Gold Nanorods/Metal-Organic Framework Hybrids: Photo-Enhanced Peroxidase-Like Activity and SERS Performance for Organic Dyestuff Degradation and Detection.

Metal-organic frameworks (MOFs) are widely used to mimic enzymes for catalyzing chemical reactions; however, low enzyme activity limit their large-scale application. In this work, gold nanorods/metal-organic frameworks (Au NRs/Fe-MOF) hybrids were successfully synthesized for photo-enhanced peroxidase-like catalysis and surface-enhanced Raman spectroscopy (SERS). The enzyme-like activity of Au NRs/Fe-MOF hybrids was significantly enhanced under localized surface plasmon resonance (LSPR), because the hot electrons produced on Au NRs surface were transferred into Fe-MOF, activating the Fenton reaction by Fe3+/Fe2+ conversion and preventing the recombination of hot electrons and holes. This photo-enhanced enzyme-like catalytic performance was investigated by X-ray photoelectron spectrometry (XPS), electrochemical analysis, activation energy measurement, and in situ Raman spectroscopy. Afterward, Methylene Blue (MB) was chosen to demonstrate the photo-enhanced peroxidase-like performance of Au NRs/Fe-MOFs. The Au NRs/Fe-MOF caused chemical and electromagnetic enhancement of Raman signals and exhibited a great potential for the detection of toxic chemicals and biological molecules. The detection limit of MB concentration is 9.3 × 10-12 M. In addition, the Au NRs/Fe-MOF hybrids also showed excellent stability and reproducibility for photo-enhanced peroxidase-like catalysis. These results show that nanohybrids have great potential in many fields, such as sensing, cancer therapy, and energy harvesting.

Perspective on interface engineering for capacitive energy storage polymer nanodielectrics.

Polymer nanodielectrics with high breakdown strength (Eb), high energy density (Ue) and low energy loss have great potential to be used as capacitive energy storage materials of high-voltage film capacitors in modern electrical and electronic equipment, such as smart grids, new energy vehicles and pulse powered weapons. Usually, inorganic nanoparticles with high dielectric constant (εr) are added into a high Eb polymer matrix to achieve simultaneously enhanced εr and Eb, thus leading to nanodielectrics with high Ue. However, this strategy was seriously hampered by the uneven distribution of electric fields and inhomogeneous microstructures of the multi-phased nanodielectrics until increasing research work was focused on interface engineering. Recent progress in nanocomposites suggests that interface engineering plays a critical role in regulating the polarization and breakdown behaviors of the nanodielectrics, such as balancing εr and Eb, enhancing Ue and energy discharge efficiency (η). This article highlights the recent advances in the interface engineering of polymer nanodielectrics, including theoretical models, interface engineering strategies, and the latest characterization and fabrication techniques of high performance nanodielectrics. Finally, the challenges and opportunities in the interface engineering of the nanodielectrics in film capacitors are discussed and predicted from a practical point of view.

Superior high-temperature capacitive performance of polyaryl ether ketone copolymer composites enabled by interfacial engineered charge traps.

Metalized film capacitors with high-temperature capacitive performance are crucial components in contemporary electromagnetic energy systems. However, the fabrication of polymer-based dielectric composites with designed structures faces the challenge of balancing high energy density (Ue) and low energy loss induced by electric field distortion at the interfaces. Here, BN nanoparticles coated with a thin layer of aminobenzoic acid (ABA) voltage stabilizer are introduced into a copolymer of aryletherketone and 2,6-bis(2-benzimidazolyl)pyridine (P(AEK-BBP)). Our results demonstrate that the ABA voltage stabilizer, possessing high electron affinity, significantly improves the dispersion of BN particles within the matrix, mitigates electric field distortion, and creates effective charge traps. This, in turn, effectively suppresses high-temperature-induced Schottky emission and P-F emission, leading to a dramatic decrease in leakage loss. As a result, the optimized composite film, filled with 0.3 vol% m-ABA-BN particles, exhibites a Ue of 10.1 J cm-3 and a η of 90% at 150 °C and 600 MV m-1, surpassing the majority of previously reported materials. Furthermore, even after undergoing 100 000 cycles at 150 °C and 250 MV m-1, the composite dielectric films demonstrate favorable charge-discharge characteristics. This work offers a novel approach to fabricate polymer-based dielectric materials with high-temperature resistance and high discharging efficiency for long-term high energy storage applications.

