Plasma-based methods were used to graft nitrogen atoms to the hexagonal lattice of vertically aligned carbon nanotubes (v-CNTs). The nitrogen grafting (as pyridinic, pyrrolic and graphitic) was ...mediated by the creation of defects induced by energetic species present in the nitrogen plasma. We investigated the effect of adding nitrogen atoms via plasma treatment on the electronic properties of both v-CNT tips and sidewalls using ultraviolet and X-ray photoemission spectroscopy and spectromicroscopy. Site selective nitrogen grafting near the tips, up to a depth of 4μm, was evaluated, beyond which the properties of the v-CNTs remain unperturbed. The N 1s XPS spectra recorded on the v-CNT tips showed three components related to nitrogen grafted as pyridinic, pyrrolic or graphitic. During thermal heating, we observed variations in the intensity ratio of these components due to the different thermal stability of the nitrogen grafting configurations; the most stable were the sp2 pyridinic and graphitic nitrogen. The area ratio variation of these components was accompanied by a change in the density of states at the Fermi energy level, thus suggesting that the nitrogen functionalization strategy employed can be used to activate the v-CNT tips allowing the tuning of electronic properties by controlling the grafting of different nitrogen species.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The number of neonates with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is increasing, and in a few there are reports of intrauterine infection.
To characterize the ...placental pathology findings in a preselected cohort of neonates infected by transplacental transmission arising from maternal infection with SARS-CoV-2, and to identify pathology risk factors for placental and fetal infection.
Case-based retrospective analysis by a multinational group of 19 perinatal specialists of the placental pathology findings from 2 cohorts of infants delivered to mothers testing positive for SARS-CoV-2: live-born neonates infected via transplacental transmission who tested positive for SARS-CoV-2 after delivery and had SARS-CoV-2 identified in cells of the placental fetal compartment by molecular pathology, and stillborn infants with syncytiotrophoblast positive for SARS-CoV-2.
In placentas from all 6 live-born neonates acquiring SARS-CoV-2 via transplacental transmission, the syncytiotrophoblast was positive for coronavirus using immunohistochemistry, RNA in situ hybridization, or both. All 6 placentas had chronic histiocytic intervillositis and necrosis of the syncytiotrophoblast. The 5 stillborn/terminated infants had placental pathology findings that were similar, including SARS-CoV-2 infection of the syncytiotrophoblast, chronic histiocytic intervillositis, and syncytiotrophoblast necrosis.
Chronic histiocytic intervillositis together with syncytiotrophoblast necrosis accompanies SARS-CoV-2 infection of syncytiotrophoblast in live-born and stillborn infants. The coexistence of these 2 findings in all placentas from live-born infants acquiring their infection prior to delivery indicates that they constitute a pathology risk factor for transplacental fetal infection. Potential mechanisms of infection of the placenta and fetus with SARS-CoV-2, and potential future studies, are discussed.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Purpose
To assess the role of radiomics parameters in predicting pathological complete response (pCR) to neoadjuvant chemotherapy (NAC) in patients with locally advanced breast cancer.
Methods
...Seventy-nine patients who had undergone pretreatment staging
18
F-FDG PET/CT and treatment with NAC between January 2010 and January 2018 were included in the study. Primary lesions on PET images were delineated, and extraction of first-, second-, and higher-order imaging features was performed using LIFEx software. The relationship between these parameters and pCR to NAC was analyzed by multiple logistic regression models.
Results
Nineteen patients (24%) had pCR to NAC. Different models were generated on complete information and imputed datasets, using univariable and multivariable logistic regression and least absolute shrinkage and selection operator (lasso) regression. All models could predict pCR to NAC, with area under the curve values ranging from 0.70 to 0.73. All models agreed that tumor molecular subtype is the primary predictor of the primary endpoint.
Conclusions
Our models predicted that patients with subtype 2 and subtype 3 (HER2+ and triple negative, respectively) are more likely to have a pCR to NAC than those with subtype 1 (luminal). The association between PET imaging features and pCR suggested that PET imaging features could be considered as potential predictors of pCR in locally advanced breast cancer patients.
Full text
Available for:
DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, VSZLJ, ZAGLJ
In Joubert syndrome, the "molar tooth" sign can be associated with several additional supra- and infratentorial malformations. Here we report on 3 subjects (2 siblings, 8-14 years of age) with ...Joubert syndrome, showing an abnormal thick bulging of the anterior profile of the mesencephalon causing a complete obliteration of the interpeduncular fossa. DTI revealed that the abnormal tissue consisted of an ectopic white matter tract with a laterolateral transverse orientation. Tractographic reconstructions support the hypothesis of impaired axonal guidance mechanisms responsible for the malformation. The 2 siblings were compound heterozygous for 2 missense variants in the
gene, while no mutations in a panel of 120 ciliary genes were detected in the third patient. The name "anterior mesencephalic cap dysplasia," referring to the peculiar aspect of the mesencephalon on sagittal MR imaging, is proposed for this new malformative feature.
The purpose of this research is the measurement of the cutaneous water loss in the 29 young and healthy Somalian people by the Evaporimeter. Ep I in order to compare it with the values of the ...european people. We did not find any significant difference.
Abstract
We investigate the sensitivity of the Laser Interferometer Space Antenna (LISA) to the anisotropies of the Stochastic Gravitational Wave Background (SGWB). We first discuss
the main ...astrophysical and cosmological sources of SGWB which are characterized by anisotropies in the GW energy density, and we build a Signal-to-Noise estimator to quantify the sensitivity of LISA to different multipoles. We then perform a Fisher matrix analysis of the prospects of detectability of anisotropic features with LISA for individual multipoles, focusing on a SGWB with a power-law frequency profile. We compute the noise angular spectrum taking into account the specific scan strategy of the LISA detector. We analyze the case of the kinematic dipole and quadrupole generated by Doppler boosting an isotropic SGWB. We find that
β
Ω
GW
∼ 2 × 10
-11
is required to observe a dipolar signal with LISA. The detector response to the quadrupole has a factor ∼ 10
3
β
relative to that of the dipole. The characterization of the anisotropies, both from a theoretical perspective and from a map-making point of view, allows us to extract information that can be used to understand the origin of the SGWB, and to discriminate among distinct superimposed SGWB sources.
Large magnitude earthquakes produce complex surface deformations, which are typically mapped by field geologists within the months following the mainshock. We present detailed maps of the surface ...deformation pattern produced by the M. Vettore Fault System during the October 2016 earthquakes in central Italy, derived from ALOS-2 SAR data, via DInSAR technique. On these maps, we trace a set of cross-sections to analyse the coseismic vertical displacement, essential to identify both surface fault ruptures and off-fault deformations. At a local scale, we identify a large number of surface ruptures, in agreement with those observed in the field. At a larger scale, the inferred coseismic deformation shows a typical long-wavelength convex curvature of the subsiding block, not directly recognizable in the field. The detection of deformation patterns from DInSAR technique can furnish important constraints on the activated fault segments, their spatial distribution and interaction soon after the seismic events. Thanks to the large availability of satellite SAR acquisitions, the proposed methodological approach can be potentially applied to worldwide earthquakes (according to the environmental characteristics of the sensed scene) to provide a wider and faster picture of surface ruptures. Thus, the derived information can be crucial for emergency management by civil protection and helpful to drive and support the geological field surveys during an ongoing seismic crisis.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Mountain gorillas are an endangered great ape subspecies and a prominent focus for conservation, yet we know little about their genomic diversity and evolutionary past. We sequenced whole genomes ...from multiple wild individuals and compared the genomes of all four Gorilla subspecies. We found that the two eastern subspecies have experienced a prolonged population decline over the past 100,000 years, resulting in very low genetic diversity and an increased overall burden of deleterious variation. A further recent decline in the mountain gorilla population has led to extensive inbreeding, such that individuals are typically homozygous at 34% of their sequence, leading to the purging of severely deleterious recessive mutations from the population. We discuss the causes of their decline and the consequences for their future survival.
