Non-apoptotic ferroptosis is of clinical importance because it offers a solution to the inevitable biocarriers of traditional apoptotic therapeutic means. Inspired by industrial electro-Fenton ...technology featured with electrochemical iron cycling, we construct ferrous-supply-regeneration nanoengineering to intervene tumorous iron metabolism for enhanced ferroptosis. Fe3+ ion and naturally derived tannic acid (TA) spontaneously form a network-like corona onto sorafenib (SRF) nanocores. The formed SRF@FeIIITA nanoparticles can respond to a lysosomal acid environment with corona dissociation, permitting SRF release to inhibit GPX4 enzyme for ferroptosis initiation. TA is arranged to chemically reduce the liberated and the ferroptosis-generated Fe3+ to Fe2+, offering iron redox cycling to, thus, effectively produce lipid peroxide required in ferroptosis. Sustained Fe2+ supply leads to long-term cytotoxicity, which is identified to be specific to H2O2-overloaded cancer cells but minimal in normal cells. SRF@FeIIITA-mediated cell death proves to follow the ferroptosis pathway and strongly inhibits tumor proliferation. Moreover, SRF@FeIIITA provides a powerful platform capable of versatile integration between apoptosis and non-apoptosis means. Typically, photosensitizer-adsorbed SRF@FeIIITA demonstrates rapid tumor imaging owing to the acid-responsive fluorescence recovery. Together with ferroptosis, imaging-guided photodynamic therapy induces complete tumor elimination. This study offers ideas about how to advance anticancer ferroptosis through rational material design.
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IJS, KILJ, NUK, PNG, UL, UM
Selective laser melting (SLM) is a metal additive manufacturing (AM) technique that can fabricate complex parts of any shape. In this paper, the interfacial microstructure and mechanical properties ...of 316L/CuSn10 bimetallic structure were studied, and the ability of self-developed multi-material SLM equipment to form multi-material bimetallic structures was described. The investigations of 316L/CuSn10 bimetallic structure involved microscopic features, phase analysis, microhardness, tensile properties and bending properties. Moreover, the mechanical properties of multi-material specimens were compared with that of single material samples. In addition, scanning electron micrograph shows that the width of the bimetallic fusion zone is about 550 μm, and dendritic crack sources was found on the boundary between the bimetallic fusion zone and the steel region. In the direction perpendicular to the interface, the Vickers microhardness value gradually changed from 233.1 ± 8.1 HV in the steel zone to 154.7 ± 6.0 HV in the bronze zone. The non-standard tensile samples were printed and tested for evaluating tensile properties, the ultimate strength of 316L/CuSn10 joint was 423.3 ± 30.2 MPa comparing with the 316L stainless steel of 673.1 ± 4.2 MPa and the CuSn10 Tin-bronze of 578.7 ± 30.6 MPa. Tensile stress-strain curves and fracture characteristics show that the fusion zone of steel and bronze exhibits brittle fracture mechanism. Furthermore, three-point bending test was used to evaluate the interfacial bonding strength of the bimetallic structure, and results show that the maximum flexural strength of 316L/CuSn10 bimetallic structure isn't in middle of but below that of 316L stainless steel and CuSn10 Tin-bronze. The research founding that SLM can obtain 316L/CuSn10 bimetallic structure with good joint strength by adopting island scanning strategy and inter-layer stagger scanning strategy in the interfacial layers.
