Operational Deflection Shape Measurements on Bladed Disks with Continuous Scanning Laser Doppler Vibrometry.

The continuous scanning laser Doppler vibrometry (CSLDV) technique is usually used to evaluate the vibration operational deflection shapes (ODSs) of structures with continuous surfaces. In this paper, an extended CSLDV is demonstrated to measure the non-continuous surface of the bladed disk and to obtain the ODS efficiently. For a bladed disk, the blades are uniformly distributed on a given disk. Although the ODS of each blade can be derived from its response data along the scanning path with CSLDV, the relative vibration direction between different blades cannot be determined from those data. Therefore, it is difficult to reconstruct the complete vibration mode of the whole blade disk. In order to measure the complete ODS of the bladed disk, a method based on ODS frequency response functions (ODS FRFs) has been proposed. While the ODS of each blade is measured by designing the suitable scanning paths in CSLDV, an additional response signal is obtained at a fixed point as the reference signal to identify the relative vibration phase between the blade and the blade of the bladed disk. Finally, a measurement is performed with a simple bladed disk and the results demonstrate the feasibility and effectiveness of the proposed extended CSLDV method.

Effect of the optical power factors on the laser-linewidth measurements.

In this paper, the effects of optical power factors like laser power, the powers of the laser beams in the two arms of the optical system, and the power of the photodetector on laser-linewidth measurements are studied. From the experiments, it can be found that when the average optical input power for the photodetector is about 50% of its linear saturation power, the measured laser line width is a minimum. When the optical powers of the laser beams in the two arms are equal in short-delay self-homodyne system, the measured laser line width is narrowest. In the low output power range of the laser, its line width decreases with the increase in optical power. By comparing experiments, it can also be clear that the conventional measurement method is seriously affected by different noise types, which causes the measured line width to become wider and not change even if the laser linewidth changes. However, based on the short-delay coherent envelope method, the measured coherent envelope changes significantly when the laser line width changes slightly, and its corresponding laser-linewidth values are also clearly visible. It confirms the low noise and high resolution of the short-delay self-homodyne coherent-envelope laser-measurement method. The outcomes of this study can provide helpful information for precision ultra-narrow laser-linewidth measurements.

An ECG Signal Acquisition and Analysis System Based on Machine Learning with Model Fusion.

Recently, cardiovascular disease has become the leading cause of death worldwide. Abnormal heart rate signals are an important indicator of cardiovascular disease. At present, the ECG signal acquisition instruments on the market are not portable and manual analysis is applied in data processing, which cannot address the above problems. To solve these problems, this study proposes an ECG acquisition and analysis system based on machine learning. The ECG analysis system responsible for ECG signal classification includes two parts: data preprocessing and machine learning models. Multiple types of models were built for overall classification, and model fusion was conducted. Firstly, traditional models such as logistic regression, support vector machines, and XGBoost were employed, along with feature engineering that primarily included morphological features and wavelet coefficient features. Subsequently, deep learning models, including convolutional neural networks and long short-term memory networks, were introduced and utilized for model fusion classification. The system's classification accuracy for ECG signals reached 99.13%. Future work will focus on optimizing the model and developing a more portable instrument that can be utilized in the field.

Precise laser linewidth measurement by feature extraction with short-delay self-homodyne.

We propose a precision measurement method of laser linewidth based on short-delay self-homodyne, using the second peak-valley difference (SPVD) feature of the coherent power spectrum to fit laser linewidth. The SPVD model of the self-homodyne coherent envelope spectrum was established. One-to-one correspondence among the values of SPVD, the delay length, and the laser linewidth was determined theoretically and through simulations, while the reliability and stability of the method was verified experimentally. By comparing the detected results, it is found that the fitted laser linewidth obtained by the self-homodyne system is closer to its true value than that obtained by the self-heterodyne system. Hence, the simpler structure of the short-delay self-homodyne coherent envelope laser linewidth measurement method proposed is expected to substitute the previous laser linewidth measurement method, including complex short-delay self-heterodyne coherent envelope laser linewidth measurement method and traditional self-homodyne/heterodyne laser linewidth measurement method, to achieve more precise laser linewidth value.

Water Status and Predictive Models of Moisture Content during Drying of Soybean Dregs Based on LF-NMR.

