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In recent years, there has been significant interest in quantum technology, characterized by the emergence of quantum computers boasting immense processing power, ultra-sensitive quantum sensors, and ultra-precise atomic clocks. Miniaturization of quantum devices using cold atoms necessitates the employment of an ultra-high vacuum miniature cell with a pressure of approximately 10-6 Pa or even lower. In this study, we developed an ultra-high vacuum cell realized by a miniature ion pump using a high-efficiency plasma source. Initially, an unsealed miniature ion pump was introduced into a vacuum chamber, after which the ion pump's discharge current, depending on vacuum pressures, was evaluated. Subsequently, a miniature vacuum cell was fabricated by hermetically sealing the miniature vacuum pump. The cell was successfully evacuated by a miniature ion pump down to an ultra-high vacuum region, which was derived by the measured discharge current. Our findings demonstrate the feasibility of achieving an ultra-high vacuum cell necessary for the operation of miniature quantum devices.
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OBJECTIVE: To compare the effectiveness of methotrexate (MTX) as initial therapy in patients with late-onset and younger-onset rheumatoid arthritis (LORA and YORA). METHODS: Of 114 patients with YORA and 96 patients with LORA, defined as RA occurring at ≥65 years of age, enrolled in a multicentre RA inception cohort study, 71 and 66 patients who had been followed up to 6 months after starting MTX treatment were included in this study. RESULTS: Proportions of patients on MTX treatment at 6 months were 96% and 92% in the YORA and LORA groups, respectively. Despite lower doses of MTX in the LORA group compared with the YORA group, no significant difference was observed in clinical disease activity index scores between the two groups throughout the follow-up period. The proportion of patients in clinical disease activity index remission at 6 months was 35% in both groups. Logistic regression analysis revealed that knee joint involvement and high Health Assessment Questionnaire-Disability Index were significant negative predictors of achieving clinical disease activity index remission at 6 months in the LORA group. CONCLUSION: Observations up to 6 months revealed that the effectiveness of MTX administered based on rheumatologist discretion in patients with LORA is comparable to that in patients with YORA in clinical settings.
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In this study, we design a highly efficient plasma source using a magnetic mirror trap with two opposing permanent magnets for a miniature high-efficiency ion pump. First, we simulated the distribution of the magnetic field line formed by the proposed magnetic mirror configuration. By optimizing the distance between two opposing permanent magnets and size of these magnets, a magnetic mirror ratio value of 27 could be obtained, which is an electron confinement efficiency of over 90%. We also conducted an experiment on a high-efficiency discharge plasma source for a miniature ion pump using an optimized magnetic circuit. As a result, we revealed that the proposed magnetic circuit has a pronounced effect on plasma generation, particularly in the high-vacuum region.
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Magnetismo , Imanes , Campos Magnéticos , Vacio , ElectronesRESUMEN
OBJECTIVE: Various guidelines recommend that patients with early rheumatoid arthritis (RA) try to achieve clinical remission within 6 months, and early therapeutic intervention is important to this end. This study aimed to investigate short-term treatment outcomes of patients with early-diagnosed RA in clinical practice and to examine predictive factors for achieving remission. METHODS: Of the 210 patients enrolled in the multicenter RA inception cohort, 172 patients who were followed up to 6 months after treatment initiation (baseline) were included. Logistic regression analysis was used to examine the impact of baseline characteristics on achievement of Boolean remission at 6 months. RESULTS: Participants (mean age, 62 years) initiated treatment after a mean of 19 days from RA diagnosis. At baseline and 3 and 6 months after treatment initiation, proportions of patients using methotrexate (MTX) were 87.8%, 89.0%, and 88.3%, respectively, and rates of Boolean remission were 1.8%, 27.8%, and 34.5%, respectively. Multivariate analysis revealed that physician global assessment (PhGA) (Odds ratio (OR): 0.84, 95% confidence interval (CI): 0.71-0.99) and glucocorticoid use (OR: 0.26, 95% CI: 0.10-0.65) at baseline were independent factors that predicted Boolean remission at 6 months. CONCLUSION: After a diagnosis of RA, satisfactory therapeutic effects were achieved at 6 months after the initiation of treatment centered on MTX according to the treat to target strategy. PhGA and glucocorticoid use at treatment initiation are useful for predicting the achievement of treatment goals.
