On‐Chip Detection of Rolling Circle Amplified DNA Molecules from Bacillus Globigii Spores and Vibrio Cholerae

For the first time DNA coils formed by rolling circle amplification are quantified on‐chip by Brownian relaxation measurements on magnetic nanobeads using a magnetoresistive sensor. No external magnetic fields are required besides the magnetic field arising from the current through the sensor, which makes the setup very compact. Limits of detection down to 500 Bacillus globigii spores and 2 pM of Vibrio cholerae are demonstrated, which are on the same order of magnitude or lower than those achieved previously using a commercial macro‐scale AC susceptometer. The chip‐based readout is an important step towards the realization of field tests based on rolling circle amplification molecular analyses.     

Adaptation of a Rare Earth Element Pre-concentration Method for Water Enriched in Al,Ca, Fe,and Mg

The use of rare earth elements (REE) as process indicators in water-rock interactions can be hampered by the fact that samples with high concentrations of total dissolved solids require dilution before ICP-MS analysis, which can lower REE concentrations close to or below detection limits. A pre-concentration method originally developed for chloride-dominated water with very low REE concentrations was tested for and adapted to sulfate-rich water from a mining-affected area with a pH of 6 and high concentrations of Ca, Fe, Mg, and sometimes Al. The adapted approach proved easy to implement in the field and produced very good recoveries and reliable REE patterns. Two factors, sample volume and ionic strength, were tested. Pre-concentration with high sample volumes (1000 mL) resulted in poor recoveries (1.8?±?0.3?% for La up to 17.8?±?0.6?% for Yb). When the sample volume was reduced to 25 mL, much better recoveries were achieved. Reducing the ionic strength by diluting the sample 1:100 or 1:1000 resulted in comparable recoveries than the approach with reduced sample volume, indicating that sample volume was more important than ionic strength. Among the tested competing elements, high concentrations of Ca, Fe, and Mg resulted in loss of light REE (La-Nd), while Al was found to reduce the recovery of all REE. Also for water with high concentrations of Ca and Fe and very low REE concentrations (ppt-range), especially La results should be considered with care after pre-concentration, and be neglected in REE patterns if necessary.     

Robust Multi-Property Combiners for Hash Functions

A robust combiner for hash functions takes two candidate implementations and constructs a hash function which is secure as long as at least one of the candidates is secure. So far, hash function combiners only aim at preserving a single property such as collision-resistance or pseudorandomness. However, when hash functions are used in protocols like TLS they are often required to provide several properties simultaneously. We therefore put forward the notion of robust multi-property combiners and elaborate on different definitions for such combiners. We then propose a combiner that provably preserves (target) collision-resistance, pseudorandomness, and being a secure message authentication code. This combiner satisfies the strongest notion we propose, which requires that the combined function satisfies every security property which is satisfied by at least one of the underlying hash function. If the underlying hash functions have output length n, the combiner has output length 2n. This basically matches a known lower bound for black-box combiners for collision-resistance only, thus the other properties can be achieved without penalizing the length of the hash values. We then propose a combiner which also preserves the property of being indifferentiable from a random oracle, slightly increasing the output length to 2n+ω(logn). Moreover, we show how to augment our constructions in order to make them also robust for the one-wayness property, but in this case require an a priory upper bound on the input length.     

Detection of lupine (Lupinus spp.) DNA in processed foods using real-time PCR

Materials from lupine (Lupinus spp.) plants are used as food ingredients. Even small amounts can evoke allergic reactions in sensitized individuals. The applicability of a recently developed real-time PCR method to the sensitive and specific detection of lupine DNA in processed foods was examined. Using the preparation of pizza as a model, changes in the amplification efficiency and in the limit of detection arising from various processing steps such as freezing and baking were observed. For the starting flour the same limit of detection (0.1 mg/kg) as in raw foods was determined. Freezing of the dough resulted in increased cycle threshold values compared to the flour and the prepared dough. In the baked pizza the detection limit was 1 mg/kg, thus demonstrating the suitability of the method for the detection of lupine DNA in processed foods.     

Caulerpenyne and Related Bis‐enol Esters Are Novel‐Type Inhibitors of Human 5‐Lipoxygenase

Caulerpenyne (CYN) is a sesquiterpene from green algae with known inhibitory properties against soybean lipoxygenase. Here we introduce a detailed structure–activity study elucidating the inhibitory effects of CYN and a library of six synthetic CYN analogues on isolated human 5‐lipoxygenase (5‐LO) and cellular 5‐LO in polymorphonuclear leukocytes. Essential structural elements are identified and a structurally simplified inhibitor is introduced. The modes of 5‐LO inhibition by CYN and the synthetic inhibitors cannot be assigned to any of the known categories of lipoxygenase inhibitors. These compounds clearly interfere directly with 5‐LO and represent rather small and flexible molecules, with unique structures among 5‐LO inhibitors identified thus far.     

Stand der Technik der Versatztechnologie im untertägigen Bergbau

In the framework of a diploma thesis an overview of the basics of backfill technology was given as can be found in literature. As rock pressure problems increase with increasing mining depth, the maximum possible extraction from a deposit may be unacceptably low, being very often the reason for backfill application. As a result of the rising importance of backfill application, basics of backfill technology like backfill placement, backfill application in underground mining as well as the importance of certain backfill properties for backfill performance and the measurement of these properties are discussed in the present paper. Additionally, information concerning questions like backfill system failure was assembled. In this article the author tries to give a coherent overview of backfill technology by presenting portions of the diploma thesis concerned.