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This study was performed to determine risk ranking of the combination of pathogen-livestock or livestock products to identify the most significant public health risks and to prioritize risk management strategies. First, we reviewed foodborne outbreak data related to livestock products and determined main vehicles and pathogens according to the number of outbreak and case. Second, expert's opinion about management priority of pathogen-live- stock product pairing was surveyed with 19 livestock experts in the university, research center, and government agency. Lastly, we used the outcome of Risk Ranger (semi-quantitative risk ranking tool) of 14 combinations of patho- gen and livestock or livestock products. We have classified the combination of pathogen-livestock products into group I (high risk), II (medium risk), and III (low risk) according to their risk levels and management priority. Group I, which is the highest risk for foodborne outbreak, includes Salmonella spp./egg and egg products, Campylobacter spp./poul- try, pathogenic E. coli/meat and processed ground meat. In conclusion, the results of this study will provide the spe- cific guideline of mid- and long-term planning for risk assessment and risk management prioritization of the combination of pathogen and livestock, or livestock product.

The feasibility of incorporating Cynanchi wilfordii powder as a value-added food ingredient in convenient food products was investigated using yanggaeng as a model system. C. wilfordii powder was incorporated into yanggaeng at 0, 2, 4, 6, and 8% weight amounts based on total weight of cooked white bean and C. wilfordii powder. pH increased significantly, and moisture content ranged from 45.40% to 47.40% with increasing levels of C. wilfordii powder (P

According to the microbiological standard, Staphylococcus aureus, Clostridium perfringens and Listeria monocytogenes should not be detected in milk and egg products in Korea. Refrigerated food such as milk must be kept under 10°C at retail markets. However, temperature abuse of refrigerated foods at such markets is often observed. We compared the growth and survival kinetics of S. aureus and C. perfringens at 10 and 15°C, and the growth kinetics of L. monocytogenes at 4 and 10°C in whole and skim milk and ready-to-eat (RTE) quail eggs to evaluate their growth possibilities at retail markets. Regardless of storage temperature, the level of S. aureus reached the maximum level (10 8 -10 9 CFU/ml) in whole milk, non-fat milk and RTE quail eggs within the expiration date. Even low contamination levels of S. aureus (10 CFU/mL) grew rapidly in milk and quail eggs to reach the maximum level within the shelf life. Survival of C. perfringens in whole milk was greater than that in non-fat milk, indicating that the fat content in milk influences the survival of C. perfringens. For L. monocytogenes, the population in milk increased by 0.5-1 log CFU/mL at 4°C, while the populations reached the maximum level at 10°C within the expiration date, regardless of initial contamination levels. In quail eggs, L. monocytogenes grew to the maximum level within the expiration date (60 days) at both temperatures. S. aureus and L. monocytogenes must be controlled to be negative, and proper temperature management should be emphasized at retail markets to protect the consumer. Since C. perfringens did not grow in milk and RTE quail eggs, there is no risk due to the growth of C. perfringens in these products at retail markets.Key words: milk, ready to eat quail egg, pathogenic microorganisms, fat, storage temperature

Ready-to-eat (RTE) Jokbal (Pig's trotter), which consists of pig's feet cooked in soy sauce and various spices, is a very popular and widely sold in Korean retail markets. Commercially, the anaerobically packed Jokbal have also become a popular RTE food in several convenience stores. This study evaluates the effects of storage temperature and packaging methods for the growth of C. perfringens in Jokbal. Growth kinetic parameters of C. perfringens in aerobically and anaerobically packed Jokbals are determined at each temperature by the modified Gompertz equation. The lag time, specific growth rate, and maximum population density of C. perfringens are being analyzed as a function of temperature and packaging method. The minimum growth temperature of C. perfringens in aerobically and anaerobically packed Jokbal is 24℃ and 18℃, respectively. The C. perfringens in Jokbal did not grow under conditions of over 50℃ regardless of the packaging methods, indicating that the holding temperature of Jokbal in markets must be maintained at above 50℃ or below 18℃. Growth of C. perfringens in anaerobically packed Jokbal is faster than in aerobically packed Jokbal when stored under the same conditions. This indicates that there are a higher risks associated with C. perfringens for anaerobically packed meat products.

We developed a versatile platform to construct heterogeneous organic and metallic elements with micrometer features on a plastic substrate in a complementary transfer-assisted patterning (CTAP) scheme. The underlying concept relies on a high-resolution transfer-printing process of a sacrificial layer, producing complementary patterns of the elements, in combination with a lift-off technique for removing the sacrificial layer to leave only active patterns on a variety of substrates. No detrimental errors in sequentially defining patterns of both an organic material and a metal are involved during lifting-off the sacrificial layers in multilayer architecture. We demonstrated the generic principle of the CTAP in the fabrication of short-channel organic thin film transistors on glass substrates and organic inverters on plastic substrates for flexible electronics.

