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1.
Fecal corticosterone concentration (FCC) was measured in 14 buck rabbits individually housed in standard-dimension cages (SC) or in bigger cages (BC; with a volume more than double that of SC and equipped with a plastic foot mat) during 4 consecutive reproductive cycles. Cage type and reproductive phase (estrous synchronization of doe rabbits, artificial insemination, partum, preweaning, and postweaning) were not statistically significant but tendentially affected FCCs (.05 < p < .10). Buck rabbits housed in SC showed higher FCCs than those housed in BC (27.42 pg g ? 1 dried feces and 25.57 pg g ? 1, respectively; SEM = 2.952). The highest FCC values were detected at artificial insemination (BC, 27.91 pg g ? 1; SC, 30.45 pg g ? 1; SEM = 3.520), highlighting that the phase of semen collection could be one of the most critical moments for buck rabbits, although further investigations are needed. These preliminary results suggest that measurement of FCC could be used as an indicator of chronic stress in buck rabbits. 相似文献
2.
Myosmine is a minor tobacco alkaloid with widespread occurrence in the human diet. Myosmine is genotoxic in human cells and is readily nitrosated and peroxidated yielding reactive intermediates with carcinogenic potential. For biomonitoring of short-term and long-term exposure, analytical methods were established for determination of myosmine together with nicotine and cotinine in plasma, saliva and toenail by gas chromatography–mass spectrometry (GC/MS). Validation of the method with samples of 14 smokers and 10 non-smokers showed smoking-dependent differences of myosmine in toenails (66?±?56 vs 21?±?15?ng?g ?1, p?<0.01) as well as saliva (2.54?±?2.68 vs 0.73?±?0.65?ng ml ?1, p <0.01). However, these differences were much smaller than those with nicotine (1971?±?818 vs 132?±?82?ng g ?1, p <0.0001) and cotinine (1237?±?818 vs <35?ng?g ?1) in toenail and those of cotinine (97.43?±?84.54 vs 1.85?±?4.50?ng ml ?1, p <0.0001) in saliva. These results were confirmed in plasma samples from 84 patients undergoing gastro-oesophageal endoscopy. Differences between 25 smokers and 59 non-smokers are again much lower for myosmine (0.30?±?0.35 vs 0.16?±?0.18?ng?ml ?1, p <0.05) than for cotinine (54.67?±?29.63 vs 0.61?±?1.82?ng ml ?1, p <0.0001). In conclusion, sources other than tobacco contribute considerably to the human body burden of myosmine. 相似文献
3.
Variations in progesterone (P 4) and testosterone (T) levels in the gonad of Octopus maya from Sisal in Yucatan State, Mexico, were investigated by radioimmunoassays and in relation to four gonad maturation stages (GMS) and to the reproductive cycle, as represented by two maturity indices (microscopic ‘MiMI’ and macroscopic ‘MaMI’). According to the GMS and the maturity indices, the reproductive season of O. maya from Yucatan occurred from February to June. In females, P 4 and T displayed the same pattern, with a tendency to increase at the same time, although on average, P 4 had seven-fold higher concentrations than T. In contrast, P 4 and T in male gonads displayed a different pattern, where T concentrations were relatively stable throughout all of the study months. In the female gonad P 4 was lowest (close to 0 pg?g –1) during both developing (GMS-I) and maturing (GMS-II) stages, and increased (189?±?53?pg?g –1) approaching the mature stage (GMS-III) to a maximum value of 611?pg?g –1. Concentrations of T in the male gonad were lowest (106?±?9?pg?g –1) during the maturing stage (GMS-II) and increased up to the mature stage (GMS-III), reaching a maximum of 440?pg?g –1. Pearson's correlation ( r) between hormones and maturity indices showed strong relationships for females (around 0.4 and ?0.7; p?<?0.05), but there were negligible or weak relationships for males (0.2 and ?0.1; p?>?0.05). Hormone correlations in females were inverse with MaMI and direct with MiMI. Our major findings showed that gonadal P 4 levels were elevated during GMS-III and GMS-IV (i.e. periods of vitellogenic oocytes), where the characteristic aspect is an ovary with very high oocyte diameters, with the primary follicle cells deeply infolded in the ooplasm for yolk synthesis. These results suggested a synchrony between P 4 and the process of folliculogenesis, and in turn, vitellogenesis. 相似文献
4.
