共查询到20条相似文献,搜索用时 31 毫秒
1.
G. Steinhauser W. Adlassnig M. Peroutka A. Musilek J. H. Sterba M. Bichler I. K. Lichtscheidl 《Journal of Radioanalytical and Nuclear Chemistry》2007,274(2):403-409
In this paper, methods for the application of radiotracers in the Cobra Lily (Darlingtonia californica), a carnivorous pitcher plant, are described. The uptake of radiotracers such as 42K and 54Mn into the pitcher trap in aqueous solution could be proven, whereas uptake of 59Fe ions could not be observed. No-carrier-added 54Mn was taken up by the plants, regardless of extremely low concentrations. In contrast to earlier experiments using 14C and 15N-based tracers, the methodology presented allows quick, simple and reliable quantification of the nutrient uptake. The results
of our experiments lead to a deeper biological understanding concerning the trace element household of this carnivorous plant
and the absorption of micro-and macronutrients from trapped prey. 相似文献
2.
Comparative plant uptake and environmental behavior of U-series radionuclides at a uranium mine-mill
Concentrations of U, Th, Ra, Pb, and Po were determined in native vegetation and underlying substrate (soil and tailings) at various sites around a conventional open pit, acid leach uranium production operation in the Western United States. Radionuclide concentrations in substrate and vegetation were generally elevated above background at all sites disturbed by mining and milling activities. Observed plant/soil CR values for vegetation growing on exposed, weathered tailings were ordered as follows:238U>230Th>210Po,226Ra>210Pb. We suspect that in the case of sulfuric acid leached tailings, Ra and Pb are sequestered as sulfates, which are highly insoluble relative to U and Th sulfates, resulting in reduced availability for plant uptake. Soil acidity and the saturation condition at the tailings impoundment edge tend to enhance radionuclide availability for plant uptake. The transport of radionuclides to foliage and subsequent retention and absorption may play a role in plant contamination. 相似文献
3.
T. M. Nakanishi M. Yamawaki S. Kannno N. Nihei S. Masuda K. Tanoi 《Journal of Radioanalytical and Nuclear Chemistry》2009,282(1):265-269
We present real-time imaging of 32P-phosphate within a living plant as well as that in culture solution toward roots. The above-ground part of the plant was
irradiated with light from LED and roots were kept in dark. The plant was Lotus japonicus, cv. Miyakojima MG20 and real-time 32P-phosphate uptake manners in young, flowering and adult phase were visualized. In the case of young plant, there was a preferential
translocation of 32P in younger leaves. When the sample was treated with phosphate deficient condition, 32P uptake amount was much higher. In an adult phase, 32P uptake was high at pods. 相似文献
4.
W. L. Robison C. L. Conrado T. F. Hamilton A. C. Stoker 《Journal of Radioanalytical and Nuclear Chemistry》2000,243(2):459-465
The United States conducted a series of nuclear tests from 1946 to 1958 at Bikini, a coral atoll, in the Marshall Islands (MI). The aquatic and terrestrial environments of the atoll are still contaminated with several long-lived radionuclides that were generated during testing. The four major radionuclides found in terrestrial plants and soils are cesium-137, strontium-90, plutonium-239+240 and americium-241. Cesium-137 in the coral soils is more available for uptake by plants than 137Cs associated with continental soils of North America or Europe. Soil-to-plant 137Cs median concentration ratios (CR) (kBq·kg-1 dry weight plant/kBq·kg-1 dry weight soil) for tropical fruits and vegetables range between 0.8 and 36, much larger than the range of 0.005 to 0.5 reported for vegetation in temperate zones. Conversely, 90Sr median CRs range from 0.006 to 1.0 at the atoll versus a range from 0.02 to 3.0 for continental silica-based soils. Thus, the relative uptake of 137Cs and 90Sr by plants in carbonate soils is reversed from that observed in silica-based soils. The CRs for 239+240Pu and 241Am are very similar to those observed in continental soils. Values range from 10-6 to 10-4 for both 239+240Pu and 241Am. No significant difference is observed between the two in coral soil. The uptake of 137Cs by plants is enhanced because of the absence of mineral binding sites and the low concentration of potassium in the coral soil. Cesium-137 is bound to the organic fraction of the soil, whereas 90Sr, 239+240Pu and 241Am are primarily bound to soil particles. Assessment of plant uptake for 137Cs and 90Sr into locally grown food crops was a major contributing factor in: (1) reliably predicting the radiological dose for returning residents and (2) developing a strategy to limit the availability and uptake of 137Cs into locally grown food crops. 相似文献
5.
