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961.
P. K. Khanna 《Plant and Soil》1967,26(2):277-284
Summary An attempt to find the relationship among the soil inorganic phosphate fractions and the soil test values determined with various common methods, has been made in the present studies. Out of the methods tried (Olsenet al., Bray and Kurtz, Datta and Kamath, Bingham) the soil-test values obtained with only Bray and Kurtz's method no. 2 have shown a positive significant relationship with Ca-P fraction while the others have shown more or less a positive significant correlation with saloid-bound P, Al-P and Fe-P fractions. Negative significant relationships of Al-P and Fe-P with Ca-P indicate that they increase or decrease at the expense of each other by fertilisation and cropping. Application of basic slag at the rate of 120 lbs P2O5 per acre indicate a maximum increase in most of the soil test values and the saloid bound P and Al-P fractions suggesting probably its high residual value in the soils. The use of the method of Datta and Kamath along with that of Olsenet al. and Bray and Kurtz no. 1 has been recommended. 相似文献
962.
Harjeet Khanna S. K. Raina Srinivasulu K. Kumar 《Journal of plant biochemistry and biotechnology.》1997,6(2):75-80
Following microprojectile mediated delivery of a plasmid construct (pAHC-25) encoding bar (bialophos resistance) gene into five-day-old scutellar calli derived from mature embryos, the effectiveness of selection procedure for bar-gene expressing tissue was compared for two indica rice cultivars (IR-64 and Karnal Local). While IR-64 transformants could be selected through the generally used semi-solid selection medium, the same procedure was not effective in the basmati cultivar Karnal Local. In the latter case, while lower concentrations (2–4 mg 1?1) of the selective agent phosphinothricin (PPT) yielded only escapes, higher concentrations (6–8 mg l?1) inhibited proliferation of transformed as well as untransformed sectors. For Karnal Local, a liquid medium based selection system was successfully utilized for recovering transformed sectors and, eventually, regenerants. The study demonstrates the generation of transformants of two elite indica cultivars using the environment-independent system of mature embryos from seeds. 相似文献
963.
Growth of the heart in hypertrophy is accompanied by changes in the phenotypic expression of cardiac genes. To explore the molecular basis of cardiac hypertrophy, we have analyzed the regulation of myosin heavy chain gene (MHC) expression. In one set of experiments, pressure overload on the rat heart was produced by constriction of the abdominal aorta. Changes in the and -MHC mRNA were then studied in overloaded hearts and following load removal. Pressure overload resulted in down-regulation of the -MHC with corresponding up-regulation of the steady state level of -MHC mRNA. Load removal (debanding) resulted in regression of cardiac hypertrophy and a rapid return of -MHC mRNA to normal values. In contrast, the recovery in -MHC mRNA was much slower to the extent that it remained substantially elevated compared to respective sham controls even after 7 weeks of post-debanding. These results suggest that putative load-related signals independently regulate two genes. Several lines of evidence indicate that adrenergic nervous system plays an important role in the induction and maintenance of cardiac hypertrophy and in the redistribution of myosin isoforms. We have analyzed the effect of cAMP inducing agents on the regulation of a-MHC gene in primary cultures of the fetal (18 day) rat cardiac myocyte. Inclusion of 8 Br-cAMP in the culture media increased the expression of -MHC promoter/reporter construct comprising of 2.9 kb upstream sequence of the -MHC gene. Several deletion mutations in the - MHC gene promoter defined the cAMP responsive boundaries to be a 32 bp region comprising of -71 to -40 bp sequences. Deletion of this region resulted in loss of cAMP response as well as in basal expression of -MHC promoter/reporter construct. These data suggest a role of -adrenergic pathway in the modulation of -MHC gene expression. 相似文献
964.
