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Squeak and Rattle (S&R) of automotive door panels seriously affect consumers' perception of vehicle quality. In order to accurately analyze the S&R problem, BP software was used to build an S&R analysis finite element model of the interior assembly of the door interior, taking into account the pre-compression between the interior door panel and the sheet metal during installation. The excitation transmitted from the body to the door through the hinge is tested, and the modal transient analysis of the model is carried out by BP software. Combined with the S&R noise risk assessment standard, the analysis results were evaluated, and the S&R points were determined. Through the bench test, it is verified that the test risk points are consistent with the analysis results, indicating the accuracy of the S&R simulation analysis. Based on the modal contribution, the S&R risk points are optimized and analyzed. Through optimization analysis, the abnormal noise risk is reduced. The results show that in the digital model design stage, the door panel S&R risk analysis based on BP software can be carried out for abnormal noise risk prediction and optimization analysis, that greatly saves development time and reduces development costs. [ABSTRACT FROM AUTHOR]

Electric power steering (EPS) system is becoming the primary source of Electric Vehicle (EV) noise due to absence of classic power train. The rattle noise produced by EPS, which is easily discernible when driving. Since the conventional subjective evaluation approach makes it difficult to identify the source, it is required to establish an objective way to solve such an issue. In this paper, the principle of multiple coherence method is first addressed analytically, and then is employed to analyze the vibration signal acquisition from EPS different points, meanwhile, combine with in-car sound signal, to accurately identify the specific location. [ABSTRACT FROM AUTHOR]

This paper mainly studies a reverse engineering of material parameters through finite element optimization algorithm based on free modal test results, focusing on free modal test and establishment of finite element optimization model. The elastic modulus and density of the material can be solved by the finite element optimization algorithm to ensure the accuracy of the simulation results. When the accurate material parameters are obtained, the accuracy of abnormal sound simulation can be improved. It plays a guiding role in the development of vehicle BSR performance, so as to improve the ride comfort of the vehicle. [ABSTRACT FROM AUTHOR]

According to the basic principle of statistical energy method, the high frequency SEA model of the full vehicle is established. Through the comparison of simulation and test results, the error of power based noise reduction (PBNR) and interior sound pressure level response is less than three dB, which proves the accuracy of high frequency simulation model. Through the design of different schemes, the sensitivity analysis of parameters such as material parameters, internal loss factor and leakage rate to the model is obtained. The research results show that the accuracy of material parameters, internal loss factor and leakage rate can improve the accuracy of high-frequency simulation model. The sensitivity analysis can provide some ideas for vehicle high frequency noise model adjustment and modification. [ABSTRACT FROM AUTHOR]

Pancreatic ductal adenocarcinoma (PDAC) elicits a dense stromal response that blocks vascular access because of pericyte coverage of vascular fenestrations. In this way, the PDAC stroma contributes to chemotherapy resistance, and the small-sized nanocarrier loaded with platinum has been adopted to address this problem which is not suitable for loading docetaxel (DTX). In the present study, we used the poly(D,L-lactide)-b-polyethylene glycol-methoxy (mPEG-b-PDLLA) to encapsulate DTX and got a small-sized polymeric micelle (SPM); meanwhile we functionalized the SPM's surface with TAT peptide (TAT-PM) for a higher permeability. The diameters of both SPM and TAT-PM were in the range of 15-26 nm. In vitro experiments demonstrated that TAT-PM inhibited Capan-2 Luc PDAC cells growth more efficiently and induced more apoptosis compared to SPM and Duopafei. The in vivo therapeutic efficiencies of SPM and TAT-PM compared to free DTX was investigated on the orthotopic transplantation model of Capan-2 Luc. SPM exerted better therapeutic efficiency than free DTX, however, TAT-PM didn't outperformed SPM. Overall, these results disclosed that SPM could represent a new therapeutic approach against pancreatic cancer, but its permeability to PDAC was not the only decisive factor [ABSTRACT FROM AUTHOR]

