A typical superhydrophobic (ultrahydrophobic) surface can repel water droplets from wetting itself, and the contact angle of a water droplet resting on a superhydrophobic surface is greater than ...150°, which means extremely low wettability is achievable on superhydrophobic surfaces. Many superhydrophobic surfaces (both manmade and natural) normally exhibit micro- or nanosized roughness as well as hierarchical structure, which somehow can influence the surface's water repellence. As the research into superhydrophobic surfaces goes deeper and wider, it is becoming more important to both academic fields and industrial applications. In this work, the most recent progress in preparing manmade superhydrophobic surfaces through a variety of methodologies, particularly within the past several years, and the fundamental theories of wetting phenomena related to superhydrophobic surfaces are reviewed. We also discuss the perspective of natural superhydrophobic surfaces utilized as mimicking models. The discussion focuses on how the superhydrophobic property is promoted on solid surfaces and emphasizes the effect of surface roughness and structure in particular. This review aims to enable researchers to perceive the inner principles of wetting phenomena and employ suitable methods for creation and modification of superhydrophobic surfaces.
(a) A glycerol drop on Euphorbia myrsinites, which is a robust specimen and well suited to show the surface's repellence against the liquid droplet. (b) The upper side surface of the lotus leaf without the shrinkage artifact. (c) The wax tubules from the upper side of the lotus leaf.
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► We review the most recent progress in preparing superhydrophobic surfaces. ► The fundamental theories of wetting phenomena are investigated. ► The natural models inspiring to the creation of superhydrophobic surfaces are inspected. ► The main discussion focuses on the formation of surface roughness and structure. ► We present the creation of superhydrophobic surfaces through a variety of techniques.
Aberrant activation of c-kit proto-oncogene contributes to abnormal cell proliferation by altering the tyrosine kinase signaling and constitutes a crucial impetus for leukemogenesis. Epigenetic ...silencing of tumor-suppressive microRNAs (miRNAs) is a key oncogenic mechanism for the activation of oncogenes in tumors. In this study, several miRNAs potentially binding to the 3'-untranslated region of human c-kit mRNA were screened by luciferase reporter assays. Among these miRNAs, miR-193a was embedded in a CpG island and epigenetically repressed by promoter hypermethylation in acute myeloid leukemia (AML) cell lines and primary AML blasts, but not in normal bone marrow cells. Importantly, miR-193a levels were inversely correlated with c-kit levels measured in 9 leukemia cell lines and 27 primary AML samples. Restoring miR-193a expression in AML cells harboring c-kit mutation and/or overexpression, either by synthetic miR-193a transfection or by DNA hypomethylating agent 5-azacytidine (5-aza) treatment, resulted in a significant reduction in c-kit expression at both RNA and protein levels and inhibition of cell growth. The growth-inhibitory activity of miR-193a was associated with apoptosis and granulocytic differentiation. Moreover, 5-aza-induced c-kit reduction could be partially blocked by miR-193a inhibitor, leading to a reversal of antiproliferative and proapoptotic effects of 5-aza. These data reveal a critical role for methylation-repressed miR-193a in myeloid leukemogenesis and the therapeutic promise of upregulating miR-193a expression for c-kit-positive AML.
The geometric and electronic properties of silicene paired with a MoS2 substrate are studied systematically by using density functional theory with van der Waals corrections. It is found that the ...nearly linear band dispersions can be preserved in the heterobilayers due to the weak interface interactions. Meanwhile, the band gap is opened because of the sublattice symmetry broken by the intrinsic interface dipole. Moreover, the band gap values could be effectively modulated under an external electric field. Therefore, a way is paved for silicene-MoS2 heterobilayers to be candidate materials for logic circuits and photonic devices.
This study aims to understand the micro-mechanisms that drive fracture propagation in concrete and to assess the roles of the strength of aggregates and of the aggregate/mortar interfacial transition ...zone (ITZ) on concrete strength. We use the Discrete Element Method (DEM) to model concrete samples. Mortar is represented by a volume of bonded spherical elements. Bonds are governed by a new displacement-softening law. Aggregate centroids are randomly placed in the DEM sample. We use CT scan images of real aggregates to plot 3D aggregate contours. The spherical elements that are contained in 3D contours around the randomly placed centroids are replaced by clusters with aggregate properties. The number and the size of the clusters are determined from the experimental Particle Size Distribution. The DEM concrete model is calibrated against uniaxial compression tests and Brazilian tests of both mortar and concrete. It is found that: At same aggregate volume fraction, a concrete sample with randomly placed aggregates and ITZ bonds is stronger; Concrete strength is linearly related to aggregate tensile strength; A linear relationship exists between the contact ratio in the mortar/aggregate ITZ and concrete strength; The ITZ has more influence on concrete strength than aggregate tensile strength.
