Layperson assessment of smile lines and upper lip combined images in smile esthetics.

STATEMENT OF PROBLEM: The esthetic assessment of smile lines by laypersons is a subject of ongoing debate. However, smile lines often appear with different types of upper lip curvature, which further complicates the esthetic assessment process, and studies on this combination are lacking. PURPOSE: The purpose of this clinical study was to investigate a layperson's esthetic perception of smile lines and upper lip combined images. MATERIAL AND METHODS: Twenty-six smile images resulting from combinations of 3 upper lip types, 4 anterior smile line types, and 3 posterior smile line types were generated by an image editing software program. Eighty-three laypersons (39 men and 44 women; 18 to 35 years of age) completed rating images using a visual analog scale. Unattractive smiles were designated to be those with scores <50 and attractive ones with scores ≥50. Data were analyzed using 1-way analysis of variance and Bonferroni post hoc tests (α=.05). RESULTS: High anterior smile line with gingival display >4 mm obtained significantly lower scores of <50 when combined with all upper lip curvatures (upward: 28.29 ±22.79, straight: 38.74 ±23.00, downward: 30.67 ±22.25, P<.01). High anterior smile lines with gingival display ≤4 mm combined with upward and straight upper lip curvature images obtained significantly higher scores, and all were ≥50 (upward: 63.24 ±22.22, straight: 61.40 ±21.58, P<.01). CONCLUSIONS: From a layperson's perspective, high anterior smile lines with gingival display >4 mm combined with any lip type were determined to be unattractive. If gingival display was ≤4 mm combined with both upward and straight lip types, the smile was assessed as attractive.

Theoretical Investigations for Kinetics of the Chemical Reactions: H + SiClx (x = 1, 2, 3).

Hydrogen atoms and SiClx (x = 1, 2, 3) radicals coexist during the hydrogenation of silicon tetrachloride (STC, SiCl4), an important process in the fabrication of industrial polysilicon. In this work, the mechanisms and kinetics of the reactions between H and SiClx (x = 1, 2, 3) were studied by theory. The structures and vibrational frequencies of reactants, products, intermediates, and transition states (TSs) were determined at the B2PLYP/may-cc-pVTZ level. The single-point energies of minima and saddle points were refined using the coupled-cluster single-double with triple perturbative (CCSD(T)) with the complete basis set extrapolation method. Some special treatments were designed to obtain reliable wave functions for unimolecular reactions without tight TSs by the density functional theory. Subsequently, Lennard-Jones (L-J) parameters between each intermediate (SiHClx) and bath gas (He) were obtained at the MP2/jul-cc-pVTZ level to derive reliable temperature- and pressure-dependent rate coefficients for unimolecular reactions according to the variational Rice-Ramsperger-Kassel-Marcus theory. For bimolecular reactions, rate coefficients were determined by the variational transition-state theory. The rate coefficients of barrierless reactions were derived based on the loose TSs with the maximum free energy. Finally, the master equation analysis was used to investigate the variation of the rate coefficients with pressure and temperature in the activated paths.

FPGA-based digital chaotic anti-interference lidar system.

We use the chaotic signal generated by a field-programmable gate array (FPGA) to establish a digital chaotic pulse lidar system, which can achieve mid-range detection and high ranging accuracy without a complex optical structure. We employ the FPGA to generate random sequences with different modulation rates based on different chaotic iterative equations and initial values. By selecting the initial value and improved logistic equations, we successfully achieve centimeter-level ranging accuracy. Experiments have proved that the digital chaotic lidar system can effectively resist the interference of chaotic signals, square wave signals, and sine wave signals with modulation frequencies of 10 MHz, 100 MHz, 200 MHz, and 1 GHz, showing its strong anti-interference capability.

Updating Emotional Stimuli in Heroin Abstainers' Working Memory: An Event-Related Potential Investigation.

