The field of valleytronics considers the creation and manipulation of "valley states", charge excitations characterized by a particular value of the crystal momentum in the Brillouin zone. Here we show, using the example of minimally gapped (≤40 meV) graphene, that there exist lightforms that create almost perfect valley contrasting current states (up to ∼80% valley purity) in the absence of a valley contrasting charge excitation. These "momentum streaked" THz waveforms act by deforming the excited state population in momentum space such that current flows at one valley yet is blocked at the conjugate valley. This approach both unlocks the potential of graphene as a materials platform for valleytronics, as gaps of 10-40 meV are robustly found in useful experimental contexts such as graphene/hBN systems, while simultaneously providing a tool toward ultrafast light control of valley currents in diverse minimally gapped matter, including many topological insulator systems.
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http://dx.doi.org/10.1021/acs.nanolett.3c02874 | DOI Listing |
Thyroid
January 2025
Department of Surgery, the Florida University School of Medicine, Tampa, Florida, USA.
Environ Int
January 2025
Dipartimento di Geoscienze, Università di Padova, Padova, Italy.
Radon (Rn) is a radioactive gas with well-documented harmful effects; the World Health Organization has confirmed it as a cancerogenic for humans. These detrimental effects have prompted Europe to establish national reference levels to protect the exposed population. This is reflected in European directive 59/2013/EURATOM, which has been transposed into the national regulations of EU Member States.
View Article and Find Full Text PDFEnviron Toxicol Chem
January 2025
Windward Environmental LLC, Seattle, WA, USA.
Monitoring selenium (Se) concentrations in fish ovaries is an important tool for evaluating the ecological risk posed by Se in aquatic systems. Most guidance recommends sampling fish ovaries as closely as possible to when fish spawn on the premise that Se is mobilized from the liver to the ovary during vitellogenesis, and therefore, sampling ovaries during the early phases of oocyte maturation may underestimate egg Se concentrations at the time of spawning. In this study, we evaluated ovary Se data from two species with synchronous oocyte development (Ptychocheilus oregonensis and Prosopium williamsoni), one species with asynchronous oocyte development (Richardsonius balteatus), and one where the mode of development is unclear (Mylocheilus caurinus).
View Article and Find Full Text PDFFood Chem X
January 2025
Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Campus de Gualtar, Braga, Portugal.
This study used integrative omics to address the response of key elements of the grapevine holobiont to contrasted pedoclimatic conditions found in distinct subregions of Douro Valley (Portugal). A metabolic OPLS-DA model predicted with 100 % accuracy the geographic origin of berries; higher UV radiation, higher temperature and lower precipitation stimulated the accumulation of phenolic acids, flavonols and malvidin conjugates, in detriment of amino acids, organic acids, flavan-3-ols, proanthocyanidins and non-malvidin anthocyanins. Metabarcoding showed a trade-off between bacteria and fungal diversity among subregions, with , and acting as intraregional microbial markers.
View Article and Find Full Text PDFCan Fam Physician
January 2025
Vice-Chair of Quality and Innovation in the DFCM at U of T; Associate Professor in the Faculty of Medicine and the Institute of Health Policy, Management and Evaluation at U of T; Scientist in the MAP Centre for Urban Health Solutions at St Michael's Hospital; and a staff physician in the DFCM at St Michael's Hospital, Unity Health Toronto.
Objective: To understand the role of primary care in the COVID-19 pandemic to provide insight into its functioning and inform potential reforms.
Composition Of The Committee: The now dissolved Ontario COVID-19 Science Advisory Table (Science Table) was formed in July 2020 to provide decision makers and the public with a synthesis of rapidly evolving evidence related to COVID-19. The Science Table was based at the Dalla Lana School of Public Health at the University of Toronto, and supported by Public Health Ontario.
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