Terpenoids are principal chemical compounds of Wedelia prostrata Hemsl. and have different biological activities, thus the study on separation and purification of terpenoids from W. prostrata Hemsl. is necessary. In this paper, high-speed counter-current chromatography (HSCCC) was successfully established for preparative isolation and purification of terpenoids from extracts of petroleum ether fraction which extracted from whole herbs of W. prostrata Hemsl. In the process, a total of 750?mg of sample was prepared for HSCCC isolation. Terpenoids were separated and purified with the two-phase solvent system n-hexane–ethyl acetate–methanol–water (9:1:9:1, 19:1:19:1, v/v/v/v). Therefore, 5α-hydroxy-2-oxo-p-menth-6(1)-ene (4.4?mg), 3α-angeloyloxy-ent-kaur-16-en-oic acid (5.6?mg), 3α-tigloyloxy-ent-kaur-16-en-oic acid (5.7?mg), 3α-phenylpropionoyloxy-ent-kaur-16-en-oic acid (7.3?mg), 3α-senecioyloxy-ent-kaur-16-en-oic acid (11.4?mg), and kaurenoic acid (12.3?mg) were obtained from W. prostrata Hemsl. and their purities reached standard determined by HPLC. Among them, 3α-phenylpropionoyloxy-ent-kaur-16-en-oic acid and 5α-hydroxy-2-oxo-p-menth-6(1)-ene were first isolated with high quantity as a useful chemical resource. The structures of these compounds were identified by ESI-MS, 1H-NMR, and 13C-NMR. The present results demonstrated that high-speed counter-current chromatography was a fast and efficient technique for preparative separation of six terpenoids from W. prostrata Hemsl. which provided a useful reference to solve the problem of their sample availability for drug development. 相似文献
6.
K. Tanoi J. Hojo M. Nishioka T. M. Nakanishi K. Suzuki 《Journal of Radioanalytical and Nuclear Chemistry》2005,263(2):547-552
Summary We present a new trial to measure real time water movement in a living plant using the positron emitting radionuclide, 15O. 15O was prepared by 14N(d,n)15O reaction and 10 ml of 15O labeled water (2 GBq) was supplied from the root of a soybean plant. To detect activity, an imaging plate (IP) as well as a BGO detector system were used. Since the half-life of 15O is extremely short, (T1/2= 122 s), water uptake measurement was performed only for 20 minutes. In order to get [15O]waterimage, an IP was exposed to the plant for 1 minute for two times. Since the exposure to an IP requires dark condition, a BGO detector system was developed to measure [15O]waterunder light condition. A couple of BGO probes was set at the lowest stem and the gamma-rays (0.511 MeV) emitted from the radionuclide were measured through coincidence counting and compared with the radioactivity measured from an IP image. Using this system, we have found that the water uptake activity of the plant was drastically reduced under high humidity (99%) and dark condition. 相似文献
7.