BACKGROUND: It is well-documented that heroin users demonstrate aberrant emotion-processing abilities. However, the mechanism by which heroin users process emotional information after it has captured their attention and entered their working memory is unclear. OBJECTIVES: A modified emotional 2-back task was used to examine whether heroin abstainers demonstrate specific bias patterns in updating emotional stimuli in their working memory. METHODS: In total, 26 male heroin abstainers and 29 healthy controls were asked to identify whether the current picture was the same as a picture that had appeared two trials earlier, while behavioral data and electroencephalogram data were collected. RESULTS: Contrary to predictions, the heroin abstainers and healthy controls demonstrated a similar pattern of P300 activity in response to emotional stimuli with no between-group differences in accuracy or reaction time. More specifically, the P300 amplitudes were larger for negative pictures than for positive and neutral pictures. Surprisingly, we found larger P300 amplitudes at Fz electrodes than at Cz and Pz electrodes in the control group, whereas there was no significant difference at midline electrodes in the heroin abstainers. CONCLUSIONS/IMPORTANCE: Although subtle differences may exist in attentional engagement toward incoming emotional stimulus between two groups, the similar P300 pattern may indicate partial preservation of emotional working memory capacity associated with adaptive emotion regulation in heroin abstainers. These results deepen our understanding of the emotion regulation impairments associated with chronic drug use.

Fiber laser spot welding of molybdenum alloy in a hyperbaric environment.

The effect of the growth of ambient pressures on the penetration of laser welded molybdenum (Mo) alloy was explored. It was found that when ambient pressure rose from 0.1 MPa to 1.8 MPa, the penetration of base metal (BM) was significantly reduced, which was only 17% of that obtained under ambient pressure of 0.1 MPa. Moreover, the mechanism underlying the significant reduction of the penetration of BM was analyzed. At first, by using a high-resolution scanning electron microscope (SEM), the size and the number of nano-sized metallic particles generated during laser welding under different ambient pressures were surveyed. Furthermore, the scattering and absorption of the nano-sized metallic particles for laser energy under different ambient pressures were investigated; afterwards, by applying a high-speed camera and a spectrometer, the transient behaviors and spectral signals of plasmas during fiber laser spot welding under different ambient pressures were monitored. On this basis, the inverse bremsstrahlung absorption of plasmas for laser energy under different ambient pressures was explored; finally, fiber laser spot welding test was carried out on glass/metal composite samples under different ambient pressures to survey the influence of the change of ambient pressure on dynamic behaviors of the molten pool during the welding.

Direct Analysis of Carbonyl Compounds by Mass Spectrometry with Double-Region Atmospheric Pressure Chemical Ionization.

Direct analysis of highly reactive volatile species such as the aliphatic aldehydes as vital biomarkers remains a great challenge due to difficulties in the sample pretreatment. To address such a challenge, we herein report the development of a novel double-region atmospheric pressure chemical ionization mass spectrometry (DRAPCI-MS) method. The DRAPCI source implements a separated structural design that uses a focus electrode to divide the discharge and ionization region to reduce sample fragmentation in the ionization process. Counterflow introduction (CFI) configuration was adopted in the DRAPCI source to reduce background noise, while ion transmission efficiency was optimized through simulating the voltage of the focus electrode and the ion trajectory of the ion source. The limits of detection (LODs) of four carbonyl compounds cyclohexanone, hexanal, heptanal, and octanal by DRAPCI-MS were between 0.1 and 3 µg·m-3, approximately two to eight times lower than those by atmospheric pressure chemical ionization mass spectrometry. Additionally, the DRAPCI-MS method carried out effective in situ analyses of the volatile components in expired milk and the exhaled breath of smokers, demonstrating the DRAPCI-MS as a practical tool to analyze complex mixtures. The DRAPCI-MS method provides a rapid, sensitive, and high-throughput technique in the real-time analysis of gaseous small-molecule compounds.

Nicotine Pharmacokinetics in Rat Brain and Blood by Simultaneous Microdialysis, Stable-Isotope Labeling, and UHPLC-HRMS: Determination of Nicotine Metabolites.

