Using angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT), an experimental and theoretical study of changes in the electronic structure (dispersion dependencies) and corresponding modification of the energy band gap at the Dirac point (DP) for topological insulator (TI) [Formula: see text] have been carried out with gradual replacement of magnetic Mn atoms by non-magnetic Ge atoms when concentration of the latter was varied from 10% to 75%. It was shown that when Ge concentration increases, the bulk band gap decreases and reaches zero plateau in the concentration range of 45-60% while trivial surface states (TrSS) are present and exhibit an energy splitting of 100 and 70 meV in different types of measurements. It was also shown that TSS disappear from the measured band dispersions at a Ge concentration of about 40%.
View Article and Find Full Text PDFA series of nanoparticles (NPs) with a hydrodynamic radius from 20 to 100 nm in PBS was developed over the solubilization of hydrophobic dye methyl pheophorbide (chlorin e derivative) by amphiphilic copolymers of N-vinylpyrrolidone with (di)methacrylates. Photophysical properties and biological activity of the NPs aqueous solution were studied. It was found that the dye encapsulated in the copolymers is in an aggregated state.
View Article and Find Full Text PDFWe show that graphene can be magnetized by coupling to a ferromagnetic Co film through a Au monolayer. The presence of dislocation loops under graphene leads to a ferrimagnetic ordering of moments in the two C sublattices. It is shown that the band gap of ∼80 meV in the K[over ¯] point has a magnetic nature and exists for ferrimagnetic ordering.
View Article and Find Full Text PDFObjective: Limited data is available to guide non-surgical management of Stage T4 larynx and hypopharynx cancer patients who have inoperable disease or refuse surgery. We aim to review the nonoperative management of T4 laryngeal and hypopharyngeal cancer and report the long-term therapeutic and functional outcomes.
Methods: We reviewed the nonoperative management of T4 laryngeal (n = 44) and hypopharyngeal (n = 53) cancer from 1997 to 2015 and performed a univariate analysis (UVA).
Background: Numerous studies and guidelines suggest an outcome detriment from radiation treatment breaks (rTBs) and the need for compensatory dosing in patients with head and neck cancer.
Methods: In a consecutive cohort of 521 patients with oropharyngeal squamous cell carcinoma (OPSCC), we investigated the impact of rTBs and prolongation of overall treatment time (OTT) on OS, DFS, LRC, and cancer recurrence using competing risk and multivariate analyses.
Results: Neither OTT prolongation by ≤2 days nor rTBs of ≤3 days were associated with detriments to clinical outcomes.
Rationale And Objectives: Radiology turnaround time is an important quality measure that can impact hospital workflow and patient outcomes. We aimed to develop a machine learning model to predict delayed turnaround time during non-business hours and identify factors that contribute to this delay.
Materials And Methods: This retrospective study consisted of 15,117 CT cases from May 2018 to May 2019 during non-business hours at two hospital campuses after applying exclusion criteria.
Spectrochim Acta A Mol Biomol Spectrosc
November 2021
Synthesis, spectral properties, and photodynamic activity of water-soluble amino acid fullerene C derivatives (AFD) and four original AFD-PPa dyads, obtained by covalent addition of dye pyropheophorbide (PPa) to AFD, were studied. In aqueous solution, these AFD-PPa dyads form nanoassociates as a result of self-assembly. In this case, a significant change in the absorption spectra and strong quenching of the dye fluorescence in the structure of the dyads were observed.
View Article and Find Full Text PDFHigh-dose (HD) cisplatin remains the standard of care with chemoradiation for locally advanced oropharyngeal cancer (OPC). Cooperative group trials mandate bolus-HD (100 mg/m × 1 day, every 3 weeks) cisplatin administration at the beginning of the week to optimize radiosensitization-a requirement which may be unnecessary. This analysis evaluates the impact of chemotherapy administration day of week (DOW) on outcomes.
View Article and Find Full Text PDFTechnological applications involving 2D MoSrequire transfer of chemical vapor deposition (CVD) grown material from its original substrate and subsequent lithographic processes. Inevitably, those steps contaminate the surface of the 2D material with polymeric residues affecting the electronic and optical properties of the MoS. Annealing in forming gas is considered an efficient treatment to partially remove such residues.
View Article and Find Full Text PDFBecause of the national emergency triggered by the coronavirus disease 2019 (COVID-19) pandemic, government-mandated public health directives have drastically changed not only social norms but also the practice of oncologic medicine. Timely head and neck cancer (HNC) treatment must be prioritized, even during emergencies. Because severe acute respiratory syndrome coronavirus 2 predominantly resides in the sinonasal/oral/oropharyngeal tracts, nonessential mucosal procedures are restricted, and HNCs are being triaged toward nonsurgical treatments when cures are comparable.
View Article and Find Full Text PDFThe effects of the newly synthesized covalent conjugates of water-soluble fullerene derivatives (WSFD) with xanthene dyes: polyanionic WSFD-fluorescein (1), polycationic WSFD-fluorescein (2), polyanionic WSFD-eosin (3), and polyanionic WSFD (4), polycationic WSFD (5), fluorescein (6) and eosin (7), on activity of the membrane-bound Ca-ATPase of the sarcoplasmic reticulum (SR Ca-ATPase) were studied. Compounds 1, 3, 4, 6, and 7 inhibit the hydrolytic function of the enzyme, the inhibition constants for these compounds are Ki=1.3×10 M (1), Ki=4.
