Enhanced electrical, mechanical and thermal properties by exfoliating graphene platelets of larger lateral dimensions

Conventional liquid-phase graphite exfoliation (LPE) dramatically reduce the lateral dimension of graphene sheets to submicrometer levels due to bond cleavage induced by high shearing force or long processing time, resulting in highly degraded properties of graphene materials. Herein, a modified high-yielding LPE for producing graphene in the cosolvents of ethanol and water is demonstrated, via the prior use of an electrochemical expansion process on graphite. The electrochemically expanded graphite allows the use of significantly lower sonication power and shorter sonication times. Therefore graphene platelets with largely increased lateral dimension were achieved compared to conventional LPE (the size can reach up to 10 μm). The electrical and mechanical properties of graphene film are significantly enhanced as a result, with the electrical conductivity doubled and the modulus increased by a factor of 4 as well as a considerably higher areal capacitance for the assembled solid supercapacitor. Furthermore, a type of multifunctional benzoxazine surfactant was used to stabilize graphene sheets, which can also facilitate to transfer graphene sheets into organic solvents from aqueous dispersions. On this basis, polymer-graphene nano-composites have been easily prepared for both water soluble poly(vinyl alcohol) (PVA) and organic soluble poly(methyl methacrylate) (PMMA) with improved mechanical properties and thermal diffusivity.S.M.N. Acknowledges support from the Australian Research Council through grant FT100100177

Isoprenoids determine Th1/Th2 fate in pathogenic T cells, providing a mechanism of modulation of autoimmunity by atorvastatin.

3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase is a critical enzyme in the mevalonate pathway that regulates the biosynthesis of cholesterol as well as isoprenoids that mediate the membrane association of certain GTPases. Blockade of this enzyme by atorvastatin (AT) inhibits the destructive proinflammatory T helper cell (Th)1 response during experimental autoimmune encephalomyelitis and may be beneficial in the treatment of multiple sclerosis and other Th1-mediated autoimmune diseases. Here we present evidence linking specific isoprenoid intermediates of the mevalonate pathway to signaling pathways that regulate T cell autoimmunity. We demonstrate that the isoprenoid geranylgeranyl-pyrophosphate (GGPP) mediates proliferation, whereas both GGPP and its precursor, farnesyl-PP, regulate the Th1 differentiation of myelin-reactive T cells. Depletion of these isoprenoid intermediates in vivo via oral AT administration hindered these T cell responses by decreasing geranylgeranylated RhoA and farnesylated Ras at the plasma membrane. This was associated with reduced extracellular signal-regulated kinase (ERK) and p38 phosphorylation and DNA binding of their cotarget c-fos in response to T cell receptor activation. Inhibition of ERK and p38 mimicked the effects of AT and induced a Th2 cytokine shift. Thus, by connecting isoprenoid availability to regulation of Th1/Th2 fate, we have elucidated a mechanism by which AT may suppress Th1-mediated central nervous system autoimmune disease

Making Continuous Improvement a Reality: Achieving High Performance in the Ottawa County, Michigan, Circuit and Probate Courts

Today, a well-functioning court is expected to resolve large volumes of work in a fair and orderly way within demanding time frames. The overall goal is quality administration in all phases of court operations, yet achieving this goal in practice means navigating the shoals of tight budgets, workplace politics, and the heavy press of daily business. Courts are under enormous stress these days, and as a result it should come as no surprise that too many courts are infected with pessimistic court leadership. Winston Churchill is often reported to have said, “The pessimist sees difficulty in every opportunity, the optimist sees the opportunity in every difficulty.”1 A high-performance court makes the effort to reject pessimism as it looks to improve its administrative practices, even in tough times. To seize the opportunity for continuous improvement and rally support throughout the court, though, takes coordinated planning and follow-through. The bottom line is that court leaders need to work together at organizational change. In two recent articles in Court Review, we emphasized the necessity of judicial involvement and commitment if administrative improvement is to take hold and thrive. One point was that developing shared, court-wide agreement among judges on how court personnel should work together requires accepting two primary responsibilities: the role each judge has in making decisions and the administrative role judges have in making the system work. Judges benefit from orderly and stable court administration because it helps enhance preparation of all parties, augments the understanding of outstanding issues, and clarifies future procedural events necessary to bring final resolution. However, in any courthouse, making effective administrative practices a reality is a team effort; it requires conscious effort to organize work processes in a way that clarifies and engages the joint contributions of judges and court staff.

Evaluation of Pt, Ni, and Ni–Mo electrocatalysts for hydrogen evolution on crystalline Si electrodes

The dark electrocatalytic and light photocathodic hydrogen evolution properties of Ni, Ni–Mo alloys, and Pt on Si electrodes have been measured, to assess the viability of earth-abundant electrocatalysts for integrated, semiconductor coupled fuel formation. In the dark, the activities of these catalysts deposited on degenerately doped p^+-Si electrodes increased in the order Ni < Ni–Mo ≤ Pt. Ni–Mo deposited on degenerately doped Si microwires exhibited activity that was very similar to that of Pt deposited by metal evaporation on planar Si electrodes. Under 100 mW cm^(−2) of Air Mass 1.5 solar simulation, the energy conversion efficiencies of p-type Si/catalyst photoelectrodes ranged from 0.2–1%, and increased in the order Ni ≈ Ni–Mo < Pt, due to somewhat lower photovoltages and photocurrents for p-Si/Ni–Mo relative to p-Si/Ni and p-Si/Pt photoelectrodes. Deposition of the catalysts onto microwire arrays resulted in higher apparent catalytic activities and similar photoelectrode efficiencies than were observed on planar p-Si photocathodes, despite lower light absorption by p-Si in the microwire structures

