Natural rubber (cis-1,4-polyisoprene) is an isoprenoid compound produced exclusively in plants by the action of rubber transferase. Despite a keen interest in revealing the mechanisms of rubber chain elongation and chain length determination, the molecular nature of rubber transferase has not yet been identified. A recent report has revealed that a 24 kDa protein tightly associated with the sma...

We analyze adsorption-desorption kinetics at significantly higher temperatures than in the accompanying study (Schneider, H. M.; Granick, S.; Smith, S. preceding paper in this issue) so as to contrast enthalpic, detachment-limited desorption with the diffusion-limited regime. The experiments involve measurements of protiopolystyrene (PS) and deuterio-cis-polyisoprene (PI) adsorbed sequentially ...

background: tumor response after multimodality treatment using combination of radiation, chemotherapeutic drugs and hyperthermia usually assessed by parameters such as tumor growth delay, volume doubling time and regression response. the study herein was conducted to investigate the usefulness of micronucleus assay for assessing the multimodality treatment. materials and methods: the induction ...

The formation of membranes from two systems has been studied. In the system polyurethanedimethylformamide-water, the mechanism for the formation of the sponge-like structure proves to be a liquid-liquid phase separation with nucleation and growth of the diluted phase. This mechanism has been confirmed for the system modified polystyrene-polyisoprene-polystyrene/ o-dichlorobenzene/(methanol-wate...

We demonstrate how tuneable Distributed Bragg Reflectors (DBRs) and resonant micro-cavities can be built by a scalable layer assembly of the transparent utility rubbers polydimethylsiloxane and polystyrene-polyisoprene. Stretching the devices by more than 60% leads to an affine contraction of the layer thicknesses thereby tuning both DBR and cavity modes across the entire visible spectrum. Such...

Rubber (cis-1,4-polyisoprene), an important raw material for many industrial uses, is synthesized in the latex of Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg. We postulated that the genes uniquely or preferentially expressed in the latex may be important for rubber biosynthesis. We constructed cDNA libraries from the latex of H. brasiliensis to investigate the genes expressed in the latex...

Latex from Hevea brasiliensis contains 30-50% (w/w) of natural rubber (cis-1,4-polyisoprene), the important raw material for many rubber industries. We have constructed a cDNA library from the latex of H. brasiliensis to investigate the expressed genes and molecular events in the latex. We analyzed 412 expressed sequence tags (ESTs). More than 90% of the EST clones showed homology to previously...

Sequential adsorption experiments were performed to determine the kinetics of polymer displacement. Protiopolystyrene (PSI and deuterio-cis-polyisoprene (PI) were allowed to adsorb sequentially at 12 O C , from dilute solution in carbon tetrachoride, onto a single surface of oxidized silicon. Whereas the net surface excess equilibrated rapidly, the individual populations of PS and PI equilibrat...