Deng Zhang

Die vorliegende Studie hat „Angst und Entängstigung“ in Kierkegaards Schrift „Begriff Angst“ zum Thema und versucht, durch detaillierte Textarbeit das hier beschriebene Phänomen der Angst als einen wesentlichen Teil des menschlichen Gefühlslebens in seiner vollen Begrifflichkeit zu entfalten. Die Arbeit ist in drei Teile gegliedert: der erste Teil beschäftigt sich mit den theologischen und metaphysisch-existentialistischen Grundlagen von Kierkegaards Schrift, der zweite Teil behandelt die Begriffe Angst und Entängstigung, der dritte Teil stellt die Angstthematik in den philosophischen Horizont der idealistischen und nachidealistischen Philosophie. Der Übergang zum dritten Kapitel ist eine detaillierte tabellarische Darstellung der Angst in ihren wesentlichen Momenten, die die komplexe Entfaltung der Angstthematik übersichtlich macht und vor allem die These von der anthropologischen Grundlegung in ihren verschiedenen Stadien nachzeichnet. Mit der sich am Text durchgängig bestätigenden These, dass Kierkegaards Ansatz eine hamartologisch begründete Anthropologie zugrunde liegt, will die Studie eine der schwierigsten und dunkelsten Abhandlungen Kierkegaards in ihrer ganzen Komplexität erhellen.

© 2017 American Society of Plant Biologists. All rights reserved.Aliphatic and aromatic lipids are both essential structural components of the plant cuticle, an important interface between the plant and environment. Although cross links between aromatic and aliphatic or other moieties are known to be associated with the formation of leaf cutin and root and seed suberin, the contribution of aromatic lipids to the biosynthesis of anther cuticles and pollen walls remains elusive. In this study, we characterized the rice male sterile mutant, defective pollen wall 2, which showed an abnormal anther cuticle, a defective pollen wall, and complete male sterility. Compared with the wild type, dpw2 anthers have increased amounts of cutin and waxes and decreased levels of lipidic and phenolic compounds. DPW2 encodes a cytoplasmically localized BAHD acyltransferase. In vitro assays demonstrated that recombinant DPW2 specifically transfers hydroxycinnamic acid moieties, using v-hydroxy fatty acids as acyl acceptors and hydroxycinnamoyl-CoAs as acyl donors. Thus, The cytoplasmic hydroxycinnamoyl-CoA:v-hydroxy fatty acid transferase DPW2 plays a fundamental role in male reproduction via the biosynthesis of key components of the anther cuticle and pollen wall.

A total of 37 original cDNA libraries and 9 derivative libraries enriched for rare sequences were produced from Chinese Spring wheat, five other hexaploid wheat genotypes, tetraploid durum wheat, diploid wheat, and two other diploid members of the grass tribe Triticeae. The emphasis in the choice of plant materials for library construction was reproductive development subjected to environmental factors that ultimately affect grain quality and yield, but roots and other tissues were also included. Partial cDNA expressed sequence tags were examined by various measures to assess the quality of these libraries. All ESTs were processed to remove cloning system sequences and contaminants and then assembled using CAPS. Following these processing steps, this assembly yielded 101,107 sequences derived from 89,043 clones, which defined 16,740 contigs and 33,213 singletons, a total of 49,953 "unigenes." Analysis of the distribution of these unigenes among the libraries led to the conclusion that the enrichment methods were effective in reducing the most abundant unigenes and to the observation that the most diverse libraries were from tissues exposed to environmental stresses including heat, drought, salinity, or low temperature.

Lithium/sulfur cells have attracted much attention due to their higher theoretical specific capacity and energy compared to those of current lithium-ion cells. However, the application of Li/S cells is still hampered by short cycle life. Sulfur-graphene oxide nanocomposites have shown promise as cathode materials for long-life Li/S cells because oxygen-containing functional groups on the surface of graphene oxide were successfully used as sulfur immobilizers by forming weak bonds with sulfur and polysulfides. While S-GO showed much improved cycling performance, the capacity decay still needs to be improved for commercially viable cells. In this study, we attempt to understand the capacity fading mechanism based on an ex situ study of the structural and chemical evolution of S-GO nanocomposite cathodes with various numbers of cycles using scanning electron microscopy, near edge X-ray absorption fine structure and X-ray photoelectron spectroscopy. It is found that both the surface morphologies and chemical structures of the cathode materials change considerably with increasing number of cycles. These changes are attributed to several unexpected chemical reactions of lithium with S-GO nanocomposites occurring during the discharge-charge processes with the formation of Li2CO3, Li2SO3, Li 2SO4, and COSO2Li species. These reactions result in the loss of recyclable active sulfur on the surface of the electrode, and thus capacity fades while coulombic efficiency is near 100%. Moreover, the reaction products accumulate on the cathode surface, forming a compact blocking insulating layer which may make the diffusion of Li ions into/out of the cathode difficult during the discharge-charge process and thus lead to lower utilization of sulfur at higher rates. We think that these two observations are significant contributors to the capacity and rate capability degradation of the Li/S-GO cells. Therefore, for the rechargeable Li/S-GO cells, we suggest that the content of oxygen-containing functional groups on GO should be optimized and more stable functional groups need to be identified for further improvement of the cycling performance. The information we gain from this study may provide general insights into the fundamental understanding of the degradation mechanisms of other rechargeable Li/S cells using similar oxygen-containing functional groups as sulfur immobilizers. © the Partner Organisations 2014.