Search

BackgroundThe COVID-19 pandemic is affecting the care of patients with colorectal cancer worldwide, resulting in the postponement of many colorectal cancer surgeries. However, the effectiveness and safety of performing colorectal cancer surgery during the COVID-19 pandemic is unknown. This study evaluated the impact of the COVID−19 pandemic on surgical outcomes in patients undergoing colorectal cancer surgery.MethodsWe retrospectively identified patients undergoing colorectal cancer surgery in January 21, 2019, to April 1, 2019, vs. January 21, 2020, to April 1, 2020. Data regarding perioperative outcomes (postoperative complications, conversion rate, duration of surgery, intraoperative blood loss, transfusion, reoperation, intensive care, histological examination, morbidity, and length of hospital stay) were retrieved and compared between the two cohorts. A meta-analysis of 14 studies was also conducted to assess the impact of the COVID−19 pandemic on surgical outcomes in patients undergoing colorectal cancer surgery.ResultsThe sample included 68 patients who underwent surgery in 2020 and 136 patients who underwent surgery in 2019. No patient was converted from laparoscopy to laparotomy or required reoperation. R0 resection was completed in all patients in both groups. There was no significant difference in postoperative complications (p = 0.508), duration of surgery (p = 0.519), intraoperative blood loss (p = 0.148), transfusion (0.217), intensive care (p = 0.379), mean lymph node yield (p = 0.205), vascular positivity rate (p = 0.273), nerve invasion rate (p = 0.713), anastomosis leak rate (p = 1), morbidity (p = 0.478), and length of hospital stay (p = 0.623) between the two groups. The meta-analysis also showed no significant difference in short-term outcomes between the two groups.ConclusionsOur study shows that the COVID-19 pandemic has not led to a deterioration in the surgical outcomes of colorectal cancer surgery or reduction in the quality of cancer removal. Therefore, we do not recommend postponing elective colorectal cancer surgery during the COVID-19 pandemic.

We study the problems of testing isomorphism of polynomials, algebras, and multilinear forms. Our first main results are average-case algorithms for these problems. For example, we develop an algorithm that takes two cubic forms $f, g\in \mathbb{F}_q[x_1,\dots, x_n]$, and decides whether $f$ and $g$ are isomorphic in time $q^{O(n)}$ for most $f$. This average-case setting has direct practical implications, having been studied in multivariate cryptography since the 1990s. Our second result concerns the complexity of testing equivalence of alternating trilinear forms. This problem is of interest in both mathematics and cryptography. We show that this problem is polynomial-time equivalent to testing equivalence of symmetric trilinear forms, by showing that they are both Tensor Isomorphism-complete (Grochow-Qiao, ITCS, 2021), therefore is equivalent to testing isomorphism of cubic forms over most fields.

Cr(VI) is toxic to the human body and environment. As a suitable wastewater treatment with low energy requirement technology, constructed wetland-microbial fuel cells (CW-MFCs) can treat Cr(VI) wastewater while generating electricity. In this study, CW-MFC and constructed wetland systems were developed to purify Cr(VI) wastewater. The removal mechanism of Cr(VI) was examined by electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy. The results demonstrated that the average pollutant removal efficiency of the CW-MFC system is 2.99–8.13% higher than that of the constructed wetland system, and the maximum power density is 505.61 mW m−2. Moreover, the XPS and EPR analyses demonstrated that Cr in substrates and Leersia hexandra Swartz primarily is in the form of Cr(III). Moreover, in plants and substrates, the Cr(III) content of the CW-MFC system was higher than that of the control, and the bioconcentration and translocation factors were 0.23 and 0.05 higher than those in the control group, respectively. Therefore, the CW-MFC system can efficiently remove Cr(VI) and promote the accumulation and transport of Cr. Microbial community diversity in the CW-MFC was significantly higher than CW. The abundance of electrogenic bacteria Geobacter and metal dissimilatory reducing bacteria Acinetobacter in CW-MFC is higher than that in CW. To summarize, the study results provide a theoretical basis for the mechanism study of Cr(VI) wastewater treatment using CW-MFC systems.