To understand the mechanism of how Phragmites australis makes valuable floating mat biotopes under oligotrophic conditions, we investigated the environmental (water chemistry) and vegetational characteristics (growth, plant species richness, and floristic composition) of a floating mat consisting of three main mat-forming species with a zonal distribution (P. australis on the land side of the floating mat, Zizania latifolia on the middle area, and Typha angustifolia on the water side). Although they showed relatively low growth in the floating mat, compared to those in land-based wetlands, P. australis grew better than other mat-forming species in terms of shoot height and biomass production. Specifically, P. australis made more below-ground parts (593?±?38 g/m2) than other mat-forming species (Z. latifolia, 100?±?10 g/m2; T. angustifolia, 167?±?8 g/m2) and more companion species were found in P. australis-dominated plots (8.5?±?1.0 species/m2) than other plots (Z. latifolia-dominated plots, 2.7?±?0.6 species/m2; T. angustifolia-dominated plots, 1.0?±?0.0 species/m2). The larger amount of below-ground P. australis parts could contribute to thicker and denser mat structures, possibly providing more favorable habitats for neighboring plant species, thus facilitating more companion species within the P. australis-dominated area of the mat. 相似文献
5.
Background: Heart-type fatty acid-binding protein (H-FABP) is considered a marker of myocardial necrosis but whether or not it is modified by myocardial ischemia is not clear. We sought to investigate if H-FABP serum levels increase following non-urgent coronary angioplasty. Methods: We studied 31 patients undergoing coronary angioplasty. Peripheral venous samples were drawn immediately before angioplasty, 1?h after the first balloon inflation and 24?h after the procedure and assayed for H-FABP. Results: Serum levels of H-FABP increased significantly at 1?h vs baseline from 2554?±?1268 to 3322?±?245?pg?ml ?1 ( p?=?0.024). However, no differences were observed between 1?h and 24?h after angioplasty (3268?±?1861 vs 3322?±?2459?pg ml ?1, p?=?0.87). Moreover, no significant difference was observed when we compared 24?h after angioplasty with the baseline (3268?±?1861vs 2554?±?1268?pg ml ?1, p?=?0.112). Conclusions: We conclude that H-FABP significantly increases after elective coronary angioplasty at 1?h compared with baseline values; whether or not this has any prognostic significance for future events, as it occurs with troponins, needs to be studied further. 相似文献
6.
Polygodial is a potent and selective inhibitor of ascidian metamorphosis that shows promise for controlling fouling by ascidians in bivalve aquaculture. The current study examined the potency of, and associated effects of seawater exposure on, a rosin-based soluble-matrix paint laced with 0.08–160?ng?polygodial?g ?1 wet paint matrix. Paint-coated surfaces were soaked in seawater for 0, 2, 4 or 12?weeks prior to screening for antifouling activity using a bioassay based on the nuisance ascidian Ciona savignyi Herdman. Mortality was greater (mean 50% lethal concentration: 5?±?2?ng?g ?1; mean 75% lethal concentration: 17?±?4?ng?g ?1) and metamorphosis was inhibited (mean 50% anti-metamorphic concentration: 2?±?0.4?ng?g ?1; mean 75% anti-metamorphic concentration: 15?±?10?ng?g ?1) in C. savignyi larvae exposed to polygodial-laced soluble-matrix paints, relative to control paints without polygodial. Soaking in seawater prior to testing reduced the efficacy of the formulation up to nearly 12-fold, but even after soaking for 12?weeks paints laced with polygodial at 160?ng?g ?1 wet paint matrix prevented ?90% of the larvae of C. savignyi from completing metamorphosis. The outcome of this experiment provides a positive first step in evaluating the suitability of polygodial-laced soluble-matrix paints for use in aquaculture. 相似文献
7.
