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1.
Eur J Pediatr ; 183(4): 1901-1910, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38337095

RESUMO

The aim of the study was to determine the relationship between flatfoot morphology and body mass and height in children aged 6-12 years. A total of 6471 Chinese children (mean age 9.0 ± 1.9 years, 41% female) were assessed for foot morphometry, body height, and body mass index. Foot morphology, including foot length, width, girth, arch height, hallux valgus angle, and rearfoot valgus angle, was measured using a 3D laser scanner. Flatfoot evaluations were conducted using the Sztriter-Godunov index (KY) from footprints. All measurements were analyzed by age and sex using the mean values of the left and right sides. Comparisons were performed between flatfoot groups, between body mass index (BMI) groups, and between body height groups. The study revealed a significant decrease in the incidence of bipedal flatfoot with age (p < 0.001), whereas the prevalence of obesity remained consistent (p > 0.05). Bipedal flatfoot was associated with distinct morphological changes, including lower arches, reduced instep height, diminished ankle heights and a greater rearfoot valgus angle (p < 0.05). When comparing the BMI groups, overweight children had larger and thicker feet (p < 0.05), but no differences were found in arch height and ankle height (p > 0.05). When comparing the body height groups, short-statured children had a shorter feet girth, shorter arches, and shorter ankle height (p < 0.05), but no differences were found in the rearfoot valgus angle (p > 0.05). CONCLUSION: The main characteristics of flat feet include lower arches and instep heights and ankle heights but higher rearfoot valgus angles. In general, overweight children's feet do not have the common features of flat feet. In contrast, short children had similar features of flatfoot except for rearfoot valgus. Assessment of posture, such as rearfoot valgus, can be critical in identifying children with flat feet. WHAT IS KNOWN: • The morphology of children's feet is associated with body growth, but the relationship between flatfeet and body mass and height remains controversial. WHAT IS NEW: • Three-dimensional foot measurement shows that body mass is generally not associated with flatfeet, while short children have lower arches but no rearfoot valgus.


Assuntos
Pé Chato , Criança , Humanos , Feminino , Masculino , Pé Chato/epidemiologia , Pé Chato/complicações , Sobrepeso , Estatura , Pé/anatomia & histologia , Obesidade/complicações
2.
Acta Obstet Gynecol Scand ; 103(5): 884-896, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38217337

RESUMO

INTRODUCTION: Previous studies have demonstrated that abnormal body mass index (BMI) is associated with adverse pregnancy outcomes in frozen-thawed embryo transfer cycles. However, the relationship between BMI and pregnancy and perinatal outcomes in patients with polycystic ovary syndrome (PCOS) remains unclear. Furthermore, whether a diagnosis of PCOS could result in adverse pregnancy and perinatal outcomes in women with different BMIs remains unknown. MATERIAL AND METHODS: A historical cohort study included 1667 women with PCOS and 12 256 women without PCOS after a freeze-all policy between January 2016 and December 2020. The outcomes encompassed both pregnancy and perinatal outcomes. Multivariate logistic regression analysis and restricted cubic spline models were performed to eliminate confounding factors when investigating the relationship between BMI and different outcomes. RESULTS: After controlling for covariates, pregnancy outcomes were comparable between underweight women with PCOS and normal weight women with PCOS. However, overweight patients had a lower clinical pregnancy rate and an overall live birth rate. Furthermore, patients with obesity had a lower rate of multiple pregnancies but a higher rate of biochemical pregnancy than in the normal BMI group. Additionally, the restricted cubic spline models showed that as maternal BMI increased to 32 kg/m2, the clinical pregnancy rate and live birth rate after blastocyst transfer decreased, but the risks of preterm birth, gestational diabetes mellitus, macrosomia, large-for-gestational age (LGA) and very LGA increased in patients with PCOS after a freeze-all strategy. Moreover, a diagnosis of PCOS resulted in a higher clinical pregnancy rate and live birth rate and a higher risk of small-for-gestational age in the normal weight group. However, women with PCOS in the overweight group exhibited higher risks of very preterm birth and gestational diabetes mellitus compared with women without PCOS. CONCLUSIONS: This study showed that a higher BMI had a detrimental impact on the pregnancy and perinatal outcomes of PCOS patients undergoing a freeze-all strategy. However, it was only statistically significant in the overweight group. A diagnosis of PCOS had a higher clinical pregnancy rate and live birth rate in normal weight women but higher risks of perinatal complications in normal weight and overweight women.