A Dual-Mode NADH Biosensor Based on Gold Nanostars Decorated CoFe2 Metal-Organic Frameworks to Reveal Dynamics of Cell Metabolism.

Nicotinamide adenine dinucleotide (NADH) is central to metabolism and implicated in various diseases. Herein, nanohybrids of gold nanostars and metal-organic frameworks are devised and demonstrated as a dual-mode NADH sensor, for which colorimetric detection is enabled by its peroxidase-like nanozyme property and Raman detection is realized by its surface-enhanced Raman scattering property with the detection limit as low as 28 pM. More importantly, this probe enables real-time SERS monitoring in living cells, providing a unique tool to investigate dynamic cellular processes involving NADH. Our experiments reveal that metabolism dynamics is accelerated by glucose and is much higher in cancerous cells. The SERS results can also be verified by the colorimetric detection. This sensor provides a new potential to detect biomarkers and their dynamics in situ.

PD-1 inhibitors plus anti-angiogenic therapy with or without intensity-modulated radiotherapy for advanced hepatocellular carcinoma: A propensity score matching study.

Background: Whether intensity-modulated radiotherapy (IMRT) can enhance the efficacy of the programmed death (PD)-1 inhibitors combined with anti-angiogenic therapy for hepatocellular carcinoma (HCC) is unclear. Therefore, we conducted this multicenter retrospective study to investigate the efficacy of the combination of PD-1 inhibitors with anti-angiogenic therapy and IMRT. Methods: From April 2019 to March 2022, a total of 197 patients with HCC [combination of PD-1 inhibitors with anti-angiogenic therapy and IMRT (triple therapy group), 54; PD-1 inhibitors plus anti-angiogenic therapy (control group), 143] were included in our study. Propensity score matching (PSM) was applied to identify two groups with similar baselines. The objective response rate (ORR), overall survival (OS), and progression-free survival (PFS) of the two groups were compared before and after matching. Results: Prior to PSM, the triple therapy group had higher ORR (42.6% vs 24.5%, P = 0.013) and more superior median OS (mOS) (20.1 vs 13.3 months, P = 0.009) and median PFS (mPFS) (8.7 vs 5.4 months, P = 0.001) than the control group. Following PSM, the triple therapy group still exhibited better mPFS (8.7 vs 5.4 months, P = 0.013) and mOS (18.5 vs 12.6 months, P = 0.043) than the control group. However, the ORR of the two groups was similar (40% vs 25%, P = 0.152). No significant difference was observed in the treatment-related adverse events between the two groups (P < 0.05 for all). Conclusions: The combination of PD-1 inhibitors with anti-angiogenic therapy and IMRT for HCC is a promising regimen.

Gamma knife radiosurgery versus transcatheter arterial chemoembolization for hepatocellular carcinoma with portal vein tumor thrombus: a propensity score matching study.

