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Nah- versus Nachtoderfahrungen
Nahtoderfahrungen (NTE) sind ein Phänomen aus der Kategorie „außergewöhnliche Bewusstseinserfahrungen“. Sie treten in unmittelbarer Nähe des eigenen Todes auf. Oft, aber nicht immer, handelt es sich dabei um Erfahrungen von Personen, die durch ärztliche Maßnahmen wiederbelebt wurden und später davon berichten (NTE-ler). Jedoch kommen solche Phänomene auch bei Menschen vor, die während einer schweren Erkrankung eine lebensbedrohliche Krise haben, hiervon aber spontan genesen.
Den NTE ähnlich sind auch sogenannte Nachtod-erfahrungen sowie spontane Erlebnisse, die im Rahmen anderer außergewöhnlicher Stresssituationen auftreten. Von Nachtoderfahrungen spricht man, wenn die Betroffenen anlässlich des Todes von geliebten Angehörigen oder Freunden Erlebnisse haben, die inhaltlich ebenfalls, zumindest aber teilweise, denen von NTE entsprechen.
Nachtoderfahrungen sowie spontane NTE-ähnliche Erlebnisse unterscheiden sich jedoch von den echten NTE zumeist sowohl quantitativ als auch qualitativ. Unter einem quantitativen Unterschied versteht man in diesem Zusammenhang eine in der Regel geringer ausgeprägte Komplexität, als sie sehr vielen NTE zu eigen ist. Da sich aber auch viele NTE selbst bezüglich ihrer Komplexität unterscheiden, ist der Hauptunterschied qualitativer Natur: Echte NTE besitzen gegenüber den anderen hier erwähnten Phänomenen eine größere inhaltliche und emotionale Tiefe. Sie begleiten die Betroffenen anschließend ein Leben lang – zumeist mit positiven, in Einzelfällen aber auch mit negativen Folgen, die bis zu einem späteren Suizid reichen können.
Die genannten außergewöhnlichen Bewusstseinsphänomene lassen sich in ihrer Gesamtheit bei rund 5 % der Bevölkerung finden. NTE im Speziellen haben hiervon einen durchaus bedeutenden Anteil. Je nach Studie geben zwischen 18 % und 40 % aller Personen, die reanimiert wurden, an, währenddessen eine NTE erlebt zu haben. Dass nicht alle eine solche Erfahrung machen, wird von Kritikern gern dahingehend interpretiert, NTE seien rein physiologischer und keineswegs spiritueller Natur. Jedoch sollte man bedenken, dass im Fall einer rein neurophysiologischen Grundlage von NTE dann bei jedem ein solches Phänomen zu erwarten wäre, so wie beispielsweise auch die Symptome einer Hypoglykämie im Wesentlichen immer dieselben sind.
A microcavity-based deoxyribonucleic acid (DNA) optical biosensor is demonstrated for the first time using synthetic sapphire for the optical cavity. Transmitted and elastic scattering intensity at 1510 nm are analyzed from a sapphire microsphere (radius 500 μm, refractive index 1.77) on an optical fiber half coupler. The 0.43 nm angular mode spacing of the resonances correlates well with the optical size of the sapphire sphere. Probe DNA consisting of a 36-mer fragment was covalently immobilized on a sapphire microsphere and hybridized with a 29-mer target DNA. Whispering gallery modes (WGMs) were monitored before the sapphire was functionalized with DNA and after it was functionalized with single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA). The shift in WGMs from the surface modification with DNA was measured and correlated well with the estimated thickness of the add-on DNA layer. It is shown that ssDNA is more uniformly oriented on the sapphire surface than dsDNA. In addition, it is shown that functionalization of the sapphire spherical surface with DNA does not affect the quality factor (Q≈104) of the sapphire microspheres. The use of sapphire is especially interesting because this material is chemically resilient, biocompatible, and widely used for medical implants.
