Distribution of Fibrosis-4 index and vibration-controlled transient elastography-derived liver stiffness measurement for patients with metabolic dysfunction-associated steatotic liver disease in health check-up.

AIMS: The multisociety consensus nomenclature has introduced steatotic liver disease (SLD) with diverse subclassifications, which are metabolic dysfunction-associated steatotic liver disease (MASLD), metabolic dysfunction and alcohol-associated steatotic liver disease (MetALD), alcohol-associated liver disease (ALD), specific etiology, and cryptogenic. We investigated their prevalence, as per the new definition, in individuals undergoing health check-ups. Additionally, we analyzed the distribution of Fibrosis-4 (FIB-4) index and vibration-controlled transient elastography (VCTE)-derived liver stiffness measurement (LSM) for MASLD. METHODS: In this cross-sectional study, 6530 subjects undergoing a health check-up in Japan were included. Conventional B-mode ultrasound was carried out on all 6530 subjects, and those with MASLD underwent VCTE. RESULTS: The prevalence of SLD was 39.5%, comprising MASLD 28.7%, MetALD 8.6%, ALD 1.2%, specific etiology SLD 0.3%, and cryptogenic SLD 0.7%. Subjects with VCTE-derived LSM ≥8 kPa constituted 2.1% of MASLD. FIB-4 ≥1.3 showed that the sensitivity, specificity, positive predictive value (PPV), and negative predictive value for diagnosing VCTE-derived LSM ≥8 kPa were 60.6%, 77.0%, 5.3%, and 98.9%, respectively. The referral rate to specialists was 23.8% using FIB-4 ≥1.30. "FIB-4 ≥1.3 in subjects <65 years and FIB-4 ≥2.0 in subjects ≥65 years" showed higher PPV (6.7%) and lower referral rate (17.1%) compared with FIB-4 ≥1.3, but the sensitivity (54.5%) did not show adequate diagnostic capability as a noninvasive test for diagnosing VCTE-derived LSM ≥8 kPa. CONCLUSIONS: Acknowledging the selection bias in hepatology centers, we undertook this prospective health check-up study. Although the FIB-4 index proves to be a convenient marker, it might not perform well as a primary screening tool for liver fibrosis in the general population (UMIN Clinical Trials Registry No. UMIN000035188).

Vitamin D combined with whole-body vibration training for the treatment of osteo-sarcopenia: study protocol for a randomized controlled trial.

BACKGROUND: Osteo-sarcopenia (OS) has become a global public health problem and a frontier research problem, as a combination of sarcopenia (SP) and osteoporosis (OP) diseases. The clinical performances include muscle weakness, systemic bone pain, standing difficulty, even falls and fractures, etc., which seriously affect the patient's life and work. The pathological mechanism of the OS may be the abnormal metabolism which disrupts the equilibrium stability of the musculoskeletal system. Therefore, this study combined vitamin D (Vit. D) and whole-body vibration training (WBVT) to intervene in subjects of OS, aiming to evaluate the effectiveness and safety of the diagnosis and treatment protocol and to explore the efficacy mechanism. METHODS: We propose a multicenter, parallel-group clinical trial to evaluate the efficacy and safety of Vit. D combined with WBVT intervention in OS. Subjects who met the inclusion or exclusion criteria and signed the informed consent form would be randomly assigned to the WBVT group, Vit. D group, or WBVT+ Vit. D group. All subjects will be treated for 1 month and followed up after 3 and 6 months. The primary outcomes are lumbar bone mineral density (BMD) and appendicular skeletal muscle mass (ASM) measured by dual-energy X-ray absorptiometry (DXA) and handgrip strength measured by grip strength meter. Secondary outcomes include serum markers of myostatin (MSTN), irisin and bone turnover markers (BTM), SARC-CalF questionnaire, 1-min test question of osteoporosis risk, patient health status (evaluated by the SF-36 health survey), physical performance measurement that includes 5-time chair stand test, 6-m walk, and the short physical performance battery (SPPB). DISCUSSION: If Vit. D combined with WBVT can well relieve OS symptoms without adverse effects, this protocol may be a new treatment strategy for OS. After therapeutic intervention, if the serum marker MSTN/irisin is significant, both have the potential to become sensitive indicators for screening OS effective drugs and treatments, which also indicates that WBVT combined with Vit. D plays a role in improving OS by regulating MSTN/irisin. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2400082269 . Registered on March 26, 2024.

