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1.
Dietary intake of technical hexachlorocyclohexane (HCH) by albino mice for 2 weeks (at 400 and 800 ppm) resulted in hyperlipemia. Significant increase in triglycerides, phospholipids and cholesterol fractions of blood was observed in these animals. Dietary intake of gamma-isomer of HCH for 2 weeks (at 200 ppm) did not have any effect on blood lipid profile, but at 400 ppm level produced higher contents of phospholipids and cholesterol. The hepatomegaly produced by dietary technical HCH or gamma-HCH was not accompanied by fatty metamorphosis of liver. Hypertriglyceridemia caused by HCH was accompanied by lower triglyceride levels in liver, suggesting a possible higher rate of secretion from liver.  相似文献   

2.
Summary The effect of three pesticidesviz, simazine, lindane and ceresan upto 100-fold of field application was studied on organic matter mineralization as well as on nitrification rates in Delhi alluvial soil. The normal rate of simazine (2 ppm) did not influence CO2 evolution but higher concentrations suppressed it. Lindane and ceresan inhibited CO2 production from soil by normal concentrations but the same CO2 production was enhanced in berseem roots treated soil upto 10 ppm of ceresan.The nitrification of ammonium sulphate in soil due to these pesticides was impaired significantly for varying periods. The inhibitory effect of higher concentrations was marked only upto 3 weeks, subsequently the rate of nitrification was restored. Among the nitrifiers, Nitrobacter were more susceptible as compared to Nitrosomonas.  相似文献   

3.
Summary Application of a granular formulation of hexachlorocyclohexane (HCH) to the potted soil at flooding decreased the concentration of iron and. to some extent, manganese in rice plants, especially at concentrations above 3 ppm active ingredient (a.i.) Likewise, HCH, applied to rice fields at transplanting (several days after submergence) caused a significant decrease in the concentration of iron, and not manganese, in the rice plant but only at concentrations above 12.5 kg a.i./ha despite high levels of reduced iron in the soil. Inhibition of iron reduction by HCH was more pronounced when applied at flooding than at several days after flooding.  相似文献   

4.
Summary The addition of 100, 1000 and 10,000 ppm copper, as oxide or hydrogen phosphate, stimulated nitrogen mineralisation and nitrification during incubation of a sandy loam (0.5% calcium carbonate) treated with 200 ppm N as dried blood. The maximum effects occurred with 1000 ppm added copper and were similar with both sources of added copper. EDTA-extractable copper was higher where copper hydrogen phosphate than where copper oxide had been added.  相似文献   

5.
K. L. Sahrawat 《Plant and Soil》1978,50(1-3):521-526
Summary Studies to evaluate 5 chelating compounds NTA (nitrilotriacetic acid), EDTA (ethylene diaminetetra acetic acid), tartaric acid, citric acid, thiourea and an insecticide, carbofuran as inhibitors of nitrifucation in a sandy loam (pH 7.7) at 10 and 50 ppm concentrations showed that except thiourea and carbofuran they had no appreciable effect on nitrification. Even thiourea and carbofuran were moderately effective at higher concentrations in retarding nitrification in soil at the most upto 3 weeks. The results of the study suggest that all the chelating compounds may not necessarily be inhibitors of nitrification process in soils as commonly believed and that carbofuran may have little effect on nitrification in soils with pH in the alkaline range under normal application rates.  相似文献   

6.
Summary Plant dry weight, total N, and total Ca was increased at 0.1 and 1 ppm N-serve. At greater 10 ppm the plants showed visual symptoms of a stunted growth, stem elongation, flowers, and pods failed to form or were aborted, young leaves were curled, and roots were club shaped with many branches. These symptoms were increasingly evident with increasing N-serve application rates. The reason was attributed to an auxin effect. Dry wt and total N in the plant was less than the control at the higher N-serve applications. There was little effect on nitrogenase activity at less than 10 ppm N-serve. Nodulation tended to increase at 0.1 and 1 ppm N-serve.Nitrification was inhibited up to 104 days at 20 ppm N-serve. The soil pH of the high N-serve rates was decreased at 104 days probably due to nitrification. Generally there were little detectable differences among treatments in soil organic N. The average soil organic N from 0 to 104 days decreased by 0.01%. Average increase in total N within each pot at harvest was equivalent to about 138 kg N/ha.  相似文献   

