Novel cage clusters of MoS2 in the gas phase

Laser evaporation of MoS(2) nanoflakes gives negatively charged magic number clusters of compositions Mo(13)S(25) and Mo(13)S(28), which are shown to have closed-cage structures. The clusters are stable and do not show fragmentation in the post-source decay analysis even at the highest laser powers. Computations suggest that Mo(13)S(25) has a central cavity with a diameter of 4.5 A. The nanosheets of MoS(2) could curl upon laser irradiation, explaining the cluster formation.     

Synthesis, physicochemical and biochemical studies of 1',2'-oxetane constrained adenosine and guanosine modified oligonucleotides, and their comparison with those of the corresponding cytidine and thymidine analogues

We have earlier reported the synthesis and antisense properties of the conformationally constrained oxetane-C and -T containing oligonucleotides, which have shown effective down-regulation of the proto-oncogene c-myb mRNA in the K562 human leukemia cells. Here we report on the straightforward syntheses of the oxetane-A and oxetane-G nucleosides as well as their incorporations into antisense oligonucleotides (AONs), and compare their structural and antisense properties with those of the T and C modified AONs (including the thermostability and RNase H recruitment capability of the AON/RNA hybrid duplex by Michaelis-Menten kinetic analyses, their resistance in the human serum, as well as in the presence of exo and endonucleases).     

Response of SII cortex to ipsilateral,contralateral and bilateral flutter stimulation in the cat

Background  

A distinctive property of SII is that it is the first cortical stage of the somatosensory projection pathway that integrates information arising from both sides of the body. However, there is very little known about how inputs across the body mid-line are processed within SII.     

Unusual geometries and questions of oxidation state in potential Sn(III) chemistry

A mixed-valence compound (Sn2I3(NPPh3)3) with nonequivalent Sn atoms in characteristic 2+ and 4+ Sn geometries, raised the idea of an average Sn3+ structure. The extended structures of Sr4Sn2Se9 and Sr4Sn2Se10 contain an unusual Sn2Se6 subunit, which has two equal Se-Sn-Se angles close to 160 degrees. This was suggestive of a Sn3+/Sn3+ compound, similar to the putative transition state for the valence state interchange in the molecular compound. These interesting geometrical features of two quite different molecules prompt a series of computations, a detective story of geometries and oxidation states, which concludes tentatively that the Sn with the abnormal angle in the extended structure is still likely to be formally Sn4+.     

Electrochemical properties and structures of surface-fluorinated graphite for the lithium ion secondary battery

Surface modification of graphite powder has been performed by elemental fluorine and radiofrequency (rf) plasma fluorination. Both methods give rise to an enlargement of the surface areas of graphite samples and a change of the pore volume distribution. The capacities of surface-fluorinated graphite samples are higher than those of original samples and even more than the theoretical capacity of graphite, 372 mAh g⁻¹, without any reduction of the first colombic efficiencies. The increments of the capacities are ∼5, 10, and 15% for graphite samples with average particle diameters of 7, 25 and 40 μm, respectively.     

An automated simultaneous measurement of thickness and wave velocity by ultrasound

The measurement of wave velocity in a sample requires an accurate determination of the sample thickness at the points of interrogation. The theory of an automated technique is presented. In its application, the thickness of the sample is first calculated by the knowledge of the wave velocity in the immersion fluid. This thickness is then used to calculate the wave velocity in the sample. The results of the application of the technique to isotropic and anisotropic materials are presented.