522 research outputs found

    KINETIC PROPERTIES AND EMG ACTIVITY OF NORMAL AND OVER-SPEED PEDALING IN TRACK SPRINT CYCLISTS: A CASE STUDY

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    Track sprint cycling requires unique skills. We investigate the pedaling kinetics and muscle coordination of a male track sprinter (170cm, 65kg, peak power 1513W) to see if they differ from that of a non-sprinter, and if the subjectā€™s own technique vary from normal riding to an under-load maximal cadence sprint. Two trials were collected using 3D motion capture technology. EMG signals of 8 leg muscles were recorded. Joint torque and power of each trial were calculated using a subject specific musculoskeletal model, with realistic pedal forces as input to our dynamic simulation. Flexion torque appears at the knee during its extension, different from the non-sprinters. Joint torque and power appears similar for both trials, but 6 of the 8 muscles showed differences in EMG patterns. These findings could potentially benefit the evolvement of training methods

    Open-Loop Neurofeedback Audiovisual Stimulation: A Pilot Study of Its Potential for Sleep Induction in Older Adults

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    This pilot study tested the efficacy of a 30-min audio-visual stimulation (AVS) program for the treatment of chronic insomnia in older adults. Chronic insomnia has been conceptualized as entailing increased cortical high frequency EEG activity at sleep onset and during NREM sleep. We hypothesized that an AVS program gradually descending from 8 to 1 Hz would potentially reduce the excessive cortical activation that is thought to contribute to difficulties with initiating and maintaining sleep. Accordingly, we conducted an intervention study of AVS using a pre-post design. Eight older adults (88 Ā± 8.7 years) complaining of chronic insomnia self-administered a 30-min AVS program nightly at bedtime for one month. Sleep was assessed at baseline and throughout the 4-week intervention. After using AVS for 4 weeks, significant improvement was reported in insomnia symptoms (ISI, p = 0.002) and sleep quality (PSQI, p = 0.004); with moderate to large effect sizes (Partial Eta2: 0.20-0.55)(Cohen\u27s d: 0.7-2.3). The training effect (self-reported sleep improvement) was observed at the end of week one and persisted through the 1-month intervention. The results from this pilot study suggest that further exploration of AVS as a treatment for insomnia is warranted

    A Pilot Study of Audio-Visual Stimulation as a Self-Care Treatment for Insomnia in Adults with Insomnia and Chronic Pain

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    This pilot study tested the efficacy of an audio-visual stimulation (AVS) program for the promotion of sleep in individuals with chronic pain. Insomnia and chronic pain are common comorbid conditions and their relationship has been viewed as bidirectional. Recent studies suggest a relatively dominant role of sleep in this dyad. The premise of this pilot study was that AVS enhances low frequency while reducing high frequency brain activity resulting in decreased hyperarousal and improved sleep with potential consequent reduction in pain. We conducted a pilot intervention study of AVS using a pre-post design. Participants self-administered a 30-min AVS program nightly at bedtime for 1 month. Sleep and pain were assessed at baseline and at the conclusion of the 4-week intervention phase. Nine adults (mean age 33 Ā± 15.8 years; female, 89 %) completed the study. After using the AVS device for 4 weeks, significant improvement was seen in reported insomnia (ISI, p = 0.003), pain severity (BPI, p = 0.005), and pain interference with functioning (BPI, p = 0.001). Large effect sizes (Partial Ī·2 0.20-0.94) (Cohen\u27s d 0.44-1.45) were observed. The results of this pilot study suggest that the AVS program may be efficacious in decreasing both insomnia and pain symptoms. In order to better assess the efficacy of AVS for sleep promotion and possible pain reduction, more definitive randomized controlled trials will be needed. These should include appropriate sample sizes, objective measures of sleep and pain, and longitudinal follow-up

    Regulation of CLC-1 chloride channel biosynthesis by FKBP8 and Hsp90Ī².