To explore the drying characteristics of soybean dregs and a nondestructive moisture content test method, in this study, soybean dregs were dried with hot air (80 °C), the moisture content was measured using the drying method, water status was analyzed using low-field nuclear magnetic resonance (LF-NMR) and the moisture content prediction models were built and validated. The results revealed that the moisture contents of the soybean dregs were 0.57 and 0.01 g/g(w.b.), respectively, after drying for 5 and 7 h. The effective moisture diffusivity increased with the decrease in moisture content; it ranged from 5.27 × 10-9 to 6.96 × 10-8 m2·s-1. Soybean dregs contained bound water (T21), immobilized water (T22) and free water (T23 and T23'). With the proceeding of drying, all of the relaxation peaks shifted left until a new peak (T23') appeared; then, the structure of soybean dregs changed, and the relaxation peaks reformed, and the peak shifted left again. The peak area may predict the moisture content of soybean dregs, and the gray values of images predict the moisture contents mainly composed of free water or immobilized water. The results may provide a reference for drying of soybean dregs and a new moisture detection method.

Ultrasensitive refractive index sensor based on enhanced Vernier effect through cascaded fiber core-offset pairs.

An ultrasensitive refractive index (RI) sensor based on enhanced Vernier effect is proposed, which consists of two cascaded fiber core-offset pairs. One pair functions as a Mach-Zehnder interferometer (MZI), the other with larger core offset as a low-finesse Fabry-Perot interferometer (FPI). In traditional Vernier-effect based sensors, an interferometer insensitive to environment change is used as sensing reference. Here in the proposed sensor, interference fringes of the MZI and the FPI shift to opposite directions as ambient RI varies, and to the same direction as surrounding temperature changes. Thus, the envelope of superimposed fringe manifests enhanced Vernier effect for RI sensing while reduced Vernier effect for temperature change. As a result, an ultra-high RI sensitivity of -87261.06 nm/RIU is obtained near the RI of 1.33 with good linearity, while the temperature sensitivity is as low as 204.7 pm/ °C. The proposed structure is robust and of low cost. Furthermore, the proposed scheme of enhanced Vernier effect provides a new perspective and idea in other sensing field.

Intra-arterial therapy of neuroendocrine tumour liver metastases: comparing conventional TACE, drug-eluting beads TACE and yttrium-90 radioembolisation as treatment options using a propensity score analysis model.

OBJECTIVES: To compare efficacy, survival outcome and prognostic factors of conventional transarterial chemoembolisation (cTACE), drug-eluting beads TACE (DEB-TACE) and yttrium-90 radioembolisation (Y90) for the treatment of liver metastases from gastroenteropancreatic (GEP) neuroendocrine tumours (NELM). METHODS: This retrospective analysis included 192 patients (58.6 years mean age, 56% men) with NELM treated with cTACE (N = 122), DEB-TACE (N = 26) or Y90 (N = 44) between 2000 and 2014. Radiologic response to therapy was assessed according to Response Evaluation Criteria in Solid Tumours (RECIST) and World Health Organization (WHO) criteria using periprocedural MR imaging. Survival analysis included propensity score analysis (PSA), median overall survival (MOS), hepatic progression-free survival, Kaplan-Meier using log-rank test and the uni- and multivariate Cox proportional hazards model (MVA). RESULTS: MOS of the entire study population was 28.8 months. As for cTACE, DEB-TACE and Y90, MOS was 33.8 months, 21.7 months and 23.6 months, respectively. According to the MVA, cTACE demonstrated a significantly longer MOS as compared to DEB-TACE (p <.01) or Y90 (p = .02). The 5-year survival rate after initial cTACE, DEB-TACE and Y90 was 28.2%, 10.3% and 18.5%, respectively. CONCLUSIONS: Upon PSA, our study suggests significant survival benefits for patients treated with cTACE as compared to DEB-TACE and Y90. This data supports the therapeutic decision for cTACE as the primary intra-arterial therapy option in patients with unresectable NELM until proven otherwise. KEY POINTS: • cTACE achieved a significantly longer overall survival in patients with unresectable NELM. • Patients treated with cTACE showed a prolonged hepatic progression-free survival. • cTACE, DEB-TACE and Y90 radioembolisation demonstrated comparable safety and toxicity profiles. • Age >70 years, extrahepatic metastases and tumour burden >50% were identified as negative predictors. • Propensity score analysis suggests the superiority of cTACE over DEB-TACE and Y90.

