• Polymer(Korea)
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• v.33 no.1
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• pp.84-90
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• 2009

Nitinol alloy (TiNi) has been widely used in vascular stents. To improve the blood compatibility of Nitinol alloy, its surface was chemically modified in this study. Nitinol was first coated with gold, then chemisorbed with L-cysteine (C/N), and followed by grafting of zwitter ionic poly(ethylene glycol) (PEG) (PEG-$N^+-SO_3{^-}$) to produce TiNi-C/N-PEG-N-S. The zwitter ionic PEG grafted on the Nitinol surface was identified by ATR-FTIR, ESCA and SEM. The hydrophilized surface was proven by the decrease of water contact angle. In addition, from the blood compatibility tests such as protein adsorption, platelet adhesion, and blood coagulation time, the surface-modified TiNi alloy exhibited a better blood compatibility as compared to the untreated Nitinol control. These results indicated a feasibility of synergistic effect of hydrophilic PEG and antithrombotic zwitter ion.

• Archives of Plastic Surgery
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• v.32 no.5
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• pp.607-612
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• 2005

A traditional tie-over dressing may be applied to support the take of a skin graft. Although there are many advantage of this method, it has significant disadvantages, including time-consuming application. Furthermore, when the dressing is changed, the gauze becomes hard and can be stuck to the graft, causing damage and pain upon removal. The purpose of our study is to evaluate the effect of semi-occlusive dressing using polyurethane foam and film dressing($Allevyn^{(R)}$, $Opsite^{(R)}$) after full thickness skin graft. The authors treated 45 cases including burn scar contracture(n=38), syndactyly (n=1), absence of nipple-areolar complex(n=4), traumatic skin defect(n=1) and contact burn(n=1) with authors' method and 39 patients including burn scar contracture (n=39) with the tie-over dressing between 2000 and 2004. The patients in polyurethane foam and film dressing group ranged from 1 to 62 years of age (mean age, 15.1 years) and the patients in tie-over dressing group ranged from 2 to 60 years of age(mean age, 21.3 years). The postoperative results were analyzed according to the following measures: (1) the duration of graft-taking, (2) the admission period, (3) complications. Compared with the traditional tie-over dressing, polyurethane foam and film dressing was shown to be more successful in a reduced duration of graft-taking, in which was similar to the former in the rate of graft-taking, a reduced admission period and patient's discomfort. We concluded that semi-occlusive dressing using $Allevyn^{(R)}$ and $Opsite^{(R)}$ was an effective method after full thickness skin graft, which was easy to shape to difficult body locations, such as web spaces, fingers and maintains a moist environment for wound healing and does not stick to the wound.

• The Plant Pathology Journal
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• v.36 no.3
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• pp.289-296
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• 2020

Type VI secretion system (T6SS) is a contact-dependent secretion system, employed by most gram-negative bacteria for translocating effector proteins to target cells. The present study was conducted to investigate T6SS in Xanthomonas oryzae pv. oryzae (Xoo), which causes bacterial blight in rice, and to unveil its functions. Two T6SS clusters were found in the genome of Xoo PXO99^A. The deletion mutants, Δhcp1, Δhcp2, and Δhcp12, targeting the hcp gene in each cluster, and a double-deletion mutant targeting both genes were constructed and tested for growth rate, pathogenicity to rice, and inter-bacterial competition ability. The results indicated that hcp in T6SS-2, but not T6SS-1, was involved in bacterial virulence to rice plants. However, neither T6SS-1 nor T6SS-2 had any effect on the ability to compete with Escherichia coli or other bacterial cells. In conclusion, T6SS gene clusters in Xoo have been characterized, and its role in virulence to rice was confirmed.