The disposition and metabolism of nicotine in the brain is an important determinant of its exposure. We have developed a novel method for the dynamic determination of nicotine and its metabolites in rat brain and blood by simultaneous microdialysis sampling, stable-isotope labeling, and ultra high-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) assaying. Microdialysis probes were inserted into both the right striatum and jugular vein of Sprague-Dawley rats. The collections of dialystes after nicotine intraperitoneal injection were analyzed by the optimized UHPLC-HRMS. Nicotine-pyridyl- d4 was used as a metabolic tracer, and several stably labeled isotopes were applied to calibrate the in vivo recoveries of retrodialysis. The quadrupole-Orbitrap HRMS provided reliable characterization of the nicotine derivatives with less than 3.5 ppm mass measurement accuracy. Good precision and accuracy were obtained for different analytes within the predefined limits of acceptability and the range of the standard curve. Nicotine and its 11 metabolites were identified in most microdialysis samples from the blood and brain tissue samples. Besides cotinine as the main metabolic product of nicotine, trans-3'-hydroxy-cotinine, nicotine- N-oxide, and norcotinine were proven to be the second most abundant metabolites. The other seven nicotine products, including 4-oxo-4-(3-pyridyl)-butanoic acid, 4-hydroxy-4-(3-pyridyl)-butanoic acid, cotinine- N-oxide, nicotine- N-glucuronide, cotinine- N-glucuronide, and trans-3'- hydroxy-cotinine- O-glucuronide, which have not been determined previously in animal brain, were present in minor amounts. The pharmacokinetic profile of nicotine metabolites indicated that the metabolic characteristic of nicotine in the brain was relatively different from that in the blood. The present work would provide comprehensive evidence for clarifying the differences between nicotine metabolism in the brain and peripheral system.

A Review of Recurrent Neural Networks: LSTM Cells and Network Architectures.

Recurrent neural networks (RNNs) have been widely adopted in research areas concerned with sequential data, such as text, audio, and video. However, RNNs consisting of sigma cells or tanh cells are unable to learn the relevant information of input data when the input gap is large. By introducing gate functions into the cell structure, the long short-term memory (LSTM) could handle the problem of long-term dependencies well. Since its introduction, almost all the exciting results based on RNNs have been achieved by the LSTM. The LSTM has become the focus of deep learning. We review the LSTM cell and its variants to explore the learning capacity of the LSTM cell. Furthermore, the LSTM networks are divided into two broad categories: LSTM-dominated networks and integrated LSTM networks. In addition, their various applications are discussed. Finally, future research directions are presented for LSTM networks.

Drilling Condition Identification Based on Sound Pressure Signal in Anterior Cervical Discectomy Surgery.

BACKGROUND In anterior cervical discectomy and fusion (ACDF) surgery, drilling operation causes a high risk of tissue injury. This study aimed to present a novel feedback system based on sound pressure signals to identify drilling condition during ACDF. MATERIAL AND METHODS ACDF surgery was performed on the C4/5 segments of 6 porcine cervical specimens. The annulus fibrosus, endplate cartilage, sub-endplate cortical bone, and posterior longitudinal ligament (PLL) were drilled until penetration using a 2-mm high-speed burr. Sound pressure signals were collected using a microphone and dynamic signal analyzer. The recorded signals of different tissues were proceeded with lifting wavelet transform for extracting harmonic components. The frequencies of harmonic components are 1, 2, 3, 4, and 5 times higher than the motor frequency. The magnitude of harmonic components was calculated to identify different drilling conditions, along a broad spectrum of frequencies (1-5 kHz). For statistical analysis, one-way ANOVA (analysis of variance) and post hoc test (Dunnett's T3) were performed. RESULTS Very good demarcation was found among the signal magnitudes of different drilling conditions. Different drilling conditions do not present the same rate of variation of frequency. Differences in magnitude among all drilling conditions were statistically significant at certain frequency points (p<0.05). In 3 cases, one tissue could not be identified with respect to another (annulus fibrosus and endplate cartilage at 2 kHz, PLL and penetration at 3 kHz, annulus fibrosus and sub-endplate cortical bone at 5 kHz, p>0.05). CONCLUSIONS Sound pressure signals may provide an auxiliary feedback system for enhancing drilling operation in ACDF surgery, especially in minimally invasive surgery.

Attenuation of response to drug-related cues in male heroin abstainers is modulated by cognitive control mechanisms.

Background: Many research studies reveal that both attentional bias and impaired cognitive control significantly influence heroin addiction. However, limited research has been conducted into how the interplay between attentional bias and cognitive control modulates heroin-seeking behavior. Objectives: A modified version of the flanker task was used to investigate whether attentional bias to drug-related stimuli is modulated by cognitive control mechanisms among heroin users. Methods: Sixty participants (30 male heroin users during their abstinence period and 30 normal controls) responded to the direction of the middle arrow, while ignoring the adjacent arrow and the pictures (drug-related cues and neutral cues) presented as part of the task. Results: The abstinent heroin users had a significantly larger flanker effect under drug-related cues compared to neutral cues, whereas the control group showed no such trend. This effect was primarily influenced by increased reaction times in the presence of drug-related cues relative to neutral cues in the incongruent condition among abstinent heroin users, but not in the control group. Conclusions/Importance: Among abstinent heroin users, attentional bias to drug-related cues was moderated by attentional control. Further, high cognitive control demand was found to reduce heroin users' ability to resist attentional capture from salient, but irrelevant, drug-related information, which may contribute to compulsive drug-seeking behavior and relapse in heroin users.

