540 research outputs found

    Study of orientation effect on nanoscale polarization in BaTiO3 thin films using piezoresponse force microscopy

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    We have investigated the effect of texture on in-plane (IPP) and out- of plane (OPP) polarizations of pulsed-laser-deposited BaTiO3 thin films grown on Pt and La0.5Sr0.5CoO3 (LSCO) buffered Pt electrodes. The OPP and IPP polarizations were observed by piezoresponse force microscopy (PFM) for three-dimensional polarization analyses in conjunction with conventional diffraction methods using x-ray diffraction and reflection high energy electron diffraction measurements. BaTiO3 films grown on Pt electrodes exhibited highly (101) preferred orientation with higher IPP component whereas BaTiO3 film grown on LSCO/Pt electrodes showed (001) and (101) orientations with higher OPP component. Measured effective d(33) values of BaTiO3 films deposited on Pt and LSCO/ Pt electrodes were 14.3 and 54.0 pm/ V, respectively. Local piezoelectric strain loops obtained by OPP and IPP-PFM showed that piezoelectric properties were strongly related to film orientation

    Large Eddy Simulation of flow and tracer transport in multichamber ozone contactors

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    Three-dimensional numerical analyses of flow and transport characteristics in two representative multichamber ozone contactor models with different chamber width were conducted using large eddy simulation (LES). Both time-averaged and instantaneous flow patterns suggest that the flow is characterized by the occurrence of large turbulent structures leading to extensive short-circuiting between chambers and internal recirculation inside the chambers. The flow is also found to be highly three-dimensional, as secondary vortices and recirculation zones develop. The simulation results further suggest that the hydrodynamics in ozone contactors can be improved by reducing the chamber width. The results of the LES are qualitatively verified using previously reported tracer test results obtained from laboratory experiments. The LES technique, applied to the ozone contactor flow and transport of a tracer for the first time, is expected to serve as a powerful tool for existing reactor flow diagnosis, reactor retrofitting as well as for new reactor design

    Quality characteristics of rice inoculated with Inonotus obliquus mycelia and incubated under different cultivating conditions

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    This study was performed to investigate the quality characteristics of Inonotus obliquus mycelia rice incubated with I. obliquus (KCTC 256152). Different volumes of mycelial culture of I. obliquus were used for production of I. obliquus mycelia rice. Twenty percent of the mycelial culture was added to rice and designated as IOR-20, 30% as IOR-30 and 40% as IOR-40. Using the I. obliquus mycelia rice, the contents of β-1,3-glucan, betulin, total polyphenol and 1,1-diphenyl-2-picrylhydrazol (DPPH) radical scavenging activity, Hunter`s color values, free amino acid content, and mineral content were investigated. The β-1,3-glucan content in I. obliquus mycelia rice were in the order of IOR-30(729.7 μg/g) > IOR-20(716.0 μg/g) > IOR-40(690.5 μg/g) and those of betulin content were OR-30(1273.7 μg/g) > IOR-40 (1247.81 μg/g) > IOR-20 (1209.82 μg/g). The highest content of total polyphenols (353.6 μg/g) and activity of DPPH radical scavenging were observed in the IOR-30. The higher contents for β-1,3-glucan, betulin, polyphenol, and DPPH radical scavenging were found in 30% mycelial culture treatment, showing the best condition for the production of I. obliquus mycelia. Aspartic acid (10.28 to 29.44 μg/100 g), threonine (5.43 to 11.00 μg/100 g), serine (8.84 to 14.53 μg/100 g), glutamic acid (31.01 to 53.61 μg/100 g), glycine (4.77 to 10.26 μg/100 g), valine (2.93 to 6.57 μg/100 g), and lysine (5.20 to 14.41 μg/100 g) contents were determined in the I. obliquus mycelia rice and the order was as follows; IOR-20>IOR-30>IOR-40. The IOR-30 sample exhibited the highest levels of K(899.1±8.1 mg/kg), Mg(427.3±9.3 mg/kg), Ca(480.2±6.9 mg/kg), Na(296.1±9.2 mg/kg).Keywords: Rice, Inonotus obliquus (KCTC 256152), β-1,3-glucan, betulin, quality characteristicsAfrican Journal of Biotechnology Vol. 12(33), pp. 5131-513

    Clinical Impact of Viral Load on the Development of Hepatocellular Carcinoma and Liver-Related Mortality in Patients with Hepatitis C Virus Infection

