Microporous metallic scaffolds supported liquid infused icephobic construction.

Ice accretion on component surfaces often causes severe impacts or accidents. Liquid-infused surfaces (LIS) have drawn much attention as icephobic materials for ice mitigation in recent years due to their outstanding icephobicity. However, the durability of LIS constructions remains a big challenge, including mechanical vulnerability and rapid depletion of lubricants. The practical applications of LIS materials are significantly restrained, and the full potential of LIS for ice prevention has yet to be demonstrated. A universal approach was proposed to introduce microporous metallic scaffolds in the LIS construction to increase the applicability and durability, and to prompt the potential of LIS for ice mitigation. Microporous Ni scaffolds were chosen to integrate with polydimethylsiloxane modified by silicone oil addition. The new LIS construction demonstrated significantly improved durability in icing/de-icing cyclic test, and it also offered a solution for the rapid oil depletion by restraining the deformation of the matrix material. Low ice adhesion strength could be maintained via a micro-crack initiation mechanism. The results indicated that the multi-phase LIS construction consisting of microporous Ni scaffolds effectively addressed the shackles of the icephobicity deterioration of LIS materials, confirming a new design strategy for the R&D of icephobic surfaces

Metallic skeleton promoted two-phase durable icephobic layers

HypothesisThe accretion of ice on component surfaces often causes severe impacts or accidents in modern industries. Applying icephobic surface is considered as an effective solution to minimise the hazards. However, the durability of the current icephobic surface and coatings for long-term service remains a great challenge. Therefore, it is indeed to develop new durable material structures with great icephobic performance.ExperimentsA new design concept of combining robust porous metallic skeletons and icephobic filling was proposed. Nickel/polydimethylsiloxane (PDMS) two-phase layer was prepared using porous Ni foam skeletons impregnated with PDMS as filling material by a two-step method.FindingsGood icephobicity and mechanical durability have been verified. Under external force, micro-cracks could easily initiate at the ice/solid interface due to the small surface cavities and the difference of local elastic modulus between the ice and PDMS, which would promote the ice fracture and thus lead to low ice adhesion strength. The surface morphology and icephobicity almost remain unchanged after water-sand erosion, showing greatly improved mechanical durability. By combining the advantages of the mechanical durability of porous Ni skeleton and the icephobicity of PDMS matrix, the Ni foam/PDMS two-phase layer demonstrates great potentials for ice protection with long-term service time

Cloning and function analysis of a Saussurea involucrata LEA4 gene

Late embryogenesis abundant proteins (LEA) help adapt to adverse low-temperature environments. The Saussurea involucrate SiLEA4, which encodes a membrane protein, was significantly up-regulated in response to low temperature stress. Escherichia coli expressing SiLEA4 showed enhanced low-temperature tolerance, as evident from the significantly higher survival numbers and growth rates at low temperatures. Moreover, tomato strains expressing SiLEA4 had significantly greater freezing resistance, due to a significant increase in the antioxidase activities and proline content. Furthermore, they had higher yields due to higher water utilization and photosynthetic efficiency under the same water and fertilizer conditions. Thus, expressing SiLEA4 has multiple advantages: (1) mitigating chilling injury, (2) increasing yields, and (3) water-saving, which also indicates the great potential of the SiLEA4 for breeding applications

Realizing Saturable Absorption and Reverse Saturable Absorption in a PEDOT:PSS Film via Electrical Modulation

Electrical tuning of the nonlinear absorption of materials has promising application potential, while studies remain rare. In this work, we show that the third-order nonlinear absorption of poly(3,4-ethylenedioxythiophene) chemically doped with poly(styrene sulfonic acid) [PEDOT:PSS] can be effectively modulated by external voltage. The nonlinear absorption of the film can be varied between reverse saturable absorption (RSA) and saturable absorption (SA) via voltage control with laser excitation at 800 nm, and the corresponding nonlinear absorption coefficient can be tuned in the range -1606 +- 73 to 521 +- 9 cm GW-1. The doping level and energy structure of PEDOT are modulated with different voltages. The undoped film affords two-photon absorption and accordingly the RSA response. A moderately doped sample has two polaron levels, and Pauli blocking associated with these two polaron levels results in SA. The bipolaron level in heavily doped PEDOT leads to excited-state absorption and therefore RSA behavior. The approach reported here can be applied to other semiconductors and is a convenient, effective, and promising method for the electrical tuning of the optical nonlinearity.DP17010041

