Laboratory bioassays were conducted to evaluate the insecticidal effect of diatomaceous earth （DE）, SilicoSec against Callosobruchus maculatus （F.）, Rhyzopertha dominica （F.）, Sitophilus zeamais （Motschulsky）,...Laboratory bioassays were conducted to evaluate the insecticidal effect of diatomaceous earth （DE）, SilicoSec against Callosobruchus maculatus （F.）, Rhyzopertha dominica （F.）, Sitophilus zeamais （Motschulsky）, and Tribolium castaneum （Herbst） in cowpea, maize and wheat, at 25-32 ℃ and 54-68% relative humidity （r.h.）. SilicoSec was applied at rates： 0 （untreated control） 250, 500, 750 and 1,000 mg/kg of commodity. Adult mortality was measured after 3 to14 days of exposure. Progeny production was assessed after 40 or 56 days. The tested species varied in sensitivity to SilicoSec, with S. zeamais being most susceptible, but no significant differences in mortality levels observed between R. dominica, C. maculatus or T, castaneum after three days of exposure. After 5 days of exposure, all C. maculates adults died on cowpea treated at 1,000 mg/kg. Similarly, after 14 days of exposure all adults of the other species died on grains treated at 1,000 mg/kg, and were ranked in decreasing order of susceptibility S. zeamais 〉T castaneurn 〉 R. dominica. SilicoSec treatments suppressed progeny production （30 to 100%） in all the tested species. The implications of these findings to DE-based control strategy are discussed.展开更多
In order to investigate the regulation mechanism of the phycocyanin gene,a series of functional analyses of the upstream sequence of cpcB gene from Arthrospira platensis were conducted in E. coli with green fluorescen...In order to investigate the regulation mechanism of the phycocyanin gene,a series of functional analyses of the upstream sequence of cpcB gene from Arthrospira platensis were conducted in E. coli with green fluorescent protein encoding gene(gfp) as the reporter. Results showed that the gfp gene could express at a high level under the promotion of the upstream sequence,suggesting the existence of some strong promoter elements in it. The expression of GFP was influenced by temperature. Higher temperature led to higher expression level. The bioinformatics analyses followed by mutation analyses on the secondary structure of translation ini-tiation region(TIR) revealed that RNA thermosensor might account for the temperature regulation.展开更多
Natural polyphenol has been widely believed to be effective in allergy remission. Currently, most of the natural poly- phenol products come from terrestrial sources such as tea, grape seeds among others, and few polyp...Natural polyphenol has been widely believed to be effective in allergy remission. Currently, most of the natural poly- phenol products come from terrestrial sources such as tea, grape seeds among others, and few polyphenols have been developed from algae for their anti-allergic activity. The aim of the study was to screen some commercial seaweed for natural extracts with anti-al- lergic activity. Five algae including Laminaria japonica, Porphyra sp., Spirulina platensis, Chlorella pyrenoidosa and Scytosiphon sp were extracted with ethanol, and the extracts were evaluated for total polyphenol contents and anti-allergic activity with the hyalu- ronidase inhibition assay. Results showed that the total polyphenol contents in the ethanol extracts ranged from 1.67% to 8.47%, while the highest was found in the extract from Scytosiphon sp. Hyaluronidase inhibition assay showed that the extracts from Scyto- siphon sp. had the lowest IC50, 0.67 mg mL-1, while Chlorella pyrenoidosa extract had the highest IC50, 15.07 mg mL-1. The anti-allergic activity of Scytosiphon sp. extract was even higher than the typical anti-allergic drug Disodium Cromoglycate （DSCG） （IC50=1.13 mg mL-1）, and was similar with natural polyphenol from Epigallocatechin gallate （EGCG） （IC50 = 0.56 mg mL-l）. These results indicated that the ethanol extract of Scytosiphon sp. contains a high concentration of polyphenol with high anti-allergic activ- ity. Potentially Scytosiphon sp. can be developed to a natural anti-allergic compound for allergy remission.展开更多