How preparation and modification parameters affect PB‐PEO polymersome properties in aqueous solution
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Joachim Habel Anayo Ogbonna Nanna Larsen Simon Krabbe Kristoffer Almdal Claus Hélix‐Nielsen 《Journal of Polymer Science.Polymer Physics》2016,54(16):1581-1592
The effect of formation and modification methods on the physical properties of polymersomes is critical for their use in applications relying on their ability to mimic functional properties of biological membranes. In this study, we compared two formation methods for polymersomes made from polybutadiene‐polyethylene oxide diblock copolymers: detergent‐mediated film rehydration (DFR) and solvent evaporation (SE). DFR‐prepared polymersomes showed a three times higher permeability compared to SE‐prepared polymersomes as revealed by stopped‐flow light scattering. SE‐prepared polymersomes broke down faster to structures <50 nm diameter when processed with extrusion, which was more pronounced at 5 mg mL?1, compared to 10, 20, and 25 mg mL?1. Our results indicate that the bilayer of SE‐prepared polymersomes has a lower apparent fluidity. We also investigated the role of n‐octyl‐β‐d ‐glucopyranoside (OG), a detergent typically used for reconstitution of membrane proteins into lipid bilayers. Specifically, we compared dialysis and biobeads for OG removal to investigate the influence of these methods on bilayer conformation and polymer rearrangement following detergent removal. There was no significant difference found between method, temperature, or time within each method. Our findings provide insight on how biocompatible polymersome production affects the physical properties of the resulting polymersomes. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1581–1592 相似文献
8.
How the various organic and inorganic arsenic species affect the nitrogen metabolism of a model plant, Tropaeolum majus, was studied in order to evaluate the toxicological impact of the various chemical forms of arsenic. For this purpose, the effects on the (a) entire nitrogen pool, (b) protein fraction, and (c) non‐protein fraction were distinguished. The arsenic‐dependent effects on the nitrogen cycle were assessed by using 15N‐labelled KNO3 as a nutritive substance and optical emission spectroscopy to analyse how 15N is incorporated into the nitrogen cycle. In addition to the 15N‐tracer experiments, the uptake and metabolization of the arsenic compounds were examined. The work shows that biochemical indicator systems like 15N‐tracer studies are able to characterize the degree of the influence of metabolic processes by arsenic species. For example, the incorporated 15N concentration decreased linearly and independently of the 15N fraction with increasing dimethylarsinate (DMA) concentrations. This behaviour indicates that DMA has prevented the uptake of 15N and hence the formation of amino acids and proteins. Arsenite‐treated plants exhibited an elevated concentration of non‐protein 15N, which could be an indication either for a stimulated uptake of nitrate or for an interrupted amino acid/protein synthesis. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
9.
Zdenka Šlejkovec Johannes T. van Elteren Hylke-Jan Glass Zvonka Jeran Radojko Jaćimović 《International journal of environmental analytical chemistry》2013,93(10):784-796
Two areas near derelict calciners in Cornwall (UK) were chosen to study the uptake of arsenic from arsenic-contaminated soil into indigenous plants (heather, Calluna vulgaris; blackberry, Rubus ulmifulmus; gorse, Ulex europaeus). With total arsenic concentrations in soil ranging from 1240 to 2860 mg kg?1 at Site 1 (Tuckingmill), no adverse effects on the growth of the plants studied were observed. Very low soil-to-plant transfer factors (0.01 to 0.03) were found although they were much higher when the extractable soil arsenic concentrations were taken into account (0.1 to 1.1). In the central dump area at Site 2 (Bissoe, 9.78% [w/w] arsenic in soil), the only plant to grow was heather, although it was severely impaired. However, heather was thriving at the edge of the dump where higher soil arsenic concentrations were found (10.32% [w/w]), indicating that arsenic is not a growth-limiting factor in itself. Soil-to-plant transfer factors in the range 2 × 10?5–9 × 10?4 confirm that arsenic is indeed effectively excluded from uptake, even taking into account extractable soil arsenic concentrations (9 × 10?4–1.2 × 10?2). Extraction of bioavailable arsenic from soil using 0.05 mol L?1 ammonium sulphate yielded recoveries from 1.18 to 3.34% of the total arsenic, predominantly in the form of arsenate. Extraction of arsenic and its metabolites from plants was achieved with water or a water/methanol mixture yielding recoveries up to 22.4% of the total arsenic, with arsenite and arsenate the predominant arsenic species and a minor fraction consisting of methylarsonic acid, dimethylarsinic acid and trimethylarsine oxide. The identity of the remainder of the non-extractable arsenic species still has to be revealed. Although the data suggest that higher plants synthesise organoarsenic compounds it cannot be excluded that symbiotic organisms have synthesised these compounds. 相似文献
10.