The River Yamuna originates from the Yamunotri glacier of the Himalayas and travels 22 km in the Delhi region. The river is used for various purposes in Delhi including drinking water supply. Twenty-eight polychlorinated biphenyls (PCBs) congeners were measured in bank sediments along the river, and their ecotoxicological risk was evaluated. Concentrations of ∑28PCBs varied from 0.20–21.16 ng g ?1 (dry wt.) with mean and median values of 6.63 ng g ?1 and 5.84 ng g ?1 (±0.69 ng g ?1), respectively. The concentration of 12 dl-PCBs concentrations varied from 0.04–2.86 ng g ?1 with a mean of 1.04 ± 0.11 ng g ?1, and their toxic equivalency ranged between <0.01–28.67 pg WHO-TEQ g ?1 with a mean of 10.77 ± 1.06 pg WHO-TEQ g ?1. CB-37, CB-44, CB-114, and CB-118 congeners were dominant among all PCBs congeners. The tri-PCBs (49%) were the main contributors to the PCB homolog followed by tetra-PCBs (35%), and penta-PCB (14%). Because there are no environmental guidelines in India for PCBs in river and marine sediments, concentrations of PCBs and their toxic equivalents were compared in a screening-level assessment with established freshwater sediment quality guidelines and found lower than those guideline values, which suggests no adverse ecotoxicological effect. 相似文献
8.
Glutathione belongs to a vital intra‐ and extra‐cellular protective antioxidant and is found almost exclusively in its reduced form. The ratio between its reduced and oxidized within cells is often used as a marker of cellular toxicity. The objectives of the study were to (i) determine both the reduced (GSH) and oxidized glutathione (GSSG) and cysteine (Cys) in the sperm of the Acipenser baerii and Acipenser ruthenus, as well as in Perca fluviatilis and Sander lucioperca, and (ii) to demonstrate the differences in concentration levels between representatives of acipenseriform and teleost species. High performance liquid chromatography with electrochemical detection was employed. The average content of the thiols determined in the sperm samples were as follows: Acipenser baerii (cysteine 55 ± 8 μg ml ?1; GSH 126 ± 19 μg ml ?1; GSSG 49 ± 7 μg ml ?1), Acipenser ruthenus (cysteine 62 ± 9 μg ml ?1; GSH 768 ± 115 μg ml ?1; GSSG 180 ± 16 μg ml ?1), Sander lucioperca (cysteine 251 ± 38 μg ml ?1; GSH 185 ± 28 μg ml ?1; GSSG 93 ± 14 μg ml ?1), Perca fluviatilis (cysteine 281 ± 42 μg ml ?1; GSH 496 ± 74 μg ml ?1; GSSG 138 ± 21 μg ml ?1). Based on the results obtained it can be concluded that this method is sensitive and selective for the determination of these compounds in real samples. Results revealed differences in cysteine content between species of the two systematic categories but also showed that ratios between GSH and GSSG can vary between species while potentially predict oxidative stress in fish sperm. 相似文献
9.
