scholarly journals [11C]Carbon Dioxide: Starting Point for Labeling PET Radiopharmaceuticals

2018 ◽  
Author(s):  
Lingyun Yang ◽  
Peter J. H. Scott ◽  
Xia Shao
Keyword(s):  
Carbon Dioxide ◽  
Starting Point ◽  
Pet Radiopharmaceuticals

The award of medals by the President, Sir George Porter, at the Anniversary Meeting, 30 November 1987

1988 ◽  
Vol 417 (1852) ◽  
pp. 1-5
Keyword(s):  
Carbon Dioxide ◽  
Electron Transfer ◽  
Chemical Analysis ◽  
Water Oxidation ◽  
Carbon Dioxide Reduction ◽  
Electron Transfer Pathway ◽  
Starting Point ◽  
Main Pathway ◽  
Isolated Chloroplasts ◽  
Detailed Chemical

The Copley Medal is awarded to Dr R. Hill, F. R. S., in recognition of his pioneering contributions to the understanding of the nature and mechanism of the main pathway of electron transport in photosynthesis. Almost fifty years ago Hill made the first important discovery that allowed detailed chemical analysis of the pathways of photosynthesis, when he demon­strated the light-driven oxidation of water by isolated chloroplasts, and this made it possible to study water oxidation separately from carbon-dioxide reduction. This was the starting point in the elucidation of the electron-transfer pathway in photosynthesis, and in 1951 Hill, with R. Scarisbrick, uncovered the first com­ponent in the chain when they discovered cytochrome and established its key properties. Subsequently, with H. E. Davenport, Hill discovered the second com­ponent of the chain, shown later by others to be ferredoxin. With F. Bendall he formulated the ‘Z-scheme’ to describe the mechanism of electron transfer in photosynthesis in chloroplasts, which showed the relation between the photochemically driven elements and conventional electron-transfer chains found in other biological systems. This proposal brought great clarity to the field and set the scene for further detailed elucidation of the mechanisms.

Predation of freshwater fish in environments with elevated carbon dioxide

2017 ◽  
Vol 68 (9) ◽  
pp. 1585 ◽  
Author(s):  
Stephen R. Midway ◽  
Caleb T. Hasler ◽  
Tyler Wagner ◽  
Cory D. Suski
Keyword(s):  
Carbon Dioxide ◽  
Elevated Co2 ◽  
Prey Capture ◽  
Micropterus Salmoides ◽  
Pimephales Promelas ◽  
Co2 Concentration ◽  
High Pco2 ◽  
Starting Point ◽  
Carbon Dioxide Co2 ◽  
Future Work

Carbon dioxide (CO2) in fresh-water environments is poorly understood, yet in marine environments CO2 can affect fish behaviour, including predator–prey relationships. To examine changes in predator success in elevated CO2, we experimented with predatory Micropterus salmoides and Pimephales promelas prey. We used a two-factor fully crossed experimental design; one factor was 4-day (acclimation) CO2 concentration and the second factor CO2 concentration during 20-min predation experiments. Both factors had three treatment levels, including ambient partial pressure of CO2 (pCO2; 0–1000 μatm), low pCO2 (4000–5000 μatm) and high pCO2 (8000–10000 μatm). Micropterus salmoides was exposed to both factors, whereas P. promelas was not exposed to the acclimation factor. In total, 83 of the 96P. promelas were consumed (n=96 trials) and we saw no discernible effect of CO2 on predator success or time to predation. Failed strikes and time between failed strikes were too infrequent to model. Compared with marine systems, our findings are unique in that we not only saw no changes in prey capture success with increasing CO2, but we also used CO2 treatments that were substantially higher than those in past experiments. Our work demonstrated a pronounced resiliency of freshwater predators to elevated CO2 exposure, and a starting point for future work in this area.

Static Compression Tests of Concentrated Crystallized Carbon Dioxide

2015 ◽  
Vol 816 ◽  
pp. 490-495 ◽  
Author(s):  
Jan Górecki ◽  
Ireneusz Malujda ◽  
Krzysztof Talaśka ◽  
Mateusz Kukla ◽  
Paweł Tarkowski
Keyword(s):  
Mechanical Properties ◽  
Carbon Dioxide ◽  
Test Methods ◽  
Test Results ◽  
Compression Tests ◽  
Static Compression ◽  
Starting Point ◽  
Ratio Limit ◽  
Limit Stress ◽  
The Relationship

This paper presents the results of static compression tests of concentrated crystallized carbon dioxide. The test results obtained under this research describe the relationship between the compressive stress and strain allowing to estimate the proportionality ratio, limit stress and critical stress values. Special test methods were used due to low temperature of crystallized carbon dioxide (minus 78.5°C) and its sublimation under standard testing conditions. The results of the mechanical properties of agglomerated CO2 were compared with the mechanical properties of other known materials. This allowed us to derive assumptions, which can become the starting point of the process to build a mathematical model describing the dry ice compaction and granulation processes.

scholarly journals Rethinking climate policy with alternative framings of carbon dioxide

