Characteristics and properties of nano-LiCoO2 synthesized by pre-organized single source precursors: Li-ion diffusivity, electrochemistry and biological assessment

Background: LiCoO2 is one of the most used cathode materials in Li-ion batteries. Its conventional synthesis requires high temperature (>800 degrees C) and long heating time (>24 h) to obtain the micronscale rhombohedral layered high-temperature phase of LiCoO2 ( HT-LCO). Nanoscale HT-LCO is of interest to improve the battery performance as the lithium (Li+) ion pathway is expected to be shorter in nanoparticles as compared to micron sized ones. Since batteries typically get recycled, the exposure to nanoparticles during this process needs to be evaluated. Results: Several new single source precursors containing lithium (Li+) and cobalt (Co2+) ions, based on alkoxides and aryloxides have been structurally characterized and were thermally transformed into nanoscale HT-LCO at 450 degrees C within few hours. The size of the nanoparticles depends on the precursor, determining the electrochemical performance. The Li-ion diffusion coefficients of our - LiCoO2 nanoparticles improved at least by a factor of 10 compared to commercial one, while showing good reversibility upon charging and discharging. The hazard of occupational exposure to nanoparticles during battery recycling was investigated with an in vitro multicellular lung model. Conclusions: Our heterobimetallic single source precursors allow to dramatically reduce the production temperature and time for HT-LCO. The obtained nanoparticles of LiCoO2 have faster kinetics for Li+ insertion/extraction compared to microparticles. Overall, nano-sized - LiCoO2 particles indicate a lower cytotoxic and (pro-)inflammogenic potential in vitro compared to their micron-sized counterparts. However, nanoparticles aggregate in air and behave partially like microparticles

Antibiotic research and development: business as usual?

This article contends that poor economic incentives are an important reason for the lack of new drugs and explains how the DRIVE-AB intends to change the landscape by harnessing the expertise, motivation and diversity of its partner

Establishment of Cohesion at the Pericentromere by the Ctf19 Kinetochore Subcomplex and the Replication Fork-Associated Factor, Csm3

The cohesin complex holds sister chromatids together from the time of their duplication in S phase until their separation during mitosis. Although cohesin is found along the length of chromosomes, it is most abundant at the centromere and surrounding region, the pericentromere. We show here that the budding yeast Ctf19 kinetochore subcomplex and the replication fork-associated factor, Csm3, are both important mediators of pericentromeric cohesion, but they act through distinct mechanisms. We show that components of the Ctf19 complex direct the increased association of cohesin with the pericentromere. In contrast, Csm3 is dispensable for cohesin enrichment in the pericentromere but is essential in ensuring its functionality in holding sister centromeres together. Consistently, cells lacking Csm3 show additive cohesion defects in combination with mutants in the Ctf19 complex. Furthermore, delaying DNA replication rescues the cohesion defect observed in cells lacking Ctf19 complex components, but not Csm3. We propose that the Ctf19 complex ensures additional loading of cohesin at centromeres prior to passage of the replication fork, thereby ensuring its incorporation into functional linkages through a process requiring Csm3

Population dynamics of the diamondback moth Plutella xylostella L. (Lepidoptera: Yponomeutidae) in the Sydney Region of Australia

The population dynamics of the diamondback moth (DBM), Plutella xylostella L. (Lepidoptera: Yponomeutidae) was investigated at three farms on the Western side of the Sydney Basin, Australia, from November 2003 to October 2004. Adult populations were monitored fortnightly by counting the number that was trapped on yellow sticky traps, which peaked around November to December (summer) in all three farms, with virtually no trap catches in the winter months (June-August). The seasonal trend of adult DBM showed a higher number per trap in summer, ranging from 34.5-41.7 compared with the other seasons. Larval and pupal densities were highest in summer (2.0-4.0 and 3.3-5.1 per plant, respectively), while the lowest numbers were recorded in winter. Rainfall had a significant impact on the DBM populations. The activity (numbers and parasitism) of the DBM parasitoid Diadegma semiclausum Héllen (Hymenoptera: Ichneumonidae) was recorded in all three farms, with the population showing a synchrony with that of the DBM. The highest number of parasitoids per trap (36.8-53.8) was recorded in summer compared with the other seasons. Parasitism was highest in the non-sprayed farm (56.3%) in summer compared with 16.4% and 31.5% in the other farms which have been sprayed with insecnticides. Canonical correspondence analysis showed environmental variables accounting for 11.2% of the variability in the insect data, out of which 83.9% was explained along the first canonical axis.© 2010 International Formulae Group. All rights reserved.Keywords: Diamondback moth, Plutella xylostella, Diadegma semiclausum, parasitism, brassic