BACKGROUND: The optimal locoregional treatment for hepatocellular carcinoma (HCC) patients with portal vein tumor thrombus (PVTT) is unclear. This study aimed to investigate the efficacy of Gamma knife radiosurgery (GKR) versus transcatheter arterial chemoembolization (TACE) in HCC patients with PVTT. METHODS: This retrospective study included 544 HCC patients with PVTT (GKR, 202; TACE, 342). Propensity score matching (PSM) analysis identified 171 matched pairs of patients. The primary endpoint was overall survival (OS). RESULTS: Before PSM, the GKR group exhibited longer median OS (mOS) than the TACE group (17.2 vs. 8.0 months, p < 0.001). We followed the Cheng's classification for PVTT. In the subgroup analysis, GKR was associated with significantly longer mOS for patients with PVTT II-IV (17.5 vs. 8.7 months, p < 0.001; 17.2 vs. 7.8 months, p = 0.001; 14.5 vs. 6.5 months, p = 0.001, respectively) and comparable OS for patients with PVTT I. After PSM, the GKR group had also a longer mOS than the TACE group (15.8 vs. 10.4 months, p < 0.001). In the subgroup analysis, the GKR group demonstrated superior mOS for patients with PVTT II-IV (all p < 0.05) and comparable OS for patients with PVTT I. CONCLUSIONS: GKR was associated better OS than TACE in HCC patients with PVTT, especially for patients with PVTT II-IV. CLINICAL TRIALS REGISTRATION: The study was registered in the Chinese Clinical Trials Registry under the registration number ChiCTR2100051057.

Bimetallic Metal-Organic Frameworks: Enhanced Peroxidase-like Activities for the Self-Activated Cascade Reaction.

Metal-organic frameworks (MOFs) are significant useful molecular materials as a result of their high surface area and flexible catalytic activities by tuning the metal centers and ligands. MOFs have attracted great attention as efficient nanozymes recently; however, it is still difficult to understand polymetallic MOFs for enzymatic catalysis because of their complicated structure and interactions. Herein, bimetallic NiFe2 MOF octahedra were well prepared and exhibited enhanced peroxidase-like activities. The synergistic effect of Fe and Ni atoms was systematically investigated by electrochemistry, X-ray photoelectron spectrometry, (XPS) and in situ Raman techniques. The electrons tend to transfer from Ni2+ to Fe3+ in NiFe2 MOFs, and the resulting Fe2+ is ready to decompose H2O2 and generate ·OH by a Fenton-like reaction. After integration with glucose oxidase (GOx), which can downgrade the pH value and generate H2O2 by oxidation of glucose, a self-activated cascade reagent is therefore established for efficiently inducing cell death. The changes of cell morphology, DNA, and protein are also successfully recorded during the cell death process by Raman spectroscopy and fluorescence imaging.

Intraductal tubulopapillary neoplasm (ITPN) of the pancreas with invasive cancer misdiagnosed as a mesenteric cyst for 12 years: a case report and literature review.

INTRODUCTION: An intraductal tubulopapillary neoplasm (ITPN) depicts a distinct entity in the subgroup of premalignant epithelial tumors of the pancreas. Due to the rarity of ITPN, information regarding the disease is currently limited. We present herein a case of pancreatic ITPN with invasive cancer that was misdiagnosed as a mesenteric cyst during a 12-year follow-up period. CASE REPORT: A 23-year-old female initially presented with an incidental asymptomatic 4-cm retroperitoneal cystic lesion in 2005. For 12 years of surveillance, the lesion remained largely unchanged in size (4-5 cm). In 2017, the cystic lesion was found to have grown to 9 cm. The pre-operative diagnosis was highly suggestive of a benign lesion. However, after total resection of the mass was performed, the final diagnosis was pancreatic ITPN with invasive cancer. The patient recovered uneventfully and is disease-free without recurrence at the time of this report (12 months post-surgery). CONCLUSION: The clinicopathologic features of ITPN remain unclear due to its rarity, thus making diagnosis difficult. Clinicians should always consider the possibility of ITPN for cystic lesions located at the retroperitoneum near the tail of the pancreas. More data are needed to understand the disease's long-term outcome to identify clinical and radiological features that can be useful for its diagnosis.

Significantly Enhanced Electromechanical Performance of PDMS Crosslinked PVDF Hybrids.

