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The pentose phosphate pathway (PPP) plays a crucial role in the material and energy metabolism in cancer cells. Targeting 6-phosphogluconate dehydrogenase (6PGD), the rate-limiting enzyme in the PPP metabolic process, to inhibit cellular metabolism is an effective anticancer strategy. In our previous study, we have preliminarily demonstrated that gambogic acid (GA) induced cancer cell death by inhibiting 6PGD and suppressing PPP at the cellular level. However, it is unclear whether GA could suppress cancer cell growth by inhibiting PPP pathway in mouse model. This study aimed to confirm that GA as a covalent inhibitor of 6PGD protein and to validate that GA suppresses cancer cell growth by inhibiting the PPP pathway in a mouse model. Cell viability was detected by CCK-8 assays as well as flow cytometry. The protein targets of GA were identified using a chemical probe and activity-based protein profiling (ABPP) technology. The target validation was performed by in-gel fluorescence assay, the Cellular Thermal Shift Assay (CETSA). A lung cancer mouse model was constructed to test the anticancer activity of GA. RNA sequencing was performed to analyze the global effect of GA on gene expression. The chemical probe of GA exhibited high biological activity in vitro. 6PGD was identified as one of the binding proteins of GA by ABPP. Our findings revealed a direct interaction between GA and 6PGD. We also found that the anti-cancer activity of GA depended on reactive oxygen species (ROS), as evidenced by experiments on cells with 6PGD knocked down. More importantly, GA could effectively reduce the production of the two major metabolites of the PPP in lung tissue and inhibit cancer cell growth in the mouse model. Finally, RNA sequencing data suggested that GA treatment significantly regulated apoptosis and hypoxia-related physiological processes. These results demonstrated that GA was a covalent inhibitor of 6PGD protein. GA effectively suppressed cancer cell growth by inhibiting the PPP pathway without causing significant side effects in the mouse model. Our study provides in vivo evidence that elucidates the anticancer mechanism of GA, which involves the inhibition of 6PGD and modulation of cellular metabolic processes. [ABSTRACT FROM AUTHOR]

Surface functionalization of diamonds is an important topic for the negatively charged nitrogen-vacancy (NV−) center based quantum sensors. We investigate the electronic properties of oxidized diamond (111) surfaces and their effects on the NV− centers using the density of functional theory. The results show that the epoxy oxidized diamond (111) surface has neither surface spin noises nor inter-bandgap states and also has a positive electron affinity (1.85 eV) with nearly 99% preferential alignment of nitrogen-vacancy, indicating the epoxy oxidized (111) surface could be a perfect host of the NV− centers. Additionally, we make further examinations by placing an NV− center ∼1 nm from the epoxy oxidized (111) surface. The results indicate that the epoxy oxidized (111) surface has no obvious effects on the defect levels and optical transitions of the single NV− center. To the best our knowledge, the epoxy oxidized (111)-(2 × 1) surface may be the first diamond surface that not only theoretically satisfies the electronic requirements of shallow NV− centers but can also be fabricated through the oxidization process. Therefore, the epoxy oxidized diamond (111)-(2 × 1) surface is the most promising candidate to be applied in NV-based quantum sensors. Image 1 [ABSTRACT FROM AUTHOR]

Highlights • Myricanol from the barks of Chinese bayberry was identified as an AMPK activator. • Myricanol inhibited adipogenesis in the initial stage of adipocytes differentiation. • Myricanol induced lipolysis and lipid oxidation in 3T3-L1 adipocytes. • Myricanol improved insulin sensitivity in mature adipocytes. • Myricanol attenuated lipid accumulation in high-fat diet-fed zebrafish. Abstract Myricanol is a diarylheptanoid isolated from Chinese bayberry. Through virtual docking strategy, myricanol was discovered as an AMP-activated protein kinase (AMPK) activator among a series of structural analogs, with high affinity for the γ subunit of AMPK. Myricanol was also evaluated for regulatory effects on lipid accumulation and insulin sensitivity in 3T3-L1 adipocytes and adiposity in high-fat diet-fed zebrafish. Myricanol suppressed lipid accumulation in 3T3-L1 cells in the initial stage (days 0–2) by suppressing adipogenesis and in the terminal stage (days 4–7) by inducing lipolysis and lipid combustion through activating AMPK. Moreover, myricanol enhanced insulin-stimulated glucose uptake by activating the insulin signaling pathway. In high-fat diet-fed zebrafish, myricanol inhibited lipid accumulation by suppressing adipogenic factors including peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding protein α (C/EBPα). In summary, the results indicate that myricanol could be a potential therapeutic agent against obesity by activating the AMPK signaling pathway. [ABSTRACT FROM AUTHOR]

