Search

Two A2B2-type zinc(II) porphyrin-modified organic polymers Poly(ZnEtPpI2/BDDA) and Poly(ZnMePpI2/BDDA) were synthesized by the free-radical copolymerization of flexible 1,4-butanediol diacrylate (BDDA) with novel A2B2-type zinc(II) porphyrins ZnEtPpI2and ZnMePpI2, respectively. The characterizations of both were carried out successfully. The two organic polymers had abundant dual-function sites (Zn2+and I–) and excellent adsorption capacity for solvent, showing high catalytic activity for the CO2fixation to cyclic carbonate under the conditions of 120 °C and 1.0 MPa CO2. Specifically, Poly(ZnEtPpI2/BDDA) displayed the highest catalytic activity with a TOF of 1480 h–1for the cycloaddition of CO2and epichlorohydrin (ECH) and wide applicability for different epoxides. Moreover, the Poly(ZnEtPpI2/BDDA) showed excellent stability and could be recycled at least 7 times. Finally, the kinetic experiments confirmed that Poly(ZnEtPpI2/BDDA) was a promising catalyst with a relatively low activation energy (35.3 kJ/mol) for the fixation of CO2to cyclic carbonate.

Background: Missed early gastric cancer (MEGC) is prevalent during esophagogastroduodenoscopy (EGD), which is the first-line recommended strategy for detecting early gastric cancer (EGC). Hence, we explored the risk factors for MEGC and different types of MEGC, based on the endoscopic resected population. Methods: This retrospective, case–control study was conducted at Nanjing Drum Tower Hospital (NJDTH). We included patients who were diagnosed with EGC during screening EGD, underwent endoscopic resection, and were confirmed by postoperative pathology at the NJDTH from January 2014 to December 2021, and classified them into different types according to the different root causes of misses. Univariable, multivariable, subgroup and propensity score analyses were used to explore the risk factors for MEGC and different types of MEGC. Results: A total of 447 patients, comprising 345 with initially detected early gastric cancer (IDEGC) and 102 with MEGC, were included in this study. Larger size (≥ 1 cm) (OR 0.45, 95% CI 0.27–0.74, P= 0.002) and invasion depth of submucosa (OR 0.26, 95% CI 0.10–0.69, P= 0.007) were negatively associated with MEGC. Use of sedation (OR 0.32, 95% CI 0.20–0.52, P< 0.001) and longer observation time (OR 0.60, 95% CI 0.37–0.96, P= 0.034) exhibited protective effect on MEGC. Conclusions: Smaller and more superficial EGC lesions are more susceptible to misdiagnosis. The use of sedation and prolonged observation time during EGD could help reduce the occurrence of MEGC.

• The effects of homogenization, ageing, hot extrusion and cold drawing on the microstructure, properties and electrical conductivity of Al-0.2Zr-0.06Sc wires are systematically investigated. • The adequate precipitation of solute atoms and avoidance of formation of fine recrystallized grains is the key to achieving high electrical conductivity of Al-Zr-Sc alloy wire. • The mechanism of strength and electrical conductivity changed by processing paths were clarified. Understanding and clarifying the evolution of microstructure and performance of Al-Zr-Sc alloy wires during processing paths is a crucial issue in developing heat-resistant conductors with high strength and high electrical conductivity (EC). In this study, the microstructure evolution and corresponding performance changes of Al-0.2Zr-0.06Sc alloy wires produced by three processing paths are investigated. Results indicate that ageing treatment + hot extrusion + cold drawing processing path can produce the highest strength Al-Zr-Sc wires attributed to favorable interactions among precipitation strengthening of Al 3 (Zr,Sc) phases, grain boundary strengthening and dislocation strengthening. High EC is attained by the hot extrusion + ageing treatment + cold drawing processing path, which reveals the importance of dynamic precipitation of Al 3 Sc phases during hot extrusion and further precipitation of solute atoms during ageing treatment for improving the EC. The processing path using hot extrusion + cold drawing + ageing treatment achieves the highest EC of the Al-Zr-Sc wire, but the strength decreases significantly due to the loss of dislocation strengthening. Additionally, the pinning effect of Al 3 Sc and Al 3 (Zr,Sc) ensures good heat resistance of Al-Zr-Sc wires. These results provide guidance for the process design of Al-Zr-Sc wires with variable combinations of strength and EC. [Display omitted] [ABSTRACT FROM AUTHOR]

