Based on first-principles plane-wave calculations, we studied the functionalization of the two-dimensional single-layer MoS2 structure through adatom adsorption and vacancy defect creation. ...Minimum-energy adsorption sites were determined for 16 different adatoms, each of which gives rise to diverse properties. Bare, single-layer MoS2, which is normally a nonmagnetic, direct-band-gap semiconductor, attains a net magnetic moment upon adsorption of specific transition-metal atoms, as well as silicon and germanium atoms. The localized donor and acceptor states in the band gap expand the utilization of MoS2 in nanoelectronics and spintronics. Specific adatoms, such as C and O, attain significant excess charge upon adsorption onto single-layer MoS2, which might be useful for tribological applications. Each MoS2 triple vacancy created in a single layer of MoS2 gives rise to a net magnetic moment, whereas other vacancy defects related to Mo and S atoms do not influence the nonmagnetic ground state. The present results are also relevant for the surface of graphitic MoS2.
This paper presents a comparative study of the lattice dynamics of three-dimensional layered MoS2 and two-dimensional single layer MoS2 based on the density functional theory. A comprehensive ...analysis of energetics and optimized structure parameters is performed using different methods. It is found that the van der Waals attraction between layers of three-dimensional (3D) layered MoS2 is weak but is essential to hold the layers together with the equilibrium interlayer spacing. Cohesive energy, phonon dispersion curves, and corresponding density of states and related properties, such as Born-effective charges, dielectric constants, Raman and infrared active modes are calculated for 3D layered as well as 2D single layer MoS2 using their optimized structures. These calculated values are compared with the experimental data to reveal interesting dimensionality effects. The absence of a weak interlayer interaction in 2D single layer MoS2 results in the softening of some of Raman active modes.
In this paper an attempt is made to study equatorial Kelvin waves using a
network of three radars: Kototabang
(0.204∘ S, 100.320∘ E)
meteor radar, Pameungpeuk (7.646∘ S, 107.688∘ E)
medium-frequency ...radar, and Pontianak
(0.003∘ S, 109.367∘ E) medium-frequency radar. We have used
the continuous data gathered from the three radars during April–May 2010.
Empirical mode decomposition (EMD), Lomb–Scargle periodogram (LSP) analysis,
and wavelet techniques are used to study the temporal and altitude structures
of planetary waves. Here, we used a novel technique called EMD to extract the
planetary waves from wind data. The planetary waves of ∼ 6.5 and
∼ 3.6 days periodicity are observed in all three radar stations with
peak amplitudes of about 12 and 11 m s−1, respectively. The 3.6-day
wave has an average vertical wavelength from the three radars of about
42 km. The 3.6- and 6.5-day planetary waves are particularly strong in the
zonal wind component. We find that the two waves are present at the
84–94 km height region. The observed features of the 3.6- and 6.5-day waves
at the three tropical-latitude stations show some correspondence with the
results reported for the equatorial-latitude stations. Keywords. Electromagnetics (wave propagation) – history of geophysics (atmospheric sciences) – meteorology and atmospheric dynamics (middle atmosphere dynamics)
The multi-kinase inhibitor (mKi) regorafenib has demonstrated efficacy in chemorefractory patients with metastatic colorectal cancer (mCRC). However, lack of predictive biomarkers and concerns over ...significant toxicities hamper the use of regorafenib in clinical practice.
Serial liquid biopsies were obtained at baseline and monthly until disease progression in chemorefractory patients with mCRC treated with regorafenib in a phase II clinical trial (PROSPECT-R n = 40; NCT03010722) and in a multicentric validation cohort (n = 241). Tissue biopsies collected at baseline, after 2 months and at progression in the PROSPECT-R trial were used to establish patient-derived organoids (PDO) and for molecular analyses. MicroRNA profiling was performed on baseline bloods using the NanoString nCounter platform and results were validated by digital-droplet PCR and/or ISH in paired liquid and tissue biopsies. PDOs co-cultures and PDO-xenotransplants were generated for functional analyses.
Large-scale microRNA expression analysis in longitudinal matched liquid and tissue biopsies from the PROSPECT-R trial identified MIR652-3p as a biomarker of clinical benefit to regorafenib. These findings were confirmed in an independent validation cohort and in a "control" group of 100 patients treated with lonsurf. Using ex vivo co-culture assays paired with single-cell RNA-sequencing of PDO established pre- and post-treatment, we modeled regorafenib response observed in vivo and in patients, and showed that MIR652-3p controls resistance to regorafenib by impairing regorafenib-induced lethal autophagy and by orchestrating the switch from neo-angiogenesis to vessel co-option.
Our results identify MIR652-3p as a potential biomarker and as a driver of cell and non-cell-autonomous mechanisms of resistance to regorafenib.
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