Manipulation of micro-components using vacuum grippers.

SUMMARY. During the past decades several microproducts have been fabricated for a great variety of applications in the traditional fields, including the medical and biomedical sectors, automotive, aeronautics and aerospace, Information Technology and telecommunication as well as in more innovative areas, such as household appliances, entertainment and sport equipment. Nevertheless, hybrid three dimensional micro products have still great difficulty in penetrating the market, mainly due to the limits of the fabrication processes that require manipulation and final assembly of microcomponents. These processes, being not yet automated, strongly affect the cost of products. Therefore, new market perspectives can be reached automating the assembly phase. The main challenge is due to the new physical scenario that appears when dealing with the assembly of millimetric and sub-millimetric parts. Indeed, at the microscale the high surface to volume ratio leads to the predominance of the superficial forces (e.g. electrostatic, van der Waals and surface tension forces) over the gravitational force; this results in an unpredictable behaviour of the traditional manipulating mechanisms, whereas an efficient and precise control of the grasp and release of thousands of microscopic and fragile parts is required. For this reason the downscaling of traditional handling strategies and the development of new handling techniques require further studies. Several solutions can be found in literature, with their advantages and limitations, i.e.: friction and jaw microgrippers, magnetic and electrical fields used to levitate objects, adhesive grippers exploiting capillary force. Also vacuum grippers can be miniaturized. Due to their intrinsic simplicity, vacuum grippers are very cheap and appear a promising solution for industrial applications, if some improvements are carried out. In this context, an experimental setup for the automatic manipulation of microcomponents through some vacuum grippers was developed. Moreover, an innovative design of a nozzle for a vacuum gripper was fabricated and tested, comparing its performance with traditional needles. The design was conceived in order to reduce the frequency of occlusions of the nozzle and handle a wide range of particles. The tests described in this paper concern mainly the success and the precision of the release of objects from the gripper. Indeed, this is one the crucial aspect of micromanipulation because microparts tend to stick to the gripper preventing the successful performance of manipulation tasks

A Vacuum manipulation device and a method for manipulating a components by means of a vacuum

A vacuum manipulation device (1 ) comprising a tube (2) in communication with a vacuum generating system for gripping a component by suction at a gripper nozzle (3) of the tube itself and a mechanical release system (8) inserted at least partially inside the tube (2). The mechanical release system (8) is movable between a release position, in which a release portion thereof projects externally from the gripper nozzle (3), and a gripping position, in which the release portion (10a) returns into the tube (2). The mechanical release system (8) comprises a transverse extension (9) made up of a perforated disk and a needle (10) solidly joined to the perforated disk and having a diameter that is smaller than the internal diameter of the tube (2). The needle (10) is inserted at least partially inside the tube (2) and comprises the release portion

Banks, debt and risk: assessing the spillovers of corporate taxes

Using bank balance sheet data, we find evidence that leverage and asset risk of European multinational banks in the crisis and post-crisis period is affected by corporate taxes in their host country as well as by the tax rates in all the jurisdictions where the banking group operates. Then, we evaluate the effects that establishing tax neutrality between debt and equity finance has on systemic risk. We show that the degree of coordination in implementing the hypothetical tax reform matters. In particular, a coordinated elimination of the tax advantage of debt would significantly reduce systemic losses in the event of a severe banking crisis. By contrast, uncoordinated tax reforms are not equally beneficial. This is because national tax policies generate spillovers through cross-border bank activities and tax-driven strategic allocation of debt and asset risk across group affiliates.JRC.B.1-Finance and Econom

