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3.
Optom Vis Sci ; 101(6): 358-367, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38990235

RESUMO

SIGNIFICANCE: This study has shown a vibrotactile sensory substitution device (SSD) prototype, VibroSight, has the potential to improve functional outcomes (i.e., obstacle avoidance, face detection) for people with profound vision loss, even with brief familiarization (<20 minutes). PURPOSE: Mobility aids such as long canes are still the mainstay of support for most people with vision loss, but they do have limitations. Emerging technologies such as SSDs are gaining widespread interest in the low vision community. The aim of this project was to assess the efficacy of a prototype vibrotactile SSD for people with profound vision loss in the face detection and obstacle avoidance tasks. METHODS: The VibroSight device was tested in a movement laboratory setting. The first task involved obstacle avoidance, in which participants were asked to walk through an obstacle course. The second was a face detection task, in which participants were asked to step toward the first face they detected. Exit interviews were also conducted to gather user experience data. Both people with low vision (n = 7) and orientation and mobility instructors (n = 4) completed the tasks. RESULTS: In obstacle avoidance task, participants were able to use the device to detect (p<0.001) and avoid (p<0.001) the obstacles within a significantly larger range, but were slower (p<0.001), when compared with without the device. In face detection task, participants demonstrated a great level of accuracy, precision, and sensitivity when using the device. Interviews revealed a positive user experience, although participants identified that they would require a lighter and compact design for real-world use. CONCLUSIONS: Overall, the results verified the functionality of vibrotactile SSD prototype. Further research is warranted to evaluate the user performance after an extended training program and to add new features, such as object recognition software algorithms, into the device.


Assuntos
Desenho de Equipamento , Auxiliares Sensoriais , Vibração , Humanos , Vibração/uso terapêutico , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Baixa Visão/fisiopatologia , Baixa Visão/reabilitação , Tato/fisiologia , Idoso , Pessoas com Deficiência Visual/reabilitação
4.
PLoS One ; 19(7): e0305351, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38980852

RESUMO

Due to the influence of coal rock shape, hardness, working environment and other factors in the cutting process of cantilever roadheader, the cutting head will produce irregular and violent vibration. As the rotary table of key stress components, its operation process stability, dynamic reliability and life affect the cutting efficiency and cutting stability of cantilever roadheader. In order to study the vibration characteristics of the rotary table in the cutting process, firstly, based on the theory of spatial force analysis and calculation, the spatial mechanical model of the rotary table of the cantilever roadheader is established. By solving the balance equation of the rotary table force system, the variation law of the load at the hinge ear of the rotary table with the cutting pitch angle and the horizontal angle is obtained. Secondly, based on the path transfer analysis method of working condition, the vibration data of cutting head, cutting cantilever, cutting lifting and rotary hydraulic cylinder under stable cutting condition are taken as input signals. By constructing the transfer path analysis model of rotary table working condition, the synthetic vibration of rotary table in cutting process is simulated, and the main vibration source of rotary table is determined. Then, the vibration contribution and contribution degree of each vibration excitation point to the hinge ear of rotary table are studied. By building a cutting test bench, the vibration response of rotary table in cutting process is tested to verify the correctness of the theoretical model.Thirdly, based on the frequency domain analysis method of random vibration fatigue life, combined with the S-N curve of the rotary table, the PSD curve at the maximum stress of the rotary table is obtained by modal excitation method, and the load data is imported into ANSYS nCode software to obtain the life cloud diagram and damage cloud diagram of the rotary table, and then the fatigue life of the rotary table under symmetrical cyclic load is solved. Finally, based on the response surface optimization analysis method, the maximum stress and maximum deformation of the rotary table are taken as the optimization objectives, and the aperture of each hinge ear of the rotary table is taken as the optimization variable. Based on Design Expert, a second-order regression model is established to realize the multi-objective optimization design of the key stress parts of the rotary table in the cutting process. The simulation results show that under the same cutting conditions, the maximum stress of the optimized rotary table is reduced by 15.82% year-on-year, and the maximum deformation is reduced by 24.70% year-on-year. The optimized rotary table structure can better adapt to the cutting process, which is beneficial to improve the service life of the rotary table and enhance its operation stability. The research results are beneficial to enrich the relevant research theory in the field of rotary table vibration of cantilever roadheader, and are beneficial to improve the service life of the rotary table and the efficiency of tunneling and mining.


