Exploring the Molecular Origin for the Long-Range Propagation of the Substrate Effect in Unentangled Poly(methyl methacrylate) Films.

The polymer/substrate interface plays a significant role in the dynamics of nanoconfined polymers because of its suppression on polymer mobility and its long-range propagation feature, while the molecular origin of the long-range substrate effect in unentangled polymer material is still ambiguous. Herein, we investigated the propagation distances of the substrate effect (h*) by a fluorinated tracer-labeled method of two unentangled polymer films supported on silicon substrates: linear and ring poly(methyl methacrylate) films with relatively low molecular weights. The results indicate that the value of h* has a molecular weight dependence of h*∝N (N is the degree of polymerization) in the unentangled polymer films, while h*∝N1/2 was presented as previously reported in the entangled films. A theoretical model, depending on the polymer/polymer intermolecular interaction, was proposed to describe the above long-range propagation behavior of the substrate effect and agrees with our experiment results very well. From the model, it revealed that the intermolecular friction determines the long-range propagation of the substrate effect in the unentangled system, but the intermolecular entanglement is the dominant role in entangled system. These results give us a deeper understanding of the long-range substrate effect.

Single-center experience in the diagnosis and treatment of lymphoepithelioma-like hepatic carcinoma.

PURPOSE: Lymphoepithelioma-like hepatic carcinoma (LELC) is a rare malignant liver tumor and its preoperative diagnosis is challenging. The aim of this study was to optimize the diagnosis and treatment of LELC in a single large center. METHODS: We conducted this retrospective analysis of 16 patients diagnosed with LELC in the First Affiliated Hospital of Zhejiang University between 2010 and 2022. Thirty-two cases of cholangiocarcinoma (ICC) and 48 cases of hepatocellular carcinoma (HCC) served as controls. RESULTS: Most of the 16 patients with LELC included in this study had no specific symptoms. Histologically, 9 patients had lymphoepithelioma-like hepatocellular carcinoma (LEL-HCC), 5 had lymphoepithelioma-like cholangiocarcinoma (LEL-ICC) and 2 had LEL-HCC-ICC. LEL-HCC was usually accompanied by hepatitis B virus infection, while LEL-ICC was often accompanied by Epstein Barr virus (EBV) infection. During the follow-up period, no complication and deaths were observed and only one patient experienced recurrence. These results were obviously better than those in patients with HCC and ICC. CONCLUSION: LELC is a rare malignant hepatic tumor. There are no specific symptoms or imaging modalities for accurate preoperative diagnosis of LELC. The diagnosis can be confirmed by pathology; however, the prognosis of LELC after resection is promising.

Enhanced H2O2 formation and norfloxacin removal by electro-Fenton process using a surface-reconstructed graphite felt cathode: New insight into synergistic mechanism of defective active sites.

The efficient catalytic activity and strong durability possibility of carbon-based three-dimensional fiber materials remains an important challenge in Electro-Fenton advanced oxidation technology. Graphite felt (GF) is a promising electrode material for 2-electron oxygen reduction reaction but with higher catalytic inertia. Anodizing modification of GF has been proved to enhance it electro-catalytic property, but the disadvantages of excessive or insufficient oxidation of GF need further improved. Herein, the surface reconstituted graphite felt by anodizing and HNO3 ultrasonic integrated treatment was used as cathode to degrade norfloxacin (NOR) and the substantial role of different modification processes was essentially investigated. Compared with the single modification process, the synergistic interaction between these two methods can generate more defective active sites (DASs) on GF surface and greatly improved 2-electron ORR activity. The H2O2 can be further co-activated by Fe2+ and DASs into •OH(ads and free) and •O2- to efficiently degrade NOR. The treated GF with 20 min anodizing and 1 h HNO3 ultrasound had the highest electrocatalytic activity in a wide electric potential (-0.4 V to -0.8 V) and pH range (3-9) in system and the efficient removal rate of NOR was basically maintained after 5 cycles. Under optimal reaction conditions, 50 mg L-1 NOR achieved 93% degradation and almost 63% of NOR was completely mineralized within 120 min. The possible NOR degradation pathways and ecotoxicity of intermediates were analyzed by LC-MS and T.E.S.T. theoretical calculation. This paper provided the underlying insights into designing a high-efficiency carbon-based cathode materials for commercial antibiotic wastewater treatment.

Anodized graphite felt as an efficient cathode for in-situ hydrogen peroxide production and Electro-Fenton degradation of rhodamine B.

