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971.
Potential water quality impacts associated with using bottom ash (BA) and composted dairy manure (CM) as a soil amendment were evaluated in this study. Two column studies were conducted to evaluate three blends of acidic BA and CM (BA:CM, v/v) namely, B1ac (95:5), B2ac (90:10), and B3ac (80:20) and three blends of alkaline BA and CM (BA:CM, v/v), namely, B1al (95:5), B2al (90:10), and B3al (80:20) under constant head water table conditions. Samples from standing water (top) and leachate (bottom) were collected at weekly intervals until day 49 to evaluate the effects of different blend ratios and elapsed time on standing water and leachate chemical and physical properties. A higher CM content in both acidic and alkaline blends resulted in higher leachate concentrations for solids and nutrients tested in this study. Alkaline blends had higher standing water and leachate nutrients concentration compared to acidic blends. After day 28, standing water total dissolved solids (TDS) concentrations for all acidic blends was below the USEPA drinking water standard however, TDS value for alkaline blend was always below the standard. Similar trends were also observed for NO3–N and phosphorus (P) concentrations for both blends. Based on these findings, it was concluded that acidic and alkaline blends B1ac, B1al, B2ac and B2al may be considered as a soil amendment material. 相似文献
972.
Alpha-glucan phosphorylase catalyzes the reversible cleavage of
α-1-4-linked glucose polymers into α-D-glucose-1-phosphate.
We report the recombinant production of an α-glucan/maltodextrin
phosphorylase (PF1535) from a hyperthermophilic archaeon,
Pyrococcus furiosus, and the first detailed
biochemical characterization of this enzyme from any archaeal source
using a mass-spectrometry-based assay. The apparent 98 kDa recombinant
enzyme was active over a broad range of temperatures and pH, with
optimal activity at 80 °C and pH 6.5–7. This archaeal
protein retained its complete activity after 24 h at 80 °C in
Tris-HCl buffer. Unlike other previously reported phosphorylases, the
Ni-affinity column purified enzyme showed broad substrate specificity
in both the synthesis and degradation of maltooligosaccharides. In the
synthetic direction of the enzymatic reaction, the lowest
oligosaccharide required for the chain elongation was maltose. In the
degradative direction, the archaeal enzyme can produce
glucose-1-phosphate from maltotriose or longer maltooligosaccharides
including both glycogen and starch. The specific activity of the
enzyme at 80 °C in the presence of 10 mM maltoheptaose and at 10
mg ml–1 glycogen concentration was 52 U
mg–1 and 31 U mg–1, respectively.
The apparent Michaelis constant and maximum velocity for inorganic
phosphate were 31 ± 2 mM and 0.60 ± 0.02 mM
min–1 µg–1, respectively. An
initial velocity study of the enzymatic reaction indicated a
sequential bi-bi catalytic mechanism. Unlike the more widely studied
mammalian glycogen phosphorylase, the Pyrococcus
enzyme is active in the absence of added AMP. 相似文献
973.
To better understand the pathogen-stress response of Brassica species against the ubiquitous hemi-biotroph fungus Leptosphaeria maculans, we conducted a comparative proteomic analysis between blackleg-susceptible Brassica napus and blackleg-resistant Brassica carinata following pathogen inoculation. We examined temporal changes (6, 12, 24, 48 and 72 h) in protein profiles of both species subjected to pathogen-challenge using two-dimensional gel electrophoresis. A total of 64 proteins were found to be significantly affected by the pathogen in the two species, out of which 51 protein spots were identified using tandem mass spectrometry. The proteins identified included antioxidant enzymes, photosynthetic and metabolic enzymes, and those involved in protein processing and signaling. Specifically, we observed that in the tolerant B. carinata, enzymes involved in the detoxification of free radicals increased in response to the pathogen whereas no such increase was observed in the susceptible B. napus. The expression of genes encoding four selected proteins was validated using quantitative real-time PCR and an additional one by Western blotting. Our findings are discussed with respect to tolerance or susceptibility of these species to the pathogen. 相似文献
974.
Gupta SK Sheikh MA Islam MS Rahman KS Jahan N Rahman MM Hoekstra RM Johnston R Ram PK Luby S 《Journal of applied microbiology》2008,104(2):388-395
Aim: To evaluate the usefulness of the hydrogen sulfide (H2S) test for assessing water quality in Bangladesh. Methods and Results: We tested 382 water samples from a variety of sources using locally produced H2S test kits and laboratory‐based membrane filtration for the detection of Escherichia coli. Compared with membrane filtration, H2S tests, when incubated for 24 h, had both a sensitivity and positive predictive value (PPV) of <40% when analysis was restricted to water samples with E. coli levels below 100 colony forming units (CFU) per 100 ml. In contrast, for E. coli levels from 1000 to 9999 CFU per 100 ml, sensitivity was 94% and PPV 88%; specificity was 97% and negative predictive value was 99%. Conclusions: The hydrogen sulfide test, when incubated at 24 h, is a promising alternative for assessing water quality where E. coli levels may be high. An improved understanding of the incremental impact of contamination level on health is needed to better determine its usefulness. Significance and Impact of the Study: The hydrogen sulfide test is inexpensive, easy to use and portable. Its use may allow rapid assessment of water quality in situations where cost or logistics prevent use of other testing methods, such as in remote areas or during floods and other natural disasters. 相似文献
975.
