海洋胶体中的氮、磷和铁对微藻生长的效应

利用错流超滤技术提取海洋胶体,研究了无氮、无磷和无铁的营养介质中海洋胶体对海水小球藻、亚心形扁藻和球等鞭金藻生长的影响。结果表明,在胶体有机碳(COC)浓度为0～238.4μmol/L的范围内,3种微藻在以胶体为N源的介质中的平均相对增长率Y分别为20.7％～44.0％,80.1％～110.1％和68.6％～106.2％;在以胶体为P源的介质中的Y值分别为19.3％～43.2％,78.3％～156.7％和77.9％～115.3％。3种微藻的Y值随COC浓度增大呈下降趋势。3种微藻在以胶体为Fe源的介质中的Y值分别为12.7％～35.3％,171.7％～266.3％和400.5％～498.8％,3种微藻的Y值随COC浓度增大呈线性上升。这意味着海洋胶体中存在微藻生长必需的N,P和Fe营养,对微藻的生长有显著的刺激作用。胶体中的Fe营养对球等鞭金藻和亚心形扁藻的效应比N和P营养的约大6～7倍,而胶体中的N和P营养对小球藻的促进作用则约比Fe的大3倍。国家教育部高等学校骨干教师计划基

Discussion of screening strategy of retinopathy of prematurity

目的:根据早产儿出生体重和出生胎龄为指标,探讨早产儿视网膜病变的临床筛查标准和初次筛查时间。方法:收集2008年2月~2011年2月厦门市妇幼保健院nICu病区1 148例早产儿,使用双目间接眼底镜进行眼底检查,收集相关临床资料进行统计分析。结果:出生体重≤1 000 g、1 001~1 250 g、1 251~1 500 g、1 501~1 750 g、1 751~2 000 g、>2 000 g各组间阈值rOP发生率比较有统计学差异(χ2=201.54,P32周时阈值rOP发病率明显降低;rOC曲线显示在出生胎龄32.07周面积最大;出现阈值rOP时的矫正胎龄﹤35周的8例早产儿,出生后周龄均在4~6周。结论:出生体重≤1 500 g和出生胎龄≤32周是rOP筛查指标;初次筛查时间在矫正胎龄≥35W或出生后4~6周。Objective:To explore the clinical screening criteria and screening time for the first time according to birth weight and birth gestational age of premature infants.Methods:A total of 1 148 premature infants from NICU of the hospital from February 2008 to February 2011 were collected,bilateral indirect ophthalmoscope was used for fundus examination,related clinical data were collected for statistical analysis.Results:There was statistically significant difference in the incidence of threshold retinopathy of prematurity(ROP) among the infants with birth weight ≤1 000 g,1 001-1 250 g,1 251-1 500 g,1 501-1 750 g,1 751-2 000 g,and >2 000 g(χ2=201.54,P1 500 g decreased significantly.The area under ROC curve was the largest in the infants with birth weight=1 532.5 g;there was statistically significant difference in the incidence of threshold ROP among the infants with birth gestational age32 weeks decreased significantly ROC curve showed that the area was the largest in the infants with birth gestational age=32.07 weeks;the gestational weeks of 8 premature infants with threshold ROP whose correct gestational weeks was less than 35 weeks were 4-6 weeks.Conclusion:Birth weight≤1 500 g and birth gestational weeks≤32 weeks are screening indexes of ROP;the screening time for the first time was correct gestational weeks≥35 weeks or at 4-6 weeks after birth.厦门市科技计划项目〔350Z20114027

THE EFFECT OF NATURAL COLLOIDS ON THE GROWTH OF ALGAE

利用错流超滤技术提取天然胶体,研究了胶体的有机碳浓度、粒径和来源对海水小球藻(Chlorellaspp.)、亚心形扁藻(Platymonassubcordiformis)和球等鞭金藻(Isochrysisgalbana)生长的影响。结果表明,当粒径为10kDa—0.2μm、胶体有机碳浓度为4.8—238.4μmol/L时,胶体使小球藻、扁藻和金藻的生长率分别提高了4.0%—7.0%、19.1%—28.9%和2.9%—8.7%。海水小球藻生长率的相对增长百分数(Y)值与胶体有机碳浓度(CCOC)呈线性正相关;亚心形扁藻和球等鞭金藻的Y与CCOC呈多项式相关;胶体对扁藻生长的刺激作用大于球等鞭金藻和海水小球藻。粒径为10kDa—0.2μm的胶体对3种藻的促进作用大于1—10kDa的胶体。河口、河流和生源胶体使小球藻的生长率提高1.5%—14.1%,不同来源的3种胶体对海水小球藻的促进作用依序是河流胶体>生源胶体>河口胶体。以上结果表明,天然胶体含有微藻生长所必需的营养元素,对微藻的生长有显著的刺激作用。Natural colloids are originated from multiple sources from river runoffs, sediment re-suspension, and marine biological processes. Colloids are contained in organic matters in different sizes and concentrations, which would impact phytoplankton growth in different manners. To study the mechanism that would help mariculture and marine pharmaceutical application, we conducted this research on the effect in terms of colloidal organic carbon(COC)concentration on the phytoplankton growth. Water samples were collected from waters near Xiamen(Amoy)of Fujian representing natural river, estuary, and sea water masses, from which natural colloids were abstracted with cross-flow ultrafiltration technique. Phytoplankton samples were algae including Chlorella spp., Platymonas subcordiformis and [WTBX]Isochrysis galbana. Biogenic colloid was isolated from the cultured solution of Chlorella spp.With the cross-flow ultrafiltration technique, the water samples were passed through a 0.2μm pore-size cartridge filter to remove suspended particulate matter, and then ultrafiltrate using a cross-flow ultrafiltration cartridge with a 10kDa or 1kDa hollow-fiber membrane. At the end of ultrafiltration, the colloids in retentate were in sizes of 10kDa? C0.2μm or 1—10kDa.The results showed that the growth rates([WTBX]k)of three algae increased respectively 4.0%—7.0%, 19.1%—28.9% and 2.9%—8.7% at COC concentrations of 4.8—238.4μmol/L and colloidal sizes in 10kDa? C0.2μm. The percentage of relative increase of growth rate([WTBX]Y)for Chlorella spp. was directly related to COC concentration, and the relations between [WTBX]Y and COC concentration for [WTBX]P.subcordiformis and [WTBX]I. galbana were polynomial. The stimulation of marine colloids on [WTBX]P.subcordiformis is greater than [WTBX]I. galbana and the [WTBX]Chlorella spp. Results also showed that the growth rates([WTBX]k)of three algae in the colloids in sizes of 1—10kDa increased respectively by 11.6%, 25.4% and 3.2%, and in the colloids sized in 10kDa? C0.2μm, by 22.5%, 29.5% and 4.5%. The values of [WTBX]k for the three algae in the presence of colloids in sizes of 10kDa? C0.2μm were 1.9, 1.2 and 1.4 times greater than that in sizes of 1—10kDa. This means that bioactivity of high molecular weight marine colloids are higher than those in low molecular weight. The adding of estuarine, riverine and biogenic colloids caused 1.5%, 14.1% and 9.7% enhancement in growth rate of [WTBX]Chlorella spp. respectively. The maximum growth stimulations of Chlorella spp. by the three colloids was riverine colloids, biogenic colloids and estuarine colloids in descending order. It is clear that natural colloids contain nutrients required in growth of phytoplankton, and they can markedly boost the algae growth and be uptaken by algae.国家教育部高等学校骨干教师计划基金资助项目,2005;; 国家自然科学基金重大研究计划重点项目,90411016