Evaluation of ��-amylase inhibitory activities of selected antidiabetic medicinal plants

Inhibitors of carbohydrate hydrolyzing enzymes such as ??-amylase play an important role for the control of diabetes mellitus especially in patients with type 2 diabetes. In this study we selected ten antidiabetic medicinal plants, because they have been recommended to treat diabetes in traditional Iranian medicine, and screened them for ??-amylase inhibitory activities. Among the tested samples, Camellia sinensis (Theaceae) leaf (IC₅₀?=?1.54?mg/mL), Trigonella foenum-graecum (Leguminosae) seed (IC₅₀?=?1.87?mg/mL) and leaf (IC₅₀?=?1.92?mg/mL), and Urtica dioica (Urticaceae) leaf (IC₅₀?=?1.89?mg/mL) revealed appreciable ??-amylase inhibitory activities in a concentration-dependent manner. Furthermore, the most active sample, Camellia sinensis leaf, was partitioned by stepwise solvent?Csolvent extraction process and the inhibitory effect of each fraction on the ??-amylase was tested. According to the results, the ethyl acetate fraction (IC₅₀?=?0.53?mg/mL) and the residue (IC₅₀?=?0.52?mg/mL) had the highest ??-amylase inhibitory activities.     

Identification of barramundi (Lates calcarifer) and tilapia (Oreochromis spp.) fillets by DNA- and protein-analytical methods

Fish and fillet of barramundi (Lates calcarifer) and tilapia (Oreochromis species) obtained from wholesale and retail trade were assigned to species by sequencing of PCR products. Two segments (358 and 464?bp) of the cytochrome b gene (cytb) were amplified using universal primers. The amplicons gave characteristic patterns in SSCP-analysis (single strand conformation polymorphism) suitable for differentiation of Lates calcarifer from Lates niloticus and Lateolabrax japonicus. Intra-specific variation of sequences and SSCP patterns were observed for barramundi. In case of tilapia species, it was found to be difficult to identify samples by BLAST due to the high similarity of cytb sequences of O. niloticus, O. mossambicus, O. aureus and Sarotherodon galileus. Four different patterns of single strand DNA (ssDNA) were obtained by SSCP analysis of the 464?bp amplicon of tilapia. Different patterns of ssDNA matched to variations in sequences. Protein profiles obtained by IEF (isoelectric focusing) of water-soluble proteins from raw fillet were found to be suitable for rapid differentiation of Lates calcarifer from Lateolabrax japonicus, but the three different Oreochromis species expressed only minor differences in protein patterns. The patterns of the tilapia and barramundi species showed a number of acidic, heat-stable proteins, presumably representing parvalbumin.     

Finite element model updating and structural damage identification using OMAX data

The main limitations in the finite element (FE) model updating technique lie in the ability of the FE model to represent the true behavior of the structure (modelling problem), and in the ability to identify enough modal parameters with sufficient accuracy, especially for large structures that are tested in operational conditions (identification problem). In this paper, the identification problem is solved with an OMAX approach, where an artificial force is used in operational conditions and a structural model is identified that takes both the forced and the ambient excitation into account. From an extensive case study on a real three-span bridge, it is observed that, while updating the FE model using the experimental output-only data yields a good fit, discrepancies show up when the more extensive set of OMAX data is used for validation, or even for updating. It can be concluded that an OMAX approach not only increases the well-posedness of the updating problem, it also allows to detect potential inaccuracies in the FE model.     

Zur numerischen Pumpversuchsauswertung in Mehrschichtgrundwasserleitern

The analysis of well tests conducted in complex geological units is often not well suited with classical analytical approaches. Numerical simulators are usually needed to account for unconventional test conditions in order to analyze data which do not fit within analytical theory. In the current work, a numerical method for simulating pumping tests is adopted, which was developed about 30 years ago in the UK. The method is expanded within the present work to allow for a consistent analysis of pumping tests, vertical interference tests, pressure pulse tests, drillstem tests, and slug tests. Two-layer formations and their dual permeability equivalents can be treated by the implemented model including nonlinear well entrance losses. The application of the model is demonstrated for a pumping test conducted in the Oligocene base formation at the Teltow-Plateau south of Berlin. The test aimed at investigating potential leakages between this poor water quality base formation and overlying high water quality aquifers envisioned for future drinking water exploitation.     

Impact of whole-building hygrothermal modelling on the assessment of indoor climate in a library building

This paper focuses on the importance of accurately modelling the hygrothermal interaction between the building and its hygroscopic content for the assessment of the indoor climate. Libraries contain a large amount of stored books which require a stable relative humidity to guarantee their preservation. On the other hand, visitors and staff must be comfortable with the indoor climate.     

The Dual GCT—A New High-Power Device Using Optimized GCT Technology

The performance of high-power inverters is determined strongly by the characteristics of the semiconductor devices. The design of suitable devices is always a compromise between on-state losses and switching losses. In this paper, a new device-the Dual Gate Commutated Thyristor (GCT)-is proposed that combines the advantages of differently optimized GCTs and realizes low conduction and low switching losses in a single semiconductor device. The concept is introduced first, before the analytical design is presented. Next, finite-element-method simulations are employed to extend the investigation to devices that are not yet available. Measurements of a hybrid Dual GCT are added to verify the advantages of the concept. Finally, the results are discussed.