Lattice metamaterials based on three-period minimum surface (TPMS) are an effective means to achieve lightweight and high-strength materials which are widely used in various fields such as aerospace and ships. However, its vibration and noise reduction, and damping properties have not been fully studied. Therefore, in this study, the TPMS structures with parameterization were designed by the method of surface migration, and the TPMS structures with high forming quality was manufactured by laser powder bed fusion (LPBF). The mechanical properties and energy absorption characteristics of the beam and TPMS structures were studied and compared by quasi-static compression. The modal shapes of the beam lattice structures and TPMS structures were obtained by the free modal analysis, and the damping properties of two structures were obtained by modal tests. For the two structures after heat treatment with the same porosity of 70%, the yield strength of the beam lattice structure reaches 40.76 MPa, elastic modulus is 20.38 GPa, the energy absorption value is 32.23 MJ·m−3, the damping ratio is 0.52%. The yield strength, elastic modulus, energy absorption value and damping ratio of the TPMS structure are 50.74 MPa, 25.37 GPa, 47.34 MJ·m−3, and 0.99%, respectively. The results show that TPMS structures exhibit more excellent mechanical properties and energy absorption, better damping performance, and obvious advantages in structural load and vibration and noise reduction compared with the beam lattice structures under the same porosity.

We theoretically show the asymmetric spin wave transmission in a coupled waveguide–skyrmion structure, where the skyrmion acts as an effective nanocavity allowing the whispering gallery modes for magnons. The asymmetry originates from the chiral spin wave mode localized in the circular skyrmion wall. By inputting two-tone excitations and mixing them in the skyrmion wall, we observe a unidirectional output magnon frequency comb propagating in the waveguide with a record number of teeth (>50). This coupled waveguide–cavity structure turns out to be a universal paradigm for generating asymmetric magnon frequency combs, where the cavity can be generalized to other magnetic structures that support the whispering gallery mode of magnons. Our results advance the understanding of the nonlinear interaction between magnons and magnetic textures and open a new pathway to exploring the asymmetric spin wave transmission and to steering the magnon frequency comb.

Photoreceptor spacing on adaptive optics imaging was significantly correlated with blood–retinal–barrier permeability and perfusion on intravenous fluorescein angiography in patients with diabetic retinopathy. Future studies with larger sample sizes are needed to understand the relationship between adaptive optics imaging and intravenous fluorescein angiography parameters in diverse patient populations.

Purpose:To present a rare case of subfoveal choroidal neovascular membrane (CNVM) secondary to idiopathic intracranial hypertension. Methods:A case was evaluated. Results:A 21-year-old woman presented with a 2-week history of painless blurred vision in the right eye. She described initial metamorphopsia and intermittent bitemporal headaches lasting 30 minutes. She denied pain with eye movements and a history of trauma. Her body mass index was 49 kg/m2. The visual acuity (VA) was 20/320 OD and 20/20 OS; there was no relative afferent pupillary defect. A dilated fundus examination showed bilateral optic disc edema and a subfoveal CNVM in the right eye. The patient was started on oral acetazolamide 500 mg twice daily and treated with 2 intravitreal antivascular endothelial growth factor (anti-VEGF) injections. Three months later, the VA was 20/30 in the right eye and the disc edema had improved. Conclusions:CNVMs in the setting of idiopathic intracranial hypertension–related papilledema may be subfoveal and have an excellent response to anti-VEGF agents.

Additive manufacturing technology is highly regarded due to its advantages, such as high precision and the ability to address complex geometric challenges. However, the development of additive manufacturing process is constrained by issues like unclear fundamental principles, complex experimental cycles, and high costs. Machine learning, as a novel artificial intelligence technology, has the potential to deeply engage in the development of additive manufacturing process, assisting engineers in learning and developing new techniques. This paper provides a comprehensive overview of the research and applications of machine learning in the field of additive manufacturing, particularly in model design and process development. Firstly, it introduces the background and significance of machine learning-assisted design in additive manufacturing process. It then further delves into the application of machine learning in additive manufacturing, focusing on model design and process guidance. Finally, it concludes by summarizing and forecasting the development trends of machine learning technology in the field of additive manufacturing.