Full text
Available for:
BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Nickel oxide (NiOx) hole transport layers (HTLs) are desirable contacts for perovskite photovoltaics because they are low cost, stable, and readily scalable; however, they deliver lower open-circuit ...voltages (VOCs) compared to organic HTLs. Here, we characterize and mitigate electron transfer-proton transfer reactions between NiOx HTLs and perovskite precursors. Using XPS and UPS characterization, we identify that Ni≥3+ metal cation sites in NiOx thin films act both as Brønsted proton acceptors and Lewis electron acceptors, deprotonating cationic amines and oxidizing iodide species, forming PbI2−xBrx-rich hole extraction barriers at the perovskite-NiOx interface. Titrating reactive Ni≥3+ surface states with excess A-site cation salts during perovskite active layer deposition yielded an increase in VOC values to 1.15 V and power conversion efficiencies of ∼20%. This may be a general finding for metal oxide contacts that act as Brønsted and Lewis acid-base reactants toward perovskite precursors, an observation that has also been made recently for TiO2 and SnO2 contacts.
Display omitted
•Ni≥3+ sites in NiOx thin films react with perovskite precursors, forming PbI2−xBrx•PbI2−xBrx-rich perovskite acts as a hole extraction barrier, reducing device VOC•Excess A-site cation in the precursor improves VOC by 200 mV to 1.15 V•20% efficient devices with NiOx HTLs are more stable than devices with organic HTLs
Perovskite solar cells have potential as a competitive commercial photovoltaic technology by combining high efficiencies with low-cost deposition techniques. Nickel oxide layers used to extract charge from the perovskite are an alternative to costly, ultra-thin organic layers that pose problems with stability and scalability. Nickel oxide layers can be deposited with industry-ready techniques, and perovskite solar cells using nickel oxide layers have passed industry-standard stability tests for solar modules. However, nickel oxide layers typically result in less efficient solar cells due to reduced device voltages compared with organic layers. We show that these voltage losses are a result of chemical reactions between the nickel oxide and the perovskite precursors, which extend to all types of nickel oxide and to multiple perovskite compositions. We then demonstrate a simple, scalable method to overcome these losses, effectively boosting the resulting device voltages and efficiencies.
Nickel oxide (NiOx) hole transport layers (HTLs) are desirable contacts for perovskite solar cells because they are low cost, stable, and readily scalable; however, they result in lower open-circuit voltages as compared with organic HTLs. We identify the cause of this as a redox reaction between NiOx and perovskite precursors. By manipulating the perovskite precursor to compensate for the reaction, we achieve voltages as high as 1.15 V and power conversion efficiencies of ∼20%.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Time-resolved polarization measurements of pulsars offer a unique insight into the geometry of their emission regions. Such measurements provide observational constraints on the different models ...proposed for the pulsar emission mechanisms. Optical polarization data of the Crab nebula were obtained from the Hubble Space Telescope (HST) archive. The data set consists of a series of observations of the nebula taken with the HST/Advanced Camera for Surveys (ACS). We produced polarization vector maps of the inner nebula and measured, for the first time, the degree of linear polarization (P.D.) and the position angle (P.A.) of the pulsar's integrated pulse beam, and of its nearby synchrotron knot. This yielded P.D. = 5.2 ± 0.3 per cent and P.A. = 105
1 ± 1
6 for the pulsar, and P.D. = 59.0 ± 1.9 per cent and P.A. = 124
7 ± 1
0 for the synchrotron knot. This is the first high-spatial resolution multi-epoch study of the polarization of the inner nebula and pulsar. None of the main features in the nebula shows evidence of significant polarization evolution in the period covered by these observations. The results for the pulsar are consistent with those obtained by S owikowska et al. using the high-time resolution photo-polarimeter - Optical Pulsar Timing Analyzer (OPTIMA), once the constant component (DC) component has been subtracted. Our results clearly prove that the knot is the main source of the DC component.
PDF