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IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Hybrid distribution transformer (HDT) is an integrated system of the conventional distribution transformer and the PWM converters, which can greatly enhance the controllability of the conventional ...distribution transformer and is important for the intelligence of the future distribution network, since HDT can support the AC–DC power network and control the voltage and current in real time. However, the impact current, over voltage, and saturation will lead to the start-up failure when an incorrect start-up scheme is adopted in HDT. Therefore, it is significant to design a reliable start-up scheme to guarantee a safe operation for HDT. Here, a three-phase circuit scheme and the control system of HDT are proposed. Then, a soft start-up scheme that can realise the constant-current charging for the DC bus capacitor is proposed. Specifically, the soft start-up scheme is based on the following measures, bypassing the DC-bus current-limiting resistors when the voltage of DC-bus capacitor exceeds the threshold, limiting the output of PI controllers during the start-up, separating the integral coefficient according to the DC-bus voltage error. Finally, the proposed start-up scheme is verified in MATLAB, which lays the foundation for the optimal design of the start-up scheme of HDT.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
This work aimed to investigate the martensitic transformation and precipitation of CoCrMo alloys fabricated by selective laser melting (SLM) under aging heat treatment. SLM-fabricated CoCrMo alloy ...was a mixture of γ-phase and ε-phase, and the content of γ-phase was about 70%. The content of ε-phase increased with the aging time. A nearly pure ε-phase was achieved by aging at 900 °C for 10 h in the SLM-fabricated part. After aging treatment for a short-time, the microhardness of the parts decreased comparing to the AS-SLM probably due to the disappearance of the honeycomb precipitates. The EDS results showed that those granular precipitates in SLM900 and SLM750 are M23C6. The content of M23C6 increased with aging time. The M23C6 precipitates and martensitic transformation enhanced the microhardness. Specimens with highest microhardness were obtained by aging at 900 °C for 10 h. This result established the relationship between the heat treatment process, microstructure and microhardness.
•CoCrMo alloys were fabricated by selective laser melting.•The honeycomb precipitates disappeared after solution heat treatment.•Long aging time and high aging temperature promoted martensitic transformation.•The quantity of carbides and microhardness increased with the aging time.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Hybrid distribution transformer (HDT) has powerful control ability, which is significant for the intelligentisation of the distribution network. A kind of HDT is presented here, the grid current ...control system of which is emphatic researched. Based on the mathematical model of ideal HDTs, a grid current control system is designed with quasi proportional-resonant controller (QPR). Using the characteristics that infinite gain and large bandwidth at the resonant frequency of QPR controller, the grid current system achieve the effects of unit power factor and sinusoidal symmetrical waveform. Tracking control with no static error of grid current was achieved in MATLAB. Compared with the traditional PI control, QPR controller can modulate AC signals in the static coordinate system, rather than rotary coordinate system. So the QPR controller has advantages of lower steady-state error, stronger anti-interference ability, and simpler calculation. Simulation results show that it has good dynamic and steady performance.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Metastasis and recurrence are two unavoidable and intractable problems in cancer therapy, despite various robust therapeutic approaches. Currently, it seems that immunotherapy is an effective ...approach to solve these problems, but the high heterogeneity of tumor tissue, inefficient presentation of tumor antigen, and deficient targeting ability of therapy usually blunt the efficacy of immunotherapy and hinder its clinical application. Herein, an approach based on combining photodynamic and immunological therapy was designed and developed. We synthesized a chimeric peptide, PpIX-1MT, which integrates photosensitizer PpIX with immune checkpoint inhibitor 1MT via a caspase-responsive peptide sequence, Asp-Glu-Val-Asp (DEVD), to realize a cascaded synergistic effect. The PpIX-1MT peptide could form nanoparticles in PBS and accumulate in tumor areas via the enhanced penetration retention effect. Upon 630 nm light irradiation, the PpIX-1MT nanoparticles produced reactive oxygen species, induced apoptosis of cancer cells, and thus facilitated the expression of caspase-3 and the production of tumor antigens, which could trigger an intense immune response. The subsequently released 1MT upon caspase-3 cleavage could further strengthen the immune system and help to activate CD8+ T cells effectively. This cascaded synergistic effect could inhibit both primary and lung metastasis tumor effectively, which may provide the solution for solving tumor recurrence and metastasis clinically.
