pCO2平面光极在生物扰动存在下水/沉积物体系中的应用

用内层包埋、外层覆盖的方法制备一种基于TOA+PTS4-离子对的pCO2平面荧光传感膜,并将该传感膜制备的pCO2平面光极系统应用于生物扰动存在的水/沉积物体系,通过连续监测体系垂直剖面pCO2的分布及变化,可得水/沉积物体系中pCO2的原位二维时空分布图.结果表明:在生物扰动作用下,体系中底层上覆水pCO2的变化较大,先上升后逐渐稳定;沉积物表层的pCO2边界扩散层逐渐消失,中层沉积物中pCO2基本不变,深层沉积物中pCO2先增大后逐渐稳定.体系中pCO2的变化是一个复杂的多维变化,涉及CO2产生和消耗的动态过程,是物理混合、颤蚓生命活动及有机质矿化等多种机制综合作用的结果.

秋冬之交雪玉洞PCO2突变的高分辨率监测与分析

雪玉洞是国内著名的旅游洞穴,洞内4-10月的异常高PCO_2,影响了洞内景观的保护,也不利于旅游活动的开展。为解译洞穴微气候的变化特征,该文利用专利技术—高分辨率洞穴CO_2浓度与水中CO_2浓度同步自动监测技术,对雪玉洞洞穴CO_2浓度及地下河水中CO_2浓度进行长达2个月的高密度连续监测,捕捉到11月份雪玉洞洞穴CO_2快速变化过程,发现雪玉洞洞穴CO_2浓度与温度、降雨的气候变化密切相关,受旅游活动的影响较小;雪玉洞洞穴CO_2浓度与地下河脱气作用程度具有同步变化的特征,地下河脱气作用主导了雪玉洞洞穴CO_2浓度变化。文章建议建立适当的通风排气系统和全面的洞穴环境监测系统,提高游客舒适度,协调洞穴景观生长的关系;加强雪玉洞地下河上游流域碳汇来源的研究,针对性地提出控制碳汇输入的方案。

秋季长江口北支表层海水pCO2变化特征

根据2009年9月首次获得的长江口北支海水pCO2实测数据,结合温度、盐度等参数,对长江口北支海水pCO2时空分布、变化特征及其影响因素进行了研究。研究结果表明,长江口北支海水pCO2总体呈现出淡水端高,咸水端低的特点;在同等盐度条件下,长江口北支海水pCO2明显高于长江口南支;长江口北支南段海水pCO2与盐度之间有着较好的负相关关系,表明该区域受潮汐影响显著,其变化过程主要受咸淡水混合作用控制;长江口北支北段海水pCO2与盐度的变化趋势一致,在该区域内海水pCO2呈现出净增加,表明其除受到咸淡水交换影响外,还可能受外源输入、生物呼吸作用以及碳酸盐分解等过程的影响。

负热电离质谱法测试硼同位素与大气pCO2的重建

海洋有孔虫的硼同位素能够反映海水酸碱度值的变化，为研究大气CO2浓度在长时间尺度上的变化提供了一种新的手段，甚至可能超出冰芯所能企及的范围。天然样品中硼同位素的测定方法最为常用的是热电离质谱法，分为正热电离质谱法与负热电离质谱法。目前海洋有孔虫硼同位素分析主要应用负热电离质谱法，该方法最大的优点是所需要的样品量比较小（〈1ngB），实验精度却相对比较高（0．6‰-2．0‰；2s．d．）。近年来，基于常规负热电离质谱法发展的全蒸发负热电离质谱法通过分析完所有样品而有效降低分析过程中所发生的分馏效应所带来的影响，并使样品的信号最大化，该方法精度能够达到0．7‰（2s．d．）。本文详细介绍了常规负热电离质谱法和全蒸发负热电离质谱法的各个分析步骤，包括样品前处理、涂样、质谱分析、同质异位素于扰以及实验分析精度等方面。随着实验分析技术的进展，海洋有孔虫硼同位素已被用来重建长时间尺度（百万年和千万年）和短时间尺度（冰期-间冰期）的大气CO2浓度变化。现有的研究证实利用海洋浮游有孔虫硼同位素重建的大气CO2浓度变化与Vostok冰芯记录的大气CO2浓度变化吻合地很好。

