蛭龙活血通瘀胶囊对H2O2诱导细胞氧化损伤的保护作用研究

目的：探讨蛭龙活血通瘀胶囊(以下简称“ZL”)对H₂O₂诱导细胞氧化损伤的保护作用。方法：以正常H9C2心肌细胞、PC12细胞作为对照,分别以不同浓度的H₂O₂处理细胞4 h,建立氧化损伤模型;在H₂O₂处理细胞前用ZL预处理24 h,作为ZL药物组,采用CCK-8法检测以上各组细胞存活率。结果：与未经H₂O₂处理的细胞比较,400 μmol/L H₂O₂处理的H9C2心肌细胞存活率下降至(47.25±4.14)%（P<0.01）;600 μmol/L H₂O₂处理的PC12细胞存活率下降至(52.53±4.31)%（P<0.01）;经10～320 mg/ml的ZL预处理后,H9C2心肌细胞、PC12细胞的存活率均高于模型组,差异有统计学意义（P<0.05）。结论：ZL对H₂O₂诱导的H9C2心肌细胞、PC12细胞氧化损伤有保护效果。     

海水中-氧化氮的化学发光法测定

基于鲁米诺-H2O2混合溶液作为发光液与海水中NO发生反应产生发光信号的原理,提出了一种测定海水中痕量NO的化学发光法.确定了化学发光法测定NO的最佳条件:pH9.2、浓度1×10-2 mol/dm3的碳酸盐为缓冲体系,鲁米诺浓度为8.4×10-5 mol/dm3,H2O2浓度为1×10-2 mol/dm3,测定温度为...     

纳米 Fe2O3-SnO2 光催化降解海水养殖废水中的氨氮

通过共沉淀法制备纳米Fe_2O_3-SnO_2光催化剂,采用XRD、SEM等测试手段对其进行形貌、物象、粒径一系列的表征,研究结果显示制得的催化剂仍保持纯SnO_2四方金红石型结构.研究了Fe_2O_3-SnO_2光催化剂投加量、Fe_2O_3与SnO_2物质的量比、煅烧温度、煅烧时间、氨氮初始浓度、p H值、H2O2浓度以及光照反应时间等因素对海水养殖废水中氨氮降解效率的影响.在紫外光照射下进行正交实验,确定最优化反应条件:催化剂投加量为0.4 g/dm3,煅烧时间为3 h,物质的量比为1∶2,氨氮初始含量为50 mg/dm3,光照反应时间为2 h.这5个因素对Fe_2O_3-SnO_2光催化氧化速率影响的大小程度依次为:Fe_2O_3与SnO_2物质的量比煅烧时间Fe_2O_3-SnO_2光催化剂投加量氨氮初始浓度光照时间.氨氮去除率可以达到85.1%,相同条件可见光下也可达到82.3%.     

Spatial variability and temporal dynamics of surface water pCO2, ��O2/Ar and dimethylsulfide in the Ross Sea, Antarctica

We report results from two surveys of pCO₂, biological O₂ saturation (??O₂/Ar) and dimethylsulfide (DMS) in surface waters of the Ross Sea polynya. Measurements were made during early spring (November 2006-December 2006) and mid-summer (December 2005-January 2006) using ship-board membrane inlet mass spectrometry (MIMS) for high spatial resolution (i.e. sub-km) analysis. During the early spring survey, the polynya was in the initial stages of development and exhibited a rapid increase in open water area and phytoplankton biomass over the course of our ∼3 week occupation. We observed a rapid transition from a net heterotrophic ice-covered system (supersaturated pCO₂ and undersaturated O₂) to a high productivity regime associated with a Phaeocystis-dominated phytoplankton bloom. The timing of the early spring phytoplankton bloom was closely tied to increasing sea surface temperature across the polynya, as well as reduced wind speeds and ice cover, leading to enhanced vertical stratification. There was a strong correlation between pCO₂, ??O₂/Ar, DMS and chlorophyll a (Chl a) during the spring phytoplankton bloom, indicating a strong biological imprint on gas distributions. Box model calculations suggest that pCO₂ drawdown was largely attributable to net community production, while gas exchange and shoaling mixed layers also exerted a strong control on the re-equilibration of mixed layer ??₂ with the overlying atmosphere. DMS concentrations were closely coupled to Phaeocystis biomass across the early spring polynya, with maximum concentrations exceeding 100 nM.During the summer cruise, we sampled a large net autotrophic polynya, shortly after the seasonal peak in phytoplankton productivity. Both diatoms and Phaeocystis were abundant in the phytoplankton assemblages during this time. Minimum pCO₂ was less than 100 ppm, while ??O₂/Ar exceeded 30% in some regions. Mean DMS concentrations were ∼2-fold lower than during the spring, although the range of concentrations was similar between the two surveys. There was a significant correlation between pCO₂, ??O₂/Ar and Chl a across the summer polynya, but the strength of these correlations and the slope of O₂ vs. CO₂ relationship were significantly lower than during the early spring. Summertime DMS concentrations were not significantly correlated to phytoplankton biomass (Chl a), pCO₂ or ??O₂/Ar. In contrast to the early spring time, there were no clear temporal trends in summertime gas concentrations. Rather, small-scale spatial variability, likely resulting from mixing and localized sea-ice melt, was clearly evident in surface gas distributions across the polynya. Analysis of length-scale dependent variability demonstrated that much of the spatial variance in surface water gases occurred at scales of <20 km, suggesting that high resolution analysis is needed to fully capture biogeochemical heterogeneity in this system.     