Correlation between BMI, amount of aspirated fat and post-operative complications in VASER liposuction: A single centre experience.

Background: Vibration amplification of sound energy at resonance (VASER) liposuction is an innovative technique that allows surgeons to selectively remove fat and shape desired areas of the body, resulting in more precise and controlled outcomes compared to traditional liposuction techniques. VASER liposuction offers several advantages, including targeted action that reduces trauma to the surrounding tissues, limiting pain, swelling and recovery time. Purpose: This study compared the complication rates among patients who underwent VASER liposuction in relation to their body mass index (BMI) and the amount of fat aspirated. Methods: The authors reviewed the medical records of all patients who underwent VASER liposuction at Scalera Clinic in Naples, dividing them into two groups: the first with BMI < 24.9 kg/m2 and second with BMI >25.0 kg/m2. Results: The authors examined 117 patients who were operated on within a year (2022/2023), with 48 of them having BMIs < 24.9 kg/m2 and 69 showing BMIs >25.0 kg/m2. In patients with a BMI >25 kg/m2, the most common complications were contusion, hematomas and abnormal skin retraction, whereas no complications were observed in the patients with normal-weight. Conclusions: To minimise post-operative complications and maximise results, it is advisable to select patients based on their BMI assessment, the anatomy of the treated body area and the volume of fat to be removed. This approach aims to ensure that the patients are suitable for the procedure and the achieved results align with their aesthetic expectations.

Development and evaluation of an automated breathing-synchronized chest wall vibration stimulation system.

[Purpose] Vibratory stimulation of the upper intercostal region enhances inspiratory movement, whereas stimulation of the lower intercostal region enhances expiratory movement and ventilation. Previous vibration stimulation devices for intercostal muscles required manual stimulation, causing a time lag between breathing and vibration stimulation. The purpose of this experiment was to compare the effects of an automatic vibration stimulation system with manual vibration stimulation in a group of individuals and to verify whether there was an increase in upper and lower chest wall displacement and respiratory flow. [Participants and Methods] Twenty healthy adults were divided into two groups, as follows: an automatic vibration stimulation group using a chest wall vibration stimulation system and a manual vibration stimulation group. Vibration stimulation was applied to the second intercostal space on both sides during inspiration, and to the seventh intercostal space on both sides during expiration. [Results] The vibration stimulation system group showed significantly higher synchronization rates during inspiration and expiration than the manual vibration stimulation group, and there was a significant increase in chest wall displacement and respiratory flow during inspiration and expiration. [Conclusion] The chest wall vibration stimulation system can effectively provide vibration stimulation to the intercostal muscles in synchrony with breathing.

Impact of whole-body vibration training on ankle joint proprioception and balance in stroke patients: a prospective cohort study.

