In the distribution network system with its neutral point grounding via arc suppression coil, when single-phase grounding fault occurred near zero-crossing point of the phase voltage, the inaccuracy of the line select...In the distribution network system with its neutral point grounding via arc suppression coil, when single-phase grounding fault occurred near zero-crossing point of the phase voltage, the inaccuracy of the line selection always existed in existing methods. According to the characteristics that transient current was different between the fault feeder and other faultless feeders, wavelet transformation was performed on data of the transient current within a power frequency cycle after the fault occurred. Based on different fault angles, wavelet energy in corresponding frequency band was chosen to compare. The result was that wavelet energy in fault feeder was the largest of all, and it was larger than sum of those in other faultless feeders, when the bus broke down, the disparity between each wavelet energy was not significant. Fault line could be selected out by the criterion above. The results of MATLAB/simulink simulation experiment indicated that this method had anti-interference capacity and was feasible.展开更多
The aim of the present study was to investigate minimum inhibitory concentration(MIC)distributions by broth microdilution(BMD)method and to determine the preliminary epidemiological cut-off value(ECV)of colistin by ep...The aim of the present study was to investigate minimum inhibitory concentration(MIC)distributions by broth microdilution(BMD)method and to determine the preliminary epidemiological cut-off value(ECV)of colistin by epidemiological cut-off(ECOFF)finder against E.coli from chickens in China.Anal swabs were collected from chicken farms in China.BMD method was used to measure MIC50 and MIC90 of colistin which were 2 and 4μg•mL^(-1),respectively.MIC frequency distributions for colistin were used to estimate preliminary ECV(8μg•mL^(-1)).High percentages of resistance to ampicillin(94.12%),nalidixic acid(94.12%),enrofloxacin(94.12%),tetracycline(94.12%),ciprofloxacin(88.24%),florfenicol(88.24%),neomycin(64.71%),gentamicin(58.82%),levofloxacin(58.82%),doxycycline(88.24%)and cefalexin(76.47%)were found.In addition,low percentages of resistance to amikacin(5.88%),spectinomycin(17.65%)and fosfomycin(41.18%)were noted.Notably,amoxicillin,sulfisoxazole and trimethoprim resulted in a 100%resistance generation efficacy rate.Prevalence of mcr-1 in E.coli(9/17)in chromosomal DNA was higher than mcr-4(2/17)gene,and mcr-1(5/17)was higher than mcr-4(3/17)in plasmid.展开更多
Baicalin(BA)is commonly used to treat inflammatory diseases and shows anti-inflammatory effects.The present study aimed to evaluate the analgesic and anti-inflammatory activities of BA both in vitro and in vivo.In ani...Baicalin(BA)is commonly used to treat inflammatory diseases and shows anti-inflammatory effects.The present study aimed to evaluate the analgesic and anti-inflammatory activities of BA both in vitro and in vivo.In animal models,acetic acid-induced writhing was used to assess analgesic activity.In addition,a variety of tests including xylene-induced ear edema test,minimum inhibitory concentration(MIC)assays and acetic acid-induced peritoneal capillary hyperpermeability test were used to evaluate antiinflammatory activity of BA.BA at 0.2 and 0.1 mg·mL-1 doses expressed analgesic as well as anti-inflammatory activities in mice.In acetic acid induced writhing test,BA applying three times,twice and once a day significantly inhibited the acetic acid-induced writhing response within 15 min by 7.80%(*p<0.05),7.50%(**p<0.01)and 6.25%(**p<0.01).In xylene-induced ear edema test,BA at 0.2,0.1 and 0.05 mg·mL-1 decreased ear edema by 45.50%(**p<0.01),15.20%(*p<0.05)and 9.10%(*p<0.05).In acetic acidinduced peritoneal capillary hyperpermeability test,BA exhibited significant inhibition(*p<0.05 versus control)of inflammation.In MIC assays,the MIC values of baicalin for S.aureus and Escherichia coli were 125 mg•mL-1,and the MIC values for the control bacteria ATCC25922 and ATCC25923 were 62.5 mg·mL-1.These findings suggested baicalin might contain analgesic and antiinflammatory agents which supported its use in traditional medicine.展开更多