• Korean Journal of Poultry Science
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• v.7 no.2
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• pp.18-27
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• 1980

Infectious bursal disease, so called Gumboro disease, is found world-wide in areas of intensive poultry farming. The clinical signs of the disease are very indicative, but most infections occur unnoticed due to the age of infection of chicken as well as the degree of virulence of virus affected. Edematous and hemorrhagic lesions in BF at early course of infection and the complete atrophies of BF in later are the most characteristic. The infection is considered highly contagious by direct contact, by fecal material and by contaminated feed and water. The virus is also highly resistant in environment and belongs to Diploma virus with size of 55 to 60nm of Ribovirus group. IBDV grows in embryos, embryonic cells and BF of susceptible chickens. Immune-diffusion using agar gel is the method of a choice to determine IBDV infection in chickens. Maternal immunity is very effective in protecting chickens of critical age when IBDV infection severely damages the function of BF. Immunosuppressive effect of IBDV causes more production losses than direct effects of clinical disease of IBD. Inclusion body hepatitis, infectious anemia and gangrenous dermatitis syndrome are the disease associated with the immunosuppressive condition of chickens.

• International Journal of Industrial Entomology and Biomaterials
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• v.36 no.2
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• pp.25-30
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• 2018

The larvae of Hermetia. illucens have a high probability of coming into contact with microorganisms such as bacteria and fungi. Therefore, the survival of H. illucens is primarily the protection of their own against microbial infection. This effect depends on the development of the innate immune system. Antimicrobial Peptides (AMPs) exhibit antimicrobial activity against other bacterial strains and can provide important data to understand the basis of the innate immunity of H. illucens. In this study, we injected larvae with Enterococcus. faecalis (gram-positive bacteria) and Serratia. marcescens as (gram-negative bacteria) to test the hypothesis that H. illucens is protected from infection by its immune-related gene expression repertoire. To identify the inducible immune-related genes, we performed and cataloged the transcriptomes by RNA-Seq analysis. We compared the transcriptomes of whole larvae and obtained a DNA fragment of 465 bp including the poly (A) tail by RACE as a novel H. illucens immune-related gene against bacteria. A novel target mRNA expression was higher in immunized larvae with E. faecalis and S. marcescens groups than non-immunized group. We expect our study to provide evidence that the global RNA-Seq approach allowed for the identification of a gene of interest which was further analyzed by quantitative RT-PCR, together with genes chosen from the available literature.

• Biomolecules & Therapeutics
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• v.22 no.6
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• pp.563-569
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• 2014

Materials with differing surfaces have been developed for clinical implant therapy in dentistry and orthopedics. This study was designed to evaluate bone response to titanium alloy containing Ti-32Nb-5Zr with nanostructure, anodic oxidation, heat treatment, and ibandronate coating. Rats were randomly assigned to two groups for implantation of titanium alloy (untreated) as the control group and titanium alloy group coated with ibandronate as the experimental group. Then, the implants were inserted in both tibiae of the rats for four weeks. After implantation, bone implant interface, trabecular microstructure, mechanical fixation was evaluated by histology, micro-computed tomography (${\mu}CT$) and the push-out test, respectively. We found that the anodized, heat-treated and ibandronate-coated titanium alloy triggered pronounced bone implant integration and early bone formation. Ibandronate-coated implants showed elevated values for removal torque and a higher level of BV/TV, trabecular thickness and separation upon analysis with ${\mu}CT$ and mechanical testing. Similarly, higher bone contact and a larger percentage bone area were observed via histology compared to untreated alloy. Furthermore, well coating of ibandronate with alloy was observed by vitro releasing experiment. Our study provided evidences that the coating of bisphosphonate onto the anodized and heat-treated nanostructure of titanium alloy had a positive effect on implant fixation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.12
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• pp.1503-1512
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• 2013

In this study, we proposed an indentation evaluation method for fracture toughness using cohesive finite element simulations. First, we examined the effect of material properties (yield strain, Poisson's ratio, and elastic modulus) on crack size during Vickers indentation and then generated a regression formula that explains the relations among fracture toughness, indentation load, and crack size. We also proposed another indentation formula for fracture toughness evaluation using the contact size a and E/H (H: hardness). Finally, we examined the relation between the crack size and the indenter shapes. Based on this, we can generate from the formula obtained using the Vickers indenter a formula for an indenter of different shapes. Using the proposed method, fracture toughness is directly estimated from indentation data.

