• Carbon letters
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• v.26
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• pp.43-50
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• 2018

In this research, a novel and efficient quinoline thioacetamide functionalized magnetic graphene oxide composite ($GO@Fe_3O_4@QTA$) was synthesized and utilized for dispersive magnetic solid phase preconcentration of Cd(II) and Ni(II) ions in urine and various food samples. A number of diverse methods were employed for characterization of the new nanosorbent. The design of experiments approach and response surface methodology were applied to monitor and find the parameters that affect the extraction performance. After sorption and elution steps, the concentrations of target analytes were measured by employing FAAS. The highest extraction performance was achieved under the following experimental conditions: pH, 5.8; sorption time, 6.0 min; $GO@Fe_3O_4@QTA$ amount, 17 mg; 2.4 mL $1.1mol\;L^{-l}$ $HNO_3$ solution as the eluent and elution time, 13.0 min. The detection limit is 0.02 and $0.2ng\;mL^{-1}$ for Cd(II), and Ni(II) ions, respectively. The accuracy of the new method was investigated by analyzing two certified reference materials (sea food mix, Seronorm LOT NO 2525 urine powder). The interfering study revealed that there are no interferences from commonly occurring ions on the extractability of target ions. Finally, the new method was satisfactorily employed for rapid extraction and determination of target ions in urine and various food samples.

• Agricultural and Biosystems Engineering
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• v.3 no.2
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• pp.65-72
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• 2002

Temperature is the most influential environment parameter which affects the quality change of agricultural products in cold storage. Therefore, it is essential to keep the uniform temperature distribution in the storage room. This study was performed to analyze the air movement and temperature distribution in the forced recirculating cold storage facility and to simulate optimum storage method of green groceries using 3-D CFD(three dimensional computational fluid dynamics) computer simulation which applied the standard $textsc{k}$-$\varepsilon$ turbulence model and FVM(finite volume method). The simulation was validated by the experimental results for onion storage and the simulation model was used to simulate the temperature and velocity distribution in the storage room with reference to the change of storage method such as location of storage, no stores, bulk storage, and pallet storage. In case of no stores, internal airflow was circulated without stagnation and consequently air movement and temperature distribution were uniform. In case of bulk storage, air movement was stagnated so much and temperature distribution of onion was not uniform. Furthermore, the inner temperature of onion roses more than the initial temperature of storage. In case of pallet storage, air movement and temperature distribution of onion were so uniform that the danger of quality change was decreased.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.3
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• pp.235-243
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• 2020

The research aims to examine the impact of leadership style on accountants' commitment with FDI firms in Vietnam based on theory of Bass and Avolio (2004). A survey with 110 accountants in FDI firms was conducted. The total of 110 respondents with full information were used for data entry and analysis. Through quantity methodology, we used Cronbach's Alpha, EFA and correlation analysis to determine the relationship between leadership style and three dependent variables including affective, normative and continuance commitment. The results showed that the leadership style had positive relationships with accountants' commitments. In particular, normative commitment with FDI firms of accountants is the most strongest. In addition, there is no statistically difference in the level of three commitments with FDI firms of accountants for three groups of job description. From the findings, this study suggests several recommendations to improve accountants' commitments such as intellectually stimulating, individualized consideration, inspirational motivation, idealized influence, and idealized influence behavior. The results are considered as a useful reference for establishing policies to attract talent personnel toward to sustainable development of firms. Commitment with the organization is a crucial factor to gain a competitive advantage and guide the success of organizations by satisfying customers, maintaining productivity and efficiency.