This study compared the toxicity mechanisms of four X-ray-based iodinated contrast media (ICM) on Escherichia coli (E. coli) and yeast microarray assays, aiming to determine the diverse toxicity mechanisms among different exposed organisms and the relationship between toxicity and their physical and chemical characteristics. The conventional phenotypic endpoint cytotoxicity and the change in reactive oxygen species (ROS) level were employed in conjunction with toxicogenomics to quantify changes in the gene/protein biomarker level in the regulation of different damage/repair pathways. The results showed that molecular toxicity endpoints, named transcriptional effect level index (TELI) and protein effect level index (PELI) for E. coli and yeast, respectively, correlated well with the phenotypic endpoints. Temporal altered gene/protein expression profiles revealed dynamic and complex damage/toxic mechanisms. In particular, compared with E. coli cells, yeast cells exposed to ICM exhibited significantly higher stress intensity and diverse stress types, resulting in stress or damage to the organism. The toxic mechanisms of ICM are concentration/property-dependent and relevant to the cellular structure and defense systems in prokaryotes and eukaryotes. In particular, the toxicity of ionic ICM is higher than that of non-ionic ICM, and eukaryotes are more susceptible than prokaryotes to ICM exposure.

Despite the high enthalpy of formation of poly(3,3-bis(azidomethyl)oxetane) (PBAMO), it is not readily applicable as a polymeric binder for propellants owing to its low chain flexibility and poor mechanical properties. The aim of this study was to improve the chain flexibility and mechanical properties of PBAMO binders by copolymerizing BAMO with tetrahydrofuran (THF) to produce a BAMO-THF copolyether (PBT). We report the preparation of energetic thermoplastic polyurethane elastomers (ETPUEs) by using PBT (soft segment), dicyclohexylmethylmethane-4,4′-diisocyanate (HMDI) (curing agent), a mixture of diols: diethyl bis(hydroxymethyl)malonate (DBM) (chain extender), 2-cyanoethyl-bis(2-hydroxyethyl)amine (CBA) (chain extender), and 1,4-butanediol (BDO) (chain extender). By systematically varying the content of the components, a series of ETPUEs was prepared. The results showed that with a fixed hard segment content, ETPUEs with CBA/BDO as chain extenders showed a stronger bonding property, lower glass transition temperature; improved mechanical properties (σm ​= ​7.60 ​MPa, εb ​= ​570.0%), and a higher enthalpy of formation (4015 ​kJ⋅mol−1). Moreover, when the ratio between CBA and BDO was 1:1, the binding strength between the binders and filler RDX was optimized, yielding a simulated propellant with decent mechanical properties (σm ​= ​5.92 ​MPa, εb ​= ​16.5%).

Human uptake abundance of microplastics via various pathways, and they accumulate in human liver, kidney, gut and even placenta (especially with a diameter of 1 μm or less). Recent scientific studies have found that exposure to microplastics causes intestinal inflammation and liver metabolic disorder, but it remains largely unknown that whether the damage and inflammation may cause further development of severe diseases. In this study, we discovered one of such potential diseases that may be induced by the exposure to small-sized microplastics (with a diameter of 1 μm) performing a multi-organ and multi-omics study comprising metabolomics and microbiome approaches. Unlike other animal experiments, the dosing strategy was applied in mice according to the daily exposure of the highly exposed population, which was more environmentally relevant and reflective of real-world human exposure. Our studies on the gut-liver axis metabolism have shown that the crosstalk between the gut and liver ultimately leaded to insulin resistance and even diabetes. We proactively verified this hypothesis by measuring the levels of fasting blood glucose and fasting insulin, which were found significantly elevated in the mice with microplastics exposure. These results indicate the urgent need of large-scale cohort evaluation on epidemiology and prognosis of insulin resistance after microplastics exposure in future.