The seeds of Clausena lansium have been used to treat acute and chronic gastro-intestinal disorders. To further explore its therapeutic value on metabolic diseases, a water soluble fraction from ethanolic extract of C. lansium seeds (HP) was evaluated on a high-fat diet (HFD) induced obesity mice model. The mice were fed with HFD for 8 weeks to induce obesity, and then orally administrated with HP for 9 weeks. The results showed HP treatment retarded body weight and fat mass gain of mice under HFD feeding. Moreover, HP significantly improved lipid profile and insulin sensitivity in HFD fed mice. 16S rRNA sequencing indicated that HP mildly reversed HFD feeding induced imbalance of Firmicutes/Bacteroidetes ratio in gut. Taken together, HP protects mice from HFD induced metabolic disorders and restores gut microbiota balance, which might be well developed as novel functional food for anti-obesity and improvement of insulin sensitivity. [ABSTRACT FROM AUTHOR]

The equipment and technological processes used in manufacturing electronic products are gradually being automated and networked. Currently, digital twin technology continues to evolve and mature. The electronics manufacturing industry is undergoing an intelligent and digital transformation. Micro-electro-mechanical system (MEMS) sensors have been widely used in the automotive field due to their small size, low cost, and high reliability. In this study, a new intelligent production line for automotive MEMS pressure sensors driven by digital twin is individually designed. The intelligent production line system consists of physical production lines, digital production lines, twin data, and data service systems. The technology of multi-source heterogeneous data acquisition is used to process and analyze data collected in real time in a physical production line. Based on the technology of parallel control, the physical and digital production lines are synchronized. To obtain optimal process parameters, a process database is established through the analysis of the key processes of the production line. Three types of automotive MEMS pressure sensors are successfully manufactured in the constructed digital twin-driven intelligent production line. The intelligent production line can realize 24-h unattended operation. The product yield is above 98 %, and the takt time is less than 16 s. [ABSTRACT FROM AUTHOR]

It has been reported that high corticosterone level could damage the normal hippocampal neurons both in vitro and in vivo. Furthermore, high concentration of corticosterone induced impair in PC12 cells has been widely used as in vitro model to screen neuroprotective agents. Cajaninstilbene acid (CSA), a natural stilbene isolated from Cajanus cajan leaves, has various activities. In present study, we investigated the effect of CSA on corticosterone-induced cell apoptosis and explored its possible signaling pathways in PC12 cells. We demonstrated that pretreatment with CSA at the concentrations of 1–8 μmol/L remarkably reduced the cytotoxicity induced by 200 μmol/L of corticosterone in PC12 cells by MTT, and further confirmed the neuroprotection by Hoechst 33342 and PI double staining and lactate dehydrogenase release (LDH) assay at the concentration of 8 μmol/L. Moreover, the cytoprotection of CSA was proved to be associated with the homeostasis of intracellular Ca 2+ , relieving corticosterone-induced oxidative stress by decreasing the contents of ROS and malondialdehyde (MDA), increasing the activities of superoxide dismutase (SOD) and catalase (CAT), and the stabilization of ER stress via down-regulating the expression of ER chaperone protein glucose-regulated protein 78 (GRP78), ER stress associated transcription factor C/EBP homologous protein (CHOP/GADD153), and the X box-binding protein-1 (XBP-1), as well as the expression of ER stress-specific protein caspase-12 and its downstream protein caspase-9. Considering all the findings, it is suggested that the neuroprotective activity of CSA against the impairment induced by corticosterone in PC12 cells was through the inhibition of oxidative stress and ER stress-mediated pathway. [ABSTRACT FROM AUTHOR]

