Community responses of arbuscular mycorrhiza fungi to hydrological gradients in a riparian Phragmites australis wetland.

The hydrological regime is considered to be the major factor that affects the distribution of arbuscular mycorrhiza (AM) fungi in wetlands. We aimed to investigate the responses of AM fungal community to different hydrological gradients. Illumina Miseq sequencing technology was used to study the AM fungal community structure in roots and rhizosphere soils of Phragmites australis in different moisture areas (dry area, alternating wet and dry area, and flooded area) in Mengjin Yellow River wetland. The rhizosphere soils and roots hosted different AM fungal communities. In roots, the AM fungal colonization and Chao1 richness in dry area were significantly higher than that in alternating wet and dry area and flooded area, but the community composition did not vary clearly under different water conditions. In rhizosphere soils, the Chao1 richness of AM fungi in flooded area was significantly higher than that in alternating wet and dry area and dry area, and the AM fungal community structure obviously differed across different areas. The redundancy analyses indicated that changes in the AM fungal community in soils were associated with altered soil properties, and the abundance of the dominant genus Glomus was mostly positively correlated with alkali-hydrolyzable nitrogen in soils. This study helps us to understand the responses of AM fungal community to hydrological gradients in wetlands.

Influence of Density Gradient on the Compression of Functionally Graded BCC Lattice Structure.

In this paper, five grading functional gradient lattice structures with a different density perpendicular to the loading direction were proposed, and the surface morphology, deformation behavior, and compression properties of the functional gradient lattice structures prepared by selective laser melting (SLM) with Ti-6Al-4V as the building material were investigated. The results show that the characteristics of the laser energy distribution of the SLM molding process make the spherical metal powder adhere to the surface of the lattice structure struts, resulting in the actual relative density of the lattice structure being higher than the designed theoretical relative density, but the maximum error does not exceed 3.33%. With the same relative density, all lattice structures with density gradients perpendicular to the loading direction have better mechanical properties than the uniform lattice structure, in particular, the elastic modulus of LF, the yield strength of LINEAR, and the first maximum compression strength of INDEX are 28.99%, 16.77%, and 14.46% higher than that of the UNIFORM. In addition, the energy absorption per unit volume of the INDEX and LINEAR is 38.38% and 48.29% higher, respectively, than that of the UNIFORM. Fracture morphology analysis shows that the fracture morphology of these lattice structures shows dimples and smooth planes, indicating that the lattice structure exhibits a mixed brittle and ductile failure mechanism under compressive loading. Finite element analysis results show that when the loading direction is perpendicular to the density gradient-forming direction, the higher density part of the lattice structure is the main bearing part, and the greater the density difference between the two ends of the lattice structure, the greater the elastic modulus.

The relationship between adult attachment and mental health: A meta-analysis.

Attachment theory provides a framework for understanding the correlations among interpersonal relationships, stress, and health. Moreover, adult attachment is an important predictor of mental health. However, there is a lack of systematic reviews that simultaneously examine the associations between adult attachment and both positive and negative indicators of mental health. Consequently, we meta-analyzed 224 studies examining the associations between adult attachment and mental health, using robust variance estimation with random effects. The results (k = 245 samples, N = 79,722) showed that higher levels of attachment anxiety and avoidance were positively correlated with negative affect (e.g., depression, anxiety, loneliness) and they were negatively correlated with positive affect (e.g., life satisfaction, self-esteem). More specifically, there were moderate associations between attachment avoidance and negative mental health (r = .28) and positive mental health (r = -.24). Likewise, there were moderate associations between attachment anxiety and negative mental health (r = .42) and positive mental health (r = -.29). Furthermore, the association between the attachment dimensions and mental health outcomes was also moderated by several variables (e.g., gender, age). Finally, these associations remained statistically significant even when the attachment dimensions were mutually controlled using meta-analytic structural equation modeling. Overall, attachment anxiety had larger associations with mental health than did attachment avoidance. Thus, the current results support robust links between adult attachment and mental health. This may have implications for future research and mental health treatments. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Flexible Self-Repairing Materials for Wearable Sensing Applications: Elastomers and Hydrogels.