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This study demonstrates room-temperature bonding using a getter layer for the vacuum packaging of microsystems. A thick Ti layer covered with an Au layer is utilized as a getter layer because it can absorb gas molecules in the package. Additionally, smooth Au surfaces can form direct bonds for hermetic sealing at room temperature. Direct bonding using a getter layer can simplify the vacuum packaging process; however, typical getter layers are rough in bonding formation. This study demonstrates two fabrication techniques for smooth getter layers. In the first approach, the Au/Ti layer is bonded to an Au layer on a smooth SiO2 template, and the Au/SiO2 interface is mechanically exfoliated. Although the root-mean-square roughness was reduced from 2.00 to 0.98 nm, the surface was still extremely rough for direct bonding. In the second approach, an Au/Ti/Au multilayer on a smooth SiO2 template is bonded with a packaging substrate, and the Au/SiO2 interface is exfoliated. The transferred Au/Ti/Au getter layer has a smooth surface with the root-mean-square roughness of 0.54 nm and could form wafer-scale direct bonding at room temperature. We believe that the second approach would allow a simple packaging process using direct bonding of the getter layer.
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OBJECTIVE: Glucocorticoids are important drugs used to treat rheumatoid arthritis. We recommend glucocorticoid discontinuation as soon as possible given the associated side-effects, but many patients continue to take oral glucocorticoids long-term. The present study aimed to explore factors associated with glucocorticoid discontinuation at 52 weeks after initiating biological disease-modifying antirheumatic drugs (bDMARDs). METHODS: Subjects were 564 patients from a Japanese multicenter registry who were administered glucocorticoids and methotrexate (MTX) followed by initiation of the first bDMARD. We examined the status of oral glucocorticoid use at 52 weeks after initiating the first bDMARD. RESULTS: By 52 weeks after bDMARD initiation, 164 patients (29.1%) discontinued glucocorticoids. Multivariable analysis identified age, MTX dose, and glucocorticoid dose as factors independently associated with glucocorticoid discontinuation. After adjusting for baseline characteristics using propensity score matching, among patient groups administered MTX ≤ 8 mg/week and MTX > 8 mg/week, 105 pairs remained. A significantly higher rate of glucocorticoid discontinuation (41.0%) was noted for patients administered MTX > 8 mg/week. CONCLUSION: Our findings suggest that glucocorticoids may be discontinued after initiating bDMARDs. Moreover, higher MTX doses (>8 mg/week) at the time of bDMARD initiation were associated with glucocorticoid discontinuation among patients treated with bDMARDs.
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Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Glucocorticoides/uso terapéutico , Metotrexato/uso terapéutico , Privación de Tratamiento , Administración Oral , Femenino , Glucocorticoides/administración & dosificación , Humanos , Japón , Masculino , Metotrexato/administración & dosificación , Persona de Mediana Edad , Puntaje de Propensión , Sistema de Registros , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
OBJECTIVES: To explore predictive factors including MMP-3 for achievement of low disease activity (LDA) at 52 weeks in bio-switch rheumatoid arthritis (RA) patients treated with abatacept, for whom obtaining a good clinical response can be difficult. METHODS: Participants were 423 consecutive patients with RA treated with abatacept who were observed for longer than 52 weeks and registered in the TBCR, a Japanese multicentre registry system. Multivariate logistic regression analysis was used to study factors that predict the achievement of LDA at 52 weeks in bio-naïve (n=234) and bio-switch (n=189) groups. RESULTS: ROC analysis revealed that MMP-3 improvement rates at 12 weeks in bio-switch patients had the highest AUC with a cut-off value of 20.0% for predicting LDA achievement at 52 weeks. Multivariate logistic regression analysis revealed that, in addition to DAS28-CRP at baseline, achieving 20% improvement in MMP-3 levels at 12 weeks was an independent predictive factor (adjusted OR: 4.277, p=0.003) in the bio-switch group, whereas DAS28 was the only predictor in the bio-naïve group. Patients who achieved 20% improvement in MMP-3 levels at 12 weeks had significantly higher achievement rates of LDA at 52 weeks compared to those who did not achieve 20% improvement in the bio-switch group (60.0 vs. 33.3%, p=0.001). CONCLUSIONS: Our findings suggest that improvement in MMP-3 levels is key to predicting the clinical efficacy of abatacept. Closer attention paid not only to major clinical indices, but also changes in MMP-3 levels, could improve our ability to optimise clinical results when treating bio-switch patients.