Poly(vinylidene fluoride)-based ferroelectric polymers have large and tunable dielectric permittivity (εr), but rather high Young's modulus (Y), which limits its electromechanical response when used as actuators. In this work, a silicone oligomer involving amino groups is employed to crosslink a non-crystallized poly(vinylidene fluoride-chlorotrifluoroethylene) matrix bearing double bonds (P(VDF-CTFE-DB)) via addition reaction. Thanks to the flexible silicone molecules, the modulus of the hybrids is reduced over 30% when compared with the pristine matrix. Most interestingly, the εr of the hybrids is improved to nearly 100% higher than that of the matrix when the silicone content reaches 30 wt %. This may be due to the dilution effect of silicone molecules, which favors macromolecular chain rearrangement and dipole orientation of the hybrids under an applied electric field. As a result, electric-field activated displacements of the above hybrid increases to 0.73 mm from 0.48 mm of the matrix under 60 MV/m. The maximum electric field-induced thickness strain increases from 1% of the matrix to nearly 3% of the crosslinked hybrid. This work may provide a facile strategy to fabricate PVDF-based hybrids with enhanced electromechanical performance under low activating voltage.

Improved Energy Storage Performance of Linear Dielectric Polymer Nanodielectrics with Polydopamine coated BN Nanosheets.

Polymer-based nanodielectrics have been intensively investigated for their potential application as energy storage capacitors. However, their relatively low energy density (Ue) and discharging efficiency (η) may greatly limit their practical usage. In present work, high insulating two-dimensional boron nitride nanosheets (BNNS), were introduced into a linear dielectric polymer (P(VDF-TrFE-CTFE)-g-PMMA) matrix to enhance the energy storage performance of the composite. Thanks to the surface coating of polydopamine (PDA) on BN nanosheets, the composite filled with 6 wt% coated BNNS (mBNNS) exhibits significantly improved breakdown strength (Eb) of 540 MV/m and an energy density (Ue) of 11 J/cm³, which are increased by 23% and 100%, respectively as compared with the composite filled with the same content of pristine BNNS. Meanwhile, η of both composites is well retained at around 70% even under a high voltage of 400 MV/m, which is superior to most of the reported composites. This work suggests that complexing polymer matrix with linear dielectric properties with surface coated BNNS fillers with high insulating 2D structure might be a facile strategy to achieve composite dielectrics with simultaneously high energy density and high discharging efficiency.

Achieving High Energy Density and Low Loss in PVDF/BST Nanodielectrics with Enhanced Structural Homogeneity.

Poor compatibility of polymer/ceramic composites used as high-pulse capacitors with high permittivity suffers from the reduced breakdown strength ( Eb) and lowered energy density ( Ue). Herein, mussel-inspired poly(dopamine) (PDA)-modified BaSrTiO3 (mBST) nanoparticle and poly(vinylidene fluoride) (PVDF) matrix are bonded together to fabricate nanocomposites with a cross-linked network and enhanced compatibility. The significantly improved Eb of 466 MV/m and the highest Ue of 11.0 J/cm3 for PVDF-based polymer/BST composites have been obtained. By comparing the properties of the three series of composites with different structures, the contribution of ferroelectric relaxation, interface polarization, and leakage conduction to the dielectric loss has been well addressed. Notably, the surface modification of BST with PDA could remarkably enhance the compatibility of the two components and the structural homogeneity of the composite. The improved bonding between the polymer matrix and the filler chemically or physically is responsible for the reduced dielectric loss from both conduction loss and interfacial polarization, which is the key to improve the Eb, Ue, and η of the composite. It has been revealed that enhancing the homogeneity of the composites by modifying ceramics and constructing cross-linked networks between the polymer matrix and the filler might be a facile strategy to achieve high energy storage performance in polymer composites.

Long noncoding RNA AFAP1­AS1 enhances cell proliferation and invasion in osteosarcoma through regulating miR­4695­5p/TCF4­ß­catenin signaling.