We studied the effects of nitrogen （N） and phosphorus （P） supply on Fv/Fm （maximal quantum yield of photosystem Ⅱ） in the algae Chaetoceros debilis, Dicrateria inornata, Platymonas subcordiformis and Heterosigm...We studied the effects of nitrogen （N） and phosphorus （P） supply on Fv/Fm （maximal quantum yield of photosystem Ⅱ） in the algae Chaetoceros debilis, Dicrateria inornata, Platymonas subcordiformis and Heterosigma akashiwo to determine the sensitivity of Fv/Fm to P-limitation of the four species. Obvious decrease of Fv/Fm value was monitored in periods of P-depletion, the decrease showing different magnitudes among algal species. A more clear decrease of Fv/Fm in Platymonas subcordiformis and Heterosigma akashiwo was observed, compared with that in Chaetoceros debilis and Dicrateria inornata. After the re-supply of P, the index Fv/Fm of the four species all recovered quickly in 24h. Cell division was maintained and chlorophyll content continued to increase until the end of the experiment in Platymonas subcordiformis and Heterosigma akashiwo, while in Chaetoceros debilis and Dicrateria inornata, the division stopped in the later period when the growth of organisms came into the stationary phase. The most obvious respond of chlorophyll content to P-additions was observed in Heterosigma akashiwo culture in 24 h. The sensitivity of Fv/Fm to nutrient limitations is different among algal species, and much should be done to improve the application of this index.展开更多
Ethanol extracts of brown seaweeds from Pakistan and China were isolated and compared for their antiallergenic activities. They included Sargassum tennerimum (ST) and Sargassum cervicorne (SC) from Pakistan, and Sarga...Ethanol extracts of brown seaweeds from Pakistan and China were isolated and compared for their antiallergenic activities. They included Sargassum tennerimum (ST) and Sargassum cervicorne (SC) from Pakistan, and Sargassum gramini- folium turn (SG), Sargassum thunbergii (STH), and Laminaria japonica (LJ) from China. The ethanol extracts of these brown seaweeds were optimized at 85% (v/v) ethanol for the maximum yield of phlorotannin, an inhibitor against hyaluronidase. Total phlorotannins contained in the crude extracts were measured as 1.71% (SG), 0.74% (STH), 0.97% (LJ), 3.30% (SC), and 5.06% (ST). The 50% inhibitory concentrations (IC50) of Pakistani SC and ST were 109.5 and 21 μg/ml, respectively, lower than those of Chinese SG, STH, and LJ (134, 269, and 148 μg/ml, respectively). An antiallergic drug, disodium cromoglycate (DSCG), had an IC50=39 μg/ml, and a natural inhibitor of hyaluronidase, catechin, had an IC50=20 μg/ml. The IC50 of ST extract was found similar to that of catechin (21 vs 20 μg/ml) and lower than that of DSCG (21 vs 39 μg/ml). This suggests that ST is a potent inhibitor of hyaluronidase, indicating a promising future development of natural antiallergic medicines or functional foods.展开更多
文摘Laboratory bioassays were conducted to evaluate the insecticidal effect of diatomaceous earth （DE）, SilicoSec against Callosobruchus maculatus （F.）, Rhyzopertha dominica （F.）, Sitophilus zeamais （Motschulsky）, and Tribolium castaneum （Herbst） in cowpea, maize and wheat, at 25-32 ℃ and 54-68% relative humidity （r.h.）. SilicoSec was applied at rates： 0 （untreated control） 250, 500, 750 and 1,000 mg/kg of commodity. Adult mortality was measured after 3 to14 days of exposure. Progeny production was assessed after 40 or 56 days. The tested species varied in sensitivity to SilicoSec, with S. zeamais being most susceptible, but no significant differences in mortality levels observed between R. dominica, C. maculatus or T, castaneum after three days of exposure. After 5 days of exposure, all C. maculates adults died on cowpea treated at 1,000 mg/kg. Similarly, after 14 days of exposure all adults of the other species died on grains treated at 1,000 mg/kg, and were ranked in decreasing order of susceptibility S. zeamais 〉T castaneurn 〉 R. dominica. SilicoSec treatments suppressed progeny production （30 to 100%） in all the tested species. The implications of these findings to DE-based control strategy are discussed.
基金This work was supported by the National Natural Science Foundation of China （No. 30471317）.
文摘In order to investigate the regulation mechanism of the phycocyanin gene,a series of functional analyses of the upstream sequence of cpcB gene from Arthrospira platensis were conducted in E. coli with green fluorescent protein encoding gene(gfp) as the reporter. Results showed that the gfp gene could express at a high level under the promotion of the upstream sequence,suggesting the existence of some strong promoter elements in it. The expression of GFP was influenced by temperature. Higher temperature led to higher expression level. The bioinformatics analyses followed by mutation analyses on the secondary structure of translation ini-tiation region(TIR) revealed that RNA thermosensor might account for the temperature regulation.