The Needs and Experiences of Patients Returning to Work After Total Knee Arthroplasty and Total Hip Arthroplasty: A Systematic Review and Meta-Synthesis.

OBJECTIVE: The objective of this study was to conduct a systematic and comprehensive review of qualitative research to examine the physical and psychological needs, as well as work experiences, of patients undergoing total knee replacement and total hip replacement surgeries during their process of returning to work. METHODS: A systematic review and meta-synthesis of qualitative literature was conducted. A systematic search was conducted across 8 databases to identify qualitative or mixed-methods research on the needs and experiences of individuals with total knee replacement and total hip replacement who have returned to work. The search period extended from the inception of each database to March 2023. Two researchers independently utilized a predetermined search strategy to retrieve relevant English-language studies published in any year. The included studies were assessed for quality using the Critical Appraisal Skills Program appraisal tool. Findings from the studies were then summarized and integrated using the pooled integration method. RESULTS: There were 10 studies in total. Three key themes were identified from the original research: needs during the return to work process and rehabilitation training, faith and support to return to work, and constraints and challenges at work. CONCLUSION: Health care professionals and employers should conscientiously consider the physical and psychological requirements of patients who have undergone total knee replacement and total hip replacement when they are resuming work, taking into account the specific constraints and challenges that may arise in the workplace. To ensure a seamless transition back to work, it is essential to develop tailored occupational interventions, implement comprehensive return to work programs, and offer patients sufficient understanding and support. IMPACT: The findings of this study offer valuable insights into the physical and psychological needs, as well as the work experiences, of patients who have undergone total knee replacement and total hip replacement during their reintegration into the workforce. These findings have the potential to assist health care professionals and employers in providing enhanced support to facilitate successful return-to-work outcomes for patients.

TS-GCN: A novel tumor segmentation method integrating transformer and GCN.

As one of the critical branches of medical image processing, the task of segmentation of breast cancer tumors is of great importance for planning surgical interventions, radiotherapy and chemotherapy. Breast cancer tumor segmentation faces several challenges, including the inherent complexity and heterogeneity of breast tissue, the presence of various imaging artifacts and noise in medical images, low contrast between the tumor region and healthy tissue, and inconsistent size of the tumor region. Furthermore, the existing segmentation methods may not fully capture the rich spatial and contextual information in small-sized regions in breast images, leading to suboptimal performance. In this paper, we propose a novel breast tumor segmentation method, called the transformer and graph convolutional neural (TS-GCN) network, for medical imaging analysis. Specifically, we designed a feature aggregation network to fuse the features extracted from the transformer, GCN and convolutional neural network (CNN) networks. The CNN extract network is designed for the image's local deep feature, and the transformer and GCN networks can better capture the spatial and context dependencies among pixels in images. By leveraging the strengths of three feature extraction networks, our method achieved superior segmentation performance on the BUSI dataset and dataset B. The TS-GCN showed the best performance on several indexes, with Acc of 0.9373, Dice of 0.9058, IoU of 0.7634, F1 score of 0.9338, and AUC of 0.9692, which outperforms other state-of-the-art methods. The research of this segmentation method provides a promising future for medical image analysis and diagnosis of other diseases.

The effect of trait anxiety on the time course of self-relevant processing: Evidence from the perceptual matching task.

Studies have widely reported that trait anxiety is associated with a range of cognitive biases toward external negative emotional stimuli. However, few studies have examined whether trait anxiety modulates intrinsic self-relevant processing. This study investigated the electrophysiological mechanism underlying trait anxiety's modulating effect on self-relevant processing. Event-related potentials (ERPs) were recorded while participants performed a perceptual matching task that assigned an arbitrary geometric shape to an association with a "self" or "non-self" label. Results showed larger N1 amplitudes under self-association than under friend-association conditions, and smaller P2 amplitudes for self- than for stranger-association conditions in individuals with high trait anxiety. However, these self-biases in the N1 and P2 stages were not observed in those with low trait anxiety until the later N2 stage, in which the self-association condition provoked smaller N2 amplitudes than the stranger-association condition. In addition, both high and low trait anxiety individuals showed larger P3 amplitudes for the self-association condition than for the friend- and stranger-association conditions. These findings suggest that, although both high and low trait anxiety individuals showed self-bias, high trait anxiety individuals distinguished between self-relevant and non-self-relevant stimuli at an earlier stage, which may reflect hypervigilance to self-relevant stimuli.