This work investigated that the graphite felt anodized by NaOH, NH4HCO3, or H2SO4 aqueous, and then as the cathode materials for in-situ hydrogen peroxide (H2O2) production and its employed for rhodamine B (RhB) degradation via Electro-Fenton (EF) process. At -0.60 V (vs. SCE), after 120 min electrolysis, the H2O2 yield by graphite felt which anodized by 0.2 M H2SO4 achieved up 110.5 mg L-1 in 0.05 M Na2SO4 electrolyte. Compared with the raw graphite felt used for cathode, the H2O2 yield increased by 15.85 times under the same conditions. The results of Raman spectroscopy demonstrated that graphite felt anodized by H2SO4 solution can be achieved the highest defect degree. For the degradation of RhB, the cathode which anodized by H2SO4 solution has the highest removal rate. For the degradation rate of RhB, the effect of applied current density, Fe2+ ions concentration, pH value were investigated. In addition, suggested that the efficient Fe3+ reduction reaction on the cathode surface was an important reason of the high efficiency of RhB degradation. 5-times continuous runs indicated that the modified cathode has remarkable stability and reusability during the EF process.

Constructing a TiO2/PDA core/shell nanorod array electrode as a highly sensitive and stable photoelectrochemical glucose biosensor.

Developing stable PEC glucose biosensors with high sensitivity and low detection limit is highly desirable in the biosensor field. Herein, a highly stable and sensitive enzymatic glucose photoelectrochemical biosensor is rationally designed and fabricated by constructing TiO2/PDA core/shell nanorod arrays. The TiO2 nanorod as the core has the advantages of increasing charge transportation towards interfaces and enhancing the absorption of incident sunlight due to its single-crystal nature and one dimensional array structure. The PDA shell not only induces a rapid charge transfer across the interfaces but also stabilizes the biosensor performance by avoiding the decomposition of enzymes induced by the strong oxidizing holes from the TiO2 core. A remarkable performance with an ultrahigh sensitivity of 57.72 µA mM-1 cm-2, a linear range of 0.2-1.0 mM, a glucose detection limit of 0.0285 mM (S/N = 3) and a high sensitivity of 8.75 µA mM-1 cm-2 in a dynamic range of 1.0-6.0 mM were obtained for the glucose detection. This study might provide a strategy for constructing inorganic/organic core/shell structures with a satisfactory PEC performance.

Reversible Hydrophobicity-Hydrophilicity Transition Modulated by Surface Curvature.

Wettability (hydrophobicity and hydrophilicity) is of fundamental importance in physical, chemical, and biological behaviors, resulting in widespread interest. Herein, by modulating surface curvature, we observed a reversible hydrophobic-hydrophilic transition on a model referred to a platinum surface. The underlying mechanism is revealed to be the competition between strong water-solid attraction and interfacial water orderliness. On the basis of the competition, we further propose an equation of wetting transition in the presence of an ordered interfacial liquid. It quantitatively reveals the relation of solid wettability with interfacial water orderliness and solid surface curvature, which can be used for predicting the critical point of the wetting transition. Our findings thus provide an innovative perspective on the design of a functional device demonstrating a reversible wettability transition and even a molecular-level understanding of biological functions.

Half-thickness inversion layer high-frequency ultrasonic transducers using LiNbO3 single crystal.

Half-thickness inversion layer high-frequency ultrasonic transducers were fabricated using lithium niobate (LiNbO3) single crystal plate. The transducers developed for this study used a 36 degrees rotated Y-cut LiNbO3 thin plate with an active element thickness of 115 microm. The designed center frequency was in the range of 30 to 60 MHz. Half-thickness inversion layer was formed after the sample was annealed at a high temperature, and it is shown that the inversion layer thickness can be controlled by the temperature. Silver powder/epoxy composite and parylene were used as acoustic matching layers. A lossy silver epoxy was used as the backing material. Using an analytical method, the electrical impedance for different inversion layer ratios was determined. The measured resonant frequency was consistent with the modeled data. Even-order higher frequency broadband ultrasonic transducers with a center frequency at 60 MHz was obtained using half-thickness inversion layer of LiNbO3 single crystal.

Design and fabrication of broadband graded ultrasonic transducers with rectangular kerfs.

Broadband ultrasound imaging is capable of achieving superior resolution in clinical applications. An effective and easy way of manufacturing broadband transducers is desired for these applications. In this work, a graded material in which the piezoelectric plate is mechanically graded with rectangular grooves is introduced. Finite element analysis (FEA) demonstrated that the graded piezoelectric material could achieve a broadband, time-domain response resulting from multiple resonant modes. Experimental tests were carried out to validate these theoretical results. Based upon the FEA designs, several single-element transducers were fabricated using either a nondiced ceramic or a diced, graded ceramics. A superior bandwidth of 92% was achieved by the graded transducer when compared to a bandwidth of 56% produced by the nondiced ceramic transducer at the expense of a reduced sensitivity.