916 research outputs found
Optical conductivity of CuO_2 infinite-layer films
The infrared conductivity of CaCuO_2, SrCuO_{2-y}, and
Sr_{0.85}Nd_{0.15}CuO_2 infinite-layer films is obtained from reflectivity
measurements by taking into account the substrate contribution. SrCuO_{2-y} and
Sr_{0.85}Nd_{0.15}CuO_2 exhibit extra-phonon modes and structured bands in the
midinfrared, not found in stoichiometric CaCuO_2. These features mirror those
observed in the perovskitic cuprates, thus showing that the polaronic
properties of high-T_c superconductors are intrinsic to the CuO_2 planes.Comment: File latex, 5 p. incl. 4 fig. in epsf. Submitted to Solid State Com
Ricerca su possibili influenze dei fenomeni climatici ed ambientali quali fattori determinanti l'assottigliamento delle popolazioni apistiche mondiali
A methodology for the capture and analysis of hybrid data: a case study of program debugging
No description supplie
The Crc global regulator binds to an unpaired A-rich motif at the Pseudomonas putida alkS mRNA coding sequence and inhibits translation initiation
Crc is a key global translational regulator in Pseudomonads that orchestrates the hierarchy of induction of several catabolic pathways for amino acids, sugars, hydrocarbons or aromatic compounds. In the presence of amino acids, which are preferred carbon sources, Crc inhibits translation of the Pseudomonas putida alkS and benR mRNAs, which code for transcriptional regulators of genes required to assimilate alkanes (hydrocarbons) and benzoate (an aromatic compound), respectively. Crc binds to the 5′-end of these mRNAs, but the sequence and/or structure recognized, and the way in which it inhibits translation, were unknown. We have determined the secondary structure of the alkS mRNA 5′-end through its sensitivity to several ribonucleases and chemical reagents. Footprinting and band-shift assays using variant alkS mRNAs have shown that Crc specifically binds to a short unpaired A-rich sequence located adjacent to the alkS AUG start codon. This interaction is stable enough to prevent formation of the translational initiation complex. A similar Crc-binding site was localized at benR mRNA, upstream of the Shine–Dalgarno sequence. This allowed predicting binding sites at other Crc-regulated genes, deriving a consensus sequence that will help to validate new Crc targets and to discriminate between direct and indirect effects of this regulator
Robotic Versus Open Kidney Transplantation from Deceased Donors : A Prospective Observational Study
Background: While robot-assisted kidney transplantation (RAKT) from living donors has been shown to achieve favourable outcomes, there is a lack of evidence on the safety and efficacy of RAKT as compared with the gold standard open kidney transplantation (OKT) in the setting of deceased donors, who represent the source of most grafts worldwide. Objective: To compare the intraoperative, perioperative, and midterm outcomes of RAKT versus OKT from donors after brain death (DBDs). Design, setting, and participants: Data from consecutive patients undergoing RAKT or OKT from DBDs at a single academic centre between October 2017 and December 2020 were prospectively collected. Intervention: RAKT or OKT. Outcome measurements and statistical analysis: The primary outcomes were intraoperative adverse events, postoperative surgical complications, delayed graft function (DGF), and midterm functional outcomes. A multivariable logistic regression analysis assessed the independent predictors of DGF, trifecta, and suboptimal graft function (estimated glomerular filtration rate [eGFR] <45 ml/min/1.73 m) at the last follow-up. Results and limitations: Overall, 138 patients were included (117 [84.7%] OKTs and 21 [15.3%] RAKTs). The yearly proportion of RAKT ranged between 10% and 18% during the study period. The OKT and RAKT cohorts were comparable regarding all graft-related characteristics, while they differed regarding a few donor- and recipient-related factors. The median second warm ischaemic time, ureterovesical anastomosis time, postoperative complication rate, and eGFR trajectories did not differ significantly between the groups. A higher proportion of patients undergoing OKT experienced DGF; yet, at a median follow-up of 31 mo (interquartile range 19-44), there was no difference between the groups regarding the dialysis-free and overall survival. At the multivariable analysis, donor- and/or recipient-related factors, but not the surgical approach, were independent predictors of DGF, trifecta, and suboptimal graft function at the last follow-up. The study is limited by its nonrandomised nature and the small sample size. Conclusions: Our study provides preliminary evidence supporting the noninferiority of RAKT from DBDs as compared with the gold standard OKT in carefully selected recipients. Patient summary: Kidney transplantation using kidneys from deceased donors is still being performed with an open surgical approach in most transplant centres worldwide. In fact, no study has compared the outcomes of open and minimally invasive (robotic) kidney transplantation from deceased donors. In this study, we evaluated whether robotic kidney transplantation using grafts from deceased donors was not inferior to open kidney transplantation regarding the intraoperative, postoperative, and midterm functional outcomes. We found that, in experienced hands and provided that there was a time-efficient organisation of the transplantation pathway, robotic kidney transplantation from deceased donors was feasible and achieved noninferior outcomes as compared with open kidney transplantation
Development of a multiplex microsphere immunoassay for the detection of antibodies against highly pathogenic viruses in human and animal serum samples
