Reoviruslike agent in stools: association with infantile diarrhea and development of serologic tests

Reoviruslike particles were visualized by electron microscopy in stool filtrates prepared from stools of infants and young children with severe acute gastroenteritis. Patients who had such particles in their stools and whose paired acute and convalescent serums were tested developed an antibody response to the reoviruslike agent, which was measured by immune electron microscopy and by complement fixation. The reoviruslike agent was antigenically related to the epizootic diarrhea of infant mice virus and the Nebraska calf diarrhea virus.     

Electrical resistance of long conjugated molecular wires

The charge transport mechanism of a wire can be revealed by how its electrical resistance varies with length. We have measured the resistance and current-voltage characteristics of conjugated molecular wires ranging in length from 1 to 7 nanometers, connected between metal electrodes. We observe the theoretically predicted change in direct-current transport from tunneling to hopping as a function of systematically controlled wire length. We also demonstrate that site-specific disruption of conjugation in the wires greatly increases resistance in the hopping regime but has only a small effect in the tunneling regime. These nanoscale transport measurements elucidate the role of molecular length and bond architecture on molecular conductivity and open opportunities for greater understanding of electrical transport in conjugated polymer films.     

Specificity and stability in topology of protein networks

Molecular networks guide the biochemistry of a living cell on multiple levels: Its metabolic and signaling pathways are shaped by the network of interacting proteins, whose production, in turn, is controlled by the genetic regulatory network. To address topological properties of these two networks, we quantified correlations between connectivities of interacting nodes and compared them to a null model of a network, in which all links were randomly rewired. We found that for both interaction and regulatory networks, links between highly connected proteins are systematically suppressed, whereas those between a highly connected and low-connected pairs of proteins are favored. This effect decreases the likelihood of cross talk between different functional modules of the cell and increases the overall robustness of a network by localizing effects of deleterious perturbations.     

担子菌中牛磺酸的检测

利用基于离子交换色谱原理氨基酸自动分析仪检测了一些常见食用菌中牛磺酸的含量。牛磺酸在磷酸丝氨酸及磷酸乙醇胺洗脱液中经色谱分析可得到清晰的对称峰。灵芝的牛磺酸含量为每100g干重含3.7～83umol。火菇在所检蘑菇中牛磺酸含量高,每100g湿重含（83.2±6.6)umol,与陆生植物相近。双孢蘑菇与香菇的牛磺酸含量相对较高,每100g湿重含量约49～55umol,牡蛎蘑菇及糙皮侧耳的鲜重含量分别为（8.9±0.712)umol、（3.7±0.3)umol,木耳及甘露地衣的干重含量分别为（19.5±2.1)umol、（9.3±1.5)umol。高牛磺酸、无胆固醇的蘑菇有望作为低胆甾醇类食物的替代品。     

Beating crystallization in glass-forming metals by millisecond heating and processing

The development of metal alloys that form glasses at modest cooling rates has stimulated broad scientific and technological interest. However, intervening crystallization of the liquid in even the most robust bulk metallic glass-formers is orders of magnitude faster than in many common polymers and silicate glass-forming liquids. Crystallization limits experimental studies of the undercooled liquid and hampers efforts to plastically process metallic glasses. We have developed a method to rapidly and uniformly heat a metallic glass at rates of 10(6) kelvin per second to temperatures spanning the undercooled liquid region. Liquid properties are subsequently measured on millisecond time scales at previously inaccessible temperatures under near-adiabatic conditions. Rapid thermoplastic forming of the undercooled liquid into complex net shapes is implemented under rheological conditions typically used in molding of plastics. By operating in the millisecond regime, we are able to "beat" the intervening crystallization and successfully process even marginal glass-forming alloys with very limited stability against crystallization that are not processable by conventional heating.     

Surface tension measurements of surface freezing in liquid normal alkanes

Surface tension measurements reveal surface freezing in liquid n-alkanes. A solid monolayer of molecules is found to exist up to 30 degrees C above the bulk freezing point. This surface phase exists only for carbon numbers 14 n 相似文献   

A magnetic nanoprobe technology for detecting molecular interactions in live cells

Technologies to assess the molecular targets of biomolecules in living cells are lacking. We have developed a technology called magnetism-based interaction capture (MAGIC) that identifies molecular targets on the basis of induced movement of superparamagnetic nanoparticles inside living cells. Efficient intracellular uptake of superparamagnetic nanoparticles (coated with a small molecule of interest) was mediated by a transducible fusogenic peptide. These nanoprobes captured the small molecule's labeled target protein and were translocated in a direction specified by the magnetic field. Use of MAGIC in genome-wide expression screening identified multiple protein targets of a drug. MAGIC was also used to monitor signal-dependent modification and multiple interactions of proteins.