7.
Padhy RN 《Microbios》2001,106(415):165-175
The effects of individual chemical fertilizers (urea, superphosphate and potash) on the toxicity of two carbamate insecticides (carbaryl and carbofuran) to the nitrogen-fixing cyanobacterium Anabaena PCC 7120, were studied in vitro at partial lethal levels of each insecticide. Urea at 10 and 50 ppm levels reduced the toxicity due to carbaryl at 50 ppm partial lethal dose and due to carbofuran at 100 and 250 ppm partial lethal doses. Urea at 100 ppm enchanced the toxicity of both insecticides. Superphosphate at 10 ppm reduced the toxicity of carbaryl at 50 ppm and carbofuran at 100 and 250 ppm, but it enhanced the toxicity due to both insecticides at 50 ppm superphosphate. The toxicity due to carbaryl at 40 and 60 ppm were reduced by 100 and 200 ppm potash, but higher potash levels caused enhancement of toxicity. Carbofuran toxicity at 100 ppm was reduced but at 250 ppm the toxicity was enhanced with 100 ppm potash. Urea, superphosphate and potash caused no significant change in number of vegetative cells between the successive heterocysts at 10 and 50 ppm of urea and superphosphate, respectively, and 100 ppm of potash.  相似文献   

8.
Summary 1,4-Naphthoquinone; 2-methyl-1,4-napthoquinone; 2,3-dichlorohydroquinone; 4,6-di-tert.butyl-o-benzoquinone; 4,6-di-tert.butylpyrocatechol and 4-tert.butylpyrocatechol at concentrations of 10 and 20 ppm inhibit mineralization of urea N by reducing urease activity and/or nitrification in soils. Coating of urea with these chemicals was more effective than direct application to the soil. There was no adverse effect of any of the chemicals either on germination or on the growth of wheat plants at concentrations of 20 and 50 ppm added to soil.  相似文献   

9.
Summary Baygon (2-isopropoxyphenyl-N-methylcarbamate) inhibited nitrification for 4 weeks at 25 and for 16 weeks at 1250 ppm. Ammonification of peptone was stimulated by baygon. Oxidation of ammonium formed from peptone was not complete in 16 weeks at 1250 ppm. of baygon. Solubilization of tricalcium phosphate was not affected by baygon. CO2 production from soil was depressed for 10 days. Glucose addition caused the higher depression of CO2 production after a week. A Pseudomonas sp. degraded baygon to 2-isopropoxyphenol. re]19730507  相似文献   

10.
Summary The effects of anthraquinones and some other quinonoid and phenolic compounds on mineralization of urea N in soils were studied by estimating the influence on urease activity and nitrification. Anthraquinones did not affect the mineralization of urea N but 1,4-naphthoquinone; 2-methyl-1,4-naphthoquinone; 2–3-dichlorohydroquinone; 4,6-di-tert.butyl-o-benzoquinone; 4-tert.butylpyrocatechol and 4,6-di-tert.butylpyrocatechol inhibited urease activity and nitrification. The hydrolysis of urea (100 ppm) was not prevented by partial reduction in urease activity. The effective substances also inhibited dehydrogenase activity.  相似文献   

11.
Summary Nitrification and ammonia volatilisation losses from urea and dicyandiamide (DCD)-treated urea were studied in a sandy loam soil. Laboratory experiments indicated that 20 ppm (of soil) DCD effectively inhibited nitrification of urea over sixty days. If the urea was treated with DCD (20 ppm), ammonia emission from the soil was extended over 105 days; with urea alone, it was negligible after 15 days. A field study indicated that DCD treatment increased volatilisation losses of ammonia tremondously if urea was applied to the soil surface; these losses were minimised if the urea was placed at 5 cm depth. It would seem that nitrification inhibitors must be combined with a placement technique.  相似文献   