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    Mutations in human CLC-1 chloride channel are associated with the skeletal muscle disorder myotonia congenita. The disease-causing mutant A531V manifests enhanced proteasomal degradation of CLC-1. We recently found that CLC-1 degradation is mediated by cullin 4 ubiquitin ligase complex. It is currently unclear how quality control and protein degradation systems coordinate with each other to process the biosynthesis of CLC-1. Herein we aim to ascertain the molecular nature of the protein quality control system for CLC-1. We identified three CLC-1-interacting proteins that are well-known heat shock protein 90 (Hsp90)-associated co-chaperones: FK506-binding protein 8 (FKBP8), activator of Hsp90 ATPase homolog 1 (Aha1), and Hsp70/Hsp90 organizing protein (HOP). These co-chaperones promote both the protein level and the functional expression of CLC-1 wild-type and A531V mutant. CLC-1 biosynthesis is also facilitated by the molecular chaperones Hsc70 and Hsp90Ī². The protein stability of CLC-1 is notably increased by FKBP8 and the Hsp90Ī² inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG) that substantially suppresses cullin 4 expression. We further confirmed that cullin 4 may interact with Hsp90Ī² and FKBP8. Our data are consistent with the idea that FKBP8 and Hsp90Ī² play an essential role in the late phase of CLC-1 quality control by dynamically coordinating protein folding and degradation

    The History, Mechanism, and Clinical Application of Auricular Therapy in Traditional Chinese Medicine

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    Auricular therapy includes acupuncture, electroacupuncture, acupressure, lasering, cauterization, moxibustion, and bloodletting in the auricle. For 2500 years, people have employed auricular therapy for treating diseases, but the methods have been limited to bloodletting and cauterization. Only after 1957, the international scientific community became aware that the map of the ear resembles an inverted fetus, its introduction has led to auricular acupuncture (AA) becoming a more systemic approach, and, following the identification and standardization of more precise points, AA has been employed in clinical applications. The mechanisms of AA are considered to have a close relationship with the autonomic nervous system, the neuroendocrine system, neuroimmunological factors, neuroinflammation, and neural reflex, as well as antioxidation. Auricular therapy has been applied, for example, for pain relief, for the treatment of epilepsy, anxiety, and obesity, and for improving sleep quality. However, the mechanisms and evidence for auricular therapy warrant further study

    The role of TonEBP in regulation of AAD expression and dopamine production in renal proximal tubule cells upon hypertonic challenge

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    a b s t r a c t Renal proximal tubule cells overexpress aromatic L-amino acid decarboxylase (AAD) to produce dopamine, which inhibits salt absorption in the hypertonic environment. We examined the effect of TonEBP on AAD expression in human proximal tubule epithelial cells, HK-2 cell line. Confocal microscopy showed that after 2 h of exposure to the hypertonic medium, TonEBP accumulation in nuclei increased as compared to the isotonic control. The activated TonEBP enhanced the mRNA expression of the representative downstream genes (i.e., SMIT and TauT). Meanwhile, AAD protein abundance also increased with TonEBP activation. EMSA and luciferase reporter assay showed that TonEBP was involved in transcriptional regulation of AAD upon hypertonic stress. Inactivation of TonEBP by the p38 inhibitor SB203580, or TonEBP shRNA significantly reduced AAD expression, which was rescued by re-expressing Myc-tagged TonEBP. Up-regulation of AAD increased dopamine synthesis, and dopamine inhibited NKA activity in hypertonic condition. These results suggested that TonEBP played an important role in the epithelial cells of renal proximal tubule upon hypertonic stress by enhancing AAD expression, which could promote dopamine secretion to negative regulate NKA activity. The elucidation of a new mechanism described in this study combined with previous findings provides more insights into this issue

    Experimental Demonstration of Stationary Dark-State Polaritons Dressed by Dipole-Dipole Interaction

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    Dark-state polaritons (DSPs) based on the effect of electromagnetically induced transparency are bosonic quasiparticles, representing the superpositions of photons and atomic ground-state coherences. It has been proposed that stationary DSPs are governed by the equation of motion closely similar to the Schr\"{o}dinger equation and can be employed to achieve Bose-Einstein condensation (BEC) with transition temperature orders of magnitude higher than that of the atomic BEC. The stationary-DSP BEC is a three-dimensional system and has a far longer lifetime than the exciton-polariton BEC. In this work, we experimentally demonstrated the stationary DSP dressed by the Rydberg-state dipole-dipole interaction (DDI). The DDI-induced phase shift of the stationary DSP was systematically studied. Notably, the experimental data are consistent with the theoretical predictions. The phase shift can be viewed as a consequence of elastic collisions. In terms of thermalization to achieve BEC, the Ī¼\mum2^2-size interaction cross-section of the DDI can produce a sufficient elastic collision rate for the stationary DSPs. This work makes a substantial advancement toward the realization of the stationary-DSP BEC

