Взаємодія напівпровідників типу АІІІВV з розчинами Н2О2 - НВr

To plan complex motions of robots with many degrees of freedom, our novel, very flexible framework builds task-relevant roadmaps (TRMs), using a new sampling-based optimizer called Natural Gradient Inverse Kinematics (NGIK) based on natural evolution strategies (NES). To build TRMs, NGIK iteratively optimizes postures covering task-spaces expressed by arbitrary task-functions, subject to constraints expressed by arbitrary cost-functions, transparently dealing with both hard and soft constraints. TRMs are grown to maximally cover the task-space while minimizing costs. Unlike Jacobian-based methods, our algorithm does not rely on calculation of gradients, making application of the algorithm much simpler. We show how NGIK outperforms recent related sampling algorithms. A <font color="blue"><a href="http://youtu.be/N6x2e1Zf_yg">video demo</a></font> successfully applies TRMs to an iCub humanoid robot with 41 DOF in its upper body, arms, hands, head, and eyes. To our knowledge, no similar methods exhibit such a degree of flexibility in defining movements

CarboxyAmido-Triazole Orotate inhibits the growth of Imatinib-resistant chronic myeloid leukaemia cells and modulates exosomes-stimulated angiogenesis

Chronic myelogenous leukemia is a myeloproliferative disorder characterized by the t(9:22) (q34:q11) reciprocal chromosomal translocation, resulting in the expression of the chimeric Bcr–Abl oncoprotein with constitutive tyrosine kinase activity. Deregulated Bcr–Abl induces the hyperactivation of various signalling pathways that promote cell growth, suppress apoptosis and alter cell adhesion. Bcr-Abl has also been involved in VEGF-mediated angiogenesis in CML and evidence indicates that the formation of new vessels plays an important role in the development and progression of CML. Imatinib mesylate (IM) is a selective well tolerated inhibitor of the Bcr–Abl tyrosine kinase that has significantly improved the prognosis of patients with chronic phase CML. Despite this remarkable progress, a major problem associated with the administration of imatinib is acquired resistance. Bcr-Abl gene amplification, increased expression of Bcr–Abl protein, point mutations in the Bcr–Abl tyrosine kinase domain have been reported as mechanisms of resistance to imatinib. Therefore, there is an urgent need for new anticancer agents and combinations that could improve responses and survival rates for CML. Recent studies from our laboratory have shown that addition of carboxyamidotriazole (CAI), an inhibitor of calcium-mediated signal transduction, to imatinib resistant human CML cells induces a marked decrease in cell viability and augmented apoptosis, events associated with downregulation of Bcr–Abl protein and inhibition of tyrosine phosphorylation of Bcr–Abl, STAT5, CrkL. Carboxyamidotriazole Orotate (CTO), is a derivate of CAI that has been developed at Tactical Therapeutics. CTO has a higher bioavailability and efficacy with respect to the parental compound. Exosomes are small vesicles of 40-100 nm diameter that are initially formed within the endosomal compartment and are secreted when a multivesicular body (MVB) fuses with the plasma membrane. These vesicles are released by many cell types including cancer cells and are considered messengers in intercellular communication. The exact function of exosomes in malignant cells has yet to be elucidated, but investigation has suggested roles in cell-to-cell communication, tumor-stroma interaction, and antigen presentation, thus potentially affecting cancer progression at different steps. Recent studies from our laboratory suggest that exosomes released from IM-sensitive CML cells directly affect endothelial cells modulating the process of neovascularization. Our data show that CTO is able to inhibit both in vitro and in vivo the growth of imatinib-resistant CML cells and to affect tumor microenvironment by modulating exosome-stimulated angiogenesis. CTO may be effective in targeting both cancer cell growth and the tumor microenvironment, thus suggesting a potential therapeutic utility in the treatment of leukemia patients

Exosome-mediated crosstalk between chronic myelogenous leukemia cells and human bone marrow stromal cells triggers an interleukin 8-dependent survival of leukemia cells

Chronic myelogenous leukemia (CML) is a myeloproliferative disorder characterized by the Bcr–Abl oncoprotein with constitutive tyrosine kinase activity. Exosomes are nanovesicles released by cancer cells that are involved in cell-to-cell communication thus potentially affecting cancer progression. It is well known that bone marrow stromal microenvironment contributes to disease progression through the establishment of a bi-directional crosstalk with cancer cells. Our hypothesis is that exosomes could have a functional role in this crosstalk. Interleukin-8 (IL 8) is a proinflammatory chemokine that activates multiple signalling pathways downstream of two receptors (CXCR1 and CXCR2). We demonstrated that exosomes released from CML cells stimulate bone marrow stromal cells to produce IL 8 that, in turn, is able to modulate both in vitro and in vivo the leukemia cell malignant phenotype

