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Accelerated life test provides a feasible and effective way to rapidly derive lifetime information by exposing products to higher-than-normal operating conditions. However, most of the previous research on accelerated life test has focused on the application of a single stress factor and a traditional censoring scheme. This article considers the reliability inference for a dual constant-stress accelerated life test model with exponential distribution and progressively Type-II censoring. Point estimates for model parameters are provided using maximum likelihood estimation and the weighted least squares method based on random variable transformation. In addition, we construct asymptotic confidence intervals, approximate confidence intervals, and bootstrap confidence intervals for the parameters of interest. Finally, extensive simulation studies and an illustrative example are presented to investigate the performance of the proposed methods. [ABSTRACT FROM AUTHOR]

As cytoplasmic protein complexes that are pivotal for innate immunity, inflammasomes act primarily through the detection of pathogen‐ or danger‐associated molecular patterns. Nucleotide oligomerisation domain‐like receptor family and caspase activation recruitment domain‐containing protein 4 (NLRC4) inflammasomes identify and eliminate intracellular pathogens, a process contingent on the ligand‐recognition capabilities of neuronal apoptosis inhibitory proteins (NAIPs). Upon detection of specific molecules indicative of intracellular infection, NAIPs discern distinct pathogenic components and subsequently transmit signals to NLRC4, thus initiating their activation and triggering an inflammatory response. However, the mechanisms underlying NLRC4 inflammasome remain unclear. In this study, we elucidated the critical role of ATG16L2 in activating the NLRC4 inflammasome. ATG16L2‐deficient macrophages exhibited reduced NLRC4 inflammasome activation, characterised by decreased oligomerisation of apoptosis‐associated speck‐like protein containing a CARD and attenuated cleavage of Pro‐caspase‐1, Pro‐IL‐1β and gasdermin D. Co‐immunoprecipitation assays revealed an interaction between ATG16L2 and NAIPs. Furthermore, ATG16L2 enhanced the association between NAIPs and NLRC4 by binding to NAIPs. For ATG16L2‐knockout mice infected with Salmonella typhimurium, pathogen clearance and survival rates markedly decreased. Collectively, our findings suggest that ATG16L2 is a significant modulator of the innate immune system, influencing the activity of the NLRC4 inflammasome and the host's defensive response to intracellular pathogens. [ABSTRACT FROM AUTHOR]

The two dependent competing risks are soft failure due to aging degradation and fragmentation caused by shocks and hard failure due to spring breakage caused by the same shock process. Considering the complexity of the product itself and the instability of the working environment, this study proposed a generalized reliability model for systems experiencing dependent competing failure processes (DCFPs) of degradation and random shocks, which considered two kinds of DCFP: (1) shock process could affect soft failure thresholds; (2) degradation process could affect hard failure thresholds. In case (1), we considered the effect that a cumulative number of shocks above a certain magnitude could have on the change in the soft failure threshold. In case (2), we considered not only the shock process's impact on the soft failure threshold but also the total degradation (including continuous degradation and sudden degradation caused by shock) on the hard failure threshold. The model captures the features that the shocks experienced by the system affect the degradation process, accelerating the system degradation and causing soft failures; the degradation process of the system affects the shock process, making the system more susceptible to failure from external shocks. Finally, an example using micro‐electro‐mechanical systems devices illustrates the effectiveness of the proposed approach with sensitivity analysis. [ABSTRACT FROM AUTHOR]

