This study aimed to investigate the effect of taekwondo shoes on anterior cruciate ligament injury risk factors in taekwondo athletes performing jump whip kicks.
The participants comprised 10 ...taekwondo athletes with no history of anterior cruciate ligament or lower extremity injuries within the past 12 months. The maximum hip flexion angle, maximum knee valgus angle, maximum knee extension moment, maximum knee lateral rotation moment, and quadriceps and hamstring muscle activity ratios were analyzed using video, ground reaction force, and electromyography analysis systems.
The maximum knee valgus angle was significantly lower when wearing taekwondo shoes while performing taekwondo jump whip kicks (p=0.04), and the activity ratio of the quadriceps and hamstring muscles was low (p=0.10).
Wearing taekwondo shoes had a positive effect on preventing anterior cruciate ligament injury; therefore, the importance of wearing taekwondo shoes should be communicated clearly to athletes and coaches to increase their frequency of use and change negative perceptions regarding taekwondo shoe use during training. Taekwondo competition movements can cause damage to the anterior cruciate ligament owing to sudden changes in direction and jump movements. Our results suggest that wearing taekwondo shoes can help prevent anterior cruciate ligament injuries.
Cette étude visait à étudier l’effet des chaussures de taekwondo sur les facteurs de risque de blessure au ligament croisé antérieur chez les athlètes de taekwondo effectuant des coups de fouet sautés.
Les participants comprenaient 10 athlètes de taekwondo sans antécédents de ligament croisé antérieur ou de blessures aux membres inférieurs au cours des 12 derniers mois. L’angle de flexion maximal de la hanche, l’angle maximal de valgus du genou, le moment maximal d’extension du genou, le moment maximal de rotation latérale du genou et les rapports d’activité des quadriceps et des ischio-jambiers ont été analysés à l’aide de systèmes d’analyse vidéo, de force de réaction au sol et d’électromyographie.
L’angle de valgus maximal du genou était significativement plus faible lorsque l’on portait des chaussures de taekwondo tout en exécutant des coups de fouet de taekwondo (p=0,04), et le rapport d’activité des quadriceps et des muscles ischio-jambiers était faible (p=0,10).
Le port de chaussures de taekwondo a eu un effet positif sur la prévention des blessures du ligament croisé antérieur; par conséquent, l’importance du port de chaussures de taekwondo doit être clairement communiquée aux athlètes et aux entraîneurs pour augmenter leur fréquence d’utilisation et changer les perceptions négatives de l’utilisation des chaussures de taekwondo pendant l’entraînement. Les mouvements de compétition de taekwondo peuvent endommager le ligament croisé antérieur en raison de changements brusques de direction et de mouvements de saut. Nos résultats suggèrent que les blessures du ligament croisé antérieur pourraient être évitées en portant des chaussures de taekwondo.
A fault diagnosis algorithm, which is necessary for constructing a reliable power conversion system, should detect fault occurrences as soon as possible to protect the entire system from fatal ...damages resulting from system malfunction. In this paper, a fault diagnosis algorithm is proposed to detect open- and short-circuit faults that occur in a boost converter switch. The inductor voltage is abnormally kept at a positive DC value during a short-circuit fault in the switch or at a negative DC value during an open-circuit fault condition until the inductor current becomes zero. By employing these abnormal properties during faulty conditions, the inductor voltage is compared with the switching function to detect each fault type by generating fault alarms when a fault occurs. As a result, from the fault alarm, a decision is made in response to the fault occurrence and the fault type in less than two switching time periods using the proposed algorithm constructed in analogue circuits. In addition, the proposed algorithm has good resistivity to discontinuous current-mode operation. As a result, this algorithm features the advantages of low cost and simplicity because of its simple analogue circuit configuration.
The development of multidrug resistance 1 (MDR1) can be mediated by a number of different mechanisms but elevated gene expression of MDR1 (P-glycoprotein) has often been a major cause of ...chemoresistance in many cancer cells. Therefore, the present study aimed to investigate the role of forkhead box-containing protein, O subfamily (FoxO), transcription factors in regulating the MDR1 gene expression. The proximal promoter region of the human MDR1 contained a putative FoxO-binding site, which partially overlapped with the enhancer/enhancer-binding protein β-binding region. Gel shift and immunoblot analysis of subcellular fractions revealed that nuclear levels of FoxO1 and its DNA-binding activity were selectively enhanced in MCF-7/ADR cells, which was reversed by a FoxO1 antibody. Reporter gene assays showed that the transcription of MDR1 gene is stimulated by FoxO1 overexpression. Moreover, both MDR1 expression and doxorubicin resistance in MCF-7/ADR cells were reversed by FoxO1 small interfering RNA (siRNA). The MDR1 expression in MCF-7/ADR cells was also inhibited by insulin, a functional FoxO1 inactivator. In conclusion, FoxO1 is a novel transcriptional activator of MDR1 and is crucial for MDR1 induction in MCF-7/ADR cells.