Probing Lorentz-violating electrodynamics with CMB polarization

We perform a comprehensive study of the signatures of Lorentz violation in electrodynamics on the Cosmic Microwave Background (CMB) anisotropies. In the framework of the minimal Standard Model Extension (SME), we consider effects generated by renormalizable operators, both CPT-odd and CPT-even. These operators are responsible for sourcing, respectively, cosmic birefringence and circular polarization. We propagate jointly the effects of all the relevant Lorentz-violating parameters to CMB observables and provide constraints with the most recent CMB datasets. We bound the CPT-even coefficient to $k_{F,E+B} < 2.31 \times 10^{-31}$ at 95\% CL. This improves previous CMB bounds by one order of magnitude. The limits we obtain on the CPT-odd coefficients, i.e. $|k_{(V)00}^{(3)}| < 1.54 \times 10^{-44} \; {\rm GeV}$ and $|\mathbf{k_{AF}}| < 0.74 \times 10^{-44} \; {\rm GeV}$ at 95\% CL, are respectively one and two orders of magnitude stronger than previous CMB-based limits, superseding also bounds from non-CMB searches. This analysis provides the strongest constraints to date on CPT-violating coefficients in the minimal SME from CMB searches

Multiple vertebral hemangiomas of the thoracic spine with atypical radiological features and aggressive behavior causing myelopathy: A case report

Abstract Background Vertebral Haemangiomas (VHs) are frequent and generally asymptomatic benign tumors, involving the spine, usually incidentally found on computed tomography and magnetic resonance. Despite being usually asymptomatic and quiescent lesions, VHs can occasionally manifest aggressive features, leading to clinical manifestations such as back pain and neurological deficits. Case report. We report a case of a 54-year-old man, presented with 5 months history of pain, associated with lower limbs paraesthesia and weakness, gait disturbance and episodes of accidental falls. Radiological evaluation by spine pre- and post-contrast MRI indicated multiple vertebral hypervascular lesions, compatible with haemangiomas, involving from T3 to T11 levels, showing several different features (typical and atypical); aggressive haemangioma radiological pattern may be valuable at T3 and T4 vertebras. A thoracic spine pre- and post-contrast computed tomography confirmed the radiological diagnosis of multiple aggressive haemangiomas. Discussion Aggressive VH consists in a very rare subset of vertebral haemangiomas characterized by a greater tendency in being symptomatic. They may show atypical radiological features, that make their diagnosis very complex. In the recent years, many strategies for treatment of symptomatic or aggressive VHs have been developed, but the optimal treatment strategy is still controversial. Conclusion Although aggressive VHs being extremely rare, recognizing radiological features of these lesions is mandatory to achieve a correct diagnosis and appropriate therapeutic targets

Perhexiline maleate enhances antitumor efficacy of cisplatin in neuroblastoma by inducing over-expression of NDM29 ncRNA

High Risk Neuroblastoma (HR-NB) is a pediatric cancer characterized by high malignancy and remarkable cell heterogeneity within the tumour nodules. In a recent study, we demonstrated that in vitro and in vivo over-expression of the non-coding RNA NDM29 (neuroblastoma differentiation marker 29) induces NB cell differentiation, dramatically reducing their malignancy. Among gene expression changes, differentiated phenotype induced by NDM29 is characterized by decrease of the expression of ABC transporters responsible for anticancer drug resistance. Thus, the pharmacological induction of NDM29, in principle, might represent a possible novel strategy to increase cytotoxic drug responses. In this work, we identify a small molecule able to induce the expression of NDM29 in NB cells, conferring to malignant cells increased susceptibility to cisplatin cytotoxic effects. We demonstrate that the pharmacological induction of NDM29 expression in vivo enhances the antitumoral effects of chemotherapy specifically on tumour initiating/cancer stem cells sub-population, usually refractory to therapies and responsible for tumour relapse. In summary, we suggest a novel therapeutical approach possibly useful to treat very aggressive NB cases with poor prognosis. This novel pharmacological strategy aims to promote differentiation of "stem-like" cells to render them more susceptible to the killing action of cytotoxic anticancer drugs

Vascular endothelial growth factor-C stimulates the migration and proliferation of Kaposi's sarcoma cells.

