[en] We have demonstrated a proof of intrinsic charge transport properties in alkanedithiol molecular junctions using a multiprobe approach combining a variety of transport techniques. The temperature-independent I(V) behavior and the correct exponential decay of conductance with respect to molecular length shows that the dominant charge transport mechanism is off-resonant tunneling. Length-dependent TVS measurements for the saturated alkane-dithiol series indicate that we did indeed probe a molecular system with CAFM. These results can provide stringent criteria to establish a valid molecular transport junction via a probabilistic measurement technique. In this study, we report a study of charge transport in alkanedithiol SAMs formed in metal-molecule-metal junctions using CAFM in combination with a variety of molecular transport techniques including temperature-and length-variable transport measurements and transition voltage spectroscopy. The main goal of this study is to probe the intrinsic transport properties of component molecules using CAFM, but not parasitic or defect-related effects

[en] Various silver nanostructures with hollow interiors, including nanoscaled cubic or quasi-cubic boxes, tubes, triangular rings, trapeziform rings and hybrid structures composed of tubes and cubic boxes, were synthesized via an extremely simple route. The method involved the modification of the solid silver nanocrystals by dithiol, and subsequent dissolving of the interior metal and assembly of the outer surface. In the whole process, only one simple step of pretreatment was needed before the transformation from Ag solid nanostructures to their corresponding hollow nanostructures. According to the morphological, spectral and structural changes in the evolution from silver solid nanostructures to their corresponding hollow nanostructures, a layer-by-layer assembly mechanism was proposed. The method is believed to open up a simple and versatile route to the fabrication of metallic hollow nanostructures with various morphologies according to the starting templates

[en] Published in summary form only

No abstract available

[en] C₅₁₁ injected 24 hours before irradiation keeps a non negligible part of its radioprotective power, unlike cysteamine. It is tried to confirm this characteristic by experiments

[en] In this study, different dithiol/dimethacrylate formulations ± octamethacryl-polyhedral oligomeric silsesquioxanes (POSS) were synthesized and fully characterized in terms of structural, morphological, and thermostability features. The obtained results indicate that the incorporation of both dithiol and octamethacryl-POSS nanofillers within dimethacrylate matrix exhibits a significant influence on the surface chemistry, polymerization kinetics, thermostability, and thermomechanical properties of the resulting networks. Kinetic analysis showed that the presence of dithiol compound improves the conversion degree of the final dithiol/dimethacrylate networks, while thermal and thermomechanical analyses exhibit that octamethacryl-POSS produces nano-hybrids with enhanced thermostability and storage moduli.

[en] To report the prevalence of anticardiolipin antibodies in patients with proliferative diabetic retinopathy (PDR) having high-risk criteria (HRC). Diabetic patients having PDR with HRC and diabetics free of retinopathy were compared for the presence of anticardiolipin antibodies. Among the 34 patients, 6 (17.7%) of diabetics having PDR with HRC were positive for anticardiolipin antibodies. There was no significant association of aCL antibodies with sex or type of diabetes. Using Pearson's correlation test, no significant associations of aCL antibodies with duration of diabetes or age of patients were found. All patients who were positive for anticardiolipin antibodies had PDR with HRC. The difference was statistically significant. Presence of anticardiolipin antibodies may represent an additional risk factor for PDR. (author)

[en] L,L-ethyl cysteinate dimer or ECD is one of the diamine dithiol (DADT) derivatives of which Tc-99m complex shows good potential as a brain perfusion imaging agent. The ECD ligand was synthesized by the methol of P. Blondeau et al (1967) which gave average yield of 22.8% (3.89 g./batch) of purified ECD dihydrochloride. The ready-to-use kit of ECD was prepared in two formulations. Sterile water for injection and 0.025 M phosphate buffer(pH 6) were used as solvent in formulation A and B, respectively. Then the kits were lyophilized and subsequently labeled with Tc-99m. The radiochemical purity was evaluated by various chromatographic systems (TLC, ITLC and HPLC) and obtained the value of 95% or higher as well as good in vitro stability up to 5 hours after labeling for both formulations. The radiochemical purity analysis by HPLC provided one peak of ^99mTc-ECD at retention time of 25 min. The biodistribution studies of ^99mTc-ECD in normal rats showed significant activity uptake in brain

[en] The crystal structure of recombinant UbiX has been determined to 1.5 Å resolution. The ubiX gene (PA4019) of Pseudomonas aeruginosa has been annotated as encoding a putative 3-octaprenyl-4-hydroxybenzoate decarboxylase from the ubiquinone-biosynthesis pathway. Based on a transposon mutagenesis screen, this gene was also implicated as being essential for the survival of this organism. The crystal structure of recombinant UbiX determined to 1.5 Å resolution showed that the protein belongs to the superfamily of homo-oligomeric flavine-containing cysteine decarboxylases. The enzyme assembles into a dodecamer with 23 point symmetry. The subunit displays a typical Rossmann fold and contains one FMN molecule bound at the interface between two subunits

[en] Au(111) surfaces modified by exposure to a dilute solution of a Ti(IV)/dithiothreitol ligand to metal charge transfer complex (Ti(DTT)₂) show a remarkable response to continuous scanning by scanning tunneling microscopy (STM). Vacancy islands on the gold surface, which are formed during the self-assembly of the molecular overlayer, coarsen and even merge during STM scanning at negative sample bias. In certain instances, the vacancy islands even line up to form parallel nanostructures. We believe the effect is due to mechanical interactions between tip and sample, which is enhanced by electrostatic effects. The Ti(DTT)₂ complex is anchored to the gold surface via Au-S bonds, but due to the fact that there are multiple thiol groups, there may be 'uncoordinated' thiols left 'dangling'. The tip-induced modification involves the interaction of the tip with these 'dangling' sulfurs, which in turn causes movement of single complex molecules with the attached sulfur-bonded gold. Under negative sample bias, the electric field weakens the binding between the sulfur-bonded gold atoms and the surrounding gold atoms in the surface allowing for the observed tip-induced dynamics. In contrast with the Ti(DTT)₂ complex, a similar Ti(IV)/3-mercapto-1,2-propanediol complex (Ti(MPD)₂) does not exhibit any tip-induced effects. In this case, there are no dangling sulfurs to interact with the STM tip. In addition, similarly prepared dithiothreitol, dithiothreitol titanium isopropoxide, and 3-mercapto-1,2-propanediol self-assembled monolayers (without dangling sulfurs) do not exhibit the tip-induced effect. (author)