• This paper first applies EI-TOF to the additive manufacturing process. • This paper is the first to monitor atmospheric composition during the L-DED process. • The degree of variation of the gases significantly changed with the laser power. Laser-based Directed Energy Deposition (L-DED) is a promising additive manufacturing technology, which has broad application prospects and practical value in many fields. The nondestructive testing technology of L-DED work piece quality monitoring requires high accuracy and capability for real-time process. This work developed an online monitoring system based on a miniature electron impact ion source time-of-flight mass spectrometer (EI-TOF) and a high-speed camera, which monitored the atmosphere above the molten pool area. The number of spatters was measured using a high-speed camera. The composition of the samples and spatters was measured by using element analyzer, inductively coupled plasma mass spectrometry, and electron spectroscopy. The variation in the atmosphere was measured using EI-TOF, and the results confirmed that the O 2 , N 2 and H 2 O content decreased during the L-DED process. At the laser power of 400 W, the oxygen consumptions were 92.5% and 86.4% compared with those at the laser power of 500 W and 600 W, respectively. During the L-DED process, the number of spatters decreased when the laser power was increased from 400 W to 600 W. And at the laser power of 600 W, the average number of spatters was reduced to 59.3% compared with the laser power of 400 W. It can be found that dust contained a large amount of virgin powder and little spatters. It also can be found that at the laser power of 400 W, 500 W and 600 W, the amount of oxygen in the dust was 0.544%, 0.242% and 0.159%, respectively. The relative content of oxygen in the cross section of the seam was 35.58%, 43.79% and 44.30%, respectively. The deviation of the monitoring results (H 2 O, N 2 , O 2) are significant at the same power when different materials was used as the substrate. [ABSTRACT FROM AUTHOR]

Abstract: Bit-patterned media are being considered as a promising approach for achieving multi-terabit per inch recording densities. The effects of different recording density of bit-patterned media of mechanical surface loading on deformation of elastic-plastic multi-layers are analyzed by using the finite element method. The thermal protrusion of a thermal flying height control (TFC) slider and the wave surface of an elastic-plastic thin film are chosen to perform a contact analysis at the head-disk interface (HDI). A two dimensional finite element model between head and patterned media is then developed. Two patterned media cases are investigated and presented in this paper. The evolution of deformation in multi-layer media due to mechanical surface loading is presented by maximum von Mises stress and contact pressure. [Copyright &y& Elsevier]

Abstract: The piezoelectric flying height control slider has recently been implemented in magnetic recording disk drives to reduce the flying height. This paper has examined the piezoelectric flying height control slider using shear-model deformation of piezoelectric transducer (PZT). A finite element model of the PZT slider using shear-model deformation has been built, and the electromechanical simulation and air-bearing simulation have been performed to investigate the effects of the shear-model deformation on the static flying attitude of the PZT slider. The results show that the flying height and pitch angle of the PZT slider can be significantly reduced with an increase in the drive voltage on the PZT sheet. However, beyond the drive voltage of 80V for the proposed PZT slider, the reduction in the flying height of PZT slider is limited owing to the high air bearing stiffness at low flying height region. Furthermore, the PZT slider can be rotated and balanced at a negative pitch angle. [Copyright &y& Elsevier]

Artemisinin and its derivatives are the most effective antimalarial drugs. Besides anti-malarial activity, artemisinin and its derivatives have displayed wide-spectrum bioactivities such as anti-parasite, anti-tumor, and anti-obesity effects. Obesity is an epidemic worldwide which is a big threat to human health, but there are only a few approved anti-obesity drugs in the world. Also, these drugs are efficient to limited patients partly because their safety and efficacy are questioned. Anti-inflammatory therapies may be valuable in obesity treatment since growing evidence shows chronic metabolic inflammation is implicated in metabolic disease pathogenesis. As artemisinin and its derivatives display effective anti-inflammatory and immunoregulatory properties with less toxicity, it provides an insight for novel drug development in obesity therapeutic strategies via immune-regulatory mechanisms. In this review, the potential of artemisinin and its derivatives to treat various metabolic diseases such as obesity and diabetes is discussed. [ABSTRACT FROM AUTHOR]

