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To raise narrow gap GMA welding efficiency while ensuring weld formation, the present work presents a thick wire swing arc narrow gap GMA welding process assisted by cold wires. This process employs the thick wire and the pre-embedded cold wires to jointly increase the welding efficiency, while improving the groove sidewall penetration by the swing arc. Two types of thick wires, being conventional single-strand welding wire (SWW) and cable-type welding wire (CWW), are respectively used as main wire. After solving the series arc problem during CWW arc-igniting, the effects of the pre-embedded wire layer number on narrow gap weld formation and welding efficiency are investigated for the thick wire welding. Experimental results show that the weld thickness and the sidewall penetration do not obviously change with increasing the number of the cold wires, while the weld layer height significantly grows. Additionally, the SWW weld formation looks more sound. Compared to the thin-wire welding, the thick wire welding without the cold wire raises the deposition rate by about 38% and 58% as respectively using SWW and CWW. When pre-embedding two layers of cold wires, the increased percentage of the deposition rate further rises respectively to about 81% and 112%. These thus demonstrate the effectiveness of the developed process in addition to the higher efficiency of the CWW welding.

Background: Brain tumors are the second most common pediatric malignancy and have poor prognosis. Understanding the pathogenesis of tumors at the molecular level is essential for clinical treatment. We conducted a retrospective study on the epidemiology of brain tumors in children based on clinical data obtained from a neurosurgical center. After identifying the most prevalent tumor subtype, we identified new potential diagnostic biomarkers through bioinformatics analysis of the public database. Methods: All children (0–15 years) with brain tumors diagnosed histopathologically between 2010 and 2020 at the Department of Neurosurgery, Xijing Hospital, were reviewed retrospectively for age distribution, sex predilection, native location, tumor location, symptoms, and histological grade, and identified the most common tumor subtypes. Two datasets (GSE44971 and GSE44684) were downloaded from the Gene Expression Omnibus database, whereas the GSE44971 dataset was used to screen the differentially expressed genes between normal and tumor samples. Gene Ontology, Disease Ontology, and Gene Set Enrichment Analysis enrichment analyses were performed to investigate the underlying mechanisms of differentially expressed genes in the tumor. Combined with methylation data in the GSE44684 dataset, we further analyzed the correlation between methylation and gene expression levels. Two algorithms, LASSO and SVM-RFE, were used to select the hub genes of the tumor. The diagnostic value of the hub genes was assessed using the receiver operating characteristic (ROC) curve. Finally, we further evaluated the relationship between the hub gene and the tumor microenvironment and immune gene sets. Results: Overall, 650 children from 18 provinces in China were included in this study. The male-to-female ratio was 1.41:1, and the number of patients reached a peak in the 10-15-year-old group (41.4%).The most common symptoms we encountered in our institute were headache and dizziness 250 (28.2%), and nausea and vomiting 228 (25.7%). The predominant location is supratentorial, with a supratentorial to infratentorial ratio of 1.74:1. Low-grade tumors (WHO I/II) constituted 60.9% of all cases and were predominant in every age group. According to basic classification, the most common tumor subtype is pilocytic astrocytoma (PA). A total of 3264 differentially expressed genes were identified in the GSE44971 dataset, which are mainly involved in the process of neural signal transduction, immunity, and some diseases. Correlation analysis indicated that the expression of 45 differentially expressed genes was negatively correlated with promoter DNA methylation. Next, we acquired five hub genes (NCKAP1L, GPR37L1, CSPG4, PPFIA4, and C8orf46) from the 45 differentially expressed genes by intersecting the LASSO and SVM-RFE models. The ROC analysis revealed that the five hub genes had good diagnostic value for patients with PA (AUC > 0.99). Furthermore, the expression of NCKAP1L was negatively correlated with immune, stromal, and estimated scores, and positively correlated with immune gene sets.Conclusions: This study, based on the data analysis of intracranial tumors in children in a single center over the past 10 years, reflected the clinical and epidemiological characteristics of intracranial tumors in children in Northwest China to a certain extent. PA is considered the most common subtype of intracranial tumors in children. Through bioinformatics analysis, we suggested that NCKAP1L, GPR37L1, CSPG4, PPFIA4, and C8orf46 are potential biomarkers for the diagnosis of PA.

