Thanks to the "secondary-ion emission microscope" (CAMECA IMS 300), we have been able to image the distribution of the stable isotopes of nitrogen 14N and 15N in sections of plant roots (spatial resolution better than 1 micron), as well as to estimate the relative concentrations of these isotopes. The plants used (Lupinus spec.) originated from seeds with natural (i.e., 14N) nitrogen and had been fed for a few days with [15N]-nitrate before sampling. We have found in root sections of 6-day-old plants (prepared at 5 mm from the root tip) a clear-cut regionalization of the distribution of 15N between the vascular cylinder and the cortex. The latter contained approximately 5% 15N (of total nitrogen), whereas the relative concentration of the heavy isotope in the vascular cylinder was significantly lower. The observed concentration difference is probably due to the Casparian strip, which is a barrier for the apoplastic diffusion of solutes from the cortex to the vascular cylinder.
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http://dx.doi.org/10.1177/36.1.3335768 | DOI Listing |
Int J Biol Macromol
January 2025
Foshan Clinical Medical School of Guangzhou University of Chinese Medicine, Guangdong Province, Foshan 528031, China. Electronic address:
Due to the limited ability to self-repair, the regeneration of bone critical-sized defects (CSD) is a significant challenge. Bone tissue engineering scaffolds are considered promising candidates for CSD repair, but low cell infiltration efficiency and a lack of nutrients greatly restrict bone regeneration abilities. Herein, we developed a dynamic culturing of large biomimetic bone scaffolds, PCL/GelMA@cells that combining 3D printed polycaprolactone (PCL) multi-channel cylinder with gelatin methacryloyl (GelMA) encapsulated with bone marrow mesenchymal stem cells (BMSCs) and rat aortic endothelial cells (RAECs).
View Article and Find Full Text PDFBJU Int
December 2024
Department of Urology, Fox Chase Cancer Center, Philadelphia, PA, USA.
Plant Physiol Biochem
November 2024
Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, College of Horticulture, China Agricultural University, Beijing, 100193, China. Electronic address:
Root knot nematodes (RKNs) induce hypertrophy and cell proliferation within the vascular cylinders of host plants, leading to the formation of giant cells (GCs) that are enlarged, multinucleate cells with high metabolic activity. These GCs are formed through repeated karyokinesis without cytokinesis and are accompanied by significant changes in cytoskeleton organization. In this study, two microtubule-binding protein genes, CsMAP65-2 and CsMAP65-3, are upregulated in cucumber roots upon RKNs infection, specifically at 3, 96, and 120 hpi.
View Article and Find Full Text PDFMed Phys
December 2024
Department of Radiation Oncology, University of California, Los Angeles, Los Angeles, California, USA.
Background: Lung computed tomography (CT) scan image registration is being used for lung function analysis such as ventilation. Given the high sensitivity of functional analyses to image registration errors, an image registration error scoring tool that can measure submillimeter image registration errors is needed.
Purpose: To propose an image registration error scoring tool, termed λ, whose spatial sensitivity can be used to quantify image registration errors in steep image gradient regions under realistic noise conditions.
Comput Methods Programs Biomed
December 2024
Department of Mechanical and Aerospace Engineering, Polito(BIO)Med Lab, Politecnico di Torino, Corso Duca degli Abruzzi, 24, Torino, Turin 10129, Italy. Electronic address:
Background And Objectives: Vascular stents are scaffolding structures implanted in the vessels of patients with obstructive disease. Stents are typically designed as cylindrical lattice structures characterized by the periodic repetition of unit cells. Their design, including geometry and material characteristics, influences their mechanical performance and, consequently, the clinical outcomes.
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