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Abstract Hybrid metal halides represent a novel type of semiconductor light emitters with intriguing excitonic emission properties, including free exciton emission and self-trapped exciton emission. Achieving precise control over these two excitonic emissions in hybrid metal halides is highly desired yet remains challenging. Here, the complete transformation from intrinsically broadband self-trapped exciton emission to distinctively sharp free exciton emission in a quasi-one-dimensional hybrid metal halide (C2H10N2)8[Pb4Br18]·6Br with a ribbon width of n = 4, is successfully achieved based on high-pressure method. During compression, pressure-induced phonon hardening continuously reduces exciton–phonon coupling, therefore suppressing excitonic localization and quenching the original self-trapped exciton emission. Notably, further compression triggers excitonic delocalization to induce intense free exciton emission, accompanied with reduced carrier effective masses and improved charge distribution. Controlled high-pressure investigations indicate that the ribbon width of n > 2 is necessary to realize excitonic delocalization and generate free exciton emissions in similar quasi-one-dimensional hybrid metal halides. This work presents an important photophysical process of excitonic transitions from self-trapped exciton emission to free exciton emission in quasi-one-dimensional hybrid metal halides without chemical regulation, promoting the rational synthesis of hybrid metal halides with desired excitonic emissions.

Abstract Background Glioblastoma is an aggressive brain tumor linked to significant angiogenesis and poor prognosis. Anti-angiogenic therapies with vascular endothelial growth factor receptor 2 (VEGFR2) inhibition have been investigated as an alternative glioblastoma treatment. However, little is known about the effect of VEGFR2 blockade on glioblastoma cells per se. Methods VEGFR2 expression data in glioma patients were retrieved from the public database TCGA. VEGFR2 intervention was implemented by using its selective inhibitor Ki8751 or shRNA. Mitochondrial biogenesis of glioblastoma cells was assessed by immunofluorescence imaging, mass spectrometry, and western blot analysis. Results VEGFR2 expression was higher in glioma patients with higher malignancy (grade III and IV). VEGFR2 inhibition hampered glioblastoma cell proliferation and induced cell apoptosis. Mass spectrometry and immunofluorescence imaging showed that the anti-glioblastoma effects of VEGFR2 blockade involved mitochondrial biogenesis, as evidenced by the increases of mitochondrial protein expression, mitochondria mass, mitochondrial oxidative phosphorylation (OXPHOS), and reactive oxygen species (ROS) production, all of which play important roles in tumor cell apoptosis, growth inhibition, cell cycle arrest and cell senescence. Furthermore, VEGFR2 inhibition exaggerated mitochondrial biogenesis by decreased phosphorylation of AKT and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α), which mobilized PGC1α into the nucleus, increased mitochondrial transcription factor A (TFAM) expression, and subsequently enhanced mitochondrial biogenesis. Conclusions VEGFR2 blockade inhibits glioblastoma progression via AKT-PGC1α-TFAM-mitochondria biogenesis signaling cascade, suggesting that VEGFR2 intervention might bring additive therapeutic values to anti-glioblastoma therapy.

In this research, a chronoamperometric biosensor based on zinc oxide (ZnO)-graphene oxide (GO) nanocomposite material was designed and employed for lactate determination. The ZnO-GO hybrid proved to be a suitable substrate for the immobilization of lactate oxidase (LOD). The presence of ZnO and GO components in hybrid material led to synergistic effects and facilitates the LOD loading and electron transfer between the receptor and screen printed carbon electrode (SPCE) surface. The LOD-GO-ZnO modified SCPE exhibits excellent lactate sensing capabilities thanks to the uniform dispersion of ultrafine ZnO nanoparticles and enhanced mass-transfer kinetics. In phosphate buffer solution (pH=7.4), this novel electrochemical lactate biosensor demonstrates a linear response to lactate within the concentration range of 0.015–1.25 mM. Limit of detection (based on S/N=3) of the assay was estimated to be 9 µM. More importantly, the presence method is a highly selective device for the analysis of lactate in biological fluids. The lactate level in saliva samples was successfully measured before and after exercise of athletes using the suggested biosensor. This method offers a simple, cost-effective, fast, and effective platform for lactate determination in typical diagnostic applications.

