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ACTN3 R577X and ACE I/D polymorphisms are associated with endurance exercise ability. This case–control study explored the association of ACTN3 and ACE gene polymorphisms with elite pure endurance in Korean athletes, hypothesizing that individuals with both ACTN3 XX and ACE II genotypes would exhibit superior endurance. We recruited 934 elite athletes (713 males, 221 females) and selected 45 pure endurance athletes (36 males, 9 females) requiring "≥90% aerobic energy metabolism during sports events", in addition to 679 healthy non-athlete Koreans (361 males, 318 females) as controls. Genomic DNA was extracted and genotyped for ACTN3 R577X and ACE I/D polymorphisms. ACE ID (p = 0.090) and ACTN3 RX+XX (p = 0.029) genotype distributions were significantly different between the two groups. Complex ACTN3-ACE genotypes also exhibited significant differences (p = 0.014), with dominant complex genotypes positively affecting endurance (p = 0.039). The presence of RX+II or XX+II was associated with a 1.763-fold higher likelihood of possessing a superior endurance capacity than that seen in healthy controls (90% CI = 1.037–3.089). Our findings propose an association of combined ACTN3 RX+XX and ACE II genotypes with enhanced endurance performance in elite Korean athletes. While causality remains to be confirmed, our study highlights the potential of ACTN3-ACE polymorphisms in predicting elite endurance. [ABSTRACT FROM AUTHOR]

Sodium bicarbonate is used as an ergogenic supplement to enhance people's performances in various exercises. This study aimed to evaluate the effects of intestinal delivery of sodium bicarbonate on bicarbonate absorption and associated side effects in an experimental human trial. After preparing and assessing enteric-coated and uncoated sodium bicarbonate tablet formulations, pharmacokinetic analysis and gastrointestinal symptom tests were performed after oral administration in the human body. The dose required to increase blood bicarbonate concentration over 5 mmol∙L−1 for the purpose of improving performance during high-intensity exercise was also determined. Enteric-coated tablet formulation protects sodium bicarbonate under acidic conditions and releases bicarbonate in the intestine. Enteric-coated tablet formulation also reduced the oral dose required to achieve a blood bicarbonate concentration over 5 mmol∙L−1 from 300 mg∙kg−1 of uncoated tablet formulation to 225 mg∙kg−1. Gastrointestinal discomfort was significantly decreased for the group given 225 mg∙kg−1 enteric-coated tablets compared to that given 300 mg∙kg−1 uncoated tablets. These results suggest that enteric-coated tablet formulation could reduce the oral dose required in order to achieve a blood bicarbonate concentration over 5 mmol∙L−1 by 25%, from 300 mg∙kg−1 to 225 mg∙kg−1, along with its ability to reduce gastrointestinal discomfort associated with the dosage. [ABSTRACT FROM AUTHOR]

