The authors describe the Ptolemy Project, a recently developed model of electronic access to medical literature for surgeons in developing countries.
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http://dx.doi.org/10.1371/journal.pmed.0030305 | DOI Listing |
Environ Res
December 2024
Environmental Studies Program, Middlebury College, Middlebury, VT, USA.
Background: Per- and polyfluoroalkyl substances (PFAS), synthetic chemicals with adverse health effects, are used extensively in consumer products. Ski waxes, applied to the base of skis, contain up to 100% PFAS by mass, but exposure and health effects are poorly characterized.
Objectives: Our objectives were to quantify serum PFAS concentrations among skiers and explore associations with reported ski wax use and biomarkers of cardiometabolic, thyroid, and immune health.
Nanomaterials (Basel)
December 2023
Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Rome, Italy.
Highly aligned multi-wall carbon nanotubes were investigated with scanning electron microscopy (SEM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) before and after bombardment performed using noble gas ions of different masses (argon, neon and helium), in an ultra-high-vacuum (UHV) environment. Ion irradiation leads to change in morphology, deformation of the carbon (C) honeycomb lattice and different structural defects in multi-wall carbon nanotubes. One of the major effects is the production of bond distortions, as determined by micro-Raman and micro-X-ray photoelectron spectroscopy.
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January 2023
Simons Machine Learning Center, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY USA.
Over the past decade, cryo-electron microscopy (cryoEM) has emerged as an important method for determining near-native, near-atomic resolution 3D structures of biological macromolecules. To meet the increasing demand for cryoEM, automated methods that improve throughput and efficiency of microscope operation are needed. Currently, the targeting algorithms provided by most data-collection software require time-consuming manual tuning of parameters for each grid, and, in some cases, operators must select targets completely manually.
View Article and Find Full Text PDFNanomaterials (Basel)
July 2022
Dipartimento di Fisica, Sapienza Università di Roma, P.le Aldo Moro 2, 00185 Rome, Italy.
Atomic deuterium (D) adsorption on free-standing nanoporous graphene obtained by ultra-high vacuum D2 molecular cracking reveals a homogeneous distribution all over the nanoporous graphene sample, as deduced by ultra-high vacuum Raman spectroscopy combined with core-level photoemission spectroscopy. Raman microscopy unveils the presence of bonding distortion, from the signal associated to the planar sp2 configuration of graphene toward the sp3 tetrahedral structure of graphane. The establishment of D-C sp3 hybrid bonds is also clearly determined by high-resolution X-ray photoelectron spectroscopy and spatially correlated to the Auger spectroscopy signal.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2021
Dipartimento di Fisica and INFN Sezione di Roma 1, Sapienza Università di Roma, P.le Aldo Moro 2, 00185 Rome, Italy.
A suitable way to modify the electronic properties of graphene-while maintaining the exceptional properties associated with its two-dimensional (2D) nature-is its functionalisation. In particular, the incorporation of hydrogen isotopes in graphene is expected to modify its electronic properties leading to an energy gap opening, thereby rendering graphene promising for a widespread of applications. Hence, deuterium (D) adsorption on free-standing graphene was obtained by high-energy electron ionisation of D2 and ion irradiation of a nanoporous graphene (NPG) sample.
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