355 research outputs found
Piezoresistive tactile sensor discriminating multidirectional forces
Flexible tactile sensors capable of detecting the magnitude and direction of the applied force together are of great interest for application in human-interactive robots, prosthetics, and bionic arms/feet. Human skin contains excellent tactile sensing elements, mechanoreceptors, which detect their assigned tactile stimuli and transduce them into electrical signals. The transduced signals are transmitted through separated nerve fibers to the central nerve system without complicated signal processing. Inspired by the function and organization of human skin, we present a piezoresistive type tactile sensor capable of discriminating the direction and magnitude of stimulations without further signal processing. Our tactile sensor is based on a flexible core and four sidewall structures of elastomer, where highly sensitive interlocking piezoresistive type sensing elements are embedded. We demonstrate the discriminating normal pressure and shear force simultaneously without interference between the applied forces. The developed sensor can detect down to 128 Pa in normal pressure and 0.08 N in shear force, respectively. The developed sensor can be applied in the prosthetic arms requiring the restoration of tactile sensation to discriminate the feeling of normal and shear force like human skin.open0
Massive transfusion protocol: the reason it is necessary
Objective. The purpose of this study is to identify problems of emergency transfusion at the bedside and to determine need for massive transfusion protocol.
Methods. We included patients who met the criteria for “trauma team activation” and were admitted to division of trauma. The amount of blood product transfused in each unit was investigated for balanced transfusion. We also investigated the compliance with assessment of blood consumption score. The correlation between the time elapsed from patient visit to first transfusion order and time elapsed from first transfusion order to transfusion start was analyzed. Finally, we investigated various factors which serve to influence the decision-making process regarding early transfusion order.
Results. Ratio of packed Red blood cells (pRBC): Fresh frozen plasma (FFP) was well-balanced, but platelet transfusion done was much lower than pRBC and FFP in emergency room. The application of emergency blood release did not match the criteria of assessment of blood consumption (ABC) score. The time from the first transfusion order to the transfusion start was found to be constant irrespective of time from patient visit to first transfusion order. And, the time from the first transfusion order to transfusion start did not differ significantly among patients with early transfusion order and delayed transfusion order. Only systolic blood pressure of < 90 mmHg was identified as a major predictor for early transfusion order.
Conclusion. Balanced transfusion is not easy and emergency transfusion could be delayed at the bedside. Integrated and systematic structures for massive transfusion protocol would be invaluable and indispensable
Quantitative agreement of Dzyaloshinskii-Moriya interactions for domain-wall motion and spin-wave propagation
The magnetic exchange interaction is the one of the key factors governing the
basic characteristics of magnetic systems. Unlike the symmetric nature of the
Heisenberg exchange interaction, the interfacial Dzyaloshinskii-Moriya
interaction (DMI) generates an antisymmetric exchange interaction which offers
challenging opportunities in spintronics with intriguing antisymmetric
phenomena. The role of the DMI, however, is still being debated, largely
because distinct strengths of DMI have been measured for different magnetic
objects, particularly chiral magnetic domain walls (DWs) and non-reciprocal
spin waves (SWs). In this paper, we show that, after careful data analysis,
both the DWs and SWs experience the same strength of DMI. This was confirmed by
spin-torque efficiency measurement for the DWs, and Brillouin light scattering
measurement for the SWs. This observation, therefore, indicates the unique role
of the DMI on the magnetic DW and SW dynamics and also guarantees the
compatibility of several DMI-measurement schemes recently proposed.Comment: 24 pages, 5 figure
Health-related quality of life with KDQOL-36 and its association with self-efficacy and treatment satisfaction in Korean dialysis patients
BACKGROUND AND OBJECTIVES: This study was conducted to measure the level of health-related quality of life (HRQOL) and to reveal the association of self-efficacy and treatment satisfaction with it in Korean dialysis patients. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: The study subjects were 237 patients receiving either hemodialysis (HD) or peritoneal dialysis (PD) from two university hospitals, from February to June in 2010. We investigated HRQOL using the Korean version of Kidney Disease Quality of Life Short Form 36 (KDQOL-36), and self-efficacy and treatment satisfaction by self-administrative questionnaire and their dialysis-related variables by reviewing clinical records. The associations of self-efficacy and treatment satisfaction with HRQOL were assessed using multiple linear regression analysis. RESULTS: The mean HRQOL results were as follows: Physical component score (PCS) was 39.1 ± 8.5, Mental component score (MCS) 44.6 ± 6.8, symptom/problem list was 67.6 ± 17.1, effects of disease score was 58.5 ± 19.6, and burden of disease score was 41.1 ± 28.4. Between PD and HD patients, we could find significant difference only in the symptom/problem list. After removing confounder’s effects by multivariate analysis, respectively, treatment goal self-efficacy and treatment management self-efficacy were significantly related with all 5 domains, except PCS. Treatment satisfaction was significantly related with PCS, MCS, and effects of kidney disease. CONCLUSIONS: Patients’ self-efficacy and treatment satisfaction could influence their HRQOL. Regular and systematic monitoring using KDQOL-36 and interventions to increase self-efficacy and treatment satisfaction should be considered in dialysis care in Korea
Initial Biopsy Outcome Prediction in Korean Patients-Comparison of a Noble Web-based Korean Prostate Cancer Risk Calculator versus Prostate-specific Antigen Testing
We developed and validated a novel Korean prostate cancer risk calculator (KPCRC) for predicting the probability of a positive initial prostate biopsy in a Korean population. Data were collected from 602 Koreans who underwent initial prostate biopsies due to an increased level of prostate-specific antigen (PSA), a palpable nodule upon digital rectal examination (DRE), or a hypoechoic lesion upon transrectal ultrasound (TRUS). The clinical and laboratory variables were analyzed by simple and multiple logistic regression analysis. The area under the receiver operating characteristic curve (AUC) was computed to compare its performance to PSA testing alone. Prostate cancer was detected in 172 (28.6%) men. Independent predictors included age, DRE findings, PSA level, and prostate transitional zone volume. We developed the KPCRC using these variables. The AUC for the selected model was 0.91, and that of PSA testing alone was 0.83 (P < 0.001). The AUC for the selected model with an additional dataset was 0.79, and that of PSA testing alone was 0.73 (P = 0.004). The calculator is available on the website: http://pcrc.korea.ac.kr. The KPCRC improved the performance of PSA testing alone in predicting the risk of prostate cancer in a Korean population. This calculator would be a practical tool for physicians and patients
Estimation of Stellate Ganglion Block Injection Point Using the Cricoid Cartilage as Landmark Through X-ray Review
BACKGROUND: Stellate ganglion block is usually performed at the transverse process of C6, because the vertebral artery is located anterior to the transverse process of C7. The purpose of this study is to estimate the location of the transverse process of C6 using the cricoid cartilage in the performance of stellate ganglion block.
