Ionic Liquid Modified Fe-Porphyrinic Metal-Organic Frameworks as Efficient and Selective Photocatalysts for CO2 Reduction.

Porphyrin-based metal-organic frameworks (MOFs) are ideal platforms for heterogeneous photocatalysts toward CO2 reduction. To further explore photocatalytic MOF systems, it is also necessary to consider their ability to fine-tune the microenvironments of the active sites, which affects their overall catalytic operation. Herein, a kind of ionic liquid (IL, here is 3-butyric acid-1-methyl imidazolium bromide, BAMeImBr) was anchored to iron-porphyrinic Zr-MOFs with different amounts to obtain ILx@MOF-526 (MOF-526 = Zr6O4(OH)4(FeTCBPP)3, FeTCBPP = iron 5,10,15,20-tetra[4-(4'-carboxyphenyl)phenyl]-porphyrin, x = 100, 200, and 400). ILx@MOF-526 series was designed to investigate the effects of the microenvironmental and electronic structural modification on the efficiency and selectivity of the photochemical reduction of CO2 after introducing IL fragments. Compared to parent MOF-526, the production and selectivity of CO were greatly improved in the absence of any photosensitizer under visible light by the ILx@MOF-526 series. Among them, the CO yield of IL200@MOF-526 was up to 14.0 mmol g-1 within 72 h with a remarkable CO selectivity of 97%, which is superior to that of MOF-526 without BAMeIm+ modification and other amounts of BAMeIm+ loaded. Furthermore, density functional theory calculations were performed to study the mechanism of the CO2 reduction.

Heterometallic MIL-125(Ti-Al) frameworks for electrochemical determination of ascorbic acid, dopamine and uric acid.

The detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA) is not only of great significance in the areas of biomedicine and neurochemistry but also helpful in disease diagnosis and pathology research. Due to their diverse structures, designability, and large specific surface areas, metal-organic frameworks (MOFs) have recently caught considerable attention in the electrochemical field. Herein, a family of heterometallic MOFs with amino modification, MIL-125(Ti-Al)-xNH2 (x = 0%, 25%, 50%, 75%, and 100%), were synthesized and employed as electrochemical sensors for the detection of AA, DA, and UA. Among them, MIL-125(Ti-Al)-75%NH2 exhibited the most promising electrochemical behavior with 40% doping of carbon black in 0.1 M PBS (pH = 7.10), which displayed individual detection performance with wide linear detection ranges (1.0-6.5 mM for AA, 5-100 µM for DA and 5-120 µM for UA) and low limits of detection (0.215 mM for AA, 0.086 µM for DA, and 0.876 µM for UA, S/N = 3). Furthermore, the as-prepared MIL-125(Ti-Al)-75%NH2/GCE provided a promising platform for future application in real sample analysis, owing to its excellent anti-interference performance and good stability.

Effectiveness and safety of REBACIN as a non-invasive intervention for persistent high-risk human papillomavirus infection: A real-world prospective multicenter cohort study.

BACKGROUND: We previously reported that REBACIN effectively eliminates persistent high-risk human papillomavirus (hrHPV) infection. Here, we conducted a prospective multicenter cohort study to evaluate the safety and effectiveness of REBACIN, taking into account factors such as specific hrHPV subtype and patient's age. METHODS: According to inclusion/exclusion criteria and participant willingness, 3252 patients were divided into REBACIN group while 249 patients into control group. Patients in REBACIN group received one course treatment of intravaginal administration of REBACIN while no treatment in control group. After drug withdrawal, participants in both groups were followed up. RESULTS: The clearance rate of persistent hrHPV infection in REBACIN group was 60.64%, compared to 20.08% in control group. Specifically, the clearance rates for single-type infection of HPV16 or HPV18 were 70.62% and 69.23%, respectively, which was higher than that of HPV52 (59.04%) or HPV58 (62.64%). In addition, the single, double, and triple/triple+ infections had a clearance rate of 65.70%, 53.31%, and 38.30%, respectively. Moreover, 1635 patients under 40 years old had a clearance rate of 65.14%, while it was 55.08% for 1447 patients over 40 years old. No serious adverse effects were found. CONCLUSION: This study confirmed that REBACIN can effectively and safely eliminate persistent hrHPV infection, which the clearance rate of HPV16/18 is higher than that of HPV52/58, the clearance rate of single-type infection is higher than that of multiple-type infections, and the clearance rate in young patients is higher than that in elder patients, providing a guidance for REBACIN application in clearing hrHPV persistent infection in real-world settings. CLINICAL TRIAL REGISTRATION: Chinese Clinical Trial Registry Registration Number: ChiCTR1800015617 http://www.chictr.org.cn/showproj.aspx?proj=26529 Date of Registration: 2018-04-11.

