High-throughput manual parallel synthesis using SynPhase crowns and lanterns

The high-throughput manual solid-phase parallel synthesis of libraries comprising thousands of discrete samples using pellicular supports (i.e. SynPhase crowns and lanterns) and a suite of novel tools and techniques is described. Key aspects of this approach include the combination of a split-split-split synthesis strategy with spatial encoding to differentiate thousands of crowns, the rapid washing and filtration of up to 48 reaction vessels in parallel, the application of an inexpensive and environmentally friendly technique to remove trifluoroacetic acid from sixteen 96-well plates in parallel, and a high-throughput method for removing cleaved crowns from reusable pin racks. Tens of thousands of discrete samples have been produced in-house using this conceptually and operationally straightforward strategy.     

Magnetic properties of iron oxides produced by bacterial oxidation of Fe2+ under acid conditions

Iron oxides synthesized under acid conditions in a bioreactor using the bacteriumThiobacillus ferrooxidans or formed in nature under similar conditions resemble relatively “well”-crystallized ferrihydrites. Mössbauer spectra, however, show up significant differences between these and ferrihydrites, indicating sulfate to play a major role in determining the properties of the bacterial samples.     

Investigation of Cobalt(III) Cage Complexes as Inhibitors of the Mitochondrial Calcium Uniporter

The mitochondrial calcium uniporter (MCU) mediates uptake of calcium ions (Ca²⁺) into the mitochondria, a process that is vital for maintaining normal cellular function. Inhibitors of the MCU, the most promising of which are dinuclear ruthenium coordination compounds, have found use as both therapeutic agents and tools for studying the importance of this ion channel. In this study, six Co³⁺ cage compounds with sarcophagine-like ligands were assessed for their abilities to inhibit MCU-mediated mitochondrial Ca²⁺ uptake. These complexes were synthesized and characterized according to literature procedures and then investigated in cellular systems for their MCU-inhibitory activities. Among these six compounds, [Co(sen)]³⁺ ( 3 , sen=5-(4-amino-2-azabutyl)-5-methyl-3,7-diaza-1,9-nonanediamine) was identified to be a potent MCU inhibitor, with IC₅₀ values of inhibition of 160 and 180 nM in permeabilized HeLa and HEK293T cells, respectively. Furthermore, the cellular uptake of compound 3 was determined, revealing moderate accumulation in cells. Most notably, 3 was demonstrated to operate in intact cells as an MCU inhibitor. Collectively, this work presents the viability of using cobalt coordination complexes as MCU inhibitors, providing a new direction for researchers to investigate.     

Near-pole polar diagram of objects and duality

The polar diagram of a set of points in a plane and its extracted dual EDPD were recently introduced for static and dynamic cases. In this paper, the near-pole polar diagram NPPD for a set of points is presented. This new diagram can be considered as a generalization of the polar diagram and has applications in several communication systems and robotics problems. After reviewing the NPPD of points, we solve the problem for a set of line segments and simple polygons in optimal time Θ(n log n), where n is the number of line segments or polygon vertices. We introduce duality for the NPPD of points and identify some applications.     

Converging Branch Multi-Stage Production Schedules with Finite Production Rates and Start-up Delays

This article considers scheduling production in a multi-stage system with converging branches and assumes an infinite time horizon, deterministic parameters, finite production rates, and constant lot sizes at each stage. The objective is the minimization of total time-averaged setup-shutdown and holding cost.The interdependence of successive stages is accounted for by delaying the initial startup at one stage relative to that at its immediate predecessors, to prevent shortages between the stages. Analytical expressions are found for such delay times and written under an "integer multiple" assumption on the cycle times at adjacent stages. Total cost is then minimized for a given set of integer multiples, and a heuristic search procedure for finding the optimal integer multiple values is described. Extensions of this procedure are then discussed.     

Competitive reactions among three monomers over a catalytic surface

We studied in this work a three-monomer reaction model on one- and two-dimensional lattices. We have taken different reactivity rates among pairs of monomers and the reaction between two selected monomers was forbidden. We have employed the mean field and the pair approximation to decouple the equations of motion for the densities of single and pairs of monomers. We found the stationary states and the phase diagram of the model. We have shown that, in two dimensions and within the pair approximation, there is a first-order transition line between active and poisoned steady states.