329 research outputs found

    Design procedure based on maximum efficiency for wireless power transfer battery chargers with lightweight vehicle assembly

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    This paper analyzes two different design procedures for a series-parallel compensated WPT battery charger, based on different definitions of the operating resonant frequency in the condition of maximum link efficiency. The behaviour of the voltage gain magnitude and the input impedance angle of the resulting WPT links is studied for different loads and coupling coefficients. The design algorithms are supported by analytical formulas derived from an exact circuit analysis of the WPT link, avoiding approximations as far as possible. To support the theoretical approach a case study is proposed, in which both design procedures are implemented considering specifications in line with the actual automotive standards. To conclude, a characterization of the efficiency in both cases is derived

    Assessment of AC Corrosion Probability in Buried Pipelines with a FEM-Assisted Stochastic Approach

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    In this paper, a stochastic approach is combined with field theory and circuit methods to study how the geometrical and electrical properties of holidays (defects or pores in the insulating coating) in a metallic pipeline influence the probability of exceeding the current density limit for corrosion. Three-dimensional FEM simulations are conducted to assess the influence of the shape and electrical resistivity of the pore on the computed spread resistance value. The obtained results are then used to evaluate the probability of exceeding a given current density value for different sizes of pore and soil resistivities. Finally, a case of 50 Hz interference along a pipeline-transmission line routing is examined. The probabilistic approach presented in this paper allows the pipeline sections more subjected to the induced AC corrosion risk to be identified to be used as an auxiliary tool for adopting preventive protection countermeasures. Lastly, unlike most papers devoted to assessing electromagnetic interference on pipelines, the present work uses a probabilistic rather than a deterministic approach, representing its main novelty aspect

    Digital upgrade in the automotive supply chain in Mexico: issues and challenges

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    The ongoing digital transformation poses diverse challenges to the automotive sector. While the process of digitalisation will lead to technical and organisational changes across and within the global value chains, the ongoing changes in the trade agreements spurred by the Trump administration may change the location advantages of previous plants and their specialisations. In addition, investment in the electric car may offer first-mover advantages in markets, while requiring the re-organisation of the value chains. Mexico, ranked in 2018 as the seventh producer at world level, is an important case study for several reasons: among these, its cost advantages, its privileged access to the US market, that attracted many OEMs from Europe, Asia, the US, and its role in the prospective regionalization of world trade. By using interviews to automotive suppliers, experts and business associations of the automotive industry, the paper aims at providing a first outline on issues to be addressed in an analysis looking at how these changes are affecting opportunities for the OEMs in their value chains based in the Mexican automotive system

    X-linked heterochromatin distribution in the holocentric chromosomes of the green apple aphid Aphis pomi

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    Chromatin organization in the holocentric chromosomes of the green apple aphid Aphis pomi has been investigated at a cytological level after C-banding, NOR, Giemsa, fluorochrome staining and fluorescent in situ hybridization (FISH). C-banding technique showed that heterochromatic bands are exclusively located on X chromosomes. This data represents a peculiar feature that clearly contradicts the equilocal distribution of heterochromatin typical of monocentric chromosomes. Moreover, silver staining and FISH carried out with a 28S rDNA probe localized rDNA genes on one telomere of each X chromosome; CMA(3) staining reveals that these silver positive telomeres are, the only GC-rich regions among A. pomi heterochromatin, whereas all other C-positive bands are DAPI positive thus containing AT-rich DNA

    A new predictive technology for perinatal stem cell isolation suited for cell therapy approaches

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    The use of stem cells for regenerative applications and immunomodulatory effect is in-creasing. Amniotic epithelial cells (AECs) possess embryonic‐like proliferation ability and multipo-tent differentiation potential. Despite the simple isolation procedure, inter‐individual variability and different isolation steps can cause differences in isolation yield and cell proliferation ability, compromising reproducibility observations among centers and further applications. We investi-gated the use of a new technology as a diagnostic tool for quality control on stem cell isolation. The instrument label‐free separates cells based on their physical characteristics and, thanks to a micro-camera, generates a live fractogram, the fingerprint of the sample. Eight amniotic membranes were processed by trypsin enzymatic treatment and immediately analysed. Two types of profile were generated: a monomodal and a bimodal curve. The first one represented the unsuccessful isolation with all recovered cell not attaching to the plate; while for the second type, the isolation process was successful, but we discovered that only cells in the second peak were alive and resulted adherent. We optimized a Quality Control (QC) method to define the success of AEC isolation using the frac-togram generated. This predictive outcome is an interesting tool for laboratories and cell banks that isolate and cryopreserve fetal annex stem cells for research and future clinical applications

    High Doses of Ursodeoxycholic Acid Up-Regulate the Expression of Placental Breast Cancer Resistance Protein in Patients Affected by Intrahepatic Cholestasis of Pregnancy

