The SDHA, TMEM127, MAX, and SDHAF2 genes may contribute to hereditary pheochromocytoma and paraganglioma. Genetic testing is recommended in patients at clinically high risk if the classic genes are mutation negative. Gene-specific prevention and/or early detection requires regular, systematic whole-body investigation.
Cerium oxide plays an important role in catalysis due
to its prominent
ability to store, transport, and release oxygen. Inverse model catalysts
have attracted strong interest since their study promises a better
understanding of the basic fundamentals of catalysis, but still a
lot remains unknown about their structure and morphology. Here, we
present an extensive growth and morphology study of the inverse catalyst
model system ceria on Ru(0001) by applying spectroscopic photoemission
and low-energy electron microscopy. Triangular three-dimensional islands
of ceria were grown by depositing cerium metal in an oxygen ambient.
We were able to control the island size, nucleation density, and oxidation
state by choosing appropriate growth conditions. For highly oxidized
ceria, we observe a commensurate (7 × 7) diffraction pattern,
demonstrating that the oxide–metal interface is well-ordered.
Furthermore, two distinct types of cerium oxide rotational domains
are identified, whose quantity, average azimuthal alignment, and distribution
with respect to the principle directions of the substrate lattice
strongly depend on the growth conditions. Together, these findings
are expected to have a high impact on the catalytic behavior of the
model system.
Amphiphilic inducer molecules such as N-acyl-L-homoserine lactones (AHLs) or isopropyl-β-D-thio-galactopyranoside (IPTG) can be utilized for the implementation of an artificial communication system between groups of E. coli bacteria encapsulated within water-in-oil microemulsion droplets. Using spatially extended arrays of microdroplets, we study the diffusion of both AHL and IPTG from inducer-filled reservoirs into bacteria-containing droplets, and also from droplets with AHL producing sender bacteria into neighboring droplets containing receiver cells. Computational modeling of gene expression dynamics within the droplets suggests a strongly reduced effective diffusion coefficient of the inducers, which markedly affects the spatial communication pattern in the neighborhood of the senders. Engineered bacteria that integrate AHL and IPTG signals with a synthetic AND gate gene circuit are shown to respond only in the presence of both types of sender droplets, which demonstrates the potential of the system for genetically programmed pattern formation and distributed computing.
Our data support the hypothesis of the existence of a renal compartment syndrome as a consequence of ischemia-reperfusion injury. Surgical pressure relief effectively prevented functional and structural renal impairment, and we speculate that this approach might be of value for improving graft function after renal transplantation.
Quorum sensing (QS) describes the capability of microbes to communicate with each other by the aid of small molecules. Here we investigate the dynamics of QS-regulated gene expression induced by acylhomoserine lactones (AHLs) in Pseudomonas putida IsoF containing a green fluorescent protein-based AHL reporter. The fluorescence time course of individual colonies is monitored following the external addition of a defined AHL concentration to cells which had previously reached the QS-inactive state in AHL-free medium. Using a microfluidic setup the experiment is performed both under flow and non-flow conditions. We find that without supplying external AHL gene expression is induced without flow while flow suppresses the induction. Both without and with flow, at a low AHL concentration the fluorescence onset is significantly delayed while fluorescence starts to increase directly upon the addition of AHL at a high concentration. The differences between no flow and flow can be accounted for using a two-compartment model. This indicates AHL accumulation in a volume which is not affected by the flow. The experiments furthermore show significant cell-to-cell and colony-to-colony variability which is discussed in the context of a compartmentalized QS mechanism.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.