119 research outputs found

    On border traps in back-side-illuminated CMOS image sensor oxides

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    CMOS image sensors (CISs) in back-side-illuminated configuration consist of photodiode arrays having metal lines and drive electronics beneath the active region with respect to the device/air interface so that the light reaches the photodiode active region directly. This enhances sensor quantum efficiency but reduces the electrical performance and reliability. The back-side configuration is realized by flipping the wafer upside down, bonding it to a handling wafer, mechanically thinning it, and opening a through-silicon via with a long plasma etch. As a result, gate oxides in back-side CISs show an increased density of donor-like border traps with respect to the conventional front-side-illuminated sensors. In this article, we try to add some information toward the comprehension of the origin and the electrical nature of those traps in back-side gate oxides. To this aim, we performed negative bias temperature instability stress on p-channel MOSFETs during which the traps were filled by holes tunneling from the substrate and then studied the relaxation transients of the drain current after the stress was removed. The characteristic emission times of a few specific levels were obtained at different temperatures. This allowed us to extract values of the trap activation energies, which resulted coherent with hole-capturing E′ donor-like centers (trivalent silicon dangling bonds) commonly attributed to ionizing radiation

    Beneficial Effects of Polydeoxyribonucleotide (PDRN) in an In Vitro Model of Fuchs Endothelial Corneal Dystrophy

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    Fuchs endothelial corneal dystrophy (FECD) is a bilateral, hereditary syndrome characterized by progressive irreversible injury in the corneal endothelium; it is the most frequent cause for corneal transplantation worldwide. Oxidative stress induces the apoptosis of corneal endothelial cells (CECs), and has a crucial function in FECD pathogenesis. The stimulation of the adenosine A2A receptor (A2Ar) inhibits oxidative stress, reduces inflammation and modulates apoptosis. Poly-deoxyribonucleotide (PDRN) is a registered drug that acts through adenosine A2Ar. Thus, the goal of this study was to assess the effect of PDRN in an in vitro FECD model. Human Corneal Endothelial Cells (IHCE) were challenged with H2O2 (200 µM) alone or in combination with PDRN (100 µg/mL), PDRN plus ZM241385 (1 µM) as an A2Ar antagonist, and CGS21680 (1 µM) as a well-known A2Ar agonist. H2O2 reduced the cells’ viability and increased the expression of the pro-inflammatory markers NF-κB, IL-6, IL-1β, and TNF-α; by contrast, it decreased the expression of the anti-inflammatory IL-10. Moreover, the pro-apoptotic genes Bax, Caspase-3 and Caspase-8 were concurrently upregulated with a decrease of Bcl-2 expression. PDRN and CGS21680 reverted the negative effects of H2O2. Co-incubation with ZM241385 abolished the effects of PDRN, indicating that A2Ar is involved in the mode of action of PDRN. These data suggest that PDRN defends IHCE cells against H2O2-induced damage, potentially as a result of its antioxidant, anti-inflammatory and antiapoptotic properties, suggesting that PDRN could be used as an FECD therapy

    A machine learning-based approach to optimize repair and increase yield of embedded flash memories in automotive systems-on-chip

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    Nowadays, Embedded Flash Memory cores occupy a significant portion of Automotive Systems-on-Chip area, therefore strongly contributing to the final yield of the devices. Redundancy strategies play a key role in this context; in case of memory failures, a set of spare word- and bit-lines are allocated by a replacement algorithm that complements the memory testing procedure. In this work, we show that replacement algorithms, which are heavily constrained in terms of execution time, may be slightly inaccurate and lead to classify a repairable memory core as unrepairable. We denote this situation as Flash memory false fail. The proposed approach aims at identifying false fails by using a Machine Learning approach that exploits a feature extraction strategy based on shape recognition. Experimental results carried out on the manufacturing data show a high capability of predicting false fails

    Beta-Blocker Use in Older Hospitalized Patients Affected by Heart Failure and Chronic Obstructive Pulmonary Disease: An Italian Survey From the REPOSI Register

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    Beta (β)-blockers (BB) are useful in reducing morbidity and mortality in patients with heart failure (HF) and concomitant chronic obstructive pulmonary disease (COPD). Nevertheless, the use of BBs could induce bronchoconstriction due to β2-blockade. For this reason, both the ESC and GOLD guidelines strongly suggest the use of selective β1-BB in patients with HF and COPD. However, low adherence to guidelines was observed in multiple clinical settings. The aim of the study was to investigate the BBs use in older patients affected by HF and COPD, recorded in the REPOSI register. Of 942 patients affected by HF, 47.1% were treated with BBs. The use of BBs was significantly lower in patients with HF and COPD than in patients affected by HF alone, both at admission and at discharge (admission, 36.9% vs. 51.3%; discharge, 38.0% vs. 51.7%). In addition, no further BB users were found at discharge. The probability to being treated with a BB was significantly lower in patients with HF also affected by COPD (adj. OR, 95% CI: 0.50, 0.37–0.67), while the diagnosis of COPD was not associated with the choice of selective β1-BB (adj. OR, 95% CI: 1.33, 0.76–2.34). Despite clear recommendations by clinical guidelines, a significant underuse of BBs was also observed after hospital discharge. In COPD affected patients, physicians unreasonably reject BBs use, rather than choosing a β1-BB. The expected improvement of the BB prescriptions after hospitalization was not observed. A multidisciplinary approach among hospital physicians, general practitioners, and pharmacologists should be carried out for better drug management and adherence to guideline recommendations