106Ru chloro and nitrosyl-nitrato complexes in sea water were separated into several species by continuous electrophoresis on
a filter paper curtain. Biological uptake experiments were carried out on sea algae Fucus virsoides with fractionated106Ru chloro and nitrosyl-nitrato complex species in sea water. The biological uptake of106Ru chloro complex species was about 8 times higher than the uptake of106Ru nitrosyl-nitrato species. Electrophoretically most mobile electrically positively charged cationic species in both systems
also showed about 8 times higher biological uptake than the most mobile negatively charged anionic species. A close relation
of the biological uptake to the sign of the electrical charge and the electrophoretic mobility of the species is demonstrated.
The results are discussed with respect to possible danger to the biological environment as a consequence of the aging of ruthenium
species in sea water resulting from106Ru waste disposal to the sea from a nuclear reprocessing plant.
On leave of absence from the National Institute of Radiological Sciences, 9-1, 4-chome, Anagawa, Chiba-shi, Japan, on a fellowship
from The Science and Technology Agency of the Japanese Govemment. 相似文献
11.
Liqin Liu Guangrong Zhong Yaqian Wei Min Zhang Xuebin Wang 《Journal of Radioanalytical and Nuclear Chemistry》2011,288(2):467-473
A conjugate of 6-hydrazinopyridine-3-carboxylic acid (HYNIC) with aminomethylenediphosphonic acid (AMDP) was synthesized through
a multiple-step reaction. HYNIC–AMDP could be labeled easily and efficiently with 99mTc using N-(2-hydroxy-1,1-bis(hydroxymethyl)ethyl)glycine (tricine) as coligand to form the 99mTc–HYNIC–AMDP complex in high yield (> 95%). Its partition coefficient indicated that it was a good hydrophilic complex. The
biodistribution studies of 99mTc–HYNIC–AMDP in normal ICR mice showed that this complex had high bone uptake and low or negligible accumulation in non-target
organs. As compared with 99mTc–MDP, 99mTc–HYNIC–AMDP had a higher bone uptake and the ratios of bone/blood and bone/muscle at early time after injection, suggesting
that it could be potentially useful for bone imaging at an earlier time after injection according to further investigations
of the biological behavior of this complex. 相似文献
12.
Faria Luis F. Figueiredo Gimenes Maria Antonieta P. Nobrega Ronaldo Pereira Nei 《Applied biochemistry and biotechnology》2002,98(1-9):449-458
Oxygen availability is the most important environmental parameter in the production of xylitol by yeasts, directly affecting
yields and volumetric productivity. This work evaluated the cell behavior in fermentations carried out with different dissolved
oxygen concentrations (0.5–30.0% of saturation), as well as a limited oxygen restriction (0% of saturation), at several oxygen
volumetric transfer coefficients (12 ≤ k
L
a ≤ 70 h−1). These experiments allowed us to establish the specific oxygen uptake rate limits to ensure high yields and volumetric productivity.
When oxygen availability was limited, the specific oxygen uptake rate values were between 12 and 26 mg of O2/of g cell·h, resulting in a yield of 0.71 g of xylitol/xylose consumed, and 0.85 g/[L·h] for the volumetric productivity.
According to the results, the effective control of the specific oxygen uptake rate makes it possible to establish complete
control over this fermentative process, for both cell growth and xylitol production. 相似文献
13.
Susan E. Howe C. M. Davidson Martin McCartney 《Analytical and bioanalytical chemistry》1999,363(5-6):582-584
Uranium was determined in extracts of inter-tidal sediment, obtained from a contaminated harbour, using the three-stage sequential extraction procedure recommended by BCR. The element was found mainly in association with reducible, or reducible and oxidisable, phases and the overall concentration was enhanced (up to 6.7 μg g–1 dry weight) with respect to typical, UK levels. The 238U/235U ratio has been measured in digests of stream sediments obtained from the vicinity of a uranium enrichment plant. Significant enhancement in 235U with respect to the natural 238U/235U ratio (137.88:1) was observed at some locations. 相似文献
14.