The effect of soil heat and autoclaving on labile inorganic P (Bray I), microbial P (P-flush) and on phosphatase activity was studied by heating five forest soils in the laboratory, which simulated the effects of heat during bushfires. Top soil was heated to 60 °C, 120 °C and 250 °C or autoclaved for 30 minutes. Soils were analysed immediately after heating and during seven months of incubation to assess immediate and longer-term effects of heating.Labile inorganic P increased immediately after heating and autoclaving soils, with the highest amount recorded for the 250 °C treatment. Phosphorus associated with microbial biomass decreased with heat, and none or small amounts were detected in soils heated to 250 °C and autoclaved, because high temperatures killed the microbial population. Most of the P released from microbes acted as a source of labile inorganic P in soils low in inorganic P, and some of the released P was fixed by the soil. In one soil high in inorganic labile P and with undetectable amounts of microbial-P, the increase in Bray P on heating could only be assigned to solubilisation of other sources of total P Because high temperatures denature enzymatic proteins, phosphatase activity diminished with the increase in temperature, and no activity was detected in 250 °C and autoclaved soils.Phosphorus released by heating decreased during incubation in three of the five soils studied, approaching values observed in unheated soils. Simultaneously, an increase in microbial P was observed in these heated soils, indicating that the partial recovery of microbial biomass acted as a sink for the decrease in Bray-P measured. Phosphatase activity recovered only partially during incubation of heated soils. 相似文献
965.
Cherukury Madhu Zoltan Gregus Curtis D. Klaassen 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1995,674(2)
A simple HPLC method has been described to quantify diquat in biological fluids and tissues. This method permits separation and quantification of diquat from blood, bile, urine, liver and kidney. It does not require special pretreatment of the samples prior to analysis, nor a specially prepared analytical column. Various concentrations of diquat were added (10–300 nmol/ml or g) to fluids or tissues. Analysis of blank samples revealed no substrates that interfere with diquat elution. Excellent recovery (95–105%) was obtained. Diquat (120 μmol/kg, i.v.) was injected to rats and quantified in bile, blood and liver. Concentration of diquat was higher in blood and bile than liver. Therefore, this method is applicable for quantification of diquat in toxicological samples, and may be used to determine structurally similar compounds such as paraquat. 相似文献
966.
Summary Intergeneric somatic hybrids Diplotaxis catholica (2n=18) + Brassica juncea (2n=36) were produced by fusing mesophyll protoplasts of the former and hypocotyl protoplasts of the latter using polyethylene glycol. Out of 52 somatic embryos, 24 produced plants of intermediate morphology. Cytological analysis of 16 plants indicated that 15 were symmetric hybrids carrying 54 chromosomes, the sum of the parental chromosome numbers. One hybrid was asymmetric with 45 chromosomes. Nuclear hybridity of five putative hybrids was confirmed by the Southern hybridization pattern of full length 18s-25s wheat nuclear rDNA probe which revealed the presence of Hind III fragments characteristic of both the parental species. The hybridization pattern of mitochondria specific gene probe cox I indicated that three of the hybrids carried B. juncea mitochondria and one carried mitochondria of D. catholica. Presence of novel 3.5 kb Hind III and 4.8 kb Bgl II fragments suggested the occurrence of mtDNA recombination in one of the hybrids. The hybrids were pollen sterile. However, seeds were obtained from most of the hybrids by back crossing with B. juncea. 相似文献
967.
When sarcoplasmic reticulum vesicles are exposed to trypsin for 1 min the adenosine triphosphatase (Mr = 102,000) is cleaved to fragments of Mr = 45,000 and 55,000. The purified ATPase, containing both fragments, transports Ca2+ when incorporated into vesicles containing excess phospholipid. The two fragments can only be dissociated in solutions containing 1% sodium dodecyl sulfate (SDS). Ca2+ transport activity is restored in SDS-dissociated preparations in a series of steps involving dilution with 5 volumes of 5% phospholipids in 0.75% sodium cholate, incubation in ice for 30 min, and passage through an anion exchange column. Vesicles formed in this procedure regain high Ca2+ transport activity if they are incubated in SDS solution at 24 degrees for less than 20 min. However, the extent of renaturation diminishes if the vesicles are incubated for longer periods and little acitivity is recovered in vesicles incubated longer than 60 min at 24 degrees. 相似文献
968.
