684 research outputs found
Reduction of Amine Emissions from an Aqueous Amine Carbon Dioxide Capture System Using Charged Colloidal Gas Aphrons
The present invention includes a system and process to reduce amine mist emissions (or MEA) from carbon capture systems using colloidal gas aphrons (CGA), and includes a method for separating and recovering an amine solvent (e.g., in the form of entrained droplets/mist and/or fine aerosol particles) from a carbon dioxide scrubbed flue gas stream exiting a carbon capture system (e.g., oil-fired power plants, coal-fired power plants, and/or natural gas combined cycle plants)
A survey of opinion: When to start oral anticoagulants in patients with acute ischaemic stroke and atrial fibrillation?
Background: There is uncertainty regarding the optimal timing for initiation of oral anticoagulant treatment (OAC) in patients with recent ischaemic stroke and atrial fibrillation (AF). We surveyed the current UK practice and assessed clinician’s opinions of when to use OAC in recent stroke patients with AF.
Methods: An online survey was sent to stroke physicians within the United Kingdom via their national societies.
Results: One hundred and twenty-one clinicians responded to the survey. Ninety-five percent of responders agreed there was uncertainty regarding timing of OAC initiation after AF-related ischaemic stroke. Thirty-six percent of responders followed the ‘1-3-6-12’ European Society of Cardiology (ESC) guidelines recommendation. Uncertainty was greater in cases of moderate stroke than in cases of TIA, mild or severe stroke. Eighty-eight percent of responders would be willing to participate in a clinical trial of early vs. later initiation of OAC after stroke. Direct-acting oral anticoagulant (DOAC) were the preferred OAC of choice.
Conclusion: There is a lack of consensus amongst stroke physicians for when to initiate OAC to prevent recurrence in stroke patients with AF. There is little uncertainty regarding TIA. A clinical trial assessing use of early vs. later initiation of DOAC in patients with recent ischaemic stroke and AF would be beneficial
Application of a Small Unmanned Aerial System to Measure Ammonia Emissions from a Pilot Amine-CO\u3csub\u3e2\u3c/sub\u3e Capture System
The quantification of atmospheric gases with small unmanned aerial systems (sUAS) is expanding the ability to safely perform environmental monitoring tasks and quickly evaluate the impact of technologies. In this work, a calibrated sUAS is used to quantify the emissions of ammonia (NH3) gas from the exit stack a 0.1 MWth pilot-scale carbon capture system (CCS) employing a 5 M monoethanolamine (MEA) solvent to scrub CO2 from coal combustion flue gas. A comparison of the results using the sUAS against the ion chromatography technique with the EPA CTM-027 method for the standard emission sampling of NH3 shows good agreement. Therefore, the work demonstrates the usefulness of sUAS as an alternative method of emission measurement, supporting its application in lieu of traditional sampling techniques to collect real time emission data
Enhancements in Mass Transfer for Carbon Capture Solvents Part I: Homogeneous Catalyst
The novel small molecule carbonic anhydrase (CA) mimic [CoIII(Salphen-COO−)Cl]HNEt3 (1), was synthesized as an additive for increasing CO2 absorption rates in amine-based post-combustion carbon capture processes (CCS), and its efficacy was verified. 1 was designed for use in a kinetically slow but thermally stable blended solvent, containing the primary amines 1-amino-2-propanol (A2P) and 2-amino-2-methyl-1-propanol (AMP). Together, the A2P/AMP solvent and 1 reduce the overall energy penalty associated with CO2 capture from coal-derived flue gas, relative to the baseline solvent MEA. 1 is also effective at increasing absorption kinetics of kinetically fast solvents, such as MEA, which can reduce capital costs by requiring a smaller absorber tower. The transition from catalyst testing under idealized laboratory conditions, to process relevant lab- and bench-scale testing adds many additional variables that are not well understood and rarely discussed. The stepwise testing of both 1 and the novel A2P/AMP solvent blend is described through a transition process that identifies many of these process and evaluation challenges not often addressed when designing a chemical or catalytic additive for industrial CCS systems, where consideration of solvent chemistry is typically the primary goal
Ontogenetic shifts in trait-mediated mechanisms of plant community assembly
Identifying the processes that maintain highly diverse plant communities remains a central goal in ecology. Species variation in growth and survival rates across ontogeny, represented by tree size classes and life history stage-specific niche partitioning, are potentially important mechanisms for promoting forest diversity. However, the role of ontogeny in mediating competitive dynamics and promoting functional diversity is not well understood, particular in high-diversity systems such as tropical forests. The interaction between interspecific functional trait variation and ontogenetic shifts in competitive dynamics may yield insights into the ecophysiological mechanisms promoting community diversity. We investigated how functional trait (seed size, maximum height, SLA, leaf N, and wood density) associations with growth, survival, and response to competing neighbors differ among seedlings and two size classes of trees in a subtropical rain forest in Puerto Rico. We used a hierarchical Bayes model of diameter growth and survival to infer trait relationships with ontogenetic change in competitive dynamics. Traits were more strongly associated with average growth and survival than with neighborhood interactions, and were highly consistent across ontogeny for most traits. The associations between trait values and tree responses to crowding by neighbors showed significant shifts as trees grew. Large trees exhibited greater growth as the difference in species trait values among neighbors increased, suggesting trait-associated niche partitioning was important for the largest size class. Our results identify potential axes of niche partitioning and performance-equalizing functional trade-offs across ontogeny, promoting species coexistence in this diverse forest community
Before it is too late: professional responsibilities in late-onset Alzheimer's research and pre-symptomatic prediction
The development of a wide array of molecular and neuroscientific biomarkers can provide the possibility to visualize the course of Alzheimer’s disease (AD) at early stages. Many of these biomarkers are aimed at detecting not only a preclinical, but also a pre-symptomatic state. They are supposed to facilitate clinical trials aiming at treatments that attack the disease at its earliest stage or even prevent it. The increasing number of such biomarkers currently tested and now partly proposed for clinical implementation calls for critical reflection on their aims, social benefits, and risks. This position paper summarizes major challenges and responsibilities. Its focus is on the ethical and social problems involved in the organization and application of dementia research, as well as in healthcare provision from a cross-national point of view. The paper is based on a discussion of leading dementia experts from neuroscience, neurology, social sciences, and bioethics in the United States and Europe. It thus reflects a notable consensus across various disciplines and national backgrounds. We intend to initiate a debate on the need for actions within the researchers’ national and international communities
Towards local electromechanical probing of cellular and biomolecular systems in a liquid environment
Electromechanical coupling is ubiquitous in biological systems with examples
ranging from simple piezoelectricity in calcified and connective tissues to
voltage-gated ion channels, energy storage in mitochondria, and
electromechanical activity in cardiac myocytes and outer hair cell stereocilia.
