Hypoxia is central to tumour evolution, growth, invasion and metastasis. Mathematical models of hypoxia based on reaction-diffusion equations provide seemingly incomplete descriptions as they fail to predict the measured oxygen concentrations in the tumour microenvironment. In an attempt to explain the discrepancies, we consider both the inhomogeneous distribution of oxygen-consuming cells in solid tumours and the dynamics of blood flow in the tumour microcirculation. We find that the low-frequency oscillations play an important role in the establishment of tumour hypoxia. The oscillations interact with consumption to inhibit oxygen diffusion in the microenvironment. This suggests that alpha-blockers-a class of drugs used to treat hypertension and stress disorders, and known to lower or even abolish low-frequency oscillations of arterial blood flow -may act as adjuvant drugs in the radiotherapy of solid tumours by enhancing the oxygen effect.
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http://dx.doi.org/10.1038/srep39762 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
KAIST - Korea Advanced Institute of Science and Technology, Department of Chemistry, Center for Nanomaterials and Chemical Reaction, IBS, 373-1, Guseong Dong, Yuseong Gu, 305-701, Daejeon, KOREA, REPUBLIC OF.
Understanding how TiO2 interacts with CO2 at the molecular level is crucial in the CO2 reduction toward value-added energy sources. Here, we report in-situ observations of the CO2 activation process on the reduced TiO2(110) surface at room temperature using ambient pressure scanning tunneling microscopy. We found that oxygen vacancies (Vo) diffuse dynamically along the bridging oxygen (Obr) rows of the TiO2(110) surface under ambient CO2(g) environments.
View Article and Find Full Text PDFSci Rep
January 2025
Univ. Grenoble Alpes, CEA, CNRS, Grenoble INP, SyMMES, Grenoble, F-38000, SyMMES, France.
Pigment particles used in tattooing may exert long terms effect by releasing diffusible degradation products. In the present work, aqueous suspensions of the organic orange diazo pigment PO13 were aged by exposure to simulated sunlight at 40 °C. The morphology and the surface charge of PO13 particles were barely modified upon aging, but primary particles were released by de-agglomeration.
View Article and Find Full Text PDFNano Lett
January 2025
National Innovation Center for Industry-Education Integration of Energy Storage Technology, College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China.
Rechargeable magnesium ion batteries (RMBs) have drawn extensive attention due to their high theoretical volumetric capacity and low safety hazards. However, divalent Mg ions suffer sluggish mobility in cathodes owing to the high charge density and slow insertion/extraction kinetics. Herein, it is shown that an ultrafast nonequilibrium high-temperature shock (HTS) method with a high heating/quenching rate can instantly introduce oxygen vacancies into the olivine-structured MgFeSiO cathode (MgFeSiO-HTS) in seconds.
View Article and Find Full Text PDFFunct Integr Genomics
January 2025
The Energy and Resources Institute, Lodi Road, New Delhi, 110003, India.
The major limiting factor of photosynthesis in C3 plants is the enzyme, rubisco which inadequately distinguishes between carbon dioxide and oxygen. To overcome catalytic deficiencies of Rubisco, cyanobacteria utilize advanced protein microcompartments, called the carboxysomes which envelopes the enzymes, Rubisco and Carbonic Anhydrase (CA). These microcompartments facilitate the diffusion of bicarbonate ions which are converted to CO by CA, following in an increase in carbon flux near Rubisco boosting CO fixation process.
View Article and Find Full Text PDFJ Phys Chem B
January 2025
McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States.
Artificial water channels (AWCs) have emerged as a promising framework for stable water permeation, with water transport rates comparable to aquaporins (3.4-40.3 × 10 HO/channel/s).
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