Assuntos
Diabetes Gestacional , Síndrome do Ovário Policístico , Nascimento Prematuro , Gravidez , Humanos , Recém-Nascido , Feminino , Síndrome do Ovário Policístico/complicações , Índice de Massa Corporal , Sobrepeso/complicações , Nascimento Prematuro/epidemiologia , Nascimento Prematuro/etiologia , Estudos de Coortes , Resultado da Gravidez , Estudos Retrospectivos
3.
J Med Virol ; 95(8): e29041, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37621182

RESUMO

The emerging outbreak of monkeypox is closely associated with the viral infection and spreading, threatening global public health. Virus-induced cell migration facilitates viral transmission. However, the mechanism underlying this type of cell migration remains unclear. Here we investigate the motility of cells infected by vaccinia virus (VACV), a close relative of monkeypox, through combining multi-omics analyses and high-resolution live-cell imaging. We find that, upon VACV infection, the epithelial cells undergo epithelial-mesenchymal transition-like transformation, during which they lose intercellular junctions and acquire the migratory capacity to promote viral spreading. After transformation, VACV-hijacked RhoA signaling significantly alters cellular morphology and rearranges the actin cytoskeleton involving the depolymerization of robust actin stress fibers, leading-edge protrusion formation, and the rear-edge recontraction, which coordinates VACV-induced cell migration. Our study reveals how poxviruses alter the epithelial phenotype and regulate RhoA signaling to induce fast migration, providing a unique perspective to understand the pathogenesis of poxviruses.


Assuntos
Mpox , Vaccinia virus , Humanos , Movimento Celular , Surtos de Doenças , Células Epiteliais
4.
J Environ Sci (China) ; 124: 544-556, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36182162

RESUMO

A hygroscopic tandem differential mobility analyser (H-TDMA) was used to observe the size-resolved hygroscopic characteristics of submicron particles in January and April 2018 in urban Beijing. The probability distribution of the hygroscopic growth factor (HGF-PDF) in winter and spring usually showed a bimodal pattern, with more hygroscopic mode (MH) being more dominant. The seasonal variation in particle hygroscopicity was related to the origin of air mass, which received polluted southerly air masses in spring and clean northwesterly air masses in winter. Particles showed stronger hygroscopic behaviour during heavy pollution episodes (HPEs) with elevated concentrations of secondary aerosols, especially higher mass fraction of nitrate, which were indicated using the PM2.5 (particulate matter with diameter below 2.5 µm) mass concentration normalised by CO mass concentration. The hygroscopic parameter (κ) values were calculated using H-TDMA (κhtdma) and chemical composition (κchem). The closure study showed that κchem was overestimated in winter afternoon when compared with κhtdma, because the organic particle hygroscopic parameter (κorg) was overestimated in the calculations. It was influenced by the presence of a high concentration of hydrocarbon-like organic aerosol (HOA) with a weak water uptake ability. A positive relationship was observed between κorg and the ratio of oxygenated organic aerosol (OOA) and HOA, thereby indicating that the strong oxidation state enhanced the hygroscopicity of the particles. This study revealed the effect of local emission sources and secondary aerosol formation processes on particle hygroscopicity, which is of great significance for understanding the pollution formation mechanism in the North China Plain.


Assuntos
Poluentes Atmosféricos , Nitratos , Aerossóis/análise , Poluentes Atmosféricos/análise , Pequim , China , Monitoramento Ambiental , Tamanho da Partícula , Material Particulado/análise , Estações do Ano , Água , Molhabilidade
5.
Am J Pathol ; 191(7): 1193-1208, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33894177

RESUMO

Pulmonary fibrosis (PF) can arise from unknown causes, as in idiopathic PF, or as a consequence of infections, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Current treatments for PF slow, but do not stop, disease progression. We report that treatment with a runt-related transcription factor 1 (RUNX1) inhibitor (Ro24-7429), previously found to be safe, although ineffective, as a Tat inhibitor in patients with HIV, robustly ameliorates lung fibrosis and inflammation in the bleomycin-induced PF mouse model. RUNX1 inhibition blunted fundamental mechanisms downstream pathologic mediators of fibrosis and inflammation, including transforming growth factor-ß1 and tumor necrosis factor-α, in cultured lung epithelial cells, fibroblasts, and vascular endothelial cells, indicating pleiotropic effects. RUNX1 inhibition also reduced the expression of angiotensin-converting enzyme 2 and FES Upstream Region (FURIN), host proteins critical for SARS-CoV-2 infection, in mice and in vitro. A subset of human lungs with SARS-CoV-2 infection overexpress RUNX1. These data suggest that RUNX1 inhibition via repurposing of Ro24-7429 may be beneficial for PF and to battle SARS-CoV-2, by reducing expression of viral mediators and by preventing respiratory complications.