• The Korean Journal of Physiology
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• v.2 no.1
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• pp.59-71
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• 1968

The uptake of phenolsulfonphthalein (PSP) and of paraaminohippuric acid (PAH) by cortical slices of the rabbit kidney was investigated while varying the composition of medium. The overall uptake of these substances displayed typical active transport characteristics and was significantly enhanced in presence of acetate. When the phosphate buffer was used the optimal pH was 7.4 for both substances. However, when the tris-buffer was used the optimal pH was 7.4 for PSP and 8.3 for PAH. Removal of $Na^+$ from the medium resulted in a significant reduction in the uptake. Similar results, though lesser in magnitude, were obtained when either $K^+\;or\;Ca^{++}$ was removed from the medium. However, there was no additive effect when $K^+\;and/or\;Ca^{++}$ were additionally removed from the $Na^+-free$ medium. The presence of ${NH_4}^+$ greatly reduced while $Li^+\;and\;Mg^{++}$ moderately reduced the uptake of both substances. However, choline had no effect. In substrate-leached slices, acetate greatly enhance the uptake of organic acids; but this action was not demonstrable in absence of $Na^+,\;K^+\;or\;Ca^{++}$.

• Nuclear Engineering and Technology
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• v.45 no.6
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• pp.707-720
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• 2013

We analyze piecewise homogenization with flux-weighted cross sections and preservation of averaged currents at the boundary of the homogenized domain. Introduction of a set of flux discontinuity ratios (FDR) that preserve reference interface currents leads to preservation of averaged region reaction rates and fluxes. We consider the class of numerical discretizations with one degree of freedom per volume and per surface and prove that when the homogenization and computing meshes are equal there is a unique solution for the FDRs which exactly preserve interface currents. For diffusion submeshing we introduce a Jacobian-Free Newton-Krylov method and for all cases considered obtain an 'exact' numerical solution (eight digits for the interface currents). The homogenization is completed by extending the familiar full assembly homogenization via flux discontinuity factors to the sides of regions laying on the boundary of the piecewise homogenized domain. Finally, for the familiar nodal discretization we numerically find that the FDRs obtained with no submesh (nearly at no cost) can be effectively used for whole-core diffusion calculations with submesh. This is not the case, however, for cell-centered finite differences.

• Korean Journal of Veterinary Pathology
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• v.1 no.1
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• pp.40-45
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• 1997

The phototoxic potentials of LB20304a a new quinolone compound being developed by LG Chemical Ltd, and reference compounds (Ciprofloxacin; CPFX, Enoxacin; ENX and Lomefloxacin; LFLX) were compared in a murine model. in addition photostability of these compunds was studied after irradiation with long-wave UV light(UVA, 0, 0.3 1 or 3 Joule/$Cm^2$) When hairless mice(9 to 11 weeks old 19-26g) were orally administered with different dose levels of test compunds and exposed to UVA(40J/$cm^2$) inflammatory reactions were observed in a dose dependent manner. Among the compounds tested, LB20304a demonstrated the least phototoxic effects and showed no inflammatroy lesions at a dose level of 100mg.kg (Low dose). ENX and LFLX demonstrated much greater phototoxic reactions while CPFX showed similar or slightly greater phototoxic reactions compared to LB20304a. Similar to the in-vivo results the solutions of LB20304a and CPFX irradiated with UVA demonstrated reduced spectral changes compared to those of ENX and LFLX. In conclusion these data suggest that phototoxic potencies of the quinolones tested were; LFLX > ENX > CPFX $\geq$ LB20304a. No phototoxic dose of LB20304a in mice was 100 mg/kg.

• Archives of Plastic Surgery
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• v.44 no.1
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• pp.65-71
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• 2017

Background This study evaluated dynamic changes in eyebrow position related to aging. Methods Female participants were recruited and separated into two groups aged 20-30 years (the younger group, n=20; mean age, 24.8 years) and 50-70 years (the older group, n=20; mean age, 55.8 years). Photogrammetry was used to determine the eyebrow position at the medial canthus (MC), lateral limbus, lateral canthus, and lateral end point (EP) for 6 actions: smooth opening (the reference action) and closing of the eye, forward gaze, maximum opening and closing of the eye, and maximum frown. Videos were also recorded. Results No differences in eyebrow position were detected at the MC when opening or closing the eyes smoothly, gazing straight ahead, or closing the eyes maximally. For all 6 actions, the position of the lateral EP in the older group was significantly lower than in the younger group (P=0.003), and the smallest degree of vertical movement at this point was found in both age groups (P<0.001). Vertical movement at the 4 landmarks of the eyebrows decreased with aging. Conclusions Eyebrow position was unchanged at the MC with aging, except at maximal eye opening and maximal frown. No differences in eyebrow position were observed between the younger and older groups when eyes were maximally closed, except at the EP. It is important to focus on correction of the lateral EP for periorbital rejuvenation.