Rotating machinery is an important and easily damaged component in large-scale equipment. Under the coupling action of system components, the occurrence rate of compound faults is very high, which seriously endangers equipment safety. The vibration signals of the damaged rotating machine include equipment operation vibration information, periodic impacts, environmental noise, and even accidental impacts. To effectively extract multi-fault features from compound fault signals, a multi-period pulse detection indicator called harmonic spectrum correlation kurtosis (HSCK) is proposed in this paper. Based on this, an adaptive matching extraction strategy for multiple fault features is proposed. By introducing variational mode decomposition, an adaptive plane paving method for signal components is designed, and an enhanced cyclic frequency estimation method is proposed to pre-determine the fault characteristic frequency as a prior parameter of HSCK, so as to obtain the optimal center frequency and bandwidth of multiple resonance bands. The implementation of this strategy can obtain more periodic pulse information with a high signal-to-noise ratio. Simulation results show that the strategy is accurate and effective. The data of wheel-bearing compound fault and bearing multi-element compound fault indicate that the proposed strategy can be used for compound fault diagnosis of rotating machinery. [ABSTRACT FROM AUTHOR]

This paper investigated reliability modeling for systems subject to dependent competing risks considering that variation of the failure threshold is not considered in most studies on competing failure reliability. Firstly, the variation of degradation quantity under shocks was analyzed, and the variation of the threshold was considered on this basis. Secondly, the cumulative degradation under the influence of the random shock process was analyzed. The attractive property of Copula functions is symmetry. Then, a linear Wiener process model was applied to model performance degradation failure, and a multi-performance degradation correlated-competition model based on a Copula function was constructed, which considered the correlated competition between multi-performance degradation failures. Lastly, a micromotor system was used to analyze the applicability of the proposed model for bivariate instances, demonstrating the rationality and effectiveness of the proposed model. [ABSTRACT FROM AUTHOR]

To inference the reliability of product at normal stress conditions, accelerated life test (ALT) is usually used to obtain failure information rapidly. However, most of the researches on ALT are focused on the statistical inference with single stress, which makes it difficult to gain accurate reliability through applying ALT method in single stress case. In this article, statistical inference is considered on dual constant-stress accelerated life test (DCSALT) model for the Weibull distribution with Type-I censored data. On the assumption that the Weibull distribution has constant shape parameter, and a log-linear acceleration model between its scale parameter and the test stress level combination. Using the profile maximum likelihood estimation (PMLE) method to estimate the unknown parameters in DCSALT model for Weibull distribution, and this process is completed by Newton-Raphson algorithm. Moreover, the observed information matrix is obtained in order to construct asymptotic confidence intervals of the unknown parameters. Finally, the numerical study is presented to illustrate the effectiveness of the maximum likelihood estimators (MLEs). [ABSTRACT FROM AUTHOR]

Convolutional sparse representation based on local orthogonal matching pursuit (SR-LocOMP) can recover wheelset-bearing fault impulses without being affected by random slippage and plays an important role in wheelset-bearing fault diagnosis. However, the performance of SR-LocOMP at a low signal-to-noise ratio (SNR) is not satisfied. In addition, when the analyzed signals contain compound faults, the fault feature extraction ability of SR-LocOMP will be greatly affected. To further improve the performance of SR-LocOMP, this article proposes an improved SR-LocOMP algorithm, named improved SR-LocOMP. The proposed method introduces scale-space representation (SSR) for frequency band segmentation and then performs SR-LocOMP for signals in each segmented frequency band. Reconstructed signals corresponding to each segmented frequency band are obtained separately. Envelope spectral ${L}2/{L}1$ norm is used to measure the fault information content of each reconstructed signal to extract more accurate and richer impulse response features caused by bearing faults. The proposed method not only has the ability to detect compound faults but also can effectively reduce noise interference. Through simulation and experimental analysis, the superiority of the proposed method is verified. [ABSTRACT FROM AUTHOR]