Assuntos
Desenho de Equipamento , Vibração , Modelos Teóricos
5.
PLoS One ; 19(7): e0307110, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38995946

RESUMO

The complex vibration phenomenon occurs in the downhole environment of the gas-liquid hydrocyclone, which affects the flow field in the hydrocyclone. In order to study the influence of vibration on hydrocyclone separation, the characteristics of the flow field in the downhole gas-liquid hydrocyclone were analyzed and studied under the condition of vibration coupling. Based on Computational Fluid Dynamics (CFD), Computational Solid Mechanics Method (CSM) and fluid-solid coupling method, a fluid-solid coupling mechanical model of a gas-liquid cyclone is established. It is found that under the condition of vibration coupling, the velocity components in the three directions of the hydrocyclone flow field change obviously. The peak values of tangential velocity and axial velocity decrease, and the asymmetry of radial velocity increases. The distribution regularity of vorticity and turbulence intensity in the overflow pipe becomes worse. Among them, the vorticity intensity of the overflow pipe is obviously enhanced, and the higher turbulence intensity near the wall occupies more area distribution range. The gas-liquid separation efficiency of the hydrocyclone will decrease with the increase of the rotational speed of the screw pump, and the degree of reduction can reach more than 10%. However, this effect will decrease with the increase of the rotational speed of the screw pump, so the excitation effect caused by the rotational speed has a maximum limit on the flow field.


Assuntos
Gases , Vibração , Gases/química , Hidrodinâmica , Modelos Teóricos , Simulação por Computador
6.
Sensors (Basel) ; 24(13)2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-39001036

RESUMO

Gear fault detection and remaining useful life estimation are important tasks for monitoring the health of rotating machinery. In this study, a new benchmark for endurance gear vibration signals is presented and made publicly available. The new dataset was used in the HUMS 2023 conference data challenge to test anomaly detection algorithms. A survey of the suggested techniques is provided, demonstrating that traditional signal processing techniques interestingly outperform deep learning algorithms in this case. Of the 11 participating groups, only those that used traditional approaches achieved good results on most of the channels. Additionally, we introduce a signal processing anomaly detection algorithm and meticulously compare it to a standard deep learning anomaly detection algorithm using data from the HUMS 2023 challenge and simulated signals. The signal processing algorithm surpasses the deep learning algorithm on all tested channels and also on simulated data where there is an abundance of training data. Finally, we present a new digital twin that enables the estimation of the remaining useful life of the tested gear from the HUMS 2023 challenge.


Assuntos
Algoritmos , Processamento de Sinais Assistido por Computador , Humanos , Vibração , Aprendizado Profundo
7.
Sensors (Basel) ; 24(13)2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-39001045

RESUMO

Nucleic acid tests are key tools for the detection and diagnosis of many diseases. In many cases, the amplification of the nucleic acids is required to reach a detectable level. To make nucleic acid amplification tests more accessible to a point-of-care (POC) setting, isothermal amplification can be performed with a simple heating source. Although these tests are being performed in bulk reactions, the quantification is not as accurate as it would be with digital amplification. Here, we introduce the use of the vibrating sharp-tip capillary for a simple and portable system for tunable on-demand droplet generation. Because of the large range of droplet sizes possible and the tunability of the vibrating sharp-tip capillary, a high dynamic range (~2 to 6000 copies/µL) digital droplet loop-mediated isothermal amplification (ddLAMP) system has been developed. It was also noted that by changing the type of capillary on the vibrating sharp-tip capillary, the same mechanism can be used for simple and portable DNA fragmentation. With the incorporation of these elements, the present work paves the way for achieving digital nucleic acid tests in a POC setting with limited resources.


