Enhancing Chiroptical Responses in Helical Nanographenes via Geometric Engineering of Double [7]Helicenes.

Helical nanographenes with high quantum yields and strong chiroptical responses are pivotal for developing circularly polarized luminescence (CPL) materials. Here, we present the successful synthesis of novel π-extended double [7]helicenes (ED7Hs) where two helicene units are fused at the meta- or para-position of the middle benzene ring, respectively, as the structural isomers of the reported ortho-fused ED7H. The structural geometry of these ED7Hs is clearly characterized by single-crystal X-ray analysis. Notably, this class of ED7Hs exhibits bright luminescence with high quantum yields exceeding 40 %. Through geometric regulation of two embedded [7]helicene units from ortho-, meta- to para-position, these ED7Hs display exceptional amplification in chiroptical responses. This enhancement is evident in a remarkable approximate fivefold increase in the absorbance and luminescence dissymmetry factors (gabs and glum), respectively, along with a boosted CPL brightness up to 176 M-1 cm-1, surpassing the performance of most helicene-based chiral NGs. Furthermore, DFT calculations elucidate that the geometric adjustment of two [7]helicene units allows the precise alignment of electric and magnetic transition dipole moments, leading to the observed enhancement of their chiroptical responses. This study offers an effective strategy for magnifying the CPL performance in chiral NGs, promoting their expanded application as CPL emitters.

Double-network hydrogel enhanced by SS31-loaded mesoporous polydopamine nanoparticles: Symphonic collaboration of near-infrared photothermal antibacterial effect and mitochondrial maintenance for full-thickness wound healing in diabetes mellitus.

Diabetic wound healing has become a serious healthcare challenge. The high-glucose environment leads to persistent bacterial infection and mitochondrial dysfunction, resulting in chronic inflammation, abnormal vascular function, and tissue necrosis. To solve these issues, we developed a double-network hydrogel, constructed with pluronic F127 diacrylate (F127DA) and hyaluronic acid methacrylate (HAMA), and enhanced by SS31-loaded mesoporous polydopamine nanoparticles (MPDA NPs). As components, SS31, a mitochondria-targeted peptide, maintains mitochondrial function, reduces mitochondrial reactive oxygen species (ROS) and thus regulates macrophage polarization, as well as promoting cell proliferation and migration, while MPDA NPs not only scavenge ROS and exert an anti-bacterial effect by photothermal treatment under near-infrared light irradiation, but also control release of SS31 in response to ROS. This F127DA/HAMA-MPDA@SS31 (FH-M@S) hydrogel has characteristics of adhesion, superior biocompatibility and mechanical properties which can adapt to irregular wounds at different body sites and provide sustained release of MPDA@SS31 (M@S) NPs. In addition, in a diabetic rat full thickness skin defect model, the FH-M@S hydrogel promoted macrophage M2 polarization, collagen deposition, neovascularization and wound healing. Therefore, the FH-M@S hydrogel exhibits promising therapeutic potential for skin regeneration.

Switchable C2/C3 positional selectivity of thioisatins in a three-component domino reaction: combined computational and experimental studies.

The nucleophile-induced domino reaction is a featured reactivity mode of thioisatin, but the C2/C3 positional selectivity towards a nucleophile has not been understood in-depth. In this work, a domino reaction of thioisatin with bromoacetophenone and tryptamine hydrochloride to produce a benzothiophene-fused eight-membered N-heterocycle was described, showing that the Brønsted acid-base form of the amine partner was crucial for the selectivity, because using tryptamine instead of tryptamine hydrochloride gave a different product. Control experiments and density functional calculations revealed that the domino reaction using tryptamine or tryptamine hydrochloride was triggered by a condensation reaction at the C2 or C3 position of thioisatin, respectively. A delicate balance between local electrophilicity and polarization effect may be responsible for the observed selectivity.

Radiofrequency ablation in the treatment of hepatocellular carcinoma.

OBJECTIVE: The purpose of this article is to discuss the use, comparative efficacy, and research progress of radiofrequency ablation (RFA), alone or in combination with other therapies, for the treatment of hepatocellular carcinoma (HCC). METHOD: To search and summarize the basic and clinical studies of RFA in recent years. RESULTS: RFA is one of the radical treatment methods listed in the guidelines for the diagnosis and treatment of HCC. It has the characteristics of being minimally invasive and safe and can obtain good local tumor control, and it can improve the local immune ability, improve the tumor microenvironment and enhance the efficacy of chemotherapy drugs. It is commonly used for HCC treatment before liver transplantation and combined ALPPS and hepatectomy for HCC. In addition, the technology of RFA is constantly developing. The birth of noninvasive, no-touch RFA technology and equipment and the precise RFA concept have improved the therapeutic effect of RFA. CONCLUSION: RFA has good local tumor control ability, is minimally invasive, is safe and has other beneficial characteristics. It plays an increasingly important role in the comprehensive treatment strategy of HCC. Whether RFA alone or combined with other technologies expands the surgical indications of patients with HCC and provides more benefits for HCC patients needs to be determined.