关于动-静脉血气分析PCO2差值的报告

目的:研究AECOPD患者动脉血及混合静脉血PCO2之间的差值,得出规律。方法选取2013年3月~2014年3月,于贵阳中医学院第二附属医院就诊的 AECOPD患者100例,观察其动脉血气分析中PCO2及静脉血PCO2指标,根据其平均差值,找出是否具有一定规律。结果患者的动-静脉血差值在(10.08±6.06)mmHg之间波动。结论临床可以适当参考静脉血PCO2结果,但仍以动脉血气分析结果为主。

舌下Pco2鉴别出血性休克优于胃粘膜Pco2和血乳酸浓度

研究证明大鼠、猪和病人的舌下的Pco2可以作为休克时灌注不足的定量指标。作者比较了出血性休克时舌下Pco2和胃粘膜Pco2的相关关系。

右美托咪定联合舒适护理模式对无痛支气管镜检查患儿SPO2、PCO2及生命体征的影响

目的分析右美托咪定联合舒适护理模式对无痛支气管镜检查患儿血氧饱和度(SPO_(2))、二氧化碳分压(PCO2)及生命体征的影响。方法2017年7月-2019年5月我院收治的60例需进行无痛支气管镜检查的患儿随机分为对照组和观察组,各30例。对照组采用利多卡因进行麻醉,观察组在对照组的基础上采用右美托咪定进行麻醉,检查期间2组均采用舒适护理模式护理至检查结束。比较2组不同时间点血氧饱和度(SPO_(2))和生命体征,检查前后镇静程度和检查后2组舒适度和不良反应发生情况。结果T2、T3、T4观察组收缩压、舒张压和HR均呈逐渐降低趋势,并低于对照组(P<0.05);T2、T3、T4观察组SPO_(2)高于对照组(P<0.05);T3、T4,观察组PCO2低于对照组(P<0.05);检查后,观察组安静率显著高于对照组(P<0.05);检查后,2组警觉/镇静评分(OAA/S)评分和Ramsay镇静评分较检查前升高,观察组高于对照组(P<0.05);检查后,观察组不良事件发生率显著低于对照组(P<0.05)。结论右美托咪定联合舒适护理模式能显著改善无痛支气管镜检查过程中患儿生命体征和血气指标,同时有助于检查过程中患儿保持镇静。

A Multilayer Study of pCO2 in the Surface Waters of the Yellow and South China Seas in Spring and the Sea-Air Carbon Dioxide Flux

A multilayer study of pCO2 for the Yellow and South China Seas in the surface waters was conducted based on data from four cruises sponsored by the China SOLAS Project in 2005 and 2006,including data for the surface microlayer(SML) ,subsurface layer(SSL) and surface layer(SL) . The carbon fluxes across the air-sea interface were calculated. The results showed that the pCO2 values in the surface waters of the study area decreased in the following order:pCO2 SML> pCO2 SSL> pCO2 SL. The highest values were found in March for all SML,SSL and SL,followed by those in April,and the lowest were in May. The pCO2 values had a significant positive correlation with temperature or salinity. While there was no relationship between pCO2 and longitude,there was a significant negative correlation between it and latitude,i.e.,'high latitude low pCO2'. By using four calculation models,the carbon dioxide fluxes(FC O2) in spring in the Yellow and South China Seas,which were found to act as a 'sink' of atmospheric CO2,were preliminarily estimated on the basis of the pCO2 data in the SML to be -7.00×106 t C and -22.35×106 t C,respectively. It is suggested that the FC O2calculated on the basis of pCO2 data in the SML is more reliable than that calculated on the basis of those in the SL.