• A new in-situ monitoring system was proposed to upscale resolution and extract geometric characteristics during AM process. • The proposed ViTSR performs better than the SOTA methods in terms of PSNR, which may reduce the cost of high-speed camera. • The molten pool and plasma arc can be simultaneously and accurately extracted by FCN with input of reconstructed frames. • The low-cost AI edge board reduces the inference time of ViTSR to 50.97 ms, which reduce the cost of computing in AM process. In additive manufacturing (AM), in-situ monitoring systems are vital for ensuring process quality. However, the widespread adoption of traditional high-speed camera-based monitoring systems is hindered by the prohibitively high cost of the required high-speed cameras. This paper introduces an innovative low-cost in-situ monitoring system that utilizes AI edge computing boards to expedite digital image processing without requiring high resolution (HR) video sequences. The system integrates a visual transformer-based video super resolution (ViTSR) network for reconstructing high resolution video frames and employs a fully convolutional network (FCN) to extract geometric characteristics of the molten pool and plasma arc simultaneously during AM processes. Comparing ViTSR with six state-of-the-art super-resolution methods, it achieved the highest peak signal-to-noise ratio (PSNR) of 38.16 dB on the test data. Moreover, the FCN utilized the reconstruction results from ViTSR, demonstrating an accuracy of 96.34% in multi-object extraction tasks. Through operator fusion and model pruning, the inference time of ViTSR and FCN on the AI edge board is optimized to 50.97 ms and 67.86 ms, respectively. Consequently, the proposed system achieves a total inference time of 118.83 ms, meeting the real-time quality monitoring needs of AM processes. Furthermore, this approach effectively reduces the expenses associated with high-speed camera-based monitoring systems, thereby promoting the widespread adoption of in-situ monitoring systems within the realm of AM. [ABSTRACT FROM AUTHOR]

• A method of 3D reconstruction for LPBF parts by light field camera is proposed. • Simple and high-precision calibration is achieved by the consistency method. • A LFEPI-Unet is designed for accuracy disparity reconstruction. • Accurately mapping of disparity, depth, and 3D spatial coordinates is established. • First-time application for in situ 3D reconstruction and monitoring of LPBF parts. The assessment of output quality in the laser powder bed fusion process entails the analysis of the three-dimensional morphology of the manufactured parts, which plays a crucial role in quality control to prevent metallurgical defects. This study proposes a novel approach of three-dimensional reconstruction for laser powder bed fusion parts using a light field camera. Initially, a consistency method for high-precision camera calibration was explored to determine the virtual camera pixel size and coefficient of effective focal length of light field camera. Subsequently, the model based light field epipolar-plane image Unet is designed to obtain disparity information without any data augmentation techniques. By leveraging both binocular and light field optical paths, a robust mapping relationship of the disparity, depth, and visually coherent three-dimensional contour was established. Finally, the three-dimensional contours of laser powder bed fusion parts were reconstructed by the established mapping with a single exposure of the light field camera. The proposed method enables three-dimensional contour visualization of laser powder bed fusion parts from multi-view perspectives, which facilitates in situ monitoring of the spattering distance, three-dimensional spatial points and lines of the printed layers and contours of printed parts. With a calibration error of 50 μm and resolution of 180 μm for the light field camera (Lytro illum camera), the maximum relative and absolute errors between reconstructed three-dimensional spatial points were 4.33 % and 260 μm respectively when compared with theoretical dimension, and 0.5 % and 210 μm respectively when compared with manufactured dimension. The maximum root-mean-square error of reconstructed three-dimensional contour surfaces was found to be 1.55 mm. This study represents the first application of a light field camera for in situ three-dimensional reconstruction of laser powder bed fusion parts, which notably can be obtained from only a single round of calibration and exposure, enabling seamless monitoring of their surface morphology and facilitating online quality control. These advancements have vast potential for enhancing high-end additive manufacturing. [ABSTRACT FROM AUTHOR]

• LSP was applied on the 50CrVA alloy to improve the mechanical properties. • Propagation characteristic of shock wave was investigated. • Influence of laser energy and spot diameter on residual stress was revealed. • Optimized process parameter and strength enhancement were obtained by LSP. Laser shock peening (LSP) was implemented to treat aircraft landing gear 50CrVA alloy to improve mechanical properties. The sensitivity investigations of time step and mesh size were used to benchmark the 3D finite element method (FEM) model. Based on the established FEM model, the dynamic propagation characteristics of the shock wave inside the sample were predicted. The influence of laser energy and spot diameter on the residual stress field was further investigated. The numerical results indicate that regulating two critical LSP parameters can effectively improve the compressive residual stress (CRS) of metals, and the spot diameter has a greater effect than the laser energy in improving the uniformity of the CRS distribution. After that, the influences of LSP on the CRS field, microstructure, and mechanical properties were experimentally studied. After LSP treatment, the surface CRS reached 494.8 ± 31.8 MPa with an affected depth of about 400 μm. The phase composition was not changed by LSP treatment, but it weakened texture strength and refines grains. Under the impact of grain refinement and CRS, the average surface microhardness of the 50CrVA alloy reached 355 HV, indicating an increase up to 5.3 %. The ultimate tensile strength and yield strength were increased by 11.3 % and 14.5 %, respectively, which were in contrast to the unchanged elongation. This work verifies the feasibility of mechanical properties enhancement of 50CrVA alloy by LSP. [ABSTRACT FROM AUTHOR]

