Significance Of CO Research Articles

The importance of and difficulties involved in creating molecular probes for a carbon monoxide gasotransmitter.

As one of the triumvirate of recognized gasotransmitter molecules, namely NO, H2S, and CO, the physiological effects of CO and its potential as a biomarker have been widely investigated, garnering particular attention due to its reported hypotensive, anti-inflammatory, and cytoprotective properties, making it a promising therapeutic agent. However, the development of CO molecular probes has remained relatively stagnant in comparison with the fluorescent probes for NO and H2S, owing to its inert molecular state under physiological conditions. In this review, starting from elucidating the definition and significance of CO as a gasotransmitter, the imperative for the advancement of CO probes, especially fluorescent probes, is expounded. Subsequently, the current state of development of CO probe methodologies is comprehensively reviewed, with an overview of the challenges and prospects in this burgeoning field of research.

(Invited) Understanding Multi-Component Transport and Reaction Phenomena in Bipolar Membranes Used for Electrosynthesis

Bipolar membranes (BPMs), which have long seen usage in electrodialysis reactors for the generation of acid and base, have recently demonstrated potential to become critical components in electrochemical synthesis devices. Because they can operate under large pH gradients, BPMs enable favorable environments for electrocatalysis at the individual electrodes. Critical to the implementation of BPMs in these devices is understanding the kinetics of water dissociation that occurs within the BPM junction as well as the co- and counter-ion crossover through the BPM, which both present significant obstacles to developing efficient and stable BPM-devices for electrosynthesis applications. Prior work has modeled ion transport in bipolar membranes in neutral salt solutions for electrodialysis. However, no model exists for the BPM under the harsh applied pH gradients that would be present in electrosynthesis, and there is significant need to explore the effects of the internal hydration on the lifetime and performance of BPMs in such environments. Additionally, a mechanistic understanding of water dissociation catalysis will be required to develop interfacial catalysts that enable the high current density operation required for scalable electrosynthesis of fuels.In this talk, we discuss modeling methodologies and physics inherent in BPMs and present our recent model of ion transport and water dissociation catalysis in BPMs across the pH scale. Specifically, we simulate multi-ion transport for a BPM with various electrolyte combinations on each side of the membrane, demonstrating the significance of co- and counter-ion crossover in BPMs operating under harsh pH gradients. We then investigate effects caused by hydration gradients that occur due to internal ion-exchange and examine potential methods for improving performance and mitigating crossover. Finally, we examine the impact of the interfacial water dissociation catalyst and perform sensitivity analysis on the key properties (catalyst point of zero charge and pKa) that dictate catalyst performance. These results provide information that is critical to developing a comprehensive understanding of multi-component phenomena in BPMs and to informing the design and implementation of BPMs in next-generation devices for the numerous electrosynthesis chemistries that benefit from operation under an applied pH gradient.

An improved method for predicting CO2 minimum miscibility pressure based on artificial neural network

The CO 2 enhanced oil recovery (EOR) method is widely used in actual oilfields. It is extremely important to accurately predict the CO 2 minimum miscibility pressure (MMP) for CO 2 -EOR. At present, many studies about MMP prediction are based on empirical, experimental, or numerical simulation methods, but these methods have limitations in accuracy or computation efficiency. Therefore, more work needs to be done. In this work, with the results of the slim-tube experiment and the data expansion of the multiple mixing cell methods, an improved artificial neural network (ANN) model that predicts CO 2 MMP by the full composition of the crude oil and temperature is trained. To stabilize the neural network training process, L2 regularization and Dropout are used to address the issue of over-fitting in neural networks. Predicting results show that the ANN model with Dropout possesses higher prediction accuracy and stronger generalization ability. Then, based on the validation sample evaluation, the mean absolute percentage error and R-square of the ANN model are 6.99 and 0.948, respectively. Finally, the improved ANN model is tested by six samples obtained from slim-tube experiment results. The results indicate that the improved ANN model has extremely low time cost and high accuracy to predict CO 2 MMP, which is of great significance for CO 2 -EOR. Cited as : Dong, P., Liao, X., Chen, Z., Chu, H. An improved method for predicting CO 2 minimum miscibility pressure based on artificial neural network. Advances in Geo-Energy Research, 2019, 3(4): 355-364, doi: 10.26804/ager.2019.04.02

