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1.
The effects of compatibility, that is combination of Prunus persica Batsch (L.) and Carthamus tinctorus (L.), and different acidity of digestive site on the species, lipopily and bioavailability of coordinated complex of iron, manganese, and zinc in medical decoction were studied. In view of octanol, a long-chain alkanol, resembled as the configuration of carbohydrate and adipose in human body, the octanol- and water-solubility were used to define the species of trace element in phytomedicine, to identify the lipopily and bioavailability of trace element, and octanol-water system was adopted to study the distribution of trace element in decoction of P. persica Batsch (L.) (A), C. tinctorus (L.) (B), and combination of medicine A and B (C) in stomach and intestine. The total concentration, water- and octanol-solubility concentration of iron, manganese, and zinc in medicinal material A, B and C or its decoction under gastric and intestinal acidity, were determined respectively by flame atomic absorption spectrometry, analyzed and compared. The compatibility of medicine A and B enhances the extract percent, octanol-solubility concentration, and stability of coordinated complex of iron, manganese, and zinc. Different acidity of digestive site and compatibility of medicines impact on the ligands of iron, manganese, and zinc, then greatly affect the species and its quantification, the lipopily and bioavailability of trace element. Such influence is quite different for different trace element. Such factors, especially the concentration of octanol-solubility trace element, could be the basis of the dosage to avoid trace element overload. 相似文献
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3.
Rudzani A. Makhado Martin J. Potgieter Wilmien J. Luus‐Powell Isaac Mapaure 《African Journal of Ecology》2017,55(4):600-608
Despite the nutritional value of Colophospermum mopane to browser's diets, there is still insufficient knowledge on the effect of browsers on concentrations of these trace elements. A field experiment was conducted in Musina Nature Reserve, Limpopo Province, South Africa, to determine the effect of pruning on the concentration of trace elements in mopane leaves. Samples were analysed for iron (Fe), manganese (Mn), boron (B), molybdenum (Mo), copper (Cu), zinc (Zn), cobalt (Co), fluoride (F) and selenium (Se) using the inductively coupled plasma atomic emission spectrometry technique. The effect of pruning was tested using the two‐tailed t‐test: two‐sample assuming equal variance and two‐tailed Mann–Whitney U‐test. Results showed that the concentration of trace elements in the control and pruned trees varies slightly through the year. Fe, Mn, Mo, Cu, Zn and Se are higher during leaf flush, but declined as the leaves matured and aged. This study concluded that simulated browsing had no significant effect on the concentration of trace elements in the mopane leaves. Seasonal variation in the amount of trace elements has implications on the distribution of browsers in the mopane woodland. 相似文献
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《Journal of trace elements in medicine and biology》2014,28(1):28-31
BackgroundIntraluminal thrombus (ILT) formation plays a significant role in the progression of infrarenal abdominal aortic aneurysms (AAA). Potentially, as ILT thickness increases the availability of trace elements in the aneurysm wall could decrease thereby leading to oxidative stress and intensifying pro-inflammatory cytokine generation.AimTo determine if thrombus thickness is related to the concentration of trace elements in the wall of infrarenal AAA.Patients and methodsThe concentrations of trace elements in the wall of the aneurysm sack and ILT obtained from 19 consecutive patients during surgery for infrarenal AAA were determined using emission spectrometry.ResultsThe concentrations of magnesium, zinc, manganese, and lead in the wall of AAA were significantly greater than in the ILT. Only the concentration of copper was lower in the AAA wall compared with the thrombus. The concentration of calcium, phosphorus, zinc, lead, copper, and magnesium increased with ILT thickness. The concentrations of no other trace elements in the wall of AAA were found to be related to the ILT thickness.ConclusionsIntraluminal thrombus thickness is not associated with a lower concentration of trace elements in the wall of the infrarenal AAA. Thus, the intraluminal thrombus participates in the progression of AAA by mechanisms independent of trace element supply to the wall of the aneurysm sack. 相似文献
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Ralf Conrad 《Biogeochemistry》1994,27(3):155-170
The flux of a trace gas between soil and atmosphere is usually the result of simultaneously operating production and consumption processes. The compensation concentration is the concentration at which the rate of production equals the rate of consumption so that the net flux between soil and atmosphere is zero. Production and uptake may be due to different processes, which are at least partially known for some of the trace gases, and which may be differently regulated. The direction and the magnitude of the flux between soil and atmosphere is a function of both the compensation concentration and the trace gas concentration in the ambient atmosphere. Compensation and/or ambient concentrations may fluctuate and thus may have a strong impact on the flux of CO, NO and NO2, and to a smaller extent also on that of H2. Compensation concentrations also exist for N2O and OCS, but are too high to affect the flux under field conditions. Compensation concentrations have so far not been demonstrated for the flux of CH4. However, the uptake of CH4 by soil exhibits a threshold concentration below which no uptake occurs.Article invited in celebration of tenth anniversary ofBiogeochemistry. 相似文献
6.