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Antirreumáticos , Artritis Reumatoide , Abatacept/uso terapéutico , Antirreumáticos/uso terapéutico , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/tratamiento farmacológico , Humanos , Metaloproteinasa 3 de la Matriz , Inducción de Remisión , Resultado del TratamientoRESUMEN
Objective: To study the clinical effectiveness and long-term retention rate of abatacept (ABA) in elderly rheumatoid arthritis (RA) patients in daily clinical practice.Methods: A retrospective cohort study was performed using data from a multicenter registry. Our study population comprised 500 consecutive RA patients treated with ABA. We compared clinical effectiveness and ABA retention rates between the Young (≤62 years), Middle (62 to 72 years), and Elderly (≥72 years) groups. We also performed separate examinations to identify predictive factors for ABA discontinuation in those with versus those without concomitant methotrexate (MTX) treatment.Results: Mean age was 52.7 years in the Young group, 67.7 years in the Middle group, and 78.1 years in the Elderly group. No significant group-dependent differences were found in mean DAS28 score, categorical distribution of DAS28, and EULAR response rate across the 52 weeks. The ABA retention rates at three years as determined by the Kaplan-Meier method were similar in all three groups. Patient age was not a significant predictor of ABA discontinuation due to adverse events in patients with concomitant MTX; however, it was found to be a significant predictor for those who did not use MTX (Cox hazard model).Conclusion: ABA would be a reasonable treatment option for elderly RA patients from the viewpoints of both clinical effectiveness and long-term retention. However, physicians should watch carefully for any serious adverse reactions in elderly RA patients with intolerance to MTX.
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Abatacept/uso terapéutico , Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Sistema de Registros , Abatacept/administración & dosificación , Abatacept/efectos adversos , Anciano , Antirreumáticos/administración & dosificación , Antirreumáticos/efectos adversos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
OBJECTIVE: This study aimed to determine whether serum matrix metalloproteinase-3 (MMP-3) levels can predict remission in rheumatoid arthritis (RA) patients treated with adalimumab (ADA). METHODS: Subjects were 114 RA patients continuously treated with ADA for 52 weeks. Predictive factors at baseline and 4 weeks after initiation of ADA therapy for the achievement of remission (28-point count Disease Activity Score-CRP (DAS28-CRP) < 2.3) at 52 weeks were evaluated by multivariate logistic regression analysis. RESULTS: DAS28-CRP at 4 weeks (odds ratio (OR) 0.614, 95% confidence interval (CI) 0.382-0.988) and improvement in serum MMP-3 levels at 4 weeks (OR 1.057, 95% CI 1.002-1.032) were independent predictors of remission at 52 weeks. The best cut-off level of DAS28-CRP and improvement in serum MMP-3 levels at 4 weeks for predicting remission at 52 weeks was 3.73 (sensitivity: 90%, specificity: 50%, area under the receiver operating characteristic curve (AUC): 62%) and 39.93% (sensitivity: 47%, specificity: 83%, AUC: 64%), respectively. CONCLUSION: Our findings suggest that a high rate of improvement in serum MMP-3 levels at 4 weeks after initiation of ADA therapy can predict remission at 52 weeks in RA patients.
