71 research outputs found

    Decomposition of Incident and Reflected Regular Wave Using One Moving Wave Gage

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    Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

    Electrically Robust Single-Crystalline WTe2 Nanobelts for Nanoscale Electrical Interconnects

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    As the elements of integrated circuits are downsized to the nanoscale, the current Cu-based interconnects are facing limitations due to increased resistivity and decreased current-carrying capacity because of scaling. Here, the bottom-up synthesis of single-crystalline WTe2 nanobelts and low- and high-field electrical characterization of nanoscale interconnect test structures in various ambient conditions are reported. Unlike exfoliated flakes obtained by the top-down approach, the bottom-up growth mode of WTe2 nanobelts allows systemic characterization of the electrical properties of WTe2 single crystals as a function of channel dimensions. Using a 1D heat transport model and a power law, it is determined that the breakdown of WTe2 devices under vacuum and with AlOx capping layer follows an ideal pattern for Joule heating, far from edge scattering. High-field electrical measurements and self-heating modeling demonstrate that the WTe2 nanobelts have a breakdown current density approaching approximate to 100 MA cm(-2), remarkably higher than those of conventional metals and other transition-metal chalcogenides, and sustain the highest electrical power per channel length (approximate to 16.4 W cm(-1)) among the interconnect candidates. The results suggest superior robustness of WTe2 against high-bias sweep and its possible applicability in future nanoelectronics

    Temporary bilateral sensorineural hearing loss following cardiopulmonary bypass -A case report-

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    Sudden sensorineural hearing loss has been reported to occur following anesthesia and various non-otologic surgeries, mostly after procedures involving cardiopulmonary bypass. Unilateral sensorineural hearing loss resulting from microembolism is an infrequent complication of cardiopulmonary bypass surgery that has long been acknowledged. Moreover, there are few reports on the occurrence of bilateral sensorineural hearing loss without other neurologic deficits and its etiology has also not been determined. We describe here a rare case of bilateral hearing loss without other neurologic deficits in an otherwise healthy 27-year-old woman who underwent cardiopulmonary bypass surgery for repair of severe mitral valve stenosis. The patient suffered from profound sensorineural hearing loss in both ears that was recognized immediately upon extubation, and audiometry tests confirmed the diagnosis. Without any treatment, her hearing recovered almost completely by the time of her discharge one week after surgery

    Reference values for respiratory system impedance using impulse oscillometry in healthy preschool children

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    PurposeThe normal values for lung resistance and lung capacity of children, as determined by impulse oscillometry (IOS), are different for children of different ethnicities. However, reference values there is no available reference value for Korean preschool children have yet to be determined. The aim of the present study was to determine the normal ranges of IOS parameters in Korean preschool children.MethodsA total of 133 healthy Korean preschool children were selected from 639 children (aged 3 to 6 years) who attended kindergarten in Seongnam, Gyeonggi province, Korea. Healthy children were defined according to the European Respiratory Society (ERS) criteria. All subjects underwent lung function tests using IOS. The relationships between IOS value (respiratory resistance (Rrs) and reactance (Xrs) at 5 and 10 Hz and resonance frequency (RF)) and age, height, and weight were analyzed by simple linear and multiple linear regression analyses.ResultsThe IOS success rate was 89.5%, yielding data on 119 children. Linear regression identified height as the best predictor of Rrs and Xrs. Using stepwise multiple linear regressions based on age, height, and weight, we determined regression equations and coefficients of determination (R2) for boys (Rrs5=1.934-0.009×Height, R2=12.1%; Xrs5=0.774+0.006×Height-0.002×Age, R2=20.2% and for girls (Rrs5=2.201-0.012×Height, R2=18.2%; Xrs5=-0.674+0.004×Height, R2=10.5%).ConclusionThis study provides reference values for IOS measurements of normal Korean preschool children. These provide a basis for the diagnosis and monitoring of preschool children with a variety of respiratory diseases

    Anesthetic considerations of percutaneous transcatheter aortic valve implantation: first attempt in Korea -A report of 2 cases-

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    Conventional aortic valve replacement for severe aortic stenosis is associated with a high operative mortality in the elderly patients with significant comorbidities, including severe respiratory dysfunction, renal insufficiency, and compromised cardiac function. Human transcatheter aortic valve implantation was first reported in 2002 and has become a valid alternative in selected high-risk patients in Europe and North America. This article describes the first attempt of transfemoral transcatheter aortic valve implantation in Korea. The procedure was applied in two consecutive patients with severe aortic stenosis. Despite several intra-operative complications during procedure, the post-operative outcomes were good for both patients. At post-operative 30 days there was satisfactory prosthetic valve function and hemodynamic stability

    Spinal Cord Injury Markedly Altered Protein Expression Patterns in the Affected Rat Urinary Bladder during Healing Stages

