Diagnostic challenge in a patient with primary bilateral Dumbbell-shaped lumbar non-Hodgkin’s lymphoma

Objective: Primary bilateral dumbbell-shaped lumbar non-Hodgkin lymphomas with epidural and extraspinal involvement, are rare occurrences. Patients presenting at advanced stages and rapid evolution towards neurological impairment lead to diagnostic dilemmas for which only immunohistochemistry can provide a correct, although delayed solution. Case report: We report the first case of a bilateral, dumbbell-shaped, lumbar lymphoma in a 65-year-old man with a medical history of chronic viral hepatitis type B and D under interferon treatment. The patient presented with back pain radiating down the right leg, with rapid progression to paraplegia and sphincter dysfunction. CT and MRI revealed a large dumbbell mass (approx. 5/5/10 cm) in the right paraspinal musculature, at the L4-L5 level, with intraspinal epidural extension. A similar mass of smaller size was described on the left side, almost mirroring the first lesion, the imagistic aspect suggesting a neural sheath tumor. Intraoperatively, in the right lumbar paraspinal musculature, a soft, yellowish region was discovered, the macroscopic appearance being rather suggestive for a diffuse infection. Clinical, imagistic and surgical findings were not conclusive, nor was the histological examination in light microscopy of the surgical specimen or of the bone marrow biopsy. Immunohistochemistry identified the presence of large B cells, leading to the diagnosis of B cell lymphoma. Although the patient was treated with systemic chemotherapy, his condition rapidly deteriorated and he died within 3 months. Conclusions: In the case of a lumbosacral, dumbbell shaped mass, developed both epidural and extraspinal, the differential diagnosis must include lymphoma. The histological examination, especially immunohistochemistry provided the final diagnosis. Delays in establishing a diagnosis, associated with a malignant evolution of lymphoma, diminish the chances of determining and applying a treatment strategy that could prolong survival

Characterization of Monochromatic Aberrated Metalenses in Terms of Intensity-Based Moments

Consistent with wave-optics simulations of metasurfaces, aberrations of metalenses should also be described in terms of wave optics and not ray tracing. In this respect, we have shown, through extensive numerical simulations, that intensity-based moments and the associated parameters defined in terms of them (average position, spatial extent, skewness and kurtosis) adequately capture changes in beam shapes induced by aberrations of a metalens with a hyperbolic phase profile. We have studied axial illumination, in which phase-discretization induced aberrations exist, as well as non-axial illumination, when coma could also appear. Our results allow the identification of the parameters most prone to induce changes in the beam shape for metalenses that impart on an incident electromagnetic field a step-like approximation of an ideal phase profile

A critical review of photovoltaic cells based on organic monomeric and polymeric thin film heterojunctions

International audienc

Estimating the 3D Printing Defects by Micro-Computed Tomography

Micro-computed tomography (µ-CT) is an X-ray technique with (sub)micron resolution, [...

Relationship between the Formation of Magnetic Clusters and Hexagonal Phase of Gold Matrix in AuxFe1−x Nanophase Thin Films

AuxFe1−x nanophase thin films of different compositions and thicknesses were prepared by co-deposition magnetron sputtering. Complex morpho-structural and magnetic investigations of the films were performed by X-ray Diffraction, cross-section Transmission Electron Microscopy, Selected Area Electron Diffraction, Magneto Optical Kerr Effect, Superconducting Quantum Interference Device magnetometry and Conversion Electron Mössbauer Spectroscopy. It was proven that depending on the preparation conditions, different configurations of defect α-Fe magnetic clusters, i.e., randomly distributed or auto-assembled in lamellar or filiform configurations, can be formed in the Au matrix. A close relationship between the Fe clustering process and the type of the crystalline structure of the Au matrix was underlined, with the stabilization of a hexagonal phase at a composition close to 70 at. % of Au and at optimal thickness. Due to different types of inter-cluster magnetic interactions and spin anisotropies, different types of magnetic order from 2D Ising type to 3D Heisenberg type, as well as superparamagnetic behavior of non-interacting Fe clusters of similar average size, were evidenced

Interactions of Chemically Synthesized Ferrihydrite Nanoparticles with Human Serum Transferrin: Insights from Fluorescence Spectroscopic Studies