Diamond (110) surface is one of the low-index diamond faces but its effects on nitrogen-vacancy (NV) based quantum sensor remain unclear. The fluorine, hydrogen, nitrogen, and oxygen-terminated diamond (110) surfaces used for the NV centers are proposed here, and their electronic properties are investigated based on first-principles calculations. The oxygen-terminated diamond (110) surface has inter-bandgap states and surface electron spins, the nitrogen-terminated (110) surface has inter-band gap states, and the hydrogen-terminated (110) surface has negative electron affinity. Thus, these three surfaces may not be suitable for shallow NV centers. The fluorine-terminated diamond (110) surface has positive electron affinity, no surface related inter bandgap states, and no surface electron spins, so it is a promising candidate for NV-based quantum sensors. [Display omitted] [ABSTRACT FROM AUTHOR]

Glycyrrhetinic acid (GA) shows great efficiency against non-small cell lung cancer (NSCLC), but the detailed mechanism is unclear, which has limited its clinical application. Herein, we investigated the potential targets of GA against NSCLC by activity-based protein profiling (ABPP) technology and the combination of histopathology and proteomics validation. In vitro and in vivo results indicated GA significantly inhibited NSCLC via promotion of peroxiredoxin-6 (Prdx6) and caspase-3 (Casp3)-mediated mitochondrial apoptosis. This original finding will provide theoretical and data support to improve the treatment of NSCLC with the application of GA. [Display omitted] • First-time integrated analysis profiling of non-small cell lung cancer (NSCLC) and Glycyrrhetinic acid (GA) treatment by integrating activity-based protein profiling (ABPP) technology, histopathology and proteomics validation both in vitro and in vivo. • Identification of GA promoted ROS accumulation and inhibited proliferation of NSCLC cells. • Identification of Casp3 and Prdx6 were direct target proteins of GA in the treatment of NSCLC cells. [ABSTRACT FROM AUTHOR]

The efficient and precise acquisition of hydrodynamic results in complex interaction scenarios for unmanned underwater vehicles (UUVs) presents a significant challenge. This study proposes a time-sequenced hydrodynamics prediction system of underwater vehicle based artificial intelligence edge computing. Firstly, a SE-CausalNet framework is proposed and a hydrodynamic prediction system for underwater vehicles is developed based on a neuromorphic computing chip. Secondly, the computational fluid dynamics (CFD) results of the Remus UUV are validated with experimental data. Two UUV motion cases are proposed to further elucidate hydrodynamics characteristics under the complex interference of submarines. Finally, the hydrodynamics of the UUV for two motion cases is analyzed, and four datasets are constructed to fully demonstrate the predictive capability of the system. Results show that the pressure field for the free offset path case differs remarkably from that of the fixed path case, and noticeable deviations are observed in both horizontal and vertical planes from the original fixed trajectory of the UUV. The prediction aligns well with CFD results, with a sample inference time within 0.3 s. The mean squared error of the four datasets is all below 2.6 × 10−4, indicating a rapid and highly accurate assessment of disturbance moments and trajectories. • The hydrodynamics characteristics of UUV during interactions with a submarine are investigated. • A hydrodynamics prediction system based on AI edge computing platform is developed. • It provides valuable insights to guide the design and motion control of UUVs. [ABSTRACT FROM AUTHOR]