The growth ofThiobacillus novellus (ATCC 8093) and of a laboratory strain was observed in a mineral salts medium (MSM) and a medium containing a trace metal solution (TMM). The generation time during growth on MSM was found to be almost half the value for growth on TMM (134 min vs 252 min), with overall yields in the latter being about one-third those on MSM. Cultures maintained for 5 weeks in trace metal media exhibited decreased generation times, but no change in overall yields. An increase in glucose concentration resulted in an increased yield but had no effect on generation times. The addition of biotin to either medium resulted in minor decrease in glucose utilization. The omission of the trace metal constituents, individually, usually resulted in shorter generation times and increased growth yields. It is concluded that differences in growth conditions have been responsible for discrepancies in data from some previous studies. 相似文献
7.
A study to monitor marine pollution with reference to trace elements (Fe, Zn, Mn and Cu) on T. attenuata, commonly called as screw shell over a period of one year on the whole body and various organs, viz. digestive diverticula, foot, mantle and ovary was conducted from the sandy beach of Porto Novo Coast (Lat 11 degrees 29' N Long: 79 degrees 46' E) of Peninsular India using Atomic Absorption Spectrophotometer (AAS). Higher concentration of all the four trace metals analysed were recorded in the digestive diverticula, whereas lower concentration of zinc and manganese were recorded in the ovary during the monsoon period. The higher level of trace metal concentration in the monsoon period may be due to the presence of these pollutants in large amounts in water. The accumulation of selected trace metals varies in different seasons according to the extent of pollution load in the marine environment. 相似文献
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Trace elements in agroecosystems and impacts on the environment. 总被引:21,自引:0,他引:21
Zhenli L He Xiaoe E Yang Peter J Stoffella 《Journal of trace elements in medicine and biology》2005,19(2-3):125-140
Trace elements mean elements present at low concentrations (mg kg-1 or less) in agroecosystems. Some trace elements, including copper (Cu), zinc (Zn), manganese (Mn), iron (Fe), molybdenum (Mo), and boron (B) are essential to plant growth and are called micronutrients. Except for B, these elements are also heavy metals, and are toxic to plants at high concentrations. Some trace elements, such as cobalt (Co) and selenium (Se), are not essential to plant growth but are required by animals and human beings. Other trace elements such as cadmium (Cd), lead (Pb), chromium (Cr), nickel (Ni), mercury (Hg), and arsenic (As) have toxic effects on living organisms and are often considered as contaminants. Trace elements in an agroecosystem are either inherited from soil parent materials or inputs through human activities. Soil contamination with heavy metals and toxic elements due to parent materials or point sources often occurs in a limited area and is easy to identify. Repeated use of metal-enriched chemicals, fertilizers, and organic amendments such as sewage sludge as well as wastewater may cause contamination at a large scale. A good example is the increased concentration of Cu and Zn in soils under long-term production of citrus and other fruit crops. Many chemical processes are involved in the transformation of trace elements in soils, but precipitation-dissolution, adsorption-desorption, and complexation are the most important processes controlling bioavailability and mobility of trace elements in soils. Both deficiency and toxicity of trace elements occur in agroecosystems. Application of trace elements in fertilizers is effective in correcting micronutrient deficiencies for crop production, whereas remediation of soils contaminated with metals is still costly and difficult although