A new sensitization technique combining CO2 and UV treatments for improved neutron dosimetry of CR-39 track detectors

Strong and ductile poly (lactic acid) achieved by carbon dioxide treatment at room temperature

The responses of photosynthesis, Rubisco activity, Rubisco protein, leaf carbohydrates and total soluble protein to three carbon dioxide treatments were studied in winter wheat [Triticum aestivum (L.)] and barley [Hordeum vulgare (L.)]. Barley and wheat plants were grown in small field plots during 1995 and 1996 in clear, acrylic chambers (1.2–2.4 m2) and were provided with continuous carbon dioxide fertilization at concentrations of 350, 525 and 700 μmol mol−1. Photosynthetic rates of barley penultimate leaves and wheat flag leaves measured at growth carbon dioxide concentrations decreased with leaf age in all three CO2 treatments during 1995 and 1996. Photosynthetic acclimation to elevated CO2 was observed on seven of eight measurement dates for barley and ten of eleven measurement dates for wheat over both years. Initial Rubisco activity, total soluble protein and Rubisco protein in barley penultimate leaves and wheat flag leaves also decreased with leaf age. Total Rubisco activity was not used because of enzyme degradation. There was a significant CO2 treatment effect on initial Rubisco activity, total soluble protein and Rubisco protein for wheat in 1995 and 1996 and for barley in 1995. Responses of barley penultimate leaf Rubisco activity and leaf protein concentrations to elevated carbon dioxide were nonsignificant in 1996. A significant CO2 treatment effect also was detected when means of Rubisco activity, soluble protein and Rubisco protein for wheat flag leaves were combined over harvests and years. These three flag leaf parameters were not significantly different in the 350 and 525 μmol mol−1 CO2 treatments but were decreased during growth in 700 μmol mol−1 CO2 relative to the other two CO2 treatments. Ratios of photosynthesis at 700 and 350 μmol mol−1 were compared to ratios of Rubisco activity at 700 and 350 μmol mol−1 using wheat flag leaf data from 1995 and 1996. Regression analysis of these data were linear [y = 0.586 + 1.103t x (r2 = 0.432)] and were significant at P ≤ 0.05. This result indicated that photosynthetic acclimation was positively correlated with changes of initial Rubisco activity in wheat flag leaves in response to CO2 enrichment. Effects of elevated CO2 on wheat leaf proteins during 1995 and 1996 and on barley during 1995 were consistent with an acceleration of senescence.

Increase in hydrophobicity of Bacillus subtilis spores by heat, hydrostatic pressure, and pressurized carbon dioxide treatments

We aimed to investigate the effects of a single carbon dioxide (CO2) treatment on arterial stiffness by monitoring the changes of aortic pulse-wave velocity (PWV) and aortic augmentation index (AIXao), which are indicators of arterial stiffness. PWV and AIXao were measured by an invasively validated oscillometric device. The measurements of stiffness parameters were performed before the CO2 treatment, and at 1, 4 and 8 h after the first treatment. Thirty-one patients were included. No significant changes were found in PWV. AIXao decreased significantly 1 h and 4 h after CO2 treatment compared to baseline values (p=0.034 and p<0.001). AIXao increased 8 h after the CO2 treatment, but remained significantly lower than baseline AIXao values (p=0.016). CO2 treatment is capable of reducing peripheral vascular resistance. We hypothesize that CO2 is not only a temporal vasodilator but is also capable of activating vasodilation pathways.

Mechanically strong and heat-resistant waste poly (ethylene terephthalate) derived by carbon dioxide treatment at ambient temperature

Water treatment facilities report that when reactivated granular activated carbon (GAC) is returned to service pH excursions may occur resulting in high pH of the treated water (e.g., pH > 9), which is a result of a calcium chemistry mechanism. Air treatments of GAC at temperatures of 673 and 723 K were found to create pH stable carbons (pH < 8.5) through the formation of acidic oxygen-containing functional groups on the carbon surface thereby neutralizing the effects of the calcium chemistry mechanism. It is proposed that carbon dioxide (CO2) treatments at ambient temperature form pH stable carbons via physisorption, and subsequent desorption, of CO2 forming carbonic acid upon water immersion.

