Currently, advanced communications and networks greatly enhance user experiences and have a major impact on all aspects of people's lifestyles in terms of work, society, and the economy. However ...improving competitiveness and sustainable vehicle network services, such as higher user experience, considerable resource utilization and effective personalized services, is a great challenge. Addressing these issues, this paper proposes a virtual network resource management based on user behavior to further optimize the existing vehicle communications. In particular, ensemble learning is implemented in the proposed scheme to predict the user's voice call duration and traffic usage for supporting user-centric mobile services optimization. Sufficient experiments show that the proposed scheme can significantly improve the quality of services and experiences and that it provides a novel idea for optimizing vehicle networks.
A freely tunable polarization rotator for broadband terahertz waves is demonstrated using a three‐rotating‐layer metallic grating structure, which can conveniently rotate the polarization of a ...linearly polarized terahertz wave to any desired direction with nearly perfect conversion efficiency. This low‐cost, high‐efficiency, and freely tunable device has potential applications as material analysis, wireless communication, and THz imaging.
By combining the advantages of both a metallic metamaterial and a dielectric interlayer, we demonstrate the general mechanism to construct the dispersion-free metastructure, in which the intrinsic ...dispersion of the metallic structures is perfectly cancelled out by the thickness-dependent dispersion of the dielectric spacing layer. As examples to apply this concept, a broadband quarter-wave plate and a half-wave plate are demonstrated. By selecting the structural parameters, the polarization state of light can be freely tuned across a broad frequency range, and all of the polarization states on the Poincaré sphere can be realized dispersion free.
The development of interfacial polymerization (IP) technique has revolutionarily changed our methods for water treatment and desalination. Over decades, researchers have devoted their efforts to ...further improve this marvelous technology through versatile approaches such as optimizing chemical compositions, improving membrane structures and reducing the thickness of selective layers. Recently, constructing interlayers on a support membrane is proven to be a powerful tool to mediate the IP kinetics, which facilitates the formation of thinner polyamide (PA) layers with desired nanostructures. Decreased permeation resistance based on thinner PA layer and enhanced permeable area derived from nanostructures synergistically bring the membrane permeability to an unprecedented height. In this review, we will comprehensively analyze these up-to-date works to discuss the functions of different interlayers from material composition, fabrication methods and designed applications. An empirical relationship between interlayer building materials (chemical composition and dimensionality on a nanoscale) and initial membrane performances (permeability and selectivity) will be established to give inspirations to future works.
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•Recent advances in interlayer enhanced TFC membranes have been summarized.•The relationship between the initial membranes permeability and selectivity and the interlayer materials has been established.•The influence of the nanoscale dimensionality of interlayer materials on the interfacial polymerization reaction has been discussed.•An outlook and challenge for fabricating interlayer enhanced reverse osmosis membranes and hollow fiber membranes have been proposed.
Neural stem cells (NSCs), capable of ischemia‐homing, regeneration, and differentiation, exert strong therapeutic potentials in treating ischemic stroke, but the curative effect is limited in the ...harsh microenvironment of ischemic regions rich in reactive oxygen species (ROS). Gene transfection to make NSCs overexpress brain‐derived neurotrophic factor (BDNF) can enhance their therapeutic efficacy; however, viral vectors must be used because current nonviral vectors are unable to efficiently transfect NSCs. The first polymeric vector, ROS‐responsive charge‐reversal poly(2‐acryloyl)ethyl(p‐boronic acid benzyl)diethylammonium bromide (B‐PDEA), is shown here, that mediates efficient gene transfection of NSCs and greatly enhances their therapeutics in ischemic stroke treatment. The cationic B‐PDEA/DNA polyplexes can effectively transfect NSCs; in the cytosol, the B‐PDEA is oxidized by intracellular ROS into negatively charged polyacrylic acid, quickly releasing the BDNF plasmids for efficient transcription and secreting a high level of BDNF. After i.v. injection in ischemic stroke mice, the transfected NSCs (BDNF‐NSCs) can home to ischemic regions as efficiently as the pristine NSCs but more efficiently produce BDNF, leading to significantly augmented BDNF levels, which in turn enhances the mouse survival rate to 60%, from 0% (nontreated mice) or ≈20% (NSC‐treated mice), and enables more rapid and superior functional reconstruction.
The first nonviral gene carrier, reactive‐oxygen‐species‐responsive charge‐reversal poly(2‐acryloyl)‐ethyl(p‐boronic acid benzyl)diethylammonium bromide (B‐PDEA), is shown to mediate efficient gene transfection to neural stem cells (NSCs). When BDNF gene plasmids are used, the transfected NSCs homing to the ischemic regions increase animal survival and reconstruct functions.
Structured Metal Film as a Perfect Absorber Xiong, Xiang; Jiang, Shang-Chi; Hu, Yu-Hui ...
Advanced materials (Weinheim),
August 7, 2013, Letnik:
25, Številka:
29
Journal Article
Recenzirano
A new type of absorber, a four‐tined fish‐spear‐like resonator (FFR), constructed by the two‐photon polymerization process, is reported. An absorbance of more than 90% is experimentally realized and ...the resonance occurs in the space between the tines. Since a continuous layer of metallic thin film covers the structure, it is perfectly thermo‐ and electroconductive, which is the mostly desired feature for many applications.