• Neonatal Medicine
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• v.16 no.2
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• pp.121-130
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• 2009

Over the past 20 years, neonatal mortality rates for preterm infants, particularly those born extremely preterm and with a very low birth weight, have decreased steadily. As more very immature preterm infants survive, provision of enteral feeding has become a major focus of concern. According to many experts on neonatal nutrition, the goal for the nutrition of preterm infants should be to achieve a postnatal growth rate approximating that of a normal fetus of the same gestational age. Total parenteral nutrition for maintaining nutritional integrity is mandatory before successful transition to enteral feeding. Early initiation of trophic enteral feeding is vital for postnatal adaptation. Recently published randomized controlled trials provide no evidence to support the practice of postponing enteral feeding to reduce the incidence of necrotizing enterocolitis. Early trophic feeding yields demonstrable benefits and there is currently no evidence of any adverse effects following early feeding. Preterm milk from the infant's own mother is the milk of choice, which can always be supplemented with a human milk fortifier. Here we review over 50 randomized controlled trials and over seven systematic reviews published on neonatal parenteral and enteral feeding of preterm infants. Neonatologists must make use of the evidence from these studies as a reference for feeding protocols for preterm infants in their NICUs are to be based.

• Journal of Food Hygiene and Safety
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• v.9 no.2
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• pp.57-66
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• 1994

The benefits of milk on the rats supplemented with cholesterol and vitamin D2 in diet was investigated. A total of 150 male rats of Sprague-Dawley strain, 5 weeks of age, were divided into 6 groups with the diet. Cholesterol control group was fed the diet containing 1.0% choleterol and 50,000 IU/100 g of vitamin D2 for 24 months, and M0.5, M1, M2 and M5 of milk groups were fed the diet containing cholesterol, vitamin D2 and 0.5, 1, 2 and 5 of reference daily intakes of whole milk, respectively. No remarkable differences of growth, diet intake, and food effciency ratio among groups were observed though rats in cholesterol control group showed abrupt decrease of diet intake and body weight showed slightly higher relative organ weights than did the rats in control group. The rats in cholesterol control group showed the highest serum total cholesterol level. The rats in milk groups showed lower total cholesterol level and higher high density lipoprotein (HDL)-cholesterol fraction than did the rats in cholesterol control group though no tendency was observed among milk groups. In milk groups, aorta, heart, kidney and liver of rats showed milder calcification and necrosis or fat degeneration compared with those in cholesterol control group. The above results suggest that whole milk could have beneficial effect on the cholesterol-and -vitamin D2-induced atherosclerosis in rats.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.3
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• pp.205-212
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• 2014

Chronological changes of soil organic carbon (SOC) must be prepared by IPCC guidelines for national greenhouse gas inventories. IPCC suggested default reference SOC stocks for mineral soils and relative stock factors for different management activities where country own factors were not prepared. 3.4 million data were downloaded from agricultural soil information system and analyzed to get chronological changes of SOC for some counties and for land use in Korea. SOC content of orchard soil was higher than the other soils but chronological SOC changes of all land use had no tendency in differences with high standard deviation. SOC contents of counties depended on their own management activities and chronological SOC changes of districts also had no tendency in differences. Thus, Korea should survey the official records and relative stock factors on management activities such as land use, tillage and input of organic matter to calculate SOC stocks correctly. Otherwise, Korea should establish a model for predicting SOC by analyzing selected representative fields and by calculating SOC differences from comparing management activities of lands with those of representative fields.