132 research outputs found

    Synthesis of 13C-labelled, bicyclic mimetics of natural enediynes

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    Using a versatile synthesis with 13CH3PPh3I and CH313CO2Et as 13C sources, the first examples of nine membered chromophores, which have been differentially labelled with 13C in their carbocyclic enediyne cores, are described

    Antiferromagnetic structure of alkali metal superoxide CsO2_2

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    We have performed a powder neutron diffraction study on CsO2_2, where the unpaired electron with s=1/2s=1/2 in the π\pi^* orbital of the O2_2^- ion is responsible for the magnetism. The magnetic reflections 0 12\frac{1}{2} 0 and 0 12\frac{1}{2} 1 were observed below the N\'{e}el temperature of about 10 K. An antiferromagnetic structure with a propagation vector of (0 ,12\frac{1}{2}, 0) and magnetic moments parallel to the aa-axis is the most plausible. The magnitude of the ordered moment is about 0.2 μB\mu_B, which is considered to be strongly suppressed due to the one-dimensionality of the system. We propose a possible π\pi^* orbital order that can explain the obtained magnetic structure, and discuss its relation to the one-dimensionality

    Gemcitabine and S-1 Combination Chemotherapy in Patients with Advanced Biliary Tract Cancer: A Retrospective Study

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    Background:The aim of this study was to investigate the efficacy and safety of gemcitabine and S-1 combination chemotherapy in patients with advanced biliary tract cancer. Patients and Methods: A retrospective study was performed on 15 consecutive patients. Gemcitabine was administered intravenously at 1,000 mg/m2 on days 8 and 15. Oral S-1 (60 mg/m2 in 2 divided doses) was given daily for the first 2 weeks, followed by 1 week of rest. This 3-week course of treatment was repeated. The primary endpoint was response rate, and the secondary endpoints were overall survival, progression-free survival, and safety. Results: The overall response rate was 26.7%, and the disease control rate was 73.4%. The overall survival was 12.0 months (95% CI, 9.5–14.5 months), and the progression-free survival was 8.0 months (95% CI, 4.3–11.7 months). Adverse events of grade 3 or 4 occurred in 33.3%, and the major grade 3/4 toxicities were anemia (20.0%), leukopenia (13.3%), and anorexia (13.3%). Conclusion:Gemcitabine and S-1 combination chemotherapy is effective and safe in patients with advanced biliary tract cancer

    Comparison and Correlation of Dynamic Postural Stability Indices Obtained during Different Dynamic Landing Tasks and Footwear Conditions

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    Objectives: To compare the dynamic postural stability indices (DPSI) from two different landing protocols with normalized jump distance (NDP) and jump height (RWDP) and footwear conditions (barefoot and shod).Design: Cross-sectional.Setting: Research laboratory.Participants: Twenty-five physically active adults (13 males/12 females, age: 22.1±4.2yrs, height: 178.3±11.1cm, weight: 75.6±19.4kg).Main Outcome Measures: Subjects jumped off two feet and landed with their preferred foot on a force-plate. From the ground reaction forces, the DPSI scores in the anterior-posterior, medial-lateral, and vertical directions, and the cumulative scores (DPSI) were calculated under two protocols and footwear conditions. Based on normality of data distribution, paired t-tests/Wilcoxon signed rank tests and Pearson/Spearman correlation coefficients were used to compare, and measure the relationship between the two protocols under two footwear conditions (p<0.05).Results: There were mixed results for DPSI scores when comparing the two protocols. There were significant differences (p=0.001–0.039) and positive correlations (r=0.660–0.870, p<0.001) on the DPSI scores between footwear conditions during the NDP protocol while the RWDP showed no significant differences.Conclusions: Different protocols and footwear conditions may impact DPSI scores. Therefore, a standardized protocol and footwear condition should be established for future studies examining dynamic postural stability

