We investigate periodical oscillations in the conductance of suspended Au and Pt atomic chains during elongation under mechanical stress. Analysis of conductance and shot noise measurements reveals that the oscillations are mainly related to variations in a specific conduction channel as the chain undergoes transitions between zigzag and linear atomic configurations. The calculated local electronic structure shows that the oscillations originate from varying degrees of hybridization between the atomic orbitals along the chain as a function of the zigzag angle. These variations are highly dependent on the directionally and symmetry of the relevant orbitals, in agreement with the order-of-magnitude difference between the Pt and Au oscillation amplitudes observed in experiment. Our results demonstrate that the sensitivity of conductance to structural variations can be controlled by designing atomic-scale conductors in view of the directional interactions between atomic orbitals.
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http://dx.doi.org/10.1021/nl4041737 | DOI Listing |
Nature
January 2025
Department of Biochemistry, University of Washington, Seattle, WA, USA.
Snakebite envenoming remains a devastating and neglected tropical disease, claiming over 100,000 lives annually and causing severe complications and long-lasting disabilities for many more. Three-finger toxins (3FTx) are highly toxic components of elapid snake venoms that can cause diverse pathologies, including severe tissue damage and inhibition of nicotinic acetylcholine receptors, resulting in life-threatening neurotoxicity. At present, the only available treatments for snakebites consist of polyclonal antibodies derived from the plasma of immunized animals, which have high cost and limited efficacy against 3FTxs.
View Article and Find Full Text PDFChempluschem
January 2025
Kaiserslautern University of Technology: Rheinland-Pfalzische Technische Universitat Kaiserslautern-Landau, Chemistry, 67663, Kaiserslautern, GERMANY.
We report the synthesis of a series of detergents with a lactobionamide polar head group and a tail containing four to seven perfluorinated carbon atoms. Critical micellar concentrations (CMCs) were determined using isothermal titration calorimetry (ITC) and surface tension (SFT) measurements, showing a progressive decrease from 27 mM to about 0.2 mM across the series.
View Article and Find Full Text PDFJ Chem Phys
January 2025
Université Paris-Saclay, UVSQ, CNRS, GEMaC, 45 Avenue des Etats Unis, 78035 Versailles, France.
Among the large family of spin-crossover (SCO) solids, recent investigations focused on polynuclear SCO materials, whose specific molecular configurations allow the presence of multi-step transitions and elastic frustration. In this contribution, we develop the first elastic modeling of thermal and dynamical properties of trinuclear SCO solids. For that, we study a finite SCO open chain constituted of successive elastically coupled trinuclear (A=B=C) blocks, in which each site (A, B, and C) may occupy two electronic configurations, namely, low-spin (LS) and high-spin (HS) states, accompanied with structural changes.
View Article and Find Full Text PDFNucl Med Biol
December 2024
Life Sciences Division, TRIUMF, BC V6T 2A3 Vancouver, British Columbia, Canada; Department of Chemistry, University of British Columbia, V6T 1Z1 Vancouver, British Columbia, Canada.
Targeted Alpha Therapy has shown great promise in cancer treatment, sparking significant interest over recent decades. However, its broad adoption has been impeded by the scarcity of alpha-emitters and the complexities related to their use. The availability of these radionuclides is often constrained by the intricate production processes and purification, as well as regulatory and logistical challenges.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Mumbai 400094, India. Electronic address:
Arsenic (As) is a potent carcinogen that enters the human food chain mainly through rice, which is one of the staple food crops worldwide. During February 2022, a market survey was conducted and 500 samples of rice grains were collected across 41 different locations in Mumbai/Navi-Mumbai. On the basis of grain As-accumulation, samples were grouped into three categories including low- (0-30 ng g DW), medium- (31-70 ng g DW) or high- (>71 ng g DW).
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