Merons which are topologically equivalent to one-half of skyrmions can exist only in pairs or groups in two-dimensional (2D) ferromagnetic (FM) systems. The recent discovery of meron lattice in ...chiral magnet Co
Zn
Mn
raises the immediate challenging question that whether a single meron pair, which is the most fundamental topological structure in any 2D meron systems, can be created and stabilized in a continuous FM film? Utilizing winding number conservation, we develop a new method to create and stabilize a single pair of merons in a continuous Py film by local vortex imprinting from a Co disk. By observing the created meron pair directly within a magnetic field, we determine its topological structure unambiguously and explore the topological effect in its creation and annihilation processes. Our work opens a pathway towards developing and controlling topological structures in general magnetic systems without the restriction of perpendicular anisotropy and Dzyaloshinskii-Moriya interaction.
The aim of the study was to summarize the clinical features, diagnosis and treatment of leucine-rich glioma inactivation protein 1 (LGI-1) antibody-associated encephalitis coexistence of minimal ...change nephrotic syndrome (MCNS), moreover, to strengthen the awareness of the disease. Increasing number of studies describe coexistence of autoimmune encephalitis and other systemic autoimmune diseases.
Here we report a case of a patient with anti- LGI1 antibody-associated encephalitis, who presented with cognitive dysfunction, faciobrachial dystonic seizures (FBDS), sleep disturbance, and hyponatremia. Treatment with immunoglobulins, corticosteroids, levetiracetam and oxcarbazepine was proven effective for this patient. The patient had a history of MCNS diagnosed by renal biopsy and responded to treatment with low dose of oral corticosteroids.
This case expanded the spectrum of autoimmune comorbidities in patients with anti-LGI1 encephalitis.
The mobility of dislocation loops in materials is a principle factor in understanding the mechanical strength, and the evolution of microstructures due to deformation and radiation. In body-centered ...cubic (BCC) iron, the common belief is that interstitial dislocation loops are immobile once formed. However, using self-adaptive accelerated molecular dynamics (SSAMD), a new diffusion mechanism has been discovered for interstitial dislocation loops. The key aspect of the mechanism is the changing of the habit planes between the {100} plane and the {110} plane, which provides a path for the loops to diffuse one-dimensionally. The migration behavior modeled with SSAMD is further confirmed by in-situ transmission electron microscopy (TEM) measurements, and represents a significant step for understanding the formation of loop walls and the mechanical behavior of BCC Fe under irradiation.
The equiatomic CrMnFeCoNi high-entropy alloy (HEA) exhibits outstanding toughness and excellent strength-ductility combination at cryogenic temperatures. However, its strength is relatively low at ...room temperature. In order to strengthen this HEA, microalloying additions of 0.8 at.% Nb and C were made and its properties and microstructure evaluated. It was found that the microalloying resulted in the formation of carbide precipitates and a reduction of the grain size to ∼2.6 μm. As a result, the room-temperature tensile yield strength (732 MPa) of the microalloyed HEA is roughly double that of the base HEA (with a concomitant increase in the ultimate strength) while its ductility is maintained at a relatively high level (elongation to fracture of ∼32%). The strengthening is due to precipitation hardening from the nanoscale carbide particles and grain refinement.
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•Nanoscale NbC particles in CrMnFeCoNi were obtained by microalloying with Nb and C.•Yield stress of NbC-added CrMnFeCoNi HEA is roughly double that of the base HEA.•The ductility of NbC-added CrMnFeCoNi HEA is maintained at a high level (∼32%).•Strengthening is due to precipitation hardening and grain refinement.
A net (
x
α
) in a vector lattice
X
is said to uo-converge to
x
if
|
x
α
−
x
|
∧
u
→
o
0
for every
u
≥ 0. In the first part of this paper, we study some functional-analytic aspects of uo-convergence. ...We prove that uoconvergence is stable under passing to and from regular sublattices. This fact leads to numerous applications presented throughout the paper. In particular, it allows us to improve several results in 27, 26. In the second part, we use uo-convergence to study convergence of Cesàro means in Banach lattices. In particular, we establish an intrinsic version of Komlós’ Theorem, which extends the main results of 35, 16, 31 in a uniform way. We also develop a new and unified approach to Banach–Saks properties and Banach–Saks operators based on uo-convergence. This approach yields, in particular, short direct proofs of several results in 20, 24, 25.
The influence of the nanosized rare earth (RE) containing precipitates on grain refinement during severe plastic deformation is investigated in detail through a study of high pressure torsion (HPT) ...processing of a solution treated and aged Mg-8.2Gd-3.8Y-1.0Zn-0.4Zr (wt%). In the early stages of HPT deformation, dislocation generation and pile-up is promoted by the nanosized RE containing β′ precipitates. With increasing strain, the precipitates are cut by the moving dislocations and gradually dissolve into the α-Mg matrix aided by dislocations serving as diffusion channels for solute atoms. After HPT for 2 turns, the hardness reaches a maximum and on further deformation the hardness decreases although the microstructure refinement continues and the dislocation density is increasing. This is due to the continuing dissolution of precipitates, which dominates the hardness evolution at this stage. After HPT for 16 turns, the precipitates have almost completely dissolved and the average grain size is ~33 nm, which is the smallest ever reported for a Mg- or Al-based alloy. The present peak-aged Mg-8.2Gd-3.8Y-1.0Zn-0.4Zr (wt%) alloy exhibits quite different microstructure evolution and hardening behaviour during HPT processing as compared to both the cast and the solutionized Mg-Gd-Y-Zn-Zr alloy.
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