Somatostatin （SS） is a hormone that inhibits the secretion of growth hormone. Immunization against SS can promote the growth of animals. This paper described the effects of DNA immunization on the growth and antibod...Somatostatin （SS） is a hormone that inhibits the secretion of growth hormone. Immunization against SS can promote the growth of animals. This paper described the effects of DNA immunization on the growth and antibody response in mice and pigs immunized with a plasmid DNA encoding SS fused with GP5 of porcine reproductive and respiratory syndrome virus （PRRSV）. A fragment of 180 bp encoding partial SS gene was amplified by PCR from the genomic DNA of peripheral blood mononuclear cells of pigs, and cloned as a fusion gene with PRRSV GP5 in plasmid pISGRTK3. Three times of immunization with the resulting plasmid pISG-SS/GP5 induced anti-GP5 antibodies in BALB/c mice and pigs, as demonstrated by GP5-specific ELISA and immunoblotting. Compared with pigs immunized with empty vector pISGRTK3, the growth performance of pigs immunized with pISG-SS/GP5 was increased by 11.1% on the 13th week after the last vaccination. The results indicated the plasmid DNA encoding SS and PRRSV GP5 fusion gene elicited anti-GP5 antibodies and improved the growth performance of immunized pigs.展开更多
The pharmacokinetics of milbemycin oxime was investigated in dogs following oral(per os, PO) and intravenous(IV) administration. Three groups of dogs received milbemycin oxime tablets as a single PO dose equal to 0.25...The pharmacokinetics of milbemycin oxime was investigated in dogs following oral(per os, PO) and intravenous(IV) administration. Three groups of dogs received milbemycin oxime tablets as a single PO dose equal to 0.25, 0.5 and 1.0 mg · kg-1 of milbemycin oxime, respectively, another group received a single IV dose of 0.5 mg · kg-1. Blood samples were collected at predetermined times after drug administration and the milbemycin oxime concentrations in plasma were determined by LC-MS/MS. The drug protein binding in dog plasma in vitro was determined by equilibrium dialysis at concentrations spanning the range of values observed in vivo in dog plasma. After PO administration at doses of 0.25, 0.5 and 1.0 mg · kg-1, milbemycin oxime was slowly absorbed and eliminated, the time to reach the maximum plasma concentration(Tmax) was 4.14±0.20, 4.27±0.14 and 4.06±0.13 h, the mean absorption time(MAT) was 19.06, 13.67 and 11.77 h, the terminal rate half-life(t1/2λz) was 15.06±0.37, 11.09±0.54 and 9.76±0.89 h and the total body clearance(Cl) was 1.15±0.05, 1.18±0.03 and 1.17±0.07 m L · min-1 · kg-1, respectively. The maximum plasma concentration(Cmax, 36.50±1.40, 76.11±2.77 and 182.05±7.20 ng · m L-1, respectively) and the area under the first-moment curve(AUC-10→∞, 985.83±49.46, 1 663.12±51.42 and 3 558.04±197.88 mg · h · L, respectively) increased accordingly to the administered dose rates; the oral bioavailabilities were estimated to be 88.61%, 74.75% and 79.96%, respectively. The values of fu were 0.12%, 0.14% and 0.13% in dog plasma, respectively. In conclusion, the pharmacokinetics of milbemycin oxime in dogs following oral administration revealed its higher oral bioavailability and advantageous pharmacokinetic properties, such as its lower total body clearance and longer elimination half-life, and indicated that the single oral dose of 0.50 mg · kg-1 of milbemycin oxime which was recommended in all the parasitological efficacy studies allowed an adequate concentration of the drug.展开更多
To investigate the antibacterial activity of commercial organic acid Activate WD （WD）, the minimal inhibitory concentration （MIC） and minimal bactericidal concentration （MBC） of WD against Staphylococcus aureus,...To investigate the antibacterial activity of commercial organic acid Activate WD （WD）, the minimal inhibitory concentration （MIC） and minimal bactericidal concentration （MBC） of WD against Staphylococcus aureus, Escherichia coli, Salmonella pullorum, and Campylobacter jejuni were determined by double broth dilution method. Bacteria were added in a mixture of water and commercial broiler feed adjusted by WD into pH 3.0, 4.0, and 5.0; the survival of bacteria was determined by a direct plate count method at 0, 0.5, 1, 4, 8, and 24 h after being mixed to test the bactericidal potential of WD. The results showed that the MIC of WD against four bacteria was 0.3125%, and the MBC was 0.625%. At pH 3.0, bacteria could not survive. Campylobacter jejuni died after 4 h of incubation at pH 4.0, 5.0, whereas for other three bacteria, the bacterium numbers were below detection limits until 8 h of incubation. In conclusion, WD had significant antibacterial activity, and could be used on farms to prevent cross-infection via rearing water.展开更多