Disulfidptosis was recently reported to be caused by abnormal disulfide accumulation in cells with high SLC7A11 levels subjected to glucose starvation, suggesting that targeting disulfidptosis was a potential strategy for cancer treatment. We analyzed the relationships between gene expression and mutations and prognoses of patients. In addition, the correlation between gene expression and immune cell infiltration was explored. The potential regulatory mechanisms of these genes were assessed by investigating their related signaling pathways involved in cancer, their expression patterns, and their cellular localization. Most cancer types showed a negative correlation between the gene-set variation analysis (GSVA) scores and infiltration of B cells and neutrophils, and a positive correlation between GSVA scores and infiltration of natural killer T and induced regulatory T cells. Single-cell analysis revealed that ACTB, DSTN, and MYL6 were highly expressed in different bladder urothelial carcinoma subtypes, but MYH10 showed a low expression. Immunofluorescence staining showed that actin cytoskeleton proteins were mainly localized in the actin filaments and plasma membrane. Notably, IQGAP1 was localized in the cell junctions. In conclusion, this study provided an overview of disulfidptosis-related actin cytoskeleton genes in pan-cancer. These genes were associated with the survival of patients and might be involved in cancer-related pathways.

In this paper, we propose deep video compression with hyperprior-based entropy coding, named HDVC. The proposed method is based on the deep video compression (DVC) framework that replaces traditional block-based video compression with end-to-end video compression based on deep learning, aiming to improve compression efficiency and reduce computational complexity while maintaining visual quality. Based on the DVC framework, we introduce hyperprior-based entropy coding into motion compression and optimize motion vector estimation (i.e. optical flow estimation) using window attention and fast residual channel attention. Moreover, we introduce residual channel attention intermediate module into both encoding and decoding to enhance residuals and the quality of reconstructed frames. We adopt hyperprior-based entropy coding in residual compression to model feature distribution. Besides, we use learned image compression for intraframe coding based on fast residual channel attention network to generate reference frames. Experimental results show that the proposed method achieves better PSNR and MS-SSIM performance than both traditional block-based and recent deep learning-based video compression methods on UVG dataset.

Abstract Two dimensional (2D) hybrid metal halides (HMHs) usually exhibit free excitonic (FE) emission, and self‐trapped excitonic (STE) emission can also be achieved by adopting appropriate halogens and organic cations. Recently, significant efforts have been made to modulate and then clarify the transformation and connection between these two types of excitonic emissions in 2D HMHs. In this study, intriguing pressure‐tuned transitions between FE emission and STE emission are observed in 2D (C7H7N2)2PbCl4. In contrast, only FE emissions with tunable emission energies are observed in 2D (C7H7N2)2PbBr4 which possesses a similar structure with (C7H7N2)2PbCl4 under compression. Such distinct halide‐dependent optical responses under pressure are experimentally revealed to arise from the intricate interplay among several factors in these HMHs, including the stiffness of the structure, the Coulomb force between the organic cations and the inorganic octahedra, and the magnitude of inorganic octahedral distortion. These high‐pressure optical explorations can unravel the underlying interrelationship between the crystal structure and excitonic emission in 2D HMHs.

Abstract The current research on noncircular hobbing mainly focuses on the linkage model and motion realization. However, the intermittent cutting characteristics of hobbing would increase uncertainties in the manufacturing process. In this paper, a hobbing machining model with tool-shifting characteristics was proposed to solve the problems of cutting force fluctuation and inconsistency of tooth profile envelope accuracy at different positions of the pitch curve in noncircular gear hobbing. Based on the unit cutting force coefficient method, the undeformed chip volume generated by interrupted cutting was used to characterize the fluctuation trend of the hobbing force. The fluctuation characteristics of the cutting force generated by different hobbing models were compared and analyzed. Using the equivalent gear tooth and hob slotting numbers, an analysis model of the tooth profile envelope error of the noncircular gear was constructed. Subsequently, the tooth profile envelope errors at different positions of the pitch curve were compared and analyzed based on the constructed model. The transmission structure of the electronic gearbox was constructed based on the proposed hobbing model, and the hobbing experiment was conducted based on the self-developed noncircular gear CNC hobbing system. This paper proposes a hobbing method that can effectively suppress the fluctuation of the peak and whole circumference cutting force and reduce the maximum envelope error of the whole circumference gear teeth.

Abstract Byzantine broadcast is a fundamental primitive in distributed computing. A highly efficient Byzantine broadcast protocol, motivated by the real‐world performance of practical state machine replication protocols, is increasingly needed. This article focuses on the state‐of‐the‐art partially synchronous Byzantine broadcast protocol proposed by Abraham et al. (PODC’21), which achieves optimal good‐case latency of two rounds and optimal resilience of n ≥ 5f − 1 in this setting. Each step of the protocol is analysed, and then improved by cutting down the number of messages required to be collected and transmitted in the heaviest step of the protocol by about half, without adding any extra cost. This benefits from a new property, named “spread”, that we identify and extract from the original protocol. It helps us to eliminate non‐essential work in its view‐change procedure. The authors also show that no further reduction is possible without violating security. A prototype is implemented and the performances of improved and original protocols are evaluated in the same environment. The results show that our improvement can achieve about 50% lower communication cost and 40% shorter latency at a scale of 100 replicas. The latency gap becomes wider as the scale further increases.

