Effects of the Transfer Method and Interfacial Adhesion on the Frictional and Wear Resistance Properties of a Graphene-Coated Polymer.

Graphene is a promising candidate used to reduce friction and wear in micro- and nano-device applications owing to its superior mechanical robustness and intrinsic lubrication properties. Herein, we report the frictional and wear resistance properties of a graphene-coated polymer and how they are affected by fabrication processes. The results show that graphene deposited on a polymer substrate effectively improves both frictional and wear resistance properties, and the degree of improvement significantly depends on the graphene transfer method and interfacial adhesion between graphene and the substrate. Dry-transferred graphene showed better improvement than wet-transferred graphene, and the strong adhesion of graphene achieved by imidazole treatment aided the improvement. A combined analysis of surface morphology and scratch trace shows that the graphene transfer method and graphene adhesion dominate the structural integrity of the transferred graphene, and the graphene/substrate interfacial adhesion plays a decisive role in the improvement of both properties by suppressing the delamination of graphene from the substrate during the nanoscratch test, thereby preventing crack formation in graphene and weakening the puckering effect.

The Longibrachiatum Clade of Trichoderma: a revision with new species.

The Longibrachiatum Clade of Trichoderma is revised. Eight new species are described (T. aethiopicum, T. capillare, T. flagellatum, T. gillesii, T. gracile, T. pinnatum, T. saturnisporopsis, T. solani). The twenty-one species known to belong to the Longibrachiatum Clade are included in a synoptic key. Trichoderma parareesei and T. effusum are redescribed based on new collections or additional observations. Hypocrea teleomorphs are reported for T. gillesii and T. pinnatum. Previously described species are annotated.

Anchored reference loci in loblolly pine (Pinus taeda L.) for integrating pine genomics.

Anchored reference loci provide a framework for comparative mapping. They are landmarks to denote conserved chromosomal segments, allowing the synthesis of genetic maps from multiple sources. We evaluated 90 expressed sequence tag polymorphisms (ESTPs) from loblolly pine (Pinus taeda L.) for this function. Primer sets were assayed for amplification and polymorphism in six pedigrees, representing two subgenera of Pinus and a distant member of the Pinaceae, Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco). On average, 89% of primer sets amplified in four species of subgenus Pinus, 49% in one species of subgenus Strobus, and 22% in Douglas-fir. Polymorphisms were detected for 37-61% of the ESTPs within each pedigree. Comparative mapping in loblolly and slash pine (P. elliottii Englm.) revealed that ESTPs mapped to the same location. Disrupted synteny or significant disruptions in colinearity were not detected. Thirty-five ESTPs met criteria established for anchor loci. The majority of those that did not meet these criteria were excluded when map location was known in only a single species. Anchor loci provide a unifying tool for the community, facilitating the creation of a "generic" pine map and serving as a foundation for studies on genome organization and evolution.

Use of haploid mixtures and heteroduplex analysis enhance polymorphisms revealed by denaturing gradient gel electrophoresis.

PCR-based codominant genetic markers were developed by using primer sequences designed from cDNA clones of loblolly pine (Pinus taeda L.). Such markers offer certain advantages relative to simple-sequence repeat (SSR), also known as short-tandem repeat (STR) markers, and include the ability to quantify and map DNA polymorphisms in expressed genes. However, detecting these DNA polymorphisms is more problematic because many DNA polymorphisms in genes involve base substitutions rather than insertions or deletions. Denaturing gradient gel electrophoresis (DGGE) is a sensitive and efficient method for detecting sequence differences among PCR fragments. This paper demonstrates the application of DGGE to genetically map expressed genes in loblolly pine. Also, heteroduplex DNA fragments, formed during the amplification of DNA from heterozygotes and from mixes of haploid DNAs from megagametophytes, enhanced and strengthened genetic interpretations and genotypic classifications.

Determination of isozyme-specific mRNAs of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase in glutamate obese rats by RNA probes.

To study the possible alterations in the metabolism of fructose 2,6-bisphosphate in glutamate induced obese rats, the mRNA levels of different isozymes coding for the bifunctional enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFK-2/F2,6Pase) were determined in various rat tissues obtained from fed and starved animals. For Northern analysis and dot blotting radioactively labeled RNA probes were synthesized by in vitro transcription. A modified ligase-free subcloning method was applied to obtain the plasmid vectors containing specific fragments of the cDNAs coding for the muscle, liver and heart isozymes of PFK-2/F2,6Pase. In liver but not in heart and skeletal muscle of glutamate obese rats the content of mRNA of PFK-2/F2,6Pase is significantly lower than in normal rats. As in normal rats short-term starvation has no effect on mRNA levels of the bifunctional enzyme. These results are compared with the maximum activities of PFK-2 and F2,6Pase determined in cell-free extracts prepared from the three organs.

Simple and rapid purification of F1-ATPase from bovine heart mitochondria by affinity chromatography.

A simple and rapid method for the isolation of bovine heart mitochondrial adenosine 5'-triphosphatase (F1-ATPase) was developed. Mitochondria were purified by differential centrifugation and stored frozen. After thawing. F1-ATPase was released by treatment with chloroform. Purification of the enzyme was achieved by polyethylene glycol precipitation followed by chromatography on Procion Navy H-ER beaded cellulose in the presence of MgCl2. F1-ATPase was eluted by ATP in the absence of MgCl2. The purity of the enzyme was proved by SDS-polyacrylamide-gel electrophoresis. The purified F1-ATPase showed slightly non-hyperbolic kinetics towards ATP and nearly complete inhibition in the presence of millimolar concentrations of ADP.