The Effects Of Air Pollution On Acute Myocardial Infarction, By Gender

Introduction: Cardiovascular diseases, especially acute myocardial infarction, are the main cause of mortality and disability in Brazil and in the world. Several studies have shown evidence about the effects of air pollution on these diseases and their impact on health system. Objective: To assess the lag structure between air pollution exposure and over 50 year old cardiovascular diseases hospital admissions, by gender. The study period was January 1, 2012 to December 31, 2013, in São José dos Campos SP. Methods: This is a time series ecological study. The daily data of hospitalizations due to AMI (by gender), pollutants CO, O3, PM10, SO2 and NO2 were analyzed to estimate the association between hospitalizations due to AMI and air pollutants. It was fitted generalized linear Poisson regressions to assess the relative risk with lagged effects of air pollutants on hospital admissions up to 5 days after exposure, adjusted for time trend, minimum temperature, relative humidity and weekdays. Results: 1837 individuals were hospitalized in the period by AMI, with 636 women and 1201 men. For women, the risks were significant for CO in Lags 0 (RR = 1.31), Lag1 (RR = 1.28) and Lag 5 (RR = 1.44) and for SO2 in Lag 0 (RR = 1.05). For men there was significance for CO on Lag 5 (RR = 1.24). Regardless of gender was significant for CO on Lag 5 (RR = 1.30) and Lag 0 for SO2 (RR = 1.01). Discussion: There are few national studies that show the effects of CO exposure and hospitalizations for AMI. Our study demonstrates that the effects of CO exposure were higher and early among female group. SO2 was significant when both genders were analyzed, however when SO2 was categorized, remained significant only in the female gender. The data presented shows the important role of CO and SO2 in the genesis of admissions and it's suggested that studies about effects of air pollution should be categorized according to gender, because the risks changes according to gender, pollutant and lag.

智能制造系统协调方法研究进展

动态多变的制造系统环境中，良好的协调机制对提高制造系统的敏捷性、适应性和鲁棒性等将起到至关重要的作用。在阐述了智能制造系统协调机制意义的基础上，分析了现有协调机制与方法(如基于拉格朗日松弛法的协调、基于合同网的协调、基于Petri Net的协调、基于生物激素的协调等)的国内外研究现状及存在的问题。最后，指出了在智能制造系统中，对协调机制与方法需要进一步的研究方向。 Good coordination mechanism will play a crucial role in improving the agility, adaptability and robustness of manufacturing systems in dynamically changing manufacturing systems environment. Based on the significance of co- ordination mechanism for intelligent manufacturing system, the research status between foreign and domestic study progresses on the coordination mechanism and method (such as coordination based on Lagrange Relaxation method, co- ordination based on contract net protocol, coordination based on Petri Net, coordination based on biological hor-mone and pheromone, and so on) is given, some existent problems for coordination mechanism in existent research methods presently are pointed out. Finally, the future research trends of the coordination mechanism and methods for intelligent manufacturing system are presented.

Elevated CO2 impacts ectomycorrhiza-mediated forest soil carbon flow: fungal biomass production, respiration and exudation

Abstract Large quantities of carbon are exchanged between terrestrial ecosystems and the atmosphere, and extensive research efforts are made to understand carbon cycling and the impact of elevated atmospheric CO 2 levels. The response of soils to increased carbon availability is largely driven by root associated ectomycorrhizal fungi in forest ecosystems, since they partition host derived carbon belowground. In this review I examine how CO 2 enrichment affects ectomycorrhizal fungal biomass production, exudation, respiration, soil carbon fluxes, and other soil microbes, and the importance of the fungal species in these responses. I briefly discuss the significance of CO 2 alterations in the mycorrhizal symbiosis in the context of consequences for carbon sequestration, and present research priorities.

China’s carbon emissions from urban and rural households during 1992–2007

In China, Rapid economic growth has stimulated fast urban expansion and rural household income and consumption expenditure. In current paper, an input–output method is used to determine the impact of China’s increased urban and rural household consumption on carbon emissions. The results shows that the direct and indirect CO 2 emission from household consumption accounted for more than 40% of total carbon emissions from primary energy utilization in China in 1992–2007. The population increase, expansion of urbanization and the increase of household consumption per capita all contribute to an increase of indirect carbon emissions, while carbon intensity decline mitigates the growth of carbon emissions. Therefore, at the domestic level, household consumption is of great significance for CO 2 emission, which could be mitigated through changing the composition of goods and services consumed by households, and switching to consumption pattern of less carbon-intensive products. The government must consider the substantial contribution of household consumption to carbon emissions when China is encouraging consumption in order to address the current global financial crisis.

Carbon Dioxide in the Nitrosation of Amine: Catalyst or Inhibitor?