BACKGROUND: Although whole-body vibration (WBV) training is acknowledged for its benefits in enhancing motor functions across several neurological disorders, its precise influence on ankle joint proprioception and balance in stroke patients is still not well understood. This research seeks to assess the impact of WBV training on ankle joint proprioception and balance in stroke patients, thereby filling this important research void. METHODS: In this prospective cohort study, thirty-five stroke patients were randomly assigned to either the WBV group (n = 17) or a control group (n = 18) using a random number table method. The control group received daily general rehabilitation for four weeks, while the WBV group received an additional 30 min of WBV training each day with the Trunsan S110 Vibration Training System. Blinded outcome assessments were conducted at baseline and post-treatment, utilizing the Berg balance scale (BBS), Functional reach test (FRT), Romberg test length (RTL) and area (RTA), and completion rates of ankle joint dorsiflexion-plantar flexion (DP) and inversion-eversion (IE) tests. Follow-up assessments were performed after four weeks of intervention, focusing on RTL, RTA, DP, and IE as primary outcomes. RESULTS: Analysis of intra-group changes from baseline to post-treatment revealed significant improvements across the BBS, FRT, RTL, RTA, and DP and IE assessments (p < 0.001). Notably, the WBV group showed significant enhancements compared to the control group in DP and IE (p < 0.001 and p < 0.05, respectively), with mean values increasing from 13.556 to 16.765 (23.7%) and from 5.944 to 8.118 (36.6%), respectively. However, WBV did not provide additional benefits over the control treatment for balance recovery parameters such as BBS, FRT, RTL, and RTA (p > 0.05). CONCLUSIONS: This study demonstrates that WBV therapy is equally effective as conventional methods in enhancing proprioception and balance in stroke patients, but it does not provide additional benefits for balance recovery. WBV significantly improves proprioceptive functions, particularly in DP and IE parameters. However, it does not surpass traditional rehabilitation methods in terms of balance recovery. These findings indicate that WBV should be incorporated into stroke rehabilitation primarily to enhance proprioception rather than to optimize balance recovery. TRIAL REGISTRATION: This study was retrospectively registered in the ISRCTN Registry on 29/07/2024 ( https://www.isrctn.com/ , ISRCTN64602845).

Effect of spider's weight on signal transmittance in vertical orb webs.

Spider orb web is a sophisticated structure that needs to fulfil multiple roles, such as trapping prey and transmitting web-borne signals. When building their web, heavier spiders tend to increase the pretension on the web, which seems counterintuitive since a tighter web would decrease the chances of stopping and retaining prey. In this article, we claim that heavier orb-weaving spiders increase tension on the web in order to reduce the attenuation of the vibratory signal coming from the bottom part of the web. We support our claim by first building a detailed spider web model, which is tuned by a tension-adjusting algorithm to fit the experimentally observed profiles. Then, the effects of the spider weight and the web tension on the signal transmittance properties are investigated using state-of-the-art finite element analysis tools.

Effect of mechanical vibration and ShotBlocker® on pain levels during heel lance in healthy term neonates: A randomized controlled trial.

PURPOSE: This study aimed to examine the effect of mechanical vibration and the ShotBlocker® device on pain level, crying time, and procedure time during a heel lance in healthy term neonates. DESIGN AND METHODS: A total of 105 healthy-term neonates were randomized into three groups: control (n = 36), mechanical vibration (n = 33), and ShotBlocker® (n = 36). The control group underwent a routine heel lance procedure. The neonates in the mechanical vibration group received mechanical vibration to the extremity for 30 s before the heel was lanced. For the ShotBlocker® group, a ShotBlocker® was placed on the area where the heel lance procedure would occur and the heel was lanced. The heel lance procedure was videotaped, and the neonates' pain scores at 1 min before, 2 min after, and 5 min after the procedure, crying time, and procedure duration were recorded and were evaluated by two independent raters. Data were evaluated using the chi-square test and analysis of variance. The analysis of variance, Bonferroni, Dunnett T3 analysis, and effect size were used in the analyses of repeated measures. The study was approved by an ethics committee. Informed consent was obtained from parents. RESULTS: The pain level of the neonates in the mechanical vibration group was lower than those of the control and ShotBlocker® group during and at 2 min and 5 min after the procedure (F = 12.063, p = 0.000; F = 4.580, p = 0.012; and F = 6.145, p = 0.003, respectively). The duration of neonate crying time in the mechanical vibration group was lower than in the control and ShotBlocker® groups (F = 4.598, p = 0.012). The heel lance duration was similar in the groups (F = 1.369, p = 0.259). CONCLUSION: Mechanical vibration is an effective method to reduce the pain level and crying time associated with heel lance procedures in neonates. PRACTICE IMPLICATIONS: This study provides evidence to nurses that the ShotBlocker is not an effective method for reducing pain associated with the heel lance procedure but that mechanical vibration is an effective method. CLINICAL TRIALS REGISTRATION: The study was registered at Clinical-Trials.gov (NCT06380556).

Impact of foam rolling with and without vibration on muscle oxidative metabolism and microvascular reactivity.

