17O-NMR研究Al(Ⅲ),Fe(Ⅲ)盐对水缔合的影响

测试了AlCl3,Al2(SO4)3,FeCl3,Fe2(SO4)3等对水的^17O-NMR化学位移和半峰宽的影响。并利用水^17O-NMR化学位移和半峰宽的变化与氢键的关系，分析了AlCl3,Al2(SO4)3。FeCl3,Fe2(SO4)3等对水缔合的影响，研究表明，AlCl3,Al2(SO4)3。FeCl3,Fe2(SO4)3等对水缔合有促进作用。且Fe^3 对水缔合的作用大于Al^3 。     

Evaluation of a prenatal screening procedure for β-thalassaemia carriers in a chinese populationbased on the mean corpuscular volume (MCV)

Haemoglobin A₂ (HbA₂) levels were determined on 25 β-thalassaemia carriers by the microcolumn method and were found to range from 4.5–7.2 per cent (mean 5.2±0.82 S.D.). The haemoglobin level (Hb), mean corpuscular volume (MCV), plasma ferritin and HbA₂ levels were measured on a further 299 cconsecutive Chinese pregnant women at a gestation of less than 24 weeks. 18 patients (6 per cent) had HbA₂ level greater than 4.5 per cent and were diagnosed to be β-thalassaemic carriers. It was observed that all these patients had a MCV below 75 fl. If this level is selected in a screening procedure based on measurement of MCV alone all β-thalassaemia carriers could be detected and 11 per cent of the population screened would require HbA₂ estimation. At a lower cut-off level of 70 fl, 8 per cent of the population screened wouid require HbA₂ measurement (a decrease of 27 per cent) but the detection rate will be lowered considerably (83 per cent). The high false positive rate at all cut-off levels of MCV was largely due to the prevalence of iron deficiency anaemia in the population. Estimation of plasma ferritin level in patients with low MCV will reduce this false positive rate, but there will be a considerable delay in diagnosis in patients with concomitant iron deficiency and β-thalassaemia. The presence of iron deficiency in β-thalassaemia carriers did not reduce their HbA₂ level below the diagnostic range in this study. Measurement of Hb level did not appear to be useful as a screening method since one third of the β-thalassaemia carriers had a Hb level over 11 g/dl. The validity of the MCV cut-off levels derived from the first part of the study was assessed in screening a larger population. 61 β-thalassaemia carriers (6 per cent) were detected out of 1166 patients screened. This incidence was not significantly different from the first part of the study. All these 61 patients had a MCV less than 75 ml. It was concluded that a two-step screening policy, based on MCV measurement followed by HbA₂ estimation when the MCV value is less than 75 fl, is suitable for our population. It is efficient, straight forward with excellent sensitivity and required less time and effort for both laboratory staff and clinicians.     

Prenatal diagnosis of congenital adrenal hyperplasia due to 21-hydroxylase deficiency by amniotic fluid steroid analysis

The concentration of 17OH-progesterone was measured in second trimester amniotic fluid samples from 12 mothers who previously had had an infant with congenital adrenal hyper-plasia due to 21-hydroxylase deficiency. In 4 affected pregnancies, the concentrations were more than 2 S.D. higher than those determined in 44 samples from normal pregnancies (mean ± S.D., 8·1 ± 2·4 nmol/1). The remaining 8 pregnancies were predicted to be unaffected based on the results of amniotic fluid concentrations within the normal range. In each instance, the infant was normal. The results indicate that measurement of amniotic fluid 17OH-progester-one concentrations during the second trimester is an accurate prenatal test for 21-hydroxylase deficiency. The results should be supplemented with determination of fetal sex by karyotype analysis on the amniotic fluid cells.     