胶州湾2017年夏季不同降雨情况下pCO2控制机制

根据胶州湾2017年6月末、7月初和7月末的调查,探讨了夏季不同降雨情况下表层二氧化碳分压(pCO2)控制机制变化。无降雨的6月末,全湾pCO2介于519~1 177μatm。污水输入和好氧呼吸导致湾东北部溶解无机碳(DIC)盈余,表现为CO2强源,而在湾西部,碳酸钙沉淀和初级生产导致DIC亏损,由于前者产生CO2大于后者消耗,这一区域表现为CO2弱源。降雨主要发生在湾区的7月初,pCO2介于269~632μatm。初级生产和碳酸钙沉淀导致全湾DIC亏损。湾东北部初级生产明显强于碳酸钙沉淀,表现为CO2汇,而其余海域碳酸钙沉淀相对更强,表现为源。降雨导致陆源输入增加的7月末,pCO2介于569~863μatm。此时全湾初级生产和好氧呼吸并存,碳酸钙沉淀使DIC亏损,且与升温过程共同导致全湾表现为CO2强源。

The Variability of Partial Pressure of Carbon Dioxide (pCO2) in a River-Influenced Coastal Upwelling System: A Case of the Northeast Pacific Coast

The Northeast Pacific coastal ocean, as a typical river-influenced coastal upwelling system, is characterized by significant variability of sea surface partial pressure of carbon dioxide (pCO2, <200 to >1000 μatm). This study reviewed the pCO2 variability and its underlying controlling mechanism in this highly dynamic region by bringing together previous scientific findings and historical data. The large pCO2 variability reflects the complex interactions between physical processes (riverine input and coastal upwelling) and the biological responses to the nutrient transportation associated with these physical processes, while temperature and air-sea gas exchange play a minor role in affecting pCO2. Both the river water and upwelled subsurface water are characterized by higher concentrations of pCO2 and nutrients when compared to the coastal surface water. The presence of high chlorophyll-a and low pCO2 in river plumes and areas adjacent to upwelling locations showed the intense biological CO2 uptake. The influences of riverine input and coastal upwelling thus mainly depend on the competing effect of high background pCO2 of river water and upwelled subsurface water vs. the biological dropdown of pCO2 resulting from the riverine- and upwelling-associated nutrient supplies. The strength of upwelling-favorable wind plays an important role in the pCO2 variability by affecting the intensity of coastal upwelling, with stronger wind speed causing more intense upwelling. The long-term pCO2 increasing rate in the Northeast Pacific coast is observed to be lower than that in the North Pacific open ocean.

Effects of Elevated Seawater pCO2 on Early Development of Scallop Argopecten irradias (Lamarck, 1819)

To investigate the effects of elevated seawater p CO_2 on the early developmental stages of marine benthic calcifying organisms, we exposed the eggs and larvae of Argopecten irradias, an important bivalve species in Chinese aquaculture, in seawater equilibrated with CO_2-enriched(1000 ppm) gas mixtures. We demonstrated that elevated seawater pCO_2 significantly interfered with fertilization and larval development and resulted in an increased aberration rate. Fertilization in the treatment(pH 7.6) was 74.3% ± 3.8%, which was 9.7% lower than that in the control(p H 8.3)(84.0% ±3.0%). Hatching success decreased by 23.7%, and aberration rate increased by 30.3% under acidic condition. Larvae in acidified seawater still developed a shell during the post-embryonic phase. However, the shell length and height in the treatment were smaller than those in the control. The development of embryos differed significantly at 12 h after fertilization between the two experimental groups. Embryos developed slower in acidified seawater. Nearly half of the embryos in the control developed into D-shaped larvae at 48 h after fertilization, which were considerably more than those in the treatment(11.7%). Results suggest that future ocean acidification(OA) would cause detrimental effects on the early development of A. irradias.