Assuntos
Enzima de Conversão de Angiotensina 2/metabolismo , COVID-19/metabolismo , Subunidade alfa 2 de Fator de Ligação ao Core/antagonistas & inibidores , Furina/metabolismo , Pulmão/efeitos dos fármacos , Fibrose Pulmonar/tratamento farmacológico , Animais , Bleomicina , Células Cultivadas , Modelos Animais de Doenças , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Feminino , Pulmão/metabolismo , Pulmão/patologia , Masculino , Camundongos , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/patologia , Resultado do Tratamento
6.
BMC Cancer ; 22(1): 498, 2022 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-35513790

RESUMO

Tubulin alpha-1c chain (TUBA1C), a subtype of α-tubulin, has been shown to be involved in cell proliferation and cell cycle progression in several cancers and to influence cancer development and prognosis. However, a pancancer analysis of TUBA1C to reveal its immunological and prognostic roles has not been performed. In this study, we first downloaded raw data on TUBA1C expression in cancers from The Cancer Genome Atlas (TCGA) database and multiple other databases and analysed these data with R software to investigate the prognostic and immunological value of TUBA1C in cancers. Immunohistochemical analysis was performed in gliomas to further validate our findings. Overall, TUBA1C was overexpressed in most cancers, and overexpression of TUBA1C was linked to poor prognosis and higher tumour grade in patients. In addition, TUBA1C expression was associated with tumour mutation burden (TMB), microsatellite instability (MSI), the tumour microenvironment (TME) and the infiltration of immune cells. TUBA1C was also coexpressed with most immune-related genes and influenced immune-related pathways. Immunohistochemical analysis showed that TUBA1C expression was highest in glioblastoma (GBM) tissues, second highest in low-grade glioma (LGG) tissues and lowest in normal tissues. Our study indicated that TUBA1C might be a biomarker for predicting the immune status and prognosis of cancers, offering new ideas for cancer treatment.


Assuntos
Glioma , Tubulina (Proteína) , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinogênese , Glioma/patologia , Humanos , Prognóstico , Tubulina (Proteína)/genética , Microambiente Tumoral/genética
7.
Environ Res ; 208: 112672, 2022 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-34999028

RESUMO

Regional transport is a key source of carbonaceous aerosol in many Chinese megacities including Beijing. The sources of carbonaceous aerosol in urban areas have been studied extensively but are poorly known in upwind rural areas. This work aims to quantify the contributions of fossil and non-fossil fuel emissions to carbonaceous aerosols at a rural site in North China Plain in winter 2016. We integrated online high resolution-time of flight-aerosol mass spectrometer (HR-TOF-AMS) observations and radiocarbon (14C) measurements of fine particles with Positive Matrix Factorization (PMF) analysis as well as Extended Gelencsér (EG) method. We found that fine particle concentration is much higher at the rural site than in Beijing during the campaign (Dec 7, 2016 to Jan 8, 2017). PMF analysis of the AMS data showed that coal-combustion related organic aerosol (CCOA + Oxidized CCOA) and more oxidized oxygenated organic aerosol (MO-OOA) contributed 48% and 30% of organic matter to non-refractory PM1 (NR-PM1) mass. About 2/3 of the OC and EC were from fossil-fuel combustion. The EG method, combining AMS-PMF and 14C data, showed that primary and secondary OC from fossil fuel contribute 35% and 22% to total carbon (TC), coal combustion emission dominates the fossil fuel sources, and biomass burning accounted for 21% of carbonaceous aerosol. In summary, our results confirm that fossil fuel combustion was the dominant source of carbonaceous aerosol during heavy pollution events in the rural areas. Significant emissions of solid fuel carbonaceous aerosols at rural areas can affect air quality in downwind cities such as Beijing and Tianjin, highlighting the benefits of energy transition from solid fuels to cleaner energy in rural areas.