Lifetime Estimation for Multi-Phase Deteriorating Process with Random Abrupt Jumps.

Owing to operating condition changing, physical mutation, and sudden shocks, degradation trajectories usually exhibit multi-phase features, and the abrupt jump often appears at the changing time, which makes the traditional methods of lifetime estimation unavailable. In this paper, we mainly focus on how to estimate the lifetime of the multi-phase degradation process with abrupt jumps at the change points under the concept of the first passage time (FPT). Firstly, a multi-phase degradation model with jumps based on the Wiener process is formulated to describe the multi-phase degradation pattern. Then, we attain the lifetime's closed-form expression for the two-phase model with fixed jump relying on the distribution of the degradation state at the change point. Furthermore, we continue to investigate the lifetime estimation of the degradation process with random effect caused by unit-to-unit variability and the multi-phase degradation process. We extend the results of the two-phase case with fixed parameters to these two cases. For better implementation, a model identification method with off-line and on-line parts based on Expectation Maximization (EM) algorithm and Bayesian rule is proposed. Finally, a numerical case study and a practical example of gyro are provided for illustration.

Simultaneous determination of nicotine and its nine metabolites in rat blood utilizing microdialysis coupled with UPLC-tandem mass spectrometry for pharmacokinetic application.

To develop a simple and rapid method for the simultaneous determination of nicotine and its nine metabolites in rat blood, an in vivo microdialysis sampling technique coupled with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was established for quantitation and characterization of the pharmacokinetics of nicotine and its metabolites. Microdialysis probes were inserted into the jugular vein of Sprague Dawley rats, and dialysates were collected after nicotine (0.5 mg/kg, i.p.) administration. Target analytes and corresponding deuterated internal standards were separated on a hydrophilic interaction liquid chromatography column (HILIC BEH 2.1. × 150 mm, 1.7 µm) and detected by UPLC-MS/MS under multiple reaction monitoring mode. The limits of quantification for nicotine and its nine metabolites ranged from 0.039 to 0.46 ng/mL. Intra- and inter-day precision and accuracy were well within the predefined limits of acceptability (<11 %). Pharmacokinetic results showed that the mean half-lives of nicotine, cotinine, nornicotine, norcotinine, nicotine-N'-oxide, cotinine-N'-oxide, trans-3'-hydroxy-cotinine, nicotine-N-glucuronide, cotinine-N-glucuronide, and trans-3'-hydroxy-cotinine-O-glucuronide in rat plasma were 63, 291, 175, 440, 251, 451, 322, 341, 488, and 516 min, respectively. The blood concentration-time profiles of nicotine and its nine metabolites indicate that nicotine is rapidly consumed after the administration and subsequently cotinine is generated as the main metabolite; meanwhile, cotinine and other eight minor metabolites exhibit longer retention times in rat body.

Implicit processing of heroin and emotional cues in abstinent heroin users: early and late event-related potential effects.

BACKGROUND: The abnormal cognitive processing of drug cues is a core characteristic of drug dependence. Previous research has suggested that the late positive potential (LPP) of heroin users is increased by heroin-related stimuli because of the attention-grabbing nature of such stimuli. OBJECTIVES: The present research used a modified emotional Stroop (eStroop) task to examine whether there was an early posterior negativity (EPN) modulation to heroin cues compared with emotional or neutral stimuli in heroin dependent subjects. METHODS: Fifteen former heroin users and 15 matched controls performed the eStroop task, which was composed of positive, negative, heroin-related, and neutral pictures with superimposed color squares. Participants responded to the color of the square and not to the picture while behavioral data and event-related potentials were recorded. RESULTS: There were no significant differences of EPN amplitudes to emotional and neutral stimuli between heroin users and controls. However, heroin users displayed increased EPN modulation for heroin cues, whereas this modulation was absent in controls. CONCLUSIONS: Drug-related cues acquire motivational salience and automatically capture the attention of heroin users at early processing stages, even when engaged in a non-drug-related task. The EPN to heroin cues could represent a novel electrophysiological index with clinical implications for selecting abstinent drug users who are at increased risk of relapse or to evaluate treatment interventions.