Carbonic anhydrase (CA) is a key enzyme in the chemical reaction of living organisms and has been found to be associated with
calcification in a number of invertebrates including calcareous sponges, but until now no direct evidence has been advanced
to show CA activity in alcyonarian corals. However, it is essential to understand the role of CA in the process of biocalcification
in alcyonarian. Here we describe the novel activity of CA and its relationship to the formation of calcified hard tissues
in alcyonarian coral, Lobophytum crassum. We find that two CA proteins, which were partially purified by electro-elution treatment, can control the morphology of
CaCO3 crystals and one of them is potentially involved in the process of biocalcification. Previously, we isolated CA from the
total extract of alcyonarian, and further, we report here a single protein, which has both calcium-binding and CA activities
and is responsible for CaCO3 nucleation and crystal growth. This matrix protein inhibited the precipitation of CaCO3 from a saturated solution containing CaCl2 and NaHCO3, indicating that it can act as a negative regulator for calcification in the sclerites of alcyonarians. The effect of an
inhibitor on the enzyme activity was also examined. These findings strongly support the idea that carbonic anhydrase domain
in alcyonarian is involved in the calcification process. Our observations strongly suggest that the matrix protein in alcyonarian
coral is not only a structural protein but also a catalyst. 相似文献
976.
977.
Functionalized Boron Nitride Nanosheets/Graphene Interlayer for Fast and Long‐Life Lithium–Sulfur Batteries 下载免费PDF全文
Ye Fan Zhi Yang Wuxing Hua Dan Liu Tao Tao Md Mokhlesur Rahman Weiwei Lei Shaoming Huang Ying Chen 《Liver Transplantation》2017,7(13)
Lithium–sulfur (Li–S) batteries have a much higher energy density than Li ion batteries and thus are considered as next generation batteries for electric vehicle applications. However, the problem of rapid capacity fading due to the shuttling of soluble polysulfides between electrodes remains the main obstacle for practical applications. Here, a thin and selective interlayer structure has been designed and produced to decrease the charge transfer resistance and mitigate the shuttling problem, simply by coating the surface of cathode with a thin film of functionalized boron nitride nanosheets/graphene. Due to this thin and ultralight interlayer, the specific capacity and cycling stability of the Li–S batteries with a cathode of sulfur‐containing porous carbon nanotubes (≈60 wt% sulfur content) have been improved significantly with a life of over 1000 cycles, an initial specific capacity of 1100 mA h g?1 at 3 C, and a cycle decay as low as 0.0037% per cycle. This new interlayer provides a promising approach to significantly enhance the performance of Li–S batteries. 相似文献
978.
Md. Giash Uddin Mohammad Salim Hossain Md. Atiqur Rahman A. H. M. Mazbah Uddin Md. Shafiullah Bhuiyan 《Biological trace element research》2017,178(2):189-193
Chronic liver disease (CLD) is associated with the destruction of liver parenchyma cell. It is the main cause of morbidity and mortality in most of the developed countries. Oxidative stress and altered levels of different trace elements in serum have been documented for different diseases including inflammation and many liver diseases. This study aims to evaluate the serum level of malondialdehyde (MDA), nitric oxide (NO), antioxidant vitamin C, C-reactive protein (CRP), and zinc (Zn) in CLD patients and to establish a correlation among the study parameters with the severity of inflammatory conditions of CLD. In this study, CLD patients and healthy volunteers were recruited. Total cholesterol and triglyceride were determined by colorimeter using enzymatic method. Serum non-enzymatic antioxidant vitamin C, reactive oxygen species nitric oxide (NO), and malondialdehyde (MDA) were determined by UV-spectrophotometric method. Trace element (Zn) levels were determined by graphite furnace atomic absorption spectroscopy. Independent sample t test and Pearson’s correlation test were performed for statistical analysis using the statistical software package SPSS, Version 20. Studies showed that the MDA (p < 0.001), NO (p < 0.001), and CRP levels were significantly higher in CLD patients than in control subjects. The antioxidant vitamin C (p < 0.001) and trace element zinc (p < 0.001) were comparatively lower in the CLD patients than in control subjects. Elemental Zn showed an inverse relationship with MDA, NO, and CRP but positively correlated with antioxidant capacity, whereas MDA showed a positive correlation with CRP level. Thus, we conclude that attenuated level of Zn and antioxidant in serum play an important role in the inflammatory status of CLD patients by elevating the concentration of MDA, NO, and CRP. 相似文献
979.