SketchMetaFace: A Learning-based Sketching Interface for High-fidelity 3D Character Face Modeling.

Modeling 3D avatars benefits various application scenarios such as AR/VR, gaming, and filming. Character faces contribute significant diversity and vividity as a vital component of avatars. However, building 3D character face models usually requires a heavy workload with commercial tools, even for experienced artists. Various existing sketch-based tools fail to support amateurs in modeling diverse facial shapes and rich geometric details. In this paper, we present SketchMetaFace - a sketching system targeting amateur users to model high-fidelity 3D faces in minutes. We carefully design both the user interface and the underlying algorithm. First, curvature-aware strokes are adopted to better support the controllability of carving facial details. Second, considering the key problem of mapping a 2D sketch map to a 3D model, we develop a novel learning-based method termed "Implicit and Depth Guided Mesh Modeling" (IDGMM). It fuses the advantages of mesh, implicit, and depth representations to achieve high-quality results with high efficiency. In addition, to further support usability, we present a coarse-to-fine 2D sketching interface design and a data-driven stroke suggestion tool. User studies demonstrate the superiority of our system over existing modeling tools in terms of the ease to use and visual quality of results. Experimental analyses also show that IDGMM reaches a better trade-off between accuracy and efficiency.

The accumulation of organic contaminants in hair with different biological characteristics.

Human hair has increasingly been used as a noninvasive biomonitoring matrix for assessment of human exposure to various organic contaminants (OCs). However, the accumulation processes of OCs in hair remains unclear thus far, which raised concerns on the reliability of hair analysis results for OCs. Herein, Chinese population was selected as the study subject, the effects of changes in hair biological characteristics, including length and color, on the accumulation of OCs in hair was investigated. With the growing of hair shaft and the increased distance from the scalp, a significant increasing trend was found for levels of polychlorinated biphenyls (PCBs) and organophosphate flame retardants (PFRs) along the hair shafts (p < 0.05). Source identification using Chemical Mass Balance model indicated that PCBs in hair were mainly from exogenous sources (air and dust). The accumulation rates of PCB and PFR individuals in the hair shaft decreased with increasing of log Kow values. Additionally, the levels of OCs in hair decreased with the change in color from black to white, probably because of the loss of melanin in white hair. The ratios (R) of Cblack/Cwhite were significantly correlated with the log Kow values for individual chemicals (p < 0.05), implying that OCs with high log Kow values tend to accumulate more readily in black hair. The results of this study demonstrated the growth and change in colors of hair, as well as the physicochemical properties of chemicals, play vital roles in the accumulation of OCs in hair. The present study provides fundamental basis for the precise assessment of human exposure to OCs using hair as a biomonitoring matrix in future studies.

An integrated analysis of bulk and single-cell sequencing data reveals that EMP1+/COL3A1+ fibroblasts contribute to the bone metastasis process in breast, prostate, and renal cancers.

Introduction: Bone metastasis (BoM) occurs when cancer cells spread from their primary sites to a bone. Currently, the mechanism underlying this metastasis process remains unclear. Methods: In this project, through an integrated analysis of bulk-sequencing and single-cell RNA transcriptomic data, we explored the BoM-related features in tumor microenvironments of different tumors. Results: We first identified 34 up-regulated genes during the BoM process in breast cancer, and further explored their expression status among different components in the tumor microenvironment (TME) of BoM samples. Enriched EMP1+ fibroblasts were found in BoM samples, and a COL3A1-ADGRG1 communication between these fibroblasts and cancer cells was identified which might facilitate the BoM process. Moreover, a significant correlation between EMP1 and COL3A1 was identified in these fibroblasts, confirming the potential connection of these genes during the BoM process. Furthermore, the existence of these EMP1+/COL3A1+ fibroblasts was also verified in prostate cancer and renal cancer BoM samples, suggesting the importance of these fibroblasts from a pan-cancer perspective. Discussion: This study is the first attempt to investigate the relationship between fibroblasts and BoM process across multi-tumor TMEs. Our findings contribute another perspective in the exploration of BoM mechanism while providing some potential targets for future treatments of tumor metastasis.

Surface and back-side defects identification combined with magnetic flux leakage and boundary magnetic perturbation.