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Adalimumab/uso terapéutico , Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Metaloproteinasa 3 de la Matriz/sangre , Adulto , Anciano , Artritis Reumatoide/sangre , Proteína C-Reactiva , Femenino , Humanos , Masculino , Persona de Mediana Edad , Inducción de Remisión , Factores de Tiempo , Resultado del TratamientoRESUMEN
OBJECTIVE: This study aimed to investigate predictors of biologic discontinuation due to insufficient response as a surrogate for relapse in patients with rheumatoid arthritis (RA) who achieved clinical remission with biologic treatment. METHODS: This study was performed based on data from a multicenter registry, and included 404 patients who achieved clinical remission within the first year of treatment with their first biologic. Cumulative retention rate of the first biologic was estimated using Kaplan-Meier curves, and the impact of patient characteristics on biologic discontinuation was assessed with Cox proportional hazards models. RESULTS: During follow-up, 50 patients discontinued their first biologic due to insufficient response. Overall discontinuation rates due to insufficient response after achieving remission were 6%, 11%, and 19% at 1, 2, and 5 years, respectively. Multivariate analysis revealed that concomitant glucocorticoids at achieving remission [hazard ratio (HR): 3.80, 95% confidence interval (CI): 1.89-7.64)] and a higher level of C-reactive protein (CRP) at achieving remission (HR: 1.47 per 1 mg/dL, 95% CI: 1.09-1.99) independently predict discontinuation due to insufficient response after achieving remission. CONCLUSION: Patients with RA who achieved remission with concomitant glucocorticoid treatment and a higher level of CRP are at high risk of subsequent biologic discontinuation due to insufficient response.
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Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Productos Biológicos/uso terapéutico , Privación de Tratamiento/normas , Adulto , Anciano , Antirreumáticos/administración & dosificación , Productos Biológicos/administración & dosificación , Quimioterapia Combinada , Femenino , Glucocorticoides/administración & dosificación , Glucocorticoides/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Sistema de Registros , Inducción de Remisión , Resultado del TratamientoRESUMEN
This study examines the hand and foot reaction force recorded independently while performing the kick-start technique. Eleven male competitive swimmers performed three trials for the kick-start with maximum effort. Three force platforms (main block, backplate and handgrip) were used to measure reaction forces during starting motion. Force impulses from the hands, front foot and rearfoot were calculated via time integration. During the kick-start, the vertical impulse from the front foot was significantly higher than that from the rearfoot and the horizontal impulse from the rearfoot was significantly higher than that from the front foot. The force impulse from the front foot was dominant for generating vertical take-off velocity and the force impulse from the rearfoot was dominant for horizontal take-off velocity. The kick-start's shorter block time in comparison to prior measurements of the grab start was explained by the development of horizontal reaction force from the hands and the rearfoot at the beginning of the starting motion.
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Pie/fisiología , Mano/fisiología , Natación/fisiología , Aceleración , Adolescente , Adulto , Conducta Competitiva/fisiología , Humanos , Masculino , Movimiento , Adulto JovenRESUMEN
This paper reviews unsteady flow conditions in human swimming and identifies the limitations and future potential of the current methods of analysing unsteady flow. The capability of computational fluid dynamics (CFD) has been extended from approaches assuming steady-state conditions to consideration of unsteady/transient conditions associated with the body motion of a swimmer. However, to predict hydrodynamic forces and the swimmer's potential speeds accurately, more robust and efficient numerical methods are necessary, coupled with validation procedures, requiring detailed experimental data reflecting local flow. Experimental data obtained by particle image velocimetry (PIV) in this area are limited, because at present observations are restricted to a two-dimensional 1.0 m(2) area, though this could be improved if the output range of the associated laser sheet increased. Simulations of human swimming are expected to improve competitive swimming, and our review has identified two important advances relating to understanding the flow conditions affecting performance in front crawl swimming: one is a mechanism for generating unsteady fluid forces, and the other is a theory relating to increased speed and efficiency.
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Simulación por Computador , Modelos Biológicos , Movimiento/fisiología , Natación/fisiología , Brazo/fisiología , Fenómenos Biomecánicos , Conducta Competitiva/fisiología , Mano/fisiología , Humanos , Hidrodinámica , Reología , RobóticaRESUMEN
OBJECTIVES: This retrospective observational study aimed to examine the efficacy of iguratimod with and without concomitant methotrexate (MTX) and to estimate the adequate observational period for predicting low disease activity (LDA) achievement at 24 weeks in patients with rheumatoid arthritis (RA). METHODS: All patients treated with iguratimod were registered in a Japanese multicenter registry. Multivariate analyses were performed to identify predictive factors for LDA achievement at 24 weeks. Receiver operating characteristic (ROC) curve analyses were performed to estimate the association of 28-joint disease activity score based on erythrocyte sedimentation rate (DAS28-ESR) at each time point with achievement of LDA at 24 weeks and determine a cut-off for DAS28-ESR. RESULTS: A total of 123 patients were treated with iguratimod with (n = 65) or without (n = 58) MTX. Iguratimod therapy resulted in significant clinical improvement in both groups. Multivariate analysis revealed that DAS28-ESR at each time point was an independent significant predictor of LDA achievement at 24 weeks. Cut-off values of DAS28-ESR at 12 weeks based on ROC curves were 3.2 and 3.6 in patients with and without MTX, respectively. CONCLUSIONS: Iguratimod was effective in RA patients in clinical practice. Our results suggest that 12 weeks may be a sufficient period to judge the medium-term efficacy of iguratimod in patients treated with and without MTX.
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Antirreumáticos/uso terapéutico , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/tratamiento farmacológico , Cromonas/uso terapéutico , Sulfonamidas/uso terapéutico , Anciano , Anciano de 80 o más Años , Sedimentación Sanguínea , Quimioterapia Combinada , Femenino , Humanos , Masculino , Metotrexato/uso terapéutico , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Sistema de Registros , Inducción de Remisión , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Resultado del TratamientoRESUMEN
OBJECTIVE: Only a few studies have assessed predictive factors for the long-term efficacy of abatacept. This study aimed to provide clinical evidence of an adequate observational period for predicting low disease activity (LDA) achievement at 52 weeks in RA patients treated with abatacept. METHODS: Participants were all patients registered in a Japanese multicentre registry who were treated with abatacept and had at least 52 weeks of follow-up (n = 254). RESULTS: Areas under the receiver operating characteristic curves for the 28-joint count with CRP (DAS28-CRP) at each time point for LDA achievement at 52 weeks were: 0.686 (cut-off score: 4.6) at baseline, 0.780 (3.8) at 4 weeks, 0.875 (3.3) at 12 weeks, and 0.900 (3.0) at 24 weeks. Although patients with a DAS28-CRP score < 3.0 at 24 weeks had the highest proportion of LDA achievement at 52 weeks (79.3%), the proportion for those with a score < 3.3 at 12 weeks was comparable (77.2%, P = 0.697). Proportions were significantly lower in patients with a score < 3.8 at 4 weeks or < 4.6 at baseline. Multivariate logistic regression demonstrated that a DAS28 score of < 3.3 at 12 weeks was an independent strong predictor for LDA at 52 weeks (adjusted odds ratio: 15.2, P < 0.001). CONCLUSION: Twelve weeks is an adequate observational period to judge the long-term clinical efficacy of abatacept, and is about as early as the period for assessing TNF blockade therapy.