View Article and Find Full Text PDFThe non-volatile spin-orbit torque magnetic random access memory (SOT-MRAM) is a very attractive memory technology for near future computers because it has various advantages such as non-volatility, high density and scalability. In the present work we propose a model of a graphene recording device for the SOT-MRAM unit cell, consisting of a quasi-freestanding graphene intercalated with Au and an ultra-thin Pt layer sandwiched between graphene and a magnetic tunnel junction. As a result of using the claimed graphene recording memory element, a faster operation and lower energy consumption will be achieved under the recording information by reducing the electric current required to record.
View Article and Find Full Text PDFBackground Though incidental pulmonary nodules are common, rates of guideline-recommended surveillance and associations between surveillance and mortality are unclear. In this study, we describe adherence (categorized as complete, partial, late and none) to guideline-recommended surveillance among patients with incidental 5-8 mm pulmonary nodules and assess associations between adherence and mortality. Methods This was a retrospective cohort study of 551 patients (≥35 years) with incidental pulmonary nodules conducted from September 1, 2008 to December 31, 2016, in an integrated safety-net health network.
View Article and Find Full Text PDFEffect of magnetization generated by synchrotron or laser radiation in magnetically-doped and pristine topological insulators (TIs) is presented and analyzed using angle-resolved photoemission spectroscopy. It was found that non-equal photoexcitation of the Dirac cone (DC) states with opposite momenta and spin orientation indicated by the asymmetry in photoemission intensity of the DC states is accompanied by the k-shift of the DC states relative to the non-spin-polarized conduction band states located at k = 0. We relate the observed k-shift to the induced surface in-plane magnetic field and corresponding magnetization due to the spin accumulation.
View Article and Find Full Text PDFA rich class of spintronics-relevant phenomena require implementation of robust magnetism and/or strong spin-orbit coupling (SOC) to graphene, but both properties are completely alien to it. Here, we for the first time experimentally demonstrate that a quasi-freestanding character, strong exchange splitting and giant SOC are perfectly achievable in graphene at once. Using angle- and spin-resolved photoemission spectroscopy, we show that the Dirac state in the Au-intercalated graphene on Co(0001) experiences giant splitting (up to 0.
View Article and Find Full Text PDFRegardless of the widely accepted opinion that there is no Raman signal from single-layer graphene when it is strongly bonded to a metal surface, we present Raman spectra of a graphene monolayer on Ni(111) and Co(0001) substrates. The high binding energy of carbon to these surfaces allows formation of lattice-matched (1 × 1) structures where graphene is significantly stretched. This is reflected in a record-breaking shift of the Raman G band by more than 100 cm relative to the case of freestanding graphene.
View Article and Find Full Text PDFTwo- and three-dimensional topological insulators are the key materials for the future nanoelectronic and spintronic devices and quantum computers. By means of angle- and spin-resolved photoemission spectroscopy we study the electronic and spin structure of the Bi-bilayer/3D topological insulator in quantum tunneling regime formed under the short annealing of BiTeSe. Owing to the temperature-induced restructuring of the topological insulator's surface quintuple layers, the hole-like spin-split Bi-bilayer bands and the parabolic electronic-like state are observed instead of the Dirac cone.
View Article and Find Full Text PDFThe implementation of future graphene-based electronics is essentially restricted by the absence of a band gap in the electronic structure of graphene. Options of how to create a band gap in a reproducible and processing compatible manner are very limited at the moment. A promising approach for the graphene band gap engineering is to introduce a large-scale sublattice asymmetry.
View Article and Find Full Text PDFBackground: As proton beam radiation therapy (PBRT) may allow greater normal tissue sparing when compared with intensity-modulated radiation therapy (IMRT), we compared the dosimetry and treatment-related toxicities between patients treated to the ipsilateral head and neck with either PBRT or IMRT.
Methods: Between 01/2011 and 03/2014, 41 consecutive patients underwent ipsilateral irradiation for major salivary gland cancer or cutaneous squamous cell carcinoma. The availability of PBRT, during this period, resulted in an immediate shift in practice from IMRT to PBRT, without any change in target delineation.
Background: Displaying radiation exposure and cost information at electronic order entry may encourage clinicians to consider the value of diagnostic imaging.
Methods: An urban safety-net health system displayed radiation exposure information for CT and cost information for CT, MRI and ultrasound on an electronic referral system for outpatient ordering. We assessed whether there were differences in numbers of outpatient CT scans and MRIs per month relative to ultrasounds before and after the intervention, and evaluated primary care clinicians' responses to the intervention.
Embedding foreign atoms or molecules in graphene has become the key approach in its functionalization and is intensively used for tuning its structural and electronic properties. Here, we present an efficient method based on chemical vapor deposition for large scale growth of boron-doped graphene (B-graphene) on Ni(111) and Co(0001) substrates using carborane molecules as the precursor. It is shown that up to 19 at.
View Article and Find Full Text PDFPurpose: Imaging results are generally communicated to patients by referring providers. Directly communicating results has been suggested as a way for radiologists to add value, though few studies have investigated patients' preferences in this regard. The aim of this study was to determine patients' preferences for receiving their imaging results.
View Article and Find Full Text PDFWith the discovery and first characterization of graphene, its potential for spintronic applications was recognized immediately. Since then, an active field of research has developed trying to overcome the practical hurdles. One of the most severe challenges is to find appropriate interfaces between graphene and ferromagnetic layers, which are granting efficient injection of spin-polarized electrons.
View Article and Find Full Text PDFObjectives: To evaluate 1) clinician attitudes towards incorporating cost information into decision making when ordering imaging studies; and 2) clinician reactions to the display of Medicare reimbursement information for imaging studies at clinician electronic order entry.
Study Design: Focus group study with inductive thematic analysis.
Methods: We conducted focus groups of primary care clinicians and subspecialty physicians (nephrology, pulmonary, and neurology) (N = 50) who deliver outpatient care in 12 hospital-based clinics and community health centers in an urban safety net health system.