scholarly journals Analysis of nitrifying bacteria growth on two new types of biomass carrier using respirometry and molecular genetic methods

2021 ◽  
Vol 225 ◽  
pp. 112795
Author(s):  
Karel Havlíček ◽  
Magda Nechanická ◽  
Tomáš Lederer ◽  
Brigita Kolčavová Sirková
1990 ◽  
Vol 22 (3-4) ◽  
pp. 161-168 ◽  
Author(s):  
G. Nyhuis

The surface-specific nitrification performance of Rotating Biological Contactors (RBC) has been improved considerably by the use of new techniques. Maximum nitrification rates of 3.3 g/m2×d (10 °C) were achieved, which cannot be approached with any other known procedure. This high oxidation efficiency is achieved with Rotating Biological Contactors by using two new measures:A large degree of separation of carbon degradation and nitrogen oxidation through filtration of the waste water before the subsequent nitrifying RBC stage, whereby the environmental conditions for the nitrifying bacteria are improved, especially in respect of an optimised supply of oxygen.Periodic reversal of the direction of flow in the RBC stage which is constructed as a cascade. This measure allows the attainment of a uniform thickness of nitrifying bacteria growth in all the compartments, which has a particularly advantageous effect in the case of unavoidable surges in load. Because of the low production of excess sludge in the nitrification stage, a subsequent stage for separating solids is not necessary. In this paper experiences with the upgrading of a full scale rotating biological contactor plant and the measuring results from an enlarged oxidation pond installation are summarized.


2002 ◽  
Vol 2 (1) ◽  
pp. 37-46 ◽  
Author(s):  
L.T.J. van der Aa ◽  
L.J. Kors ◽  
A.P.M. Wind ◽  
J.A.M.H. Hofman ◽  
L.C. Rietveld

In winter 1995-1996 the RSF of AWS River-Lake Waterworks suffered from ammonium breakthrough. Research indicated that the nitrification was limited by stagnated growth of the nitrifying bacteria due to low phosphate concentrations at low temperatures (0-3°C). Phosphoric acid was dosed prior to the RSF (dose 35-50 μg PO43- -P.l-1) to stimulate bacteria growth. Two weeks after starting the addition, ammonium removal in the RSF had recovered. AWS is conducting research on alternatives for production capacity extension. Several alternatives involve the construction of an additional RSF prior to the reservoir. Pilot experiments on RSF prior to the reservoir show that complete nitrification in these additional RSF is possible. The phosphate concentration should amount at least 10 μg PO43- -P.l-1. A model has been developed to predict nitrification in RSF. The model confirms the results from both the River-Lake Waterworks' RSF as from the pilot RSF. The model is used for process control and scenario studies.


2015 ◽  
Vol 54 (03) ◽  
pp. 94-100 ◽  
Author(s):  
P. B. Musholt ◽  
T. J. Musholt

SummaryAim: Thyroid nodules > 1 cm are observed in about 12% of unselected adult employees aged 18–65 years screened by ultrasound scan (40). While intensive ultrasound screening leads to early detection of thyroid diseases, the determination of benign or malignant behaviour remains uncertain and may trigger anxieties in many patients and their physicians. A considerable number of thyroid resections are consecutively performed due to suspicion of malignancy in the detected nodes. Fine needle aspiration biopsy (FNAB) has been recommended for the assessment of thyroid nodules to facilitate detection of thyroid carcinomas but also to rule out malignancy and thereby avoid unnecessary thyroid resections. However, cytology results are dependent on experience of the respective cytologist and unfortunately inconclusive in many cases. Methods: Molecular genetic markers are already used nowadays to enhance sensitivity and specificity of FNAB cytology in some centers in Germany. The most clinically relevant molecular genetic markers as pre-operative diagnostic tools and the clinical implications for the intraoperative and postoperative management were reviewed. Results: Molecular genetic markers predominantly focus on the preoperative detection of thyroid malignancies rather than the exclusion of thyroid carcinomas. While some centers routinely assess FNABs, other centers concentrate on FNABs with cytology results of follicular neoplasia or suspicion of thyroid carcinoma. Predominantly mutations of BRAF, RET/PTC, RAS, and PAX8/PPARγ or expression of miRNAs are analyzed. However, only the detection of BRAF mutations predicts the presence of (papillary) thyroid malignancy with almost 98% probability, indicating necessity of oncologic thyroid resections irrespective of the cytology result. Other genetic alterations are associated with thyroid malignancy with varying frequency and achieve less impact on the clinical management. Conclusion: Molecular genetic analysis of FNABs is increasingly performed in Germany. Standardization, quality controls, and validation of various methods need to be implemented in the near future to be able to compare the results. With increasing knowledge about the impact of genetic alterations on the prognosis of thyroid carcinomas, recommendations have to be defined that may lead to individually optimized treatment strategies.