Long noncoding RNA AFAP1­AS1 has been shown to promote tumor progression in several human cancer types, such as thyroid cancer, tongue squamous cell carcinoma and lung cancer. However, the role of AFAP1­AS1 in osteosarcoma (OS) has not been investigated. In the present study, the expression of AFAP1­AS1 was significantly upregulated in OS tissues and cell lines. Moreover, AFAP1­AS1 expression was negatively correlated with OS patient prognosis. Besides, AFAP1­AS1 knockdown significantly inhibited the proliferation and invasion of OS cells in vitro. Furthermore, in vivo xenograft experiments indicated that AFAP1­AS1 depletion delayed tumor growth. Regarding the underlying mechanism, AFAP1­AS1 served as a sponge to repress the level of microRNA (miR)­4695­5p, which targeted transcription factor (TCF)4, a pivot effector of Wnt/ß­catenin signaling pathway. It was demonstrated that overexpression of AFAP1­AS1 inhibited the expression of miR­4695­5p, while miR­4695­5p overexpression decreased TCF4 expression and reduced activation of Wnt/ß­catenin pathway. Through rescue assays, it was demonstrated that restoration of TCF4 expression reversed the effects of AFAP1­AS1 knockdown or miR­4695­5p overexpression on OS cells. Taken together, these findings demonstrated that the AFAP1­AS1/miR­4695­5p/TCF4­ß­catenin axis played an important role in OS progression.

Fabrication of Stretchable Nanocomposites with High Energy Density and Low Loss from Cross-Linked PVDF Filled with Poly(dopamine) Encapsulated BaTiO3.

In this report, a simple solution-cast method was employed to prepare poly(dopamine) (PDA) encapsulated BaTiO3 (BT) nanoparticle (PDA@BT) filled composites using PVDF matrix cross-linked by the free radical initiator. The effects of both the particle encapsulation and matrix cross-linking on the mechanical and dielectric properties of the composites were carefully investigated. The results suggested that the introduction of BT particles improved permittivity of the composites to ∼30 at 100 Hz when particle contents of only 7 wt % were utilized. This was attributed to the enhanced polarization, which was induced by high permittivity ceramic particles. Compared to bare BT, PDA@BT particles could be dispersed more homogeneously in the matrix, and the catechol groups of PDA layer might form chelation with free ions present in the matrix. The latter might depress the ion conduction loss in the composites. Other results revealed that the formation of hydrogen-bonding between the PDA layer and the polymer, especially the chemical cross-linking across the matrix, resulted in increased Young' modulus by ∼25%, improved breakdown strength by ∼40%, and declined conductivity by nearly 1 order of magnitude when compared to BT filled composites. The composite films filled with PDA@BTs indicated greater energy storage capacities by nearly 190% when compared to the pristine matrix. More importantly, the excellent mechanical performance allowed the composite films to adopt uni- or biaxially stretching, a crucial feature required for the realization of high breakdown strength. This work provided a facile strategy for fabrication of flexible and stretchable dielectric composites with depressed dielectric loss and enhanced energy storage capacity at low filler loadings (<10 wt %).

[A study of correlation between the blood supply types of PHcc on spiral CT and the level of VEGF expression in PHcc].

OBJECTIVE: To study the correlation between the blood supply types of primary hepatocellar carcinoma (PHcc) on Spiral CT and the level of vascular endothelial growth factor (VEGF) expression in PHcc for improvement in treatment strategies and prognostication. METHODS: Forty-five cases of PHcc identified by operation and pathology were investigated. Immunohistochemistry staining in SP was performed. The relationships between blood supply types of PHcc on Spiral CT during dual-phase scanning and the expression levels of VEGF in well-differentiated, moderately differentiated and poorly differentiated PHcc were analyzed. RESULTS: There were four blood supply types of PHcc on Spiral CT. Both the strong positive staining and the positive staining were most frequently seen in the hepatic artery blood supply type, and then were frequently in the double blood supply type, i. e. the hepatic arterial supply combining with the portal blood supply type. The positive staining results were rarely seen in the portal blood supply type and poor blood supply type (P<0.001). And with the escalation of the Edmonson- Steiner histological grades, the VEGF expression levels were shown to increase correspondingly (P < 0.05). CONCLUSION: We can ascertain the blood supply type of PHcc and infer the VEGF expression levels that reflect the PHcc angiogenesis condition and the histological grades by means of Spiral CT during dual- phase scanning. Hence this method is useful for the selection of PHcc treatment plans, including anti-angiogenesis and evaluating the prognosis.