Nitrosamines are a class of carcinogenic, mutagenic, and teratogenic compounds generally produced from the nitrosation of amine. This paper investigates the mechanism for the formation of nitrosodimethylamine (NDMA) from the nitrosation of dimethylamine (DMA) by four common nitrosating agents (NO(2)(-), ONOO(-), N(2)O(3), and ONCl) in the absence and presence of CO(2) using the DFT method. New insights are provided into the mechanism, emphasizing that the interactions of CO(2) with amine and nitrosating agents are both potentially important in influencing the role of CO(2) (catalyst or inhibitor). The role of CO(2) as catalyst or inhibitor mainly depends on the nitrosating agents involved. That is, CO(2) shows the catalytic effect when the weak nitrosating agent NO(2)(-) or ONOO(-) is involved, whereas it is an inhibitor in the nitrosation induced by the strong nitrosating agent N(2)O(3) or ONCl. To conclude, CO(2) serves as a "double-edged sword" in the nitrosation of amine. The findings will be helpful to expand our understanding of the pathophysiological and environmental significance of CO(2) and to develop efficient methods to prevent the formation of carcinogenic nitrosamines.

A Decade of Debate: Significance of CO2 Permeation through Membrane Channels still Controversial

An interesting and lively discussion on the role of aquaporins and rhesus channels in the permeation of gases such as carbon dioxide across biological membranes unfolded during the Epithelial Transport Workshop, held in Strobl, Austria, from June 25–27, 2010, organized by the German Biophysical Society and the Johannes Kepler University of Linz. The classical view that such hydrophobic molecules can diffuse freely across phospholipid bilayer membranes (known as Overton’s rule) is supported by measurements of Pohl and coworkers. On the other hand, experiments reported by Gros, Boron and coworkers suggest reproducible and significant channel-facilitated gas permeation. The difficulty to resolve this long-standing issue (the literature discussion already goes back more than a decade) is a technical one. First of all, in aqueous solution, CO2 is in equilibrium with bicarbonate, rendering it difficult to unambiguously measure absolute CO2 concentrations. In fact, this phenomenon is exploited experimentally by the Boron group to deduce CO2 concentration changes via a change in pH. However, this indirect assessment of CO2 concentration is not without challenges, as the reaction between CO2 and the bicarbonate HCO 3 is catalyzed by the enzyme carbonic anhydrase (CA), the concentration of which therefore changes the kinetics of the reaction. Likewise, the red blood cell (RBC) CO2 permeability estimates from the build-up of extracellular isotope labeled CO2 after administering labeled HCO 3 in the absence and presence of RBCs, as carried out in the Gros lab, depends not only on the CO2 permeability of the RBC membrane, but also on the CA activity, the membrane’s permeability to protons, and unstirred layer effects. In addition, the bicarbonate itself may also permeate the membrane, via anion exchanger proteins. Nevertheless, the observed results are intriguing. Both the experiments carried out in the Gros and Boron labs observe a clear difference with and without aquaporin and rhesus channels present. Backed up by mutant and inhibitor studies, these results suggest a clear role of these channels in CO2 permeation. Not presented during the workshop, but noteworthy to mention, are the experiments of Kaldenhoff and coworkers, who have proposed a role of aquaporins in CO2 permeation in plant membranes, thereby supporting photosynthesis. Another set of experiments, however, carried out in the Pohl group on planar membranes, suggest that rather than the membrane itself, unstirred layer effects, i.e. slow diffusion across membrane-adjacent solvent layers that are not efficiently stirred, form the main barriers to gas permeation. In this view, the membrane itself, as predicted from Overton’s rule, does not pose a substantial barrier to hydrophobic molecules such as CO2. A substantial part of the Strobl discussion focused on the validity of artificial membranes to model the biological cellular counterparts. Roughly 50% of the RBC membrane, for instance, are occupied by proteins, and additional proteins on the intracellular side may further modulate the membrane permeability. In contrast, the membranes used in the Pohl experiments are typically composed of E. coli lipids enriched with sphingomyelin and cholesterol. The water permeability of these membranes closely resemble the water permeability of the oocyte membranes also studied in the Boron lab, suggesting that artificial membranes provide a valid model for biological membranes. However, it is not clear yet whether the permeation of polar water molecules requires different physicochemical mechanisms and thus may not allow one to conclude on the permeation the apolar CO2. Molecular dynamics simulations show that both Rhesus channels and aquaporins may be permeated by CO2, but that the pathway across model phospholipid bilayer membranes such as POPE, POPC, or mixtures of PE, PC and PG is much more energetically favourable. High concentrations of cholesterol of 40mol% or more increase the membrane barrier, but not to the extent that channels such as rhesus channels or aquaporins, even at high expression levels, are expected to play a major role in gas permeation. Noteworthy, whereas single-channel water permeabilities derived from aquaporin simulations are in good agreement with experimental values, the simulations predict single-channel CO2 permeabilities for rhesus and aquaporin channels that are two orders or magnitude lower than implied by the experiments carried out in the Gros lab, which suggest large permeabilities of ~10 12 cms . Given the persistence of the discrepancy, rather than experimental artifacts being responsible, it appears more likely that the different experiments are probing different phenomena. In live cells, due to the complex equilibria including many components and factors, it seems difficult to rule out the possibility [a] Prof. B. L. de Groot Max-Planck-Institute for Biophysical Chemistry Gcttingen (Germany) Fax: (+49)551-2012302 E-mail : bgroot@gwdg.de [b] Dr. J. S. Hub Department for Cell and Molecular Biology Uppsala University, Uppsala (Sweden) Fax: (+46)18-511755 E-mail : jochen@xray.bmc.uu.se