• A multiphysics simulation model of LU inspection is established. • Propagation characteristics of excited ultrasonic waves in different LPBF alloys is studied. • Interaction between ultrasonic waves and submillimeter artificial defects is investigated. • Four typical LPBF alloys are fabricated and measured by the LU through-transmission inspection. In the development of additive manufacturing (AM) technology, laser powder bed fusion (LPBF) is one of the important processing methods. However, the hole defects in the fabricated samples limit the development. Laser ultrasonic (LU) technology plays a major role in the detection of LPBF parts with tiny defects, which has the advantages of non-contact and non-destructive. In this work, the detection of submillimeter internal defects in four typical LPBF alloys by LU technology is studied numerically and experimentally. A multiphysics simulation model of LU detection is established to investigate the propagation characteristics of excited ultrasonic waves in different LPBF alloys and their interaction with submillimeter artificial defects. Simulation results show that the amplitude of longitudinal (L) wave at the defect is the largest in AlSi10Mg alloy, and the amplitude of L wave in the 316L alloy, Ti6Al4V alloy and In718 alloy are very close, but their phases are slightly different. The amplitude of L wave tends to decrease nearly linearly with the increase in defect diameter. Then, four typical LPBF alloys are fabricated and measured by the LU through-transmission detection. The geometric information of artificial holes with a diameter larger than 0.2 mm are clearly characterized by the LU C-scan results, indicating the prominent applicability and feasibility of LU detection on different materials fabricated by LPBF. [ABSTRACT FROM AUTHOR]

The accurate and rapid prediction of hydrodynamic characteristics greatly affects the monitoring of the manoeuvring performance of unidentified underwater vehicles. This work proposes a novel SEConv1D framework for the hydrodynamics prediction of the unidentified underwater vehicle. Firstly, a novel framework integrated with one-dimensional convolutional neural networks (Conv1D) and a squeeze-and-excitation network (SENet) is proposed. Secondly, a hydrodynamic dataset based on computational fluid dynamics (CFD) is constructed and verified by experiments. Finally, the proposed framework is applied to predict the total resistance coefficient (C d) of REMUS UUV and SUBOFF AFF-1. The predicted results agree well with experimental results, and the error of C d between the experimental data and predicted results for REMUS UUV and SUBOFF AFF-1 is less than 3.39% and 1.97%, respectively, which proved that the proposed framework is effective. Compared with those of the most popular networks (i.e., support vector machine, multilayer perceptron, artificial neural network and Conv1D), the mean error of the C d and friction resistance coefficient (C f) between the CFD and predicted results is small at only 0.19%, depicting reductions of 91.5%, 85.9%, 66.7% and 40.6%, respectively. The per inference time of the proposed framework is only 0.164 s form the real-time prediction. • A novel SEConv1D framework is proposed for the unidentified underwater vehicle resistance coefficient prediction. • A hydrodynamics dataset based on the Opt LHD algorithm, experimental and CFD simulation method is constructed. • It provides a powerful approach for the accurate and rapid prediction of the hydrodynamic characteristics. [ABSTRACT FROM AUTHOR]

Thermal fatigue is one of the main causes of device failure in micro-electro-mechanical systems (MEMS). Gold wire bonding plays the role of electrical connection and signal transmission, which is the key structure of MEMS pressure sensor. In this paper, the fatigue failure of gold wire bonding solder joints caused by the thermal cycling test was studied. The thermal cycling test on MEMS pressure sensor was conducted using a temperature chamber with the cycling temperature range from −40 °C to 150 °C. After 1600 cycles, the solder joints were found with significant resistance increase to about 25 Ω or even overrange value by electrical measurement. In addition, the computed tomography (CT) scanning results showed that the solder joints on the substrate underwent thermal fatigue failure and one joint was separated from the pad with a distance of 36 μm, while the solder joints on the chip were still in good bonding conditions. The mechanism of thermal fatigue failure can be summarized as the thermal mismatch of solder joint materials, residual stress due to the bonding process, and stress concentration caused by the wedge area. • The resistance variation of bonding pairs during thermal cycling test was investigated. • CT scanning results characterized the bonding state after the thermal cycling test. • The thermal fatigue of Au Au and Au Ag bonding were analyzed. [ABSTRACT FROM AUTHOR]

