Polyamide/Polyimide Aerogels

An aerogel and method of making the aerogel is disclosed. The aerogel is a polyimide/polyamide hybrid with a cross-linking agent that induces gelation

A cross-national study on the antecedents of work–life balance from the fit and balance perspective

Drawing on the perceived work–family fit and balance perspective, this study investigates demands and resources as antecedents of work–life balance (WLB) across four countries (New Zealand, France, Italy and Spain), so as to provide empirical cross-national evidence. Using structural equation modelling analysis on a sample of 870 full time employees, we found that work demands, hours worked and family demands were negatively related to WLB, while job autonomy and supervisor support were positively related to WLB. We also found evidence that resources (job autonomy and supervisor support) moderated the relationships between demands and work–life balance, with high resources consistently buffering any detrimental influence of demands on WLB. Furthermore, our study identified additional predictors of WLB that were unique to some national contexts. For example, in France and Italy, overtime hours worked were negatively associated with WLB, while parental status was positively associated with WLB. Overall, the implications for theory and practice are discussed.Peer ReviewedPostprint (author's final draft

A whole-genome shotgun approach for assembling and anchoring the hexaploid bread wheat genome

Citation: Chapman, J. A., Mascher, M., Buluç, A., Barry, K., Georganas, E., Session, A., . . . Rokhsar, D. S. (2015). A whole-genome shotgun approach for assembling and anchoring the hexaploid bread wheat genome. Genome Biology, 16(1). doi:10.1186/s13059-015-0582-8Polyploid species have long been thought to be recalcitrant to whole-genome assembly. By combining high-throughput sequencing, recent developments in parallel computing, and genetic mapping, we derive, de novo, a sequence assembly representing 9.1 Gbp of the highly repetitive 16 Gbp genome of hexaploid wheat, Triticum aestivum, and assign 7.1 Gb of this assembly to chromosomal locations. The genome representation and accuracy of our assembly is comparable or even exceeds that of a chromosome-by-chromosome shotgun assembly. Our assembly and mapping strategy uses only short read sequencing technology and is applicable to any species where it is possible to construct a mapping population. © 2015 Chapman et al. licensee BioMed Central.Additional Authors: Muehlbauer, G. J.;Stein, N.;Rokhsar, D. S

AI is a viable alternative to high throughput screening: a 318-target study

: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Seven-membered rings

The review covers work published in the calendar year 2010. Novel reaction chemistry and new ring synthetic methods for azepines, benzoazepines, oxepines, thiepines, diazepines, benzodiazepines, dioxepines, dithiepines are reviewed

Synthesis and Properties of Step-Growth Polyamide Aerogels Cross-linked with Triacid Chlorides

We report the first synthesis of step-growth aromatic polyamide (PA) aerogels made using amine end-capped polyamide oligomers cross-linked with 1,3,5-benzenetricarbonyl trichloride (BTC). Isophthaloyl chloride (IPC) or terephthaloyl chloride (TPC) were combined with <i>m</i>-phenylenediamine (mPDA) in <i>N</i>-methylpyrrolidinone (NMP) to give amine-capped polyamide oligomers formulated with up to 40 repeat units. Addition of the cross-linker, BTC, typically induces gelation in under 5 min. Solvent exchange of the resulting gels into ethanol followed by supercritical CO₂ drying gives colorless aerogels with densities ranging from 0.06 to 0.33 g/cm³, compressive moduli between 5 and 312 MPa, and surface areas as high as 385 m²/g. Dielectric properties were also measured in the X-band frequency range. It was found that relative dielectric constant decreased with density as seen with other aerogels with the lowest relative dielectric constant being 1.15 for aerogels with densities of 0.06 g/cm³. Because of their superior mechanical properties, these aerogels can be utilized in a number of aerospace related applications, such as insulation for rovers, habitats, deployable structures, and extravehicular activity suits, as well as low dielectric substrates for antennas and other electronics. Because of potentially lower cost relative to polyimide and other polymer aerogels, they also have potential for use in more terrestrial applications as well, such as insulation for refrigeration, building and construction, and protective clothing