The effect of sintering conditions on the austenite stability and strain-induced martensitic transformation of nanocrystalline FeCrC alloy is investigated. Nanocrystalline FeCrC alloys are successfully fabricated by spark plasma sintering with an extremely short densification time to obtain the theoretical density value and prevent grain growth. The nanocrystallite size in the sintered alloys contributes to increased austenite stability. The phase fraction of the FeCrC sintered alloy before and after deformation according to the sintering holding time is measured using X-ray diffraction and electron backscatter diffraction analysis. During compressive deformation, the volume fraction of strain-induced martensite resulting from austenite decomposition is increased. The transformation kinetics of the strain-induced martensite is evaluated using an empirical equation considering the austenite stability factor. The hardness of the S0W and S10W samples increase to 62.4-67.5 and 58.9-63.4 HRC before and after deformation. The hardness results confirmed that the mechanical properties are improved owing to the effects of grain refinement and strain-induced martensitic transformation in the nanocrystalline FeCrC alloy.

민자주방망이버섯의 대량 생산 및 상업적 실용화를 위하여 야생 균주에 비해 재배기간이 짧고 자실체 발생이 잘 이루어지는 신품종을 육성하기 위하여 본 연구를 수행하였다. 민자주방망이버섯 유전자원 18계통을 수집하고 볏짚발효배지를 이용한 상자 재배를 통해 자실체가 발생한 4계통을 교배모본으로 선발하였다. 단포자 교배를 통해 671조합의 교배를 하였으나 ‘CBMLN-19’ 계통과 ‘CBMLN-30’ 계통을 교배한 17조합만이 교배가 이루어 졌다. 그 중 균사 생장이 빠르고 밀도가 높은 8계통을 1차 선발하였다. 볏짚발효배지에 유전자원 14계통, 교배계통 8계통을 접종 후 배양기간을 조사한 결과 교배계통 중 6계통은 20일만에 배양이 완료되었으며 유전자원 14계통 중 7계통은 배양이 완료되기 까지 40일 이상이 소요되어 대부분의 교배계통에서 배양기간이 20일 이상 단축되었다. 배양이 완료된 계통은 식양토를 1~2 cm 복토하여 후 배양을 하였고 균사 배양이 완전히 완료되었을 때 균긁기를 한 후 자실체 발생을 유도하였다. 발생 유도 환경은 온도 14 ̊C, 상대습도 95% 이상, CO2농도 1,500~2,000 ppm 이었으며, 야간에 6℃로 온도를 낮추어 하온 충격을 주었다. 그 결과 유전자원 ‘CBMLN-31’, ‘CBMLN-44’ 2계통, 교배계통 ‘CBMLN-96’, ‘CBMLN-103’ 2계통 총 4계통에서 자실체가 발생하였다. 접종 후 자실체가 발생되기까 지의 기간은 대조구인 유전자원 ‘CBMLN-31’이 100일로 가장 길었고, 교배계통인‘CBMLM-103’이 45일로 가장 짧았다. 자실체 특성 조사 결과 교배계통인 ‘CBMLN- 103’은 개체중이 1.9 g으로 작은 형태를 나타냈으며, 상자 당 유효경수 123개로 4계통 중 발생량이 가장 많았다. 또 다른 교배계통 ‘CBMLN-96’은 개체중이 5.5 g 으로 ‘CBMLN-103’ 보다 큰 형태를 나타냈으나, 상자 당 유효 경수는 30개로 발생량이 적었다. 수량성 조사 결과 대조구인 ‘CBMLN-31’계통에서 상자 당 수량 783 g으로 가장 높게 나타났고, 교배계통 ‘CBMLN-96’은 165 g, ‘CBMLN-103’은 232 g으로 나타났다. 교배계통 2계통에서 수량성은 대조구 ‘CBMLN-31’보다 낮았지만 자실체 발생량이 많았으며, 재배기간이 40일~55일 단축되어 이 2계통을 우량계통으로 선발하고자 한다.