Tao Lin Luis F. Rodríguez Sarah Davis Madhu Khanna Yogendra Shastri Tony Grift Steve Long K. C. Ting 《Global Change Biology Bioenergy》2016,8(1):160-170
Biomass‐based biofuels have gained attention because they are renewable energy sources that could facilitate energy independence and improve rural economic development. As biomass supply and biofuel demand areas are generally not geographically contiguous, the design of an efficient and effective biomass supply chain from biomass provision to biofuel distribution is critical to facilitate large‐scale biofuel development. This study compared the costs of supplying biomass using three alternative biomass preprocessing and densification technologies (pelletizing, briquetting, and grinding) and two alternative transportation modes (trucking and rail) for the design of a four‐stage biomass–biofuel supply chain in which biomass produced in Illinois is used to meet biofuel demands in either California or Illinois. The BioScope optimization model was applied to evaluate a four‐stage biomass–biofuel supply chain that includes biomass supply, centralized storage and preprocessing (CSP), biorefinery, and ethanol distribution. We examined the cost of 15 scenarios that included a combination of three biomass preprocessing technologies and five supply chain configurations. The findings suggested that the transportation costs for biomass would generally follow the pattern of coal transportation. Converting biomass to ethanol locally and shipping ethanol over long distances is most economical, similar to the existing grain‐based biofuel system. For the Illinois–California supply chain, moving ethanol is Biomass‐based biofuels have gained attention because they are renewable energy sources that could facilitate energy independence and improve rural economic development. As biomass supply and biofuel demand areas are generally not geographically contiguous, the design of an efficient and effective biomass supply chain from biomass provision to biofuel distribution is critical to facilitate large‐scale biofuel development. This study compared the costs of supplying biomass using three alternative biomass preprocessing and densification technologies (pelletizing, briquetting, and grinding) and two alternative transportation modes (trucking and rail) for the design of a four‐stage biomass–biofuel supply chain in which biomass produced in Illinois is used to meet biofuel demands in either California or Illinois. The BioScope optimization model was applied to evaluate a four‐stage biomass–biofuel supply chain that includes biomass supply, centralized storage and preprocessing (CSP), biorefinery, and ethanol distribution. We examined the cost of 15 scenarios that included a combination of three biomass preprocessing technologies and five supply chain configurations. The findings suggested that the transportation costs for biomass would generally follow the pattern of coal transportation. Converting biomass to ethanol locally and shipping ethanol over long distances is most economical, similar to the existing grain‐based biofuel system. For the Illinois–California supply chain, moving ethanol is $0.24 gal?1 less costly than moving biomass even in densified form over long distances. The use of biomass pellets leads to lower overall costs of biofuel production for long‐distance transportation but to higher costs if used for short‐distance movement due to its high capital and processing costs. Supported by the supply chain optimization modeling, the cellulosic‐ethanol production and distribution costs of using Illinois feedstock to meet California demand are $0.08 gal?1 higher than that for meeting local Illinois demand. 相似文献
969.
Molecular crowding impacts the structure of apolipoprotein A‐I with potential implications on in vivo metabolism and function
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Madhu Budamagunta Joan Domingo‐Espín John C. Voss Jens O. Lagerstedt 《Biopolymers》2016,105(10):683-692
The effect molecular crowding, defined as the volume exclusion exerted by one soluble inert molecule upon another soluble molecule, has on the structure and self‐interaction of lipid‐free apoA‐I were explored. The influence of molecular crowding on lipid‐free apoA‐I oligomerization and internal dynamics has been analyzed using electron paramagnetic resonance (EPR) spectroscopy measurements of nitroxide spin label at selected positions throughout the protein sequence and at varying concentrations of the crowding agent Ficoll‐70. The targeted positions include sites previously shown to be sensitive for detecting intermolecular interaction via spin–spin coupling. Circular dichroism was used to study secondary structural changes in lipid‐free apoA‐I imposed by increasing concentrations of the crowding agent. Crosslinking and SDS‐PAGE gel analysis was employed to further characterize the role molecular crowding plays in inducing apoA‐I oligomerization. It was concluded that the dynamic apoA‐I structure and oligomeric state was altered in the presence of the crowding agent. It was also found that the C‐terminal was slightly more sensitive to molecular crowding. Finally, the data described the region around residue 217 in the C‐terminal domain of apoA‐I as the most sensitive reporter of the crowding‐induced self‐association of apoA‐I. The implications of this behavior to in vivo functionality are discussed. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 683–692, 2016. 相似文献
970.