    THE EFFECT OF LOADED FATIGUE ON LOADED POSTURAL STABILITY

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    Military personnel are often required to carry heavy loads for long distances over unpredictable terrain. Additional load carriage, in conjunction with fatigue, has the potential to influence postural control mechanisms which may in turn increase injury risk. The purpose of this study was to determine if a loaded incremental march to fatigue negatively influences loaded postural stability. Loaded postural stability was measured using the NeuroCom Sensory Organization Test (SOT) and kinetic force plate variables (vertical ground reaction forces: SDvGRF, and TotSway) before and after a loaded incremental march to fatigue in 23 physically active men and women (age: 24.1 4.0 years, height: 172.3 11.1 cm, weight: 162.2 38.2 lbs) while subjects were adorned with a weighted vest equating to 30% of their body weight. The SOT consisted of six conditions (C1-C6) aimed to perturb the sensorimotor system, which were performed before and after a loaded fatigue protocol. C1, C2 and C3 challenged the somatosensory system, C4 challenged the visual system, while C5 and C6 challenged the vestibular system. Fatigue was induced with a treadmill march at 4mph with increasing grades of 2% every three minutes until volitional fatigue. After testing for normality, paired sample t-tests or Wilcoxon signed rank tests were conducted to assess pre- to post-fatigue differences. Significant reductions in SOT scores were found in overall composite scores (pre: 82.8 4.7, post: 81.6 5.2, p = 0.010), SDvGRF of C1 (pre: 1.3 0.5, post: 2.0 0.9, p < 0.001), C2 (pre: 1.4 0.6, post: 1.9 1.2, p < 0.001), C3 (pre: 1.4 0.5, post: 2.1 1.8, p = 0.026), and C6 (pre: 2.5 2.2, post: 3.5 3.2, p < 0.001) and TotSway of all conditions. Results suggest that significant changes in loaded postural stability were caused by loaded fatigue. Findings could aid in future postural stability screenings, load carriage training and strategies for injury prevention in the military

    Impact of Increased Load Carriage Magnitude on the Dynamic Postural Stability of Men and Women

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    The impact of load carriage on dynamic postural stability affects the survivability of the Warfighter by influencing performance capabilities and injury incidence. Further, sex may interact with the relationship between load carriage and dynamic postural stability to further compromise survivability. PURPOSE: To investigate the effect of load carriage magnitude on dynamic postural stability of men and women and its relationship to jumping ability. METHODS: 32 subjects (16 men, 16 women) were investigated for maximum jump height and dynamic postural stability. Dynamic postural stability was assessed by subjects jumping a horizontal distance of 40% their height over a 30cm hurdle, landing on one leg on a force plate (sample rate = 1200 Hz). 3 trials were completed for 3 load conditions: +0, +20 and +30% body weight (BW). Dynamic postural stability was determined from ground reaction force data during landings, by calculation of the dynamic postural stability index (DPSI). Maximum jump height was assessed by subjects performing 3 countermovement jumps (sample rate = 1000 Hz). Two-way repeated measures ANOVA were used to compare mean DPSI scores between sexes and conditions (α = 0.05). Pearson’s Correlation Coefficients were used to determine the relationship between jump height and change in DPSI scores between conditions (α = 0.05). RESULTS: Load condition significantly affected DPSI (F = 100.304, p = 0.001). DPSI scores increased between the 0% (0.359 ± 0.041), 20% (0.396 ± 0.034) and 30% (0.420 ± 0.028) BW load conditions. No significant effect of sex on DPSI was found (F = 0.131). No significant sex by load interaction on DPSI was found (F = 0.393). No significant correlations were found between jump height and change in DPSI scores between conditions. CONCLUSION: Increased load was found to negatively affect dynamic postural stability, most likely as a result of modifying the demands of the task. Therefore, the dynamic postural stability of men and women changes comparably in response to increased load carriage magnitude. Future research should focus on the effects of load on dynamic postural stability under higher loads and during more military-specific tasks

    Proto-Flight Model of SAR for 100kg Class Small Satellite

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    This paper presents the proto-flight model results of X band synthetic aperture radar for small satellites including the RF power amplifier, high speed data storage/transmission system, and the ground SAR response test results. The specifications of SAR performance are single polarization SAR with 3m ground resolution for strip map mode. 1 m ground resolution can be achieved with sliding spot light mode under condition of limited value of NESZ at 600km altitude orbit. The data down link is high speed X band down link with 2-3 Gbps. In May, 2019, 2.5Gbps down link with 64APSK modulation in dual polarization channels was demonstrated by RAPIS-1 Satellite. We will launch the first demonstration SAR satellite in 2020 as collaboration with a private company
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