2010 ◽  
Vol 30 (S 01) ◽  
pp. S153-S155
Author(s):  
D. Delev ◽  
S. Pahl ◽  
J. Driesen ◽  
H. Brondke ◽  
J. Oldenburg ◽  
...  

1995 ◽  
Vol 73 (05) ◽  
pp. 756-762 ◽  
Author(s):  
Yoshiaki Tomiyama ◽  
Hirokazu Kashiwagi ◽  
Satoru Kosugi ◽  
Masamichi Shiraga ◽  
Yoshio Kanayama ◽  
...  

SummaryWe analyzed the molecular genetic defect responsible for type I Glanzmann’s thrombasthenia in a Japanese patient. In an immunoblot assay using polyclonal anti-GPIIb-IIIa antibodies, some GPIIIa (15% of normal amount) could be detected in the patient’s platelets, whereas GPIIb could not (<2% of normal amount). Nucleotide sequence analysis of platelet GPIIb mRNA-derived polymerase chain reaction (PCR) products revealed that patient’s GPIIb cDNA had a 75-bp deletion in the 3’ boundary of exon 17 resulting in an in-frame deletion of 25 amino acids. DNA analysis and family study revealed that the patient was a compound heterozygote of two GPIIb gene defects. One allele derived from her father was not expressed in platelets, and the other allele derived from her mother had a 9644C → T mutation which was located at the position -3 of the splice donor junction of exon 17 and resulted in a termination codon (TGA). Moreover, quantitative analysis demonstrated that the amount of the abnormal GPIIb transcript in the patient’s platelets was markedly reduced. Thus, the C → T mutation resulting in the abnormal splicing of GPIIb transcript and the reduction in its amount is responsible for Glanzmann’s thrombasthenia.


1997 ◽  
Vol 77 (02) ◽  
pp. 238-242 ◽  
Author(s):  
J Oldenburg ◽  
J K Picard ◽  
R Schwaab ◽  
H H Brackmann ◽  
E G D Tuddenham ◽  
...  

SummaryMolecular genetic studies have shown that development of antibodies to factor VIII (inhibitors) occurs most frequently in patients with severe haemophilia due to major gene lesions including inversions, stop codons and large deletions. Previous studies of HLA type were performed on inhibitor and non-inhibitor patients with diverse uncharacterised mutations which may have confounded detection of significant associations. We therefore selected a group of patients with a single mutation type, the prevalent intron 22 inversion, with or without inhibitors, to determine HLA genotype. Seventy-one such patients, 42 without and 29 with inhibitors (13 high, 9 low and 7 transient responders) were genotyped for MHC Class I HLA-A, -B, -C and Class II HLA-DQA, -DQB and -DRB loci. No strong correlation of any HLA-allele to inhibitor or non-inhibitor status was found. However, alleles of the haplotype HLA-A3, HLA-B7, HLA-C7, HLA-DQA0102, HLA-DQB0602, HLA-DR15 occurred more often in inhibitor patients. Since the alleles of this extended haplotype are common in the North European population only a very strong association would achieve statistical significance. Further studies of groups of patients similar to those studied here will be needed to confirm or exclude this association.


1996 ◽  
Vol 16 (02) ◽  
pp. 114-138 ◽  
Author(s):  
R. E. Scharf

SummarySpecific membrane glycoproteins (GP) expressed by the megakaryocyte-platelet system, including GPIa-lla, GPIb-V-IX, GPIIb-llla, and GPIV are involved in mediat-ing platelet adhesion to the subendothelial matrix. Among these glycoproteins, GPIIb-llla plays a pivotal role since platelet aggregation is exclusively mediated by this receptor and its interaction with soluble macromolecular proteins. Inherited defects of the GPIIb-llla or GPIb-V-IX receptor complexes are associated with bleeding disorders, known as Glanzmann's thrombasthenia, Bernard-Soulier syndrome, or platelet-type von Willebrand's disease, respectively. Using immuno-chemical and molecular biology techniques, rapid advances in our understanding of the molecular genetic basis of these disorders have been made during the last few years. Moreover, analyses of patients with congenital platelet membrane glycoprotein abnormalities have provided valuable insights into molecular mechanisms that are required for structural and functional integrity, normal biosynthesis of the glycoprotein complexes and coordinated membrane expression of their constituents. The present article reviews the current state of knowledge of the major membrane glycoproteins in health and disease. The spectrum of clinical bleeding manifestations and established diagnostic criteria for each of these dis-orders are summarized. In particular, the variety of molecular defects that have been identified so far and their genetic basis will be discussed.


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