Understanding biological complexity arising from patterns of gene expression requires accurate and precise measurement of RNA levels across large numbers of genes simultaneously. Real time PCR (RT-PCR) in a microtiter plate is the preferred method for quantitative transcriptional analysis but scaling RT-PCR to higher throughputs in this fluidic format is intrinsically limited by cost and logistic considerations. Hybridization microarrays measure the transcription of many thousands of genes simultaneously yet are limited by low sensitivity, dynamic range, accuracy and sample throughput. The hybrid approach described here combines the superior accuracy, precision and dynamic range of RT-PCR with the parallelism of a microarray in an array of 3072 real time, 33 nl polymerase chain reactions (RT-PCRs) the size of a microscope slide. RT-PCR is demonstrated with an accuracy and precision equivalent to the same assay in a 384-well microplate but in a 64-fold smaller reaction volume, a 24-fold higher analytical throughput and a workflow compatible with standard microplate protocols.

Young’s modulus and hardness of TiN films are reported. The films, deposited on 440C stainless steel, range between 0.25 and 1.0 μm in thickness. They fall to within 3% of stoichiometry and have a 〈111〉 texture. Within experimental resolution, the properties of films with different thickness are indistinguishable: calculated values of Young’s modulus and hardness are 550±50 GPa and 31±4 GPa, respectively. Properties are obtained from a continuous indentation technique. A new correlation is used for identifying whether all films have the same properties, independent of thickness, and for measuring hardness of thin films. The same correlation is utilized for measuring machine compliance and obtaining the profile of the indenter tip. An elasticity analysis aids in obtaining elastic modulus from compliance data.

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The hardness, H, and rate sensitivity of the hardness, m = ∂ ln H/∂ ln ∊eff|xp, where ∊eff is an effective strain rate and xp the plastic depth, are measured in molybdenum at room and low temperature (160 and 170 K) using as-received and annealed specimens. Based on these measurements it is found that H separates into two components: one depending on indentation rate and temperature, and the other depending on the starting state of the material. An activation volume is defined, v∗ = 9kT/mH, which falls within the range of values derived from other experimental techniques. The values of m obtained from indentation creep, indentation load relaxation, and indentation rate-change experiments agree closely with each other provided a consistent analysis is used. The results of these experiments suggest that the rate- and temperature-dependence of the hardness can be used to discriminate between strengthening mechanisms at low temperature.

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