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    The influence of spinal cord injury (SCI) on protein expression in the rat urinary bladder was assessed by proteomic analysis at different time intervals post-injury. After contusion SCI between T9 and T10, bladder tissues were processed by 2-DE and MALDI-TOF/MS at 6 hr to 28 days after SCI to identify proteins involved in the healing process of SCI-induced neurogenic bladder. Approximately 1,000 spots from the bladder of SCI and sham groups were visualized and identified. At one day after SCI, the expression levels of three protein were increased, and seven spots were down-regulated, including heat shock protein 27 (Hsp27) and heat shock protein 20 (Hsp20). Fifteen spots such as S100-A11 were differentially expressed seven days post-injury, and seven proteins including transgelin had altered expression patterns 28 days after injury. Of the proteins with altered expression levels, transgelin, S100-A11, Hsp27 and Hsp20 were continuously and variably expressed throughout the entire post-SCI recovery of the bladder. The identified proteins at each time point belong to eight functional categories. The altered expression patterns identified by 2-DE of transgelin and S100-A11 were verified by Western blot. Transgelin and protein S100-A11 may be candidates for protein biomarkers in the bladder healing process after SCI

    Hyperghrelinemia does not accelerate gastric emptying in Prader-Willi syndrome patients

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    Prader-Willi syndrome (PWS) is the most common form of syndromic obesity associated with hyperphagia. Because ghrelin stimulates gastric motility in rodents, and PWS patients have 3- to 4-fold higher fasting plasma ghrelin concentrations than normal subjects, we hypothesized that hyperphagia associated with PWS may be partly explained by rapid gastric emptying due to the increased gastric motility caused by ghrelin. We determined gastric emptying times (GETs) and measured ghrelin levels in 11 PWS children and 11 age-, sex-, and body mass index-matched controls using a standard meal containing [(99m)Tc]diaminetriaminepentacetate. Median plasma ghrelin levels before (precibum) and after the GET study were higher in PWS patients than in controls (P = 0.004 and P = 0.001, respectively). Median percent gastric retentions at 90 min after the standard meal were 57.1% (range, 34.0-83.2%) in PWS patients and 40.2% (range, 27.2-60.2%) in controls (P = 0.03). In particular, precibum ghrelin concentrations were not significantly correlated with the rate of gastric emptying in PWS patients (P = 0.153; r = 0.461) or controls (P = 0.911; r = 0.048). Our results show that gastric emptying in PWS is reduced despite higher ghrelin levels, and that the voracious appetite associated with PWS is related to another mechanism

    Diet and Airway Obstruction: A Cross Sectional Study from the Second Korean National Health and Nutrition Examination Survey

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    Background/Aims: Several dietary factors, such as antioxidant vitamins, have potential roles in the development of obstructive lung diseases. However, the results of studies on the relationships between dietary factors and obstructive lung diseases are inconsistent. The aim of this study was to determine which nutrients are related to airway obstruction (AO) in the Korean population.&Methods: We used data obtained as part of the Korean National Health and Nutrition Examination Survey (NHANES II) in 2001. Analysis was restricted to 1,005 adults who were 18 years of age and older, who had two or more acceptable spirometry curves, and who had participated in the nutrition examination survey. AO was defined as the ratio of forced expiratory volume in one second (FEV1) to forced vital capacity (FVC) of less than 0.7.&Results: Of the 1,005 study subjects, 78 (7.8%) had AO. Statistically significant factors associated with AO were 55 years of age or older (p = 0.032), central obesity (p = 0.047), hypertension (p < 0.001), smoking of 20 pack-years or more (p < 0.001), low income (p < 0.001), and low dietary protein intake expressed as a ratio of protein to recommended dietary allowance for Koreans (p = 0.037). Multiple logistic regression analyses revealed four factors that were independently associated with AO: smoking of 20 pack-years or more (odds ratio [OR], 5.801; p < 0.001), hypertension (OR, 3.905; p < 0.001), low protein intake (OR, 0.992; p = 0.004), and low income (OR, 1.962; p = 0.018).&Conclusions: In the Korean NHANES, smoking, hypertension, and low income were related to AO. Among dietary factors, only low protein intake was associated with AO

    A randomized controlled trial of physical activity, dietary habit, and distress management with the Leadership and Coaching for Health (LEACH) program for disease-free cancer survivors

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    Background We aimed to evaluate the potential benefits of the Leadership and Coaching for Health (LEACH) program on physical activity (PA), dietary habits, and distress management in cancer survivors. Methods We randomly assigned 248 cancer survivors with an allocation ratio of two-to-one to the LEACH program (LP) group, coached by long-term survivors, or the usual care (UC) group. At baseline, 3, 6, and 12 months, we used PA scores, the intake of vegetables and fruits (VF), and the Post Traumatic Growth Inventory (PTGI) as primary outcomes and, for secondary outcomes, the Ten Rules for Highly Effective Health Behavior adhered to and quality of life (QOL), the Hospital Anxiety and Depression Scale (HADS), and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30). Results For primary outcomes, the two groups did not significantly differ in PA scores or VF intake but differed marginally in PTGI. For secondary outcomes, the LP group showed a significantly greater improvement in the HADS anxiety score, the social functioning score, and the appetite loss and financial difficulties scores of the EORTC QLQ-C30 scales from baseline to 3 months. From baseline to 12 months, the LP group showed a significantly greater decrease in the EORTC QLQ-C30 fatigue score and a significantly greater increase in the number of the Ten Rules for Highly Effective Health Behavior. Conclusion Our findings indicate that the LEACH program, coached by long-term survivors, can provide effective management of the QOL of cancer survivors but not of their PA or dietary habits. Trial registration Clinical trial information can be found for the following: NCT01527409 (the date when the trial was registered: February 2012)
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