Flexible pressure and strain sensors have great potential for applications in wearable and implantable devices, soft robots, and artificial skin. The introduction of self-healing performance has made a positive contribution to the lifetime and stability of flexible sensors. At present, many self-healing flexible sensors with high sensitivity have been developed to detect the signal of organism activity. The sensitivity, reliability, and stability of self-healing flexible sensors depend on the conductive network and mechanical properties of flexible materials. This review focuses on the latest research progress of self-healing flexible sensors. First, various repair mechanisms of self-healing flexible materials are reviewed because these mechanisms contribute to the development of self-healing flexible materials. Then, self-healing elastomer flexible sensor and self-healing hydrogel flexible sensor are introduced and discussed respectively. The research status and problems to be solved of these two types of flexible sensors are discussed in detail. Finally, this rapidly developing and promising field of self-healing flexible sensors and devices is prospected.

Three-Dimensional Porous Carbon Nanotubes/Reduced Graphene Oxide Fiber from Rapid Phase Separation for a High-Rate All-Solid-State Supercapacitor.

Graphene fiber-based supercapacitors (SCs) are rising as having the greatest potential for portable/wearable energy storage devices. However, their rate performance is not well pleasing, which greatly impedes their broad practical applications. Herein, three-dimensional porous carbon nanotube/reduced graphene oxide fibers were prepared by a nonsolvent-induced rapid phase separation method followed by hydrazine vapor reduction. Benefitting from their three-dimensional porous structure, large specific surface area, and high conductivity, the fabricated SC exhibits a high volume capacitance of 54.9 F cm-3 and high energy and power densities (4.9 mW h cm-3 and 15.5 W cm-3, respectively). Remarkably, the SC works well at a high scan rate of 50 V s-1 and shows a fast frequency response with a short time constant of 78 ms. Furthermore, the fiber-shaped SC also exhibits very stable electrochemical performances when it is subjected to mechanical bending and succeeding straightening process, indicating its great potential application in flexible electronic devices.

Improved photoelectric performance of all-inorganic perovskite through different additives for green light-emitting diodes.

The exceptional optical and electronic properties of all-inorganic cesium lead bromide (CsPbBr3) perovskite make it an ideal new optoelectronic material, but low surface coverage limits its performance. The morphological characteristics of thin films have a great influence on the performance of perovskite light emitting diodes, especially at low coverage, and an inhomogeneous surface will lead to current leakage. To tackle this problem, the widespread adoption of composite layers including polymers poly(ethylene oxide) (PEO) and organic insulating poly(vinylpyrrolidone) (PVP) and all-inorganic perovskites is an effective way to increase the surface coverage and uniformity of perovskite films and improve the performance of perovskite light emitting devices. In our work, the perovskite thin films are investigated by using PEO and PVP dual additives, and the optimized CsPbBr3-PEO-PVP LED with maximum luminance, current efficiency, and external quantum efficiency of 2353 cd m-2 (at 7.2 V), 2.14 cd A-1 (at 6.5 V) and 0.85% (at 6.5 V) was obtained. This work indicates that the method of using additives is not only the key to enhancing the quality of perovskite thin film, but also the key to achieving a higher performance perovskite LED.

The contributions of underground-nesting ants to CO2 emission from tropical forest soils vary with species.

The aboveground ant nests are admitted as hot spots for CO2 emissions which increase heterogeneity of soil carbon (C) flux in forest ecosystems. However, little is known about effects of underground-nesting ant species on C emissions in tropical forests, where the ants have high diversity and abundance. In this study, we chose three underground-nesting ant species with different feeding-behaviors (Pheidole capellini - predominantly honeydew harvester, Odontoponera transversa - predominantly predator, and Pheidologeton affinis - scavenger) to explore their impacts on soil CO2 emission in Xishuangbanna tropical forest, China. We observed a pronounced effect of ants on CO2 emission, and the effect varied with ant species. The mean CO2 emissions were 2.4 times higher in P. capellini nests than in the reference soils, while those in nests of O. transversa and P. affinis were 2.0 and 1.6 folds, respectively. The contribution of total CO2 flux from nests of three ant species comprised 0.01-0.54% of total annual CO2 efflux from the forest floor. The CO2 emission in ant nests and reference soils increased exponentially with soil temperature and water. Soil water was considerably increased by ant nesting, which explained nearly 93-97% of CO2 emissions. However, soil temperature was not significantly different between nests and reference soils, and it only explained about 54-70% of CO2 emission. Ant species differed in increase of soil microbial biomass carbon, total organic carbon, readily oxidizable organic carbon, soil bulk density and pH, which also contributed to a diverse effect on soil CO2 emission. We suggest that the different effects of ant species on C emission may be closely associated with diversity of ant population size, feeding-behaviors and nesting modification on soil microbial biomass carbon, and physicochemical properties (i.e., temperature, moisture, pH, Bulk density, total and readily oxidizable organic carbon) in the tropical forest.