Piezoresponse force microscopy (PFM) has originally emerged as a technique to
study electromechanical phenomena in ferroelectric materials, and in recent
years, has been employed to study a broad range of non-ferroelectric polar
materials, including piezoelectric biomaterials. At the same time, the
technique has been extended from ambient to liquid imaging on model
ferroelectric systems. Here, we present results on local electromechanical
probing of several model cellular and biomolecular systems, including insulin
and lysozyme amyloid fibrils, breast adenocarcinoma cells, and
bacteriorhodopsin in a liquid environment. The specific features of SPM
operation in liquid are delineated and bottlenecks on the route towards
nanometer-resolution electromechanical imaging of biological systems are
identified.Comment: 37 pages (including refs), 8 figure
QuPath Digital Immunohistochemical Analysis of Placental Tissue
Background: QuPath is an open‑source digital image analyzer notable for its user‑friendly design, cross‑platform compatibility, and customizable functionality. Since it was first released in 2016, at least 624 publications have reported its use, and it has been applied in a wide spectrum of settings. However, there are currently limited reports of its use in placental tissue. Here, we present the use of QuPath to quantify staining of G‑protein coupled receptor 18 (GPR18), the receptor for the pro‑resolving lipid mediator Resolvin D2, in placental tissue. Methods: Whole slide images of vascular smooth muscle (VSM) and extravillous trophoblast (EVT) cells stained for GPR18 were annotated for areas of interest. Visual scoring was performed on these images by trained and in‑training pathologists, while QuPath scoring was performed with the methodology described herein. Results: Bland–Altman analyses showed that, for the VSM category, the two methods were comparable across all staining levels. For EVT cells, the high‑intensity staining level was comparable across methods, but the medium and low staining levels were not comparable. Conclusions: Digital image analysis programs offer great potential to revolutionize pathology practice and research by increasing accuracy and decreasing the time and cost of analysis. Careful study is needed to optimize this methodology further
QuPath Digital Immunohistochemical Analysis of Placental Tissue
Background: QuPath is an open-source digital image analyzer notable for its user-friendly design, cross-platform compatibility, and customizable functionality. Since it was first released in 2016, at least 624 publications have reported its use, and it has been applied in a wide spectrum of settings. However, there are currently limited reports of its use in placental tissue. Here, we present the use of QuPath to quantify staining of G-protein coupled receptor 18 (GPR18), the receptor for the pro-resolving lipid mediator Resolvin D2, in placental tissue.
Methods: Whole slide images of vascular smooth muscle (VSM) and extravillous trophoblast (EVT) cells stained for GPR18 were annotated for areas of interest. Visual scoring was performed on these images by trained and in-training pathologists, while QuPath scoring was performed with the methodology described herein.
Results: Bland-Altman analyses showed that, for the VSM category, the two methods were comparable across all staining levels. For EVT cells, the high-intensity staining level was comparable across methods, but the medium and low staining levels were not comparable.
Conclusions: Digital image analysis programs offer great potential to revolutionize pathology practice and research by increasing accuracy and decreasing the time and cost of analysis. Careful study is needed to optimize this methodology further
Telomeric expression sites are highly conserved in trypanosoma brucei
Subtelomeric regions are often under-represented in genome sequences of eukaryotes. One of the best known examples of the use of telomere proximity for adaptive purposes are the bloodstream expression sites (BESs) of the African trypanosome Trypanosoma brucei. To enhance our understanding of BES structure and function in host adaptation and immune evasion, the BES repertoire from the Lister 427 strain of T. brucei were independently tagged and sequenced. BESs are polymorphic in size and structure but reveal a surprisingly conserved architecture in the context of extensive recombination. Very small BESs do exist and many functioning BESs do not contain the full complement of expression site associated genes (ESAGs). The consequences of duplicated or missing ESAGs, including ESAG9, a newly named ESAG12, and additional variant surface glycoprotein genes (VSGs) were evaluated by functional assays after BESs were tagged with a drug-resistance gene. Phylogenetic analysis of constituent ESAG families suggests that BESs are sequence mosaics and that extensive recombination has shaped the evolution of the BES repertoire. This work opens important perspectives in understanding the molecular mechanisms of antigenic variation, a widely used strategy for immune evasion in pathogens, and telomere biology
- …