Buzz, squeak and rattle (BSR) noise has become apparent in vehicles due to the significant reductions in engine noise and road noise. The BSR often occurs in driving condition with many interference signals. Thus, the automatic BSR detection remains a challenge for vehicle engineers. In this paper, a rattle signal denoising and enhancing method is proposed to extract the rattle components from in-vehicle background noise. The proposed method combines the advantages of wavelet packet decomposition and mathematical morphology filter. The critical frequency band and the information entropy are introduced to improve the wavelet packet threshold denoising method. A rattle component enhancing method based on multi-scale compound morphological filter is proposed, and the kurtosis values are introduced to determine the best parameters of the filter. To examine the feasibility of the proposed algorithm, synthetic brake caliper rattle signals with various SNR ratios are prepared to verify the algorithm. In the validation analysis, the proposed method can well remove the disturbance background noise in the signal and extract the rattle components with well SNR ratios. It is believed that the algorithm discussed in this paper can be further applied to facilitate the detection of the vehicle rattle noise in industry. [ABSTRACT FROM AUTHOR]

Background: Sepsis is a life-threatening disease characterized by multiple organ failure due to excessive activation of the inflammatory response and cytokine storm. Despite recent advances in the clinical use of anti-cytokine biologics, sepsis treatment efficacy and improvements in mortality remain unsatisfactory, largely due to the mechanistic complexity of immune regulation and cytokine interactions. Methods: In this study, a broad-spectrum anti-inflammatory and endotoxin neutralization strategy was developed based on autologous "cryo-shocked" neutrophils (CS-Neus) for the management of sepsis. Neutrophils were frozen to death using a novel liquid nitrogen "cryo-shock" strategy. The CS-Neus retained the source cell membrane structure and functions related to inflammatory site targeting, broad-spectrum inflammatory cytokines, and endotoxin (LPS) neutralizing properties. This strategy aimed to disable harmful pro-inflammatory functions of neutrophils, such as cytokine secretion. Autologous cell-based therapy strategies were employed to avoid immune rejection and enhance treatment safety. Results: In both LPS-induced sepsis mouse models and clinical patient-derived blood samples, CS-Neus treatment significantly ameliorated cytokine storms by removing inflammatory cytokines and endotoxin. The therapy showed notable anti-inflammatory therapeutic effects and improved the survival rate of mice. Discussion: The results of this study demonstrate the potential of autologous "cryo-shocked" neutrophils as a promising therapeutic approach for managing sepsis. By targeting inflammatory organs and exhibiting anti-inflammatory activity, CS-Neus offer a novel strategy to combat the complexities of sepsis treatment. Further research and clinical trials are needed to validate the efficacy and safety of this approach in broader populations and settings. [ABSTRACT FROM AUTHOR]

With focus on NVH performance, this paper studies the range extender system control strategy such as the initial start speed, operating points, speed up and down control method between operating points of the range extender, etc. At the same time, the confirmation of the operating points of the range extender based on the full vehicle frequency distribution and vibration and noise level of key points (seat rail, driver’s inner ear) was performed. Finally, we conducted objective test and compared the test data with benchmark vehicles. [ABSTRACT FROM AUTHOR]

In this paper, the take-up judder phenomenon caused by the accumulated geometric deviation of clutch plates is simulated and verified by experiments. Firstly, the vibration test and data analysis are carried out for the sample vehicle and related benchmark vehicles, and the vibration target is determined. Then, a simulation analysis and optimization model of the clutch engagement process in the vehicle take-up process was established, and the optimal control target was determined by multi-condition analysis of the accumulation geometric deviation factors of the clutch. Finally, several clutch deviation samples are verified, and total deviation of clutch control strategy is given. This paper provides a quantitative analysis method of the clutch cumulative geometric deviation in the take-up process, which provides a reference for the clutch parameter setting and the vibration control of the vehicle in the take-up process. [ABSTRACT FROM AUTHOR]

