37 research outputs found

    Effect of Texture of AZ31 Magnesium Alloy Sheet on Mechanical Properties and Formability at High Strain Rate

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    The mechanical properties and formability of AZ31 magnesium alloy strips having different textures were investigated at a high strain rate based on that occuring in mass production by press forming. Forming at a high strain rate on the order of 10 0 s À1 requires a high temperature of over 473 K. To obtain accurate stress-strain curves, a high-speed testing machine that can maintain a constant true strain rate was used, and the change in gauge length on a test piece in a furnace was measured during the testing time of about 0.5 s. For the specimens, rolled strips consisting of fine grains (about 10 mm) and an extruded strip consisting of coarse grains (about 40 mm) were used. The {0001} textures of the extruded strip and one of the rolled strips were strongly oriented parallel to the rolled surface, but the texture of another rolling strip had two peaks that were inclined at 5 15deginfrontofandbehindtherollingdirection.Atthehighstrainrateof100sAˋ1,elongationdecreasedforeveryspecimen.Nevertheless,alimitingdrawingratio(LDR)of2:1 15 deg in front of and behind the rolling direction. At the high strain rate of 10 0 s À1 , elongation decreased for every specimen. Nevertheless, a limiting drawing ratio (LDR) of 2:1 2:2 was obtained under uniform heating above 503 K in all the specimens except for the extruded strip. The high LDR of the rolled strip having a two-peak texture was maintained in forming at temperatures down to 473 K, in contrast to the LDR of the strongly oriented rolled strip, which reduced rapidly when formed at temperatures less than 503 K

    Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

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    Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≄ II, EF ≀35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

    Humidity Sensitivity of Chemically Synthesized ZnAl2O4/Al

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    Humidity sensitivity is evaluated for chemically synthesized ZnAl2O4/Al devices. We succeeded in synthesizing the ZnAl2O4/Al device by applying chemical techniques only. Hydrothermal treatment for the anodized aluminum (AlOx/Al) gives us the device of the ZnAl2O4/Al structure. All fabrication processes were conducted under 400 °C. The key was focusing on ZnAl2O4 as the sensing material instead of MgAl2O4, which is generally investigated as the humidity sensor. The evaluation of this ZnAl2O4/Al device clarified its effectiveness as a sensor. Both electrical capacitance, Cp, and the resistivity, Rp, measured by an LCR meter, obviously responded to the humidity with good sensitivity and appreciable repeatability. Our synthesis technique is possible in principle to improve on the process for the device with a complex structure providing a large surface area. These characteristics are believed to expand the application study of spinel aluminate devices as the sensor

    Effect of Age at Injury on Walking Ability Following Incomplete Cervical Spinal Cord Injury: A Retrospective Cohort Study

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    Introduction: Recently, the cases of elderly individuals with spinal cord injuries are increasing in Japan. For individuals with spinal cord injury, regaining the ability to walk independently after an injury is one of the most important aspects of rehabilitation. Nevertheless, instead of age-optimized programs, uniform rehabilitation programs are currently provided to all patients because there is no information available for predicting prognosis based on age at the time of injury. This study aimed to elucidate the effect of age at the time of injury on the walking ability of patients with incomplete cervical spinal cord injury. Methods: Of the 1,195 patients registered in the Japan single-center study for spinal cord injury database, those hospitalized within 28 days after injury, followed up for >180 days, had a cervical spinal cord injury, and had a lower extremity motor score of 42 points were examined. Patients were stratified into three groups according to the age at the time of injury (59, 60-69, or 70 years). The walking ability scores and independence levels of mobility were compared; these data were evaluated based on indoor mobility (item 12) and outdoor mobility (item 14) in the Spinal Cord Independence Measure III and Walking Index for Spinal Cord Injury II. All comparisons used data at discharge. Results: The walking ability scores and independence levels of mobility were significantly lower in the group aged 70 years than those in the remaining two groups. Conclusions: In patients with cervical spinal cord injuries with the same limb function, if the age at the time of injury was 70 years, the decline in physical function due to aging exerted a substantial effect on walking ability
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