A wealth of experimental evidence has validated that butyrate is capable of inhibiting tumorigenesis, while the potential role of butyrate metabolism in the tumor immune microenvironment (TIME) has been rarely explored. This study aims to explore the potential of butyrate-metabolism-related genes as prognostic biomarkers and their correlations with immune infiltrates in clear cell renal cell carcinoma (ccRCC) patients. Based on The Cancer Genome Atlas dataset (TCGA; n = 539), a total of 22 differentially expressed genes (DEGs) related with butyrate metabolism in ccRCC and normal samples were identified. Among them, a prognostic signature involving six butyrate-metabolism-related genes was created (Bu-Meta-GPS) in the training set (n = 271) and validation set (n = 268), and risk scores were calculated based on them. ccRCC patients with high-risk scores exhibited an unfavorable prognosis, high immunoscore, upregulated immuno-oncological targets (PD1, PD-L1, CTLA4, and CD19), and distinct immune-cell infiltration than those with low-risk scores. High-risk ccRCC patients without radiotherapy had a better survival rate than radiotherapy-treated patients. The negative regulation of cytokine production and cytokine-mediated signaling pathways was remarkably enriched in ccRCC patients with high-risk scores. A nomogram was then formulated to assess the overall survival (OS) of ccRCC patients. In summary, we illuminated the key role of butyrate metabolism in ccRCC TIME. The developed Bu-Meta-GPS was a sensitive predictive biomarker for the prognosis of ccRCC, which also provided new perspectives in improving immunotherapeutic efficacy.

In light of recent advances in deep learning and Synthetic Aperture Radar (SAR) technology, there has been a growing adoption of ship detection models that are based on deep learning methodologies. However, the efficiency of SAR ship detection models is significantly impacted by complex backgrounds, noise, and multi-scale ships (the number of pixels occupied by ships in SAR images varies significantly). To address the aforementioned issues, this research proposes a Pyramid Pooling Attention Network (PPA-Net) for SAR multi-scale ship detection. Firstly, a Pyramid Pooled Attention Module (PPAM) is designed to alleviate the influence of background noise on ship detection while its parallel component favors the processing of multiple ship sizes. Different from the previous attention module, the PPAM module can better suppress the background noise in SAR images because it considers the saliency of ships in SAR images. Secondly, an Adaptive Feature Balancing Module (AFBM) is developed, which can automatically balance the conflict between ship semantic information and location information. Finally, the detection capabilities of the ship detection model for multi-scale ships are further improved by introducing the Atrous Spatial Pyramid Pooling (ASPP) module. This innovative module enhances the detection model’s ability to detect ships of varying scales by extracting features from multiple scales using atrous convolutions and spatial pyramid pooling. PPA-Net achieved detection accuracies of 95.19% and 89.27% on the High-Resolution SAR Images Dataset (HRSID) and the SAR Ship Detection Dataset (SSDD), respectively. The experimental results demonstrate that PPA-Net outperforms other ship detection models.

The accurate prediction of significant wave height (SWH) offers major safety improvements for coastal and ocean engineering applications. However, the significant wave height phenomenon is nonlinear and nonstationary, which makes any prediction work a non-straightforward task. The aim of the research presented in this paper is to improve the predicted significant wave height via a hybrid algorithm. Firstly, an empirical mode decomposition (EMD) is used to preprocess nonlinear data, which are decomposed into several elementary signals. Then, a least squares support vector machine (LSSVM) with nonlinear learning ability is adopted to predict the SWH, and a particle swarm optimization (PSO) automatically performs the parameter selection of the LSSVM modeling. The results show that the EMD–PSO–LSSVM model can compensate for the lag in the prediction timing of the prediction models. Furthermore, the prediction performance of the hybrid model has been greatly improved in the deep-sea area; the prediction accuracy of the coefficient of determination (R2) increases from 0.991, 0.982, and 0.959 to 0.993, 0.987, and 0.965, respectively. The prediction performance results show that the proposed EMD–PSO–LSSVM performs better than the EMD–LSSVM and LSSVM models. Therefore, the EMD–PSO–LSSVM model provides a valuable solution for the prediction of SWH.

