Search

IntroductionChange of direction (COD) maneuvers are frequently performed during soccer games and are critical for performance. Adolescent players often display immature COD maneuvers, suggesting that COD technique modification training may be a more effective approach for adolescent athletes. This study investigated the acute effects of COD modification training on COD performance and kinematics in male adolescent soccer players.MethodsTwenty-nine male junior high school soccer players participated in this study and were divided into two groups: 16 players underwent 15-min COD technique modification training (COD group), while 13 players engaged in 15-min linear sprint training. The participants performed Pro-Agility and 20-m sprint tests before and after the intervention, and the total times were measured. COD deficit (CODD) was calculated as the difference between these times. Center of mass (COM) velocity and trunk and lower limb kinematics were computed from three-dimensional kinematic data collected during the Pro-Agility test using a markerless motion capture system. Each section of the Pro-Agility test was divided into acceleration and deceleration phases based on the COM velocity; Stop marks the moment of direction change. Two-way (group and time) mixed ANOVA was conducted with Bonferroni corrections for post-hoc comparisons.ResultsNo significant interactions were observed in the total time of the Pro-Agility test, CODD, 20-m sprint time, or average acceleration and deceleration in each phase (p > 0.05). On the other hand, the COD group showed significant interactions and improvements in average deceleration from final foot (FF) contact to Stop (p = 0.012, g = 0.639), penultimate foot hip flexion angle at Stop (p = 0.042, g = 0.496), COM-FF horizontal distance at Stop (p = 0.008, g = 0.650), and FF ground contact time (p

BackgroundIt is still unclear whether body mass index (BMI) affects bleeding and cardiovascular events in patients requiring oral anticoagulants (OAC) for atrial fibrillation (AF) and antiplatelet agents after percutaneous coronary intervention (PCI) for coronary artery disease (CAD). The aim of this study was to evaluate the relationship between BMI and clinical events in patients who underwent PCI under OAC therapy for AF.MethodThis was a multicenter, observational cohort study conducted at 15 institutions in Japan. AF patients who underwent PCI with drug-eluting stents for CAD were retrospectively and prospectively included. Patients were divided into the Group 1 (BMI ResultsIn the 720 patients, 180 patients (25.0%) had BMI value ConclusionsAmong the patients undergoing PCI for CAD and requiring OAC for AF, BMI value was a useful indicator to predict major adverse clinical events.

Although coronary artery perforation can be a fatal complication during percutaneous coronary intervention, it is rarely observed in in-stent restenotic lesions. We present a case with coronary artery perforation after balloon dilatation for a recurrent in-stent restenotic lesion with calcified nodule inside the double-layered stents that were previously implanted. (Level of Difficulty: Advanced.)

Abstract This case study reports the effects of six sessions of repeated sprint training in hypoxia (RSH) over 3 weeks on explosive power production capacity and repeated sprint ability (RSA) in two Japanese international‐level foil fencers. The six RSH sessions (60‐s sprints in total per session: consisting of two sets of five 6‐s sprints with 30‐s passive recovery, at simulated altitude of 3000 m) caused improvements of peak power output (PPO; Athlete A: 5.1%; Athlete B: 3.2%) and mean power output (MPO; Athlete A: 4.4%; Athlete B: 1.6%) over the 10 repeated sprints, respectively. The observed findings suggest that as few as six RSH sessions over 3 weeks can improve, at least to some extent, explosive power production capacity (PPO) and RSA (MPO) in the two elite fencers. To the best of our knowledge, this is the first study to apply short‐term RSH in combat sport (fencing) with international‐level athletes. Further studies are required to explore the effectiveness of short‐term RSH in combat sports with a more robust study design (e.g., randomized control trial with adequate statistical power) as the modality of RSH would suit physical and physiological demands in the majority of combat sports (e.g., wrestling, boxing).

