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The batch bioreduction of Cr(VI) by the cells of newly isolated chromium-resistant Acinetobacter sp. bacteria, immobilized on glass beads and Ca-alginate beads, was investigated. The rate of reduction and percentage reduction of Cr(VI) decrease with the increase in initial Cr(VI) concentration, indicating the inhibitory effect of Cr(VI). Efficiency of bioreduction can be improved by increasing the bioparticle loading or the initial biomass loading. Glass bioparticles have shown better performance as compared to Ca-alginate bioparticles in terms of batch Cr(VI) reduction achieved and the rate of reduction. Glass beads may be considered as better cell carrier particles for immobilization as compared to Ca-alginate beads. Around 90% reduction of 80 ppm Cr(VI) could be achieved after 24 h with initial biomass loading of 14.6 mg on glass beads. Artificial neural network-based models are developed for prediction of batch Cr(VI) bioreduction using the cells immobilized on glass and Ca-alginate beads.  相似文献   
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Utilization of industrial solid wastes for the treatment of wastewater from another industry could help environmental pollution abatement, in solving both solid waste disposal as well as liquid waste problems. Red mud (RM) is a waste product in the production of alumina and it poses serious pollution hazard. The present paper focuses on the possibility of utilization of RM as an adsorbent for removal of Remazol Brilliant Blue dye (RBB), a reactive dye from dye-contaminated water. Adsorption of RBB, from dye-contaminated water was studied by adsorption on powdered sulfuric acid-treated RM. The effect of initial dye concentration, contact time, initial pH, and adsorbent dosage were studied. Langmuir isotherm model has been found to represent the equilibrium data for RBB?CRM adsorption system better than Freundlich model. The adsorption capacity of RM was found to be 27.8?mg dye/g of adsorbent at 40?°C. Thermodynamic analysis showed that adsorption of RBB on acid-treated RM is an endothermic reaction with ?H 0 of 28.38?kJ/mol. The adsorption kinetics is represented by second-order kinetic model and the kinetic constant was estimated to be 0.0105?±?0.005?g/mg?min. Validity of intra-particle diffusion kinetic model suggested that among the mass transfer processes during the dye adsorption process, pore diffusion is the controlling step and not the film diffusion. The process can serve dual purposes of utilization of an industrial solid waste and the treatment of liquid waste.  相似文献   
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The union of potato monoploid genotypes (2n=1x =12) through protoplast fusion may result in vigorous somatic hybrids due to a reduction of the “genetic load” normally present in this highly heterozygous tetraploid (2n=4x=48) crop. More than 100 androgenic monoploids derived from diploid (2n=2x=24)Solanum phureja Juz. & Buk. andS. chacoense Bitt. xS. phureja clones were evaluated in field trials during 1996 and 1997 to identify the most promising genotypes for protoplast fusion experiments. Compared to the total population, the 1996 selected genotypes had higher means for tuber number (30.1 vs 11.2 tubers/plant), average tuber weight (3.0 vs 1.8 g/tuber) and total yield (66.1 vs 20.4 g/plant). Similarly, the 1997 selected genotypes had higher means for tuber number (42.8 vs 25.4 tubers/plant), average tuber weight (3.6 vs 2.5 g/tuber) and total yield (114.0 vs 63.4 g/plant) compared to the total population. The 31 selected monoploid genotypes from 1996-97 varied in their response to protoplast isolation and culture from no growth (9), cell enlargement (5), limited cellular divisions (8), callus formation (5) to plant regeneration from callus (4). Chemical fusion and electrofusion produced three groups of intermonoploid somatic hybrids. Polymorphic simple sequence repeat (SSR) loci enabled distinction of somatic hybrids from parental somaclones. Rapid DNA extraction with SSR analysis enabled screening of calluses to identify somatic hybrid tissue prior to plant regeneration. The somatic hybrids were highly polyploid, mostly hexaploid (2n=6x=72), possibly due to fusion of endopolyploid protoplasts and/or chromosomal doubling during plant regeneration.  相似文献   
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ABSTRACT:   In the present study, the role of carbonic anhydrase (CA) and Na/K-ATPase in the gill and epidermal tissues in the giant freshwater prawn Macrobrachium rosenbergii was examined as a function of molting stage. CA activity levels in the front and back gills were low at the intermolt stage C0, but increased significantly at premolt stage D3, and then decreased after molting. In the epidermal tissue, activity levels decreased gradually towards premolt to a minimum level at stage D3, but became elevated at postmolt stages A and B. Na/K-ATPase levels in the front and back gills did not change significantly during the molt cycle. CA in the gill is possibly involved in supplying counter-ions for ion uptake, while CA in the epidermal tissue may play a role in mineralizing the exoskeleton after ecdysis. Na/K-ATPase in the gills may function in ion uptake from the ambient medium; however, since its activity was not influenced by the molt cycle, it probably does not have a major role in osmoregulation in the freshwater environment.  相似文献   
7.
L Vidya  P Varalakshmi 《Fitoterapia》2000,71(5):535-543
Urolithiasis, the process of formation of stones in the kidney and the urinary tract, is the major clinical manifestation of hyperoxaluria. Crystal deposition, as indicated by increased stone-forming constituents in urine, such as calcium, oxalate and uric acid, and decreased concentration of inhibitors, such as magnesium and glycosaminoglycans, was observed in pyridoxine-deficient hyperoxaluric rats. Renal tubular damage was indicated by increased excretion of enzymes such as alkaline phosphatase, lactate dehydrogenase, gamma-glutamyl transferase, beta-glucuronidase and N-acetyl glucosaminidase. Fibrinolytic activity was found to be reduced. Administration of pentacyclic triterpenes such as lupeol and its structural analogue betulin to hyperoxaluric rats minimised the tubular damage and reduced the markers of crystal deposition in the kidneys. In this connection, lupeol was found to be more effective than betulin.  相似文献   
8.