Photoelectric Conversion and Device Stability of PM6:PY-IT Solar Cells Based on a Water Solution-Processed MoO3 Hole Transport Layer.

To enhance the power conversion efficiency (PCE) and stability of all-polymer solar cells (all-PSCs), a new precursor solution based on an in situ chemical reaction of nanomolybdenum powder (Mo), hydrogen peroxide (H2O2), and ammonia (NH3·H2O) was developed for preparing a MoO3 hole transport layer (HTL) for all-PSCs. The results showed that the PCE and stability of PM6:PY-IT solar cells based on the MoO3 HTL were better than those based on a PEDOT:PSS layer. To further understand the relationship between the HTL and the device performance, ultrafast photophysical processes of all-PSCs based on different HTLs were contrastively analyzed. Our research indicated that the micromorphology of active layers could be influenced by the interfacial layer material, consequently determining the photoelectric conversion process of all-PSCs. The MoO3-based all-PSCs had longer charge lifetime, higher charge mobility, and lower charge recombination characteristics compared with the devices based on the PEDOT:PSS layer during the operation time. As a result, the MoO3-based PM6:PY-IT solar cells achieved an initial PCE of 15.2%, and they still maintained more than 80% of their initial efficiency after 1000 h.

Preparation of a bionic lotus leaf microstructured surface and its drag reduction performance.

Reducing machinery surface friction resistance can improve the efficiency of energy utilization. The lotus leaf, as everyone knows, has a strong capacity for self-cleaning and hydrophobicity. In this paper, the bionic surface of the lotus leaf was prepared in large-area, and its drag reduction performance was studied by both numerical simulation and experimental analysis. Experimental results showed that the maximum drag reduction rate of the bionic surface was 6.29% which appeared at a velocity of 3 m s-1. The contact state between liquid and bionic surface changed from Cassie state to Wenzel state with the increase of water flow velocity. The surface free energies of the bionic surface and smooth surface were 1.09 mJ m-2 and 14.26 mJ m-2, respectively. In the droplet rolling experiment, the water droplet was a hemisphere when it rolled on the smooth surface, while it was an ellipsoid on the bionic surface. This study provides a theoretical basis for the structural design of bionic drag reduction surfaces, which are expected to be applied in underwater vehicles.

Liver T1 relaxation time of the 'normal liver' in healthy Asians: measurement with MOLLI and B1-corrected VFA methods at 3T.

OBJECTIVES: Liver T1 is a potential magnetic resonance imaging biomarker for liver diseases. This study aimed to determine the T1 relaxation time of the normal liver (PDFF<5%) in healthy Asian volunteers using modified look-locker inversion recovery (MOLLI) and B1 inhomogeneity-corrected variable flip angle (B1-corrected VFA). METHODS: 60 healthy Asian volunteers without focal or diffuse liver disease underwent a liver scan at 3T magnetic resonance. Proton density fat fraction (PDFF) and liver stiffness measurements were applied for the quantification of liver fat and fibrosis. T1 mapping was performed with MOLLI and B1-corrected VFA sequences. Bland-Altman, linear regression, Student t-test, and one-way analysis of variance were used for statistical analysis. RESULTS: The mean T1 relaxation times of the whole liver were 901 ± 34 ms by MOLLI, and 948 ± 29 ms by B1-corrected VFA in healthy volunteers. There was a strong correlation (r = 0.86, p < 0.0001) for liver T1 between two T1 mapping methods. There were significant differences between the right and left lobes in liver T1 relaxation times using both methods (p < 0.05). Gender and Asian ethnic disparities had no impact on liver T1 relaxation times. CONCLUSION: T1 relaxation times of the normal liver (PDFF<5%) in healthy volunteers were established by MOLLI and B1-corrected VFA T1 mapping methods at 3T. It may provide suitable and robust baseline values for the assessment of liver diseases. ADVANCES IN KNOWLEDGE: Gender and Asian ethnic disparities do not impact liver T1 relaxation time measurements.

Effects of Wet Fermented Soybean Dregs on Physical and Mechanical Properties of Pellets of Corn Stover.