Objective The aim of this study was to investigate whether declining mobility and muscle strength predict new-onset hypertension in suburban-dwelling elderly individuals. Methods This study was designed as a longitudinal prospective cohort study. It was comprised of 362 individuals (mean age = 67.8 ± 6.2; 157 men) without hypertension at baseline. At baseline, all participants completed health questionnaires and underwent measurements of mobility [the Timed Up and Go test (TUGT) and 4-m walking test] and muscle strength (grip strength). At 1-year follow-up, we determined the number of participants who had developed new-onset hypertension. We then evaluated the relationship between above metrics and the development of hypertension. Results In the present study, 94 (26.0%) participants developed hypertension after 1 year. After adjusting for mixed factors, the TUGT scores [hazard ratio = 1.15; 95% confidence interval (CI), 1.10–1.31; P = 0.030] were positively associated with the development of hypertension, while the 4-m walking test scores (hazard ratio = 0.07; 95% CI, 0.01–0.47; P = 0.007) showed an inverse relationship with hypertension incidence. Grip strength (hazard ratio = 1.03; 95% CI, 0.99–1.06; P = 0.098) was not significantly associated with hypertension incidence. Conclusion Our results indicate that people with declining mobility are significantly more likely to develop hypertension. Hence, improving mobility could be protective against hypertension for elderly individuals.

Purpose To explore the inflammation-prognosis correlation and potential regulatory molecules in adamantinomatous craniopharyngioma (ACP) Methods 61 ACP patients who received surgery by either sub-resection or total-resection were included. Kaplan-Meier Curves were drafted to clarify patients’ prognosis in different sub-groups. Kinds of histological staining were used to evaluate the infiltration and activation of inflammatory cells. The expression dataset of GSE94349 was downloaded from Gene Expression Omnibus (GEO) database for series of bioinformatic analysis. Online bioinformatic analysis databases (Oncomine, GEPIA, TIMER, and NetworkAnalyst, et al) were used for a pan-cancer analysis on potential molecules. Finally, fluorescence in situ hybridization (FISH) and western bolt were conducted to verify the connection between target biomarkers and macrophages. Results The extent of resection was irrelevant to the progress free survival (PFS) of the ACP patients. Patients with high grade of inflammation showed worse prognosis than those with low and medium grade. More inflammatory cells infiltrated in recurrent tumor but represented with an immune inhibitory phenotype. Fraction of immune cells was calculated, and ACP was loaded with more M0 macrophages and plasma cells. SERPINs were identified and then a pan-cancer analysis was conducted to verify its value in clinic. At last, single cell sequencing database and FISH results reveals SERPINs mainly expressed in macrophages and monocytes. Conclusion Our study reveals a connection between inflammation response and poor prognosis in ACP patients. And SERPINs, especially SERPINE1 might be key inflammatory gene, which is relevant to macrophages.

The effect of ER5356 and ER5087 welding wires on fatigue property of MIG-welded 7N01-T4 aluminium alloy joints was investigated. The microstructure of ER5087 welded joint is similar to that of ER53...

As an effective welding method, rotating arc narrow gap MAG welding must ensure sidewall penetration, which is hard to realize when the groove is irregular in practical production. Therefore, it is significant to construct a weld form modeling for control weld penetration under the variable groove conditions. At first, the welding experiment system and the sensor system were set up. Arc sensing and visual sensing were applied to monitor the welding process, and effective algorithms were developed to extract the weld groove features. Three typical groove forms were considered and sufficient experiments were carried out to obtain enough experimental data. Furthermore, support vector machine is used to model the process. Welding current and the shortest distance between the arc center and the groove sidewall were used to predict the sidewall penetration. The verification results show that the model is effective under the condition that the height change of the groove is not more than 2 mm, the width change is not more than 2 mm, or the inclination angle of the bottom of the groove is not more than 10 degrees. The establishment of this model is very helpful to further control the formation of narrow gap welding.