12.
The effect of prefeeding of dehydrated E. officinalis (amla) powder at 5 and 10% levels on hexachlorocyclohexane (HCH)-induced changes in multicomponent antioxidant system and lipid peroxides in rat liver was studied. HCH induced significant elevation in hepatic malondialdehyde, conjugated dienes and hydroperoxides. The prefeeding of amla at 10% level could decrease the formation of these lipid peroxides significantly. The HCH abuse resulted in a significant reduction in hepatic glutathione S-transferase (GST), glucose-6-phosphate dehydrogenase (G-6-PDH) and superoxide dismutase (SOD) activities with an elevation in the activities of glutathione peroxidase and gamma-glutamyl transpeptidase (GGT). On the other hand, the HCH-induced impairment in hepatic catalase, G-6-PDH and SOD activities were modulated by amla at the 10% level of intake. Prefeeding of amla at 5 and 10% levels appeared to reduce the HCH-induced raise in renal GGT activity. The results show the elevation of hepatic antioxidant system and reduction of cytotoxic products as a result of prefeeding of amla, which were otherwise affected by the HCH administration.  相似文献   

13.
We have developed the long-term life support system that enables the experiment of aquatic animals breeding for 90 days or more for the future experiments in orbit. In order to enable long-term breeding of wide aquatic animals, it is necessary to remove nitrate produced by biological nitrification. Then, we examined a denitrification method to use an electrochemical reaction of biofilm-electrode reactor. In this research, we have not kept the aquatic animals actually but imitated breeding of five goldfish. The ammonia of about 250 ppm was added in breeding water through 90 days. As a result, neither ammonia nor nitrite accumulated 0.1 ppm and nitrate could be suppressed to about 10 ppm.  相似文献   

14.
The ability of eastern subterranean termites, Reticulitermes flavipes (Kollar), to penetrate various concentrations and treatment thicknesses ranging from 1.0 to 50.0 mm of Dursban TC and Premise 75 was evaluated in a laboratory bioassay. Termites penetrated only a few millimeters into 500 ppm Dursban TC-treated soil at all thicknesses. As concentration decreased, termite penetration into Dursban TC-treated soil increased with termites generally penetrating completely through 5.0- and 0.5-ppm treatments. Termites penetrated at least 30% into 10-, 25-, and 50-mm thicknesses of 100 ppm Premise 75. Termites generally completely penetrated all concentrations < or = 100 ppm and thicknesses < or = 5 mm. At 7 d, termite mortality was 100% at all treatment thicknesses of Dursban TC at 500 and 50 ppm. At 5.0 and 0.5 ppm Dursban TC, termite mortality ranged from approximately 45 to 98% across all treatment thicknesses. At 100- and 10-ppm concentrations of Premise 75-treated soil, termites suffered > or = 75% mortality. Premise 75 at 1.0 and 0.1 ppm generally killed < or = 50% of the assayed termites at all treatment thicknesses.  相似文献   

15.
Summary A laboratory study was made of the influence of the sulpha drugs sulphathiazole, sulphanilamide, sulphapyridine, sulphaguanidine, sulphadiazine and sulphadiamidine on nitrification of urea applied to a sandy clay loam soil of pH 7.8. Sulphathiazole applied at 2 ppm inhibited the nitrification of urea most effectively. Sulphadiazine and sulphadiamidine were also found to have nitrification inhibitory properties and need further testing. About 14% of applied urea N accumulated as nitrites after 1 week of incubation. Application of sulpha drugs along with urea reduced nitrite accumulation. re]19760203  相似文献   

16.
Summary Nine insecticides (six organophosphates and three carbamates) were tested for their effects on soil nitrification, growth of legume seedlings, and growth of four species of rhizobia bacteria. No inhibition of nitrification was found at normal field rates (5 ppm) of application. Some instances of inhibition were observed at 50 ppm and at 500 ppm. Similarly, 5 ppm applications did not inhibit growth of alfalfa or sweetclover seedlings ... with one exception. Disc inhibition tests of the rhizobia bacteria showed thatRhizobium leguminosarum andRhizobium trifolii were most sensitive to the pesticides.Rhizobium meliloti, and particularlyRhizobium japonicum, were resistant to the insecticides. No consistent correlation was observed between tests on the nodulating bacteria and the tests on legume growth.Published with the approval of the Director of the North Dakota Agricultural Experiment Station as Journal Article No.309. Portion of a thesis presented by the senior author in partial fulfillment of the requirements for the M.S. degree in bacteriology at North Dakota State University.  相似文献   