大规模哺乳动物细胞培养中pCO2的控制策略

细胞培养工艺放大是生物抗体药物从实验室工艺走向临床和商业生产的必经之路,基于生物反应器的大规模细胞培养技术是制药企业的核心竞争力。哺乳动物细胞对环境变化高度敏感,大小规模反应器中工艺表现不一致成为放大的主要挑战,其中高二氧化碳分压(pCO2)问题给大规模反应器中细胞生长、代谢和蛋白产量与质量带来严重影响。二氧化碳(CO2)积累主要来自于细胞代谢产生CO2与反应器传质水平的失衡。通过分析CO2积累的原因,从培养工艺的优化和放大参数的合理设计两方面总结了降低大规模CO2积累的方法,最后结合新型大规模反应器pCO2预测模型,为工艺放大过程中pCO2的有效控制提供参考。

经鼻同步间歇正压通气治疗新生儿呼吸窘迫综合征的疗效及对患儿PcO2和PcCO2的影响

目的探究经鼻同步间歇正压通气(NSIPPV)治疗新生儿呼吸窘迫综合征(NRDS)的疗效及对患儿Pc O2和PcCO2的影响。方法回顾性分析2016年6月-2018年12月该院经NSIPPV治疗(NSIPPV组)及经鼻持续气道正压通气(NC-PAP)治疗(NCPAP组)的NRDS患儿各41例的临床资料。记录两组患儿治疗成功率、并发症及病情转归情况(呼吸机辅助时间、呼吸支持时间、住院时间),比较两组患儿治疗前及治疗结束时动脉血气分析指标(Pa O2、Pa CO2)、经皮血气分析指标(Pc O2、Pc CO2)的差异,并分析动脉血气分析指标与经皮血气分析指标的相关性。结果 NSIPPV组患儿治疗成功率明显高于NCPAP组,并发症总发生率及呼吸机辅助时间、呼吸支持时间、住院时间则明显低于NCPAP组,差异均有统计学意义(均P<0.05)。治疗结束时,两组患儿Pa O2、Pc O2均高于治疗前,且NSIPPV组患儿高于NCPAP组,差异均有统计学意义(均P<0.05)。两组患儿Pa CO2、Pc CO2均低于治疗前,且NSIPPV组低于NCPAP组,差异均有统计学意义(均P<0.05)。Pearson相关分析结果显示,新生儿Pa O2与Pc O2呈显著正相关关系(r=0.792,P<0.05),Pa CO2与Pc CO2也呈显著正相关关系(r=0.863,P<0.05)。结论 NSIPPV治疗NRDS效果显著,能有效纠正患儿血气,减少并发症,且Pa O2、Pa CO2监测结果与Pc O2、Pc CO2具有良好一致性,临床可将Pc O2、Pc CO2作为新生儿血气监测手段。

Impact of Elevated PCO2 on Mass Flow of Reduced Nitrogen in Trees

To analyze the effects of elevated carbon dioxide concentration （PCO2） on the mass flow of reduced nitro- gen （N） in the phloem and xylem of trees, juvenile beech （Fagus sylvatica L.） and spruce （Picea abies （L.） Karst.） were grown in phytotrons and exposed to ambient and elevated PCO2 （plus 687.5 mg/m^3 CO2） for three growing seasons. Elevated PCO2 significantly decreased the mass flow of N from the shoot to roots of beech by significantly reducing the concentration of soluble amino compounds in the phloem, even if the area of conductive phloem of cross-sectional bark tissue was significantly increased, because of less callus deposition in the sieve elements. In spruce, the downward mass flow of reduced N also tended to be decreased, similar to that in beech. Resembling findings in the phloem, N mass flow from roots to shoot in both tree species was significantly diminished owing to significantly reduced concentrations of amino compounds in the xylem and a lower transpiration rate. Therefore, the mass flow of reduced N between shoots and roots of trees was mainly governed by the concentrations of soluble amino compounds in the phloem and xylem in relation to the loading of reduced N in both long-distance transport pathways.

