Colorless Polyimides Derived from 5,5'-bis(2,3-norbornanedicarboxylic anhydride): Strategies to Reduce the Linear Coefficients of Thermal Expansion and Improve the Film Toughness.

In this paper, novel colorless polyimides (PIs) derived from 5,5'-bis(2,3-norbornanedicarboxylic anhydride) (BNBDA) were presented. The results of single-crystal X-ray structural analysis using a BNBDA-based model compound suggested that it had a unique steric structure with high structural linearity. Therefore, BNBDA is expected to afford new colorless PI films with an extremely high glass transition temperature () and a low linear coefficient of thermal expansion (CTE) when combined with aromatic diamines with rigid and linear structures (typically, 2,2'-bis(trifluoromethyl)benzidine (TFMB)).

Structure vs. chemistry: Alternate mechanisms for controlling leaf microbiomes.

The analysis of phyllosphere microbiomes traditionally relied on DNA extracted from whole leaves. To investigate the microbial communities on the adaxial (upper) and abaxial (lower) leaf surfaces, swabs were collected from both surfaces of two garden plants, Rhapis excelsa and Cordyline fruticosa. Samples were collected at noon and midnight and at five different locations to investigate if the phyllosphere microbial communities change with time and location.

Short-range contributions of local sources to ambient air.

Recent developments in aerobiology have enabled the investigation of airborne biomass with high temporal and taxonomic resolution. In this study, we assess the contributions of local sources to ambient air within a 160,000 m tropical avian park (AP). We sequenced and analyzed 120 air samples from seven locations situated 160 to 400 m apart, representing distinct microhabitats.

Vertical stratification of the air microbiome in the lower troposphere.

The troposphere constitutes the final frontier of global ecosystem research due to technical challenges arising from its size, low biomass, and gaseous state. Using a vertical testing array comprising a meteorological tower and a research aircraft, we conducted synchronized measurements of meteorological parameters and airborne biomass ( = 480) in the vertical air column up to 3,500 m. The taxonomic analysis of metagenomic data revealed differing patterns of airborne microbial community composition with respect to time of day and height above ground.

Experimental parameters defining ultra-low biomass bioaerosol analysis.

Investigation of the microbial ecology of terrestrial, aquatic and atmospheric ecosystems requires specific sampling and analytical technologies, owing to vastly different biomass densities typically encountered. In particular, the ultra-low biomass nature of air presents an inherent analytical challenge that is confounded by temporal fluctuations in community structure. Our ultra-low biomass pipeline advances the field of bioaerosol research by significantly reducing sampling times from days/weeks/months to minutes/hours, while maintaining the ability to perform species-level identification through direct metagenomic sequencing.

The genomic characterisation and comparison of Bacillus cereus strains isolated from indoor air.

Background: Bacillus cereus is ubiquitous in nature, found in environments such as soil, plants, air, and part of the insect and human gut microbiome. The ability to produce endospores and biofilms contribute to their pathogenicity, classified in two types of food poisoning: diarrheal and emetic syndromes. Here we report gap-free, whole-genome sequences of two B.

Environmental fungal sensitisation associates with poorer clinical outcomes in COPD.

Introduction: Allergic sensitisation to fungi such as are associated to poor clinical outcomes in asthma, bronchiectasis and cystic fibrosis; however, clinical relevance in COPD remains unclear.

Methods: Patients with stable COPD (n=446) and nondiseased controls (n=51) were prospectively recruited across three countries (Singapore, Malaysia and Hong Kong) and screened against a comprehensive allergen panel including house dust mites, pollens, cockroach and fungi. For the first time, using a metagenomics approach, we assessed outdoor and indoor environmental allergen exposure in COPD.

Complete Genome Sequence of Penicillium oxalicum Strain SGAir0226 Isolated from Outdoor Tropical Air in Singapore.

Penicillium oxalicum strain SGAir0226 was isolated from a tropical air sample collected in Singapore. The complete genome was assembled from long reads obtained from single-molecule real-time sequencing and was further polished and error corrected using short read sequencing data. The assembly comprises 20 contigs with a total length of 30.

Complete genome of strain SGAir0282 isolated from air in Singapore.