Tuning 2D magnetism in Fe3+XGeTe2 films by element doping.

Two-dimensional (2D) ferromagnetic materials have been discovered with tunable magnetism and orbital-driven nodal-line features. Controlling the 2D magnetism in exfoliated nanoflakes via electric/magnetic fields enables a boosted Curie temperature (T C) or phase transitions. One of the challenges, however, is the realization of high T C 2D magnets that are tunable, robust and suitable for large scale fabrication. Here, we report molecular-beam epitaxy growth of wafer-scale Fe3+XGeTe2 films with T C above room temperature. By controlling the Fe composition in Fe3+XGeTe2, a continuously modulated T C in a broad range of 185-320 K has been achieved. This widely tunable T C is attributed to the doped interlayer Fe that provides a 40% enhancement around the optimal composition X = 2. We further fabricated magnetic tunneling junction device arrays that exhibit clear tunneling signals. Our results show an effective and reliable approach, i.e. element doping, to producing robust and tunable ferromagnetism beyond room temperature in a large-scale 2D Fe3+XGeTe2 fashion.

Sustainable access to benzothiophene derivatives bearing a trifluoromethyl group via a three-component domino reaction in water.

A catalyst-free three-component domino reaction was developed for the synthesis of benzothiophene fused pyrrolidones bearing a CF3 group for the first time. The notable advantages of this strategy over the existing methods include the use of water as a solvent at room temperature, transition metal-free conditions, a broad substrate scope, and easy scale-up synthesis. More importantly, the benzothiophene derivatives have been found to show potent anticancer activities using the Cell Counting Kit-8 (CCK-8) assay.

Recurrent acute portal vein thrombosis with severe abdominal infection after right hemihepatectomy in a patient with perihilar cholangiocarcinoma: A case report and literature review.

INTRODUCTION AND IMPORTANCE: Portal vein thrombosis (PVT) is a serious complication after hepatobiliary-pancreatic surgery. There have been few studies on recurrent PVT after hepatectomy for perihilar cholangiocarcinoma. CASE PRESENTATION: We report the case of a 66-year-old woman who was diagnosed with perihilar cholangiocarcinoma and treated with right hemihepatectomy. On the sixth day, the patient developed acute portal vein thrombosis, and emergency portal vein incision and surgical thrombectomy were performed. On the seventh day after thrombectomy, the patient developed acute portal vein thrombosis again, and portal vein thrombectomy+portal vein bridging was performed again. There was still thrombosis after the operation. The patient was then treated with superior mesenteric arteriography + indirect portal vein catheterization thrombolysis and local thrombolysis + anticoagulation and systemic anticoagulation therapy. The patient had a complicated abdominal infection. The total hospital stay was 84 days. There was no thrombosis in the portal vein at discharge. CLINICAL DISCUSSION: Although the procedure was carefully performed with a preoperative plan and fine intraoperative vascular anastomosis, postoperative PVT occurred. There are many factors of portal vein thrombosis, and there are many treatment methods. CONCLUSION: PVT often develops in patients with liver cirrhosis postoperatively and after liver transplantation. Recurrent PVT after hepatectomy for perihilar cholangiocarcinoma is a rare complication.

The Positive Temperature Coefficient of Resistivity in BiFeO3 Films.

The use of lead-free ceramic film materials with positive temperature coefficient of resistivity (PTCR) is widespread in temperature heaters and sensors in micro-electromechanical systems. In this research, the out of plane transport properties of the BiFeO3 (BFO) films have been studied. Surprisingly, PTCR was found in the BFO ceramic films due to the strongly correlated interaction between the multiferroic material BFO and the superconductor YBCO perovskite oxides. To our knowledge, this is the first report on the PTCR effect of BFO films. The BFO/YBCO interface and the bulk conductivity of BFO are important for the PTCR effect, as they make it possible to compare the transport properties of Au/BFO/YBCO- and YBCO/BFO/YBCO-type structures. PTCR was observed in Au/BFO/YBCO at a bias voltage of more than 2 V, but not in the YBCO/BFO/YBCO, even with a 40 V bias voltage. PTCR was found after BFO breakdown of a YBCO/BFO/YBCO capacitor. This indicated that the conductivity of BFO is critical for PTCR. The dependence of PTCR on the superconducting transition temperature illustrates that a cooper-pair can be injected into BFO. Our work presents a method by which to produce a lead-free ceramic film material with PTCR.