Background and Purpose: There is a growing interest in use vibration foam rolling as a warm up and recovery tool. However, whether vibration foam rolling offers additional benefits to traditional foam rolling is unclear. The current study aims to compare the effects of acute foam rolling, with and without vibration, on skeletal muscle metabolism and microvascular reactivity. Methods: Fifteen physically active young males were tested on two different days, with gastrocnemius muscle microvascular function assessed using near-infrared spectroscopy coupled with the post-occlusive reactive hyperemia technique, before and after foam rolling, performed with or without vibration. The slope of tissue saturation index (TSI) decrease during occlusion between 120 s to 150 s (TSI occlusion slope) was assessed for muscle metabolic rate. Three commonly used microvascular function indexes, including the first10s TSI slope after occlusion (TSI10), time for TSI to reach half of peak magnitude (TSI1/2), and TSI peak reactive hyperemia, were also assessed. Results: None of the measured indexes showed significance for interaction or method (all p > 0.05). However, there was a main effect for time for TSI occlusion slope, TSI1/2, and TSI peak reactive hyperemia (p = 0.005, 0.034 and 0.046, respectively). No main effect for time for TSI10 was detected (p = 0.963). Conclusions: The application of foam rolling can decrease muscle metabolism, and may improve some aspects of muscle microvascular function. However, vibration foam rolling does not seem to offer any additional benefits compared to traditional foam rolling alone.

Whole body vibration therapy and diabetes type 2: a systematic review and meta-analysis.

Background: Vibration platforms have demonstrated systemic effects generated by the use of mechanical vibrations, which are similar to those of any physical activity. The effect that whole body vibration (WBV) generates on the organism could be recommended in Diabetes Mellitus 2 (DM 2) patients. Objective: To systematically review and meta-analyze the available evidence on the effects of WBV on glycemic control in patients with DM 2. Material and methods: Exhaustive bibliographic searches were carried out until October 2023 in different biomedical portals and databases: Public Medline (PubMed), Scientific Electronic Library Online (SciELO), VHL Regional Portal, Cochrane Central and Latin American and Caribbean Literature in Health Sciences (LILACS). Randomized clinical trials based on the effects of Whole Body Vibration on glycosylated hemoglobin levels, with control group and participants were non-insulin dependent were the inclusion criteria. Two reviewers extracted data independently. A third reviewer was available for discrepancies. Results: Six articles with 223 participants met the criteria and were included in the systematic review; only four of them met the criteria to be part of the meta-analysis. This meta-analysis reveals a positive and significant effect size (µ ê=0.5731), indicating a substantial difference between the groups studied. Although there is some variability between studies (heterogeneity of 30.05%), the overall direction of the effects is consistent. These findings conclusively suggest the presence of a significant influence of the variable evaluated, underscoring the robustness and consistency of the relationship observed in the literature reviewed. Conclusion: There are no conclusive results due to the lack of data for some variables, which prevents comparison; but WBV may be an effective therapy to improve glycemic control in DM 2 patients. More studies with more patients and longer follow-up are needed.

Analysis of biomechanical passive synergistic vibration reduction inspired by the structure, morphology, nano-mechanics of the beetles' hindwing.

Using scanning electron microscopy (SEM), a small animal imaging system, and biological tissue sections, the relationships between the flapping vibrations in the hindwings of Trypoxylus dichotomus and their morphology, structure, and hemolymph dynamics were investigated. Based on these findings, a three-degree-of-freedom (3-DOF) model incorporating nano-mechanical properties was developed to investigate spanwise passive synergistic vibration reduction (PSVR) in the hindwing elements. To ensure precision, the Runge-Kutta and incremental harmonic balance (IHB) methods were employed for both solving and comparing solutions. Analysis of the spanwise force (FOX) signals confirmed the validity of the PSVR model. Parametric analysis revealed that reducing system mass and stiffness increased the resonance amplitude while shifting the resonance frequency in the opposite direction. The resonance frequency and flexible deformation amplitude of the hindwing system could be controlled by adjusting mass and stiffness within the synergistic framework. The mass and damping of the wing base, along with the stiffness of the wing membrane, were identified as critical factors in the system. This model provides valuable insights into the PSVR mechanism, potentially informing the design and manufacture of bionic flexible flapping wings.

