Red AIE Luminogens with Tunable Organelle Specific Anchoring for Live Cell Dynamic Super Resolution Imaging

Lysosomes and mitochondria play an important role in maintaining cell homeostasis. Visualizing the long-term activities of lysosomes and mitochondria on the nanometer scale in live cells is essential for further understanding their functions but remains challenging due to the limitations of existing fluorescent probes, such as aggregation-caused quenching (ACQ) effect, limited signal-to-noise ratio from fluorescence “always on” in the process of targeting organelle and poor photobleaching resistance. Herein, two efficient red-emitting aggregation-induced emission (AIE) luminogens are reported, which showed “off-on” fluorescence characteristic and specific lysosomes as well as mitochondria targeting capability. Owing to their AIE characteristics, a Stokes’ shift larger than 100 nm, good biocompatibility, and excellent photostability, the AIE luminogens have been successfully utilized for high fidelity imaging of lysosomes and mitochondria. By virtue of these two probes, stimulated emission depletion (STED) images of dynamic lysosomal fusion and mitochondrial fission with a high resolution of 65.6 nm are obtained. Furthermore, the interactions between lysosomes and mitochondria in the process of mitophagy are recorded. This study also provides practical guidance for designing specific organelle targeting probes to support live cell dynamic super-resolution imaging.     

Strategic Engineering of Sub-5 nm Dyes@CDs Nanoassemblies Platform for Super Resolution Imaging

The design and construction of fluorescence probes with small size, high quantum yield, photostability, and solubility in an aqueous solution to achieve biomarker have become a focus of interest in super-resolution bioimaging application. Herein, four kinds of GFP-like supramolecular nanoassemblies (SNAs) are constructed in a very facile manner by the host–guest interaction between isopercolic acid derivatives (IADs) and cyclodextrin (CD). ¹H NMR, Fourier transform infrared spectroscopy (FT-IR) and single crystal structure well prove the formation of SNAs. Moreover, compared to the initial state, the fluorescence quantum yield of the SNAs is dramatically improved through suppressing nonradiative relaxation pathways and shielding quenchers. The bimolecular exciton–exciton annihilation (bmEA) process under the high pumping fluence has been suppressed effectively. Both the improved gain and the reduced loss facilitate the buildup of stimulated emission and enable the high stimulated emission efficiency of these SNAs. Sub-5 nm IADs@β-CDs-mediated STED imaging exhibits excellent stimulated emission depletion (STED) performance: high photostability, low saturation intensity ( ≈ 0.50 MW cm⁻²), and high resolution (30 nm) under P_STED-775 nm of 109 MW cm⁻². This supramolecular strategy avoids the tedious molecular synthesis process and paves a new pathway for insights into building up novel high-performance STED probes.     

A fast non-singular terminal sliding mode control based on perturbation estimation for piezoelectric actuators systems

Piezoelectric actuators (PEAs) are the key devices in micro/nano positioning system. However, the PEA performance is significantly degraded by the inherent non-linear behaviour. This behaviour is a consequence of the hysteresis properties contained within PEAs. Therefore, in micro/nano positioning applications, a robust control system has to be adopted for such actuators. This paper proposes a systematic control method that utilises a fast non-singular terminal sliding mode (FNTSM) based on online perturbation estimation technique for PEAs. Unlike other sliding mode methods, the FNTSM control method is characterised by chatter free. Besides, a zero error convergence can be guaranteed in finite time in the presence of disturbance and system uncertainties (i.e., hysteresis and gain changes). The design of the FNTSM control based on perturbation estimation (FNTSMPE) is presented. A model-free robust exact differentiator is used to estimate the states of the feedback system from merely measurable position signal. Theoretical analysis and the experimental results of FNTSMPE control reveal that high-precision and robust performance is achieved in comparison with ordinary FNTSM control.     

Determination of slip melting point in palm oil blends by partial least squares and principal component regression modeling of FTIR spectroscopic data

The determination of slip melting point (SMP) in refined, bleached, and deodorized palm oil is a common and regular requirement in the manufacture of this oil. An FTIR spectrometer in the mid-IR wavelength region (4000-750 cm⁻¹) can provide the basis for a suitable on-line and off-line quantitative analytical methodology if used with a suitable calibration model. In this study, by using data from selected regions, the calibration models, including principal component regression and partial least squares regression, have been examined and evaluated for efficacy in determining SMP directly in palm oil blends. Results indicate that orthogonal models using selected wavelength data offer superior predictive performance.     

Study on SO2 Poisoning Mechanism of CO Catalytic Oxidation Reaction on Copper–Cerium Catalyst

CuO–CeO₂ (Cu–Ce) catalyst with a CuO/CeO₂ mass ratio of 1 prepared by a sol–gel method is used in the CO catalytic oxidation reaction in the actual industrial sulfur-containing atmosphere. At a reaction temperature of 200 °C, the catalyst exhibits quite different stability under sulfur-containing and sulfur-free conditions. When 30 ppm SO₂ was added to the feed gas, the Cu–Ce catalyst had an initial CO conversion rate of 100%, gradually decreasing after 26 h, and this catalyst completely deactivated at about 50 h. However, the CO conversion rate of the catalyst under sulfur-free conditions could be nearly maintained at 100% within the measured time range (60 h). The results of IR, Raman, and XPS characterizations proved that the accumulation of cerium sulfate on the Cu–Ce catalyst would cover the active sites of the catalyst, eventually leading to the complete deactivation of the catalyst, which provides favorable evidence for the actual industrial anti-sulfur application.

Graphical Abstract

     

脱氢枞胺键合交联聚苯乙烯树脂的制法和应用

分3个步骤制备脱氢枞胺键合交联聚苯乙烯树脂：醚化反应，双键环氧化和脱氢枞胺与环氧基开环反应。为了提高树脂中功能基的转化率，针对每一步合成做了正交实验，得出了最佳工艺条件。采用红外光谱对每一步合成产物进行结构表征。并用脱氢枞胺键合交联聚苯乙烯树脂进行对映体分离的初步应用。     

无纺布专用树脂的研制开发

根据无纺布原料的要求，分析了进口和自产聚丙烯（PP）树脂质量上的差异，确定改进目标为分子量分布变窄，断裂伸长率变高，选用N型高效催化剂，经过优化聚合工段的生产，稳定粉料的熔体流动指数（MI），在造粒过程中，选用过氧化物TX301作降解剂，调整造粒添加剂配方和挤压造粒操作温度，采用降解法生产工艺，将低MI的PP粉料降解为高MI的无纺布专用树脂（JNW28），JNW28的分子量分布窄（达2．11），断裂伸长率高（达1000％），经国内外用户试用，用其生产的高档无纺布产品质量合格，满足生产的要求。     

Vertically aligned carbon nanotubes grown on geometrically different types of surface

Aligned carbon nanotubes (CNTs) which were always perpendicular to the surface of substrate were synthesized on geometrically different surface through microwave plasma chemical vapour deposition (MWPCVD) at the low temperature of 550 °C. Growth was performed in a flowing mixture of CH₄ and H₂. Scanning electron microscopy (SEM) shows that the vertically aligned growth occurred under the effect of plasma. When the substrate was not contacted with plasma, only randomly entangled CNTs had grown on the substrate. The research results demonstrate that the electrical self-bias imposed on the surface is the primary mechanism responsible for the alignment of CNTs.