Objective: This study aims to realize the adulteration detection of camellia oil mixed with rapeseed oil, soybean oil and corn oil. Methods: The electronic nose detection platform was used for the adulteration detection of camellia oil mixed with different proportion of rapeseed oil, soybean oil and corn oil. Firstly, the linear discriminant analysis （LDA） and support vector machine （SVM） were used for the qualitative identification of camellia oil adulteration. Then multilayer perceptron （MLP） and partial least squares regression （PLSR） were used to establish quantitative prediction models for camellia oil adulteration. Results: The accuracy of SVM for qualitative authentication was higher than that of LDA, and the average precision rate, average recall rate and average F1-score were 94.85%, 96.11% and 95.34%, respectively, which were 5.17%, 4.44% and 5.29% higher than those of LDA. For quantitative prediction, MLP outperforms PLSR. In particular, the determination coefficients of MLP were 0.98, 0.99 and 0.98, and the root mean square errors were 4.02%, 1.45% and 3.74%, respectively, for camellia oil mixed with rapeseed oil, soybean oil and corn oil. Conclusion: The SVM-based identification model and MLP-based prediction model can effectively detect oil adulteration by using electronic nose platform.

Accurate estimating of above-ground biomass (AGB) of vegetation in urbanized areas is essential for urban ecosystem services. NASA’s Global Ecosystem Dynamics Investigation (GEDI) mission can obtain precise terrestrial vegetation structure, which is very useful for AGB estimation in large forested areas. However, the spatial heterogeneity and sparse distribution of vegetation in urban areas lead to great uncertainty in AGB estimation. This study proposes a method for estimating vegetation heights by fusing GEDI laser observations with features extracted from optical images. GEDI is utilized to extract the accurate vegetation canopy height, and the optical images are used to compensate for the spatial incoherence of GEDI. The correlation between the discrete vegetation heights of GEDI observations and image features is constructed using Random Forest (RF) to obtain the vegetation canopy heights in all vegetated areas, thus estimating the AGB. The results in Xuzhou of China using GEDI observations and image features from Sentinel-2 and Landsat-8 satellites indicate that: (1) The method of combining GEDI laser observation data with optical images is effective in estimating AGB, and its estimation accuracy (R2 = 0.58) is higher than that of using only optical images (R2 = 0.45). (2) The total AGB in the shorter vegetation region is higher than the other two in the broadleaf forest and the coniferous forest, but the AGB per unit area is the lowest in the shorter vegetation area at 33.60 Mg/ha, and it is the highest in the coniferous forest at 46.60 Mg/ha. And the highest average AGB occurs in October–December at 59.55 Mg/ha in Xuzhou. (3) The near-infrared band has a greater influence on inverted AGB, followed by textural features. Although more precise information about vegetation should be considered, this paper provides a new method for the AGB estimation and also a way for the evaluation and utilization of urban vegetation space.

Gastric cancer (GC) is a deadly malignant tumor with a high fatality rate and limited curative options. A growing body of research suggests that network pharmacology can replace traditional methods for determining the precise mechanism of action of medicinal substances in conditions such as cancer. The goal of this study was to clarify the biological mechanism of chelerythrine (CHE) and develop a prediction target for CHE against GC using network pharmacology. First, the genes related to GC were identified from the databases Genecards, Disgenet, Online Mendelian Inheritance in Man, Therapeutic Target Database, and Drugbank, and the targets of CHE were obtained from the SwissTargetPrediction database. Fifty linked targets were identified as anti-GC targets of CHE. Functional enrichment and pathway analyses revealed important biological mechanisms mediated by these targets. The core target PIK3CA of CHE anti-GC was obtained using the protein–protein interaction network, CytoHubba plug-in, and Human Protein Atlas. Molecular docking studies revealed that CHE has a strong affinity for PIK3CA (−10.5 kcal/mol). In addition, we used MTT, colony formation, wound-healing, Transwell®, and flow cytometry experiments to confirm that CHE inhibited the proliferation and migration of GC cells and induced cell cycle arrest and apoptosis. Finally, western blotting results showed that CHE downregulated the expression of the PIK3CA protein and inhibited the activation of the PI3K/AKT signaling pathway. Therefore, we concluded that CHE inhibited GC cell proliferation and migration and induced cell cycle arrest and apoptosis by targeting the PIK3CA protein to inhibit the PI3K/AKT pathway activity.

