Restraining algal growth by algaecide has been studied by many researchers, but the dosing time has not yet been studied. In this study, we examined the appropriate dosing time of algaecide through a series of experim...Restraining algal growth by algaecide has been studied by many researchers, but the dosing time has not yet been studied. In this study, we examined the appropriate dosing time of algaecide through a series of experiments. In the experiments, the pH value of water is significantly affected by Microcystis aeruginosa, and the variation of the pH value is in favor of the growth of the alga. Therefore, using acid algaecide in the period with maximum pH values, i.e., the stable phase, would change the acidity-alkalinity of the water significantly, and would negatively affect algal growth. Acid algaecide does not eliminate the alga effectively if the acid algaecide is dosed in the logarithmic growth phase. Using acid algaecide in the decline phase after algal bloom not only is unfavorable for eliminating the alga, but also prolongs the decline phase, and even brings about next larger algal bloom.展开更多
AIM To identify the optimal oral dosing time of Da-Cheng-Qi decoction(DCQD) in rats with acute pancreatitis(AP) based on the pharmacokinetic and pharmacodynamic parameters.METHODS First, 24 male Sprague-Dawley rats we...AIM To identify the optimal oral dosing time of Da-Cheng-Qi decoction(DCQD) in rats with acute pancreatitis(AP) based on the pharmacokinetic and pharmacodynamic parameters.METHODS First, 24 male Sprague-Dawley rats were divided into a sham-operated group [NG(a)] and three model groups [4 h G(a), 12 h G(a) and 24 h G(a)]. The NG(a) and model groups were administered DCQD(10 g/kg.BW) intragastrically at 4 h, 4 h, 12 h and 24 h, respectively, after AP models induced by 3% sodium taurocholate. Plasma samples were collected from the tails at 10 min, 20 min, 40 min, 1 h, 2 h, 4 h, 8 h, 12 h and 24 h after a single dosing with DCQD. Plasma and pancreatic tissue concentrations of the major components of DCQD were determined by high-performance liquid chromatography tandem mass spectroscopy. The pharmacokinetic parameters and serum amylase were detected and compared. Second, rats were divided into a sham-operated group [NG(b)] and three treatment groups [4 h G(b), 12 h G(b) and 24 h G(b)] with three corresponding control groups [MG(b)s]. Blood and pancreatic tissues were collected 24 h after a single dosing with DCQD. Serum amylase, inflammatory cytokines and pathological scores of pancreatic tissues were detected and compared.RESULTS The concentrations of emodin, naringin, honokiol, naringenin, aloe-emodin, chrysophanol and rheochrysidin in the 12 h G(a) group were higher than those in the 4 h G(a) group in the pancreatic tissues(P < 0.05). The area under the plasma concentration-time curve from time 0 to the time of the last measurable concentration values(AUC0→t) for rhein, chrysophanol, magnolol and naringin in the 12 h G(a) group were larger than those in the 4 h G(a) or 24 h G(a) groups. The 12 h G(a) group had a higher Cmax than the other two model groups. The IL-10 levels in the 12 h G(b) and 24 h G(b) groups were higher than in the MG(b)s(96.55 ± 7.84 vs 77.46 ± 7.42, 251.22 ± 16.15 vs 99.72 ± 4.7 respectively, P < 0.05), while in the 24 h G(b) group, the IL-10 level was higher than in the other two treatment groups(251.22 ± 16.15 vs 154.41 ± 12.09/96.55 ± 7.84, P < 0.05). The IL-6 levels displayed a decrease in the 4 h G(b) and 12 h G(b) groups compared to theMG(b)s(89.99 ± 4.61 vs 147.91 ± 4.36, 90.82 ± 5.34 vs 171.44 ± 13.43, P < 0.05). CONCLUSION Late-time dosing may have higher concentrations of the most major components of DCQD, with better pharmacokinetics and pharmacodynamics of antiinflammation than early-time dosing, which showed the late time to be the optimal dosing time of DCQD for AP.展开更多
A two-step method was developed to quantitatively assess the infection rate of the entomophthoraceous fungus, Zoophthora anhuiensis (Li) Humber, on the green peach aphid, Myzus persicae (Sulzer) .Firstly, a standard t...A two-step method was developed to quantitatively assess the infection rate of the entomophthoraceous fungus, Zoophthora anhuiensis (Li) Humber, on the green peach aphid, Myzus persicae (Sulzer) .Firstly, a standard time-dose-mortality relationship, established by modeling data from bioassay 1 at varying conidial dosages (0.4- 10.4 conidia/mm^2) of Z. anhuiensis F97028, was used to yield an estimate of expected mortality probability at a given dosage. Secondly, bioassay 2 was conducted by simultaneously exposing six ≤4-day-old nymphal colonies to a shower of Z. anhuiensis conidia at each of four dosages (resulting from exposures of 0.3 - 8.0 min) . Subsequently, the colonies were separately immersed in a 0.1% chlorothalonil solution for 0.5 min to disinfect all surviving conidia on the host integument from 1 - 12 h after exposure under temperature treatments of 15 and 20℃, respectively. The infection rate during a specific period from the end of the exposure to the immersion was then estimated as the ratio of the observed mortality over the expected mortality probability at a particular dosage. The results showed that the infection of M. persicae from Z. anhuiensis was highly rapid with little difference between aphid colonies maintained at 15 and 20℃ before being immersed in the fungicidal solution after exposure. The first 6-hour period after exposure was most crucial to successful infection of the fungus with the infection rate greatly depending on conidial dosages. It took ≤ 1 h to infect > 50% of the aphids at a dosage of > 1.5 conida/mm^2 and > 90% at > 50 conidia/mm^2 .展开更多
基金supported by the Special Fund for Public Welfare Industry of Ministry of Water Resources of China(Grant No.200801001)National Science and Technology Major Projects of China(Grant No.2012ZX07506003-4)Central Public-interest Scientific Institution Basal Research Fund(Grants No.Y110002 and Y110005)
文摘Restraining algal growth by algaecide has been studied by many researchers, but the dosing time has not yet been studied. In this study, we examined the appropriate dosing time of algaecide through a series of experiments. In the experiments, the pH value of water is significantly affected by Microcystis aeruginosa, and the variation of the pH value is in favor of the growth of the alga. Therefore, using acid algaecide in the period with maximum pH values, i.e., the stable phase, would change the acidity-alkalinity of the water significantly, and would negatively affect algal growth. Acid algaecide does not eliminate the alga effectively if the acid algaecide is dosed in the logarithmic growth phase. Using acid algaecide in the decline phase after algal bloom not only is unfavorable for eliminating the alga, but also prolongs the decline phase, and even brings about next larger algal bloom.