Seed- and clonally-propagated plants of Big Sagebrush (Artemisia tridentata var.tridentata) were grown under atmospheric carbon dioxide regimes of 270, 350 and 650 μl l-1 and fed toMelanoplus differentialis andM. sanguinipes grasshoppers. Total shrub biomass significantly increased as carbon dioxide levels increased, as did the weight and area of individual leaves. Plants grown from seed collected in a single population exhibited a 3-5 fold variation in the concentration of leaf volatile mono- and sesquiterpenes, guaianolide sesquiterpene lactones, coumarins and flavones within each CO2 treatment. The concentration of leaf allelochemicals did not differ significantly among CO2 treatments for these seed-propagated plants. Further, when genotypic variation was controlled by vegetative propagation, allelochemical concentrations also did not differ among carbon dioxide treatments. On the other hand, overall leaf nitrogen concentration declined significantly with elevated CO2. Carbon accumulation was seen to dilute leaf nitrogen as the balance of leaf carbon versus nitrogen progressively increased as CO2 growth concentration increased. Grasshopper feeding was highest on sagebrush leaves grown under 270 and 650 μl l-1 CO2, but varied widely within treatments. Leaf nitrogen concentration was an important positive factor in grasshopper relative growth but had no overall effect on consumption. Potential compensatory consumption by these generalist grasshoppers was apparently limited by the sagebrush allelochemicals. Insects with a greater ability to feed on chemically defended host plants under carbon dioxide enrichment may ultimately consume leaves with a lower nitrogen concentration but the same concentration of allelochemicals. Compensatory feeding may potentially increase the amount of dietary allelochemicals ingested for each unit of nitrogen consumed.

This study was conducted to investigate the effects of carbon dioxide (CO2) and modified atmosphere (MA) packaging on the quality of strawberry during long distance transportation. “Maehyang” strawberries (Fragaria x ananassa Duch.) with red color on 70% of the fruit surface were harvested in Gyeongnam province, Korea. The samples were placed in gas-tight chamber with 30% CO2 concentration for 3 hours at 3°C. Strawberry samples were then packaged with modified atmosphere-modified humidity (MA/MH) packaging film. Samples treated with CO2 alone and combined CO2 with MA packaging were stored for one day at 1°C, transported for 10 days at 1°C, and distributed for 3 days at 4°C. Carbon dioxide alone or combination with MA packaging was effective in maintaining quality of “Maehyang” strawberries. Carbon dioxide treatment significantly increased firmness and reduced softening index and decay rate during 14 day transportation and distribution. Samples treated with CO2 + MA had higher overall score with low softening index and weight loss after 14 days of transportation and low temperature distribution compared to CO2 treatment only. The results indicated that a short term application of CO2 or combination treatment of CO2 and MA could be good postharvest handling for maintaining freshness of “Maehyang” strawberries during long distance vessel export.

High concentrations of carbon dioxide influence kiwifruit ripening

ABSTRACTRepeated measures analysis was used to evaluate the effect of long‐term CO2 enhancement on seasonal trends of light‐saturated rates of net photosynthesis (Asat) and stomatal conductance to water vapour (gsat) of 9‐year‐old loblolly pine (Pinus taeda L.) trees grown in a 2 × 2 factorial experimental design of nutrition and water. A significant interaction effect of CO2 and nutrition on mean Asat was observed for juvenile foliage. Also, juvenile foliage exposed to +350 μmol mol−1 CO2 had a higher rate of increase of Asat between late summer and early autumn. This would lead to a greater potential for recharging carbohydrate reserves for winter. Mature foliage was affected by COsat, water and nutrient treatments in two ways. First, Asat was significantly increased as a result of elevated CO2 in January, a period when stomatal conductance was only 47% of the maximum observed rate. Secondly, the rate of increase of Asat from winter to early spring was accelerated as a result of both nutrient + water and + 350 μmol mol−1 CO2 treatments. This accelerated response resulted in a greater potential for photosynthate production during the period when growth initiation occurred. Nutrient, water or carbon dioxide treatments did not significantly alter trends in gsat for mature or juvenile foliage. A significant nutrition × CO2 interaction was observed for the mature foliage, suggesting that gsat increased with increasing CO2 and nutrition. These results may have important consequences for the determination of the water use efficiency of loblolly pine. In spite of low gsat in the winter to early spring period, there was a substantial gain in Asat attributable to elevated CO2 concentrations.