Assuntos
Técnicas de Amplificação de Ácido Nucleico , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/instrumentação , Vibração , Sistemas Automatizados de Assistência Junto ao Leito , Humanos , Ácidos Nucleicos/análise , DNA/análise , DNA/genética , DNA/química
8.
Int J Mol Sci ; 25(13)2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38999952

RESUMO

Vibration and sound are the shaping matrix of the entire universe. Everything in nature is shaped by energy vibrating and communicating through its own sound trail. Every cell within our body vibrates at defined frequencies, generating its peculiar "sound signature". Mitochondria are dynamic, energy-transforming, biosynthetic, and signaling organelles that actively transduce biological information. Novel research has shown that the mitochondrial function of mammalian cells can be modulated by various energetic stimuli, including sound vibrations. Regarding acoustic vibrations, definite types of music have been reported to produce beneficial impacts on human health. In very recent studies, the effects of different sound stimuli and musical styles on cellular function and mitochondrial activity were evaluated and compared in human cells cultured in vitro, investigating the underlying responsible molecular mechanisms. This narrative review will take a multilevel trip from macro to intracellular microenvironment, discussing the intimate vibrational sound activities shaping living matter, delving deeper into the molecular mechanisms underlying the sound modulation of biological systems, and mainly focusing our discussion on novel evidence showing the competence of mitochondria in acting as energy portals capable of sensing and transducing the subtle informational biofields of sound vibration.


Assuntos
Microambiente Celular , Mitocôndrias , Som , Vibração , Humanos , Mitocôndrias/metabolismo , Animais , Música , Metabolismo Energético
9.
PLoS One ; 19(7): e0305545, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38990906

RESUMO

BACKGROUND: Non-invasive neurostimulation like muscle tendon vibration (VIB) and transcranial magnetic stimulation (TMS) can provide valuable insights on mechanisms underlying sensorimotor dysfunctions. However, their feasibility in the context of painful musculoskeletal disorders like shoulder impingement syndrome (SIS) remain uncertain. METHODS: The present work used a case series design including 15 participants with SIS, as well as a secondary group-based analysis comparing participants with SIS to 15 healthy counterparts. Proprioceptive processing was tested by VIB-induced kinesthetic illusions of shoulder abduction, and TMS tested corticospinal excitability of the upper trapezius. Detailed individual data were collected, including any technical challenges and feasibility issues encountered. RESULTS: VIB was in general well-tolerated and elicited a perceptible kinesthetic illusion in 13 participants with SIS and 14 controls. TMS presented with several challenges related to discomfort, fear-related behaviors, technical problems and high motor thresholds, especially in participants with SIS. It was only possible to collect all TMS measures in 5 participants with SIS (for both the painful and non/less-painful sides), in 7 controls on their dominant side and 10 controls on the non-dominant side. The only significant group-based analysis was a lower illusion speed/amplitude on the painful versus non-painful side in persons with SIS (p = 0.035). CONCLUSION: Our study provides preliminary data on challenges encountered with TMS and VIB of trunk/proximal muscle in persons with SIS and healthy counterparts. It might help future studies to better address those challenges beforehand and improve the overall feasibility and impact of neurostimulation tools in musculoskeletal disorders.


Assuntos
Síndrome de Colisão do Ombro , Tendões , Estimulação Magnética Transcraniana , Vibração , Humanos , Estimulação Magnética Transcraniana/métodos , Feminino , Masculino , Síndrome de Colisão do Ombro/terapia , Síndrome de Colisão do Ombro/fisiopatologia , Pessoa de Meia-Idade , Vibração/uso terapêutico , Adulto , Tendões/fisiopatologia , Estudos de Casos e Controles , Propriocepção/fisiologia
10.
Methods Mol Biol ; 2816: 241-252, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38977603

RESUMO

Bioactive lipids have been identified as dynamic signaling lipid mediators (LMs). These fats have the ability to activate responses and control bodily functions either directly or indirectly. Linoleic Acid (LA) and Alpha Linoleic Acid (ALA) are types of omega 3 fatty acids that possess inflammatory properties and promote resolution of inflammation either through their own actions or through their metabolites known as oxylipins. In this chapter, we provide an explanation of a method that combines chromatography with tandem mass spectroscopy (LC MS/MS) to identify and measure all the metabolites derived from LA and ALA. Additionally, we employed the described methodology to analyze human serum samples obtained before and after whole-body vibration exercise training. The results indicated an increase in some of the LA and ALA LMs that have beneficial effects in regulating the cardiovascular system.