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Antirreumáticos/uso terapéutico , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/tratamiento farmacológico , Inmunoconjugados/uso terapéutico , Sistema de Registros , Índice de Severidad de la Enfermedad , Abatacept , Anciano , Artritis Reumatoide/epidemiología , Biomarcadores/sangre , Proteína C-Reactiva/metabolismo , Femenino , Estudios de Seguimiento , Humanos , Japón/epidemiología , Modelos Logísticos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Resultado del Tratamiento , Factor de Necrosis Tumoral alfa/antagonistas & inhibidoresRESUMEN
This observational retrospective study examined whether abatacept efficacy could be augmented with concomitant methotrexate (MTX) or tacrolimus (TAC) in patients with rheumatoid arthritis (RA) who experienced failure with prior biological disease-modifying antirheumatic drugs (DMARDs) and in whom favorable therapeutic efficacy is difficult to achieve. All patients with a prior biological DMARD history who were treated with abatacept for 52 weeks and registered in a Japanese multicentre registry were included. Clinical efficacy and safety of abatacept according to the concomitant drug used, i.e., none (ABT-mono), MTX (ABT-MTX), and TAC (ABT-TAC), were compared. A greater mean percent change of DAS28-ESR was observed in the ABT-TAC group compared with the ABT-mono group at weeks 12 (-20.5 vs. -5.4 %, p = 0.035) and 24 (-25.0 vs. -11.0 %, p = 0.036). ABT-MTX and ABT-TAC groups had a significantly higher proportion of patients who achieved low disease activity (LDA) within 52 weeks compared with the respective baselines, while no significant change was observed in the ABT-mono group. A higher proportion of patients in the ABT-TAC group achieved EULAR moderate response compared with the ABT-mono group at week 52 (66.7 vs. 35.0 %, p = 0.025). Multivariate logistic regression analysis revealed that concomitant TAC use was independently associated with the achievement of LDA and EULAR response at 52 weeks, while concomitant MTX use was not. Concomitant TAC use may offer a suitable option for RA patients treated with abatacept after prior biological DMARD failure, likely because both abatacept and TAC affect T cell activation.
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Abatacept/uso terapéutico , Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Metotrexato/uso terapéutico , Tacrolimus/uso terapéutico , Anciano , Sinergismo Farmacológico , Quimioterapia Combinada , Femenino , Humanos , Masculino , Persona de Mediana Edad , Inducción de Remisión , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
The purpose of this study was to clarify factors to perform the hole-entry technique in the backstroke start. A total of 16 well-trained Japanese competitive swimmers were divided into two groups (backstroke specialists and non-specialists) to compare their backstroke start motions. Their backstroke motions were videotaped, and two-dimensional co-ordinates for the swimmers were obtained from the video images using direct linear transformation methods. A non-paired t-test and Mann-Whitney U-test were used to analyse the statistical difference of the kinematic variables between the groups. Backstroke specialists showed a significantly shorter 5 m time (P = 0.009, effect size = -1.54), a significantly higher position of the toe (P = 0.010, effect size = 1.47) at signal and of the hip at toe-off (P = 0.002, effect size = 1.94), a significantly larger hip joint angle at toe-off (P = 0.007, effect size = 1.60) and a significantly higher angular velocities of the hip joints (45-85%; P < 0.05) for the normalised time as compared to that of non-specialists. An earlier initiation of the extension and the maintenance of a higher extension speed at the hip joints were important factors in achieving an arched-back posture, which facilitated and water entrance with a small entry range.
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Rendimiento Atlético , Articulación de la Cadera , Cadera , Competencia Profesional , Rango del Movimiento Articular , Natación , Análisis y Desempeño de Tareas , Adulto , Atletas , Fenómenos Biomecánicos , Femenino , Humanos , Japón , Masculino , Dedos del Pie , Adulto JovenRESUMEN
Increasing the velocity of the lower-limb movement is crucial for improving underwater undulatory swimming (UUS) velocity. However, the underlying mechanism of how these movements influence swimming velocity have remained unclear. This study aimed to clarify the relationship between changes in swimming movement and the resulting changes in flow field as a result of changes in test flow velocity (U) in a water flume. A male student swimmer was tested with the following three U settings 0.8, 1.0 and 1.2 m/s. The lower-limb movements and wake flow behind the swimmer were compared. A motion capture system was employed for motion analysis, and a stereo PIV for visualizing the flow field. The findings revealed that, as U increased, the velocity vectors of the flow field in all directions (u, v, w) increased, as did the toe velocity. It was also suggested that with increasing U, the outward change in the toe velocity vector down-kick and the inward change in the toe velocity vector up-kick may have a positive effect on the vortices, contributing to an increase in the velocity vectors in the flow field. Furthermore, the high U, vortex re-capturing occurred during the transition from down-kick to up-kick, indicating that this might contribute to increased momentum. This suggests that the transition from the down-kick to the up-kick is necessary for gaining greater momentum. Notably, this study is the first to identify the factors that increase the swimming velocity of the UUS in the context of movement and flow field.