Influence of the elevation effect of slope blasting on the vibration velocity of existing buried steel pipes.

Blasting vibration(BV) may cause the instability and damage to the surrounding structures and infrastructures, even leading to serious accident. As far as slope blasting is concerned, more and more attention has been paid to the elevation effect of BV of rock mass. However, scarce information is available on the influence of the elevation effect of slope blasting on the BV of surrounding structures, especially the existing buried pipes. As a consequence, the influence of the elevation effect of slope blasting on the BV of steel pipes was numerically investigated according to finite element model, which was verified against the experimental result. Moreover, the formula is presented to predict the peak vibration velocity (PVV) of steel pipes under slope blasting. It is found that PVV of the steel pipes has the elevation amplification effect in the terrain with positive or negative elevation difference. PVV of the pipes in the terrain with positive elevation difference is greater than that in the terrain with the same negative elevation difference. The elevation effect is more obvious under the condition of the positive elevation difference (2.1-5.1 m). The modified Sadovsky's empirical formula is more suitable to predict PVV of the buried steel pipes during the slope blasting process.

Acoustic radiation characteristics of shark skin inspired surface modified plates.

This paper aims to evaluate the acoustic radiation characteristics of thin plates featuring a layer of small-scale biomimetic shark skin type additive surface treatment. The shark skin dermal denticles are modelled as point masses arranged in a bi-directional pattern on both the upper and lower surfaces of the plate. The governing equations are obtained through a variational approach, incorporating the Dirac Delta function in the derivation of the proposed semi-analytical model for the shark skin layer. A semi-analytical method based on the Rayleigh-Ritz formulation is utilized to analyze the vibrations of these plates with surface modification. The sound radiation characteristics are then derived from the solution of the Rayleigh integral. A comprehensive investigation is performed on the influence of surface modification on different vibro-acoustic characteristics, using a continuous structural mode and power transfer matrix-based approach. Notable observations include a reduction in peak vibro-acoustic responses with dense denticle arrangements, especially at resonance, demonstrating a direct relationship with mass ratios, i.e., the ratio of denticle mass to plate mass. The study further reveals a shift of vibro-acoustic responses towards low frequencies with an increase in mass ratios. A thorough comparative study indicates that while additive surface modifications inspired by shark skin may weaken sound radiation characteristics at resonance frequencies, a reverse effect can be observed at intermittent operational frequencies.

The effect of three different nonpharmacological methods on cannulation success during peripheral intravenous catheter placement in the emergency unit: a randomized controlled trial.

BACKGROUND: Peripheral intravenous catheterization is frequently performed in emergency units, but it is a procedure which is difficult for healthcare professionals and painful for patients. The primary objective of the present study was to examine the effect on venous dilation, procedure duration and pain severity of local heat, cold and vibration applications performed on the intervention area before peripheral intravenous catheterization in adults. The second objective of the study was to examine the effects of age and gender variables on the participants' pain intensity levels. METHODS: A single-blinded randomized controlled trial. The study included 120 adults who were randomly selected between March and August 2023. One application group (n = 30) received local heat application, one group (n = 30) received local cold application, and one (n = 30) received local vibration using the Buzzy® device. The applications, to the site of the peripheral intravenous catheterization, lasted one minute. The control group (n = 30) received standard peripheral intravenous catheterization application. The groups' vein dilation was assessed with the vein assessment scale, pain felt during catheterization with the visual analog scale, and the duration of the procedure with a chronometer. RESULTS: It was found that the venous dilation of the cold application group was significantly higher (p = 0.010, p = 0.015 respectively) and procedure duration was shorter (p = 0.013, p < 0.001 respectively) than that of the heat and vibration application groups, and its pain severity was significantly lower (p = 0.002, p = 0.001 and p = 0.001 respectively) than that of the control group and the heat and vibration application groups. CONCLUSIONS: It was determined that local cold application for one minute to the area of peripheral intravenous catheterization increased venous dilation, shortened application time, and reduced pain. TRIAL REGISTRATION: ClinicalTrials.gov ID NCT06378424, retrospectively registered 20/04/2024.