Interactions of Multiple Gas-Transducing Systems: Hallmarks and Uncertainties of CO, NO, and H2S Gas Biology

The diverse physiological actions of the "biologic gases," O2, CO, NO, and H2S, have attracted much interest. Initially viewed as toxic substances, CO, NO, and H2S play important roles as signaling molecules. The multiplicity of gas actions and gas targets and the difficulty in measuring local gas concentrations obscures detailed mechanisms whereby gases exert their actions, and many questions remain unanswered. It is now readily apparent, however, that heme-based proteins play central roles in gas-generation/reception mechanisms and provide a point where multiple gases can interact. In this review, we consider a number of key issues related to "gas biology," including the effective tissue concentrations of these gases and the importance and significance of the physical proximity of gas-producing and gas-receptor/sensors. We also take an integrated approach to the interaction of gases by considering the physiological significance of CO, NO, and H2S on mitochondrial cytochrome c oxidase, a key target and central mediator of mitochondrial respiration. Additionally, we consider the effects of biologic gases on mitochondrial biogenesis and "suspended animation." By evaluating gas-mediated control functions from both in vitro and in vivo perspectives, we hope to elaborate on the complex multiple interactions of O2, NO, CO, and H2S.

2608 CO_2地下貯留のための変容法を用いた岩石のCO_2収着挙動評価に関する研究(S31-2 温室効果ガス排出抑制技術(2),21世紀地球環境革命の機械工学:人・マイクロナノ・エネルギー・環境)

It is an important step to understand the capacity of host reservoir rocks for CO_2 storage in order to assess the potential of CO_2 geological sequestration. In this study, CO_2 sorption capacity of rocks (granite and sandstone) under air dry and water saturated conditions was evaluated experimentally at temperatures of 33, 40 and 50℃, and pressures up to 20 MPa using a volumetric method. As a result, sorption isotherms for CO_2 showed that the CO_2 sorption capacity of both the rocks increased with the increasing CO_2 pressure, and decreased with the increasing temperature under both the air dry and water saturated conditions. The amount of CO_2 sorption are significantly larger than theoretical value based on a solubility model, which assumes that CO_2 injected within water-filled reservoir will dissolve into pore water. These CO_2 sorption capacities could not fully be explained by CO_2 dissolution in water alone. Furthermore, it has been shown very interestingly that the amount of CO_2 sorption measured for the air dry condition was close to that obtained for water saturated condition. The amount of CO_2 sorption for the sandstone is approximately two times larger than that of the granite. This investigation may point out the significance of CO_2 sorption onto rock minerals for the possible mechanism in CO_2 geological sequestration.

Origin, fate and significance of CO2 in tree stems

Although some CO(2) released by respiring cells in tree stems diffuses directly to the atmosphere, on a daily basis 15-55% can remain within the tree. High concentrations of CO(2) build up in stems because of barriers to diffusion in the inner bark and xylem. In contrast with atmospheric [CO(2)] of c. 0.04%, the [CO(2)] in tree stems is often between 3 and 10%, and sometimes exceeds 20%. The [CO(2)] in stems varies diurnally and seasonally. Some respired CO(2) remaining in the stem dissolves in xylem sap and is transported toward the leaves. A portion can be fixed by photosynthetic cells in woody tissues, and a portion diffuses out of the stem into the atmosphere remote from the site of origin. It is now evident that measurements of CO(2) efflux to the atmosphere, which have been commonly used to estimate the rate of woody tissue respiration, do not adequately account for the internal fluxes of CO(2). New approaches to quantify both internal and external fluxes of CO(2) have been developed to estimate the rate of woody tissue respiration. A more complete assessment of internal fluxes of CO(2) in stems will improve our understanding of the carbon balance of trees.