Assuntos
Ácido Linoleico , Lipidômica , Espectrometria de Massas em Tandem , Vibração , Humanos , Ácido Linoleico/metabolismo , Lipidômica/métodos , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida/métodos , Exercício Físico/fisiologia , Oxilipinas/metabolismo , Oxilipinas/sangue , Metabolismo dos Lipídeos
11.
PeerJ ; 12: e17501, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38952987

RESUMO

Stridulation is used by male katydids to produce sound via the rubbing together of their specialised forewings, either by sustained or interrupted sweeps of the file producing different tones and call structures. There are many species of Orthoptera that remain undescribed and their acoustic signals are unknown. This study aims to measure and quantify the mechanics of wing vibration, sound production and acoustic properties of the hearing system in a new genus of Pseudophyllinae with taxonomic descriptions of two new species. The calling behaviour and wing mechanics of males were measured using micro-scanning laser Doppler vibrometry, microscopy, and ultrasound sensitive equipment. The resonant properties of the acoustic pinnae of the ears were obtained via µ-CT scanning and 3D printed experimentation, and numerical modelling was used to validate the results. Analysis of sound recordings and wing vibrations revealed that the stridulatory areas of the right tegmen exhibit relatively narrow frequency responses and produce narrowband calls between 12 and 20 kHz. As in most Pseudophyllinae, only the right mirror is activated for sound production. The acoustic pinnae of all species were found to provide a broadband increased acoustic gain from ~40-120 kHz by up to 25 dB, peaking at almost 90 kHz which coincides with the echolocation frequency of sympatric bats. The new genus, named Satizabalus n. gen., is here derived as a new polytypic genus from the existing genus Gnathoclita, based on morphological and acoustic evidence from one described (S. sodalis n. comb.) and two new species (S. jorgevargasi n. sp. and S. hauca n. sp.). Unlike most Tettigoniidae, Satizabalus exhibits a particular form of sexual dimorphism whereby the heads and mandibles of the males are greatly enlarged compared to the females. We suggest that Satizabalus is related to the genus Trichotettix, also found in cloud forests in Colombia, and not to Gnathoclita.


Assuntos
Ortópteros , Asas de Animais , Animais , Masculino , Asas de Animais/fisiologia , Asas de Animais/anatomia & histologia , Colômbia , Ortópteros/fisiologia , Ortópteros/anatomia & histologia , Comunicação Animal , Florestas , Vocalização Animal/fisiologia , Acústica , Feminino , Vibração
12.
J Biomed Opt ; 29(Suppl 2): S22711, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38952688

RESUMO

Significance: Biomanufacturing utilizes modified microbial systems to sustainably produce commercially important biomolecules for use in agricultural, energy, food, material, and pharmaceutical industries. However, technological challenges related to non-destructive and high-throughput metabolite screening need to be addressed to fully unlock the potential of synthetic biology and sustainable biomanufacturing. Aim: This perspective outlines current analytical screening tools used in industrial cell strain development programs and introduces label-free vibrational spectro-microscopy as an alternative contrast mechanism. Approach: We provide an overview of the analytical instrumentation currently used in the "test" portion of the design, build, test, and learn cycle of synthetic biology. We then highlight recent progress in Raman scattering and infrared absorption imaging techniques, which have enabled improved molecular specificity and sensitivity. Results: Recent developments in high-resolution chemical imaging methods allow for greater throughput without compromising the image contrast. We provide a roadmap of future work needed to support integration with microfluidics for rapid screening at the single-cell level. Conclusions: Quantifying the net expression of metabolites allows for the identification of cells with metabolic pathways that result in increased biomolecule production, which is essential for improving the yield and reducing the cost of industrial biomanufacturing. Technological advancements in vibrational microscopy instrumentation will greatly benefit biofoundries as a complementary approach for non-destructive cell screening.