BackgroundMeta-analyses have demonstrated that indocyanine green (ICG) can effectively prevent anastomotic leakage (AL) after colorectal surgery. However, recent evidence from large randomized controlled trial (RCT) has suggested that ICG fluorescence angiography does not reduce the incidence of AL in colorectal surgery. This study was conducted to evaluate the value of ICG for the prevention of AL following colorectal surgery.MethodsUp to September 16, 2021, PubMed, Embase, China National Knowledge Infrastructure, Web of Science, Scopus, Cochrane Library, and VIP databases were searched for RCTs and propensity-score matched (PSM) studies evaluating the use of ICG for prevention of AL after colorectal surgery. Mean differences (MDs) or odds ratios (ORs) and 95% confidence intervals (CI) were calculated.ResultsTwenty studies (5 RCTs and 15 PSM studies) with a total of 5,125 patients were included. ICG did not reduce the reoperation rate (OR, 0.71; 95% CI, 0.38, 1.30), conversion rates (OR, 1.34; 95% CI, 0.65, 2.78), or mortality (OR, 0.50; 95% CI, 0.13, 1.85), but ICG did reduce the incidence of AL (OR, 0.46; 95% CI, 0.36, 0.59) and symptomatic AL (OR, 0.48; 95% CI, 0.33, 0.71), and reduced the length of hospital stay (MD,−1.21; 95% CI,−2.06,−0.35) and intraoperative blood loss (MD,−9.13; 95% CI,−17.52,−0.74). In addition, ICG use did not increase the incidence of total postoperative complications (OR, 0.93; 95% CI, 0.64, 1.35), postoperative ileus (OR, 1.26; 95% CI, 0.53, 2.97), wound infection (OR, 0.76; 95% CI, 0.44, 1.32), urinary tract infection (OR, 0.87; 95% CI, 0.30, 2.59), pulmonary infection (OR, 0.23; 95% CI, 0.04, 1.45), urinary retention (OR, 1.08; 95% CI, 0.23, 5.04), anastomotic bleeding (OR, 1.53; 95% CI, 0.27, 8.60), anastomotic stricture (OR, 0.74; 95% CI, 0.24, 2.29), or operative time (MD,−9.64; 95% CI,−20.28, 1.01).ConclusionsICG can effectively reduce the incidence of AL, without prolonging the operation time or increasing postoperative complications in colorectal surgery.Systematic Review Registrationwww.crd.york.ac.uk/prospero/#recordDetails, identifier: CRD42021279064.

Background Postoperative ileus is a major problem following gastrointestinal cancers surgery, several randomized controlled trials have been conducted investigating the use of probiotics or synbiotics to reduce postoperative ileus, but their findings are controversial. Objective We conducted a meta-analysis to determine the effect of probiotics or synbiotics on early postoperative recovery of gastrointestinal function in patients with gastrointestinal cancer. Methods The Embase, Cochrane Library, PubMed, and Web of Science databases were comprehensively searched for randomized controlled trials (RCTs) that evaluated the effects of probiotics or synbiotics on postoperative recovery of gastrointestinal function as of April 27, 2021. Outcomes included the time to first flatus, time to first defecation, days to first solid diet, days to first fluid diet, length of postoperative hospital stay, incidence of abdominal distension and incidence of postoperative ileus. The results were reported as the mean difference (MD) and relative risk (RR) with 95% confidence intervals (CI). Results A total of 21 RCTs, involving 1776 participants, were included. Compared with the control group, probiotic and synbiotic supplementation resulted in a shorter first flatus (MD, -0.53 days), first defecation (MD, -0.78 days), first solid diet (MD, -0.25 days), first fluid diet (MD, -0.29 days) and postoperative hospital stay (MD, -1.43 days). Furthermore, Probiotic and synbiotic supplementation reduced the incidence of abdominal distension (RR, 0.62) and incidence of postoperative ileus (RR, 0.47). Conclusion Perioperative supplementation of probiotics or synbiotics can effectively promote the recovery of gastrointestinal function after gastrointestinal cancer surgery.

