MscS-like mechanosensitive channels in plants and microbes

The challenge of osmotic stress is something all living organisms must face as a result of environmental dynamics. Over the past three decades, innovative research and cooperation across disciplines have irrefutably established that cells utilize mechanically gated ion channels to release osmolytes and prevent cell lysis during hypoosmotic stress. Early electrophysiological analysis of the inner membrane of Escherichia coli identified the presence of three distinct mechanosensitive activities. The subsequent discoveries of the genes responsible for two of these activities, the mechanosensitive channels of large (MscL) and small (MscS) conductance, led to the identification of two diverse families of mechanosensitive channels. The latter of these two families, the MscS family, consists of members from bacteria, archaea, fungi, and plants. Genetic and electrophysiological analysis of these family members has provided insight into how organisms use mechanosensitive channels for osmotic regulation in response to changing environmental and developmental circumstances. Furthermore, determining the crystal structure of E. coli MscS and several homologues in several conformational states has contributed to our understanding of the gating mechanisms of these channels. Here we summarize our current knowledge of MscS homologues from all three domains of life and address their structure, proposed physiological functions, electrophysiological behaviors, and topological diversity

Crosslinking of alkylpolysiloxane films on various types of glass surfaces including fused silica using γ-radiation of a⁶⁰cobalt-source. Comparison to crosslinking by thermal peroxid treatment

Crosslinking of alkylpolysiloxane stationary phases, especially in thick film capillary columns, is useful for the homogenous coating of fused silica and pretreated alkaliglass surfaces. The films of the stationary liquid are immobilized against solvent rinsing using CH2Cl2, pentane, and acetone, and maintain homogenity even at high temperature. Various doses of γ-radiation from a60Co. source were used for the crosslinking instead of the thermal peroxid treatment recently described by other authors. The effect of the γ-radiation crosslinking-procedure was investigated in comparison to the peroxid method in regard of: decrease of stationary phase content by solvent rinsing, separation efficiency, tailing behaviour, and bleeding of the columns obtained. Similar results as with the cumylperoxid-treatment were achieved using the γ-radiation-method. By γ-radiation no polar functional groups or moleculs are introduced into the stationary phase, however, as with the peroxid method. Less than 20% of the various stationary liquids are usually removed from the columns by solvent rising after crosslinking using both methods depending on the doses of radiation and the cumylperoxid concentration applied respectively

Crosslinking of alkylpolysiloxane filsm on various types of glass surfaces including fused silica using γ-radiation of a60cobalt-source. Comparison to crosslinking by thermal peroxid treatment

Crosslinking of alkylpolysiloxane stationary phases, especially in thick film capillary columns, is useful for the homogenous coating of fused silica and pretreated alkaliglass surfaces. The films of the stationary liquid are immobilized against solvent rinsing using CH2Cl2, pentane, and acetone, and maintain homogenity even at high temperature. Various doses of γ-radiation from a60Co. source were used for the crosslinking instead of the thermal peroxid treatment recently described by other authors. The effect of the γ-radiation crosslinking-procedure was investigated in comparison to the peroxid method in regard of: decrease of stationary phase content by solvent rinsing, separation efficiency, tailing behaviour, and bleeding of the columns obtained. Similar results as with the cumylperoxid-treatment were achieved using the γ-radiation-method. By γ-radiation no polar functional groups or moleculs are introduced into the stationary phase, however, as with the peroxid method. Less than 20% of the various stationary liquids are usually removed from the columns by solvent rising after crosslinking using both methods depending on the doses of radiation and the cumylperoxid concentration applied respectively.Peer reviewe

The development of a high throughput reactor for the catalytic screening of three phase reactions

The design and utilisation of a reactor for the optimisation of multiple heterogeneous catalytic reactions in liquid phase is described. With the ability to screen up to 25 samples simultaneously at a maximum pressure of 50 bar, the reactor is one of the first to be designed specifically for what is termed stage II, the optimisation phase, of catalytic high throughput experimentation (HTE). Experiments demonstrating the reliability and reproducibility of the reactor are described, including the use of the reactor to study the catalytic hydrogenation of crotonaldehyde (CrAld) over bimetallic samples based on a commercial 5 wt.% Pt on activated carbon catalyst. Modification of the mono-metallic Pt sample by the impregnation of aqueous metal salts and various pre-treatments, resulted in 140 bimetallic catalysts that were used in the hydrogenation study. The changes observed in both selectivity and reactivity of the modified catalysts are described and show, by way of example, how the speed of catalyst screening can be increased by at least an order of magnitude

Voraussetzungen fuer eine staerkere Verknuepfung der Taxen und Mietwagen mit den anderen Verkehrsmitteln des OePNV

SIGLEAvailable from TIB Hannover: FR 4765+MF / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Funktionsfaehigkeit des Gelegenheitsverkehrs mit Taxen - Entwicklung eines Instrumentariums und Feststellung in Berlin (West)

SIGLETIB: FR 919 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman