Different Body Partialization Procedures Considering Maximum Strength and Explosiveness: Factorial Analysis Approach

SUMMARY: The aim of this study was to determine the sensitivity of different methods of partialization, in terms of different body component indices in relation to indicators of strength and explosiveness. The research involved 187 subjects who were divided into two groups based on sex. This research consisted of measuring body composition characteristics by multichannel bioimpedance analysis (BIA) InBody 720, as well as contractile characteristics of different muscle groups with tenziometric Dinamometry method. Based on the results of the factor analysis we found that regardless of the sex the most sensitive variable for partialization of absolute body isometric strength variable (ABiS) is partialization by allometric scaling (0.964 for females and 0.947 for males explained factor variance). However, in the case of absolute body isometric explosiveness (ABiE), the results of this study have demonstrated that partialization relative to skeletal muscle mass according to the body longitudinality - skeletal muscle mass index (SMMI) is the methodological choice disregarding the sex (0.982 for females and 0.980 for males explained factor variance). The results of the study have shown that for the purpose of scaling the maximal strength relative to body composition, the allometric method can be considered as a choice, while for the partialization of maximal isometric explosiveness skeletal muscle mass index is the best choice insensitive of the sex.

El objetivo de este estudio fue determinar la sensibilidad de distintos métodos de parcialización, en términos de diferentes índices de componentes corporales en relación a los indicadores de fuerza y explosividad. En la investigación participaron 187 sujetos que se dividieron según el sexo en dos grupos. Esta investigación consistió en medir las características de composición corporal mediante análisis de bioimpedancia multicanal (BIA) InBody 720, así como las características contráctiles de diferentes grupos musculares con el método de Dinamometría tenciométrica. Con base en los resultados del análisis factorial, encontramos que, independientemente del sexo, la variable más sensible para la parcialización de la variable de fuerza isométrica corporal absoluta (ABiS) fue la parcialización mediante escala alométrica (0,964 para las mujeres y 0,947 para los hombres). Sin embargo, en el caso de la explosividad isométrica corporal absoluta (ABiE), los resultados de este estudio han demostrado que la parcialización relativa a la masa del músculo esquelético según la longitudinalidad del cuerpo - índice de masa del músculo esquelético (SMMI) es la opción metodológica sin tener en cuenta el sexo (0,982 para las mujeres y 0,980 para los hombres). Los resultados del estudio han demostrado que para escalar la fuerza máxima en relación con la composición corporal, el método alométrico puede considerarse como una opción, mientras que para la parcialización de la explosividad isométrica máxima, el índice de masa del músculo esquelético es la mejor opción independiente del sexo.

Risk Factors for Postoperative Sore Throat in Patients with a Double-lumen Endotracheal Tube / 中山大学学报(医学科学版)

ObjectiveTo investigate risk factors for postoperative sore throat in patients with double-lumen endotracheal intubation. MethodsThe data used in this post-hoc analysis were prospectively collected from a randomized， controlled trial. Age from 18 to 65 years old， ASAI-Ⅲ patients undergoing general anesthesia with a double-lumen endotracheal tube were enrolled. The perioperative data collected retrospectively were as follows： gender， age， smoking history， endotracheal tube diameter， duration of endotracheal tube， dose of Sufentanil， use of Flurbiprofen Axetil， cough after extubation， etc..Dynamometer was applied to assess extubation force. According to occurrence of postoperative sore throat， patients were divided into two groups： those who experienced sore throats and those who did not. Comparative analysis and multivariate logistic regression analysis were performed to screen the risk factors. ROC curve was used for predicting the predictive value of risk factors. ResultsAmong the 163 patients ， 74 （45.4%） had postoperative sore throat vs 89 （54.6%） not had. Multivariate logistic regression showed female ［OR95%CI=3.83（1.73， 8.50）， P=0.000 1］ and extubation force ［OR95%CI=1.78（1.45， 2.17）， P＜0.001］ were independent risk factors for postoperative sore throat. AUC value showed the extubation force was 0.773［95%CI（0.701， 0.846）， P＜0.001］. Youden index was 0.447， and the cut-off valve of extubation force was 13N. ConclusionFemale and extubation force were risk factors for sore throat in patients with double lumen endotracheal intubation.

