根据2014—2017年南海北部200m等深线以浅海域渔业资源调查的短尾大眼鲷(Priacanthusmacracanthus)数据,结合遥感获得的海表温度(seasurfacetemperature,SST)数据,首次将渔场水深(D)与SST的乘积(SSTD)引入作为新的变量,采用灰色关联度...根据2014—2017年南海北部200m等深线以浅海域渔业资源调查的短尾大眼鲷(Priacanthusmacracanthus)数据,结合遥感获得的海表温度(seasurfacetemperature,SST)数据,首次将渔场水深(D)与SST的乘积(SSTD)引入作为新的变量,采用灰色关联度方法筛选与渔场关联度最高的变量,将关联度最高的变量与标准化后的单位捕捞努力量(catch per unit effect, CPUE)采用一元非线性回归建立模型,对模型理论CPUE与实际CPUE的时空变化进行分析。结果表明,南海北部短尾大眼鲷渔场随季节变化明显,各季节CPUE随SST呈先增大后减小的趋势;不同季节CPUE最高的海域水深不同,春季为160 m,夏季为140 m,秋季为60 m,冬季为140 m; CPUE与SST、D、SSTD进行灰色关联度分析发现,各季节CPUE与SSTD关联度最高且关联度均超过0.5;将SSTD作为变量, CPUE作为表征渔场好坏的指标值,建立环境因子与CPUE的关系模型,模型理论CPUE高值区有明显的季节变化,且实际CPUE高值区的分布与理论CPUE高值区分布一致,以上结果 P值均小于0.05,模型预测准确。展开更多
Objective: To investigate phytochemical constituents, antibacterial and antioxidant activity of the root extracts of Carduus macracanthus (C. macracanthus). Methods: Phytochemical screening tests were conducted as per...Objective: To investigate phytochemical constituents, antibacterial and antioxidant activity of the root extracts of Carduus macracanthus (C. macracanthus). Methods: Phytochemical screening tests were conducted as per of the standard procedure to identify the classes of compounds present in the root extract of C. macracanthus. Silica gel column chromatographic technique was applied to separate the constituents from chloroform/methanol (1:1) root extracts. Various spectroscopic techniques were applied to determine the structure of the isolated compound. In vtiro antibacterial activities of crude extracts were evaluated via disc diffusion method. Minimum inhibitory concentration and minimum bacterial concentration were determined by broth dilution method. Moreover, antioxidant activities of extracts were determined by DPPH assay, the phosphomolybdenum method and total flavonoid contents were determined as per of the standard procedures. Results: Phytochemical screening of root extracts of C. macracanthus revealed the presence alkaloids, flavonoids, triterpenes, tannins and steroids. Silica gel column chromatography separation of root extract using chloroform/methanol (1:1 ratio) yielded a known plant steroid stigmasterol. The result revealed that methanol extract had the greatest DPPH scavenging (IC50= 97.50 ± 4.38 μg/mL) and total antioxidant (1.92 ± 0.24 mg AAE/g of dried extract) activities. Chloroform/methanol (1:1), and methanol extracts showed that growth suppression of Bacillus cereus and Staphylococcus aureus at a concentration above 25 mg/mL, and minimum inhibitory concentration was found to be 25 mg/mL. Methanol extract showed growth suppression against Escherichia coli at a concentration of 50 mg/mL. The antibacterial activities of the extracts were compared with a commercially available antibiotic (chloramphenicol) and showed moderate antibacterial activities, with inhibition zones ranging between 18–28 mm. However, the extracts had no antibacterial effects on Salmonella typhi. Conclusions: The present study found that polar extracts of the root of C. macracanthus possessed antibacterial and antioxidant activities.展开更多
文摘根据2014—2017年南海北部200m等深线以浅海域渔业资源调查的短尾大眼鲷(Priacanthusmacracanthus)数据,结合遥感获得的海表温度(seasurfacetemperature,SST)数据,首次将渔场水深(D)与SST的乘积(SSTD)引入作为新的变量,采用灰色关联度方法筛选与渔场关联度最高的变量,将关联度最高的变量与标准化后的单位捕捞努力量(catch per unit effect, CPUE)采用一元非线性回归建立模型,对模型理论CPUE与实际CPUE的时空变化进行分析。结果表明,南海北部短尾大眼鲷渔场随季节变化明显,各季节CPUE随SST呈先增大后减小的趋势;不同季节CPUE最高的海域水深不同,春季为160 m,夏季为140 m,秋季为60 m,冬季为140 m; CPUE与SST、D、SSTD进行灰色关联度分析发现,各季节CPUE与SSTD关联度最高且关联度均超过0.5;将SSTD作为变量, CPUE作为表征渔场好坏的指标值,建立环境因子与CPUE的关系模型,模型理论CPUE高值区有明显的季节变化,且实际CPUE高值区的分布与理论CPUE高值区分布一致,以上结果 P值均小于0.05,模型预测准确。
文摘Objective: To investigate phytochemical constituents, antibacterial and antioxidant activity of the root extracts of Carduus macracanthus (C. macracanthus). Methods: Phytochemical screening tests were conducted as per of the standard procedure to identify the classes of compounds present in the root extract of C. macracanthus. Silica gel column chromatographic technique was applied to separate the constituents from chloroform/methanol (1:1) root extracts. Various spectroscopic techniques were applied to determine the structure of the isolated compound. In vtiro antibacterial activities of crude extracts were evaluated via disc diffusion method. Minimum inhibitory concentration and minimum bacterial concentration were determined by broth dilution method. Moreover, antioxidant activities of extracts were determined by DPPH assay, the phosphomolybdenum method and total flavonoid contents were determined as per of the standard procedures. Results: Phytochemical screening of root extracts of C. macracanthus revealed the presence alkaloids, flavonoids, triterpenes, tannins and steroids. Silica gel column chromatography separation of root extract using chloroform/methanol (1:1 ratio) yielded a known plant steroid stigmasterol. The result revealed that methanol extract had the greatest DPPH scavenging (IC50= 97.50 ± 4.38 μg/mL) and total antioxidant (1.92 ± 0.24 mg AAE/g of dried extract) activities. Chloroform/methanol (1:1), and methanol extracts showed that growth suppression of Bacillus cereus and Staphylococcus aureus at a concentration above 25 mg/mL, and minimum inhibitory concentration was found to be 25 mg/mL. Methanol extract showed growth suppression against Escherichia coli at a concentration of 50 mg/mL. The antibacterial activities of the extracts were compared with a commercially available antibiotic (chloramphenicol) and showed moderate antibacterial activities, with inhibition zones ranging between 18–28 mm. However, the extracts had no antibacterial effects on Salmonella typhi. Conclusions: The present study found that polar extracts of the root of C. macracanthus possessed antibacterial and antioxidant activities.