Somatostatin subtype-2 receptor-targeted metal-based anticancer complexes

Conjugates of a dicarba analogue of octreotide, a potent somatostatin agonist whose receptors are overexpressed on tumor cells, with [PtCl 2(dap)] (dap = 1-(carboxylic acid)-1,2-diaminoethane) (3), [(η 6-bip)Os(4-CO 2-pico)Cl] (bip = biphenyl, pico = picolinate) (4), [(η 6-p-cym)RuCl(dap)] + (p-cym = p-cymene) (5), and [(η 6-p-cym)RuCl(imidazole-CO 2H)(PPh 3)] + (6), were synthesized by using a solid-phase approach. Conjugates 3-5 readily underwent hydrolysis and DNA binding, whereas conjugate 6 was inert to ligand substitution. NMR spectroscopy and molecular dynamics calculations showed that conjugate formation does not perturb the overall peptide structure. Only 6 exhibited antiproliferative activity in human tumor cells (IC 50 = 63 ± 2 μ in MCF-7 cells and IC 50 = 26 ± 3 μ in DU-145 cells) with active participation of somatostatin receptors in cellular uptake. Similar cytotoxic activity was found in a normal cell line (IC 50 = 45 ± 2.6 μ in CHO cells), which can be attributed to a similar level of expression of somatostatin subtype-2 receptor. These studies provide new insights into the effect of receptor-binding peptide conjugation on the activity of metal-based anticancer drugs, and demonstrate the potential of such hybrid compounds to target tumor cells specifically. © 2012 American Chemical Society

Wireless Sensors for Intraoral Force Monitoring

A device for wireless intraoral forces monitoring is presented. Miniaturized strain gauge sensors are used for the measurements of forces applied by tongue and lips. A sensor interface IC is able to multiplex among four sensors and a low energy transmission module, equipped with an ARM Cortex–M0 core, is used for signal elaboration and remote wireless data transmission using Bluetooth® Low Energy standard protocol. The main novelty rely in the dynamic correction of the output corrupted by the prestrain issue. Moreover, the device shows a reduced dimension and the ability to transmit data wirelessly, without the use of external cables normally used in state-of-the-art intraoral monitoring devices

Abrasive grains micro geometry: a comparison between two acquisition methods

One of the aspects that makes difficult grinding processes modelling is the non-deterministic nature of the cutting tool, in particular the abrasive grains of the grinding wheel have a random distribution and an undefined geometry that influences the grinding forces. In order to develop a reliable 3D model of the grinding process the actual microgeometry of abrasive grains must be acquired. This paper compares the results of two different acquisition methods: the geometry acquired via a laser non-contact instrument is confronted with the one acquired using a computer tomography; the accuracy of the grain micro geometry provided by the two approaches is discussed

Projection based Image Processing for Automatic Tool Wear Detection

Tool wear monitoring is a fundamental aspect in the evolution of modern machining operations. As the quality of the tool is directly related to the quality of the product, automatic tool wear evaluation is vital to ensure smooth automatic control of machining processes [1]. In this paper, an automatic tool wear detection procedure is presented, where real time collected sequence images of the cutting tool during turning tests are subjected to image processing. The procedure can be divided into four steps: (1) Standardization of tool images; (2) Adjustment of pixel color density to obtain clear edges of the tool wear region; (3) Drawing of the projection line to find out the coordinates of the edge lines; (4) Calculation of tool wear development characteristics. The tool wear characteristics and extension area are evaluated on the basis of the processed edge. One by one, sequence images are processed to automatically provide the growth of tool wear characteristics. In order to verify the procedure accuracy, the tool wear characteristics and extension area are also evaluated manually using a grid number counting technique on paper images. The comparison of the results confirmed that the automatic evaluations achieve a high degree of accuracy. The experimental results indicate that the proposed procedure can be a viable technique to assess the tool wear development characteristics on an on-line basis

Feasibility study of using microorganisms as lubricant component in cutting fluids

This work intends to lay the basis for a Biological Transformation in Manufacturing (BTM) industrial breakthrough aimed at developing new sustainable microbial-based cutting fluids for greener machining processes. The point of departure is that conventional cutting fluids for machining are either entirely based on mineral oils or, in the case of water-based cutting fluids, contain significant percentages of mineral oils. The world annual consumption of cutting fluid concentrate amounts to several billion litres, highlighting their importance for the manufacturing industry and their criticality in terms of environmental impact. Furthermore, the depletion of mineral oil reserves worldwide is already driving cutting fluid industries to search for new renewable raw materials. A contribution to the solutions of these problems can be provided by the development of microbial-based cutting fluids, incorporated in the machine tool, that contain microorganisms with significant lubricating properties in order to substitute mineral oil-based cutting fluids for use in metal alloy machining

An improved impedance-based damage classification using Self-Organizing Maps

The identification and severity of structural damages, especially in the early stage, is critical in structural health monitoring (SHM) systems. Among several approaches used to accomplish this goal, the electromechanical impedance (EMI) technique has taken place within non-destructive evaluation (NDE) methods. On the other hand, neural networks (NN) based on self-organizing maps (SOM) has been a promising tool in many engineering classification problems. However, there is a gap of application regarding the combination of the EMI technique and SOM NN. To encourage this, an enhanced EMI-based damage classification method using self-organizing features is proposed in the present research paper. A SOM NN architecture was implemented whose inputs were derived from representative features of the impedance signatures. As a result, self-organizing maps can be used as an effective tool to enhance the damage classification in EMI-based SHM applications. For the present application, the results indicated a promising and useful contribution to the grinding field

An Efficient and Effective Image Segmentation Approach using Spatially Constrained Finite Mixture Model

This study introduces a novel image segmentation approach based on clustering using finite mixture model. The proposed approach utilizes the Kullback-Leibler divergence as the prior probability to incorporate spatial information into a mixture model. To alleviate the complicated learning process after incorporating the spatial prior, a multinomial logistic model is adapted, and a novel entropy approximation method is introduced so that the learning process keeps the same time complexity as in standard expectation maximization algorithm. Further, a noise removal and edge preserving method is proposed to deal with the under-smoothing and over-smoothing problem for better segmentation results. Experiments using synthetic and real images of Computer Tomography (CT) scan of the teeth are conducted, and the study shows convincing results obtained by the proposed approach

A study on the drilling process of hemp/epoxy composites by using different tools

As result of the increasing environmental awareness, the interest of bio-composite materials is growing rapidly in the last years in order to use them in various engineering application fields. For some of these applications, drilling is often required to facility the assembly of the parts and to make final products. However, drilling can induce a number of problems such as delamination, pull-out and strength reduction depending on the used cutting tools and cutting process parameters that can negatively affect the final product properties. Therefore, in order to reduce these problems on hemp/epoxy composites the aim of this study is to evaluate the effect of both the drilling parameters and tools on the drilling forces and delamination factors