Pelleting experiments were carried out in this study to clarify the influence mechanism of wet-fermented soybean dregs on the forming of corn stover. The effects of addition of water or wet fermented soybean dregs on the forming quality of corn stover were comparatively studied under different corn stover particle sizes and compression displacement. The fermented soybean dregs significantly affected the relaxed density, dimensional stability coefficient, and hardness of feed pellets. The relaxed density, dimensional stability coefficient, and hardness of feed pellets increased first and then decreased with the increase of fermented soybean dregs. The forming quality of corn stover added with fermented soybean dregs was higher than that of corn stover added with the same amount of water. The mechanism allowed soybean dregs to strengthen the bonding between corn stover particles and thus improved the quality of feed pellets. A certain amount of water was favorable for corn stover pelleting, but excessive water may decrease the quality of pellets. The comprehensive analysis showed that the addition of 5-10% fermented soybean dregs to the corn stover improved the relaxed density, dimensional stability coefficient, and hardness of feed pellets by 10.76-23.51%, 7.32-15.74%, and 33.39-454.47%, respectively.

A K-nearest Neighbor Model to Predict Early Recurrence of Hepatocellular Carcinoma After Resection.

Background and Aims: Patients with hepatocellular carcinoma (HCC) surgically resected are at risk of recurrence; however, the risk factors of recurrence remain poorly understood. This study intended to establish a novel machine learning model based on clinical data for predicting early recurrence of HCC after resection. Methods: A total of 220 HCC patients who underwent resection were enrolled. Classification machine learning models were developed to predict HCC recurrence. The standard deviation, recall, and precision of the model were used to assess the model's accuracy and identify efficiency of the model. Results: Recurrent HCC developed in 89 (40.45%) patients at a median time of 14 months from primary resection. In principal component analysis, tumor size, tumor grade differentiation, portal vein tumor thrombus, alpha-fetoprotein, protein induced by vitamin K absence or antagonist-II (PIVKA-II), aspartate aminotransferase, platelet count, white blood cell count, and HBsAg were positive prognostic factors of HCC recurrence and were included in the preoperative model. After comparing different machine learning methods, including logistic regression, decision tree, naïve Bayes, deep neural networks, and k-nearest neighbor (K-NN), we choose the K-NN model as the optimal prediction model. The accuracy, recall, precision of the K-NN model were 70.6%, 51.9%, 70.1%, respectively. The standard deviation was 0.020. Conclusions: The K-NN classification algorithm model performed better than the other classification models. Estimation of the recurrence rate of early HCC can help to allocate treatment, eventually achieving safe oncological outcomes.

Effectiveness and Tolerability of Nifedipine GITS in Patients with Chronic Kidney Disease and Uncontrolled Hypertension: A Prospective, Multicenter, Observational Study (ADRENAL).

INTRODUCTION: Achieving target blood pressure (BP) goals in patients with chronic kidney disease (CKD) and uncontrolled hypertension is a challenge. Various studies have shown the efficacy of nifedipine gastrointestinal therapeutic system (GITS) 60 mg in patients with hypertension. However, there is a paucity of clinical studies in patients with CKD. Hence, we conducted this study to evaluate the effectiveness and tolerability of nifedipine GITS 60 mg in Chinese patients with CKD and uncontrolled hypertension in real-world clinical settings. METHODS: In a prospective, multicenter, observational study, Chinese patients with CKD and uncontrolled hypertension were given nifedipine GITS 60 mg with a primary endpoint of change in office systolic BP (SBP) at 12 weeks. The secondary endpoints included changes at 12 weeks in office diastolic BP (DBP), office SBP and DBP in SBP subgroups (140-160 mmHg and ≥ 160 mmHg) and CKD stages subgroups, SBP and DBP control rate, and the adverse events (AEs). Statistical analysis was performed using SAS® version 9.4. RESULTS: In total, 871 and 622 patients were included in the safety analysis set and efficacy analysis set respectively. The mean office SBP and DBP at baseline were 162.9 and 97.3 mmHg, respectively. At week 12, the mean change in SBP was - 24.0 mmHg (95% confidence interval [CI] - 25.32, - 22.65 mmHg); after missing data were accounted for, it was - 23.9 mmHg (95% CI - 25.25, - 22.60 mmHg). Marked decreases in DBP, and office SBP and DBP in baseline SBP subgroups as well as CKD stages were observed at week 12. The BP control rate at week 12 was 50.0%. Twenty-three (2.6%) patients reported at least one drug-related AEs. No event of hypotension or death occurred during the study. CONCLUSION: Nifedipine GITS 60 mg showed effectiveness and tolerability in reducing office SBP and DBP in Chinese patients with CKD and uncontrolled hypertension. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT03194633.

