Solution-Synthesized Multifunctional Janus Nanotree Microswimmer

Synthetic active matters are perfect model systems for non-equilibrium thermodynamics and of great potential for novel biomedical and environmental applications. However, most applications are limited by the complicated and low-yield preparation, while a scalable synthesis for highly functional microswimmers is highly desired. In this paper, an all-solution synthesis method is developed where the gold-loaded titania-silica nanotree can be produced as a multi-functional self-propulsion microswimmer. By applying light, heat, and electric field, the Janus nanotree demonstrated multi-mode self-propulsion, including photochemical self-electrophoresis by UV and visible light radiation, thermophoresis by near-infrared light radiation, and induced-charge electrophoresis under AC electric field. Due to the scalable synthesis, the Janus nanotree is further demonstrated as a high-efficiency, low-cost, active adsorbent for water decontamination, where the toxic mercury ions can be reclaimed with enhanced efficiency.     

Influence of fluorine-containing side chain on the properties of waterborne polyurethane-urea

In order to prepare waterborne polyurethane with excellent water resistance and thermodynamic properties, a series of side chain fluorinated waterborne polyurethane-urea (FWPU-UA) was synthesized with polytetramethylene ether glycol, N-(2-methyl-1,3-propanediol-2′-)-perfluoro-1-butanesulfonyl amine (NPBA), isophorone diisocyanate, and isophoronediamine. With the increase of NPBA content, the weight loss temperature, glass transition temperature, and tensile strength of FWPU-UA were all improved. Gaussian fitting analysis of infrared data and density functional theory simulation proved that the introduction of fluorine side chains increased the interaction of hydrogen bonding in the FWPU-UA. X-ray photoelectron spectroscopy analysis indicated that the aggregation of fluorine atoms on the surface of film were caused by the migration and enrichment of fluorine side chains. Furthermore, the water resistance of polyurethane-urea film could be significantly improved by adding a small amount of NPBA, and the seven-day water absorption rate of polyurethane-urea film was reduced from 30.13% to 12.55%.     

4-Methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene,a Major Active Metabolite of Bisphenol A,Triggers Pancreatic β-Cell Death via a JNK/AMPKα Activation-Regulated Endoplasmic Reticulum Stress-Mediated Apoptotic Pathway

4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene (MBP), a major active metabolite of bisphenol A (BPA), is generated in the mammalian liver. Some studies have suggested that MBP exerts greater toxicity than BPA. However, the mechanism underlying MBP-induced pancreatic β-cell cytotoxicity remains largely unclear. This study demonstrated the cytotoxicity of MBP in pancreatic β-cells and elucidated the cellular mechanism involved in MBP-induced β-cell death. Our results showed that MBP exposure significantly reduced cell viability, caused insulin secretion dysfunction, and induced apoptotic events including increased caspase-3 activity and the expression of active forms of caspase-3/-7/-9 and PARP protein. In addition, MBP triggered endoplasmic reticulum (ER) stress, as indicated by the upregulation of GRP 78, CHOP, and cleaved caspase-12 proteins. Pretreatment with 4-phenylbutyric acid (4-PBA; a pharmacological inhibitor of ER stress) markedly reversed MBP-induced ER stress and apoptosis-related signals. Furthermore, exposure to MBP significantly induced the protein phosphorylation of JNK and AMP-activated protein kinase (AMPK)α. Pretreatment of β-cells with pharmacological inhibitors for JNK (SP600125) and AMPK (compound C), respectively, effectively abrogated the MBP-induced apoptosis-related signals. Both JNK and AMPK inhibitors also suppressed the MBP-induced activation of JNK and AMPKα and of each other. In conclusion, these findings suggest that MBP exposure exerts cytotoxicity on β-cells via the interdependent activation of JNK and AMPKα, which regulates the downstream apoptotic signaling pathway.     

Advanced Understanding of the Electron Transfer Pathway of Cytochrome P450s

Cytochrome P450s are heme-thiolate enzymes that participate in carbon source assimilation, natural compound biosynthesis and xenobiotic metabolism in all kingdoms of life. P450s can catalyze various reactions by using a wide range of organic compounds, thus exhibiting great potential in biotechnological applications. The catalytic reactions of P450s are driven by electron equivalents that are sourced from pyridine nucleotides and delivered by cognate or matching redox partners (RPs). The electron transfer (ET) route from RPs to P450s involves one or more redox center-containing domains. As the rate of ET is one of the main determinants of P450 efficacy, an in-depth understanding of the P450 ET pathway should increase our knowledge of these important enzymes and benefit their further applications. Here, the various P450 RP systems along with current understanding of their ET routes will be reviewed. Notably, state-of-the-art structural studies of the two main types of self-sufficient P450 will also be summarized.     

Highly oriented α-Al2O3 transparent ceramics shaped by shear force

Alumina platelets were arranged horizontally in submicron alumina particles by shear force in the flow of slurries during casting. The obtained alumina green bodies with platelets were pressureless-sintered in vacuum, producing ceramics with thoroughly oriented grains and high transmittance. The effects of sintering parameters on the densification, microstructure evolution, and orientation degree of alumina ceramics were investigated and discussed. The results showed that the densification, grain size, orientation degree, and in-line transmittance were increased with increasing sintering temperature. The enhancement of orientation degree was mainly coherent with grain growth. The grain-oriented samples exhibited a much higher in-line transmittance (at 600 nm) of 61 % than that of the grain random sample (29 %). Moreover, the transmission remained a high level in the ultraviolet range (<300 nm).     

