3,142 research outputs found
Cardiac Surgery in a Patient with Idiopathic Aplastic Anemia: A Case Report
Major surgery in a patient with pancytopenia might be associated with increased surgical risks, especially for bleeding and infection. A 66-yr-old man was admitted to the hospital due to shortness of breath. His dyspnea was classified by the New York Heart Association (NYHA) as functional class III. Prior to admission, he had a 5-yr history of medical management for idiopathic aplastic anemia. The severity of aplastic anemia of the patient was graded as non-severe aplastic anemia. Echocardiography revealed reduced left ventricular function and severe aortic valve regurgitation (grade IV) with left ventricular end diastolic dimension measuring 87 mm. Because of dyspnea and echocardiographically documented aortic valve insufficiency, the patient underwent elective aortic valve replacement. Although extracorporeal circulation for valve operations might be associated with aggravation of impaired blood cell function, the patient recovered from surgery uneventfully. Here, we report a successful cardiac surgery with extracorporeal cardiopulmonary bypass in a patient with severe aortic valve insufficiency and concomitant idiopathic aplastic anemia
Laparoscopic Removal of a Broken Sewing Needle in a Patient with Irritative Bladder Symptoms
A foreign body near the bladder is rare. Although foreign bodies in the bladder can be easily found and removed by endoscopic transurethral removal, extravesical foreign bodies may require the use of an open or laparoscopic procedure. Here, we report a case of a patient complaining of frequency and urgency in whom an extravesical sewing needle was successfully removed by a laparoscopic approach. A 4.5 cm rusty sewing needle was found between the bladder and the left external iliac vessels and was removed through a 5 mm trocar port by use of endo forceps with no complications
A Development of Motivation Scale of Sport Website Users: A Perspective of Motivation Factors on Attitude and Behavioral Intention
Solubility of red palm oil in supercritical carbon dioxide: measurement and modelling
The solubility of red palm oil (RPO) in supercritical carbon dioxide (scCO2) was determined using a dynamic method at 8.5–25 MPa and, 313.15–333.15 K and at a fixed scCO2 flow rate of 2.9 g·min− 1 using a full factorial design. The solubility was determined under low pressures and temperatures as a preliminary study for RPO particle formation using scCO2. The solubility of RPO was 0.5–11.3 mg·(g CO2)− 1 and was significantly affected by the pressure and temperature. RPO solubility increased with pressure and decreased with temperature. The Adachi–Lu model showed the best-fit for RPO solubility data with an average relative deviation of 14% with a high coefficient of determination, R2 of 0.9667, whereas the Peng–Robinson equation of state thermodynamic model recorded deviations of 17%–30%
A Passivity-based Nonlinear Admittance Control with Application to Powered Upper-limb Control under Unknown Environmental Interactions
This paper presents an admittance controller based on the passivity theory
for a powered upper-limb exoskeleton robot which is governed by the nonlinear
equation of motion. Passivity allows us to include a human operator and
environmental interaction in the control loop. The robot interacts with the
human operator via F/T sensor and interacts with the environment mainly via
end-effectors. Although the environmental interaction cannot be detected by any
sensors (hence unknown), passivity allows us to have natural interaction. An
analysis shows that the behavior of the actual system mimics that of a nominal
model as the control gain goes to infinity, which implies that the proposed
approach is an admittance controller. However, because the control gain cannot
grow infinitely in practice, the performance limitation according to the
achievable control gain is also analyzed. The result of this analysis indicates
that the performance in the sense of infinite norm increases linearly with the
control gain. In the experiments, the proposed properties were verified using 1
degree-of-freedom testbench, and an actual powered upper-limb exoskeleton was
used to lift and maneuver the unknown payload.Comment: Accepted in IEEE/ASME Transactions on Mechatronics (T-MECH
Effect of software version and parameter settings on the marginal and internal adaptation of crowns fabricated with the CAD/CAM system