• Health Policy and Management
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• v.7 no.2
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• pp.89-108
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• 1997

The purpose of this study is to investigate drug information sources which influence physician's prescriptions, and to compare the differences of drugh information sources between private practitioners and hospital physicians. In addition, the ultimate goal of this study is to provide better quality of drug information for both groups of physicians through the professional drug information system. 264 physicians, including general practitioners and all types of specialists who were working in hospitals and private clinics in Taejon and Chungnam area, participated in this study which was conducted by mail. The results are summarized as follows ; 1. Both physician groups received drug informations mainly from medical journals, but there were differences in secondary sources of drug information. Namely, hospital physicians got drug information from annual meetings and textbooks, and private practitioners got it from detail men and colleagues. 2. Drug effect was the first consideration for drug selection in both physician groups. But, in the 2nd consideration, private practitioners concerned about the price, insurance and rebates, but hospital physicians were not. 3. Only 9.2% of the private practitioners satisfied with the sufficiency of drug information, whereas 22.0% of hospital physicians satisfied with it. The most insufficient area of information was drug interaction in both groups and 91.9% of the physicians suggested that a professional drug information system should be introduced. 4. Both physician groups had contacted with detail men frequently. However, it was rare for them to contact with a pharmacist. This phenomenon was more severe in the case of private practitioners. 5. Neither physician groups knew very much about drug informatio centers. However, they would be willig to participate if a professional drug information system were established. Also, they indicated that the information most required was drug interaction.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.842-847
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• 1998

Ohmic thawing in combination with conventional water immersion thawing was investigated. Frozen meat chunks $(10{\times}10{\times}10{\;}cm)$ were immersed in a water reservoir $(12{\times}12{\times}12{\;}cm)$ which temperature was maintained at $10^{\circ}C{\;}or{\;}20^{\circ}C$, and were positioned between two stainless-steel electrodes $(10{\times}10{\;}cm)$ having no direct contact with the samples. Alternating current $(60{\;}V{\sim}210{\;}V)$ at various frequency $(60{\;}Hz{\sim}60{\;}kHz)$ was used to generate internal heat by the electrical resistance. When the frequency was fixed to 60Hz, thawing time was reduced as the voltage increased. Frequency changes gave no significant effect on thawing time. Ohmically-thawed samples treated with lower voltage showed lower drip loss and higher water holding capacity.

• Journal of Biomedical Engineering Research
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• v.27 no.5
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• pp.218-223
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• 2006

We examined the effects of ${\beta}$-glucan-reinforced PLGA film and scaffold on HDFs (human dermal fibroblast) attachment and proliferation. The PLGA films were prepared by simple solvent-casting method. The prepared films were grafted with $(1{\to}3)(1{\to}6)-{\beta}-glucan$ in various ratios after plasma treatment on surface. The surface of the film was characterized by contact angle measurement, scanning electron microscope (SEM), and Fourier-transform infrared spectrophotometer (FT-IR). The amount of $(1{\to}3)(1{\to}6)-{\beta}-glucan$ in the prepared film was indirectly determined by phenol-sulfuric acid method. The HDFs (Human dermal fibroblasts) were used to evaluate the cell attachment and proliferation on PLGA specimens before and after plasma/${\beta}-glucan$ treatment. The result showed that the plasma treated groups exhibited more mont of ${\beta}-glucan$ might be grafted than the non plasma treated groups. Cell attachment was significantly enhanced in the plasma/${\beta}-glucan$ grafted group after 4 hours incubation (p<0.05) due to the improved hydrophilicity and cytoactivity effect of the ${\beta}-glucan$. The cell proliferation of plasma/${\beta}-glucan$ (2mg/ml) grafted group was the highest rate among the groups (p<0.05).