Simultaneous determination of NNK and its metabolites in mouse tissue for evaluating the effects of chronic alcohol consumption on the metabolism of NNK in mouse liver and lung.

A hydrophilic-interaction liquid chromatography-tandem mass spectrometry (HILIC-MS-MS) method was developed for the determination of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and its metabolites in mouse liver and lung. The limits of detection of all analytes were in the range 0.017-0.057 ng mL(-1), and recovery ranged from 88.4-119.8 % with intra and inter-day precision in the range 0.89-6.03 % and 1.01-6.97 %, respectively. This simple and accurate method was used to evaluate the effect of chronic alcohol consumption on NNK bioactivation in mouse tissue. Time-course curves for NNK and its metabolites were generated, and the areas under the curves (AUCs) were compared. It was found that target tissues of NNK carcinogenesis in C57BL/6 mice contained high levels of α-hydroxylation metabolites of NNK and its carbonyl reduction metabolite, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL). The most pronounced effect of alcohol was to enhance α-hydroxylation of NNK in mouse lung and liver, which suggests that chronic alcohol consumption may increase the risk of carcinogenicity associated with NNK in mice.

Noninvasive electrical impedance sensor for in vivo tissue discrimination at radio frequencies.

Compared to traditional open surgery, minimally invasive surgery (MIS) allows for a more rapid and less painful recovery. However, the lack of significant haptic feedback in MIS can make tissue discrimination difficult. This paper tests a noninvasive electrical impedance sensor for in vivo discrimination of tissue types in MIS. The sensor consists of two stainless steel spherical electrodes used to measure the impedance spectra over the frequency range of 200 kHz to 5 MHz. The sensor helps ensure free movement on an organ surface and prevents soft tissues from being injured during impedance measurement. Since the recorded electrical impedance is correlated with the force pressed on the electrode and the mechanical property of the tissue, the electrode-tissue contact impedance is calculated theoretically. We show that the standard deviation of the impedance ratio at each frequency point is sufficient to distinguish different tissue types. Both in vitro experiment in a pig kidney and in vivo experiment in rabbit organs were performed to demonstrate the feasibility of the electrical impedance sensor. The experimental results indicated that the sensor, used with the proposed data-processing method, provides accurate and reliable biological tissue discrimination.

Application of a novel quaternized ammonium poly(vinyl alcohol)-based hybrid anion exchange membrane for the removal of Cr(VI) from wastewater.

Two quaternized ammonium poly(vinyl alcohol) (QPVA)-based hybrid anion exchange membranes were successfully fabricated by using sol-gel method. The mass ratios of QPVA aqueous solution to polydimethyl allyl chloride (PDADMAC) aqueous solution were 4:1 and 2:1, then 10 wt% tetraethyl orthosilicate (TEOS) was added. The obtained membranes were separately designated as QPVA/0.25PDADMAC/0.1TEOSm and QPVA/0.5PDADMAC/0.1TEOSm. The properties for the adsorption removal of Cr(VI) and the effect on the Cr(VI) saturation adsorption amount and removal rate were investigated. Results indicated the adsorption was an exothermal reaction. Thus, low temperature was beneficial for the removal of Cr(VI). Optimal removal of Cr(VI) was achieved using the QPVA/0.5PDADMAC/0.1TEOSm membrane at a pH value of 2. Dynamic simulation was carried out simultaneously to determine if particle diffusion was the sole contributor for the adsorption rate, which was in accordance with the Langmuir isotherm adsorption model. Furthermore, the static adsorption amount (Q0) was 61.77 mg/g, and the efficiency of recycling the hybrid membranes was higher than 90%. Scanning electron microscopy (SEM) characterization showed the surface and the cross-section tightened after the Cr(VI) adsorption, thereby demonstrating the potential application of these hybrid membranes for Cr(VI) removal.

Low-Velocity Impact of Clamped Rectangular Sandwich Tubes with Fiber Metal Laminated Tubes.

