303 research outputs found
The role of endoscopic ultrasound-guided fine-needle aspiration/biopsy in the diagnosis of mediastinal lesions
ObjectiveEndoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS-FNA/FNB) is an accurate technique for sampling the pancreas and mediastinum. The aim of this study was to determine the value of EUS-FNA/FNB in the diagnosis of mediastinal lesions.MethodsData from 107 patients who underwent EUS-FNA/FNB for mediastinal lesions were evaluated.ResultsThe sensitivity, specificity, positive predictive value, and negative predictive value of EUS-FNA/FNB for mediastinal lesions were 92.00%, 100%, 100%, and 85%, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of EUS-FNA for malignant mediastinal lesions were 92.00%, 100%, 100%, and 86.00%, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of EUS-FNB for malignant mediastinal lesions were 92.00%, 100%, 100%, and 82.00%, respectively. Except for the discomfort caused by conventional gastroscopy, none of the patients had any complications, such as damage to surrounding large blood vessels or nerves.ConclusionEUS-FNA/FNB is an effective tool for diagnosing unknown mediastinal lesions, without any obvious complications
Aqua[N-phenyl-2-(quinolin-8-yloxy)acetamide]dinitratozinc(II)
In the title complex, [Zn(NO3)2(C17H14N2O2)(H2O)], the six-coordinated Zn atom is in a distorted octahedral geometry, the donor centers being two O atoms and one N atom from the tridentate organic ligand, a water O atom and two O atoms from two monodentate nitrate ions. In the crystal, O—H⋯O hydrogen bonds between the coordinated water molecules and nitrate O atoms and N—H⋯O hydrogen bonds between the main ligand and nitrate O atoms consolidate the three-dimensional network
Bis{4-bromo-2-[(2-hydroxyethyl)iminomethyl]phenolato}nickel(II) monohydrate
The title mononuclear nickel complex, [Ni(C9H9BrNO2)2]·H2O, was obtained by the reaction of 5-bromosalicylaldehyde, 2-aminoethanol and nickel nitrate in methanol. The NiII atom is six-coordinated by two phenolate O, two imine N and two hydroxy O atoms from two crystallographically different Schiff base ligands, forming an octahedral geometry. In the crystal, molecules are linked by intermolecular O—H⋯O and O—H⋯Br hydrogen bonds, forming a three-dimensional network
Stellar Atmospheric Parameters for Cool Dwarfs in Gaia DR3
We provide a catalogue of atmospheric parameters for 1,806,921 cool dwarfs
from Gaia DR3 which lie within the range covered by LAMOST cool dwarf
spectroscopic parameters: 3200 K < T_{eff}< 4300 K, -0.8 < [M/H] < 0.2 dex, and
4.5 <log{g} < 5.5 dex. Our values are derived based on Machine Learning models
trained with multi-band photometry corrected for dust. The photometric data
comprises of optical from SDSS r, i, z bands, near-infrared from 2MASS J, H, K
and mid-infrared from ALLWISE W1, W2. We used both random forest and LightGBM
machine learning models and found similar results from both with an error
dispersion of 68 K, 0.22 dex, and 0.05 dex for T_{eff}, [M/H], and log {g},
respectively. Assessment of the relative feature importance of different
photometric colors indicated W1 -- W2 as most sensitive to both T_{eff} and
log{g}, with J -- H most sensitive to [M/H]. We find that our values show a
good agreement with APOGEE, but are significantly different to those provided
as part of Gaia DR3.Comment: 14 pages, 12 figures, accepted by ApJ
Stellar Atmospheric Parameters for Cool Dwarfs in Gaia Data Release 3
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/We provide a catalog of atmospheric parameters for 1,806,921 cool dwarfs from Gaia Data Release 3 (DR3) that lie within the range covered by LAMOST cool dwarf spectroscopic parameters: 3200 K < T eff < 4300 K, −0.8 < [M/H] < 0.2 dex, and 4.5 < log g < 5.5 dex. Our values are derived based on machine-learning models trained with multiband photometry corrected for dust. The photometric data comprise optical data from the Sloan Digital Sky Survey r, i, and z bands, near-infrared data from the Two Micron All Sky Survey J, H, and K bands, and mid-infrared data from the ALLWISE W1 and W2 bands. We used both random forest and light gradient boosting machine machine-learning models and found similar results from both, with an error dispersion of 68 K, 0.22 dex, and 0.05 dex for T eff, [M/H], and log g, respectively. Assessment of the relative feature importance of different photometric colors indicated W1 − W2 as most sensitive to both T eff and log g, with J − H being most sensitive to [M/H]. We find that our values show a good agreement with the Apache Point Observatory Galactic Evolution Experiment, but are significantly different to those provided as part of Gaia DR3.Peer reviewe
Electronic Structures of Graphene Layers on Metal Foil: Effect of Point Defects
Here we report a facile method to generate a high density of point defects in
graphene on metal foil and show how the point defects affect the electronic
structures of graphene layers. Our scanning tunneling microscopy (STM)
measurements, complemented by first principle calculations, reveal that the
point defects result in both the intervalley and intravalley scattering of
graphene. The Fermi velocity is reduced in the vicinity area of the defect due
to the enhanced scattering. Additionally, our analysis further points out that
periodic point defects can tailor the electronic properties of graphene by
introducing a significant bandgap, which opens an avenue towards all-graphene
electronics.Comment: 4 figure
Atomic resolution imaging of the two-component Dirac-Landau levels in a gapped graphene monolayer
The wavefunction of massless Dirac fermions is a two-component spinor. In
graphene, a one-atom-thick film showing two-dimensional Dirac-like electronic
excitations, the two-component representation reflects the amplitude of the
electron wavefunction on the A and B sublattices. This unique property provides
unprecedented opportunities to image the two components of massless Dirac
fermions spatially. Here we report atomic resolution imaging of the
two-component Dirac-Landau levels in a gapped graphene monolayer by scanning
tunnelling microscopy and spectroscopy. A gap of about 20 meV, driven by
inversion symmetry breaking by the substrate potential, is observed in the
graphene on both SiC and graphite substrates. Such a gap splits the n = 0
Landau level (LL) into two levels, 0+ and 0-. We demonstrate that the amplitude
of the wavefunction of the 0- LL is mainly at the A sites and that of the 0+ LL
is mainly at the B sites of graphene, characterizing the internal structure of
the spinor of the n = 0 LL. This provides direct evidence of the two-component
nature of massless Dirac fermions.Comment: 4 Figures in main text and 4 Figures in S
Transcriptome analysis reveals self-incompatibility in the tea plant (Camellia sinensis) might be under gametophytic control
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