Assuntos
Poluentes Atmosféricos , Material Particulado , Aerossóis/análise , Poluentes Atmosféricos/análise , Carbono/análise , China , Monitoramento Ambiental/métodos , Combustíveis Fósseis , Fósseis , Material Particulado/análise , Estações do Ano
8.
Int J Mol Sci ; 23(18)2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36142734

RESUMO

Malignant tumors are always a critical threat to human health, with complex pathogenesis, numerous causative factors, and poor prognosis. The features of cancers, such as gene mutations, epigenetic alterations, and the activation and inhibition of signaling pathways in the organism, play important roles in tumorigenesis and prognosis. MicroRNA (miRNA) enables the control of various molecular mechanisms and plays a variety of roles in human cancers, such as radiation sensitivity and tumor immunity, through the regulation of target genes. MiR-149-5p participates in the process and is closely related to lipogenesis, the migration of vascular endothelial cells, and the expression of stem-cell-related proteins. In recent years, its role in cancer has dramatically increased. In this review, we summarize the regular physiological roles of miRNAs, specifically miR-149-5p, in the organism and discuss the tumor-suppressive or oncogenic roles of miR-149-5p in different human cancers with respect to signaling pathways involved in regulation. Possible clinical applications of miR-149-5p in future targeted therapies and prognosis improvement in oncology are suggested.


Assuntos
Células Endoteliais , MicroRNAs , Carcinogênese/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Células Endoteliais/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Oncogenes
9.
J Med Internet Res ; 23(8): e29328, 2021 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-34435957

RESUMO

BACKGROUND: Previous studies have shown promising results in identifying individuals with autism spectrum disorder (ASD) by applying machine learning (ML) to eye-tracking data collected while participants viewed varying images (ie, pictures, videos, and web pages). Although gaze behavior is known to differ between face-to-face interaction and image-viewing tasks, no study has investigated whether eye-tracking data from face-to-face conversations can also accurately identify individuals with ASD. OBJECTIVE: The objective of this study was to examine whether eye-tracking data from face-to-face conversations could classify children with ASD and typical development (TD). We further investigated whether combining features on visual fixation and length of conversation would achieve better classification performance. METHODS: Eye tracking was performed on children with ASD and TD while they were engaged in face-to-face conversations (including 4 conversational sessions) with an interviewer. By implementing forward feature selection, four ML classifiers were used to determine the maximum classification accuracy and the corresponding features: support vector machine (SVM), linear discriminant analysis, decision tree, and random forest. RESULTS: A maximum classification accuracy of 92.31% was achieved with the SVM classifier by combining features on both visual fixation and session length. The classification accuracy of combined features was higher than that obtained using visual fixation features (maximum classification accuracy 84.62%) or session length (maximum classification accuracy 84.62%) alone. CONCLUSIONS: Eye-tracking data from face-to-face conversations could accurately classify children with ASD and TD, suggesting that ASD might be objectively screened in everyday social interactions. However, these results will need to be validated with a larger sample of individuals with ASD (varying in severity and balanced sex ratio) using data collected from different modalities (eg, eye tracking, kinematic, electroencephalogram, and neuroimaging). In addition, individuals with other clinical conditions (eg, developmental delay and attention deficit hyperactivity disorder) should be included in similar ML studies for detecting ASD.


Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Transtorno do Espectro Autista/diagnóstico , Criança , Tecnologia de Rastreamento Ocular , Fixação Ocular , Humanos , Aprendizado de Máquina
10.
Ergonomics ; 64(8): 995-1001, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33663344

RESUMO

Accidental falls often occur during gait initiation. Excess body weight has been identified as a risk factor for accidental falls. This study aimed to examine the differences of gait initiation between overweight and normal-weight individuals. Fourteen overweight and 14 normal-weight young adults participated in the study. They were instructed to perform the gait initiation task under single-task and dual-task conditions. Dependent variables for the assessment of gait initiation included spatial-temporal measures and postural stability measures. The results showed that overweight could compromise postural stability during gait initiation, primarily by decreasing margin of stability in the anterior-posterior direction. Cognitive task interference with gait initiation was found to be similar between the overweight and normal weight groups. The findings from the present study can aid in better understanding the mechanisms associated with increased fall risks among overweight individuals. They also highlight the importance of overweight control in fall prevention. Practitioner summary: Overweight was found to compromise postural stability during gait initiation, primarily by decreasing margin of stability in the anterior-posterior direction. The findings highlight the importance of overweight control in fall prevention. Abbreviations: ANOVA: analyses of variance; AP: anterior-posterior; APA: anticipatory postural adjustment; BOS: base of support; BW: Body weight; COM: centre-of-mass; COP: center-of-pressure; CT: cognitive task; GI: Gait initiation; GRF: ground reaction force; HC: heel-contact; HO: heel-off; ML: medial-lateral; MOS: margin of stability; SD: standard deviation; SE: step execution; SL: step length; SW: step width; VEL_COM: velocity of the COM; XCOM: extrapolated center of mass.