This work presents the design and analytical model of a novel flexure hinge with variable elliptical-fillet cross-section, which can be considered as an extension of existing results on rectangular and/or circular cross-sectional flexure hinges. The closed-form solutions in full degrees of freedom were derived for the compliance, rotational precision, and the maximum von Mises stress under various loads. To validate the analytical model, the theoretical results were compared with finite element analysis based on a set of parabolic notched flexure hinges. Finally, numerical simulations were conducted to evaluate the impact of the cross-sectional geometric parameters on the compliance and stress performance of the flexure hinges. The proposed method casts a unified framework on extended flexure hinges with a cross-sectional shape, which facilitates the systematic optimizations and performance evaluations of flexure hinges in various configurations.

High precision tracking of mechatronic systems is often subject to the adverse impact of various disturbances. In this article, a novel prescribed disturbance observer-based adaptive dynamic surface control scheme is proposed to solve the tracking control problem for a class of uncertain nonlinear systems with both mismatched disturbances and matched disturbances. More specifically, the dynamic surface control technique is introduced to eliminate the explosion of complexity problem in the existing backstepping-based design. The prescribed disturbance observers with pre-specified estimation accuracy are first designed to handle the mismatched disturbances, and the adaptive laws are synthesized to deal with the parametric uncertainties and the bound of matched disturbances. Moreover, it can be shown that the tracking error converges to an arbitrarily small neighborhood of zero. Finally, the proposed control algorithm is applied to a customize-designed high-precision motion stage driven by voice coil motors, where numerical simulations and real-time experiments demonstrate excellent tracking performance and disturbance rejection capability, achieving tracking precision error less than 0.5‰in multifrequency trajectory tracking.

Carbonaceous aerosols (CA) from anthropogenic emissions have been significantly reduced in urban China in recent years. However, the relative contributions of fossil and nonfossil sources to CA in rural and background regions of China remain unclear. In this study, the sources of different carbonaceous fractions in fine aerosols (PM2.5) from five background sites of the China Meteorological Administration Atmosphere Watch Network during the winter of 2019 and 2020 were quantified using radiocarbon (14C) and organic markers. The results showed that nonfossil sources contributed 44–69% to total carbon at these five background sites. Fossil fuel combustion was the predominant source of elemental carbon at all sites (73 ± 12%). Nonfossil sources dominated organic carbon (OC) in these background regions (61 ± 13%), with biomass burning or biogenic-derived secondary organic carbon (SOC) as the most important contributors. However, the relative fossil fuel source to OC in China (39 ± 13%) still exceeds those at other regional/background sites in Asia, Europe, and the USA. SOC dominated the fossil fuel-derived OC, highlighting the impact of regional transport from anthropogenic sources on background aerosol levels. It is therefore imperative to develop and implement aerosol reduction policies and technologies tailored to both the anthropogenic and biogenic emissions to mitigate the environmental and health risks of aerosol pollution across China.

The design of transfer lines is a key factor affecting the transmission performance of petroleum transportations in vacuum distillation units of the petrochemical industry. Therefore, this study established a simulation method to describe compressible fluids in transfer lines and validated this method using a planar nozzle model and industrial data. Subsequently, the simulation results of pressure, velocity, and Manumber distribution were analyzed and discussed for seven sets of industrial transfer lines. The results indicate that the structure of the transition section and connection section is the key factor affecting the performance of the transfer line, and the connection forms of horizontal direct insertion (Case 1) and gradual expansion (Case 4 and Case 5) help to reduce the pressure drop in the transition section and connection section. For this reason, based on Case 1, a detailed analysis was conducted on the internal flow field and pressure drop at the connection under different mass flow rates, and a universal optimization method was proposed to connect the transition section and low-speed section in the transfer line. The results show that the optimized structure can eliminate large eddies at the connection section and reduce the pressure drop by 36.8%. The modeling methodology and the results presented will be useful for evolving better designs of transfer lines accompanying compressible fluids.