phytoremediation appears promising as a cost-effective approach. Soil microorganisms are the first living organisms subjected to the impacts of metal contamination. Being responsive and sensitive, changes in microbial biomass, activity, and community structure as a result of increased metal concentration in soil may be used as indicators of soil contamination or soil environmental quality. Future research needs to focus on the balance of trace elements in an agroecosystem, elaboration of soil chemical and biochemical parameters that can be used to diagnose soil contamination with or deficiency in trace elements, and quantification of trace metal transport from an agroecosystem to the environment. 相似文献
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《Comp. Biochem. Physiol. C, Comp. Pharmacol. Toxicol.》1995,110(3):329-335
Studies were performed regarding the effect of cadmium accumulation on the levels of essential elements (copper, zinc and iron) in the tissues of a marine bivalve mollusc, Mizuhopecten yessoensis, exposed to cadmium at 250 ppb during 2 weeks. It was found that the concentration of cadmium in the tissues increased in the order gonads < gills < hepatopancreas < kidney during exposure time. However, the highest value of concentration factor was recorded in the gills. Our data demonstrate that cadmium accumulation in all mollusc tissues is followed by the alterations in copper, zinc and iron concentration, but that the pattern of these changes varies with each tissue. Cadmium had the most pronounced effects on essential trace element homoeostasis in the kidney. The present study suggests that levels of the essential metals in a particular tissue can be modified depending on the level of cadmium accumulation. The possible mechanisms of the effects of cadmium on the essential trace elements are discussed. 相似文献
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The mechanism through which the geomagnetic field might have influenced the extinction of the species has been proposed. It has been assumed that the concentration factor for essential trace elements is dependent on the magnetic field.Supported in part by the R. A. Welch Foundation 相似文献
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Splenectomy is found to be followed by an increase of the calcium level in blood. Administration of the spleen extract (splenin) decreases the calcium concentration in blood plasma of splenectomized animals. The normalizing splenin effect is observed in the presence of stress when the concentration of the studied trace element sharply increases as well. It is supposed that the humoral spleen factors participate in maintenance of the constant calcium level in blood preventing its elimination from tissues. 相似文献
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M. A. Chaudhri M. Koulmanda M. T. Haukka N. Noorbakhs 《Biological trace element research》1987,12(1):429-429
The effect of diabetes on trace elements concentration in blood of experimental animals has been studied by thin-target X-ray
fluorescence analysis. Balb/C young adult mice, 6–8 wk old, were used in the study. About 100–200 μL venous blood was taken
from each mouse for trace element analysis. The measurements were carried out on a commercial Wave-Length-Dispersive XRF System,
with different X-ray tubes being used for maximizing the detection sensitivity of different groups of elements.
Later on, the mice were made diabetic by an intravenous injection of Streptozotocin (250 mg/kg). Then, 2 and 3 wk after the
injection, 100 μL of venous blood was drawn from each of the mice and analyzed for trace element concentration. In this way
we were able to study the changes in blood trace elements caused by diabetes.
The results and advantages of using experimental animals, under controlled conditions, to study trace element variations caused
by different diseases, are discussed in the paper. 相似文献
13.
