Hydraulic failure is one of the main causes of tree mortality in conditions of severe drought. Resistance to cavitation is known to be strongly related to drought tolerance and species survival in conifers, but the threshold of water-stress-induced embolism leading to catastrophic xylem dysfunction in angiosperms has been little studied. We investigated the link between drought tolerance, survival and xylem cavitation resistance in five angiosperm tree species known to have contrasting desiccation resistance thresholds. We exposed seedlings in a greenhouse to severe drought to generate extreme water stress. We monitored leaf water potential, total plant water loss rate, leaf transpiration, stomatal conductance and CO2 assimilation rate during drought exposure and after rewatering (recovery phase). The time required for the recovery of 50% of the maximum value of a given ecophysiological variable after rewatering was used to determine the critical water potential corresponding to the threshold beyond which the plant failed to recover. We also investigated the relationship between this potential and stem xylem cavitation resistance, as assessed from vulnerability curves. This minimum recoverable water potential was consistent between ecophysiological variables and varied considerably between species, from -3.4 to -6.0 MPa. This minimum recoverable water potential was strongly correlated with P50 and P88, the pressures inducing 50 and 88% losses of stem hydraulic conductance, respectively. Moreover, the embolism threshold leading to irreversible drought damage was found to be close to 88%, rather than the 50% previously reported for conifers. Hydraulic failure leading to irreversible drought-induced global dysfunction in angiosperm tree species occurred at a very high level of xylem embolism, possibly reflecting the physiological characteristics of their stem water-transport system.
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http://dx.doi.org/10.1093/treephys/tpt030 | DOI Listing |
J Med Chem
January 2025
Inner Mongolia Key Laboratory for Molecular Regulation of the Cell, Inner Mongolia University, Hohhot 010021, People's Republic of China.
In this study, we synthesized 12 monofunctional tridentate ONS-donor salicylaldimine ligand ()-based Ru(II) complexes with general formula [(Ru()(-cymene)]·Cl (-), characterized by H NMR, C NMR, UV, FT-IR spectroscopy, HR-ESI mass spectrometry, and single-crystal X-ray analysis showing ligand's orientation around the Ru(II) center. All 12 of these 12 complexes were tested for their anticancer activities in multiple cancer cells. The superior antitumor efficacy of , , and was demonstrated by reduced mitochondrial membrane potential, impaired proliferative capacity, and disrupted redox homeostasis, along with enhanced apoptosis through caspase-3 activation and downregulation of Bcl-2 expression.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, Grenoble INP, LEPMI 38000 Grenoble, France.
An original approach to characterize electrochemical interfaces at the atomic level, a challenging topic toward the understanding of electrochemical reactivity, is reported. We employed surface resonant X-ray diffraction experiments combined with their simulation using first-principle density functional theory calculations and were thus able to determine the molecular and electronic structures of the partially ionic layer facing the electrode surface, as well as the charge distribution in the surface metal layers. Pt(111) in an acidic medium at an applied potential excluding specific adsorption was studied.
View Article and Find Full Text PDFFront Public Health
January 2025
Department of Occupational Health and Radiological Protection, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, China.
Objective: Assess the level of radiation-related knowledge (RRK) and nuclear energy-related knowledge (NERK) among residents near the Sanmen Nuclear Power Plant, the first project adopted the Advanced Passive Pressurized Water Reactor (AP1000) technology.
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Cureus
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Breast Surgery, James Cook University Hospital, Middlesbrough, GBR.
Introduction: Breast surgeries are classified as clean procedures associated with a lower risk of post-operative infections; however, the reported infection rates post-breast surgeries are still significantly high. Surgical site infections (SSIs) are indeed one of the most common and serious complications following breast surgery.
Methodology: A retrospective study assessed the rate of SSIs post-breast reconstructive surgery after the implementation of the infection control protocol at James Cook University Hospital and Friarage Hospital from December 2022 to June 2024.
Front Microbiol
January 2025
Graduate School of Medicine, Science and Technology, Shinshu University, Nagano, Japan.
Cholera, a disease caused by , remains a pervasive public health threat, particularly in regions with inadequate water sanitation and hygiene infrastructure, such as Bangladesh. This review explores the complex interplay between water pollution and cholera transmission in Bangladesh, highlighting how contaminated water bodies serve as reservoirs for . A key focus is the potential role of probiotics as a novel intervention approach for cholera prevention and management.
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