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871.
The results of a study of photocatalytic degradation of phenol using aqueous oxygenated TiO2 (anatase) suspensions in a batch Pyrex photoreactor are reported. The influence on the photodegradation rate of various parameters as pH, phenol and TiO2 content, oxygen partial pressure, anions present in the dispersions was investigated. A complete oxidation of phenol was observed. Intermediate compounds, catechol and quinone, were detected. It was observed that the photodegradation also proceeded with sunlight radiation. A mechanistic and kinetic model, which accounts for the results obtained, is given. Likely reasons for inactivity of the rutile modification for this reaction are also given.  相似文献   
872.
Binding affinity of metanil yellow and its breakdown product p‐aminodiphenylamine to serum proteins has been studied employing chromatographic separation on Sephadex G‐200 and by paper and polyacrylamide gel electrophoresis. Metanil yellow has more affinity towards albumin than to globulins. The complexing is presumably through electrostatic forces. p‐Aminodiphenylamine on the other hand, preferably binds to globulin fractions of serum protein. However, a stable binding with BSA alone was also observed. The binding was quite stable and was accompanied by a shift in absorbance from 430 nm to 500 nm. Aspartic acid moiety of protein was found to be one of the units involved in the binding of p‐ADPA to proteins.  相似文献   
873.
The biochemical and toxicological significance of cesium is scarcely understood, and could be evaluated in comparison with lithium widely used as a psychotropic drug. Two male Wistar rat groups of 200–220 g are administered independently, lithium, sodium, rubidium and cesium chloride, in doses of 3mEq/Kg/day (0.024 Eq/L drinking water) during 29 days. Motor activity was measured after the injection of 70 mg pargyline/Kg animal i.p. as inhibitor of MAO A + B with an activimeter of Tedeschy type. Accumulative movements per minute are presented in function of time. Total brain proteins, alkaline and acid phosphatases and blood parameters, haematocrit, haemoglobin and erythrocytes, were determined.

The maximal increase of motor activity was seen in rats treated with RbCl 2 h after the pargyline administration and the diminution was Rb>Li>Cs. Cesium induced a decrease of the total serum protein concentration from 6.39 ± 0.1 to 5.8±0.5mg/100ml serum in controls. Acid and alkaline phosphatase were decreased in cesium treated rats. The three determined blood parameters, haematocrit, haemoglobin and erythrocytes, show also a decrement with cesium treatment compared to the control ones.  相似文献   
874.
During the incineration of the chlorinated hydrocarbons originating as the side products in vinyl chloride plant, hypochlorite ion appears as a pollutant in plant waste water. To remove it to the permitted level of 2 mg/l the process of the catalytic oxidation by cobalt (II, III) oxide, followed by sodium sulphite treatment has been chosen. It was shown that the above choice gives satisfactory results. The influence of some parameters such as retention time, effluent pH and temperature versus removal efficiency have been determined.  相似文献   
875.
European starling (Sturnus vulgaris) nestlings were used as a surrogate to study the effect of chlorpyrifos application to a corn agroecosystem on songbird reproduction. Chlorpyrifos was applied in a T‐band at 1.3 kg AI/ha, and residues were measured in soil, earthworms, ground‐dwelling insects, and diet items collected from the crop of starling nestlings. Chlorpyrifos levels in soil peaked at 34.2 μg/g, 4 days post‐application, and dissipated to trace levels by 64 days post‐application. Concentrations of chlorpyrifos in earthworms and ground‐dwelling insects reached 0.9 and 0.7 ug/g, respectively. Starling nestling diet items included invertebrates from eight orders with chlorpyrifos concentrations ranging from trace levels to 10.6 μg/g in earthworms. Nestling brain and plasma cholinesterase (ChE) activity and body mass measurements were taken at 3, 8, and 13 days post‐hatch (DPH). Adult starling fecundity was also measured. Body mass differences between treatment and reference site nestlings at 3 and 13 DPH were not significant at α = 0.05. However, 8 DPH nestlings from the Treatment Site had a transient reduction in weight (p = 0.03) when compared with 8 DPH reference nestlings. There were no significant differences in brain or plasma ChE activities of 3, 8, or 13 DPH nestlings. Further, multiple measures of fecundity (i.e., clutch size, hatching percentage, and fledging percentage) indicated that chlorpyrifos application did not affect starling nestling survival to fledging, as the values from the Treatment and Reference Site were nearly identical. This screening‐level study suggests that although one age group of starling nestlings from the Treatment Site weighed less than their Reference Site counterparts, a single T‐band application of chlorpyrifos did not impair starling nesting success.  相似文献   
876.
