122 research outputs found

    Strength Gains by Motor Imagery with Different Ratios of Physical to Mental Practice

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    The purpose of this training study was to determine the magnitude of strength gains following a high-intensity resistance training (i.e., improvement of neuromuscular coordination) that can be achieved by imagery of the respective muscle contraction imagined maximal isometric contraction (IMC training). Prior to the experimental intervention, subjects completed a 4-week standardized strength training program. 3 groups with different combinations of real maximum voluntary contraction (MVC) and mental (IMC) strength training (M75, M50, M25; numbers indicate percentages of mental trials) were compared to a MVC-only training group (M0) and a control condition without strength training (CO). Training sessions (altogether 12) consisted of four sets of two maximal 5-s isometric contractions with 10 s rest between sets of either MVC or IMC training. Task-specific effects of IMC training were tested in four strength exercises commonly used in practical settings (bench pressing, leg pressing, triceps extension, and calf raising). Maximum isometric voluntary contraction force (MVC) was measured before and after the experimental training intervention and again 1 week after cessation of the program. IMC groups (M25, M50, M75) showed slightly smaller increases in MVC (3.0% to 4.2%) than M0 (5.1%), but significantly stronger improvements than CO (−0.2%). Compared to further strength gains in M0 after 1 week (9.4% altogether), IMC groups showed no “delayed” improvement, but the attained training effects remained stable. It is concluded that high-intensity strength training sessions can be partly replaced by IMC training sessions without any considerable reduction of strength gains

    Connecting and changing places : globalisation and tourism mobility on the Otago Peninsula, Dunedin, New Zealand

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    Globalisation, localisation and tourism are processes that are closely interconnected. They relate to historical mobilities and non-mobilities of humans, ideas and capital that impact on environment, economy, culture, politics and technology. Yet, these impacts on local tourism destinations are not well researched. Small destinations are not researched in relation to the impact of globalisation and tourism over time. The thesis develops an historical understanding of globalisation, localisation and tourism within the context of the Otago Peninsula in Dunedin, New Zealand. It portrays the 'glocalisation' processes, the specific mix of local and global forces that shaped the Otago Peninsula and created the basis for the current conditions, especially for tourism. The research on the Otago Peninsula clearly identifies different stages of mobilities to the place, generally following a similar pattern to other places in New Zealand settled in the latest phase of colonialism. The first settlers, the Polynesians, were followed by white explorers, sealers and whalers at the beginning of the 19th century who exploited a local resource that was valuable to international markets. After the overexploitation of the resource white settlers arrived to 'conquer' nature and to improve , on their living conditions in a new country. They provided the basis for the following mobilities by developing or facilitating a local, national, regional and international infrastructure. Towards the end of the 19th century the major European migration had ended. The next major mobility movement was recreationists from the close urban centre of Dunedin who used the infrastructure on the Otago Peninsula at weekends, as time, money and technology limited mobilities to places further away. From the 1920s onwards, when these limitations were reduced by, for example, a better infrastructure and new technological developments such as the car and more disposable income and time, New Zealanders started to more widely discover their own country. Finally, international travellers started to arrive in the 1960s after the main obstacle, the distance and time needed to travel to New Zealand and the Otago Peninsula, was reduced by technological development, especially airplanes. During all of these phases of mobility, the Otago Peninsula became increasingly interconnected with other places on the globe, creating the conditions for tourism. In this study, within the context of the phase model of mobilities, a variety of research methods were used to assess the impact of globalisation, localisation and tourism on the Otago Peninsula. These methods include literature, newspaper, local promotional materials and photographic images analysis, as well as participant observation and historical interviews. The research clearly highlights the changes to the Otago Peninsula created by historical events that happened as a consequence of human mobility. Internal and external conditions at different geographical scales, ranging from the local to the global, changed the economy, the environment, culture, politics and the use of technology on the Otago Peninsula. The place was (and still is) constantly globalised. Consequently, international tourism, as one of the more recent forces, has to be managed within this historical framework of stretched social relations, the intensification of flows, increasing global interactions and the development of global infrastructure and networks

    Diagnostic vascular ultrasonography with the help of color Doppler and contrast-enhanced ultrasonography

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    The use of ultrasonography and especially of contrast-enhanced ultrasonography (CEUS) in the diagnosis of vascular pathologies before and after interventions has significantly increased over the past years due to the broader availability of modern ultrasound systems with CEUS capabilities and more trained user experience in this imaging modality. For the preinterventional and postinterventional work-up of carotid diseases, duplex ultrasound as well as CEUS have been established as the standard-of-care examination procedures for diagnosis, evaluation, and follow-up. In addition to its use for carotid arterial diseases, ultrasonography has also become the primary modality for the screening of vascular pathologies. This review describes the most common pathologies found in ultrasonography of the carotid arteries, the abdominal aorta, and the femoral arteries

    Magnetic Resonance Imaging-Guided Focused Ultrasound Treatment of Symptomatic Uterine Fibroids Impact of Technology Advancement on Ablation Volumes in 115 Patients