Fault diagnosis is beneficial to process safety and quality improvement. Due to the high cost and time-consuming natures of labeling, most methods may encounter poor performance when there are noat sufficient labeled training samples. To address this issue, a semi-supervised method called dynamic reconstruction feature-based graph attention networks (DRF-GAT), which incorporates dynamic reconstruction feature (DRF) and graph attention networks (GAT), is developed for process fault diagnosis. The proposed DRF-GAT focuses on exploiting the similarity information between samples by graph-based semi-supervised learning (GSSL) to make use of the unlabeled samples. The potential dynamic features are extracted from temporal dimension of samples by DRF, while GAT is used to aggregate information from similar samples and enable samples of the same type to obtain similar expressions. Using DRF, the similarities between samples can be measured reasonably. Finally, the effectiveness of the proposed method is verified by the Tennessee Eastman (TE) process case studies.

Biochar as a soil amendment has recently gained popularity in China. However, the effect sizes of biochar application on rice yield and soil quality in a low-productivity paddy soil shows great uncertainties. A 4-year field experiment was conducted to evaluate how biochar and inorganic NPK fertilizers applied affect rice yield and soil quality variables. The experiment included four treatments: Control (without biochar and NPK fertilizers applied), NPK (inorganic fertilizers applied alone), Biochar (biochar addition alone), NPKB (both NPK fertilizers and biochar applied). Soil samples from both soil layers (0–15 cm and 15–30 cm) were collected and evaluated for sixteen soil physicochemical and biological parameters. Compared to NPK fertilizers, biochar was less effective for increasing 4-year average rice yield (5.9% vs. 47.6%). Yet, biochar was more effective than NPK fertilizers for increasing soil quality variables (e.g. soil organic carbon, total N, available P, and pH). Soil exchangeable K, NH4+, and pH were important predictors of rice yield response. Partial least squares path modelling analysis showed that both biochar and chemical fertilization increased rice yield mainly via improving nutrients status of soil. The co-application of biochar and NPK fertilizers had the highest rice yield (9.81 t ha–1) and soil quality index (SQI). A significantly positive relationship was observed between SQI and rice yield, indicating that soil quality played an essential role in boosting rice productivity.The NPKB was a benefit practice for improving both rice grain yield and soil quality in yellow clayey paddy soil.

Aim: Pediatric pneumonia, a common disease, is the major cause of mortality in young children in China. However, the knowledge, attitude, and practice (KAP) of parents in China on etiologies, prevention, and care of pediatric pneumonia are still unclear. Here we investigated the KAP of parents on pediatric pneumonia. Subject and methods: This cross-sectional study enrolled parents in the Yungang area, Fengtai, Beijing and surrounding areas from September 1, 2022 to October 31, 2022. The demographic characteristics of subjects were collected for KAP score evaluation. The KAP scores of parents with different demographic characteristics were compared. Results: In total, 502 subjects participated in this study, of which the mean knowledge score was 9.61 ± 3.25, the attitude score was 33.85 ± 4.03, and the practice score was 17.87 ± 2.38. The findings showed that gender, age, residence, education, medical-field work, income per capita, previous pediatric pneumonia, and smoking significantly differed in knowledge score (P< 0.05). Gender, residence, education, and previous pediatric pneumonia were significantly different in attitude score (P< 0.05). Parental age, children's numbers, and smoking were significantly different in practice score (P< 0.05). Conclusion: Parents of young children exhibit a good attitude and practice toward prevention and treatment of pediatric pneumonia, while the relevant knowledge about the same disease was lower. It was recommended to carry out further studies in different regions; government and health institutions could take steps to improve the KAP of parents.

This article explores deep reinforcement learning (DRL) for the flocking control of unmanned aerial vehicle (UAV) swarms. The flocking control policy is trained using a centralized-learning-decentralized-execution (CTDE) paradigm, where a centralized critic network augmented with additional information about the entire UAV swarm is utilized to improve learning efficiency. Instead of learning inter-UAV collision avoidance capabilities, a repulsion function is encoded as an inner-UAV “instinct.” In addition, the UAVs can obtain the states of other UAVs through onboard sensors in communication-denied environments, and the impact of varying visual fields on flocking control is analyzed. Through extensive simulations, it is shown that the proposed policy with the repulsion function and limited visual field has a success rate of 93.8% in training environments, 85.6% in environments with a high number of UAVs, 91.2% in environments with a high number of obstacles, and 82.2% in environments with dynamic obstacles. Furthermore, the results indicate that the proposed learning-based methods are more suitable than traditional methods in cluttered environments.

