The c-axis reflectivity spectrum of underdoped YBa2Cu3O6.6 (YBCO) is measured below T(c)=59 K in parallel magnetic fields H parallel CuO2 up to 7 T. Upon application of a parallel field, a new peak appears at finite frequency in the optical conductivity at the expense of suppression of c-axis condensate weight. We conclude that the dramatic change originates from different Josephson coupling strengths between bilayers with and without Josephson vortices. We find that the 400 cm(-1) broad conductivity peak in YBCO gains the spectral weight under parallel magnetic field; this indicates that the condensate weight at omega=0 is distributed to this peak as well as to the new optical Josephson mode.
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http://dx.doi.org/10.1103/PhysRevLett.89.247001 | DOI Listing |
Nat Commun
January 2025
The Faculty of Data and Decisions Sciences, Technion - Israel Institute of Technology, Haifa, Israel.
Large Language Models (LLMs) have shown success in predicting neural signals associated with narrative processing, but their approach to integrating context over large timescales differs fundamentally from that of the human brain. In this study, we show how the brain, unlike LLMs that process large text windows in parallel, integrates short-term and long-term contextual information through an incremental mechanism. Using fMRI data from 219 participants listening to spoken narratives, we first demonstrate that LLMs predict brain activity effectively only when using short contextual windows of up to a few dozen words.
View Article and Find Full Text PDFNat Commun
January 2025
NMR Based Structural Biology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
Aggregation intermediates play a pivotal role in the assembly of amyloid fibrils, which are central to the pathogenesis of neurodegenerative diseases. The structures of filamentous intermediates and mature fibrils are now efficiently determined by single-particle cryo-electron microscopy. By contrast, smaller pre-fibrillar α-Synuclein (αS) oligomers, crucial for initiating amyloidogenesis, remain largely uncharacterized.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China. Electronic address:
Proto-oncogene RET is overexpressed in many cancers, and its expression level is positively related to the size and malignancy of the tumors. Effective inhibition of its overexpression can be used to potentially treat cancers. A guanine-rich GC-boxes (I-V) sequence in its promoter region folds into noncanonical G-quadruplex (G4) DNA structures, negatively regulating its expression by interactions with small molecules.
View Article and Find Full Text PDFVet Res Commun
January 2025
Division of Animal Anatomy, Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Wrocław, Poland.
Clinically, the rodent thorax is important because of the variety of problems that may affect the heart, lungs, and other thoracic structures. Syrian hamsters are the most common pet and experimental hamster species. Sectional imaging of small mammals is widely increasing in use for clinical and research settings; however, no reports on the thoracic sectional imaging anatomy in this species have been made.
View Article and Find Full Text PDFWomens Health (Lond)
January 2025
Department of Pharmacy Practice, Midwestern University College of Pharmacy, Glendale Campus, Glendale, AZ, USA.
In 2023, a breast cancer risk assessment and a subsequent positive test for the BRCA-2 genetic mutation brought me to the uncomfortable intersection of a longstanding career as an advocate for high-quality medical evidence to support shared patient-provider decision making and a new role as a high-risk patient. My search for studies of available risk-management options revealed that the most commonly recommended approach for women with a ⩾20% lifetime breast cancer risk, intensive screening including annual mammography and/or magnetic resonance imaging beginning at age 25-40 years, was supported only by cancer-detection statistics, with almost no evidence on patient-centered outcomes-mortality, physical and psychological morbidity, or quality of life-compared with standard screening or a surgical alternative, bilateral risk-reducing mastectomy. In this commentary, I explore parallels between the use of the intensive screening protocol and another longstanding women's health recommendation based on limited evidence, the use of hormone therapy (HT) for postmenopausal chronic disease prevention, which was sharply curtailed after the publication of the groundbreaking Women's Health Initiative trial in 2002.
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