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    Objectives: The aim of this study was to assess the impact of the advanced technology of the new ExAblate 2100 system (Insightec Ltd, Haifa, Israel) for magnetic resonance imaging (MRI)-guided focused ultrasound surgery on treatment outcomes in patients with symptomatic uterine fibroids, as measured by the nonperfused volume ratio. Materials and Methods: This is a retrospective analysis of 115 women (mean age, 42 years; range, 27-54 years) with symptomatic fibroids who consecutively underwent MRI-guided focused ultrasound treatment in a single center with the new generation ExAblate 2100 system from November 2010 to June 2011. Mean +/- SD total volume and number of treated fibroids (per patient) were 89 +/- 94 cm(3) and 2.2 +/- 1.7, respectively. Patient baseline characteristics were analyzed regarding their impact on the resulting nonperfused volume ratio. Results: Magnetic resonance imaging-guided focused ultrasound treatment was technically successful in 115 of 123 patients (93.5%). In 8 patients, treatment was not possible because of bowel loops in the beam pathway that could not be mitigated (n = 6), patient movement (n = 1), and system malfunction (n = 1). Mean nonperfused volume ratio was 88% +/- 15% (range, 38%-100%). Mean applied energy level was 5400 +/- 1200 J, and mean number of sonications was 74 +/- 27. No major complications occurred. Two cases of first-degree skin burn resolved within 1 week after the intervention. Of the baseline characteristics analyzed, only the planned treatment volume had a statistically significant impact on nonperfused volume ratio. Conclusions: With technological advancement, the outcome of MRI-guided focused ultrasound treatment in terms of the nonperfused volume ratio can be enhanced with a high safety profile, markedly exceeding results reported in previous clinical trials

    Reducing tumor growth and angiogenesis using a triple therapy measured with Contrast-enhanced ultrasound (CEUS)

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    Background To evaluate the in vivo response by detecting the anti-angiogenic and invasion-inhibiting effects of a triple-combination-therapy in an experimental-small-animal-squamous-cell-carcinoma-model using the “flash-replenishment” (FR) method to assess tissue hemodynamics via contrast-enhanced-ultrasound (CEUS). Methods Human hypopharynx-carcinoma-cells were subcutaneously injected into the left flank of 22-female-athymic-nude-rats. After seven days of subcutaneous tumor growth, FR-measurements were performed on each rat. Treatment-group and control-group were treated every day for a period of one week, with the treatment-group receiving solvents containing a triple therapy of UpamostatÂź, CelecoxibÂź and IlomastatÂź and the control-group solvents only. On day seven, follow-up measurements were performed using the same measurement protocol to assess the effects of the triple therapy. VueBoxÂź was used to quantify the kinetic parameters and additional immunohistochemistry analyses were performed for comparison with and validation of the CEUS results against established methods (Proliferation/Ki-67, vascularization/CD31, apoptosis/caspase3). Results Compared to the control-group, the treatment-group that received the triple-therapy resulted in a reduction of tumor growth by 48.6% in size. Likewise, the immunohistochemistry results showed significant decreases in tumor proliferation and vascularization in the treatment-group in comparison to the control-group of 26%(p≀0.05) and 32.2%(p≀0.05) respectively. Correspondingly, between the baseline and follow-up measurements, the therapy-group was associated with a significant(p ≀ 0.01) decrease in the relative-Blood-Volume(rBV) in both the whole tumor(wt) and hypervascular tumor(ht) areas (p≀0.01), while the control-group was associated with a significant (p≀0.01) increase of the rBV in the wt area and a non-significant increase (p≀0.16) in the ht area. The mean-transit-time (mTT) of the wt and the ht areas showed a significant increase (p≀0.01) in the follow-up measurements in the therapy group. Conclusion The triple-therapy is feasible and effective in reducing both tumor growth and vascularization. In particular, compared with the placebo-group, the triple-therapy-group resulted in a reduction in tumor growth of 48.6% in size when assessed by CEUS and a significant reduction in the number of vessels in the tumor of 32% as assessed by immunohistochemistry. As the immunohistochemistry supports the CEUS findings, CEUS using the “flash replenishment”(FR) method appears to provide a useful assessment of the anti-angiogenic and invasion-inhibiting effects of a triple combination therapy

    High resolution carotid black-blood 3T MR with parallel imaging and dedicated 4-channel surface coils