Introduction:To review the literature regarding surgical management of full-thickness macular holes (FTMHs) spontaneously arising from lamellar MHs (LMHs). Methods:The literature on surgically managed FTMHs arising from LMHs was reviewed via Ovid MEDLINE and Embase through June 5, 2022. Results:Seventy-six eyes from 16 articles were included. Forty eyes had internal limiting membrane (ILM) peeling, 32 inverted ILM flap techniques, and 4 an unclear surgical technique. The FTMH closure rate was not significantly different between ILM peeling (34/40 [85%]) and the inverted ILM flap techniques (28/32 [88%]) (P= .761). The mean (±SD) logMAR visual acuity improved from 0.64 ± 0.46 to 0.25 ± 0.22 (Snellen 20/87 to 20/36) with ILM peeling (n = 30); similar data were not available for inverted ILM flap techniques. Conclusions:Foveal tissue loss, flat hole edges, and limited retinal hydration may result in inverted ILM flap techniques having outcomes similar to those of ILM peeling in repairing FTMHs from LMHs. Future studies are needed to compare techniques.

Aspongamide F (1), a novel N-acetyldopamine (NADA) dimer possessing a 6/6/6 ring system, and (±)-aspongamides G (2) and H (3), rare NADA derivatives with fragmented benzene rings, were isolated from Aspongopus chinensis. (±)-Cicadamides C (4) and D (5), the first 1,4-Benzodioxane NADA dimers featuring a seco-benzene system, and (±)-cicadamides E (6) and F (7), the NADA dimers derivatives, were isolated from Periostracum cicadae. The structures of all compounds were elucidated by spectroscopic analyses and computational methods. A plausible biosynthetic pathway for compounds 1–5was proposed. The biological assay revealed that (+)–4and (−)–4exhibit renal protection in a dose-dependent manner.

In this article, we consider the disturbance observer (DOB) design supporting high performance nano-positioning with sensor-induced time delays, where the standard robust disturbance observer design methodology is extended to time-delay systems by employing an infinite dimensional approach. In particular, the dynamic model including the piezo-induced hysteresis and the measurement delays are investigated and the infinite dimensional $\mathcal {H}^\infty$ optimization problem is formulated to achieve an optimal Q-filter design in the DOB control framework. The fragility resulting from unstable pole-zero cancellations in the infinite dimensional Q-filter is further discussed and the direct-moment-matching-based rational approximation is developed for stable digital implementations of the proposed method. Comprehensive experimental studies are conducted on a piezo-actuated stage, where the proposed method successfully demonstrates excellent performances on hysteresis compensation, disturbance suppression, and trajectory tracking, significantly outperforming existing approaches.

This article presents the first experimental demonstration of an energy-efficient electronic-photonic co-designed transceiver circuit heterogeneously 3D co-integrated with high-density, low-parasitic Direct Bond Interconnect (DBI) featuring 32-channel microdisk modulator/filter based optical transceivers for Wavelength Division Multiplexing (WDM) scheme. The silicon photonic chip is fabricated in AIM Photonics' integrated photonic technology, and the optical transceiver chip is fabricated in GlobalFoundries 12 nm FinFET process. The optical transmitter consumes 2.823 mW at 18 Gb/s, with 1.2 Vppd electrical modulation differential swing, and achieves an extinction ratio of 7 dB. The optical receiver utilized quarter-rate sampling via Injection-Locked Oscillator (ILO) and forward clocking architecture, consumes 6.11 mW, and achieves the Optical Modulation Amplitude (OMA) sensitivity of −20.3 dBm at 12 Gb/s under the photodiode responsivity of 0.8 A/W. The receiver can further operate at 25 Gb/s with a sensitivity of −17.01 dBm and 191 fJ/bit. The transceiver pair at 18 Gb/s achieves 496 fJ/bit link efficiency.