    Directional control of weakly localized Raman from a random network of fractal nanowires

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    Disordered optical media are an emerging class of materials capable of strongly scattering light. Their study is relevant to investigate transport phenomena and for applications in imaging, sensing and energy storage. While such materials can be used to generate coherent light, their directional emission is typically hampered by their very multiple scattering nature. Here, we tune the out-of-plane directionality of coherent Raman light scattered by a fractal network of silicon nanowires. By visualizing Rayleigh scattering, photoluminescence and weakly localized Raman light from the random network of nanowires via real-space microscopy and Fourier imaging, we gain insight on the light transport mechanisms responsible for the material's inelastic coherent signal and for its directionality. The possibility of visualizing and manipulating directional coherent light in such networks of nanowires opens venues for fundamental studies of light propagation in disordered media as well as for the development of next generation optical devices based on disordered structures, inclusive of sensors, light sources and optical switches

    Multicenter Experience Using Total Lymphoid Irradiation and Antithymocyte Globulin as Conditioning for Allografting in Hematological Malignancies

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    A non myeloablative conditioning with total lymphoid irradiation (TLI) and antithymocyte globulin (ATG) was shown to protect against graft-versus-host disease (GVHD). To evaluate the effects of TLI-ATG in a multicenter study, 45 heavily pretreated patients, median age 51, with lymphoid (n = 38) and myeloid (n = 7) malignancies were enrolled at 9 centers. Twenty-eight patients (62%) received at least 3 lines of treatment before allografting, and 13 (29%) had refractory/relapsed disease at the time of transplantation. Peripheral blood hematopoietic cells were from HLA identical sibling (n = 30), HLA-matched (n = 9), or 1 antigen HLA-mismatched (n = 6) unrelated donors. A cumulative TLI dose of 8 Gy was administered from day -11 through -1 with ATG at the dose of 1.5 mg/kg/day (from day -11 through -7). GVHD prophylaxis consisted of cyclosporine and mycophenolate mofetil. Donor engraftment was reached in 95% of patients. Grade II to IV acute GVHD (aGVHD) developed in 6 patients (13.3%), and in 2 of these patients, it developed beyond day 100. Incidence of chronic GVHD (cGVHD) was 35.8%. One-year nonrelapse mortality was 9.1%. After a median follow-up of 28 months (range, 3-57 months) from transplantation, median overall survival was not reached, whereas median event-free survival was 20 months. This multicenter experience confirms that TLI-ATG protects against GVHD and maintains graft-vs-tumor effects

    Incidence and Outcome of Invasive Fungal Diseases after Allogeneic Stem Cell Transplantation: A Prospective Study of the Gruppo Italiano Trapianto Midollo Osseo (GITMO).

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    AbstractEpidemiologic investigation of invasive fungal diseases (IFDs) in allogeneic hematopoietic stem cell transplantation (allo-HSCT) may be useful to identify subpopulations who might benefit from targeted treatment strategies. The Gruppo Italiano Trapianto Midollo Osseo (GITMO) prospectively registered data on 1858 consecutive patients undergoing allo-HSCT between 2008 and 2010. Logistic regression analysis was performed to identify risk factors for proven/probable IFD (PP-IFD) during the early (days 0 to 40), late (days 41 to 100), and very late (days 101 to 365) phases after allo-HSCT and to evaluate the impact of PP-IFDs on 1-year overall survival. The cumulative incidence of PP-IFDs was 5.1% at 40 days, 6.7% at 100 days, and 8.8% at 12 months post-transplantation. Multivariate analysis identified the following variables as associated with PP-IFDs: transplant from an unrelated volunteer donor or cord blood, active acute leukemia at the time of transplantation, and an IFD before transplantation in the early phase; transplant from an unrelated volunteer donor or cord blood and grade II-IV acute graft-versus-host disease (GVHD) in the late phase; and grade II-IV acute GVHD and extensive chronic GVHD in the very late phase. The risk for PP-IFD was significantly higher when acute GVHD was followed by chronic GVHD and when acute GVHD occurred in patients undergoing transplantation with grafts from other than matched related donors. The presence of PP-IFD was an independent factor in long-term survival (hazard ratio, 2.90; 95% confidence interval, 2.32 to 3.62; P < .0001). Our findings indicate that tailored prevention strategies may be useful in subpopulations at differing levels of risk for PP-IFDs
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