Fiber metal laminated sandwich tubes are made up of alternating fiber-reinforced composite and metal layers. Fiber metal laminated tubes have the advantages of the high strength and high stiffness of fiber and the toughness of metal, so they have become an excellent load-bearing and energy-absorbing, lightweight structure. Due to the complexity of the fiber layup, it is difficult to establish an analytical model of the relevant structural properties. In this work, introducing the number and volume fraction of fiber layup, based on the modified rigid-plastic model, an analytical model is established for low-velocity impacts on sandwich tubes with fiber metal laminated tubes, which provided a theoretical basis for the design of fiber-metal composite tubes. In addition, a numerical simulation was conducted for low-velocity impacts on clamped rectangular sandwich tubes with fiber metal laminated (FML) tubes and a foam core. By comparing the results obtained from the theoretical analysis and numerical calculations, it is shown that the analytical results can reasonably agree with the numerical results. The influences of the metal volume fraction (MVF), the strength ratio factor of the FML metal layer to the FML composite layer, and the relative strength of the foam on the dynamic response of the rectangular sandwich tubes with FML tubes and a metal foam core (MFC) are discussed. It is shown that by increasing the fiber content and fiber strength of the FML tubes and the foam strength, the load-carrying and energy-absorbing capacity of the rectangular sandwich tubes can be effectively improved, especially by changing the fiber properties. In addition, present analytical solutions can be applied to make predictions about the dynamic response of the rectangular sandwich tubes with FML tubes and MFC during impacts with low-velocity and reasonably heavy-mass.

Developing a novel strategy for fabricating matrix film to assess the distribution of potassium perfluorooctanic sulfonate by matrix-assisted laser desorption/ionization mass spectrometry imaging.

Matrix deposition plays a critical role in image quality of matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI). To improve the ionization efficiency and overcome the limitation of traditional matrix deposition methods in the face of difficult-to-sublimate or difficult-to-dissolve matrix, covalent organic frameworks (COFs) named COF-DhaTab was successfully synthesized and firstly used as matrix film. It was fabricated by imprinting of sieved COF-DhaTab powder on the surface of a double-sided adhesive tape. Outstanding reproducibility and uniformity of COF-DhaTab film were demonstrated by relative standard deviation (RSD) within 8.37% and 7.71% from dot-to-dot and plate-to-plate, respectively. With the introduction of double-sided adhesive tape, water contact angle (WCA) of COF-DhaTab film increased from 55° to 141°, resulting in significant suppression of analyte diffusion. Moreover, the intensity of potassium perfluorooctanic sulfonate (PFOS, C8F17SO3-, m/z 498.93) was 9.3 × 105, more than six hundred times higher than that using DHB matrix. This enhancement was attributed to the rough surface and multiple branches of the synthesized COF-DhaTab. To verify the ability of COF-DhaTab film as substrate, the spatial distribution of PFOS in zebrafish, rat liver and kidney tissues was explored. Superior imaging capability was displayed with high-spatial resolution and reliable location distribution. These results not only demonstrate the outstanding ability of COF-DhaTab as matrix for MALDI-MS and MALDI-MSI, but also provide a facile approach for fabrication of novel matrix films for MALDI-MSI.

Twice-walk strategy based on three-dimensional DNA walking machine driven by duplex-specific nuclease.

A twice-walk strategy based on a three-dimensional (3D) cleat-equipped DNA walking machine with a high signal amplification efficiency was investigated for ultrasensitive detection of miRNA. Impressively, addition of duplex-specific nuclease (DSN) just once drove the twice-walk strategy, making the strategy simpler. With the advantages of being simple, rapid and ultrasensitive, the biosensor offers potential for use in early clinical diagnosis.

A rapid one-step electrochemical method based on cleat-equipped molecular walking machine.

Various nucleic acid molecular machines have emerged in recent years. However, when the nucleic acid tracks are fully depleted, these walkers are highly susceptible to premature release or stalling in regions where the tracks are locally exhausted. In this work, a molecular walking machine with a cleat domain preventing dissociation from the track was explored for ultrasensitive detection of miRNA. It has been verified that the cleat design can enhance the signal amplification efficiency of molecular walking machines for electrochemical miRNA-141 detection. Notably, the single-step electrochemical biosensing platform utilizing the cleat-equipped molecular walking machine (CMWM) is exceptionally straightforward and rapid, concluding the reaction within 90 min and achieving a remarkable low detection limit of 0.26 fM. The proposed molecular walking machine with this specific cleat structure was utilized for the identification of miRNA-141 in cellular lysates, exhibiting remarkable selectivity and consistent reproducibility, showcasing its effective utility in bioanalysis. Therefore, the cleat walker developed in this study introduces an innovative method for constructing a miRNA electrochemical biosensing platform, offering new perspectives for its application in biomolecule detection and clinical disease diagnosis.