Background: Recent theory on the "gut-brain axis" suggests a close relationship between the dysfunction of the gut and the disorders of the brain.Methods: We performed a systemic literature search followed by a multi-step inclusion selection for all studies on the risk of Colorectal cancer (CRC) in Parkinson's disease (PD) patients using the following databases: PubMed, EMBASE and WOS. Relative risk (RR) and the 95% confidence intervals (CI) were calculated using either the random-effects model or the fixed-effects meta-analysis model, based on the assessment of heterogeneity.Results: Seventeen studies involving a total of 375,964 PD patients and 879,307 cancer patients were included. Independent meta-analyses for cohort studies and case-control studies showed that the overall pooled RR of the cohort studies was 0.78 (0.66-0.91), and that of the case-control studies was 0.78 (0.65-0.94), indicating that patients with PD have a significantly decreased risk for CRC. The significant lower risk is present in both the colon and the rectum subgroups classified by tumor location. Moreover, the risk for CRC is significantly lower in America (RR = 0.58), Europe (RR = 0.82) and Asia (RR = 0.83) compared to the control population.Conclusion: The occurrence of CRC was significantly lower in patients with diagnosis of PD. [ABSTRACT FROM AUTHOR]

Since minimum correlated generalized Lp/Lq deconvolution (MCG-Lp/Lq-D) cannot simultaneously have a good sensing ability to repetitive fault impulses and a strong robustness to noise when processing low SNR signals, a new deconvolution method, minimum improved correlated generalized Lp/Lq deconvolution (MICG-Lp/Lq-D), is proposed in this article. The proposed method is designed based on a novel norm, the improved correlated generalized Lp/Lq (ICG-Lp/Lq) norm. The ICG-Lp/Lq norm not only has the low-order statistics form that is similar to the correlated generalized Lp/Lq (CG-Lp/Lq) norm used in MCG-Lp/Lq-D, but also has the high shift-order signal correlation construction similar to the correlated kurtosis (CK) norm used in maximum correlated kurtosis deconvolution (MCKD). This guarantees that the proposed norm is robust enough to strong noise and can improve its sensing ability for repetitive impulses simultaneously. This feature of the ICG-Lp/Lq norm ensures that MICG-Lp/Lq-D can suppress outliers and extract weak impacts when processing low SNR signals. Simulated and experimental case studies verify the performance of the proposed method. The results indicate that the proposed method is robust enough to strong noise and very sensitive to repetitive impulses simultaneously, which indeed overcomes the aforementioned defects of MCG-Lp/Lq-D. Therefore, MICG-Lp/Lq-D can be considered a promising tool for detecting repetitive impulses. [ABSTRACT FROM AUTHOR]

Multidrug resistance (MDR) of cancer cells is a significant challenge in chemotherapy, highlighting the urgent medical need for simple and reproducible strategies to reverse this process. Here, we report the development of an active tumor-targeting and redox-responsive nanoplatform (PA-ss-NP) using hyaluronic acid-g-cystamine dihydrochloride-poly-ε-(benzyloxycarbonyl)-L-lysine (HA-ss-PLLZ) to co-deliver paclitaxel (PTX) and apatinib (APA) for effective reversal of MDR. This smart nanoplatform specifically bound to CD44 receptors, leading to selective accumulation at the tumor site and uptake by MCF-7/ADR cells. Under high concentrations of cellular glutathione (GSH), the nanocarrier was degraded rapidly with complete release of its encapsulated drugs. Released APA effectively inhibited the function of the P-glycoprotein (P-gp) drug pump and improved the sensitivity of MDR cells to chemotherapeutic agents, leading to the recovery of PTX chemosensitivity in MDR cells. As expected, this newly developed intelligent drug delivery system could effectively control MDR, both in vitro and in vivo. [ABSTRACT FROM AUTHOR]

In order to evaluate the reliability of high reliability and long life products under normal stress conditions effectively and quickly, a confidence reliability evaluation model of dual constant-stress accelerated life lest (DCSALT) for Weibull distribution product is proposed. Firstly, the generalized Eyring-Weibull reliability model is established by using the accelerated life test (ALT) technology. In this model, it is assumed that the Weibull distribution has constant shape parameter and a log-linear relation between its scale parameter and each stress level combination. Secondly, a maximum likelihood estimation (MLE) method for DCSALT with fixed time censoring of the Weibull distribution, the Fisher information matrix related to the likelihood function, and the asymptotic covariance matrix of the model parameters is presented. Furthermore, the asymptotic confidence intervals of the model parameters and some reliability indexes are constructed. Finally, the simulation example demonstrates the feasibility of the proposed method. [ABSTRACT FROM AUTHOR]