This study used the finite element method(FEM) to investigate how pressure on the lumbar spine changes during dynamic movements in different postures: standing, erect sitting on a chair, slumped sitting on a chair, and sitting on the floor. Three load modes (flexion, lateral bending, and axial rotation) were applied to the FEM, simulating movements of the lumbar spine. Results showed no significant difference in pressure distribution on the annulus fiber and nucleus pulposus, representing intradiscal pressure, as well as on the cortical bone during movements between standing and erect sitting postures. However, both slumped sitting on a chair and sitting on the floor postures significantly increased pressure on the nucleus pulposus, annulus fibrosus, and cortical bone in all three movements when compared to standing or erect sitting on a chair. Notably, sitting on the floor resulted in even higher pressure on the nucleus pulposus and annulus fibers compared to slumped sitting on a chair. The decreased lumbar lordosis while sitting on the floor led to the highest increase in pressure on the annulus fiber and nucleus pulposus in the lumbar spine. In conclusion, maintaining an erect sitting position with increased lumbar lordosis during seated activities can effectively reduce intradiscal pressure and cortical bone stress associated with degenerative disc diseases and spinal deformities. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to verify whether bioelectrical impedance vector analysis (BIVA) can support the clinical evaluation of sarcopenia in elderly individuals and evaluate the relationships between phase angle (PhA), physical performance, and muscle mass. Methods: The sample comprised 134 free-living elderly individuals of both sexes aged 69–91 years. Anthropometric parameters, grip strength, dual-energy X-ray absorptiometry findings, bioimpedance analysis results, and physical performance were also measured. The impedance vector distributions were evaluated in elderly individuals using BIVA. Results: BIVA revealed significant differences between the sarcopenia and non-sarcopenia groups (both sexes). The sarcopenia group had a significantly lower PhA than the non-sarcopenia group in both sexes (p < 0.05). PhA was significantly correlated with age, appendicular skeletal muscle (ASM), handgrip strength (HGS), and muscle quality in both sexes and significantly correlated with ASM/Height2 and physical performance in males. Conclusion: BIVA can be used as a field assessment method in elderly Koreans with sarcopenia. PhA is a good indicator of muscle strength, muscle quality, and physical performance in males. These methods can help diagnose sarcopenia in elderly individuals with reduced mobility. [ABSTRACT FROM AUTHOR]

The validity of the impedance parameters of the five body segments estimated using octapolar segmental bioelectrical impedance analysis (OS-BIA) has not been confirmed. This study aimed to verify the accuracy of the resistance (R), reactance (Xc), and phase angle of each five-body segment. The accuracy of the OS-BIA at 50 kHz was measured based on the direct tetrapolar segmental BIA. The differences in the estimated impedance parameters of the five body segments were compared to those measured from the OS-BIA in elderly men (N = 73) and women (N = 63). The estimated 50 kHz-R (Ω) was significantly higher than the measured 50 kHz-R in the right and left arms, and lower than the measured 50 kHz-R of the trunk, right leg, and left leg (all, p < 0.05). The estimated 50 kHz-phase angles in all the five body segments were significantly lower than the measured ones (all, p < 0.05). The findings suggest that the estimated impedance parameters, R, Xc, and phase angle of the trunk, were remarkedly underestimated, limiting the assessment of the physiological state of the organs in the body. Therefore, further intensive research is needed in the field of estimated segmental BIA in the future. [ABSTRACT FROM AUTHOR]

Runners with exercise-induced high blood pressure have recently been reported to exhibit higher levels of cardiac markers, vasoconstrictors, and inflammation. The authors attempted to identify correlations between exercise-related personal characteristics and the levels of biochemical/cardiac markers in marathon runners in this study. Forty healthy runners were enrolled. Blood samples were taken both before and after finishing a full marathon. The change in each cardiac/biochemical marker over the course of the marathon was determined. All markers were significantly (P<.001) increased immediately after the marathon (creatine kinase-MB [CK-MB]: 7.9 ± 2.7 ng/mL, cardiac troponin I (cTnI): 0.06 ± 0.10 ng/mL, N-terminal pro-B-type natriuretic peptide (NT-proBNP): 95.7 ± 76.4, endothelin-1: 2.7 ± 1.16, high-sensitivity C-reactive protein [hs-CRP]: 0.1 ± 0.09, creatine kinase [CK]: 315.7 ± 94.0, lactate dehydrogenase [LDH]: 552.8 ± 130.3) compared with their premarathon values (CK-MB: 4.3 ± 1.3, cTnI: 0.01 ± 0.003, NT-proBNP: 27.6 ± 31.1, endothelin-1: 1.11 ± 0.5, hs-CRP: 0.06 ± 0.07, CK: 149.2 ± 66.0, LDH: 399 ± 75.1). In middle-aged marathon runners, factors related to increased blood pressure were correlated with marathon-induced increases in cTnI, NT-proBNP, endothelin-1, and hs-CRP. These correlations were observed independent of running history, records of finishing, and peak oxygen uptake. [ABSTRACT FROM AUTHOR]