南海东北部春季海表pCO_2分布及海-气CO_2通量

2013年南海东北部春季共享航次采用走航观测方式,现场测定了表层海水和大气的二氧化碳分压(pCO2)及相应参数。结合水文、化学等同步观测要素资料,对该海域pCO2的分布变化进行了探讨。结果表明,陆架区受珠江冲淡水、沿岸上升流及生物活动的影响,呈现CO2的强汇特征;吕宋海峡附近及吕宋岛西北附近海域受海表高温、黑潮分支\"西伸\"、吕宋岛西北海域上升流等因素影响,呈现强源特征。根据Wanninkhof的通量模式,春季整个南海东北部海域共向大气释放约4.25×104 t碳。     

High-resolution measurement of Southern Ocean CO2 and O2/Ar by membrane inlet mass spectrometry

This paper evaluates the simultaneous measurement of dissolved gases (CO₂ and O₂/Ar ratios) by membrane inlet mass spectrometry (MIMS) along the 180° meridian in the Southern Ocean. The calibration of pCO₂ measurements by MIMS is reported for the first time using two independent methods of temperature correction. Multiple calibrations and method comparison exercises conducted in the Southern Ocean between New Zealand and the Ross Sea showed that the MIMS method provides pCO₂ measurements that are consistent with those obtained by standard techniques (i.e. headspace equilibrator equipped with a Li–Cor NDIR analyser). The overall MIMS accuracy compared to Li–Cor measurements was 0.8 μatm. The O₂/Ar ratio measurements were calibrated with air-equilibrated seawater standards stored at constant temperature (0 ± 1 °C). The reproducibility of the O₂/Ar standards was better than 0.07% during the 9 days of transect between New Zealand and the Ross Sea.The high frequency, real-time measurements of dissolved gases with MIMS revealed significant small-scale heterogeneity in the distribution of pCO₂ and biologically-induced O₂ supersaturation (ΔO₂/Ar). North of 65°S several prominent thermal fronts influenced CO₂ concentrations, with biological factors also contributing to local variability. In contrast, the spatial variation of pCO₂ in the Ross Sea gyre was almost entirely attributed to the biological utilization of CO_2, with only small temperature effects. This high productivity region showed a strong inverse relationship between pCO₂ and biologically-induced O₂ disequilibria (r² = 0.93). The daily sea air CO₂ flux ranged from − 0.2 mmol/m² in the Northern Sub-Antarctic Front to − 6.4 mmol/m² on the Ross Sea shelves where the maximum CO₂ influx reached values up to − 13.9 mmol/m². This suggests that the Southern Ocean water (south of 58°S) acts as a seasonal sink for atmospheric CO₂ at the time of our field study.     

考洲洋牡蛎养殖海域海-气界面CO2交换通量的时空变化

根据2018年7月、11月和2019年1月、4月对广东考洲洋牡蛎养殖海域进行4个季节调查获得的p H、溶解无机碳(DIC)、水温、盐度、溶解氧(DO)及叶绿素a(Chla)等数据,估算该区域表层海水溶解无机碳体系各分量的浓度、初级生产力(PP)、表层海水CO₂分压[p(CO₂)]和海-气界面CO₂交换通量(FCO₂),分析牡蛎养殖活动对养殖区碳循环的影响。结果表明:牡蛎养殖区表层海水中Chl a、DIC、HCO₃^–和PP显著低于非养殖区;养殖淡季表层海水中pH、DO、DIC、HCO₃^–、和CO₃^2–显著大于养殖旺季,养殖旺季的p(CO₂)和FCO₂显著大于养殖淡季。牡蛎养殖区表层海水夏季、秋季、冬季和春季的海-气界面CO₂交换通量FCO₂平均值分别是(42.04±9.56)、(276...     

中国贝类养殖对海洋碳循环的贡献评估

造成全球暖化的主要原因是温室气体的过量排放,其中CO₂的贡献率达60%,贝类养殖具有碳沉积作用。依据农业部渔业局编制的《中国渔业统计年签》,以2001年到2010年的年平均产量计算贝类捕获和养殖的碳沉积能力,并评估其碳沉积潜力;计算牡蛎、蛤、扇贝与贻贝4种贝壳单位面积的碳沉积能力并与森林、珊瑚礁的碳沉积能力进行比较分析。分析表明中国近10年贝类总产量稳定在1100万t以上,并有增加的趋势,其中海水养殖贝类约占87.34%。贝类养殖和捕获总产量的碳沉积和海水养殖产量的碳沉积量分别为58.57、51.15万t/a,碳沉积能力分别相当于122.28、106.78万ha的造林,可分别减少大气CO₂增加量的0.0125%、0.0109%。牡蛎、蛤、扇贝与贻贝的单位面积碳沉积速率分别为1.573、0.388、0.301、1.039t碳/(ha·a);牡蛎和贻贝高于森林的碳沉积能力0.479t碳/(ha·a);但低于珊瑚礁的碳沉积能力1.8t碳/(ha·a)。中国贝类淡、海水养殖产量可分别创造约268.4万元/a、12711.2万元/a的碳权商机。