To address the rattling noise issue of a Twin-tube hydraulic shock absorber for a electric vehicle, a road test and subjective evaluation were performed. The diagnostic method of the rattling noise source of the shock absorber is studied, and three methods are used to process the test date: the fast Fourier transform can only obtain the main frequency band of the rattling noise; and the short-time Fourier transform can roughly diagnose the frequency band and the occurrence time; using wavelet transform technology combined with displacement signal can accurately lock the source of rattling noise in the rebound stroke. Furthermore, combined with the internal valve configuration of the shock absorber, the rattling noise source is diagnosed in the rebound valve and the compensation valve. The time of rattling noise and the corresponding working stroke of shock absorber can be quickly locked by using the wavelet transform, which is of great significance to solve the problem of shock absorber rattling noise caused by deficiency design of the internal valve architecture of the shock absorber. [ABSTRACT FROM AUTHOR]

Squeak and Rattle problems seriously affect the quality of the vehicles. In the adjustment stage of the automobile development process, engineers mainly rely on subjective evaluation to diagnose squeak and rattle noises, which is prone to misjudgment, missed judgment and time-consuming problems. There are gaps in relevant objective evaluation methods. This article proposed that speaker identification is used to identify squeak and rattle noises from the audio recorded in the test, to achieve objective and accurate results. In this paper, four kinds of squeak and rattle noise audios are used as samples, Mel Frequency Cepstrum Coefficient is extracted as feature vector to construct target Gaussian mixture models (GMM). The expectation, variance and correlation coefficient of the Gaussian mixture model can be calculated to describe the difference of multiple squeak and rattle noises. Using samples to judge accuracy rate, the results indicated that the acceptance accuracy rate reaches 100 %, and the rejection accuracy rate reaches more than 95 %. [ABSTRACT FROM AUTHOR]

A shearing motion inevitably occurs along the creep distance on the macroscopic surface of two objects before the friction transformed from static into kinetic state when they come into contact each other. In the process of shearing, it will creep to the characteristic distance before slipping on the supporting surface, then proceed to slip on the contacting points, such an alternating motion between contact surfaces is prone to result in rattling noise. In this paper, the mechanism of the automotive rattling or clicking noise produced in bolted joints surface will be addressed mathematical through the characteristic distance of stick-slip model. Finally, it is suggest that how to prevent these noises in the early design phase. [ABSTRACT FROM AUTHOR]

Hydroxyapatite is a scaffold material widely used in clinical repair of bone defects, but it is difficult for traditional methods to make customized artificial bone implants with complicated shapes. 3D printing biomaterials used as personalized tissue substitutes have the ability to promote and enhance regeneration in areas of defected tissue. The present study aimed at demonstrating the capacity of one 3D printing technique, digital light processing (DLP), to produce HA scaffold. Using HA powder and photopolymer as raw materials, a mixture of HA mass ratio of 30 wt% was prepared by viscosity test. It was used for forming ceramic sample by DLP technology. According to differential scanning calorimetry and thermal gravity analysis, it was revealed that the main temperature range for the decomposition of photopolymer was from 300 to 500 °C. Thus, the two-step sintering process parameters were determined, including sintering temperature range and heating rate. XRD analysis showed that the phase of HA did not change after sintering. SEM results showed that the grain of the sintered ceramic was compact. The compression model was designed by finite element analysis. The mechanical test results showed that the sample had good compression performance. The biological properties of the scaffold were determined by cell culture in vitro. According to the proliferation of cells, it was concluded that the HA scaffold was biocompatible and suitable for cell growth and proliferation. The experimental results show that the DLP technology can be used to form the ceramic scaffold, and the photopolymer in the as-printed sample can be removed by proper high-temperature sintering. The ceramic parts with good compression performance and biocompatibility could be obtained. [ABSTRACT FROM AUTHOR]