A Freezing-Thawing Damage Characterization Method for Highway Subgrade in Seasonally Frozen Regions Based on Thermal-Hydraulic-Mechanical Coupling Model.

Seasonally frozen soil where uneven freeze-thaw damage is a major cause of highway deterioration has attracted increased attention in China with the rapid development of infrastructure projects. Based on Darcy's law of unsaturated soil seepage and heat conduction, the thermal-hydraulic-mechanical (THM) coupling model is established considering a variety of effects (i.e., ice-water phase transition, convective heat transfer, and ice blocking effect), and then the numerical solution of thermal-hydraulic fields of subgrade can be obtained. Then, a new concept, namely degree of freeze-thaw damage, is proposed by using the standard deviation of the ice content of subgrade during the annual freeze-thaw cycle. To analyze the freeze-thaw characteristics of highway subgrade, the model is applied in the monitored section of the Golmud to Nagqu portion of China National Highway G109. The results show that: (1) The hydrothermal field of subgrade has an obvious sunny-shady slopes effect, and its transverse distribution is not symmetrical; (2) the freeze-thaw damage area of subgrade obviously decreased under the insulation board measure; (3) under the combined anti-frost measures, the maximum frost heave amount of subgrade is significantly reduced. This study will provide references for the design of highway subgrades in seasonally frozen soil areas.

Timely and atomic-resolved high-temperature mechanical investigation of ductile fracture and atomistic mechanisms of tungsten.

Revealing the atomistic mechanisms for the high-temperature mechanical behavior of materials is important for optimizing their properties for service at high-temperatures and their thermomechanical processing. However, due to materials microstructure's dynamic recovery and the absence of available in situ techniques, the high-temperature deformation behavior and atomistic mechanisms of materials are difficult to evaluate. Here, we report the development of a microelectromechanical systems-based thermomechanical testing apparatus that enables mechanical testing at temperatures reaching 1556 K inside a transmission electron microscope for in situ investigation with atomic-resolution. With this unique technique, we first uncovered that tungsten fractures at 973 K in a ductile manner via a strain-induced multi-step body-centered cubic (BCC)-to-face-centered cubic (FCC) transformation and dislocation activities within the strain-induced FCC phase. Both events reduce the stress concentration at the crack tip and retard crack propagation. Our research provides an approach for timely and atomic-resolved high-temperature mechanical investigation of materials at high-temperatures.

Divergent Construction of Benzothiophene-Fused N-Heterocycles via Stereotunable Three-Component Domino Reactions.

A stereotunable three-component domino strategy among thioisatin, 2-bromo-1-phenylethan-1-one, and cyclohexane-1,2-diamine under catalyst-free conditions was disclosed. A wide range of benzothiophene-fused polycycles and eight-membered N-heterocycles were synthesized by regulating the stereoconfiguration of cyclohexane-1,2-diamines. The detailed mechanism and the origin of the chemoselectivity were explored by density functional calculations. Analysis of the geometrical structures of key transition states revealed that the existence of favorable intramolecular attractions, and the steric effect governed the chemoselectivity observed.

Full Concentration Gradient-Tailored Li-Rich Layered Oxides for High-Energy Lithium-Ion Batteries.

Lithium-rich layered oxides (LLOs) are prospective cathode materials for next-generation lithium-ion batteries (LIBs), but severe voltage decay and energy attenuation with cycling still hinder their practical applications. Herein, a series of full concentration gradient-tailored agglomerated-sphere LLOs are designed with linearly decreasing Mn and linearly increasing Ni and Co from the particle center to the surface. The gradient-tailored LLOs exhibit noticeably reduced voltage decay, enhanced rate performance, improved cycle stability, and thermal stability. Without any material modifications or electrolyte optimizations, the gradient-tailored LLO with medium-slope shows the best electrochemical performance, with a very low average voltage decay of 0.8 mV per cycle as well as a capacity retention of 88.4% within 200 cycles at 200 mA g-1 . These excellent findings are due to spinel structure suppression, electrochemical stress optimization, and Jahn-Teller effect inhibition. Further investigation shows that the gradient-tailored LLO reduces the thermal release percentage by as much as about 41% when the battery is charged to 4.4 V. This study provides an effective method to suppress the voltage decay of LLOs for further practical utilization in LIBs and also puts forward a bulk-structure design strategy to prepare better electrode materials for different rechargeable batteries.

