Primary parapharyngeal leiomyosarcoma: A case report.

Leiomyosarcoma is a rare malignant soft-tissue tumor whose cells resemble smooth-muscle tissue. It has been reported to arise in different areas of the head and neck region. Primary leiomyosarcoma of the parapharyngeal space, however, is extremely rare, as only 4 cases have been previously reported to date. We describe the somewhat urgent case of a primary leiomyosarcoma of the right parapharyngeal space in a 30-year-old man. We also review the diagnostic and therapeutic challenges that clinicians face in managing this rare tumor

All-dry, one-step synthesis, doping and film formation of conductive polypyrrole

Oxidative chemical vapor deposition (oCVD) is an extremely effective method for solvent-free deposition of highly conductive polypyrrole films, where polymer synthesis, doping, and film formation are combined in a single step. Here we show that by carefully tuning the reaction parameters, namely the deposition temperature, the reactor pressure and the oxidant to monomer flow rate ratio, homogeneous polypyrrole films with a record conductivity of 180 S cm-1 for a solvent-free method were produced. Fourier transform infrared spectroscopy, UV-vis spectrophotometry, X-ray photoelectron spectroscopy, scanning electron microscopy, and four-probe surface resistivity measurements were performed to gain insights into the relationship between different reaction conditions and the structure of oCVD-deposited polypyrrole, the development of defects, the film morphology and its physical properties

Smart city pilot projects using LoRa and IEEE802.15.4 technologies

Information and Communication Technologies (ICTs), through wireless communications and the Internet of Things (IoT) paradigm, are the enabling keys for transforming traditional cities into smart cities, since they provide the core infrastructure behind public utilities and services. However, to be effective, IoT-based services could require different technologies and network topologies, even when addressing the same urban scenario. In this paper, we highlight this aspect and present two smart city testbeds developed in Italy. The first one concerns a smart infrastructure for public lighting and relies on a heterogeneous network using the IEEE 802.15.4 short-range communication technology, whereas the second one addresses smart-building applications and is based on the LoRa low-rate, long-range communication technology. The smart lighting scenario is discussed providing the technical details and the economic benefits of a large-scale (around 3000 light poles) flexible and modular implementation of a public lighting infrastructure, while the smart-building testbed is investigated, through measurement campaigns and simulations, assessing the coverage and the performance of the LoRa technology in a real urban scenario. Results show that a proper parameter setting is needed to cover large urban areas while maintaining the airtime sufficiently low to keep packet losses at satisfactory levels

WO3-SiO2 nanomaterials synthesized using a novel template-free method in supercritical CO2 as heterogeneous catalysts for epoxidation with H2O2

A series of tungsten oxide-silica (WO3-SiO2) composite nanomaterials were synthesized through a novel, template-free sol-gel method, in which supercritical-CO2 (scCO(2)) was utilized as synthesis medium. The efficacy of the synthesis method stems from a tailored reactor design that allows the contact of the reactants only in the presence of scCO(2). Selected synthetic parameters were screened with the purpose of enhancing the performance of the resulting materials as heterogeneous catalysts in epoxidation reactions with H2O2 as environmentally friendly oxidant. A cyclooctene conversion of 73% with epoxide selectivity of > 99% was achieved over the best WO3-SiO2 catalyst under mild reaction conditions (80 degrees C), equimolar H2O2 amount (1:1) and low WO3 loading (similar to 2.5 wt%). The turnover number achieved with this catalyst (TON = 328), is significantly higher than that of a WO3-SiO2 prepared via a similar sol-gel route but without supercritical CO2, and that of commercial WO3. A thorough characterization with a combination of techniques (ICP-OES, N-2-physisorption, XRD, TEM, STEM-EDX, SEM-EDX, FT-IR and Raman spectroscopy, XPS, TGA and FT-IR analysis of adsorbed pyridine) allowed correlating the physicochemical properties of the WO3-SiO2 nanomaterials with their catalytic performance. The high catalytic activity was attributed to: (i) the very high surface area (892 m(2)/g) and (ii) good dispersion of the W species acting as Lewis acid sites, which were both brought about by the synthesis in supercritical CO2, and (iii) the relatively low hydrophilicity, which was tuned by optimizing the tetramethyl orthosilicate concentration and the amount of basic solution used in the synthesis of the materials. Our optimum catalyst was also tested in the reaction of cyclohexene with H2O2, resulting in cyclohexane diol as main product due to the presence of strong BrOnsted acid sites in the catalyst, whereas the reaction with limonene yielded the internal epoxide as the major product and the corresponding diol as side product. Importantly, the catalyst did not show leaching and could be reused in five consecutive runs without any decrease in activity. (C) 2020 The Authors. Published by Elsevier Ltd