Exploring Scientific Connotation of "Fried Charcoal Survivability" of Lonicerae Japonicae Flos Based on Color-composition Correlation / 中国实验方剂学杂志

ObjectiveTo explore the scientific connotation of fried charcoal survivability of Lonicerae Japonicae Flos（LJF） by analyzing the correlation between the color change and the intrinsic components during the processing of LJF Carbonisata（LJFC）， and taking pH， charcoal adsorption and microscopic characteristics as indexes. MethodLJFC samples with different degrees of processing were prepared according to the stir-frying time of 0.0， 1.5， 3.0， 4.5， 6.0， 7.5， 9.0， 10.5 min（numbered S1-S8）， and the contents of gallic acid， chlorogenic acid， cryptochlorogenic acid， rutin， luteoloside， isochlorogenic acid A and isochlorogenic acid C were determined by high performance liquid chromatography（HPLC）， and the L*（brightness）， a*（red-greenness） and b*（yellow-blueness） of LJFC samples with different degrees of processing were determined by spectrophotometer， and the correlation analysis and principal component analysis（PCA） between the contents of seven representative components and the color of the samples were carried out by SPSS 26. 0 and SIMCA-P 14.1. Then pH， adsorption force and characteristic structure of different samples of LJFC were detected and the processing pattern of LJFC was analyzed. ResultThe results of quantitative analysis revealed that the contents of luteoloside， rutin， chlorogenic acid and isochlorogenic acid A gradually decreased， and the contents of cryptochlorogenic acid， isochlorogenic acid C and gallic acid firstly increased and then decreased. The L* and b* of the sample powders decreased， and a* showed a trend of increasing and then decreasing. The L* and b* were positively correlated with the contents of chlorogenic acid， rutin， luteoloside， isochlorogenic acid A， b* was positively correlated with the content of gallic acid， and a* was positively correlated with the contents of cryptochlorogenic acid and isochlorogenic acid C. PCA revealed that samples could be clearly divided into 3 groups， S1-S2 as one group， S3-S5 as one group， and S6-S8 as one group， with S3 having the highest score. The results of regression analysis showed that only isochlorogenic acid C could be used to predict the contents of components by colorimetric values combined with regression equations. Physicochemical analysis showed that pH of LJFC increased with the increase of degree of charcoal stir-frying， while adsorption force showed a tendency of increasing and then decreasing， with the highest adsorption force in the S5 sample， and the non-glandular hairs， calcium oxalate clusters and pollen grains had a varying degree of decreasing with the deepening of processing degree， and the microstructures of S6-S8 samples were obviously charred with pollen grains almost invisible. ConclusionThe changes in chemical composition and color characteristics of LJFC during the processing have certain correlations， combined with the changes in physicochemical properties， S5 sample is found to be the optimal processed products， which can provide a reference for the processing standardization and quality evaluation of LJFC， and enrich the scientific connotation of fried charcoal survivability of LJF.

Assessment the retentive force and XRD analysis on the recycling esthetic thermoplastic acetal clasps / Avaliação da força de retenção e análise de DRX dos grampos de resina estética termoplástica acetal reciclada

Objective: To reduce environmental biohazards, technicians should be educated with safe biological waste disposal procedures and dental material recycling. The present study assesses the retentive force, deformation test and XRD analysis of re-injection acetal resin clasps. Material and Methods: specimens were prepared for clasp retention test injection according to the manufacture's instruction for acetal resin. The first group represent control group with (100% New) and other five groups as experimental groups (group II (25% old +75% new), group III (50% old + 50%) new, and group IV (75% old + 25% new) with different percentages between new acetal materials and old acetal materials, while two last groups with several times (group V (100% old) and group VI (re-injection two times)) only used old acetal materials. The X-ray diffraction (XRD) device used to give structural information for the materials to be tested. The study data were analyzed via One-way ANOVA (LSD) at a significant P-value of (p≤0.05) and a confidence level of 95%. Results: After comparing the results, a significant improvement in the retentive force of acetal clasp specimens after re-injection two times there was found high mean value in group re-injection two times and lower mean value recorded in control group. In XRD patterns of there was no diffraction peak refers to crystal structure of acetal resin. Conclusion: the present study findings concluded that the recycling of acetal resin enhanced the retentive force of acetal clasp and not affected on the crystal structures of material(AU)

Objetivo: Para reduzir os riscos biológicos ambientais, os técnicos devem ser educados com procedimentos seguros de eliminação de resíduos biológicos e reciclagem de material dentário. O presente estudo avalia a força de retenção, teste de deformação e análise de DRX de grampos de resina acetal reinjetada. Material e Métodos: as amostras foram preparadas para o teste de retenção dos grampos e a injeção realizada de acordo com as instruções do fabricante para resina de acetal. O primeiro grupo representa o grupo controle com (100% novo) e os outros cinco grupos como grupos experimentais (grupo II (25% antigo + 75% novo), grupo III (50% antigo + 50% novo) e grupo IV (75% antigo + 25% novo) com porcentagens diferentes entre materiais de acetal novos e antigos, enquanto os dois últimos grupos (grupo V (100% antigo) e grupo VI (reinjeção duas vezes)) utilizaram apenas materiais de acetal antigos. O dispositivo de difração de raios X (DRX) foi utilizado para fornecer informações estruturais dos materiais a testados. Os dados do estudo foram analisados por ANOVA um fator (LSD) com um valor P significativo de (p≤0,05) e um nível de confiança de 95%. Resultados: Após a comparação dos resultados, foi encontrada uma melhora significativa na força de retenção das amostras de grampo de acetal após duas reinjeções, além disso, foi registrado um maior valor médio no grupo reinjeção duas vezes e menor valor médio no grupo controle. Nos padrões de DRX não houve pico de difração referente à estrutura cristalina da resina acetal. Conclusão: os resultados do presente estudo concluíram que a reciclagem da resina de acetal aumentou a força retentiva do grampo e não afetou as estruturas cristalinas do material(AU)