Construction of Benzothiophene or Benzothiopheno[2,3-e]azepinedione Derivatives via Three-Component Domino or One-Pot Sequences.

An efficient three-component domino or one-pot strategy has been developed for the synthesis of medicinally important benzothiophene and benzothiopheno[2,3-e]azepinedione derivatives for the first time. Amine-promoted selective cleavage of C-S bond of thioisatin is the key step in this process. The reported methodology benefits from environmentally friendly solvent (H2O), wide substrate scope, good functional group tolerance, and high reaction yields.

Recent Advances in the Cycloaddition Reactions of 2-Benzylidene-1-benzofuran-3-ones, and Their Sulfur, Nitrogen and Methylene Analogues.

Benzothiophene, benzofuran, indole, and indene derivatives are privileged heterocyclic motifs. These are present in a wide range of bioactive natural products and pharmaceutical drugs and are the subject of materials science research. However, the construction of benzothiophene, benzofuran, indole, and indene frameworks have been long-standing challenges to organic chemists. In this review, we classify the derivatives of four structures synthesized from 2-benzylidene-1-benzofuran-3-one and their analogues in terms of their ring size (from three- to ten-membered) and type (fused or spiro), as well as summarizing the developments of this field. Finally, we discuss the ring opening and 1,4-addition reactions.

Tailoring Au Films at the Atomic Scale with an Electron Beam Tweezer.

A thin, clean pristine Au film created in a transmission electron microscope chamber was tailored by an electron beam. Various kinds of nanopatterns, including hexagonal holes and dumbbell-like patterns, were fabricated by different doses of the electron beam. A high-quality series of in situ images were recorded to explore the irradiation mechanism. The electron-matter collision enabled the electron beam to act as a tweezer to arrange atoms into a specified pattern.

Tunable Mechanical Property and Structural Transition of Silicon Nitride Nanowires Induced by Focused Ion Beam Irradiation.

Tailoring mechanical properties of the nanowire (NW) with intricate composite structure helps to design nanodevices with novel functionalities. Here, we performed in situ tensile deformation electron microscopy for the evaluation of the mechanical properties of the focused ion beam (FIB) irradiated silicon nitride (Si3N4) nanowires (NWs). Young's modulus of the FIB-fabricated NWs was mediated between the range of 522 and 65 GPa by modifying the shell thickness of the core-shell structure. The ion-beam-induced amorphization is found to induce the structural transition from an utter crystalline state to a composite NW with an amorphous shell, which results in a brittle-to-ductile transition and an unexpected plastic deformation. These results have practical implications for optimizing nanostructures with the desired mechanical properties, which are of fundamental relevance in designing and fabricating nanomechanical devices.

Low expression of organic anion-transporting polypeptide 1B3 predicts a poor prognosis in hepatocellular carcinoma.

OBJECTIVE: To detect the expression level of organic anion-transporting polypeptide 1B3 (OATP1B3) in hepatocellular carcinoma (HCC) and to determine the relationship between OATP1B3 expression, clinicopathological features, and prognosis. METHODS: Immunohistochemical (IHC) staining was performed to detect the expression of OATP1B3 in 131 HCC specimens and in 89 adjacent nontumorous tissues. Moreover, the expression levels of OATP1B3 in 30 pairs of tumor and matched adjacent nontumorous tissues were detected by quantitative real-time polymerase chain reaction, and 34 pairs of tumor and matched adjacent nontumorous tissues were detected by Western blotting. The χ2 test was applied to analyze the correlation between OATP1B3 expression and the clinical parameters of HCC patients. The prognostic value of OATP1B3 in HCC patients was estimated by Kaplan-Meier survival analysis and the Cox stepwise proportional hazards model. RESULTS: Compared with that in adjacent nontumorous tissues (25.8%, 23/89), OATP1B3 expression was significantly downregulated in tumor tissues (59.5%, 78/131) (P < 0.0001). Moreover, OATP1B3 expression was markedly correlated with tumor size, recurrence, tumor differentiation, and tumor node metastasis (TNM) stage (P < 0.05 for each). However, age, sex, tumor capsule status, HBsAg, cirrhosis, tumor number, vascular invasion, and serum alpha fetoprotein were not associated with OATP1B3 expression. The overall survival (OS) and disease-free survival (DFS) of HCC patients who had high expression of OATP1B3 were significantly longer than those of patients with low expression (33.0% vs 12.9%, P = 0.001; 18.8% vs 5.3%, P < 0.0001). Cox multivariate analysis showed that OATP1B3, invasion, and TNM stage (P < 0.05 for each) were independent prognostic factors of OS in HCC patients and that OATP1B3 and TNM stage (both P < 0.05) were independent prognostic factors of DFS in HCC patients. CONCLUSIONS: The expression of OATP1B3 in HCC patients was significantly lower than that in adjacent nontumorous tissues. OATP1B3 expression may be a potential prognostic marker in HCC patients.

