There have been a number of articles recently claiming that Dedicated Outdoor Air Systems (DOAS) plus active chilled beam (ACB) systems are superior to Variable Air Volume Reheat (VAVR) systems on energy efficiency, first cost, air quality, etc.[see references 1-4].  The ASHRAE Golden Gate Chapter recently decided to hold a head-to-head competition to put these claims to the test.  Three mechanical engineering firms with offices in the Bay Area each provided a Design Development (DD) level design for a real office building currently in design, the U.C. Davis Medical Center Graduate Studies Building (GSB) in Davis, California.  One firm designed an ACB+DOAS system, another firm designed a VAVR system, and the third firm designed a hybrid combination of these two systems.  A fourth engineering firm then simulated each of the three designs using the EnergyPlus energy simulation program.  Finally, a major mechanical contractor provided a detailed HVAC construction cost estimate for each design.  The VAV reheat system had both the lowest first costs and the lowest energy costs of the three systems.  The analysis also showed that many of the other supposed advantages of ACB+DOAS relative to VAVR, such as improved indoor air quality and a lower floor/floor height, also turned out to be largely overstated.  Note that the results of this analysis are only strictly applicable to these three designs and this building and climate, but the conclusions may also apply more broadly. 

Although the pharmaceutical industry has “mined” the world of soil bacteria,streptomycetes and fungi to find novel antimicrobial molecules, the emergence of resistant superbugs necessitates identifying new antibiotic sources. Recent research into the innate immune system has focused attention on antimicrobial peptides – molecules that equip animals to resist infection without assistance from antibodies and other accoutrements of adaptive immunity. In recent years, potent antimicrobial peptides have been identified in the blood cells (hemocytes) of horseshoe crabs, shrimp, mussels and tunicates ("sea squirts"). Our studies centered on three tunicates (Styela clava, Styela plicata and Ciona intestinalis) that are abundant in Southern California's shallow waters.

A calix[4]arene scaffolding has been used to construct bisporphyrin ("jaws" porphyrin) hosts for supramolecular binding of fullerene guests. Fullerene affinities were optimized by varying the nature of the covalent linkage of the porphyrins to the calixarenes. Binding constants for C60 and C70 in toluene were explored as a function of substituents at the periphery of the porphyrin, and 3,5-di-tert-butylphenyl groups gave rise to the highest fullerene affinities (26,000 M(-1) for C60). The origin of this high fullerene affinity has been traced to differential solvation effects rather than to electronic effects. Studies of binding constants as a function of solvent (toluene < benzonitrile < dichloromethane < cyclohexane) correlate inversely with fullerene solubility, indicating that desolvation of the fullerene is a major factor determining the magnitude of binding constants. The energetics of fullerene binding have been determined in terms of DelatH and DeltaS and are consistent with an enthalpy-driven, solvation-dependent process. A direct relationship between supramolecular binding of a fullerene guest to a bisporphyrin host and the appearance of a broad NIR absorption band have been established. The energy of this band moves in a predictable manner as a function of the electronic structure of the porphyrin, thereby establishing its origin in porphyrin-to-fullerene charge transfer.

Aptameric receptors are important biosensor components, yet our ability to identify them depends on the target structures. We analyzed the contributions of individual functional groups on small molecules to binding within 27 target-aptamer pairs, identifying potential hindrances to receptor isolation-for example, negative cooperativity between sterically hindered functional groups. To increase the probability of aptamer isolation for important targets, such as leucine and voriconazole, for which multiple previous selection attempts failed, we designed tailored strategies focused on overcoming individual structural barriers to successful selections. This approach enables us to move beyond standardized protocols into functional group-guided searches, relying on sequences common to receptors for targets and their analogs to serve as anchors in regions of vast oligonucleotide spaces wherein useful reagents are likely to be found.