Background: complex (ECC) bacteria, such as , , , and , have been emerging as nosocomial pathogens. Many strains isolated from medical clinics were found to be resistant to antibiotics, and in the worst cases, acquired multidrug resistance. We present the whole genome sequence of SGAir0282, isolated from the outdoor air in Singapore, and its relevance to other ECC bacteria by in silico genomic analysis.

Whole-Genome Sequencing of Aspergillus terreus Species Complex.

Aspergillus terreus species complex is an opportunistic fungal pathogen increasingly implicated in invasive infection, as well as chronic respiratory disease. Currently, an understanding of A. terreus pathogenicity is impeded by a limited number of whole-genome sequences of this fungal pathogen.

Whole-Genome Sequence of Bacillus megaterium Strain SGAir0080, Isolated from an Indoor Air Sample.

strain SGAir0080 was isolated from a tropical air sample in Singapore. Its genome was assembled using single-molecule real-time (SMRT) sequencing and MiSeq reads. It has one chromosome of 5.

Complete Genome Sequence of sp. Strain SGAir0471, Isolated from Singapore Air Samples.

sp. strain SGAir0471 was isolated from tropical air samples collected in Singapore. The genome was assembled using PacBio RS II long reads and Illumina MiSeq short paired-end reads.

Microbial communities in the tropical air ecosystem follow a precise diel cycle.

The atmosphere is vastly underexplored as a habitable ecosystem for microbial organisms. In this study, we investigated 795 time-resolved metagenomes from tropical air, generating 2.27 terabases of data.

Complete Genome Sequence of Micrococcus luteus Strain SGAir0127, Isolated from Indoor Air Samples from Singapore.

strain SGAir0127 was isolated from indoor air samples collected in Singapore. The assembly, based on single-molecule real-time sequencing reads, resulted in two contigs, one chromosomal contig with a length of 2.57 Mbp and one nonchromosomal contig of 8.

Complete Genome Sequence of sp. Strain SGAir0479, Isolated from Indoor Air Collected in Singapore.

The complete genome sequence of sp. strain SGAir0479 is presented here. This organism was isolated from an air sample collected in an indoor location in Singapore.

Complete Genome Sequence of sp. Strain SGAir0095, Isolated from Tropical Air Samples Collected in Singapore.

sp. strain SGAir0095 was isolated from tropical air samples collected in Singapore, and its complete genome was sequenced with a hybrid strategy using single-molecule real-time sequencing and short reads. The genome consists of one chromosome of 4.

Genome Sequence of the Tropical Atmosphere Bacterium sp. Strain SGAir0037.

The bacterial genus has been detected in marine and soil environments. Here, we report the genome sequence of sp. strain SGAir0037, which was isolated from outdoor air samples collected in Singapore.

Complete Genome Sequence of Citricoccus sp. Strain SGAir0253, Isolated from Indoor Air in Singapore.

sp. strain SGAir0253 was isolated from indoor air collected in Singapore. Its genome sequence was assembled using single-molecule real-time sequencing.

Complete Genome Sequence of Streptomyces sp. Strain SGAir0924, an Actinobacterium Isolated from Outdoor Air in Singapore.

sp. strain SGAir0924 was isolated from outdoor air collected in Singapore. Its genome was assembled using long reads generated by single-molecule real-time sequencing.

Complete Genome Sequence of sp. Strain SGAir0191, Isolated from Tropical Air Collected in Singapore.

sp. strain SGAir0191 was isolated from an air sample collected in Singapore, and its genome was sequenced using a combination of long and short reads to generate a high-quality genome assembly. The complete genome is approximately 5.

Complete Genome Sequence of sp. Strain SGAir0570, Isolated from Tropical Air Collected in Singapore.

sp. strain SGAir0570 was isolated from air samples collected in Singapore. Its genome was assembled using single-molecule real-time sequencing and MiSeq short reads.

Complete Genome Sequence of Enterococcus faecalis Strain SGAir0397, Isolated from a Tropical Air Sample Collected in Singapore.

strain SGAir0397 was isolated from a tropical air sample collected in Singapore. Its genome was assembled using single-molecule real-time sequencing data and comprises one circular chromosome with a length of 2.69 Mbp.