Toxocara canis(T.canis)is one of the most important zoonotic parasites of dogs.The aim of the present study was to perform an in vitro analysis of the effect of Milbemycin oxime on T.canis eggs following exposure to a...Toxocara canis(T.canis)is one of the most important zoonotic parasites of dogs.The aim of the present study was to perform an in vitro analysis of the effect of Milbemycin oxime on T.canis eggs following exposure to a concentration gradient of the drug and to determine the inflammatory reaction produced by the infective T.canis larvae in mice.The present study was undertaken using the model nematode,T.canis,to investigate the effect of Milbemycin oxime on T.canis eggs and larvae.T.canis eggs were exposed to a concentration gradient of Milbemycin oxime in vitro,the higher concentration of Milbemycin oxime was,the lower percentage of infective stage larvae was.Light micrographs showed that Milbemycin oxime induced eggs dissolved and eggshell broken.Histological analyses of mice that stained with hematoxylin and eosin(H&E)showed in lower dosing(10-7 and 10-8 g·mL-1)drug-treated groups,atrophy of alveolar space and interalveolar septum thickening appeared,inflammatory infiltrates accompanied with erythrocytes around blood vessels and bronchioles presented.In higher dosing(10-6,10-5 and 10-4 g·mL-1)drug-treated groups,low-grade or no pathological changes occurred,indicating that Milbemycin oxime could obviously decrease the inflammatory reaction produced by the infection of T.canis larvae in vivo.展开更多
文摘In the distribution network system with its neutral point grounding via arc suppression coil, when single-phase grounding fault occurred near zero-crossing point of the phase voltage, the inaccuracy of the line selection always existed in existing methods. According to the characteristics that transient current was different between the fault feeder and other faultless feeders, wavelet transformation was performed on data of the transient current within a power frequency cycle after the fault occurred. Based on different fault angles, wavelet energy in corresponding frequency band was chosen to compare. The result was that wavelet energy in fault feeder was the largest of all, and it was larger than sum of those in other faultless feeders, when the bus broke down, the disparity between each wavelet energy was not significant. Fault line could be selected out by the criterion above. The results of MATLAB/simulink simulation experiment indicated that this method had anti-interference capacity and was feasible.
基金Supported by the National Key Research and Development Program of China(2016YFD0501302)the National Natural Science Foundation of China(31772801)。
文摘The aim of the present study was to investigate minimum inhibitory concentration(MIC)distributions by broth microdilution(BMD)method and to determine the preliminary epidemiological cut-off value(ECV)of colistin by epidemiological cut-off(ECOFF)finder against E.coli from chickens in China.Anal swabs were collected from chicken farms in China.BMD method was used to measure MIC50 and MIC90 of colistin which were 2 and 4μg•mL^(-1),respectively.MIC frequency distributions for colistin were used to estimate preliminary ECV(8μg•mL^(-1)).High percentages of resistance to ampicillin(94.12%),nalidixic acid(94.12%),enrofloxacin(94.12%),tetracycline(94.12%),ciprofloxacin(88.24%),florfenicol(88.24%),neomycin(64.71%),gentamicin(58.82%),levofloxacin(58.82%),doxycycline(88.24%)and cefalexin(76.47%)were found.In addition,low percentages of resistance to amikacin(5.88%),spectinomycin(17.65%)and fosfomycin(41.18%)were noted.Notably,amoxicillin,sulfisoxazole and trimethoprim resulted in a 100%resistance generation efficacy rate.Prevalence of mcr-1 in E.coli(9/17)in chromosomal DNA was higher than mcr-4(2/17)gene,and mcr-1(5/17)was higher than mcr-4(3/17)in plasmid.