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Extremidad Inferior , Natación , Humanos , Masculino , Fenómenos Biomecánicos , Movimiento (Física) , MovimientoRESUMEN
This study aimed to elucidate the foot kinematics and foot pressure difference characteristics of faster swimmers in undulatory underwater swimming (UUS). In total, eight faster and eight slower swimmers performed UUS in a water flume at a flow velocity set at 80% of the maximal effort swimming velocity. The toe velocity and foot angle of attack were measured using a motion capture system. A total of eight small pressure sensors were attached to the surface of the left foot to calculate the pressure difference between the plantar and dorsal sides of the foot. Differences in the mean values of each variable between the groups were analysed. Compared to the slower swimmers, the faster swimmers exhibited a significantly higher swimming velocity (1.53 ± 0.06 m/s vs. 1.31 ± 0.08 m/s) and a larger mean pressure difference in the phase from the start of the up-kick until the toe moved forward relative to the body (3.88 ± 0.65 kPa vs. 2.66 ± 1.19 kPa). The faster group showed higher toe vertical velocity and toe direction of movement, switching from lateral to medial at the time of generating the larger foot pressure difference in the up-kick, providing insight into the reasons behind the foot kinematics of high UUS performance swimmers.
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This study investigated the extent of contact-lens use in Japanese college water-polo male players over 20 years (1991-2011, once every five years). Information about the use of contact lenses during play and the types of contact lens was obtained through a self-report questionnaire. The proportion of contact lens use among the players while playing water polo differed from 1991 to 2011 (χ2(4) = 25.28, P < 0.001, Cohen's d = 0.63). Fifty-four per cent of the players used contact lenses while playing in 1991 (P < 0.001); more than 74% in 1996; 89% in 2001; 84% in 2006; and 86% in 2011. While 96% of the contact lenses used by the players in 1991 were the soft type, 74%, 92%, 86%, and 88% of the contact lenses used in 1996, 2001, 2006, and 2011, respectively, were the disposable type. These findings indicated a high percentage of players were using contact lenses while playing water polo between 1996 and 2011. This could be because the majority of players used disposable lenses. The results suggest that increasing use of contact lenses by water-polo players is beneficial.
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Lentes de Contacto/estadística & datos numéricos , Deportes/estadística & datos numéricos , Agua , Adulto , Lentes de Contacto Hidrofílicos/estadística & datos numéricos , Humanos , Japón , Masculino , Autoinforme , Encuestas y Cuestionarios , Adulto JovenRESUMEN
OBJECTIVES: The purpose of this study was to examine the treatment retention and efficacy of abatacept, the first member of a new class of biologic agents, in Japanese rheumatoid arthritis (RA) patients during clinical practice. METHODS: A retrospective multicenter study was conducted with patients who underwent abatacept therapy for 24 weeks (n = 143). RESULTS: Patients at baseline had a mean age of 63.5 years, a mean disease duration of 11.3 years, and a mean disease activity score in 28 joints (DAS28) of 4.5. Overall retention of abatacept treatment was 83.2 % at 24 weeks, when 46.2 % of patients achieved DAS28-defined low disease activity (LDA; DAS28 <3.2) and 26.6 % achieved DAS28-defined remission (DAS28 <2.6). LDA was achieved in a significantly higher proportion of patients without prior biologics therapy compared to those with prior biologics (60.9 vs. 34.2 %, p = 0.001). There was no significant difference between patients with or without concomitant methotrexate (MTX) therapy (45.2 vs. 47.5 %). CONCLUSIONS: Abatacept therapy appears to be highly effective and well tolerated during clinical treatment of RA. Abatacept was particularly effective in patients with no history of biologics use, and did not appear to be dependent on concomitant MTX therapy.