Assuntos
Marcha , Equilíbrio Postural , Acidentes por Quedas , Cognição , Humanos , Sobrepeso , Adulto Jovem
11.
Opt Lett ; 45(14): 4028-4031, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32667346

RESUMO

In this Letter, we present single-pixel spiral phase contrast imaging that enables optical edge detection of both amplitude and phase objects. This technique utilizes single-pixel detection to directly acquire the Fourier spectrum of the edge-enhanced object by scanning spiral phase-encoded plane waves in k-space. Experimentally, we exploit a digital micromirror device to simultaneously generate the plane wave and reference field for illuminating the object and scan the plane wave for spectrum sampling. During the process, four-step phase-shifting is adopted, and synchronized intensity measurements are made with a single-pixel detector. Applying an inverse Fourier transform to the obtained spectrum directly yields the edge information of objects. As a demonstration, digital and real objects are imaged, and results verify that isotropic edge detection can be achieved with our technique for both amplitude and phase objects.

12.
Int J Sports Med ; 41(4): 255-263, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31935773

RESUMO

Basketball activity classification can help document players' statistics, allow coaches, trainers and the medical team to quantitatively supervise players' physical exertion and optimize training strategy, and further help prevent potential injuries. Traditionally, sports activity classification was done by manual notational, or through multi-camera systems or motion sensing technology. These methods were often erroneous and limited by space. This study presents a basketball activity classification model based on Dynamic Time Warping (DTW) and body kinematic measures. Twenty participants, including 10 experienced players and 10 novice players, were involved in an experimental study. The experienced and novice players differed in their years of playing basketball. Four basketball movements, including shooting, passing, dribbling, and lay-up were classified by kinematic measures. The results indicate that the proposed model can successfully classify different basketball movements with high accuracy and efficiency. Specifically, with the resultant acceleration of the hand, this model can achieve classification precision, recall, and specificity up to 0.984, 0.983 and 0.994, respectively. Findings from this study supported the feasibility of using DTW in real-time sports activity classification and provided insights into the optimal sensor placement for basketball activity classification applications.


Assuntos
Basquetebol/fisiologia , Aprendizado de Máquina , Aceleração , Basquetebol/classificação , Fenômenos Biomecânicos , Antebraço/fisiologia , Mãos/fisiologia , Humanos , Masculino , Movimento , Reprodutibilidade dos Testes , Ombro/fisiologia , Estudos de Tempo e Movimento , Adulto Jovem
13.
Hum Factors ; 62(6): 919-927, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-31385721

RESUMO

OBJECTIVE: The objective was to examine how physical fatigue and mental fatigue affected balance recovery from unexpected trips. BACKGROUND: Trips are the leading cause for occupational falls that are a multifactorial problem. Recognizing risk factors is the first step in accident control. Fatigue is one of the most common task-related risk factors for occupational falls. Fatigue typically can be divided into physical fatigue and mental fatigue, both of which are common in occupational settings. METHOD: One hundred eight young volunteers participated in the experiment. They were evenly divided into three groups: no fatigue group, physical fatigue group, and mental fatigue group. Each participant performed four walking trials on a linear walkway at their self-selected normal speed. The first three trials were normal walking trials. A trip was induced to participants in the fourth walking trial using a metal pole. Balance recovery from unexpected trips was characterized by trunk flexion and first recovery step measures. RESULTS: Recovery step length was smaller and maximum trunk flexion became larger in the mental fatigue group compared with those in the no fatigue group. Physical fatigue did not significantly affect trunk flexion and first recovery step measures. CONCLUSION: Mental fatigue increased the likelihood of loss of balance. Thus, mental fatigue could be a risk factor for trips and falls. To prevent trip-related falls, interventions should be adopted to prevent prolonged exposures to cognitively demanding activities in occupational settings.