Proximity-induced surface superconductivity in Dirac semimetal Cd3As2.

Cd3As2 is a three-dimensional Dirac semimetal with separated Dirac points in momentum space. In spite of extensive transport and spectroscopic studies on its exotic properties, the evidence of superconductivity in its surface states remains elusive. Here, we report the observation of proximity-induced surface superconductivity in Nb/Cd3As2 hybrid structures. Our four-terminal transport measurement identifies a pronounced proximity-induced pairing gap (gap size comparable to Nb) on the surfaces, which exhibits a flat conductance plateau in differential conductance spectra, consistent with our theoretical simulations. The surface supercurrent from Nb/Cd3As2/Nb junctions is also achieved with a Fraunhofer/SQUID-like pattern under out-of-plane/in-plane magnetic fields, respectively. The resultant mapping shows a predominant distribution on the top and bottom surfaces as the bulk carriers are depleted, which can be regarded as a higher dimensional analog of edge supercurrent in two-dimensional quantum spin Hall insulators. Our study provides the evidence of surface superconductivity in Dirac semimetals.

Targeting autophagy enhances heat stress-induced apoptosis via the ATP-AMPK-mTOR axis for hepatocellular carcinoma.

PURPOSE: Radiofrequency ablation (RFA) is widely accepted as a curative treatment for small hepatocellular carcinoma (HCC). However, insufficient RFA (IRFA) can lead to rapid local recurrence. The underlying mechanisms remain poorly understood. This study aimed to elucidate the role and regulatory mechanisms of autophagy in the recurrence of HCC after IRFA. MATERIALS AND METHODS: SMMC7721 and Huh7 cells were exposed to sublethal heat stress to stimulate the transition zone of IRFA treatment. The levels of autophagy were measured by western blot, immunofluorescence and transmission electron microscopy. Functional assays, such as CCK-8, EdU incorporation and flow cytometry, were performed to determine the role of heat-induced autophagy. The involved signaling pathways were explored by western blot. Finally, the antitumor effects of chloroquine (CQ) on heat-treated HCC cells were evaluated via an in vivo xenograft tumor model. RESULTS: Sublethal heat stress induced autophagy in a temperature- and time-dependent manner in HCC cells. Furthermore, the inhibition of autophagy by CQ or siRNA targeting the autophagy-related genes Beclin-1 and Atg5 enhanced heat-induced apoptosis. The combination of CQ and heat treatment significantly suppressed tumor growth both in vitro and in vivo. Mechanistically, we reported for the first time that the ATP-AMPK-mTOR signaling pathway was involved in heat-induced autophagy. CONCLUSIONS: Heat stress induced protective autophagy against heat-induced apoptosis in HCC via the ATP-AMPK-mTOR axis, suggesting that targeting autophagy may be a promising strategy for improving the efficacy of RFA treatment for HCC.

Synthesis of 4-Methoxy-1, 3-Benzenediolylhydrazones and Evaluation of Their Anti-Platelet Aggregation Activity.

In our present investigation, a series of novel 4-methoxy-1,3-benzenediolyl-hydrazones were designed and synthesized, and their ability to inhibit platelet aggregation was evaluated by adenosine diphosphate (ADP) and arachidonic acid (AA). The structures of the synthesized compounds were confirmed by spectral data. Results demonstrated that the activities of all compounds excelled the positive drug Picotamide (25.1% inhibition rate) and seven compounds (PNN01, PNN03, PNN05, PNN07, PNN09, PNN12, and PNN14) have efficiently inhibited platelet aggregation even higher than Clopidogrel (37.6% inhibition rate) induced by AA. Among them, PNN07 (39.8% inhibition rate) was considered as the most potent analogue. Evaluation of cytotoxic activity of the compounds against L929 cell line revealed that none of the compounds have significant cytotoxicity. Thus, diolylhydrazones derives are potential to be antiplatelet aggregation inhibitors and maybe working in AA-induced selectively.