In this paper, a tightly coupled dipole reflectarray antenna as well as a variant-coupling-capacitance method to improve the antenna aperture efficiency is presented. Tightly coupled elements and true-time-delay lines are employed in the design of a wideband reflectarray. The proposed reflectarray can operate from 2 GHz to 5 GHz with the gain varying from 11.3 dBi to 21 dBi. Moreover, we propose a variant-coupling-capacitance method to improve the reflectarray aperture efficiency at lower frequency. By changing the coupling capacitance between neighboring elements according to their positions in the reflecting surface, a more linear equivalent distance delay line is achieved. Hence, phase error is reduced. According to measurement, the reflectarray gain in 2 GHz using the proposed method is increased by 3 dBi compared with the previous design. Aperture efficiency in 2 GHz is improved by 21.6%.

Shikonin (SK), a botanical drug extracted from Lithospermum erythrorhizon, has been shown to inhibit tumour growth through apoptosis and necrosis. However, whether SK induces pyroptosis in cancer cells is still unknown.This study aims to investigated the mechanisms of SK-induced pyroptosis in tumour cells and mice.In vivo and in vitro methods were used in this study. Cell deaths were analysed by LDH and CCK-8 assay and western blotting. To investigated the signalling pathway of SK-induced pyroptosis, various genes expressions were supressed by shRNA or inhibitors. High-sensitivity mass spectrometry assay was used to identified potential factors that regulate GSDME-mediated pyroptosis. Finally, a mouse model was used to investigate the effect of SK administration on tumour growth in vivo.The activation of BAX/caspase-3 signalling was essential for GSDME-mediated pyroptosis by SK. Mechanistically, the intracellular reactive oxygen species (ROS) generation induced by SK treatment initiated GSDME-dependant pyroptosis. SK stimulation induced protective autophagy in a ROS-dependant manner, and repressed autophagy significantly enhanced SK-induced pyroptosis. Moreover, MAPK14/p38α, a ROS sensor, modulated SK-induced autophagy and ultimately affected GSDME-dependant pyroptosis.Here, for the first time we demonstrated that SK treatment induced GSDME-dependant pyroptosis in tumour cells. Our results demonstrated that SK initiates ROS signalling to drive pyroptosis in cancer cells.

Shikonin is one of the major bioactive components of Lithospermum erythrorhizon. It has a good killing effect in a variety of tumor cells. Its antitumor effect involves multiple targets and pathways and has received extensive attention and study in recent years. In this review, we systematically review recent progress in determining the antitumor mechanism of shikonin and its derivatives, specifically their induction of reactive oxygen species production, inhibition of EGFR and PI3K/AKT signaling pathway activation, inhibition of angiogenesis and induction of apoptosis and necroptosis. We also discuss the application of nanoparticles loaded with shikonin in the targeted therapy of various cancers. Finally, we suggest new strategies for the clinical application of shikonin and its derivatives.

Due to the limited neurogenesis capacity, there has been a big challenge in better recovery from neurological dysfunction caused by stroke for a long time. Neural stem cell (NSC) programmed death is one of the unfavorable factors for neural regeneration after stroke. The types of death such as apoptosis and necroptosis have been deeply investigated while the pyroptosis of NSCs is not quite understood. Although it is well accepted that hyperbaric oxygen (HBO) alleviates the oxygen-glucose deprivation (OGD) injury after stroke and reduces programmed death of NSCs, whether NSC pyroptosis is involved in this process is still unknown. Therefore, this study is aimed at studying the potential effect of HBO treatment on NSC pyroptosis following OGD exposure, as well as its influence on NSC proliferation and differentiation in vitro. The results revealed that OGD increased NOD-like receptor protein 3 (NLRP3) expression to induce the pyroptotic death of NSCs, which was rescued by HBO treatment. And the upregulated lncRNA-H19 functioned as a molecular sponge of miR-423-5p to target NLRP3 for NSC pyroptosis following OGD. Most importantly, it was confirmed that HBO exerted protection of NSCs against pyroptosis by inhibiting lncRNA-H19/miR-423-5p/NLRP3 axis. Moreover, HBO restraint of lncRNA-H19-associated pyroptosis benefited the proliferation and neuronal differentiation of NSCs. It was concluded that HBO attenuated NSC pyroptosis via lncRNA-H19/miR-423-5p/NLRP3 axis and enhanced neurogenesis following OGD. The findings provide new insight into NSC programmed death and enlighten therapeutic strategy after stroke.