Antimicrobial activity of Er, Cr: YSGG and Ultrasonic on E. faecalisbiofilm in the mesial root canal systems of lower molars / Atividade antimicrobiana de Er, Cr: YSGG e Ultrassônico no biofilme de E. faecalis nos sistemas de canais radiculares mesiais de molares inferiores

The internal topography of the root canal is complex, especially for the permanent molar's mesial root. In response to such issues, improved irrigation techniques have been created, which use laser pulses to agitate fluids and improve microbial deposit removal. Objective: To assess the effectiveness of the Er,Cr:YSGG laser with a wavelength of 2,780 nm via photon-induced photoacoustic streaming (PIPS) protocol which agitated of 2% chlorohexidine (CHX) in removing mature Enterococcus faecalis (E. faecalis) biofilm in root canal systems of lower molars. Material and Methods: The mesial roots of lower first and second molars were separated and inoculated with E. faecalis bacterial suspension for 30 days. The roots were irrigated with CHX, some of them were agitated with a passive ultrasonic device (PUI), while the other roots were agitated by an Er,Cr:YSGG laser in PIPS at 60 µs/pulse, 5 Hz, (0.25, 0.5, 0.75, and 1) W. An atomic force microscope (AFM) was used as a new method to get the results in the isthmus area; the obtained results from each group were compared with each other. Results: Based on the AFM and SEM analyses, laser and ultrasonic activation groups showed higher antimicrobial efficacy than the conventional syringe irrigation group (P<0.05). Conclusion: Based on the investigation's findings, the activation of 2% CHX solution by Er,Cr:YSGG laser in PIPS and PUI offers better mature bacterial biofilm removal in the mesial root of lower human molars than the same irrigant with the SI technique (AU)

A topografia interna do canal radicular é complexa, especialmente para a raiz mesial do molar permanente. Em resposta a esses problemas, foram criadas técnicas aprimoradas de irrigação, que utilizam pulsos de laser para agitar fluidos e melhorar a remoção de depósitos microbianos. Objetivo: Avaliar a eficácia do laser Er,Cr:YSGG com comprimento de onda de 2.780 nm via protocolo de streaming fotoacústico induzido por fótons (PIPS) que agitou clorohexidina a 2% (CHX) na remoção de Enterococcus faecalis maduro (E. faecalis) biofilme em sistemas de canais radiculares de molares inferiores. Material e Métodos: As raízes mesiais de 28 primeiros e segundos molares inferiores foram separadas e inoculadas com suspensão bacteriana de E. faecalis por 30 dias. As raízes foram irrigadas com CHX, sendo algumas delas agitadas com aparelho ultrassônico passivo (PUI), enquanto as demais raízes foram agitadas com laser Er,Cr:YSGG em PIPS a 60 µs/pulso, 5 Hz (0,25, 0,5, 0,75 e 1) W. Um microscópio de força atômica (AFM) foi utilizado como um novo método para obter os resultados na área do istmo; os resultados obtidos de cada grupo foram comparados entre si. Resultados: Com base nas análises de AFM e SEM, os grupos de ativação por laser e ultrassom apresentaram maior eficácia antimicrobiana do que o grupo de irrigação com seringa convencional (P<0.05). Conclusão: Com base nos achados da investigação, a ativação da solução de CHX a 2% pelo laser Er,Cr:YSGG em PIPS a (60 µs/pulso, 5 Hz, 0,75 W) oferece melhor remoção de biofilme (AU)

Relationship between bite force, occlusal contact area, and three-dimensional facial soft tissue in dentofacial deformities

ABSTRACT Purpose This study aimed to investigate three-dimensional facial soft tissue dimensions, maximum bite force (MBF), and occlusal contact area in patients with DFD. In addition, we analyzed the relationship between MBF and the three-dimensional facial measurements. Methods Thirty-two patients with skeletal Class III DFD and 20 patients with Class II DFD underwent a soft tissue evaluation using surface laser scanning, as well as MBF and occlusal contact area assessments. The DFD groups were compared with each other and with 25 healthy subjects. Results Significant morphological differences were found in the transversal, vertical, and anteroposterior dimensions between Class II DFD and Class III DFD. Both DFD groups presented an increased linear distance of chin height, which was strongly related with decreased MBF magnitude. The DFD groups exhibited lower MBF and occlusal contact area, with no significant differences between Class II and Class III DFD. Conclusion The presence of DFD affected 3D measurements of facial soft tissue, causing variations beyond normal limits, lower MBF, and occlusal contact area in both Class II and Class III DFD patients. The vertical dimension might have influenced the lower MBF magnitude in the studied skeletal deformities.

