β-环糊精接枝羧甲基壳聚糖吸附剂的制备及其性能

采用γ-氨丙基三乙氧基硅烷化学修饰活化后的硅胶,以戊二醛为交联剂,接上羧甲基壳聚糖,继而接枝上β-环糊精作为功能单体,制备了一种用于分离富集水样中Cu(Ⅱ)的固相萃取新材料。利用红外光谱(FT-IR)、比表面分析(BET)、X射线衍射光谱(XRD)以及热重分析(TG)等方法对吸附剂进行结构表征。采用火焰原子吸收(FAAS)作为检测手段,考察了溶液p H、振荡时间、吸附剂用量、样品流速、洗脱液浓度和体积等对吸附剂吸附Cu(Ⅱ)的影响。吸附剂饱和吸附容量为9.37 mg/g,最大富集倍数高达350。吸附过程能用准二级动力学模型和Langmuir等温吸附方程进行很好的拟合。应用于环境水样中Cu(Ⅱ)的分离富集与测定,回收率在96.8%~105.2%之间,效果较好。     

BPA暴露对本体和子代胰岛β细胞转录组差异对比分析

双酚A(BPA)作为一种典型的环境内分泌干扰物,与二型糖尿病和肥胖症等代谢类疾病密切相关.在这项研究中,旨在探讨BPA直接暴露以及围产期暴露对本体和子代胰岛β细胞影响的差异,从而实现对不同易感人群的精准预防与治疗.通过对GEO数据库中GSE126297和GSE82175两个数据集进行分析,共筛选出108个共有的差异基因...     

Aerobic degradation of methyl tert-butyl ether by a Proteobacteria strain in a closed culture system

The contamination of methyl ten-butyl ether （MTBE） in underground waters has become a widely concerned problem all over the world. In this study, a novel dosed culture system with oxygen supplied by H2O2 was introduced for MTBE aerobic biodegradation. After 7 d, almost all MTBE was degraded by a pure culture, a member of β-Proteobacteria named as PMI, in a closed system with oxygen supply, while only 40% MTBE was degraded in one without oxygen supply. Dissolved oxygen （DO） levels of the broth in closed systems respectively with and without H2O2 were about 5-6 and 4 mg/L. Higher DO may improve the activity of monooxygemase, which is the key enzyme of metabolic pathway from MTBE to tert-butyl alcohol and finally to CO2, and may result in the increase of the degrading activity of PM1 cell. The purge and trap GC-MS result of the broth in closed systems showed that tea-butyl alcohol, isopronol and acetone were the main intermediate products.     

β-环糊精衍生物对甲基对硫磷的增溶洗脱和光降解

研究了3种新型β-环糊精衍生物(谷氨酸-β-环糊精、乙二胺-β-环糊精、羧甲基-β-环糊精)对甲基对硫磷的增溶作用、土壤中甲基对硫磷的洗脱作用以及对甲基对硫磷的光降解作用.研究表明,这三种β-环糊精衍生物都能显著地增加甲基对硫磷在水中的溶解度,并且相对增溶倍数与β-环糊精衍生物的浓度成正相关;120g/L的上述3种β-环糊精衍生物溶液中,甲基对硫磷的溶解度比在纯水中分别提高了117.82倍、80.99倍、47.28倍;β-环糊精衍生物能有效洗脱去除土壤中的甲基对硫磷,其中120g/L的谷氨酸-β-环糊精溶液的累积去除率最高,达103.9%,洗脱液浓度是影响洗脱去除率的主要因素;β-环糊精衍生物能促进甲基对硫磷的光降解,在3g/L的谷氨酸-β-环糊精、乙二胺-β-环糊精、羧甲基-β-环糊精溶液中甲基对硫磷光解速率分别为80.26%、91.53%、76.39%。     

Prenatal diagnosis of thalassemia major by fetal blood analysis: Experience with 1000 cases

In this report we have summarized our experience with the prenatal diagnosis of β-thalassemia in 1000 pregnancies followed at least until 12 months after birth. In the majority of these cases, the thalassemia lesion was the nonsense mutation at the codon corresponding to amino acid 39, which produces the hematological phenotype of β-thalassemia. Fetal blood sampling was carried out by placental aspiration, by which a sufficient amount of fetal blood for analysis was obtained in the majority of cases (99 per cent). The fetal mortality associated with fetal blood sampling was 6·3 per cent. Those placental samples contaminated by maternal cells were successfully purified by Ørskov lysis. Fetal blood was analysed by globin chain synthesis on CM–52 columns, which gave reliable results. Two misdiagnoses (0·2 per cent) have been made of which one was due to a non-globin protein co-migrating with the β-chains while the other resulted from a misclassification of the type of thalassemia segregating in the family.     

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.     

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.