基金Supported by the National Natural Science Foundation of China(31772801)Academic Backbone Project of Northeast Agricultural University(18XG23)。
文摘Baicalin(BA)is commonly used to treat inflammatory diseases and shows anti-inflammatory effects.The present study aimed to evaluate the analgesic and anti-inflammatory activities of BA both in vitro and in vivo.In animal models,acetic acid-induced writhing was used to assess analgesic activity.In addition,a variety of tests including xylene-induced ear edema test,minimum inhibitory concentration(MIC)assays and acetic acid-induced peritoneal capillary hyperpermeability test were used to evaluate antiinflammatory activity of BA.BA at 0.2 and 0.1 mg·mL-1 doses expressed analgesic as well as anti-inflammatory activities in mice.In acetic acid induced writhing test,BA applying three times,twice and once a day significantly inhibited the acetic acid-induced writhing response within 15 min by 7.80%(*p<0.05),7.50%(**p<0.01)and 6.25%(**p<0.01).In xylene-induced ear edema test,BA at 0.2,0.1 and 0.05 mg·mL-1 decreased ear edema by 45.50%(**p<0.01),15.20%(*p<0.05)and 9.10%(*p<0.05).In acetic acidinduced peritoneal capillary hyperpermeability test,BA exhibited significant inhibition(*p<0.05 versus control)of inflammation.In MIC assays,the MIC values of baicalin for S.aureus and Escherichia coli were 125 mg•mL-1,and the MIC values for the control bacteria ATCC25922 and ATCC25923 were 62.5 mg·mL-1.These findings suggested baicalin might contain analgesic and antiinflammatory agents which supported its use in traditional medicine.
基金This study was supported by the National Basic Research Priorities Programme （973 Program） of China （G1999011902） the National Natural Science Foundation of China （30470072）.
文摘Somatostatin （SS） is a hormone that inhibits the secretion of growth hormone. Immunization against SS can promote the growth of animals. This paper described the effects of DNA immunization on the growth and antibody response in mice and pigs immunized with a plasmid DNA encoding SS fused with GP5 of porcine reproductive and respiratory syndrome virus （PRRSV）. A fragment of 180 bp encoding partial SS gene was amplified by PCR from the genomic DNA of peripheral blood mononuclear cells of pigs, and cloned as a fusion gene with PRRSV GP5 in plasmid pISGRTK3. Three times of immunization with the resulting plasmid pISG-SS/GP5 induced anti-GP5 antibodies in BALB/c mice and pigs, as demonstrated by GP5-specific ELISA and immunoblotting. Compared with pigs immunized with empty vector pISGRTK3, the growth performance of pigs immunized with pISG-SS/GP5 was increased by 11.1% on the 13th week after the last vaccination. The results indicated the plasmid DNA encoding SS and PRRSV GP5 fusion gene elicited anti-GP5 antibodies and improved the growth performance of immunized pigs.
