Electrospun dual-layer mats with covalently bonded ZnO nanoparticles for moisture wicking and antibacterial textiles

The fast growing demand for advanced sportswear suitable for tropical countries has led to research on fabrics with both moisture wicking and anti-bacterial properties. In this work, to improve the water transport behaviour, dual-layer nanofibrous nonwoven mats composed of a hydrophilic polyacrylonitrile (PAN) outer layer and a hydrophobic poly(vinylidene fluoride) (PVDF) inner layer are fabricated by electrospinning. The distinct difference in surface hydrophobicity between the inner and outer layers induces a push-pull effect to transport water from the inner to the outer surface efficiently. To render an antibacterial property, zinc oxide (ZnO) nanoparticles are covalently attached to the PVDF nanofibers. The good anti-wash properties and anti-bacterial function of the ZnO-PDVF/PAN dual layer mats are demonstrated

Regeneration of Different Plant Functional Types in a Masson Pine Forest Following Pine Wilt Disease

Pine wilt disease is a severe threat to the native pine forests in East Asia. Understanding the natural regeneration of the forests disturbed by pine wilt disease is thus critical for the conservation of biodiversity in this realm. We studied the dynamics of composition and structure within different plant functional types (PFTs) in Masson pine forests affected by pine wilt disease (PWD). Based on plant traits, all species were assigned to four PFTs: evergreen woody species (PFT1), deciduous woody species (PFT2), herbs (PFT3), and ferns (PFT4). We analyzed the changes in these PFTs during the initial disturbance period and during post-disturbance regeneration. The species richness, abundance and basal area, as well as life-stage structure of the PFTs changed differently after pine wilt disease. The direction of plant community regeneration depended on the differential response of the PFTs. PFT1, which has a higher tolerance to disturbances, became dominant during the post-disturbance regeneration, and a young evergreen-broad-leaved forest developed quickly after PWD. Results also indicated that the impacts of PWD were dampened by the feedbacks between PFTs and the microclimate, in which PFT4 played an important ecological role. In conclusion, we propose management at the functional type level instead of at the population level as a promising approach in ecological restoration and biodiversity conservation

Low-temperature synthesis of two-dimensional nanostructured Co3O4 and improved electrochemical properties for lithium-ion batteries

Urea as a cheap reagent is very useful in preparation two-dimensional metal oxides with tunable crystal morphologies, while refluxing method is a simple route to control the decomposition of urea. Here, a low temperature refluxing in the presence of urea is developed to prepare porous Co3O4 as anode material for lithium-ion batteries. The self-assembly cobalt hydrotalcite-like compounds (Co-HLC) is firstly synthesized through refluxing the mixture of cobaltous nitrate and urea. After pyrolysis, the flower-like morphology of Co-HLC is successfully maintained in the final product of Co3O4. The ordered two-dimensional Co3O4 nanosheets provide good contact with electrolyte and stable porous structure during lithiation/delithiation. Co3O4-120 synthesized under refluxing temperature of 120 °C shows the initial charge capacities of 722 and 741 mAh g−1 at the 2nd and 100th cycle under 100 mA g−1. Moreover, Co3O4-120 as electrode for a supercapacitor presents excellent capacitance, 167 F g−1 after 3000 cycles at 1 A g−1. Under 5, 10 and 20 A g−1, Co3O4-120 electrode delivers 128, 104 and 90 F g−1, respectively. The porous structure in Co3O4 with enhanced electrochemical performance indicates low temperature refluxing preparation is an applicable and energy-saved method to synthesize transitional metal oxide with tunable crystal morphologies

Materials design towards sport textiles with low-friction and moisture-wicking dual functions

In the field of sportswear, the structure and morphology of textiles are of great importance to achieve good moisture transport and low friction, which are two critical comfort-related properties. To improve these properties, dual-layer nanofibrous nonwoven mats were studied in this work. Core–shell nanofibers with a polyacrylonitrile (PAN)-rich core and a poly(vinylidene fluoride) (PVDF)-rich shell were fabricated by single-spinneret electrospinning and used as the inner layer of the dual-layer mats, while thick base-treated Cellulose Acetate (CA) nanofibrous mats were used as the outer layer. The core-located PAN and a small amount of PAN on the PAN/PVDF nanofiber surface ensure good moisture transport through the nanofibrous mats. The synergistic combination of a considerably hydrophobic PAN/PVDF inner layer and a highly hydrophilic CA outer layer induces a strong push–pull effect, resulting in efficient moisture transport from the inner to the outer layer. Furthermore, the fluorine-rich PVDF shell of the inner layer touches the human skin and provides a lubricating effect to enhance comfortability. This design provides a promising route for sports textiles with both good moisture-wicking and low friction