Amorphous AlN films grown by ALD from trimethylaluminum and monomethylhydrazine

The great interest in aluminium nitride thin films has been attributed to their excellent dielectric, thermal and mechanical properties. Here we present the results of amorphous AlN films obtained by atomic layer deposition. We used trimethylaluminum and monomethylhydrazine as the precursors at a deposition temperature of 375-475 °C. The structural and mechanical properties and chemical composition of the synthesized films were investigated in detail by X-ray diffraction, X-ray photoelectron spectroscopy, electron and probe microscopy and nanoindentation. The obtained films were compact and continuous, exhibiting amorphous nature with homogeneous in-depth composition, at an oxygen content of as low as 4 at%. The mechanical properties were comparable to those of AlN films produced by other techniques

Highly Efficient Remediation of Chloridazon and Its Metabolites:The Case of Graphene Oxide Nanoplatelets

The contamination of aqueous environments by aromatic pollutants has become a global issue. Chloridazon, a herbicide considered as harmless to the ecosystem, has been widely used in recent decades and has accumulated, together with its degradation products desphenyl-chloridazon and methyl-desphenyl-chloridazon, to a non-negligible level in surface water and groundwater. To respond to the consequent necessity for remediation, in this work, we study the adsorption of chloridazon and its metabolites by graphene oxide and elucidate the underlying mechanism by X-ray photoelectron spectroscopy. We find a high adsorption capacity of 67 g kg-1for chloridazon and establish that bonding of chloridazon to graphene oxide is mainly due to hydrophobic interaction and hydrogen bonding. These findings demonstrate the potential of graphene-based materials for the remediation of chloridazon and its metabolites from aqueous environments

Different healing characteristics of thiol-bearing molecules on CVD-grown MoS₂

Vacancies in atomically thin molybdenum disulphide play an essential role in controlling its optical and electronic properties, which are crucial for applications in sensorics, catalysis or electronics. For this reason, defect engineering employing thiol-terminated molecules is used to heal and/or functionalise defective nanosheets. In this work, chemical vapour deposition-grown MoS2 with different defect densities was functionalised with three molecules: 4-aminothiophenol (ATP), biphenyl-4-thiol (BPT) and 4-nitrothiophenol (NTP). The molecules’ efficacy in functionalising MoS2 was probed by x-ray photoelectron, Raman and photoluminescence (PL) spectroscopy. The results show that exposing a defective single layer of MoS2 to either ATP, BPT or NTP molecules heals the defects, however the chemical structure of these molecules affects the optical response and only for BPT the PL intensity increases.</p

New insights in polydopamine formation via surface adsorption

Polydopamine is a biomimetic self-adherent polymer, which can be easily deposited on a wide variety of materials. Despite the rapidly increasing interest in polydopamine-based coatings, the polymerization mechanism and the key intermediate species formed during the deposition process are still controversial. Herein, we report a systematic investigation of polydopamine formation on halloysite nanotubes; the negative charge and high surface area of halloysite nanotubes favour the capture of intermediates that are involved in polydopamine formation and decelerate the kinetics of the process, to unravel the various polymerization steps. Data from X-ray photoelectron and solid-state nuclear magnetic resonance spectroscopies demonstrate that in the initial stage of polydopamine deposition, oxidative coupling reaction of the dopaminechrome molecules is the main reaction pathway that leads to formation of polycatecholamine oligomers as an intermediate and the post cyclization of the linear oligomers occurs subsequently. Furthermore, TRIS molecules are incorporated into the initially formed oligomers

Zinc(II) tetraphenylporphyrin on Au(111) investigated by scanning tunnelling microscopy and photoemission spectroscopy measurements

Porphyrins are a versatile class of molecules, which have attracted attention over the years due to their electronic, optical and biological properties. Self-assembled monolayers of porphyrins were widely studied on metal surfaces in order to understand the supramolecular organization of these molecules, which is a crucial step towards the development of devices starting from thebottom-upapproach. This perspective could lead to tailor the interfacial properties of the surface, depending on the specific interaction between the molecular assembly and the metal surface. In this study, we revisit the investigation of the assembly of zinc-tetraphenylporphyrins on Au(111) in order to explore the adsorption of the molecular network on the noble metal substrate. The combined analysis of scanning tunneling microscopy (STM) imaging and core levels photoemission spectroscopy measurements support a peculiar arrangement of the ZnTPP molecular network, with Zn atoms occupying the bridge sites of the Au surface atoms. Furthermore, we prove that, at few-layers coverage, the interaction between the deposited layers allows a relevant molecular mobility of the adlayer, as observed by STM and supported by core levels photoemission analysis