Möglichkeiten und Grenzen der genetischen Manipulation

Examples for genetic engineering are the transfer of nuclei between cells of higher animals and the introduction of heterologous DNA into bacteria by means of plasmids. The former approach will help to establish new ways in animal breeding, the latter provides bacterial cells that produce proteins of medical importance. The moral justification of related studies in man is still open, but the possible risks of gene technology can be coped with by adhering to proper safety regulations.     

Grenzen und Möglichkeiten der Immuntherapie von Tumoren

Immunological treatment of malignant human tumors has so far met with little success. Based on methods and insights obtained by investigation of corresponding animal models, this article attempts to elucidate the reasons for this failure and to suggest ways and means to improve immunotherapeutic approaches to human neoplasms.     

Bionik: Grenzen und Perspektiven

Bionics, based on analogies between living beings and technical systems, neglect fundamental differences, e.g., on the one hand, technology uses high temperatures, a mean closed to all living beings and, on the other hand, the cells of all organisms keep high autonomy. The first fact makes it possible, e.g., to construct airplanes three or four powers of ten heavier than the heaviest birds, whereas the second fact enables each cell to reproduce itself, to restore lost limbs or even the whole organism, far beyond the reach of technology. The symbiosis of organisms and technical installations (biotechnology) or, on a higher level, of mankind and environment, may be a guiding star for future development.     

Grenzen der modernen Laser-Spektralanalyse

The different methods of laser spectroscopy allow the detection of few atoms in a laser beam. There are several theoretical, physical limitations of atom detection. However, in normal extreme trace analysis, in most cases, several limitations arise due to contamination problems in sample handling and problems connected with sample atomization.     

RETRACTED ARTICLE: Using pyrosequencing and quantitative PCR to analyze microbial communities

New high-throughput technologies continue to emerge for studying complex microbial communities. In particular, massively parallel pyrosequencing enables very high numbers of sequences, providing a more complete view of community structures and a more accurate inference of the functions than has been possible just a few years ago. In parallel, quantitative real-time polymerase chain reaction (QPCR) allows quantitative monitoring of specific community members over time, space, or different environmental conditions. In this review, the principles of these two methods and their complementary applications in studying microbial ecology in bioenvironmental systems are discussed. The parallel sequencing of amplicon libraries and using barcodes to differentiate multiple samples in a pyrosequencing run are explained. The best procedures and chemistries for QPCR amplifications are also described and advantages of applying automation to increase accuracy are addressed. Three examples in which pyrosequencing and QPCR were used together to define and quantify members of microbial communities are provided: in the human large intestine, in a methanogenic digester whose sludge was made more bioavailable by a high-voltage pretreatment, and on the biofilm anode of a microbial electrolytic cell. The key findings in these systems and how both methods were used in concert to achieve those findings are highlighted.