Surveillance of highly pathogenic viruses circulating in both human and animal populations is crucial to unveil endemic infections and potential zoonotic reservoirs. Monitoring the burden of disease by serological assay could be used as an early warning system for imminent outbreaks as an increased seroprevalance often precedes larger outbreaks. However, the multitude of highly pathogenic viruses necessitates the need to identify specific antibodies against several targets from both humans as well as from potential reservoir animals such as bats. In order to address this, we have developed a broadly reactive multiplex microsphere immunoassay (MMIA) for the detection of antibodies against several highly pathogenic viruses from both humans and animals. To this aim, nucleoproteins (NP) of Ebola virus (EBOV), Marburg virus (MARV) and nucleocapsid proteins (NP) of Crimean-Congo haemorrhagic fever virus, Rift Valley fever virus and Dobrava-Belgrade hantavirus were employed in a 5-plex assay for IgG detection. After optimisation, specific binding to each respective NP was shown by testing sera from humans and non-human primates with known infection status. The usefulness of our assay for serosurveillance was shown by determining the immune response against the NP antigens in a panel of 129 human serum samples collected in Guinea between 2011 and 2012 in comparison to a panel of 88 sera from the German blood bank. We found good agreement between our MMIA and commercial or in-house reference methods by ELISA or IIFT with statistically significant higher binding to both EBOV NP and MARV NP coupled microspheres in the Guinea panel. Finally, the MMIA was successfully adapted to detect antibodies from bats that had been inoculated with EBOV- and MARV- virus-like particles, highlighting the versatility of this technique and potentially enabling the monitoring of wildlife as well as human populations with this assay. We were thus able to develop and validate a sensitive and broadly reactive high-throughput serological assay which could be used as a screening tool to detect antibodies against several highly pathogenic viruses
Hypoxia-resistant profile implies vulnerability of cancer stem cells to physiological agents, which suggests new therapeutic targets.
Image resampling and discretization effect on the estimate of myocardial radiomic features from T1 and T2 mapping in hypertrophic cardiomyopathy
Radiomics is emerging as a promising and useful tool in cardiac magnetic resonance (CMR) imaging applications. Accordingly, the purpose of this study was to investigate, for the first time, the effect of image resampling/discretization and filtering on radiomic features estimation from quantitative CMR T1 and T2 mapping. Specifically, T1 and T2 maps of 26 patients with hypertrophic cardiomyopathy (HCM) were used to estimate 98 radiomic features for 7 different resampling voxel sizes (at fixed bin width), 9 different bin widths (at fixed resampling voxel size), and 7 different spatial filters (at fixed resampling voxel size/bin width). While we found a remarkable dependence of myocardial radiomic features from T1 and T2 mapping on image filters, many radiomic features showed a limited sensitivity to resampling voxel size/bin width, in terms of intraclass correlation coefficient (> 0.75) and coefficient of variation (< 30%). The estimate of most textural radiomic features showed a linear significant (p < 0.05) correlation with resampling voxel size/bin width. Overall, radiomic features from T2 maps have proven to be less sensitive to image preprocessing than those from T1 maps, especially when varying bin width. Our results might corroborate the potential of radiomics from T1/T2 mapping in HCM and hopefully in other myocardial diseases
Bimetallic Ru-Au catalysts: Effect of the support
Ru-Au catalysts supported on SiO2 were characterized by using H2 and O2 chemisorption, wide-angle X-ray scattering, diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. Catalytic activity was measured for the hydrogenolysis of propane and ethane. The hydrogenolysis activity of ruthenium decreased by two orders of magnitude with addition of gold. This suggested that Ru and Au did not exist as separate particles but formed bimetallic aggregates. Chemisorption and XPS experiments showed a surface composition similar to the bulk. A comparison was made with a previously studied Ru-Au-on-MgO system, on which an enrichment of Ru on the surface of bimetallic Ru-Au clusters was discovered. It is suggested that the strength of the metal-support interaction can affect the surface composition of multimetallic supported systems.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24360/1/0000629.pd
Prediction of the information processing speed performance in multiple sclerosis using a machine learning approach in a large multicenter magnetic resonance imaging data set
Many patients with multiple sclerosis (MS) experience information processing speed (IPS) deficits, and the Symbol Digit Modalities Test (SDMT) has been recommended as a valid screening test. Magnetic resonance imaging (MRI) has markedly improved the understanding of the mechanisms associated with cognitive deficits in MS. However, which structural MRI markers are the most closely related to cognitive performance is still unclear. We used the multicenter 3T-MRI data set of the Italian Neuroimaging Network Initiative to extract multimodal data (i.e., demographic, clinical, neuropsychological, and structural MRIs) of 540 MS patients. We aimed to assess, through machine learning techniques, the contribution of brain MRI structural volumes in the prediction of IPS deficits when combined with demographic and clinical features. We trained and tested the eXtreme Gradient Boosting (XGBoost) model following a rigorous validation scheme to obtain reliable generalization performance. We carried out a classification and a regression task based on SDMT scores feeding each model with different combinations of features. For the classification task, the model trained with thalamus, cortical gray matter, hippocampus, and lesions volumes achieved an area under the receiver operating characteristic curve of 0.74. For the regression task, the model trained with cortical gray matter and thalamus volumes, EDSS, nucleus accumbens, lesions, and putamen volumes, and age reached a mean absolute error of 0.95. In conclusion, our results confirmed that damage to cortical gray matter and relevant deep and archaic gray matter structures, such as the thalamus and hippocampus, is among the most relevant predictors of cognitive performance in MS
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