Comparative analysis reveals the long-term co-evolutionary history of parvoviruses and vertebrates [preprint]

Parvoviruses (family Parvoviridae) are small, non-enveloped DNA viruses that infect a broad range of animal species. Comparative studies, supported by experimental evidence, show that many vertebrate species contain sequences derived from ancient parvoviruses embedded in their genomes. These ‘endogenous parvoviral elements’ (EPVs), which arose via recombination-based mechanisms in infected germline cells of ancestral organisms, constitute a form of ‘molecular fossil record’ that can be used to investigate the origin and evolution of the parvovirus family. Here, we use comparative approaches to investigate 198 EPV loci, represented by 470 EPV sequences identified in a comprehensive in silico screen of 752 published vertebrate genomes. We investigated EPV loci by constructing an open resource that contains all of the data items required for comparative sequence analysis of parvoviruses and uses a relational database to represent the complex semantic relationships between them. We used this standardised framework to implement reproducible comparative phylogenetic analysis of combined EPV and virus data. Our analysis reveals that viruses closely related to contemporary parvoviruses have circulated among vertebrates since the Late Cretaceous epoch (100-66 million years ago). We present evidence that the subfamily Parvovirinae, which includes ten vertebrate-specific genera, has evolved in broad congruence with the emergence and diversification of major vertebrate groups. Furthermore, we infer defining aspects of evolution within individual parvovirus genera - mammalian vicariance for protoparvoviruses (genus Protoparvovirus), and inter-class transmission for dependoparvoviruses (genus Dependoparvovirus) - thereby establishing an ecological and evolutionary perspective through which to approach analysis of these virus groups. We also identify evidence of EPV expression at RNA level and show that EPV coding sequences have frequently been maintained during evolution, adding to a growing body of evidence that EPV loci have been co-opted or exapted by vertebrate species, and especially by mammals. Our findings offer fundamental insights into parvovirus evolution. In addition, we establish novel genomic resources that can advance the development of parvovirus-related research - including both therapeutics and disease prevention efforts - by enabling more efficient dissemination and utilisation of relevant, evolution-related domain knowledge

PEO-PPO-PEO surfactant exfoliated graphene cyclodextrin drug carriers for photoresponsive release

Liquid exfoliated graphene sheets were incorporated within α-cyclodextrin-triblock copolymer supramolecular hydrogels prepared with a range of polyethylene oxide and polypropylene oxide block sizes and ratios allowing control over the release properties. The strong photothermal activity of graphene was employed to externally activate drug release from within the gels using near-infrared (NIR) irradiation. These supramolecular hybrid hydrogels showed thermoreversible changes in viscosity, which is necessary for an injectable, multiple release point drug delivery depot. This hybrid graphene-surfactant-α-CD gel system with thermoreversible properties is demonstrated herein to be externally NIR activated to induce controllable drug release.S.M.N. acknowledge financial support under the ARC Future Fellowship scheme FT100100177

Cellular electroporation induces dedifferentiation in intact newt limbs

AbstractNewts have the remarkable ability to regenerate lost appendages including their forelimbs, hindlimbs, and tails. Following amputation of an appendage, the wound is rapidly closed by the migration of epithelial cells from the proximal epidermis. Internal cells just proximal to the amputation plane begin to dedifferentiate to form a pool of proliferating progenitor cells known as the regeneration blastema. We show that dedifferentiation of internal appendage cells can be initiated in the absence of amputation by applying an electric field sufficient to induce cellular electroporation, but not necrosis or apoptosis. The time course for dedifferentiation following electroporation is similar to that observed following amputation with evidence of dedifferentiation beginning at about 5 days postelectroporation and continuing for 2 to 3 weeks. Microarray analyses, real-time RT-PCR, and in situ hybridization show that changes in early gene expression are similar following amputation or electroporation. We conclude that the application of an electric field sufficient to induce transient electroporation of cell membranes induces a dedifferentiation response that is virtually indistinguishable from the response that occurs following amputation of newt appendages. This discovery allows dedifferentiation to be studied in the absence of wound healing and may aid in identifying genes required for cellular plasticity

Technology-Based Innovations in Child Maltreatment Prevention Programs: Examples from SafeCare®

Each year, hundreds of thousands of children in the U.S. are victims of child maltreatment. Experts recommend behavioral, skill-based parent training programs as a strategy for the prevention of child abuse and neglect. These programs can be enhanced using innovative technology strategies. This paper presents a brief history of the use of technology in SafeCare®, a home visiting program shown to prevent child neglect and physical abuse, and highlights current work that takes a technology-based hybrid approach to SafeCare delivery. With this unique approach, the provider brings a tablet computer to each session, and the parent interacts with the software to receive psychoeducation and modeling of target skills. The provider and parent then work together to practice the targeted skills until mastery is achieved. Initial findings from ongoing research of both of these strategies indicate that they show potential for improving engagement and use of positive parenting skills for parents and ease of implementation for providers. Future directions for technology enhancements in SafeCare are also presented