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IJS, KILJ, NUK, PNG, UL, UM
We report on the benzoporphyrin-based metal–organic framework (TBP-MOF), with 10-connected Zr6 cluster and much improved photophysical properties over the traditional porphyrin-based MOFs. It was ...found that TBP-MOF exhibited red-shifted absorption bands and strong near-infrared luminescence for bioimaging, whereas the π-extended benzoporphyrin-based linkers of TBP-MOF facilitated 1O2 generation to enhance O2-dependent photodynamic therapy (PDT). It was demonstrated that poly(ethylene glycol)-modified nanoscale TBP-MOF (TBP-nMOF) can be used as an effective PDT agent under hypoxic tumor microenvironment. We also elucidated that the low O2-dependent PDT of TBP-nMOF in combination with αPD-1 checkpoint blockade therapy can not only suppress the growth of primary tumor, but also stimulate an antitumor immune response for inhibiting metastatic tumor growth. We believe this TBP-nMOF has great potential to serve as an efficient photosensitizer for PDT and cancer immunotherapy.
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IJS, KILJ, NUK, PNG, UL, UM
Hypoxia, a ubiquitously aberrant phenomenon implicated in tumor growth, causes severe tumor resistance to therapeutic interventions. Instead of the currently prevalent solution through intratumoral ...oxygen supply, we put forward an “O2-economizer” concept by inhibiting the O2 consumption of cell respiration to spare endogenous O2 and overcome the hypoxia barrier. A nitric oxide (NO) donor responsible for respiration inhibition and a photosensitizer for photodynamic therapy (PDT) are co-loaded into poly(d,l-lactide-co-glycolide) nanovesicles to provide a PDT-specific O2 economizer. Once accumulating in tumors and subsequently responding to the locally reductive environment, the carried NO donor undergoes breakdown to produce NO for inhibiting cellular respiration, allowing more O2 in tumor cells to support the profound enhancement of PDT. Depending on the biochemical reallocation of cellular oxygen resource, this O2-economizer concept offers a way to address the important issue of hypoxia-induced tumor resistance to therapeutic interventions, including but not limited to PDT.
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IJS, KILJ, NUK, PNG, UL, UM
In this research, a body-center-cubic (BCC) gradient porous structure has been designed. Selective laser melting (SLM) was used to fabricate the Ti6Al4V BCC gradient porous structures. The effects of ...different heat treatments on the microstructure and mechanical properties were investigated by X-ray diffraction, scanning electron microscopy and compression tests. The microstructure morphologies show that α laths became coarser and amount of nano-sized β particles decreased after higher temperature solution heat treatment. The fracture morphologies show that fracture mechanism of Ti6Al4V gradient porous structure changed from brittle fracture to ductile fracture after heat treatment at 800 °C for 120 min and furnace cooling (SLM800FC). The energy absorption mode can be optimized by solution heat treatment and the energy absorption at ε = 50% of SLM800FC is 76.40 ± 12.65 MJ/m3, which is the highest value among the five group. These findings suggest that the gradient structure and specific heat treatment can improve the stability and predictability of Ti6Al4V porous structure.
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IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UM, UPCLJ, UPUK, ZRSKP
Low strength and poor performance of SiC–WC composite for seals, attributable to the use of a large amount of liquid phase sintering additives, limit the application prospects of these materials. ...This study focuses on preparing high-strength, high-toughness, and wear-resistant SiC–WC composite using a small amount of aluminum and carbon black as sintering additives. The results revealed that the specimen containing 50 wt% WC exhibited the maximum flexural strength and fracture toughness of 645.9 MPa and 7.49 Mpa m1/2, respectively. These improvements were attributed to the deoxidizing and solid-solution effects of Al and the reinforcing effect of the WC second phase. Moreover, the specific wear rate was measured at 8.06 × 10−7 mm3 N−1 m−1, which was 56.9 % lower than that of monolithic SiC. Results from Raman spectral analysis provided evidence of the presence of W–O bonds on the wear surface, indicating that the SiO2 film could be successfully replaced by a WO3 film.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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