Shrimp farming industries are subjected to severe economic loss due to a disease called white spot syndrome, a viral disease caused by white spot syndrome virus (WSSV) in penaeid shrimp. Numerous active compounds in the market possess anti-viral activity against the white spot syndrome virus, yet the issue remains unsolved. The present study was carried out to determine the anti-viral activity of methyl 1-chloro-7-methyl-2-propyl-1h-benzo[d] imidazole-5-carboxylate (C13H15N2O2Cl) against WSSV. The anti-viral activity of the synthetic compound was determined in freshwater crabs. Crabs were divided into three different experimental groups: healthy control groups (N.C.) received NTE buffer, positive control group (P.C.) crabs received WSSV, and treatment group crabs received WSSV along with synthetic weight compound. Experimental groups were observed for 30 days post-infection. Three different organs (gills, muscles, and head soft tissue (HST)) were dissected from all three groups and analyzed using molecular-based techniques, including polymerase chain reaction (PCR), Western blot, and histopathology. Clinical signs of WSSV were observed in the positive and N.C. groups; however, the treatment group showed a 100% survival rate. Confirmation was done using PCR, Western blot, and histopathology. These results demonstrated that the given synthetic compound has significant anti-viral activity against WSSV.

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9.

Purpose

The balance of micronutrients in soils is important in nutrient use efficiency, environmental protection and the sustainability of agro-ecological systems. The deficiency or excess of micronutrients in the plough layer may decrease crop yield and/or quality. Therefore, it is essential to maintain appropriate levels of micronutrients in soil, not only for satisfying plant needs in order to sustain agricultural production but also for preventing any potential build-up of certain nutrients.

Materials and methods

A long-term fertilizer experiment started in 1969 at Central Rice Research Institute, Cuttack, Odisha, India. Using this experiment, a study was conducted to analyze the balance of micronutrients and their interrelationship. The experiment was composed of ten nutrient management treatments viz. control; nitrogen (N); N + phosphorus (NP); N + potassium (NK); nitrogen, phosphorus and potassium (NPK); farmyard manure (FYM); N + FYM; NP + FYM; NK + FYM; and NPK + FYM with three replications. Micronutrients in soil (total and available), added fertilizers and organic manures and in rice plant were analyzed. Besides, atmospheric deposition of the micronutrients to the experimental site was also calculated. A micronutrient balance sheet was prepared by the difference between output and input of total micronutrients.

Results and discussion

Application of FYM alone or in combination with chemical fertilizer increased the diethylenetriamine pentaacetate (DTPA)-extractable Fe, Mn and Zn over the control treatment. The treatment with NPK + FYM had the highest soil DTPA-extractable Fe, Mn, Zn and Cu after 41 years of cropping and fertilization. Application of chemical fertilizers without P decreased the DTPA-extractable Zn over the control while the inclusion of P in the fertilizer treatments maintained it on a par with the control. The application of P fertilizer and FYM either alone or in combination significantly increased the contents of total Fe, Mn, Zn and Cu in soil mainly due to their micronutrient content and atmospheric depositions. A negative balance of Zn was observed in the N, NP, NK and NPK treatments, while a positive balance observed in the remaining treatments. The balance of Mn was negative in all the treatments, due to higher uptake by the rice crop than its addition.

Conclusions

Long-term application of chemical fertilizers together with FYM maintained the availability of micronutrients in soil and, thus, their uptake by rice crop.
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10.
The effectiveness of 20 kg/ha sulphur (S) of the S‐containing compounds iron sulphate (FeSO4), gypsum, phosphogypsum, elemental S, and pyrite on groundnut (Arachis hypogaea L.) productivity was determined for plants grown on calcareous soil in the field. Plants grown with S compared to those without S had increased plant height, number of flowers, nodule numbers and weight, higher dry matter, seed, haulm (leaves and stems), and oil yields; higher tissue concentrations of nitrogen (N), phosphorus (P), S, iron (Fe), and zinc (Zn); and higher total uptake of mineral nutrients. Elemental S, pyrite, and FeSO4 were more effective than gypsum and phosphogypsum, with FeSO4 being the most effective source of S for improving plant growth traits, yield, and nutrient uptake. The most effective method of FeSO4 application was half to the soil at planting time (basal) followed by the remainder in three equal foliar sprays at 30,50, and 70 days after plant emergence (DAE). Pyrite and elemental S were most effective when applied to the soil only, half as a basal soil dressing, and the remainder in two equal doses at 25 and 50 DAE. Plant concentrations of S, P, and potassium (K) were similar for each source of S, but elemental S, pyrite, and FeSO4 enhanced N, Fe, manganese (Mn), and Zn uptake. Gypsum and phosphogypsum enhanced calcium (Ca) uptake. Elemental S and FeSCM provided similar results when half was applied to the soil followed by three equal foliar sprays. The best results from pyrite, gypsum, and phosphogypsum were obtained when soil applied.  相似文献   
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