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Natural steroid estrogens (e.g., 17 β-estradiol, E2), synthetic steroid estrogens (e.g., 17 α-ethinylestradiol, EE2) and pharmaceutical antibiotics (e.g., ciprofloxacin) are chemicals detected in biosolids and sewage sludges because they partition into the solids fraction during the wastewater treatment process. This research utilized a three-way factorial design (six media × two estrogens × three antibiotic treatments) to quantify cumulative E2 and EE2 mineralization over 133 d (MAX) in a range of sewage sludge and biosolid samples in the presence (4 and 40 mg kg?1) and absence of ciprofloxacin. The same three-way factorial design was utilized to quantify the impact of the six media, E2 or EE2, and ciprofloxacin on cumulative soil respiration over 133 d (RESP). Minimal ciprofloxacin mineralization was observed (<0.05% over 133 d), but despite its persistence, ciprofloxacin had no significant effect on MAX of E2 or EE2, and, in general, no significant effect on RESP. MAX ranged from 38.38% to 48.44% for E2 but from only 0.72% to 24.27% for EE2 although RESP was relatively similar, ranging from 101.00 to 866.54 mg CO2 in the presence of E2 and from 69.55 to 893.95 mg CO2 in the presence of EE2. The sorption-limited bioavailability of EE2, which is inherently resistant to biodegradation due to chemical structure, as MAX and Freundlich sorption coefficients (Kf) were negatively correlated. As such, the Kf values of EE2 were largest in composted biosolids in which EE2 was particularly resistant to microbial degradation as the MAX of EE2 was <3%. In contrast, the MAX of E2 showed a positive association with the Kf values of E2 because some steps in the E2 transformation process have been found to occur in the sorbed phase. The MAX of E2 was significantly greater in the biosolid and composted biosolid media than in any other media, whereas the MAX of E2 decreased in the following order: secondary sewage sludge > primary sewage sludge > biosolid = composted biosolid. This suggests that sewage sludges in municipal lagoons and pre-treatment holding lagoons are a more favorable media for mineralization of EE2, whereas biosolids in post-treatment storage lagoons are a more favorable media for the mineralization of E2. The presence of ciprofloxacin will have no impact on the potential E2 or EE2 mineralization rates in these cases.  相似文献   
73.
Concentration of pregnancy-specific β1-glycoprotein (SP1) was studied in second and third trimester amniotic fluid from pregnancies with various fetal developmental disorders. The material consisted of 26 cases with chromosomal disorders and 19 cases with nonchromosomal fetal malformations. The SP1 concentration was elevated in two cases of Meckel's syndrome (mean + 2.7–4.0 S.D.) as well as in one case of fetal triploidy (mean + 22 S.D.), while it was normal in all other 14 different fetal disorders.  相似文献   
74.
硅烷化粉煤灰固定化胰脂肪酶   总被引:1,自引:0,他引:1  
以硅烷化粉煤灰为载体 ,戊二醛为交联剂 ,交联法固定化自制胰脂肪酶 ,考察了固定化时间、给酶量、戊二醛浓度对固定化酶活力的影响 ,并着重研究了固定化胰脂肪酶的热稳定性。固定化酶在 55℃仍可保持较高的酶活。  相似文献   
75.
Prenatal diagnosis of long-chain 3-hydroxyacyl-CoA dehydrogenase (3-HAD) deficiency was performed in a family at risk. The diagnosis of an affected fetus was carried out by enzyme assay in cultured chorionic villus cells.  相似文献   
76.
This study describes three couples a t risk for homozygous β-thalassaemia in which one of the partners carried a short deletion β-thalassaemia defect. Detection of short deletions in trophoblast DNA was accomplished by the very simple procedure of non-denaturing polyacrylamide gel electrophoresis. This method may be applied to detect β-thalassaemia mutations due to deletion or addition of more than two nucleotides.  相似文献   
77.
The formation of heteroduplexes from polymerase chain reaction (PCR) products has recently become a diagnostic tool that is routinely used for the prenatal detection of small deletions or insertions in a number of disease-causing alleles. We present evidence illustrating that heterozygous PCR products can manifest ‘invisible’ heteroduplexes that can ultimately lead to genotyping errors. Justifications for these ‘invisible’ heteroduplexes and requisite parameters to optimize their detection are presented.  相似文献   
78.
Trisomy 21 maternal serum marker screening has led to screening for other anomalies, including trisomy 18. Trisomy 18 is generally prenatally diagnosed because of major morphological defects. However, in up to 30% of cases ultrasound signs are unclear, and in most cases diagnosis is performed late in pregnancy. Of the different maternal serum markers, PAPP-A is now considered as the best for trisomy 18 screening. However, pregnancy-associated plasma protein A (PAPP-A) is of value in first trimester screening for trisomy 21, but not in the second trimester. We therefore propose a two-step screening strategy. Based on 45 trisomy 18 cases, we confirm the values of alpha-fetoprotein (AFP) (median 0.61 MoM), free β-human chorionic gonadotrophin (β-hCG) (median 0.24 MoM) and of PAPP-A (median 0.08 MoM). In the first step, a 0.5 MoM cut-off for AFP or for free β-hCG resulted in detection of 37/45 trisomy 18 cases (82%) with a 10% false-positive rate. The second step consisted of the measurement of PAPP-A for all these false-positive cases. Using a PAPP-A cut-off of 0.5 MoM, all the 37 trisomy 18 cases were detected, but now with a 0.1–0.2% false-positive rate. Amniocentesis was only offered to these few patients. This two-step second trimester screening will be of value for patients who have not been included in first trimester screening based on nuchal translucency (NT) measurement combined with the first trimester markers, PAPP-A and free β-hCG. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
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