Nickel nanoparticles generated by pulsed laser ablation in liquid CO2

Research on Chemical Intermediates - Nickel nanoparticles with various structures were synthesized by a pulsed laser ablation process in liquid CO2 at 17 °C and 5.2 MPa. A...     

What is the future of electrophoresis in large-scale genomic sequencing?

Although a finished human genome reference sequence is now available, the ability to sequence large, complex genomes remains critically important for researchers in the biological sciences, and in particular, continued human genomic sequence determination will ultimately help to realize the promise of medical care tailored to an individual's unique genetic identity. Many new technologies are being developed to decrease the costs and to dramatically increase the data acquisition rate of such sequencing projects. These new sequencing approaches include Sanger reaction-based technologies that have electrophoresis as the final separation step as well as those that use completely novel, nonelectrophoretic methods to generate sequence data. In this review, we discuss the various advances in sequencing technologies and evaluate the current limitations of novel methods that currently preclude their complete acceptance in large-scale sequencing projects. Our primary goal is to analyze and predict the continuing role of electrophoresis in large-scale DNA sequencing, both in the near and longer term.     

Can configuration entropy losses be predicted from the binding affinities of hydrogen-bonded complexes with varying numbers of single bonds?

The design of new supramolecular complexes often depends on reducing entropic contributions to improve binding. However, few studies provide reliable values for the cost of entropic contributions. Here, the binding affinities of a series of six alpha,omega-diamides to alpha,omega-dicarboxylates are calculated using a predominant states method and an implicit solvent model based upon finite difference solutions of the Poisson-Boltzmann equation. The calculations are able to reproduce the observed increase in binding free energy as the number of single bonds increases. However, calculations show that the increase in binding free energy is not due to an increase in entropy. Instead, the increase is due to the changing ability of the alpha,omega-diamides to form internal hydrogen bonds that must be disrupted to bind to the dicarboxylate receptors. This suggests that interpreting experimental free-energy trends to give rotational entropy contributions may be problematic.