Tammela P Wennberg T Vuorela H Vuorela P 《Analytical and bioanalytical chemistry》2004,380(4):614-618
High performance liquid chromatography (HPLC) micro-fractionation was successfully coupled to an automated 45Ca2+ uptake assay using GH4C1 cells for the separation of natural product extracts and for the primary detection of their calcium antagonistic components. The reliability of the procedure was first established with a reference solution consisting of pure compounds with a known effect on the Ca2+ uptake. No loss of activity was observed to occur after HPLC micro-fractionation. Extracts of Peucedanum palustre and Pinus sylvestris, showing high and no inhibition of Ca2+ uptake as total extracts, respectively, were analysed and the inhibitory activity of the P. palustre extract could be traced to two components, identified as columbianadin and isoimperatorin. As expected, no significant inhibition was observed with the micro-fractionated P. sylvestris samples. In summary, the procedure was found to be applicable for primary detection of calcium antagonistic components in complex matrices and to significantly reduce the time previously needed for bioactivity-guided isolation. 相似文献
15.
Ryoko Fujiyoshi Naoki Takekoshi Kazumasa Okamoto 《Journal of Radioanalytical and Nuclear Chemistry》2014,299(3):1365-1371
Radiopotassium isotopic composition (40K/K, %) of several forest soils did not show a constant value of generally known 1.17 × 10?2 %, but they were varied significantly from 0.4 × 10?2 to 1.3 × 10?2 % at different locations under different environmental conditions. Surface portion of a soil (2–4 cm in depth) gave always lower 40K/K values compared with those of deeper soil layer (35–40 cm in depth). Ion exchange of K+ with NH4 + did not affects the 40K/K value in any soils, which revealed with chemical leaching experiments in the laboratory. Some plant species showed much lower 40K/K values than those in the surface soil. Possible reasons for varying 40K/K values obtained in this study may result from a dynamic behavior of potassium in soil, probably due to biological activity including root uptake and decomposing soil organic matter by microorganisms in the forest floor. 相似文献
16.
N. Miekeley E. A. Casartelli R. M. Dotto 《Journal of Radioanalytical and Nuclear Chemistry》1994,182(1):75-89
Plants and soils from a natural thorium and rare-earth element occurrence (Morro do Ferro, Brazil) were analyzed by alpha spectrometry (Th) and ICP-AES (REE), after pre-concentration of the elements by solvent extraction, co-precipitation and ion exchange procedures. Leaching experiments with humic acid solutions and different soils were performed to estimate the fraction of elements biologically available. High concentrations of the light rare-earth elements (LREE) and of Th, reaching some hundreds of g/g-ash, were measured in plant leaves from the areas of the highest concentration of these elements in soil and in near-surface waters. Chondrite normalized REE plots of plant leaves and corresponding soils are very similar, suggesting that there is no significant fractionation between the REE during uptake from the soil solution and incorporation into the leaves. However, Ce-depletion was observed for some plant species, increasing forSolanum ciliatum in the sequence: leaves<fruits<seeds. Soil to plant concentration ratios (CR's) for Th and the REE, based on the total concentration of these elements in soils, are in the range of 10–3 to 10–2. Leaching experiments confirmed the importance of humic acid complexation for the bio-uptake of Th and REE and further showed that only a very small fraction of these elements in soil is leachable. The implications of these results on the calculated CR's will be discussed. 相似文献
17.
Jan Reent Köster Roland Bol Melanie J. Leng Adrian G. Parker Hilary J. Sloane Jian F. Ma 《Rapid communications in mass spectrometry : RCM》2009,23(16):2398-2402
Rice (Oryza sativa L.) accumulates large amounts of silicon which improves its growth and health due to enhanced resistance to biotic and abiotic stresses. Silicon uptake and loading to xylem in rice are predominantly active processes performed by transporters encoded by the recently identified genes Lsi1 (Si influx transporter gene) and Lsi2 (Si efflux transporter gene). Silicon deposition in rice during translocation to upper plant tissues is known to discriminate against the heavier isotopes 29Si and 30Si, resulting in isotope fractionation within the plant. We analyzed straw and husk samples of rice mutants defective in Lsi1, Lsi2 or both for silicon content and δ29Si using isotope ratio mass spectrometry (IRMS) and compared these results with those for the corresponding wild‐type varieties (WT). The silicon content was higher in husk than in straw. All the mutant rice lines showed clearly lower silicon content than the WT lines (4–23% Si of WT). The δ29Si was lower in straw and husk for the uptake defective mutant (lsi1) than for WT, albeit δ29Si was 0.3‰ higher in husk than in straw in both lines. The effect of defective efflux (lsi2) differed for straw and husk with higher δ29Si in straw, but lower δ29Si in husk while WT showed similar δ29Si in both fractions. These initial results show the potential of Si isotopes to enlighten the influence of active uptake on translocation and deposition processes in the plant. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
18.