Breast cancer is the most common cancer among women worldwide and metastasis is the leading cause of death among patients with breast cancer. The transforming growth factor-β (TGF-β) pathway plays ...critical roles during breast cancer epithelial-mesenchymal transition (EMT) and metastasis. SMAD2, a positive regulator of TGF-β signaling, promotes breast cancer metastasis through induction of EMT.
The expression of miR-190 and SMAD2 in breast cancer tissues, adjacent normal breast tissues and cell lines were determined by RT-qPCR. The protein expression levels and localization were analyzed by western blotting and immunofluorescence. ChIP and dual-luciferase report assays were used to validate the regulation of ZEB1-miR-190-SMAD2 axis. The effect of miR-190 on breast cancer progression was investigated both in vitro and in vivo.
miR-190 down-regulation is required for TGF-β-induced EMT. miR-190 suppresses breast cancer metastasis both in vitro and in vivo by targeting SMAD2. miR-190 expression is down-regulated and inversely correlates with SMAD2 in breast cancer samples, and its expression level was associated with outcome in patients with breast cancer. Furthermore, miR-190 is transcriptionally regulated by ZEB1.
Our data uncover the ZEB1-miR-190-SMAD2 axis and provide a mechanism to explain the TGF-β network in breast cancer metastasis.
Ultrathin polyamide nanofilms are desirable as the separation layers for the highly permeable thin-film composite (TFC) membranes, and recently, their lowest thickness limits have attracted a lot of ...attention from researchers. Due to the interference of the underlying substrate, preparing a defect-free, ultrathin polyamide nanofilm directly on top of a membrane substrate remains a great challenge. Herein, we report a novel fabrication technique of TFC membranes, named
(IFIP), where the IP reaction occurs at the uniform, free oil-water interface dozens of microns above the substrate, and then the resulting nanofilm spontaneously assembles into the TFC structure without extra manual transfer. This IFIP method not only overcomes the limitations of conventional IP, succeeding in preparing ultrathin-nanofilm composite membranes for nanofiltration and reverse osmosis application, but also enables scale membrane manufacturing that is not feasible via previously reported free-standing IP. Based on the IFIP method, the thickness of the polyamide nanofilm was successfully reduced to ca. 3-4 nm, which we believe is close to the ultrathin limit of the polyamide nanofilm for separation application. Meanwhile, the structure-performance relationship revealed that the strategy of increasing TFC membrane permeance by reducing polyamide layer thickness also had a limit. Besides, the IP mechanisms in regard to the formation of surface morphology and film growth were explored by combining experimental and molecular simulation methods. Overall, this work is expected to push forward the fundamental study and practical application of the ultrathin-film composite membrane.
In recent years, international research on the toxicity of the heavy metal, antimony, has gradually changed focus from early medical and pharmacological toxicology to environmental toxicology and ...ecotoxicology. However, little research has been conducted for sources identification and risk management of heavy metals pollution by long-term antimony mining activities. In this study, a large number of investigations were conducted on the temporal and spatial distribution of antimony and related heavy metal contaminants (lead, zinc, and arsenic), as well as on the exposure risks for the population for the Yuxi river basin in the Hunan province, China. The scope of the investigations included mine water, waste rock, tailings, agricultural soil, surface water, river sediments, and groundwater sources of drinking water. Health and ecological risks from exposure to heavy metal pollution were evaluated. The main pollution sources of heavy metals in the Yuxi River basin were analyzed. Remediation programs and risk management strategies for heavy metal pollution were consequently proposed. This article provides a scientific basis for the risk assessment and management of heavy metal pollution caused by antimony basin ore mining.
Breast cancer is the most common malignant tumor and the main cause of cancer-associated mortality in females worldwide. Long non-coding RNAs (lncRNAs) have been reported to play vital roles in ...breast cancer development and progression; however, our understanding of most lncRNAs in breast cancer is still limited. In this study, we demonstrated that small nucleolar RNA host gene 5 (SNHG5) promotes breast cancer cell proliferation both in vitro and in vivo, and depletion of SNHG5 significantly led to cell-cycle arrest at G1 phase. Accumulating evidence has shown that many lncRNA transcripts could function as competing endogenous RNAs (ceRNAs) by competitively binding common microRNAs (miRNAs). We found that SNHG5 acts as a sponge for miR-154-5p, reducing its ability to repress proliferating cell nuclear antigen (PCNA). SNHG5 promoted breast cancer proliferation and cell-cycle progression by upregulation of PCNA expression. Clinically, we observed an increased SNHG5 expression in breast cancer, whereas miR-154-5p was decreased in breast cancer tissues compared with the adjacent normal breast tissues. Furthermore, the SNHG5 expression was significantly negatively correlated with miR-154-5p expression. Taken together, our data uncover the SNHG5-miR-154-5p-PCNA axis and provide a novel mechanism to explain breast cancer proliferation.
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