Background. Excessive exercise such as marathon running increases the risk of cardiovascular events that may be related to myocardial infarction and sudden death. We aimed to investigate that the exercise characteristics can be used as a novel indicator of masked hypertension. Methods. A total of 571 middle-aged recreational male marathoners were assigned to a high blood pressure group (HBPG; n=214) or a normal blood pressure group (NBPG; n=357). A graded exercise test was used to examine the hemodynamic response and cardiac events, and the personal exercise characteristics were recorded. Results. Systolic blood pressure and diastolic blood pressure were higher in the HBPG than in the NBPG (p<0.05, all). The marathon history, exercise intensity, and time were longer and higher, whereas the marathon completion duration was shorter in the HBPG than in NBPG (p<0.05, all). HBPG showed a higher frequency of alcohol consumption than NBPG (p<0.05). Conclusion. More excessive exercise characteristics than the normative individuals. If the individuals exhibit high blood pressure during rest as well as exercise, the exercise characteristics could be used as a novel indicator for masked hypertension. [ABSTRACT FROM AUTHOR]

Objective To examine the association between body mass index (BMI) and symptom severity and quality of life (QOL) in patients with fibromyalgia. Methods We assessed BMI status and its association with symptom severity and QOL in 888 patients with fibromyalgia who were seen in a fibromyalgia treatment program and who completed the Fibromyalgia Impact Questionnaire (FIQ) and the Short Form 36 (SF-36) health survey. Results The BMI distribution of nonobese (BMI <25.0 kg/m2), overweight (BMI 25.0-29.9 kg/m2), moderately obese (BMI 30.0-34.9 kg/m2), and severely obese (BMI ≥35.0 kg/m2) patients was 28.4% (n = 252), 26.8% (n = 238), 22.2% (n = 197), and 22.6% (n = 201), respectively. Age was significantly different among the 4 groups, with those having a greater BMI being older ( P = 0.004). After adjustment for age, group differences were significant in the number of tender points ( P = 0.003) and the FIQ and SF-36 scores. The groups with the greater BMI had greater fibromyalgia-related symptoms with worse FIQ total scores ( P < 0.001), as well as worse scores in the FIQ subscales of physical function ( P < 0.001), work missed ( P = 0.04), job ability ( P = 0.003), pain ( P < 0.001), stiffness ( P < 0.001), and depression ( P = 0.03). These groups also had poorer SF-36 scores in physical functioning ( P < 0.001), pain index ( P = 0.005), general health perceptions ( P = 0.003), role emotional ( P = 0.04), and physical component summary ( P < 0.001). Post hoc analysis among the 4 groups showed that differences resided primarily in the severely obese group compared with the other groups. Conclusion In patients with fibromyalgia, severe obesity (BMI ≥35.0 kg/m2) is associated with higher levels of fibromyalgia symptoms and lower levels of QOL. [ABSTRACT FROM AUTHOR]

Here, we report the fabrication of high efficiency poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) and [6,6]-diphenyl-C62-bis(butyric acid methyl ester) (bis-PCBM) blended photovoltaic cells. Bulk heterojunction photovoltaic cells with an ITO/G-PH/P3HT:PCBM (or bis-PCBM)/TiOx/Al configuration were fabricated, and the device using P3HT:bis-PCBM (1:0.7) showed the best performance compared with those using P3HT:PCBM (1:0.7). A maximum power conversion efficiency (PCE) of 4.50% (Voc = 0.64 V, FF = 0.62) was achieved with P3HT:bis-PCBM (1:0.7). [ABSTRACT FROM AUTHOR]