Xue Qiang Liang Bing Wang Hui-yun Liu Lei 《Journal of trace elements in medicine and biology》2006,20(2):97-104
An understanding of the dynamic behavior of trace elements leaching from coal mine spoil is important in predicting the groundwater quality. The relationship between trace element concentrations and leaching times, pH values of the media is studied. Column leaching tests conducted in the laboratory showed that there was a close correlation between pH value and trace element concentrations. The longer the leaching time, the higher the trace element concentrations. Different trace elements are differently affected by pH values of leaching media. A numerical model for water flow and trace element transport has been developed based on analyzing the characteristics of migration and transformation of trace elements leached from coal mine spoil. Solutions to the coupled model are accomplished by Eulerian-Lagrangian localized adjoint method. Numerical simulation shows that rainfall intensity determined maximum leaching depth. As rainfall intensity is 3.6ml/s, the outflow concentrations indicate a breakthrough of trace elements beyond the column base, with peak concentration at 90cm depth. And the subsurface pollution range has a trend of increase with time. The model simulations are compared to experimental results of trace element concentrations, with reasonable agreement between them. The analysis and modeling of trace elements suggested that the infiltration of rainwater through the mine spoil might lead to potential groundwater pollution. It provides theoretical evidence for quantitative assessment soil-water quality of trace element transport on environment pollution. 相似文献
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The concentration of trace elements in L-cells has been studied as a function of the trace metal content of the growth medium. Cells were cultured in synthetic media which contained varying trace amounts of the elements manganese, iron, cobalt, copper, zinc and molybdenum. The cellular concentration of the elements potassium, iron, copper and zinc were then determined. It was found that the cell accumulates trace metals at a different rate than they are made available. Deficiencies in zinc could be “induced” in the cell by increasing the concentration of iron, manganese and cobalt; cellular iron deficiencies were observed at larger medium concentrations of zinc, manganese, copper and cobalt. Trace metal uptake by the cell was seen to parallel the utilization by multicellular organisms. 相似文献
15.
K. T. O'GRADY 《Freshwater Biology》1981,11(6):561-565
SUMMARY. The concentration of zinc in the scales of unripe, prespawning, estuarine sea trout was compared to that in the scales of sea trout about to spawn in fresh water. Zinc concentrations in scales from estuarine sea trout were in agreement with a published concentration factor but those from fresh water were not — a 43–52% reduction in the zinc concentration of the scales was observed. This withdrawal of trace metals from scales was also likely for iron but these data were less conclusive. This reclamation of trace metals from scales may represent the withdrawal of stored nutrients from body reserves to be used in gonad development and maturation. 相似文献
16.
T. Fagerström 《Oecologia》1977,29(2):99-104
Summary Consequences of size-dependent metabolic rate on the turnover of trace substances in animals are investigated. At steady state, the biological half-life, body burden, and whole body concentration of a trace substance are shown to be proportional to body weight raised to (1-b), 1, and 0, respectively, where b is the exponent relating body weight to standard metabolic rate. The condition is that the trace substance is turned over in proportion to the standard metabolic rate; the derived equations can accordingly be used to test whether a given substance is feasible as a tracer of energy flow in ecologic systems. 相似文献
17.
《Journal of Fermentation and Bioengineering》1993,75(5):368-374
The effect of trace elements on the methanogenesis from methanol and acetate was studied utilizing granular sludge obtained from an anaerobic wastewater treatment plant. The methanogenic activity from methanol was dramatically stimulated by the addition of a cocktail of trace elements in the basal medium. When trace elements were supplied individually, cobalt greatly stimulated methanogenesis which equalled the stimulation observed with the complete trace element mixture. No remarkable influence of any trace element was observed when acetate was used as the substrate. Two Upflow Anaerobic Sludge Blanket (UASB) reactors were operated with and without supplementation of cobalt. Cobalt greatly stimulated both acetogenesis in the initial operational phase and later methanogenesis. The cobalt sufficient column provided almost 3 times the methane productivity compared to the cobalt deprived column. At an organic loading rate of 8 g COD/l·d, 87% of the COD was converted to methane in the cobalt sufficient column. Under low cobalt concentration, methanogens compete better for cobalt than acetogens. 相似文献
18.
