Active rectifier circuits with sequential charging of storage capacitors (SCSC) for energy harvesting in autonomous sensors

n/

Nonlinear Multi-Frequency Converter Array for Vibration Energy Harvesting in Autonomous Sensors☆

Abstract This work proposes and experimentally validates a vibration energy harvester which combines the multi-frequency and nonlinear approaches into a converter array. The converter array consists of four piezoelectric cantilevers composed of ferromagnetic substrates with screen-printed lead zirconate titanate (PZT) layers coupled with a single permanent magnet elastically suspended on the array base in order to create a nonlinear behaviour. The presence of a moving magnet and the possibility to realize cantilevers with different potential curves can be useful to obtain a collective nonlinear behaviour due to strong coupling irrespective of the amplitude of the mechanical excitation, therefore increasing the overall effectiveness of the converter array. The experimental results confirm that combining cantilevers with different potential curves can be useful to obtain a collective bistable behaviour, therefore increasing the overall effectiveness of the converter array

From ESR to continuous CC-ESRR process: development in remelting technology towards better products and productivity

This work describes the development of the Electro Slag Remelting process at Valbruna, starting in the 1997 with an innovative INTECO ESR plant equipped with protective gas hood (for inert atmosphere remelting), electrode change system and fully computer controlled. The second step was made a couple of years later when the plant was upgraded to ESRR® (Electro Slag Rapid Remelting). With this new feature Acciaierie Valbruna was able to obtain ready to roll remelted billets (145, 160 and 200 mm square), getting rid of the traditional forging or blooming operations needed in case of traditional ESR ingot remelting. This was surely a dramatic cut off in product cost accounting and production lead time without loosing any of the special characteristics typical of ESR products. Unfortunately the ESRR® process, very promising in terms of cycle complexity reduction and quality of the product, because of its “batch-type” operation, was uneconomical in regard of productivity of the plant and not feasible in industrial scale. The final step of this development was made at the beginning of 2002 when t he ESRR® plant was upgraded again and equipped with an innovative INTECO automatic manipulator, which resulted in a continuous process. This was the birth of the very first CC-ESRR® (continuous casting electro slag rapid remelting) plant in the world. The first part of this paper focuses o n the development of processes and equipment, giving a brief description of ESR, ESRR® and CC-ESRR® process while the second part describes the results of a series of test remelting used for product and CC-ESRR® process characterization

Vitronectin Increases Vascular Permeability by Promoting VE-Cadherin Internalization at Cell Junctions

Cross-talk between integrins and cadherins regulates cell function. We tested the hypothesis that vitronectin (VN), a multi-functional adhesion molecule present in the extracellular matrix and plasma, regulates vascular permeability via effects on VE-cadherin, a critical regulator of endothelial cell (EC) adhesion.Addition of multimeric VN (mult VN) significantly increased VE-cadherin internalization in human umbilical vein EC (HUVEC) monolayers. This effect was blocked by the anti-α(V)β(3) antibody, pharmacological inhibition and knockdown of Src kinase. In contrast to mult VN, monomeric VN did not trigger VE-cadherin internalization. In a modified Miles assay, VN deficiency impaired vascular endothelial growth factor-induced permeability. Furthermore, ischemia-induced enhancement of vascular permeability, expressed as the ratio of FITC-dextran leakage from the circulation into the ischemic and non-ischemic hindlimb muscle, was significantly greater in the WT mice than in the Vn(-/-) mice. Similarly, ischemia-mediated macrophage infiltration was significantly reduced in the Vn(-/-) mice vs. the WT controls. We evaluated changes in the multimerization of VN in ischemic tissue in a mouse hindlimb ischemia model. VN plays a previously unrecognized role in regulating endothelial permeability via conformational- and integrin-dependent effects on VE-cadherin trafficking.These results have important implications for the regulation of endothelial function and angiogenesis by VN under normal and pathological conditions

Isthmin exerts pro-survival and death-promoting effect on endothelial cells through alphavbeta5 integrin depending on its physical state

10.1038/cddis.2011.37Cell Death and Disease25

Morphologically and immunohistochemically undifferentiated gastric neoplasia in a patient with multiple metastatic malignant melanomas: a case report

