Unraveling the Nature of Charge Excitations in La2_2CuO4_4 with Momentum-Resolved Cu KK-edge Resonant Inelastic X-ray Scattering

Results of model calculations using exact diagonalization reveal the orbital character of states associated with different Raman loss peaks in Cu $K$-edge resonant inelastic X-ray scattering (RIXS) from La$_{2}$CuO$_{4}$. The model includes electronic orbitals necessary to highlight non-local Zhang-Rice singlet, charge transfer and $d$-$d$ excitations, as well as states with apical oxygen 2$p_z$ character. The dispersion of these excitations is discussed with prospects for resonant final state wave-function mapping. A good agreement with experiments emphasizes the substantial multi-orbital character of RIXS profiles in the energy transfer range 1-6 eV.Comment: Original: 4.5 pages. Replaced: 4 pages and 4 figures with updated content and reference

Chitosan-PEO nanofiber mats for copper removal in aqueous solution using a new versatile electrospinning collector

Electrospun chitosan–polyethylene oxide nanofiber mats were fabricated using a new collector design. Besides being reusable, it allows to assess the desired morphology of the mat in a quicker way. To test its efficiency, nonwoven mats designed for water treatment applications were prepared using conditions never been reported before. Under these conditions, continuous and flawless nanofibers of 151 ± 36 nm in diameter were achieved. Adsorption capacity of the mats for copper ions in aqueous solutions were investigated. Results showed that sorption equilibrium was achieved within 150 min with a homogenous distribution of copper ions within the nanofibrous mats. The pseudo-second order kinetic model best fitted the experimental data. The Langmuir isotherm best described the sorption process with a maximum adsorption capacity of 124 mg/g for trial temperatures ranging from 25 to 60 °C. Thermodynamic parameters (ΔG°, ΔH° and ΔS°) demonstrate that the adsorption was feasible, endothermic and spontaneous. The desorption potential and mat’s reusability were also studied. Results reveal that the electrospun chitosan mats can be desorbed and reused up to 5 cycles without significant loss in adsorption performance. © 2020, Springer Nature Switzerland AG

Fast-neutron induced background in LaBr3:Ce detectors

The response of a scintillation detector with a cylindrical 1.5-inch LaBr3:Ce crystal to incident neutrons has been measured in the energy range En = 2-12 MeV. Neutrons were produced by proton irradiation of a Li target at Ep = 5-14.6 MeV with pulsed proton beams. Using the time-of-flight information between target and detector, energy spectra of the LaBr3:Ce detector resulting from fast neutron interactions have been obtained at 4 different neutron energies. Neutron-induced gamma rays emitted by the LaBr3:Ce crystal were also measured in a nearby Ge detector at the lowest proton beam energy. In addition, we obtained data for neutron irradiation of a large-volume high-purity Ge detector and of a NE-213 liquid scintillator detector, both serving as monitor detectors in the experiment. Monte-Carlo type simulations for neutron interactions in the liquid scintillator, the Ge and LaBr3:Ce crystals have been performed and compared with measured data. Good agreement being obtained with the data, we present the results of simulations to predict the response of LaBr3:Ce detectors for a range of crystal sizes to neutron irradiation in the energy range En = 0.5-10 MeVComment: 28 pages, 10 figures, 4 Table

Cellulose reinforced electrospun chitosan nanofibers bio-based composite sorbent for water treatment applications

Electrospun chitosan–polyethylene oxide/TEMPO-oxidized cellulose (CS–PEO/TOC) bio-based composite was fabricated for the first time for water treatment applications. This new concept allows cellulose and chitosan to be combined in a simpler and efficient way, avoiding the use of harmful solvents, compared to previously published related work. The “Sandwich-like” material is composed of a porous oxidized cellulosic fibers central core (TOC handsheet) and a thin layer of electrospun CS–PEO nanofibers on both sides of the core. Average diameters for CS–PEO and TOC were 159.3 ± 33.7 nm and 21.7 ± 5.1 µm, respectively. Fourier Transform Infrared Spectroscopy (FTIR) was carried out on the bio-based composite. Results suggest that no covalent bonds are involved but rather electrostatic interactions occur which allows bonding of the electrospun nanofiber layers on TOC core and no delamination. CS–PEO electrospinning time was varied to study the effect of nanofiber’s coating weight on strength, permeability and adsorption capacity of the bio-based material. Mechanical properties of the composite were improved over the electrospun nanofiber mat. The CS–PEO provides greater elasticity (strain%) and the TOC provides a higher tensile strength to the material. However, tensile index was reduced by 48% with electrospinning time, while burst index was almost constant. The best conditions were achieved for 2 h electrospinning time. Under these conditions, a high permeable material (290.13 L/m2 hbar) was developed. The adsorption capacity for Cu (II) ions reached up to 27% with only 12 mg of chitosan onto the CS–PEO/TOC (12.42 mg/g). The data fit better to the pseudo-second order model, suggesting chemisorption as the main mechanism involved for copper adsorption. This study opens-up potential opportunities for the development of a robust material for wastewater applications at an industrial scale. Graphic abstract: [Figure not available: see fulltext.] © 2021, The Author(s), under exclusive licence to Springer Nature B.V

Resonant inelastic x-ray scattering in electronically quasi-zero-dimensional CuB2O4

We explore the general phenomenology of resonant inelastic scattering (RIXS) using CuB2O4, a network of CuO4 plaquettes electronically isolated by B+3 ions. Spectra show a small number of well-separated features, and we exploit the simple electronic structure to explore RIXS phenomenology by developing a calculation which allows for intermediate-state effects ignored in standard approaches. These effects are found to be non-negligible and good correspondence between our model and experiment leads to a simple picture of such phenomenology as the genesis of d-d excitations at the K edge and intermediate-state interference effects.Comment: Phys. Rev. B 80, 092509 (2009

CAR-T cell. the long and winding road to solid tumors

Adoptive cell therapy of solid tumors with reprogrammed T cells can be considered the "next generation" of cancer hallmarks. CAR-T cells fail to be as effective as in liquid tumors for the inability to reach and survive in the microenvironment surrounding the neoplastic foci. The intricate net of cross-interactions occurring between tumor components, stromal and immune cells leads to an ineffective anergic status favoring the evasion from the host's defenses. Our goal is hereby to trace the road imposed by solid tumors to CAR-T cells, highlighting pitfalls and strategies to be developed and refined to possibly overcome these hurdles

Pleural mesothelioma in a nine-month-old dog

This paper reports on an unusual case of pleural epitheloid mesothelioma in a nine-month-old male, mixed breed dog. The dog was presented in-extremis and, on post mortem examination, multiple, exophytic, frequently pedunculated, yellowish-red, soft to firm masses ranging from 3 mm to 6 cm in diameter were diffusely distributed over, and attached to, the pericardial and parietal pleural surfaces. Microscopically, these masses consisted of round to partially polygonalshaped, anaplastic cells with minimal cytoplasm and hyperchromatic nuclei covering papillomatous projections or as part of more densely cellular masses. A supporting fibrovascular stroma and mitotic figures were also evident. Constituent tumour cells were labeled positively with antibodies against both vimentin and cytokeratin. In contrast, the same cells exhibited equivocal labeling with an antibody directed against calretinin antigen and did not label with antibodies against carcinoembryonic antigen (CEA) and milk fat globule-related antigen (MFGRA). Such tumours are rare in dogs, particularly in such a young animal

An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics

For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types