A new cultivar ‘Sansanhyang’ was bred from monokaryotic strains of Sanbackhyang and SANJO 707ho by mono-mono hybridization method. Cap was convex and brown, it was 70 mm in diameter and 16 mm in thickness. The distribution of scales was whole and the scales were brown and slightly brown. The arrangement of gill was ripple and gill density was dense. Stipe was cream colored and fluff was medium. Sansanhyang had 100day cultivation period and fruiting bodies sporadic occurrence. It was a medium-low temperature strain and the temperature for fruiting body formation was 10-16°C. The ratio of fruiting body production was the 1st flush 89%, the 2nd flush 6% and the 3rd flush 5%. Sansanhyang was different from Sanbackhyang by its convex cap, 70 mm of cap diameter, and 40.5 mm of stipe length. Sanbackhyang had convex cap, 71 mm of cap diameter and 56.9 mm of stipe length.

The aim of this study was to identify strain KCOM 1265 isolated from subgingival plaque at the species level by comparing 16S ribosomal RNA gene (16S rDNA) and genome sequences. The whole genome of strain KCOM 1265 was extracted using the phenol–chloroform extraction method. 16S rDNA was amplified using polymerase chain reaction and sequenced using the dideoxy chain termination method. Pairwise genome comparison was performed using average nucleotide identity (ANI) and genome-to-genome distance (GGD) analyses. The data showed that the percent similarity of 16S rDNA sequence of strain KCOM 1265 was 99.6% as compared with those of Fusobacterium polymorphum ATCC 10953T and Fusobacterium hwasookii KCOM 1249T. The ANI values of strain KCOM 1265 with F. polymorphum ATCC 10953T and F. hwasookii KCOM 1249T were 95.8% and 93.0%, respectively. The GGD values of strain KCOM 1265 with F. polymorphum ATCC 10953T and F. hwasookii KCOM 1249T were 63.9% and 49.6%, respectively. These results indicate that strain KCOM 1265 belongs to F. polymorphum.

This study deals with the yielding behavior and strain aging properties of three bake hardening steels with dualphase microstructure, fabricated by varying the annealing temperature. Bake hardening and aging tests are performed to examine the correlation of martensite volume fraction with yielding behavior and strain aging properties of the bake hardening steels with dual-phase microstructure. The volume fraction of martensite increases with increasing annealing temperature. Roomtemperature tensile test results show that the yielding behavior changes from discontinuous-type to continuous-type with increasing volume fraction of martensite due to higher mobile dislocation density. According to the bake hardening and aging tests, the specimen with the highest fraction of martensite exhibited high bake hardening with low aging index because solute carbon atoms in ferrite and martensite effectively diffuse to dislocations during the bake hardening test, while in the aging test they diffuse at only ferrite due to lower aging temperature.

In this study, the properties of the substances fermented soybean producted by manufacturing with several Aspergillus strains were investigated. The five soybean cultivar that includes miso, jinpung, pyeongwon, cheonga and chamol were used in this experiment. The pH and total acidity were 6.30~6.66%, and 0.27~0.48%, respectively with differences depending on the samples. The color values for L value, a, and b value were 60.28~69.80, 0.64~3.68, and 11.48~31.21, respectively. The amylase activities, protease activities, and amino-type nitrogen of the jinpung samples were the highest among all cultivars. The mold counts the fermented soybean products by cultivars were 6.18~9.14 log CFU/g, and miso was the highest. Free amino acid and organic acid contents were highest in the jinpung and showed different composition depending on each sample. A total of 18 volatile aroma-compounds, including two acids, four alcohols, four ketones, three phenols, one furan, three pyrazines, and one miscellaneous compounds. In conclusion, it is expected that manufacturing A. oligze inoculation fermented soybean products using jinpung cultivar will improve quality.