Introduction: Malignant melanoma is a neoplasia which frequently involves the gastrointestinal tract (GIT). GIT metastases are difficult to diagnose because they often recur many years after treatment of the primary cutaneous lesion and also manifest clinically at an advanced stage of the neoplasia. Furthermore, GIT metastases can appear in various morphological forms, and therefore immunohistochemistry is often useful in distinguishing between a malignant melanoma and other malignancies. Case presentation: We report the case of a 60-year-old man with a multiple metastatic melanoma who underwent an upper endoscopy to clarify the possible involvement of the gastric wall with a mass localized in the upper abdomen involving the pancreas and various lymph nodes, which was previously described with computed tomography. Clinically, the patient reported a progressive loss of appetite, nausea and vomiting. The upper endoscopy and histological examination revealed a gastric location of an undifferentiated neoplasm with an absence of immunohistochemical characteristics referable to the skin malignant melanoma that was removed previously. Conclusion: The present case report shows the difficulty in diagnosing a metastatic melanoma in the GIT and therefore, it seems worthwhile to consider metastatic malignant melanoma in the differential diagnosis of undifferentiated neoplasia. © 2008 Alghisi et al; licensee BioMed Central Ltd

Evaluation of α2-Integrin Expression as a Biomarker for Tumor Growth Inhibition for the Investigational Integrin Inhibitor E7820 in Preclinical and Clinical Studies

E7820 is an orally active inhibitor of α2-integrin mRNA expression, currently tested in phases I and II. We aimed to evaluate what levels of inhibition of integrin expression are needed to achieve tumor stasis in mice, and to compare this to the level of inhibition achieved in humans. Tumor growth inhibition was measured in mice bearing a pancreatic KP-1 tumor, dosed at 12.5–200 mg/kg over 21 days. In the phase I study, E7820 was administered daily for 28 days over a range of 0–200 mg, followed by a 7-day washout period. PK-PD models were developed in NONMEM. α2-Integrin expression measured on platelets, corresponding to tumor stasis at t = 21 in 50% and 90% of the mice (Iint,50, Iint,90) were calculated. It was evaluated if these levels of inhibition could be achieved in patients at tolerable doses. One hundred nineteen α2-Integrin measurements and 210 tumor size measurements were available from mice. The relationship between PK and α2-integrin expression was modeled using an indirect-effect model, subsequently linked to an exponential tumor growth model. Iinh,50 and Iinh,90 were 14.7% (RSE 7%) and 17.9% (RSE 8%). Four hundred sixty two α2-integrin measurements were available from 29 patients. Using the schedule of 100 mg qd (MTD), α2-integrin expression was inhibited more strongly than the Iint,50 and Iint,90 in greater than 95% and greater than 50% of patients, respectively. Moderate inhibition of α2-integrin expression corresponded to tumor stasis in mice, and similar levels could be reached in patients with the dose level of 100 mg qd

A tyrosine-rich amelogenin peptide promotes neovasculogenesis in vitro and ex vivo

H.D.A. is grateful for the financial support provided by a Dorothy Hodgkin Postgraduate Award (jointly funded by the Engineering and Physical Sciences Research Council, UK and the Institut Straumann, Switzerland) and the Research Discretionary Funds of the Periodontology Unit, UCL Eastman Dental Institute. Financial support was also provided by the NIHR Comprehensive Biomedical Research Centre, UK and the WCU Program of the National Research Foundation of Korea (NRF), funded by the Ministry of Education, Science and Technology, South Korea (No. R31-10069)

Combination of RGD Compound and Low-Dose Paclitaxel Induces Apoptosis in Human Glioblastoma Cells

) peptide, to human glioblastoma U87MG cells with combination of low dose Paclitaxel (PTX) pre-treatment to augment therapeutic activity for RGD peptide-induced apoptosis. peptide induced U87MG programmed cell death. The increased expression of PTX-induced integrin-αvβ3 was correlated with the enhanced apoptosis in U87MG cells.This study provides a novel concept of targeting integrin-αvβ3 with RGD peptides in combination with low-dose PTX pre-treatment to improve efficiency in human glioblastoma treatment

Ambient Monitoring WSNs with Harvesting-aware Power Management

Capillary wireless sensor networks dedicated to air quality monitoring have provided essential information on hazardous air condition, generating early warnings to prevent danger situation for human health. The main challenge of capillary networks is the adoption of environmentally generated energy as primary and/or unique energy source instead of the replacement of hundreds or even thousands of batteries on a regular basis that leads to high costs and practical problems of devices management. We present in this paper a battery-less, autonomous, multi-parametric sensing platform for air quality monitoring, that is harvesting energy from the surrounding environment for perpetual operation. We present a complete system design and experimental results of the evaluation of the energy harvesting section and the budget allocation of the power consumption. Moreover, the paper shows the experimental results of the studies conducted on the sensors section. A tailored calibration process for the sensors' sensitivity and a standard portfolio of different energy sources around the power recovery section could effectively enable the system to trace air quality levels in indoor and outdoor application, in a sort of set and forget scenario.Scopu