Relationship between mastication and malnutrition in community-dwelling older adults: a meta-analysis

ABSTRACT Purpose To determine the relationship between mastication and malnutrition in community-dwelling older adults. Research strategies To establish the eligibility criteria, the acronym PECOS was used: Population: non-institutionalized older adults; Exposure: older adults with malnutrition; Control: older adults without malnutrition; Outcome: masticatory problems in malnourished older adults; Study types: observational studies. Selection criteria It selected studies assessing malnutrition and mastication difficulties in non-institutionalized adults over 60 years old, of both sexes. Mastication and malnutrition were evaluated with questionnaires on self-reported symptoms and clinical and instrumental assessments. There were no restrictions on language, year of publication, or ethnicity. Data analysis The included studies were evaluated for methodological quality with the Joanna Briggs Institute tool for cross-sectional studies. For the cross-sectional studies included, the odds ratio (OR) was calculated with 95% confidence intervals. Results After searching the databases, 692 references were retrieved, with three studies selected for quantitative and qualitative analysis. The values obtained in the meta-analysis for association show that malnutrition and mastication difficulties were 2.21 times as likely to occur (OR = 2.21; 95%CI = 0.93 - 5.26; I2 = 94%) as individuals without malnutrition (p < 0.001). The assessment of the risk of bias presented a high-risk, a moderate-risk, and a low-risk study. The certainty of evidence was rated very low with the GRADE tool. Conclusion Individuals at risk of malnutrition are 2.21 times as likely to have mastication difficulties.

Análisis de Variables Antropométricas y su Relación con la Fuerza Pinch / Analysis of the Anthropometric Variables and their Relationship with the Pinch Force

Resumen: La evaluación de la fuerza en la mano es utilizada en ámbitos de salud y laborales, está compuesta por la fuerza de agarre y la fuerza de pellizco o fuerza pinch (Palmar Pinch - PP y Key Pinch - KP). La fuerza pinch ha sido poco estudiada y relacionada con variables antropométricas. El objetivo del presente trabajo fue determinar la relación entre la fuerza PP y KP con el género, la dominancia, la edad y variables antropométricas. Haciendo uso de un dinamómetro Jamar y con la participación de 681 sujetos (48,9 % F y 51.1 % M) aparentemente sanos de la Ciudad de Bogotá (Colombia), quienes desempeñaban diferentes actividades ocupacionales, se encontró que las fuerzas PP y KP fueron significativamente más altas en los hombres que en las mujeres tanto en la mano no dominante (8.27 Kgf Vs 6.0 Kgf) como en la mano dominante (8.57 Kgf Vs 6.27 Kgf). Se propusieron modelos predictivos que definieron como variables principales la edad, espesor, circunferencia y circunferencia máxima de la mano. En el género femenino se estableció como variable primordial la edad, mientras que en el masculino en dos modelos se define la circunferencia de la mano y en otros dos la circunferencia máxima de la mano.

Abstract: The evaluation of the force in the hand is used in health and labor fields; it is composed of the grip force and the pinch force (Palmar Pinch - PP and Key Pinch - KP). The pinch force has not had significant amount of studies and connections with anthropometric variables. This work aimed to determine the relationship between the PP and KP strength with gender, dominance, age, and anthropometric variables. Using a Jamar dynamometer and with the participation of 681 subjects apparently healthy (48.9 % F and 51.1 % M) from the City of Bogotá (Colombia), who performed different occupational activities, it was found that the PP and KP forces were significantly higher in men than in women both in the non-dominant hand (8.27 Kgf Vs. 6.0 Kgf) and in the dominant hand (8.57 Kgf Vs 6.27 Kgf). The predictive models proposed in this study defined age, thickness, circumference, and maximum circumference of the hand as the main variables. In the female gender, age was established as the primary variable. At the same time, in the male, the circumference of the hand was defined in two models, and the maximum circumference of the hand in another two.