This study was conducted to separate microorganisms with excellent odor component decomposition ability from nature. Microorganisms growing sulfur and ammonia compounds as substrates were isolated and identified in the tidal flat of Suncheon Bay. The strain YUN4 cultured on ammonia and sulfur compound substrates was found to have 100% genetic homology to Streptomyces fulvissimus. The optimum growth temperature of YUN4 was 20oC to 40oC, and the optimum pH was investigated in the range of pH 5 to pH 9. In addition, in order to evaluate the ability to reduce odor, after mixing the culture strain with each concentration of 1%, 5%, and 10% in the malodor generating sample, the efficiency of malodor reduction was evaluated after 30 minutes. As a result, the ammonia decomposition efficiency was 82.4%~93.9%, and hydrogen sulfide was 88.7%~94.9%.

최근 표고버섯의 맛과 기능성이 알려지면서 동아시아는 물론 전세계적으로 관심이 집중되는 가운데 기후변화와 재배자들의 수요를 충족시킬 수 있는 고품질의 표고버섯 품종개발의 요구도는 날로 높아지는 실정이다. ‘밤빛향’은 산백향과 산조707호을 모본으로 하여 일핵 균주간의 교잡을 통해 새로이 육성된 품종이다. 배양기간 은 100일이며, 발생온도가 11-20°C로 한여름과 한겨울을 제외한 모든 계절에 재배가 가능한 품종이다. 버섯의 형태는 평반구형으로 대는 갓의 중심에 위치하며, 갓의 직 경은 69.6 mm이며, 갓의 두께는 15.2 mm이다. 버섯 갓의 색깔은 진한 갈색으로 일반적인 표고의 갓 색깔보다 짙다 . 버섯의 주름살 측면의 모양은 부정형으로 주름살의 밀도는 보통이지만, 폭이 좁다. 인편의 색깔은 옅은 미(米)색 이며 인편은 갓의 전체에 퍼져 있다. 대의 모양은 기둥형과 깔대기형이 섞인 모양이고, 색깔은 옅은 미(米)색으로 주름살의 색깔과 같다. 대의 표면에는 털이 있으며 털의 색, 대의 털 색, 갓의 인편 모두 옅은 미(米)색으로 존재한다. 버섯은 산발 발생하여 솎아주기가 거의 필요 없다. 모 균주인 산백향과 산조 707호와의 대치배양에서 확연하게 대치선을 형성하였다. 종합적으로 자실체의 형태는 정성적으로 양호한 평가를 얻었고 정량적으로 대조품종 산백 향의 대길이보다 약 9% 줄이는 효과와 갓두께는 16.9% 두꺼운 결과를 얻었다. 목표로 했던 모균주 산조707호의 짧은 대길이의 특성이 유전되었고 산백향의 생산성이 유전된 것으로 판단된다.

This study investigated the efficacy of four Brucella (B.) abortus recombinant proteins, namely adenylate kinase (Adk), nucleoside diphosphate kinase (Ndk), 50S ribosomal protein (L7/L12) and preprotein translocase subunit (SecB), as a combined subunit vaccine (CSV) against B. abortus infection in BALB/c mice. Immunoblotting assay showed that these four recombinant proteins as well as pcold-TF vector reacted individually with Brucella-positive serum, but not with Brucella-negative serum. The peripheral blood CD4+ T cell population was increased in CSV-immunized mice compared to PBS and pcold-TF vector groups. In addition, CSV and pcold-TF groups displayed induced IgG1 and IgG2a antibodies production compared to PBS and RB51 group, whereas IgG2a titer was higher than IgG1 titer in CSV group. The secretion profiles of IgG1 and IgG2a production together with an enhancement of CD4+ T cell population suggested that CSV did not only induce T helper 1 (Th1) T cell immunity but also humoral immunity. Therein, Th1 T cell immunity is more predominant in eliminating intracellular bacteria B. abortus. Furthermore, CSV immunization significantly reduced the bacterial burden in the spleen as well as the spleen weight in comparison to PBS and pcold-TF groups. Altogether, combination of these antigens could be potential to induce protective immunity against B. abortus infection in animals.

