Self-organisation of molecular nanostructures triggered by atomic force microscopy

Scanning probe microscopy are an extraordinary tools for surfaces characterization at nano and atomic scale and also for nanofabrication whose major limitation depends on the serial nature of the related techniques. Here we propose an interesting approach applied to a supramolecular system (rotaxane) that contributes to overcome this limitation. When a local mechanical perturbation is applied to the surface of a thin film of a rotaxane, the molecules self-organize into periodic arrays of discrete dots or lines. The dimensionality of the nanostructures depends on whether the mechanical stimulus acts along a 1D line or over a 2D area. The size and periodicity of the patterns are controlled solely by the film thickness. The phenomenon can be exploited as a new bottom-up nanofabrication method

Numerical test of the Schoemberg-Muir theory

The Schoenberg-Muir theory states that an equivalent, homogeneous and anisotropic medium can be constructed from a layered medium composed of several thin layers, each anisotropic, under the assumption of stationarity. To test the theory we considered single transversely isotropic layers with different orientations of the symmetry axis and performed numerical simulations of wave propagation with a full-wave solver. The equivalent media have orthorhombic and monoclinic symmetries, respectively. The theory performed very well from the kinematical and dynamical points of view, even for strong anisotropy and layers described by media whose symmetry axes have different orientations.Fil: Carcione, José M.. Istituto Nazionale di Oceanografia e di Geofisica Sperimentale; ItaliaFil: Picotti, Stefano. Istituto Nazionale di Oceanografia e di Geofisica Sperimentale; ItaliaFil: Cavallini, Fabio. Istituto Nazionale di Oceanografia e di Geofisica Sperimentale; ItaliaFil: Santos, Juan Enrique. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto del Gas y del Petróleo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Partial Discharges in Electrical Machines for the More Electric Aircraft—Part I: A Comprehensive Modeling Tool for the Characterization of Electric Drives Based on Fast Switching Semiconductors

This paper proposed a modelling approach for the comprehensive analysis of high-frequency challenges in electrical drives designed for aerospace applications, in particular the overvoltage at the machine terminals and the voltage distribution within windings. After a separate description of the models for the estimation of these insulation stress sources, the combined model was detailed. The main benefit of developing a combined, flexible and comprehensive tool is that both overvoltage at machine terminals and uneven voltage distribution can be calculated simultaneously, without neglecting the voltage overshoot when estimating the voltage distribution (and vice versa). In fact, an accurate calculation of the terminal overvoltage is necessary to provide a good estimation of the voltage within winding turns since its waveform shape can be quite different with respect to the converter output, even with cables of a few meters. A case study based on a real aerospace application was considered to investigate the model validity and accuracy. Experimental results were performed on a complete system comprising a SiC-based converter, a connecting cable and a machine stator, proving the simulation model accuracy in terms of peak voltages of both the line-to-line terminal voltage and the turn voltage distribution across the first turns, which are the most relevant quantities for the sake of this study as well as for the investigations of the subsequent companion papers. In the forthcoming papers, the effects of different rise times and cable lengths on the inception of partial discharges will be investigated through fast parametric simulation carried out using the proposed combined model. The feasibility of using conventional insulation systems for aircraft applications using SiC drives fed by a ±270 V DC bus voltage will be discussed, with the aim of signaling and finding solutions to improve the overall reliability

The effects of chronic lifelong activation of the AHR pathway by industrial chemical pollutants on female human reproduction

Environmental chemicals, such as heavy metals, affect female reproductive function. A biological sensor of the signals of many toxic chemical compounds seems to be the aryl hydrocarbon receptor (AHR). Previous studies demonstrated the environmental of heavy metals in Taranto city (Italy), an area that has been influenced by anthropogenic factors such as industrial activities and waste treatments since 1986. However, the impact of these elements on female fertility in this geographic area has never been analyzed. Thus, in the present study, we evaluated the AHR pathway, sex steroid receptor pattern and apoptotic process in granulosa cells (GCs) retrieved from 30 women, born and living in Taranto, and 30 women who are living in non-contaminated areas (control group), who were undergoing in vitro fertilization (IVF) protocol. In follicular fluids (FFs) of both groups the toxic and essential heavy metals, such as chromiun (Cr), Manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), cadmium (Cd) and lead (Pb), were also analyzed. Higher levels of Cr, Fe, Zn and Pb were found in the FFs of the women from Taranto as compared to the control group, as were the levels of AHR and AHR-dependent cytochrome P450 1A1 and 1B1; while CYP19A1 expression was decreased. The anti-apoptotic process found in the GCs of women fromTaranto was associated with the highest levels of progesterone receptor membrane component 1(PGRMC1), a novel progesterone receptor, the expression of which is subjected to AHR activated by its highest affinity ligands (e.g., dioxins) or indirectly by other environmental pollutants, such as heavy metals. In conclusion, decreased production of estradiol and decreased number of retrieved mature oocytes found in women from Taranto could be due to chronic exposure to heavy metals, in particular to Cr and Pb

Electrocardiography for diagnosis of left ventricular hypertrophy in hypertensive patients with atrial fibrillation