Multiempleo en salud en provincia de Buenos Aires: estudio transversal de profesiones afectadas al cuidado de pacientes con COVID-19 / Multi-employment in health in the province of Buenos Aires: cross-sectional study of professions involved in COVID-19 patient care

RESUMEN INTRODUCCIÓN La pandemia de COVID-19 expuso el impacto del multiempleo en los servicios de salud. El objetivo de este estudio fue caracterizar el multiempleo en médicos y enfermeros que trabajaron en internación general y cuidados críticos durante la pandemia en la provincia de Buenos Aires. MÉTODOS Se realizó un estudio exploratorio, descriptivo y transversal. Los datos se recolectaron en el primer trimestre de 2021 con una encuesta estructurada anónima autoadministrada mediante muestreo no probabilístico en cadena. RESULTADOS El 96,3% de los médicos y el 68,1% de los enfermeros declararon estar multiempleados. La media de empleos fue 3,1 para médicos (entre 1 y 5) y 1,9 para enfermeros (entre 1 y 3). Los enfermeros declararon trabajos con mayor carga horaria, predominio del empleo público y contratación estable. Los médicos multiempleados manifestaron mayor diversidad en la forma de contratación. En ambas profesiones el multiempleo es motivado principalmente por razones de índole económica. DISCUSIÓN El multiempleo es difícil de medir mediante los registros oficiales. La proporción de multiempleo autorreportado en este estudio supera las cifras comunicadas por las estadísticas e informes oficiales. Aun así, las diferencias halladas entre médicos y enfermeros respecto al número de empleos son coincidentes con estudios previos. El problema del multiempleo requiere ser abordado desde la desprecarización del empleo, con mejoras en las condiciones económicas y de trabajo.

ABSTRACT INTRODUCTION The COVID-19 pandemic exposed the impact of multi-employment in health services. The objective of this study was to characterize multi-employment among physicians and nurses working in general hospitalization and critical care during the pandemic in the province of Buenos Aires. METHODS An exploratory, descriptive, cross-sectional study was conducted. Data were collected in the first quarter of 2021 with a structured anonymous self-administered survey using non-probabilistic chain sampling. RESULTS A total of 96.3% of physicians and 68.1% of nurses reported being multi-employed. The mean number of jobs was 3.1 for physicians (between 1 and 5) and 1.9 for nurses (between 1 and 3). Nurses reported having jobs with longer hours, mostly public and stable employment. Multi-employed physicians reported greater variety in the form of hiring. In both professions, multi-employment is mainly motivated by economic reasons. DISCUSSION Multi-employment is difficult to measure through official records. The proportion of self-reported multiemployment in this study exceeds the figures shown by official statistics and reports. The differences found between physicians and nurses regarding the number of jobs are still consistent with previous studies. The problem of multi-employment needs to be tackled by making employment less precarious, with improvements in economic and working conditions.

Effect of acupuncture on the molar bite force in women with chronic neck pain / Efecto de la acupuntura sobre la fuerza de mordida en mujeres con cervicalgia crónico

Objetive: To investigate the maximum molar bite force in women with chronic neck pain after treatment with acupuncture. Materials and Methods: Twenty-three women with chronic neck pain participated. Dynamometer was used to measure the right and left maximum molar bite force. Dong Bang acupuncture needles - 0.25 mm x 30 mm was inserted into the integumentary tissue. Treatment was 10 sessions, each 30 minutes long and twice a week. Results: The right (p = 0.01) and left (p = 0.004) molar bite force was assessed after treatment with acupuncture, and showed increased occlusal strength. Conclusions: This study suggests a functional improvement in the stomatognathic system in women with chronic cervical pain after treatment with acupuncture. However, it is important to note that further research is needed to fully elucidate the long-term effects and potential clinical implications of these findings in the field of pain management and rehabilitation.

Objetivo: Investigar la fuerza masticatoria máxima en mujeres con dolor crónico de cuello después del tratamiento con acupuntura. Materiales y Métodos: Participaron veintitrés mujeres con dolor crónico de cuello. Se utilizó un dinamómetro para medir la fuerza máxima de mordida del molar derecho e izquierdo. Agujas de acupuntura Dong Bang se insertaron 0,25 mm x 30 mm en el tejido tegumentario. El tratamiento fue de 10 sesiones, cada una de 30 minutos de duración, dos veces por semana. Resultados: Se observó la fuerza de mordida del molar derecho (p=0.01) e izquierdo (p=0.004) después del tratamiento con acupuntura, que mostró un aumento de la fuerza oclusal. Conclusión: Este estudio sugiere una mejora funcional en el sistema estomatognático en mujeres con dolor cervical crónico después del tratamiento con acupuntura. Sin embargo, es importante señalar que se necesita más investigación para dilucidar por completo los efectos a largo plazo y las posibles implicaciones clínicas de estos hallazgos en el campo del tratamiento y la rehabilitación del dolor.