Effect of a concentrated "inert" macromolecular cosolute on the stability of a globular protein with respect to denaturation by heat and by chaotropes: a statistical-thermodynamic model
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Minton AP 《Biophysical journal》2000,78(1):101-109
An equilibrium statistical-thermodynamic model for the effect of volume exclusion arising from high concentrations of stable macromolecules upon the stability of a trace globular protein with respect to denaturation by heat and by chaotropes is presented. The stable cosolute and the native form of the trace protein are modeled by effective hard spherical particles. The denatured state of the trace protein is represented as an ensemble of substates modeled by random coils having the same contour length but different rms end-to-end distances (i.e., different degrees of compaction). The excess or nonideal chemical potential of the native state and of each denatured substate is calculated as a function of the concentration of stable cosolute, leading to an estimate of the relative abundance of each state and substate, and the ensemble average free energy of the transition between native and denatured protein. The effect of the addition of stable cosolute upon the temperature of half-denaturation and upon the concentration of chaotrope required to half-denature the tracer at constant temperature is then estimated. At high cosolute concentration (>100 g/l) these effects are predicted to be large and readily measurable experimentally, provided that an experimental system exhibiting a fully reversible unfolding equilibrium at high total macromolecular concentration can be developed. 相似文献
19.
Satoshi Urushidate Masashi Matsuzaka Noriyuki Okubo Hiroki Iwasaki Tatsuya Hasebe Ryosuke Tsuya Kaori iwane Ryo Inoue Kiyonori Yamai Kazuma Danjo Ippei Takahashi Takashi Umeda Shigeatsu Ando Kazuyoshi Itai Shigeyuki Nakaji 《Journal of trace elements in medicine and biology》2010,24(4):236-242
Background and aimsA number of previous studies had revealed the association between trace elements in serum and bronchial asthma. However, only a few researches had focused on serum concentration of trace elements in a general population. In this study, an association between trace elements in serum and bronchial asthma was investigated in a general population.MethodsSubjects were 1025 volunteers (385 males and 640 females between ages 19 and 82 years old) who had participated in the Iwaki Health Promotion Project 2005. Bronchial asthma was diagnosed based on the European Community Respiratory Health Survey II according to the self-questionnaires on health conditions of subjects. The serum concentrations of certain trace elements (manganese, copper, zinc, selenium and iron) were measured and compared. Also, an association between serum trace elements level and neutrophil-related functions (oxidative burst activity, phagocytic activity, serum opsonic activity) were determined.ResultsIn males, no significant differences were seen in any serum trace elements concentrations. In females, serum zinc level was significantly higher in bronchial asthma group than in control. A positive correlation was seen between serum concentration of zinc and serum opsonic activity in both genders.ConclusionsIn female asthmatics, increase of oxidative stress was suggested to be caused by superoxide dismutase pathway (elimination system of reactive oxygen species) rather than serum opsonic activity (production system of reactive oxygen species from neutrophils) pathway, as the zinc concentration in bronchial asthma group was higher than that in control. 相似文献
20.
Factors Affecting the Methanogenic Activity of Methanothrix soehngenii VNBF 总被引:2,自引:2,他引:0
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Babu Z. Fathepure 《Applied microbiology》1987,53(12):2978-2982
Methane production by Methanothrix soehngenii VNBF grown on acetate (50 mM) as the sole carbon and energy source was influenced by the addition of Fe, trace elements, and pesticides. The addition of Fe and trace elements significantly enhanced the rate of CH4 production. The addition of pesticides in the early growth phase caused complete inhibition. However, less inhibition was noted when pesticides were added during early exponential growth phase. Addition to culture tubes of Co, Ni, or Mo at 2 μM produced 64, 41, or 17%, respectively, more CH4 than that produced in tubes lacking the corresponding trace element. A concentration of more than 5 μM of these trace elements in the medium resulted in decreased CH4 production, presumably because of toxic effects. 相似文献