We develop an experimental approach to analyze the water distribution around a core-shell micelle formed by polystyrene-block-poly[styrene-g-poly(ethylene oxide (PEO)] block copolymers in aqueous media at a fixed polymeric concentration of 10 mg/ml through contrast variation small angle neutron scattering (SANS) study. Through varying the D(2)O/H(2)O ratio, the scattering contributions from the water molecules and the micellar constituent components can be determined. Based on the commonly used core-shell model, a theoretical coherent scattering cross section incorporating the effect of water penetration is developed and used to analyze the SANS I(Q). We have successfully quantified the intramicellar water distribution and found that the overall micellar hydration level increases with the increase in the molecular weight of hydrophilic PEO side chains. Our work presents a practical experimental means for evaluating the intramacromolecular solvent distributions of general soft matter systems.
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http://dx.doi.org/10.1063/1.3493331 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zürich, Zürich 8093, Switzerland.
Chemotaxis enables marine bacteria to increase encounters with phytoplankton cells by reducing their search times, provided that bacteria detect noisy chemical gradients around phytoplankton. Gradient detection depends on bacterial phenotypes and phytoplankton size: large phytoplankton produce spatially extended but shallow gradients, whereas small phytoplankton produce steeper but spatially more confined gradients. To date, it has remained unclear how phytoplankton size and bacterial swimming speed affect bacteria's gradient detection ability and search times for phytoplankton.
View Article and Find Full Text PDFRadiol Imaging Cancer
January 2025
From Case Western Reserve University School of Medicine, Cleveland, Ohio (A.M.); University of Pittsburgh School of Medicine, Pittsburgh, Pa (E.C.); and Department of Radiology, University Hospitals, 11000 Euclid Ave, Bolwell B2600, Cleveland, OH 44115 (K.B., N.R., S.H.T.).
Prostate cancer is the second most common malignancy among male individuals in the United States and requires careful imaging approaches because of its varied presentations. This review examines prostate cancer imaging guidelines from leading organizations, including the American College of Radiology, American Urological Association, European Association of Urology, American Society of Clinical Oncology, and National Comprehensive Cancer Network, and serves as a reference highlighting commonalities and divergences in current imaging recommendations across prostate cancer states. We outline these organizations and their methods, focusing on their approaches to panel expertise, guideline development, evidence grading, and revision schedules.
View Article and Find Full Text PDFElife
January 2025
School of Psychology, Korea University, Seoul, Republic of Korea.
Recent studies suggest that calcitonin gene-related peptide (CGRP) neurons in the parabrachial nucleus (PBN) represent aversive information and signal a general alarm to the forebrain. If CGRP neurons serve as a true general alarm, their activation would modulate both passive nad active defensive behaviors depending on the magnitude and context of the threat. However, most prior research has focused on the role of CGRP neurons in passive freezing responses, with limited exploration of their involvement in active defensive behaviors.
View Article and Find Full Text PDFMagn Reson Med
January 2025
Department of Radiology & Nuclear Medicine, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
Purpose: To correct maternal breathing and fetal bulk motion during fetal 4D flow MRI.
Methods: A Doppler-ultrasound fetal cardiac-gated free-running 4D flow acquisition was corrected post hoc for maternal respiratory and fetal bulk motion in separate automated steps, with optional manual intervention to assess and limit fetal motion artifacts. Compressed-sensing reconstruction with a data outlier rejection algorithm was adapted from previous work.
BMC Plant Biol
January 2025
Key Laboratory of Biology and Genetic Improvement of Oil Crops of the Ministry of Agriculture, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, 430062, China.
Background: Perilla frutescens (L.) Britt. (Lamiaceae) leaves are essential culinary and medicinal herbs, native to East Asian countries.
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