In magnetic flux leakage (MFL) detection, the identification of surface and back-side defects is required to obtain more accurate defect quantification and risk assessment results. However, current MFL techniques can detect both surface and back-side defects but are generally unable to distinguish between them. Therefore, this paper proposes a new boundary magnetic perturbation (BMP) testing method, combining the results of MFL to distinguish between surface and back-side defects. First, the detection mechanism of the BMP testing method and the impact of the tested magnetic flux density components are presented and analyzed by simulations to further develop an identification method. Then, the influences of the BMP sensor's lift-off and installation position are investigated by experiments to improve distinguishing performance. Finally, the repeated measurements show that the surface and back-side defects within the wide range of sizes can be identified accurately, even when the defect depths are in the range of 12.5%-87.5% of the sample thickness. Furthermore, the BMP testing method neither increases the length of the detection device nor requires additional magnetizers or signal generators. Therefore, the proposed method is highly suitable for the existing MFL detection devices to distinguish between surface and back-side defects.

Biomimetic synthesis of L-DOPA inspired by tyrosine hydroxylase.

L-3,4-dihydroxyphenylalanine (L-DOPA) is in high demand as the cornerstone for treatment of Parkinson's disease. The current production of L-DOPA is associated with poor productivity and long production period. Biomimetic system inspired from tyrosine hydroxylase was developed to achieve the production of L-DOPA from tyrosine with high reactivity, efficiency, and specificity. The biomimetic system owned close resemblance of component and structure in comparison with tyrosine hydroxylase, consisting of tyrosine as substrate, a redox complex of Fe2+ and EDTA as the catalyst to simulate the active center of the natural tyrosine hydroxylase, hydrogen peroxide as the oxidant, and ascorbic acid as the reductant. HPLC, HPLC-MS/MS, 1H NMR, and specific rotation identified L-DOPA was generated. The system showed high catalytic activity and regioselectivity for hydroxylation of tyrosine as equal to tyrosine hydroxylase. FeIVO2+ was formed as the major active species, and NIH shift was observed. EDTA accelerated the reaction by reducing the redox potential of Fe3+/Fe2+ couple. Density functional theory calculation suggested formation of FeIVO2+ was more thermodynamically favorable. The biomimetic system shared analogous catalytic mechanism with TyrH. Process parameters was optimized for maximum production of L-DOPA, namely 6.4 mM tyrosine, 1.6 mM Fe2+, 1.92 mM EDTA, 150 mM H2O2, and 35 mM ascorbic acid in 0.2 M glycine-HCl buffer at pH 4.5 and 60 °C. The yield, titer, and productivity were obtained as 52.01%, 3.22 mM, and 48,210.68 mg L-1 h-1, respectively. The proposed method exhibited an amazing productivity, might provide a promising strategy to industrialize L-DOPA production.

Linking oxidative DNA lesion 8-OxoG to tumor development and progression.

Cells of the aerobic metabolic organism are inevitably subjected to the damage from reactive oxygen species (ROS). ROS cause multiple forms of DNA damage, among which the oxidation product of guanine G 8-hydroxyguanine (8-oxoG) is the most frequent DNA oxidative damage, recognized by the specific glycosidase OGG1 that initiates the base excision repair pathway. If left unrepaired, 8-oxoG may pair with A instead of C, leading to a mutation of G: C to T: A during replication. Thus, the accumulation of 8-oxoG or the abnormal OGG1 repair is thought to affect gene function, which in turn leads to the development of tumor or aging-related diseases. However, a series of recent studies have shown that 8-oxoG tends to be produced in regulatory regions of the genome. 8-oxoG can be regarded as an epigenetic modification, while OGG1 is a specific reader of this information. Substrate recognition, binding or resection by OGG1 can cause DNA conformation changes or affect histone modifications, causing up-regulation or down-regulation of genes with different properties. Thus, in addition to the potential genotoxicity, the association of guanine oxidative damage with development of tumors is closely related to its aberrant initiation of gene expression through epigenetic mechanisms. In this review, we summarize the underlying mechanism of 8-oxoG and repair enzyme OGG1 in tumor development and progression, with aims to interpret the relationship between DNA oxidative damage and tumor from a new perspective, and provide new ideas and targets for tumor treatment.

Humping Formation and Suppression in High-Speed Laser Welding.