Assuntos
Equilíbrio Postural , Caminhada , Acidentes por Quedas , Fenômenos Biomecânicos , Humanos , Amplitude de Movimento Articular
14.
Opt Express ; 26(2): 1796-1808, 2018 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-29402048

RESUMO

Shaping complex fields with a digital micromirror device (DMD) has attracted much attention recently due to its potential application in optical communication and microscopy. In this paper, we present an optimized Lee method to achieve dynamic shaping of orbital-angular-momentum (OAM) beams using a binary DMD. An error diffusion algorithm is introduced to enhance the accuracy for binary-amplitude hologram design, making it possible to achieve high fidelity wavefront shaping while retaining a high resolution. As a proof of concept, we apply this method to create different classes of OAM beams. The numerical simulations verify that a fidelity of F > 0.985 can be achieved for all the test OAM fields with fully independent phase and amplitude modulation. Moreover, we experimentally demonstrate the dynamic shaping of different OAM beams including pure modes and mixed modes with a switching rate of up to 17.8 kHz. On this basis, accurate information encoding into the generated multiplexed OAM beams is accomplished, which provides access to high speed classical and quantum communications that employ spatial mode encoding.

15.
Opt Lett ; 43(22): 5677-5680, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30439926

RESUMO

Optical spin-orbit interaction has gained much interest recently due to its universality and importance in modern photonics. In this Letter, we theoretically demonstrate that orbit-induced localized spin angular momentum (SAM) conversion can occur in the tight focusing of spin-free linearly polarized vortex beams (LPVBs). By analysis of the polarization states that are associated with the SAM density, we attribute the occurrence of such a conversion to the helical-phase-induced change of local polarization states in the focused field. In the local SAM, density can be further regulated by altering the sign and value of the orbital angular momentum in the incident LPVBs, as well as their polarization orientations. This Letter is expected to advance our understanding of optical spin-orbit coupling and benefit applications of optical microscopy and trapping.

16.
Sensors (Basel) ; 18(2)2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29389857

RESUMO

Postural control is a complex skill based on the interaction of dynamic sensorimotor processes, and can be challenging for people with deficits in sensory functions. The foot plantar center of pressure (COP) has often been used for quantitative assessment of postural control. Previously, the foot plantar COP was mainly measured by force plates or complicated and expensive insole-based measurement systems. Although some low-cost instrumented insoles have been developed, their ability to accurately estimate the foot plantar COP trajectory was not robust. In this study, a novel individual-specific nonlinear model was proposed to estimate the foot plantar COP trajectories with an instrumented insole based on low-cost force sensitive resistors (FSRs). The model coefficients were determined by a least square error approximation algorithm. Model validation was carried out by comparing the estimated COP data with the reference data in a variety of postural control assessment tasks. We also compared our data with the COP trajectories estimated by the previously well accepted weighted mean approach. Comparing with the reference measurements, the average root mean square errors of the COP trajectories of both feet were 2.23 mm (±0.64) (left foot) and 2.72 mm (±0.83) (right foot) along the medial-lateral direction, and 9.17 mm (±1.98) (left foot) and 11.19 mm (±2.98) (right foot) along the anterior-posterior direction. The results are superior to those reported in previous relevant studies, and demonstrate that our proposed approach can be used for accurate foot plantar COP trajectory estimation. This study could provide an inexpensive solution to fall risk assessment in home settings or community healthcare center for the elderly. It has the potential to help prevent future falls in the elderly.


Assuntos
Pé/fisiologia , Dispositivos Eletrônicos Vestíveis/economia , Dispositivos Eletrônicos Vestíveis/normas , Fenômenos Biomecânicos , Humanos , Dinâmica não Linear , Pressão , Sapatos
17.
J Appl Biomech ; 34(3): 205-210, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29364038

RESUMO

The objective of this study was to examine the effects of subsensory noise and fatigue on knee biomechanics during the athletic task of landing followed by cross-over cutting. A total of 32 healthy male athletes participated in the study. They were evenly divided into 2 groups: no fatigue group and fatigue group. Fatigue was induced to the lower extremity by a repetitive squatting exercise in the fatigue group. Subsensory noise was generated by linear miniature vibrators bilaterally placed around the knee joints. During data collection, the participants were instructed to perform landing followed by cross-over cutting in both the subsensory on and off conditions. Dependent variables were selected to assess knee biomechanics in the phases of landing and cross-over cutting, separately. Results showed that fatigue resulted in larger knee flexion during landing and larger knee internal rotation during cross-over cutting. Subsensory noise was found to reduce knee rotation impulse during cross-over cutting. These findings suggest that cross-over cutting is more dangerous than landing in the fatigue condition, and subsensory noise may lead to changes in knee biomechanics consistent with reduced risk of anterior cruciate ligament injuries, but the changes may be task-specific.


