Identification of a structure specific Bcl-2 phosphorylating homoisoflavone molecule from Vietnamese coriander (Polygonatum odoratum) that induces apoptosis and G2/M cell cycle arrest in breast cancer cell lines

Bcl-2 is an anti-apoptotic protein which is over-expressed in many cancers. Modulating Bcl-2 expression is one of the most important strategies in the combat of cancer. We have isolated and identified a structure specific homoisoflavone from Vietnamese coriander (Polygonatum odoratum or Solomon seal) root which induces Bcl-2 phosphorylation, thereby causing mitotic arrest in breast cancer cells. Bioassay-directed fractionations resulted in a biologically active fraction for Bcl-2 phosphorylation. HPLC separation followed by mass spectrometry and NMR studies identified two compounds. We currently combine the chemistry and biological activity of Vietnamese coriander extracts by using bioassay directed fractionation to identify the structure specific Bcl-2 phosphorylating molecules, as well as their molecular mechanism of action. Only one molecule was responsible for Bcl-2 phosphorylation; it was identified as 2,3-dihydro3-[(15-hydroxyphenyl) methyl]-5,7-dihydroxy-6(8-dimethyl-4H-1-benzopyran-4-one) or 8-methyl-dihydrobenzopyranone (8-methyl-DBP, MW 314). The effect on Bcl-2 was structure specific, because 2,3 dihydro3-[(15-hydroxyphenyl) methyl]-5,7-dihydroxy-6-methyl-8-methoxy-4H-1-benzopyran-4-one or 8-methoxy-dihydrobenzopyranone (8-methoxy-DBP, MW 330), in contrast to 8-methyl-DBP, was not capable of Bcl-2 phosphorylation. Pure 8-methyl-DBP induced Bcl-2 phosphorylation in breast tumor cells, causes G2/M cell cycle arrest, up regulates the expression of p21 and p53 proteins and decreases cell viability demonstrated by a clonogenic assay. Therefore, these data demonstrate that Vietnamese coriander root contains 8-methyl-dihydrobenzopyrone (8-methyl-DBP, MW 314), which induces Bcl-2 phosphorylation, apoptosis, and G2/M cell cycle arrest in breast tumor cells.     

Various Shapes of 3 D Resonators Pass-Band Filters

The integral equations technique based on a three dimensional finite element method is applied as a quick and accurate analysis tool for the design of microwave passband filters. A three resonator H-plane bandpass filters with the various shapes of cavities and the irises are analyzed with this method in a single step and for only one mode, take into account all the electromagnetic effects. Consequently, it consumes less memory and CPU time.We propose also to study the same filters filled by homogeneous high dielectric material (ε_τ = 9.6) for Both resonator and coupling section.All these numerical results have been validated through a comparison with the results available in the scientific literature.     

Reactions of cellulose and wood superficial hydroxy groups with organometallic compounds

Various lignocellulosic substrates, including microcrystalline cellulose, pinewood and hemp fibres, were treated with triethylaluminium and triethylboron in suspensions, in non‐swelling media. Chemical and spectroscopic analyses show that coupling surface reactions took place between one or two metal‐to‐carbon (Mt–C) bonds and the OH groups of the natural polymers. The remaining unreacted Mt–C bonds were exploited to graft numerous molecular structures derived from alcohols and amines. The occurrence of the second reaction was proved by Fourier‐transform infrared spectroscopy, elemental analyses, X‐ray photoelectron spectroscopy and contact angle measurements. Copyright © 2004 Society of Chemical Industry     

Parameter Estimation in Groundwater Hydrology Using Artificial Neural Networks

The capability of artificial neural networks to act as universal function approximators has been traditionally used to model problems in which the relation between dependent and independent variables is poorly understood. In this paper, the capability of an artificial neural network to provide a data-driven approximation of the explicit relation between transmissivity and hydraulic head as described by the groundwater flow equation is demonstrated. Techniques are applied to determine the optimal number of nodes and training patterns needed for a neural network to approximate groundwater parameters for a simulated groundwater modeling case study. Furthermore, the paper explains how such an approximation can be used for the purpose of parameter estimation in groundwater hydrology.     