Increasing welding speed can promote the productivity of laser welding. However, humping defects often occur, which limits the application of this strategy. The existing explanations for the humping formation remain vague, and mitigation and suppression methods are limited. In this research, high-speed imaging experiments and numerical simulation of the high-speed laser welding process are performed. Through careful examination, the humping phenomenon is explained. At high welding speed, the high-speed melt flow caused by recoil pressure is hindered by the solidified region in the melt pool, leading to the occurrence of a swelling. The swelling then grows, forming a valley in front of the swelling under the effect of surface tension. The solidification of the valley results in the occurrence of a second swelling. This process repeats and humping defect forms. Marangoni force and viscous force also have influence on this process. In addition, it is found that adding a Tungsten Inert Gas arc behind the laser beam can effectively suppress the humping.

Assessment and nonpharmacological management for patients with cancer anorexia-cachexia syndrome: a best practice implementation project.

INTRODUCTION AND AIMS: Cancer anorexia-cachexia syndrome (CACS) is a common multifactorial syndrome, which affects up to 80% patients with advanced cancer. At present, evidence to support the benefit of pharmacological intervention in the management of CACS is limited. Patients would benefit from standard procedures for early assessment and identification of cancer anorexia-cachexia, and using nonpharmacological strategies to manage patients with CACS. This best practice implementation project aimed to implement an evidence-based practice in assessing and managing patients with CACS, thereby improving the compliance of clinical practice with the best evidence and the quality of life of patients with CACS. METHODS: This was an evidence-based audit and feedback project that used a three-phase approach at a public hospital in China. Phase 1 included the development of seven evidence-based audit criteria and carrying out a baseline audit on 30 patients using the JBI's Practical Application of Clinical Evidence System in the Department of Radiation Oncology of Nanfang Hospital. Phase 2 utilized the Getting Research into Practice component of the Practical Application of Clinical Evidence System to identify barriers to compliance with best practice principles and developed strategies and resources to improve compliance. Phase 3 involved conducting a follow-up audit using the same sample size and audit criteria to assess the results of interventions implemented to improve practice and identify issues that would be addressed in future audit. RESULTS: The compliance rates of audit criteria 1, 2 and 6 were 100% at both baseline and follow-up audit. After the application of evidence, the compliance rate increased from 0 to 100% for audit criterion 3, from 0 to 76.6% for audit criterion 4, from 23 to 70% for audit criterion 5, and from 0 to 40% for audit criterion 5. CONCLUSION: The best evidence for the assessment and nonpharmacological management of cancer patients with CACS can improve clinical practice, the quality of clinical nursing, and patient satisfaction. The application of electronic informatization promotes the implementation and maintenance of best practice.

Mixed-Linker Strategy for the Construction of Metal-Organic Framework Combined with Dyes toward Alcohol Detection.

Herein, a N-rich metal-organic framework (MOF) with four kinds of cages, Zn4(ade)2(TCA)2(H2O) (NENU-1000, Hade = adenine, H3TCA = 4,4',4″-tricarboxytriphenylamine, NENU = Northeast Normal University), was prepared by the mixed-ligand strategy. Cationic dyes can be selectively absorbed by NENU-1000 at proper concentrations, but not neutral and anionic dyes, which perhaps can be assigned to the N-rich neutral framework of NENU-1000. When NENU-1000 was introduced to a relatively lower concentration of cationic dye solutions (e.g., rhodamine B or basic red 2), the colors of these systems faded quickly. Furthermore, the faded solutions can be used for the detection of methanol and other small alcohol molecules with either the naked eye or common UV-vis spectra. The effect of the length of carbon chain, the position of the -OH group, and the number of the hydroxyl group of the alcohols was explored for the color development rate. In addition, the performance of NENU-1000 in iodine sorption and release was also studied.

SAniHead: Sketching Animal-Like 3D Character Heads Using a View-Surface Collaborative Mesh Generative Network.

In the game and film industries, modeling 3D heads plays a very important role in designing characters. Although human head modeling has been researched for a long time, few works have focused on animal-like heads, which are of more diverse shapes and richer geometric details. In this article, we present SAniHead, an interactive system for creating animal-like heads with a mesh representation from dual-view sketches. Our core technical contribution is a view-surface collaborative mesh generative network. Initially, a graph convolutional neural network (GCNN) is trained to learn the deformation of a template mesh to fit the shape of sketches, giving rise to a coarse model. It is then projected into vertex maps where image-to-image translation networks are performed for detail inference. After back-projecting the inferred details onto the meshed surface, a new GCNN is trained for further detail refinement. The modules of view-based detail inference and surface-based detail refinement are conducted in an alternating cascaded fashion, collaboratively improving the model. A refinement sketching interface is also implemented to support direct mesh manipulation. Experimental results show the superiority of our approach and the usability of our interactive system. Our work also contributes a 3D animal head dataset with corresponding line drawings.