This article analyzes the forward kinematics and inverse kinematics of the seven-degree-of-freedom exoskeleton rehabilitation manipulator. Denavit–Hartenberg coordinates are used to model the forward kinematics, and the working space of the end effector of the manipulator is analyzed according to the joint motion range of the human arm. In the inverse solution of the seven-degree-of-freedom exoskeleton rehabilitation manipulator, the self-motion angle ϕ of the elbow is used. The minimum energy standard is used to calculate the self-motion angle ϕ . The minimum energy mainly includes the gravitational potential energy of the upper limbs and the elastic potential energy stored in the muscles. Thus, the inverse solution formula of the seven-degree-of-freedom exoskeleton rehabilitation manipulator is derived. When calculating the angle θ 4 , an auxiliary parameter is introduced to solve the self-motion manifold of the manipulator. Finally, the theoretical derivation and verification of the forward and inverse kinematics are carried out in this article, and through analysis of the results, it is concluded that the inverse kinematics of this article has some limitations but the theory of inverse kinematics is feasible.

Fault diagnosis of rolling bearings under variable speed is a common issue in engineering practice, but it lacks an effective diagnosis algorithm, while approaches developed for steady speed cannot be directly applied. Therefore, for effectively identifying bearing faults under variable speed, this paper proposed a multiscale fractional dimensionless indicator (MSFDI) and put forward a fault diagnosis method with random forest (RF). It can overcome the feature space aliasing problem of traditional dimensionless indicators, which will lead to increased diagnosis uncertainty. The multiorder fractional Fourier transform is carried out on bearing signals to get a series of fractional Fourier domain components, which will be used to construct the original MSFDI feature set. Moreover, reliefF selects the sensitive MSFDIs as the input of the RF algorithm to determine the health condition. The effectiveness of the proposed method is verified by experiments and case studies.

Cr (VI) is hazardous to humans and our environment. Leersia hexandra Swartz (L. hexandra) is the first wet chromium hyperaccumulator found in China. This study constructed the L. hexandra constructed wetland-microbial fuel cell (CW-MFC) system to treat Cr (VI) wastewater. It also determined the effects of different dissolved oxygen (DO) concentrations on power generation, pollutant removal, and Cr (VI) reduction. Cathode aeration promoted the voltage output and pollutant removal of the L. hexandra CW-MFC when the DO concentration was 4.5 mg·L−1: the highest voltage was 520 mV, the chemical oxygen demand (COD) removal rate was 93.73%, and the Cr (VI) removal rate was 97.77%. Moreover, the increase in the DO concentration improved the absorption of heavy metal Cr by the substrate and L. hexandra, and promoted the transformation from Cr (VI) to Cr (III). Chromium mostly exists as a residue with low toxicity and low mobility in L. hexandra and the substrate. This proves that the increased DO concentration promotes the redox reaction in the system and plants, reducing Cr (VI) to Cr (III). At the same time, the key micro-organism Geobacter that enhances the performance of the system and Cr (VI) reduction was found. The research results can provide a reference for the subsequent CW-MFC treatment of actual Cr-containing wastewater.

A suitable trajectory in a port inspection mission is important for unmanned aerial vehicles (UAVs). Motion planning can help UAVs quickly generate an optimal trajectory that meets the constraints. The motion planning of UAVs is achieved in this paper as follows: firstly, a collision detection (CD) function is applied that evaluates whether the bias_RRT* (rapidly exploring random tree) algorithm needs to be called. Secondly, an isosceles triangle optimization function optimizes the path. Next, a trajectory is generated based on the minimum snap trajectory method. Lastly, the bias_RRT* algorithm and the improved bias_RRT* algorithm are used in the two experimental scenes for path planning comparison, and trajectory planning is carried out. The results show that, in the improved method, the path length and calculation time are shortened, and the trajectory cost and trajectory deviation are also significantly reduced. Overall, it appears that a camera-equipped UAV under the proposed approach can accomplish monitoring tasks more effectively and safety in port environment.