Assuntos
Análise Espectral Raman , Análise Espectral Raman/métodos , Vibração , Bactérias/metabolismo , Bactérias/química
13.
Luminescence ; 39(7): e4822, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39019842

RESUMO

Holmium (Ho3+)-doped boro-bismuth-germanate glasses having the chemical composition (30-x)B2O3 + 20GeO2 + 20Bi2O3 + 20Na2O + 10Y2O3 + xHo2O3, where x = 0.1, 0.5, 1.0, and 2.0 mol% were prepared by melt-quenching technique. The prepared glasses were examined for thermal, optical, vibrational, and photoluminescent properties. The prepared glasses were found to be thermally very stable. The optical bandgap and Urbach energies of 0.1 mol% Ho2O3-doped boro-bismuth-germanate glass were calculated to be 3.3 eV and 377 MeV, respectively, using the absorption spectrum. The Judd-Ofelt analysis was performed on the 0.1 mol% Ho2O3-doped glass and compared the obtained parameters with literature. The branching ratio (ß) and emission cross-section (σem) of the green band were determined to be 0.7 and 0.24 × 10-20 cm2, respectively. Under 450 nm excitation, a strong green emission around 550 nm was observed and assigned to the (5S2 + 5F4) → 5I8 (Ho3+) transition. Upon an increase of Ho2O3 content from 0.1 to 2.0 mol%, the intensities of all observed emission bands as well as decay time of the (5S2 + 5F4) → 5I8 transition have been decreased gradually. The reasons behind the decrease in emission intensity and decay time were discussed. The strong green emission suggests that these glasses may be a better option for display devices and green emission applications.


Assuntos
Bismuto , Germânio , Vidro , Hólmio , Luminescência , Hólmio/química , Vidro/química , Germânio/química , Bismuto/química , Vibração , Medições Luminescentes , Fenômenos Ópticos
14.
Nature ; 631(8019): 118-124, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38898274

RESUMO

Locating sound sources such as prey or predators is critical for survival in many vertebrates. Terrestrial vertebrates locate sources by measuring the time delay and intensity difference of sound pressure at each ear1-5. Underwater, however, the physics of sound makes interaural cues very small, suggesting that directional hearing in fish should be nearly impossible6. Yet, directional hearing has been confirmed behaviourally, although the mechanisms have remained unknown for decades. Several hypotheses have been proposed to explain this remarkable ability, including the possibility that fish evolved an extreme sensitivity to minute interaural differences or that fish might compare sound pressure with particle motion signals7,8. However, experimental challenges have long hindered a definitive explanation. Here we empirically test these models in the transparent teleost Danionella cerebrum, one of the smallest vertebrates9,10. By selectively controlling pressure and particle motion, we dissect the sensory algorithm underlying directional acoustic startles. We find that both cues are indispensable for this behaviour and that their relative phase controls its direction. Using micro-computed tomography and optical vibrometry, we further show that D. cerebrum has the sensory structures to implement this mechanism. D. cerebrum shares these structures with more than 15% of living vertebrate species, suggesting a widespread mechanism for inferring sound direction.


Assuntos
Sinais (Psicologia) , Cyprinidae , Audição , Localização de Som , Animais , Feminino , Masculino , Algoritmos , Audição/fisiologia , Pressão , Som , Localização de Som/fisiologia , Vibração , Microtomografia por Raio-X , Cyprinidae/fisiologia , Movimento (Física) , Reflexo de Sobressalto , Material Particulado
15.
J Acoust Soc Am ; 155(6): 3822-3832, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38874464

RESUMO

This study proposes the use of vocal resonators to enhance cardiac auscultation signals and evaluates their performance for voice-noise suppression. Data were collected using two electronic stethoscopes while each study subject was talking. One collected auscultation signal from the chest while the other collected voice signals from one of the three voice resonators (cheek, back of the neck, and shoulder). The spectral subtraction method was applied to the signals. Both objective and subjective metrics were used to evaluate the quality of enhanced signals and to investigate the most effective vocal resonator for noise suppression. Our preliminary findings showed a significant improvement after enhancement and demonstrated the efficacy of vocal resonators. A listening survey was conducted with thirteen physicians to evaluate the quality of enhanced signals, and they have received significantly better scores regarding the sound quality than their original signals. The shoulder resonator group demonstrated significantly better sound quality than the cheek group when reducing voice sound in cardiac auscultation signals. The suggested method has the potential to be used for the development of an electronic stethoscope with a robust noise removal function. Significant clinical benefits are expected from the expedited preliminary diagnostic procedure.


