The mechanism of T cell lineage commitment remains controversial; to examine it we deleted the CD4-silencer element in the germ line of a mouse using a combination of gene targeting and Cre/LoxP-mediated recombination. We found that these mice were unable to extinguish CD4 expression either in immature thymocytes or mature CD8+ cytotoxic T cells (CTLs), which resulted in the development of major histocompatibility complex class II-restricted double-positive CTLs in the periphery. This finding strongly supports a stochastic over an instructive mechanism of coreceptor down-regulation.
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http://dx.doi.org/10.1038/ni733 | DOI Listing |
Microorganisms
January 2025
State Environmental Protection Key Laboratory of Coastal Ecosystem, National Marine Environmental Monitoring Center, Dalian 116023, China.
As transitional ecosystems between land and sea, estuaries are characterized by a unique environment that supports complex and diverse microbial communities. A comprehensive analysis of microbial diversity and ecological processes at different trophic levels is crucial for understanding the ecological functions of estuarine ecosystems. In this study, we systematically analyzed the diversity patterns, community assembly, and environmental adaptability of bacterial and protist communities using high-throughput sequencing techniques.
View Article and Find Full Text PDFInt J Cancer
January 2025
Princess Margaret Cancer Centre, University Health Network, Toronto, Canada.
Prostate cancer is a common malignancy that in 5%-30% leads to treatment-resistant and highly aggressive disease. Metastasis-potential and treatment-resistance is thought to rely on increased plasticity of the cancer cells-a mechanism whereby cancer cells alter their identity to adapt to changing environments or therapeutic pressures to create cellular heterogeneity. To understand the molecular basis of this plasticity, genomic studies have uncovered genetic variants to capture clonal heterogeneity of primary tumors and metastases.
View Article and Find Full Text PDFBiomimetics (Basel)
January 2025
Laboratory for Robot Mobility Localization and Scene Deep Learning Technology, Guizhou Equipment Manufacturing Polytechnic, Guiyang 550025, China.
In recent years, unmanned aerial vehicle (UAV) technology has advanced significantly, enabling its widespread use in critical applications such as surveillance, search and rescue, and environmental monitoring. However, planning reliable, safe, and economical paths for UAVs in real-world environments remains a significant challenge. In this paper, we propose a multi-strategy improved red-tailed hawk (IRTH) algorithm for UAV path planning in real environments.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
State Key Laboratory of Frigid Zone Cardiovascular Diseases (SKLFZCD), Research Center for Innovative Technology of Pharmaceutical Analysis, College of Pharmacy, Harbin Medical University, Heilongjiang 150081, PR China.
Surface-enhanced Raman spectroscopy (SERS) has become an indispensable tool for biomolecular analysis, yet the detection of DNA signals remains hindered by spectral interference from citrate ions, which overlap with key DNA features. This study introduces an innovative, ultrasensitive SERS platform utilizing thiol-modified silver nanoparticles (Ag@SDCNPs) that overcomes this challenge by eliminating citrate interference. This platform enables direct, interference-free detection and structural characterization of a wide range of DNA conformations, including single-stranded DNA (ssDNA), double-stranded DNA (dsDNA), i-motif, hairpin, G-quadruplex, and triple-stranded DNA (tsDNA).
View Article and Find Full Text PDFSci Rep
January 2025
Dipartimento di Fisica "G. Galilei", Università di Padova, Via Marzolo 8, 35131, Padua, Italy.
Logarithmic growth-rates are fundamental observables for describing ecological systems and the characterization of their distributions with analytical techniques can greatly improve their comprehension. Here a neutral model based on a stochastic differential equation with demographic noise, which presents a closed form for these distributions, is used to describe the population dynamics of microbiota. Results show that this model can successfully reproduce the log-growth rate distribution of the considered abundance time-series.
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