Abstract The multilayer development of coalbed methane (CBM) is affected by many factors, and the gas production contribution of each seam is unclear. In this study, 12 geological and 10 engineering parameters were adopted to reveal the key factors affecting the combined‐layer drainage productivity of CBM wells before using numerical simulation to clarify the contribution of each coal seam. The results show that the coal reservoir in the Laochang mining area exhibited the advantages of high gas content, intact coal body structure, and large thickness of the combined coal seams, and it was deficient with low saturation and ratio of critical desorption pressure to reservoir pressure. The medium permeability after fracturing and the influence of a small range of fracturing leads to the steep and deep pressure drop funnel of the coal reservoir, and most of the reservoir pressure drop is ineffective; this may be the reason for the unstable production and rapid attenuation of most CBM wells in the study area. The gas production of the Nos. 13 and 18 coal seams is stable and makes a significant contribution, and they can be used as the key objects of follow‐up CBM exploration and development in this area. Geological factors, such as coal body structure, ratio of critical desorption pressure to reservoir pressure, thickness of combined coal seams, and gas saturation, as well as engineering factors, such as permeability and half length of fractures after fracturing, are the main factors affecting the productivity of the CBM wells in the Laochang mining area.

As a physical carrier of energy Internet， integrated energy system can improve energy utilization efficiency. Therefore， its optimal dispatching has attracted extensive attention of scholars all over the world. Firstly， the comprehensive demand response and the operation model of multi-energy storage device are modeled； Then， the minimum total operation cost of the integrated energy system is taken as the objective function to construct the optimal dispatching model of the integrated energy system considering the comprehensive demand response and multi-energy storage devices； Then， the CVaR （conditional value at risk） is used to deal with the output uncertainty of renewable energy； Finally， an example of an electric-heat-cold integrated energy system is analyzed. The results show that the model proposed in this paper can reduce the operation cost of the integrated energy system and measure the operational risk caused by output uncertainty of renewable energy.

Topological modification of gear surface is used to achieve better meshing transmission performance and accuracy. However, in the traditional gear modification grinding process, the topological modified tooth surface is usually simplified to the control of profile modification and lead modification, which is difficult to achieve the coincidence of machining and design. To solve this problem, a flexible topology flank modification method based on polynomial interpolation function is proposed in this paper. Based on the gear meshing principle and polynomial interpolation technology, the method realizes a topological modification of the gear by controlling multiple axes’s position on the machine tool. Firstly, a gear grinding model of worm grinding wheel with controllable grinding precision is established. Then the axial, radial and tangential motions of worm grinding wheel is expressed as fifth order polynomials, and the polynomial coefficients is optimized by particle swarm optimization algorithm. Finally, numerical simulation was used to compare the proposed method with the sensitivity matrix method, and the results showed that the proposed method had better optimization effect. The new flexible topological modification method can realize the topological modification machining by controlling the motion of each axis of the tool, and the problem that the topological modification machining does not match the design is solved.

Aiming at current problems of low gear shaping efficiency and large cutting force fluctuations in non-circular gears，and based on the gear shaping cutting force modeling and the relationship established between the cutting force and the cutting area，the article proposes circular feed rate optimization method based on constant cutting force constraint. To improve the processing efficiency of the workpiece and reduce the fluctuation of the cutting force，with the machine parameters and the constant cutting area as the constraints，and taking the curvature radius of the pitch curve as the segmented basis，an optimization model of variable circumferential feed is established. Through the analysis of the third-order elliptic gear slotting example，the effectiveness of the variable circle feed optimization model is verified. The segmented optimization avoids frequent and severe changes in the speed of each axis of motion，and realizes the optimization of the processing parameters of non-circular gears.

In order to process the workpiece with internal gearing power honing technology，the honing wheel is usually dressed with the customized diamond dressing wheel corresponding to the workpiece. A method of internal gearing power honing modification based on flexible dressing of honing wheel is proposed to increase the commonality of diamond dressing wheel，reduce the cost of internal gearing power honing technology. Firstly，the tooth surface mathematical model of dressing and honing is established according to the motion relationship of each axis of gear honing machine. Then，the multi axis linkage of honing wheel dressing is expressed in polynomial form，the influence of each axis movement on the final workpiece tooth surface is expressed as sensitivity matrix，and the polynomial coefficients of each axis are optimized with the target modification tooth surface. Finally，the final tooth surface of the workpiece is calculated according to the optimized motion parameters of honing，and the tooth contact is analyzed. The results show the standard diamond dressing wheel can be used for flexible dressing of honing wheel，and the effective modification workpiece can be machined finally.