J. Furukawa 《Journal of Radioanalytical and Nuclear Chemistry》2001,249(2):495-498
We present real time vanadate (V5+ ) uptake imaging in acowpea plant by positron emitting tracer imaging system (PETIS). Vanadium-48was produced by bombarding a Sc foil target with 50 MeV -particlesat Takasaki Ion Accelerators for Advanced Radiation Application (TIARA) AVFcyclotron. Then 48 V was added to the culture solution to investigatethe V distribution in a cowpea plant. The real time uptake of the 48V was monitored by PETIS. We measured the distribution of 48Vin a whole plant after 3, 6 and 20 hours of V treatment by Bio-imaging AnalyzerSystem (BAS). After the 20 hour treatment, vanadate was detected at the up-groundpart of the plant. To know the effect of V uptake on plant activity, 18F-labeled water uptake was analyzed by PETIS. When a cowpea plantwas treated with V for 20 hours before 18 F-labeled water uptakeexperiment, the total amount of 18F-labeled water absorption wasdrastically decreased. Results suggest the inhibition of water uptake wasmainly caused by the vanadate already moved to the up-ground part of the plant. 相似文献
19.
M. Felipe-Sotelo A. Carlosena J.M. Andrade M.J. Cal-Prieto E. Fernndez D. Prada 《Microchemical Journal》2005,81(2):217-224
Two slurry-based ETAAS methodologies are compared to determine directly Cr, Ni and V in coal fly ash, soils and sediments: current slurry analysis (USS) and ‘slurry extraction’ (SE). Slurries for USS-ETAAS were prepared in 0.5% HNO3. HF and HNO3 were evaluated as chemical modifiers. HF was the extractant for the SE-ETAAS approach.A unique slurry-based procedure to measure Cr, Ni and V could not be established. Cr concentrations up to 100 μg g− 1 were accurately determined by USS (0.5% HNO3; λ = 429.0 nm; LOD = 0.35 μg g− 1) whereas higher contents required the SE procedure (sample grinding, 30% HF; LOD = 0.02 μg g− 1). Both methods were appropriate to determine Ni (LOD = 0.11 and 0.08 μg g− 1, for USS and SE, respectively). V was satisfactorily quantified only with the USS approach (LOD = 0.80 μg g− 1). 相似文献
20.
The transfer of 137Cs and 40K from soil to vegetation was studied in an Atlantic blanket bog ecosystem along the Atlantic coast of Ireland where the dominant
vegetation is a mixture of Calluna vulgaris, Eriophorum vaginatum and Sphagnum mosses. The impact of soil chemistry and nutritional status of vegetation on the uptake of both radionuclides was also examined.
Cesium-137 transfer factors values ranged from 1.9 to 9.6 and accumulation of 137Cs was higher in the leaves of C. vulgaris than in the stems. Transfer factors values for 137Cs in both C. vulgaris and E. vaginatum were similar indicating that for the vegetation studied, uptake is not dependent on plant species. The uptake of 137Cs in bog vegetation was found to be positively correlated with the nutrient status of vegetation, in particular the secondary
nutrients, calcium and magnesium. Potassium-40 transfer factors ranged from 0.9 to 13.8 and uptake was higher in E. vaginatum than in C. vulgaris, however, unlike 137Cs, the concentrations of 40K within the leaves and stems of C. vulgaris were similar. The concentration of both 137Cs and 40K found in moss samples were in general lower than those found in vascular plants. 相似文献