Electrical Tuning of the Fifth‐Order Optical Nonlinearity of Antimony‐Doped Tin Oxide

In this work, the electrical tuning of the fifth-order nonlinear absorption of antimony-doped tin oxide (ATO) by ionic liquid gating is demonstrated. The pristine ATO film exhibits two-photon-induced excited-state absorption (2PA-ESA) with laser excitation at 1030 nm. The fifth-order nonlinear absorption coefficient (γeff) of the ATO film can be monotonically modified in the range of 0.51 to 3.46 cm3 GW−2 by varying the sample bias, with a maximum enhancement factor of 6.8. The fundamental processes occurring during electrical tuning are revealed. The electrostatic and electrochemical capacitance is responsible for the modification in the number of free carriers in the conduction band of ATO. The electrical modulation of the nonlinear absorption of the ATO is ascribed to the voltage-dependent diameter of the undepleted core of ATO. A smaller voltage results in the charging of ATO and a larger undepleted core, and consequently the size of the active component for 2PA-ESA is larger. The electrochemical capacitance results from the chemisorption of H+ and OH− on the surface of the ATO, the larger water content in the ionic liquid affording a larger modulation range for the number of free carriers and the γeff.DP17010041

Study on the influencing factors of spontaneous wettability transition behaviour on metallic-based surfaces

Hydrophobic surfaces and coatings have attracted more and more interest in recent years due to their broad applications in diverse areas. In many cases, a metallic surface would demonstrate a reversible wettability from hydrophilic state to hydrophobic state spontaneously. However, the wetting behavior and hydrophobic mechanism of metallic surfaces are far from clear. In this work, 304 stainless steel (SS) surface and Ni–Cu–P coatings have been chosen to investigate the intrinsic mechanism of the surface wettability transition with the help of X-ray photoelectron spectroscopy (XPS) and ambient air/vacuum storage treatment. The surface topographies, wetting behaviors and surface chemistry were studied systemically. The results showed that water contact angle (WCA) variation of the as-prepared surfaces changing from hydrophilic state to hydrophobic state is largely associated with the specific surface area. The recovery of water repellency is related to a time constant which mainly depends on micro-scale surface convolution or surface roughness. Rougher surface tends to accelerate the surface adsorption of airborne hydrocarbon species in the ambient atmosphere, leading to a more intensive WCA increase. The study provides a generic theoretical justification for relevant time-dependent wettability studies

Mom’s Good Mood: screening and management of perinatal depression within primary healthcare system in China–protocol for an effectiveness–implementation design study

Introduction The management of perinatal depression (PND) is challenging in China. The Thinking Healthy Programme (THP), developed under the core theory of cognitive–behavioural therapy, is an evidence-based approach that is recommended as a psychosocial intervention for managing PND in low/middle-income countries. Sparse evidence has been generated, however, to assess the effectiveness of THP and guide its implementation in China.Methods and analysis A hybrid type II effectiveness–implementation study is ongoing in four cities in Anhui Province, China. A comprehensive online platform, Mom’s Good Mood (MGM), has been developed. Perinatal women are screened using the WeChat screening tool (ie, Edinburgh Postnatal Depression Scale embedded as metrics) in clinics. Different intensities of the intervention are delivered through the mobile application for different degrees of depression, according to the stratified care model. The THP WHO treatment manual has been tailored to be the core component of intervention. Guided by the Reach, Effectiveness, Adoption, Implementation and Maintenance framework, process evaluations will be conducted to identify the facilitators and barriers to implementation and to modify the implementation strategy; summative evaluations will be carried out to examine the effectiveness of MGM in the management of PND within the primary healthcare system in China.Ethics and dissemination Ethics approval and consent for this programme were obtained from Institutional Review Boards in China: Anhui Medical University, Hefei, People’s Republic of China (20170358). Results will be submitted to relevant conferences and peer-reviewed journals.Trial registration number ChiCTR1800016844