The levels of soil parameters and selected heavy metals around a solid waste dumpsite receiving untreated wastes from all sources and a control site within Port Harcourt, Nigeria have been examined. Top soil (0–15 cm) and sediment samples were collected and analysed for pH value, particle size, total nitrogen, potassium, available phosphorus, organic matter, effective cation exchange capacity, cadmium, nickel and lead using standard methods. The results showed that the waste dump contributed to the high levels of nutrients and heavy metals. The dry season mean concentrations were: organic matter (5.28 ± 1.34% or 132,422.4 kg ha ?1), K (1.60 ± 0.52 meq per 100 g), N (0.09 ± 0.06% or 2257.2 kg ha ?1), Av.P (15.11 ± 7.57 μg g ?1), Cd (1.34 ± 0.72 μg g ?1), Ni (4.10 ± 1.63 μg g ?1) and Pb (38.85 ± 22.18 μg g ?1) while the wet season mean concentrations were organic matter (5.46 ± 1.39% or 136,936.8 kg ha ?1), K (2.79 ± 0.81 meq per 100 g), N (0.10 ± 0.05% or 2508 kg ha ?1), Av.P (9.22 ± 2.69 μg g ?1), Cd (1.72 ± 1.22 μg g ?1), Ni (14.95 ± 14.94 μg g ?1) and Pb (53.50 ± 40.09 μg g ?1). There was efficient mineralization process in the area. The texture of soil on the main dumpsite was loamy sand, which suggests that the ground water in the area is susceptible to contamination by surface pollutants. The texture of soil at the control site is sandy loam while sediment has the textural class of sand. Decomposed organic materials and agricultural activities influenced the texture of soils. The soils from the main dump and sediment were slightly alkaline while the control soil was moderately acidic. In both seasons, a significant variation exists ( P < 0.05) between the metal concentrations in soil at the main dump and those in the sediments with a positive correlation ( r = 0.572149) in the wet season and ( r = 0.956647) in the dry season. The presence of liming materials and activities of microorganisms on the waste dump increased the pH of the soils. The accumulation of nutrients results in the luxuriant growth of plants/crops on the waste dump. 相似文献
10.
Toxin analysis of 15 species of Kareniaceae revealed the presence of karlotoxin, KmTx 2, in only a single species ( Karlodinium veneficum) but with variable activity in strains from the Swan (Km SwanTx 2‐1, 2.1 pg · cell ?1; and Km SwanTx 2‐2, 0.53 pg · cell ?1), Huon (Km HuonTx 2, 0.86 pg · cell ?1), and Derwent rivers (<0.001 pg · cell ?1) in Australia. A newly isolated Southern Ocean species, Karlodinium conicum, contained a novel poorly hemolytic karlotoxin analogue (Km conicumTx, 2.8 pg · cell ?1). The hemolytic potency (HD50%) of the Australian karlotoxins were as follows: Km SwanTx 2‐1 (65.9 ± 4.8 ng) and Km SwanTx 2‐2 (63.4 ± 3.7 ng), Km HuonTx 2 (343 ± 4.9 ng), and Km conicumTx (>4,000 ng). Species from the closely related genera Takayama ( T. helix, T. tasmanica, T. tuberculata), Karenia ( K. asterichroma, K. brevis, K. mikimotoi, K. papilionacea, K. umbella), and Karlodinium ( Ka. australe, Ka. antarcticum, Ka. ballantinum, Ka. corrugatum, Ka. decipiens) were all consistently negative for karlotoxin production. Brevetoxin (PbTx) was only detected in K. brevis, and hemolytic activity was only observed in Ka. veneficum strains. 相似文献
11.
This study was conducted to create a nutritional database on brown seaweeds and to popularize their consumption and utilization in Iran. The fatty acid contents, amino acids profiles, and certain mineral elements composition of some brown seaweeds, Padina pavonica (L.) Thivy, Dictyota dichotoma (Huds.) J. V. Lamour., and Colpomenia sinuosa (Mert. ex Roth) Derbés et Solier were determined. Total lipid content ranged from 1.46 ± 0.38 to 2.94 ± 0.94 g · 100 g ?1dry weight (dwt), and the most abundant fatty acids were C16:0, C18:1, C20:4 ω6, and C20:5 ω3. The unsaturated fatty acids predominated in all species and had balanced sources of ω3 and ω6 acids. Highest total polyunsaturated fatty acid (PUFA) levels occurred in C. sinuosa. The protein content of D. dichotoma was 17.73 ± 0.29 g · 100 g ?1dwt, significantly higher than the other seaweeds examined. Among amino acids essential to human nutrition, methionine (Met; in D. dichotoma and P. pavonica) and lysine (Lys; in C. sinuosa) were present in high concentrations. The crude fiber content varied by 9.5 ± 11.6 g · 100 g ?1dwt in all species. Chemical analysis indicated that ash content was between 27.02 ± 0.6 and 39.28 ± 0.7 g · 100 g ?1dwt, and that these seaweeds contained higher amounts of both macrominerals (7,308–9,160 mg · 100 g ?1dwt; Na, K, Ca) and trace elements (263–1,594 mg · 100 g ?1dwt; Fe, Ni, Mn, Cu, Co) than have been reported for edible land plants. C. sinuosa had the highest amount of Ca, Fe, and a considerable content of Na was measured in P. pavonica. 相似文献
12.