Finite element analysis of 14-year-old adolescent after spinal foraminoplasty at L / 解剖学报

Objective To establish the three-dimensional finite element model of lumbar spine(L) 3-5 segments of the normal spine of 14-year-old adolescents to analyze the biomechanical changes of the lumbar spine after different degrees of lumbar foraminal plasty, and to provide reference for improvement of adolescent foraminoplasty. Methods A14-year-old female volunteer with no previous history of lumbar spine was selected to collect lumbar CT image data and we imported it into Mimics 16.0 software for modeling. ABAQUS software was used to conduct finite element model force analysis. Models M

A Review of the Analysis of Ground Reaction Force among Adults with Lower Limb Problems (Tinjauan Analisis Daya Tindak Balas Tanah di Kalangan Orang Dewasa dengan Masalah Anggota Bawah) / Jurnal Sains Kesihatan Malaysia

@#The ground reaction force (GRF) is the equal opposing load transfer from the body to the ground, also called vertical load transfer. The GRF would produce stress waves transmitted toward the lower extremities during the heel strike of a gait cycle. Too much force imposed on the lower extremities for an extended period will cause harmful effects such as injuries or alterations in gait. This article presents a review of the literature on GRF analysis among adults with lower limb problems where comparisons between healthy and unhealthy subjects were analyzed, focusing on the compensation in each lower limb. A literature search of published articles in Science Direct and PubMed databases from August 2015 to March 2021 was analyzed. The keywords used for the search were (plantar force OR vertical load transfer OR ground reaction force) AND (lower limb OR lower extremities OR leg OR foot) AND (impairment OR problem OR injury). The literature search identified 22 relevant studies which were screened independently by two reviewers. Lower limb problems such as unilateral transfemoral amputation, unilateral transtibial amputation, patellofemoral pain, anterior cruciate ligament injury, knee arthroplasty, knee osteoarthritis, diabetic foot, total hip replacement, pronated foot proved to alter the GRF significantly. Patients used to shift their weight on the opposite leg as compensation, which acts as a pain-free mechanism. This paper has provided sufficient understanding regarding GRF among adults with lower limb problems. The knowledge concerning compensation may help physical therapists implement the appropriate intervention for patients with lower limb problems.

One-year clinical observation of muscular force balance reconstruction technique for the correction of secondary nasal malformation after cleft lip surgery / 华西口腔医学杂志

OBJECTIVES@#The long-term effect of muscular force balance reconstruction technique combined with intranasal fixation for correcting secondary nasolabial deformity after unilateral cleft lip was evaluated. The aim was to provide a basis for further improving the surgical treatment effect of secondary nasolabial deformity of acleft lip.@*METHODS@#A total of 40 patients aged 4-28 years with secondary nasal deformity and unilateral cleft lip were selected as research subjects. The two-dimensional photo measurement analysis method was used in comparing the surgical results before and immediately after the operation (7 d) and 1 year after the operation.@*RESULTS@#Columellar angle, nostril height ratio (NHR), alar rim angle, alar rim angle ratio, and nostril shape (NS) increased dimmediately after the operation, whereas alar base width ratio (ABWR) and nostril width ratio decreased (NHR) immediately after the operation (P<0.01). The ABWR, NHR, and NS immediately after the operation were not significantly different from those 1 year after the operation (P>0.05).@*CONCLUSIONS@#Muscular force balance reconstruction technique combined with intranasal fixation is effective in the repair of unilateral secondary nasolabial deformity, and stable results can be obtained 1 year after surgery.

The Effects of Different Degrees of Leg Length Discrepancy on Vertical Ground Reaction Force in Children and Adults: Treatment Implications

@#Introduction: Previous studies on the degree of leg length discrepancy that causes limb biomechanical problems did not differentiate between adults and children. We conducted this study to determine the effects of simulated leg length discrepancy on vertical ground reaction force in children and adults to enable decision-making for intervention in patients with leg length discrepancy for different age groups or heights. Materials and methods: This cross-sectional study involved male volunteers of children 150cm and adults with 170cm in height. Vertical ground reaction force was measured using a gait analysis study. The first measurement was taken without any leg length discrepancy as a baseline. Subsequently, different amounts of leg length discrepancy were simulated on the left leg with shoe lifts of 2, 3, and 4cm. The measurements were repeated on each volunteer with similar shoe lifts on the right leg. Therefore, 14 volunteers provided simulations of 28 leg length discrepancies for each group. The first and second peaks of vertical ground reaction force were separately analysed. The vertical GRF of a simulated leg length discrepancy was compared with the baseline. Repeated measurement of analysis of variance (ANOVA) within each group was done. Results: In both groups, the second peak of vertical ground reaction force in the longer leg reduced gradually as the shoe lift increased sequentially from 2 to 3cm and then to 4cm. A discrepancy of 3cm and above was statistically significant to cause a reduction in the vertical GRF on the longer limb in both height groups. Conclusion: The degree of leg length discrepancy that caused significant changes in second peak ground reaction force in children with 150 and adults with 170cm height population was similar at 3cm. Therefore, the cut-off point for intervention for both groups are similar with additional consideration of future growth in children.