Configurational Isomers Induced Significant Difference in All-Polymer Solar Cells

The design of polymer acceptors plays an essential role in the performance of all-polymer solar cells. Recently, the strategy of polymerized small molecules has achieved great success, but most polymers are synthesized from the mixed monomers, which seriously affects batch-to-batch reproducibility. Here, a method to separate γ-Br-IC or δ-Br-IC in gram scale and apply the strategy of monomer configurational control in which two isomeric polymeric acceptors (PBTIC-γ-2F2T and PBTIC-δ-2F2T) are produced is reported. As a comparison, PBTIC-m-2F2T from the mixed monomers is also synthesized. The γ-position based polymer (PBTIC-γ-2F2T) shows good solubility and achieves the best power conversion efficiency of 14.34% with a high open-circuit voltage of 0.95 V when blended with PM6, which is among the highest values recorded to date, while the δ-position based isomer (PBTIC-δ-2F2T) is insoluble and cannot be processed after parallel polymerization. The mixed-isomers based polymer, PBTIC-m-2F2T, shows better processing capability but has a low efficiency of 3.26%. Further investigation shows that precise control of configuration helps to improve the regularity of the polymer chain and reduce the π–π stacking distance. These results demonstrate that the configurational control affords a promising strategy to achieve high-performance polymer acceptors.     

An Injectable Hydrogel for Simultaneous Photothermal Therapy and Photodynamic Therapy with Ultrahigh Efficiency Based on Carbon Dots and Modified Cellulose Nanocrystals

The convenience of injectable hydrogels that can provide high loading of diverse phototherapy agents and further long-time retention at the tumor site has attracted tremendous interest in simultaneous photothermal and photodynamic cancer therapies. However, to incorporate the phototherapy agents into hydrogels, complex modifications are generally unavoidable. Moreover, these phototherapy agents usually suffer from low efficiency and work at different irradiation wavelengths outside the near infrared windows. Hence, a method for the fabrication of an injectable hydrogel for simultaneous photothermal therapy and photodynamic therapy, through the Schiff-base reaction between amido modified carbon dots (NCDs) and aldehyde modified cellulose nanocrystals is proposed. The NCDs act as both phototherapy agents and crosslinkers to form hydrogels. Significantly, the NCDs demonstrate an extremely high photothermal conversion efficiency of 77.6% which is among the highest levels for photothermal agents and a high singlet quantum yield of 0.37 under a single 660 nm light-emitting diode irradiation. The hydrogels are examined through in vitro and in vivo animal experiments which show nontoxic and effectively tumor inhibition. Thus, the strategy of direct reaction of phototherapy agents and the matrix not only provides new strategies for injectable hydrogel fabrication but paves a new road for advanced tumor treatment.     

基于JESD204B协议高速并行8 bit/10 bit解码电路设计

提出了一种高速低延时8 bit/10 bit解码电路结构,采用四路并行通道同时处理输入数据,每一路具有K码检测、输入数据查错功能,能够在输入四路10 bit数据后的一个时钟周期内正确完成解码.所设计的解码电路通过搭建的通用验证方法学系统完成系统级功能验证,并基于65 nm工艺库进行综合、布局和布线,解码电路的面积为1 449 μm2.后仿真结果显示,解码电路的最高工作频率达415 MHz,四路可支持最高16.6 Gibit/s的串行数据传输速率,满足JESD204B协议标准推荐的最高传输速率12.5 Gibit/s的要求.将该解码电路用于支持JESD204B协议的高速数模转换器电路中,经测试,其传输速率最高达10.5 Gibit/s.     

Micromembrane absorber with deep-permeation nanostructure assembled by flowing synthesis

A micromembrane adsorber with deep-permeation nanostructure (DPNS) has been successfully fabricated by flowing synthesis. The nanoparticles are in-situ assembled in membrane pores and immobilized in each membrane pore along the direction of membrane thickness. The nanoparticles with a lower size and thinner size distribution can be achieved owing to the confined space effect of the membrane pores. As a concept-of-proof, the nano ZIF-8 and ZIF-67 are fabricated in porous membrane pores for methyl orange (MO) and rhodamine B (RhB) adsorption. The adsorption rate is increased significantly owing to the enhanced contact and mass transfer in the confined space. The adsorption capacity for the RhB is also increased, since the size of the nanoparticles assembled in membrane pores is smaller with more active sites exposed. This micromembrane adsorber with DPNS has good reusability and can provide a promising prospect for industrial application.     

Precise quantification of the antibacterial activity of chitosan by NB medium neutralizer

In the present research,nutrient broth(NB)medium was identified to be able to neutralize the antibac-terial activity of chitosan and its derivatives.Therefore,an improved test method independent of NB medium was proposed to precisely quantify the antibacterial effectiveness and efficiency of chitosan.The minimum bactericidal concentration(MBC)of chitosan was 60 μg mL-1 against S.aureus and E.coli,and 0.01％(w/v)chitosan could kill 100％of bacteria within 3 min.From another point of view,the neutralizing efficiency of NB could be tripled by adding 25 g L-1 of sodium chloride.Then the neutraliz-ing mechanism of NB medium was ascribed to flocculation between chitosan and protein.Adding extra sodium chloride could significantly reduce the size of floccules,and smaller floccules would lose the ability of binding with bacteria directly,showing higher neutralizing rate on the macro scale.