The Influence of Music Tempo on Inhibitory Control: An ERP Study.

The purpose of the present study is to investigate the influence of music tempo on inhibition control. An electroencephalogram (EEG) was recorded when participants performed a Go/No-go task while listening to slow (54 bpm), medium-paced (104 bpm), fast (154 bpm), or no music. The behavioral results showed that the accuracies for the No-go trials were lower in the fast than in the slow tempo music conditions, while the accuracies for the Go trials were also lower in the fast tempo than in no music conditions. The event-related potential (ERP) study results showed that larger N2 and P3 amplitudes were elicited by No-go than by Go conditions. Moreover, the difference N2 (N2d) amplitudes observed by No-go vs. Go condition were larger in fast music than in medium-paced, slow, and no music conditions, indicating more consumption of cognitive resources in the process of conflict monitoring under the fast music condition. However, no such differences were observed among medium-paced, slow, and no music conditions. In addition, the difference P3 (P3d) amplitudes, an index of response inhibition, were not significant among these four music conditions. The present study showed a detrimental influence of music tempo on inhibition control. More specifically, listening to fast music might impair an individual's ability to monitor conflict when performing the inhibitory control task.

Temporal features of individual and collective self-referential processing: an event-related potential study.

BACKGROUND: Individual and collective self are two fundamental self-representations and are important to human experience. The present study aimed to investigate whether individual and collective self have essential difference in neural mechanism. METHODS: Event-related potentials were recorded to explore the electrophysiological correlates of individual and collective self in a self-referential task in which participants were asked to evaluate whether trait adjectives were suitable to describe themselves (individual self-referential processing), a famous person (individual non-self-referential processing), Chinese (collective self-referential processing) or American (collective non-self-referential processing). RESULTS: At the early stages, results showed that larger P2 and smaller N2 amplitudes were elicited by individual self-referential than by individual non-self-referential processing whereas no significant differences were observed between collective self-referential and collective non-self-referential processing at these stages. In addition, at the late P3 stage (350-600 ms), larger P3 amplitudes were also elicited by individual self-referential than by individual non-self-referential processing during 350-600 ms interval. However, the collective self-reference effect, indicated by the differences between collective self-referential and collective non-self-referential processing, did not appear until 450 ms and extended to 600 ms. Moreover, individual self-reference effect was more pronounced than collective self-reference effect in the 350-500 ms interval, whereas individual and collective self-reference effect had no significant difference in the 500-600 ms interval. These findings indicated that the time courses of neural activities were different in processing individual and collective self.

Dispositional Self-Construal Modulates Neural Representation of Self: An ERP Study.

This study aimed to investigate the influence of dispositional self-construal on self-related processing. Event-related potentials (ERPs) were recorded for a participant's own and a famous person's name in a three-stimulus oddball task. The results showed greater P2 and P3 amplitudes induced by one's own than by a famous person's name in both independent and interdependent self-construal groups. However, no N2 amplitude differences were found between the partcipant's own name and a famous person's name in either group. Moreover, the strength of the P2 effect (own vs. famous person's name) was stronger in the independent than in the interdependent self-construal group, whereas the P3 effect was similar between these two groups. Thus, these findings might reflect fast modulation of self-related processing by dispositional self-construal.

Drag reduction mechanism of Paramisgurnus dabryanus loach with self-lubricating and flexible micro-morphology.

Underwater machinery withstands great resistance in the water, which can result in consumption of a large amount of power. Inspired by the character that loach could move quickly in mud, the drag reduction mechanism of Paramisgurnus dabryanus loach is discussed in this paper. Subjected to the compression and scraping of water and sediments, a loach could not only secrete a lubricating mucus film, but also importantly, retain its mucus well from losing rapidly through its surface micro structure. In addition, it has been found that flexible deformations can maximize the drag reduction rate. This self-adaptation characteristic can keep the drag reduction rate always at high level in wider range of speeds. Therefore, even though the part of surface of underwater machinery cannot secrete mucus, it should be designed by imitating the bionic micro-morphology to absorb and store fluid, and eventually form a self-lubrication film to reduce the resistance. In the present study, the Paramisgurnus dabryanus loach is taken as the bionic prototype to learn how to avoid or slow down the mucus loss through its body surface. This combination of the flexible and micro morphology method provides a potential reference for drag reduction of underwater machinery.