Analysis of Postural Control following Anterior Cruciate Ligament Reconstruction with Ipsilateral Peroneus Longus Tendon Graft

@#Introduction: Harvesting peroneus longus for ACL reconstruction is thought to create ankle instability which could add to postural instability from an ACL injury. This apprehension prevents its use as a graft of primary choice for many surgeons. To date, there is no evidence available describing changes in postural control after its use in ACL reconstruction. The purpose of the study was to analyse the changes in postural control in the form of static and dynamic body balance after ACL reconstruction with Peroneus Longus Tendon Graft and compare it with the unaffected limb at different time intervals. Materials and methods: Thirty-one participants with ACL injury were selected and subjected to an assessment of static and dynamic balance before and after ACL reconstruction using the HUMAC balance system. Outcome measures for Centre of Pressure (COP) assessment were average velocity, path length, stability score, and time on target. Comparison of scores was done pre-operatively as well as at three- and six-months post-reconstruction with Peroneus longus tendon graft. Results: Static balance of the affected limb showed significant improvement with a decrease in average velocity (F=4.522, p=0.026), path length (F=4.592: p=0.024) and improvement of stability score (F=8.283, p=0.001). Dynamic balance measured by the time on the target variable also showed significant improvement at six-month follow-up (F=10.497: p=0.000). There was no significant difference between the affected and non-affected limb when compared at the different time intervals. Conclusion: The static and dynamic balance, which is impaired after ACL injury, improves with ACL reconstruction with PLT autologous graft. Hence PLTG can be safely used as a graft for ACL reconstruction without affecting postural control and body balance.

Time-course changes of intraosseous environment and shear resistance mechanical properties of jawbone in SD rats with fluorosis / 环境与职业医学

Background At present, a large number of reports focus on the bones of limbs and trunk, while there are few studies on the effect of fluorosis on jawbone which is the inevitable structural basis for the development and treatment of oral diseases. Objective To preliminarily investigate the effect of fluoride exposure on the mechanical properties of jawbone by observing the changes in the intraosseous environment and the maximum load against shearing force (LSFmax) of the jawbone in rats with chronic fluoride treatment. Methods Screening experiment: 48 SD male rats were randomly divided into a control group and three fluoride exposure groups (50, 150, and 250 mg·L−1 fluoride concentration), 12 rats in each group. The fluoride exposure groups were molded by feeding different concentrations of sodium fluoride solution, and the control group drank tap water from Guizhou area. Each group was further divided into 4 subgroups with 3 animals each according to observation time points after 0, 2, 4, and 6 months. The LSFmax of the jawbone was measured with an electronic universal ergometer, the expression of type I collagen (Col1) was shown by Sirius red staining, and the expression of runt-related transcription factor 2 (Runx2) was determined semi-quantitatively by immunohistochemistry at selected time points. Formal experiment: 12 male SD rats were randomly divided into a fluoride exposure group and a control group. The fluoride exposure group were fed with 150 mg·L−1 sodium fluoride solution, and the control group drank tap water from Guizhou. After feeding with fluoride for 5 months, the ergometer was used to measure the LSFmax of the jawbone. Osteoclasts were counted after tartrate resistant acid phosphatase (TRAP) staining. Col1, Runx2, bone morphogenetic protein 2 (BMP-2), alkaline phosphatase (ALP), and cathepsin K (Cath K) were detected semi-quantitatively by immunohistochemistry expression and Sirius red staining. Micro computed tomography (Micro CT) was used to observe the trabecular bone microstructure. Results Screening experiment: The LSFmax of the control group and the 50 mg·L−1 fluoride exposure group reached the peak value at the 2nd month, and the LSFmax of the 50 mg·L−1 fluoride exposure group reached the valley value at the 4th month. The LSFmax of the 150 mg·L−1 fluoride exposure group at the 4th month was higher than that at the 6th month (P<0.05). There was no significant difference in the LSFmax at each time point in the 250 mg·L−1 fluoride exposure group. At the same time point, there was no statistically significant difference in LSFmax among the groups. The Col1 levels of the 50 mg·L−1, 150 mg·L−1, and 250 mg·L−1 fluoride exposure groups were higher than the time point 0 from the 2nd month (P＜0.05). The Runx2 showed no statistically significant difference by concentration or time. Formal experiment: After feeding with 150 mg·L−1 fluoride for 5 months, the LSFmax of the fluoride exposure group was greater than that of the control group (P<0.05). The expressions of Col1, Runx2, BMP2, ALP, and Cath K in the fluorosis exposure group were higher than those in the control group (P<0.05). There were no statistically significant differences in osteoclast count or indicators of bone trabecular microstructure. Conclusion Chronic fluoride exposure may increase the shear strength of jaw bone.

