More studies are needed on the mechanism and effective prediction of bird diversity in various habitats. The primary purpose of this study was to explore the difference in the species richness and ...evenness of various habitats. The secondary purpose was to explore which habitat types and compositions predict a high bird diversity. The 2010-2016 Taiwan Breeding Bird Survey was used to analyze the relationship between landscape habitat and bird ecology. Landscape habitat type was divided into seven categories and 26 sub-types: forestland, farmland, grassland, freshwater wetland, aquaculture pond and saltpan, coastland, and building area. Four ecological indexes were used: the number of bird individuals, the number of species, the Margalef Richness Index, and the Pielou Evenness Index. The result indicated that forestland decreased bird numbers, except in a windbreak forest. Natural and farmland-related habitats increased bird species richness. Similarly, the natural habitat increased species evenness. Urban greenspace could not replace the effect of forestland on species richness and evenness. Conifer forest, bamboo forest, windbreak forest, mixed tree, tall grassland, and orchard were important habitats for promoting higher species richness and evenness.
Porous carbon materials demonstrate extensive applications for their attractive characteristics. Mechanical flexibility is an essential property guaranteeing their durability. After decades of ...research efforts, compressive brittleness of porous carbon materials is well resolved. However, reversible stretchability remains challenging to achieve due to the intrinsically weak connections and fragile joints of the porous carbon networks. Herein, it is presented that a porous all‐carbon material achieving both elastic compressibility and stretchability at large strain from −80% to 80% can be obtained when a unique long‐range lamellar multi‐arch microstructure is introduced. Impressively, the porous all‐carbon material can maintain reliable structural robustness and durability under loading condition of cyclic compressing–stretching process, similar to a real metallic spring. The unique performance renders it as a promising platform for making smart vibration and magnetism sensors, even capable of operating at extreme temperatures. Furthermore, this study provides valuable insights for creating highly stretchable and compressible porous materials from other neat inorganic components for diverse applications in future.
A porous spring‐like all‐carbon material achieving both elastic compressibility and stretchability at large strain from −80% to 80% is obtained when a unique long‐range lamellar multi‐arch microstructure is designed. The excellent mechanical performance combined with the intrinsic advantages of carbon makes it a promising platform for making smart vibration and magnetism sensors that can work at extreme temperatures.
The evolutionary outcomes of high elevation adaptation have been extensively described. However, whether widely distributed high elevation endemic animals adopt uniform mechanisms during adaptation ...to different elevational environments remains unknown, especially with respect to extreme high elevation environments. To explore this, we analysed the phenotypic and genomic data of seven populations of plateau zokor (Myospalax baileyi) along elevations ranging from 2,700 to 4,300 m. Based on whole‐genome sequencing data and demographic reconstruction of the evolutionary history, we show that two populations of plateau zokor living at elevations exceeding 3,700 m diverged from other populations nearly 10,000 years ago. Further, phenotypic comparisons reveal stress‐dependent adaptation, as two populations living at elevations exceeding 3,700 m have elevated ratios of heart mass to body mass relative to other populations, and the highest population (4,300 m) displays alterations in erythrocytes. Correspondingly, genomic analysis of selective sweeps indicates that positive selection might contribute to the observed phenotypic alterations in these two extremely high elevation populations, with the adaptive cardiovascular phenotypes of both populations possibly evolving under the functional constrains of their common ancestral population. Taken together, phenotypic and genomic evidence demonstrates that heterogeneous stressors impact adaptations to extreme elevations and reveals stress‐dependent and genetically constrained adaptation to hypoxia, collectively providing new insights into the high elevation adaptation.
Biological materials relied on multiple synergistic structural design elements typically exhibit excellent comprehensive mechanical properties. Hierarchical incorporation of different biostructural ...elements into a single artificial material is a promising approach to enhance mechanical properties, but remains challenging. Herein, a biomimetic structural design strategy is proposed by coupling gradient structure with twisted plywood Bouligand structure, attempting to improve the impact resistance of ceramic‐polymer composites. Via robocasting and sintering, kaolin ceramic filaments reinforced by coaxially aligned alumina nanoplatelets are arranged into Bouligand structure with a gradual transition in filament spacing along the thickness direction. After the following polymer infiltration, biomimetic ceramic‐polymer composites with a gradient Bouligand (GB) structure are eventually fabricated. Experimental investigations reveal that the incorporation of gradient structure into Bouligand structure improves both the peak force and total energy absorption of the obtained ceramic‐polymer composites. Computational modeling further suggests the substantial improvement in impact resistance by adopting GB structure, and clarifies the underlying deformation behavior of the biomimetic GB structured composites under impact. This biomimetic design strategy may provide valuable insights for developing lightweight and impact‐resistant structural materials in the future.
Translating different biostructural elements into a single synthetic material represents a promising pathway to achieve improved mechanical properties. Here, one new‐style biomimetic structure is designed by coupling gradient structure with Bouligand structure, resulting in a ceramic‐polymer composite with synergistically enhanced impact resistance. This work highlights the importance of hierarchical structural design for future impact‐resistant structural materials.