Abstract Background Most of the proteases classified into the M23 family in the MEROPS database exhibit staphylolytic activity and have potential as antibacterial agents. The M23 family is further classified into two subfamilies, M23A and M23B. Proteases of the M23A subfamily are thought to lack the capacity for self-maturation by auto-processing of a propeptide, which has been a challenge in heterologous production and application research. In this study, we investigated the heterologous expression, in Bacillus subtilis, of the Lysobacter enzymogenes beta-lytic protease (BLP), a member of the M23A subfamily. Results We found that B. subtilis can produce BLP in its active form. Two points were shown to be important for the production of BLP in B. subtilis. The first was that the extracellular proteases produced by the B. subtilis host are essential for BLP maturation. When the host strain was deficient in nine extracellular proteases, pro-BLP accumulated in the supernatant. This observation suggested that BLP lacks the capacity for self-maturation and that some protease from B. subtilis contributes to the cleavage of the propeptide of BLP. The second point was that the thiol-disulfide oxidoreductases BdbDC of the B. subtilis host are required for efficient secretory production of BLP. We infer that intramolecular disulfide bonds play an important role in the formation of the correct BLP conformation during secretion. We also achieved efficient protein engineering of BLP by utilizing the secretory expression system in B. subtilis. Saturation mutagenesis of Gln116 resulted in a Q116H mutant with enhanced staphylolytic activity. The minimum bactericidal concentration (MBC) of the wild-type BLP and the Q116H mutant against Staphylococcus aureus NCTC8325 was 0.75 μg/mL and 0.375 μg/mL, respectively, and the MBC against Staphylococcus aureus ATCC43300 was 6 μg/mL and 3 μg/mL, respectively. Conclusions In this study, we succeeded in the secretory production of BLP in B. subtilis. To our knowledge, this work is the first report of the successful heterologous production of BLP in its active form, which opens up the possibility of industrial use of BLP. In addition, this study proposes a new strategy of using the extracellular proteases of B. subtilis for the maturation of heterologous proteins.

Abstract Olympic sailing is a complex sport where sailors are required to predict and interpret weather conditions while facing high physical and physiological demands. While it is essential for sailors to develop physical and physiological capabilities toward major competition, monitoring training status following the competition is equally important to minimize the magnitude of detraining and facilitate retraining. Despite its long history in the modern Olympics, reports on world‐class sailors' training status and performance characteristics across different periodization phases are currently lacking. This case study aimed to determine the influence of training cessation and subsequent retraining on performance parameters in a world‐class female sailor. A 31‐year old female sailor, seventh in the Women's Sailing 470 medal race in Tokyo 2020, completely stopped training for 4 weeks following the Olympics, and resumed low‐intensity training for 3 weeks. Over these 7 weeks, 12.7 and 5.3% reductions were observed in 6 s peak cycling power output and jump height, respectively, with a 4.7% decrease in maximal aerobic power output. Seven weeks of training cessation‐retraining period induced clear reductions in explosive power production capacities but less prominent decreases in aerobic capacity. The current findings are likely attributed to the sailor's training characteristics during the retraining period.

We aimed to examine the annual changes in various physical characteristics of Japanese Division I (D1) Collegiate American footballers according to their positional groups. We measured body mass, and assessed performance in three gym tests (bench press, back squat, and power clean) and three field tests (40-yard dash, pro-agility shuttle, and broad jump) at each pre-season from 2014 to 2016 for players from a Japanese D1 university. Data from 55 players who completed ≥ 50% (three out of six) of the performance measurements in consecutive years were used in this analysis. Performance data across the two positional groups (skill players and linemen) were analyzed using pairwise t-tests to determine annual changes. The skill players’ body mass increased from their freshman to sophomore years (p < 0.05, Cohen’s d > 0.8), but not from their sophomore to junior or junior to senior years. The skill players’ 40-yard sprint time was shorter between all the annual comparisons (p < 0.05, d > 0.8). The linemen’s body mass increased from their freshman to sophomore years, and maintained from their sophomore to junior years and junior to senior years. There were significant improvements in strength and power outputs, but limited improvements in the pro-agility run and broad jump among most of the annual class comparisons for each positional group. These results indicate that annual improvements in the physical characteristics occur nonlinearly for Japanese D1 footballers. They will benefit from targeted strength and conditioning programs. However, the improvements of jumping and agility performances may be limited.

Background Chronic systemic inflammatory diseases (CSIDs) such as rheumatoid arthritis (RA) are reportedly associated with an increased risk of ischemic cardiovascular events including acute myocardial infarction (MI). However, data are limited on clinical characteristics and ischemic and bleeding outcomes after acute MI in patients with CSIDs. Methods This bi-center registry included a total of 1001 patients with acute MI undergoing percutaneous coronary intervention. CSIDs included inflammatory rheumatological conditions (RA, systemic lupus erythematosus, vasculitis, etc.) and organ-specific diseases (chronic hepatitis, psoriasis, inflammatory bowel disease, etc.). The primary endpoint was net adverse clinical events (NACE), a composite of ischemic (all-cause death, MI, and ischemic stroke) and major bleeding (Bleeding Academic Research Consortium type 3 or 5) events, during hospitalization and after discharge. Results Of the 1001 patients, 58 (5.8%) had CSIDs. The proportion of women was higher in patients with CSIDs than those without (37.9% vs. 22.1%, p = 0.009). During the hospitalization, no significant differences in the primary endpoint of NACE were observed between patients with and without CSIDs (10.3% vs. 12.7%, p = 0.84). During the median follow-up of 42.6 months after discharge, patients with CSIDs had a higher risk of NACE (22.5% vs. 10.1%, p = 0.01) than those without, mainly driven by an increased risk of ischemic events (18.4% vs. 8.4%, p = 0.03). Conclusions A small but significant proportion of patients with acute MI (5.8%) had CSIDs. While the incidence of in-hospital events was similar, patients with CSIDs had worse outcomes after discharge, suggesting that further clinical investigations and therapeutic approaches are needed in this patient subset.