2019 ◽  
Vol 2 ◽  
Author(s):  
Jarkko Levänen ◽  
Janne I. Hukkinen
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Climate Policy ◽  
International Climate Policy ◽  
Starting Point ◽  
International Climate ◽  
Mitigate Climate Change ◽  
Combat Climate Change

Abstract Since the earliest stages of international climate policy, carbon dioxide (CO2) has been framed and widely accepted as a problem that needs to be solved by reducing its amount in the atmosphere. In principle this is a correct and relevant starting point for efforts to decarbonize societies. At the same time, however, the unquestioned and one-sided framing of CO2 as a problem has significantly biased the strategies for tackling climate change. We introduce the origins, meanings and implications of one-sided framing of CO2 in climate policy. We also discuss how alternative framings could impact policymaking and eventually our capacity to mitigate climate change. We introduce a paradox: framing CO2 as a problem often translates into policies that hamper the implementation of technologies to decrease the amount of CO2 emitted into the atmosphere. We suggest that plurality in framing CO2 could lead to innovative ways and strategies to combat climate change.

scholarly journals Relation between CO2 emissions and crude oil combustion in Iraq

2021 ◽  
Vol 30 (3) ◽  
pp. 379-387
Author(s):  
Ahmed Hassan ◽  
Hasan Azeez
Keyword(s):  
Carbon Dioxide ◽  
Crude Oil ◽  
Co2 Emissions ◽  
Carbon Dioxide Emissions ◽  
Co2 Concentration ◽  
Annual Data ◽  
Co2 Concentrations ◽  
Starting Point ◽  
The World ◽  
Analysis Center

Fossil fuel is the main source for CO2 emissions that causes global warming. This fact is the starting point for this paper, that consider on three different sources of data: crude oil used to calculate CO2 emissions for Iraq for the period from 1980 to 2018; annual data of total CO2 emissions available from the Carbon Dioxide Information Analysis Center (CDIAC) for Iraq and the world for the period from 1980 to 2014; and CO2 concentrations for Iraq for the period from 2002 to 2006 and for the world for the period from 1980 to 2018. The result is a multifaceted according to the dataset sources. Carbon dioxide emissions calculated from Iraqi crude oil was increased from 1.29 Mt in 2012 to 1.97 Mt in 2018. The world and Iraq CO2 emissions with different slop of average line that was 0.5 for world, 0.003 for Iraq, while increased exponential function from 2008 to 2014 to reach 36 and 0.17 Mt, respectively. The highest value of Iraqi CO2 concentration was 403 ppm in 2016, while the global CO2 concentrations slowly increased with slop line equal to 1.75 ppm per year, from minimum value of 338.6 ppm was in 1980, while maximum value of 407.05 ppm was in 2018, that’s mean no decreased in CO2 concentration unless emissions addressed.

The award of medals by the President, Sir George Porter, at the Anniversary Meeting, 30 November 1987

1988 ◽  
Vol 233 (1273) ◽  
pp. 379-383
Keyword(s):  
Carbon Dioxide ◽  
Electron Transfer ◽  
Chemical Analysis ◽  
Water Oxidation ◽  
Carbon Dioxide Reduction ◽  
Electron Transfer Pathway ◽  
Starting Point ◽  
Main Pathway ◽  
Isolated Chloroplasts ◽  
Detailed Chemical

The Copley Medal is awarded to Dr R. Hill, F. R. S., in recognition of his pioneering contributions to the understanding of the nature and mechanism of the main pathway of electron transport in photosynthesis. Almost fifty years ago Hill made the first important discovery that allowed detailed chemical analysis of the pathways of photosynthesis, when he demonstrated the light-driven oxidation of water by isolated chloroplasts, and this made it possible to study water oxidation separately from carbon-dioxide reduction. This was the starting point in the elucidation of the electron-transfer pathway in photosynthesis, and in 1951 Hill, with R. Scarisbrick, uncovered the first component in the chain when they discovered cytochrome and established its key properties. Subseqently, with H. E. Davenport, Hill discovered the second component of the chain, shown later by others to be ferredoxin. With F. Bendall he formulated the ‘Z-scheme’ to describe the mechanism of electron transfer in photosynthesis in chloroplasts, which showed the relation between the photochemically driven elements and conventional electron-transfer chains found in other biological systems. This proposal brought great clarity to the field and set the scene for further detailed elucidation of the mechanisms.

scholarly journals Carbon dioxide for euthanasia: concerns regarding pain and distress, with special reference to mice and rats

2005 ◽  
Vol 39 (2) ◽  
pp. 137-161 ◽  
Author(s):  
K M Conlee ◽  
M L Stephens ◽  
A N Rowan ◽  
L A King
Keyword(s):  
Carbon Dioxide ◽  
Flow Rate ◽  
Hypodermic Needle ◽  
Fixed Rate ◽  
Department Of Agriculture ◽  
Laboratory Rodents ◽  
Starting Point ◽  
Key Issues ◽  
Research Standards ◽  
Do So