Ultrasonic energy is introduced into the Metal Inert Gas (MIG) welding arc and weld pool by superposition of an ultrasonic frequency current. In this study, the arc shape, arc energy, and ultrasonic energy that responded to ultrasonic excitation voltage and frequency is investigated. The comprehensive influence of arc and ultrasonic energy on weld formation, microstructure, and mechanical properties is further studied. The arc and ultrasonic energy are analyzed by using a high-speed camera and microphone, respectively. The results showed that the arc width increased, and the arc energy density decreased after the superposition of ultrasonic current. The arc height could be compressed under certain ultrasonic excitation parameters. The ultrasonic excitation voltage and frequency had a direct influence on the ultrasonic energy. The arc height, arc energy density, and ultrasonic energy together determined the weld width. Ultrasound could effectively refine the microstructure of the weld zone and fusion zone but had little effect on the heat-affected zone. Ultrasound improved the hardness of the joint by refining the grain and the second phase. The joint hardness was the highest when the ultrasonic excitation voltage was 100 V, and the frequency was 30 kHz.

Finite element analysis is performed to understand multi-layer rotating arc narrow gap MAG welding for medium steel plate. Four-point heat source and two equivalent heat sources were proposed and compared according to heat equivalent and welding characteristics. Temperature field was solved and analyzed in multi-layer rotating arc welding based on element birth and death technique. The simulation results in good agreement with the experimental data, especially in the middle of the workpiece where welding was stable and less affected by the interference. Residual stress was calculated based on temperature field in four different welding conditions. Deformations were also calculated and compared. The difference between the experimental and simulated deformation is within 1.5 mm. The proposed method is helpful for the microstructural analysis and welding structure analysis of rotating arc narrow gap MAG welding.

A new type of slag-free self-shielded metal-cored wire with various Mo contents has been developed to fabricate an experimental hardfacing alloy. The developed metal-cored wire exhibits an average Mo transfer coefficient of 90%. All the hardfacing alloys have a hypereutectic microstructure consisting of primary M7C3 carbide, and eutectic of M3C carbide plus martensite and residual austenite. The primary carbide fraction is about 38 vol. % in the Mo-free hardfacing alloy; it increases to about 45 vol. % in the alloy when the Mo content increases to 1.35 wt. %. No significant increase in the primary carbide fraction has been observed when the Mo content in the hardfacing alloy is increased further. The wear resistance of Mo-containing hardfacing alloys is better than the Mo-free hardfacing alloy. However, the wear resistance does not increase significantly when the Mo content in the hardfacing alloy is increased beyond 1.35 wt. %. Thermodynamic driving force calculations provide an explanation for the observed primary carbide fraction change in the hardfacing alloys as a function of Mo levels, and the fraction of primary M7C3 carbide seems to play a key role in deciding the wear performance of the hardfacing alloys.

A new type of cobalt-containing iron-based slag-free self-shielded flux-cored wire was developed for hardfacing. The influence of cobalt additions on the microstructure and wear performance of the hardfacing was investigated. The cobalt-containing iron-based hardfacing alloy has a typical hypereutectic microstructure consisting of primary M7(C, B)3 carbide, and a eutectic of M3(C, B) carbide and austenite (part of which subsequently transformed into martensite). Cobalt promoted the formation of austenite and changed the morphology of the primary carbide and eutectic colonies. The morphology of primary carbide became fragmented with increasing cobalt due to the possible impeding effect of cobalt to the movement of the M7(C, B)3/liquid interface. Different structures of the eutectic carbides were observed—the chrysanthemum structure for 1.42 wt.% cobalt, the skeleton form for 2.88 wt.% cobalt, the radial stripe 4.37 wt.% cobalt and the discrete stripe for 5.75 wt.% cobalt. Wear loss of the hardfacing alloy containing 2.88 wt.% cobalt was the smallest among all the alloys, owing to the large primary large carbide and skeleton-shaped eutectic carbides, the proper amount of austenite phase separating the M7(C, B)3 and M3(C, B) carbides, the solid solution strengthening by cobalt in the matrix, and the high hardness of the alloy. Moreover, the wear resistance has a tendency to decrease with the increase in velocity as well as load.