Coronary microvascular dysfunction (CMD) is described as an important subset of ischemia with no obstructive coronary artery disease. Resistive reserve ratio (RRR) and microvascular resistance reserve (MRR) have been proposed as novel physiological indices evaluating coronary microvascular dilation function. The aim of this study was to explore factors associated with impaired RRR and MRR. Coronary physiological indices were invasively evaluated in the left anterior descending coronary artery using the thermodilution method in patients suspected of CMD. CMD was defined as a coronary flow reserve p < 0.001) and MRR (3.4 ± 1.9 vs. 6.9 ± 3.5, p < 0.001) were lower in the CMD group. In the receiver operating characteristic curve analysis, RRR (area under the curve 0.84, p < 0.001) and MRR (area under the curve 0.85, p < 0.001) were both predictive of the presence of CMD. In the multivariable analysis, previous myocardial infarction, lower hemoglobin, higher brain natriuretic peptide levels, and intracoronary nicorandil were identified as factors associated with lower RRR and MRR. In conclusion, the presence of previous myocardial infarction, anemia, and heart failure was associated with impaired coronary microvascular dilation function. RRR and MRR may be useful to identify patients with CMD.

We determined the marker-less barbell auto-tracking accuracy using the Kanade-Lucas-Tomasi (KLT) algorithm in a digital video for two-dimensional analysis (2D-AT). The position coordinates of the barbell's right end during multiple loads (60%-90% of one-repetition maximum) of snatch motion in eight participants were recorded using a three-dimensional motion capture system. Simultaneously, the snatch motion was recorded by a digital camera from the right side. Based on the digital video, the center of the barbell's right end was auto-tracked using the KLT algorithm. Six barbell kinematic variables (forward, backward, and vertical displacement, peak forward, backward, and vertical velocity) were calculated. Intraclass correlation coefficient (ICC) analysis was performed to establish the agreement level between the methods. The Bland-Altman plots and regression were used to examine the agreement between the methods. ICCs of 0.999-0.971 revealed a strong agreement level between the methods. The Bland-Altman plot showed small bias (-0.001-0.001 m, -0.034 --0.005 m/s). We considered that 2D-AT could obtain barbell position coordinates with sufficient accuracy to discriminate the difference in the lifter's level and a successful or unsuccessful lift.

Patients with vasospastic angina (VSA) who are resuscitated from sudden cardiac arrest (SCA) are at a high risk of recurrent lethal arrhythmia and cardiovascular events. However, the benefit of the implantable cardioverter-defibrillator (ICD) therapy in this population has not been fully elucidated. The present study aimed to analyze the prognostic impact of ICD therapy on patients with VSA and SCA. A total of 280 patients who were resuscitated from SCA and received an ICD for secondary prophylaxis were included in the present multicenter registry. The patients were divided into two groups on the basis of the presence of VSA. The primary endpoint was a composite of all-cause death and appropriate ICD therapy (appropriate anti-tachycardia pacing and shock) for recurrent ventricular arrhythmias. Of 280 patients, 51 (18%) had VSA. Among those without VSA, ischemic cardiomyopathy was the main cause of SCA (38%), followed by non-ischemic cardiomyopathies (18%) and Brugada syndrome (7%). Twenty-three (8%) patients were dead and 72 (26%) received appropriate ICD therapy during a median follow-up period of 3.8 years. There was no significant difference in the incidence of the primary endpoint between patients with and without VSA (24% vs. 33%, p = 0.19). In a cohort of patients who received an ICD for secondary prophylaxis, long-term clinical outcomes were not different between those with VSA and those with other cardiac diseases after SCA, suggesting ICD therapy may be considered in patients with VSA and those with other etiologies who were resuscitated from SCA.