Hp-β-环糊精包络臭氧氧化去除水中PPCPs研究

为提高臭氧的稳定性,采用臭氧化Hp-β-环糊精溶液的方法对臭氧进行包络。考察了臭氧/Hp-β-环糊精包络物的氧化特性,臭氧化量和Hp-β-环糊精浓度对臭氧/Hp-β-环糊精包络物氧化能力的影响,并研究了臭氧/Hp-β-环糊精包络物对二级出水中添加的10种药品和个人护理用品(PPCPs)的去除效果。结果表明:臭氧/Hp-β-环糊精包络物具有持续的氧化能力,增加臭氧化量或Hp-β-环糊精浓度可显著提升臭氧/Hp-β-环糊精包络物的氧化能力。臭氧/Hp-β-环糊精包络物有较强的氧化性;向0.7 g/L的Hp-β-环糊精溶液中通入6 mg臭氧后,PPCPs的去除率为50%~70%,去除率受PPCPs分子结构影响。臭氧/Hp-β-环糊精包络物氧化可与其他氧化技术联合应用于污染物去除或用作臭氧化后的持续氧化。     

Microcystin-LR inhibited hippocampal long-term potential via regulation of the glycogen synthase kinase-3β pathway

We previously demonstrated that Cyanobacteria-derived microcystin-LR (MCLR) is able to induce cognitive dysfunction, but the mechanism is not understood. Long-term potential (LTP) in hippocampus is regarded as an important cellular mechanism of learning and memory. Here, the aim of this study was to evaluate the role of MCLR in LTP of hippocampal dentate gyrus (DG) by in vivo electrophysiological recording. We found that MCLR could suppress the induction of LTP in rat hippocampus, whereas simultaneous inhibition of glycogen synthase kinase-3β (GSK-3β) by LiCl or SB216763 attenuated the LTP impairments by MCLR. Furthermore, a decrease of the phosphorylated level at Ser9 of GSK-3β was observed by western blotting after intracerebroventricular (ICV) injection of MCLR, indicating GSK-3β was activated by MCLR. In addition, we showed that ICV administration of MCLR slightly stimulated activity of protein phosphatases (PPs) in the brain, which might activate GSK-3β via dephosphorylation of Ser9 site. Taken together, these findings demonstrated that GSK-3β plays a crucial role in regulating MCLR-induced cognitive deficit.     

Microbial degradation of 17β -estradiol and 17α -ethinylestradiol followed by a validated HPLC-DAD method

This work aimed at studying the biodegradation of two estrogens, 17α -estradiol (E2) and 17β -ethinylestradiol (EE2), and their potential metabolism to estrone (E1) by microbial consortia. The biodegradation studies were followed by High Performance Liquid Chromatography–Diode Array Detector (HPLC–DAD) using a specifically developed and validated method. Biodegradation studies of the estrogens (E2 and EE2) were carried out with activated sludge (consortium A, CA) obtained from a Wastewater Treatment Plant (WWTP) and with a microbial consortium able to degrade recalcitrant compounds, namely fluorobenzene (consortium B, CB). E2 was more extensively degraded than EE2 by CA whereas CB was only able to degrade E2. The addition of acetate as a supplementary carbon source led to a faster biodegradation of E2 and EE2. E1 was detected as a metabolite only during the degradation of E2. The 16S rRNA gene sequence analyses of strains recovered from the degrading cultures revealed the presence of the genera Pseudomonas, Chryseobacterium and Alcaligenes. The genera Pseudomonas and Chryseobacterium were retrieved from cultures supplied with E2 and EE2, while the genus Alcaligenes was found in the presence of E2, suggesting that they might be involved in the degradation of these compounds.     

