The recommended duration was based on the technical specifications (window length, overlap) of the TFA, rather than studies testing various recording durations. ...characterizing the minimal ...monitoring duration for dCA parameters to stabilize requires further definition. The authors found significant variability in the dCA parameters of phase and gain for data lengths up to 7 min, with stable values for longer recordings in the relevant low and very low frequency bands. The modality of BP measurement has been shown to affect autoregulatory parameters, and this may extend to the optimal monitoring duration 5. ...the results of this study may not be broadly applicable, and it is possible that noninvasive or lower quality recordings require a longer monitoring duration for stable estimation of dCA parameters.
Scientific advances have informed many aspects of acute stroke care but have also highlighted the complexity and heterogeneity of cerebrovascular diseases. While practice guidelines are essential in ...supporting the clinical decision-making process, they may not capture the nuances of individual cases. Personalized stroke care in ICU has traditionally relied on integrating clinical examinations, neuroimaging studies, and physiologic monitoring to develop a treatment plan tailored to the individual patient. However, to realize the potential of precision medicine in stroke, we need advances and evidence in several critical areas, including data capture, clinical phenotyping, serum biomarker development, neuromonitoring, and physiology-based treatment targets. Mathematical tools are being developed to analyze the multitude of data and provide clinicians with real-time information and personalized treatment targets for the critical care management of patients with cerebrovascular diseases. This review summarizes research advances in these areas and outlines principles for translating precision medicine into clinical practice.
Methane is the second most important greenhouse gas after carbon dioxide and approximately 11% of the global anthropogenic methane emissions originate from rice fields. Sulfate amendment is a ...mitigation strategy to reduce methane emissions from rice fields because sulfate reducers and methanogens compete for the same substrates. Cable bacteria are filamentous bacteria known to increase sulfate levels via electrogenic sulfide oxidation. Here we show that one-time inoculation of rice-vegetated soil pots with cable bacteria increases the sulfate inventory 5-fold, which leads to the reduction of methane emissions by 93%, compared to control pots lacking cable bacteria. Promoting cable bacteria in rice fields by enrichment or sensible management may thus become a strategy to reduce anthropogenic methane emissions.
Cable bacteria are filamentous members of the Desulfobulbaceae family that oxidize sulfide with oxygen or nitrate by transferring electrons over centimeter distances in sediments. Recent studies show ...that freshwater sediments can support populations of cable bacteria at densities comparable to those found in marine environments. This is surprising since sulfide availability is presumably low in freshwater sediments due to sulfate limitation of sulfate reduction. Here we show that cable bacteria stimulate sulfate reduction in freshwater sediment through promotion of sulfate availability. Comparing experimental freshwater sediments with and without active cable bacteria, we observed a three- to tenfold increase in sulfate concentrations and a 4.5-fold increase in sulfate reduction rates when cable bacteria were present, while abundance and community composition of sulfate-reducing microorganisms (SRM) were unaffected. Correlation and ANCOVA analysis supported the hypothesis that the stimulation of sulfate reduction activity was due to relieve of the kinetic limitations of the SRM community through the elevated sulfate concentrations in sediments with cable bacteria activity. The elevated sulfate concentration was caused by cable bacteria-driven sulfide oxidation, by sulfate production from an indigenous sulfide pool, likely through cable bacteria-mediated dissolution and oxidation of iron sulfides, and by enhanced retention of sulfate, triggered by an electric field generated by the cable bacteria. Cable bacteria in freshwater sediments may thus be an integral component of a cryptic sulfur cycle and provide a mechanism for recycling of the scarce resource sulfate, stimulating sulfate reduction. It is possible that this stimulation has implication for methanogenesis and greenhouse gas emissions.
In this issue of the Neurocritical Care, the authors submit an innovative analysis showing that early aggressive reduction in systolic blood pressure is associated with increased mortality and worse ...in-hospital outcome after intracerebral hemorrhage (ICH) 1. Furthermore, the majority of subjects in the Antihypertensive Treatment of Acute Cerebral Hemorrhage (ATACH-II) and the Implementation of Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial (INTERACT-2) had small- to moderate-sized hematomas in subcortical locations, leaving those with large and more severe hemorrhages an understudied population. ...characterizing patients that are likely to benefit remains crucial, and the interaction between timing, intensity, and duration of different BP interventions and outcome requires further definition. Information on blood pressure management or the use of antihypertensive medication is not available, and treatment practices likely varied across centers and during the extended timeframe of data collection.