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    Aim. This study aimed to assess clinical impact of hepatitis C viral load on the development of hepatocellular carcinoma (HCC) and liver-related mortality in HCV-infected patients. Methods. A total of 111 subjects with chronic HCV infection who were available for serum quantitation of HCV RNA were recruited in this retrospective cohort. Cox-proportional hazards models were used to calculate hazard ratio (HR) of developing HCC and liver-related mortality according to serum HCV RNA titers. Results. HCC was developed in 14 patients during follow-up period. The cumulative risk of HCC development was higher in subjects with high HCV RNA titer (log HCV RNA IU/mL > 6) than subjects with low titer (log HCV RNA IU/mL ≦ 6) (HR = 4.63, P=0.032), giving an incidence rate of 474.1 and 111.5 per 10,000 person-years, respectively. Old age (HR = 9.71, P=0.014), accompanying cirrhosis (HR = 19.34, P=0.004), and low platelet count (HR = 13.97, P=0.009) were other independent risk factors for the development of HCC. Liver-related death occurred in 7 patients. Accompanying cirrhosis (HR = 6.13, P=0.012) and low albumin level (HR = 9.17, P=0.002), but not HCV RNA titer, were significant risk factors related to liver-related mortality. Conclusion. Serum HCV RNA titer may be considered an independent risk factor for the development of HCC but not liver-related mortality

    The Association between Disturbed Eating Behavior and Socioeconomic Status: The Online Korean Adolescent Panel Survey (OnKAPS)

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    Background: A limited amount of research, primarily conducted in Western countries, has suggested that higher socioeconomic status (SES) is associated with higher risk of eating disorders (EDs). However, little is known about this association in Asian countries. We examined the association of SES with disturbed eating behavior (DEB) and related factors in Korean adolescents. Subjects A nationwide online panel survey was conducted in a sample of adolescents (n = 6,943, 49.9% girls). DEB was measured with the 26-item Eating Attitudes Test (EAT-26). Participants who scored ≥20 on the EAT-26 were considered to have DEB. Participants’ SES was determined based on self-reported household economic status. Results: The prevalence of DEB was 12.7%: 10.5% among boys and 14.8% among girls. Both boys and girls with DEB were more likely to perceive themselves as obese, experience higher levels of stress, and have lower academic achievement. The risk for DEB was significantly higher in boys of higher SES than in those of middle SES (OR = 1.45, 95%CI = 1.05–1.99 for high SES; OR = 5.16, 95%CI: 3.50–7.61 for highest SES). Among girls, higher risk of DEB was associated with the highest and lowest SES (OR = 1.52, 95%CI: 1.13–2.06 for lowest SES; OR = 2.22, 95%CI: 1.34–3.68 for highest SES). Conclusions: Despite the lower prevalence of obesity in Korea compared with Western countries, the prevalence of DEB in Korean adolescents was high, especially among girls. Moreover, the association between SES and DEB followed a U-shaped curve for girls and a J-shaped curve for boys

    Assessment of Allergic Rhinitis Websites in Korea

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    Objectives. The internet has become an important source of medical information and a great amount of information related to allergic rhinitis (AR) is available on the internet. However, the quality of this information is still a matter of debate. Therefore, this study was conducted to assess the AR-related information on Korean websites. Methods. The key word "allergic rhinitis" was entered into 4 popular search engines, and this led to identifying 40 websites. After being categorized according to authorship, the informational value of these websites was evaluated using 4 different assessment tools such as the Journal of the American Medical Association (JAMA) benchmarks, the DISCERN questionnaire, the Allergic Rhinitis and its Impact on Asthma (ARIA) 2008 Update and the Health On the Net (HON) code. Results. The 40 websites containing AR-related information were categorized according to their authorship as Western physician: 20, Oriental physician: 14, commercial: 1, and others: 5. The mean citation frequencies of the JAMA benchmarks and the ARIA 2008 Update concepts was 1.23 out of 4 and 4.33 out of 8, respectively, while the mean DISCERN score was 1.92 out of 5. When the websites were evaluated based on the type of authorship, the mean citation frequencies of the AMA 2008 Update concepts were Western physician: 5.35, Oriental physician: 2.64. Additionally, three websites authored by Western physicians and 13 authored by Oriental physicians contained unreliable information. Among these 16 websites, only 3 websites met the requirements for the HON code "Justification". Conclusion. AR-related information available on Korean websites is of variable quality and not all of the information provided is justifiable. Thus, performing surveillance of the medical information on these websites is necessary. Furthermore, common criteria that can be used to evaluate the websites created by both Western and Oriental physicians are also needed.Bousquet J, 2008, ALLERGY, V63, P8*HLTH NET FDN, 2006, HLTH NET COD COND VESILVA LVE, 2005, BRAZILIAN J OTHORHIN, V71, P590Park HW, 2004, J KOREAN MED SCI, V19, P364Winker MA, 2000, JAMA-J AM MED ASSOC, V283, P1600Charnock D, 1999, J EPIDEMIOL COMMUN H, V53, P105Silberg WM, 1997, JAMA-J AM MED ASSOC, V277, P1244
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