Hobbing is one of the most important gear machining process，forming process of which is complicated and involves a large number of cutting parameters. In order to quantify the influence of machining parameters on the cutting force in hobbing process，a method for predicting the cutting force of gear hobbing based on three-dimensional （3D） geometric simulation is studied. The relative position and motion relationship between hob and workpiece are determined according to the geometric parameters and cutting parameters of hob and workpiece， the 3D simulation of hobbing process is realized in CAD environment，and the 3D model of undeformed chips is obtained. According to the selected cutting force model，the instantaneous cutting force of a single cutting edge is calculated by using the cross-section size of undeformed chips model，and the overall cutting force process of hobbing is obtained. The influence of different cutting parameter on hobbing cutting force is analyzed quantitatively. The predictive model helps to optimize the design of the gear hobbing process to improve the quality and efficiency of the machining and reduce the cost.

Abstract Objective This study investigates the effects of COMTval158met gene polymorphism on maternal anxiety and pain during delivery and on the analgesic and anxiety efficacy of dexmedetomidine during delivery. Methods Sixty-one pregnant women, who were hospitalized in our hospital from January to November of 2016 were recruited and randomly divided into two groups, F and D groups. The pregnant women in the F group were given labor analgesia with ropivacaine combined with fentanyl. The pregnant women in the D group were given labor analgesia with ropivacaine combined with dexmedetomidine. Before and after labor analgesia, the genotype of COMT in the blood from two groups was detected, and the situation of labor anxiety and analgesia was analyzed. Then, the relationship between labor anxiety, analgesia, and COMT polymorphism was analyzed. Results In the 61 pregnant women, there were 30 women of wild homozygotes (GG) of COMT, 22 women of mutant heterozygotes (GA), and nine women of mutant homozygotes (AA), the mutation rate of allele A was 23.77%. The anxiety status score, anxiety trait score, and pain score in the AA genotype were significantly higher than those in the GG and GA genotype (p 0.05); there was no significant difference in pain between group D and F in GG, GA, and AA genotypes (p > 0.05). There was no significant difference in pain and anxiety scores between the three genotypes in group D (p > 0.05), there was significant difference in pain scores among the three genotypes in group F (p 0.05). Conclusions The mutation of the COMTval158met gene leads to increased anxiety and pain during childbirth. The effect of dexmedetomidine on the anxiety of GG and AA genotypes is better than that of fentanyl, and the mutation of the COMTval158met gene has no impact on dexmedetomidine effect.

Objective To summarize the clinical features and outcomes of patients with rhinocerebral mucormycosis involving cranial nerve. Methods and Results Eight pathologic confirmed cases of rhinocerebral mucormycosis with cranial nerves involvement since February 2012 to January 2020 were collected and evaluated. All patients were diagnosed at Beijing Tongren Hospital, Capital Medical University. The main clinical manifestations were headache, eye and face swelling. In addition to the paranasal sinuses, the ocular motor nerve, extraocular muscle, meninges, brain parenchyma, optic nerve, cerebrovascular and vestibulocochlear nerve were also involved. There were 5 patients with the primary disease of type 2 diabetes mellitus, one patient with acute leukemia receiving chemotherapy, one patient with severe aplastic anemia receiving immunosuppressive therapy, and one patient with craniocerebral trauma. Six patients were confirmed by pathological biopsy of paranasal sinus mucosa, the other 2 patients underwent brain parenchymal biopsy and temporal muscle biopsy respectively. In addition to one patient with meningeal involvement who gave up treatment and finally died, the other 7 patients received amphotericin B (one case was combined with posaconazole) or amphotericin B liposome antifungal therapy. Among them 4 patients underwent simultaneous transnasal endoscopic radical lesion removal treatment and 3 patients with brain parenchymal involvement died despite of active treatment. Conclusions The mortality of rhinocerebral mucormycosis with brain parenchyma involvement is extremely high. For patients with sinusitis with immunocompromised state, if there is acute progression of cranial nerve involvement, swelling around the eyes and headache, attention should be paid to the identification of the disease, and antifungal drugs and combined surgery treatment should be given early. Pathological biopsy of the affected mucosal tissue is the first choice for quick diagnosis.