Among patients with acute myocardial infarction (MI) complicated by cardiogenic shock (CS), in-hospital mortality remains high. In the present study, we aimed to identify factors associated with clinical outcomes of acute MI patients with CS in a contemporary setting. A total of 1102 patients with acute MI undergoing primary percutaneous coronary intervention were included, among whom 196 (17.8%) were complicated by CS. The primary outcome was all-cause death during hospitalization, and factors associated with in-hospital mortality were explored in patients with acute MI and CS. Of the 196 patients with acute MI complicated by CS, 77 (39.3%) died during hospitalization. The rates of non-ST-segment elevation MI (NSTEMI) (33.8% vs. 19.3%, p = 0.02) and culprit lesion in the left main or left anterior descending coronary artery (68.8% vs. 47.9%, p = 0.004) were higher, while left ventricular ejection fraction (LVEF) was lower (24.4 ± 11.7% vs. 39.7 ± 13.8%, p < 0.001) in non-survivors than in survivors. Multivariable analysis identified NSTEMI presentation and lower LVEF as independent predictors of in-hospital death. In conclusion, NSTEMI and low LVEF were identified as factors associated with higher in-hospital mortality. The identification of even higher-risk subsets and targeted therapeutic strategies may be warranted to improve survival of patients with acute MI and CS.

This study examined the movement characteristics of the double-leg attack in elite and non-elite wrestlers. Twenty light-weight male wrestlers were divided by skill level: Elite group (n = 11) who participated in international-level competitions and Non-Elite group (n = 9) consisting of college-level wrestlers. Each wrestler performed the double-leg attacks against a defender. Three-dimensional coordinates of anatomical landmarks and the ground reaction force (GRF) of the trailing limb were analyzed. The forward velocity and displacement of the whole-body center of mass (COM) and the 7th cervical spine (C7), which represents the upper body, were calculated. Additionally, joint torques were calculated by a standard inverse dynamics method. No significant differences were observed between groups for movement duration and the C7 forward displacement, which relates to the interpersonal distance. Still, they were significantly correlated in the non-elite wrestlers, as well as in all wrestlers (r = 0.78, p < 0.05 and r = 0.65, p < 0.01, respectively). While there were no group differences in joint angles at both limbs and torques at the trailing limb, the time-to-peak resultant GRF was shorter, and peak resultant GRF was greater at the trailing limb in the elite wrestlers compared to that in the non-elite wrestlers (p < 0.05). There were no group differences in peak forward velocity of the COM and the C7. However, the C7 forward velocity at 0.20, 0.25, and 0.30 s and the C7 forward displacement at 0.35 s after the start of the attack was significantly greater in the elite wrestlers compared to that in the non-elite wrestlers (p < 0.05). This disparity in the C7 forward velocity made a positive contribution in forward displacement by 0.08 m at 0.35 s. Thus, during a double-leg attack, elite wrestlers quickly move their upper body forward while rapidly pushing-off the trailing foot reaching the defender's legs in advance of defensive actions, irrespective of the interpersonal distance. These characteristics may improve the success rate of the double-leg attack.

Studies evaluating the physical fitness levels of elite wrestlers during junior high school are limited. This study aimed to examine the body composition and physical fitness profiles of elite Japanese female wrestlers aged 20 years. There were 114 elite female wrestlers enrolled. Measurements were conducted in the following age categories: 20 years (senior). Body composition variables consisted of body mass index (BMI), percent body fat, fat free mass, and fat free mass index (FFMI). Fitness measurements included grip strength, back strength, sit-up, rope-climbing, and endurance running tests. The wrestlers in this study demonstrated comparable or greater FFMI values (e.g., FFMI: 17.9 ± 0.4 kg/m2 for light and 19.8 ± 0.9 kg/m2 for heavy weight categories in U-20), when compared with young female wrestlers in previous studies, whereas stature, body mass, and BMI of the wrestlers in our study were unremarkable. Regarding the fitness assessment, a remarkable increase in back strength was observed after late puberty. An outstanding enhancement of muscle strength after late puberty, which is unlikely to occur in ordinary women, would be an important requirement to become the world’s top female wrestler.

Sound masking is a method that used for protecting speech privacy of conversation at public open space such as a pharmacy or a bank window. In a conventional masking, a masking sound is used to cover contents of conversation. This masking sound which is generated from a loudspeaker allow a third party not to understand what is said, but there is a problem that the sound level is increased because of a masking sound. Against this problem, we proposed Low-noise sound masking method using active noise control (ANC). The approach of this method is to make spectrum of phonemes flat by control sound. It is difficult to recognize phonemes that are processed by this method because the major factor determining the phonemes in speech recognition is the relative relationship of the peaks of its spectrum. In this paper, the sound attenuation performance of the proposed method is validated by control experiments in an anechoic chamber. Moreover, a listening experiment is carried out to investigate the sound masking performance. The result show that comparing with the conventional sound masking method, the proposed method can achieve the sound masking effect with a smaller sound pressure level.