Objective This study investigated the marginal and internal adaptation of individual dental crowns fabricated using a CAD/CAM system (Sirona’s BlueCam), also evaluating the effect of the software version used, and the specific parameter settings in the adaptation of crowns.Material and Methods Forty digital impressions of a master model previously prepared were acquired using an intraoral scanner and divided into four groups based on the software version and on the spacer settings used. The versions 3.8 and 4.2 of the software were used, and the spacer parameter was set at either 40 μm or 80 μm. The marginal and internal fit of the crowns were measured using the replica technique, which uses a low viscosity silicone material that simulates the thickness of the cement layer. The data were analyzed using a Friedman two-way analysis of variance (ANOVA) and paired t-tests with significance level set at
A highly active and durable lanthanum strontium cobalt ferrite cathode for Intermediate-Temperature solid Oxide fuel cel
Solid oxide fuel cells (SOFCs) are promising techniques for high energy efficiency, fuel flexibility, and low pollutant emissions. For commercialization of SOFCs, it is required to decrease the operating temperature. At this intermediate temperature region, the cathodic polarization resistance significant due to the thermally activated oxygen reduction reaction (ORR). To compensate this, highly active cathode materials have been considered and lanthanum strontium cobalt ferrite (LSCF6428, La0.6Sr0.4Co0.2Fe0.8O3-δ) has been attracted as a cathode material for SOFCs because of its high mixed electronic and ionic conducting (MIEC) nature. However, one of the major concerns of LSCF6428 is the degradation during the long-term operation. Currently, Sr segregation has been reported as one of the major reasons for the LSCF degradation. In this study, we investigated LSCF2882 (La0.2Sr0.8Co0.8Fe0.2O3-δ) and compared with LSCF6428 as a SOFC cathode. X-ray diffraction (XRD) and Rietveld refinement were applied to analyze phase structures. By electrical conductivity relaxation (ECR) technique, Oxygen surface exchange coefficients (kchem) and chemical diffusion coefficients (Dchem) of LSCF2882 were evaluated and we observed enhancements compare to LSCF6428. For interpretation of enhanced oxygen transport kinetics, we tried to visualize the interstitial oxygen conduction pathways and the bond valence sum (BVS) mapping method was utilized by Valence program. BVS mapping results show clearly demonstrating the 3D network of the interstitial pathways at 600oC in LSCF2882. Electrochemical performances were investigated by EIS (Electrochemical Impedance Spectroscopy) and single cell performance was also evaluated. In addition, long-term stability test was performed for over 500 hours. LSCF2882 showed better performances and it exhibited no degradation during the stability test.
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Locally Controlled Sensing Properties of Stretchable Pressure Sensors Enabled by Micro-Patterned Piezoresistive Device Architecture.
For wearable health monitoring systems and soft robotics, stretchable/flexible pressure sensors have continuously drawn attention owing to a wide range of potential applications such as the detection of human physiological and activity signals, and electronic skin (e-skin). Here, we demonstrated a highly stretchable pressure sensor using silver nanowires (AgNWs) and photo-patternable polyurethane acrylate (PUA). In particular, the characteristics of the pressure sensors could be moderately controlled through a micro-patterned hole structure in the PUA spacer and size-designs of the patterned hole area. With the structural-tuning strategies, adequate control of the site-specific sensitivity in the range of 47~83 kPa-1 and in the sensing range from 0.1 to 20 kPa was achieved. Moreover, stacked AgNW/PUA/AgNW (APA) structural designed pressure sensors with mixed hole sizes of 10/200 µm and spacer thickness of 800 µm exhibited high sensitivity (~171.5 kPa-1) in the pressure sensing range of 0~20 kPa, fast response (100~110 ms), and high stretchability (40%). From the results, we envision that the effective structural-tuning strategy capable of controlling the sensing properties of the APA pressure sensor would be employed in a large-area stretchable pressure sensor system, which needs site-specific sensing properties, providing monolithic implementation by simply arranging appropriate micro-patterned hole architectures
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