The tracking performance of mobile robot is often affected by uncertainties from the deviation of initial conditions, external disturbances and varying loads, etc. An Udwadia-Kalaba based adaptive robust control is proposed for the trajectory tracking of an omnidirectional mobile robot in the presence of uncertainties. The proposed control includes nominal control part based on Udwadia-Kalaba theory and adaptive robust control part. The desired trajectory is considered as a virtual servo constraint applied to the robot system and converted into the second order standard form. So that the analytical form of constraint force could be obtained via Udwadia-Kalaba Fundamental Equation (UKFE). The system will precisely obey the given constraint (i.e., the desired trajectory) under the obtained constraint force in ideal cases. No auxiliary variables are required and it is effective whether the constraints are holonomic or nonholonomic. The designed adaptive law is in leakage type and the adaptive parameters are adjusted according to the performance of the system in order to compensate for the effect caused by uncertainty in the system. No extra information of uncertainty is needed except for the existence of uncertainty bound. Comparing with PID control, it can be found that the proposed control has better performance and can realize higher precision trajectory tracking control.

Gear flank twist occurs when threaded wheel grinds crowning lead modified helical gears, which reduces gear machining accuracy. To overcome this problem, a flank twist compensation method based on flexible electronic gearbox is proposed in this paper, the method can reduce the degree of twist and improve gear machining accuracy. Firstly, flank equations of gear and threaded wheel are established, coordinates and normal vectors of gear flank are used to represent twist. Secondly, coordinate transformation matrix between workpiece and tool coordinate system is established based on multi-body system theory and homogeneous coordinate transformation, and relationship between coordinates and normal vectors of gear flank and master-slave axis (B-axis, C-axis, X-axis, Y-axis, Z-axis) movement amount is obtained by inverse kinematics and electronic gearbox, then master-slave axis movement compensation amount between crowning lead modified flank and twisted flank is obtained. Finally, twist is compensated by compensating for master-slave axis movement amount, and flank contact analysis based on KISSsoft is carried out to observe normal force and contact stress of flanks. This paper uses inverse kinematics and electronic gearbox to realize flank twist compensation, which makes up for long period and high cost of traditional flank twist compensation by changing shape of threaded wheel. Simulation results show that this method can effectively compensate for flank twist and improve accuracy and efficiency when threaded wheel grinds crowning lead modified helical gears.

Wearable lower limb hydraulic exoskeletons can be used to augment the human performance in heavy load transportation. Nonlinear and walking phase-dependent dynamics make the lower limb hydraulic exoskeleton become difficult to be modeled. This paper presents a generalized multiphase dynamic modeling method in which the dynamic model of each walking phase can all be solved based on a general higher dimensional dynamic model and different holonomic constraints. Compared to traditional lower limb exoskeleton modeling methods where the modeling of each walking phase is done independently, the proposed method is simple and applicable to arbitrary walking phases, especially for double leg support phase (closed-chain dynamics). Based on the established dynamic models, MIMO adaptive robust cascade force controllers (ARCFC) are designed both for double leg support phase and single leg support phase to effectively address high-order nonlinearities and various modeling uncertainties in hydraulic exoskeletons. An additional torque allocation method is proposed to deal with the overactuated characteristic in double leg support. Comparative simulations are conducted to verify the excellent human-machine interaction force control performance of the proposed scheme.

Abstract Background Metabolic syndrome (MetS) has been suggested to be a risk factor for many cancers, including breast cancer. However, it remains unclear whether MetS predicts poor prognosis in women with breast cancer. A meta-analysis was performed to summarize the association between MetS and clinical outcome in women with breast cancer. Methods Cohort studies were identified by search of PubMed and Embase databases. A random-effect model incorporating the potential heterogeneity was applied to pool the results. Subgroup analyses according to the ethnicity and study design were performed. Results Nine cohort studies with 17,892 women with breast cancer were included. Pooled results showed that MetS was significantly associated with an increased risk of breast cancer recurrence (adjusted risk ratio [RR] = 1.52, 95%, p = 0.02). Subgroup analyses showed that MetS was independently associated with increased recurrence of breast cancer in Caucasians (adjusted RR = 1.75, p = 0.02), but not in Asians (adjusted RR = 1.07, p = 0.81), and MetS was associated with a trend of increased risk of breast cancer recurrence in both the prospective and retrospective studies. Although we failed to show a significant association between MetS and breast cancer related deaths (adjusted RR = 1.24, p = 0.41), MetS was associated with increased risk of all-cause deaths in these patients (adjusted RR = 1.80, p