Downregulation of miR-491-5p promotes neovascularization after traumatic brain injury.

MicroRNA-491-5p (miR-491-5p) plays an important role in regulating cell proliferation and migration; however, the effect of miR-491-5p on neovascularization after traumatic brain injury remains poorly understood. In this study, a controlled cortical injury model in C57BL/6 mice and an oxygen-glucose deprivation model in microvascular endothelial cells derived from mouse brain were established to simulate traumatic brain injury in vivo and in vitro, respectively. In the in vivo model, quantitative real-time-polymerase chain reaction results showed that the expression of miR-491-5p increased or decreased following the intracerebroventricular injection of an miR-491-5p agomir or antagomir, respectively, and the expression of miR-491-5p decreased slightly after traumatic brain injury. To detect the neuroprotective effects of miR-491-p, neurological severity scores, Morris water maze test, laser speckle techniques, and immunofluorescence staining were assessed, and the results revealed that miR-491-5p downregulation alleviated neurological dysfunction, promoted the recovery of regional cerebral blood flow, increased the number of lectin-stained microvessels, and increased the survival of neurons after traumatic brain injury. During the in vitro experiments, the potential mechanism of miR-491-5p on neovascularization was explored through quantitative real-time-polymerase chain reaction, which showed that miR-491-5p expression increased or decreased in brain microvascular endothelial cells after transfection with an miR-491-5p mimic or inhibitor, respectively. Dual-luciferase reporter and western blot assays verified that metallothionein-2 was a target gene for miR-491-5p. Cell counting kit 8 (CCK-8) assay, flow cytometry, and 2?,7?-dichlorofluorescein diacetate (DCFH-DA) assay results confirmed that the downregulation of miR-491-5p increased brain microvascular endothelial cell viability, reduced cell apoptosis, and alleviated oxidative stress under oxygen-glucose deprivation conditions. Cell scratch assay, Transwell assay, tube formation assay, and western blot assay results demonstrated that miR-491-5p downregulation promoted the migration, proliferation, and tube formation of brain microvascular endothelial cells through a metallothionein-2-dependent hypoxia-inducible factor-1α/vascular endothelial growth factor pathway. These findings confirmed that miR-491-5p downregulation promotes neovascularization, restores cerebral blood flow, and improves the recovery of neurological function after traumatic brain injury. The mechanism may be mediated through a metallothionein-2-dependent hypoxia-inducible factor-1α/vascular endothelial growth factor signaling pathway and the alleviation of oxidative stress. All procedures were approved by Ethics Committee of the First Affiliated Hospital of Chongqing Medical University, China (approval No. 2020-304) on June 22, 2020.

Surface-Displayed Amuc_1100 From Akkermansia muciniphila on Lactococcus lactis ZHY1 Improves Hepatic Steatosis and Intestinal Health in High-Fat-Fed Zebrafish.

Fatty liver and intestinal barrier damage were widespread in most farmed fish, which severely restrict the development of aquaculture. Therefore, there was an urgent need to develop green feed additives to maintain host liver and intestinal health. In this study, a probiotic pili-like protein, Amuc_1100 (AM protein), was anchored to the surface of Lactococcus lactis ZHY1, and the effects of the recombinant bacteria AM-ZHY1 on liver fat accumulation and intestinal health were evaluated. Zebrafish were fed a basal diet, high-fat diet, and high-fat diet with AM-ZHY1 (108 cfu/g) or control bacteria ZHY1 for 4 weeks. Treatment with AM-ZHY1 significantly reduced hepatic steatosis in zebrafish. Quantitative PCR (qPCR) detection showed that the expression of the lipogenesis [peroxisome-proliferator-activated receptors (PPARγ), sterol regulatory element-binding proteins-1c (SREBP-1c), fatty acid synthase (FAS), and acetyl-CoA carboxylase 1 (ACC1)] and lipid transport genes (CD36 and FABP6) in the liver were significantly downregulated (p < 0.05), indicating that AM-ZHY1 could reduce liver fat accumulation by inhibiting lipid synthesis and absorption. Moreover, supplementing AM-ZHY1 to a high-fat diet could significantly reduce serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, indicating that liver injury caused by high-fat diets was improved. The expression of tumor necrosis factor (TNF)-a and interleukin (IL)-6 in the liver decreased significantly (p < 0.05), while IL-1ß and IL-10 did not change significantly in the AM-ZHY1 group. Compared to the high-fat diet-fed group, the AM-ZHY1 group, but not the ZHY1 group, significantly increased the expression of intestinal tight junction (TJ) proteins (TJP1a, claudina, claudin7, claudin7b, claudin11a, claudin12, and claudin15a; p < 0.05). Compared to the high-fat diet group, the Proteobacteria and Fusobacteria were significantly reduced and increased in the AM-ZHY1 group, respectively. In conclusion, the recombinant bacteria AM-ZHY1 has the capacity to maintain intestinal health by protecting intestinal integrity and improving intestinal flora structure and improving fatty liver disease by inhibiting lipid synthesis and absorption. This study will lay a foundation for the application of AM protein in improving abnormal fat deposition and restoring the intestinal barrier in fish.