Members of the species Bacillus pumilus get more and more in focus of the biotechnological industry as potential new production strains. Based on exoproteome analysis, B. pumilus strain Jo2, possessing a high secretion capability, was chosen for an omics-based investigation. The proteome and metabolome of B. pumilus cells growing either in minimal or complex medium was analyzed. In total, 1542 proteins were identified in growing B. pumilus cells, among them 1182 cytosolic proteins, 297 membrane and lipoproteins and 63 secreted proteins. This accounts for about 43% of the 3616 proteins encoded in the B. pumilus Jo2 genome sequence. By using GC–MS, IP-LC/MS and H NMR methods numerous metabolites were analyzed and assigned to reconstructed metabolic pathways. In the genome sequence a functional secretion system including the components of the Sec- and Tat-secretion machinery was found. Analysis of the exoproteome revealed secretion of about 70 proteins with predicted secretion signals. In addition, selected production-relevant genome features such as restriction modification systems and NRPS clusters of B. pumilus Jo2 are discussed.
The ideal combination among biomolecules and nanomaterials is the key for reaching biosensing units with high sensitivity. The challenge, however, is to find out a stable and sensitive film architecture that can be incorporated on the sensor’s surface. In this paper, we report on the benefits of incorporating a layer-by-layer (LbL) nanofilm of polyamidoamine (PAMAM) dendrimer and carbon nanotubes (CNTs) on capacitive electrolyte-insulator-semiconductor (EIS) field-effect sensors for detecting urea. Three sensor arrangements were studied in order to investigate the adequate film architecture, involving the LbL film with the enzyme urease: (i) urease immobilized directly onto a bare EIS [EIS-urease] sensor; (ii) urease atop the LbL film over the EIS [EIS-(PAMAM/CNT)-urease] sensor; and (iii) urease sandwiched between the LbL film and another CNT layer [EIS-(PAMAM/CNT)-urease-CNT]. The surface morphology of all three urea-based EIS biosensors was investigated by atomic force microscopy (AFM), while the biosensing abilities were studied by means of capacitance–voltage (C/V) and dynamic constant-capacitance (ConCap) measureaments at urea concentrations ranging from 0.1 mM to 100 mM. The EIS-urease and EIS-(PAMAM/CNT)-urease sensors showed similar sensitivity (∼18 mV/decade) and a nonregular signal behavior as the urea concentration increased. On the other hand, the EIS-(PAMAM/CNT)-urease-CNT sensor exhibited a superior output signal performance and higher sensitivity of about 33 mV/decade. The presence of the additional CNT layer was decisive to achieve a urea based EIS sensor with enhanced properties. Such sensitive architecture demonstrates that the incorporation of an adequate hybrid enzyme-nanofilm as sensing unit opens new prospects for biosensing applications using the field-effect sensor platform.
Our knowledge on tree responses to drought is mainly based on short-term manipulation experiments which do not capture any possible long-term adjustments in this response. Therefore, historical water channels in inner-Alpine dry valleys were used as century-long irrigation experiments to investigate adjustments in tree growth to contrasting water supply. This involved quantifying the tree-ring growth of irrigated and non-irrigated (control) Scots pine (Pinus sylvestris L.) in Valais (Switzerland), as well as European larch (Larix decidua Mill.) and black pine (Pinus nigra Arnold) in Vinschgau (Italy). Furthermore, the adjustments in radial growth of Scots pine and European larch to an abrupt stop in irrigation were analyzed.
Irrigation promoted the radial growth of all tree species investigated compared to the control: (1) directly through increased soil water availability, and (2) indirectly through increased soil nutrients and humus contents in the irrigated plots. Irrigation led to a full elimination of growth responses to climate for European larch and black pine, but not for Scots pine, which might become more sensitive to drought with increasing tree size in Valais. For the control trees, the response of the latewood increment to water availability in July/August has decreased in recent decades for all species, but increased in May for Scots pine only. The sudden irrigation stop caused a drop in radial growth to a lower level for Scots pine or similar level for larch compared to the control for up to ten years. However, both tree species were then able to adjust to the new conditions and subsequently grew with similar (Scots pine) or even higher growth rates (larch) than the control.
To estimate the impact of climate change on future forest development, the duration of manipulation experiments should be on longer time scales in order to capture adjustment processes and feedback mechanisms of forest ecosystems.