17.
A green house study was conducted on the effect of P and Zn on nodulation and N fixation in chickpea (Cicer arietinum L.) in a loamy sand (Typic Torripsamments) using treatment combinations of five levels of P (0, 25, 50, 100 and 250 ppm), and six levels of Zn (0, 5, 10, 20, 40 and 100 ppm). The number, dry matter and leghaemoglobin content of nodules, and amount of N fixed generally increased with Zn alone upto 19 ppm and P alone upto 50 ppm, and decreased with their higher levels. Application of 25 to 50 ppm P and 5 to 10 ppm Zn counteracted to a greater extent the adverse effect of 40 and 100 ppm Zn, and 250 ppm P, resp. Maximum nodulation and N fixation (91 to 145% over zero P and Zn, at maturity) was recorded with 25 to 50 ppm P applied along with 5 to 10 ppm Zn. At 64 days, depletion in soil-N was noted, particularly when P was applied, whereas at maturity there was a gain in soil-N, ranging from 10.5 to 44.5 kg/2×106 kg soil depending upon P and Zn treatments. The increase in nodulation and N fixation with balanced P and Zn nutrition might be attributed to an increase in leghaemoglobin, and K and Fe concentration in nodules, and increased plant growth, resulting into enhanced activity of N fixing organisms. The results showed that balanced P and Zn nutrition is essential not only for plant growth but also for maximum activity of Rhizobium for N fixation. Work done at Harvana Agricultural University, Hissar, India.  相似文献   

18.
Several chemicals used as nitrification inhibitors were tested to determine their effect on dentrification by a Pseudomonas sp. and in soil. Denitrification by the bacterium was suppressed by 2-chloro-6(-trichloromethyl)-pyridine (N-Serve) at a concentration of 50 ppm, while 2,5-dichloroaniline caused the accumulation of nitrite in the culture medium. The nitrification inhibitors had little effect on the denitrifying activity in soil under anaerobic conditions. 2-Sulfanilamidothiazole inhibited denitrification to some extent and samples supplied with potassium azide produced N2O rather than N2 as the predominant gas.  相似文献   

19.
Female mink were fed a basal diet supplemented with either 0, 10 100, or 1000 ppm iodine, as potassium iodide, from breeding through lactation. In addition, females were housed in pens sanitized just prior to whelping with 100 or 1000 ppm titratable iodine disinfectant to investigate the effects of these treatments on their reproductive performance. The gestation periods of the iodine-treated mink were shorter than the controls. Kit birth weights were not significantly different from the controls. The average number of kits whelped per female mated in the control group was 5.0. No detrimental effects were observed on litter size or kit survival in the group fed 10 ppm supplemental iodine. Only 2.1 kits per female mated were whelped by the mink fed 100 ppm supplemental iodine and none of the females that received the 1000 ppm supplemental iodine diet whelped. Body weights of kits whelped and nursed by the females that received the 100 ppm supplemental iodine diet were significantly lighter at 4 weeks of age. Kits nursed by females housed in pens sanitized with 100 or 1000 ppm titratable iodine had the greatest biomass at 4 weeks of age.  相似文献   

20.
The efficacy of the synthetic estrogen, diethylstilbestrol (DES), for sex-reversal in the Java tilapia, Oreochromis mossambicus was investigated. Fry of 8–10 mm total length were fed diets containing 25, 50 and 100 ppm of DES for 30 days in plastic pools; this was followed by 45–65 days rearing in fertilized cement cisterns where hormone-free diet was given. DES at 50 and 100 ppm induced 100% sex-reversal; DES at 25 ppm resulted in only a slightly larger proportion of females to males. The untreated control group had a higher proportion of males than females. No intersex or sterile individuals were observed among the steroid-treated fish. The present investigation demonstrates that 50 ppm DES administered for 30 days is sufficient to induce a 100% sex-reversal in O. mossambicus.  相似文献   

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