Auditory pathway for detection of vibration in the tokay gecko.

Otolithic endorgans such as the saccule were thought to be strictly vestibular in amniotes (reptiles, birds, and mammals), with little evidence supporting the auditory function found in fish and amphibians (frogs and salamanders). Here, we demonstrate an auditory role for the saccule in the tokay gecko (Gekko gecko). The nucleus vestibularis ovalis (VeO) in the hindbrain exclusively receives input from the saccule and projects to the auditory midbrain, the torus semicircularis, via an ascending pathway parallel to cochlear pathways. Single-unit recordings show that VeO is exquisitely sensitive to low-frequency vibrations. Moreover, VeO is present in other lepidosaurs, including snakes and Sphenodon. These findings indicate that the ancestral auditory function of the saccule is likely preserved at least in the lepidosaurian lineage of amniotes and mediates sensitive encoding of vibration.

Topology optimization of adaptive sandwich plates with magnetorheological core layer for improved vibration attenuation.

In this study the optimum topology distribution of the magnetorheological elastomer (MRE) layer in an adaptive sandwich plate is investigated. The adaptive sandwich plate consists of an MR elastomer layer embedded between two thin elastic plates. A finite element model has been first formulated to derive the governing equations of motion. A design optimization methodology incorporating the developed finite element model has been subsequently developed to identify the optimum topology treatment of the MR layer to enhance the vibration control in wide-band frequency range. For this purpose, the dynamic compliance and density of each element are defined as the objective function and design variables in the optimization problem, respectively. The method of the solid isotropic material with penalization (SIMP), is extended for material properties interpolation leading to a new MRE-based penalization (MREP) model. Method of moving asymptotes (MMA) has been subsequently utilized to solve the optimization problem. The developed finite element model and design optimization method are first validated using benchmark problems. The proposed design optimization methodology is then effectively utilized to investigate the optimal topologies of the magnetorheological elastomer (MRE) core layer in MRE-based sandwich plates under various boundary and loading conditions. Results show the effectiveness of the proposed design optimization methodology for topology optimization of MRE-based sandwich panels to mitigate the vibration in wide range of frequencies.

A hybrid LSTM random forest model with grey wolf optimization for enhanced detection of multiple bearing faults.

Bearing degradation is the primary cause of electrical machine failures, making reliable condition monitoring essential to prevent breakdowns. This paper presents a novel hybrid model for the detection of multiple faults in bearings, combining Long Short-Term Memory (LSTM) networks with random forest (RF) classifiers, further enhanced by the Grey Wolf Optimization (GWO) algorithm. The proposed approach is structured in three stages: first, time and frequency domain features are manually extracted from vibration signals; second, these features are processed by a dual-layer LSTM network, which is specifically designed to capture complex temporal relationships within the data; finally, the GWO algorithm is employed to optimize feature selection from the LSTM outputs, feeding the most relevant features into the RF classifier for fault classification. The model was rigorously evaluated using a dataset comprising six distinct bearing health conditions: healthy, outer race fault, ball fault, inner race fault, compounded fault, and generalized degradation. The hybrid LSTM-RF-GWO model achieved a remarkable classification accuracy of 98.97%, significantly outperforming standalone models such as LSTM (93.56%) and RF (98.44%). Furthermore, the inclusion of GWO led to an additional accuracy improvement of 0.39% compared to the hybrid LSTM-RF model without optimization. Other performance metrics, including precision, kappa coefficient, false negative rate (FNR), and false positive rate (FPR), were also improved, with precision reaching 99.28% and the kappa coefficient achieving 99.13%. The FNR and FPR were reduced to 0.0071 and 0.0015, respectively, underscoring the model's effectiveness in minimizing misclassifications. The experimental results demonstrate that the proposed hybrid LSTM-RF-GWO framework not only enhances fault detection accuracy but also provides a robust solution for distinguishing between closely related fault conditions, making it a valuable tool for predictive maintenance in industrial applications.