Assuntos
Joelho/fisiologia , Movimento , Fadiga Muscular , Adulto , Lesões do Ligamento Cruzado Anterior , Atletas , Fenômenos Biomecânicos , Humanos , Masculino , Fatores de Risco , Rotação , Adulto Jovem
18.
Biomed Eng Online ; 15(1): 61, 2016 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-27251528

RESUMO

Pre-impact fall detection has been proposed to be an effective fall prevention strategy. In particular, it can help activate on-demand fall injury prevention systems (e.g. inflatable hip protectors) prior to fall impacts, and thus directly prevent the fall-related physical injuries. This paper gave a systematical review on pre-impact fall detection, and focused on the following aspects of the existing pre-impact fall detection research: fall detection apparatus, fall detection indicators, fall detection algorithms, and types of falls for fall detection evaluation. In addition, the performance of the existing pre-impact fall detection solutions were also reviewed and reported in terms of their sensitivity, specificity, and detection/lead time. This review also summarized the limitations in the existing pre-impact fall detection research, and proposed future research directions in this field.


Assuntos
Acidentes por Quedas , Monitorização Ambulatorial/métodos , Algoritmos , Humanos , Fenômenos Mecânicos , Fatores de Tempo
19.
Opt Express ; 23(19): 24108-19, 2015 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-26406617

RESUMO

In optical tweezers, a piezo-stage (PZT) is widely used to precisely position samples for force clamp, calibrating optical trap and stretching DNA. For a trapped bead in solution, the oscillation response of PZT is vital for all kinds of applications. A coupling ratio, actual amplitude to nominal amplitude, can be calibrated by power spectral density during sinusoidal oscillations. With oscillation frequency increasing, coupling ratio decreases in both x- and y-directions, which is also confirmed by the calibration with light scattering of scanning two aligned beads on slide. Those oscillation responses are related with deformability of chamber and the intrinsic characteristics of PZT. If we take nominal amplitude as actual amplitude for sinusoidal oscillations at 50 Hz, the amplitude is overestimated ~2 times in x-direction and ~3 times in y-direction. That will lead to huge errors for subsequent calibrations.

20.
Heliyon ; 10(6): e28089, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38533063

RESUMO

Procollagen c-protease enhancer protein (PCOLCE) performs an essential action in improving the recreation of procollagen c-protease and promoting the reconstruction of extracellular matrix. High PCOLCE expression was associated with a negative prognosis of stomach cancer, ovarian cancer, and osteosarcoma. The goal of this work is to investigate the function of PCOLCE in glioma. Multiple bioinformatics techniques have been employed to investigate the roles of PCOLCE in glioma, consisting of the correlation between PCOLCE and prognosis, immune checkpoints, immune cell infiltrates, and tumor microenvironment (TME). The gene ontology (GO) annotations and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were used to assess the potential function of PCOLCE in glioma. PCOLCE was found to be increased in glioma. We revealed that PCOLCE was a potential prognostic factor and related to tumor grade. Up-regulated PCOLCE was related to poor prognosis in lower-grade glioma (LGG), glioblastoma multiforme (GBM), and recurrent glioma. PCOLCE was correlated with immune cell infiltration, particularly B cells, CD4+ T cells, macrophages, neutrophils, and dendritic cells (DCs) in LGG, and DCs infiltration in GBM. PCOLCE was co-expressed with many genes related to the immune and the immune checkpoint. In addition, glioma patients with low expression of PCOLCE had a higher response to the immunological checkpoint blockade (ICB). Additionally, PCOLCE may exert its roles via several immune-related biological processes or pathways, such as leukocyte migration, activation of T cells, adaptive immune response, neutrophil-mediated immunity, NF-κB, and TNF signaling pathways. In conclusion, PCOLCE may be a new immune-related gene and regulate tumor development through immunological pathways.

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