聚合硫酸铁絮凝剂的绝热合成研究

本文通过对聚合硫酸铁（ＰＦＳ） 的动力学研究，发现ＰＦＳ的合成温度控制在５０ ℃以上就显著地提高了反应速度，缩短了反应周期。当相对水量Ｃ＝ ４ ．５ ～５ ．５ 时，采用工业级硫酸亚铁为原料，在催化氧化作用下，可以实现ＰＦＳ 的绝热合成工艺，去除加热设备，优化工艺过程。与直接氧化法ＰＦＳ相比，绝热法聚合硫酸铁（ＨＰＦＳ） 具有更优的混凝性能。     

Microsatellite length polymorphisms associated with dispersal-related agonistic onset in male wild house mice (Mus musculus domesticus)

Dispersal propensity, reflecting one of the most decisive mammalian life history traits, has been suggested to vary heritably and to locally adapt to prevailing dispersal conditions in wild house mouse populations. Because individual dispersal propensity highly significantly covaries with the developmental timing of the onset of agonistic interactions between littermate brothers, we used agonistic onset as an endophenotype to explore the potential genetic basis of dispersal-related behavioral variation in male house mice. We found significant covariation of microsatellite marker compositions with the probability of fraternal pairs to exhibit agonistic relationships before the age of 2 months. In particular, the presence of two alleles associated with a serotonin transporter protein gene (Slc6a4) and a testosterone dehydrogenase gene (Cyp3a11), respectively, strongly covaried with the probability of early agonistic onset. These results are congruent with recent findings of microsatellite length polymorphisms marking regulatory variation of gene expression that is relevant for social behavior, including dispersal propensity development, in other mammals. Genetic variability for ontogenetic timing of agonistic onset would be in agreement with genotypic differentiation of the dispersive behavioral syndrome in natural populations that could lead to local adaptation.     

Effect of sunlight radiation,rainfall and droplet spectra of sprays on persistence of bacillus thuringiensis deposits after application of dipel® 76af formulation onto conifers

Abstract

The effect of sunlight radiation, rainfall and droplet spectra of sprays on per ‐sistence of a Bacillus thuringiensis subspp. kurstaki (Btk) formulation, DiPel^® 76AF, was examined after application onto spruce [Picea glauca (Moench) Voss] foliage. The investigation consisted of three studies: (i) Study I: a laboratory microcosm study to examine the photostability of DiPel 76AF deposits on foliage after different periods of exposure to two radiation intensities, (ii) Study II: a laboratory microcosm study to examine the rainfastness of foliar deposits after exposure to different amounts of rainfall consisting of two separate droplet spectra, and (iii) Study III: a field microcosm study to investigate the influence of two different droplet spectra of DiPel 76AF sprays on foliar persistence of Btk under natural weathering conditions. In all studies, persistence of Btk was investigated both by bioassay [using spruce budworm (Choristoneura fumiferana Clemens)] and total protein assay.

The findings of Study I indicated that bioactivity of foliar deposits decreased with increasing duration of exposure to radiation, and with increasing radiation intensity. The half‐life (DT₅₀, the exposure period required for 50% of the initial bioactivity to disappear) was 5.1 d for the low intensity, and 3.9 d for the higher intensity. In contrast with the bioassay results, the total protein levels [determined by the bicinchoninic acid (BCA) method] showed no decrease with increasing duration of exposure, or with increasing radiation intensity.

The findings of Study II indicated that bioactivity of foliar deposits decreased with increasing cumulative rainfall. A new term, RF₅₀ [the amount of rain (in mm) required to washoff 50% of the initial deposit], was introduced to understand the relationship between rainfall intensity and reduction in bioactivity. When the same amount of rain was applied in different droplet sizes, the RF₅₀ value was high (5.2 mm) for the small rain droplets, and was low (2.9 mm) for the large rain droplets. Similar to the bioassay results, the total protein concentrations (determined by the BCA method) decreased with increasing amount of rain and with increasing rainfall intensity. The RF₅₀ value (obtained using ng protein /cm²) was 5.4 mm for the small rain droplets, and was 3.4 mm for the large rain droplets.

The field microcosm study indicated that when DiPel 76AF was applied in small droplets (D_v.5 of 65 μm), the persistence of bioactivity was ca 8.0 d, whereas when it was applied in large droplets (D_v.5 of 130 nm) it was ca 11 d. Bioactivity decreased with time after spray, and the DT₅₀ was 1.98 d for the spray of small droplets, and 2.87 d for that of large droplets. Similar to the bioactivity, the total protein concentrations also decreased with time after spray, and the DT₅₀ values for the small and large droplet spectra were 3.45 and 6.07 d respectively.     

Molecular structure of extracellular poly(3-hydroxybutyrate) depolymerase fromAlcaligenes faecalis T1

The amino acid sequence of a peptide containing an active serine was examined with poly(3-hydroxybutyrate) (PHB) depolymerase ofAlcaligenes faecalis T1. The sequence Cys-Asn-Ala-Trp-Ala-Gly-Ser-Asn-Ala-Gly-Lys was obtained. This amino acid sequence around the active serine does not fit any reported sequence of other esterases and proteases. On the other hand, a segment of the amino acid sequence of PHB depolymerase ofA. faecalis was homologous to the type III sequence of fibronectin. Similar sequences have been reported in some type of bacterial chitinase and cellulases, and PHB depolymerase seems to have an overall similarity to these bacterial extracellular hydrolases.     

