Molecular wires, switches, and memories.

Design and measurements of molecular wires, switches, and memories offer an increased device capability with reduced elements. We report: Measurements on through-bond electronic transport properties of nanoscale metal-1,4-phenylene diisocyanide-metal junctions are reported, where nonohmic thermionic emission is the dominant process, with isocyanide-Pd showing the lowest thermionic barrier of 0.22 eV; robust and large reversible switching behavior in an electronic device that utilizes molecules containing redox centers as the active component, exhibiting negative differential resistance (NDR) and large on-off peak-to-valley ratio (PVR) are realized; erasable storage of higher conductivity states in these redox-center-containing molecular devices are observed; and a two-terminal electronically programmable and erasable molecular memory cell with long bit retention time is demonstrated.

Analysis of yeast protein kinases using protein chips.

We have developed a novel protein chip technology that allows the high-throughput analysis of biochemical activities, and used this approach to analyse nearly all of the protein kinases from Saccharomyces cerevisiae. Protein chips are disposable arrays of microwells in silicone elastomer sheets placed on top of microscope slides. The high density and small size of the wells allows for high-throughput batch processing and simultaneous analysis of many individual samples. Only small amounts of protein are required. Of 122 known and predicted yeast protein kinases, 119 were overexpressed and analysed using 17 different substrates and protein chips. We found many novel activities and that a large number of protein kinases are capable of phosphorylating tyrosine. The tyrosine phosphorylating enzymes often share common amino acid residues that lie near the catalytic region. Thus, our study identified a number of novel features of protein kinases and demonstrates that protein chip technology is useful for high-throughput screening of protein biochemical activity.

The experience of head injury on the impairment of gender identity and gender role.

OBJECTIVES: This study explored the disruption of gender identity and gender role as a result a traumatic brain injury (TBI). METHOD: Four adults (two men, two women) who sustained a TBI between the ages of 18 and 30 years and were at least 1 year postinjury participated in six 1-hr interviews concerning changes in (a) perceived masculinity or femininity, (b) involvement in intimate relationships, (c) enactment of gender roles, and (d) organization of activities that support gender roles. RESULTS: The men expressed greater feelings of gender inadequacy postinjury than did the women and appeared to have greater difficulty resolving rites of passage (e.g., achievement of the adult work role, marriage, parenting) and developmental issues characteristic of the life stage at which they experienced their injury. The men appeared to depend more heavily on traditional gender-specific activities before and after injury to define and support gender role; the women relied more on cross-gender activities. The women appeared to be able to maintain more preinjury activities postinjury than did the men. CONCLUSION: Postinjury possession of a personally satisfying sense of gender appears to be related to the ability to maintain much of the preinjury activities that defined and supported the participants' sense of masculinity or femininity. The ability to satisfactorily resolve rites of passage or developmental issues characteristic of the life stage at which the brain injury occurred appears to be related to the ability to participate in activities that define and express gender role during that particular life stage.