As an efficient underwater cutting method, flux cored arc cutting is not clear in its mechanism because it is difficult to directly observe the process. In this paper, we studied the mechanism of flux cored arc cutting in air first. The impact of cutting parameters was studied by cutting workpiece’s edge and observing it with a high-speed camera system. Secondly, a sandwich structure was designed to observe the underwater cutting process. The characteristics of air and underwater cutting were analyzed and compared, and it showed that the arc moved up and down while moving forward with the cutting torch in both circumstances. Based on the arc movement characteristics and the underwater circumstance, a numerical simulation of the underwater cutting process was conducted. The simulation results showed that different cutting parameters led to different cutting mode and kerf forming. The numerical results of temperature distribution and kerf shape were consistent to the experimental data, which revealed the cutting mechanism. This work is significant for further process optimization and cutting automation.

The improved phase-change temperature control can be obtained by the rational graded cellular design as the thermal conductivity enhancer. 3D printing as an advanced manufacture technique provides a possibility to fabricate the integrated structure with precisely defined complex geometric architecture including the graded cellular structure, which is changing the design profoundly. In this paper, a three-dimensional numerical analysis method is proposed for the integrated phase-change temperature controller simultaneously containing internal graded cellular material and external packaging structure fabricated by additive manufacturing. In the numerical model, the two-equation model considering the phase change process is employed to describe the heat transfer of internal graded cellular material filled with the paraffin wax and the thermal conduction equation is used to calculate the temperature field of the external packaging structure. In addition, the direct couple strategy in the solving process is adopted by setting the same temperature at the interface. The experiment is carried out in order to verify the effectiveness of the numerical model. The measured temperatures under the different heating powers are all in good agreement with ones by the numerical model, which indicate that the experimental and numerical results are reliable. The parameter analysis shows that the distribution of porosity in the cellular material and the wall thickness of packaging structure have a significant influence on phase change process, and the heat transfer performance of thermal controller should be improved by the collaborative design of the internal cellular material and external packaging structure.

Background Posterior fossa ependymoma (EPN-PF) can be classified into Group A posterior fossa ependymoma (EPN-PFA) and Group B posterior fossa ependymoma (EPN-PFB) according to DNA CpG island methylation profile status and gene expression. EPN-PFA usually occurs in children younger than 5 years and has a poor prognosis. Methods Using epigenome and transcriptome microarray data, a multi-component weighted gene co-expression network analysis (WGCNA) was used to systematically identify the hub genes of EPN-PF. We downloaded two microarray datasets (GSE66354 and GSE114523) from the Gene Expression Omnibus (GEO) database. The Limma R package was used to identify differentially expressed genes (DEGs), and ChAMP R was used to analyze the differential methylation genes (DMGs) between EPN-PFA and EPN-PFB. GO and KEGG enrichment analyses were performed using the Metascape database. Results GO analysis showed that enriched genes were significantly enriched in the extracellular matrix organization, adaptive immune response, membrane raft, focal adhesion, NF-kappa B pathway, and axon guidance, as suggested by KEGG analysis. Through WGCNA, we found that MEblue had a significant correlation with EPN-PF (R = 0.69, P = 1 × 10–08) and selected the 180 hub genes in the blue module. By comparing the DEGs, DMGs, and hub genes in the co-expression network, we identified five hypermethylated, lower expressed genes in EPN-PFA (ATP4B, CCDC151, DMKN, SCN4B, and TUBA4B), and three of them were confirmed by IHC. Conclusion ssGSEA and GSVA analysis indicated that these five hub genes could lead to poor prognosis by inducing hypoxia, PI3K-Akt-mTOR, and TNFα-NFKB pathways. Further study of these dysmethylated hub genes in EPN-PF and the pathways they participate in may provides new ideas for EPN-PF treatment.