Workplace Pedagogic Practices: Co–participation and Learning

This paper advances tentative bases for understanding workplace pedagogic practices. It draws on a series of studies examining learning through everyday work activities and guided learning in the workplace. These studies identified the contributions and limitations of these learning experiences. However, whether referring to the activities and interactions arising through work or intentional guided learning, the quality and likely contributions of these learning experiences are underpinned by workplace participatory practices. These practices comprise the reciprocal process of how workplaces afford participation and how individuals elect to engage with the work practice, termed co–participation. Workplace experiences are not informal. They are a product of the historical–cultural practices and situational factors that constitute the particular work practice, which in turn distributes opportunities for participation to individuals or cohorts of individuals. That is, they shape the conduct of work and learning through these practices. However, how individuals construe what is afforded by the workplace shapes how they elect to engage in that practice and learn. There is no separation between engaging in conscious thought – such as when participating in socially derived activities and interactions – and learning. Learning is conceptualised as an inter–psychological process of participation in social practices such as workplaces. It is not reserved for activities and interactions intentionally organised for learning (e.g. those in educational institutions). Nevertheless, particular kinds of activities are likely to have particular learning consequences, regardless of whether they occur in the workplace or in educational institutions. The significance of co–participation is discussed in terms of the affordance of the workplace and individuals’ construction of that affordance and subsequent engagement. Co–participation is proposed as a platform to build an understanding of workplace pedagogic practices. This includes understanding the likely contributions of learning through everyday work activities and the use of intentional workplace learning strategies, such as guided workplace learning (e.g. modelling, coaching, questioning, etc.). Instances of co–participatory practices are illustrated and discussed. Following this, a tentative scheme, founded in socio–historical activity theory, is advanced as a means for describing the requirements for work and bases for participation. The scheme comprises two dimensions: activities and interdependencies.

On the significance of CO 2 inclusions in plagioclase microphenocrysts in tholeiite from Moeraki, New Zealand

On the significance of CO 2 inclusions in plagioclase microphenocrysts in tholeiite from Moeraki, New Zealand

Genetic significance of Co, Cr, Ni, Sc and V content of andesites

The vanadium content of calc-alkaline andesites averages 175 ppm and is similar to that observed in basalts (average 200 ppm). The average nickel content of andesites is about 18 ppm, which is much lower than the nickel contents of alkali or tholeiitic basalts (average 120 ppm) but is similar to concentrations observed in high-A1 basalts (average 25 ppm). The Ni/Co ratios of calc-alkaline andesites and high-A1 basalts are less than one,in contrast to ratios of greater than two in alkali and tholeiitic basalts. The data are difficult to explain by previous hypotheses for the origin of andesite magma, that involve 1. (1) removal of magnetite 2. (2) mixing or assimilation of basic, or acid material, or deep-sea sediments, 3. (3) partial melting of quartz eclogite at high pressures and 4. (4) fractional crystallisation from a parent high-A1 basalt, under low pressures. A two-stage process of partial melting from pyrolite is consistent with the ferromagnesian trace element abundances.

Factors affecting protein synthesis in Hymenolepis diminuta (Cestoda)

1. 1. The cestode, Hymenolepis diminuta, incorporated C 14-labeled amino acids from the ambient medium into protein. The amino acids tested were incorporated at rates which did not correspond directly to the apparent internal concentration of the amino acid. The incorporation rate of lysine-C 14 was linear during a 2-hr incubation period. 2. 2. Starvation produced a depression in the corporation of lysine-C 14. Preincubation of starved worms in glucose slightly stimulated the incorporation whereas 3-0-methylglucose produced no stimulation. 3. 3. The presence of CO 2 caused a marked stimulation of lysine-C 14 incorporation in both starved and unstarved worms. The presence of glucose in the preincubation medium further enhanced this stimulation in starved worms. 4. 4. Incubation with 2,4-dinitrophenol inhibited the incorporation of lysine-C 14 by per cent. DNP abolished the stimulatory effects of CO 2 and glucose on lysine-C 14 incorporation in starved worms, substantiating the central role of CO 2 in energy metabolism of the worm. 5. 5. Galactose stimulated lysine-C 14 incorporation, but was not as effective as glucose. 6. 6. The significance of CO 2 and glucose in the metabolism of the parasite is discussed.