The effects of salinity, light intensity and sediment on Gracilaria tenuistipitata C.F. Chang & B.M. Xia on growth, pigments, agar production, and net photosynthesis rate were examined in the laboratory under varying conditions of salinity (0, 25 and 33 psu), light intensity (150, 400, 700 and 1000 µmol photons m ?2 s ?1) and sediment (0, 0.67 and 2.28 mg L ?1). These conditions simulated field conditions, to gain some understanding of the best conditions for cultivation of G. tenuistipitata. The highest growth rate was at 25 psu, 700 µmol photons m ?2 s ?1 with no sediments, that provided a 6.7% increase in weight gain. The highest agar production (24.8 ± 3.0 %DW) was at 25 psu, 150–400 µmol photons m ?2 s ?1 and no sediment. The highest pigment contents were phycoerythrin (0.8 ± 0.5 mg g ?1FW) and phycocyanin (0.34 ± 0.05 mg g ?1 FW) produced in low light conditions, at 150 µmol photons m ?2 s ?1. The highest photosynthesis rate was 161.3 ± 32.7 mg O 2 g ?1 DW h ?1 in 25 psu, 400 µmol photons m ?2 s ?1 without sediment in the short period of cultivation, (3 days) and 60.3 ± 6.7 mg O 2 g ?1 DW h ?1 in 25 psu, 700 µmol photons m ?2 s ?1 without sediment in the long period of cultivation (20 days). The results indicated that salinity was the most crucial factor affecting G. tenuistipitata growth and production. This would help to promote the cultivation of Gracilaria cultivation back into the lagoon using these now determined baseline conditions. Extrapolation of the results from the laboratory study to field conditions indicated that it was possible to obtain two crops of Gracilaria a year in the lagoon, with good yields of agar, from mid‐January to the end of April (dry season), and from mid‐July to the end of September (first rainy season) when provided sediment was restricted. 相似文献
13.
Our study compares the status of human seminal plasma immunoglobulin G (IgG) and IgA secretory component (SC) fucosylation between infertile leukocytospermic and normal, fertile normozoospermic patients. The seminal IgG and SC are decorated with AAL-reactive core fucose, and antennary UEA- and LTA-reactive fucose of Lewis y and Lewis x structures, respectively. However, a correlation between IgG core fucosylation and IgG concentration ( r?=??0.52; p?<?0.0003) was observed. The IgG present in leukocytospermic samples is characterized by lower expression of core fucose than in the normal group (0.82?±?0.3 AU and 1.2?±?0.3 AU, respectively; p?<?0.002). In seminal plasma the SC is present in two forms: 78-kDa and 63-kDa. The present study has also shown a higher AAL and LTA specific reactivity of glycans expressed in 63-kDa SC, in comparison to 78-kDa SC, in the normal group. In leukocytospermia, the values of specific lectin reactivity for core fucose, fucose α(1-2)- and α(1-3)- linked, were similar for both SC bands. Moreover, the present study has shown that in leukocytospermic samples the mean concentrations of IgG and S-IgA are twice as high (131.68?±?102.6 mg/l and 36?±?27 mg/l, respectively) as in the normal group (67.68?±?29.2 mg/l; p?<?0.02, and 19?±?18 mg/l, p?<?0.019, respectively). The analysis of IgG and SC fucosylation status and the determination of IgG and S-IgA concentrations in seminal plasma might constitute a valuable diagnosis tools for the evaluation of male infertility associated with leukocytospermia with accompanying inflammation. 相似文献
14.
