1,311 research outputs found

    Renormalization of Coulomb interactions in s-wave superconductor Nax_xCoO2_2

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    We study the renormalized Coulomb interactions due to retardation effect in Nax_xCoO2_2. Although the Morel-Anderson's pseudo potential for a1ga_{1g} orbital μa1g∗\mu^*_{a1g} is relatively large because the direct Coulomb repulsion UU is large, that for interband transition between a1ga_{1g} and eg′e_g' orbitals μa1g,eg′∗\mu^*_{a1g,eg'} is very small since the renormalization factor for pair hopping JJ is square of that for UU. Therefore, the s-wave superconductivity due to valence-band Suhl-Kondo mechanism will survive against strong Coulomb interactions. The interband hopping of Cooper pairs due to shear phonons is essential to understand the superconductivity in Nax_xCoO2_2.Comment: 2pages, 2figures, Proceedings of ICM in Kyoto, 200

    Response of Honeycomb Core Sandwich Panel with Minimum Gage GFRP Face-Sheets to Compression Loading After Impact

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    A compression after impact study has been conducted to determine the residual strength of three sandwich panel constructions with two types of thin glass fiber reinforced polymer face-sheets and two hexagonal honeycomb Nomex core densities. Impact testing is conducted to first determine the characteristics of damage resulting from various impact energy levels. Two modes of failure are found during compression after impact tests with the density of the core precipitating the failure mode present for a given specimen. A finite element analysis is presented for prediction of the residual compressive strength of the impacted specimens. The analysis includes progressive damage modeling in the face-sheets. Preliminary analysis results were similar to the experimental results; however, a higher fidelity core material model is expected to improve the correlation

    Polar catastrophe and electronic reconstructions at the LaAlO3/SrTiO3 interface: evidence from optical second harmonic generation

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    The so-called "polar catastrophe", a sudden electronic reconstruction taking place to compensate for the interfacial ionic polar discontinuity, is currently considered as a likely factor to explain the surprising conductivity of the interface between the insulators LaAlO3 and SrTiO3. We applied optical second harmonic generation, a technique that a priori can detect both mobile and localized interfacial electrons, to investigating the electronic polar reconstructions taking place at the interface. As the LaAlO3 film thickness is increased, we identify two abrupt electronic rearrangements: the first takes place at a thickness of 3 unit cells, in the insulating state; the second occurs at a thickness of 4-6 unit cells, i.e., just above the threshold for which the samples become conducting. Two possible physical scenarios behind these observations are proposed. The first is based on an electronic transfer into localized electronic states at the interface that acts as a precursor of the conductivity onset. In the second scenario, the signal variations are attributed to the strong ionic relaxations taking place in the LaAlO3 layer

    The BovMAS Consortium: investigation of bovine chromosome 14 for quantitative trait loci affecting milk production and quality traits in the Italian Holstein Friesian breed

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    Many studies have demonstrated that quantitative trait loci (QTL) can be identified and mapped in commercial dairy cattle populations using genetic markers in daughter and granddaughter designs.The final objective of these studies is to identify genes or markers that can be used in breeding schemes via marker assisted selection (MAS)

    Osteogenic potential of fast set bioceramic cements: Molecular and in vitro study

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    Recently, pre-mixed bioceramics in fast set formulations have been increasingly utilized in clinical practice as an alternative to mineral trioxide aggregate (MTA) for their shorter setting time and better handling properties. However, the impact on their osteogenic potential, due to modifications in chemical composition to promote a fast setting, is still unclear. This molecular and in vitro study compared the osteogenic potential of root repairing material putty fast set (FSP) with root-repairing material putty (RRMPU), root-repairing material paste (RRMPA), Biodentine™ and MTA. The null hypothesis tested was that there are no differences among the tricalcium silicate materials in terms of osteogenic potential. Standardized discs were cultured with MG-63 human osteoblastic-like cells to assess biocompatibility, the activity of alkaline phosphatase (ALP) and osteogenic potential. Biocompatibility was evaluated at baseline and after 24 and 48 h. Osteogenic differentiation was assessed after 15 days. Data were analyzed with one-way ANOVAs and Tukey’s post-hoc test (p < 0.05). All materials showed biocompatibility and bioactivity. ALP activity, which induces mineral nodule deposition, increased in all the cements tested, with a significant increase in RRMPU (p < 0.001) and FSP (p < 0.001) samples versus MTA. In vitro mineralization was significantly increased for RRMPU (p < 0.0001), FSP (p = 0.00012) and Biodentine™ (p < 0.0001) versus MTA. The bioceramics tested showed higher levels of biocompatibility and bioactivity than MTA; a higher capacity for mineralization was observed with RRMPU and FSP versus MTA