Flight time is widely used to calculate jump height because of its simple and inexpensive application. However, this method is known to give different results than the calculation from vertical velocity at takeoff. The purpose of this study is to quantify the effect of postural changes between takeoff and landing on the jump height from flight time. Twenty-seven participants performed three vertical jumps with arm swing. Three-dimensional coordinates of anatomical landmarks and the ground reaction force were analyzed. Two methods of calculating jump height were used: (1) the vertical velocity of the whole-body center of mass (COMwb) at takeoff and (2) flight time. The jump height from flight time was overestimated by 0.025 m compared to the jump height from the takeoff velocity (p < 0.05) due to the lower COMwb height at landing by −0.053 m (p < 0.05). The postural changes in foot, shank, and arm segments mainly contributed to decreasing the COMwb height (−0.025, −0.014, and −0.017 m, respectively). The flight time method is reliable and had low intra-participant variability, but it cannot be recommended for a vertical jump when comparing with others (such as at tryouts) because of the potential “cheating” effect of differences in landing posture.

In a competitive sport, the outcome of a game is determined by an athlete's relationship with an unpredictable and uncontrolled opponent. We have previously analyzed the preparatory state of ground reaction forces (GRFs) dividing non-weighted and weighted states (i.e., vertical GRFs below and above 120% of body weight, respectively) in a competitive ballgame task and demonstrated that the non-weighted state prevented delay of the defensive step and promoted successful guarding. However, the associated kinetics of lower extremity joints during a competitive sports task remains unknown. The present study aims to investigate the kinetic characteristics of a real-time competitive sport before movement initiation. As a first kinetic study on a competitive sport, we initially compared the successful defensive kinetics with a relatively stable preparatory state and the choice-reaction sidestep as a control movement. Then, we investigated the kinetic cause of the outcome in a 1-on-1 dribble in terms of the preparatory states according to our previous study. The results demonstrated that in successful defensive motions in the non-weighted state guarding trial, the times required for the generation of hip abduction and three extension torques for the hip, knee, and ankle joints were significantly shortened compared with the choice-reaction sidestep, and hip abduction and hip extension torques were produced almost simultaneously. The sport-specific movement kinetics emerges only in a more-realistic interactive experimental setting. A comparison of the outcomes in the 1-on-1 dribble and preparatory GRF states showed that, in the non-weighted state, the defenders guarded successfully in 68.0% of the trials, and the defender's initiation time was earlier than that in the weighted state (39.1%). In terms of kinetics, the root mean squares of the derivative of hip abduction and three extension torques in the non-weighted state were smaller than those in the weighted state, irrespective of the outcome. These results indicate that the preparatory body state as explained by short-term joint torque fluctuations before the defensive step would help explain the performance in competitive sports, and will give insights into understanding human adaptive behavior in unpredicted and uncontrolled environments.

Copyright of Ido Movement for Culture. Journal of Martial Arts Anthropology is the property of Idokan Poland Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of the study was to examine the relationship between pitching ball velocity and segmental (trunk, upper arm, forearm, upper leg, and lower leg) and whole-body muscle volume (MV) in high school baseball pitchers. Forty-seven male high school pitchers (40 right-handers and seven left-handers; age, 16.2 ± 0.7 years; stature, 173.6 ± 4.9 cm; mass, 65.0 ± 6.8 kg, years of baseball experience, 7.5 ± 1.8 years; maximum pitching ball velocity, 119.0 ± 9.0 km/hour) participated in the study. Segmental and whole-body MV were measured using segmental bioelectrical impedance analysis. Maximum ball velocity was measured with a sports radar gun. The MV of the dominant arm was significantly larger than the MV of the non-dominant arm (P < 0.001). There was no difference in MV between the dominant and non-dominant legs. Whole-body MV was significantly correlated with ball velocity (r = 0.412, P < 0.01). Trunk MV was not correlated with ball velocity, but the MV for both lower legs, and the dominant upper leg, upper arm, and forearm were significantly correlated with ball velocity (P < 0.05). The results were not affected by age or years of baseball experience. Whole-body and segmental MV are associated with ball velocity in high school baseball pitchers. However, the contribution of the muscle mass on pitching ball velocity is limited, thus other fundamental factors (ie, pitching skill) are also important. [ABSTRACT FROM AUTHOR]