final purity comparable to that obtained in DNA synthesis.(1) In addition, the CEM method has the potential for application to the synthesis of very long RNA oligonucleotides.
In ACI/N rats pretreated with cyclophosphamide (CY) growth of the bladder cancer, BC-47, and adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) activities in lymphocytes were investigated to clarify the possible antitumor effect via the immune system of the chemotherapeutic agent. A single dose of 50 mg/kg of CY with the tumor implantation 3 days later gave rise to tumor regression following temporary progression around day 15 and significant increase of peripheral lymphocytes with higher PNP activity on days 7 to 10 of the tumor implantation. In the thymus such lymphocytes increased 3 days earlier. The antitumor effect was not demonstrated in athymic nude mice. In the light of the results and elimination of suppressor T precursors by CY, it was postulated that T lymphocytes with higher PNP activity act as effector cells in the antitumor immunity whereas suppressor T precursors belong to the cell population with lower PNP activity.
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