    Cyclooxygenase-2 enhances Ī±2Ī²1 integrin expression and cell migration via EP1 dependent signaling pathway in human chondrosarcoma cells

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    <p>Abstract</p> <p>Background</p> <p>Cyclooxygenase (COX)-2, the inducible isoform of prostaglandin (PG) synthase, has been implicated in tumor metastasis. Interaction of COX-2 with its specific EP receptors on the surface of cancer cells has been reported to induce cancer invasion. However, the effects of COX-2 on migration activity in human chondrosarcoma cells are mostly unknown. In this study, we examined whether COX-2 and EP interaction are involved in metastasis of human chondrosarcoma.</p> <p>Results</p> <p>We found that over-expression of COX-2 or exogenous PGE<sub>2 </sub>increased the migration of human chondrosarcoma cells. We also found that human chondrosarcoma tissues and chondrosarcoma cell lines had significant expression of the COX-2 which was higher than that in normal cartilage. By using pharmacological inhibitors or activators or genetic inhibition by the EP receptors, we discovered that the EP1 receptor but not other PGE receptors is involved in PGE<sub>2</sub>-mediated cell migration and Ī±2Ī²1 integrin expression. Furthermore, we found that human chondrosarcoma tissues expressed a higher level of EP1 receptor than normal cartilage. PGE<sub>2</sub>-mediated migration and integrin up-regulation were attenuated by phospholipase C (PLC), protein kinase C (PKC) and c-Src inhibitor. Activation of the PLCĪ², PKCĪ±, c-Src and NF-ĪŗB signaling pathway after PGE<sub>2 </sub>treatment was demonstrated, and PGE<sub>2</sub>-induced expression of integrin and migration activity were inhibited by the specific inhibitor, siRNA and mutants of PLC, PKC, c-Src and NF-ĪŗB cascades.</p> <p>Conclusions</p> <p>Our results indicated that PGE<sub>2 </sub>enhances the migration of chondrosarcoma cells by increasing Ī±2Ī²1 integrin expression through the EP1/PLC/PKCĪ±/c-Src/NF-ĪŗB signal transduction pathway.</p

    Associations between Aerosol Types and Chlorophyll-a Concentration over Coastal Area in East Asia from Satellite Observations

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    This study improved significantly the relationship between aerosol optical depth (AOD) and sea surface chlorophyll-a concentration (Chl-a), after considering the effects of sea surface temperature (SST), ocean surface current (OSC) and type of aerosols. The decadal satellite-retrieved Orbview-2/SeaWiFS Chl-a and Terra/MODIS AOD550nm data (from March 2000 to December 2010) were used to investigate the impact of atmospheric aerosols on the Chl-a concentration in the coastal water around the region of East Asia (equator to 75ƂĀ°N and from 100ƂĀ°E to 180ƂĀ°E). Two sets of sequential areas (A1 to A10 and B1 to B9) were selected for examining and excluding the influence of SST and OSC. After taking the potential location of aerosol deposition from OSC into account, an obvious correlation between AOD550nm and Chl-a concentration was demonstrated around the site of study area A. For aerosol partition, the Normalized Gradient Aerosol Index (NGAI) was applied to MODIS AOD products for aerosol type identification and mixed status determination. The results indicated that the type of mineral dust (DS) significantly increases the Chl-a while the biomass burning (BB) aerosols may restrain the Chl-a. This seems to be a non-impact of anthropogenic pollutant (AP) on Chl-a within the surface layer. The other area, B (B1 to B9), next to the region of area A, also shows similar results with high consistency; thus, the significant impact of DS aerosols on Chl-a production is suggested over the coastal region of East Asia
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