Two sets of cross-correlated relaxation rates involving chemical shift anisotropy and dipolar interactions have been measured in an RNA kissing complex. In one case, both the CSA and dipolar interaction tensors are located on the same nucleotide base and are rigidly fixed with respect to each other. In the other case, the CSA tensor is located on the nucleotide base whereas the dipolar interaction is located on the adjoining ribose unit. Analysis of the measured rates in terms of isotropic or anisotropic rotational diffusion has been carried out for both cases. A marked difference between the two models is observed for the cross-correlation rates involving rigidly fixed spin interactions. The influence of internal motions about the glycosidic linkage between the nucleotide base and the ribose unit on cross-correlated relaxation rates has been estimated by applying a model of restricted rotational diffusion. Local motions seem to have a more pronounced effect on cross-correlated relaxation rates when the two spin interactions are not rigidly fixed with respect to each other. [ABSTRACT FROM AUTHOR]

Reports on the investigation of the dynamics and conformation of the membrane-interacting HA2 domain of the hemagglutinin protein of the influenza virus. What the surface of the influenza virus is coated with; Nature of the beginnings of virus infections; Subunits hemagglutinin (HA) protein consists of; Procedures used in investigation.

Presents a study examining subsequent pH-dependent changes of a membrane-bound hemagglutinin (HA2) construct. Materials and methods used; Previous studies which indicated that under mildly acidic conditions HA1 is dissociated from HA2; results and discussion of the study.

In spite of the recent extension of our knowledge on technological innovation, little inquiry has been made of the distinctive characteristics between R&D firms and non-R&D firms, as well as between product-innovative firms and process-innovative firms. To this end, the main objective of this empirical study, grounded on a large-scale innovation survey of Korean manufacturing firms, is to contrast these two types of firms. The results were mixed. Some hypotheses were confirmed while others were discordant with expectation. By and large, R&D firms and product-innovative firms seem to share a similar propensity, whereas non-R&D firms and process-innovative firms are alike in character. However, there were some unexpected findings which merit attention and are worthy of in-depth examination. Although the study is subject to limitations in terms of its research design and data gathering, the results render some important policy implications. Furthermore, comparative analyses between different types of innovations need to be addressed more extensively in future research. [ABSTRACT FROM AUTHOR]

Background: An inversion device, which is used to suspend one's body and perform traction therapy, was introduced as an inversion table under the name of "Geokkuri" in South Korea. Fall injuries while hanging on inversion tables are among the most devastating spine injuries, as the likelihood of severe neurological sequelae such as tetraplegia increases. However, its enormous danger has been overlooked and this devastating injury has become a common clinical entity over time. The limited number of studies reported imply the lack of interest of researchers in these injuries. We reviewed three cases of spinal cord injury sustained on inversion tables in different environments and report the potential danger associated with the use of inversion tables to facilitate a safer exercise environment. [ABSTRACT FROM AUTHOR]

Objectives: We aimed to determine the usefulness and effectiveness of a submandibular push exercise with visual feedback from a pressure sensor in patients with dysphagia through continuous exercise sessions. Methods: Twelve patients with dysphagia of various etiologies were included. A total of five exercise sessions (every 3 or 4 days) over three weeks were conducted. During the submandibular push exercise, patients were instructed to maintain a maximum force for 3 s, repeated for 1 min to measure the number of exercises, the maximum pressure, and the area of the pressure-time graph. We statistically compared the values of each exercise trial. Results: Among the 12 patients, eight completed the exercise sessions. As the number of exercise trials increased, the maximum pressure and the area in the pressure-time graph showed a significant increase compared to the previous attempt (p < 0.05). The maximum pressure and the area of the pressure-time graph improved from the first to the fourth session (p < 0.05). The values were maintained after the fourth session, and there was no significant difference between the fourth and the fifth exercise (p > 0.05). There was no significant difference between successful and non-successful groups, except for the Modified Barthel Index (p < 0.05). Conclusion: Through repetitive exercise training, the submandibular push exercise using visual feedback from a pressure sensor can be applied as an exercise method to strengthen swallowing related muscles, such as the suprahyoid and infrahyoid muscles. However, additional studies including more patients and a long-term study period are warranted to evaluate the effects of the exercise for improvement of dysphagia. [ABSTRACT FROM AUTHOR]