Human serum transferrin (HST) is a glycoprotein involved in iron transport that may be a candidate for functionalized nanoparticles to bind and target cancer cells. In this study, the effects of the simple and doped with cobalt (Co) and copper (Cu) ferrihydrite nanoparticles (Fh-NPs, Cu-Fh-NPs, and Co-Fh-NPs) were studied by spectroscopic and molecular approaches. Fluorescence spectroscopy revealed a static quenching mechanism for all three types of Fh-NPs. All Fh-NPs interacted with HST with low affinity, and the binding was driven by hydrogen bonding and van der Waals forces for simple Fh-NPs and by hydrophobic interactions for Cu-Fh-NPs and Co-Fh-NPs binding, respectively. Of all samples, simple Fh-NPs bound the most to the HST binding site. Fluorescence resonance energy transfer (FRET) allowed the efficient determination of the energy transfer between HST and NPs and the distance at which the transfer takes place and confirmed the mechanism of quenching. The denaturation of the HST is an endothermic process, both in the case of apo HST and HST in the presence of the three types of Fh-NPs. Molecular docking studies revealed that Fh binds with a low affinity to HST (Ka = 9.17 × 103 M−1) in accord with the fluorescence results, where the interaction between simple Fh-NPs and HST was described by a binding constant of 9.54 × 103 M−1

On the Structural, Morphological, and Electrical Properties of Carbon Nanowalls Obtained by Plasma-Enhanced Chemical Vapor Deposition

In this study, we investigated the morphological, structural, and electrical properties of carbon nanowall (CNW) structures obtained by plasma-enhanced chemical vapour deposition (PECVD) and underlined the induced effects of argon/nitrogen (Ar/N2) postsynthesis plasma treatment on the electrical behaviour. The top view and cross-section scanning electron microscopy micrographs revealed that the fabricated samples are about 18 μm height, and the edges are less than 10 nm. The Raman analysis showed the presence of the specific peaks of graphene-based materials, i.e., D-band, G-band, D′-band, 2D-band, and D+G-band. The average values of the electrical resistance of fabricated samples were evaluated by current-voltage characteristics acquired at room temperature, in the ranges of 0 V–0.2 V, and an increase was noticed with about 50% after the Ar/N2 postsynthesis plasma treatment compared to pristine samples. Moreover, the Hall measurements proved that the obtained CNW structures had p-type conductivity (Hall coefficient was 0.206 m3/C), and the concentration of charge carriers was 7.8×1019 cm-3, at room temperature

Effect of RF Power on the Physical Properties of Sputtered ZnSe Nanostructured Thin Films for Photovoltaic Applications

Zinc selenide (ZnSe) thin films were deposited by RF magnetron sputtering in specific conditions, onto optical glass substrates, at different RF plasma power. The prepared ZnSe layers were afterwards subjected to a series of structural, morphological, optical and electrical characterizations. The obtained results pointed out the optimal sputtering conditions to obtain ZnSe films of excellent quality, especially in terms of better optical properties, lower superficial roughness, reduced micro-strain and a band gap value closer to the one reported for the ZnSe bulk semiconducting material. Electrical characterization were afterwards carried out by measuring the current–voltage (I-V) characteristics at room temperature, of prepared “sandwich”-like Au/ZnSe/Au structures. The analysis of I-V characteristics have shown that at low injection levels there is an Ohmic conduction, followed at high injection levels, after a well-defined transition voltage, by a Space Charge Limited Current (SCLC) in the presence of an exponential trap distribution in the band gap of the ZnSe thin films. The results obtained from all the characterization techniques presented, demonstrated thus the potential of ZnSe thin films sputtered under optimized RF plasma conditions, to be used as alternative environmentally-friendly Cd-free window layers within photovoltaic cells manufacturing

Effect of the Cadmium Telluride Deposition Method on the Covering Degree of Electrodes Based on Copper Nanowire Arrays

In this work, we report the preparation of nanostructured electrodes based on dense arrays of vertically-aligned copper (Cu) nanowires (NWs) to be subsequently covered by cadmium telluride (CdTe) thin films, with great potential to be used within “substrate”-type photovoltaic cells based on AII-BVI heterojunctions. In particular, the multi-step preparation protocol presented here involves an electrochemical synthesis procedure within a supported anodic aluminum oxide (AAO) nanoporous template for first generating a homogeneous array of vertically-aligned Cu NWs, which are then further embedded within a compact CdTe thin film. In a second stage, we tested three deposition methods (vacuum thermal evaporation, VTE; radio-frequency magnetron sputtering, RF-MS; and electrochemical deposition, ECD) for use in obtaining CdTe layers potentially able to consistently penetrate the previously prepared Cu NWs array. A comparative analysis was performed to critically evaluate the morphological, optical, and structural properties of the deposited CdTe films. The presented results demonstrate that under optimized processing conditions, the ECD approach could potentially allow the cost-effective fabrication of absorber layer/collecting electrode CdTe/Cu nanostructured interfaces that could improve charge collection mechanisms, which in turn could allow the fabrication of more efficient solar cells based on AII-BVI semiconducting compounds