This study reports the synthesis of Ni-TiN composite nanocoatings on a Q235 steel matrix using the electrodeposition technique, and were then treated at different temperatures. The surface morphology, structure, hardness, and abrasion performances of composite nanocoatings were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), and friction-abrasion testing machine. SEM images illustrated smooth/dense surface morphology for Ni-TiN composite nanocoatings treated at 250 °C. XRD patterns revealed Ni and TiN phase appearance within Ni-TiN composite nanocoatings. The broader and low-intensity XRD peaks were observed for the composite following heat treatment at 250 °C, indicating the smallest size of TiN particle and Ni grain. Furthermore, Ni-TiN composite nanocoatings exhibited the highest hardness of 821 Hv following heat treatment at 250 °C. The frictional coefficient, wear rate, and indentation depth for Ni-TiN composite nanocoatings were found to be lowest at 0.45, 0.58 mg/min, and 13.8 μm, respectively after heat treatment at 250 °C. Furthermore, the Ni-TiN composite nanocoatings had peak abrasion resistance across three composite nanocoatings following heat treatment at 250 °C.

Various piezoelectric beam based approaches have been well studied to support vibrational energy harvesting, where the natural frequency of the energy harvester is purposely designed to match the external vibrations. Note that the external vibrations usually exhibit a low frequency nature, which significantly limits the output of piezoelectric beam based energy conversion because the operational frequency for such systems is much higher. In this work, we propose a novel compliant mechanism based energy harvester combining the piezoelectric beam structure with a multi-stable compliant mechanism, which is capable of harvesting vibrational energy with multiple frequency up conversion modes to improve the efficiency of such systems. The proposed design is developed and analyzed from electro-mechanical perspective. A prototype of the proposed method is designed and comprehensively evaluated in various experiments to verify the performance and effectiveness of the piezoelectric energy harvester.

Oxoglutarate dehydrogenase-like (OGDHL) is considered to be the isoenzyme of oxyglutarate dehydrogenase (OGDH) in the OGDH complex, which degrades glucose and glutamate. OGDHL was reported to reprogram glutamine metabolism to suppress HCC progression in an enzyme-activity-dependent manner. However, the potential subcellular localization and non-canonical function of OGDHL is poorly understood. We investigated the expression of OGDHL and its effect on HCC progression. By employing a variety of molecular biology techniques, we revealed the underlying mechanism of OGDHL-induced DNA damage in HCC cells in vitro and in vivo. AAV loaded with OGDHL exerts therapeutic effect on mouse HCC and prolongs survival time. OGDHL induces DNA damage in HCC cells in vitro and in vivo. We also observed that OGDHL possesses nuclear localization in HCC cells and OGDHL-induced DNA damage was independent of its enzymatic activity. Mechanistically, it was demonstrated that OGDHL binds to CDK4 in the nucleus to inhibit the phosphorylation of CDK4 by CAK, which in turn attenuates E2F1 signaling. Inhibition of E2F1 signaling downregulates pyrimidine and purine synthesis, thereby inducing DNA damage through dNTP depletion. We clarified the nuclear localization of OGDHL and its non-canonical function to induce DNA damage, which demonstrated that OGDHL may serve as a select potential therapeutic target for HCC.

Purpose:To report a case of acquired conforming-type focal choroidal excavation (FCE) secondary to a pachychoroid choroidal neovascular membrane (CNVM) triggered by central serous chorioretinopathy (CSCR). Methods:A case and its findings were analyzed. Results:A 54-year-old Asian man who had spontaneous resolution of CSCR in the right eye presented with a pachychoroid CNVM and FCE 1 year after the initial CSCR diagnosis. Intravitreal antivascular endothelial growth factor injections were initiated, and the subretinal fluid and intraretinal hemorrhage resolved. The patient was followed for FCE progression for 3 years. Conclusions:Acquired FCE can occur secondary to CSCR and pachychoroid CNVM. The pathogenesis may be focal choroidal ischemia, choroidal vascular collapse, and fibrosis leading to choroidal excavation. This case highlights the progression of the spectrum of pachychoroid disorders from CSCR, pachychoroid CNVM, and subsequent acquired confirming-type FCE. Further research is needed to assess other diseases leading to acquired FCE and to determine the underlying mechanism.