Molecular dynamics simulation of force-regulated interaction between glycoprotein Ib α and filamin / 生物医学工程学杂志

In resting platelets, the 17 th domain of filamin a (FLNa17) constitutively binds to the platelet membrane glycoprotein Ibα (GPIbα) at its cytoplasmic tail (GPIbα-CT) and inhibits the downstream signal activation, while the binding of ligand and blood shear force can activate platelets. To imitate the pull force transmitted from the extracellular ligand of GPIbα and the lateral tension from platelet cytoskeleton deformation, two pulling modes were applied on the GPIbα-CT/FLNa17 complex, and the molecular dynamics simulation method was used to explore the mechanical regulation on the affinity and mechanical stability of the complex. In this study, at first, nine pairs of key hydrogen bonds on the interface between GPIbα-CT and FLNa17 were identified, which was the basis for maintaining the complex structural stability. Secondly, it was found that these hydrogen bonding networks would be broken down and lead to the dissociation of FLNa17 from GPIbα-CT only under the axial pull force; but, under the lateral tension, the secondary structures at both terminals of FLNa17 would unfold to protect the interface of the GPIbα-CT/FLNa17 complex from mechanical damage. In the range of 0~40 pN, the increase of pull force promoted outward-rotation of the nitrogen atom of the 563 rd phenylalanine (PHE 563-N) at GPIbα-CT and the dissociation of the complex. This study for the first time revealed that the extracellular ligand-transmitted axial force could more effectively relieve the inhibition of FLNa17 on the downstream signal of GPIbα than pure mechanical tension at the atomic level, and would be useful for further understanding the platelet intracellular force-regulated signal pathway.

The study on the characteristics of active force of neck muscles under rapid braking conditions / 生物医学工程学杂志

This paper studies the active force characteristics of the neck muscles under the condition of rapid braking, which can provide theoretical support for reducing the neck injury of pilots when carrier-based aircraft blocks the landing. We carried out static loading and real vehicle braking experiments under rapid braking conditions, collected the active contraction force and electromyography (EMG) signals of neck muscles, and analyzed the response characteristics of neck muscle active force response. The results showed that the head and neck forward tilt time was delayed and the amplitude decreased during neck muscle pre-tightening. The duration of the neck in the extreme position decreased, and the recovery towards the seat direction was faster. The EMG signals of trapezius muscle was higher than sternocleidomastoid muscle. This suggests that pilots can reduce neck injury by pre-tightening the neck muscles during actual braking flight. In addition, we can consider the design of relevant fittings for pre-tightening the neck muscles.

Molecular dynamics simulation of force-regulated interaction between talin and Rap1b / 生物医学工程学杂志

The binding of talin-F0 domain to ras-related protein 1b (Rap1b) plays an important role in the formation of thrombosis. However, since talin is a force-sensitive protein, it remains unclear whether and how force regulates the talin-F0/Rap1b interaction. To explore the effect of force on the binding affinity and the dynamics mechanisms of talin-F0/Rap1b, molecular dynamics simulation was used to observe and compare the changes in functional and conformational information of the complex under different forces. Our results showed that when the complex was subjected to tensile forces, there were at least two dissociation pathways with significantly different mechanical strengths. The key event determining the mechanical strength difference between the two pathways was whether the β4 sheet of the F0 domain was pulled away from the original β1-β4 parallel structure. As the force increased, the talin-F0/Rap1b interaction first strengthened and then weakened, exhibiting the signature of a transition from catch bonds to slip bonds. The mechanical load of 20 pN increased the interaction index of two residue pairs, ASP 54-ARG 41 and GLN 18-THR 65, which resulted in a significant increase in the affinity of the complex. This study predicts the regulatory mechanism of the talin-F0/Rap1b interaction by forces in the intracellular environment and provides novel ideas for the treatment of related diseases and drug development.

Musculoskeletal multibody dynamics investigation for the different medial-lateral installation position of the femoral component in unicompartmental knee arthroplasty / 生物医学工程学杂志

The surgical installation accuracy of the components in unicompartmental knee arthroplasty (UKA) is an important factor affecting the joint function and the implant life. Taking the ratio of the medial-lateral position of the femoral component relative to the tibial insert (a/A) as a parameter, and considering nine installation conditions of the femoral component, this study established the musculoskeletal multibody dynamics models of UKA to simulate the patients' walking gait, and investigated the influences of the medial-lateral installation positions of the femoral component in UKA on the contact force, joint motion and ligament force of the knee joint. The results showed that, with the increase of a/A ratio, the medial contact force of the UKA implant was decreased and the lateral contact force of the cartilage was increased; the varus rotation, external rotation and posterior translation of the knee joint were increased; and the anterior cruciate ligament force, posterior cruciate ligament force and medial collateral ligament force were decreased. The medial-lateral installation positions of the femoral component in UKA had little effect on knee flexion-extension movement and lateral collateral ligament force. When the a/A ratio was less than or equalled to 0.375, the femoral component collided with the tibia. In order to prevent the overload on the medial implant and lateral cartilage, the excessive ligament force, and the collision between the femoral component and the tibia, it is suggested that the a/A ratio should be controlled within the range of 0.427-0.688 when the femoral component is installed in UKA. This study provides a reference for the accurate installation of the femoral component in UKA.