Aims: To evaluate an integrated cell culture (ICC)–multiplex‐nested PCR using the buffalo green monkey kidney (BGMK) cells for the simultaneous detection of both enteroviruses and adenoviruses in ...surface water and tap water samples and optimize the procedure for more sensitive detection of virus showing no apparent cytopathic effect (CPE).
Methods and Results: A total of 69 surface water and 50 tap water samples were analysed by the ICC–multiplex‐nested PCR. All the PCRs were performed five times with a cell lysate from each flask after at least 2 weeks incubation. Forty‐six surface water samples (66·7%) and 23 tap water samples (46·0%) exhibited CPE by the cell culture method. By using an ICC–multiplex‐nested PCR, 53 surface water samples (76·8%) and 29 tap water samples (58·0%) were determined as containing infectious enteric viral particles.
Conclusions: An ICC–PCR method with a long incubation time using BGMK cells enables the simultaneous detection of enteroviruses and adenoviruses from environmental water samples, including tap water, even with low numbers of viruses.
Significance and Impact of the Study: A method capable of detecting small numbers of viral particles is necessary.
A cyclic shear testing system was established to investigate the mechanical behavior of rough rock joints under cyclic loading conditions. Laboratory cyclic shear tests were conducted for two joint ...types of Hwangdeung granite and Yeosan marble: saw-cut and split tensile joints. Prior to test, the roughness of each specimen was characterized by measuring the surface topography using a laser profilometer. Several important aspects of cyclic joint behavior, such as high peak shear strength and non-linear dilation in the first loading cycle, different frictional resistance for the reversed shear loading direction, and anisotropic shear behavior and its dependence on the normal stress level were identified from the cyclic shear test results. These features and their variations in the subsequent loading cycles are mainly due to the effect of second order asperities and strength of rock material. It was also observed from experimental results that degradation of asperities under cyclic shear loading also followed the exponential degradation laws for asperity angle and the mechanism for asperity degradation would be different depending upon the shearing direction and the type of asperities. Based on the experimental results an elasto-plastic constitutive model, which can consider the degradation of second order asperities, was proposed. Numerical simulations for the monotonic and cyclic shear loading indicated agreement with the laboratory test results.
Deep images of 10 early-type galaxies in low-density environments have been obtained with the Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope. The global properties of the ...globular cluster (GC) systems of the galaxies have been derived in order to investigate the role of the environment in galaxy formation and evolution. Using the ACS Virgo Cluster Survey as a high-density counterpart, the similarities and differences between the GC properties in high- and low-density environments are presented. We find a strong correlation of the GC mean colours and the degree of colour bimodality with the host galaxy luminosity in low-density environments, in good agreement with high-density environments. In contrast, the GC mean colours at a given host luminosity are somewhat bluer Δ(g−z) ∼ 0.05 than those for cluster galaxies, indicating more metal poor (ΔFe/H ∼ 0.10 − 0.15) and/or younger (Δage > 2 Gyr) GC systems than those in dense environments. Furthermore, with decreasing host luminosity, the colour bimodality disappears faster, when compared to galaxies in cluster environments. Our results suggest that: (1) in both high- and low-density environments, the mass of the host galaxy has the dominant effect on GC system properties; (2) the local environment has only a secondary effect on the history of GC system formation; and (3) GC formation must be governed by common physical processes across a range of environments.