九江市地下水易污性评价——基于DPASTIC指标的模糊综合评价模型

从污染物入渗土壤-包气带-含水层的过程出发，以地质、地貌、水文地质条件为主控因素，选取地下水埋深〖WTBX〗(D)、降雨入渗补给量(P)、含水层岩性(A)、土壤类型(S)、地形坡度(T)、非饱和带介质(I)及含水层渗透系数(C)〖WTBZ〗7个指标，建立了九江市地下水易污性评价DPASTIC指标体系。结合模糊数学理论和方法，建立了基于DPASTIC指标的模糊综合评价模型。该模型克服了指标参数级别划分定额差异和指标值不连续性变化的缺陷，寻求出最优的级别定额划分状态和指标值的连续性变化情况；在指标级别定额划分上，引用了指标标准特征值的概念，根据实测参数数据资料，建立了10个级别的指标标准特征值矩阵，确定指标参数的最优相对隶属度。结合MAPGIS软件得出最后的地下水易污性分区，评价结果与规划区的实测及预测的水环境质量相吻合。     

Molecular analysis of genomic DNA allows rapid,and accurate,prenatal diagnosis of peroxisomal D-bifunctional protein deficiency

Prenatal diagnosis was requested for a couple with a previous child affected by the peroxisomal disorder D-bifunctional protein deficiency. Prior analysis of the D-bifunctional protein cDNA sequence from the propositus had shown that it was missing 22 bp. This was subsequently attributed to a point mutation in the intron 5 donor site (IVS5+1G>C) of the D-bifunctional protein gene. Consistent with parental consanguinity, the patient was shown to be homozygous for this mutation, which is associated with loss of a Hph 1 restriction site in the genomic sequence. Prenatal testing of the fetus using genomic DNA isolated from uncultured amniocytes indicated that both alleles of the D-bifunctional protein had the IVS5+1G>C substitution. The peroxisomal defect was later confirmed biochemically using cultured amniocytes, which were found to have elevated levels of very long chain fatty acids (VLCFA). This is the first report of prenatal diagnosis of D-bifunctional protein deficiency using molecular analysis of genomic DNA. Copyright © 2002 John Wiley & Sons, Ltd.     

Maternal serum human chorionic gonadotrophin and pregnancy-associated plasma protein a,markers for fetal down syndrome at 8–14 weeks

Maternal serum levels of human chorionic gonadotrophin and its subunits (intact, α, and free βhCG) and pregnancy-associated plasma protein A (PAPP-A) were measured in 279 women between 8 and 14 weeks' gestation. This group included 23 pregnancies in which the fetus had Down syndrome (DS), diagnosed either at birth or during the second trimester (n=17) or from chorionic villus sampling (CVS) (n=6). Normal medians were determined from the 258 apparently normal pregnancies. The median levels of intact hCG (1·4 MOM) and free βhCG (2·1 MOM) were significantly raised, whereas the median level of PAPP-A (0·39 MOM) was significantly lower in the DS pregnancies when compared with the control group. Levels of αhCG were similar in both the control and the DS pregnancies. Analysis of samples taken prior to 14 weeks' gestation demonstrated that only PAPP-A (0·34 MOM) was significantly altered in DS pregnancies. However, after the exclusion of DS cases diagnosed at CVS, the median intact hCG (1·56 MOM), free βhCG (2·27 MOM), and αhCG (1·8 MOM) were all raised in DS pregnancies. This emphasizes the problem of the interpretation of biochemical markers when DS cases are diagnosed at CVS.     

营养失衡下的分层分质EPS对异型膨胀污泥及其沉降性差异影响

为探索EPS对膨胀污泥沉降性的影响,通过减少进水P源、N源的方式培养异型膨胀活性污泥,分析不同层、不同组分EPS对异型膨胀污泥沉降性影响.结果表明：异型膨胀（非丝状菌粘性膨胀、丝状菌膨胀）活性污泥EPS多糖组分Total-PS、中层组分（L-PS）含量均高于正常污泥.非丝状菌粘性膨胀污泥EPS各层多糖含量高于丝状菌膨胀污泥,而各层蛋白质（PN）含量均低于丝状菌膨胀污泥.非丝状菌粘性膨胀污泥Total-EPS（（229±94）mg/g MLSS）、PS/PN值不仅显著高于正常活性污泥（（86±16）mg/g MLSS）,也高于丝状菌膨胀污泥（（108±30）mg/g MLSS）.非丝状菌粘性膨胀污泥EPS多糖总量Total-PS、蛋白质总量Total-PN越高,SVI值越大,污泥沉降性越差,越易膨胀,且EPS蛋白质组分对污泥膨胀作用大于多糖;从不同层EPS看,松散外层（S层）EPS对非丝状菌粘性膨胀作用最大（S-PN与SVI值相关性最大,r为0.881,P<0.05）,是主要影响因子.丝状菌膨胀污泥,除了内层紧密型T-PN对SVI值影响较大外,其他各层、各组分EPS含量与SVI均呈微弱负相关.     

蛋白质及无机离子对纳滤膜去除PFOS的影响

以全氟辛烷磺酸（PFOS）为目标去除物,选取牛血清蛋白（BSA）为典型蛋白质类有机物,考察了BSA及其浓度,以及BSA与无机离子共存时,离子强度、离子种类对聚酰胺纳滤膜去除水中PFOS的影响.研究发现,原液中存在BSA时,PFOS的去除率有显著提高,而且BSA浓度越高,PFOS的去除率越高;当BSA与无机离子共存时,离子强度越大,PFOS去除率越高.这可能是因为BSA不但会吸附一部分PFOS,还会造成膜污染,BSA浓度越大,膜污染越严重,膜的筛分能力越强,且膜面与PFOS之间的静电排斥力越大,从而提高了PFOS的截留率.而无机离子的存在减小了BSA分子之间及与膜面之间的静电排斥力,使BSA污染层更加厚实,进一步增强了膜的筛分能力.此外,Ca²⁺提高PFOS去除率的能力优于Na⁺.