基金Supported by Natural Science Fund of Heilongjiang Province(C201424)
文摘The pharmacokinetics of milbemycin oxime was investigated in dogs following oral(per os, PO) and intravenous(IV) administration. Three groups of dogs received milbemycin oxime tablets as a single PO dose equal to 0.25, 0.5 and 1.0 mg · kg-1 of milbemycin oxime, respectively, another group received a single IV dose of 0.5 mg · kg-1. Blood samples were collected at predetermined times after drug administration and the milbemycin oxime concentrations in plasma were determined by LC-MS/MS. The drug protein binding in dog plasma in vitro was determined by equilibrium dialysis at concentrations spanning the range of values observed in vivo in dog plasma. After PO administration at doses of 0.25, 0.5 and 1.0 mg · kg-1, milbemycin oxime was slowly absorbed and eliminated, the time to reach the maximum plasma concentration(Tmax) was 4.14±0.20, 4.27±0.14 and 4.06±0.13 h, the mean absorption time(MAT) was 19.06, 13.67 and 11.77 h, the terminal rate half-life(t1/2λz) was 15.06±0.37, 11.09±0.54 and 9.76±0.89 h and the total body clearance(Cl) was 1.15±0.05, 1.18±0.03 and 1.17±0.07 m L · min-1 · kg-1, respectively. The maximum plasma concentration(Cmax, 36.50±1.40, 76.11±2.77 and 182.05±7.20 ng · m L-1, respectively) and the area under the first-moment curve(AUC-10→∞, 985.83±49.46, 1 663.12±51.42 and 3 558.04±197.88 mg · h · L, respectively) increased accordingly to the administered dose rates; the oral bioavailabilities were estimated to be 88.61%, 74.75% and 79.96%, respectively. The values of fu were 0.12%, 0.14% and 0.13% in dog plasma, respectively. In conclusion, the pharmacokinetics of milbemycin oxime in dogs following oral administration revealed its higher oral bioavailability and advantageous pharmacokinetic properties, such as its lower total body clearance and longer elimination half-life, and indicated that the single oral dose of 0.50 mg · kg-1 of milbemycin oxime which was recommended in all the parasitological efficacy studies allowed an adequate concentration of the drug.
文摘To investigate the antibacterial activity of commercial organic acid Activate WD （WD）, the minimal inhibitory concentration （MIC） and minimal bactericidal concentration （MBC） of WD against Staphylococcus aureus, Escherichia coli, Salmonella pullorum, and Campylobacter jejuni were determined by double broth dilution method. Bacteria were added in a mixture of water and commercial broiler feed adjusted by WD into pH 3.0, 4.0, and 5.0; the survival of bacteria was determined by a direct plate count method at 0, 0.5, 1, 4, 8, and 24 h after being mixed to test the bactericidal potential of WD. The results showed that the MIC of WD against four bacteria was 0.3125%, and the MBC was 0.625%. At pH 3.0, bacteria could not survive. Campylobacter jejuni died after 4 h of incubation at pH 4.0, 5.0, whereas for other three bacteria, the bacterium numbers were below detection limits until 8 h of incubation. In conclusion, WD had significant antibacterial activity, and could be used on farms to prevent cross-infection via rearing water.
基金Supported by the Post-doctoral Research Foundation of Heilongjiang Province(LBH-Q18019)。
文摘Toxocara canis(T.canis)is one of the most important zoonotic parasites of dogs.The aim of the present study was to perform an in vitro analysis of the effect of Milbemycin oxime on T.canis eggs following exposure to a concentration gradient of the drug and to determine the inflammatory reaction produced by the infective T.canis larvae in mice.The present study was undertaken using the model nematode,T.canis,to investigate the effect of Milbemycin oxime on T.canis eggs and larvae.T.canis eggs were exposed to a concentration gradient of Milbemycin oxime in vitro,the higher concentration of Milbemycin oxime was,the lower percentage of infective stage larvae was.Light micrographs showed that Milbemycin oxime induced eggs dissolved and eggshell broken.Histological analyses of mice that stained with hematoxylin and eosin(H&E)showed in lower dosing(10-7 and 10-8 g·mL-1)drug-treated groups,atrophy of alveolar space and interalveolar septum thickening appeared,inflammatory infiltrates accompanied with erythrocytes around blood vessels and bronchioles presented.In higher dosing(10-6,10-5 and 10-4 g·mL-1)drug-treated groups,low-grade or no pathological changes occurred,indicating that Milbemycin oxime could obviously decrease the inflammatory reaction produced by the infection of T.canis larvae in vivo.