Abstract Left ventricular (LV) hypertrophy at electrocardiography (ECG) predicts incident atrial fibrillation (AF). However, the diagnostic performance of ECG for diagnosis of LV hypertrophy in patients with AF is still not well characterized. We analyzed 563 hypertensive patients enrolled in the Umbria-Atrial Fibrillation (Umbria-FA) registry, an ongoing prospective observational registry in patients with AF. All patients underwent ECG and standard echocardiography at their entry in the Register. Mean age was 74 years and 43% of patients were women. Prevalence of ECG-LV hypertrophy, defined by Perugia criterion corrected for body mass index, was 23%. Echocardiographic LV mass was the reference standard. Sensitivity, specificity and diagnostic accuracy of ECG-LV hypertrophy were 37.4% (95% confidence interval [CI]: 31.6–43.4), 90.0% (95% CI: 86.0–93.2) and 64.5% (95% CI: 60.4–68.3), respectively. Performance was comparable in patients with AF or sinus rhythm at ECG recording. The area under the receiver-operating characteristic (ROC) curve was 0.622 (95% CI: 0.580–0.664) in the group with AF and 0.662 (95% CI: 0.605–0.720) in that with sinus rhythm (p = 0.266 for comparison). These data suggest that standard ECG is reliable for diagnosis of LV hypertrophy in patients with a history of AF, regardless of the presence of AF or sinus rhythm at the time of ECG recording

Decision-making competence in younger and older adults: which cognitive abilities contribute to the application of decision rules?

Older adults perform worse than younger adults when applying decision rules to choose between options that vary along multiple attributes. Although previous studies have shown that general fluid cognitive abilities contribute to the accurate application of decision rules, relatively little is known about which specific cognitive abilities play the most important role. We examined the independent roles of working memory, verbal fluency, semantic knowledge, and components of executive functioning. We found that age-related decline in applying decision rules was statistically mediated by age-related decline in working memory and verbal fluency. Our results have implications for theories of aging and decision-making

Information Storage Using Supramolecular Surface Patterns

Non

Continuous monitoring of Naproxen by a cytochrome P450-based electrochemical sensor

This paper reports the characterization of an electrochemical biosensor for the continuous monitoring of Naproxen based on cytochrome P450. The electrochemical biosensor is based on the drop-casting of multi-walled carbon-nanotubes (MWCNTs) and microsomal cytochrome P4501A2 (msCYP1A2) on a graphite screen-printed electrode (SPE). The proposed biosensor was employed to monitor Naproxen (NAP), a well-known anti-inflammatory compound, through cyclic voltammetry. The dynamic linear range for the amperometric detection of NAP had an upper limit of 300 µM with a corresponding limit of detection (LOD) of 16±1 µM (S/N=3), which is included in NAP physiological range (9–300 µM). The MWCNT/msCYP1A2-SPE sensor was also calibrated for NAP detection in mouse serum that was previously extracted from mice, showing a slightly higher LOD (33±18 µM). The stability of the msCYP1A2-based biosensor was assessed by longtime continuous cyclic voltammetric measurements. The ability of the sensor to monitor drug delivery was investigated by using a commercial micro-osmotic pump. Results show that the MWCNT/msCYP1A2-SPE sensor is capable of precisely monitoring the real-time delivery of NAP for 16 h. This work proves that the proposed electrochemical sensor might represent an innovative point-of-care solution for the personalization of drug therapies, as well as for pharmacokinetic studies in both animals and humans

Primary cutaneous plasmacytoma after rejection of a transplanted kidney: case report and review of the literature.

Immunosuppressed organ allograft recipients are at risk of developing lymphomas and lymphoproliferative disorders as a consequence of immunosuppressive therapy and long-term antigenic stimulation from both the graft and possible viral infections. No more than 4% of the malignant tumors detected in organ recipients are plasmacytomas. Primary cutaneous plasmacytoma is a rare type of cutaneous B-cell lymphoma arising primarily in the skin. It is derived from clonally expanded plasma cells with various degrees of maturation and atypia. We report the occurrence of a solitary cutaneous plasmacytoma in a 56-year-old male patient undergoing hemodialysis after rejection of a grafted kidney. The diagnosis was made a few months after the kidney had been surgically removed. A thorough examination showed no evidence of systemic disease. Skin lesions were successfully treated with local radiotherapy. After 2 years of follow-up there were no local or systemic recurrences

Hyaluronan mixed esters of butyric and retinoic acid drive cardiac and endothelial fate in term placenta human mesenchymal stem cells and enhance cardiac repair in infarcted rat hearts.

We have developed a mixed ester of hyaluronan with butyric and retinoic acid (HBR) that acted as a novel cardiogenic/vasculogenic agent in human mesenchymal stem cells isolated from bone marrow, dental pulp, and fetal membranes of term placenta (FMhMSCs). HBR remarkably enhanced vascular endothelial growth factor (VEGF), KDR, and hepatocyte growth factor (HGF) gene expression and the secretion of the angiogenic, mitogenic, and antiapoptotic factors VEGF and HGF, priming stem cell differentiation into endothelial cells. HBR also increased the transcription of the cardiac lineage-promoting genes GATA-4 and Nkx-2.5 and the yield of cardiac markerexpressing cells. These responses were notably more pronounced in FMhMSCs. FMhMSC transplantation into infarcted rat hearts was associated with increased capillary density, normalization of left ventricular function, and significant decrease in scar tissue. Transplantation of HBR-preconditioned FMhM-SCs further enhanced capillary density and the yield of human vWF-expressing cells, additionally decreasing the infarct size. Some engrafted, HBR-pretreated FMhMSCs were also positive for connexin 43 and cardiac troponin I. Thus, the beneficial effects of HBR-exposed FMhMSCs may be mediated by a large supply of angiogenic and antiapoptotic factors, and FMhMSC differentiation into vascular cells. These findings may contribute to further development in cell therapy of heart failure