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    BACKGROUND: Ursodeoxycholic acid (UDCA) administration in intrahepatic cholestasis of pregnancy (ICP) induces bile acids (BA) efflux from the foetal compartment, but the molecular basis of this transplacental transport is only partially defined. AIM: To determine if placental breast cancer resistance protein (BCRP), able to transport BA, is regulated by UDCA in ICP. METHODS: 32 pregnant women with ICP (14 untreated, 34.9\ub15.17 years; 18 treated with UDCA--25 mg/Kg/day, 32.7\ub14.62 years,) and 12 healthy controls (33.4\ub13.32 years) agreed to participate in the study. Placentas were obtained at delivery and processed for membrane extraction. BCRP protein expression was evaluated by immunoblotting techniques and chemiluminescence quantified with a luminograph measuring emitted photons; mRNA expression with real time PCR. Statistical differences between groups were evaluated by ANOVA with Dunn's Multiple Comparison test. RESULTS: BCRP was expressed only on the apical membrane of the syncytiotrophoblast. A significant difference was observed among the three groups both for mRNA (ANOVA, p\u200a=\u200a0.0074) and protein (ANOVA, p<0.0001) expression. BCRP expression was similar in controls and in the untreated ICP group. UDCA induced a significant increase in placental BCRP mRNA and protein expression compared to controls (350.7\ub1106.3 vs 100\ub118.68% of controls, p<0.05 and 397.8\ub156.02 vs 100\ub111.44% of controls, p<0.001, respectively) and untreated ICP (90.29\ub117.59% of controls, p<0.05 and 155.0\ub113.87%, p<0.01). CONCLUSION: Our results confirm that BCRP is expressed only on the apical membrane of the syncytiotrophoblast and show that ICP treatment with high dose UDCA significantly upregulates placental BCRP expression favouring BA efflux from the foetal compartment

    Neurodevelopmental outcomes of very preterm infants born following early foetal growth restriction with absent end-diastolic umbilical flow

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    This study aims to assess the impact of time of onset and features of early foetal growth restriction (FGR) with absent end-diastolic flow (AEDF) on pregnancy outcomes and on preterm infants' clinical and neurodevelopmental outcomes up to 2 years corrected age. This is a retrospective, cohort study led at a level IV Obstetric and Neonatal Unit in Bologna, Italy. Pregnant women were eligible if having singleton pregnancies, with no major foetal anomaly detected, and diagnosed with early FGR + AEDF (defined as FGR + AEDF detected before 32 weeks gestation). Early FGR + AEDF was further classified according to time of onset and specific features into very early and persistent (VEP, FGR + AEDF first detected at 20-24 weeks gestation and persistent at the following scans), very early but transient (VET, FGR + AEDF detected at 20-24 weeks gestation and progressively improving at the following scans) and later (LA, FGR + AEDF detected between 25 and 32 weeks gestation). Pregnancy and neonatal outcomes and infant follow-up data were collected and compared among groups. Neurodevelopment was assessed using the revised Griffiths Mental Developmental Scales (GMDS-R) 0-2 years. A regression analysis was performed to identify early predictors of preterm infants' neurodevelopmental impairment. Fifty-two pregnant women with an antenatal diagnosis of early FGR + AEDF were included in the study (16 VEP, 14 VET, 22 LA). Four intrauterine foetal deaths occurred, all in the VEP group (p = 0.010). Compared to LA infants, VEP infants were born with lower gestational age and lower birth weight, had lower arterial cord blood pH and were at higher risk for intraventricular haemorrhage and periventricular leukomalacia (p &lt; 0.05 for all comparisons). At 12 months, VEP infants had worse GMDS-R scores, both in the general quotient (mean [SD] 91.8 [12.4] vs 104.6 [8.7] in LA) and in the performance domain (mean [SD] 93.3 [15.4] vs 108.8 [8.8] in LA). This latter difference persisted at 24 months (mean [SD] 68.3 [17.0] vs 92.9 [17.7] in LA). In multivariate analysis, at 12 months corrected age, PVL was found to be an independent predictor of impaired general quotient, while the features and timing of antenatal Doppler alterations predicted worse scores in the performance domain.Conclusion: Timing of onset and features of early FGR + AEDF might impact differently on neonatal clinical and neurodevelopmental outcomes. Shared awareness of the importance of FGR + AEDF features between obstetricians and neonatologists may offer valuable tools for antenatal counselling and for tailoring pregnancy management and neonatal follow-up in light of specific antenatal and neonatal risk factors

    Valutazione dell’esposizione a sostanze chimiche: il ruolo del monitoraggio biologico in lavoratori esposti a TCE.

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    L’obiettivo di questo studio era esaminare i profili di un gruppo di lavoratori di un reparto di manutenzione di un’industria aeronautica espostio a tricloroetilene (TCE) dopo il 2001/59/ce ed il DL n. 197 06/14/2002, e di verificare l’utilità e la validità del monitoraggio biologico come fattore determinante per la sicurezza degli operatori

    Pregnancy Loss in Women with HIV is not Associated with HIV Markers: Data from a National Study in Italy, 2001-2018.

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    BACKGROUND: There is limited information on pregnancy loss in women with HIV, and it is still debated whether HIV-related markers may play a role.Objectives: To explore potential risk factors for pregnancy loss in women with HIV, with particular reference to modifiable risk factors and markers of HIV disease. METHODS: Multicenter observational study of HIV-positive pregnant women. The main outcome measure was pregnancy loss, including both miscarriage (&lt;22 weeks) and stillbirth ( 6522 weeks). Possible associations of pregnancy loss were evaluated in univariate and multivariate analyses. RESULTS: Among 2696 eligible pregnancies reported between 2001 and 2018, 226 (8.4%) ended in pregnancy loss (miscarriage 198, 7.3%; stillbirth 28, 1.0%). In multivariate analyses, only older age (adjusted odds ratio [AOR] per additional year of age: 1.079, 95% confidence interval [CI] 1.046-1.113), HIV diagnosis before pregnancy (AOR: 2.533, 95%CI 1.407-4.561) and history of pregnancy loss (AOR: 1.625, 95%CI 1.178-2.243) were significantly associated with pregnancy loss. No significant association with pregnancy loss was found for parity, coinfections, sexually transmitted diseases, hypertension, smoking, alcohol and substance use, CD4 cell count, HIV-RNA viral load, and CDC HIV stage. CONCLUSIONS: Older women and those with a previous history of pregnancy loss should be considered at higher risk of pregnancy loss. The severity of HIV disease and potentially modifiable risk factors did not increase the risk of pregnancy loss
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