Effects of whole-body vibration on bone properties in type 2 diabetes model rats.

Objectives: We examined the effects of whole-body vibration (WBV) on bone properties in type 2 diabetes (T2DM) model rats. Methods: Twenty male Hos:ZFDM-Lepr fa , fa/fa rats (divided into DM and WBV groups, N = 10 each) and 10 Hos:ZFDM-Lepr fa , fa/+ rats (as the control (CON) group) were used. The WBV group underwent WBV at 45 Hz frequency, with 0.5 g acceleration (15 min/day, 5 days/week) for 8 weeks. Trabecular and cortical bone mass, trabecular bone microstructure (TBMS), and cortical bone geometry (CBG) were analyzed via micro-computed tomography. Bone mechanical strength (maximum load, break point, and stiffness) was also measured. Additionally, bone metabolic and DM-related markers were determined. Results: The bone mechanical strength of the femur improved in the WBV group, although muscle atrophy and bone deterioration were observed in the DM and WBV groups. The serum levels of bone-specific alkaline phosphatase and tartrate-resistant acid phosphatase-5b were significantly higher in the DM and WBV groups than in the CON group. Serum glucose and blood urea nitrogen levels were significantly lower in the WBV group than in the DM group. Conclusions: This study suggests that WBV potentially improves the decrease in the bone mechanical strength of the femur, although it does not prevent the deterioration of bone mineral content, TBMS, and CBG parameters. Further studies are needed to investigate the effective timing and duration of WBV and the conditions that prevent T2DM and deterioration of bone properties and clarify the mechanism underlying WBV effects on bone properties in DM animals.

Nonlinear dynamic modeling and vibration analysis for early fault evolution of rolling bearings.

In rotating machinery, the condition of rolling bearings is paramount, directly influencing operational integrity. However, the literature on the fault evolution of rolling bearings in their nascent stages is notably limited. Addressing this gap, our study establishes an innovative nonlinear dynamic model for early fault evolution of rolling bearings based on collision impact. Firstly, considering the fault evolution characteristics, the influence of the rolling element and fault structure, the dynamic model of early fault evolution between the rolling element and the local fault is established. Secondly, according to the Hertzian contact deformation theory, a nonlinear dynamic model of rolling bearings expressed as mass-spring is established. Thirdly, the energy contribution method is used to integrate the fault evolution model and the nonlinear dynamic model of the rolling bearing. A nonlinear dynamic model of early fault evolution of the rolling bearing is proposed by using the Lagrangian equation. Comparing the simulation results of the nonlinear dynamic with the experimental results, it can be seen that the numerical model can effectively predict the evolution process and vibration characteristics of the fault evolution of rolling bearings in the early stage.

Actuation Performance and Versatility of Photothermally Driven Organic Crystals.

Photomechanical crystals exhibit mechanical motion upon light irradiation and may thus find applications as actuators. Over the last decades, many photomechanical organic crystals have been developed, commonly via photochemical reactions, particularly photoisomerization. However, photochemical crystal actuation is associated with several drawbacks, including a limited number of available crystals, slow actuation speed (< 5 Hz), and narrow wavelength range (< 550 nm). Such constraints have hindered the widespread use of crystals as actuation materials. In this minireview, we focus on crystal actuation by employing more universal physical phenomena (the photothermal effect and photothermally resonated natural vibration) and quantitatively evaluate actuation performance. Both mechanisms, particularly the latter, outperformed conventional photomechanical crystal activation in terms of both speed (maximum: 1,350 Hz) and the useful wavelength range (ultraviolet to near-infrared). The oscillation frequencies of the crystals exceeded those of polymers, efficiently filling the gap between soft and hard materials. Both the photothermal effect and natural vibration can actuate any crystal that absorbs light. These two versatile physical actuation mechanisms could expand 40 years of research on photomechanical crystals-which had been based on photochemical reactions-from the realm of chemistry into engineering and lead to their practical applications in actuators and soft robots.