Differential physiological responses of the coastal cyanobacterium Synechococcus sp. PCC7002 to elevated pCO2 at lag, exponential,and stationary growth phases

We studied the effects of expected end-of-the-century p CO_2(1000 ppm)on the photosynthetic performance of a coastal marine cyanobacterium Synechococcus sp.PCC7002 during the lag,exponential,and stationary growth phases.Elevated p CO_2significantly stimulated growth,and enhanced the maximum cell density during the stationary phase.Under ambient p CO_2conditions,the lag phase lasted for 6 days,while elevated p CO_2shortened the lag phase to two days and extended the exponential phase by four days.The elevated p CO_2increased photosynthesis levels during the lag and exponential phases,but reduced them during the stationary phase.Moreover,the elevated p CO_2reduced the saturated growth light(Ik)and increased the light utilization efficiency(α)during the exponential and stationary phases,and elevated the phycobilisome:chlorophyll a(Chl a)ratio.Furthermore,the elevated p CO_2reduced the particulate organic carbon(POC):Chl a and particulate organic nitrogen(PON):Chl a ratios during the lag and stationary phases,but enhanced them during the exponential phase.Overall,Synechococcus showed differential physiological responses to elevated p CO_2during different growth phases,thus providing insight into previous studies that focused on only the exponential phase,which may have biased the results relative to the effects of elevated p CO_2in ecology or aquaculture.

心内直视手术患者心肺转流期间PCO_2间隙和胃粘膜pH的变化

目的观察胃粘膜二氧化碳分压(PgCO2)与动脉血二氧化碳分压(PaCO2)之差PCO2间隙(PCO2gap)以及胃粘膜pH(i-pH)值在心内直视手术心肺转流(CPB)期间的监测作用.方法 15例心内直视手术病人,于手术开始时、CPB 30～45 min、心脏复跳后30 min和手术结束时测定PgCO2、PaCO2和i-pH值,计算PCO2gap.结果与转流前比较,CPB期间i-pH值显著降低(P＜0.05),PCO2gap显著增高(P＜0.01);心脏复跳后,这些改变甚至更明显(P＜0.05).结论临床CPB期间确实存在胃粘膜低灌流和酸中毒,胃粘膜产生CO2增加,且此低灌流状态于循环恢复后仍持续存在.PCO2gap和i-pH监测在CPB病人中的组织集合.

温度及CO_2对方解石、白云石溶解度影响特征分析

借助水文地球化学模拟软件——PHREEQC对不同PCO2(0～100bar)和不同温度条件下(0～100℃)方解石、白云石在纯水中的溶解度进行模拟和分析。结果表明,PCO2和温度对方解石和白云石溶解度的影响均很大:无PCO2时其溶解度随着温度的升高而逐渐增大,这是因为对于方解石、白云石晶格破坏及溶解高温能提供的能量较大所致;当PCO2较大时(PCO2≥10-3.5bar)其溶解度随温度的升高而降低,原因主要是CO2在高温下形成碳酸的能力较差;当PCO2很小(0<PCO2<10-3.5bar)、温度较低时,方解石、白云石的溶解度随着温度的升高而逐渐降低,当温度升高到一定程度后其溶解度则随着温度的升高而逐渐升高,其原因是在低温时方解石和白云石的溶解主要是CO2发挥作用,而在高温时主要是温度起作用;在高PCO2条件下方解石、白云石的溶解度大于同温度、低PCO2条件下的溶解度;当含较多CO2的深部高温地下热水与浅部常态地下水混合时,其溶蚀能力将明显增强。

大型藻类规模化养殖水域海-气界面CO_2交换通量估算

选择山东俚岛湾大型藻类养殖水域作为研究区域,根据2011年4、8、10月和2012年1月4个航次的大面调查获得的pH、总碱度(TA)、叶绿素a等基础数据,分析了该区域表层海水溶解无机碳(DIC)体系各分量的浓度、组成比例及时空变化特征,估算了海-气界面CO2的交换通量。结果表明,该区域表层海水DIC、HCO-3、CO2-3及CO2的年平均浓度分别为2024.8±147.0、1842.4±132.1、170.0±42.8和12.4±2.5μmol/L。养殖区与非养殖区之间DIC、HCO-3浓度差异不显著(P>0.05),而CO2浓度差异极显著(P<0.01)。表层海水pCO2和海-气界面CO2的交换通量的年平均值分别为287.8±37.9μatm和-32.7±17.2mmol/m2.d,养殖区与非养殖区之间、不同季节之间均差异极显著(P<0.01)。大型藻类的养殖活动有利于海洋对大气CO2的吸收。