In this study, we comprehensively explored graphene oxide (GO)-induced systemic immune responses and interference with hematopoiesis in mice upon GO intravenous injection. In the liver and spleen, GO led to alterations in immune components at different time points. GO exposure showed an effect on the populations of different types of hepatic macrophages. In the liver, the populations of macrophages mainly affected by GO including Kupffer cells and monocyte-derived macrophages. Stimulated hepatic inflammation led to the infiltration of platelets from the circulation into the liver and decreased peripheral platelets population at day 1. Interestingly, a decreased platelet population was observed on day 7 in the spleen. GO also led to accelerated hematopoiesis in the spleen. Therefore, the possible forced generation of more platelets and the release of mature platelets from the spleen contributed to the increased circulating platelet count on day 7. Therefore, although GO showed a low potential to induce severe inflammation in the liver and spleen, it disrupted hematopoiesis in the spleen, which contributed to fluctuations in circulating platelet counts. The interaction of GO with the immune system warrants comprehensive study for gaining better understanding.

Post-pancreaticoduodenectomy infections cause mortality, morbidity, and prolonged antibiotic use. Probiotics or synbiotics may be advantageous for preventing postoperative infections, but their benefits on pancreaticoduodenectomy outcomes are controversial. This study evaluated the efficacy of probiotics and synbiotics in pancreaticoduodenectomy. The Embase, Web of Science, PubMed, and Cochrane Library databases were comprehensively searched for randomized controlled trials (RCTs) that evaluated the effects of probiotics or synbiotics on pancreaticoduodenectomy as of April 16, 2021. Outcomes included perioperative mortality, postoperative infectious complications, delayed gastric emptying, hospital stay length, and antibiotic-use duration. The results were reported as mean differences (MDs) and relative risks (RRs) with 95% confidence intervals (CI). Six RCTs involving 294 subjects were included. Probiotic or synbiotic supplementation did not reduce the perioperative mortality (RR, 0.34; 95% CI, 0.11, 1.03), but reduced the incidences of postoperative infection (RR, 0.49; 95% CI, 0.34, 0.70) and delayed gastric emptying (RR, 0.27; 95% CI, 0.09, 0.76) and also reduced the hospital stay length (MD, −7.87; 95% CI, −13.74, −1.99) and antibiotic-use duration (MD, −6.75; 95% CI, −9.58, −3.92) as compared to the controls. Probiotics or synbiotics can prevent infections, reduce delayed gastric emptying, and shorten the hospital stay and antibiotic-use durations in patients undergoing pancreaticoduodenectomy. These findings are clinically important for promoting recovery from pancreaticoduodenectomy, reducing the incidences of antibiotic resistance and iatrogenic infections, and reducing the medical burden.

Electrocaloric effect (ECE) of ferroelectrics has attracted considerable interest due to its potential application in environmentally friendly solid-state refrigeration. The discovery of giant ECE in ferroelectric thin films has greatly renewed the research activities and significantly stimulated experimental and theoretical investigations. In this review, the recent progress on the theoretical modeling of ECE in ferroelectric and antiferroelectric materials are introduced, which mainly focuses on the phase field modeling and first-principles based effective Hamiltonian method. We firstly provide the theoretical foundation and technique details for each method. Then a comprehensive review on the progress in the application of two methods and the strategies to tune the ECE are presented. Finally, we outline the practical procedure on the development of multi-scale computational method without experiemtal parameters for the screening of optimized electrocaloric materials.