Recent evidence suggesting vascular endothelial growth factor-C (VEGF-C), which is a regulator of lymphatic and vascular endothelial development, raised the question whether this molecule could be involved in Kaposi's sarcoma (KS), a strongly angiogenic and inflammatory tumor often associated with infection by human immunodeficiency virus-1. This disease is characterized by the presence of a core constituted of three main populations of "spindle" cells, having the features of lymphatic/vascular endothelial cells, macrophagic/dendritic cells, and of a mixed macrophage-endothelial phenotype. In this study we evaluated the biological response of KS cells to VEGF-C, using an immortal cell line derived from a KS lesion (KS IMM), which retains most features of the parental tumor and can induce KS-like sarcomas when injected subcutaneously in nude mice. We show that VEGFR-3, the specific receptor for VEGF-C, is expressed by KS IMM cells grown in vitro and in vivo. In vitro, VEGF-C induces the tyrosine phosphorylation of VEGFR-2, a receptor also for VEGF-A, as well as that of VEGFR-3. The activation of these two receptors in KS IMM cells is followed by a dose-responsive mitogenic and motogenic response. The stimulation of KS IMM cells with a mutant VEGF-C unable to bind and activate VEFGR-2 resulted in no proliferative response and in a weak motogenic stimulation, suggesting that VEGFR-2 is essential in transducing a proliferative signal and cooperates with VEGFR-3 in inducing cell migration. Our data add new insights on the pathogenesis of KS, suggesting that the involvement of endothelial growth factors may not only determine KS-associated angiogenesis, but also play a critical role in controlling KS cell growth and/or migration and invasion

Design of a miniaturized work-cell for micro-manipulation

The paper describes the design and development of a miniaturised workcell devoted to the robotized micro manipulation and assembly of extremely small components, jointly carried out by the University of Brescia, University of Bergamo, University of Ancona and the Institute of Industrial Technologies and Automation of the Italian National Research Council in the framework of the project PRIN2009 MM&A, funded by MIUR. Besides analyzing theoretical and practical aspects related to the design of the work cell components (positioning and orienting devices, grippers, vision and control systems), an automated test bed for the assembly of micro pieces whose typical dimension belongs to the submillimeter scale range has been implemented. The perspective is to contribute to the realization of general automatic production systems at the moment absent for objects of these dimensions

Design of a miniaturized work-cell for micro-manipulation

The paper describes the design and development of a miniaturised workcell devoted to the robotized micro manipulation and assembly of extremely small components, jointly carried out by the University of Brescia, University of Bergamo, University of Ancona and the Institute of Industrial Technologies and Automation of the Italian National Research Council in the framework of the project PRIN2009 MM&A, funded by MIUR. Besides analyzing theoretical and practical aspects related to the design of the work cell components (positioning and orienting devices, grippers, vision and control systems), an automated test bed for the assembly of micro pieces whose typical dimension belongs to the submillimeter scale range has been implemented. The perspective is to contribute to the realization of general automatic production systems at the moment absent for objects of these dimensions

Selection of Candidate Housekeeping Genes for Normalization in Human Postmortem Brain Samples

The most frequently used technique to study the expression profile of genes involved in common neurological disorders is quantitative real-time RT-PCR, which allows the indirect detection of very low amounts of selected mRNAs in tissue samples. Expression analysis by RT-qPCR requires an appropriate normalization to the expression level of genes characterized by a stable, constitutive transcription. However, the identification of a gene transcribed at a very stable level is difficult if not impossible, since significant fluctuations of the level of mRNA synthesis often accompanies changes of cell behavior. The aim of this study is to identify the most stable genes in postmortem human brain samples of patients affected by Alzheimer’s disease (AD) suitable as reference genes. The experiments analyzed 12 commonly used reference genes in brain samples from eight individuals with AD and seven controls. After a careful analysis of the results calculated by geNorm and NormFinder algorithms, we found that CYC1 and EIF4A2 are the best reference genes. We remark on the importance of the determination of the best reference genes for each sample to be analyzed and suggest a practical combination of reference genes to be used in the analysis of human postmortem samples