    2/3D imaging based on photonics-enabled multi-band MIMO radar system

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    Photonics-enabled coherent MIMO radars have been numerically investigated to evaluate the benefits of coherence and multi-band operation in 2/3D imaging

    Chemo-radiotherapy plus durvalumab for loco-regional relapse of resected NSCLC

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    Background tumor recurrence after NSCLC surgical resection is the most common cause of treatment failure that sharply reduces the patient's life expectancy. The optimal treatment strategy for loco-regional recurrences developing after surgical resection in patients with non-small-cell lung cancer (NSCLC) is not established yet. This report aims to describe the pattern of relapse, PFS, and OS in patients treated with radio-chemotherapy and durvalumab for loco-regional relapse after surgery. Methods We conducted a multicenter, retrospective study including subjects who underwent surgical resection for NSCLC and were treated with Pacific protocol after loco-regional relapse. Results Twenty-four patients met the inclusion criteria. At the time of diagnosis mean age was 65 years (range 47-78), the majority being male (58.3%). The 12-month progression-free survival rate was 68.7%, the 18-month progression-free survival rate was 45.8%, and the 24-month progression-free survival rate was 34.3%. There were three deaths: the 12-month survival rate was 91%, and the 18-month survival rate was 82.8%. Conclusions In this article, we propose a treatment strategy that might prolong post recurrence survival in patients with good performance status experiencing loco-regional relapse after surgery

    Potential for Lung Recruitment and Ventilation-Perfusion Mismatch in Patients With the Acute Respiratory Distress Syndrome From Coronavirus Disease 2019

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    OBJECTIVES: Severe cases of coronavirus disease 2019 develop the acute respiratory distress syndrome, requiring admission to the ICU. This study aimed to describe specific pathophysiological characteristics of acute respiratory distress syndrome from coronavirus disease 2019. DESIGN: Prospective crossover physiologic study. SETTING: ICU of a university-affiliated hospital from northern Italy dedicated to care of patients with confirmed diagnosis of coronavirus disease 2019. PATIENTS: Ten intubated patients with acute respiratory distress syndrome and confirmed diagnosis of coronavirus disease 2019. INTERVENTIONS: We performed a two-step positive end-expiratory pressure trial with change of 10\u2009cm H2O in random order. MEASUREMENTS AND MAIN RESULTS: At each positive end-expiratory pressure level, we assessed arterial blood gases, respiratory mechanics, ventilation inhomogeneity, and potential for lung recruitment by electrical impedance tomography. Potential for lung recruitment was assessed by the recently described recruitment to inflation ratio. In a subgroup of seven paralyzed patients, we also measured ventilation-perfusion mismatch at lower positive end-expiratory pressure by electrical impedance tomography. At higher positive end-expiratory pressure, respiratory mechanics did not change significantly: compliance remained relatively high with low driving pressure. Oxygenation and ventilation inhomogeneity improved but arterial CO2 increased despite unchanged respiratory rate and tidal volume. The recruitment to inflation ratio presented median value higher than previously reported in acute respiratory distress syndrome patients but with large variability (median, 0.79 [0.53-1.08]; range, 0.16-1.40). The FIO2 needed to obtain viable oxygenation at lower positive end-expiratory pressure was significantly correlated with the recruitment to inflation ratio (r = 0.603; p = 0.05). The ventilation-perfusion mismatch was elevated (median, 34% [32-45%] of lung units) and, in six out of seven patients, ventilated nonperfused units represented a much larger proportion than perfused nonventilated ones. CONCLUSIONS: In patients with acute respiratory distress syndrome from coronavirus disease 2019, potential for lung recruitment presents large variability, while elevated dead space fraction may be a specific pathophysiological trait. These findings may guide selection of personalized mechanical ventilation settings
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