Effects of earthquakes and antecedent droughts on landslide initiation in Italy

Earthquake and antecedent drought (drought for short) play important roles in triggering landslides, which change the formation condition of landslides by affecting topography, loose solid materials and water content. However, in most cases, landslide early warnings rely on rainfall thresholds or(/and) soil moisture conditions, without considering the effects of earthquake and drought. In this study, an analysis has been carried out on the latest version of Parametric Catalogue of Italian Earthquakes (Italian acronym CPTI15) and standardized precipitation index (SPI) (to represent droughts) and the landslide events in a northern Italian region in the past 116-years period 1901-2016. Based on the quantitative analysis on the relationship in time between landslides, earthquake activities and drought events, the interacting relationship between landslides, seismic activities and droughts were explored. It has been found that the impacts from earthquakes and droughts on landslides do exist. The impacts from earthquakes in the study area was less significant comparing with other regions (such as Wenchuan, China), and droughts play a complementarily minor role on landslides. Finally, a method is proposed for predicting the landslides based on early earthquake and drought monitoring and used on some cases. We expect this study can provide useful information for combining earthquake and drought in the landslide early warnings

Tailoring surface hydrophilicity of porous electrospun nanofibers to enhance capillary and push-pull effects for moisture wicking

In this article, liquid moisture transport behaviors of dual-layer electrospun nanofibrous mats are reported for the first time. The dual-layer mats consist of a thick layer of hydrophilic polyacrylonitrile (PAN) nanofibers with a thin layer of hydrophobic polystyrene (PS) nanofibers with and without interpenetrating nanopores, respectively. The mats are coated with polydopamine (PDOPA) to different extents to tailor the water wettability of the PS layer. It is found that with a large quantity of nanochannels, the porous PS nanofibers exhibit a stronger capillary effect than the solid PS nanofibers. The capillary motion in the porous PS nanofibers can be further enhanced by slight surface modification with PDOPA while retaining the large hydrophobicity difference between the two layers, inducing a strong push–pull effect to transport water from the PS to the PAN layer

Modelling the high-resolution dynamic exposure to flood in city-region

Urban flooding exposure is generally investigated with the assumption of stationary disasters and disaster-hit bodies during an event, and thus it cannot satisfy the increasingly elaborate modeling and management of urban floods. In this study, a comprehensive method was proposed to simulate dynamic exposure to urban flooding considering residents' travel behavior. First, a flood simulation was conducted using the LISFLOOD-FP model to predict the spatiotemporal distribution of flooding. Second, an agent-based model was used to simulate residents' movements during the urban flooding period. Finally, to study the evolution and patterns of urban flooding exposure, the exposure of population, roads, and buildings to urban flooding was simulated using Lishui, China, as a case study. The results showed that water depth was the major factor affecting total urban exposure in Lishui. Urban exposure to fluvial flooding was concentrated along the river, while exposure to pluvial flooding was dispersed throughout the area (independent from the river). Additionally, the population distribution on weekends was more variable than on weekdays and was more sensitive to floods. In addition, residents' response behavior (based on their subjective consciousness) may result in increased overall exposure. This study presents the first fully formulated method for dynamic urban flood exposure simulation at a high spatiotemporal resolution. The quantitative results of this study can provide fundamental information for urban flood disaster vulnerability assessment, socioeconomic loss assessment, urban disaster risk management, and emergency response plan establishment

Molecular traces of alternative social organization in a termite genome

Although eusociality evolved independently within several orders of insects, research into the molecular underpinnings of the transition towards social complexity has been confined primarily to Hymenoptera (for example, ants and bees). Here we sequence the genome and stage-specific transcriptomes of the dampwood termite Zootermopsis nevadensis (Blattodea) and compare them with similar data for eusocial Hymenoptera, to better identify commonalities and differences in achieving this significant transition. We show an expansion of genes related to male fertility, with upregulated gene expression in male reproductive individuals reflecting the profound differences in mating biology relative to the Hymenoptera. For several chemoreceptor families, we show divergent numbers of genes, which may correspond to the more claustral lifestyle of these termites. We also show similarities in the number and expression of genes related to caste determination mechanisms. Finally, patterns of DNAmethylation and alternative splicing support

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