This study aimed to analyze the use of the revised International Prognostic Scoring System (IPSS-R) assessed after hypomethylating treatment (HMT) for patients with myelodysplastic syndrome (MDS) ...undergoing an allogeneic stem cell transplantation (SCT). Among 115 patients who received pre-SCT HMT, comparison analysis of the prognostic values between the IPSS-R at the time of HMT (IPSS-R@HMT) and at the time of SCT after HMT (IPSS-R@SCT) showed a significantly higher predictive power for overall survival (OS) of the latter. Alteration in IPSS-R risk occurred in 60%, while the patients with 'down-staged' IPSS-R@SCT showed better OS compared with those with 'unchanged' or 'up-staged' risk. On multivariate analysis in all 201 patients, IPSS-R@SCT, monosomal karyotype, treatment failure to pre-SCT treatment, and high hematopoietic cell transplantation-comorbidity index were independently associated with OS. Constructed using these factors, the MDS Transplantation Prognostic Scoring System (MTPSS) identified four risk groups with 4-year OS of 76.4% in low, 61.4% in intermediate-1 and 21.9% in intermediate-2 risk groups, whereas all in the high risk group died within 2 years after SCT (P<0.001). Our study emphasizes the need for further studies aiming to evaluate a transplantation prognostic model such as the MTPSS to make appropriate decisions for transplantation in MDS.
A novel, solution immersed silicon (SIS)-based sensor has been developed which employs the non-reflecting condition (NRC) for a p-polarized wave. The SIS sensor's response is almost independent of ...change in the refractive index (RI) of a buffer solution (BS) which makes it capable of measuring low-concentration and/or low-molecular-weight compounds.
Background and Objective: Alveolar bone resorption is a characteristic feature of periodontal diseases and involves removal of both the mineral and the organic constituents of the bone matrix, a ...process mainly carried out by multinucleated osteoclast cells. (‐)‐Epigallocatechin gallate, the main constituent of green tea polyphenols, has been reported to induce the apoptotic cell death of osteoclasts and to modulate caspase activation in various tumor cells. In the present study, we investigated the inhibitory effect of (‐)‐epigallocatechin gallate on osteoclast survival and examined if (‐)‐epigallocatechin gallate mediates osteoclast apoptosis via caspase activation.
Material and Methods: The effect of (‐)‐epigallocatechin gallate on osteoclast survival was examined by tartrate‐resistant acid phosphatase (TRAP) staining in osteoclasts differentiated from RAW 264.7 cells. In addition, we evaluated the apoptosis of osteoclasts by (‐)‐epigallocatechin gallate using a DNA‐fragmentation assay. Involvement of caspase in (‐)‐epigallocatechin gallate‐mediated osteoclast apoptosis was evaluated by treatment with a general caspase inhibitor, Z‐VAD‐FMK. Moreover, the effect of (‐)‐epigallocatechin gallate on the activation of caspase‐3 was assessed by a colorimetric activity assay and western blotting.
Results: (‐)‐Epigallocatechin gallate significantly inhibited, in a dose‐dependent manner, the survival of osteoclasts differentiated from RAW 264.7 cells and induced the apoptosis of osteoclasts. Treatment with (‐)‐epigallocatechin gallate resulted in DNA fragmentation and induced the activation of caspase‐3 in RAW 264.7 cell‐derived osteoclasts. Additional treatment with Z‐VAD‐FMK suppressed these effects of (‐)‐epigallocatechin gallate.
Conclusion: From these findings, we could suggest that (‐)‐epigallocatechin gallate might prevent alveolar bone resorption by inhibiting osteoclast survival through the caspase‐mediated apoptosis.
Helium refrigeration system for the KSTAR Choi, C.H.; Chang, H.-S.; Park, D.S. ...
Fusion engineering and design,
11/2006, Volume:
81, Issue:
23
Journal Article, Conference Proceeding
Peer reviewed
The KSTAR, a tokamak with fully superconducting (SC) magnets, is under construction in the National Fusion Research Center (NFRC). For the proper operation of the KSTAR, the superconducting magnets ...have to be maintained below the critical temperature of the SC components while charged at their corresponding operation current values. In this paper, a large scale helium refrigeration system (HRS) which has been designed and developed to fulfill such a mission is presented.
The cold components of the KSTAR are kept at their operating temperatures thanks to various kinds of cryogenic helium which are produced in the cold box (C/B) of the HRS in combination with the supercritical helium (SHe) cryogenic circulators and a liquid helium (LHe) thermal damper (TD) located in the primary helium distribution box (D/B #1). The relative distribution of the cryogenic helium among the cooling channels of each cold component of the KSTAR is performed by the secondary helium distribution system which consists of the secondary distribution box (D/B #2) and the cryogenic transfer lines (CTL’s).
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