This article develops reliability models for systems subject to two dependent competing failure processes, considering the correlation between additional damage size on degradation in soft failure process and stress magnitude of shock load in hard failure process, both of which are caused by the same kth random shock. The generalized correlative reliability assessment model based on copulas is proposed, which is then extended to three different shock patterns: (1) δ‐shock, (2) m‐shock, and (3) m‐run shocks. There are some statistical works to be introduced in reliability modeling, including data separation of total degradation amount, inferring the distribution of amount of aging continuous degradation at time t, and fitting copula to the specific correlation. The developed reliability models are demonstrated for an application example of a micro‐electro‐mechanical system. [ABSTRACT FROM AUTHOR]

In this paper, we named the composition by a real-valued measurable function and an uncertain variable as a composite uncertain variable. We focused on the uncertainty distribution for two kinds of composite uncertain variables. The conclusions show: (1) it exists a lower bound when the composed function is continuous and strictly monotonically decreasing at first and then strictly monotonically increasing (e.g. convex downward functions); (2) it exists an upper bound when the composed function is continuous and strictly monotonically increasing at first and then strictly monotonically decreasing (e.g. convex upward functions). [ABSTRACT FROM AUTHOR]

An intumescent waterborne amino-resin fire-retardant coating for wood (C) was synthesized and its fire-retardant and smoke-suppressant properties were investigated. The main film-builder of C was urea-formaldehyde resin blended with polyvinyl acetate resin. The intumescent fire-retardant system of C consisted of guanylurea phosphate (GUP), ammonium polyphosphate (APP), pentaerythritol (PER) and melamine (MEL). Specimens of plywood painted, respectively, with a commercial intumescent fire-retardant coating (A), a synthesized coating (C), and the main film-builder of coating C (B), as well as an unpainted plywood (S-JHB), were analyzed by cone calorimetry (CONE). The results show a marked decrease in the heat release rate (HRR) and the total heat release (THR), an increased mass of residual char (Mass), a marked postponement in time to ignition (TTI) and a reduced carbon monoxide production rate ( P CO). The smoke production rate (SPR) and total smoke production (TSP) of the plywood painted with coating C were observed with the CONE test. The overall fire-retardant and smoke-suppressant performance of the synthesized coating C was much better than that of the commercial coating A. The thermo-gravimetric analysis (TGA) results of coating C and its film-builder B indicated that the thermal degradation process of B was slowed down by the addition of the intumescent fire-retardant system; the increase in the amount of charring of coating C was considerable. [ABSTRACT FROM AUTHOR]

Long non-coding RNAs (lncRNAs) contribute to colorectal cancer (CRC). However, the role of lncRNAs in CRC metabolism, especially glucose metabolism remains largely unknown. In this study, we identify a lncRNA, GLCC1, which is significantly upregulated under glucose starvation in CRC cells, supporting cell survival and proliferation by enhancing glycolysis. Mechanistically, GLCC1 stabilizes c-Myc transcriptional factor from ubiquitination by direct interaction with HSP90 chaperon and further specifies the transcriptional modification pattern on c-Myc target genes, such as LDHA, consequently reprogram glycolytic metabolism for CRC proliferation. Clinically, GLCC1 is associated with tumorigenesis, tumor size and predicts poor prognosis. Thus, GLCC1 is mechanistically, functionally, and clinically oncogenic in colorectal cancer. Targeting GLCC1 and its pathway may be meaningful for treating patients with colorectal cancer. lncRNA and cellular metabolism are frequently dysregulated in cancer. In this study, the authors discover the lncGLCC1 is increased in colorectal cancer cells under glucose starvation conditions and correlates with poor prognosis in this cancer. [ABSTRACT FROM AUTHOR]