This work proposes a novel method, namely contour-extraction-based (CEB) method, which extracts the wake flow contours in the channels as the geometry contours of the pin fin to enhance thermal and hydraulic performances of micro-pin-fin heat sink (MPFHS). By employing this method, a novel heat sink with bream-body-like fins, namely micro-bream-fin heat sink (MBFHS), is generated by improving the geometry of the micro-circular-fin heat sink (MCFHS). The fluid flow and heat transfer characteristics of the novel MBFHS are simulated using a conjugate 3D numerical model with RNG k-ε turbulence model which is analytically validated by the energy balance theory. The thermal and hydraulic performances of the novel MBFHS are evaluated in terms of the junction temperature, Nusselt number, friction factor, and overall performance indexes. It is found that MBFHS has a larger convection heat transfer surface area, a better fluid-solid interaction, a higher flow velocity, a better fluid mixing, and more solid materials compared to the conventional MCFHS, which all contribute to the enhancement in the heat transfer performance. And the promotion is more pronounced at high spacing ratios and Reynolds numbers. The pin convection performance of the novel bream fin could be up to 34% higher than that of the original circular fin, and the thermal resistance and bottom-wall temperature difference of MBFHS are lower by 26% and 38% than those of MCFHS, respectively. [ABSTRACT FROM AUTHOR]

During metal additive manufacturing, porosity is one of the main quality defects of products. Laser post-processing is an effective method of reducing porosity of the metal surface and sub-surface. Herein, the evolution mechanism of multi pores during this process is studied. Two samples for each alloy, Ti6Al4V and AlSi10Mg, were fabricated by laser powder bed fusion (LPBF), and the upper surface of one sample of each alloy was scanned using a laser beam for comparison. Then, the inner layer morphology and pores distribution of these four samples were measured by micro-computed tomography (micro-CT) technology. It was found that the porosity reduced from 0.7961% to 0.6034% for Ti6Al4V and from 3.7105% to 3.6287% for AlSi10Mg after laser post-processing and the phenomenon of combination of pores was obvious for AlSi10Mg alloy. Next, the laser post-processing mechanisms of Ti6Al4V and AlSi10Mg alloys, including heat transfer, Marangoni flow, mass transfer related to recoil pressure and other phenomena, were numerically simulated, and the evolution of pores was tracked by the level-set method. Moreover, the effects of preheating temperature on porosity reduction were discussed. • The porosity of Ti6Al4V alloy and AlSi10Mg alloy with and without laser post-processing was detected by micro-computed tomography. • The evolution of multi pores during laser post-processing was discussed. • The differences between Ti6Al4V alloy and AlSi10Mg alloy during laser post-progressing were analyzed. • The effects of preheating temperature on porosity reduction during laser post-processing was studied. [ABSTRACT FROM AUTHOR]

Malaria has been a global epidemic health threat since ancient times. It still claims roughly half a million lives every year in this century. Artemisinin and its derivatives, are frontline antimalarial drugs known for their efficacy and low toxicity. After decades of wide use, artemisinins remain our bulwark against malaria. Here, we review decades of efforts that aim to understand the mechanism of action (MOA) of artemisinins, which help explain the specificity and potency of this anti-malarial drug. We summarize the methods and approaches employed to unravel the MOA of artemisinin over the last three decades, showing how the development of advanced techniques can help provide mechanistic insights and resolve some long-standing questions in the field of artemisinin research. We also provide examples to illustrate how to better repurpose artemisinins for anti-cancer therapies by leveraging on MOA. These examples point out a practical direction to engineer artemisinin for broader applications beyond malaria. [ABSTRACT FROM AUTHOR]

• High laser energy density lead to the spatter connected with the molten pool. • An in situ monitoring method for acquiring spatter images in SLM. • A novel image processing algorithm for spatter signature eliminated three errors. • Spatter signature variation with changing laser energy density. Although selective laser melting (SLM) has the advancements of fabricating complex geometric, multi-material and multi-functional structures, several defects still affect the process stability, in particular spatter. The formation of spatter in SLM depends on the process parameters, and these can potentially be used to tune the process to obtain better product quality. However, there is still a lack of efficient methods for processing spatter images to allow in situ detection of the onset of spatter. In this paper, an in situ monitoring method for acquiring spatter images in SLM was presented. A maximum-entropy double-threshold image processing algorithm based on genetic algorithm (MEDTIA-GA) was proposed to recognize spatter from images, and its results were compared with three conventional threshold segmentation methods: Otsu's method, Triangle threshold segmentation algorithm, and K -means clustering algorithm. Results show that MEDTIA-GA method was able to eliminate three types of errors: noise sensitivity, spatter conglutination, and spatter omission. In addition, the average processing time of 37 ms for MEDTIA-GA method was far shorter than those for other three conventional threshold segmentation methods. Finally, the relationship between the spatter area as well as the number and the laser energy density were analyzed [ABSTRACT FROM AUTHOR]