Joint effects of recent stressful life events and adverse childhood experiences on perinatal comorbid anxiety and depression

Abstract Background Stressful life events (SLEs) and adverse childhood experiences (ACEs) have been reported to be associated with perinatal depression (PND) or perinatal anxiety (PNA) alone; however, in most cases, majority of PND and PNA coexist and could lead to more serious health consequences. The independent effect of recent SLEs and their joint effects with ACEs on perinatal comorbid anxiety and depression (CAD) remain inadequately explored. Methods Based on a longitudinal study, 1082 participants receiving prenatal care in Ma’anshan, China were included. Women were recruited in the first trimester (T1: ≤14+ 6 weeks) and followed up at 15 ~ 27 weeks (T2), 28 ~ 40 weeks (T3), and postpartum (T4). Depression and anxiety status were assessed at all time points, while recent SLEs and ACEs were measured at T1. Logistic regression was conducted to examine the associations of SLEs with the risks of CAD at different time points, as well as their joint effects with ACEs on CAD. Results Approximately 38.5% of women experienced at least one SLE, which was significantly associated with higher risks of CAD at all time points (p < 0.05). As the number of SLEs increased, the risk of CAD increased (p for trend < 0.05). Specific types of SLEs were associated with CAD in different periods, while only interpersonal events were consistently associated with risks of CAD throughout the whole perinatal period. The joint effects of SLEs with ACEs on CAD were identified throughout the perinatal period, with the highest observed in the first trimester (aOR = 7.47, 95% CI: 3.73–14.95; p for trend < 0.001). Conclusion Our study demonstrated independent associations of recent SLEs and their joint effects with ACEs with risks of perinatal CAD. SLEs combined with ACEs should be recognized as a major risk factor for perinatal CAD and managed at the earliest time to prevent and control CAD

Switching the Nonparametric Optical Nonlinearity of Tungsten Oxide by Electrical Modulation

This work shows the electrical switching of the nonparametric optical nonlinearity of tungsten oxide (WO ). The sign and magnitude of the effective nonlinear absorption coefficient (β ) can be modulated via application of an external bias. With laser excitation at 1030 nm, WO shows a relatively large saturable absorption (SA) under an applied voltage (V ) of −2.5 V, with β being as large as −632 cm GW , while reverse saturable absorption (RSA) is found for V larger than −1.5 V. The electrical switching of the nonlinear optical (NLO) response is reproducible and durable. Both electrostatic and electrochemical dopings of WO occur during V variation, with SA resulting mainly from the electrochemical doping (the intercalation of H into the lattice of WO ). The wavelength-dependent NLO performance of pristine WO is attributed to competition between one-photon absorption and two-photon absorption, while the V -derived NLO response is correlated with variation in the band structure and its population. These results suggest a promising approach for the postsynthesis modulation of the NLO response and a potential device configuration for further optoelectric applications.H.L. and R.H. contributed equally to this work. This research was financially supported by the National Natural Science Foundation of China (Grant Nos. 51772214, 51432006, and 51701170), the Ministry of Science and Technology of China (Grant No. 2011DFG52970), the Ministry of Education of China (Grant No. IRT14R23), 111 Project (B13025), the Innovation Program of Shanghai Municipal Education Commission, the National Youth Talent Support Program (W03070073), and the Project of Science and Technology Plan of Fujian Province (Grant No. 2018J01520). M.G.H. and C.Z. thank the Australian Research Council for support (DP170100411