The development of simple and generic principles for microfluidics should have an impact on a wide range of distinct areas, including chemical synthesis, medical diagnostics, and designer emulsions. For advanced applications such as the purification of nucleic acids from a large number of cells, multiple connection of liquid-core/liquid-cladding waveguides, and sorting colloidal emulsions or vesicles in complex solutions, a high level of selectivity in a highly branched architecture is an essential element of designing a robust platform. However, existing technologies including an electro-kinetic or a hydrodynamic method, successfully employed for a simple or parallel Y-channel structure with a single junction, are not easily applicable for serial branches, due to the requirement of either a high voltage (or pressure) between the junctions or a complicated structure. Herein, we present a concept of nematofluidics that provides a simple, programmable, and hierarchically branched architecture of microfluidics where a nematic liquid crystal (LC) is used as an anisotropic fluid. This anisotropic-fluid-based approach allows precise and concurrent control of the flow resistance and streamlines in multi-junction networks, in analogy to the resistance and current in electrical circuits, by the application of a low electric field to each channel. The anisotropic flow resistance, associated with the nematodynamic viscosities, is electrically controlled through molecular reorientation to steer nanoor microparticles immersed in the LC into a specific channel at each junction. Moreover, due to the channel-independent controllability of the LC, a hierarchically branched architecture of microfluidics with high-level of selectivity is designed. For the flow selection capability at a channel junction, two different microfluidic environments that can be switched are required, namely the effective dynamic viscosity along the flow direction (h1) and that perpendicular to the flow direction (h3). The perpendicular viscosity h3 is much larger than the parallel shear viscosity h1 because the rotational motion of the LC molecules is mostly involved in the former. The backflow effect incurred during the switching of one environment to the other should not play a significant role in the steady state. Note that dynamic viscosities will depend on the surface interactions of the LC with a wall as well as the geometric shape of a channel, particularly in a microfluidic system with a high surface-tovolume ratio. In our case, the anisotropic nature of the nematodynamic viscosities is produced through the change in the direction of the LC alignment by an electric field applied perpendicular to the flow. A LC material, 4-cyano-4’-pentylbiphenyl (5CB), was filled into a rectangular microfluidic channel with a cross section of 100 mm in width (w) and 15 mm in height (h), by capillary action. The contact angles of the LC on the glass substrate and on polydimethylsiloxane (PDMS) were measured as 22 18 and 20 28, respectively, indicating that the surface energy difference between the glass and the PDMS is essentially negligible. In such a thin structure with similar surfaces, the front propagation of the LC along the channel is predominantly driven by the capillary force at the two side walls irrespective of the orientation of the LC director. This is clearly seen in the two inset microphotographs with large radii of curvature of the capillary meniscus in Figure 1b. We measured the front displacements of the capillary meniscus in time along the channel in two different LC alignment configurations. For the application of an electric field, electrode segments of indium–tin oxide (ITO) and metal electrodes were prepared on the glass substrate and the PDMS film, respectively. In the absence of an applied voltage, the LC molecules are homogeneously aligned by capillary action along the flow. Under crossed polarizers (A and P), the homogeneously aligned LC transmits the light as shown in the left inset in Figure 1b when the LC director makes a nonzero angle (458) with respect to one of the polarizers. Above the Freederickz threshold, the LC becomes homeotropically reoriented. An applied voltage of 20 V (an electric field of about 1.3 Vmm ) in square waveform at 1 kHz was used. The LC behaves as an optically isotropic medium and is dark under crossed polarizers as shown in the right inset of Figure 1b. Less dark regions along two side walls and near the meniscus front are observed due to the presence of the director distortions on a micrometer scale as the LC is homogeneously aligned on the plasmatreated PDMS surfaces and homeotropically aligned on the air interface. Note that the meniscus front between the top and bottom substrates has a smaller radius of curvature than that between the two side walls because of the geometric shape of the channel. The apparent meniscus angles formed between the two side walls are about 198 in the homogeneous configuration and about 288 in the homeotropic configuration. The front displacements of the capillary meniscus in time, measured using a polarizing optical microscope with a home-made [a] Dr. Y.-J. Na, S. Park, Prof. B. Lee, Prof. S.-D. Lee School of Electrical Engineering Seoul National University Kwanak, P.O.Box 34, Seoul 151-600 (Korea) Fax: (+82)2-874-9769 E-mail : sidlee@plaza.snu.ac.kr [b] Prof. T.-Y. Yoon Department of Physics Korea Advanced Institute of Science and Technology Daejeon 305-701 (Korea) Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/cphc.200900778.

The fundamental aspects of the wettability and the elasticity of soft matters, particularly, functional polymer solutions, lipid membranes, and biological cells in the development of new technologies are overviewed from the basic principles and underlying physics. The key concept is how to control interfacial interactions between solid substrates and soft matters through surface modification. Two representative examples are demonstrated to discuss the underlying physics behind the pattern and domain formation; one of them is multi-dimensional generation of heterogeneous organic arrays and the other is micro-patterning of red blood cells on lipid membranes

We report on a nondisruptive method of patterning fluid membranes into micrometer-scale arrays through a selective vesicular rupture pathway by nanotopography. The site- and pathway-selective formation of supported lipid bilayers (SLBs) was achieved by different vesicular adsorption and rupture processes between nanocorrugated and nanosmooth topographies. The SLBs were first developed in the nanocorrugated region due to fast vesicular adsorption and then grew into the nanosmooth region through bilayer edge-induced vesicular rupture. Our topographic approach provides a viable scheme, yet unattainable in conventional ways, of actively controlling the position and the coverage of the SLBs on a variety of substrates without disrupting two-dimensional fluidity for highly integrated membrane devices.