The photoprotective response in the dinoflagellate Glenodinium foliaceum F. Stein exposed to ultraviolet‐A (UVA) radiation (320–400 nm; 1.7 W · m 2) and the effect of nitrate and phosphate availability on that response have been studied. Parameters measured over a 14 d growth period in control (PAR) and experimental (PAR + UVA) cultures included cellular mycosporine‐like amino acids (MAAs), chls, carotenoids, and culture growth rates. Although there were no significant effects of UVA on growth rate, there was significant induction of MAA compounds (28 ± 2 pg · cell ?1) and a reduction in chl a (9.6 ± 0.1 pg · cell ?1) and fucoxanthin (4.4 ± 0.1 pg · cell ?1) compared to the control cultures (3 ± 1 pg · cell ?1, 13.3 ± 3.2 pg · cell ?1, and 7.4 ± 0.3 pg · cell ?1, respectively). In a second investigation, MAA concentrations in UVA‐exposed cultures were lower when nitrate was limited ( P < 0.05) but were higher when phosphate was limiting. Nitrate limitation led to significant decreases ( P < 0.05) in cellular concentration of chls (chl c1, chl c2, and chl a), but other pigments were not affected. Phosphate availability had no effect on final pigment concentrations. Results suggest that nutrient availability significantly affects cellular accumulation of photoprotective compounds in G. foliaceum exposed to UVA. 相似文献
15.
The aim of this study was to determine the suitability of water quality in the Roanoke River of North Carolina for supporting shortnose sturgeon Acipenser brevirostrum, an endangered species in the United States. Fathead minnows Pimephales promelas were also evaluated alongside the sturgeon as a comparative species to measure potential differences in fish survival, growth, contaminant accumulation, and histopathology in a 28‐day in situ toxicity test. Captively propagated juvenile shortnose sturgeon (total length 49 ± 8 mm, mean ± SD) and fathead minnows (total length 39 ± 3 mm, mean ± SD) were used in the test and their outcomes were compared to simultaneous measurements of water quality (temperature, dissolved oxygen, pH, conductivity, total ammonia nitrogen, hardness, alkalinity, turbidity) and contaminant chemistry (metals, polycyclic aromatic hydrocarbons, organochlorine pesticides, current use pesticides, polychlorinated biphenyls) in river water and sediment. In the in situ test, there were three non‐riverine control sites and eight riverine test sites with three replicate cages (25 × 15‐cm (OD) clear plexiglass with 200‐μm tear‐resistant Nitex ® screen over each end) of 20 shortnose sturgeon per cage at each site. There was a single cage of fathead minnows also deployed at each site alongside the sturgeon cages. Survival of caged shortnose sturgeon among the riverine sites averaged 9% (range 1.7–25%) on day 22 of the 28‐day study, whereas sturgeon survival at the non‐riverine control sites averaged 64% (range 33–98%). In contrast to sturgeon, only one riverine deployed fathead minnow died (average 99.4% survival) over the 28‐day test period and none of the control fathead minnows died. Although chemical analyses revealed the presence of retene (7‐isopropyl‐1‐methylphenanthrene), a pulp and paper mill derived compound with known dioxin‐like toxicity to early life stages of fish, in significant quantities in the water (251–603 ng L ?1) and sediment (up to 5000 ng g ?1 dry weight) at several river sites, no correlation was detected of adverse water quality conditions or measured contaminant concentrations to the poor survival of sturgeon among riverine test sites. Histopathology analysis determined that the mortality of the river deployed shortnose sturgeon was likely due to liver and kidney lesions from an unknown agent(s). Given the poor survival of shortnose sturgeon (9%) and high survival of fathead minnows (99.4%) at the riverine test sites, our study indicates that conditions in the Roanoke River are incongruous with the needs of juvenile shortnose sturgeon and that fathead minnows, commonly used standard toxicity test organisms, do not adequately predict the sensitivity of shortnose sturgeon. Therefore, additional research is needed to help identify specific limiting factors and management actions for the enhancement and recovery of this imperiled fish species. 相似文献
16.