This paper proposes a method to study the machining error when one is generating gear grinding based on the mapping relationship between the grinding wheel surface and the tooth flank. The profile of the grinding wheel after grinding is collected, and the theoretical tooth flank is derived according to a model of generating gear grinding. By comparing the normal deviation of the theoretical tooth flank with the measured tooth flank, the machining error characteristics are identified. Firstly, the mathematical model of generating gear grinding is established according to a multi-body theory and coordinate transformation. Secondly, the experiments of the lead modification for helical gear were performed on a YW7232 CNC gear grinding machine. The tooth flank twist compensation function was turned off in experiments No. 1–No. 3, and it was turned on in experiments No. 4–No. 6, while the other process parameters kept the same. Then, the corresponding theoretical tooth flank data were derived from the grinding wheel surface which were measured using the laser profilometer LJ-V7000. Finally, the machining error characteristics were obtained by analyzing the difference between the theoretical and measured tooth flank deviations. The result of this paper can provide theoretical and practical references for the improvement of the gear grinding accuracy and gear modification design.

Droplet ejection technology is widely used in green and intelligent manufacturing. A stable jetting can be defined as no obvious satellite droplets during the whole ejection process, which is of great importance to ensure the quality and efficiency of the printed products; However, due to the multi-parameter features and the interaction between different physics, using traditional analytical-based approaches to analyze and/or optimize is usually difficult and even unfeasible. Experimental tests using a PZT printhead design-optimization method based on surrogate modeling are proposed in this paper to overcome this challenge, which can synthesize the advantages of numerical simulation. The basic data for surrogate model construction was obtained by the Computational Fluid Dynamics (CFD) numerical-based model, which was developed to predict the flow characteristic under different parameter settings of the printhead. The accuracy of the developed numerical model was validated by performing experimental tests; thereby, the predictive ability of the numerical model in droplet ejection was verified. With the validated numerical model, the Design of Experiments (DoE) was performed to generate the necessary training and validation sample dataset required by the surrogate modeling. Thereafter, four surrogate modeling methods were adopted to construct the relationship between the design parameters and flow features, where the Kriging (KRG) was identified as the optimal modeling method. Based on the developed KRG model, global sensitivity analysis (GSA) of the parameters was carried out with Sobol’s method; thereby, the influence of different parameters can be quantified. Finally, a genetic algorithm (GA) was used to optimize the structure of the droplet printhead. Through validation, the optimized design model increases the droplet ejection speed by 20.84% while keeping no satellite droplet formation, confirming the efficient and stable printhead ejection, and verifying the feasibility and effectiveness of the analysis/optimization method proposed in this paper.

To improve the stability and accuracy of non-circular gear transmission, a beveloid non-circular gear transmission scheme was developed to reduce the meshing impact and achieve backlash adjustment. When using the beveloid rack as the medium, the instantaneous contact line of the beveloid non-circular gear pair was shown to be a straight line, and the tooth surface was shown to be a ruled surface based on the transmission relationship between the rack centerline and the non-circular pitch curve. The zero-modification method was employed to develop the beveloid non-circular gear. Further, the generation method for the tooth profile of the modified non-circular gear was reviewed, and a digital solid model was developed for the beveloid non-circular gear. The physical contact simulation method was used to analyze the meshing backlash, and the influence of the axial displacement adjustment on the meshing backlash of the gear pair was obtained. By considering a pair of beveloid elliptic gears as an example, machining and transmission experiments were conducted, with results showing smooth gear-pair meshing and the anticipated backlash adjustment effect.

Background: Association between metabolic syndrome (MetS) and incidence of breast cancer remains to be validated. Moreover, whether menopausal status of the women affects this association is unclear. A meta-analysis was performed to summarize the association between MetS and breast cancer risk.Methods: Follow-up studies were identified by search of PubMed and Embase databases published until May 26, 2019. A random-effect model or fixed-effect model was applied to pool the results according to the heterogeneity. Subgroup analyses according to the menopausal status, ethnic groups, cancer histopathological features, and study design characteristics.Results: Overall, 17 follow-up studies with 602,195 women and 15,945 cases of breast cancer were included. Results of meta-analysis showed that MetS defined by the revised National Cholesterol Education Program's Adults Treatment Panel III criteria was associated with significantly increased risk for breast cancer incidence (adjusted risk ratio [RR] = 1.15, p = 0.003). Subgroup analyses showed that MetS was associated with significantly increased risk of breast cancer in postmenopausal women (adjusted RR = 1.25, p < 0.001), but significantly reduced breast cancer risk in premenopausal women (adjusted RR = 0.82, p < 0.001). Further analyses showed that the association between MetS and increased risk of breast cancer were mainly evidenced from studies including Caucasian and Asian women, reporting invasive breast cancer, and of retrospective design.Conclusions: Menopausal status may affect the association between MetS and breast cancer incidence. Postmenopausal women with Mets are associated with increased risk of breast cancer.