Assuntos
Auscultação Cardíaca , Processamento de Sinais Assistido por Computador , Estetoscópios , Humanos , Auscultação Cardíaca/instrumentação , Auscultação Cardíaca/métodos , Auscultação Cardíaca/normas , Masculino , Feminino , Adulto , Ruídos Cardíacos/fisiologia , Espectrografia do Som , Desenho de Equipamento , Voz/fisiologia , Pessoa de Meia-Idade , Qualidade da Voz , Vibração , Ruído
17.
J Bodyw Mov Ther ; 39: 518-524, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38876678

RESUMO

INTRODUCTION: Whole-Body Vibration (WBV) can be a therapeutic recovery strategy for patients hospitalized for COVID-19. OBJECTIVES: To evaluate the effects of a 36-session WBV protocol on the risk of falls, balance, mobility and heart rate variability (HRV). STUDY DESIGN: A randomized clinical trial. METHODS: 13 patients affected by COVID-19, trained with WBV, 3×/week on alternate days, totaling 36 sessions, were evaluated before and after the intervention. RESULTS: WBV training at 2 mm and 4 mm amplitude resulted in a reduction in the risk of falls when compared to Sham (p = 0.023), with effect size of 0.530. No changes were observed for mobility and balance outcomes (p = 0.127) or for any of the HRV variables (p = 0.386). CONCLUSION: WBV training reduced the risk of falls in post-COVID patients. No changes were observed regarding balance and mobility, nor for HRV.


Assuntos
Acidentes por Quedas , COVID-19 , Frequência Cardíaca , Equilíbrio Postural , Vibração , Humanos , Vibração/uso terapêutico , Frequência Cardíaca/fisiologia , Acidentes por Quedas/prevenção & controle , Equilíbrio Postural/fisiologia , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Modalidades de Fisioterapia , SARS-CoV-2
18.
J Bodyw Mov Ther ; 39: 598-605, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38876693

RESUMO

INTRODUCTION: Whole-body vibration (WBV) is used to improve muscle function but is important to know if doses can affect the objective function outcomes. OBJECTIVE: To compare the effect of two frequencies of WBV on objective physical function outcomes in healthy young adults. METHODS: Forty-two volunteers were randomized into three groups: sham group (SG), and WBV groups with 30 (F30) and 45 Hz (F45). A 6-week WBV intervention protocol was applied by a vibrating platform twice a week, with the platform turn-off for SG and with two frequencies according to group, 30 or 45 Hz. The objective physical functions outcomes assessed were the proprioceptive accuracy, measured by proprioceptive tests, and quasi-static and dynamic balances, measured by Sensory Organization Test (SOT) and Y Balance Test, respectively. The outcomes were assessed before and after the WBV intervention. We used in the results comparisons, by GzLM test, the deltas percentage. RESULTS: After the intervention, no statistical differences were observed in percentage deltas for any outcomes (proprioceptive accuracy, quasi-static and dynamic balances). CONCLUSION: Objective physical function outcomes, after the 6-week WBV protocol, did not present statistically significant results in any of the intervention groups (F30 or F45) and SG.


Assuntos
Equilíbrio Postural , Vibração , Humanos , Vibração/uso terapêutico , Masculino , Feminino , Adulto Jovem , Equilíbrio Postural/fisiologia , Adulto , Propriocepção/fisiologia , Modalidades de Fisioterapia
19.
PLoS One ; 19(6): e0299586, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38889193