Expert consensus of the Chinese Association for the Study of Pain on pain treatment with the transdermal patch.

Chronic pain lasting more than 3 mo, or even several years can lead to disability. Treating chronic pain safely and effectively is a critical challenge faced by clinicians. Because administration of analgesics through oral, intravenous or intramuscular routes is not satisfactory, research toward percutaneous delivery has gained interest. The transdermal patch is one such percutaneous delivery system that can deliver drugs through the skin and capillaries at a certain rate to achieve a systemic or local therapeutic effect in the affected area. It has many advantages including ease of administration and hepatic first pass metabolism avoidance as well as controlling drug delivery, which reduces the dose frequency and side effects. If not required, then the patch can be removed from the skin immediately. The scopolamine patch was the first transdermal patch to be approved for the treatment of motion sickness by the Food and Drug Administration in 1979. From then on, the transdermal patch has been widely used to treat many diseases. To date, no guidelines or consensus are available on the use of analgesic drugs through transdermal delivery. The pain branch of the Chinese Medical Association, after meeting and discussing with experts and based on clinical evidence, developed a consensus for promoting and regulating standard use of transdermal patches containing analgesic drugs.

Vacuum Brazing of C/C Composite and TiAl Intermetallic Alloy Using BNi-2 Brazing Filler Metal.

C/C composite was brazed to TiAl intermetallic compound using a commercial BNi-2 brazing filler metal under vacuum brazing condition. The brazing temperature was 1030~1150 °C and the holding time was 20 min. The joint interfacial microstructures and mechanical properties were studied, and the fracture behavior and joining mechanism were also investigated. The effect of brazing temperature on the joint shear strength was explored. The results showed that a perfect interface joint can be obtained by using BNi-2 to braze C/C and TiAl. During brazing, Ti, Cr, and other carbide forming elements diffused to C/C composite side, forming Cr3C2, Cr7C3, TiC, and other carbides, and realizing metallurgical joining between the brazing filler metal and C/C composite. The microstructure of the interface of C/C composite and TiAl intermetallic compound joint is as follows: TiAl alloy → TiAl + AlNi3 → AlNi2Ti → Ni(s, s) + Ti3Al + Ni3Si → Ni(s, s) + Ni3(Si, B) + CrB → Ni(s, s) + Ni3Si + TiCr2 → (Ti, Cr)C → C/C composite. When the holding time is fixed, with the increase of brazing temperature, the shear strength of the joint increases first and then decreases. The maximum average room temperature shear strength of the brazed joint was 11.62 MPa, while the brazing temperature was 1060 °C and the holding time was 20 min.

Multi-Output Monitoring of High-Speed Laser Welding State Based on Deep Learning.

In order to ensure the production quality of high-speed laser welding, it is necessary to simultaneously monitor multiple state properties. Monitoring methods combining vision sensing and deep learning models are popular but most models used can only make predictions on single welding state property. In this contribution, we propose a multi-output model based on a lightweight convolutional neural network (CNN) architecture and introduce the particle swarm optimization (PSO) technique to optimize the loss function of the model, to simultaneously monitor multiple state properties of high-speed laser welding of AISI 304 austenitic stainless steel. High-speed imaging is performed to capture images of the melt pool and the dataset is built. Test results of different models show that the proposed model can achieve monitoring of multiple welding state properties accurately and efficiently. In addition, we make an interpretation and discussion on the prediction of the model through a visualization method, which can help to deepen our understanding of the relationship between the melt pool appearance and welding state. The proposed method can not only be applied to the monitoring of high-speed laser welding but also has the potential to be used in other procedures of welding state monitoring.