A highly efficient organic light‐emitting diode (OLED) with an in‐cell polarizer made of an imprinted liquid crystalline polymer (LCP) layer doped with dichroic dye molecules is presented. The in‐cell polarizer was found to be capable of effectively polarizing the emission light of the OLED and of significantly improving the luminance through the periodic microstructures fabricated using an imprinting method. This type of OLED with an imprinted in‐cell polarizer is useful for efficient light source applications in liquid crystal displays (LCDs).

However, due to blurs and errorsinthelateraldefinitionoftheelementpatternsgeneratedbythosemethods, a new patterning and integration technology with highprecision in 2D and 3D is required for producing high-performance combinatorial arrays. Recently, a substrate pattern-ing method creating wetting contrast patterns for solutions wasdemonstrated to fabricate organic thin-film transistors

Background: Sensory impairment is a common condition that exerts negative effects on health-related quality of life (HRQoL) in the elderly. This study aimed to determine the relationship between sensory impairment and HRQoL and identify sensory-specific differences in the HRQoL of elderly. Methods: This study used data from the Korean National Health and Nutrition Examination Survey V (2010-2012), analyzing 5,260 subjects over 60 years of age who completed ophthalmic and otologic examinations. Vision and hear-ing impairment were measured and classified. HRQoL was determined according to the European QoL five dimen-sion test (EQ-5D). Multivariate logistic regression analysis and analysis of covariance were performed to identify rela-tionships between sensory impairment and HRQoL dimensions as well as differences in HRQoL scores. Results: In the final adjusted multivariate model, there was a statistically higher proportion of those with dual sensory impairment who reported problems with mobility (adjusted odds ratio [aOR] 2.30, 95% confidence interval [CI] 1.45–5.03), usual activities (aOR 2.32, 95% CI 1.16–4.64), and pain/discomfort among EQ-5D subcategories (aOR 1.79, 95% CI 1.07–2.97). In the EQ-5D dimensions, the means and standard deviations of vision impairment (0.86 [0.01]) and dual sensory impairment (0.84 [0.02]) appeared meaningfully lower than those for no sensory impairment (0.88 [0.00]) or hearing impairment (0.88 [0.01]); P = .02). Conclusion: Sensory impairment reduces HRQoL in the elderly. Improvement of HRQoL in the elderly thus requires regular screening and appropriate management of sensory impairment.

We demonstrate a polarization-insensitive grating device based on a liquid crystal (LC) doped with azo-dyes in polymer networks. The polarization-insensitive diffraction is obtained by periodically modulating the optic axis of a homogeneously aligned nematic LC layer. The polymer networks formed in the doped LC medium play a critical role in achieving the optic axis modulation of the LC by a single pump irradiation. The optically induced effect in the dye-doped LC system is permanent, polarization-insensitive, and electrically controllable.

We report on the stability of the optical reorientation of doped nematic liquid crystals(LCs)with azo-dyes in polymer networks. The photo-reactive polymer networks formed within the doped LC medium play a critical role in achieving the stable optical reorientation of the LC originating from the trans-cis transformation of the dye molecules. Moreover, the photo-reactive polymer layer on the substrate surface is required to produce the surface memory effect of the dye-doped LC. The optically induced memory is well retained in the dye-doped LC only in the presence of the polymer network medium.

We report on a site-selective assembly and fixation process for setting colloidal particles onto a two-dimensional array on a wettability-patterned surface. The site-selectivity originates from the control of the wettability of a liquid crystal (LC)/prepolymer composite, used as a colloidal suspension, on an alignment layer exposed to ultraviolet light. The fixation of close-packed colloidal particles was achieved on a supported polymer film formed through the anisotropic phase separation of the LC/prepolymer. This wettability-based assembly and fixing process for colloidal particles could be useful for biomedical and photonic applications.

We developed a simple and versatile patterning method for advanced organic displays with high resolution and uniformity in large area. Our patterning method involves the optical formation of selective wetting regions, where a regular array of functional polymer patterns is obtained by a standard spin-casting process. It is demonstrated that polymeric semiconductors and light-emitting polymers can be patterned to produce periodic arrays with feature resolution down to sub-micrometers using the selective wettability. This wettability-based patterning technique of soluble functional polymers would be directly applicable for organic displays and plastic electronics.

The authors report on the multistage optical memory of a liquid crystal (LC) diffraction grating fabricated using a dye-dispersed LC/polymer composite medium. Under a single pump beam, the reorientation of dye molecules, confined within spatially periodic interpolymer networks produced by a patterned exposure of ultraviolet light, allows for a pure optic-axis modulation which gives high diffraction efficiency in a planar LC configuration. The resultant multistage optical memory of the LC grating is controlled solely by the polarization state of a single rewriting beam without the use of an erasing step prior to every rewriting process.