基金financially supported by Shandong Province Young and Middle-Aged Scientists Research Awards Fund(BS2011HZ020)the National Natural Science Foundation of China(No.31371730)Program for Changjiang Scholars and Innovative Research Team in University
文摘Natural polyphenol has been widely believed to be effective in allergy remission. Currently, most of the natural poly- phenol products come from terrestrial sources such as tea, grape seeds among others, and few polyphenols have been developed from algae for their anti-allergic activity. The aim of the study was to screen some commercial seaweed for natural extracts with anti-al- lergic activity. Five algae including Laminaria japonica, Porphyra sp., Spirulina platensis, Chlorella pyrenoidosa and Scytosiphon sp were extracted with ethanol, and the extracts were evaluated for total polyphenol contents and anti-allergic activity with the hyalu- ronidase inhibition assay. Results showed that the total polyphenol contents in the ethanol extracts ranged from 1.67% to 8.47%, while the highest was found in the extract from Scytosiphon sp. Hyaluronidase inhibition assay showed that the extracts from Scyto- siphon sp. had the lowest IC50, 0.67 mg mL-1, while Chlorella pyrenoidosa extract had the highest IC50, 15.07 mg mL-1. The anti-allergic activity of Scytosiphon sp. extract was even higher than the typical anti-allergic drug Disodium Cromoglycate （DSCG） （IC50=1.13 mg mL-1）, and was similar with natural polyphenol from Epigallocatechin gallate （EGCG） （IC50 = 0.56 mg mL-l）. These results indicated that the ethanol extract of Scytosiphon sp. contains a high concentration of polyphenol with high anti-allergic activ- ity. Potentially Scytosiphon sp. can be developed to a natural anti-allergic compound for allergy remission.
基金support from the National Natural Science Foundation of China (No. 41076065)the National Basic Research Program of China (973 Program) (No. 2010CB428701)
文摘We studied the effects of nitrogen （N） and phosphorus （P） supply on Fv/Fm （maximal quantum yield of photosystem Ⅱ） in the algae Chaetoceros debilis, Dicrateria inornata, Platymonas subcordiformis and Heterosigma akashiwo to determine the sensitivity of Fv/Fm to P-limitation of the four species. Obvious decrease of Fv/Fm value was monitored in periods of P-depletion, the decrease showing different magnitudes among algal species. A more clear decrease of Fv/Fm in Platymonas subcordiformis and Heterosigma akashiwo was observed, compared with that in Chaetoceros debilis and Dicrateria inornata. After the re-supply of P, the index Fv/Fm of the four species all recovered quickly in 24h. Cell division was maintained and chlorophyll content continued to increase until the end of the experiment in Platymonas subcordiformis and Heterosigma akashiwo, while in Chaetoceros debilis and Dicrateria inornata, the division stopped in the later period when the growth of organisms came into the stationary phase. The most obvious respond of chlorophyll content to P-additions was observed in Heterosigma akashiwo culture in 24 h. The sensitivity of Fv/Fm to nutrient limitations is different among algal species, and much should be done to improve the application of this index.
基金Project supported by the Hi-Tech Research and Development Program(863)of China(No.2006AA09Z427)the National Natural Science Foundation of China(Nos.30800859 and 30871948)
文摘Ethanol extracts of brown seaweeds from Pakistan and China were isolated and compared for their antiallergenic activities. They included Sargassum tennerimum (ST) and Sargassum cervicorne (SC) from Pakistan, and Sargassum gramini- folium turn (SG), Sargassum thunbergii (STH), and Laminaria japonica (LJ) from China. The ethanol extracts of these brown seaweeds were optimized at 85% (v/v) ethanol for the maximum yield of phlorotannin, an inhibitor against hyaluronidase. Total phlorotannins contained in the crude extracts were measured as 1.71% (SG), 0.74% (STH), 0.97% (LJ), 3.30% (SC), and 5.06% (ST). The 50% inhibitory concentrations (IC50) of Pakistani SC and ST were 109.5 and 21 μg/ml, respectively, lower than those of Chinese SG, STH, and LJ (134, 269, and 148 μg/ml, respectively). An antiallergic drug, disodium cromoglycate (DSCG), had an IC50=39 μg/ml, and a natural inhibitor of hyaluronidase, catechin, had an IC50=20 μg/ml. The IC50 of ST extract was found similar to that of catechin (21 vs 20 μg/ml) and lower than that of DSCG (21 vs 39 μg/ml). This suggests that ST is a potent inhibitor of hyaluronidase, indicating a promising future development of natural antiallergic medicines or functional foods.