Learning tactile skills through curious exploration

We present curiosity-driven, autonomous acquisition of tactile exploratory skills on a biomimetic robot finger equipped with an array of microelectromechanical touch sensors. Instead of building tailored algorithms for solving a specific tactile task, we employ a more general curiosity-driven reinforcement learning approach that autonomously learns a set of motor skills in absence of an explicit teacher signal. In this approach, the acquisition of skills is driven by the information content of the sensory input signals relative to a learner that aims at representing sensory inputs using fewer and fewer computational resources. We show that, from initially random exploration of its environment, the robotic system autonomously develops a small set of basic motor skills that lead to different kinds of tactile input. Next, the system learns how to exploit the learned motor skills to solve supervised texture classification tasks. Our approach demonstrates the feasibility of autonomous acquisition of tactile skills on physical robotic platforms through curiosity-driven reinforcement learning, overcomes typical difficulties of engineered solutions for active tactile exploration and underactuated control, and provides a basis for studying developmental learning through intrinsic motivation in robots

AutoIncSFA and vision-based developmental learning for humanoid robots

Abstract—Humanoids have to deal with novel, unsupervised high-dimensional visual input streams. Our new method Au-toIncSFA learns to compactly represent such complex sensory input sequences by very few meaningful features corresponding to high-level spatio-temporal abstractions, such as: a person is approaching me, or: an object was toppled. We explain the advantages of AutoIncSFA over previous related methods, and show that the compact codes greatly facilitate the task of a reinforcement learner driving the humanoid to actively explore its world like a playing baby, maximizing intrinsic curiosity reward signals for reaching states corresponding to previously unpredicted AutoIncSFA features. I

Role of exosomes released by chronic myelogenous leukemia cells in angiogenesis

The present study is designed to assess if exosomes released from Chronic Myelogenous Leukemia (CML) cells may modulate angiogenesis. We have isolated and characterized the exosomes generated from LAMA84 CML cells and demonstrated that addition of exosomes to human vascular endothelial cells (HUVEC) induces an increase of both ICAM-1 and VCAM-1 cell adhesion molecules and interleukin-8 expression. The stimulation of cell-cell adhesion molecules was paralleled by a dose-dependent increase of adhesion of CML cells to a HUVEC monolayer. We further showed that the treatment with exosomes from CML cells caused an increase in endothelial cell motility accompanied by a loss of VE-cadherin and β-catenin from the endothelial cell surface. Functional characterization of exosomes isolated from CML patients confirmed the data obtained with exosomes derived from CML cell line. CML exosomes caused reorganization into tubes of HUVEC cells cultured on Matrigel. When added to Matrigel plugs in vivo, exosomes induced ingrowth of murine endothelial cells and vascularization of the Matrigel plugs. Our results suggest for the first time that exosomes released from CML cells directly affect endothelial cells modulating the process of neovascularization

In Vitro Antitumor Effects of the Cold-Water Extracts of Mediterranean Species of Genus Pleurotus (Higher Basidiomycetes) on Human Colon Cancer Cells

The aim of the present study was to evaluate whether the cold-water extract of Pleurotus eryngii var. ferulae (CWE-Pef) and Pleurotus nebrodensis (CWE-Pn), two of the most prized wild and cultivated edible mushrooms can affect the tumour phenotype of human colon cancer HCT116 cells. Our results showed that treatment with CWE-Pef and CWE-Pn resulted in a significant inhibition of the viability of HCT116 cells and promoted apoptosis as also demonstrated by the increase of bax/bcl-2 mRNA ratio. Moreover, we observed that both extracts were able to inhibit cell migration and to affect homotypic and heterotypic cell-cell adhesion. It was also found that treatment with CWE-Pef and CWE-Pn negatively modulated the protein tyrosine phosphorylation as well as the phosphorylation levels of ERK1/2. In conclusion, the in vitro antitumor effects of CWE-Pef and CWE-Pn indicate that they can be considered as possible sources for new alternative therapeutic agents for cancer treatment