RESUMO

The composite laminated rotationally stiffened shell is widely applied in aviation, aerospace, ship, machinery and other fields. To investigate the vibration characteristics of composite laminated rotationally stiffened shells with varying elastic boundary conditions, a modeling method of composite laminated rotationally stiffened shells is established. Firstly, the first-order shear deformation theory (FSDT) and the modified Fourier series method are effectively applied to establish the allowable displacement function of the composite laminated rotationally stiffened shell. Secondly, the energy function of composite laminated rotationally stiffened shell is established, and the simulation of complex elastic boundary and coupling boundary is realized by using artificial virtual spring technology. Thirdly, the Rayleigh-Ritz method is used to solve the energy function. Finally, the vibration characteristics of composite laminated rotationally stiffened shells are obtained and analyzed. In the analysis of numerical results, the fast and uniform convergence of analysis modeling and the accuracy of the calculated results are verified. On this basis, the effect of some important parameters such as thickness-to-radius ratio and length-to-radius ratio of shell, boundary spring stiffness values, cone apex angle, thickness and width of laminated beams, number of stiffeners on the vibration characteristics of composite laminated rotationally stiffened shell is studied. In theory, it makes up for the vibration characteristics analysis of composite laminated rotationally stiffened shells. In practical application, it guides the noise reduction design of related structures.


Assuntos
Vibração , Modelos Teóricos , Elasticidade , Exoesqueleto
20.
BMJ Open ; 14(6): e080777, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890140

RESUMO

OBJECTIVES: The occurrence of hand and forearm disorders related to vibration exposure, adjusted for relevant background factors, is scarcely reported. We analysed the prevalence of such conditions in a large population cohort, stratified by sex, and associations with exposure to vibrating hand-held tools. DESIGN: This is a retrospective cohort study. SETTING: Individuals in the Malmö Diet and Cancer Study cohort (MDCS; inclusion 1991-1996; followed until 2018) were asked, 'does your work involve working with vibrating hand-held tools?' (response: 'not at all', 'some' and 'much'). Data were cross-linked with national registers to identify treatment for carpal tunnel syndrome (CTS), ulnar nerve entrapment (UNE), Dupuytren's disease, trigger finger or first carpometacarpal joint (CMC-1) osteoarthritis (OA). Cox regression models, unadjusted and adjusted (age, sex, prevalent diabetes, smoking, hypertension and alcohol consumption), were performed to analyse the effects of reported vibration exposure. PARTICIPANTS: Individuals in the MDCS who had answered the questionnaire on vibration exposure (14 342 out of the originally 30 446 individuals in MDCS) were included in the study. RESULTS: In total, 12 220/14 342 individuals (76%) reported 'no' exposure, 1392/14 342 (9%) 'some' and 730/14 342 (5%) 'much' exposure to vibrating hand-held tools. In men, 'much' exposure was independently associated with CTS (HR 1.71 (95% CI 1.11 to 2.62)) and UNE (HR 2.42 (95% CI 1.15 to 5.07)). 'Some' exposure was independently associated with UNE in men (HR 2.10 (95% CI 1.12 to 3.95)). 'Much' exposure was independently associated with trigger finger in women (HR 2.73 (95% CI 1.49 to 4.99)). We found no effect of vibration exposure on Dupuytren's disease or CMC-1 OA. 'Much' vibration exposure predicted any hand and forearm diagnosis in men (HR 1.44 (95% CI 1.08 to 1.80)), but not in women. CONCLUSIONS: Vibration exposure by hand-held tools increases the risk of developing CTS and UNE and any common hand and forearm conditions in men, whereas women only risk trigger finger and CMC-1 OA. Adjustment for relevant confounders in vibration exposure is crucial.


Assuntos
Síndrome do Túnel Carpal , Exposição Ocupacional , Vibração , Humanos , Masculino , Feminino , Estudos Retrospectivos , Suécia/epidemiologia , Pessoa de Meia-Idade , Vibração/efeitos adversos , Síndrome do Túnel Carpal/epidemiologia , Síndrome do Túnel Carpal/etiologia , Idoso , Exposição Ocupacional/efeitos adversos , Doenças Profissionais/epidemiologia , Doenças Profissionais/etiologia , Dedo em Gatilho/epidemiologia , Contratura de Dupuytren/epidemiologia , Mãos , Prevalência , Fatores de Risco , Síndromes de Compressão do Nervo Ulnar/epidemiologia , Síndromes de Compressão do Nervo Ulnar/etiologia , Adulto , Modelos de Riscos Proporcionais
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