Transport properties in polypyrrole–PVA composites: Evidence for hopping conduction

Experimental results on electrical conductivity and thermoelectric power for FeCl₃-doped polyvinyl alcohol-polypyrrole composites, with polypyrrole content exceeding the percolation threshold, are presented. The electrical conductivity is analyzed in terms of the hopping theory, whereas the thermoelectric power displays a metallic-like dependence. A model involving both the intrinsic resistance of the fibrils (V.R.H. hopping mechanisms) and the resistance of the junctions between fibrils (fluctuations-induced tunneling conduction) has been retained.     

Dislocation structure and deformation in iron processed by equal-channel-angular pressing

The evolution of dislocation structure in pure Fe during equal-channel-angular pressing (ECAP) is investigated. Also, the effect of the formation of this dislocation structure on deformation and fracture behavior is examined. The results show that intensive dislocation cell blocks are present after one pass and even more after subsequent pressings. The low-energy dislocation structures (LEDS) may have changed into the high-energy dislocation structures (HEDS) in the final several pressings. The high-density array of dislocations plays a significant role in strengthening. The HEDS may cause the materials to lose work-hardening ability and show a cleavage morphology of the fracture surface. A proper subsequent annealing treatment will lead to the evolution of HEDS to LEDS while maintaining little grain growth. This change in the nature of dislocation structures allows ultrafine-grained materials to achieve an excellent combination of high strength and high ductility.     

Feedback stabilization of a class of distributed parameter systems with control constraints

The feedback stabilization problem for a class of infinite-dimensional linear systems with control constraints is investigated. The approach is developed using a state space system framework which is based on a semigroup formulation. In contrast to the previous works in this direction, it is not assumed that the C₀ semigroup we deal with is a semigroup of contractions. The main result links the problem with the positive invariance of appropriate polyhedral sets. Verifiable necessary and sufficient conditions for this latter property are stated.     

Residue levels of DDE and PCBs in the blood serum of women in the Port Said region of Egypt.

An investigation was conducted to detect residues of 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE) and polychlorinated biphenyls (PCBs) in blood serum samples collected from a cohort of fasting females attending the health insurance outpatient clinic at Port Said between July 1999 and July 2000. Females involved in the study included 43 females diagnosed with invasive adenocarcinoma of the breast, 21 female suffering benign breast disease, and 11 normal healthy females. Serum was separated and its contents of DDE and PCBs were extracted and determined, using gas chromatography, equipped with electron capture detector. Mean residues of DDE detected in the three examined groups of females were 41+/-5.2, 48+/-6.2 and 31+/-2.5ng/g for breast cancer cases, benign breast disease cases and controls, respectively, indicating some significantly less residues in blood serum of control females. While PCBs residues detected were 54+/-17, 59+/-23 and 61+/-21ng/g, for the three groups, respectively. Residues of DDE detected in all females alike in the present study are about 15 times higher than residues detected in Canada and The Netherlands.     

Parking buses in a depot using block patterns: A Benders decomposition approach for minimizing type mismatches

In a transit authority bus depot, buses of different types arrive in the evening to be parked in the depot for the night, and then dispatched in the morning to a set of routes, each of which requests a specific bus type. A type mismatch occurs when the requested type is not assigned to a morning route. We consider the problem of assigning the buses to the depot parking slots such that the number of mismatches is minimized, under the constraint that the buses cannot be repositioned overnight. As in Hamdouni et al. [Dispatching buses in a depot using block patterns. Technical Report, Les Cahiers du GERAD G-2004-51, HEC Montreal, Montreal, Canada, 2004, Transportation Science, to appear], we seek robust solutions by assigning a block pattern to each depot. This pattern partitions the lane into at most two blocks, each block containing buses of a given type. Since it may not be possible to respect the selected block patterns, the problem also involves a second objective which is to minimize the discrepancy between the bus type assignment to the parking slots and the block patterns. In this paper, we first study the simplified case where only the second objective is taken into account. We model this simplified problem as an integer linear program and show that practical instances of it can easily be solved using a commercial MIP solver. Then we formulate the general case as an extension of the simplified model and propose to solve it with a Benders decomposition approach embedded in a branch-and-bound procedure. This procedure is required because the Benders decomposition yields a subproblem with integrality constraints. Of particular interests, we develop strong pruning criteria and an innovative branching strategy that imposes decisions on the master problem variables which already take integer values. Computational results for the general case are also reported.