METHODS: We reviewed cervical lateral neutral-flexion-extension views of 48 patients who visited our pain clinic between January and June of 2010. We drew a horizontal line at the surface of the cricoid cartilage in the neutral and extension views of cervical lateral x-rays. We then measured the change in the shortest distance from this horizontal line to the lowest point of the transverse process of C6 between the neutral and extension views.
RESULTS: There was a statistically significant difference in the shortest distance from the horizontal line at the surface of the cricoid cartilage to the lowest point of transverse process of C6 between neutral position and neck extension position in both males and females, and between males and females in both neutral position and neck extension position. The cricoid cartilage level was 4.8 mm lower in males and 14.4 mm higher in females than the lowest point of transverse process of C6 in neck extension position.
CONCLUSIONS: Practitioners should recognize that the cricoid cartilage has cephalad movement in neck extension. In this way, the cricoid cartilage can be still useful as a landmark for stellate ganglion block.ope
Methane as an effective hydrogen source for single-layer graphene synthesis on Cu foil by plasma enhanced chemical vapor deposition
A single-layer graphene is synthesized on Cu foil in the absence of H2 flow
by plasma enhanced chemical vapor deposition (PECVD). In lieu of an explicit H2
flow, hydrogen species are produced during methane decomposition process into
their active species (CHx<4), assisted by the plasma. Notably, the early stage
of growth depends strongly on the plasma power. The resulting grain size (the
nucleation density) has a maximum (minimum) at 50 W and saturates when the
plasma power is higher than 120 W because hydrogen partial pressures are
effectively tuned by a simple control of the plasma power. Raman spectroscopy
and transport measurements show that decomposed methane alone can provide
sufficient amount of hydrogen species for high-quality graphene synthesis by
PECVD.Comment: 22 pages, 6 figure
Clinical and Genetic Analysis of Korean Patients with Miyoshi Myopathy: Identification of Three Novel Mutations in the DYSF Gene
Miyoshi myopathy (MM) is an autosomal recessive distal muscular dystrophy caused by mutations in the dysferlin gene (DYSF) on chromosome 2p13. Although MM patients and their mutations in the DYSF gene have been found from all over the world, there is only one report of genetically confirmed case of MM in Korea. Recently, we encountered three unrelated Korean patients with MM and two of them have previously been considered as having a type of inflammatory myopathy. The clinical and laboratory evaluation showed typical features of muscle involvement in MM in all patients but one patient initially had moderate proximal muscle involvement and another showed incomplete quadriparesis with rapid progression. Direct sequencing analysis of the DYSF gene revealed that each patient had compound heterozygous mutations (Gln832X and Trp992Arg, Gln832X and Trp999Cys, and Lys1103X and Ile1401HisfsX8, respectively) among which three were novel. Although MM has been thought to be quite rare in Korea, it should be considered in a differential diagnosis of patients exhibiting distal myopathy
Inorganic Arsenite Potentiates Vasoconstriction through Calcium Sensitization in Vascular Smooth Muscle
Chronic exposure to arsenic is well known as the cause of cardiovascular diseases such as hypertension. To investigate the effect of arsenic on blood vessels, we examined whether arsenic affected the contraction of aortic rings in an isolated organ bath system. Treatment with arsenite, a trivalent inorganic species, increased vasoconstriction induced by phenylephrine or serotonin in a concentration-dependent manner. Among the arsenic species tested—arsenite, pentavalent inorganic species (arsenate), monomethylarsonic acid (MMA(V)), and dimethylarsinic acid (DMA(V))—arsenite was the most potent. Similar effects were also observed in aortic rings without endothelium, suggesting that vascular smooth muscle plays a key role in enhancing vasoconstriction induced by arsenite. This hypercontraction by arsenite was well correlated with the extent of myosin light chain (MLC) phosphorylation stimulated by phenylephrine. Direct Ca(2+) measurement using fura-2 dye in aortic strips revealed that arsenite enhanced vasoconstriction induced by high K(+) without concomitant increase in intracellular Ca(2+) elevation, suggesting that, rather than direct Ca(2+) elevation, Ca(2+) sensitization may be a major contributor to the enhanced vasoconstriction by arsenite. Consistent with these in vitro results, 2-hr pretreatment of 1.0 mg/kg intravenous arsenite augmented phenylephrine-induced blood pressure increase in conscious rats. All these results suggest that arsenite increases agonist-induced vasoconstriction mediated by MLC phosphorylation in smooth muscles and that calcium sensitization is one of the key mechanisms for the hypercontraction induced by arsenite in blood vessels
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