In this study, to improve pulverization of Fe–Si alloy, the evolution of its microstructure under container and containerless solidification conditions were investigated using electromagnetic levitation melting technology. The results indicated that the microstructure changed from dendritic crystals during container solidification to equiaxed crystals with containerless solidification. With an undercooling of 280Kobtained by containerless solidification, the pulverizing sensitive elements (Al, P) disperse better in FeSi2phase. The equiaxed Si grains with relatively uniform grain size obtained under ΔT=280Kare distributed in random orientation. High angle grain boundaries are significantly more present with the increase of misorientation within FeSi2grains. This texture is closely related to recrystallization in favor of grain refinement, which is attributed to the melt oscillation and dendrites remelting-recrystallization effects occurring in containerless solidification.

Wire arc additive manufacturing (WAAM) is a kind of additive manufacturing technology with excellent development potential in recent years. This work aims to summarize the current research status and challenges in WAAM and provide quality improvement methods. The research status of WAAM in surface finish and forming accuracy, microstructure and mechanical properties, residual stress and deformation, porosity and other defects is given. The methods of eliminating the above shortcomings and improving the microstructure and mechanical properties are summarized from pre-processing, on-line processing and post-processing perspectives. It is concluded that there are still many challenges to the widespread adoption of WAAM, and various perspectives may be needed to achieve this. The development of path planning and slicing algorithm, the combination of online monitoring systems with existing WAAM equipment, and composite post-processing technology will be the key research directions in the future.

Ash content is an important factor affecting the quality and combustion performance of biochar. In this paper, a method of ash removal from biomass is proposed by carbonization followed by CO2-enhanced water leaching. The effects of the carbonization temperature of bagasse, the temperature and time of CO2-enhanced water leaching on the deashing were investigated. The results show that the deashing rate firstly increases and then decreases with the carbonization temperature, while the opposite trend is obtained with increasing the water leaching temperature and time. For bagasse biochar carbonized at 300 °C, the deashing rate reaches 57% at the water leaching temperature of 40 °C for 4 h. Compared with water leaching without carbonization, the proposed method can increase the content of fixed carbon and the char yield by 7% and 3%, respectively. It is because in the process of deashing, CO2diffuses and dissolves into water to form carbonic acid which reacts with part of metal salts to form water-soluble salts, resulting in the removal rate of K, Na and Ca up to above 50%, and part removal of calcite and dolomite. Also, the proposed process shows higher deashing efficiency and universality, but the deashing degree is closely related to the ash composition and kinds in biochar. As to peanut shell and poplar, the deashing rate exceeds 30% by carbonization at 300 °C and CO2-enhanced water leaching at 40 °C for 4 h.

Targeted inhibition of a drug efflux transporter P-glycoprotein (P-gp) is an important strategy to reverse multidrug resistance in cancer chemotherapy. In this study, a rationally structural simplification to natural tetrandrine was performed based on molecular dynamics simulation and fragment growth, leading to an easily prepared, novel, and simplified compound OY-101with high reversal activity and low cytotoxicity. Its excellent synergistic anti-cancer effect with vincristine (VCR) against drug-resistant cells Eca109/VCR was confirmed by reversal activity assay, flow cytometry, plate clone formation assay, and drug synergism analysis (IC50= 9.9 nM, RF = 690). Further mechanism study confirmed that the OY-101was a specific and efficient P-gp inhibitor. Importantly, OY-101increased VCR sensitization in vivowithout obvious toxicity. Overall, our findings may provide an alternative strategy for the design of novel specific P-gp inhibitor as an anti-tumor chemotherapy sensitizer.

As a new type of lightweight structure, metallic lattice structure has higher stiffness and strength to weight ratio. To freely obtain 316L lattice structures with designed cell structure and adjustable porosity, additive manufacturing combined with investment casting was conducted to fabricate the 316L lattice structures with Kelvin cell. The compression simulation of 316L lattice structures with different porosities was carried out by using the finite element method. The numerical simulation results were verified by compression experiment, and the simulated results were consistent with the compression tests. The compressive mechanical properties of 316L lattice structures are directly related to porosity and independent of strut diameters. The 316L lattice structures with Kelvin cell have a smooth stress-strain curve and obvious plastic platform, and the hump stress-strain curves are avoided.