气体差分检测中光电检测系统的设计

基于差分检测原理,设计了用于气体传感中微弱信号测量的增益可调的便携式双光路光电检测和采集系统。系统采用以Ad795为核心的低噪声、高灵敏度前置放大器,通过有效的抗干扰措施,实现了微弱信号的高精度低噪声检测,并配以具有极强抗噪性能的24bITS∑-△模数转换芯片Ad7794,完成高分辨率的数据采集。通过AVr单片机控制实现电路增益的自动调节,解决了差分检测中存在的小信号放大,大信号饱和的问题

Effects of Lanthanum on Redox Systems in Plasma Membranes of Casuarina equisetifolia Seedlings Under Acid Rain Stress

The effects of La3 + on the growth and the ATPases activities of plasma membrane (PM) vesicles isolated from Casuarina equisetifolia seedlings under artificial acid rain (pH 4. 5) stress were studied. The results show that the height , length of roots , fresh weight and PM H+2ATPase activites of Casuarina equisetifolia seedlings increase by the treatments of soaking seeds in LaCl3 solutions with lower concentrations , and those can reach their peak values by treating with 200 mg ·L - 1 La3 + . However , in comparison with the CK, those are inhibited by the higher La3 + concentrations ; PM Ca2 +2AT2 Pase activity is inhibited with the treatments of La3 + . The results also reveal that the H+2ATPase activity and the growth of cell enlarge have a remarkable positive correlation , and La3 + activating H+2ATPase can facilitate plant growth. La3 + al2 so can alleviate cytosolic acidification of plant under acid rain stress and indirectly maintain the stability of intracellular environment . In order to resistant to acid rain and accelerate the growth of Casuarina equisetifolia , the suitable range of La3 + concentrations to soak seeds for 8 h is 50～200 mg·L - 1

Abundance and production of bacteria and their correlations with environmental factor

以2014年8月南海北部海水样品为研究对象,利用平板计数法和流式细胞仪计数法对南海北部表层和垂直海域可培养细菌和细菌总数分布状况进行研究,对细菌; 生产力进行测定,并结合环境因子进行相关性分析。结果表明:珠江口到南海北部海域,水平方向可培养细菌总数变化范围是3.70*10~2 ~; 1.42*10~3 CFU/mL,细菌总数变化范围是5.12 * 10~5 ~1.61 * 10~6; cells/mL,细菌生产力的变化范围是0.03 ~0.40 mg/m~3/h;垂直方向上可培养细菌变化范围是1.08 *10~3 ~9.00; *10~3 CFU/mL,细菌生产力变化范围是0.01 ~0.08; mg/m~3/h,其中表层海水中的细菌生产力明显高于底层。与环境因子相关性分析表明,水平方向上,影响南海北部表层海水细菌总数和细菌生产力的主要因; 素是温度、盐度、硝酸盐(NO_3-N)、硅酸盐(SiO_3-Si)、亚硝酸盐(NO_2-N)和磷酸盐(PO_4-P)(P<0.05);垂直方向上; ,影响南海北部可培养细菌总数的主要因素是NO_2-N(P<0.05),影响细菌生产力的主要影响因素是温度和盐度(P; <0.05)。可见,南海北部表层海水中细菌总数高于可培养细菌总数2; ~3个数量级,表明该海域表层海水存在大量不可培养细菌;细菌的生命活动在海水表层相较底层更为活跃。Distribution of abundance and production of bacteria and their; correlations with environmental factor were investigated, using plate; count method and flow cytometry, in the surface and vertical waters of; the northern south China sea in August 2014. The cultivable bacterial; abundance ranged from 3.70 * 10~2 CFU/mL to 1.42 * 10~3 CFU/ mL, the; total bacterial abundance ranged from 5.12 * 10~5 cells/mL to 1.61 *; 10~6 cells/mL and the bacterial productions varied from 0.03 mg/m~3/h to; 0.40 mg/m~3/h in horizontal distribution. In vertical distribution, the; cultivable bacterial abundance ranged from 1.08 * 10~3 CFU/mL to 9.00 *; 10~3 CFU/mL and the bacterial productions varied from 0.01 mg/m~3/h to; 0.08 mg/m~3/h, respectively. The correlation analysis results showed; that the environmental factors affecting the abundance of total bacteria; and bacterial productivity included temperature, salinity,; nitrate(NO_3-N),silicate (SiO_3-Si), nitrite (NO_2-N),and phosphate; (PO_4-P) (P<0.05). NO_2-N was the main influencing factor to cultivable; bacteria abundance (P < 0.05), while bacterial productivity was highly; correlated with temperature and salinity in vertical distribution of; northern south China sea (P < 0.05). The total bacterial abundance was 2; ~ 3 orders of magnitude higher than cultivable bacteria, suggesting that; there were many uncultured bacterium in surface water of northern south; China sea and bacterial activities in the surface maybe more active than; in the bottom.全球变化与海气交互作用; 国家重点研发计划全球变化及应对专项; 海洋公益性行业科研专