High Dielectric and Mechanical Properties Achieved in Cross-Linked PVDF/α-SiC Nanocomposites with Elevated Compatibility and Induced Polarization at the Interface.

Remarkably improved dielectric properties including high-k, low loss, and high breakdown strength combined with promising mechanical performance such as high flexibility, good heat, and chemical resistivity are hard to be achieved in high-k dielectric composites based on the current composite fabrication strategy. In this work, a family of high-k polymer nanocomposites has been fabricated from a facile suspension cast process followed by chemical cross-linking at elevated temperature. Internal double bonds bearing poly(vinylidene fluoride-chlorotrifluoroethylene) (P(VDF-CTFE-DB)) in total amorphous phase are employed as cross-linkable polymer matrix. α-SiC particles with a diameter of 500 nm are surface modified with 3-aminpropyltriethoxysilane (KH-550) as fillers for their comparable dielectric performance with PVDF polymer matrix, low conductivity, and high breakdown strength. The interface between SiC particles and PVDF matrix has been finely tailored, which leads to the significantly elevated dielectric constant from 10 to over 120 in SiC particles due to the strong induced polarization. As a result, a remarkably improved dielectric constant (ca. 70) has been observed in c-PVDF/m-SiC composites bearing 36 vol % SiC, which could be perfectly predicted by the effective medium approximation (EMA) model. The optimized interface and enhanced compatibility between two components are also responsible for the depressed conductivity and dielectric loss in the resultant composites. Chemical cross-linking constructed in the composites results in promising mechanical flexibility, good heat and chemical stability, and elevated tensile performance of the composites. Therefore, excellent dielectric and mechanical properties are finely balanced in the PVDF/α-SiC composites. This work might provide a facile and effective strategy to fabricate high-k dielectric composites with promising comprehensive performance.

Enhanced nanoflow behaviors of polymer melts using dispersed nanoparticles and ultrasonic vibration.

In the micro/nano fabrication of polymer nanostructures, a key factor is the favorable nanoflow behavior of polymer melts. Compared with the fluidic hydrodynamics of simple liquids through micro- or macrochannels, the nanoflow behavior of polymer melts, however, is affected much more by nanoscale effects and surface interactions. Therefore, achieving a favorable nanoflow of polymer melts in nanochannels is the key to fabricate high quality polymer nanoproducts. In this paper, the improved nanoflow behaviors of polystyrene melts in ordered porous alumina templates with the addition of nanoparticles and ultrasonic vibration were reported for the first time. Compared with bulk polystyrene (PS), the nanoflow rate of PS melts was enhanced when nanoparticles, such as surface-modified nano-silica (nano-SiO(2)) or ß-cyclodextrin (ß-CD), were added in a dispersed phase into a polystyrene matrix due to the decrease of the melts' viscosity caused by interactions between nanoparticles and PS segments. The enhancement action of ß-CD was observed to be more significant than that of nano-SiO(2) based on the adsorption and the supramolecular self-assembly interactions between PS segments and ß-CD. The enhanced nanoflow rate has shown to be more pronounced under ultrasonic vibration than those of the static condition and the low frequency vibration attributed to the synergetic effects of mechanical vibration and ultrasonic oscillation. The nanoflow rate of polymer melts increases with the gradual increase of vibration frequency. The optimal nanoflow behavior can be obtained by simultaneously adding ß-CD as dispersed phase into PS matrix and applying ultrasonic vibration in one nanoflow system. These new findings will help the preparation of polymer-based functional nanocomposites, ultrasonic vibration-assisted nanofluidics, and micro/nano injection molding etc.