Carbon dioxide (CO2) is the most commonly used agent for euthanasia of laboratory rodents, used on an estimated tens of millions of laboratory rodents per year worldwide, yet there is a growing body of evidence indicating that exposure to CO2 causes more than momentary pain and distress in these and other animals. We reviewed the available literature on the use of CO2 for euthanasia (as well as anaesthesia) and also informally canvassed laboratory animal personnel for their opinions regarding this topic. Our review addresses key issues such as CO2 flow rate and final concentration, presence of oxygen, and prefilled chambers (the animal is added to the chamber once a predetermined concentration and flow rate have been reached) versus gradual induction (the animal is put into an empty chamber and the gas agent(s) is gradually introduced at a fixed rate). Internationally, animal research standards specify that any procedure that would cause pain or distress in humans should be assumed to do so in non-human animals as well (Public Health Service 1986, US Department of Agriculture 1997, Organization for Economic Cooperation and Development 2000). European Union guidelines, however, specify a certain threshold of pain or distress, such as 'skilled insertion of a hypodermic needle', as the starting point at which regulation of the use of animals in experimental or other scientific procedures begins (Biotechnology Regulatory Atlas n.d.). There is clear evidence in the human literature that CO2 exposure is painful and distressful, while the non-human literature is equivocal. However, the fact that a number of studies do conclude that CO2 causes pain and distress in animals indicates a need for careful reconsideration of its use. Finally, this review offers recommendations for alternatives to the use of CO2 as a euthanasia agent.

Electron Cytochemical Study of Carbon Dioxide Laser Effect on Rhesus Monkey Cornea

1974 ◽  
Vol 32 ◽  
pp. 224-225
Author(s):  
K. C. Tsou ◽  
J. Morris ◽  
P. Shawaluk ◽  
B. Stuck ◽  
E. Beatrice
Keyword(s):  
Carbon Dioxide ◽  
Electron Microscope ◽  
Rhesus Monkey ◽  
Carbon Dioxide Laser ◽  
Cytochemical Study ◽  
Laser Effect

While much is known regarding the effect of lasers on the retina, little study has been done on the effect of lasers on cornea, because of the limitation of the size of the material. Using a combination of electron microscope and several newly developed cytochemical methods, the effect of laser can now be studied on eye for the purpose of correlating functional and morphological damage. The present paper illustrates such study with CO2 laser on Rhesus monkey.

The Critical Point Drying Method Applied to Scanning Electron Microscopy of L-929 Cells

1970 ◽  
Vol 28 ◽  
pp. 278-279
Author(s):  
Charles TurnbiLL ◽  
Delbert E. Philpott
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
Surface Tension ◽  
Critical Point ◽  
Freeze Drying ◽  
Attractive Alternative ◽  
Crystal Formation ◽  
Critical Point Drying ◽  
Time Required ◽  
Scanning Electron

The advent of the scanning electron microscope (SCEM) has renewed interest in preparing specimens by avoiding the forces of surface tension. The present method of freeze drying by Boyde and Barger (1969) and Small and Marszalek (1969) does prevent surface tension but ice crystal formation and time required for pumping out the specimen to dryness has discouraged us. We believe an attractive alternative to freeze drying is the critical point method originated by Anderson (1951; for electron microscopy. He avoided surface tension effects during drying by first exchanging the specimen water with alcohol, amy L acetate and then with carbon dioxide. He then selected a specific temperature (36.5°C) and pressure (72 Atm.) at which carbon dioxide would pass from the liquid to the gaseous phase without the effect of surface tension This combination of temperature and, pressure is known as the "critical point" of the Liquid.

Crystal structure images of large gold clusters and growing crystals by HRTEM

1984 ◽  
Vol 42 ◽  
pp. 428-429
Author(s):  
L.R. Wallenberg ◽  
J.-O. Bovin ◽  
G. Schmid
Keyword(s):  
Crystal Structure ◽  
Nucleation And Growth ◽  
Close Packing ◽  
Gold Clusters ◽  
Molecular Weight Determination ◽  
Growth Mechanisms ◽  
Starting Point ◽  
Different Types ◽  
Nucleation And Growth Mechanisms ◽  
Points Of View

Metallic clusters are interesting from various points of view, e.g. as a mean of spreading expensive catalysts on a support, or following heterogeneous and homogeneous catalytic events. It is also possible to study nucleation and growth mechanisms for crystals with the cluster as known starting point.Gold-clusters containing 55 atoms were manufactured by reducing (C6H5)3PAuCl with B2H6 in benzene. The chemical composition was found to be Au9.2[P(C6H5)3]2Cl. Molecular-weight determination by means of an ultracentrifuge gave the formula Au55[P(C6H5)3]Cl6 A model was proposed from Mössbauer spectra by Schmid et al. with cubic close-packing of the 55 gold atoms in a cubeoctahedron as shown in Fig 1. The cluster is almost completely isolated from the surroundings by the twelve triphenylphosphane groups situated in each corner, and the chlorine atoms on the centre of the 3x3 square surfaces. This gives four groups of gold atoms, depending on the different types of surrounding.

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