Diversity of CO_2 fixation gene in the surface waters of northern South China Sea in the Calvin cycle

为揭示南海北部表层海水中参与卡尔文循环的固碳基因多样性及其与环境因子的关系,本研究以卡尔文循环中的关键酶核酮糖-1,5-二磷酸羧化酶/加氧酶(Rubis CO)的Ⅰ、Ⅱ型基因(cbbL、cbbM)作为分子标记,采用Illumina Miseq高通量测序技术对海水中的固碳基因多样性进行分析,并结合多元统计分析的方法,探讨了固碳基因多样性与环境因子的关系.结果显示,在南海北部表层海水中,含cbbL基因固碳基因主要归属于变形菌门(Proteobacteria)、蓝藻门(Cyanobacteria)和厚壁菌门(Firmicutes),其中,优势亚群分别是γ-变形菌亚门(45.3%)、蓝细菌(30.9%)和β-变形杆菌亚门(23.8%);而含cbbM基因的固碳菌群未检测到;近岸的A9站位与其他站位物种组成有一定的差异,异着色菌属(Allochromatium)、硫杆菌属(Thiobacillus)和硫单胞菌属(Thiohalomonas)为其特有菌属.相关性和冗余分析(RDA)结果显示,含cbbL基因的固碳基因丰度与水温、盐度呈显著负相关(p<0.01),与硝酸盐、亚硝酸盐、硅酸盐呈显著正相关(p<0.01).To elucidate the diversity of CO_2 fixation and its relationship with environmental factors in surface water of northern South China Sea,the coding gene form I( cbbL) and form II( cbbM)( that encodes Ribulose-1,5-biphosphate carboxylase/oxygenase( Rubis CO) were chosen as biomarkers in Calvin-Benson-Bassham cycle( a common carbon fixation pathway for chemolithoautotrophic microorganisms) to analyze the carbon sequestration gene diversity. The Illumina Miseq sequencing method and multivariate statistical analysis were employed. The cbbM gene was not detected in any of samples,while the cbbL gene was found in all samples. The cbbL-containing genetic communities were dominated by Proteobacteria,Cyanobacteria and Firmicutes,in which γ-Proteobacteria( 45. 3%),Cyanobacteria( 30. 9%),β-Proteobacteria( 23. 8%) were predominant subpopulation. There were differences between the nearshore station of A9 with other stations,in which Allochromatiu,Thiobacillus and Thiohalomonas were unique species in A9 station.Relativity and redundancy analysis suggest that water temperature, salinity, nitrate, nitrite, silicate were highly statistically significant factors.Temperature and salinity were positively( p < 0. 01),while the other three factors negatively influenced CO_2 fixation gene of cbbL gene abundance( p <0. 01).全球变化与海气交互作用专项(No.GASI-03-01-02-05);; 海洋公益性行业科研专项(No.201305030,201405007)~

ST段抬高型急性心肌梗死院前溶栓治疗中国专家共识

急性心肌梗死仍然严重威胁我国人民健康,在我国广大城乡地区,形势更为严峻[1,2]。及时救治急性心肌梗死患者,降低死亡率和保护心脏功能刻不容缓。鉴于我国的实际情况,院前溶栓治疗在大城市以外的城乡地区具有重要意义。为此,中国医师协会胸痛专业委员会及中国医学救援协会心血管急救分会专门组织有关专家制订了本共识,旨在帮助院前医疗急救人员对急性心肌梗死患者选择最佳

痴呆行为和精神症状的临床研究进展

介绍痴呆的行为和精神症状的病因学、症状学、诊断及治疗等方面的研究进展