The experiment was organized in a 3×2 factorial arrangement with three dietary fat blends and a basal (20 mg kg ?1 diet) or supplemented (220 mg kg ?1) level of α-tocopheryl acetate. Dietary vitamin E and monounsaturated to polyunsaturated fatty acid ratio (dietary MUFA/PUFA) affected muscle α-tocopherol concentration (α-tocopherol [log μg g ?1]=0.18 (±0.105)+0.0034 (±0.0003)·dietary α-tocopherol [mg kg ?1 diet] ( P<0.0001)+0.39 (±0.122)·dietary MUFA/PUFA ( P<0.0036)). An interaction between dietary α-tocopherol and dietary MUFA/PUFA exists for microsome α-tocopherol concentration (α-tocopherol [log μg g ?1]=1.14 (±0.169) ( P<0.0001)+0.0056 (±0.00099)·dietary α-tocopherol [mg kg ?1 diet] ( P<0.0001)+0.54 (±0.206)·dietary MUFA/PUFA ( P<0.0131)?0.0033 (±0.0011)·dietary α-tocopherol [mg kg ?1)]×dietary MUFA/PUFA ( P<0.0067)), and hexanal concentration in meat (hexanal [ng·g ?1]=14807.9 (±1489.8)?28.8 (±10.6) dietary α-tocopherol [mg·kg ?1] ( P<0.01)?8436.6 (±1701.6)·dietary MUFA/PUFA ( P<0.001)+24.0 (±11.22)·dietary α-tocopherol·dietary MUFA/PUFA ( P<0.0416)). It is concluded that partial substitution of dietary PUFA with MUFA lead to an increase in the concentration of α-tocopherol in muscle and microsome extracts. An interaction between dietary α-tocopherol and fatty acids exists, in which at low level of dietary vitamin E inclusion, a low MUFA/PUFA ratio leads to a reduction in the concentration of α-tocopherol in microsome extracts and a concentration of hexanal in meat above the expected values. 相似文献
17.
ABSTRACTThe dissipation and detoxification of nicosulfuron (NS) by Pseudomonas aeruginosa B9 isolated from a cornfield soil was investigated. The fastest decline of NS occurred at 40 µg ml ?1 in liquid media with 0.25% glucose plus 0.05% yeast extract (DT 50 = 4 days) with a notable pH reduction (pH ? 5). Bioassay tests showed considerable phytotoxicity of NS for Cress ( Lepidium sativum L.) with 50% shoot growth inhibition (SGI) at 40 µg ml ?1. The dissipation of NS (40 µg ml ?1) by the B9 isolate reduced the SGI significantly (SGI: up to 45 ± 3%) compared to the non-inoculated media (SGI: up to 58 ± 4%). In soils with the B9 isolate, NS dissipation, especially at 0.3 µg g ?1, was faster with a more significant SGI reduction (k = 0.08 ± 0.00 day ?1; SGI = 2 ± 1%) compared to non-inoculated samples (k = 0.03 ± 0.00 day ?1; SGI = 8 ± 1%). NS initially inhibited soil respiration, microbial biomass carbon, and dehydrogenase activity. The effect was however transient, and these parameters recovered within 10 days, especially in the presence of the isolate. Overall, this study proves Pseudomonas aeruginosa B9 as a suitable candidate for bioremediation of NS in contaminated sites. 相似文献
18.