The purpose of this study was to investigate whether opposing electroacupuncture (EA) could produce similar analgesic effects as operated side EA after knee surgery in rats. Sprague Dawley rats were randomly divided into the sham surgery group, and three surgery groups: opposing EA, operated side EA, and model. After surgery, compared with the sham surgery group, three kinds of pain behavior test methods (mechanical withdrawal threshold (MWT), cumulative pain score [CPS], and mechanical hypersensitivity of knee) were used to assess the pain behavior of the rats in the surgery groups. After knee surgery, the three surgery groups were intervened for three consecutive days: EA on the nonoperated side in the opposing EA group, EA on the operated side in the operated side EA group, and no intervention in the model group. It was shown that MWT was higher and CPS was lower in the two EA groups than in the model group on the first and second days after surgery. On the third day after surgery, MWT in the two EA groups was the highest among the 3 days, CPS was the lowest among the 3 days, and the number of nonvocalizations in rats also increased compared with the model group. Moreover, the MWT of the nonoperated side increased more in the opposing EA group than in the model and operated side EA groups. This indicated that both opposing EA and operated side EA methods can be used to relieve pain after knee joint surgery.

Peptidoglycan recognition proteins (PGRPs) are the most important pattern recognition receptors (PRRs) in insects. PGRPs can recognize pathogenic microorganism peptidoglycans (PGs) and play an important role in innate immunity. Twelve PGRPs have been identified in silkworms. However, the specific roles played by these PGPRs in the silkworm innate immune system have not been elucidated to date. In this study, we systematically investigated the biological functions of BmPGRP-S1 in silkworms. We observed that BmPGRP-S1 was highly expressed in silkworm immune-related organs and was upregulated in response to bacterial challenges. Furthermore, we determined that BmPGRP-S1 can bind to bacteria or PGs and activate antimicrobial peptide (AMP) expression. Inhibition of the expression of BmPGRP-S1 by siRNA reduced AMP gene expression in silkworms. Further experiments demonstrated that BmPGRP-S1 is involved in IMD pathway activation to induce AMP expression. Taken together, these results demonstrate that BmPGRP-S1 serves as a receptor to activate AMP gene expression through the IMD pathway to address bacterial challenges.

Liver X receptors (LXRs) are receptors that belong to the nuclear receptor superfamily (NRs). It was originally called the “orphan receptor” when it was firstly discovered. Then it was found to be activated by oxysterol and it was officially named LXRs. LXRs are activated by ligands and bind to the retinol X receptor to form a heterodimer and regulate metabolism. Numerous studies have shown that LXRs are involved in regulating immune function and maintaining immune tolerance. Activating LXRs can also inhibit the tumorigenesis and promote apoptosis of tumor cells, which make LXRs as potential targets in cancer treatment. This review will discuss the recent progress of LXRs from the structure and function of LXRs, the signaling pathway of LXRs, the molecular mechanism of LXRs activation in cancers, and the potential targets of LXRs in cancer therapy.

IntroductionThere are no well-recognised guidelines for intraoperative fluid management in patients with end-stage renal failure (ESRF). Goal-directed fluid therapy (GDFT) is a concept of perioperative fluid management that improves patients’ prognosis. In this study, we assessed a GDFT protocol with monitoring of pulse pressure variation (PPV) in patients with ESRF undergoing parathyroidectomy.Material and methodsA total of 102 patients who underwent elective parathyroidectomy were randomised into a control group (restrictive group, n = 51), managed with a restricted fluid regimen, or a PPV group (GDFT group, n = 51), given a normal saline infusion, and they were monitored for changes in PPV. If PPV reached > 13%, 250 ml of normal saline was administered over 15 min. Ephedrine was given to keep the mean arterial pressure > 65 mm Hg. Haemodynamic variables in the perioperative period were recorded. The primary endpoint was the occurrence of postoperative hypotension.ResultsThe occurrence of postoperative hypotension (0 vs. 11.67%, p = 0.027) and complications (35.3% vs. 54.9%, p = 0.047) in the GDFT group was lower than in the restrictive group. The volume of saline infused during the operation was 364 (219–408) ml and 50 (50–50) ml, respectively (p = 0.001). Ephedrine was given to 16/51 (29.4%) patients of the GDFT group and 27/51 (52.9%) patients of the restrictive group (p = 0.027).ConclusionsThe use of GDFT with dynamic PPV monitoring in patients with ESRF undergoing parathyroidectomy could potentially be used to guide the administration of infused fluids, with the possibility of reducing the occurrence of postoperative hypotension.