877.
The effect of white African mineral dye Yombofita (YF) on the activities of alkaline phosphatase (ALP), acid phosphatase (ACP) and malondialdehyde (MDA) levels in the skin, liver, kidney and serum of albino rats was investigated. The chemical analysis of the dye was first carried out using solubility test, pH determination and X-ray fluorescence (XRF) elemental analysis. Six different concentrations (0.05, 0.15, 0.25, 0.5, 0.75 and 1.00%) of the dye were prepared using hydrogen peroxide (30 volume) as solvent. A total of 80 albino rats (Rattus norvegicus) were used for the study. The rats were divided into 8 groups of 10 each and were maintained on commercial feed for the period of the experiment i.e. 30 days. In group 1, the control group, the animals were applied distilled water on their heads, whereas in group 2 the vehicle i.e. hydrogen peroxide was applied. In groups 3 to 8 various concentrations of YF (white) dye ranging from 0.05, 0.15, 0.25, 0.5, 0.75 to 1.00% was applied respectively. At the end of the experiment, blood samples were collected and portions of the selected tissues were excised for the determination of ALP and ACP activities. The MDA level was also determined in the skin of experimental animals. The results revealed a significant decrease (p?p?相似文献   
878.
Fluoride (Fl) exerts an inhibitory effect on many metabolic enzymes of various tissues. A study was carried out among individuals residing in a Fl-affected area in India. The biochemical parameters including serum enzyme activities of alkaline phosphatase (ALKP), glutamic pyruvic transaminase (SGPT), lactate dehydrogenase (LDH), and serum creatinine (CRTN) were estimated in 259 subjects compared to 233 controls. The results showed that among the Fl-exposed population, ALKP and SGPT were significantly increased compared to control. The CRTN levels were also significantly increased compared to the control subjects. LDH levels were not markedly altered. Data suggest that Fl exposure affects renal and hepatic functions in endemic areas of India.  相似文献   
879.
A study to understand the mobility and transport of heavy metals (HMs) from soil and soil amended with sewage sludge to maize plants was carried out. The total and ethylenediaminetetraaceticacid (EDTA)-extractable HMs in agricultural soil and untreated domestic sewage sludge samples, and the correlation between the total and extractable metals in soil and sewage sludge were carried out. Pot experiments were performed to study the transfer of HMs to maize grains, grown in soil (control) and in soil amended with sewage sludge (test samples). The total and extractable HMs in soil, sewage sludge, and maize grains were analysed by FAAS/ETAAS (flame atomic absorption spectrometer/electrothermal atomic absorption spectrometer) after digestion in microwave oven. Statistically significant correlations were obtained between the total contents of Cu, Cd, As and their respective extractable fractions in soil, while in domestic wastewater sludge (DWS) the better correlation was observed only for Ni and Cd. The edible part of maize plants (grains) from test samples presented high concentration of Zn, Pb, Ni, Cd, Cu, As, and Cr concentrations (80.7–85.6, 3.8–3.95, 2.35–2.5, 0.75–0.82, 3.21–3.29, 0.23–0.27, and 0.22–0.29?mg?kg?1, respectively). Good correlations were found between metals in exchangeable fractions of both soil and DWS and total metals in control and test samples of maize grains. The transfer factor of all HMs from DWS to maize grains was also determined.  相似文献   
880.
An examination of hospital records at Ngaoundere in Cameroon showed that there were 51 reported cases of pesticide poisoning in a 27-month period (January 2004 to April 2006) and of those, only two deaths were attributed to insecticides. One feature was that apart from a high proportion of unidentified poisons, rodenticide poisoning was reported more often than other pesticides. Many cases of poisoning might go unrecorded if an individual does not go to hospital.  相似文献   
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