Shamshad A. Khan Priyanka Verma Suchitra Banerjee Arnab Chaterjee Sudeep Tandon Alok Kalra Abdul Khaliq Laiq ur Rahman 《Plant Growth Regulation》2017,81(3):365-376
The flowers of Pyrethrum (Chrysanthemum cinerariaefolium) are known to contain Pyrethrins that are naturally occurring potential insecticide. Hairy roots were induced from leaves of C. cinerariaefolium using Agrobacterium rhizogenes strain A4. The root clones were characterized in to four groups i.e. thick, unbranched (D2 and D5), thin, highly branched (D3), thick, branched (B2) and thick, highly branched (D1, D6). Six established hairy root clones showed the presence of pyrethrin and were selected for elicitation studies. Growth kinetics studies revealed highest growth index in hairy root clone D1 (592.0) followed by D6 and D3 on dry weight basis after 40 days of culture. The maximum pyrethrin content was found in the clone D3 (7.2 mg/g dw) which is comparable to the flowers obtained from the variety “Avadh”. Hairy root clone D2 (5.2 mg/g dw) and D6 (1.3 mg/g dw) contained pyrethrin but in less amount as compared to clone D3. The PCR analysis showed the presence of rol B and rol C genes in all the six hairy root clones while rol A was detected only in D2 clone. The methanolic extract of D3 clone showed antifungal activities against phytopathogenic fungal strains which were found maximum against Curvuleria andropogonis followed by Colletotrichum acutatum and Rhizoctonia solani. Hairy root clones D2, D3 and D6 were elicited with culture filtrate of endophytic fungus (Fusarium oxysporum) and bacteria (Bacillus subtilis). The culture filtrate (4.0?%v/v) of both the fungal and bacterial origin was found to be effective in enhancing the pyrethrin content in all the tested hairy root clones. Clone D3 showed maximum pyrethrin content on elicitation with F. oxysporum (9.7 mg/g dw) and B. subtilis (9.7 mg/g dw) culture filtrate, which is 32?% higher than the non elicited D3 hairy roots (7.2 mg/g dw). F. oxysporum also enhanced the hairy root growth resulting into the higher biomass yield of D3 (50?%) and D2 (76?%) in comparison to control non elicited hairy root clones of D3 and D2, respectively leading to higher pyrethrin yield. 相似文献
980.
Pooja Singh Sana Khan Susheel Kumar Laiq ur Rahman 《Plant Cell, Tissue and Organ Culture》2017,129(1):35-44
Rose-scented geranium is an important aromatic herb, have eminent for oil. The oil of geranium commercially utilized in the perfumery, cosmetic and aromatherapy industries all over the world. It is also helpful to cure many of the diseases, since it possess antibacterial, antifungal, antioxidant, anti-inflammatory and anticancer activities. However rose scented geranium suffer from several biotic and abiotic stresses, which reduced the yield of oil. So there is need to genetically improve the geranium using biotechnological approaches. The present study demonstrates the establishment of direct regeneration and Agrobacterium tumefaciens (LBA4404) mediated transformation protocol in Pelargonium graveolens (cv. CIM-BIO 171). Different media combinations such as benzyl amino purine (BAP), kinetin, naphthalene acetic acid (NAA), and adenine di-sulphate (ADS) were standardised to induce direct regeneration in P. graveolens. The maximum regeneration frequency i.e. 90.56?±?1.2% per explant was achieved from petiolar segments in medium containing 2.5 mg/l BAP, 0.1 mg/l NAA, 1 mg/l ADS. However, with the leaf explants only 45.94?±?2.91% frequency was achieved. In the present study, A. tumefaciens strain LBA4404 was used carrying binary vector pBI121 with the gusA as a reporter gene and neomycin phosphotransferase II (nptII) gene as a plant selectable marker. Parameters like bacterial optical density, infection time, acetosyringone concentration and kanamycin concentration were optimised to achieve maximum transformation frequency (69.5?±?2.3%).The putative transgenic shoots were subsequently rooted on half strength MS medium and successfully transferred to the greenhouse. The transgenic plants were characterised by gus histochemical assay, PCR analysis (nptII-786 bp and gus A- 1707 bp) and Southern hybridization tests using gusA gene probe. The regeneration as well as transformation protocol will no doubt provide the basis to decipher the insights of metabolic pathways in geranium. Also could be useful for genetic improvement, to make it more tolerant/resistant against biotic and abiotic stresses and ultimately fruitful for Indian farmers in agronomic traits like high biomass, oil content, yield and better quality. 相似文献