Lightweight structural materials with a unique combination of high stiffness, strength, toughness, and hardness, are highly desired yet challenging to be artificially fabricated. Biological ...structural materials, on the other hand, ingeniously integrate multiple mutually exclusive mechanical properties together relying on their hierarchically heterogeneous structures bonded with gradient interfaces. Here, a scalable bottom‐up approach combining continuous nanofiber‐assisted evaporation‐induced self‐assembly with laminating, pressure‐less sintering and resin infiltration is reported to fabricate bioinspired heterogeneous ceramic–resin composites with locally tunable microstructure to fulfill specific properties. A gradient interlayer is introduced to provide a gradual transition between adjacent heterogeneous layers, effectively alleviating their property mismatch. The optimized heterogeneous nacre‐like composite, as a demonstration, exhibits an attractive combination of low density (≈2.8 g cm−3), high strength (≈292 MPa), toughness (≈6.4 MPa m1/2), surface hardness (≈1144 kgf mm−2) and impact‐resistance, surpassing the overall performance of engineering alumina. This material‐independent approach paves the way for designing advanced bioinspired heterogeneous materials for diverse structural and functional applications.
By developing a simple bottom‐up assembly approach, nacre‐like ceramic–resin composites with tunable heterogeneous architectures are scalably manufactured. The composites are designed with a strong and tough nacre‐like main body, and a stiff and hard surface layer bonded by a gradient interlayer to alleviate property mismatch. This structural design achieves an impressive combination of low density and multiple desired mechanical properties.
An ideal bone repair scaffold is expected to possess superior architectural characteristics to facilitate the adhesion, proliferation, and migration of bone‐repair‐related cells, while excluding ...nonosteogenic cells and fibrous tissues from interfering with normal bone regeneration. Unfortunately, such scaffold material has rarely been reported. Herein, nanocomposite scaffolds with a radially ordered porous structure are presented, manufactured using a modified directional freeze‐casting method, and are promising bone defect repair materials to satisfy this requirement. The prepared nanocomposite scaffolds consist of a natural bio‐macromolecule, chitosan, and bioactive hydroxyapatite nanoparticles derived from porcine cortical bone, demonstrating favorable biocompatibility and biological functions. Both in vitro cell studies and in vivo animal studies reveal the great superiority of the radially oriented porous structure of the scaffolds in guiding bone regeneration, while simultaneously preventing the invasion of surrounding nonosteogenic cells and fibrous tissue, compared to the axially oriented porous structure. This work indicates the distinctive potential of radially oriented porous scaffolds for repairing tabular and lacunar bone defects.
A nanocomposite scaffold with a radially oriented porous structure is engineered via a modified freeze‐casting method. The unique structural feature renders the nanocomposite scaffold with great superiority in guiding the infiltration and migration of bone‐repair‐related cells into the scaffold, while preventing the invasion of surrounding nonosteogenic cells and fibrous tissues from interfering with the normal bone regeneration process.
Plants are known for their capacity to regenerate the whole body through de novo formation of apical meristems from a mass of proliferating cells named callus. Exogenous cytokinin and auxin determine ...cell fate for the establishment of the stem cell niche, which is the vital step of shoot regeneration, but the underlying mechanisms remain unclear. Here, we show that type-B ARABIDOPSIS RESPONSE REGULATORs (ARRs), critical components of cytokinin signaling, activate the transcription of WUSCHEL (WUS), which encodes a key regulator for maintaining stem cells. In parallel, type-B ARRs inhibit auxin accumulation by repressing the expression of YUCCAs, which encode a key enzyme for auxin biosynthesis, indirectly promoting WUS induction. Both pathways are essential for de novo regeneration of the shoot stem cell niche. In addition, the dual regulation of type-B ARRs on WUS transcription is required for the maintenance of the shoot apical meristem in planta. Thus, our results reveal a long-standing missing link between cytokinin signaling and WUS regulator, and the findings provide critical information for understanding cell fate specification.
Effective and safe hemodialysis is essential for patients with acute kidney injury and chronic renal failures. However, the development of effective anticoagulant agents with safe antidotes for use ...during hemodialysis has proven challenging. Here, we describe DNA origami-based assemblies that enable the inhibition of thrombin activity and thrombus formation. Two different thrombin-binding aptamers decorated DNA origami initiates protein recognition and inhibition, exhibiting enhanced anticoagulation in human plasma, fresh whole blood and a murine model. In a dialyzer-containing extracorporeal circuit that mimicked clinical hemodialysis, the origami-based aptamer nanoarray effectively prevented thrombosis formation. Oligonucleotides containing sequences complementary to the thrombin-binding aptamers can efficiently neutralize the anticoagulant effects. The nanoarray is safe and immunologically inert in healthy mice, eliciting no detectable changes in liver and kidney functions or serum cytokine concentration. This DNA origami-based nanoagent represents a promising anticoagulant platform for the hemodialysis treatment of renal diseases.
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