The relation between role overload and work performance remains insufficiently understood. Drawing upon conservation of resources theory, we expected role overload to negatively relate to performance through psychological strain and this relation to be buffered by leader–member exchange (LMX). Study 1 (N = 212) examined depression as a severe type of strain that mediates between role overload and in-role performance, job dedication, and voice behavior. Study 2 (N = 191) used generic, perceived strain as a mediator between role overload and in-role performance and reward recommendations. Both studies tested LMX’s buffering effect, controlling for role ambiguity and conflict. A supplementary panel study (N = 99) assessed the temporal relationship between role overload and strain. Role overload triggered psychological strain, which undermined performance, and LMX acted as a buffer on role overload, but not on role ambiguity or role conflict. We discuss the implications of these findings for theory and practice.

In the past few years, Synthetic Aperture Radar (SAR) has been widely used to detect marine ships due to its ability to work in various weather conditions. However, due to the imaging mechanism of SAR, there is a lot of background information and noise information similar to ships in the images, which seriously affects the performance of ship detection models. To solve the above problems, this paper proposes a new ship detection model called Feature enhancement and Land burial Net (FLNet), which blends traditional image processing methods with object detection approaches based on deep learning. We first design a SAR image threshold segmentation method, Salient Otsu (S-Otsu), according to the difference between the object and the noise background. To better eliminate noise in SAR images, we further combine image processing methods such as Lee filtering. These constitute a Feature Enhancement Module (FEM) that mitigates the impact of noise data on the overall performance of a ship detection model. To alleviate the influence of land information on ship detection, we design a Land Burial Module (LBM) according to the morphological differences between ships and land areas. Finally, these two modules are added to You Only Look Once V5 (YOLO V5) to form our FLNet. Experimental results on the SAR Ship Detection Dataset (SSDD) dataset show that FLNet comparison with YOLO V5 accuracy when performing object detection is improved by 7% and recall rate by 6.5%.

The early weak fault characteristics of rolling bearings are extremely weak and are easily overwhelmed by other noises. In order to effectively extract the characteristics of the early weak faults of the rolling bearings and draw on the multilayer wavelet decomposition idea, a method for diagnosing the early weak faults of the rolling bearing based on the multilayer reconstruction filter is proposed. As we all know, empirical wavelet transform (EWT) makes full use of wavelet filter bank, and variational mode decomposition (VMD) uses Wiener filter bank. This paper fully combines the advantages of the above two methods, adaptively determines the number of modes through empirical wavelet decomposition and divides the original signal, extracts the frequency band that contains the fault characteristic information, and effectively eliminates noise interference. These steps are repeated until the optimal component of the condition is obtained. In the output layer, the weak fault impact components are further separated by the strong filtering and signal decomposition capability of VMD. The advantages of the proposed method are proved by the experiment of weak fault of rolling bearing and the accelerated failure experiment of full life. The proposed method has the advantages of reducing noise influence and adaptive estimation of decomposed modes, which can be applied more efficiently in practice.

The best enzymolysis conditions that fit actual production were determined via multiple-enzyme hydrolysis of waste shrimp heads through orthogonal experiment, taking frozen Litopenaeus vannamei as the starting material. The parameters including a material-water ratio of 1:4, initial pH of 8.5 and enzyme dosage of 0.4% contributed to average DH (degree of hydrolysis) value of 18.38% when the reaction was carried out at 55°C for 5 h. Microwave Maillard reaction of enzymatic hydrolysate was then performed to develop shrimp flavor juice, the optimal preparation conditions were determined based on reaction extent and sensory evaluation, including a power of 200W, temperature of 90°C and duration time of 30 min, with the addition of 3% reducing sugar and 3% amino acid.

Crystal facet orientations of the polycrystalline hybrid lead halide perovskite thin films play a crucial role in determining the device performance. Here Zheng et al. demonstrate effective control of the crystal stacking mode by cation cascade doping, which promotes the charge transport in the photovoltaic device.