Summary
Cable bacteria are sulfide‐oxidising, filamentous bacteria that reduce toxic sulfide levels, suppress methane emissions and drive nutrient and carbon cycling in sediments. Recently, cable ...bacteria have been found associated with roots of aquatic plants and rice (Oryza sativa). However, the extent to which cable bacteria are associated with aquatic plants in nature remains unexplored.
Using newly generated and public 16S rRNA gene sequence datasets combined with fluorescence in situ hybridisation, we investigated the distribution of cable bacteria around the roots of aquatic plants, encompassing seagrass (including seagrass seedlings), rice, freshwater and saltmarsh plants.
Diverse cable bacteria were found associated with roots of 16 out of 28 plant species and at 36 out of 55 investigated sites, across four continents. Plant‐associated cable bacteria were confirmed across a variety of ecosystems, including marine coastal environments, estuaries, freshwater streams, isolated pristine lakes and intensive agricultural systems. This pattern indicates that this plant–microbe relationship is globally widespread and neither obligate nor species specific.
The occurrence of cable bacteria in plant rhizospheres may be of general importance to vegetation vitality, primary productivity, coastal restoration practices and greenhouse gas balance of rice fields and wetlands.
See also the Commentary on this article by Cardini & Malkin, 232: 1897–1900.
Endovascular thrombectomy (EVT) has changed the landscape of acute stroke therapy and has become the standard of care for selected patients presenting with anterior circulation large-vessel occlusion ...(LVO) stroke. Despite successful reperfusion, many patients with LVO stroke do not regain functional independence. Particularly, patients presenting with extremes of blood pressure (BP) or hemodynamic variability are found to have a worse clinical recovery, suggesting blood pressure optimization as a potential neuroprotective strategy. Current guidelines acknowledge the lack of randomized trials to evaluate the optimal hemodynamic management during the immediate post-stroke period. Following reperfusion, lower blood pressure targets may be warranted to prevent reperfusion injury and promote penumbral recovery, but adequate BP targets adjusted to individual patient factors such as degree of reperfusion, infarct size, and overall hemodynamic status remain undefined. This narrative review outlines the physiological mechanisms of BP control after EVT and summarizes key observational studies and clinical trials evaluating post-EVT BP targets. It also discusses novel treatment strategies and areas of future research that could aid in the determination of the optimal post-EVT blood pressure.
Acute stroke is associated with high morbidity and mortality. In the last decades, new therapies have been investigated with the aim of improving clinical outcomes in the acute phase post stroke ...onset. However, despite such advances, a large number of patients do not demonstrate improvement, furthermore, some unfortunately deteriorate. Thus, there is a need for additional treatments targeted to the individual patient. A potential therapeutic target is interventions to optimize cerebral perfusion guided by cerebral hemodynamic parameters such as dynamic cerebral autoregulation (dCA). This narrative led to the development of the INFOMATAS (Identifying New targets FOr Management And Therapy in Acute Stroke) project, designed to foster interventions directed towards understanding and improving hemodynamic aspects of the cerebral circulation in acute cerebrovascular disease states. This comprehensive review aims to summarize relevant studies on assessing dCA in patients suffering acute ischemic stroke, intracerebral haemorrhage, and subarachnoid haemorrhage. The review will provide to the reader the most consistent findings, the inconsistent findings which still need to be explored further and discuss the main limitations of these studies. This will allow for the creation of a research agenda for the use of bedside dCA information for prognostication and targeted perfusion interventions.
Pulmonary Surfactant: A Mighty Thin Film Possmayer, Fred; Zuo, Yi Y.; Veldhuizen, Ruud A. W. ...
Chemical reviews,
12/2023, Volume:
123, Issue:
23
Journal Article
Peer reviewed
Pulmonary surfactant is a critical component of lung function in healthy individuals. It functions in part by lowering surface tension in the alveoli, thereby allowing for breathing with minimal ...effort. The prevailing thinking is that low surface tension is attained by a compression-driven squeeze-out of unsaturated phospholipids during exhalation, forming a film enriched in saturated phospholipids that achieves surface tensions close to zero. A thorough review of past and recent literature suggests that the compression-driven squeeze-out mechanism may be erroneous. Here, we posit that a surfactant film enriched in saturated lipids is formed shortly after birth by an adsorption-driven sorting process and that its composition does not change during normal breathing. We provide biophysical evidence for the rapid formation of an enriched film at high surfactant concentrations, facilitated by adsorption structures containing hydrophobic surfactant proteins. We examine biophysical evidence for and against the compression-driven squeeze-out mechanism and propose a new model for surfactant function. The proposed model is tested against existing physiological and pathophysiological evidence in neonatal and adult lungs, leading to ideas for biophysical research, that should be addressed to establish the physiological relevance of this new perspective on the function of the mighty thin film that surfactant provides.
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