The effect of high carbon dioxide and ethylene treatment on postharvest ripening regulation of red kiwifruit (Actinidia melanandra) was investigated during cold storage. Physio-chemical properties such as weight loss, firmness, SSC, acidity, and market quality were analysed in red kiwifruit held at 10oC compared to the fruit treated with carbon dioxide and ethylene during 75 days of storage. No significant weight loss was detected in red kiwifruit treated with carbon dioxide until 75 days of storage while the most rapid loss was found in fruit treated with ethylene. In ethylene-treated fruit, the firmness was dramatically reduced from 4.2kg on the first day to 1.2 kg after 27 days of storage at 10℃. However, the firmness of the carbon dioxide-treated fruit was 1.8kg after 54 days of storage. The highest level of SSC(%) was investigated within the 27 storage days at 10℃ for fresh red kiwifruit treated with exogenous ethylene,whereas the carbon dioxide-treated fruit exhibited a greatly increasedSSC after 64 days. The carbon dioxide-treated red kiwifruit maintained statistically(p<.01) higher levels of acidity compared to the control and the exogenous ethylene-treated ones during 41 days of storage at 10℃. The SSC/Acid ratio of fruit treated with carbon dioxide was significantly lower (p<.01) maintained than the other two treatments (ethylene-treated and control fruit)throughout the 75-dayexperiment. Based on the quality characteristics of postharvest red kiwifruit, it could be concluded that the carbon dioxide treatment significantly delayed the ripening process and maintained the market quality of harvested red kiwifruit, which can be a potential application for commercial use in the kiwi industry

It is commonly known that two carbon dioxide treatments accelerate the beginning of egg laying in honey bee queens. However, the minimum time between anaesthesias needed for ovary activation has not yet been examined. The aim of the study was to investigate the effect of time between carbon dioxide treatments on the onset of oviposition in instrumentally inseminated and virgin queen honey bees. About half of the queens were anaesthetised before insemination and a second time during insemination, and the rest of the queens were anaesthetised two times without insemination. The time between carbon dioxide treatments was as follows: 96, 48, 24, 12, 6, 3 hrs, 10 min, 5–6 sec. Queens in a control group were anaesthetised only once. The mean number of days between the second treatment and the onset of oviposition in particular groups and in the control group was 10.3, 7.6, 9.9, 10.5, 7.8, 10.9, 14.2, 15 and 21.9, respectively, and the median was 9, 7, 7, 8, 7, 8.5, 11.5, 13 and 21 days, respectively. Queens in groups 5–6 sec and 10 min began oviposition significantly earlier than those in control group, but significantly later than in groups from 3 to 96 hrs. Instrumentally inseminated queens started to lay eggs at the same time (mean 12 and median 9 days after second treatment) as queens treated with carbon dioxide without insemination (mean 11.7 and median 9 days).

Trees growing in urban areas face increasing stress from atmospheric pollutants, with limited attention given to the early responses of young seedlings. This study aimed to address the knowledge gap regarding the effects of simulated pollutant exposure, specifically particulate matter (PM), elevated ozone (O3), and carbon dioxide (CO2) concentrations, on young seedlings of five tree species: Scots pine (Pinus sylvestris L.); Norway spruce (Picea abies (L.) H.Karst.); silver birch (Betula pendula Roth); small-leaved lime (Tilia cordata Mill.); and Norway maple (Acer platanoides L.). The main objectives of this paper were to evaluate the seedling stem growth response and the biochemical response of seedling foliage to pollutant exposure. Four treatments were performed on two- to three-year-old seedlings of the selected tree species: with PM (0.4 g per seedling) under combined O3 = 180 ppb + CO2 = 650 ppm; without PM under combined O3 = 180 ppb + CO2 = 650 ppm; with PM (0.4 g per seedling) under combined O3 < 40-45 ppb + CO2 < 400 ppm; and without PM under combined O3 < 40-45 ppb + CO2 < 400 ppm. Scots pine and Norway maple showed no changes in growth (stem height and diameter) and biochemical parameters (photosynthetic pigments, total polyphenol content (TPC), total flavonoids content (TFC), and total soluble sugars (TSS)), indicating a neutral response to the combined PM, O3, and CO2 treatment. The chlorophyll response to PM alone and in combination with elevated O3 and CO2 exposure varied, with silver birch increasing, Norway maple-neutral to increasing, Scots pine-neutral to decreasing, and Norway spruce and small-leaved lime-decreasing. The TPC indicated stress responses in Scots pine, small-leaved lime, and Norway maple under increased combined O3 and CO2 and in Norway spruce under single PM treatment. Hence, Scots pine and Norway maple seedlings showed greater resistance to increased PM under combined O3 and CO2 with minimal change in growth, while silver birch seedlings showed adaptation potential with increasing chlorophyll under simulated pollutant stress.

A short-term carbon dioxide treatment inhibits the browning of fresh-cut burdock

A simple and effective method to enhance the level of gamma-aminobutyric acid in Chinese yam tubers while preserving its original appearance.