Viral protein 2 (VP2) of porcine parvovirus (PPV) is responsible for inducing neutralizing antibodies in immunized animals. It is the major viral structural protein. In this study, novel subunit vaccines against PPV based on virus-like particles (VLPs) formed from VP2 proteins (PPV 13-7 Korean strain) were expressed in an insect baculovirus cell system and purified using Ni-NTA affinity column chromatography. These VP2 proteins assembled into virus-like particles (VLPs). They showed antigenic properties similar to those of natural PPV. In addition, they showed high hemagglutination (HA) titers (211 for PPV 13-7 Korean strain). This study provides a foundation for the application of the difference immunization of recombinant protein in the diversity of PPV VP2 genes and in vaccination against PPV in the future.

Porcine epidemic diarrhea virus (PEDV) infects all-age pigs and causes enteric diseases. Genetic diversities in isolates been reported from each country, and those diversities highlighted in pathogenicity and vaccine. In this manuscript, we are reporting of new PEDV isolation in Korea, and with genetic characteristics. Our new isolate belongs to G2b and put the name as CNUP6-2018.

노란달걀버섯은(Amanita javanica) 국내에서 산림법으 로 보호받고 있는 식용 가능한 외생균근성 버섯이나, 중요한 산림자원으로서 활용하기 위한 기초적인 특성 연구에 대한 자료는 부족한 실정이다. 이에 본 연구는 국내 채집 야생버섯 자실체로부터 분리한 노란달걀버섯 NIFoS 1267 균주를 이용하여 PDA 배지 상에서 물리적 요인(온도, pH, 광)과 화학적인 요인(염분, 중금속, 농약)에 따른 균사생장 특성을 조사하였다. 최적의 물리적 환경은 온도가 30oC, pH가 5-6, 암조건으로 배양이었을 때 노란달걀 버섯 균주의 균사생장이 가장 좋은 것으로 나타났다. 화학적 요인으로서 염분은 2.0% 농도 조건까지 버섯균주의 균사 생장이 가능하였다. 50 ppm 농도의 중금속 이온 환경에서 비소(As) 이온은 노란달걀버섯 균주의 균사생장에 영향을 주지 않았으나 카드뮴(Cd)와 납(Pb) 이온은 균사 생장이 불가능하게 하였다. 국내 산림에 사용되고 있는 2가지 농약의 경우, Abamectin 첨가 배지에서는 노란달걀 버섯 균주의 균사 생장에 영향이 없었으나 Acetamiprid, Emamectin benzoate, Thiacloprid가 첨가된 배지 환경에서는 균사 생장이 모두 다 저해 되었다. 본 연구 결과는 향후 상업적 생산을 위한 새로운 자원으로서 노란달걀버섯의 인공재배 연구에 도움이 될 것으로 기대된다.

Tissue engineering has been rapidly developed in oral and maxillofacial reconstruction. Biocompatible scaffold from chemically composites seeded with stem cells is essential and several growth factors for bone formation and angiogenesis are also required. To overcome limited activity of new bone formation with scaffolds, several biomechanical stimulation methods on cells have been made to grow cells in scaffold. Several bioreactors have been developed for real tissue growth in culture laboratory. In addition to biological stimulants like BMP, growth factors and exogenous drugs, biomechanical stimulation technique has also been known as an effective method in cell differentiation. We developed our own bioreactor with tensile mechanical strains. Then we tested with it for detection of suitable biomechanical effect on the cell differentiation and proliferation. And we also compared the results with the effect of low intensity pulsed ultrasound (LIPUS). Mechanical strain group showed more rapid reaction with cell differentiation and proliferation than non-mechanical strain group. Mechanical strain groups stimulated with 0.5∼0.7Hz for 6 hours and 8 hours showed more active cell differentiation than the group with 0.5∼0.7Hz for 2.5 hours tensile strain stimulation. Group of LIPUS also showed more rapid reaction in cell differentiation and proliferation. LIPUS with 3MHz showed more cell reaction than the LIPUS group with 1MHz. Our results showed the positive effect on differentiation and proliferation of cell with mechanical tensile strain, LIPUS both.