四种环境雌激素对斑马鱼内脏团抗氧化防御系统的影响研究——17B-雌二醇与三种增塑剂DMP、DBP、DOP的影响

以斑马鱼(Danio rerio)为受试动物,研究了四种环境雌激素-17β-雌二醇(E2)和三种增塑剂(DMP、DBP、DOP)对其内脏团的氧化损伤及应激效应。经急性毒性实验,得到E2、DMP、DBP、DOP对成体斑马鱼96 h的半数致死浓度(LC50)分别为2.51、12.33、9.67、9.89 mg·L-1。在此基础上分别设置5个浓度梯度,研究E2(暴露2 d,4 d)、DMP、DBP、DOP(暴露4 d)对斑马鱼内脏团的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽硫转移酶(GST)活性以及丙二醛(MDA)含量的影响。结果表明,SOD、CAT、GST、MDA对这四种环境激素都非常敏感,其中SOD、CAT、GST活性的影响均呈现先诱导后抑制的趋势,而MDA含量则随着污染物浓度的升高而增加。高浓度暴露条件下,E2(0.4 mg·L-1)和DMP、DBP、DOP(0.8 mg·L-1)对SOD、CAT、GST活性均有显著抑制(p0.05),MDA的含量有显著升高(p0.05)。可见,E2、DMP、DBP、DOP会导致斑马鱼内脏团氧化损伤,并且在同等浓度下E2的毒性明显高于三种增塑剂。     

Comparison of biochemical characteristics between PAO and DPAO sludges

A successful enhanced biological phosphorus removal(EBPR) was observed in both anaerobicaerobic sequencing batch reactor(An-Ox SBR) to induce growth of phosphorus accumulating organism(PAO) and anaerobic-anoxic(An-Ax) SBR to induce growth of denitrifying PAO(DPAO).Although the EBPR performance of An-Ox SBR was higher by 11.3% than that of An-Ax SBR,specific phosphorus release rates in the An-Ax SBR(22.8 ± 3.5 mg P/(g VSS·hr)) and the An-Ox SBR(22.4 ± 4.8 mg P/(g VSS·hr)) were similar. Specific phosphorus uptake rates under anoxic and aerobic conditions were 26.3 ± 4.8 mg P/(g VSS·hr)(An-Ax SBR) and 25.6 ± 2.8 mg P/(g VSS·hr)(An-Ox SBR), respectively, which were also similar. In addition, an analysis of relationship of poly-β-hydroxyalkanoates(PHA) synthesized under anaerobic conditions with phosphorous release(Preleased/PHAsynthesized) and of PHA utilized under anoxic and aerobic conditions with phosphorous uptake(Puptaked/PHAutilized) verified that biological activities of EBPR per unit biomass between DPAO and PAO were similar. An analysis of the specific denitrification rate of DPAO showed that NO-3-N can be denitrified at a rate that does not substantially differ from that of an ordinary denitrifier without additional consumption of organic carbon when the PHA stored inside the cell under anaerobic conditions is sufficiently secured.     

Monitoring The Turbidity and Surface Temperature Changes and Effects of the 17 August 1999 Earthquake in the İzmİt Gulf,Turkey by the Landsat TM/ETM Data

The temporal turbidity and surface temperature changes and effects of the 17 August 1999 earthquake in the İzmit Gulf, Turkey have been investigated using Landsat TM/ETM data. The gulf is in the Mediterranean–Black Sea transition climatic zone and is partially surrounded by green vegetation cover and degraded and densely urbanized-industrialized areas. Landsat TM/ETM data acquired in 1990–1999 confirms increase in turbidity. Turbidity is always low in the southern part and high in the northern part of the gulf, because the more urbanized and industrialized areas are located in the northern part. The Landsat-7 ETM data acquired in the same year (1999) shows seasonal changes in turbidity. Moreover, the two high turbidity and surface temperature anomalies, one of which is parallel to the 17 August 1999 earthquake surface rupture (east–west) and the other which is in the northwest–southeast direction were mapped from Landsat-5 TM data acquired the day (18.08.1999) following the earthquake in the east end of the gulf. On the basis of turbidity implying the sea bottom movement, it is possible to state that a second rupture in the northwest and southeast direction could have occurred at the sea bottom during the earthquake. The distribution of the seismicity centers and the orientation of the lineaments in the area support this finding.