30,911 research outputs found
Fermi surface of the Weyl type-II metallic candidate <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>WP</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math>
No full textWeyl type-II fermions are massless quasiparticles that obey the Weyl equation and which are predicted to occur at the boundary between electron and hole pockets in certain semimetals, i.e., the (W,Mo)(Te₁,P)₂ compounds. Here, we present a study of the Fermi surface of WP₂ via the Shubnikov-de Haas (SdH) effect. Compared to other semimetals, WP₂ exhibits a very low residual resistivity, i.e., ρ₀≃10 nΩ cm, which leads to perhaps the largest nonsaturating magnetoresistivity [ρ(H)] reported for any compound. For the samples displaying the smallest ρ₀, ρ(H) is observed to increase by a factor of 2.5×10⁷% under μ₀H=35 T at T=0.35 K. The angular dependence of the SdH frequencies is found to be in excellent agreement with the first-principles calculations when the electron and hole bands are shifted by 30 meV with respect to the Fermi level. This small discrepancy could have implications for the predicted topological character of this compound.DOE-BES through Award No. DE-SC0002613; NSF through NSF-DMR-1157490.School of Natural Sciences and Mathematic
William Tarn, Hellenistic Civilisation. Third Edition revised by the Author and G. T. Griffith
No full textNachtergael Georges. William Tarn, Hellenistic Civilisation. Third Edition revised by the Author and G. T. Griffith. In: L'antiquité classique, Tome 44, fasc. 2, 1975. p. 782
William Tarn, Hellenistic Civilisation. Third Edition revised by the Author and G. T. Griffith
No full textNachtergael Georges. William Tarn, Hellenistic Civilisation. Third Edition revised by the Author and G. T. Griffith. In: L'antiquité classique, Tome 44, fasc. 2, 1975. p. 782
Men inspecting a diagram of the new G-3 shaft, Climax Uranium Company
No full textDonor: Colorado Mining Association.Five men outside sit, kneel, and bend over diagram, G-3 Shaft, Climax Uranium Company.Caption reads: "Right to Left: T. E. McCandless, Production Superintendent; R. Bolles, Contractor; E. A. Roberts, Mine Foreman; G. H. Clark, Master Mechanic; F. C. Harvey, Lead Man. Inspecting new G-3 Shaft.
Selective tumor cell death induced by irradiated riboflavin through recognizing DNA G-T mismatch
No full textRiboflavin (vitamin B2) has been thought to be a promising antitumoral agent in photodynamic therapy, though the further application of the method was limited by the unclear molecular mechanism. Our work reveals that riboflavin was able to recognize G-T mismatch specifically and induce singlestrand breaks in duplex DNA targets efficiently under irradiation. In the presence of riboflavin, the photo-irradiation could induce the death of tumor cells that are defective in mismatch repair system selectively, highlighting the G-T mismatch as potential drug target for tumor cells. Moreover, riboflavin is a promising leading compound for further drug design due to its inherent specific recognition of the G-T mismatch
Detailed study of the Fermi surfaces of the type-II Dirac semimetallic candidates XTe2 (X =Pd, Pt)
No full textWe present a detailed quantum oscillatory study on the Dirac type-II semimetallic candidates PdTe2 and PtTe2 via the temperature and the angular dependence of the de Haas-van Alphen (dHvA) and Shubnikov-de Haas (SdH) effects. In high quality single crystals of both compounds, i.e. displaying carrier mobilities between 10 3 and 10 4 cm 2 /Vs, we observed a large non-saturating magnetoresistivity (MR) which in PtTe 2 at a temperature T = 1. 3 K, leads to an increase in the resistivity up to 5 × 10 4 % under a magnetic field μ 0 H = 62 T. These high mobilities correlate with their light effective masses in the range of 0.04 to 1 bare electron mass according to our measurements. For PdTe2 the experimentally determined Fermi surface cross-sectional areas show an excellent agreement with those resulting from band-structure calculations. Surprisingly, this is not the case for PtTe2 whose agreement between calculations and experiments is relatively poor even when electronic correlations are included in the calculations. Therefore, our study provides a strong support for the existence of a Dirac type-II node in PdTe 2 and probably also for PtTe2. Band structure calculations indicate that the topologically non-trivial bands of PtTe2 do not cross the Fermi-level (εF). In contrast, for PdTe2 the Dirac type-II cone does intersect εF, although our calculations also indicate that the associated cyclotron orbit on the Fermi surface is located in a distinct kz plane with respect to the one of the Dirac type-II node. Therefore it should yield a trivial Berry-phase
f(G,T) and its Cosmological Implications
No full textA coupled formulation of the Gauss-Bonnet invariant term G and the
energy momentum trace T term provide a modified f(G,T) gravity,
has been analyzed in this study. The functional form for the
f(G,T) gravity has been taken as f(G,T)=αT+ βGThe presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
Identification of Immune Gene Signature Associated with T Cells and Natural Killer Cells in Type 1 Diabetes [Corrigendum]
No full textWang N, Wang G, Feng X, Yang T. Diabetes Metab Syndr Obes. 2024;17:2983—2996.
The authors have advised the affiliation callouts in the author list on page 2983 are incorrect. The correct author callouts should read as follows:
Na Wang1, Guofeng Wang1,2, Xiuli Feng1, Teng Yang
Synthesis and functionalization of β-alkyl-meso-triarylcorroles
No full textAfter the definition of efficient synthetic routes for the preparation of triarylcorroles, the functionalization of these macrocycles is becoming a necessary and challenging field of research. One important synthetic step is the introduction of substituents able to influence the electronic distribution in the macrocyclic ring. A valuable target would be a corrole macrocycle with some b-pyrrole positions occupied by methyl groups, while exploiting other positions to introduce electronwithdrawing substituents. To explore the scope of this approach, we investigated the bromination and the nitration of the corrole ring and the desired products have been obtained in moderate to good yield. The successful preparation of selectively halogenated corroles is particularly interesting since they are suitable substrates for the preparation of more complex partially alkylated structures using modern cross coupling methodologies
Corrole and nucleophilic aromatic substitution are not incompatible: a novel route to 2,3-difunctionalized copper corrolates
No full textThe insertion of a –NO2 group onto the corrole framework represents a key step for subsequent synthetic manipulation of the macrocycle based on the chemical versatility of such a functionality. Here we report results of the investigation of a copper 3-NO2-triarylcorrolate in nucleophilic aromatic substitution reactions with “active” methylene carbanions, namely diethyl malonate and diethyl 2-chloromalonate. Although similar reactions on nitroporphyrins afford chlorin derivatives, nucleophilic attack on carbon-2 of corrole produces 2,3-difunctionalized Cu corrolates in acceptable yields (ca. 30%), evidencing once again the erratic chemistry of this contracted porphyrinoid
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