The caloric contents of 42 species and their composition in a Leymus chinensis steppe community of Inner Mongolia, China were determined and analyzed based on the field experiment for 11 years. The caloric content (x ± SD) of aboveground parts of plant species varied from (13156 ± 1141) J·g ?1 (ash contained) to (18141 ± 527) J·g ?1. The average caloric content of all species was (16899 ± 840) J·g ?1 and the inter-specific CV (coefficient of variation) was 4.9%. Of all the species, Caragana microphylla had the highest caloric content (18142 J·g ?1). Grasses had a higher average caloric content ((17425 ± 291) J·g ?1) than forbs ((16734 ± 844)J·g ?1). When the herbaceous species were classified into subgroups according to life-form and growth-form, the order of average caloric contents, from high to low, was: tall grasses ((17717 ± 92) J·g ?1) > legume ((17228 ± 433) J·g ?1) > short grasses ((17250 ± 218) J·g ?1) > remaining forbs ((16784 ± 529) J·g ?1) > subshrubs ((16719 ± 69) J·g ?1) > annuals and biennials ((15911 ± 1759) J·g ?1). There was a positive correlation (P < 0.05) between the caloric contents of 42 species and their relative biomass in the community. When all species were classified into 3 groups according to their composition in the community, the average caloric contents, weighed by the species relative biomass, followed the order: dominant (17740 J·g ?1) > companion (17244 J·g ?1) > incidental (16653 J·g ?1). The plants with high caloric contents were more competitive, which allowed them to gain a dominant status, whereas the competitive abilities of plants with low caloric contents were generally weak. The latter made up the companion or incidental species in a steppe community. 相似文献
19.
The caloric contents of 42 species and their composition in a Leymus chinensis steppe community of Inner Mongolia, China were determined and analyzed based on the field experiment for 11 years. The caloric content (x ± SD) of aboveground parts of plant species varied from (13156 ± 1141) J·g ?1 (ash contained) to (18141 ± 527) J·g ?1. The average caloric content of all species was (16899 ± 840) J·g ?1 and the inter-specific CV (coefficient of variation) was 4.9%. Of all the species, Caragana microphylla had the highest caloric content (18142 J·g ?1). Grasses had a higher average caloric content ((17425 ± 291) J·g ?1) than forbs ((16734 ± 844)J·g ?1). When the herbaceous species were classified into subgroups according to life-form and growth-form, the order of average caloric contents, from high to low, was: tall grasses ((17717 ± 92) J·g ?1) > legume ((17228 ± 433) J·g ?1) > short grasses ((17250 ± 218) J·g ?1) > remaining forbs ((16784 ± 529) J·g ?1) > subshrubs ((16719 ± 69) J·g ?1) > annuals and biennials ((15911 ± 1759) J·g ?1). There was a positive correlation (P < 0.05) between the caloric contents of 42 species and their relative biomass in the community. When all species were classified into 3 groups according to their composition in the community, the average caloric contents, weighed by the species relative biomass, followed the order: dominant (17740 J·g ?1) > companion (17244 J·g ?1) > incidental (16653 J·g ?1). The plants with high caloric contents were more competitive, which allowed them to gain a dominant status, whereas the competitive abilities of plants with low caloric contents were generally weak. The latter made up the companion or incidental species in a steppe community. 相似文献
20.
Inhaled endotoxin (lipopolysaccharide, LPS) initiates an inflammatory response and leads to the expression of CR3 (CD11b/CD18) receptors on polymorphonuclear leukocytes (PMNs). We determined if PMN activation in nasal lavage fluid (NLF) is a possible biomarker of occupational endotoxin exposure. Seven subjects exposed to endotoxin provided NLF samples that were split into three aliquots (negative control – 1?M nicotinamide; sham; positive control – 11 ηg of exogenous LPS) and PMN activation was measured using a chemiluminometer. Differences in mean PMN activation were apparent, negative control: 548?±?15.65 RLU 100 μl ?1; sham: 11469?±?2582 RLU 100 μl ?1; positive control: 42026?±?16659 RLU 100 μl ( n?=?7; p <0.05). This technique shows promise as a diagnostic method for measuring upper airway LPS exposure. 相似文献
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