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    Background: Most of the carotid plaque MR studies have been performed using black-blood protocols at 1.5 T without parallel imaging techniques. The purpose of this study was to evaluate a multi-sequence, black-blood MR protocol using parallel imaging and a dedicated 4-channel surface coil for vessel wall imaging of the carotid arteries at 3 T. Materials and methods: 14 healthy volunteers and 14 patients with intimal thickening as proven by duplex ultrasound had their carotid arteries imaged at 3 T using a multi-sequence protocol (time-of-flight MR angiography, pre-contrast T1w-, PDw- and T2w sequences in the volunteers, additional post-contrast T1w- and dynamic contrast enhanced sequences in patients). To assess intrascan reproducibility, 10 volunteers were scanned twice within 2 weeks. Results: Intrascan reproducibility for quantitative measurements of lumen, wall and outer wall areas was excellent with Intraclass Correlation Coefficients >0.98 and measurement errors of 1.5%, 4.5% and 1.9%, respectively. Patients had larger wall areas than volunteers in both common carotid and internal carotid arteries and smaller lumen areas in internal carotid arteries (p < 0.001). Positive correlations were found between wall area and cardiovascular risk factors such as age, hypertension, coronary heart disease and hypercholesterolemia (Spearman's r = 0.45-0.76, p < 0.05). No significant correlations were found between wall area and body mass index, gender, diabetes or a family history of cardiovascular disease. Conclusion: The findings of this study indicate that high resolution carotid black-blood 3 T MR with parallel imaging is a fast, reproducible and robust method to assess carotid atherosclerotic plaque in vivo and this method is ready to be used in clinical practice

    Integrated System Built for Small-Molecule Semiconductors via High-Throughput Approaches

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    High-throughput synthesis of solution-processable structurally variable small-molecule semiconductors is both an opportunity and a challenge. A large number of diverse molecules provide a possibility for quick material discovery and machine learning based on experimental data. However, the diversity of molecular structure leads to the complexity of molecular properties, such as solubility, polarity, and crystallinity, which poses great challenges to solution processing and purification. Here, we first report an integrated system for the high-throughput synthesis, purification, and characterization of molecules with a large variety. Based on the principle of Like dissolves like, we combine theoretical calculations and a robotic platform to accelerate the purification of those molecules. With this platform, a material library containing 125 molecules and their optical-electric properties was built within a timeframe of weeks. More importantly, the high repeatability of recrystallization we design is a reliable approach to further upgrading and industrial production

    Integrated System Built for Small-Molecule Semiconductors via High-Throughput Approaches

    Get PDF
    High-throughput synthesis of solution-processable structurally variable small-molecule semiconductors is both an opportunity and a challenge. A large number of diverse molecules provide a possibility for quick material discovery and machine learning based on experimental data. However, the diversity of the molecular structure leads to the complexity of molecular properties, such as solubility, polarity, and crystallinity, which poses great challenges to solution processing and purification. Here, we first report an integrated system for the high-throughput synthesis, purification, and characterization of molecules with a large variety. Based on the principle “Like dissolves like,” we combine theoretical calculations and a robotic platform to accelerate the purification of those molecules. With this platform, a material library containing 125 molecules and their optical-electronic properties was built within a timeframe of weeks. More importantly, the high repeatability of recrystallization we design is a reliable approach to further upgrading and industrial production

    Reducing tumor growth and angiogenesis using a triple therapy measured with Contrast-enhanced ultrasound (CEUS)

    Get PDF
    Background To evaluate the in vivo response by detecting the anti-angiogenic and invasion-inhibiting effects of a triple-combination-therapy in an experimental-small-animal-squamous-cell-carcinoma-model using the “flash-replenishment” (FR) method to assess tissue hemodynamics via contrast-enhanced-ultrasound (CEUS). Methods Human hypopharynx-carcinoma-cells were subcutaneously injected into the left flank of 22-female-athymic-nude-rats. After seven days of subcutaneous tumor growth, FR-measurements were performed on each rat. Treatment-group and control-group were treated every day for a period of one week, with the treatment-group receiving solvents containing a triple therapy of UpamostatÂź, CelecoxibÂź and IlomastatÂź and the control-group solvents only. On day seven, follow-up measurements were performed using the same measurement protocol to assess the effects of the triple therapy. VueBoxÂź was used to quantify the kinetic parameters and additional immunohistochemistry analyses were performed for comparison with and validation of the CEUS results against established methods (Proliferation/Ki-67, vascularization/CD31, apoptosis/caspase3). Results Compared to the control-group, the treatment-group that received the triple-therapy resulted in a reduction of tumor growth by 48.6% in size. Likewise, the immunohistochemistry results showed significant decreases in tumor proliferation and vascularization in the treatment-group in comparison to the control-group of 26%(p≀0.05) and 32.2%(p≀0.05) respectively. Correspondingly, between the baseline and follow-up measurements, the therapy-group was associated with a significant(p ≀ 0.01) decrease in the relative-Blood-Volume(rBV) in both the whole tumor(wt) and hypervascular tumor(ht) areas (p≀0.01), while the control-group was associated with a significant (p≀0.01) increase of the rBV in the wt area and a non-significant increase (p≀0.16) in the ht area. The mean-transit-time (mTT) of the wt and the ht areas showed a significant increase (p≀0.01) in the follow-up measurements in the therapy group. Conclusion The triple-therapy is feasible and effective in reducing both tumor growth and vascularization. In particular, compared with the placebo-group, the triple-therapy-group resulted in a reduction in tumor growth of 48.6% in size when assessed by CEUS and a significant reduction in the number of vessels in the tumor of 32% as assessed by immunohistochemistry. As the immunohistochemistry supports the CEUS findings, CEUS using the “flash replenishment”(FR) method appears to provide a useful assessment of the anti-angiogenic and invasion-inhibiting effects of a triple combination therapy
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