Precision machining (e.g., fine grinding, polishing) induced residual stress is very small and often not constant across the wafer and it is difficult to be directly obtained by stress testing equipment or Stoney equation. The residual stress could be obtained theoretically based on the principle of superposition in which the entire wafer deformation is taken as the sum of all deformations induced by the residual stresses of different positions on the wafer surface. However, the solved residual stress is affected greatly by deformation measurement errors and fluctuates greatly across the wafer surface. To solve the problem, a regularization method with continuity constraints was proposed in this study. The mechanisms for the discontinuity of the residual stress distribution and the sensitivity of calculation results to the measurement errors were studied. The influences of the number of subareas of the silicon wafer were investigated and the continuity constraint term was constructed based on the positional relationship of different subareas. Stable and continuous residual stress distribution was successfully obtained after using the proposed regularization method. The method may also be applied to estimate the residual stress from surface deformation for thin substrate plates of other materials.

In the silicone material extrusion (MEX) process, product profile error and performance defects are common problems due to changes in strand shape. A process optimization method considering strand morphology, denoted as SMO, which allows adjustment of the strand shape by adjusting process parameters during the printing process is presented. The relation between process parameters (extrusion speed, moving speed, nozzle height, and nozzle radius) and the geometric parameters (strand width and strand height) of the cross-section, as well as the relationship between strand spacing, layer height, and process parameters in no void constraint is discussed and verified. SMO was utilized to produce specimens with tunable strand width and strand height. Tensile tests and profile scans were performed to compare SMO with other methods to verify its feasibility. Specimens fabricated using the SMO method have up to a 7% increase in tensile strength, up to a 10% reduction in processing time, and about a 60% reduction in strand height error over unused ones. The results show that the SMO method with adjustable strand width can effectively balance efficiency and mechanical properties compared to uniform infill, and the SMO method with adjustable strand height can provide higher accuracy compared to uniform strand height. The proposed method is validated and improves the efficiency and accuracy of silicone MEX.

In power gear honing, the random distribution of abrasive grains on the tooth surface of the honing wheel is the main factor that influences the machining performance of high-quality hardened gears. In order to investigate the micro-edge cutting performance of the active abrasive grains on the workpiece gear, the real honing process is simplified into a micro-edge cutting model with random distribution of active abrasive grains in the cells of the meshing area by obtaining the random distribution states such as the position, orientation and quantity of the honing wheel teeth. The results show that although the active abrasive grains are distributed at different locations, they all experience three types of material removal—slip rubbing, plowing and cutting—allowing the gear honing process to have the combined machining characteristics of grinding, lapping and polishing. The active abrasive grains in first contact produce high honing force, high material removal efficiency and poor surface roughness on the machined workpiece, while the latter ones have the opposite effects. The dislocation angle affects the chip shape and chip discharging direction, and the highest honing force and material removal efficiency is achieved with a dislocation angle of 135°. The higher the number of active abrasive grains in a given contact area, the higher the material removal efficiency.

Hydraulic lower limb exoskeletons are wearable robotic systems, which can help people carry heavy loads. Recently, underactuated exoskeletons with some passive joints have been developed in large numbers for the purpose of decreasing the weight and energy consumption of the system. There are many control algorithms for a multi-joint fully actuated exoskeleton, which cannot be applied for underactuated systems due to the reduction in the number of control inputs. Besides, since the hydraulic actuator is not a desired force output source, there exist high order nonlinearities in hydraulic exoskeletons, which makes the controller design more challenging than motor driven exoskeleton systems. This paper proposed a precision interaction force controller for a 3DOF underactuated hydraulic stance leg exoskeleton. First, the control effect of the wearer is considered and the posture of the exoskeleton back is assumed as a desired trajectory under the control of the wearer. Under this assumption, the system dynamics are changed from a 3DOF underactuated system in joint space to a 2DOF fully actuated system in Cartesian space. Then, a three-level interaction force controller is designed in which the high-level controller conducts human motion intent inference, the middle level controller tracks human motion and the low-level controller achieves output force tracking of hydraulic cylinders. The MIMO adaptive robust control algorithm is applied in the controller design to effectively address the high order nonlinearities of the hydraulic system, multi-joint couplings and various model uncertainties. A gain tuning method is also provided to facilitate the controller gains selection for engineers. Comparative simulations are conducted, which demonstrate that the principal human-machine interaction force components can be minimized and good robust performance to load change and modeling errors can be achieved.