基金Supported by the National Natural Science Foundation of China,No.81374042,No.81370091 and No.81603480
文摘AIM To identify the optimal oral dosing time of Da-Cheng-Qi decoction(DCQD) in rats with acute pancreatitis(AP) based on the pharmacokinetic and pharmacodynamic parameters.METHODS First, 24 male Sprague-Dawley rats were divided into a sham-operated group [NG(a)] and three model groups [4 h G(a), 12 h G(a) and 24 h G(a)]. The NG(a) and model groups were administered DCQD(10 g/kg.BW) intragastrically at 4 h, 4 h, 12 h and 24 h, respectively, after AP models induced by 3% sodium taurocholate. Plasma samples were collected from the tails at 10 min, 20 min, 40 min, 1 h, 2 h, 4 h, 8 h, 12 h and 24 h after a single dosing with DCQD. Plasma and pancreatic tissue concentrations of the major components of DCQD were determined by high-performance liquid chromatography tandem mass spectroscopy. The pharmacokinetic parameters and serum amylase were detected and compared. Second, rats were divided into a sham-operated group [NG(b)] and three treatment groups [4 h G(b), 12 h G(b) and 24 h G(b)] with three corresponding control groups [MG(b)s]. Blood and pancreatic tissues were collected 24 h after a single dosing with DCQD. Serum amylase, inflammatory cytokines and pathological scores of pancreatic tissues were detected and compared.RESULTS The concentrations of emodin, naringin, honokiol, naringenin, aloe-emodin, chrysophanol and rheochrysidin in the 12 h G(a) group were higher than those in the 4 h G(a) group in the pancreatic tissues(P < 0.05). The area under the plasma concentration-time curve from time 0 to the time of the last measurable concentration values(AUC0→t) for rhein, chrysophanol, magnolol and naringin in the 12 h G(a) group were larger than those in the 4 h G(a) or 24 h G(a) groups. The 12 h G(a) group had a higher Cmax than the other two model groups. The IL-10 levels in the 12 h G(b) and 24 h G(b) groups were higher than in the MG(b)s(96.55 ± 7.84 vs 77.46 ± 7.42, 251.22 ± 16.15 vs 99.72 ± 4.7 respectively, P < 0.05), while in the 24 h G(b) group, the IL-10 level was higher than in the other two treatment groups(251.22 ± 16.15 vs 154.41 ± 12.09/96.55 ± 7.84, P < 0.05). The IL-6 levels displayed a decrease in the 4 h G(b) and 12 h G(b) groups compared to theMG(b)s(89.99 ± 4.61 vs 147.91 ± 4.36, 90.82 ± 5.34 vs 171.44 ± 13.43, P < 0.05). CONCLUSION Late-time dosing may have higher concentrations of the most major components of DCQD, with better pharmacokinetics and pharmacodynamics of antiinflammation than early-time dosing, which showed the late time to be the optimal dosing time of DCQD for AP.
文摘A two-step method was developed to quantitatively assess the infection rate of the entomophthoraceous fungus, Zoophthora anhuiensis (Li) Humber, on the green peach aphid, Myzus persicae (Sulzer) .Firstly, a standard time-dose-mortality relationship, established by modeling data from bioassay 1 at varying conidial dosages (0.4- 10.4 conidia/mm^2) of Z. anhuiensis F97028, was used to yield an estimate of expected mortality probability at a given dosage. Secondly, bioassay 2 was conducted by simultaneously exposing six ≤4-day-old nymphal colonies to a shower of Z. anhuiensis conidia at each of four dosages (resulting from exposures of 0.3 - 8.0 min) . Subsequently, the colonies were separately immersed in a 0.1% chlorothalonil solution for 0.5 min to disinfect all surviving conidia on the host integument from 1 - 12 h after exposure under temperature treatments of 15 and 20℃, respectively. The infection rate during a specific period from the end of the exposure to the immersion was then estimated as the ratio of the observed mortality over the expected mortality probability at a particular dosage. The results showed that the infection of M. persicae from Z. anhuiensis was highly rapid with little difference between aphid colonies maintained at 15 and 20℃ before being immersed in the fungicidal solution after exposure. The first 6-hour period after exposure was most crucial to successful infection of the fungus with the infection rate greatly depending on conidial dosages. It took ≤ 1 h to infect > 50% of the aphids at a dosage of > 1.5 conida/mm^2 and > 90% at > 50 conidia/mm^2 .
